Abstract
Melatonin, the primary hormone of the pineal gland, acts as a powerful “chronobiotic,” maintaining normal circadian rhythms. In patients with sleep disorders and exogenously-generated desynchrony of circadian rhythms such as occurs in jet lag, oral administration of melatonin can provide the necessary resynchronization of those cycles, at dosages ranging from 0.3 to 8 mg. Synthesis of melatonin from the amino acid tryptophan has been shown to be decreased by exposure to magnetic fields and by the aging process. Melatonin also possesses potent free radical scavenging properties and has been recognized as exerting direct inhibition of cancer growth. Various cancer types have been shown to be responsive to oral melatonin (10 to 50 mg daily), including breast cancer, non-small-cell lung cancer, metastatic renal cell carcinoma, hepatocellular carcinoma, and brain metastases due to solid tumors. Melatonin has also been reported to lower total cholesterol and LDL levels in rats, and abnormally low melatonin levels have been theorized to be a factor in multiple sclerosis, sudden infant death syndrome, coronary heart disease, epilepsy, and postmenopausal osteoporosis. These reports, while preliminary, serve to further illustrate the wide range of potential effects exerted by melatonin. (Alt Med Rev 1996;1(2):94-102)