title: Inhibition of malonaldehyde formation in oxidized calf thymus DNA with synthetic and natural antioxidants.
abstract: Calf thymus DNA was oxidized by Fenton's reagent with or without synthetic antioxidants (Trolox and DMPO) and natural antioxidants-quercetin, apigenin, 2''-O-glycosylisovitexin (2''-O-GIV), (+)-catechin, cyanidin, pelargonidin, keracyanin, and callistephin. Malonaldehyde (MA) formed in oxidized DNA was analyzed using gas chromatography. MA formed from oxidized DNA without antioxidants was 4.0 +/- 0.53 nmol/mg of DNA in buffer solution, 3.7 +/- 0.34 nmol/mg of DNA in NaOH solution, and 4.6 +/- 0.19 nmol/mg of DNA in HCl solution. MA formed from DNA with antioxidants (at the level of 0.1 micromol/mL) ranged from 1.90 +/- 0.18 (catechin) to 4.10 +/- 0.18 nmol/mg of DNA (cyanidin). Trolox and DMPO inhibited MA formation from DNA by 41.2% and 18.6%, respectively, at the level of 0.1 micromol/mL. Trolox (water-soluble vitamin E) exhibited dose-dependent inhibition. The decreasing order of inhibitory effect by flavonoids at the level of 0.1 micromol/mL was catechin (48.5%) > quercetin (47.1%) > 2''-O-GIV (40.5%) > apigenin (29.9%) and by the anthocyanins at the level of 0.1 micromol/mL was callistephin (45%) > keracyanin (33.2%) > pelargonidin (25.1%) > cyanidin (10.2%).
authors.affiliation: Department of Environmental Toxicology, University of California-Davis, One Shields Avenue, Davis, California 95616, USA.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsufuji
authors.forename: Takayuki
authors.initials: T
authors.lastname: Shibamoto
mesh_terms: D000818:Animals; D000872:Anthocyanins / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology*; D002417:Cattle; D002839:Chromans / Q000494:pharmacology; D002849:Chromatography, Gas; D004247:DNA / Q000737:chemistry* / Q000187:drug effects*; D005419:Flavonoids / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D008315:Malondialdehyde / Q000032:analysis / Q000737:chemistry*; D010084:Oxidation-Reduction; D013950:Thymus Gland / Q000737:chemistry
chemical_list: D000872:Anthocyanins; D000975:Antioxidants; D002839:Chromans; C045076:Fenton's reagent; D005419:Flavonoids; D008315:Malondialdehyde; D004247:DNA; D006861:Hydrogen Peroxide; D007501:Iron; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid