Water-soluble viscous substance of Jew's mellow leaves lowers serum and liver cholesterol concentrations and increases fecal steroid excretion in rats fed a high cholesterol diet.

Abstract

The effect of Jew's mellow leaf powder and its water soluble viscous substance on cholesterol metabolism in rats fed a high cholesterol diet was examined. When compared to the controls, total serum and liver cholesterol concentrations were significantly decreased or tended to decrease in the groups given dry powder of fresh Jew's mellow leaves, dry powder purchased from the market or residual powder after extracting with ethanol, whereas no difference was observed in those given residual powder after extracting with water. There were significant increases or increasing tendencies in the fecal excretion of bile acids, total neutral sterols and cholesterol in those fed the experimental diets when compared to the control group. Rats fed a diet containing a water-soluble viscous substance (1.7%, about 1% as dietary fiber) obtained from the dry powder of Jew's mellow leaves showed significant decreases in serum and liver cholesterol concentrations and increases in fecal excretions of bile acids and neutral sterols. Based on the above, the component of dry powder of Jew's mellow leaves that is effective in decreasing serum and liver cholesterol concentrations was found to be a soluble dietary fiber, and the mechanism was assumed to be largely due to the increased excretion of bile acids and neutral sterols.