Antioxidants suppress plasma levels of lectinlike oxidized low-density lipoprotein receptor-ligands and reduce atherosclerosis in watanabe heritable hyperlipidemic rabbits

Oxidative modification of low-density lipoprotein (LDL) has been implicated in the pathogenesis of atherosclerosis. In this study, we investigated the effects of antioxidants including probucol, vitamin E, and fluvastatin, an HMG-CoA (hydroxy-3-methylglutaTyl coenzyme A) reductase inhibitor with antioxidative property, on plasma levels of oxidized LDL (OxLDL) during the progression of atherosclerosis in Watanabe heritable hyperlipidemic (WHHL) rabbits. OxLDL were measured as ligand for lectin-like OxLDL receptor-1 (LOX-1). LOX-1-ligand was higher in WHHL rabbits than in control rabbits as early as 2 months of age and was sustained throughout the experimental period. Supplementation of probucol (1%) and vitamin E (0.5%) to the diet reduced LOX-1-ligand but had little effect on total cholesterol (T-CHO). Fluvastatin (0.03%) significantly reduced both LOX-1-ligand and T-CHO. The extent of reduction in T-CHO was less prominent than in the case of LOX-1-ligand. All of the agents reduced the atherosclerotic lesion area and lipid contents of aortic arches. These parallel results indicate that oxidatively modified LDL elevated in the early stages of atherogenesis is of functional importance in the progression of the disease and can be suppressed by antioxidant treatment. Furthermore, fluvastatin may reduce the evolution of atherosclerosis, not only by lowering plasma cholesterol but also by reducing oxidative modification of LDL.