Melatonin: Circadian Regulation of Biomarkers of Oxidative Stress

Melatonin, released primarily from the pineal gland, controls the 24 hour biological clock. It is now known that melatonin also controls circannual reproductive cycles in animals and plays a role in neuroprotection, tumor-suppression, and immunomodulation. The hormone is also a potent antioxidant. This review is an attempt to document the pleiotropic biological effects of melatonin.