title: Antioxidant activities and xanthine oxidase inhibitory effects of extracts and main polyphenolic compounds obtained from Geranium sibiricum L.
abstract: The antioxidant capacity and xanthine oxidase inhibitory effects of extracts and main polyphenolic compounds of Geranium sibiricum were studied in the present work. The antioxidant capacity was evaluated by ferric reducing antioxidant power, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, superoxide radical scavenging, nitric oxide scavenging, beta-carotene-linoleic acid bleaching, and reducing power assays. Among the extracts and four fractions, the ethyl acetate fraction showed the highest phenolic content (425.36 +/- 9.70 mg of gallic acid equivalent/g extracts) and the best antioxidant activity. The IC(50) values of the ethyl acetate fraction were 0.93, 3.32, 2.06, 2.66, and 1.64 microg/mL in the DPPH radical scavenging, superoxide radical scavenging, nitric oxide scavenging, beta-carotene-linoleic acid bleaching, and reducing power assays, respectively. Of the polyphenolic compounds separated from the ethyl acetate fraction, geraniin showed a higher activity than corilagin and gallic acid. The IC(50) values ranged from 0.87 to 2.53 microM, which were even lower than the positive control (except for allopurinol). All test samples except for the petroleum ether fraction showed xanthine oxidase inhibitory effects. We conclude that G. sibiricum represents a valuable natural antioxidant source and is potentially applicable in the healthy food industry.
authors.affiliation: Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, Harbin 150040, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Wu
authors.forename: Yuangang
authors.initials: Y
authors.lastname: Zu
authors.forename: Yujie
authors.initials: Y
authors.lastname: Fu
authors.forename: Yu
authors.initials: Y
authors.lastname: Kong
authors.forename: Jintong
authors.initials: J
authors.lastname: Zhao
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Li
authors.forename: Ji
authors.initials: J
authors.lastname: Li
authors.forename: Michael
authors.initials: M
authors.lastname: Wink
authors.forename: Thomas
authors.initials: T
authors.lastname: Efferth
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005419:Flavonoids / Q000494:pharmacology*; D031315:Geranium / Q000737:chemistry*; D010636:Phenols / Q000494:pharmacology*; D010936:Plant Extracts / Q000494:pharmacology*; D059808:Polyphenols; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors*
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols; D014969:Xanthine Oxidase