Shenqi Jiangtang Granule Ameliorates Kidney Function by Inhibiting Apoptosis in a Diabetic Rat Model

Diabetic nephropathy (DN) is a major microvascular complication of diabetes. In addition to moderating hyperglycemia, Shenqi Jiangtang Granule (SJG) had a beneficial effect on kidney function in a clinical trial. However, the mechanism involved remains unclear. This study was conducted to identify the underlying molecular mechanisms. A diabetic rat model was generated by using a high-fat diet and streptozotocin (STZ) injection. Then, rats were given SJG at dosages of 400 mg/kg/d or 800 mg/kg/d by gavage for 8 weeks. After 8 weeks of treatment, blood glucose, serum creatinine, blood urea nitrogen (BUN), and 24-h urinary albumin were measured. Histochemical staining and TdT-mediated dUTP nick-end labeling (TUNEL) assays were performed in kidney. Kidney genomic expression in the SJG-treated group and diabetic group was detected by using a genome expression microarray. We found that SJG treatment reduced blood glucose, serum creatinine, BUN, and 24-h urinary albumin and affected kidney histology. The gene array revealed that the expression of 99 genes increased and the expression of 91 genes decreased in the HSJG group, compared with those of in the diabetic group. Pathway and gene ontology analysis of the differentially expressed genes showed an enrichment of the apoptosis pathway. SJG treatment reduced TUNEL- and caspase-3-positive cells in diabetic kidneys. SJG upregulated Bcl-2 and regucalcin expressions and reduced casp3 and Apaf1 expressions in diabetic rats. Our results suggest that SJG exerts a renal protective effect through the inhibition of cell apoptosis in a diabetic rodent model.