Abstract:

Objective To discuss the protective effect of ginsenoside Rh2 on kidney injury in the rats with diabetic kidney lesions （DKL），and to clarify its mechanism. Methods The DKL rat model was established by using the high-fat and high-energy diet combined with intraperitoneal injection of streptozotocin（STZ）.Thirty SD model rats were randomly divided into model group， low dose （10 mg·kg^－1） of Rh2 group and high dose （20 mg·kg^－1） of Rh2 group， and there were 10 rats in each group；other ten SD rats were regared as normal control group.The body weights and kidney weights of the rats in various groups were detected，and the kidney index was caculated；after intervented for 8 weeks， automatic analyzer was used to detect the levels of serum creatinine （Scr）， urea nitrogen （BUN） and 24 h urinary protein （UP）in serum of the rats in various groups；enzyme linked immunosorbent assay （ELISA） method was used to detect the levels of collagen type Ⅳ（Col Ⅳ） in kidney tissue of the rats in various groups； Western blotting method was used to detect the expression levels of transforming growth factor-β1 （TGF-β1），Smad3 and Smad7 proteins in kidney tissue of the rats in various groups. Results Compared with normal control group， the body weight of the rats in model group was decreased（P<0.01），the kidney weight and kidney index were significantly increased （P<0.01）， the levels of Scr， BUN and 24 h UP in serum were increased （P<0.01）， the level of Col Ⅳ in kidney tissue was increased（P<0.01）， the expression levels of TGF-β1 and Smad3 proteins in kidney tissue were increased（P<0.01）， and the expression level of Smad7 protein in renal tissue was decreased （P<0.01）. Compared with model group，the body weight of the rats in low and high doses of Rh2 groups were inecreased （P<0.05 or P<0.01）， the kidney weight and kidney index were decreased （P<0.05 or P<0.01），the levels of Scr， BUN and 24 h UP in serum were significantly decreased （P<0.05 or P<0.01）， the level of Col Ⅳ in kidney tissue was decreased（P<0.01）， the expression levels of TGF-β1 and Smad3 proteins in kidney tissue were decreased（P<0.01）， and the expression level of Smad7 protein in kidney tissue was increased （P<0.01）. Conclusion Ginsenoside Rh2 can inhibit the kidney fibrosis and improves the kidney function in the DKL rats， and has a protective effect on the kidney of DKL rats； its mechanism may be related to regulating the expression of TGF-β1/Smads signaling pathway.

Key words: Ginsenoside Rh2, Diabetic kidney lesions, Kidney injury, Transforming growth factor-β1, Smad protein