Studies on the anti-inflammatory and analgesic activity of Curatella americana L

Curatella americana L. (Dilleneaceae) popularly known as 'cajueiro-bravo' and 'sambaiba' is used in Brazilian folk medicine for the treatment of inflammation and ulcer. The anti-inflammatory and analgesic tests were conducted with the hydroalcoholic extract (HAE) of the bark of the plant. The HAE inhibited mouse ear oedema induced by o-tetradecanoyl phorbol acetate (TPA) and by capsaicin. While the ID50 values obtained for the HAE against these two irritants were 40.8 +/- 1.7 and 30 +/- 1.2 mg/kg i.p. (mean +/- S.E.M., n = 6), respectively, the corresponding value for carrageenan induced paw oedema (3 h) was 21.8 +/- 2.1 mg/kg, i.p., n = 6. In the established adjuvant-induced arthritis model, the HAE significantly inhibited the oedema in daily doses of 50 mg/kg, i.p. (n = 10). The HAE also inhibited acetic acid-induced writhing (ID50 23.2 +/- 0.8 mg/kg, i.p., n = 6) and the formalin-induced late phase paw licking response (ID50 11.9 +/- 1.2 mg/kg, i.p., n = 10) in the mice. However, the HAE was inactive in the formalin-induced initial paw licking response in mice or heat induced tail flick response in rats. The HAE has shown both anti-inflammatory and peripheral analgesic activities when administrated in the mouse by the intraperitoneal route in doses which are at least 12 times lower than its LD50 dose of 647 mg/kg, i.p.