The Science Behind SQUALENE

The Human Antioxidant

 Dr. BIKUL DAS

 

 

Foreword By

Dr. Sylvain Baruchel

 

 

This Book discusses the function of Squalene in the human body and has been written for the reader interested in the changing perspective of research on bioactive nutrients, including Squalene. To substantiate the explanations in this book we have included research findings concerning the role of Squalene in the prevention of cancer and heart disease and in the enhancement of the immune function. This book does not suggest that people take Squalene as a dietary supplement, nor that they should not. It is the author’s sincere advice that before considering Squalene dietary supplementation, readers consult their physicians as this book is not meant as a substitute for competent medical care.

Despite rapid progress in medical research, fundamental biological mechanisms governing our body are still incompletely understood. However, a discussion of these

mechanisms is needed to link diverse research findings on nutrients. We encourage readers to take a science- oriented approach on nutrition rather than one based on

passive belief. Bear in mind that this book discusses biological hypotheses that should not be taken as established fact.

The author has checked the scientific literature referred to throughout this book in an effort to provide credible information on Squalene. However the possibility of human error cannot be discounted and the author, publisher and editor cannot and do not warrant the accuracy of the information contained herein.

The author hopes that this book will help to generate a further awareness of the need for environmental protection. Without a clean environment, even the best drug or dietary supplement is fighting a tough battle against both existent and newly-emerging diseases.

The author, editor and publisher expressly disclaim responsibility from the use or application of information described in this book.

 

I dedicate this book to my mother Mahindri and my wife Britta whose support is unending and who have graciously accepted my repeated absence from them in my

pursuit of knowledge.

 

 

Foreword                                                 6

Preface                                                 8

Editor’s note                                         10

Introduction 11

 

 

PART 1 – What is Squalene? 14

1 – The Primordial balance 14

The first antioxidants 15

Free Radicals 16

Types of antioxidants 16

Oxidant-antioxidant balance 17

Oxidative damage 17

Oxidative stress and antioxidant metabolism 19

Antioxidant metabolism and Squalene 19

Conclusion 20

 

2 – A History of Squalene 21

Squalene’s importance in the origins of life 21

Early Squalene research 22

The Isoprenoid synthesis pathway 22

Squalene’s importance recognized 23

Clinical applications of Squalene 24

Two forms of Squalene 24

Conclusion 26

 

3 – Squalene the antioxidant 27

Isoprene 27

Biomembrane structure 29

Vitamin E and Squalene compared 29

Squalene in the skin 31

Squalene’s role in the immune system 31

Squalene metabolism and cell growth 31

Squalene and aging 32

Conclusion 33

 

4 – Balance and stress in bodily systems 34

Immune imbalance 34

Effective immune balance 35

Oxidative Stress and immune imbalance 36

Apoptosis 37

Metabolic stress 39

An example of metabolic stress 39

Metabolic stress and immune suppression 39

Conclusion 40

 

Carcinogenesis 41

The evolution of Cancer 41

Cancer’s secret to success 42

The ras oncogene 42

Squalene’s inhibition of cancer proliferation 43

Carcinogenic agents 44

Squalene’s preventive/therapeutic potential 44

A growing body of research 45

Potential clinical applications 46

Cytoprotection – an undervalued modality 46

Criteria for a cytoprotective agent 47

Squalene’s cytoprotective roles 47

A multi-target approach to cancer therapy 49

Conclusion 49

 

6 – Cholesterol and heart disease 50

Coronary heart disease 50

Atherosclerosis 50

Good Cholesterol 51

Bad Cholesterol 51

Cholesterol transport 51

The worst cholesterol of all 53

Cholesterol lowering effects of Squalene 53

Conclusion 55

 

Part 11 – Squalene and Disease – Squalene and Disease Contents 5 – Squalene’s role in cancer & cancer therapy 41

 

 

Part 111

Squalene and environmental pollution 56

7 – Human skin: first casualty of ozone depletion

The epithelium – a protective coat 56

Ultraviolet radiation 57

The skin 58

Absorption of UV rays by skin 58

The skin’s natural antioxidant 59

Evolutionary Adaptation to Loss of Hair 59

Ozone depletion 60

Skin Cancer 60

Immune depression 60

Protecting against UV radiation 61

Are we safe? 62

Conclusion 62

 

8 – Background radiation 63

Sources of radiation 63

Ionizing radiation 63

Medical sources 63

Internal sources 63

Depleted uranium 63

Geological radiation 64

Cosmic radiation 64

Non-ionizing radiation 64

Consequences of background radiation 64

The radio protective role of Squalene 65

Squalene depletion due to radiation 65

 

Depleted uranium 63

Geological radiation 64

Cosmic radiation 64

Non-ionizing radiation 64

Consequences of background radiation 64

The radio protective role of Squalene 65

Squalene depletion due to radiation 65

Conclusion 66

 

9 – Air pollution, allergies and lung disease 67

Lipid peroxidation and allergies 67

Squalene synthesis – a potential adaptive mechanism

Conclusion 68

 

10 – The fat cell – A Storehouse of Toxins 69

Adipose Tissue – Depot or Organ? 69

Toxin Accumulation 70

Detoxification by the Liver 71

Detoxification by Adipose Tissue 71

The Xenobiotic Squalene Link 72

Conclusion 72

 

11 – Metabolic stress and chaos 73

Metabolic response to stress 73

Squalene metabolism 74

 

Squalene in the skin 74

 

Squalene in the fat tissue 74

Cyclic and Acyclic Squalene 75

Two metabolic pools 75

State of disequilibrium 76

The mechanism of metabolic stress 76

Chaos 77

Metabolic stress & chaos 77

Conclusion 78

 

Epilogue 79

Glossary 80

References

Index

 

Foreword

 

We talk daily about dietary nutrients, yet give little thought to how they work at the cellular level. Many people are amazed to learn that individual cells actually

synthesize some of the nutrients they need to maintain inner health. We pay even less attention to how research is progressing and which directions will reveal therapeutic solutions based on dietary nutrients. It is customary in our society to leave such questions in the hands of doctors and researchers. Few people are interested, perhaps in part because eating a salad is much more enjoyable than pondering its nutritional value. However, nutritional research is providing us with information crucial to our long-term health. Soon, more people will want to understand how nutrients work at a cellular level so they can adjust their diets to life style, specific disease risk and perhaps even according to genetic makeup.

 

The emerging awareness of cell signaling in nutrient research suggests that such an era of nutritional self-awareness is approaching. Our under-standing of cell signaling is revolutionizing nutrient research, but lay people remain largely unaware of the fact. Cell signaling describes how cells communicate with each other right into their interior. This information exchange employs molecules like a telephone network, one molecule relaying information to another in a domino sequence that eventually carries it to specific genes. Several such pathways are active in specific cells, just as one home may have several telephones. Cells rely on signaling pathways for growth, proliferation and various functional activities. Hormones and other biomolecules influence cells by acting on these signaling pathways.

 

In the last fifteen years, great progress has been made in unlocking the code of these signaling pathways, suggesting that many diseases are either caused or exacerbated by faulty cell signaling. This list includes cancer, diabetes, immune disorders and disorders of the nervous system. Signaling research shows that certain nutrients influence the signaling pathways and prevent or inhibit the growth of cancer. This research provides hope for the effective prevention and even the adjuvant treatment of some cancers.

 

The most promising approach seems to be the use of a nutrient combination to influence several signaling pathways at once in the hope that this will be more

effective than using a single nutrient. In this multi-target strategy “cocktails” of various nutrients would be given to people either at risk of a certain cancer or already suffering from it. Such nutrient cocktails may also sensitize tumor cells to chemotherapeutic agents, making conventional anti-cancer therapy both more effective and less toxic.

 

Only vigorous research can determine which signaling pathways to target and how. This explains why research into various bioactive nutrient groups is becoming

increasingly important. Isoprenoids are one such group of nutrients and are particularly significant to cellular growth and proliferation. There are hundreds, and

some are found to influence various signaling pathways. Squalene and its cyclic derivatives are non toxic Isoprenoids with great promise. The molecular activities of

Squalene and its related Isoprenoids – ursolic acid, oleanolic acid , geranyl and geraniol – can play a role in the anticancer cocktail and may contribute to other nutrient cocktails formulated to prevent such other disease states as elevated cholesterol.

 

This book’s appearance is very timely and reveals a new approach to nutrient

 

research. It discusses Squalene and its metabolism in the light of the latest understanding of molecular biology, giving an overview of Squalene metabolism and

how it seems to be much more than a mere cholesterol metabolite. Squalene is a powerful antioxidant with a potentially crucial role in the cellular antioxidant defense

system. However, Doctor Bikul Das points out that this research is still at an early stage and he discusses hypotheses about areas of fundamental biology that are not yet fully understood. This book is also an example of how ideas develop and scientific knowledge grows. Readers should therefore maintain caution and apply a critical eye in their interpretation of this book.

 

Dr. Das also hopes to provoke new directions in the study of pollution-induced disease. The idea of metabolic stress and its relation to oxidative stress outlined in this book, though not yet completely understood, shines a new light on the biology of such pollution-related health problems as UV radiation induced immune suppression.

 

We appreciate innovative thinking and hard work of the author and encourage him to continue his research on nutrients and their metabolism.

 

Dr. Sylvain Baruchel. M.D.

Associate Professor of Pediatrics, University of Toronto.

Staff Oncologist, Division of Hematology & Oncology.

Senior Scientist & Director of New Agent and Innovative Therapy Program

The Hospital for Sick Children, Toronto.

 

 

PREFACE

 

This book calls attention to Squalene – a remarkable nutrient produced in our body and also found in nature. Just a few decades ago, nutrients were thought to have

minimal research value. Today, nutrient research is a hot topic among medical circles, the research community and the general public. Several factors account for this

changing trend.

 

Firstly, there are today many calls for nontoxic, natural therapies to prevent or treat various disease processes. The hope is that understanding the cellular mechanism

of healing nutrients may lead to combination therapies in which several nutrients each target different mechanisms of a disease to achieve a common goal. Rapid advances in cell signaling research provide hope for such natural combinations, which may become more effective than artificial drugs. Squalene and its various cyclic derivatives such as ursolic acid are showing great promise in preventive therapy, particularly in the chemoprevention of cancer.

 

Secondly, there is also a great interest in the innate healing processes of the body. By understanding them we will learn to help and enhance our natural defenses.

Individual cells have sophisticated abilities to heal themselves. The cellular DNA repair process is an impressive example. During cell division, DNA divides into two identical strands of daughter DNA. When- as happens on occasion- this process leads to damage, a repairing process corrects it. Another example of cellular healing is when the cell systematically checks the cell membrane for defects or damage and employs several molecules to fix it. There are other examples of self-healing, for example the healing of skin lesions and broken bones. In these processes body tissues synthesize and distribute additional nutrients to facilitate repair and regeneration. For example, the concentration of glutathione – a cellular antioxidant – increases around a wound and facilitates the healing process.

 

Vitamins and other nutrients are already known to contribute to the healing processes of the body and there are probably many others, either synthesized by our

body or obtained from diet. An understanding of their function will shed new insight into innate healing processes. Dietary Squalene has been found to enhance the

elimination of toxins and minimize the toxic effect of UV radiation. With this in mind, the presence of very high levels of Squalene in human skin and adipose tissue is

attracting significant interest among researchers who are exploring the cellular mechanism of Squalene.

 

The third reason for renewed interest in nutrient research is an appreciation and understanding of the evolutionary dynamics of health and sickness. Evolution

focuses on the survival of a species. It helps organisms adapt to changing environments. During our species” turbulent evolution, we have learned to protect our

health. There is every reason to believe that the tissue distribution of certain nutrients has an evolutionary history. The presence of Squalene in our skin could be an example of such an evolutionary protective mechanism. I have taken Theodosius Dobzhansky’s famous quotation, “Nothing in biology makes sense except tin the light of evolution,” as encouragement to examine the evolutionary aspect of Squalene’s presence in our skin.

 

The growing interest in nutrient research has three general themes: medical practitioners are interested in using nutrients in preventative therapy, other individuals are interested in strengthening the innate healing processes through the use of scientifically proven nutrients, and medical researchers and biologists want to understand the evolutionary aspect of health and sickness.

ling processes through the use of scientifically proven nutrients, and medical researchers and biologists want to understand the evolutionary aspect of health and sickness.

 

The evolutionary aspect of nutrient research particularly interests me and I believe it may provide clues as to how pollution is affecting us. Health, evolution, and

pollution are very much related to each other. Research into such nutrients as Squalene may help clarify this relationship. In this industrial era, pollution is affecting all

biological systems. The question is, how can we best understand the long term impact of pollution: This new theme is discussed in part three.

 

Beyond this emerging frontier of nutrient research in the skin, Squalene’s rich history is primitive life, the ancient legends surrounding its healing power and the

modern insights into its unique presence in our skin is a fascinating human story that can bridge ancient legends and modern medical research.

 

The cover of the book illustrates a human cell against a background of the Earth. This image came to me as I was writing chapter 1, and thinking of human

vulnerability and our interdependence with the entire biosphere. The more we understand about our cells and organs and about nutrients like Squalene, the better we

will appreciate the need to maintain our own health and that out our environment. It is my sincere hope that this book will bring a fresh perspective to nutrient research.

 

Dr. Bikul Das

Research Fellow

Hospital For Sick Children

Toronto, Canada,

August 2000

 

 

 

Editor’s Note

  

Squalene is an Isoprenoid – an ancient biochemical that made it possible for archaic bacteria to flourish when our planet was an inhospitable, unrecognizable place.

Life began here on surfaces hot enough to boil water, with a virtual absence of atmospheric oxygen and no ozone layer to filter out the fierce ultraviolet radiation of

the sun. In fact, Earth’s surface looked more like Mars than the green orb we now cling to so precariously.

 

Under the protection of this lowly molecule, ancient bacteria proliferated, transforming the atmosphere so that green plants could emerge and harness the sun’s energy. They too depended on Isoprenoids to avoid being burned into a crisp in the process. Plant life in turn transformed the atmosphere into an oxygen-rich soup that made oxygen respiration possible – yet another reaction in which Squalene protects living tissue from oxyradicals. Then something extraordinary happened – and has been happening ever since – the linear Squalene curled up and provided the basis for the sterol nucleus of cholesterol, without which the modern animal cell would be unthinkable. This biochemical reaction, still not fully explained, remains “the most complex single step reaction in the biological world”. Among other things, it enabled

our forefathers to shed their furry outer coat and expose their naked skin to the sun’s rays without being destroyed by UV radiation.

 

Today, Squalene protects the biomembrane of cells and the myriad organelles within from oxidative stress. It helps the cholesterol metabolism maintain order and

keep levels of harmful LDL –cholesterol to a minimum. It contributes to the cell-renewal cycle and keeps cancer at bay.

 

But now this ubiquitous life-enabling Isoprenoid is under stress. Our environment is undergoing unprecedented oxidative and metabolic attack at the hands of p9ollutants, carcinogens and increased ultraviolet radiation. Has the molecule that has protected life for billions of years finally met its match? Or does this simple

substance, for so long considered virtually insignificant hole the clues to our evolutionary survival?

 

I share the author’s hope that this book will help to generate further awareness of the need to protect ourselves and our fragile planet. We must acknowledge that there is no guarantee of ultimate victory unless we act together to ensure that our environment remains amenable to life.

 

Stephen Schettini

Montreal May 2000

 

Stephen Schettini is a writer, illustrator and designer of medical books for professionals

and the general public. He has developed extensive training guides and learning

programs on the cardiovascular system, arthritis, hormone replacement therapy,

allergies & antihistamines, dermatology and prostate cancer. He has also coauthored

Glutathione [GSH]: Your Body’s Most Powerful Healing Agent [with Dr. Jimmy

Gutman] and the Osteoporosis Remedy [with Dr. I. William Lane]

 

 

 

Introduction

 

It has been clear for some years that Mediterranean peoples tend to suffer considerably less than others from heart disease and certain cancers. Scientists have

linked this to relatively high levels of olive oil consumption, but they aren’t first to make this connection. Many ancient Mediterranean cultures believed that olive oil

increases strength and longevity, and indeed the olive tree is a rich source of Squalene!

 

The olive tree has always been more than just another food source. Since the earliest days of Mediterranean civilization it has been surrounded by a wealth of cultural

symbolism. Ancient kings ruled with scepters of olive wood, priests still anoint the worthy with olive oil, and the olive branch is a recognized symbol of peace in many

cultures. Early Mediterranean peoples considered it a gift from the gods, worthy of be adored and defended. Old Greek and Roman writers referred to it as the Eternal Tree of Peach and the Jewish bible includes dozens of references to the tree. Ancient Indian physicians were well aware of the great healing power of the olive tree and its oil. The Koran too describes it as a “Precious Condiment.”

 

The city of Athens was mythically named after Pallas Athena, goddess of peace and wisdom. She was said to have created a tree able to light up the night [olive

oil lamps produce a warm, gentle light], to soothe wounds and to produce a food rich in flavor and energy. According to Roman legend, Hercules strode along the shores of the Mediterranean, his olive staff sending out roots every time it struck the ground and sprouting new trees. The Phoenicians helped spread the tree westward from Asia Minor and around the shores of the Mediterranean.

 

Olive trees live for centuries, even millennia. When a main trunk dies, new shoots sprout from its base and grow. Add to this the many uses which it is put and the distinctive cuisine that has emerged from it, it is not surprising that it has become so rich in myth. And now we discover there may be some factual basis to its reputation for health and healing.

 

Another rich source of herbal Squalene is the amaranth plant, an extremely robust type of grain that can survive both scorching heat and extremely dry soil. It

produces six-foot stalks with brilliant feathery red or magenta plumes. The Greek word “amarantus” means “never withering.” In India the amaranth herb has been

widely used for thousands of years. It is as rich in Squalene and as common in that region as the olive tree in the Mediterranean basin. In the great epics of the ancient Indian cultures the herb is believed to be empowered with immortal strength and fertility. The Sanskrit word for the plant “amaranth” [not “amaranth”] means “King of Immortality.”

 

Once a North American staple and the preferred grain of Aztec royalty, the broad leafed grain was believed to have sacred healing power. Aztec soldiers are a very

thick soup of this herb before going to war, and the amaranth plant was outlawed by Spanish missionaries who were disturbed by its association with human sacrifice. In fact, they believed the key to suppression of the Aztec culture was the annihilation of the plant.

 

The Swedish Order of the Amaranth dates back to the 1653 reign of Queen Christina, who brought European culture to her country and negotiated the landmark

Peace Treaty of Westphalia in 1648. The amaranth has frequently represented distinction and honour, and was formed into the “Amaranthine Wreath” symbol of the

Swedish Order and of the Bond of Fraternal Friendship representing the strength and power of the plant.

 

In Japan, a rich source of Squalene is shark liver oil [sharks belong to the species squali]. In ancient times, this rich oil was thought to increase strength and longevity. This miraculous healing power of shark liver oil is even mentioned in some old Japanese folk stories. The shark was considered a legendary creature living in the ocean depths. Many Japanese people believed the liver of the shark to contain powerful healing agents. Like the Aztecs who drank a soup of amaranth, ancient warriors of Japan and China – and even the Maoris of New Zealand- were known to drink shark liver oil before leaving for war.

 

We can therefore trace cultural recognition of Squalene-rich products with unique survival qualities to the Mediterranean region, Scandinavian, the Indian subcontinent, the Far East and Central America. The claims made by the ancient peoples of these lands may not be based on science, but they lend color and warmth to our research and prompt us to place the full glare of the scientific spotlight on this intriguing substance.

 

Chinese healers were the first to conduct pre-scientific research into a rich natural source of Squalene. In 1596 Lee Ji Chin, a Chinese healer of the Ming Dynasty

[1369 – 1644] composed a 52 volume compendium of some two thousand herbs, including the liver oil of the deep sea shark. Chinese traders subsequently brought the

book to Japan, where it was known as Honzokomoku. Samurai warriors used this oil to increase their strength.

 

Villagers of Suruga Bay on the Izu Peninsula of Japan were accustomed to drinking the same oil. The local name of this special extract was Samedawa or “cureall.:

In 1906, Dr. Mitsumaru Tsujimoto, a Japanese industrial engineer, discovered that Samedawa contains extremely large quantities of an unsaturated hydrocarbon. He

named the hydrocarbon Squalene, from the Latin root squalus [shark]. Dr. Tsujimoto was presented the Imperial Award of the Japan Academy in honor of his achievement.

 

Squalene was first found in the human body in the 1950’s, when the cholesterol metabolism was first identified. This is a complex pathway by which glucose is converted to the all-important cholesterol molecule. The pathway entails dozens of transformations of one biochemical to another. Squalene is just one of those

intermediate steps. At the time the significance of the transitional biochemicals was lost in the excitement of the greater picture. They were considered just a means to an end, and not significant in their own right. However, three of the biochemicals in that pathway – molecules that perform vital functions including the regulation of cell growth and proliferation through a process named after them – isoprenylation. Without this process, cell membranes could not anchor proteins vital to cell growth.

Some Isoprenoids –notably Squalene- are also strong antioxidants. They have lately been discovered to play protective roles not only in the antioxidant system but also in the immune function. Isoprenoids also play a part in the regulation of apoptosis [programmed cell death].

 

The history of Isoprenoids goes back billions of years. There are thousands of varieties, some of which played a crucial role in the protection of early life on this planet. This Isoprenoid nature of vitamin A, vitamin E, beta-carotene and other well known nutrients is discussed in chapters 2 and 3.

 

Indeed there has been a flurry of experimental activity around Isoprenoids, and things are now known about these humble molecules that were never imagined by the researchers who first identified Squalene. This book is a synopsis of that research and weaves the threads of these various experimental findings into a overall picture.

and things are now known about these humble molecules that were never imagined by the researchers who first identified Squalene. This book is a synopsis of that research and weaves the threads of these various experimental findings into a overall picture.

 

In fact this bigger picture is still growing. Squalene has been found abundantly in the skin, the membranous lining of the gastrointestinal and respiratory tracts and in adipose tissue [fat]. There is serves independent functions of great importance to hour health.

 

This skin of primates has virtually no Squalene but the sebum secreted by human skin contains about 12% -a huge proportion. This appears to be an evolutionary requirement of our unique nakedness, protecting us from our unparalleled exposure to the sun’s ultraviolet radiation. As environmental pollution leading to ozone depletion exposes us to rising levels of these harmful rays, the burden on Squalene in our inner and outer protective coatings may exceed its ability to cope. This could stress Squalene metabolism and contribute to immune suppression.

 

This book examines our body’s natural use of Squalene as well as research suggesting its potential dietary usefulness. Emphasis has been placed on the impact of pollution upon antioxidant balance, using Squalene metabolism as a model. It has three parts:

 

PART ONE – WHAT IS SQUALENE?

 

Squalene is a strong antioxidant Isoprenoid. It helps our cells avoid oxidative

stress and prevents lipid peroxidation. It also contributes to a balanced immune

response. Part One describes Squalene’s role:

 

• As an antioxidant

• As a regulator of the Isoprenoid metabolism

• In an effective immune response.

 

PART TWO – SQUALENE AND DISEASE

 

Squalene’s influence on the vital pathway that transforms glucose into

cholesterol may be pivotal. It regulates or controls the rate of synthesis of the enzyme

HMG Co-A reductase, and may contribute to effective treatments for cancer and heart

disease. Several research studies have already demonstrated Squalene’s anticancer and

cholesterol lowering activities. Part Two describes the potential use of Squalene in

disease management, especially against;

 

• Cancer, and

• Heart disease.

 

PART THREE – SQUALENE AND ENVIRONMENTAL POLLUTION

 

Squalene is present in high concentrations in human skin and in fat cells. This

may be an evolutionary requirement. Most likely the pressure of evolution in the

human protective coat and the requirements of its macrophage system have led to the

storage of large amounts of Squalene in the cellular protective system of the skin and

underlying fat tissue. Rapid changes in the environment may be placing oxidative

pressure on the protective coat of our body with potentially disastrous effects. Part

Three describes:

 

• Environmental pollution, and

• Pollution-induced oxidative stress leading to stress in Squalene metabolism

 

Part 1 - What is Squalene?

 

This part of the book describes Squalene and how it works in the healthy

individual, suggesting the possibility that stress in Squalene metabolism contributes to

immune suppression. It also raises questions about the possible therapeutic and

preventive role of Squalene modulation.

 

1 - The Primordial Balance

 

During most of the twentieth century medical researchers were preoccupied

with identifying various disease states and treating them as they arose. Extensive

studies of the immune system contributed to the development of effective

pharmaceutical drubs that today successfully deal with a wide variety of bacterial and

viral illnesses. However, many diseases remain only partly understood and relatively

intractable, including Alzheimer’s disease, Parkinson’s disease, diabetes, mellitus,

rheumatoid diseases and most common and most feared of all, heart disease and

cancer. New research and technology is at last enabling doctors and scientists to better

explain the mechanisms of these and many other diseases.

 

Some of the most striking advances in recent years are emerging from

research into free radical biology. It is now clear that specific disease agents are not the

only source of ill-health. Cells and tissue can also be destroyed by a breakdown of the

very molecules of which they are composed. Polluting free radicals such as oxyradicals

 

– noxious by-products of the energy production process in each cell – constantly

threaten the inner environment of our body. Free radical molecules are unbalanced by

having too few or too many electrons. They are dangerous because in their attempt to

regain balance they upset the stability of surrounding molecules, Sometimes initiating

chain reactions that can spiral out of control.

Still, free radicals are necessary for our survival as well. The are used in

intracellular communication, and immune cells produce huge amounts of free radicals

to attack bacteria and other harmful agents. Sometimes they produce to many, yet the

free radicals do not harm the cell. Each cell possesses its own defense mechanism –

the antioxidant defense system – that maintains a dynamic internal balance between

free radicals and antioxidant nutrients. Without this balance the cell would not survive,

tissue would degenerate and we would be unable to maintain our health. This oxidant-

antioxidant balance is presumably a primordial equilibrium without which life would

never have been possible.

 

Increased generation of free radicals can lead to oxidative stress, producing

imbalance and resulting in oxidative damage, cell death, tissue damage and disease.

Fortunately, cells and tissues implement a compensatory mechanism, tending to

minimize oxidative stress by synthesizing more antioxidants as they need them. This

dependence on endogenous rather than dietary antioxidants suggests that a study of the

metabolism of endogenous antioxidants will enlighten our understanding of the

relationship between oxidant- antioxidant balance and oxidative stress.

 

The purpose of this chapter is to discuss the role of endogenous anti-oxidants

in oxidant-antioxidant balance. Since Squalene is an endogenous antioxidant that is

where we will begin.

 

The First Antioxidants.

 

Primitive living cells first emerged on this planet about four billion years ago.

They survived by converting light energy into chemical food, just as plants harvest the

sun’s energy. Plants initiate photosynthesis with chlorophyll, which is activated by

sunlight and helps carbon dioxide interact with water to produce glucose and release

oxygen. This activation is sometimes transferred to oxygen molecules in the form of

extra electrons, and they become oxyradicals. In addition, the early biosphere lacked

any protective ozone layer and was subject to fierce ultraviolet radiation. This too

generated free radicals. For years, biologists have wondered how these primitive

organisms protected themselves from such strong radiation and so many free radicals.

It was presumed that the “skin” enclosing their single-celled bodies must have

contained a protective agent.

 

Recent breakthroughs by NASA scientists may provide a piece of the puzzle.

They have speculated that the powerful antioxidant quinine was deposited on Earth by

incoming meteorites. It seems that quinone was the first Isoprenoid. Quinone is

especially able to neutralize the free radicals generated by ultraviolet rays and may have

enabled a few lucky cells to become evolutionary survivors. Without quinone and

other antioxidant molecules primordial organisms would not have survived the hazards

of unshielded ultraviolet radiation. Today, quinone is one among many Isoprenoid

antioxidants found abundantly in the plant and animal kingdoms.

 

Light harvesting complexes [LHCs] are another type of Isoprenoid that

protects plants. These are a group of carotenoids antioxidants that surround the

chlorophyll molecules and use an electron transfer reaction to protect them from

ultraviolet radiation damage, principally by preventing the oxidation of molecular

oxygen. They also help absorb extra electrons before they can damage other

molecules. The outer coating of many seeds and fruits also contains Isoprenoids. For

example, tomatoes contain the antioxidant Isoprenoid lycopene.

 

Unlike plant cells, animal cells absorb oxygen and derive energy from its

reaction with glucose. In this process, protons flow through special molecules in the

mitochondria [energy producers] of each cell.

 

Electrical energy is produced and moves through the mitochondria as

electrons are shunted from one molecule to another in a process known as the

reduction-oxidation [redox] reaction. Molecules in the mitochondria are alternatively

reduced [receive electrons] and oxidized [donate electrons]. This generates electricity,

which is converted into chemical energy. During redox reactions electrons sometimes

escape, damaging either the redox molecule itself or the cell. However, redox

molecules such as ubiquinone have an Isoprenoid tail capable of neutralizing numerous

free radicals and keeping the mother molecule extremely stable.

 

Once again, Isoprenoids helps protect the organism. The Isoprenoid

ubiquinone [also known as coenzyme Q10] – is synthesized inside the cell and is

involved in the energy releasing process of the mitochondria. Many antioxidants are

either isoprenoids or have an Isoprenoid tail. Vitamin E, vitamin A and flavonoid are

all isoprenoids.

 

Free Radicals

 

The damage caused by free radicals occurs at a subatomic level. In any stable

atom, electrons orbit the nucleus in pairs and any breakup of this pairing makes the

atom unstable. It or the molecule of which it is part is said to be in a state of

imbalance and is called a free radical.

 

One of the most common sources of free radicals is the process burns

glucose with oxygen to produce energy through oxidation reduction [redox] reactions

in the mitochondria. The type of free radical it releases – an oxyradicals – is a routine

by-product. As you might expect, the production of oxyradicals increases when our

energy requirements increase – for example when exercising, fighting sickness or

eating.

 

Not all free radicals are manufactured within the cells of our body. They are

everywhere. Ultraviolet radiation can create them in the skin and even turn ground

level oxygen molecules into free radicals. We are surrounded by pollutants, some of

which are themselves free radicals and some of which interact with metabolic

processes, causing further subatomic damage.

 

Types of Antioxidants

 

Antioxidants are antidotes to free radicals, including oxyradicals. Many

substances act as antioxidants, but they all have one thing in common – the capacity to

stabilize the imbalance of unpaired electrons and neutralize the harmful potential of

free radicals without themselves becoming unstable. If it is true that the first

isoprenoids arrived from outer space, we living organisms can literally thank the stars

for our evolutionary survival. However, even though we still benefit from

environmental antioxidants – chiefly from food sources – most forms of life have

learned to produce antioxidants endogenously [within the cells where they are needed].

In the human body they include glutathione sulfhydride [GSH], superoxide dismutase

[SOD] catalase, Squalene and coenzyme Q10 [ubiquinone]. These last two are both

isoprenoids. The protective coat of many organisms – from the biomembranes of

cellular organelles to human skin – are protected from free radical damage by

antioxidant isoprenoids.

 

Other antioxidant isoprenoids are obtained from nutrients and are said to be

exogenous. The include substances like vitamins E and A, lycopene and beta-carotene.

These are usually found in various foods but they are also frequently taken as

concentrates in pills, food supplements or nutriceuticals. They are used by health-

conscious individuals in many ways, usually in the hope that they will maintain good

health, prevent all sorts of disease and hopefully slow the aging process. Their

usefulness is not in question, but there is wide disagreement over what constitutes an

appropriate dosage. It is well known, for example, that taking too much Vitamin A or

E can have harmful toxic consequences. There is also growing evidence that having

too many antioxidants is just as harmful as not having enough. In fact our body as a

whole must maintain a proper balance between oxidants antioxidants.

 

Oxidant-Antioxidant Balanc-Antioxidant Balance

 

The idea of oxidant-antioxidant balance emerged from research showing that

for any given level of free radicals, tissue damage is prevented most effectively by just

the right concentration of antioxidants. We have long known that during periods of

oxidative stress the antioxidant defense system increases the synthesis of antioxidants.

Now we are learning that at other times our body actually decreases production

because too many antioxidants can harm the body as well. Such adjustments suggest

the existence of any antioxidant defense system – an overseeing mechanism used by the

body to monitor and maintain an appropriate balance, just as the immune defense

system controls the synthesis and activity of immune cells.

 

However, in the same way that the immune defense system can lose its

balance, this system too can be disrupted. Our focus should not be to take as many

antioxidants as possible but to help the system maintain its oxidant-antioxidant balance.

It alone knows its precise needs, and therefore endogenous antioxidants-those

synthesized in the cell – will play a greater role in oxidant-antioxidant balance than

exogenous [dietary] ones. To do this of course, the body must have the necessary raw

materials [precursors] at hand. Aging makes it increasingly difficult for us to maintain

this balance, because synthesis of Squalene, GHS and coenzyme Q10 all decline as we

get older.

 

The direct result of a disrupted oxidant-antioxidant balance is cellular damage,

and one of the worst types of damage caused by free radicals is to the cell wall

[biomembrane].

 

Oxidative Damage

 

Cell and tissue damage caused by oxidant-antioxidant imbalance is referred to

as oxidative damage. The first step of this damage process is the lipid peroxidation

chain reaction, which breaks down cell membranes.

 

Every living cell is enclosed by a membrane – a double layer of lipids [fats]. A

cell also has organelles [functional parts] that help it grow, replicate and do its work.

These organelles include the nucleus, mitochondria and ribosomes. Like the cell itself,

each organelle has its own membranous wall, known as the biomembrane. The

biomembrane’s surface is a sort of complex electric fence, with biological devices such

as receptors [entry points for specific molecules] and electrical channels through which

energy is exchanged. All these devices generate free radicals. In fact, free radicals are

produced constantly within and outside the cell, some as by-products of energy-

releasing oxidation in the mitochondria, others quite usefully, as in the case of immune

cells that use them as weapons against invading pathogens. The biomembranes

themselves are highly vulnerable to free radical damage, especially in the hydrophobic

[waterless] band between the two lipid layers.

 

The fatty acids that constitute the two layers of the cell membrane are lipid

molecules and like gasoline, are flammable hydrocarbons. They are packed very close

to each other and are oxidized [catch fire] quickly. When one molecule is ignited it

quickly triggers the same reaction in its neighbors – a chain reaction called lipid

peroxidation. Lipid peroxidation [the burning of liquids] quickly damages the entire

biomembrane and threatens adjoining cells.

 

Lipid peroxidation is the most common and pernicious source of damage to

biomembranes. It impairs the cells function and leads to its eventual death. Diseased

cells spill their contents into surrounding tissue and cause inflammation. As more cells

are damaged or destroyed tissue damage follows and disease sets in. The effects of

lipid peroxidation are initially microscopic and not immediately apparent, but they

accumulate over time and are important factors in the progression of chronic diseases

such as atherosclerosis and the rheumatoid group of disorders. In fact such diseases

are turning out to be more numerous than was ever imagined.

 

A large portion of the biological molecules that form the basic building blocks

of life are glucose, fatty acids and amino acids and the constituent atoms of these

molecules can be destabilized by many types of biochemical reactions leaving them

with unpaired electrons. Free radicals spontaneously seek to correct their imbalance by

stealing electrons from any available molecule. Hopefully they encounter antioxidant

molecules, which render them harmless. Not infrequently however they encounter

defenseless neighboring molecules that in turn lose electrons and become free radicals

themselves. This can promote an ever-widening chain reaction leading to a disruption

and destruction of living tissue leading to oxidative damage.

 

Even when these chain reactions are eventually stopped by our body’s

antioxidant defenses, the damage already caused to cells, tissues and organs

accumulates over time and provides a foothold for incoming pathogens [disease

causing substances]. The damage also contributes to the progression of such diseases

as cancer, heart disease, arthritis and AIDS. An unconventional but significant

segment of the scientific community even considers aging itself to be largely

preventable disease, caused mostly by free radical damage. Nowadays there is

enormous scientific and public interest in reinforcing the antioxidant defense system as

a way to break the cycle of free radical damage, slow the aging process, extend life-span

and improve overall health.

 

Diseases associated with oxidative damage

 

1. Cancer

2. Diabetes Mellitus [peripheral neuropathy of this disease is due to free radical damage to the nerve heath

3. Heart failure and ischemia-reperfusion injury

4. Autoimmune disorders e.g. the rheumatoid group

5. Kidney disorders e.g. glomerulo-nephritis, tubulointerstitial diseases

6. Infective disorders e.g. AIDS and AIDS related dementia, pulmonary fibrosis due to tuberculosis, secondary anemia due to malaria

7. Neurodegenerative disorders such as Alzheimer’s disease

8. Dermatological disorders such as photosensitivity disorder, psoriasis, pemphigus vulgaris

9. Atherosclerosis

 

Free radicals are thought to cause many pathological conditions including the transformation of a normal cell into a cancer cell. Also, redox molecules which are

normally immune to free radicals can sometimes be overcome by them, with disastrous consequences. At the root of these many specific occurrences of oxidative damage lies the bigger and even more disturbing picture of oxidative stress. the bigger and even more disturbing picture of oxidative stress.

 

Oxidative Stress & Antioxidant

Metabolism

 

Oxidative stress results when antioxidant balance fails. Although oxidative

damage is implicated in the progression of many diseases, it develops only when

oxidative stress rises above a certain threshold. As soon as cells and tissues experience

oxidative stress, the compensatory mechanism of the oxidant-antioxidant balance

immediately tries to preempt oxidative damage by synthesizing antioxidants. Only if

and when the stress crosses a certain threshold does the mechanism fail and oxidative

damage occur. The mechanism of oxidative damage is not unlike that of heart failure.

In response to failure, the heart accommodates the increased load by increasing in size,

but beyond a certain limit its pumping ability declines sharply and eventually fails.

Similarly, although the antioxidant defense system can increase its synthesis of

antioxidants, oxidative stress may cross the threshold at which the compensatory

mechanism fails. Endogenous antioxidants [those synthesized in the cell] probably play

a greater role in this compensatory mechanism because their rate of production is

within the control of the body. Exogenous antioxidants like Vitamin E may help

reduce oxidative stress but cannot directly affect the compensatory mechanism. This is

supported by the evidence that as age-related tissue levels of endogenous antioxidants

decrease, the body is more prone to oxidative stress. Therefore oxidative stress results

from the failure of endogenous antioxidants.

 

Such a reciprocal relationship between oxidative stress and endogenous

antioxidants suggests that endogenous antioxidants and their metabolisms require

further study. If we can understand when and why the compensatory mechanism fails,

we may find ways to prevent its failure. We hypothesize that metabolic stress

determines the failure of the compensatory mechanism. Examining this hypothesis will

provide valuable insight into the relationship between oxidant- antioxidant balance and

oxidative stress.

 

Antioxidant Metabolism and Squalene

 

The above discussion suggests the great importance of clearly defining

metabolic stress, why it occurs and how it leads to oxidative stress. These questions

may lead to new insights into balance and stress in the immune system. They may also

provide more insight into oxidant-antioxidant balance, which we can justifiably

consider primordial balance. Since Squalene is synthesized in our cells, it is an

endogenous antioxidant. It may therefore serve as an appropriate model for the study

of antioxidant metabolic stress its influence on oxidative stress. We examine this

possibility in chapters 4 & 11.

 

We must also consider Squalene’s history as a antioxidant. The cell

membranes of archae and bacteria that lived about 3.5 billion years ago were rich in

Squalene. Along with coenzyme Q, lycopene and some other isoprenoids, Squalene

was among the first antioxidant group to take part in the primordial balance of life.

Indeed, research reveals that Squalene’s antioxidant properties resemble those of

vitamin E and other Isoprenoid antioxidants. The natural presence of this strong

antioxidant in human cells and its particularly high concentration in human skin do not

seem coincidental. Our job is to identify the exact antioxidant role it plays in the body.

 

Conclusion

 

All life forms must deal with the everyday threat of free radicals. While early

life first benefited by exogenous [environmental] antioxidants, those organisms that

were able to manufacture endogenous antioxidants in their own metabolism gained the

evolutionary upper hand. The new science of free radical biology suggests that

oxidative damage is responsible for some of the most intractable diseases of the

twentieth century and that maintaining an oxidant-antioxidant balance is a crucial first

step to overcoming some of them. Since levels of endogenous antioxidants decline

with the aging process, it becomes increasingly difficult to maintain this balance and the

question naturally arises of whether the process of disease and aging can be slowed by

therapies that might arrest or reverse this antioxidant decline.

 

A History of Squalene

Squalene’s Importance in the Origin of Life

 

Squalene has served as an antioxidant for terrestrial life for over three billion

years, a fact due in great part to its nature as a pure Isoprenoid. Without isoprenoids,

the history of life on Earth would be unrecognizable, if indeed there were any life at all.

About 3.5 billion years ago during the Precambrian era, the surface of Earth was very

hot and the atmosphere was filled with methane, ammonia and other toxic gases.

Nevertheless, huge colonies of archae and cyanobacteria [organisms resembling

bacteria seem to have thrived. They left a vivid fossil record. Archae – which date

from that time – survived in temperatures of 100 deg Celsius and on very little oxygen.

The membrane of their cells was rich acyclic isoprenoids – mainly Squalene. These

Isoprenoid-rich life forms dominated the Earth right up to the Cambrian era – a period

of more than three billion years. Fungi, plants and animal life forms appeared only

about 500 million years ago and primitive humans barely two million. The fossils of

these three billion year old isoprenoids are found well preserved in the deep sediments

under the ocean floor. Marine biologists routinely use Squalene, lycopene and other

isoprenoids as biological markers of these sediments.

 

Isoprenoids may also one day help astrobiologists trace the evidence of life

beyond this planet. Just as several billion year old isopreniods fossils are found in all

sorts of terrestrial rock, they hope that similar fossils on meteorites will indicate the

existence of life in outer space.

 

A 1999 scientific paper published in the journal Science traces the probably

origin of quinone an early Isoprenoid molecule – right back to the cosmos. Author

Max P. Bernstein writes that isoprenoid molecules were probably carried to Earth by

meteorites and that their presence enabled primitive cells and organisms to protect

themselves from the harsh living conditions of early life, especially exposure to extreme

ultraviolet radiation. At that time, the ozone layer of Earth was not fully formed and

the surface of the planet was relatively unshielded from the full effects of the sun’s rays.

The earliest evidence of life on Earth is a several billion year old isoprenoid fossil –

pentamethyleicosane [PME], the molecular structure of which is similar to Squalene.

PME is an acyclic isoprenoid, the product of primitive methane-producing bacteria.

This is why the PME fossil is so significant, especially given its striking molecular

resemblance to Squalene. A present day study of Squalene will help us understand the

probable function of PME and other acyclic isopreniods in ancient life forms.

 

Early Squalene Research

 

In 1936, Nobel laureate Paul Karrer described the biochemical structure of

Squalene for the first time. This medical researcher was already famous for his account

of the chemical structures of Vitamins E and A. He was surprised to find that

Squalene had a similar structure to these two antioxidant vitamins. This may have

hinted at Squalene’s antioxidant characteristics, but far more interesting things were yet

to be discovered.

 

In the 1950’s Squalene was found to occur naturally in the human body,

although it was not considered particularly significant at the time. Researchers were

trying to describe how cholesterol is synthesized in the cell when it was discovered that

Squalene happens to be one of the steps in the transformation of glucose into this vital

substance.

 

High cholesterol levels are so feared these days that many people are unaware

that normal levels are absolutely essential to health. Cholesterol is manufactured in

individual cells in a complex series of biochemical steps known as the mevalonate

pathway [see below]. Glucose is first converted into mevalonic acid, and this in turn

produces isoprenoids – geranyl, farnesyl and squalene. Some two dozen steps later, the

cell has a supply of cholesterol, essential for the manufacture of hormones and bile salts.

The Greater mevalonate pathway

Glucose

Mevalonic acid

Geranyl

Farnesyl

Co-enzyme Q10 Squalene Dolichol

Cyclic squalene

About 20 steps

Cholesterol

 

The Isoprenoid Synthesis Pathway

 

 Within the greater mevalonate pathway, the four steps from mevalonate to

squalene are known as the isoprenoid synthesis pathway. We now know that they are

of critical importance in a range of functions including cell growth and proliferation as

well as cholesterol synthesis. Many of the discussions in this book are concerned with

this pathway as well as the step immediately preceding it – the synthesis of HMG

Coenzyme-A reductase [HMG Co-A]. It turns out that these are mot merely

intermediates, but also rate-controlling steps – reactions that slow down or speed up

according to the body’s requirements. They have profound implications for the

function, growth, replication and life span of individual cells. The presence of squalene

in cells affects the rate of synthesis of HMG Co-A reductase, which in turn affects the

entire synthesis of cellular isoprenoids and cholesterol, offering tantalizing possibilities

for the prevention and treatment of high blood levels of bad cholesterol – one of the

most important risk factors for heart disease. But we are getting ahead of the scientific

detective story. When its natural occurrence was discovered in the body in the 1950’s

Squalene’s antioxidant function was still unknown.

function, growth, replication and life span of individual cells. The presence of squalene

in cells affects the rate of synthesis of HMG Co-A reductase, which in turn affects the

entire synthesis of cellular isoprenoids and cholesterol, offering tantalizing possibilities

for the prevention and treatment of high blood levels of bad cholesterol – one of the

most important risk factors for heart disease. But we are getting ahead of the scientific

detective story. When its natural occurrence was discovered in the body in the 1950’s

Squalene’s antioxidant function was still unknown.

 

Squalene’s Importance Recognized

 

There was in face a delay of over a decade before the spotlight was finally

placed upon this antioxidant agent found in olives, amaranth and shark liver oil. The

abundant folk tales and anecdotal stories created a negative bias in the scientific

community – squalene was considered a “mere” folk cure and its potential was ignored.

In any case, limited research funding and the relative immaturity of biochemical

technology hindered further understanding.

 

Research avenues reopened in 1963, when an article in the scientific journal

Nature demonstrated that squalene stimulates macrophages – the principal immune

cells in the inner and outer protective coat of our body. This empirical observation was

exciting news, but an explanation of how and why it was so remained elusive.

 

In 1950, researchers led by McKenna found that human skin secretes very

high levels of squalene. Subsequently, C.K. George and others at Rockefeller

University, New York demonstrated the widespread occurrence of squalene in

subcutaneous and submucosal human tissue. This finding of significant squalene levels

in the protective coat of the body raised the immediate question of whether it plays a

protective role. This second research group also found a separate source [pool] of

human squalene in the body, quite independent of the cellular cholesterol metabolism.

Its biological function there remained unknown but its existence could not be ignored.

There was no longer any doubt – squalene was much more than a simple by product of

cholesterol metabolism.

 

In 1982, R. Tilvis and his group found another pool of squalene synthesis –

this time in fat cells. And in 189 C. De Luca and colleagues compared the squalene

content of human skin to that of other primates and found it to be much greater. The

sebum of gorillas, for example, contains about 0.1% squalene, whereas human sebum

contains about 12% - 120 times more! This led to an entirely new notion – that the

presence of squalene in human skin may be an evolutionary requirement.

 

In an earlier study conducted in 1977, M. Gloor and A. Karenfield had found

that the body’s consumption of squalene increases when skin is exposed to ultraviolet

[UV] radiation. Then in 1993, O. Salamoto and his research group conducted more

specific tests and demonstrated that the first molecule targeted by UV rays as they enter

the human skin is squalene. Since ultraviolet radiation is known to harm unprotected

tissue, the implication is that they protect the skin from UV damage – at least until they

are depleted Several research groups got to work on this question and finally in 1995 a

Japanese team clearly demonstrated that squalene can prevent UV induced oxidation of

lipids in skin – a key finding that finally placed squalene in the scientific spotlight.

 

23

 

In 1982 squalene’s detoxifying function was demonstrated in several research

experiments and in 1993 its radioprotective effects were revealed. These discoveries

set the stage for the medicinal use of squalene.

 

Clinical Applications of Squalene

 

During the early part of the twentieth century, it was believed in Japan that

squalene could reduce the risk of cancer, and combat tuberculosis and other microbial

diseases. Dr. Keijiro Kogami, a medical research from the Tokyo Imperial University,

conducted extensive research and developed a squalene treatment for tuberculosis. His

work apparently showed significant success but the hospital where he worked and his

records were destroyed in 1945 by World War two bombings and his work was taken

up later by the Yokota Research Institute in Tokyo.

 

Two prominent Japanese physicians and researchers – Dr. Ryosuke Yokota

and his son Dr. Takashi Yokota – pioneered research on clinical applications. They

established the Yokota Health Institute and worked together from 1968 to 1989.

There they undertook the longest running clinical research trials on the health benefits

of highly purified and carefully preserved squalene obtained from the deep sea shark.

Several laboratory research studies showed that dietary squalene can strengthen the

immune response, especially against radioactive poisoning.

 

In 1996 a human clinical trial of squalene was performed to examine its

effectiveness in lowering blood cholesterol. As a result of these and consequent

research studies, dietary squalene has been found to:

 

1. Lower blood cholesterol

2. Enhance the anti-tumor action of chemotherapeutic agents

3. Inhibit cancer growth

4. Increase the efficiency of the immune system

In order to understand these developments, we will examine the isoprenoid

synthesis pathway in which squalene’s role has been expanded from that of a mere

precursor to an important metabolic player in its own right. This is discussed in

chapter 3. First we must describe the squalene molecule.

 

Two Forms of Squalene

 

There are two molecular forms of squalene - linear and cyclic. Both have the

same constituents but each one has its own distinct molecular shape and biological

properties. Linear squalene is a long wavy strand – an extremely stable and powerful

antioxidant that protects the biomembrane [envelope] of living cells from lipid

peroxidation [the most dangerous form of free radical damage]. Under certain

conditions acyclic squalene loses this stability, curls in on itself and becomes cyclic,

losing much of its antioxidant potential but becoming the sterol nucleus.

 

The transformation of acyclic to cyclic squalene has defied synthesis in the

laboratory. It is still a mystery how the molecules form is reconfigured without any

change in its composition. All we know is that the acyclic molecule enters the deep

pocket of a cone shaped protein complex where it is broken down into its six

component isoprene’s and then reassembled in a new configuration. Only then can the

molecule become the nucleus of cholesterol and many other sterols. It has been said

that this cyclization reaction is the most complex single step reaction in the biological

world.

molecule become the nucleus of cholesterol and many other sterols. It has been said

that this cyclization reaction is the most complex single step reaction in the biological

world.

 

This transformation first took place several billion years ago, during the

Precambrian period, opening up whole new possibilities for life on this planet. The

wavy shape of linear squalene provoked considerable interest when scientist noticed

that it resembled the molecular structures found abundantly in very primitive cells. It

turns out that the cell membranes of archaea – one of the oldest forms of life – are

composed of acyclic isoprenoids like lycopene and squalene. In addition, marine

geologists discovered large amounts of the isoprenoids squalene and lycopene in deep

sea sediments dating back to primordial geological ages [the Precambrian era].

Squalene is a principal constituent of the cell membrane of the archaea that live in such

inhospitable environments as sulfur springs and deep sea volcanic vents. It is believed

that these archaea survived these environments because of the protective acyclic

squalene and other antioxidants in the biomembrane.

 

As we move up the evolutionary ladder we find that the eubacteria and

cyanobacteria are liberally composed of hopanoids – cyclic squalene molecules that

undergo further modifications to form triterpene compounds. This transformation of

acyclic to cyclic squalene was an evolutionary step of enormous significance.

Cyanobacteria are a product of a relatively temperate oxygen environment and do not

need to maintain such robust protective mechanisms as archaea. Instead, they

developed genes able to provoke the enzymatic transformation of acyclic squalene into

hopanoids, resulting in a stronger cell membrane able to engage in more sophisticated

evolutionary activity. In modern mammal’s cyclic squalene forms the vital sterol

nucleus – the building block of such essential substances as steroids, other hormones,

vitamin D and of course cellular cholesterol.

 

Although the emergence of cyclic squalene is considered an evolutionary

development, living organisms continued to depend on linear squalene. A very

significant portion of this protective isoprenoid does not become cyclic and the

organism benefits from its antioxidant properties. Today acyclic isoprenoids like

squalene and lycopene are found throughout the plant world. In the animal kingdom,

acyclic isoprenoids remain an invaluable constituent of cellular membranes.

 

Linear squalene is found abundantly in human skin, where it is also reduced to

squalane, a reverse step that cannot be taken by cyclic squalene. [Squalane is formed

when hydrogen ions saturate squalene’s double bond neutralizing its antioxidant

abilities. Squalane is nevertheless an effective moisturizer used in cosmetic

preparations]. Humans are the only primates with such concentrations of Squalene in

their skin, apparently because of our susceptibility to ultraviolet B radiation. Medical

research has shown that squalene is the first target molecule of UV radiation – it

apparently takes the brunt of UV’s damaging ionizing potential. This radiation may

nevertheless induce stress in squalene metabolism an idea explored in chapters 4 & 11.

 

Conclusion

The first hints of squalene’s importance in our body were uncovered when it

was found to be an integral part of the cholesterol synthesis pathway in individual cells.

Later discoveries that it stimulates the activity of macro-phage immune cells and also

protects the skin from UV radiation damage have left no doubt as to the body’s day to

day dependence upon squalene.

 

Following centuries of traditional use in Japan, researchers using natural

squalene in therapeutic applications were rewarded with success, but their findings were

not clearly understood. Recent understanding of squalene’s isoprenoid origins and its

metabolism began to unravel the puzzle, but the big breakthrough was the realization

that it performs a regulatory role in the cholesterol synthesis pathway. There is good

reason to believe that continued research into this regulatory role may help explain and

refine the successes of the applications developed in Japan. The presence of very high

levels of squalene in human skin may have to do with its ability to protect against UV

radiation and other sources of free radicals.

 

Squalene the Antioxidant

 

Squalene is an isoprenoid antioxidant – a type of organic molecule vital for

the very existence of life on Earth. Hundreds of thousands of isoprenoids are found in

nature, of which squalene and some others are potent antioxidants – notably Vitamin

E, beta-carotene, lycopene, phytol and coenzyme Q10. They all contain isoprene units.

This chapter outlines the antioxidant mechanism of squalene and its significance in

cellular protection.

 

Isoprenes

 

Isoprene units are very small molecules containing five carbon atoms and are

found in all isoprenoids. There are many isoprenoids on Earth – perhaps several

hundred thousand. Each contains isoprenes attached in different configurations or to

different molecules. Molecules containing only isoprene’s – like Squalene – are said to

be pure isoprenoids. Those with one or more isoprene units attached to the mother

molecule – like Coenzyme Q10 and Vitamin E – are mixed isoprenoids. The isoprene

unit contributes to the antioxidant properties of the whole molecule but does not by

itself account for them. Dolichol, for example is a pure isoprenoid of twelve isoprene

units with no significant antioxidant abilities, whereas coenzyme Q10, a mixed

isoprenoid with ten units, is a good antioxidant. Squalene’s six units give the molecule

an effective and stable antioxidant configuration. All these isoprenoids, it should be

noted, are intermediate metabolites of the mevalonate pathway.

 

The usefulness of an antioxidant is largely determined by its ability to stop a

lipid peroxidation chain reaction. Lipids [fatty acids] in the biomembrane [outer

envelope] of a cell are arranged like long chains of molecules, aligning themselves in

parallel. When a free radical approaches one of these fatty acid chains, it liberates a

lipid peroxide radical – a fatty acid chain with an oxyradicals at the end. This radical

then goes on to attack another fatty acid chain, liberating a new peroxide radical.

However, when it encounters an antioxidant molecule, it is quenched and the chain

reaction is stopped.

 

Antioxidant isoprenoids are ideal for stopping lipid peroxidation chain

reactions in the biomembrane. They are water insoluble and can be easily incorporated

into the lipid bilayer. Squalene and coenzyme Q10 – two endogenous antioxidant

isoprenoids – are indeed found there and laboratory research has shown them to be

effective.

 

Not every isoprenoid has antioxidant properties, and even an antioxidant can

be overwhelmed by free radicals. Its effectiveness all depends upon the stability of the

molecule. Like any other molecule encountering a free radical, antioxidants are obliged

to either donate or receive an electron. Unlike other molecules, the loss of the electron

does not destabilize them. Squalene is an excellent antioxidant because of its great

capacity to receive or donate electrons without suffering molecular disruption. There

are two ways in which it can neutralize [or quench] a free radical, either physically or

chemically. Physical quenching involves the donation of an electron by squalene,

stabilizing the radical without itself becoming unstable. In a chemical quenching

reaction the radical is chemically incorporated with the squalene molecule, producing

squalene hydroperoxide – a new molecule. Squalene hydroperoxide is not an

antioxidant but is an excellent emollient that in the skin serves as a natural sunscreen.

 

In the case of physical quenching, the squalene molecule contributes an

electron without changing its own nature. This is a necessary prerequisite for any

antioxidant, but squalene does so in a particularly effective way. The key to its stability

is the configuration of atoms in its constituent quaternary carbon and methyl group,

known as its pi electron system. It is a quaternary carbon group because the central

carbon atom is directly connected only to other carbon atoms, making it particularly

stable. In additions, the pi electron systems of six isoprene units enable each unit to

interconnect forty-four hydrogen atoms, providing it with extraordinary stability.

 

Because of all this, squalene is said to have a low ionization threshold – its

atoms are held in place by a strong natural bond that is maintained with little

expenditure of energy. Therefore, even when it donates electrons its energy field

remains stable. Squalene’s very low ionization threshold accounts for its very large

capacity to donate electrons, like vitamin E. This unique stability is the key to

squalene’s ability to terminate a lipid peroxidation chain reaction.

 

Once a lipid peroxidation chain reaction is underway it will damage one lipid

molecule after another unless it is stopped by the intervention of a terminator – an

appropriate antioxidant molecule standing in its path. Most terminator molecules

contain isoprene units. Isoprenes have excellent shock absorbing capabilities and are

the right molecule to terminate the chain reaction. This is why antioxidant isoprenoids

are vital to such a vast range of living tissue.

 

The antioxidant property of squalene has been known for a long time, and

laboratory research has shown that squalene specifically terminates lipid peroxidation

chain reactions in the skin’s surface. Y. Kohno and his colleagues have shown that

squalene is stable [i.e. cannot be easily oxidized] and is capable of terminating chain

reactions. It is reasonable to assume that it performs a similar function wherever it is

found, for example within individual cells and in the biomembrane.

 

M.K. Rao first wrote of squalene’s antioxidant properties in 1968 in an article

published in the Journal of the American Oil Chemical Society. However the origin of

these properties was still unknown. Only recently – in the light of free radical biology –

have scientists realized that they derive from squalene’s isoprenoid nature.

In both plant and animal life isoprene’s play a significant role in protecting the

cell or redox molecule from free radical induced damage. In the cytoplasm [ the whole

cell except the nucleus] where most of the cell’s work takes place, electrons are

produced by many of its metabolic reactions. Especially, large numbers are released as

by-products of the energy generating activity of the mitochondria. Electrons reacting

with water inside a cell will generate hydroxyl ions {OH} and hydrogen ions [H] – both

free radicals and highly toxic to lipid and protein molecules within the cell. Leaked

electrons may also collide with molecular oxygen inside the cell, producing superoxide

ions [O]. Most importantly, free radicals may convert molecular oxygen in the

cytoplasm into free radicals.

 

Plant chloroplasts contain LHC [light harvesting complex] isoprenoid

molecules to prevent molecular oxygen from being rendered into oxyradicals.

However, we still do not know whether similar defense mechanisms exist in the

mammalian cell. Does cytoplasm contain isoprenoid molecules to recognize and

neutralize these free radicals? It is highly possible that squalene may act in animal cells

 

Biomembrane Structure

 

The part of the body where the biological properties of isoprenes are in

greatest demand is the biomembrane. This two layered lipid skin envelops each cell

and each of the various organelles within. In particular, the biomembranes of the

mitochondria – the site of energy releasing electrical activity – are particularly prone to

a lipid peroxidation chain reaction. There, nutrients are oxidized, constantly releasing

free radicals in the midst of this intense concentration of lipids.

 

Each of the biomembrane’s two layers is a collection of longitudinally

arranged lipid molecule chains, including cholesterol, vitamin E and fatty acids. The

molecule chains have one hydrophobic [water avoiding] end and one hydrophilic [water

seeking] end. Like a magnet, they are said to be polarized, and naturally arrange

themselves in a n orderly pattern. By avoiding the watery environments both outside

and inside the cell, the hydrophobic ends enclose a waterless band between the two

layers. Acyclic squalene is entirely hydrophobic and is not anchored in the

biomembrane. It is therefore attracted to this waterless band and accumulates there

where it performs its crucial antioxidant function. Squalene’s ability to protect the

biomembrane from free radical damage is discussed below.

 

Vitamin E & Squalene Compared

 

Of all isoprenoids that can act as antioxidants, we so far know most about

vitamin E. Its structure of three isoprenoid side chains and two phenol rings makes it a

very effective antioxidant. It is commonly believed that Vitamin E is the principal

antioxidant of lipid peroxidation chain reactions in the biomembrane, but this may not

be the case after all.

An ideal antioxidant should fulfill three criteria. It must:

 

1. stop the chain reaction

2. be synthesized and regulated on demand [so the body does not need to depend upon an outside supply]:

3. incorporate itself into the biomembrane without altering or damaging the membrane

 

We can compare vitamin E and squalene in the light of these requirements.

Vitamin E’s ability to completely protect the biomembrane is limited by its uneven

distribution throughout the biomembrane. Because it is an exogenous antioxidant and

must be obtained from dietary sources, the body has no control over where and when

it is available. Squalene on the other hand, is synthesized within the cell from glucose –

a readily available nutrient under normal circumstances.

 

Also, the large benzene structure in vitamin E limits its integration into the

biomembrane, which can incorporate no more than two molecules per 2,000 lipid

molecules. Too many vitamin E molecules disturb the biomembrane’s physiological

properties. It has been shown that large quantities of squalene do not alter the

physiological property of the biomembrane.

 

Squalene has additional advantages over vitamin E. It does not require

recycling, whereas Vitamin E must be continuously recycled by endogenous

 

29

 

antioxidants such as glutathione and squalene. And, during periods of oxidative stress,

the availability of antioxidants decreases, limiting the potential of recycling Vitamin E.

 

For all these reasons, the usefulness of vitamin E as the primary antioxidant in

the biomembrane may be exaggerated and the role played by squalene may be more

significant. Also, squalene is not fixed in the biomembrane and scavenges free radicals

in the hydrophobic intermembrane band. It is also highly resistant to free radical

attacks on itself.

 

Squalene has an additional advantage – it can recycle Vitamin E. Antioxidant

molecules such as Vitamin E neutralize free radicals by donating electrons but then

become radical themselves. However they are recycled by the intracellular antioxidants

glutathione and squalene and sent back to work. This recycling is a reduction process

involving a biochemical “ENE” reaction which stabilizes a free radical by donating a

hydrogen atom.

Comparisons of vitamin E and squalene

Vitamin E.

 

A mixed isoprenoid of three isoprene units and very good antioxidant

capacity

Exogenous [dependent upon dietary sources] and not necessarily available

when needed

Cannot be synthesized in the body – available only in certain foods

Limited integration into the biomembrane, where it becomes embedded in the

lipid bilayers

Is fixed in the lipid layer and cannot move freely

Too many vitamin E molecules alter the biomembrane’s physiological

properties and structural configuration

Vitamin E requires recycling by endogenous antioxidants such as glutathione

and squalene

Is itself susceptible to free radical attacks

The usefulness of vitamin E as the sole terminator in the biomembrane is limited

 

Squalene:

 

A pure isoprenoid of six isoprene units and very good antioxidant capacity

Endogenous [manufactured on demand] readily available under normal

circumstances

Manufactured within the cell from readily available glucose

Strongly attracted to the hydrophobic band between the two lipid layers of the

biomembrane, where risk of lipid peroxidation is greatest

Can move freely thoroughly the biomembrane

Large quantities do not alter the physiological properties of the biomembrane

Does not require recycling

Relatively resistant to free radical attacks on itself

The role played by squalene as a terminator in the biomembrane is significant

 

Usually a molecule’s methyl group supplies the hydrogen atom for the ENE

reaction. Squalene has six methyl groups capable of participating in the ENE reaction.

This may explain squalene’s ability to recycle oxidized vitamin E back in to recycled

vitamin E.

 

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Squalene in the Skin

 

 

The human cell synthesizes two isoprenoid antioxidants: ubiquinone

[coenzyme Q10] and squalene. The former is mostly distributed within the

mitochondria [energy production centres] of our cells. Squalene is found mainly in the

biomembrane, but also in the fatty layer just beneath the skin. In addition, the outer

surface of our skin is covered by a coating of squalene rich fat. Laboratory research

has shown that squalene is capable of protecting the skin surface from free radical

induced lipid peroxidation confirming its antioxidant properties.

 

Squalene’s Role in the Immune System

 

Squalene’s antioxidant properties also contribute to protective functions in the

immune system. As primitive organisms learned to survive the threat of free radicals

and proliferate in number and variety, they needed increasingly to protect themselves

from viruses and bacteria, which were also proliferating. Only those able to do so

avoided extinction. The first step was the emergence of the macrophage – an immune

cell that kills, eats and digests bacteria and viruses. Today the macrophage remains the

principal immune defense of fish and many invertebrates. Humans have developed a

more sophisticated army of immune mechanisms, including lymphocytes that can

attack different antigens in specific ways and can even recognize particular invaders and

know how to overcome them. But we still depend largely on the macrophage for

protection. In fact it remains the frontline defense in the present day human body

especially in the protective coat – those parts of the body in direct contact with the

outside environment.

 

Laboratory tests have shown that squalene enhances the function of

macrophages. It seems that the concentration and distribution of squalene in skin and

adipose tissue is an evolutionary requirement to strengthen the defense function of the

protective coat of our body.

 

Squalene Metabolism & Cell Growth

 

Researchers developed ways to arrest the mevalonate pathway by blocking it

at the squalene stage, preventing the progress of glucose into cholesterol. But there

was an unexpected consequence – cell growth came to a halt, obviously because

something crucial was missing. However, adding cholesterol to the cell culture medium

afterwards did not correct the problem. The researchers deduced that one or more

intermediaries of the pathway were essential for cell functions. These intermediate

metabolites obviously play a more significant role than was previously thought.

 

The squalene synthesis segment of the mevalonate pathway produces some

isoprenoids essential for cell growth and proliferation. Of these four products, the two

isopreniods geranyl and farnesyl are derived from mevalonic acid and are direct

precursors of squalene.

 

In order to perform its work – and particularly when it undergoes division –

the cell depends upon certain proteins and growth factors. The isoprenoids geranyl

 

31

 

and farnesyl help the cell by providing an anchorage in the biomembrane for these

proteins. This is called protein isoprenylation.

 

Deficient squalene precursors at this stage can prevent protein isoprenylation

and inhibit cell growth. For cells to function efficiently, squalene and its precursors are

essential.

 

These precursors also function as signaling molecules for cell growth and

proliferation. Close to the beginning of the mevalonate pathway the synthesis of HMG

–Co-A immediately precedes the four steps of the squalene synthesis segment –

mevalonic acid to geranyl to farnesyl to squalene [see below]. This step is of particular

interest because it determines the mevalonate pathway’s rate of production as a whole

and is the key to many cellular functions. The production of HMG Co-A is dependent

upon the availability of HMG Co-A reductase, which determines several important

cellular functions including:

 

Control of the rate of production of cellular cholesterol

The entire mevalonate pathway in the cell, including production of geranyl

and farnesyl – two isoprenoids crucial to cellular growth and proliferation

Squalene has been found to regulate HMG Co-A activity

The regulatory role of squalene on HMG Co-A reductase and the roles of

squalene’s molecular cousins and precursors geranyl and farnesyl are the key to

understanding squalene’s full metabolic role in the cell.

 

The Squalene synthesis segment of the mevalonate pathway controls the isoprenoid metabolism by

regulating enzyme HMG Co-A reductase levels

Glucose

HMG Co-A Reductase

 

Mevalonic acid

Squalene synthesis segment Geranyl

Farnesyl

SQUALENE

 

Cyclic Squalene

 

About 20 steps

 

CHOLESTEROL

HMG Co-A reductase is the rate-limiting enzyme of the mevalonate pathway and therefore the

controller of the mevalonate production factory

 

Squalene & Aging

 

For unknown reasons the distribution and concentration of squalene and

other isoprenoids including coenzyme Q10 changes as a person ages. The activity of

HMG Co-A reductase too is age specific. Generally speaking isoprenoid

concentrations decrease with aging, particularly in the brain. It is not clearly known

why such changes occur but this undoubtedly affects our health adversely. More

research is required to uncover the implication of the age specific change in the

isoprenoid metabolism and to investigate the possibilities of modulating it.

 

32

 


 

 

Conclusion

 

 

Squalene is an ancient and potent isoprenoid antioxidant. Its isoprene

constituents and its special molecular structure provide its antioxidant properties. It is

stable enough to resist oxidation itself when quenching free radicals and also recycles

vitamin E.

 

The biochemical structure of squalene not only makes it a stable antioxidant

but also a regulator of cellular growth. It has recently been discovered that squalene

plays a key role in the regulation of the cholesterol synthesis pathway through its

influence on the enzyme HMG Co-A reductase – an enzyme crucial for growth and

cellular proliferation. There is no doubt that squalene’s protective role in the body is

profound and the question arises of whether squalene levels in the body can be

modulated to provide antioxidant protection in ways similar to dietary vitamin E. This

is especially significant in elderly people whose isoprenoid concentrations are

particularly depleted.

 

33

 

 

4 - Balance & Stress In Bodily Systems

 

Our body is an extraordinary network of interconnected operating systems.

In good health, the balanced interaction of these systems keeps our cells healthy and

happy. However – as we know from the second law of thermodynamics – entropy [the

tendency to fall into disorder] universally increases in all systems. For example, the

homeostatic conditions of water flow – when the flow rises or falls beyond a certain

threshold, entropy disrupts the phenomenon and it disappears.

 

Systems in our bodies are no exception – when balance is disturbed, disease

results. However, biological systems are sophisticated masters of entropy that work

hard to maintain a state of balance [low entropy] and some biologists consider life to be

the antithesis of entropy. Life has its own control mechanisms that maintain constant,

dynamic balance. Scientists call this “homeostasis” a sort of inherent wisdom of the

biological system. It is also called “health”.

 

Invading viruses or bacteria interfere with our health by targeting bodily

control systems and creating imbalance. More complex disease processes such as

diabetes and rheumatoid arthritis also break down control systems. Those most

commonly targeted are the immune control system, the oxidant-antioxidant control

system and the metabolic control system. Each has evolutionary niches that can be

targeted by pathogens, resulting in increased entropy for all. A good example is the

way the human immuno-deficiency virus [HIV] targets the immune system and leads to

AIDS. There are some experimental evidence to suggest that it upsets key processes of

the oxidant-antioxidant control system by creating a deficiency of glutathione. This

results in oxidative stress and immune imbalance that undermine the oxidant-

antioxidant control system eventually contributing to its collapse.

 

This finding suggests that a proper balance in the antioxidant metabolism is a

prerequisite for an effective immune system and indeed, squalene’s immune enhancing

properties have been long known, Since squalene metabolism is an antioxidant

metabolism, a study of its role in the immune balance may provide more insight into

the crucial relation between antioxidant metabolism and immune function. Such

insight will contribute to the development of useful therapies to reinforce the immune

system.

 

This chapter describes the fundamentals of immune balance and the role of

squalene and its metabolism in effective immune response.

 

Immune Imbalance

 

The balanced immune response defines the meaning of immunodeficiency.

The function of the immune system is to keep the internal environment of our body

free of pathogens and xenobiotics. To do this it relies on a network of special cells and

molecules, principally macrophages, lymphocytes and cytokines. It was long thought

that a large number of immune cells resulted in a stronger and more balanced internal

environment. In parallel to the concept of oxidant-antioxidant balance however, it has

become increasingly apparent that too active or too many immune cells can lead to

immune deficiency s readily as too few. Our body’s ability to resist disease does not

depend on the brute strength or numbers of immune cells but on their state of balance.

 

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Consider the case history of a thirty-eight year old woman suffering from

chronic pharyngitis [sore throat] for two years. When she eventually developed lesions

in her mouth, her doctor diagnosed bacterial pharyngitis. His examination led him to

suspect her immune status. A battery of tests revealed large numbers of lymphocytes

[immune cells] and high levels of immunoglobulin [antibodies] in the blood and yet

infectious bacteria were found in a throat swab. The doctor wondered “If she has so

many antibodies and immune cells, why aren’t they killing the viruses and bacteria?”

He was forced to conclude that something was wrong with the woman’s immune

response.

-eight year old woman suffering from

chronic pharyngitis [sore throat] for two years. When she eventually developed lesions

in her mouth, her doctor diagnosed bacterial pharyngitis. His examination led him to

suspect her immune status. A battery of tests revealed large numbers of lymphocytes

[immune cells] and high levels of immunoglobulin [antibodies] in the blood and yet

infectious bacteria were found in a throat swab. The doctor wondered “If she has so

many antibodies and immune cells, why aren’t they killing the viruses and bacteria?”

He was forced to conclude that something was wrong with the woman’s immune

response.

 

The imbalance in this woman’s immune system is probably due to some

underlying disorder that prevents it from effectively responding to outside attacks.

Such diseases are characterized by an excessive immune response to a real or imagined

threat, resulting in damage to the host. Thus immunodeficiency does not always imply

a reduced number of immune cells or fewer antibodies. Rather, it refers to the lack of a

balanced immune response in which the internal functioning of immune cells plays the

main role.

 

Effective Immune Balance

 

Individual immune cells are the functional units of effective immune

response. Among them, macrophages are the frontline protective cells. They are large

white blood cells that simply engulf invaders and metabolic debris – old red blood cells,

dead tissue and even cells that have become malignant. Once it is safely contained

within the macrophage, the material is “digested” and conveyed safely out of our body.

 

Other immune cells such as lymphocytes use extremely sophisticated means

to fight off equally sophisticated viruses, but macrophages operate by brute force.

They create within themselves vesicles [sacs] filled with the free radical hydrogen

peroxide, which are transported to the outer cell membrane and squirted into the path

of oncoming enemies. Once released, the enormous quantities of these free radicals

are as potentially dangerous to the immune cell’s own membrane as to the invaders. In

a battle situation, immune cells are often called upon to grow and proliferate rapidly.

Their ability to do so depends upon effective biomembrane protection which is a

function of the antioxidant defense system. Antioxidants such as glutathione and

vitamin E prevent and stop lipid peroxidation chain reactions. Squalene has been

found to optimize the macrophage’s function.

 

Evidence suggests that the immune cells biomembrane s protected by

squalene during phagocytosis, and the synthesis and consumption of squalene probably

increases at this time, as do other antioxidants such as glutathione.

 

Quite apart from the oxidant-antioxidant balance within individual immune

cells, the immune response as a whole must maintain its own balance. Many types of

immune cells must work together as a team. This is maintained by a system of

communication that not only distinguishes friendly from enemy cells, but also identifies

the type of threat and encourages the growth and activity of the appropriate immune

response. Like a ball game in which players cooperate for the sake of the whole, each

one recognizes different needs in different parts of the field and communicates with

the others through words and signals.

 

35

 

The communication mechanism that ensures a balanced response and lets

immune cells know what to expect from each other is called negative feedback and is a

universal law of bodily control systems. According to our body’s needs, over excited

cells receive signals to slow down and follow an overall strategy, while sluggish cells are

encouraged to become more active. In short, macrophages, lymphocytes and other

immune cells work as a team, exciting or inhibiting each other with chemical signals to

maintain over balance.

 

The messengers of the immune system are cytokines – chemicals released by

immune cells that travel quickly through the blood, lymph and other body fluids to and

from the battle site. They carry excitatory or inhibitory messages, encouraging or

restraining other immune cells. Simply put, cytokines regulate the immune response.

 

Keeping the immune system working as a unit requires a balanced expression

of cytokines. Each immune cell synthesizes both excitatory and inhibitory cytokines

and releases them on demand. This cytokine balance depends upon a balanced internal

environment in the immune cell and here the squalene metabolic process plays an

important role.

 

Two precursors of squalene – geranyl and farnesyl – have been found to

influence cytokine synthesis and secretion. Experimental research shows that

deficiency of these two precursors inhibits the macrophage’s ability to synthesize

cytokines causing the cytokine system to lose its balanced expression.

 

Individual cells use squalene to protect their biomembrane, and two squalene

precursors are used for cytokine synthesis and secretion. In addition, research on

oxidative stress induced immune imbalance shows that endogenous antioxidant

metabolisms are factors in an effective immune balance. It therefore appears that

squalene and its metabolism may contribute to effective immune balance. This is

hardly surprising when we consider that squalene is an endogenous antioxidant. The

metabolism of glutathione – another endogenous antioxidant – also contributes to

effective immune balance.

 

Oxidative Stress & Immune Imbalance

 

A system falls into stress when it is overburdened by the demands placed on

it. Disease agents such as HIV encourage the release of large numbers of free radicals.

These destructive agents either burn up the cell or trigger its suicide [apoptosis]. These

combined assaults on the cells of our body are referred to as cellular oxidative stress.

 

Oxidative stress occurs when our body cannot access enough antioxidants

and free radicals gain the upper hand. Once balance is lost, the deficiency of

antioxidants becomes increasingly acute and the cytokine expression becomes overexcited.

Our body’s defense systems spiral out of control. Instead of slowing down,

they frantically secrete excitatory cytokines, worsening the situation. The immune

system becomes more and more aggressive, desperately trying to maintain our health

but in fact pushing the body into greater and greater levels of imbalance. This is like a

ball game in which the players see themselves facing defeat, become desperate, lose

their emotional balance and enter into uncoordinated attack leaving themselves

increasingly vulnerable. Excessive levels of excitatory cytokines cause untold damage

to healthy tissue.

 

36

 


 

 

Over excitation of cytokines can initiate positive feedback, further increasing

oxidative stress. This soon depletes endogenous antioxidants such as glutathione and

squalene leaving the cell membrane open to lipid peroxidation. Each state of

imbalance causes further imbalances, amplifying the damage in an ever-widening spiral

of destruction. The greater part of acute damage leading to disease occurs through this

vicious circle of amplification. Positive feedback poses two dangers in particular the

appearance of autoantibodies and further unrestrained amplification of cytokines

induced tissue damage.

oxidative stress. This soon depletes endogenous antioxidants such as glutathione and

squalene leaving the cell membrane open to lipid peroxidation. Each state of

imbalance causes further imbalances, amplifying the damage in an ever-widening spiral

of destruction. The greater part of acute damage leading to disease occurs through this

vicious circle of amplification. Positive feedback poses two dangers in particular the

appearance of autoantibodies and further unrestrained amplification of cytokines

induced tissue damage.

 

1.

While antibodies are normally produced by the immune response to

pathogens, autoantibodies turn on our body’s own proteins. Normally they

are controlled when negative feedback causes antibodies to inhibit their

production. When oxidative stress disrupts negative feedback however,

positive feedback takes over and autoantibodies can cause considerable

damage. The appearance of autoantibodies in AIDS is an example of positive

feedback initiated by stress.

2.

The other danger of positive feedback is an unbalanced cytokine expression

leading to lipid peroxidation and subsequent tissue damage. The damage

caused by too many excitatory cytokines leads to progressive and wide-

ranging destruction of all sorts of tissue, as demonstrated by the activity of the

human immunodeficiency virus {HIV] in the human brain. Although HIV

cannot replicate in the brain as it does in other parts of the body, AIDS

patients frequently develop marked symptoms of dementia, such as memory

loss and shortened attention span. The damage is triggered by the few HI

viruses that do pass into the brain. Although they cannot themselves act,

their presence stimulates immune cells in the brain to secrete an aggressive

cytokine {TNF-alpha]. This cytokine in turn amplifies cytokine secretion by

activating more immune cells, resulting in oxidative stress that further

increases the secretion of excitatory cytokines. The production of TNF-alpha

is caught in the vicious circle of positive feedback. By disrupting the balance

expression of cytokines, this tiny population of HI viruses – unable even to

replicate – can initiate a snowball leading to extensive brain tissue damage.

Such effects are seen in many ailments, including allergies, tuberculosis and

kidney failure. Increasing oxidative stress in brain leads to extensive damage

at the hands of apoptosis. In other words, oxidative stress pushes normal

cells towards programmed cell death [apoptosis]. And apoptosis is a major

contributing factor to oxidative stress induced immune suppression.

Apoptosis

 

Every second 25 million cells die [and 25 million are born] inside our body,

and the body needs to maintain order. This order is maintained by apoptosis – a

natural process of cell death which is normally harmless. Healthy cells have several

inherited genetic mechanisms that, when triggered, force them to commit

“suicide”. If apoptosis were not a controlled mechanism and cell deaths were

random, toxic debris would be strewn about surrounding tissue. Many cells

contain free radicals and other toxic substances. For example, pancreatic cells

 

37

 

have powerful digestive enzymes. Macrophages and neutrophils contain hydrogen

peroxide and digestive enzymes within special sacs in their cells. If the cell

membranes break – for example due to a lipid peroxidation chain reaction – the

release of these substances into surrounding tissue causes extensive inflammation.

Apoptosis is a way for our body to contain these toxins. Dead cells are engulfed

by the trash-collecting macrophages before their membranes break open.

 

Apoptosis is an essential part of overall health and development of the body.

It is for example, responsible for the resorption of a tadpole’s tail, the removal of

webbing between the fingers and toes of a human fetus, the formation of adequate

gaps, [synapses] between neurons in the brain and the sloughing off of the inner

lining of the uterus [the endometrium] at the start of menstruation. Apoptosis is

not the random death of worn-out cells but highly organized behavior, which is

 

why it is defined as programmed cell death. Without apoptosis, these processes

would not proceed in a systematic fashion and would result in severe

inflammation. Some body cells only undergo apoptosis at the end of their useful

life, when they begin to malfunction. But other cells are discarded as part of a

particular bodily function – for example, endometrial cells die not according to

their age or condition but according to the rhythms of the menstrual cycle.

 

The complex cellular mechanisms that decide a cell’s fate are known as

apoptosis regulators. An example is the tumor suppressor gene [a killer gene] that

identifies cells about to become cancerous and forces them to undergo apoptosis.

A link between apoptosis and the squalene synthesis pathway has been established

experimentally, although the precise mechanism has not yet been explained. In

these research experiments, cells underwent apoptosis when their squalene

synthesis pathway was inhibited. It has been found that apoptosis can also be

induced by free radicals. During periods of oxidative stress, for example, the

incidence of apoptotic cell death increases. This has been blamed for the

development of Alzheimer’s disease, Parkinson’s disease, diabetes mellitus and

other illnesses. In cases of myocardial infarction too, many cardiac cells die of

apoptosis. In AIDS a large number of healthy immune cells die due to forced

apoptosis triggered by oxidative stress.

 

Disease agents and disease processes generate additional free radicals,

resulting in increased production of excitatory cytokines. This in turn promotes

uncontrollable excitement in the immune response, increasing the generation of

free radicals and thus oxidative stress levels. The response of the endogenous

antioxidant metabolism is to increase production of antioxidants, in order to meet

increased demand. For reasons which are still unclear however, the metabolism

fails, resulting in diminished antioxidant synthesis. The cause of this failure must

be clarified. In chapter one, we hypothesized that stress in the antioxidant

metabolism may cause such failure. What is this metabolic stress and why does it

occur?

 

38

 

 


 

 

Metabolic Stress

 

The cell must produce various biochemicals on demand and its ability to

respond depends on the competence of metabolic pathways. These pathways are

sequences of events that in the healthy body lead to the manufacture of the right

molecule in the right place at the right time. When our body is in a state of

metabolic stress, the competence of these metabolic pathways is easily disturbed.

Once consequence of this disturbance is metabolic stress.

 

We have already explained that a system falls into stress when it is

overwhelmed by the demands placed upon it. Just as oxidative stress can lead to

an oxidant-antioxidant imbalance; this imbalance in turn can lead to the greater

problem of metabolic stress.

 

An Example of Metabolic Stress

 

A well known cause of metabolic stress is hypoxia reperfusion injury – a

common consequence of blocked coronary arteries. The blockage cuts off the

blood supply to the heart tissues, resulting in hypoxia – inadequate levels of

oxygen. If the tissue is reperfused – replenished with oxygenated blood – it

consumes the incoming oxygen as desperately as we gasp for air after being under

water for too long. The first part of the problem is that much of the tissue’s

antioxidant supply has been exhausted during the period of hypoxia and it is

unable to cope with even normal levels of oxyradicals, resulting in oxidative stress.

The second part is that the production of cellular antioxidants suddenly increases

to counteract their increased consumption. However, this production depends

upon the metabolic process of antioxidant synthesis, which is overwhelmed by the

demands placed on it, leading to metabolic stress. Tissue levels of antioxidants

then plummet, leading to hypoxia-reperfusion injury.

 

Thus, oxidative stress increases demand for a particular nutrient, leading to

stress in its metabolism and in turn compounding oxidative stress.

 

Metabolic Stress & Immune

Suppression

 

This idea that metabolic stress may lead to an ineffective immune response or

even immune collapse is central to this chapter. This immune system is normally

able to operate effectively even in the midst of free radicals because the

endogenous antioxidant metabolisms synthesize enough antioxidants to counter

the oxidative threat. However, this stress reaches a certain threshold when the

body’s ability to synthesize endogenous antioxidants has reached its limit, at which

point the antioxidant metabolism falls into a state of stress. Cytokine synthesis,

membrane protection and other normal cellular functions are then impaired,

leading to immune imbalance.

 

Since metabolic stress therefore limits the ability of the immune system to

operate in normally acceptable situations of oxidative stress, prevention of

metabolic stress should help to maintain the immune function in spite of oxidative

stress.

 

Conclusion

 

Immune suppression is a result of an imbalance in the immune system rather

than a simple lack of immune cells. Oxidative stress may increase the

consumption of antioxidants, create stress in the antioxidant metabolism and lead

to immune suppression.

 

Experimental studies have shown that squalene-supplemented diets lead to

increased performance of the immune system. This can be explained by squalene’s

essential roles in the protection of the biomembrane of immune cells against

oxidative stress.

 

Most importantly, the squalene metabolic process is an antioxidant

metabolism. It is there for vulnerable to oxidative stress induced metabolic stress.

Such stress may contribute to free radical induced immune suppression particularly

in the skin. This is discussed in detail in the last chapter of the book: Metabolic

Stress and Chaos.

 

39 40

 

 


 

 

Part 11

Squalene & Disease

 

 

This part of the book describes how squalene has the potential to be used as a

cytoprotective agent against cancer and as a cholesterol lowering agent.

 

5 -Squalene’s Role in Cancer &

Cancer Therapy: Carcinogenesis

 

Cancer’s biological mechanism has been so mysterious for so long, that of all

diseases in the modern world it is one of the most difficult to treat. During the

last decade however, many of its secrets have been revealed, including its genetic

evolution.

 

It is commonly believed that healthy cells suddenly and inexplicably become

cancerous and develop quickly into tumors. Nothing could be further from the

truth. Cancer develops in a single cell through a process of evolution, and in most

cases – excepting acute childhood cancers – cancer cells must struggle for years to

divide and proliferate into a tiny mass of one-thousand cells. The initial

development of cancer is extremely slow but once a certain limit is reached tumors

progress rapidly and aggressively.

 

This chapter describes how a healthy cell becomes cancerous and how it

develops into a large mass. It also discusses the role of squalene metabolism in the

evolution of cancer cells and how dietary squalene shows significant potential for

cancer chemoprevention and Cytoprotection.

 

The Evolution of Cancer

 

Cancer is like a sleepy settlement that hardly changes for centuries, and then

in a few decades suddenly grows into a town, a city and finally a metropolis that

consumes the surrounding countryside in concrete, smoke, dust and noise.

 

Cancer begins when a cell suddenly breaks away from the control systems

governing surrounding tissue and looks after itself, irrespective of the needs of the

body. It grows into a multicellular mass and develops its own autonomous

biomechanisms that can survive attacks by the immune system and by even the

most brutal radiation and chemical therapy. This development is known as the

clonal evolution of cancer.

 

As it divides and evolves, a cancer cell transfers its hereditary blueprint to the

child cell. This child cell acquires all the strengths of its parent cell, most notably

its ability to grow independently and to survive attacks from immune cells. This

child cell itself acquires new techniques to grow more rapidly and aggressively.

When it multiplies, its own child cells inherit and benefit from the parent’s hard

earned techniques. Thus, with each cell division, the cancer becomes stronger and

more resilient. Like any other living thing, only those cells that can acquire strong

 

survival properties will make it. Even cancer obeys the Darwinian law of natural

selection. Through evolutionary processes the cancer becomes autonomous,

resistant to immune attack and increasingly dangerous.

 

The cloned child cells eventually grow into a small colony. At some point they

differentiate [take on different roles] and acquire new properties. Some become

invaders, some metastasize [mobilize and seek new sites to colonize] and some

become specialists in the art of survival. Their environment [the body] is

extremely hostile. After all, the immune system recognizes the threat, uses every

weapon at its disposal and is often victorious. Cancers that survive this hostility are

inherently tenacious.

 

All but a few types of cancer develop very slowly. Breast cancer cells divide

every 100 days and a one centimeter growth in diameter [about a billion cells] takes

an average of nine year to evolve. Lung cancer growths reach this size in ten to

twelve years. However the next step is considerably more rapid. Both breast and

lung cancers progress from a one gram mass to a one kilogram mass within three

years.

 

Cancer’s Secret to Success

 

Every cell in the body has the potential to become cancerous. Most of those

that tend to do so inadvertently activate a gene called p53, which generally triggers

their self destruction through a process called apoptosis. Alternatively, the

immune system routinely detects cells with cancerous tendencies and sends

macrophages to engulf and destroy them. Only an extremely small number of

cells that attempt to become cancerous actually succeed in gaining a foothold.

Still, even one is enough to eventually kill the whole organism.

 

Cancer’s secret to success lies in the early, clonal stage of its growth. During

this time it learns to survive as an independent mass by controlling its genetic

expression and gaining “immortality” – in the sense that it is no longer subject to

apoptosis. Cancer cells bypass the body’s defenses by activating oncogenes

[cancer genes]. Oncogenes are usually inactive in normal cells, but are relocated

and mutated in cancer cells so that they are “switched” on.

 

The Ras Oncogene

 

Ras was the first and most common family of oncogenes to be discovered – it

is found in some 30% of cancers. Although many others have since been

identified, ras remains the most dangerous and most triumphant because in

combination with other oncogenes an evolved ras oncogene can transform a

normal cell into a cancerous one in a single step. It also plays a somewhat central

role in the activation of other oncogenes. In normal cells ras acts as a switch to

trigger cell growth when conditions are right. In many human cancers, ras is

hyperactivated - permanently switched on – enabling the cancerous cell to grow

autonomously. Oncogenes are a potent factor in cancer evolution – in fact they are

the backbone of cancer evolution. Without them few cancers if any would survive

 

41 42

 

 


 

 

the coordinated opposition of the immune system and the apoptosis control

system. Cancer’s perverse ability to invade and consume increasingly large areas of

healthy tissue distinguishes it as a powerful evolutionary force in the biological

system.

system. Cancer’s perverse ability to invade and consume increasingly large areas of

healthy tissue distinguishes it as a powerful evolutionary force in the biological

system.

 

Cancer cells activate the ras gene, which in turn synthesizes ras proteins and

performs ras functions. The activation of these proteins depends upon the

isoprenoid metabolism in the cancer cells. Through protein isoprenylation,

farnesyl anchors the ras protein to the cell membrane. Without this vital step, the

ras oncogene cannot get to work. This is extremely interesting because of

farnesyl’s place in the isoprenoid synthesis pathway and it’s dependence upon

HMG Co-A reductase, which is regulated by squalene.

 

A dietary supply of exogenous squalene can inhibit isoprenoid production in

cancer cells and hamper their growth and development. It has been suggested that

this may explain olive oil’s anticancer property. Several experiments have

demonstrated that the anticancer property of dietary squalene. Before we recount

them we will see how chemical carcinogens induce oncogene activity and the role

of squalene in the detoxification of such carcinogens.

 

Squalene’s Inhibition of Cancer

Proliferation

 

When dividing and multiplying, cells go through four phases. Cancer cells are

no exception. These phases are G1 [pre DNA synthetic phase], S [DNA synthesis

phase], G2 [Post DNA synthesis phase], and M [Mitosis or cell division phase]. A

G1 phase cell moving towards the S phase requires two products of the

mevalonate pathway for protein isoprenylation – geranyl pyrophosphate and

farnesyl pyrophosphate. Protein isoprenylation attaches some important proteins

to the cell membrane or nuclear envelope. However, the presence of exogenous

squalene sets up negative feedback inhibition by down-regulating the enzyme

HMG Co-A reductase, decreasing farnesyl synthesis, disrupting the mevalonate

synthesis pathway and inhibiting protein isoprenylation. Protein isoprenylation is

even more important in tumor cells than in normal cells, especially when the ras

oncogene is hyperactivated [permanently turned on] so its disruption is calamitous

to the cancer cell. By locking the cell in the G1 phase, squalene prevents cancer

cell growth and proliferation.

 

Both caution and further research are necessary. The degree of squalene’s

inhibitory effects varies from one cancer to another. Also, squalene has other

mechanisms that may prevent cancer, apart from its role in cell growth.

 

Carcinogenic Agents

 

 

43

 

 

Certain carcinogens [cancer causing chemicals] can activate oncogenes or

cause mutations, making a normal cell cancerous and initiating the ominous

evolution of clonal proliferation.

 

Many carcinogens – such as 4-[methylnitrosamino]-1 – [pyridyl] – 1 –

butanone [NNK] found in tobacco smoke – target the ras oncogene. With

increasing frequency, environmental pollutants and some types of radiation

promote the transformation of normal cells into cancerous ones. Increased

amounts and varieties of industrial carcinogens are blamed for the growing rate of

cancer throughout the world. We are only just beginning to identify these

substances and learning to avoid them.

 

Squalene’s Preventive/Therapeutic

Potential

 

Squalene’s potential detoxification properties may be useful against chemical

carcinogens. T.J. Smith and his colleagues demonstrated that dietary squalene can

prevent lung carcinogenesis induced by NNK 4-methylnitrosamino-1-3-pyridyl-1butanone]

and also proved squalene able to detoxify NNK in laboratory mice.

Squalene has been also found to inhibit the carcinogenesis induced by TPA [12tetradecanoyl

phorbol-13-acetate] a [7-12-dimethylbenz[a]anthracene]. C.V. Rao’s

team successfully used squalene to neutralize the potent carcinogen AOM

[azoxymethane].

 

Two properties of squalene may contribute to its anti-carcinogenic activity –

its separate abilities to prevent ras activation and to detoxify harmful chemicals.

 

Any way to inhibit oncogene activation is an extremely interesting and

potentially powerful weapon in the anticancer arsenal. Because it combats cancer

at the earliest stages, squalene’s preventive and therapeutic possibilities are

extremely promising. Several research findings show that squalene and other

closely related isoprenoids may play a very important role and deserve in depth

investigation. Squalene has been shown to:

 

1. prevent the occurrence of certain cancers

2. prevent carcinogenic agents from inducing cancer

3. act directly against tumor activity

4. optimize the activity of chemotherapeutic agents.

It has been found that several plant-derived isoprenoids share squalene’s

cancer inhibiting mechanism, and apparently exogenous isoprenoids are the most

effective ras inhibitors. Although the precise mechanism has yet to be clarified, the

cancer preventing action of squalene is supported by many epidemiological and

laboratory findings.

 

44

 

 


 

 

A Growing Body of Research

 

 

Several laboratory experiments have shown squalene to be anticarcinogenic. A

particularly interesting article appeared in the April 1998 issue of Carcinogenesis, a peer

review journal for physicians specializing in Cancer. It describes an experiment in

which three separate groups of female mice were fed a diet containing 5% corn

[control group] 19.6% olive oil [second group] and 2% squalene [third group], starting

3 weeks before being given a single dose of the potent carcinogen NNK. Sixteen

weeks after the NNK had been given all the mice in the control group had multiple

lung tumors averaging 16 tumors per mouse. The mice in the olive oil and squalene

groups exhibited significantly decreased lung tumor multiplicity – 46% & 58%

respectively. The squalene diet also decreased lung hyperplasia by 70%. Hyperplasia is

the abnormal proliferation of normal cells – a first step towards cancer.

 

A research paper published two months earlier in the same journal reported

research carried out by the Nutritional Carcinogenesis division of the American Health

Foundation, Valhalla, New York. Male mice on a diet enriched with one-percent

squalene were exposed to AOM –azoxymethane – a chemical which can cause colonic

aberrant crypt foci, a pre-cancerous condition of colon cancer. These mice did not

develop colonic aberrant crypt foci, while the control group on a normal diet did so.

These results are considered a highly significant indication of squalene’s cancer

preventing properties.

 

Olive oil contains a certain percentage of squalene and several studies have

been conducted in Mediterranean countries to examine the oil’s possible cancer

prophylactic properties. Mediterranean people consume relatively large amounts of

olive oil and high consumption levels have been associated with lessened risk of breast

and prostate cancers among others.

 

For many years researchers have been trying to understand why. It was first

thought that oleic acid – a monounsaturated fatty acid – might account for the cancer

protective effects of olive oil. However research by major research institutions around

the world has found that oleic acid may not possess such properties. Now there is an

increasing tendency to link the cancer preventive role of olive oil to its high

concentration of squalene.

 

Several laboratory experiments have found that squalene is beneficial even as

an adjunct to conventional cancer treatments. Usually, cancerous cells develop a

mechanism that will pump out any anti-tumor drugs. Squalene somehow promotes

their accumulation in the cancer cell, making the drug much more effective. More

research is underway.

 

There are many similar research experiments. However one report deserves

particular attention. Published in the October 1985 issue of the Japan Journal for

Cancer Research, it describes an experiment showing squalene’s ability to enhance the

action of anticancer drugs. This research finding strongly suggests several major

therapeutic advantages to using squalene as an adjunct to anticancer chemotherapy and

radiotherapy. By inhibiting the development of drug resistance, tumors can be

overcome with a decreased dose of anticancer agents. This has the two fold advantage

of attacking the cancer more aggressively while causing considerably less damage to

healthy tissue – a common undesirable and often dangerous side effect of conventional

chemotherapy and radiotherapy. Similar research findings from several such

 

45

 

experiments are encouraging more and more physicians to include squalene in the

anticancer arsenal.

 

Potential Clinical Applications

 

Squalene’s powerful antioxidant and cytoprotective effects are very significant.

Chemotherapeutic agents such as cyclophosphamide and cisplatin induce bone marrow

and kidney damage by generating free radicals or enhancing the oxidative metabolism.

Since it is a strong antioxidant, squalene may be able to minimize such tissue damage.

Also, squalene has been found to potentiate the cancer killing abilities of some

chemotherapeutic agents. In addition squalene’s ability to protect cells from the effects

of radiation makes it a suitable protector of healthy cells against cancer radiotherapy.

Cytoprotective therapy promises to play a much greater role in future cancer

treatments. Squalene in combination with some cytoprotective agents such as

amifostine may bring considerable relief to cancer patients. Further clinical and

laboratory research is necessary to explore such possibilities. We outline these

possibilities below.

 

Cytoprotection – an Undervalued

Modality

 

The last decades have seen the development of many anticancer drugs, some

of which have shown great promise. However, most of them have the short coming of

producing severe side effects – including the free radical destruction of bone marrow

and kidney failure. Another problem is that cancer cells are ferociously adaptable and

soon learn to tolerate or resist these drugs. To achieve effective results, it is often

necessary to increase the dose – and the corresponding side effects. This includes

cellular DNA damage and mutation leading to further cancers.

 

One emerging avenue of research focuses on substances that help our bodies

tolerate anticancer drugs and radiation and/or make cancer cells more susceptible to

these treatments. To be truly useful, these substances must have a differentiating

action and must maximize the benefits of the anticancer agent at a minimum dose.

This is called cytoprotective therapy. A good cytoprotective agent must:

 

1. discriminate a normal cell from a cancer cell

2. protect the former but not the latter

So far a mere handful of cytoprotective agents has been developed and of

these only one is considered in any way satisfactory – amifostine. It has broad range of

cytoprotective action against several anticancer drugs, but is not without its drawbacks

 

– it promotes hypotension and allergic reaction. It is also very poorly tolerated by

children. It must be given intravenously and since it rapidly loses its effectiveness, it

cannot protect against the long term accumulation of drugs in the bodily tissue.

The development of a powerful and effective cytoprotective agent would be a

significant advance in anticancer therapy. However the list of necessary requirements is

 

46

 


 

 

long and every potential candidate must undergo extensive laboratory and clinical

testing. This chapter examines these requirements and considers squalene’s

qualifications as a cytoprotective agent.

clinical

testing. This chapter examines these requirements and considers squalene’s

qualifications as a cytoprotective agent.

 

Criteria for a Cytoprotective Agent

 

Although it primary function is not to actually attack the cancer, an ideal

cytoprotective agent will promote some sort of direct anticancer action – however

slight – as a reassurance that it does not protect cancer cells in any way. This is asking

a great deal. Most early candidates for this sophist aced job turn out to either have no

anticancer activity or to indiscriminately protect both cancerous and normal cells.

Another factor that must be countered is the direct activity of cancer cells against

pharmaceutical threats – an efflux mechanism enables them to pump anticancer drugs

out of the cell, while healthy cells have no such protection. An ideal cytoprotective

agent should do precisely the opposite – protect healthy cells from the toxicity of

anticancer drugs while disarming the cancer cells self protecting mechanism.

 

A cytoprotective agent should therefore provide selective protection of

normal tissue against chemotherapeutic agents in two ways:

 

1.

by entering more readily into normal tissue than cancerous tissue – a higher

accumulation in normal tissue and lesser in cancer cells is the key to selective

protection

2.

by decreasing the cancer cells efflux [ability to pump out anticancer drugs] the

unique efflux mechanism of cancer cells may differentiate them from normal

cells and enhance selective action

After successful laboratory experiments a potential agent should be evaluated

in human clinical trials. Experimental therapy in cancer patients may reveal a reduction

of side effects to the anticancer therapy, but this is not enough. Researchers should not

lose sight of the most important criterion of all – without measurable tumor shrinkage;

no candidate can be considered a true cytoprotective agent.

 

Squalene’s Cytoprotective Roles

 

Six properties of dietary squalene lead us to suggest its great potential as a

cytoprotective agent:

 

1.

ANTI CANCER ACTION: Squalene’s ability to inhibit protein

isoprenylation prevents the unrestrained growth characteristic of cancer cells.

Like many molecules with isoprenoid side chains squalene may also act as a

differentiating agent, making cancer cells less dangerous by prompting them

to divide normally.

2.

ANTI EFFLUX ACTION: Squalene has already been found to increase the

accumulation of chemotherapeutic drugs like adriamycin and bleomycin in

cancer cells by decreasing the cells ability to pump them out. This

biochemical resistance is effective against a variety of drugs. The pump is

built from the p-glycoprotein complex and usually expels large amounts of

47

 

hydrophobic compounds. Squalene is a hydrophobic compound and could

potentially monopolize the cell’s pumping functions, enabling the anti-cancer

drugs to destroy the cell before they are expelled. In this way, Nakagawa and

colleagues found that dietary squalene supplementation caused cisplatin,

adriamycin and bleomycin to accumulate in cancer cells. This is an important

property of squalene. Research is needed to further explore these

mechanisms and to determine the effective doses that produce such a result.

 

3.

ANTIOXIDANT ACTIVITY: Many anti cancer drugs damage body tissues

by generating highly toxic free radicals. Adriamycin – a widely used drug –

generates a superoxide anion that damages heart tissues. Cyclophosphamide,

another very potent and important anti-cancer drug is metabolized in the

kidney into a highly toxic free radical, chloroacetaldehyde, which may generate

oxidative stress leading to kidney damage. Anti cancer drugs that employ

platinum cause bone marrow damage by generating free radicals. Squalene

protects against oxidative stress and free radical damage. Squalene’s proven

antioxidant properties may neutralize these free radicals and protect normal

tissue.

4.

EFFECTIVE TISSUE DISTRIBUTION: The tissue distribution of dietary

squalene has been studied in laboratory animals. Dr. H. M. Storm and his

colleagues at the Kansas Medical Center fed mice a squalene rich diet. After

two weeks the squalene concentration in their intestinal mucosa increased

fifteen fold. There is every reason to expect a similar distribution in humans.

This finding is extremely significant since both anti cancer drugs and

radiotherapy can damage the intestinal mucosa and disrupt the cytokine

network, threatening the integrity of the epithelium. The researchers

concluded that squalene protects intestinal cells from high doses of radiation

by increasing the cellular metabolism and thus minimizing tissue damage.

5.

SAFETY PROFILE: Complementary health practitioners usually promote a

dietary supplement of one to four grams of squalene per day as an anti cancer

therapy. So far, no serious side effects have been reported. Generally

speaking, squalene can be consumed safely as a dietary supplement in food or

capsules [but it should not be drunk since this may result in accidental

inhalation, leading to lipoid pneumonia]. This does not , however, mean that

all squalene dietary supplements on the market are safe. Some have been

found to contain PCB’s and other carcinogens. In other words, squalene is

safe as long as it is carefully extracted and a purity of 99.9% is maintained at

every stage of production.

6.

IMMUNE RESPONSE BOOSTER: Cancer induces a nonspecific immune

response, increasing opportunistic infections and diminishing quality of life.

Squalene’s ability to protect and enhance the immune response is therefore

one more advantage.

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A Multi-Target Approach To Cancer

Therapy

-Target Approach To Cancer

Therapy

 

The progress of potential anti cancer treatments was for some time frustrated

by our poor understanding of the generation and progression of cancer cells. Recent

advances in cancer biology are helping us see cancer cells in a whole new light. Step by

step cancer biologists are learning the survival secrets of cancer. Much effort is made

to understand how cancer cells feed on the same glucose and amino acid nutrients as

normal cells, and yet achieve such enormously successful proliferation and growth.

 

So far we know that the hallmark of cancer’s success is its ability to survive

even in the midst of genetic and metabolic instability. Although our knowledge of

what goes on within these cells is still incomplete, we do know that they explore many

avenues of survival. A new approach to cancer treatment is to target as many of these

avenues as possible by natural agents such as flavonoids and isoprenoids. This multi

target strategy aims to challenge cancer from as many directions as possible by targeting

its metabolism, its cell signaling, its angiogenesis, etc. Cancer researchers no longer

seriously expect to find a single miracle drug to defeat cancer as definitively as penicillin

was able to defeat bacterial infections. Squalene contributes to at least two of these

approaches. Most promising is squalene’s cytoprotective activity and research is

ongoing in Canada to discover its full potential. Also, it can control the isoprenoid

metabolism by inhibiting HMG Co-A reductase and activating the differential pathway

that pushes cancer cells to slow down and grow like normal cells.

 

Conclusion

 

Various epidemiological and laboratory data suggest that squalene may help

prevent cancer at its outset and can also fight established tumors. These findings are

consistent with the known role of squalene in the regulation of the isoprenoid

metabolism.

 

The isoprenoid metabolism in the cancer cell is highly active, and protein

isoprenylation is an essential first step in the activities of oncogenes such as ras.

However, exogenous isoprenoids rapidly enter cancer cells, which are very susceptible

to their action. Their production of isoprenoids is inhibited as the enzyme HMG Co-A

reductase is down regulated and their growth is curbed as they become more

susceptible to the body’s natural defense system. Squalene may also exert its anti cancer

effect through other mechanisms, notably by detoxifying carcinogens and augmenting

the natural defense systems of the body. Extensive research into the link between

carcinogenesis and the anti-cancer properties of squalene is imperative.

 

Squalene may have a valuable role to play as a cytoprotective agent in cancer

chemotherapy. At present, ongoing laboratory and clinical research is exploring the

cytoprotective role of squalene in cancer chemotherapy

 

49

 

 

6 – Cholesterol & Heart Disease.

Coronary Heart Disease

 

Coronary heart disease [CHD] is a widespread disease often blamed on

modern lifestyle. In the United States, the number of victims is 1.5 million per year, of

whom about one quarter do not survive. An additional 150,000 people die within one

year of the attack. In 1995, 40% of all deaths in the USA were due to CHD. In Britain

300,000 people suffer from a heart attach each year, of whom more than half – approx

170,000 – die.

 

CHD is the leading cause of death, disease and health care spending in the

modern world. In India, Brazil, China and other developing nations the death rate due

to CHD is rising alarmingly and the cost of hospitalization for survivors is extremely

high. The World Health Organization [WHO] warns that unless this trend is reversed

the increasing costs of treating heart diseases and the rapid growth of a sedentary

middle class in developing nations will rapidly erode their advances in healthcare.

 

 Governments have generously funded scientific research and scientists have made

enormous efforts to identify the risk factors of CHD.

Four major risk factors are known to increase the chances of coronary heart

disease:

 

1. high blood pressure

2. cigarette smoking

3. lack of physical exercise

4. high levels of bad cholesterol in the blood

During the last two decades of the twentieth century, the world of healthcare

has had some success in controlling blood pressure levels. Social groups are always

hard at work trying to lower smoking rates and more people than ever before – though

still only a fraction – are excising regularly. The fight against cholesterol however

remains an uphill battle.

 

More than nine out of ten heart attacks are precipitated by the narrowing of

the inner passage of coronary arteries as they are blocked by plaque that includes

cholesterol deposits. Any artery can be damaged by atherosclerosis. The most

common sites of damage are the blood vessels of the heart, abdomen, lower extremities

and brain.

 

Atherosclerosis

 

The heart is a muscular pump that forces oxygenated nutrient rich blood

through the arteries to all the cells of the body. These nutrients include sugar, amino

acids and fats. Like any other part of the body, the heart itself requires fresh blood,

which is delivered through the coronary arteries. If these arteries become blocked and

worse still, the tissue may die due to lack of oxygen and the patient suffers cardiac

arrest.

 

There are two major coronary arteries, right and left. Each divides and

spreads over the surface of the heart rather as the roots of a tree spread over a rock.

 

50

 


 

 

Hundreds of branches form small arteries, creating a network over the surface of the

heart. Each artery is a conduit. Cholesterol is sometimes deposited in the lumen

[interior] of these arteries just as silt accumulates on a river bed. The deposits of

cholesterol harden, constricting the artery and reducing its flexibility. These are the

mechanics of atherosclerosis. Its exact cause has still not been clearly explained,

although many risk factors have been identified. Cholesterol deposition on blood vessel

walls is a principal one.

heart. Each artery is a conduit. Cholesterol is sometimes deposited in the lumen

[interior] of these arteries just as silt accumulates on a river bed. The deposits of

cholesterol harden, constricting the artery and reducing its flexibility. These are the

mechanics of atherosclerosis. Its exact cause has still not been clearly explained,

although many risk factors have been identified. Cholesterol deposition on blood vessel

walls is a principal one.

 

Artery walls have two layers – inner [intima] and outer [media].

Atherosclerosis begins when the smooth muscle cells of the media migrate to the

intima. If bad cholesterol levels rise in the blood, build up of cholesterol plaque in the

intima gradually hardens and narrows the arteries.

 

Good Cholesterol

 

Cholesterol is widely believed by the general public to be an unmitigated evil.

It is in fact vital to life – an important lipid in the cell membrane structure and in nerve

fiber sheaths. It is also the basic molecule for the production of certain important

hormones, including corticosteroids and sex hormones. It is only harmful when –

having built up high concentrations in the arteries – it becomes a major constituent of

atherosclerotic plaque.

 

Bad Cholesterol

 

Medical researcher Dr. Joseph L. Goldstein – awarded the 1985 Nobel Prize

for Medicine following his research into the cholesterol regulatory mechanism of the

liver – once remarked that cholesterol is “…. A Dr. Jekyll & Mr. Hyde thing,” because

it is both necessary and a harmful agent. Dr. Goldstein discovered how the liver filters

excess cholesterol from blood. He and his colleague M.S. Brown published a research

article in the Journal Science, prompting the major pharmaceutical companies to

develop drugs to increase the liver’s cholesterol filtering function.

 

For good or bad, the liver is the body’s main manufacturer of cholesterol –

which is manufactured along the mevalonate pathway as in any other cell. Quite apart

from this, cholesterol also enters the body from dietary source. The blood circulation

transports it to the liver where it is normally filtered. However some of it leaves the

liver and circulates in the blood supply. This is the cholesterol that contributes to

plaque build up in the arteries and is known as “bad cholesterol”. It is not chemically

different from “good” cholesterol but is associated with fats that transport it through

the body differently.

 

Cholesterol Transport

 

Cholesterol cannot swim. Or to put it more scientifically, it cannot travel

alone through the body because it is not water soluble. It is carried through the

bloodstream on a “boat” of fat and protein called a lipoprotein. There are three types

 

51

 

of lipoprotein – high density [heavyweight], low density and very low density

[lightweight].

 

1.

High density lipoproteins [HDLs] transport cholesterol into the liver without

harming the body – this is known as good cholesterol.

2.

Low density lipoproteins [LDLs] and very low density lipoproteins [VLDLs]

transport cholesterol out of the liver and around the body, where it is often

deposited in arteries. This is known as bad cholesterol.

One of the liver’s functions is to filter excess cholesterol from the blood.

LDL receptors constitute the filtering system of the liver. These receptors [attractive

doorways] protrude from liver cells and snag the LDLs, which are either put to

metabolic use or – if not required by the body – are consumed by the macrophages that

populate the liver. However if the liver’s macrophages can’t keep up with the flow of

incoming LDLs they end up back in the blood stream where they contribute to the

buildup of atherosclerotic plaque.

 

The filtering mechanism depends greatly on the feedback inhibition of HMG

Co-A reductase. Researchers have found that if this enzyme is inhibited the production

of LDL receptors is stepped up, thus increasing the liver’s filtering capacity. As a result

of these findings, pharmaceutical drugs were developed to inhibit HMG Co-reductase

notably a group of drugs called statins. During the nineteen nineties, three large long

term epidemiological studies comparing different population groups examined the

efficacy of these drugs with encouraging results.

 

Harvard School of Medicine researchers described the positive results of the

Cholesterol and Recurrent Events [CARE] study, which employed pravastatin. The

other two studies – the West Scotland Coronary Prevention Study {WOSCOPS] and

the Scandinavian Simvastatin Survival Study [4S] showed that either pravastatin or

Simvastatin can significantly reduce heart attack deaths. The success of these trials

provides empirical support for the theory of cholesterol and LDL receptor synthesis.

 

These large scale research results have encouraged doctors to prescribe these

cholesterol lowering drugs in order to reduce the chances of heart attacks and to

prolong the lives of heart attack survivors. However, they are expensive and their side

effects are very much at issue since their effectiveness depends on long term use.

 

A report from the United Kingdom National Health Service Center for

Reviews and Dissemination criticized the routine use of cholesterol lowering drugs

such as pravastatin, commenting that “… the intervention represents poor value for

money.” The report estimated that the cost of one year of life gained from taking

Simvastatin is 7,240 pounds [about U.S. $11,656]. The report reflects the wider

concerns of hearth service economists around the world. A huge number of people are

at high risk for CHD and the costs of pharmacological prevention of coronary heart

disease are simply becoming unmanageable.

 

Patients must take statins for at least four years to derive positive results.

Since the drug can damage the liver its use must be monitored during this period along

with certain blood parameters. Prolonged use can cause myopathy [muscle damage

leading to inflammation], especially if dosage is raised. Newer variations like

pravastatin can also damage the liver, pancreas, muscles and skin. Accounts of such

negative effects have been published in various clinical journals.

 

Statins interrupt the cholesterol synthesis pathway before the synthesis of

squalene and ubiquinone [coenzyme Q10]. Perhaps at the same time that they preempt

 

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the buildup of harmful cholesterol levels in endothelial cells, they also deprive them of

these two vitally important endogenous antioxidants and give rise to some of the long

term side effects of the drug. Indeed, it has recently been suggested that statins may

actually help turn bad cholesterol into the worst cholesterol.

these two vitally important endogenous antioxidants and give rise to some of the long

term side effects of the drug. Indeed, it has recently been suggested that statins may

actually help turn bad cholesterol into the worst cholesterol.

 

The Worst Cholesterol of All

 

It appears that an imbalance in the cholesterol metabolism underlies CHD

and atherosclerosis. However, bad cholesterol alone is not the only culprit in CHD.

When bad cholesterol is attacked by free radicals it becomes an even more harmful

substance – oxidized cholesterol [oxLDL] – increasingly known as the worst

cholesterol. This may be the greatest risk factor in atherosclerosis. And oxidized LDL

may increase the proliferation of vascular smooth muscle cells [SMC] a crucial event in

atherosclerosis.

 

Lipid peroxidation of LDL leads to the MDA-modification [malondialdehyde]

of oxidized LDL, which has been found in atherosclerotic lesions. The body responds

by producing MDA specific antibodies in these sites and the presence of these

antibodies is used to predict the progression of carotid atherosclerosis and CHD.

 

Oxidized LDL cholesterol accumulates as plaque on the inner walls of the

blood vessels in the heart and sets up oxidative stress in the affected areas. This

irritates the smooth muscle cells just beneath the intima and they migrate inwards

towards the lumen where they are subjected to oxidative stress by oxLDL free radicals.

The result is lipid peroxidation and inflammation. In an attempt to correct the

situation, macrophages accumulate, engulf the cholesterol and soon become fatty

themselves [foam cells]. Instead of clearing up the mess, they become part of it. The

result is a thick plaque and significantly narrowed blood vessels.

 

Cholesterol-Lowering Effects of

Squalene

 

Dietary squalene has been found to lower cholesterol levels in blood,

apparently increasing the liver’s filtering capacity. This mechanism seemingly derives

from Squalene’s ability to down regulate the HMG Co-A reductase, which in turn

enhances the liver’s capacity to filter bad cholesterol. These laboratory findings are

supported by epidemiological correlations of squalene rich olive oil consumption with a

low incidence of CHD.

 

The laboratory evidence of the cholesterol lowering ability of squalene has

prompted pharmacologists to combine statin drugs with squalene. This may lead to

reduced statin doses, thus reducing its side effects. At the same time, squalene may

prevent the lipid peroxidation of bad cholesterol and prevent the formation of “worst”

cholesterol. A large clinical trial conducted in Taiwan and published in the Journal of

Clinical Pharmacology documented the effectiveness and safety of squalene in

combination with pravastatin – the statin drug used in the Harvard CARE study.

 

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A double blind, placebo controlled, 20 week trial was conducted on a

randomized selection of 102 elderly people, all suffering from high cholesterol levels.

They received 10 mg pravastatin and /or 860 mg squalene daily, either separately or in

combination. The results showed that both pravastatin and squalene effectively

reduced levels of total cholesterol and LDL cholesterol, while increasing levels of HDL

cholesterol.

 

Interestingly, combination therapy reduced all bad cholesterol parameters and

increased HDL cholesterol to a greater extent than either agent alone. The research

paper concluded, “Co-administration of pravastatin and squalene combines the specific

effects of the two drugs on lipoprotein in elderly patients with hypercholesterolemia,

who might have a higher incidence of side effects when using larger doses of

pravastatin alone.”

 

The protective role of a diet rich in squalene [such as olive oil] suggested by

some epidemiological studies may be due not only to the squalene0induced reduction

in LDL cholesterol levels, but also to its role in preventing oxidation of LDL.

Squalene’s powerful antioxidant properties are well known but further research is

expected to clarify its ability to prevent conversion of bad cholesterol to the worst type.

 

Historical research into squalene’s cholesterol-diminishing potential

 

In 1953 D. Kritchevsky and his fellow researchers explored squalene’s HDL

cholesterol diminishing role in a laboratory study on four groups of rabbits on various

diets for seven weeks. Their aortae were subsequently examined for signs of

atherosclerotic plaques and it was concluded that, unlike cholesterol, dietary squalene

did not induce atherosclerosis.

 

In 1974, another experiment conducted by I. Prance and his colleagues found

that squalene protects laboratory mice against gallstone formation. They hypothesized

that squalene reduced cholesterol synthesis in the liver.

 

In 1985, T.A. Miettinen presented findings to the seventh International

Atherosclerosis Symposium in Melbourne, Australia suggesting that a squalene rich

olive oil diet could effectively reduce serum cholesterol levels.

 

In 1989, T.E. Strandberg and his fellow researchers reported that rats given

1% dietary squalene for 5 days experienced strongly suppressed [-80%] HMG Co-A

reductase activity in the liver cells.

 

In 1990, Miettinen and his colleagues published the results of another study in

the Journal of Lipid Research. They fed human subjects 900mg of squalene per day for

seven to ten days and produced a seventeen fold increase in serum squalene, with no

significant increase in serum cholesterol level.

 

In 1994, Miettinen and his colleagues proposed that the cholesterol reducing

mechanism of dietary squalene may result from the down regulation of HMG Co-A

reductase activity, leading to decreased cholesterol synthesis in the liver.

 

The relationship between cholesterol synthesis and LDL receptor synthesis in

liver cells was first proposed by Dr. Joseph L. Goldstein [1985 Nobel Laureate] who

proposed that increased cholesterol levels in the liver decreased LDL receptor

synthesis.

 

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Conclusion

 

 

The liver’s filtering mechanism removes bad cholesterol from blood. Central

to this mechanism is the liver’s LDL receptor. Synthesis of this receptor is linked to

the activity of the enzyme HMG Co-A reductase, which is involved in cholesterol

manufacture in the liver. By inhibiting this enzyme’s activity, squalene increased the

bad cholesterol filtering capacity of liver cells. Squalene may also play an important

role in preventing the oxidation of bad cholesterol into worst cholesterol. Further

research is required to explore this potential therapeutic application in combination

with existing cholesterol lowering drugs. Such use may reduce the cost and toxicity of

the statin groups of drugs while simultaneously enhancing their effectiveness.

 

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Part 111

Squalene & Environmental Pollution

 

 

In this part of the book, we seek a model to explain the impact of pollution upon the

evolutionary mechanism of our body. Readers may be surprised to encounter the term

“evolution” in this book, but without it we cannot properly explore the impact of

pollution, which in evolutionary terms has come upon us suddenly and with great

force.

Theodosius Dobzhansky, one of the greatest biologists of the twentieth century

remarked that “Nothing in biology makes sense except in the light of evolution”.

We ourselves are biological systems and in order to understand the impact of pollution

in our bodies we must understand the full implications of this new evolutionary

pressure.

The arguments in Part Three depend upon an understanding of the martial presented

in Part One.

 

Human Skin: First Casualty of Ozone

Depletion

 

In this chapter, we try to identify the body’s natural protective system against

UV radiation and to examine how it is affected by ozone depletion.

 

We have already discussed oxidative stress in the immune system and its

impact on squalene metabolism. Now we will apply this knowledge to the effects of

oxidative stress in the protective coat of our body, comprising the skin [external

surfaces]. Ultraviolet-B rays from the sun generate free radicals in exposed skin. They

also convert ground-level oxygen to ozone, a powerful oxidant that attacks the internal

protective coat. As the ozone layer is depleted, more UV rays reach the Earth’s

surface, increasing these threats. Both the external and internal surfaces of the

protective coat therefore suffer oxidative attack due to the diminishing ozone layer and

increasing levels of UV radiation.

 

The Epithelium – A Protective Coat

 

The epithelium coat is a fine layer covering the skin and the lining of the

mouth, throat, lungs and digestive tract and constitutes a protective coat with a surface

area greater than a tennis court. These surfaces of the body are all in direct contact

with environmental substances – air, food and drink, plus of course, bacteria, viruses

and toxins. The layer covering the outermost surface of the skin is also in direct

contact with sunlight and is covered by a combination of lipids called sebum of which

almost one part in eight is squalene. The inner parts of the protective coat are covered

by a mucosal layer. The adipose [fat] layers beneath both skin and mucosal cells also

contain a large proportion of squalene.

 

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Skin contains a large number of macrophages that defend the body against

outside invaders. They may be part of the original immune system developed in

mammals. We have already seen that their main function is to destroy and consume

incoming bacteria and viruses. They also bring a part of the dead intruder to the

internal immune system – a process called antigen presentation. This enables the body

to recognize the antigen in the future so that it can respond more efficiently.

t

outside invaders. They may be part of the original immune system developed in

mammals. We have already seen that their main function is to destroy and consume

incoming bacteria and viruses. They also bring a part of the dead intruder to the

internal immune system – a process called antigen presentation. This enables the body

to recognize the antigen in the future so that it can respond more efficiently.

 

Unlike the internal mucosae, the skin is subjected to direct sunlight, which

includes UV-B radiation, a source of free radicals and potential skin damage. This may

help explain why sebum contains such a high proportion [12%] of squalene. If the

performance of macrophages is increased by squalene, it is reasonable to assume that

the substantial presence of squalene in the skin is helpful to their role, providing a

protection unique in the animal world. This high concentration may be an evolutionary

requirement for the defense of the protective coat against UV radiation and other

outside threats.

 

Because the skin and mucosae are constantly exposed to the outside

environment, the chances of oxidative stress here are high. We know that the threat of

UV-B rays is very serious, and that many environmental toxins can also initiate

oxidative stress in the skin. Therefore we must ask:

 

Does skin have a normal defense against oxidative stress and if so,

Could ongoing ozone depletion overwhelm this defense?

It is known that intense UV-B radiation can suppress the immune function in

the skin, perhaps because of increased oxidative stress and subsequent stress in

squalene metabolism.

 

Ultraviolet Radiation

 

Sunlight includes a wide spectrum of radiation; of which visible light is just

one tiny slice. All energy from the sun moves at the speed of light and comes in waves

of varying frequency. Waves of shorter length are more energetic [vibrate more

frequently] than those with a longer wavelength. The wavelengths of visible light rays

range from 400 to 700 nm [nanometers] and produce the different colors we see.

 

Ultraviolet light has a shorter wavelength than visible light, ranging from

400nm to 10nm in length. It is generally divided into categories, UV-A [from 400nm

to 32nm], UV-B [from 32nm to 290nm] and UV-C [from 290nm to 10nm].

 

UV-B and UV-C are harmful to the body. The upper atmosphere’s ozone

layer usually absorbs all rays shorter than 310nm, blocking them from the Earth’s

surface. Normally, only UV-A and a small portion of UV-B rays reach us. A paradox

of nature is that although UV-B rays can profoundly damage skin DNA and lead to

skin cancer, small portions are actually used in the skin to synthesize vitamin D, a

nutrient of great importance to normal bone maintenance.

 

Even slight exposure of the skin’s surface to UV-B rays can turn molecular

oxygen into singlet oxygen, which attacks skin lipids, creates lipid radicals and starts a

chain reaction. Skin lipids are particularly vulnerable to such oxygen derived free

radicals and these chain reactions can lead to inflammation and oxidative stress in the

skin.

 

57

 

It is believed that increased UV-B radiation is responsible for worldwide

increase in skin cancer. Other possible consequences may include immune

suppression, allergies, memory loss, blood cancer and cataracts.

 

On the one hand UV-B in direct sunlight damages our skin directly. On the

other hand it converts normal oxygen molecules into ground level ozone – free radicals

that threaten our protective coat around the clock. Ozone [O3] may accumulate near

the ground in polluted cities. Ozone’s volatile union of the three oxygen atoms make it

a powerful free radical. Ozone is an irritant to the skin and can be a major source of

oxidative damage to the protective coat. It may also be responsible for the rising

incidence of asthma and other respiratory diseases within urban populations.

 

The Skin

 

The skin is the largest organ in the body and among other functions serves as

a protective covering. It has an outer [epithelial] and an inner layer. The cells of the

outer layer produce three important substances:

 

1.

sebum – a mainly lipid secretion of the sebaceous glands

2.

keratin – a fibrous protein that acts as a waterproof barrier [letting us swim in

fresh water without swelling, or in salt water without shrinking]

3.

melanin – secreted by melanocytes, acts as an ultraviolet filter, controlling the

passage of ultraviolet rays into the skin.

Our discussion focuses on sebum since it coats the outermost skin surface.

The total surface area of the skin is between 16 and 20 square feet. The outer layer is

only 1 millimeter thick and its surface layer of fatty sebum measures about one quarter

of a millimeter. Sebum keeps the skin’s surface smooth and moist and also serves an

antibacterial and antifungal function.

 

Absorption of UV Rays by Skin

 

Ultraviolet rays penetrate the skin and product vitamin D without harming

surrounding tissue – at least for a while. However, UV-B radiation also reacts with

atmospheric oxygen to produce singlet oxygen [oxygen with an extra electron] and can

set up severe oxidative stress throughout the entire skin surface, Sebum is the first

victim of this stress and lipid peroxidation would normally set in immediately.

 

Our ancestors spent most of their waking hours out under the sun. Without

some sort of protection, even very low doses of UV-B rays would produce harmful

consequences, and they must have developed a skin defense against UV-B rays.

Human skin should have sufficient antioxidants to neutralize these free radicals while

still allowing UV-B radiation to penetrate for the purpose of vitamin D synthesis.

Therefore we can expect to find some natural protection in the skin against UV-B

radiation.

 

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The Skin’s Natural Antioxidant

 

 

The skin’s natural antioxidant would have to fulfill four roles to protect the

skin from UV radiation and its consequent oxidative stress:

 

1.

It should be able to prevent or limit UV radiation induced lipid peroxidation.

2.

It should not become toxic or harmful after absorbing UV rays.

3.

It should not transform into a pro-oxidant [an agent that at first behaves like

an antioxidant, then becomes a free radical]

4.

The skin should be able to synthesize and accumulate it without any harmful

effects

Three isoprenoids in the skin fulfill the first criteria – vitamin E, vitamin A

and squalene. The two vitamins are relatively scarce in the skin, which cannot

synthesize them. Squalene on the other hand is abundant [ 12 % of the sebum] and is

also synthesized in the skin. In fact, squalene is one of the skin’s major surface lipids

and is also present in underlying fat [subcutaneous tissue].

 

Given that it is an excellent antioxidant, this makes squalene a likely candidate

to be the skin’s best natural protector and has led researchers to test its antioxidant

properties in the skin. In a unique research project sebum was tested for its ability to

prevent lipid peroxidation or to neutralize singlet oxygen. Y. Kohno and colleagues

compared the antioxidant capacity of squalene with that of sixteen other fats found in

skin. They showed that squalene more than any other could protect the skin’s surface

from lipid peroxidation. They also discovered that squalene’s stable molecular

structure resists outside attack by peroxide radicals – meaning that it does not act as a

pro-oxidant. Finally, they found that squalene more efficiently recycles oxidized

vitamin E than such strong antioxidant skin fats as methol oleate. Other research

reports substantiate squalene’s role in protecting skin from UV radiation.

 

Unlike vitamin E, squalene is readily available and is synthesized locally. So

under normal circumstances squalene is instrumental in protecting the lipid content of

sebum from UV induced lipid peroxidation. In fact, the action of squalene in skin and

subcutaneous fat resembles that of the light harvesting complex [LHC] in plant leaves.

Both seem to prevent molecular oxygen from undergoing oxidation.

 

Evolutionary Adaptation to Loss of

Hair

 

Compared to human beings, apes and other primates have insignificant

amounts of squalene in their skin. C. Luca and his colleagues studies the skin surface

lipids of nine different species of monkeys and found only trace amounts. The sebum

of gorillas for example is only 0.1% squalene [one thousandth] compared to a human’s

12% [almost one eighth]. Indeed, human skin secretes 125-420 mg of squalene daily.

What accounts for such a discrepancy: The obvious answer is that in the process of

losing our fur, squalene protected our increasingly naked skin from oxidative stress.

Apart from its fur covering, the skin of nonhuman primates is much thicker, adding to

its protection against UV-B radiation. Evolution may have covered human skin with

squalene for good reason.

 

59

 

However, the world we live in is changing more quickly than our evolutionary

ability to adapt. Squalene and its synthetic pathway are likely suffering from increasing

stress. This danger is exacerbated by the fact that the squalene synthesis pathway in

skin is not only involved in vitamin D synthesis but also in effective immune response.

 

Ozone Depletion

 

The ozone layer in the uppermost layer of the Earth’s atmosphere is

continuously formed by the interaction of very strong, short-wavelength ultraviolet rays

[ below 100nm] with oxygen and acts as a shield to prevent strong UV rays [below

290nm] from entering the earth’s atmosphere. Chlorofluorocarbons [CFCs] deplete

the ozone layer, thinning our protective shield and making pollution a constantly

growing threat.

 

Industrial societies have long been releasing two atmospheric pollutants –

CFCs and methyl bromide – into the upper atmosphere. These have already thinned

the ozone layer to the extent that holes are appearing in it, so more UV-B radiation is

getting through to our skin. The planet’s surface at the end of the twentieth century

was getting four times as much ultraviolet radiation as it had done a half century earlier.

Scientists have found that UV rays can now penetrate non turbulent ocean water to an

unprecedented depth of nine feet. This has very tangible health implication.

 

Skin Cancer

 

Industrialization has changed the world, and this change is mirrored in our protective

coat – skin and respiratory and intestinal mucosae. During the last two decades of the

twentieth century the incidence of skin cancer has risen significantly around the world.

Medical research has confirmed that strong UV-B rays break the molecular bonds of

skin DNA, leading to mutation and significantly increasing the risk of skin cancer.

 

The United Nations Environmental Program estimates that each 1% decrease

in upper atmospheric ozone will result in a 2% increase in UV-B radiation and a 6%

increase in squamous cell carcinoma – one of the most common forms of skin cancer.

The incidence of melanoma – another common and lethal skin cancer – has doubled in

the United States in 20 years. This is the result of both direct ultraviolet radiation on

the skin and indirect oxidative stress caused by UV induced free radicals in the air.

 

Immune Depression

 

Doctors worldwide are also seeing an increased incidence of allergy related

disorders. Not only are viral infections more common, they are appearing on a global

scale and their behavior is changing – even the common cold now takes much longer

to overcome than it used to. HIV and its attack on the immune system [AIDS]

continues to create havoc, despite the developments of potent drugs. All of these

threats have a common theme – a weakened immune system. One factor known to

contribute to weakened immunity is excessive UV-B radiation, which alters the

 

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function of skin macrophages and promotes the secretion of inhibitory cytokines,

leading to depression of the entire immune system.

secretion of inhibitory cytokines,

leading to depression of the entire immune system.

 

Another source is ground level ozone, which takes up where UV radiation

leaves off. Cities with highly polluted air are partially shielded from the sun’s rays by

dust and smog, but are breeding grounds for ozone. This toxin can damage the

protective coat, particularly in the bronchi and bronchioles [air passages of the lungs],

causing chronic coughs, lung infections, asthma, and even lung cancer. It is also

capable of generating oxidative stress which in turn leads to immune suppression.

 

Protecting Against UV Radiation

 

There is no realistic hope that ozone depletion will cease in the foreseeable

future. The most optimistic outlook is a possible stabilization or slight reduction in

atmospheric pollution within one or two generations. The burden therefore falls on

medical science to protect us from its harmful effects.

 

The first way to avoid UV triggered disorders is to minimize our exposure to

sunlight – something easier said than done. Almost everybody enjoys the sensation of

sun on skin from time to time, and it is claimed that a sunscreen with a Sun Protection

Factor of at least 15 blocks harmful UV radiation. However the effectiveness of such

products is more theoretical than real. Even under ideal conditions it must be

reapplied every two hours. Sweat and water – not to mention towels – easily displace

even so called waterproof sunscreens, and exposed patches quickly appear.

 

Researchers have therefore been searching for other protective agents. Their

first thought was that topical antioxidants would help, but any product layered on the

surface of the skin suffers the same disadvantages as sunscreen. In any case, UV rays

rapidly consume these antioxidants and they must be reapplied even more frequently

then sun blocking lotions.

 

Nevertheless, the idea of an enhanced antioxidant defense has not been

abandoned. Vitamin A and its related compounds – carotenoids – are known to

protect skin against oxidative damage and lipid peroxidation. OF all carotenoids,

lycopene provides the best UV protection but also causes abnormal skin pigmentation

and may lead to a growth known as lycoma

 

Researchers have also turned to vitamin E – a natural antioxidant in the skin.

However it has recently been discovered that upon exposure to UV rays, vitamin E acts

as a pro-oxidant – it turns into a free radical itself.

 

So far no truly effective method exists to protect the skin from UV-B

radiation. The only effective escape is to stay indoors during periods of bright sunlight

and to cover the skin when outside. Similarly the best way to escape ground level

ozone is to stay away from polluted cities or to wear a protective mask. However for

most people these solutions are both inconvenient and socially extreme, and

widespread adherence is unlikely. The development of an ointment with a

combination of such natural antioxidants as squalene, vitamin E and glutathione might

prove very effective but cannot guarantee protection from ozone depletion. The only

sure solution is a reduction in ozone depleting pollutants.

 

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Are We Safe?

 

 

The slightest exposure of any part of the protective coat to UV rays or

polluted air may promote oxidative stress. The protective coat is highly vulnerable –

after all, its total surface area exceeds that of a tennis court. How significant might

oxidative stress be over this huge surface? It depends on the extent to which oxidative

stress exacerbates metabolic stress.

 

Oxidative stress generated by even a brief period of exposure to UV radiation

or polluted air might induce stress in squalene metabolism. O. Sakamoto and

colleagues found that the first target of UV-B radiation in skin is squalene and that

exposure of skin to UV-B radiation increases its synthesis and consumption.

 

Considering what we know of the relation between oxidative stress and

squalene metabolism in the immune system, a larger picture emerges. A UV-B induced

increase of squalene synthesis and consumption in the skin may not remain localized

and could spread into the general squalene metabolism throughout the body and this

effect may remain even after the initiating pollutant or UV-B radiation is removed.

Indeed, metabolic stress may be a nonlinear phenomenon in which biological events

can product effects out of proportion toi their stimuli. Such a possibility is the subject

of chapter 11.

 

Therefore although we tend to focus on the localized effects of UB-B

radiation – such as DNA damage or cytokine synthesis by immune cells – the internal

environment of our body may be undergoing very slow, systemic, long term damage.

Such gradual changes could make us a victim of Darwinian natural selection.

 

Conclusion

 

The presence of high concentrations of squalene in the skin presumably

results from an evolutionary survival mechanism. Ozone depletion and the consequent

exposure of the body to significantly stronger UV-B radiation is increasing this

requirement beyond the body’s ability to cope, placing squalene metabolism in stress,

with unknown consequences. New, more effective types of skin protection from

ultraviolet radiation may evolve from the use of internal rather than topical substances,

and their impact may go beyond mere protection of skin and help diminish the impact

of general metabolic stress, which is discussed in chapter 11. The only sure solution

however, is a reduction in the use of ozone depleting pollutants.

 

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8 - Background Radiation - Background Radiation

 

The Universe and the environment in which we live have always been permeated with

radiation. It rises out of the ground and pours down from the cosmos. Light itself is a

form of radiation. The sun and every star in the cosmos emit incalculable amounts of

energy in the form of radiation. It is found in rocks and air. Even our bodies generate

radiation, though negligible amounts.

 

Some types of radiation pose much more of a threat than others and there are

many each with its own wavelength and frequency.

 

Sources of Radiation

 

Our bodies long ago developed mechanisms to protect ourselves from the

normal threat of background radiation. However our exposure to it has increased

considerably in the last century – since the discovery of radioactivity and mankind’s use

of uranium and other radioactive materials. Dozens of nuclear bombs have been

exploded in the atmospheres and underground, and their radioactive residue though

highly diluted, takes centuries or millennia to lose its toxicity. We are exposed

repeatedly to X-rays and other forms of medical radiation. Nuclear power reactors

occasionally leak small amounts of radiation. Some nuclear weapons lie disintegrating

on the sea floor along with the reactors of sunken and irretrievable nuclear submarines.

The storage or transport of growing piles of nuclear waste sometimes leads to leakage

too. In general background radiation threatens and destroys fewer lives than the toxic

by-products of burned fossil fuels, but it is one more form of pollution and it is not

insignificant. Overall background radiation can only be detected with the help of

sensitive equipment but it is on the rise and is harmful to living cells.

 

Pressure placed by background radiation on the internal environment of the

body may consume squalene in new ways, adding to our overall need for this protective

substance. The consequences of such new requirements and stress in squalene

metabolism are discussed in chapter 11.

 

Background radiation is either non-ionizing [longer wavelengths, to the left]

or ionizing [shorter wavelengths, to the right].

IONIZING RADIATION

 

Various frequencies of ionizing radiation are so called because they ionize

body tissue – tear electrons away from their constituent atoms and molecules. There

are several natural and man made sources of ionizing radiation.

MEDICAL SOURCES

 

Diagnostic X-ray equipment and other machines such as those used in nuclear

medicine, including radiation therapy, all emit ionizing radiation. Exposure to these

sources has doubled in the past 20 years.

INTERNAL SOURCES

 

Our bodies are composed of radioactive potassium and carbon, accounting

for about 8% of total background radiation absorbed per year.

DEPLETED URANIUM

 

Mankind’s use of refined radioactive materials has made increased exposure to

radiation a problem of our times. There are many sources, some quite unexpected.

 

63

 

For the 1991 Gulf War, for example, a new, exceptionally hard, armor casing was

manufactured from depleted uranium [DU] alloy. DU is a form of nuclear waste –

mainly from uranium-238. The casing itself carries minimal radioactivity, but upon

impact it contaminates the atmosphere with a highly radioactive and easy to inhale

uranium oxide dust in particles as fine as 0.5 microns. These highly toxic armaments,

designed and financed by the Pentagon, are exported around the world. The subject of

depleted uranium and its radioactive nature was initially understated or hidden for

obvious reasons. Since it has become public knowledge, however, it has become the

subject of an emotionally charged political debate that has unfortunately made

objective information very hard to come by.

GEOLOGICAL RADIATION

 

Geological radiation results from the radioactive decay of thorium and

uranium radio nuclides in the Earth’s crust. Billions of years ago, gravitation caused the

Earth to collapse into its present size, forming elements like uranium-238. Its various

stages of radioactive decay have led to the present day emission of alpha, beta and

gamma rays – much stronger than UV radiation and able to promote cancer and

immune suppression.

 

Electrically charged subatomic particles emitted by such radiation can

penetrate several centimeters into the body. Colorless, odorless radon [also known as

uranium gas] originates from both uranium deposits and nuclear waste and is believed

to account for about 55% of our background radiation.

COSMIC RADIATION

 

Cosmic radiation is composed of protons, electrons, neutrons and heavy

nuclei from galactic sources, contributing about 9% of the total background radiation.

The amount doubles with every 1500m increase in altitude.

NON_IONIZING RADIATION

 

Longer wavelength rays from UV radiation, radio waves, microwaves and

infrared sources do not penetrate out body – that is to say, they do not product free

radicals inside the body. For example, ultraviolet [UV] rays are classified an nonionizing

because they do not penetrate the body deeply like X-rays or gamma rays.

However, they can ionize molecules in the skin, leading to lipid peroxidation. Infrared

waves, microwaves and radio waves on the other hand, do not ionize even the

outermost layers of skin.

 

Very low frequency radio and other electromagnetic waves have been found

to modulate ion flow and interfere with cellular RNA transcription and DNA synthesis,

but their overall effect in humans remains unknown.

 

Consequences of Background

Radiation

 

Our increased exposure to background radiation has both immediate and long

term consequences. In the short-term we can expect an increase in all kinds of cancers,

and a generally weakened immune response. The long range prognosis includes

accelerated aging and changes in psychological behavior. Some scientists have warned

of decreased fertility – human sperm count may be declining because of increased

overall radiation exposure.

 

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Those exposed to chronic radiation injury commonly experience fatigue, non

restorative sleep, joint pain, weight gain, low self esteem, memory loss, rashes,

headaches, allergic tendencies, asthma, urticaria, sore throats and fever.

igue, non

restorative sleep, joint pain, weight gain, low self esteem, memory loss, rashes,

headaches, allergic tendencies, asthma, urticaria, sore throats and fever.

 

The high energy of background radiation generates free radicals in our bodies

and initiates oxidative stress. It can increase synthesis and secretion of excitatory

cytokines, unbalancing the immune response. Exposure to very strong ionizing

radiation, such as whole body irradiation with X-rays beyond levels of normal medical

use, leads to a massive release of excitatory cytokines, resulting in severe inflammation,

cell death and the ultimate death of the organism.

 

The Radioprotective Role of Squalene

 

Ionizing radiation can inflict either acute or chronic oxidative stress on the

body, depending on its source. The antioxidant defense system, including glutathione,

vitamin E and SOD [superoxide dismutase] can reduce this oxidative stress.

Laboratory experiments show that squalene can protect the body against acute ionizing

radiation, although its exact mechanism remains unknown. Squalene’s antioxidant

nature, its immune stimulant action and its ability to protect cellular structures and

improve cellular repair response may all play a role.

 

A laboratory study conducted by the Walter Reed Army Institute of Research

entitled “The Ability of Squalene to Protect Against Radiation Injury” was submitted to

the Cosmetics, Fragrance and Toiletry Association [CFTA] in February 1960. In the

experiment, 20 mice were fed 2000 mg/kg of undiluted squalene 15 minutes prior to

receiving 575 roentgens of X-rays. Sixty percent of the animals survived for 30 days.

In a control group [mice not given squalene] only 25% survived.

 

More recent research at the University of Kansas Medical Center, USA,

confirmed the radioprotective action of squalene. Dr. H. M. Storm and his colleagues

at the Kansas Medical Center published their report in the June 1993 issue of the

medical research journal Lipids. Healthy mice were fed a diet rich in pure squalene and

14 days later exposed to gamma rays. Seven days later total while cell counts and total

lymphocyte counts revealed that the squalene-fed group’s blood count was consistently

18-19% higher than a control group’s. The survival of the squalene fed mice was much

higher than control fed mice [P=0.0054]. So it seems that squalene provides a type of

cellular and systemic radioprotection.

 

Squalene Depletion Due to Radiation

 

Radiation induced oxidative stress may affect squalene metabolism with

adverse results. In the human body, squalene is distributed in the fatty tissues of

various organs including lungs, kidneys, spleen and brain. Strong ionizing radiation

may consume the squalene content of these sites when the body suffers chronic

radiation injury. In fact, during each of the experiments described above, the animals’

squalene levels were high before irradiation and low afterwards, confirming that

squalene was consumed. People suffering from chronic radiation injury usually

experience fatigue and loss of energy, perhaps due to impaired energy distribution and

 

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consumption in our body. Given the link between squalene synthesis and coenzyme

Q10 synthesis – which is intricately linked to the energy metabolism – there may

reasonably be a connection between increased squalene consumption and fatigue.

Radiation exposure also leads to immune suppression which may have to do with

increased consumption of squalene and other antioxidants.

 

Thus, the increased background radiation may place new pressure on squalene

metabolism, the consequences of which are discussed in chapter 11.

 

Conclusion

 

The health hazards of chronic exposure to ionizing radiation are many.

However the ways in which chronic low doze ionizing radiation are a health hazard are

still not clearly known. It is likely that squalene is rapidly consumed when exposed to

high levels of ionizing radiation, leading to the increased synthesis and subsequent

redistribution of squalene and its immediate isoprenoids in the vital organs of the body.

Moreover, squalene metabolism coincides with the metabolism of coenzyme Q10. The

latter is part of the energy production process inside the cell. Therefore, by affecting

squalene metabolism, chronic radiation may affect the energy metabolism in the body.

There is every reason to believe that research into squalene replenishment during or

following radiation exposure would be justified.

 

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9 - Air Pollution, Allergies & Lung

Disease

- Air Pollution, Allergies & Lung

Disease

 

Each breath we take of the polluted air in today’s towns and cities fills our

lungs with two nasty toxins – carbon monoxide and the total suspended particulate

matter [TSP]. Carbon monoxide combines rapidly with blood, reducing its capacity to

transport oxygen. TSP from vehicle exhaust reduces lung function over a period of

time.

 

The All-India Institute of Medical Sciences in New Delhi – a city particularly

afflicted by vehicle emission and other pollutants – recently conducted a two year large

scale study of over 100,00 people that showed a clear correlation between air pollution

and emergency room admissions for asthma, bronchitis and heart complaints. The

study found a 41% increase in asthma cases, 39% in chronic bronchitis, and 30% in

heart attack cases over a ten year period.

 

Many such studies have been conducted in recent decades and the link

between air pollutants and allergies – especially asthma – is no longer in doubt.

 

Lipid Peroxidation & Allergies

 

Carbon monoxide vehicle emissions and ground level ozone are a deadly

combination. They each act as powerful free radicals, causing lipid peroxidation in the

mucosae of mouth, throat, nose and lungs. When combined this attack can lead to

increased oxidative stress and an imbalance in the cytokine expression of the mucosae’s

macrophage cells.

 

Without balanced immune protection, the mucosal cells then become prone

to amplified allergic processes. An example of this amplification is seen when a simple

 

– normally tolerable – cold requires hospital admission. The hospital admissions for

asthma and other pollution exacerbated conditions have grown at an alarming rate in

cities where pollution levels are particularly high.

Squalene Synthesis – A Potential

Adaptive Mechanism

 

Squalene concentrations in the mouth and respiratory mucosae are minimal

compared with skin levels, possibly because frequent exposure to toxic air is a relatively

recent evolutionary pressure on the body. In earlier centuries, there was no need for

such extensive protection of the inner mucosae because air was much cleaner. The

increase in air pollution may be exerting pressure on squalene metabolism in the lungs

to increase the synthesis and consumption of squalene in the lung. But such changes

take time. The adaptability of a biological system to acute and massive environmental

pressure is quite unknown. What we do know of evolutionary change in various species

has been the product of millions of years of gradual environmental change.

 

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It is important to know whether squalene consumption increases in the lung

mucosae after exposure to air pollutants. The long term effect of a consistent increase

in Squalene consumption in the respiratory coat may be deleterious, leading to stress in

squalene metabolism. In particular, it is important to understand the sensitivity of the

mast and other immune cells of the respiratory mucosae to squalene metabolic stress.

 

Conclusion

 

The allergic response of the body’s immune system is increasing in urban

environments due to the overwhelming effects of air pollutants on the lung mucosa.

This may increase the consumption of and demand for squalene, leading to metabolic

stress with adverse consequences. Further research is needed to explore the link

between pollution induced lipid peroxidation and amplified allergic conditions such as

asthma and allergic rhinitis, as well as the connection between the isoprenoid

metabolism and the immune response to allergens in the lung. Research is also needed

to find ways to augment the immune response throughout the internal protective coat

in which squalene clearly plays such a profound role.

 

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10 -The Fat Cell: A Storehouse of

Toxins

-The Fat Cell: A Storehouse of

Toxins

 

Fat. The word quickly brings to mind oil and grease, or the ring around your

middle which just won’t go away! In the medical world fat is called adipose tissue.

Surgeons slice through it happily because it is soft, hardly bleeds and has no apparent

function other than storage.

 

However, medical attitudes towards adipose tissue are changing considerably.

New findings suggest that fat could be regarded as an important organ. Adipose tissue

has a highly organized communication network with an connection to the brain. It also

synthesizes large amounts of squalene and stores it in droplet form. Notably, adipose

tissue is found in the protective coat of the body and is engaged in energy metabolism.

Considering what we have learned so far about squalene it seems unlikely that such rich

stores of this valuable substance are there by accident. We need to understand the

significance of squalene stores in adipose tissue.

 

It is known that many organic solvents including dioxins are deposited in fat

cells. These man made chemicals are called xenobiotics and several researchers have

discovered that squalene enhances the elimination of xenobiotics. Squalene may play a

role in this detoxification. To find out, we much investigate the potential impact of

accumulated toxins on squalene synthesis in fat cells.

 

Adipose Tissue: Depot or Organ?

 

A ‘depot’ is merely a place for storage and distribution. An ‘organ’ is a

coherent element of the body with an organized structure and a specific function. The

heart is an organ and so is the skin. Adipose tissue has long been considered a lowly

depot, but scientists are beginning to reconsider this simplistic view. It is true that

adipose tissue stores and later distributes fat according to energy requirements [it also

acts as a heat insulator] but it is slowly gaining recognition as a full fledged organ – for

some people, the largest in the body. Fat cells can grow very large, increasing their

diameter by as much as twenty times and their volume by a thousand. The average

person ‘s 10 – 20 kg of fat stores some 90,000 to 180,000 calories.

 

Fat cells store triglycerides – long chain hydrocarbons bound to a glycerol

molecule – in liquid form. Triglycerides can be broken down into fatty acids by the

enzyme lipase and are released when the body requires extra energy – during physical

exertion for example, or to compensate for starvation. Indeed, fat is by far the richest

food source of energy.

 

The new attitudes towards adipose tissue follow remarkable discoveries about

the activity of the fat storage cell – the adipocyte. This humble cell was thought to be

no more than a storage manager until the hormone leptin [a secretion of the adipocyte]

was discovered in the blood. In 1995 a research article appeared in the journal Cell.

Author J.S. Flier, a researcher at the Beth Israel Research Institute, Bethesda, Maryland,

described the hormone leptin in an article entitled, The Adipocyte: Storage Depot or

Node on the Energy Information Superhighway. Flier was the first to recognize the

high activity levels of adipose tissue and to describe it as an organ.

 

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Fat cells synthesize leptin and secrete it into the blood. This hormone is just

one component of a highly organized control system that regulates the long term

balance of energy intake and expenditure. Obesity is generally believed to result from

overeating but this is not quite true. Rather it is is a result of this lost balance when

intake chronically exceeds expenditure. Some obese people believe that their bodies

are more energy efficient, meaning that their internal metabolism uses less energy. This

too is not quite true. Obese people in fact burn more energy than the non-obese.

 

Adipose tissue and the brain regulate leptin secretion via an as yet unidentified

control system. However, a hypothetical model suggests that leptin is an afferent loop

[a loop that sends information from the periphery to the central regulatory body] of a

brain controlled energy regulatory system.

 

The discovery of leptin and the suggestion that adipose tissue is an organ

triggered a multi-million dollar race as the pharmaceutical industry searched for ways to

control obesity with drugs. Unfortunately, they soon discovered that obese people are

leptin resistant. Although their leptin blood levels may be high, their brains become

insensitive to it. Nevertheless, the discovery of leptin reinvigorated fat cell research

and after the commercial euphoria died down several other surprising molecules were

discovered in adipose tissue. TNF-alpha, a cytokine secreted by fat cells, can cause

fatigue and increase insulin resistance in diabetic patients. This may help explain why

obese people are particularly prone to diabetes.

 

Some diabetics – particularly obese ones – need more insulin than others.

When their requirements exceed 200 units per day, they are said to be insulin resistant.

This was previously thought to result from some genetic predisposition or a decrease in

insulin receptors. Now it is thought that more fat leads to increased secretion of TNF-

alpha, and therefore greater insulin resistance.

 

Large amounts of adipose tissue are also thought to contribute to high blood

pressure. Sufferers are often prescribed angiotensin converting enzyme [ACE]

inhibitors that effectively reduce blood pressure by limiting production of angiotensin

11 – a peptide synthesized in the lungs from angiotensionogen and secreted by the

kidneys. It is now known that fat cells too secrete angiotensionogen. Previously the

kidneys were believed the only source.

 

Since increased adipose tissue has been associated with an increased

circulating level of leptin and angiotensionogen, the links connecting obesity, diabetes

and hypertension are becoming clearer.

 

Fat cells also maintain large stores of squalene. The average person’s 10 – 20

kilograms of fat contain 5 – 10 grams of squalene, 90% of which is stored unchanged

by the fat cell – only 10% being converted to cholesterol. Of the stored portion, four-

fifths are maintained as liquid droplets within the cell and the remainder is bound to

the cell membrane. However the function of this stored squalene remains unknown.

 

Toxin Accumulation

 

Many man made toxins enter the body and accumulate in adipose tissue

without ever being eliminated. The discovery of leptin may have made the fat cell an

object of renewed respect among obesity researchers, but environmental scientists still

 

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view it as a reservoir of dioxins, PCB’s and other xenobiotics, including natural

compounds, drugs, environmental agents, carcinogens and insecticides.

luding natural

compounds, drugs, environmental agents, carcinogens and insecticides.

 

Some xenobiotics act as pro-carcinogens. Some mimic estrogen receptors.

Some are not inherently harmful but become toxic following biotransformation within

the body. For example, the liver enzyme system cytochrome P450 turns some

xenobiotics into dangerous carcinogens.

 

Increased deposits in adipose tissue of dioxins, dibenzofurans,

polychlorinated biphenyls [PCPs] DDT, DDE, hexachlorbenzene, alkylphenols, and

several organochlorine pesticides have recently been associated with testicular cancer,

lymphoma, leukemia, prostate cancer, malignant melanoma and endometrial cancer.

The many ways in which xenobiotics can harm our bodies have been only partially

uncovered.

 

Most man-made chemical compounds are lipophilic – they are irresistibly

drawn to fat. The liver breaks down xenobiotics substances into smaller molecules in

an attempt to eliminate the, but some end up more toxic, not less.

 

Detoxification By the Liver

 

The detoxification processes of the liver have two phases.

 

In phase 1, the toxic molecules are modified by oxidation, reduction,

hydroxylation, methylation and other biochemical processes. The reactions are carried

out with cytochrome P450, glutathione S-acyltransferase, and other molecules

synthesized by the liver cells. In these reactions, drugs such as diazepam are

inactivated. However, the same chemical reactions may activate some other drugs such

as prednisone, which is activated to prednisolone. The phase 1 detoxification process

can render some molecules of relatively low toxicity even more dangerous. For

example, the tuberculosis drug isoniazid may cause hepatic failure. Inactive

carcinogens are sometimes converted to active carcinogens by the same process.

 

The phase 11 reaction attempts to render fat- soluble molecules water-soluble

so they can be more easily excreted – through bile or urine. Unfortunately, the liver is

unable to eliminate all toxins. Xenobiotics that do not submit to this process are

carried by the blood to the adipose tissue and stored in fat cells. There they

accumulate, reach toxic doses and overflow into surrounding tissue where they may act

as carcinogens. It has even been suggested that the increased incidence of breast cancer

may result from the accumulation of xenobiotics in breast tissue.

 

Detoxification By Adipose Tissue

 

An organism’s ability to detoxify itself is a crucial step in its evolution. Given

the significance of adipose tissue – where xenobiotics accumulate – the question arises,

does adipose tissue have its own detoxification system?

 

There is good reason to believe that squalene stored in fat cells may act as a

detoxifying agent. Four independent researchers have tested the detoxifying abilities of

squalene by measuring the extent to which squalene helps cleanse the bodies of

laboratory animals of xenobiotics. Results have been encouraging. Squalene-rich diets

 

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leading to increased squalene blood levels do seem to improve the elimination of

organochlorine xenobiotics such as hexachloro-benzene [HCB] and hexachlorobiphenyl

[6-CB].

 

Other experimental studies also suggest that squalene may be a useful antidote

to drug overdosing. Oral squalene seems to enhance the elimination of theophylline,

Phenobarbital and strychnine in rats. Although its detoxifying mechanism is still not

clearly known, it is thought that squalene may possibly increase the mobilization of

lipid soluble xenobiotics enabling elimination through the intestine.

 

T.J. Smith and colleagues suggested that squalene may exert its detoxifying

effects by stimulating the body’s central detoxification system in the liver [cytochrome

P450]. Fat cells also contain cytochrome P450 so the question naturally arises of

whether the squalene stored in fat cells also has a detoxifying function.

There is more to squalene’s detoxifying activity. When xenobiotics accumulate

in fat cells, stored squalene may be released into the general circulation, stimulating bile

flow and enhancing xenobiotics elimination. Scientific testing of this hypothesis could

lead to the development of effective new means of detoxification.

 

The Xenobiotic-Squalene Link

 

Xenobiotics stored in fat cells may alter the fat cell metabolism. One way to

explore this possibility would be laboratory studies on the sensitivity of squalene

metabolism to various xenobiotics. Since squalene metabolism is found to play an

important role in the cytokine secretion of immune cells, it may also take part in the

cytokine secretion of fat cells. Indeed, the accumulation of xenobiotics may incline the

isoprenoid pathway to either increase or decrease squalene synthesis. This could alter

the way fat cells secrete cytokines such as tumor necrosis factor [TNF]-alpha – an

excitatory cytokine. TNF-alpha is known to sometimes cause fatigue, lethargy, fever,

and increased insulin resistance in diabetics.

 

Two disorders –chronic fatigue syndrome [CFS] and fibromyalgia – are

commonly found in populations living a modern lifestyle. CFS is characterized by

increased secretion of TNF-alpha, perhaps from fat cells. Studying the relationship

between squalene metabolism and various xenobiotics may help clarify the link

between environmental pollutants and modern illnesses.

 

Most importantly the accumulated xenobiotics stored in fat cells place

additional stress on squalene metabolism and are yet one more factor contributing to

overall metabolic stress.

 

Conclusion

 

When considered as an organ, adipose tissue is responsible for maintaining

the body’s energy balance by producing and secreting leptin – an important hormone in

the highly organized energy control system. It is probably that fat cells must remain

toxin free for optimal functioning and the considerable squalene store of the fat cells

may help keep them so.

 

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11 -Metabolic Stress & Chao-Metabolic Stress & Chaos

 

 

What is the fate of dietary squalene? Where does it go? Is it converted into

cholesterol? And why does skin contain such high levels of squalene? Why is it not

converted into cholesterol? As they attempt to answer these questions, scientists are

slowly discovering another side of squalene research – its metabolic response to

pollution. The increased synthesis and consumption of squalene in skin following UV

exposure is one illustration of this.

 

However metabolic response may eventually fall into a state of stress. When

does metabolic stress occur and how does it affect the immune response? [These

questions came up in our chapter 4 discussion of the negative influence of oxidative

stress on effective immune response]. The existence of a state of disequilibrium makes

squalene metabolism an ideal place to seek answers to these questions. We will first

elaborate on the concept of metabolic response to stress, then briefly discuss the

physiology of squalene metabolism, and finally discuss the mechanism of stress in

squalene metabolism.

 

Metabolic Response to Stress

 

We believed that an understanding of stress in antioxidant metabolism is best

approached by examining the metabolic response to stress. In many cases, such as a

response follows oxidative stress. It is well known, for example, that surgery causes

oxidative stress. Recovering patients tend to lose weight for a week or so afterwards,

even when fed above normal levels of good food. The body responds to surgical stress

by burning more protein and fat in an attempt to accelerate healing. This normal

metabolic response to stress is perfectly understandable and is generally helpful to the

patient.

 

However, this response may cross a threshold at which point the metabolic

response to stress becomes itself a source of stress. Positive feedback causes the

metabolic response to continue in an uncontrolled way damaging the body. This is

metabolic stress.

 

The consequences of metabolic stress have been well studied in the context of

protein energy malnutrition and prolonged fasting. In both cases, doctors observe

accelerated tissue damage, wasting and even immune suppression actually induced by

the over responsive protein energy metabolism.

 

Hypoxia reperfusion injury is one example of metabolic response to oxidative

stress. Increased squalene synthesis during UV exposure to skin is another. Thus, the

metabolic response to stress is an event of the early adaptive mechanism. It is not itself

a state of stress. Only when the response reaches a certain threshold does the adaptive

mechanism fail and give way to stress. Once that threshold is passed, antioxidant levels

decline in spite of increased antioxidant synthesis. We will try to understand the

threshold concept in antioxidant metabolism by examining the physiology of squalene

metabolism.

 

 

 

Squalene Metabolism

 

 

To identify stress in squalene metabolism, we must consider how squalene

metabolism is related to the cholesterol metabolism. As a precursor of cholesterol,

squalene was commonly believed by scientists to be entirely converted to cholesterol.

The suggestion of an independent squalene metabolism is new, and based on research

findings that only a very smell portion of dietary squalene is actually converted. The

rest remains either unchanged or converted into some metabolite other than

cholesterol.

 

Various human tissues maintain separate squalene concentrations, as follows:

100mcg/dl in plasma, 500mg/kg in adipose tissue, 1g/kg [dry weight] in skin and

50mg/kg in liver. Increased dietary intake of squalene can increase these tissue

concentrations by several times their normal values. The question remains, how does

tissue maintain its own squalene concentration and why is this squalene not converted

into cholesterol?

 

By discussing squalene metabolism in skin and fat we present evidence that

squalene metabolism is independent of the cholesterol metabolism and explain why

different tissues maintain independent squalene levels.

 

Squalene in the Skin

 

Squalene is found abundantly in skin, where it acts to protect against free

radicals. When stimulated, synthesis of squalene in the skin increases independently of

cholesterol synthesis, suggesting that an independent squalene metabolism exists in the

skin.

 

Both cyclic and acyclic forms of squalene are present in skin. Acyclic squalene

serves as a potent antioxidant and cyclic squalene is used in the synthesis of vitamin D,

cholesterol and other sterols.

 

Squalene in Fat Tissue

 

Fat cells have an entirely independent squalene metabolism. The acyclic squalene

remains linear at all times and only 10% is transformed into its cyclic form. This raises

the question of whether there is an acyclic squalene metabolism separate from the

cholesterol metabolism and is supported by the phylogenetic [evolutionary] evidence

that the linear squalene metabolism in fat cells is an unchanged descendant of this

archaic squalene metabolism. Perhaps the skin too retained that metabolism even after

is acquired a cholesterol [cyclic squalene] metabolism.

 

Experimental evidence suggests that squalene bound in the biomembrane of

the microsome [a cellular organelle] is metabolically active and that approximately 90%

of the newly formed squalene is stored in a lipid droplet and only 10% is used in

cholesterol synthesis. This suggests that 90% of membrane-bound squalene may

remain in its active, linear form.

 

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Cyclic & Acyclic Squalene

 

 

Acyclic squalene’s history in metabolic processes began with archaea, the

ancient life form that lives on in deep sea volcanoes under extreme pressures [200

atmospheres] and temperatures [85deg celcius]. Archae’s biomembrane is a teeming

soup of biomolecules that includes isoprenoids and acyclic squalene molecules. We

have seen that although vitamin E has been considered one of the most powerful

terminators of lipid peroxidation chain reactions, its large size limits its ability to fit into

the biomembrane. Acyclic squalene’s excellent antioxidant properties make it as

effective as vitamin E, but because of its small size and mobility it encounters far more

lipid molecules and probably neutralizes more oxyradicals than Vitamin E. This is

probably why archae’s biomembrane contains squalene and not vitamin E. As we have

noted earlier, both skin and adipose tissue contain acyclic squalene. Is this acyclic

squalene ever rendered into cholesterol? Perhaps the body somehow determines which

portion fo squalene becomes cyclic and which does not. These are very big questions

to which the answer at the moment is a resounding “Don’t know”. However, the

presence of two distinct forms of squalene in our body tissues strongly suggests that

squalene metabolism takes place in two metabolic pools – one cyclic and one acyclic.

 

Two Metabolic Pools

 

Our hypothesis that squalene metabolism is independent of the cholesterol

metabolism is first supported by evidence turned up at Rockefeller University where in

1974 K. Liu and his colleagues investigated the squalene content of the body.

 

The squalene content of the body was measured back in the days when it is

only known role was as a cholesterol precursor. However, the Rockefeller University

team found that barely one-tenth of plasma squalene is actually converted into

cholesterol. They referred to it a active squalene in contrast to the approximately

2.6grams of so called inactive squalene that mysteriously does not. To identify these

two squalene stores in the body we refer to them as separate pools. The smaller

squalene pool is metabolically transient because it proceeds on its way down the

cholesterol pathway. The other is metabolically stable because it does not.

 

It is tempting to think that the transient pool is cyclic squalene and the stable

pool is acyclic. The transient pool can also be considered inactive, as it is rapidly

converted into cholesterol. The stable [acyclic] pool can be considered active since it

provides the antioxidant function. Most dietary squalene is probably acyclic and

therefore active.

 

We have shown that both skin and fat contain very high levels of active

[stable] squalene that is not converted into cholesterol. The active squalene

concentration in skin is about 1g/kg dry weight of skin. However, skin also contains a

very small amount of inactive [transient] squalene which is rapidly converted into

cholesterol. We have also shown that there are two squalene pools in fat tissue. This

distinction between active and inactive pools suggests the significant possibility of

squalene metabolic stress.

 

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State of Disequilibrium

 

 

So far we have found that active squalene pools [ASPs] exist in the skin and in

fatty tissue for specific functions, such as protection of skin from UV damage. We

hypothesize that ASP’s also exist in immune and other cells. The discussion in the first

part of the book reveals squalene’s independent role in biomembrane protection. It

seems natural that an independent squalene metabolism exists in the cell to control the

cellular distribution of squalene and requires an ASP. It is thus likely that ASP’s exists

even at the cellular level. ASPs may also exist in the liver as hepatic cholesterol

synthesis is affected by dietary squalene.

 

Of the four active squalene pools, each one has its own level of active

squalene. The skin pools contain about 1g/kg, adipose tissue contains about 500

mg/kg, the body as a whole holds about 20mg/kg in individual cells and the liver

contains about 50mg/kg. The body contains a total of about three grams of active

squalene. Its inactive squalene pool [destined for conversion into cholesterol] adds up

to about 300mg. There is thus a state of disequilibrium between the active and inactive

squalene pools [3gm to 300mg]. The force maintaining this disequilibrium is crucial to

the existence of the active squalene pool. Without it, all active squalene would be

converted into cholesterol. K. Liu and colleagues were surprised to discover such a

state of disequilibrium. It may be visualized as a force that keeps a liquid in the two

arms of a U-tube at different levels.

 

The Mechanism of Metabolic Stress

 

A state of disequilibrium similar to that among the squalene metabolic pools

may be common to all endogenous antioxidant metabolisms. It is well known that

oxidant and antioxidants are never in a state of equilibrium. An example is the ratio of

reduced to oxidized glutathione [GSSH: GSSG] in cells and tissue. The value never

settles down to 1:1

 

This state of disequilibrium suggests the possibility of stress in the antioxidant

metabolism. If sufficient liquid is added to one column of the “tube”, the state of

disequilibrium diminishes and difference in levels will fall. Similarly, when antioxidant

synthesis reaches a certain threshold, the disequilibrium will be disturbed, leading to

rapid consumption of antioxidants. Thus, the very existence of a state of

disequilibrium makes the antioxidant metabolism vulnerable to stress. In the U-tube

example, the magnitude of the force of disequilibrium determines how much liquid

must be added to column A to upset the disequilibrium. Similarly, the performance of

the adaptive mechanism determines the threshold at which stress is provoked in the

antioxidant metabolism. In the squalene metabolic pool, metabolic stress would occur

when the compensatory or adaptive mechanism fails to maintain the state of

disequilibrium. What is this compensatory or adaptive mechanism? How does it

operate on the squalene metabolic pool? When and why will it fail to maintain the state

of disequilibrium? To seek an answer to above questions, we turn to the chaos theory.

 

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Chaos

 

 

Biological systems are organized differently from mechanical systems. They

are chaotic, but not disorganized. Chaotic organization can fluctuate, enabling

biological systems to adapt to new situations quickly.

 

Chaos theory grew out of a need to explain phenomena that could not be

explained by linear dynamics, in which an effect is proportional to its cause. Many

bodily processes – such as the normal variations of a heartbeat – can only be well

described by nonlinear dynamics [NLD]. Nonlinear dynamics begins by setting aside

the concept of proportionality. The causal components of an nonlinear system form a

network with multiple interactions, so a small change in a system can have large,

sometimes unanticipated consequences.

 

The complex fluctuations in the heart rate of a healthy individual are a typical

example. Contrary to the expectations of linear thinking, the beat of a diseased heart –

one for example suffering congestive cardiac failure – is less chaotic than a healthy

heartbeat. It seems that disease states render the biological system more predictable.

 

Metabolic Stress & Chaos

 

It seems most likely that the squalene metabolic pools are organized in a nonlinear

fashion. As an example of chaotic organizations, even the small metabolic pool

of an individual immune cell mirrors that of a large one. All metabolic pools, no matter

how large or small, maintain a state of organized disequilibrium. This organization is

not dissimilar to the computer generated leaf, in which even the smallest details always

resemble the largest. This non-linear organization of all squalene metabolic pools

enables the adaptive mechanism to effectively maintain the state of disequilibrium so

that under normal conditions metabolic stress is preempted. However, the generation

of free radicals – for example by the action of UV radiation on skin – stimulates

squalene synthesis. When this synthesis passes its threshold value, the compensatory

mechanism fails and leads to metabolic stress. Chaos theory provides a different

perspective from the mechanistic explanation of metabolic stress, suggesting it to be a

non-linear phenomenon determined by the body’s adaptive mechanism. Metabolic

stress occurs only when the adaptive mechanism fails.

 

Chaos theory also predicts that disease states will render biological systems

both more predictable and less adaptable. Adaptive mechanisms fail when our systems

fall sick. During normal immune response, the antioxidant metabolism of the adaptive

mechanism maintains the state of disequilibrium until it reaches it s threshold, thereby

minimizing the chances of metabolic stress. But when an existing condition or

repeated oxidative stress pushes the immune system over the antioxidant threshold, the

normal state of disequilibrium fails and metabolic stress follows. This nonlinear

account of metabolic stress satisfactorily explains oxidative stress induced immune

suppression described in chapter 4.

 

Now we must ask, can pollution induced generation of free radicals cause

squalene metabolic stress in the body’s protective coat. The discussions in chapters 7 –

10 strongly suggest that rising levels of oxidative stress in our environment – due to

ozone depletion, increased background radiation and accumulation of xenobiotics –

 

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put tremendous pressure on the squalene metabolism in the protective coat. An

incident of metabolic stress on the protective coat may be transient, but it may also be

sudden and intense, - especially considering the huge surface area of the coat [more

than 400sq.m].

 

We introduced part three of this book as a search for a model with which to

study the impact of pollution in the evolutionary mechanism of the body. Bearing in

mind that evolution is no more than an extension over many generations of the greater

adaptive mechanism of the body, we have proposed that metabolic stress puts pressure

on the adaptive mechanism implying that squalene metabolic stress would also put

pressure on our evolutionary mechanisms.

 

Thus, the evolutionary presence of squalene in skin makes squalene

metabolism in suitable model to study the long term impact of pollution in the body.

 

Conclusion

 

The existence of two squalene pools in the body is a special characteristic of

squalene metabolism. They are maintained by some force of disequilibrium.

 

Environmental pollution may create metabolic stress in squalene metabolism,

disrupting the disequilibrium and resulting in chaotic fluctuation of squalene and other

isoprenoids. Such fluctuation may produce gradual but significant changes in our body,

mainly in the protective coat defense system. We have already suggested that the high

concentration of squalene in skin and fat cells is probably due to the accumulated

evolutionary requirements of thousands or millions of years. In contrast, the present

change in our environment is both sudden and enormous, with potentially disastrous

results. Squalene metabolism in skin may serve as a useful model to study the impact

of pollution in the evolutionary dynamics of health and disease.

 

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Epilogue

 

 

Geological and evolutionary evidence shows that life on this planet has developed a

profound dependence upon antioxidant isoprenoids such as squalene for protection

against the rigors of the environment. Homo sapiens – the most sophisticated product

of evolution – has not outgrown that dependence. The thick coating of squalene on

our skin is an example. It appears that without squalene we could not have shed the

furry outer coat still worn by our fellow primates.

 

This simple biochemical has played a crucial role in the protection of living

systems for billions of years. Now however, we have inadvertently changed the

environment in ways that are taxing our protective systems, perhaps pushing them to

their very limit. Our voracious industrial societies have produced and propagated

countless carcinogens and other pollutants, diminished atmospheric protection against

ultraviolet radiation, spread new sources of terrestrial radiation and exposed our bodies

to previously unknown chemicals that increase the chances of oxidative stress in the

body.

 

The greatest threat to terrestrial life is the speed at which these changes are

taking place. The marvelous ability of biological systems to adapt is now profoundly

challenged. We cannot reverse the damage we have done. Nor can we realistically

enumerate the various threats and devise a pharmaceutical remedy for each one –

although sometimes it seems that is exactly what we are attempting. What we can do is

to study our inner protective mechanisms and find ways to help them resist the

oxidative pressure of this sudden and potentially catastrophic environmental change.

 

Squalene and its metabolism in the skin may serve as a model for such studies.

 

79

 

 

Glossary

 

 

Acetone [Ch3Coch3]

Compound with solvent properties and characteristic odor; obtained by fermentation

or synthetically

 

Acetyl Co-A

 

A compound from which many other vital substances are derived; derived from sugar

in our cells

 

Acyltransferase

 

Enzyme involved in the antioxidant activity of glutathione

 

Adaptive Mechanism

 

Control mechanism of the body that adapts to new situations, environmental changes

or generalized threats.

 

Adipocyte [Fat cell]

 

Chief constituent cell of adipose [fat] tissue

 

Adipose tissue

 

Body’s fat deposits where triglycerides are stored until needed to provide energy; also

provides heat insulation for the body.

 

Afferent

 

Signal pathway from the periphery to the center of the body; for example touch

provokes an afferent signal

 

Aids [Acquired immune deficiency syndrome]

 

A deficiency in the immune system due to infection by the human immunodeficiency

virus [HIV]

 

Alkylphenol

 

Toxic industrial detergent that promotes endocrine disrupting effects

 

Allergen

 

Agent that may trigger an allergic reaction in the body;’ for example, dust particles,

pollen, etc

 

Allergy

 

Altered response of immune system to an allergen

 

Alpha Particle

 

Elemental particle composed of two protons and two neurons; alpha particles have

very strong ionizing power but cannot penetrate the body easily

 

Alpha-Tocopherol

 

Chemical name of vitamin E

 

Amaranth

 

Plant found in North and South America and in Asia; rich in squalene

Amifostine

Agent used in cancer treatment to protect normal tissue from the damaging effect of

chemotherapeutic agents.

 

Amyloidosis

 

A common complication of several diseases [leprosy, tuberculosis], often associated

with immune disorder

 

Anaplasia

 

Process of transformation of less cancerous cells to highly cancerous cells; degree of

malignancy

 

80

 


 

 

Angiotensin converting enzyme [ACE inhibitor]

 

Potent antihypertensive drug used to treat high blood pressure by converting

angiotensin to angiotensin 11

 

Angiotensin 11

 

Potent blood pressure increasing agent, used by the body when kidney blood flow

decreases; patients experiencing high blood pressure often suffer increased levels of

level of angiotensin and angiotensin 11 in the blood

 

Ankylosing spondylitis

 

A polyarthritis involving the spine, characterized by progressive, painful stiffening of

the joints and ligaments that almost exclusively affects young men

 

Antibody

 

Protein molecule produced by specialized cells when encountering an antigen;

antibodies remember and act specifically against the antigen which originally provoked

their synthesis

 

Anti-carcinogen

 

One of three types of cancer fighting agents; those that prevent chemical precursors

forming carcinogens, those that prevent carcinogens from reaching or acting on target

sites and those that suppress the expression of neoplasia in cells already exposed to

carcinogens

Antigen presentation’

Process by which lymphocytes are made aware of a particular antigen

 

Antioxidant

 

Molecules able to counteract the damaging effects of free radical induced oxidation by

donating an electron to neutralize free radicals

 

Antioxidant metabolism

 

Cellular and tissue synthesis, maintenance and recycling of antioxidants

 

AOM [Azoxymethane]

 

Chemical that can cause colonic aberrant crypt foci – a precancerous condition of

colon cancer

 

Apoptosis control system

 

Hypothetical control system that regulates programmed cell death

 

Archae

 

An ancient form of life, formerly considered a type of bacteria but now considered a

separate and distinct evolutionary branch, found in deep sea hot springs and other

unusual habitats; along with bacteria and eukarya, one of the three domains of life –

while archae resemble bacteria in morphology and genetic organization, they resemble

eukarya in their method of genetic replication.

Asthma

Lung disorder characterized by airway obstruction and recurrent shortness of breath

due to spasmodic contraction of the lung’s airways.

Atherosclerosis

Thickening and hardening of blood vessels resulting in narrowed lumen and

obstruction of blood flow

 

Atom

 

Smallest particle of an element; a positively charged nucleus orbited by negatively

charged electrons

 

81

 

 

Atopic dermatitis

 

An allergic, inflammatory skin disorder resulting in an itchy rash

 

Auto-antibody

 

Antibody formed in response to and reacting against a constituent of an individuals

own tissues

 

Beta Carotene

 

Group of antioxidant carotenoids found in plants

 

Biomembrane

 

Membranous envelope of a living organism such as that enclosing a cell or organelle

 

Biotransformation

 

Chemical alteration of a substance by or in a biological system

Bronchi

The larger air passages of the lungs starting at the point where the trachea branches

into two

 

Bronchiole

 

Smaller airway of the lungs connecting bronchi to air-sacs [alveoli]

Cachexia

Profound and marked general ill health and malnutrition

 

Cancer

 

Malignant cellular tumor

 

Carbohydrate

 

Compound of carbon, hydrogen and oxygen, e.g. cellulose, sugar, starch

 

Carbon Dioxide [CO2]

 

Odorless, colorless gas produced by oxidation [burning] of carbon; naturally formed in

animal tissue and eliminated by the lungs, or produced by the burning of fossil fuels

Carbon Monoxide [CO]

Odorless, colorless gas produced by burning carbon or organic fuels in a low oxygen

environment, when inhaled, prevents blood from absorbing oxygen and quickly leads

to death

 

Carcinogen

 

Substance able to transform normal cell into cancer cell

 

Carotenoids

 

Plant derived substances belonging to the isoprenoid antioxidant family, such as

vitamin A

 

Catalase

 

Enzyme that catalyzes decomposition of hydrogen peroxide: found in most cells

 

Cataract

 

Partial or complete opacity of the lens of the eye, impairing vision or causing blindness

 

Cell Cycle Proliferation

 

Proliferation of cells by division into two identical new cells

 

Cell

 

Fundamental structural and functional unit of living organisms, consisting of a nucleus

and cytoplasm enclosed in a plasma membrane

 

Cellular Defense System

 

System that protects cells from environmental toxins, free radicals, drugs and various

other noxious agents

 

82

 


 

 

Cellular Homeostasis

Dynamic balance of the internal environment of the cell Dynamic balance of the internal environment of the cell

 

Cellular Oxidative Distress

 

Inability of cellular microenvironment to maintain oxidant-antioxidant balance due to

intense generation of free radicals inside the cell

 

Cellular Redox System

 

System enabling cells to carry out oxidation-reduction reactions and consisting of

special redox molecules to keep the oxidant-antioxidant ratio in balance

 

Cellular

 

Pertaining to structure or system of a cell

 

CFC [Chlorofluorocarbon]

 

Type of hydrocarbon containing both chlorine and fluorine, used as refrigerants,

blowing agents, cleaning fluids, solvents and for fire extinguishing CFCs – are known

to cause ozone depletion

 

Chaos Theory [Non-linear Dynamics]

 

Study of systems that respond in a nonlinear way to initial conditions or perturbing

stimuli; fractal [non-linear] representations of chaotic systems often reveal similar but

nonidentical patterns across varying scales of time and space

 

Chemical Quenching

 

Reaction in which a free radical is chemically incorporated with a neutralizing

antioxidant by the sharing, rather than the exchange of an electron

 

Chlorophyll

 

Green pigment in plants that harnesses light energy making water and carbon dioxide

react to produce oxygen and glucose

 

Chloroplast

 

Chlorophyll-bearing bodies of plant cells

 

Cholesterol Regulatory Mechanism

 

Mechanism that controls the synthesis and distribution of cholesterol in the body

 

Cholesterol

 

Waxy substance used in construction of cell membranes and synthesis of steroid

hormones; also a precursor of bile acids; mostly manufactured in the liver but also

partially absorbed from diet

 

Chromanol Ring

 

Aromatic ring structure; main backbone of vitamin E

 

Chronic Fatigue Syndrome [CFS]

 

Long term [six months or more] affliction characterized by persistent or recurrent

fatigue, diffuse musculoskeletal pain, sleep disturbances and subjective cognitive

impairment

 

Chronic Radiation Injury

 

Harmful effects of long term exposure to ionizing or non-ionizing radiation

Cirrhosis of the Liver

Damage, scarring and subsequent hardening of the liver

 

Clonal Evolution

 

Development of genetically identical cells descended from a single ancestral cell by

division and multiplication, during which daughter cells acquire new properties through

natural selection; used especially regarding development of cancer mass

 

83

 

 

Co-Enzyme Q

 

Ubiquinone, a quinone with isoprenoid side chains found in mitochondria and

involved in energy production

 

Colon Cancer

 

Tumors or cancer of the large intestine

 

Colonic Aberrant Crypt Foci

 

Change in normal structure of the epithelial coat of the large intestine; a precancerous

sign

Control Group

A group of subjects used in a test but not undergoing test conditions; used to produce

normal data for comparative purposes

 

Control System

 

Operating system that navigates and commands internal body processes

 

Coronary Artery

 

Either of two arteries that carries oxygenated blood to the muscular tissue of the heart

 

Coronary Heart Disease

 

Disease resulting from a blocked coronary artery, usually due to atherosclerotic plaque

 

Corticosteroid

 

Group of hormones that regulate various functions of the body including the energy

metabolism, healing and stress response; corticosteroids are involved in growth,

development and bodily vitality

 

Cosmic Radiation

 

High energy radiation of particles originating from extraterrestrial space

 

Crohn’s Disease

 

A chronic inflammation in the digestive tract; similar to but more severe than ulcerative

colitis

 

Cysteine

 

A sulfur-containing amino acid; scarcest of the three constituents of glutathione

 

Cytochrome P450

 

Type of enzyme used in biotransformation of many foreign compounds

 

Cytokine system

 

Component of the immune system that regulates messaging among immune cells

 

Cytokine

 

Protein mostly secreted by immune cells to regulate immune function by inducing

inhibitory and excitatory activity of other immune cells

 

Cytoplasm

 

Substances other than nucleus, mitochondria and chloroplasts that make up the cell

body

 

Cytoprotection

 

Process by which chemical compounds protect cells from harmful agents

 

Cytoprotective Therapy

 

Use of substances that protect normal tissue from harmful effects of disease processes

or aggressive therapies used to combat them, such as anticancer radiation or

chemotherapy

 

Cytotoxin

 

Substance toxic or harmful to cell and its function

DDE An organochlorine pesticide ethylene metabolite of DDT

 

84

 


 

 

DDT

 

A polychlorinated pesticide resistant to destruction by light and oxidation and believed

to be carcinogenic

 

Dementia

 

An acquired organic mental disorder with significant loss of intellectual abilities

 

Depleted Uranium

 

Radioactive by-product of nuclear weapon manufacturing and reactor use

 

Dibenzofuran

 

Group of ether compounds related to dioxin and PCBs, used by petrochemical,

pulp/paper and many other industries

 

Differentiating Action

 

Drug action pushing a cancer cell towards its normal behavior and function; eg.

Vitamin A can push nerve cancer cell to become a normal nerve cell

 

Dioxin

 

Man made chemical found to act as a persistent carcinogen

 

Disease progression

 

Progressive damage to the body tissue by a disease process

 

DNA Synthesis

 

Cellular production of DNA

 

Dolichol

 

Derivative of the mevalonate pathway used for carbohydrate synthesis

 

Down-Regulation

 

Process on cell surfaces that decreases interaction with incoming biochemicals by

reducing the number of available receptors

 

Drug Resistance

 

Inherent or acquired ability of a disease process to resist effectiveness of a therapeutic

chemical or drug

 

Efflux

 

Pumping mechanism of cancer cells by which they expel anticancer drugs; movement

of drug from interior to the exterior of the cell

 

Electrical Channel

 

Special doors in a cell wall guarded by proteins and charged with a specific voltage; only

specific ions are allowed to enter through such channels, hence sodium channel,

calcium channel etc

 

Electron Imbalance

 

The lack of an electron in an atom’s outer electron ring, such that it seeks a

replacement; usually the result of free radical damage

 

Electron Transfer Reaction

 

Chemical reaction within a special molecule involving the transfer of electrons from

one molecule to another

 

Electron

 

Negatively-charged particle orbiting the nucleus of an atom; the number or orbits and

the number of electrons in the outer orbit determine all the atom’s physical and

chemical properties except mass and radioactivity

 

Emit

 

To liberate, to give off

 

85

 

 

Endogenous Anti-Oxidant

 

Antioxidant synthesized within the body, including glutathione [GSH], coenzyme Q10

catalase, superoxide dismutase [SOD] and squalene

 

Endogenous

 

Produced within or caused by factors within an organism

 

Endogenous Antioxidant Metabolism

 

Metabolism of antioxidants synthesized within the body e.g. glutathione and squalene

 

Endometrial Cancer

 

Tumors or cancer of the inner lining of the uterus

 

Endometrium

 

Mucous membrane lining of the uterus

 

ENE Reaction

 

Hydrogen atom donation and reception in a biochemical reaction

 

Entropy

 

Tendency of all physical systems to fall into disorder

Environmental Pollutant

Substance present in high enough concentrations to produce adverse effects on the

environment

 

Enzymatic Transformation

 

Change of one substance to another by enzyme induced chemical reaction; e.g.

transformation of acyclic squalene to cyclic squalene by the enzyme squalene cyclase

Enzyme

Protein produced in a cell and able to accelerate a chemical reaction without being

altered by the reaction

 

Epidemiology

 

Branch of medical science dealing with the incidence, distribution and control of

disease in a population; the sum of factors controlling the presence or absence of a

disease or pathogen

 

Epidermal Fat

 

Fat present in the epidermis, including cholesterol, triglycerides and various methyl

sterols; a very significant portion – about 12% of epidermal fat in human beings is

squalene

 

Epidermis

 

Outermost layer of skin, varying in thickness from 0.07mm to 1.4mm in human beings

 

Epioxide

 

Substance formed after oxidation; e.g. squalene epioxide formed by reaction of oxygen

with squalene under the influence of the enzyme squalene epioxidase

 

Epithelial

 

Of or relating to the epithelium

 

Epithelium

 

Cellular covering of the outer and inner body surfaces, including the lining of vessels

and small cavities

 

Estrogen Receptor

 

Protein combination on the surface of a cell that attracts and ‘hooks’ estrogen for use

in cellular activity

 

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Eukarya

 

Cells of more complex living organisms, containing a true nucleus enveloped by a

nuclear membrane

 

Evolution

 

Developmental process by which an organ or organism becomes more and more

complex through differentiation of its parts

 

Evolutionary Mechanism

 

Mechanism of a species that adapts to a changing environment

 

Evolutionary Pressure

 

Pressure exerted by the threat of extinction on an organism or a species

 

Excitatory Cytokine

 

Cytokine causing increased proliferation of immune cells

Excitatory – Stimulatory

Exfoliative Dermatitis

 

A scaly dermatitis often associated with the loss of hair and nails, thickening of skin in

the palms and soles and intense itching

 

Exogenous Antioxidant

 

Antioxidant not synthesized within the body, usually derived from dietary sources

 

Exogenous

 

Originating outside or caused by factors outside the organism

 

Farnesyl

 

Small isoprenoid derived from mevalonate and a precursor of squalene and coenzyme

Q10

 

Fat Transport

 

The circulation of non-water soluble fats through the water based blood circulation in

combination with proteins, called lipoproteins

 

Fatty Acid

 

An acid containing only carbon, hydrogen and oxygen which combine with glycerin to

form fat

 

Feed Back Control System

 

Systems used by the body to maintain balance in various metabolic and other processes

 

Fibromyalgia

 

Common rheumatic syndrome not affecting the joints and characterized by muscle

tenderness and pain

 

Force of Disequilibrium

 

Force by which various parts of a normally balanced system are maintained at different

levels

 

Free Radical

 

Molecule or atom containing an unpaired electron in its outer orbit

 

Free Radical Biology

 

Branch of medicine that studies and explains disease processes resulting from or

contributed to b y free radicals in the biological system

 

Frequency

 

[Of light and other electromagnetic radiation] the number of waves per second; higher

frequency waves have more energy

 

87

 

 

Gene

 

Functional unit of hereditary material determining characteristics such as blood type,

eye color, etc

 

Genetic Control System

 

Biological control system dealing with functioning of genes

 

Genetic Evolution

 

Evolution of energetic trends and character

 

Geranyl

 

Small isoprenoid of the mevalonate pathway; a precursor to farnesyl ad involved in

protein isoprenylation

 

Glomerulonephritis

 

An inflammatory kidney condition; a suspected autoimmune disorder

 

Glutathione S-Acyltransferase

 

Enzyme involved in glutathione metabolism

 

Glutathione

 

Intracellular antioxidant found in almost all organism; the major component of the

cellular redox system that helps maintain thiol homeostasis within a cell

 

Glycerol

 

Type of sugar alcohol

Good Cholesterol [HDL] High Density Lipoprotein

Protein fat complex [lipoprotein] that transports cholesterol from tissue to liver for

excretion in the bile

 

Granulomatous Disorder

 

A genetic defect in which phagocytes ingest but fail to digest bacteria, resulting in

recurring bacterial infections

 

Hepatic [liver] failure

 

Severe inability of the liver to function normally

 

Hepatitis

 

Inflammation of the liver

 

Hereditary Blueprint

 

Biological description [genetic information] of an organism passed from parent to child

in genes carried in its cellular nucleus

 

Hexachlorobenzene

 

Agricultural fungicide and seed treatment agent

 

Hexachloro – Biphenyl

 

Biphenyl group of xenobiotics related to PCBs [PolyChlorinated Biphenyls]

 

High Density Lipoproteins [HDL; Good Cholesterol]

 

Protein fat complex [lipoprotein] that transports cholesterol from tissue to liver for

excretion in the bile

HIV [HI virus; Human Immunodeficiency Virus]

Virus believed to cause AIDA [acquired immune deficiency syndrome]

 

 

Histamine

 

A neurotransmitter that plays an important role in the regulation of several

physiological processes, including dilation of capillaries, contraction of most smooth

muscle tissue, induction of increased gastric secretion [ it most important use], and

acceleration of heart rate

 

88

 


 

 

HMG Co-A Reductase -A Reductase

 

Enzyme that helps conversion of acetyl coenzyme A into mevalonate; the rate limiting

enzyme of the mevalonate pathway controlling the entire isoprenoid metabolism

 

Homeostasis

 

Maintenance of normal stability in physio-logical states of an organism, enabling us to

adapt to changing environmental conditions; maintained by the internal control systems

of the body such as genetic control system, immune control system, etc; these systems

operate through negative feedback and positive feedback

 

Hopanoid

 

Class of organic compounds derived from cyclic squalene

 

Hydrogen Peroxide [H2O2]

 

Strong oxidizing agent

 

Hydrophobic

 

Averse to water

 

Hydroxyl [OH,OH+]

 

Ion consisting of one atom of hydrogen and one of oxygen, either neutral or positively

charged

 

Hydroxylation

 

Introduction of hydroxyl into ion or radical usually by replacement of hydrogen

 

Hyper activation

 

Over stimulation

 

Hypercholesterolemia

 

Abnormally high levels of cholesterol in the blood

 

Hyperplasia

 

Abnormal, non cancerous increase in number of cells in a tissue or organ

 

Hypoxia

 

Decreased cellular oxygen content

 

Hypoxia reperfusion Injury

 

Cellular damage caused by sudden flow of oxygen to oxygen deprived tissue

 

Immune Cell

 

Cells of the immune system principally macrophages, T cells and B cells but including

many others

 

Immune Defense System

 

The coordinated system that protects the body from microorganisms and other foreign

agents

 

Immune Response

 

Coordinated response of the body to invasion, such as bacterial or viral infection

 

Immune Suppression [Immunosuppression]

 

Prevention or diminution of the host’s immune response

 

Immunodeficiency

 

Imbalance of immune response due to too much or too little immune activity

 

Inactivate

 

Transformation of molecule from functioning to nonfunctioning state

 

Inactive Squalene [Stable Squalene]

 

Obsolete term describing the portion of linear squalene that is not metabolized in the

mevalonate pathway and which maintains its antioxidant properties

 

89

 

 

Industrial Carcinogen

 

Industrial cancer causing chemical substance

 

Infarction

 

Sudden pathological fall in blood supply to an area resulting in cell death and loss of

function of that particular area

 

Inflammation

 

Protective response of tissue to injury and potential destruction; attempt to destroy,

dilute or block the injurious agent and the injured tissues; classical signs of

inflammation pain include warmth, redness, swelling and loss of function

 

Inflammatory Bowel Disease

 

Types of chronic intestinal inflammation, including ulcerative colitis and Crohn’s

disease

 

Inhibitor

 

Agent that slows or prevents a biological process

 

Inhibitory Cytokine

 

Cytokine causing decreased proliferation of immune cells

 

Insulin Resistance

 

Diminished response of blood sugar levels to insulin

 

Internal Metabolic Process

 

Operating system of a metabolic process such as enzymatic control of a metabolic

pathway, feedback inhibition and hormonal influence

 

Intima

 

Innermost coat of an organ

 

Intracellular Anti-oxidant

 

Antioxidant present inside the cell

 

Ion

 

Atom or molecule with one electron more or less than normal, resulting in an acquired

positive or negative charge

 

Ionization Threshold

 

Amount of stimulation required for an electron within a molecular system to break free

 

Ionization

 

Break up of a substance into ions

 

Ionizing Radiation

 

Radiation that can split atoms and molecules in the body

 

Iron

 

Chemical element and essential constituent of hemoglobin, cytochrome, and other

components of the respiratory enzyme system

 

Irradiate

 

To expose to radiation

 

Isoniazid

 

Therapy of choice for tuberculosis

 

Isoprene [Isoprene unit]

 

Building block of isoprenoids; an isoprene unit contains five carbon atoms and a

double bond

 

Isoprenoid Metabolism

 

Chemical process that synthesizes three secondary isoprenoids in the mevalonate

pathway; geranyl, farnesyl and squalene

 

90

 


 

 

Isoprenoid Synthesis Pathway

 

See – Squalene synthesis pathway

 

Isoprenoid

 

Group of molecules with isoprene units

 

Isoprenylation [ Protein isoprenylation]

 

Modification of proteins on the surface of a cell by the attachment of one of two

isoprenoids; farnesyl diphosphate or geranyl diphosphate

 

Keratin

 

Principal protein constituent of epidermis, hair and nails

 

LDL [Low Density Lipoprotein; Bad Cholesterol]

 

Protein fat complex [lipoprotein] that transports cholesterol from the liver through

blood into other tissues, where it leads to plaque buildup

 

LDL Receptor

 

Protein complex on the surface of a cell that attracts and ‘hooks’ LDL; prevalent in the

cell membrane of liver cells

 

Leptin

 

Hormone secreted by fat cells

 

Leukemia

 

Progressive, malignant disease of blood forming organs

Light Harvesting Complex

[LHC] Group of carotenoids antioxidant isoprenoids present in a plant’s chloroplasts

that gather light and make photosynthesis efficient

 

Light Harvesting Compound

 

Same as LHC

 

Linear Dynamics

 

Conventional branch of physics, in which an effect is proportional to its cause [ in

contrast to chaos theory or nonlinear dynamics]; a branch of mathematics dealing with

systems that obey laws of proportion.

 

Lipase

 

An enzyme that is produced by tongue glands and the pancreas, initiating digestion of

dietary fats

 

Lipid

 

Fat or fat like substance including fatty acids, neutral fats, waxes, isoprenoids and

steroids, insoluble in water

 

Lipid Bilayer

 

Double layer of fats [lipids] forming a biomembrane

 

Lipid Peroxidation Chain Reaction

 

Domino effect in which free radical damage to a lipid [fat] molecule renders it radical

itself and similarly affects neighboring molecules; analogous to a multi-vehicle highway

pile up in a rapid sequence of single steps

 

Lipid Peroxidation

 

Chemical reaction in which a lipid molecule consisting of mainly unsaturated fat is

oxidized injury that triggers inflammation

 

Lipophilic

 

Having an affinity for fat

 

Lipoprotein

 

Combination of fats within a protein coat by which lipids are transported in the blood

 

91

 

Liquid Chromatography

 

Method of separating mixtures into their constituent substances

 

Long Chain Hydrocarbon

 

Carbon compound with a long chain of interlinked carbon atoms, e.g. petroleum

 

Lumen

 

Cavity of a tubular organ

 

Lycoma

 

Tumor Metabolic Stress

resulting from excessive application of lycopene in the skin

 

Lycopane

 

Reduced form of lycopene

 

Lycopene

 

Red carotenoids pigment of tomatoes and various berries and fruits

 

Lymph Gland

 

Bodily tissue containing lymphocytes and other immune cells that filter micro

organisms and toxins from the body

 

Lymphocyte

 

White blood cells formed in the body’s lymphoid tissue

 

Lymphoma

 

General term for various cancerous diseases of the lymphoid tissue

 

Macrophage

 

Immune cell that envelops and digests incoming pathogens by the process of

phagocytosis; the major cellular constituent of the mucosal defense system;

macrophages also interact with lymphocytes to facilitate antibody production

 

Mass

 

In relating to cancer; autonomous accumulation of cancer cells

 

Mast Cell

 

Type of white blood cell involved in allergic reaction

 

MCG/GM

 

Measure of concentration of one substance within another; microgram [one millionth

of a gram] per gram

 

Media

 

Outside wall of an artery

 

Melanin

 

Pigments in skin and hair

 

Melanoma

 

Type of skin cancer; malignant cell growth originating from cells normally forming

melanin and spreading widely to lymph nodes, liver, lungs, and brain

 

Metabolic Pathway

 

Process in which a substance is produced in a series of chemical transformations from

another substance

 

Metabolic Pool

 

Portion of a substance that, in contrast to another portion of the same substance, is

destined for different biological activity

Inability of the metabolism to respond to a situation in which demand for a substance

exceeds its production

 

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Metabolism

 

Sum of all chemical and physical processes by which living organisms produce organic

substances; also, the transformation by which energy is made available for the uses of

the organism [catabolism]

 

Metabolite

 

Any biochemical product of metabolism

 

Methyl Bromide

 

Chloroform like volatile and toxic chemical used as fumigant, powerfully destructive of

ozone layer

 

Methyl Group [CH3]

 

An organic chemical group

 

Methylation

 

Introduction of the methyl group into a chemical compound

 

Mevalonate Pathway

 

Metabolic sequence of biochemical reactions leading from glucose to cholesterol;

 

Mevalonate

 

Mother molecule of all isoprenoids in the biological system; derived from glucose by

several complex enzymatic process

 

Mevalonic Acid [C6H12O4]

 

Precursor of squalene in the biosynthetic pathway forming cholesterol

 

MG/KG

 

Measure of concentration of one substance within another; microgram [one millionth

of a gram] per kilogram

 

Migrate

 

The departure of a group of cell or tissue from its natural location to another

 

Mitochondria

 

Energy production factories within a cell that burn nutrients to produce electrons and

generate electricity which is converted into chemical energy and stored in the cell for

future use

 

Mitosis

 

Formation of two new nuclei from a single parent nucleus, each having the same

number of chromosomes as the parent

 

Mixed isoprenoid

 

Substance composed of isoprene units attached to some other organic group, in

contrast to pure isoprenoid; e.g. vitamin E, which contains a chomarol group attached

to three isoprenoid side chains

 

Modulate

 

To adjust; to influence the fate of a chemical or physical function

 

Molecular Oxygen [O2]

 

Oxygen in the form of two combined atoms present in air and surface water; ultraviolet

radiation can break molecular oxygen into separate oxygen atoms [oxygen radicals]

which in turn can combine with molecular oxygen to form ozone

 

Molecule

 

Smallest amount of a substance which can exist alone; an aggression of atoms forming

a specific chemical substance

 

Mucosa

 

Mucous membrane coating the lumen of intestines, lung, nose mouth etc

 

93

 

Mucosal Defense System

 

Immune system of skin and mucosae

 

Myocardial infarction

 

Sudden death of part of the heart muscle due to interrupted blood supply, a heart

attack

 

Myopathy

 

Disorder of muscle tissue or muscles

 

Nanometer

 

Billionth of a meter

 

Natural Defense System

 

Term used in this book to denote the immune system and the antioxidant defense

system [ cellular protective system]

 

Negative Feedback

 

Modulating process of biological control systems; too much or too little activity of a

particular sort may initiate negative feedback and return the activity to normal levels; a

source of homeostasis

 

Nerve Fiber Sheath [Myelin]

 

Electrical insulator covering nerve fibers enabling faster, more efficient transmission of

impulses

 

Neuron

 

Principal cells of nervous tissue able to transmit and receive nervous impulses

 

Neutrophil

 

Immune cell involved in phagocytosis

 

NNK [4 Methlynitro-samino -1-3-Pyridyl-1-Butanone]

 

A potent carcinogen used in laboratory experiments

 

Non-Ionizing Radiation

 

Radiation unable to penetrate and ionize deep tissue

 

Non-Linear Behavior

 

Behavior that does not follow simple, predictable patterns; biological behavior that

does not obey proportionality; see chaos theory

 

Non-Linear Dynamics [Chaos Theory]

 

Study of systems which respond disproportionately [nonlinearly] to initial conditions or

perturbing stimuli; nonlinear systems may exhibit ‘chaos’ classically characterized as

sensitive dependence on initial conditions; chaotic systems are neither ordered in a

mechanistic way nor random; their behavior over time is displayed in ‘phase space’ in

which constraints are described as ‘strange attractors;’ these representations usually

reveal fractal patterns – self-similarity across time scales; biological systems often

display nonlinear dynamics and chaos

 

Non Specific

 

An immune response to a pathogen that is not tailored to its specific propertied and or

weaknesses

 

Normal Chaotic Fluctuation

 

Fluctuation normally considered abrupt [in linear dynamics] but within normal range of

nonlinear [chaotic] dynamics; e.g. daily fluctuations of heart rate

 

Nucleus

 

The ‘heart’ of a cell, containing genes

 

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Oleic Acid

 

An unsaturated fatty acid; the most widely distributed and abundant fatty acid in nature

 

Oncogene

 

Cancer promoting gene; gene that transmits the cancer character as cancerous cells

multiply

 

Oncologist

 

Specialist in the study of tumors

 

Organ

 

Somewhat independent body part with a specialized function

 

Organelle

 

Specialized functional structure within a cell

 

Organochlorine

 

A pesticide

 

Oxidant-antioxidant Balance

 

Appropriate ratio of free radicals to antioxidants under which cells, and tissue can

operate optimally

 

Oxidation

 

Removal of electrons

 

Oxidation- Reduction

 

Chemical reaction in which electrons are removed [oxidized] from a substance and

transferred to those being reduced [ reduction]

 

Oxidative Injury

 

Free radical induced damage to a cell

 

Oxidative Phosphorylation

 

Complex electrochemical process by which mitochondria derive energy from nutrients

and oxygen

 

Oxidative Stress

 

Overproduction of free radicals causing tissue damage

 

Oxidized Cholesterol [oxLDL]

 

Bad Cholesterol subjected to lipid peroxidation; the worst type of cholesterol

 

Oxygen

 

Chemical element constituting about 20% of atmospheric air; essential for respiration

in plants and animals

 

Oxyradical

 

Oxygen derived free radical

 

Ozone [O3]

 

Bluish explosive gas or blue liquid; an antiseptic and a disinfectant; an irritant, toxic to

the respiratory system

 

Ozone Layer

 

Outermost layer of the planet’s atmosphere, composed principally of ozone, that filters

a portion of the sun’s harmful ultraviolet radiation

 

P53 Gene

 

Natural anticancer defence; tumor suppressor gene located on the short arm of human

chromosome 17 and coding for the phosphoprotein P53

 

Pathogen

 

Any specific agent causing or threatening the body with disease

 

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Pathology

 

Structural and functional manifestations of disease

 

PCBs

 

See polychlorinated biphenyls

 

Peer Review Journal

 

Medical research journal in which research articles are subjected to the approval of a

select committee of established scientists

 

Pemphigus Vulgaris

 

A chronic, relapsing sometimes fatal skin disease characterized among other symptoms

by serum autoantibodies directed against antigens in the intracellular zones of the

epidermis

 

Pentamethyleicosane [PME]

 

Ancient, acyclic isoprenoid present in primitive bacteria

 

Phagocyte

 

Bacteria-eating immune cell

 

Phagocytosis

 

Process of engulfing microorganisms and other foreign particles by immune cells

 

Phenobarbital

 

A nonselective central nervous system depressant; a barbituric acid derivative

 

Phenol [C6H5OH]

 

An antiseptic and disinfectant

 

Photooxidation

 

Oxidation of organic molecules by light energy

 

Photosynthesis

 

Light induced formation of carbohydrates from carbon dioxide and water in the

chlorophyll tissue of plants

 

Physical Quenching

 

Neutralization of free radicals by antioxidant’s donation of an electron without

chemical reaction

 

PI Electron System

 

Special arrangement of electrons I a carbon-carbon double bond that activates nearby

hydrogen atoms; each isoprene unit has one double bond and therefore one pi electron;

all pi electrons in an isoprenoid molecule combine to make one pi electron system,

each one stabilizing the molecule’s hydrogen atoms

 

Plasma

 

Fluid part especially of blood, lymph, or milk, apart from suspended material

 

Polarized

 

To be separated into polar opposites such as off and on; positive and negative,

hydrophilic and hydrophobic

 

Polychlorinated Biphenyls [PCBs]

 

Highly lipophilic industrial products and compounds that accumulate in fat stores,

many of which are potential environmental pollutants

 

Positive Feedback

 

Process into which many biological control systems fall as they lose homeostatic

control; leads to instability, disease and death; positive feedback is occasionally a

normal process, for example in sexual intercourse

 

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Pravastatin

 

Drug acting as a competitive inhibitor of HMG Co-A reductase

 

Precambrian Era

 

Geological time that spanned from 3.8 billion to 570 million years ago. The great

Precambrian era is divided into two parts; during the archean period from 3.8 to 2.5

billion years ago archae and cyanobacteria dominated life. The proterozoic era – from

 

2.5 billion

To 570 million years ago – includes over 85% of living history

Prednisolone [C21H28O5]

 

Glucocorticoid used in systemic corticosteroid therapy of inflammatory diseases

 

Prednisone

 

A synthetic anti-inflammatory glucorticoid derived from cortisone; biologically inert

and converted to prednisolone in the liver

 

Premature Apoptosis

 

Apoptosis forced upon a young and active cell; an offensive strategy for example of

HIV

 

Pro-Carcinogen

 

Normally noncancerous chemical transformed into a carcinogen within the body

 

Proliferation

 

Increase in number, as in cell proliferation [[multiplication]

 

Pro-oxidant

 

Antioxidant molecule that has lost its stability and becomes a free radical

 

Prostate Cancer

 

Tumors or cancer of the prostate – a male gland surrounding the neck of bladder and

the urethra

 

Protective Coat

 

Term used in this book to encompass those bio-surfaces of the body exposed to the

outside environment – skin, mouth, intestine, nose, throat and lung

 

Proton

 

Stable elementary particles possessing the smallest known positive charge and found in

the nuclei of all elements

 

Pure Isoprenoid

 

Isoprenoid composed exclusively of isoprene units

 

Pyrophosphate

 

Inorganic salt of phosphoric acid containing phosphate groups

 

Quaternary Carbon Group

 

Carbon atom within an organic compound in which each of its four bonds are

connected directly to another carbon atom

 

Quench

 

To neutralize a free radical

 

Quinone

 

Benzene derivative in which two hydrogen atoms are replaced by two oxygen atoms;

ubiquinone [Coenzyme Q10] is quinone with an isoprenoid tail

 

Ras Oncogene

 

Family of most commonly found oncogenes in human cancerous tumors

 

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Reactive Arthritis

 

Also known as Reiter’s syndrome. An aberrant reaction of the immune system to the

presence of bacterial infections in the genital, urinary, or gastrointestinal systems and

leading to inflammation in the joints and eyes

 

Receptor

 

Protein molecule within or on the surface of a cell that recognizes and binds with

specific molecules, producing a specific effect in the cell

 

Redox Molecule

 

Type of organic molecule able to participate in reduction oxidation reaction

 

Redox Reaction

 

See oxidation – reduction

 

Reduction

 

Addition of electron

 

Reduction – oxidation

 

Electron transfer from one molecule to another; gain [ reduction] and loss [oxidation]

of electrons

 

Reperfuse

 

Restoration of blood flow to oxygen deprived tissue or organ

 

Respiratory Tract Disease

 

Disease in airway tubes; e.g. asthma

 

Rheumatic Fever

 

Probable autoimmune disease following streptococcal infection and involving

inflammation of joints and damage to heart valves

 

Rheumatic Heart Disease

 

The most important manifestation of and sequel to rheumatic fever

 

Rheumatoid Arthritis

 

Chronic inflammatory destruction of joints considered by some to be an autoimmune

disorder

 

Rhinitis

 

Inflammation of the mucous membrane of the nose

 

Ribosome

 

Organelle [ functional unit within a cell] rich in RNA and proteins; site of protein

synthesis

 

Risk Factor

 

Contributing cause or circumstance of disease or potential disease

 

RNA Transcription

 

Synthesis of RNA from its complementary DNA strand

 

Roentgen

 

German term for X-ray – inventor of x-rays

 

Sarcoidosis

 

Disease of unknown etiology involving chronic inflammatory Granulomatous lesions

in the lymph nodes and other organs

 

Scleroderma

 

Hardening of the skin

 

Sebum

 

Fatty, lubricating secretion of skin’s sebaceous glands

 

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Serum Sickness

 

A hypersensitivity response to the injection of large amounts of antigen

 

Sex Hormone

 

Steroid substances that differentiate male and female beings; testosterone for males and

estrogen for females

 

Simvastatin

 

Drug derivative of lovastatin and potent competitive inhibitor of HMG Co-A reductase

 

– the rate limiting enzyme in cholesterol biosynthesis

Singlet Oxygen

 

Molecular oxygen with one missing electron

 

Spleen

 

Large gland like organ situated in the upper left part of the abdominal cavity

 

Splenomegaly

 

Enlargement of the spleen

 

Squalane

 

Natural emollient found in skin; squalene with an added hydrogen atom

 

Squalene

 

Isoprenoid hydrocarbon consisting of six isoprene units; in linear form an excellent

antioxidant; in cyclic form a principal constituent of the sterol nucleus of cholesterol

 

Squalene Metabolism

 

Metabolic process involving production and storage of squalene in the body

 

Squalene synthase

 

Enzyme that converts farnesyl to squalene

 

Squalene synthesis pathway

 

Metabolic pathway that synthesizes squalene from mevalonate via production of

geranyl and farnesyl; part of the isoprenoid metabolism

 

Squamous Cell Carcinoma

 

A type of skin cancer on the increase due to ozone depletion

 

Statins

 

Group of drugs that lower production of cholesterol in the body by inhibiting the

enzyme HMG Co-A reductase

 

Sterol

 

Solid steroid alcohol widely distributed in animal and plant lipids; fundamental building

block of cholesterol

 

Strychnine

 

Alkaloid found in the seeds of nux vomica; a convulsant and poison

 

Subcutaneous

 

Beneath the skin

 

Submucosal

 

Beneath the mucosa

 

Superoxide Dismutase [SOD]

 

Intracellular antioxidant present mostly in a cell’s mitochondria

 

Superoxide

 

Highly reactive compound produced when oxygen is reduced by a single electron

 

Synapse

 

Specialized junctions from which neurons communicate with target cells

 

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Synthesis

 

Creation of compound by the union of elements; manufacture

 

Systemic Lupus Erythematosus

 

A probably autoimmune disease characterized by antinuclear and other antibodies in

plasma

 

Terminator

 

Antioxidant that can stop [terminate] a lipid peroxidation chain reaction

 

Terrestrial Radiation

 

Earthbound radiation from radioactive materials in rocks and sediments

 

Testicular Cancer

 

Cancer of the Testicle

 

Theophylline

 

Drug that stimulates the heart and central nervous system, dilates bronchi and blood

vessels and causes diuresis

 

Threshold

 

[In metabolism] Limit at which biochemical processes undergo drastic change

 

Tissue

 

Aggregation of similar cells which together perform certain special functions

 

TNF-Alpha

 

Tumor necrosing factor; an excitatory cytokine; increased release of this cytokine can

cause insulin resistance

 

Topical

 

Designed for or involving local application to a bodily part

 

Total Suspended Particulate Matter [TSP]

 

Solid or liquid atmospheric particles [diameter 10 micrometers] from sources including

diesel exhaust, wood- stoves and power plants; may be formed in the atmosphere from

reaction of So2, NOx and other gaseous pollutants

 

Toxic Shock Syndrome

 

A staphylococcal infection of blood

 

Transient

 

Temporary

 

Triglyceride

 

Compound consisting of three molecules of fatty acid and the usual storage form of

lipids in animals; a neutral fat

 

Triterpene

 

Group of isoprenoid compounds having thirty carbon atoms, such as squalene

 

Tuberculosis

 

A lung infection caused by a species of mycobacterium

 

Tumor necrosis Factor [TNF-Alpha]

 

Type of stimulatory cytokine secreted by immune and fat cells; increased release can

cause insulin resistance

 

Tumor Neoplasm

 

New abnormal growth of tissue

 

Tumor Suppressor Gene

 

Gene causing suicide of a cell to prevent malignant transformation

 

Ulcerative Colitis

 

Chronic inflammatory disease of the mucous membranes of the colon leading to ulcers

 

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Uranium – 238 – 238

 

Radioactive uranium of atomic mass 238

 

Urticaria

 

Vascular reaction of the skin to allergy, characterized by redness, heat and pain in the

affected area

 

UV Radiation

 

Portion of the electromagnetic spectrum immediately below the visible range and

extending into the x-ray frequencies

 

UV-A Radiation

 

Ultraviolet spectrum from 320 to 400 nm wavelength; contributes to aging of the skin

 

UV-B Radiation

 

Ultraviolet spectrum from 280 to 320 nm wavelength; contributes to sunburn, aging of

the skin and development of skin cancer

 

Vasculitis

 

Inflammation of any vessel

 

Vesicle

 

Membranous, usually fluid filled pouch

 

Vitamin

 

Group of chemically unrelated organic substances occurring in many foods in small

amounts and necessary in trace amounts for the normal metabolic functioning of the

body

 

Wavelength

 

Length of a wave from trough to trough or crest to crest; the wave length of light is

measured in nanometers

 

White Blood Cells

 

Cells in plasma without red cells; all immune cells are white cells

 

Xenobiotic

 

Chemical substances foreign to the biological system