MELATONIN, IMMUNE MODULATION AND AGING

Melatonin is a hormone secreted by the pineal gland in response to pho toperiods and influences many important biological processes. For one, Melatonin has been shown to produce resistance to cancer and infectio us diseases in aged animals. Studies in animals have demonstrated mela tonin-related mechanisms of action on immunoregulation. Additionally, melatonin has been successfully used in humans, along with interleukin -2, as a treatment of solid tumors. In vivo and in vitro studies show melatonin enhances both natural and acquired immunity in animals. Desp ite all of this intriguing evidence, melatonin's mechanism of action o n the immune system is only partially defined. It does, however, appea r to act through lymphocyte receptors, and perhaps, receptors on other immune tissues, to modulate immune cells. In order to understand immu nomodulation and anti-cancer effects, information on melatonin and it' s interactions with other endocrine hormones are summarized.