ABSTRACT
Objective:To observe the effect of Liuwei Dihuangtang on the mitochondrial apoptotic pathway in rats with chronic renal failure. Method:The 45 male SD rats were randomly divided into normal group （n=10）， sham group （n=10） and operation group （n=25）. The operation group received 5/6 nephrectomy， and the rats in operation group were randomly divided into the model group and the treatment group after successful modeling. The treatment group received Liuwei Dihuangtang by gavage administration， while the rest of the three groups received equal volume of distilled water by gavage administration， with a treatment course of 8 weeks. The quantitative levels of serum creatinine （SCr）， blood urea nitrogen （BUN） and urine protein in each group were determined. Hematoxylin eosin （HE） staining and Masson staining were used to observe the histopathological changes of rat kidney. The structural changes of mitochondria in renal tubular epithelial cells were observed under electron microscope. The apoptotic rate was detected by terminal-deoxynucleoitidyl transferase mediated nick end labeling（TUNEL）. The expression of B cell lymphoma -2 （Bcl-2）， Bcl-2 associated X protein （Bax）， cytochrome C （Cyt C） and cysteine aspartic acid protease -3 （Caspase-3） were analyzed by Western blot and Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. Result:As compared with the normal group， the quantitative levels of SCr， BUN and urinary protein in the model group were significantly increased （P<0.01）， and the above indicators were improved in the treatment group as compared with the model group （P<0.05）. No significant pathological changes and damage of mitochondrial structure were observed in the kidney tissues of the control group and the sham group. In the model group， there were different degrees of renal tubular atrophy and dilatation， interstitial inflammatory cell infiltration and collagen deposition， and mitochondria swelling and breaking， but such lesions were significantly alleviated in the treatment group. As compared with the normal group， apoptotic rate was increased significantly in model group （P<0.01）， the expression of Bax and Caspase-3 was significantly increased （P<0.01）， and the expression of Bcl-2 was significantly decreased （P<0.01）. As compared with the model group， apoptotic rate was significantly reduced in the treatment group （P<0.01）， the expression of Bax and Caspase-3 was significantly decreased （P<0.01）， and the expression of Bcl-2 was significantly increased （P<0.01）. In the normal group and sham group， Cyt C was mainly located in mitochondria. The expression of Cyt C in the cytoplasm of the model group was increased significantly （P<0.01）， while that of the treatment group was decreased （P<0.01）. Conclusion:Liuwei Dihuangtang can alleviate renal fibrosis and delay the progression of renal function. The mechanism of reducing apoptosis may be associated with protecting mitochondrial structure and regulating the expression of proteins related to mitochondrial apoptotic pathway.