Dietary restriction reduces atherosclerosis and oxidative stress in the aorta of apolipoprotein E-deficient mice

Dietary restriction (DR) has been shown to inhibit almost all the age-related diseases, e.g. cardiomyopathy and cancers, in rodents. However, there is little information for the effect of DR on atherosclerosis. In the present study, we examined the effect of DR on the development of atherosclerosis in mice homozygous knockout for apolipoprotein E gene (ApoE^-/-). The ApoE^-/- mice were fed either ad libitum (AL) or 60% of the diet consumed by the mice fed AL. Atherosclerotic lesions in the proximal aorta of these mice were measured. Our results showed that ApoE^-/- mice fed the calorie-restricted diet had smaller and relatively early stages of atherosclerotic lesions (e.g. foam cells and free lipids) when compared to ApoE^-/- mice fed AL, who developed more advanced lesions (e.g. fibrous caps and acellular areas). In addition, ApoE^-/- mice fed the calorie-restricted diet showed a significant decrease in the level of lipid hydroperoxides and the production of superoxide and hydrogen peroxide in the aorta as compared to ApoE^-/- mice fed AL. These observations suggest that reduction of oxidative stress in the arterial wall may contribute to the anti-atherogenic effect of DR in ApoE^-/- mice.