title: Antioxidative and free radical scavenging activities of pineal indoles.
abstract: The antioxidant action, free radical scavenging activity and pro-oxidant effect of pineal indoles were studied. Serotonin, 5-hydroxytryptophol, 5-methoxytryptophol and 5-methoxytryptamine potently inhibited lipid peroxidation in rat brain, liver and kidney homogenates and hemolysis of rat erythrocytes. 5-Methoxyindole-3-acetic acid and 5-hydroxyindole-3-acetic acid potently suppressed superoxide radical formation. 5-Hydroxytryptophol and 5-hydroxyindole-3-acetic acid inhibited hydroxyl radical generation. Serotonin, 5-hydroxytryptophol and 5-hydroxyindole-3-acetic acid exhibited a pro-oxidant action in the bleomycin-Fe system. This study demonstrated that 5-methoxytryptamine, among the various pineal indoles tested, exhibited the most potent antioxidant action and was devoid of pro-oxidant effect. Serotonin, 5-hydroxytryptophol and 5-methoxytryptophol also had high antioxidative activity. By comparison melatonin had a lower antioxidant potency.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories.
authors.forename: T B
authors.initials: TB
authors.lastname: Ng
authors.forename: F
authors.initials: F
authors.lastname: Liu
authors.forename: L
authors.initials: L
authors.lastname: Zhao
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001921:Brain / Q000201:enzymology; D004912:Erythrocytes / Q000187:drug effects / Q000502:physiology; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006461:Hemolysis / Q000187:drug effects; D007211:Indoles / Q000032:analysis / Q000494:pharmacology*; D007668:Kidney / Q000201:enzymology; D008054:Lipid Peroxides / Q000037:antagonists & inhibitors; D008099:Liver / Q000201:enzymology; D008297:Male; D010870:Pineal Gland / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000975:Antioxidants; D016166:Free Radical Scavengers; D007211:Indoles; D008054:Lipid Peroxides