Anti-inflammatory activity of extracts and compounds from Vitex negundo

The antiinflammatory activity of the leaf extract of Vitex negundo was investigated on topical administration using the TPA (tetradecanoylphorbol acetate) -induced mouse ear inflammation model. The crude methanolic extract of V. negundo showed moderate inhibition (74%) at a dose of 2 mg per ear. The methanol extract was then subjected to liquid-liquid fractionation with petroleum ether, chloroform, ethyl-acetate and ethanol. Bioassay-guided chromatographic fractionation of these fractions led to the isolation of 3,4-dihydroxybenzoic acid as the bioactive principle responsible for the anti-inflammatory activity. The structures of the pure compounds were elucidated using various spectroscopic techniques.