American Journal of Clinical Nutrition, Vol 66, 1240-1249, Copyright © 1997 by The American Society for Clinical Nutrition, Inc

ORIGINAL RESEARCH COMMUNICATIONS

Effect of cholesterol-rich diets with and without added vitamins E and C on the severity of atherosclerosis in rabbits

MM Mahfouz, H Kawano and FA Kummerow
Burnsides Research Laboratory, University of Illinois, Urbana, IL 61801, USA.

Oxysterols as oxidation products of cholesterol are considered an atherogenic factor in the development of atherosclerosis in the arteries of cholesterol-fed rabbits. We compared the atherogenic effects of diets enriched either with 0.5% oxidized cholesterol (OC; characterized by high amounts of oxysterols) or with pure cholesterol (PC). The effects of antioxidant vitamins E and C added to the PC diet were also evaluated in view of their antioxidative properties for lipoproteins and cholesterol and how this could affect the severity of atherosclerosis. Four groups of rabbits were fed the following for 11 wk: 1) a nonpurified stock diet, 2) this stock diet plus 0.5% OC, 3) the stock diet plus 0.5% PC, and 4) the stock diet plus 0.5% PC and 1000 mg vitamin E and 500 mg vitamin C/kg diet (PC + antioxidants). The OC and PC diets were equally hyperlipidemic and hypercholesterolemic. The severity of atherosclerotic lesions was highest with the OC diet and lowest with the PC + antioxidants diet. The plasma oxysterol concentration was proportional to the severity of atherosclerosis in all three groups of cholesterol-fed rabbits. beta-Very-low-density- lipoprotein modification was minimized by vitamins E and C as indicated by its polyacrylamide gel electrophoretic pattern and its increased binding to the rabbit liver membrane in vitro. This study indicated that OC and PC were equally atherogenic but that the addition of antioxidants to the PC diet significantly reduced its severity, even when hypercholesterolemia persisted. This indicated that atherogenesis can result from an excessive accumulation of oxidation products of cholesterol in the plasma.

This article has been cited by other articles:

				D. W. Seo, H.-S. Choi, S. P. Lee, and R. Kuver Oxysterols from human bile induce apoptosis of canine gallbladder epithelial cells in monolayer culture Am J Physiol Gastrointest Liver Physiol, December 1, 2004; 287(6): G1247 - G1256. [Abstract] [Full Text] [PDF]

				S. J. Padayatty, A. Katz, Y. Wang, P. Eck, O. Kwon, J.-H. Lee, S. Chen, C. Corpe, A. Dutta, S. K Dutta, et al. Vitamin C as an Antioxidant: Evaluation of Its Role in Disease Prevention J. Am. Coll. Nutr., February 1, 2003; 22(1): 18 - 35. [Abstract] [Full Text] [PDF]

				R. Ringseis and K. Eder Insufficient Dietary Vitamin E Increases the Concentration of 7{beta}-Hydroxycholesterol in Tissues of Rats Fed Salmon Oil J. Nutr., December 1, 2002; 132(12): 3732 - 3735. [Abstract] [Full Text] [PDF]

				J. Plat, H. Brzezinka, D. Lutjohann, R. P. Mensink, and K. von Bergmann Oxidized plant sterols in human serum and lipid infusions as measured by combined gas-liquid chromatography-mass spectrometry J. Lipid Res., December 1, 2001; 42(12): 2030 - 2038. [Abstract] [Full Text] [PDF]

				J. X. Rong, L. Shen, Y. H. Chang, A. Richters, H. N. Hodis, and A. Sevanian Cholesterol Oxidation Products Induce Vascular Foam Cell Lesion Formation in Hypercholesterolemic New Zealand White Rabbits Arterioscler. Thromb. Vasc. Biol., September 1, 1999; 19(9): 2179 - 2188. [Abstract] [Full Text] [PDF]

				D. C. Schwenke and S. R. Behr Vitamin E Combined With Selenium Inhibits Atherosclerosis in Hypercholesterolemic Rabbits Independently of Effects on Plasma Cholesterol Concentrations Circ. Res., August 24, 1998; 83(4): 366 - 377. [Abstract] [Full Text] [PDF]