Salvianolic Acid B Inhibits Low-Density Lipoprotein Oxidation and Neointimal Hyperplasia in Endothelium-Denuded Hypercholesterolaemic Rabbits

BACKGROUND: Atherosclerosis and restenosis are inflammatory responses involving free radicals and lipid peroxidation and may be prevented/cured by antioxidant-mediated lipid peroxidation inhibition. Salvianolic acid Sal B, a water- soluble antioxidant obtained from a Chinese medicinal herb , is believed to have multiple preventive and therapeutic effects against human vascular diseases. In this study the in vitro and in vivo inhibitory effects of Sal B on oxidative stress were determined. RESULTS: In human aortic endothelial cells HAECs, Sal B reduced oxidative stress, inhibited low-density lipoprotein LDL oxidation and reduced oxidised LDL-induced cytotoxicity. Sal B inhibited Cu2+- induced LDL oxidation in vitro with a potency 16.3 times that of probucol and attenuated HAEC-mediated LDL oxidation as well as reactive oxygen species ROS production. In cholesterol-fed New Zealand White rabbits with probucol as positive control, Sal B intake reduced Cu2+-induced LDL oxidation, lipid deposition in the thoracic aorta, intimal thickness of the aortic arch and thoracic aorta and neointimal formation in the abdominal aorta. CONCLUSION: The data obtained in this study suggest that Sal B protects HAECs from oxidative injury-mediated cell death via inhibition of ROS production. The antioxidant activity of Sal B may help explain its efficacy in the treatment of vascular diseases