The acetic acid-induced writhing test was evaluated according to procedures reported previously (13 – 15). The experimental animals were randomly divided into control, positive control and test groups with six mice in each group. The animals of test groups received test substance at the doses of 250 and 500 mg/kg body weight, positive control group was administered diclofenac sodium at the dose of 25 mg/kg of body weight and vehicle control group was treated with 1% Tween 80 in water at the dose of 10 ml/kg body weight orally 30 min before intraperitoneal administration of 0.6% acetic acid. After an interval of five minutes, the mice were observed for specific contraction of body referred as ‘writhing’ for 30 min. The percent inhibition of writhing was measured using the formula, Percent inhibition of writhing = (1-Wt/Wc) x 100