Ability of antioxidants to prevent oxidative mutations in Salmonella typhimurium TA102.
An assay for the ability of antioxidants to prevent mutations induced by various oxidants in Salmonella typhimurium TA102 cells was developed. Protection against hydrogen-peroxide-induced mutagenicity was observed for quercetin, caffeic acid, ascorbic acid and dimethyl sulfoxide (used as a solvent for water-insoluble antioxidants). No protective effect was observed for green tea extract (weakly pro-oxidative), catechin, rutin, sinigrin, ferulic acid and alpha-tocopherol. Mutagenicity caused by tert-butyl hydroperoxide (tBOOH) was prevented most effectively by quercetin and ascorbic acid, whereas weaker effects were observed for green tea extract and for rutin, and no effect being observed for the other antioxidants tested. The results for hydrogen peroxide indicate iron chelation to be the most important protective mechanism. Radical scavenging appeared to be effective only with dimethyl sulfoxide and ascorbic acid, which are effective scavengers of hydroxyl radicals and were used here in high concentrations. It is proposed that the hydrogen-peroxide-induced mutations in the Salmonella cells are caused by hydroxyl radicals generated by iron ions closely associated with DNA. Protection against mutagenicity caused by tert-butyl hydroperoxide appears to occur mainly through the scavenging of alkoxyl and possibly of alkyl radicals.
Grey
Carl Elovson
CE
Department of Biotechnology, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden.
Adlercreutz
Patrick
P
D016587:Antimutagenic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology; D002109:Caffeic Acids / Q000494:pharmacology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D016166:Free Radical Scavengers / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology; D017665:Hydroxyl Radical / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D009153:Mutagens / Q000494:pharmacology; D009154:Mutation; D011794:Quercetin / Q000494:pharmacology; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000235:genetics; D020122:tert-Butylhydroperoxide / Q000494:pharmacology
D016587:Antimutagenic Agents; D000975:Antioxidants; D002109:Caffeic Acids; D016166:Free Radical Scavengers; D009153:Mutagens; D017665:Hydroxyl Radical; D020122:tert-Butylhydroperoxide; D011794:Quercetin; D006861:Hydrogen Peroxide; D007501:Iron; D001205:Ascorbic Acid; D004121:Dimethyl Sulfoxide