Anti-Inflammatory and Antinociceptive Activity of Pavonia zeylanica Linn

Pavonia zeylanica Linn. (Family: Malvaceae) commonly known as Sittramutti (Tamil) is an herb distributed in the tropical and sub-tropical regions of the world, and also found abundantly in India. It has considerable reputation as a potent medicament in the treatment of various ailments such as inflammation, fever and toothache. The antiinflammatory effect of the leaves of P. zeylanica, was evaluated using carrageenan induced paw oedema and cotton pellet induced granuloma (chronic) in rat models. The extract was also evaluated by hot plate and acetic acid induced abdominal constriction assay to assess analgesic activity. The alcoholic extract of P. zeylanica (AEPZ) exhibited significant (P < 0.01) anti-inflammatory effect at the dose 50, 100 and 200 mg/kg. Maximum inhibition 46.16 % was noted at the dose of 200 mg/kg after 3 h of drug treatment in carrageenan induced paw oedema, whereas the Indomethacin 10 mg/kg (standard drug) produced 65.38 % of inhibition. In the chronic model (cotton pellet induced granuloma) the AEPZ (200 mg/kg) and standard drug showed decreased formation of granuloma tissue by 40.30 % and 67.20 % (P < 0.01) respectively. The extract also found to possess antinociceptive activity against acetic acidinduced writhing and hot plate reaction in mice. In acetic acid-induced abdominal constriction assay ) the AEPZ (200 mg/kg) and standard drug aspirin showed reduction in abdominal constriction by 47.64% and 62.38% (P < 0.01) respectively.Thus, the present study revealed that the alcoholic extract of P. zeylanica exhibited significant antinociceptive and anti-inflammatory activity in the tested models.