Hypolipidemic and antioxidative effects of the plant glycoprotein (36 kDa) from Rhus verniciflua stokes fruit in triton WR-1339-induced hyperlipidemic mice

Abstract

We investigated the hypolipidemic and antioxidative effects on male ICR mice of a glycoprotein isolated from Rhus verniciflua Stokes (RVS) fruit. The administration of the RVS glycoprotein (100 mg/kg) for two weeks resulted in a significant decrease in such plasma lipid levels as total cholesterol (TC), triglyceride (TG), and low-density lipoprotein (LDL). The levels of TC, TG and LDL in the hyperlipidemic model were significantly increased, whereas the high-density lipoprotein (HDL) level was considerably decreased. The 3-hydroxy-3-methylglutaryl CoA (HMG-CoA) reductase activity and the level of thiobarbituric acid-reactive substances (TBARS) were significantly elevated, whereas the production of nitric oxide (NO) was diminished. Moreover, the administration of the RVS glycoprotein prior to inducing hyperlipidemic mice suppressed the increase in the plasma lipid levels (TC, TG and LDL), and decrease in the HDL level in Triton WR-1339-induced hyperlipidemic mice. Furthermore, the RVS glycoprotein significantly inhibited the activity of HMG-CoA reductase and the levels of TBARS in the hyperlipidemic mice. In addition, the activities of detoxicant enzymes [catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx)] were gradually augmented after a supplement with the RVS glycoprotein. The results suggest that the RVS glycoprotein would be effective in preventing an increase in the plasma lipid levels and in improving the antioxidant levels. This protein might be useful as a therapeutic agent.