ABSTRACT
Objective: To investigate the effects of C-21 steroidal glucosides from Cynanchum auriculatum on renal fibrosis in rats caused by unilateral ureteral ligation and explore its mechanisms. Methods: A total of 15 rats were randomly chosen as sham operation group (Sham), while the remaining rats underwent unilateral ureteral ligation. The rats after the operation were randomly divided into four groups, namely the Sham operation group, the model group, the positive control group (20 mg/kg), C. auriculatum high group (400 mg/kg), C. auriculatum low group (200 mg/kg), 15 per group, and the rats in each group were administrated with corresponding drugs. After the intervention of 28 d, all the rats were sacrificed and the kidneys were then removed. The content of hydroxyproline was measured. HE and Masson staining were conducted to assess kidney pathological changes and renal fibrosis. The protein expression of TGF-β1, α-SMA, and E-cadherin were tested with immunohistochemistry and Western blotting. The mRNA expression of collagen-I and collagen-III was evaluated using qRT-PCR. Results: Compared with the model group, C-21 steroid glycosides significantly alleviated the kidney pathological injury and renal fibrosis, and reduced fibrous tissue and collagen proliferation. C-21 steroid glucosides from C. auriculatum can significantly reduce the kidney/body weight ratio and the content of hydroxyproline in kidney tissue (P < 0.05, 0.01), and it showed in a dose-dependent manner. Compared with the model group, the expression of α-SMA and TGF-β1 was decreased significantly, and the expression of E-cadherin was increased significantly (P < 0.05, 0.01) in C. auriculatum group. Moreover, compared with the model group, C-21 steroidal glucosides significantly down-regulated the mRNA expression of collagen-I and collagen-III mRNA (P < 0.01). Conclusion: C-21 steroid glycosides from C. auriculatum can effectively attenuate renal fibrosis in rats with unilateral ureteral ligation and its underlying mechanisms may be related to inhibiting the over-expression of collagen-I and collagen-III, down-regulating the expression of α-SMA and TGF-β1, and up-regulating the expression of E-cadherin. By regulating the tubular epithelial-mesenchymal transition, it exerts its anti-fibrotic effect.
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.