Effect of ethanol extracts of three Chinese medicinal plants with anti-diarrheal properties on ion transport of the rat intestinal epithelia.

Effects of ethanol extracts of three Chinese medicinal plants, namely, Qinpi (Fraxini cortex), Kushen (Sophora flavescens, AITON), and Huanglian (Coptis teeta, WALLICH), on ion transport of the rat intestinal epithelia were determined in this study. Rat intestinal epithelia mounted in an Ussing chamber attached to a voltage/current clamp were used for measuring changes in the short circuit current across the epithelia. Activation of the intestinal epithelia by serosal administration of 5 microM forskolin resulted in an increase in basal short circuit current. The ethanol extracts of each of the three plants partially reduced the current stimulated by forskolin. In the following experiments, ouabain and bumetanide were added prior to adding the ethanol extract of these plants for revealing their effect on Na(+) and Cl(-) movement. The results suggest that the ethanol extract of the Qinpi would affect Cl(-) transport. On the contrary, the ethanol extract of Kushen would affect Na(+) transport rather than Cl(-) movement. This study provides evidences that reveal the pharmacological mechanism of the Chinese plants with anti-diarrheal properties.