Du-zhong (Eucommia ulmoidesOliver) Leaf Extract Mediates Hypolipidemic Action in Hamsters Fed a High-Fat Diet

Abstract

This study examined the effect of a Du-zhong (Eucommia ulmoides Oliver) leaf extract (0.175 g/100 g diet) that was supplemented with a high-fat diet (10% coconut oil, 0.2% cholesterol, wt/wt) on hyperlipidemic hamsters. Hamsters fed with Du-zhong leaf extract for 10 weeks showed a smaller size of epididymal adipocytes compared to the control group. The supplementation of the Du-zhong leaf extract significantly lowered the plasma levels of triglyceride, total cholesterol, LDL-cholesterol, non HDL-cholesterol, and free fatty acid, whereas it elevated the HDL-cholesterol/total cholesterol ratio and apolipoprotein A-I levels. The hepatic cholesterol concentration was lower in the Du-zhong group than in the control group. The plasma total cholesterol concentration was positively correlated with hepatic HMG-CoA reductase activity (r = 0.547, p < 0.05) and hepatic cholesterol concentration (r = 0.769, p < 0.001). The hepatic fatty acid synthase and HMG-CoA reductase activities were significantly lowered by a Du-zhong leaf extract supplement in high fat-fed hamsters. Hepatic fatty acid synthase activity was positively correlated with plasma fatty acid concentration (r = 0.513, p < 0.05) that was lower in the Du-zhong group. These results demonstrate that the Du-zhong leaf extract exhibits antihyperlipidemic properties by suppressing hepatic fatty acid and cholesterol biosynthesis with the simultaneous reduction of plasma and hepatic lipids in high fat-fed hamsters.