Vitamin E attenuates homocysteine and cholesterol induced damage in rat aorta

BackgroundThe aim of this study was to investigate the effect of vitamin E on homocysteine and cholesterol-induced damage of rat aorta.MethodsWistar rats (all fed with a vitamin E poor diet) were divided into five groups. Control group was fed with the diet only, the second group received 1 mg kg−1 day−1l-methionine in drinking water, the third group was fed with 2% cholesterol containing diet, the fourth group received l-methionine and cholesterol together, and the fifth group was fed with l-methionine and cholesterol and received intramuscular injections of vitamin E. After 4 weeks serum homocysteine, cholesterol and vitamin E levels were measured; aortas were removed; collagen and elastin and the major extracellular matrix components were evaluated microscopically as indicators of aortic degeneration. Aortic collagen content was measured by a colorimetric hydroxyproline assay.ResultsFour-week diet supplementation with methionine and cholesterol caused a twofold increase in serum homocysteine and 22% increase in serum cholesterol levels; endothelial damage and degenerative alterations in the aortic media were observed, as indicated by the dissociation of elastic fibers and accumulation of collagen. Vitamin E completely prevented the accumulation of collagen and largely prevented aorta damage as shown by the morphological data.ConclusionThe results indicate that, even moderate increases in homocysteine and cholesterol levels are sufficient to induce vascular degeneration that may be prevented by vitamin E supplementation.