title: Marchantin H as a natural antioxidant and free radical scavenger.
abstract: The antioxidant activity of marchantin H was investigated using various experimental models. Marchantin H inhibited nonenzymatic iron-induced lipid peroxidation in rat brain homogenates with an IC50 value of 0.51 +/- 0.03 microM. It was more potent than desferrioxamine or other classical antioxidants. Marchantin H also suppressed NADPH-dependent microsomal lipid peroxidation with an IC50 value of 0.32 +/- 0.01 microM without affecting microsomal electron transport of NADPH-cytochrome P450 reductase. Marchantin H could scavenge the stable free radical 1,1-diphenyl-2-picrylhydrazyl and peroxyl radical derived from 2,2 '-azobis(2-amidinopropane) dihydrochloride in aqueous phase, but not the peroxyl radical derived from 2,2 '-azobis(2,4-dimethylvaleronitrile) in hexane. The oxygen consumption during peroxyl radical-induced human erythrocyte ghost oxidation was decreased in a concentration-dependent manner by marchantin H. Furthermore, it was reactive toward superoxide anion generated by the xanthine/xanthine oxidase system. On the other hand, marchantin H inhibited copper-catalyzed oxidation of human low-density lipoprotein, as measured by fluorescence intensity, thiobarbituric acid-reactive substance formation, and electrophoretic mobility in a concentration-dependent manner. Our results indicate that marchantin H is a potentially effective and versatile antioxidant and can be used as a chaperone protecting biomacromolecules against peroxidative damage.
authors.affiliation: Pharmacological Institute, College of Medicine, National Taiwan University, Taipei.
authors.forename: G
authors.initials: G
authors.lastname: Hsiao
authors.forename: C M
authors.initials: CM
authors.lastname: Teng
authors.forename: C L
authors.initials: CL
authors.lastname: Wu
authors.forename: F N
authors.initials: FN
authors.lastname: Ko
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D001632:Bibenzyls; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002396:Catechols / Q000737:chemistry / Q000494:pharmacology*; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000378:metabolism; D004988:Ethers, Cyclic; D005231:Fatty Acids, Unsaturated; D005456:Fluorescent Dyes; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology*; D005609:Free Radicals / Q000737:chemistry; D006801:Humans; D066298:In Vitro Techniques; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008077:Lipoproteins, LDL / Q000378:metabolism; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects; D010545:Peroxides / Q000737:chemistry; D010647:Phenyl Ethers / Q000737:chemistry / Q000494:pharmacology*; D010944:Plants; D051381:Rats; D017208:Rats, Wistar; D013481:Superoxides / Q000378:metabolism
chemical_list: D000975:Antioxidants; D001632:Bibenzyls; D002396:Catechols; D004988:Ethers, Cyclic; D005231:Fatty Acids, Unsaturated; D005456:Fluorescent Dyes; D016166:Free Radical Scavengers; D005609:Free Radicals; D008051:Lipid Bilayers; D008077:Lipoproteins, LDL; D010545:Peroxides; D010647:Phenyl Ethers; C102015:marchantin H; D013481:Superoxides; C049375:perhydroxyl radical; C013641:parinaric acid