title: Actions of melatonin in the reduction of oxidative stress. A review.
abstract: Melatonin was discovered to be a direct free radical scavenger less than 10 years ago. Besides its ability to directly neutralize a number of free radicals and reactive oxygen and nitrogen species, it stimulates several antioxidative enzymes which increase its efficiency as an antioxidant. In terms of direct free radical scavenging, melatonin interacts with the highly toxic hydroxyl radical with a rate constant equivalent to that of other highly efficient hydroxyl radical scavengers. Additionally, melatonin reportedly neutralizes hydrogen peroxide, singlet oxygen, peroxynitrite anion, nitric oxide and hypochlorous acid. The following antioxidative enzymes are also stimulated by melatonin: superoxide dismutase, glutathione peroxidase and glutathione reductase. Melatonin has been widely used as a protective agent against a wide variety of processes and agents that damage tissues via free radical mechanisms.
authors.affiliation: Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA. Reiter@uthscsa.edu
authors.forename: R J
authors.initials: RJ
authors.lastname: Reiter
authors.forename: D X
authors.initials: DX
authors.lastname: Tan
authors.forename: C
authors.initials: C
authors.lastname: Osuna
authors.forename: E
authors.initials: E
authors.lastname: Gitto
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology; D004798:Enzymes / Q000378:metabolism; D016166:Free Radical Scavengers / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D008550:Melatonin / Q000378:metabolism / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects*; D010100:Oxygen / Q000378:metabolism / Q000633:toxicity; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000975:Antioxidants; D004798:Enzymes; D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D008550:Melatonin; D010100:Oxygen