Effects of total C-21 steroidal glucosides from Cynanchum auriculatum on oxidative stress pathway in mice with liver injury

Abstract

The study aimed to investigate the mechanism of hepatoprotective effect of C-21 steroidal glucosides from Cynanchum auriculatum( Baishouwu) on oxidative stress in mice with liver injury. Mice were randomly divided into normal group,model group,positive control group,Baishouwu high group and Baishouwu low group. The liver injury model was induced by intraperitoneal injection of CCl4 peanut oil solution. All mice were sacrificed to collect blood and liver specimens. The activities of serum levels of ALT and AST were detected. The content of MDA and the activity of SOD in liver homogenate were examined by colorimetry method. Tissues were stained with hematoxylin-eosin for histological examination. The hepatic protein expressions of NF-κB p65,p-IκBα,i NOS and COX-2 were detected by Western blot. The mRNA expressions of TNF-α and IL-6 were determined by RT-PCR. It was found that treatment with C-21 steroidal glucosides from Baishouwu successfully attenuated liver injury induced by CCl4,as shown by decreased levels of serum biochemical indicators( AST,ALT)( P<0. 01). Administration of total C-21 steroidal glucosides enhanced the activity of SOD( P<0. 01) and decreased the content of MDA( P<0. 01) in liver homogenate. Microscopic features suggested that treatment with C-21 steroidal glucosides from Baishouwu was effective in inhibiting CCl4-induced hepatocyte edema and degeneration. Further studies showed that NF-κB p65 overexpression induced by CCl4 was decreased by C-21 steroidal glucosides,leading to the markedly down-regulated protein expression levels of p-IκBα,i NOS and COX-2,as well as the depression of TNF-α and IL-6 mRNA expressions. In conclusion,total C-21 steroidal glucosides from Baishouwu exhibited potent effect on oxidative stress pathway in mice with liver injury induced by CCl4,with enhanced activity of SOD,decreased content of MDA,and down-regulated levels of NF-κB p65,p-IκBα,i NOS and COX-2.