A new anti-inflammatory flavonol glycoside from Alchornea floribunda leaves

• Published in: Natural product research 2010-02, Vol.24 (3), p.266-273
• Main Authors: Okoye, F.B.C., Osadebe, P.O.
• Format: Article
• Language: English
• Subjects: Alchornea; Alchornea floribunda; Animals; anti-inflammatory; Anti-Inflammatory Agents, Non-Steroidal - chemistry; Anti-Inflammatory Agents, Non-Steroidal - pharmacology; Edema - drug therapy; Euphorbiaceae; Euphorbiaceae - chemistry; flavonol glycoside; Flavonols - chemistry; Flavonols - pharmacology; Glycosides - chemistry; Glycosides - pharmacology; membrane stabilisation; Molecular Structure; Plant Extracts - chemistry; Plant Extracts - pharmacology; Plant Leaves - chemistry; Rats
• ISSN: 1478-6419; 1478-6427
• DOI: 10.1080/14786410902986894

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-α-L-rhamnoside, using a combination of UV, IR, 1D and 2D (COSY) 1 H-NMR spectroscopy. This compound, in part, accounts for the anti-inflammatory effect of A. floribunda leaves.