Cholesterol-Lowering Activity of Naringenin via Inhibition of 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase and Acyl Coenzyme A:Cholesterol Acyltransferase in RatsLee S.H. · Park Y.B. · Bae K.H. · Bok H. · Kwon Y.K. · Lee E.S. · Choi M.S.
aDepartment of Nutrition and Food Science and bDepartment of Genetic Engineering, Kyungpook National University, Taegu, cChungnam National University School of Pharmacy, Taejon, and dKorea Institute of Bioscience and Biotechnology, KIST, Taejon, South Korea
The effects of dietary supplementation of a citrus bioflavonoid, naringenin, on the cholesterol metabolism were studied. For 42 days male rats were fed a 1% (wt/wt) high-cholesterol diet with or without a naringenin supplementation (0.1%, wt/wt) to study its effect on plasma lipid levels, hepatic lipid contents, activities of hepatic acyl coenzyme A:cholesterol O-acyltransferase (ACAT) and 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, and the excretion of fecal neutral sterols. Naringenin did not significantly alter the concentration of plasma triglycerides, but lowered the plasma cholesterol (3.80 vs. 3.12 mmol/l) concentration and the hepatic cholesterol content (70.3 vs. 54.0 mg/g) significantly (p < 0.05) compared to those of the controls. HMG-CoA reductase (1,879.0 vs. 1,715.0 pmol/min/mg) and ACAT activities (806.0 vs. 563.0 pmol/min/mg) were significantly lower in the naringenin-supplemented group than in controls. Naringenin supplementation caused a marked decrease in the excretion of fecal neutral sterols (242.9 mg/day) compared to the controls (521.9 mg/day). These results show that naringenin lowers the plasma and hepatic cholesterol concentrations by suppressing HMG-CoA reductase and ACAT in rats fed a high-cholesterol diet.