title: Antioxidant activity of some polyphenol constituents of the medicinal plant Phyllanthus amarus Linn.
abstract: Phyllanthus amarus Linn is a widely distributed tropical medicinal plant highly valued for its therapeutic properties. The antioxidant activity of some of its principal constituents, namely amariin, 1-galloyl-2,3-dehydrohexahydroxydiphenyl (DHHDP)-glucose, repandusinic acid, geraniin, corilagin, phyllanthusiin D, rutin and quercetin 3-O-glucoside were examined for their ability to scavenge free radicals in a range of systems including 2,2-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azobis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS)/ferrylmyoglobin, ferric reducing antioxidant power (FRAP) and pulse radiolysis. In addition, their ability to protect rat liver mitochondria against oxidative damage was determined by measuring the ROO* radical induced damage to proteins and lipids and *OH radical induced damage to plasmid DNA. The compounds showed significant antioxidant activities with differing efficacy depending on the assays employed. Amariin, repandusinic acid and phyllanthusiin D showed higher antioxidant activity among the ellagitannins and were comparable to the flavonoids, rutin and quercetin 3-O-glucoside.
authors.affiliation: Department of Zoology, University of Pune, Pune, India.
authors.forename: Jayant S
authors.initials: JS
authors.lastname: Londhe
authors.forename: Thomas P A
authors.initials: TP
authors.lastname: Devasagayam
authors.forename: L Yeap
authors.initials: LY
authors.lastname: Foo
authors.forename: Saroj S
authors.initials: SS
authors.lastname: Ghaskadbi
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D005260:Female; D005419:Flavonoids / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects; D008930:Mitochondria, Liver / Q000187:drug effects; D010636:Phenols / Q000494:pharmacology*; D029803:Phyllanthus / Q000737:chemistry*; D010957:Plasmids / Q000187:drug effects; D059808:Polyphenols; D050050:Protein Carbonylation / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D016166:Free Radical Scavengers; D010636:Phenols; D059808:Polyphenols