Analgesic and antiinflammatory activity of kaur-16-en-19-oic acid from Annona reticulata L. bark.

Kaur-16-en-19-oic acid was isolated from the bark of Annona reticulata and studied for its analgesic and antiinflammatory activity. Analgesic activity was assessed using the hot plate test and acetic acid-induced writhing, and the antiinflammatory activity using the carrageenan induced rat paw oedema method. Kaur-16-en-19-oic acid, at doses of 10 and 20 mg/kg, exhibited significant (p < 0.05) analgesic and antiinflammatory activity. These activities were comparable to the standard drugs used, and furthermore the analgesic effect of kaur-16-en-19-oic acid was blocked by naloxone (2 mg/kg) in both analgesic models.