EVALUATION OF ANTIDIARRHEAL ACTIVITY OF 80% METHANOLIC STEM BARK EXTRACT OF TERMINALIA BROWNII FRESEN (COMBRETACEAE)

Abstract

Terminalia brownii is a medicinal plant traditionally used in Africa to manage diarrhea. Despite its ethnomedicinal significance, the safety and efficacy of its extracts remain underexplored in preclinical studies. This study aimed to evaluate the antidiarrheal properties and acute toxicity of an 80% methanolic stem bark extract of Termination brownii to bridge this scientific gap. The antidiarrheal activity of the 80% methanolic extract of Terminalia brownii was assessed using three models: the castor oil-induced diarrheal model, charcoal meal test, and enteropooling test in mice. Negative controls were treated with distilled water (10 mL/kg, oral), Test groups received the extract orally at doses of 100, 200, and 400 mg/kg. while positive controls received loperamide hydrochloride (3 mg/kg, oral). The extract delayed the onset of diarrhea and reduced the number and weight of wet feces, as well as total fecal weight, in a dose-dependent manner in the castor oil-induced diarrhea model. The diarrheal inhibition percentages were 28%, 53.42%, and 74.12% at doses of 100 mg/kg, 200 mg/kg, and 400 mg/kg, respectively, demonstrating a substantial dose-dependent increase in efficacy.The extract at 200 and 400 mg/kg demonstrated peristaltic indices of 54.5% and 37.3%, respectively, alongside significant inhibition of charcoal transit (39.5% and 58.9%) in the charcoal meal test. In the enteropooling test, the 400 mg/kg dose significantly reduced intestinal content weight and volume to 0.29 g and 0.24 mL, respectively, comparable to the loperamide-treated group (0.28 g and 0.22 mL). The in vivo antidiarrheal index revealed diarrhea inhibition values of 20.87%, 56.06%, and 86.81% for the extract (100, 200, and 400 mg/kg, respectively) and 92.77% for loperamide (3 mg/kg). This study demonstrated that the 80% methanolic stem bark extract of Terminalia brownii has significant antidiarrheal effects, validating its traditional use. The mechanism of action and long-term toxicity remain uncharacterized. Future studies should isolate bioactive compounds, assess chronic toxicity, and conduct clinical trials to confirm human efficacy. They should also focus on elucidating the mechanism of action behind the antidiarrheal effect.