Proanthocyanidin-rich extract from grape seeds attenuates the development of aortic atherosclerosis in cholesterol-fed rabbits

The aim of this study was to evaluate the antiatherosclerotic effect of pro anthocyanidin-rich extracts from grape seeds in cholesterol-fed rabbits. Pr oanthocyanidin-rich extracts (0.1% and 1% in diets [w/w]) did not appreciab ly affect the changes in serum lipid profile of cholesterol-fed rabbits. Th e level of cholesteryl ester hydroperoxides (ChE-OOH) induced by 2,2'-azobi s(2-amidinopropane-dihydrochloride (AAPH) were lower in the plasma of rabbi ts fed proanthocyanidin-rich extract plus cholesterol than in the plasma of rabbits fed cholesterol alone, but not in the low-density lipoprotein (LDL ). Aortic malondialdehyde (MDA) content decreased in rabbits fed proanthocy anidin-rich extract. Feeding proanthocyanidin-rich extracts (0.1 and 1% in the diet) to rabbits significantly reduced severe atherosclerosis in the ao rta. Immunohistochemical analysis revealed a decrease in the number of oxid ized LDL-positive macrophage-derived foam cells in atherosclerotic lesions in the aorta of rabbits fed proanthocyanidin-rich extract. When proanthocya nidin-rich extract was administered orally to rats, proanthocyanidin was de tected in the plasma by Porters method but not in the lipoproteins (LDL plu s VLDL). In an in vitro experiment using human plasma, proanthocyanidin-ric h extract added to the plasma inhibited the oxidation of cholesteryl linole ate in LDL, but not in the LDL isolated after the plasma and the extract we re incubated in advance. These results suggested that proanthocyanidins, th e major polyphenols in red wine, might trap reactive oxygen species in aque ous series such as plasma and interstitial fluid of the arterial wall, ther eby inhibiting oxidation of LDL and showing an antiatherosclerotic activity . (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.