Anti-inflammatory and analgesic properties of the ethanolic extract of Cnidoscolus aconitifolius in rats and mice

Abstract

Ethanolic leaf extract of Cnidoscolus aconitifolius was evaluated for analgesic and anti-inflammatory activities. The analgesic activity of the extract was assayed by the formalin-induced paw licking test, acetic acid-induced abdominal writhing and hot plate test, whereas its anti-inflammatory activity was determined by its effects on carrageenan-induced paw edema. The extract of C. aconitifolius prolonged the reaction time of mice to pain in a dose-dependent manner. The optimal analgesic effect of the extract was obtained when the extract was administered 90 min before pain stimulation in the hot plate test. The extract of C. aconitifolius (100 or 200 mg/kg b.w.) inhibited acetic acid-induced irritation of paws of rats comparably with that of indomethacin (10 mg/kg b.w.) and had significantly lower mean number of lickings of paws than the control rats (p<0.05). Carrageenan-induced edema was markedly inhibited (p<0.05) by the extracts (100 and 200 mg/kg b.w.) when compared with control rats. Inhibition of writhing movement in rats administered with the extract was lower (p<0.05) than rats administered with indomethacin but its effect was dose-dependent. Our investigations show that C. aconitifolius possesses significant anti-inflammatory and analgesic activities that should be explored.