Comparison of the antidiarrheal effects of wood creosote and loperamide inthe rat jejunum and colon in vitro

Wood creosote, a mixture of guaiacol. creosol and related compounds, has Lo ng been used as an antidiarrheal agent. The goal of our study was to invest igate the antisecretory effect of wood creosote and to compare it to the ef fect of loperamide, a synthetic opioid widely used in the treatment of diar rhea, Experiments were performed in rat jejunal and colonic mucosal sheets, mounted in modified Ussing chambers. Active electrogenic transport was mon itored electrically as short circuit current (Isc) and hypersecretory respo nses were induced by acetylcholine (ACh), Neither loperamide nor wood creos ote had any significant effect on basal Ist, when added to the serosal bath ing solution at concentrations of 0.1-50 mu g/ml. In contrast. under hypers ecretory conditions, both agents showed concentration-dependent (0.1-100 mu g/ml) antisecretory effects inhibiting ACh-induced responses in the jejunu m and colon. However, the effects suggest regional differences, with lopera mide being most potent in the jejunum, while wood creosote showed equal pot ency in both jejunum and colon. Based upon these irt vitro findings, we con clude that like loperamide. the antidiarrheal action of wood creosote is du e, at least in part, to its antisecretory activity.