A new anti-inflammatory flavonol glycoside from Alchornea floribunda leaves.
Alchornea floribunda leaves are widely used in African ethnomedicine for the management of acute and chronic inflammatory disorders. In the present study, bioactivity-guided fractionation of the ethyl acetate fraction of the methanol leaf extract of the plant material led to the isolation of a new flavonol glycoside (AFF1). The anti-inflammatory activity of this novel compound was evaluated using egg albumen-induced rat paw oedema as a model of inflammation. AFF1 showed significant inhibition of the rat paw oedema in a dose-dependent manner. The activity of AFF1 (50 mg kg(-1)) was higher than that of the standard anti-inflammatory drug, aspirin (100 mg kg(-1)). The compound also significantly (p < 0.001) inhibited heat-induced haemolysis of human erythrocytes in vitro. The structure of AFF1 was elucidated as 3,5,7,3'-tetrahydroxyflavone-3-O-alpha-L-rhamnoside, using a combination of UV, IR, 1D and 2D (COSY) 1H-NMR spectroscopy. This compound, in part, accounts for the anti-inflammatory effect of A. floribunda leaves.
Okoye
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Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Nigeria, Nsukka, 410001 Enugu State, Nigeria. basdenc@yahoo.com
Osadebe
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D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000737:chemistry / Q000494:pharmacology*; D004487:Edema / Q000188:drug therapy; D019665:Euphorbiaceae / Q000737:chemistry*; D044948:Flavonols / Q000737:chemistry / Q000494:pharmacology*; D006027:Glycosides / Q000737:chemistry / Q000494:pharmacology*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry*; D051381:Rats
D000894:Anti-Inflammatory Agents, Non-Steroidal; D044948:Flavonols; D006027:Glycosides; D010936:Plant Extracts