Effects of Qizhi Jiangtang Capsule on BMP-7 and TGF-β_1/Smads Signaling Pathway of Kidney in Diabetic Nephropathy Rats

Objective: To study the effects of Qizhi Jiangtang Capsule( QJC) on BMP- 7 and TGF- β1,Smad2 and Smad7expressions of renal interstitial fibrosis in diabetic nephropathy rats. Methods: 48 male Wistar rats were randomly divided into 5 groups( n =8) : the sham operation group,the model group,Valsartan group( control group),the low- dosage of QJC group( low dosage group) and high dosage of QJC group( high dosage group). Except the rats in the sham operation group,the other rats were established DN animal model by removal of the right kidney with intraperitoneal injection of STZ. Medicine was given to each group according to the designed concentration and dosage from 2 days of the model established. Urine microAlbumin( mAlb),α1- microglobulin( α1-MG) and serum creatinine( Scr),blood urea nitrogen( BUN) of DN rats were detect ed at 12th week. All animals were put to death after 12 weeks. Histological change in the kidney tissue of DN rats was examined by HE stain,PAS stain and Masson stain. The protein expression of BMP- 7,TGF- β1,Smad2 and Smad7 in kidney tissues were detected by ELISA respectively. Results: At 12th week,to compared with the sham group,mAlb,α1- MG of model group were significantly raised( P 0. 01). These indicators of 3 treated groups rats were significantly reduced( P 0. 01). To compared with the control group,the above contents of 2 groups of QJC were obviously decreased( P 0. 05 ~ 0. 01),and dose- dependent manner. Scr、BUN of the model group were also significantly raised( P 0. 01) at same time. Scr,BUN of the control group was shown no significant change( P 0. 05). ocompared with the control group,these indicators of 2 groups of QJC were obviously decreased( P 0. 05 ~ 0. 01). HE staining showed that renal pathological damage of3 treated groups rats were lessened. Renal pathological of 2 groups of QJC was improved more obvious than that of control group. PAS staining showed that TII of 3 treated groups was significantly lower than that of the model group,and TII of 2 groups of QJC was more lower than the control group. Tubulointerstitial was improved by Masson stain in the 2 groups of QJC. Compared with the model group,the protein expression of TGF- β1,Smad2 were down- regulated in the renal tissue of 3 treated groups,while the protein expression were further down- regulated by QJC. At the same time,the protein expression of BMP- 7、Smad7 were up- regulated in the 3 treated groups,and that were further up- regulated by QJC. Conclusion: The renal interstitial fibrosis may be inhibitted by QJC through TGF- β1/ Smads signaling pathway was interferenced in the renal tissues of DN rats.