Antidiarrhoeal activity of aqueous extract of Mangifera indica L. leaves in female albino rats

Ethnopharmacological relevance: Mangifera indica L leaves have a long history of indigenous use, as an antidiarrhoeal agent among others, without any scientific study that has substantiated or refuted this claim. Therefore, the aims of this study were to determine the secondary metabolites in the aqueous extract of Mangifera indica leaves and its acclaimed antidiarrhoeal activity in rats. Materials and methods: The aqueous leaf extract of Mangifera indica was screened for its constituent secondary plant metabolites. In each of the diarrhoeal models, female albino rats were assigned into 5 groups (A, B, C, D and E) containing five animals each such that rats in groups A and B were the positive and negative controls respectively while those in groups C, D and E received 25, 50 and 100 mg/kg body weight of the extract respectively in addition to specific requirements of the model. Results: The extract contained alkaloids (4.20 mg/g), flavonoids (13.60 mg/g), phenolics (1.50 mg/g) and saponins (3.10 mg/g) while tannins, anthraquinones, cardiac glycosides and steroids were not detected. In the castor oil-induced diarrhoeal model, the onset time of diarrhoea was significantly prolonged by the 25 and 50 mg/kg body weight whereas there was no episode in the 100 mg/kg body weight treated animals. The extract (25 and 50 mg/kg body weight) decreased the number, water content, fresh weight and total number of wet feaces and increased the inhibition of defecations. All the doses of the extract significantly increased the Na+ -K+ ATPase activity in the small intestine. The extract dose dependently decreased the masses and volume of intestinal fluid with corresponding increase in inhibition of intestinal fluid content in the castor oil-induced enteropooling model. The extract also reduced the distance travelled by charcoal meal in the 30 min gastrointestinal transit model. All these changes were similar to the reference drugs with the 100 mg/kg body weight of the extract exhibiting the most profound antidiarrhoeal activity. Conclusion: The study concluded that the aqueous extract of Mangifera indica leaves possess antidiarrhoeal activity in chemical induced diarrhoeal models and thus justifies its age long folkloric use in managing diarrhoea. The presence of alkaloids, flavonoids, phenolics, saponins and enhancement of Na+ -K+ ATPase activity might play roles in the antidiarrhoeal activity of the plant extract. (C) 2015 Elsevier Ireland Ltd. All rights reserved.