Evaluation of Antidiarrheal, Antispasmodic, and Antisecretory Activities of Extract and Fractions of Castanopsis costata Leaves in Animal Models

Background: The use of traditional medicinal plants Castanopsis costata in the management of diarrhea is an ancient practice in North Sumatra, Indonesia, but its safety and efficacy have not been examined scientifically in animal models. Therefore, this study aims to determine the antidiarrheal effect of C. costata leaf extract and fractions in vivo. Methods: The antidiarrheal activity was evaluated against animal models of diarrhea induced by castor oil, charcoal meal, and entero-pooling test. The extract group received doses of 25, 50, 100, and 200 mg/kg, while the fraction groups was treated with WFCC, EAFCC, and nHFCC, in doses of 50 and 100 mg/kg, respectively. The negative control received 10 mL/kg of the dissolving vehicle, while the positive was treated with loperamide 3 mg/kg. Results: The results showed that EECC doses of 200 mg/kg, WFCC, and EAFCC at 50 and 100 mg/kg, respectively significantly delayed the onset of diarrhea, while WFCC and EAFCC at 100 mg/kg significantly reduced the amount of wet feces output and total feces output. In addition, only WFCC and EAFCC (at 50 and 100 mg/kg, respectively) significantly reduced the mean weight of wet feces and total feces. The percentage of maximum diarrhea inhibition was observed at the EAFCC dose of 100 mg/kg. Based on the charcoal meal test results, only EAFCC significantly inhibited the distance traveled by charcoal meal and reduced the peristaltic index at a dose of 100 mg/kg, while the percentage decrease in gastrointestinal motility was 46.87%. Similarly, in the entero-pooling test, WFCC and EAFCC significantly reduced the volume and weight of intestinal contents at a dose of 100 mg/kg, respectively. Conclusion: The results confirm that the extract and fractions of C. costata have antidiarrheal activity. Therefore, this study provides scientific support for the traditional use of C. costata in treating diarrhea.