In Vivo Antidiarrheal Potential of the Leaf Extract of Maytenus addat (Loes.) Sebsebe and Its Major Compound

Diarrhea continues to be one of the top causes of death in children under the age of five, particularly in developing nations. In Ethiopian traditional medicine, a variety of medicinal plants are used to treat diarrhea. One of these plants is Maytenus addat (Loes.) Sebsebe (fam. Celastraceae), which is endemic to the Afromontane forests, especially along forest margins, of Ethiopia. The air-dried powdered leaves of M. addat were macerated with 80% methanol to yield a crude extract. Additionally, the powdered plant material underwent sequential solvent extraction using chloroform, methanol, and water to obtain solvent fractions. The 80% methanol leaf extract, solvent fractions, and an isolated compound from M. addat were evaluated for their antidiarrheal activity using castor oil-induced diarrheal model, anti-enteropooling test, and charcoal meal test in mice. The results showed that the 80% methanolic leaf extract significantly reduced the onset of diarrhea, the weight of feces, and the frequency of defecation in all the tested doses. The methanol and water fractions of the hydroalcoholic extract also exhibited dose-dependent antidiarrheal activity, with the methanol fraction showing the highest activity at 400 mg/kg dose. Subsequently, the most active methanol fraction was subjected to C-18 solid phase extraction, resulting in the isolation of a 3-hydroxyflavone, identified as quercetin by ESI-qToF-MS, ¹H, and ¹³C-NMR spectroscopic techniques. Quercetin demonstrated a strong antidiarrheal activity in a dose-dependent manner. Thus, the present study provided evidence that the leaves of M. addat possess genuine antidiarrheal activity upholding the traditional medicinal use of the plant for the treatment of diarrhea. The findings also suggest that quercetin is responsible, in full or in part, for the activity of the plant.