title: Mechanism of antioxidant action of pueraria glycoside (PG)-1 (an isoflavonoid) and mangiferin (a xanthonoid).
abstract: The antioxidant activities of pueraria glycoside (PG)-1 (isoflavonoid) and mangiferin (xanthonoid) were studied and compared with PG-3 and daidzein (isoflavonoids) and with wogonin (flavonoid). PG-1 and mangiferin rapidly scavenged 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, and inhibited lipid peroxidation which was initiated enzymatically by reduced nicotinamide adenine dinucleotide phosphate (NADPH) or non-enzymatically by ascorbic acid or Fenton's reagent (H2O2 + Fe2+) in rat liver microsomes. Wogonin inhibited the enzymatically induced lipid peroxidation but had no scavenging effect on DPPH radical or on the non-enzymatic peroxidation. PG-3 and daidzein did not show any of these effects. Formation of Fe2+ by NADPH-dependent cytochrome P-450 reductase was inhibited by wogonin, but not by PG-1 or mangiferin. PG-1 and mangiferin had no effect on terminating radical chain reaction during the lipid peroxidation in the enzymatic system of microsomes or in the linoleic acid hydroperoxide-induced peroxidation system. These results suggest that PG-1 and mangiferin have an antioxidant activity, probably due to their ability to scavenge free radicals involved in initiation of lipid peroxidation. In contrast, wogonin may affect NADPH-dependent cytochrome P-450 reductase action, since it inhibited only the enzymatically induced lipid peroxidation.
authors.affiliation: Department of Biochemistry, Kyoto Pharmaceutical University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Sato
authors.forename: A
authors.initials: A
authors.lastname: Kawamoto
authors.forename: A
authors.initials: A
authors.lastname: Tamura
authors.forename: Y
authors.initials: Y
authors.lastname: Tatsumi
authors.forename: T
authors.initials: T
authors.lastname: Fujii
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001578:Benzopyrans / Q000737:chemistry / Q000494:pharmacology*; D015764:Bepridil / Q000031:analogs & derivatives / Q000737:chemistry; D001713:Biphenyl Compounds; D005419:Flavonoids / Q000737:chemistry*; D016166:Free Radical Scavengers; D005960:Glucosides / Q000737:chemistry / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D007529:Isoflavones / Q000737:chemistry; D015227:Lipid Peroxidation / Q000187:drug effects*; D008862:Microsomes, Liver / Q000378:metabolism; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism; D010851:Picrates; D051381:Rats; D013329:Structure-Activity Relationship; D014966:Xanthenes / Q000737:chemistry / Q000494:pharmacology*; D044004:Xanthones
chemical_list: D000975:Antioxidants; D001578:Benzopyrans; D001713:Biphenyl Compounds; C045076:Fenton's reagent; D005419:Flavonoids; D016166:Free Radical Scavengers; D005960:Glucosides; D007529:Isoflavones; D010851:Picrates; D014966:Xanthenes; D044004:Xanthones; C075169:pueraria glycoside; C013592:mangiferin; C004742:daidzein; D015764:Bepridil; D006861:Hydrogen Peroxide; C004931:1,1-diphenyl-2-picrylhydrazyl; D007501:Iron; D009251:NADPH-Ferrihemoprotein Reductase