Melatonin is a hormone of the pineal gland. Hormone; mediates photoperiodicity in mammals; inhibits cerebellar nitric oxide synthetase; peroxynitrite scavenger. Melatonin has complex effects on apoptotic pathways, inhibiting apoptosis in immune cells and neurons but enhancing apoptotic cell…

An indoleamine neurohormone whose levels vary in a daily cycle, thereby allowing the entrainment of the circadian rhythms of several biological functions in animals, plants, and microbes; acts as a powerful antioxidant that protects lipids, proteins, and DNA against oxidative damage.