Analgesic and anti-inflammatory activities of the ethanol extract of the leaves of Helianthus Annus in Wistar rats

摘要

Objective: To investigate the anti-inflammatory and analgesic effects of the ethanol extract of leaves of Helianthus annus L. (H. annus) in acclimatized Wistar rats. Methods: It was undertaken using the albumin induced paw edema model of inflammation as well as both the hotplate and tail immersion analgesic test methods. Doses of the extract tested in experimental rats were 0.5 g/kg, 2 g/kg and 4 g/kg while negative and positive control rats received distilled water and indomethacin respectively. Results: It was shown that treatment with the tested doses of the extract effectively inhibited paw edema induced by egg albumin. This effect was comparable if not better than the observations made in rats treated with 10 mg/kg of indomethacin orally. Treatment with the extract was also observed to have significantly increased the mean tolerance time of rats to thermal noxious stimuli compared to control animals that had distilled water and appeared to be more effective than 10 mg/kg of indomethacin treatment. Conclusions:These observations confirmed the presence of a strong anti-inflammatory and anti-noiciceptive activity in the ethanol extract of the leaves of H. annus and therefore validated the folkloric use of the leaves of this plant in treatment of pro-inflammatory, post traumatic situations.