An Overview of Melatonin as an Antioxidant Molecule: A Biochemical Approach

Melatonin is an endogenous hormone derived from tryptophan that is mainly released from the pineal gland in the dark. Melatonin regulates many biological functions such as sleep, circadian rhythm, immunity, and reproduction. Melatonin has a free radical scavenger, anti-inflammatory, and antioxidant effects. It scavenges reactive oxygen and nitrogen species and increases antioxidant defenses, thus it prevents tissue damage and blocks transcriptional factors of pro-inflammatory cytokines. Due to its small size and amphiphilic nature, it increases the efficacy of mitochondrial electron transport chain and reduces electron leakage. Melatonin prevents degenerative changes in the central nervous system in models of Alzheimer’s and Parkinson’s disease and reduces free radical damage to DNA which may lead to cancer and many other situations. Consequently, melatonin has beneficial effects including stimulation of antioxidant enzymes, inhibition of lipid peroxidation, and so it contributes to protection from oxidative damages