Rhus verniciflua Stokes glycoprotein (36 kDa) has protective activity on carbon tetrachloride-induced liver injury in mice

This study was carried out to investigate the hepatoprotective effect of the glycoprotein isolated from Rhus verniciflua Stokes (RVS), which has traditionally been used for healing of inflammatory diseases. We evaluated the activities of alanine aminotransferase (ALT), lactate dehydrogenase (LDH), thiobarbituric acid-reactive substances (TBARS), and antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx)] activities in treatment with carbon tetrachloride (CCl4) in vivo. When mice were treated with CCl4 in the absence of RVS glycoprotein, the activities of ALT, LDH, and TBARS were increased, while the antioxidant enzymes activities were decreased. However, when the mice were treated with CCl4 in the presence of RVS glycoprotein, the activities of ALT, LDH, and TBARS were significantly reduced and SOD, CAT, and GPx activities were remarkably increased. In addition, RVS glycoprotein increased the nitric oxide (NO) production and decreased the nuclear factor-kappa B (NF-κB) and activator protein-1 (AP-1) activation in CCl4-treated mice. Collectively, these results pointed out that RVS glycoprotein can inhibit lipid peroxidation, enhance the activities of antioxidant enzymes, increase the NO production, and decrease the NF-κB and AP-1 activations. Therefore, we speculate that RVS glycoprotein protects from liver damage through its radical scavenging ability.