Antidiarrheal activity assessment of Operculina turpethum stem extract and in silico analysis of its compounds

Operculina turpethum is widely known for its use in traditional treatment practices to heal several diseases, such as bronchitis, pectoralgia, arthralgia, diarrhea, obesity, helminthiasis, gastropathy, ascites, sporadic fever, leucoderma, inflammation, pruritis, ulcers, erysipelas, tumors, jaundice, hemorrhoids, and ophthalmia. In this study, the antidiarrheal potential of the ethanolic extract of O. turpethum stem was assessed in an animal model, and molecular docking of previously reported stem-derived compounds was performed to determine the possible mechanism of action. The in vivo antidiarrheal effect was assessed using a castor oil-induced mouse model. In silico molecular docking analysis was performed using the ‘Vina Wizard’ program in PyRx 0.8. The stem extracts at 250 and 500 mg/kg produced significant, dose-dependent antidiarrheal activity. Among the four previously isolated compounds, three (22,23-dihydro-α-spinosterol-ß-D-glucoside, paprazine, and sitogluside) showed satisfactory binding affinity against the target M3 muscarinic acetylcholine receptor, comparable to the reference standard drug loperamide. These findings suggest that the O. turpethum stem has significant potential to prevent diarrhea that warrants further phytochemical, pharmacological, and mechanistic investigations.