Antidiarrheal activity of some selected Nigerian plants used in traditional medicine

Context: Herbal preparations of the various parts of Vitellaria paradoxa, Neorautanenia mitis, Senna surattensis, and Hydnora abyssinica have been used in the Nigerian traditional medical practice to treat the symptoms of diarrhea in humans and animals. Aims: This study aims to validate claims of the traditional use of these plants in the treatment of diarrhea and provide a scientific basis for further studies. Materials and Methods: The median lethal dose (LD50) values of the extracts were obtained using the Limit test. Castor oil induced diarrhea and intestinal transit (motility) models in albino rats were used to determine the antidiarrheal activity. Graded doses of the extracts were administered to 3 test groups, while the positive control groups were given standard drugs (atropine and loperamide) and the negative control groups received distilled water per os. Results: The LD(50)was considered higher than 2000 mg/Kg for all the extracts. In the castor oil-induced diarrhea model, the highest percentage inhibition of defecation was observed in the test groups treated with the extracts of H. abyssinica (82%) followed by S. surattensis (81%), N. mitis (66%), and V. paradoxa (32%). H. abyssinica extract significantly decreased the intestinal transit of charcoal meal compared to the other extracts. Conclusion: The antidiarrheal activities of all the extracts give credence to their traditional use. H. abyssinica comparatively had the best antidiarrheal activity and has the potential as an antidiarrheal agent. Thus, the need for further studies of this extract to investigate active fractions, isolate and characterize active compounds, and determine their activities and safety.