Melatonin in the Promotion of Health PDF

Preface

Melatonin is a small molecule, a derivative of the amino acid tryptophan, N-acetyl-5 methoxytryptamine. It is a potent hormone with well-recognized activities and the potential to influence many bodily functions. It is produced by the pineal gland in the brain and is secreted when the body recognizes darkness. Melatonin has intense effects on the timing of the sleep/awake cycle, regulating the circadian rhythms of several biological functions. This is its most studied biological activity. Melatonin, as a multifunctional hormone, appears to regulate or modulate other functions in humans through the activation of its receptors and works as a strong antioxidant that protects the DNA. Melatonin's antioxidant activity may reduce Parkinson's disease development, prevent cardiac arrhythmia, and, in animals, promote longevity. Studies on human disease prevention and treatment are more limited and will be a major area of review in this book. Aging involves many changes in our physiology, and only a few are understood. It has been recognized that melatonin levels decline with age and may play a role in many age-related changes. Melatonin is a powerful antioxidant with numerous effects on the metabolism and health of older people. Melatonin has been available as a dietary supplement in the United States since 1993 as well as in Canada and some European countries. In moderate doses, melatonin has routinely been found to be safe, with very low toxicity in animals and humans. There is evidence that melatonin supplementation or level in human affect headaches, fertility, attention deficit–hyperactivity disorder, mood disorders, cancer, gall stones, circadian rhythm disorders (sleep). They help prevent ischemic damage, autism, immune regulation, dreaming, oxidant removal, as well as recent but more limited evidence of roles in other human health conditions. The editor selected researchers with experience in studying the role of melatonin in various disease and physiological states primarily in humans. Thus, this book has a wide variety of expert reviews on the biology of melatonin relevant to health in humans. The editor, Dr. Watson, has done research with melatonin as a modulator of immune function and regulator of AIDS in mice.

Section I reviews key areas of melatonin, including a history of melatonin and its use in various therapies, as well as melatonin and circadian rhythms. The focus of Section II relates to melatonin's action in the prevention of diseases such as cardiovascular diseases, reproductive diseases, solar skin damage, diabetes, immune function, uveitis, and gut function, among others. There are three other sections with clinical potential importance and varying levels of study. The key section, Section III, relates to melatonin's action in the treatment of diseases and physiological disorders such as surgery, bone, breast cancer, gastrointestinal function, reproduction, and pancreas diseases. In some cases, the role of melatonin is still controversial in certain human health conditions, and the researchers define what is known for the various conditions being treated. Section IV describes melatonin in the context of sleep and circadian rhythm regulation. Finally, Section V describes how melatonin's actions on physiological functions in humans focus on the effects of loss of pineal function and the subsequent reduction in melatonin production as well as its replacement as a therapy. These include neuroendocrine effects, inflammation, age-related degeneration, collagen synthesis, vascular structure, DNA protection, oxidation, and traumatic stress, among others. Understanding melatonin is critical, as it is a hormone that is sold over the counter as a dietary supplement and is thus readily available to consumers in many countries.