Protective effects of She Jing Xiao Bai capsule on diabetic nephropathy in a diabetic rat model

Objective: To investigate the protective effects and mechanism of She Jing Xiao Bai capsule, a traditional Chinese medicine, on diabetic nephropathy (DN) in a rat diabetes model. Methods: Diabetes was induced in 32 male Sprague-Dawley rats by intraperitoneal injection of streptozotocin (STZ). Rats were randomly allocated to a control group, and groups given She Jing Xiao Bai capsule, irbesartan, or She Jing Xiao Bai capsule plus irbesartan. Serum creatinine and 24 h urine protein were assayed, and renal pathology was evaluated at 2, 4, 6 and 8 weeks after treatment. Transforming growth factor-beta (TGF-beta) and connective tissue growth factor (CTGF) were assayed by immunohistochemistry. Spleen CD4(+)Foxp3(+)T cells were assayed by flow cytometry. Results: Urine protein levels were significantly lower in rats treated with She Jing Xiao Bai capsule, irbesartan, or She Jing Xiao Bai capsule plus irbesartan than in control rats. Renal TGF-beta and CTGF expression decreased, and splenic CD4(+)Foxp3(+)T cells increased, with treatment. The strongest effect was observed following treatment with She Jing Xiao Bai capsule plus irbesartan. Conclusion: She Jing Xiao Bai capsule significantly reduced renal injury in this STZ-induced DN model. Treatment was associated with decreased TGF-beta and CTGF expression and increased numbers of CD4(+)Foxp3(+)T cells.