ANALYSIS OF THE GASTROINTESTINAL RELAXING EFFECT OF THE STEM EXTRACT OF GONGRONEMA-LATIFOLIUM

Aqueous extract of the stem of Gongronema latifolium was screened for effects on the gastrointestinal tract of rats and mice. On the isolate d rat intestine, the extract (5-80 mu g) evoked reproducible and conce ntration-related relaxation which were attenuated by yohimbine and phe noxybenzamine. Intraperitoneal (i.p.) administration of the extract in mice significantly reduced small intestinal transit dose-dependently. This effect was also attenuated by yohimbine and phenoxybenzamine, bu t not prazosin and propranolol. Phytochemical analysis revealed the pr esence of some bioactive constituents, while the i.p. LD(50) value of the extract in mice was established as 1678.63 +/- 78 mg/kg. The resul ts suggest the involvement of the alpha(2)-adrenoceptors in the effect of the extract on the intestinal function.