Evaluation of anti-inflammatory activity of Vitex agnus

Vitex agnus-castus L., (Verbenaceae) traditional Chinese medicinal plant recommended for various inflammatory ailments, but its mechanism of anti-inflammatory action is still unclear. The present study reports the anti-inflammatory activities of various extracts and elucidate possible mechanism(s) with the quantification of flavonoids by RP-HPLC. The petroleum ether, ethyl acetate, methanol and aqueous extracts obtained by successive solvent extraction from Vitex agnus castus leaves were subjected to standard acute, subacute and chronic models of inflammation at 200 and 400 mg/kg. Further, in vitro cytokine release estimation (IL-6 and TNF-α) using ELISA and the identification and quantification of major constituents with the RP-HPLC was done. All extracts (200 and 400 mg/kg) produced significant inhibition while methanol extract (400 mg/kg) caused a maximum inhibition of 43% in paw edema, 75% inhibition in subacute and 59.28% inhibition in the chronic inflammation model. Methanol extract (400 mg/kg) showed 77.87% and 63.34% decline in the IL-6 and TNF-α levels respectively. Kaempferol (0.24%) and luteolin (0.12%) were quantified in a bioactive methanol extract using HPLC analysis. It was concluded that the anti-inflammatory activity might be due to flavonoids in the extracts and plant regulates the inflammation by a significant decrease of TNF-α and IL-6 by macrophages, which mediates crucial events for the initiation. Information revealed that the methanol extract of Vitex agnus castus leaves can be used as effective anti-inflammatory agent.