Molecular basis by which garlic suppresses atherosclerosis

The aim of this study was to determine the mechanism by which the aged garl ic extract "Kyolic" has a protective effect against atherosclerosis. Plasma cholesterol of rabbits fed a 1% cholesterol-enriched diet for 6 wk was not reduced by supplementation with 800 muL Kyolic/(kg body . d). In spite of this, Kyolic reduced by 64% (P < 0.05) the surface area of the thoracic aor ta covered by fatty streaks and significantly reduced aortic arch cholester ol. Kyolic also significantly inhibited by <similar to>50% the development of thickened, lipid-filled lesions in preformed neointimas produced by Foga rty 2F balloon catheter injury of the right carotid artery in cholesterol-f ed rabbits. In vitro studies found that Kyolic completely prevented vascula r smooth muscle phenotypic change from the contractile. high volume fractio n of filament (V(v)myo) state, and inhibited proliferation of smooth muscle cells in the synthetic state with a 50% effective dose (ED50) of 0.2%. Kyo lic also slightly inhibited the accumulation of lipid in cultured macrophag es but not smooth muscle, and had no effect an the expression of adhesion m olecules on the surface of the endothelium or the adherence of leukocytes. It is concluded that Kyolic exerts antiatherogenic effects through inhibiti on of smooth muscle phenotypic change and proliferation, and by another (un clarified) effect on lipid accumulation in the artery wall.