Anti-inflammatory and analgesic activities of the aqueous extract of Acacia karroo stem bark in experimental animals.

The aqueous extract of the stem bark of Acacia karroo Hayne was investigated for its anti-inflammatory and analgesic activities in animal models. The extract at 100 and 200 mg/kg reduced significantly the formation of oedema induced by carrageenan and histamine. In the acetic acid-induced writhing model, the extract showed a good analgesic effect characterized by a significant reduction in the number of writhes with two doses (100 and 200 mg/kg) used when compared to the untreated control group. In the tail immersion test, the extract at the doses used (100 and 200 mg/kg) increased reaction time to pain after 30 min. of oral administration of the extract. Indomethacin at 10 mg/kg served as reference drug in all these tests. The results gave a scientific basis to the traditional uses of Acacia karroo mainly for wound poultices, eye treatments and cold remedies.