OBJECTIVETo investigate the effect of Tongshenluo Capsule (TSL) on the components of extracellular matrix (ECM) and their metabolism in kidney of rats with diabetic nephropathy (DN), and to explore its mechanism of kidney protecting.

METHODSThe DN model rats established by one side nephrectomy and intraperitoneal injection of streptozotocin were randomly divided into 5 groups, the sham-operation group, the model group, the Valsartan group, the Gliquidon group, and the TSL group, 10 in each group. Levels of fasting blood glucose (FBG) and 24-h urinary micro-content of albumin (24 h mAlb) were determined dynamically; the serum glycosyl hemoglobin (HbA1c)was determined after the last medication; the ultrastructural changes of kidney were observed by transmission electron microscope; the expressions of collagen IV (IV-C), fibronctin (FN), laminin(LN), and the ECM metabolism influencing factors, including MMP-2, tissue inhibitor of metalloproteinase (TIMP-2), transfer growth factor-beta1 (TGF-beta1) in renal tissue were detected by immunohistological chemistry and image collecting analytical system. Results TSL could decrease the levels of FBG, HbA1c, 24 h mAlb (P < 0.05 or P < 0.01), ameliorate the thickness of glomerular basement membrane (GBM), decrease the components of ECM, down-regulate TGF-beta1 and TIMP-2 expression, and up-regulate MMP-2 expression (P < 0.05 or P < 0.01).

CONCLUSIONTSL plays a role of kidney protection by decreasing the ECM components expression and regulate ECM metabolism.