Title:Cyclic-3-hydroxymelatonin (C3HOM), A Potent Antioxidant, Scavenges Free Radicals and Suppresses Oxidative Reactions
Volume: 21
Issue: 13
Author(s): Dun-Xian Tan, R. Hardeland, L.C. Manchester, A. Galano and R.J. Reiter
Affiliation:
Keywords:
Antioxidant, cyclic-3-hydroxymelatonin, cytochrome C, free radical chemiluminescence, melatonin.
Abstract: Cyclic 3-hydroxymelatonin (C3HOM) is an immediate product of melatonin’s interaction with reactive oxygen
species. Its presence has been detected in mice, rats and humans. In the current study, the antioxidant capacity and reducing
power of this molecule have been systematically studied. C3HOM is found to be a more potent antioxidant than melatonin
or vitamin C in terms of its ability to scavenge the hydroxyl radical (HO.) and to recover oxidized horseradish peroxidase
to its ground state. The antioxidative mechanism of C3HOM is similar to that of the classic antioxidant, vitamin
C, rather than to its precursor melatonin. C3HOM effectively prevents the oxidative degradation of cytochrome C induced
by hydrogen peroxide (H2O2). It is speculated that some antioxidative activities of melatonin may be mediated by its metabolite,
C3HOM. C3HOM prevents mitochondrial cytochrome C injury and, thus, it is likely to inhibit cellular apoptosis
induced by the release of oxidized cytochrome C from mitochondria.