Amelioration of atherosclerosis by tanshinone IIA in hyperlipidemic rabbits through attenuation of oxidative stress

Oxidative stress plays a crucial role in atherogenesis, which raises the possibility of using antioxidants to ameliorate atherosclerosis. In the present study, we aim to determine the effects of tanshinone IIA (TSIIA) on atherosclerosis in hyperlipidemic rabbits. After feeding the rabbits on a high-lipid diet for 90 days, they developed severe atherosclerotic lesions both morphologically and biochemically and exhibited significantly elevated serum lipid, malondialdehyde (MDA) and oxidized low density lipoprotein (oxLDL) levels. Oral administration of TSIIA (3-30 mg/kg) greatly inhibited the formation of atherosclerotic lesions. In TSIIA-treated rabbits, there was a marked reduction in serum and aortic lipid peroxide product content, represented by MDA and oxLDL, whereas enhanced activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) were observed. However, TSIIA had no effect on serum lipid profiles. These results suggest that TSIIA attenuates oxidative stress by decreasing oxLDL production and enhancing activities of SOD and GPx, which might be contributed to the amelioration of atherosclerosis.