Melatonin: detoxification of oxygen and nitrogen-based toxic reactants.
In the last decade, melatonin has been found to be highly protective against damage to macromolecules resulting from oxygen and nitrogen-based reactants. Considering this, numerous studies have examined the mechanisms whereby this indoleamine directly detoxifies these damaging agents. The evidence is compelling that melatonin scavenges several oxygen-derived reactive agents including the hydroxyl radical (OH), hydrogen peroxide (H2O2), singlet oxygen (1O2) and hypochlorous acid (HOCl). Additionally, melatonin reportedly reacts with nitric oxide (NO), the peroxynitrite anion (ONOO-) and/or peroxynitrous acid (ONOOH) to detoxify them. In some cases the products that are formed as a consequence of melatonin's scavenging actions have been identified. Whereas the ability of melatonin to neutralize these toxic agents likely accounts, in part, for the antioxidant activity of melatonin, it is not the only means by which melatonin serves to protect molecules from oxygen and nitrogen-based reactive metabolites.
Reiter
Russel J
RJ
Department of Cellular and Structural Biology, The University of Texas Health Science Center, San Antonio, Texas 78229-3900, USA. reiter@uthscsa.edu
Tan
Dun-Xian
DX
Manchester
Lucien C
LC
Lopez-Burillo
Silvia
S
Sainz
Rosa M
RM
Mayo
Juan C
JC
D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D004249:DNA Damage; D016166:Free Radical Scavengers / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D008550:Melatonin / Q000378:metabolism*; D026361:Reactive Nitrogen Species / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*
D000975:Antioxidants; D016166:Free Radical Scavengers; D026361:Reactive Nitrogen Species; D017382:Reactive Oxygen Species; D008550:Melatonin