Effect of Aqueous Ethanol Stem Extract of Entada africana Guill. Et Perrott. on Castor Oil and Magnesium Sulphate-Induced Diarrhoea Models in Mice

Abstract

This study investigated the phytochemical, elemental analysis, acute toxicity study of aqueous ethanol stem bark extract of Entada africana, as well as its antidiarrhoeal activity in mice and its effects on isolated rabbit jejunum. The preliminary phytochemical screening revealed the presence of alkaloids, flavonoids, cardiac glycosides, phenols, saponins, steroids, tannins and terpenoids. Elemental analysis of the extract showed the presence of magnesium (Mg), manganese (Mn), iron (Fe), copper (Cu), lead (Pb), zinc (Zn) and sodium (Na) while acute toxicity study revealed intraperitoneal median lethal dose (LD50) values for the extract to be 774.6 mg/kg body weight. The antidiarrheal effect of the extract was studied using castor-oil and magnesium sulphate induced diarrhoeal models (dropping test) and gastrointestinal transit test in mice. The result showed that the extract produced a dose-dependent protection against diarrhoea induced by castor oil and magnesium sulfate, with the highest protection (80 and 100%), obtained at 100 and 200 mg/kg. The extract significantly (p≤0.01) reduced the small intestinal transit of charcoal meal in mice at all doses tested. The extract (0.4-3.2 mg/ml) produced a concentration dependent relaxation of the rabbit jejunum, and the effects were blocked by propranolol (0.04 and 0.64 μg/ml). The results of this study showed that the extract contain pharmacologically active substance with antidiarrhoeal properties mediated through inhibition of hyper secretion and reduced gastrointestinal motility. These properties may explain the rationale for use of it’s stem bark as antidiarrhoeal remedy in traditional medicine.