INCREASE OF VITAMIN-E CONTENT IN LDL AND REDUCTION OF ATHEROSCLEROSISIN CHOLESTEROL-FED RABBITS BY A WATER-SOLUBLE ANTIOXIDANT-RICH FRACTION OF SALVIA-MILTIORRHIZA

Antioxidants that prevent LDL from oxidation may reduce atherosclerosi s. Salvia miltiorrhiza Bunge is a Chinese herb widely used for the tre atment of atherosclerosis-related disorders. Salvianolic acid B (Sal B ), a water-soluble polyphenolic antioxidant isolated from the roots of this plant, was found to scavenge 1,1-diphenyl-2-picrylhydrazyl radic als and inhibit LDL oxidation more effectively than probucol. In order to evaluate the antiathterogenic potential, New Zealand White rabbits were fed for 12 weeks a normal diet, a high cholesterol diet, a high cholesterol diet containing 1% probucol, or a high cholesterol diet co ntaining a 5% water-soluble extract of S miltiorrhiza (SM). Both SM an d probucol feeding reduced plasma cholesterol. LDLs from the SM-treate d group were more resistant to Cu2+-induced more vitamin E (21.7+/-2.1 nmol/mu mol LDL cholesterol) than did LDLs from the high cholesterol diet group (9.6+/-1.8 nmol/mu mol LDL cholesterol) (P<.005). Endotheli al damage, determined at week 6, was reduced by 53% in the SM group (P <.01). SM treatment reduced the atherosclerotic area in the abdominal aorta by 56% (P<.005) and cholesterol deposition in the thoracic aorta by 50% (P<.005), The severity of atherosclerosis in the SM group was significantly reduced after adjustment by using cholesterol exposure a s an index of the cholesterol-lowering effect. This study concludes th at the reduction of atherosclerosis by SM relies not only on its chole sterol-lowering effect but more heavily on its antioxidant potential t o prevent endothelial damage and inhibit LDL oxidative modification in hypercholesterolemic animals.