Antidiarrheal Activity of the Ethanolic Extract of Operculina turpethum Stem and in silico Molecular Docking and ADMET Analysis of Its Isolated Compounds

Background: Operculina turpethum (OT) 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, ophthalmia, etc. In this report, the antidiarrheal potential of the O. turpethum (EEOT) stem was assessed in an animal model along with a molecular docking study of previously isolated compounds to determine the mechanism involved in identifying prospective phytocompounds against diarrhea. Methods: Ethanolic stem extract was used in a mouse model of castor oil-induced in vivo antidiarrheal syndrome. In silico molecular docking analysis was performed using the ‘Vina Wizard’ program in PyRx – Python Prescription 0.8. Results: At 250 and 500 mg/kg, the EEOT stem dose-dependently demonstrated significant differences in antidiarrheal potential. During molecular docking analysis, out of four previously isolated compounds from O. turpethum stem, three (22,23-dihydro-α-spinosterol-ß-D-glucoside, 3-(4-hydroxy-phenyl)-N-[2-(4-hydroxy phenyl)-ethyl]-acrylamide and β-sitosterol-β-D-glucoside) have shown satisfactory binding affinity against the target M3 muscarinic acetylcholine receptor compared with the reference standard drug loperamide. Conclusion: The EEOT stem has significant potential to prevent diarrhea, which can be rationalized by molecular docking analysis, in which secondary plant metabolites were found to bind promisingly to their target receptor.