In vivo antidiarrheal activity of the crude extract and solvent fractions of Rhamnus prinoides (Rhamnaceae) leaves

BACKGROUND: Even though numerous conventional anti-diarrheal agents are available, the inherent toxicities of the drugs urge the search for alternative drugs that are safe and effective. OBJECTIVE: To evaluate the in-vivo anti-diarrheal activity of crude extract and solvent fractions of Rhamnus prinoides leaves. MATERIALS AND METHODS: The Rhamnus prinoides leaves were macerated using absolute methanol and then fractionated using solvents of different polarity indexes. For in-vivo antidiarrheal activity evaluation of the crude extract and solvent fraction, castor oil-induced diarrhea, castor oil-induced anti-enteropolling, and intestinal transit models were used. One-way analysis of variance was used to analyze the data, followed by a Tukey post-test. The standard and negative control groups were treated with loperamide and 2% tween 80 respectively. RESULTS: A significant (p˂0.01) reduction in the frequency of wet stools and watery content of diarrhea, intestinal motility, intestinal fluid accumulation, and delaying the onset of diarrhea as compared with controls were observed in mice treated with 200 mg/kg and 400 mg/kg methanol crude extract. However the effect increased dose-dependently, and the 400 mg/kg methanol crude extract produced a comparable effect with the standard drug in all models. Amongst the solvent fractions, n-BF significantly delayed the time of diarrheal onset and reduced the frequency of defecation, and intestinal motility at doses of 200 mg/kg and 400 mg/kg. Furthermore, the maximum percentage inhibition of intestinal fluid accumulation was observed in mice treated with 400 mg/kg n-butanol extract (p˂0.01; 61.05%). CONCLUSIONS: The results of this study showed that crude extract and solvent fractions of Rhamnus prinoides leaves showed a significant anti-diarrheal activity which supports its traditional use as a diarrhea treatment.