The leaves of the plants Daniellia oliveri (Fabaceae) and Ficus sycomorus (Moraceae) used in diarrhea treatment in Hausa ethnomedicine of Northern Nigeria were investigated. The study was carried out on perfused isolated rabbit jejunum and castor oil-induced diarrhea in mice. The n-butanol extracts: NBD and NBF (0.16-3.2 mg/ml) caused a dose-dependent relaxation of isolated rabbit jejunum. The acute toxicity test for NBD and NBT in mice established an i.p LD(50) of > 4000 mg/kg for D. oliveri and 1131.4 mg/kg for F. sycomorus. In castor oil-induced diarrhea, 80% protection was observed for D. oliveri at doses of 200 mg/kg and 60% protection was observed at 100 mg/kg and 50 mg/kg respectively. For F. sycomorus 100% protection was observed at doses of 120 mg/kg and 60 mg/kg, for the n-butanol extract. The antidiarrheal activity was comparable to loperamide 5 mg/kg. The result revealed that the extracts have pharmacological activity against diarrhea.
Keywords: Anti-diarrhea; castor oil; n-butanol extracts; tissue relaxation.