Antihypercholesterolemic property of naringin alters plasma and tissue lipids, cholesterol-regulating enzymes, fecal sterol and tissue morphology in rabbits

Background & aims: Hyperlipidemia is a major risk factor for cardiovas cular diseases. This study was designed to confirm the hypocholesterolemic role of naringin. Methods: Mate rabbits were fed 0.5% high-cholesterol diet or high-cholesterol diet supplemented with either 0.05% naringin or 0.03% lovastatin for 8 weeks. Results: The naringin and lovastatin supplements significantly towered plasma total- and LDL-cholesterol and hepatic lipids levels, while significantly increasing HDL-C/total-C ratio compared to the control group. Hepatic 3-hydroxy-3-methyl-glutaryl CoA reductase and acyl-CoA: cholesterol acyltransferase activities were significantly higher and lower, respectively, in both supplemented groups than the control group. Total fecal sterol content was significantly increased in lovastatin and especially naringin group. In histopathological analyses, only control group exhibited hepatic lipid droplets, cardiac adipocyte infiltration and slight damage of endothelial lining in aortic wall, but two supplements retarded these atherogenic signs. Conclusion: It would appear that both naringin and lovastatin contributed to hypocholesterolemic action via down-regulated ACAT activity and higher excretion of fecal sterols in response to high-cholesterol feeding. Also, naringin supplement seemed to preserve tissue morphology from damages induced by high cholesterol diet. (C) 2004 Elsevier Ltd. All rights reserved.