Antidiarrheal Activities of the Methanol Leaf Extracts of Olinia rochetiana (Oliniaceae) Against Castor Oil-Induced Diarrhea in Mice

BACKGROUND: Olinia rochetiana has been used traditionally to cure diarrheal disease. Therefore, this study aimed to investigate the acute toxicity and antidiarrheal effect of O. rochetiana leaf extracts. METHODS: Cold maceration was used to extract plant leaf powder with 80% methanol. The extract’s antidiarrheal action was tested against a castor oil-induced diarrheal model, a charcoal meal test, and enteropooling tests at doses of 100, 200, and 400 mg/kg. Negative controls received the vehicle at 10 mL/kg, while positive controls received loperamide at 3 mg/kg. RESULTS: From the study, no apparent toxicity was observed when a single dose of 2000 mg/kg was administered. In the castor oil-induced model, the extract delayed the onset of diarrhea, reduced stool frequency, and decreased wet feces weight and number in a dose-dependent manner at 200 mg/kg (p < 0.05) and 400 mg/kg (p < 0.01). The percent reduction in moist feces at 100, 200, and 400 mg/kg was 54.2, 23.97, and 18.26%, respectively, indicating a significant dose-dependent decrease. In a charcoal meal test, the extracts at 200 and 400 mg/kg revealed a peristaltic index of 65 and 46%, respectively, with considerable inhibition of charcoal transport at 23 and 39%. The weight and volume of intestinal contents dropped significantly at a dose of 400 mg/kg (p < 0.01), which is 0.43 mg/kg, in the enteropooling test when compared with the tested dose. The computed in vivo antidiarrheal index revealed diarrheal inhibition values of 46.06 and 71.06% at 200 and 400 mg/kg, respectively. CONCLUSION: In the current investigation, O. rochetiana showed significant antidiarrheal activity with no symptoms of toxicity in mice.