The Effect of Crude Drugs on Experimental Hypercholesteremia: Mode of Action of (–)-Epigallocatechin Gallate in Tea Leaves

Abstract

The mechanism of the anti-hypercholesteremic effect of (–)-epigallocatechin gallate (EGCG), a component of green tea, was explored in rats from the viewpoint of cholesterol metabolism. 1) The in vitro incorporation of 14C-acetate into cholesterol was not affected by the presence of EGCG in liver slices from normal rats or by oral pretreatment of the animals with EGCG in liver slices from normal and Triton-induced hypercholesteremic rats. 2) The kinetics of serum levels of 14C-cholesterol given orally and of 3H-cholesterol given intravenously revealed that EGCG, when orally administered, suppressed the absorption of 14C-cholesterol from the digestive tract and had an enhancing effect on elimination of serum 3H-cholesterol at higher doses. 3) In situ uptake in the intestine of 14C-cholesterol given in the lumen was suppressed by the presence of EGCG. In conclusion, these results indicated that the anti-hypercholesteremic effect of EGCG in rats is mainly due to suppression of the absorption of exogenous cholesterol from the digestive tract, and partly due to the enhancement of the elimination of endogenous cholesterol. © 1988, The Pharmaceutical Society of Japan. All rights reserved.