Effect of methanolic extract of Cassia nigricans leaves on rat gastrointestinal tract.

The effects of the methanolic extract of Cassia nigricans leaves were investigated on experimentally-induced diarrhoea and ulceration in rat. The extract dose-dependently reduced both the small intestinal propulsive movement (P<0.01-0.001), and castor oil-induced fluid accumulation (P<0.05-0.001). Its inhibitory effects on intestinal propulsive movement and fluid accumulation were significantly (P<0.05) antagonised by yohimbine. However, castor oil-induced diarrhoea was increased. The extract also reduced significantly (P<0.05-0.001) the ulcers induced by both indomethacin and ethanol. The results indicate that the observed antidiarrhoeal effect might in part be due to alpha(2)-adrenoceptor stimulation.