Control of TGF-βl/Smads signaling pathway in diabetic nephropathy rats by Danzhijiangtang capsule / 中国药理学通报

ABSTRACT

Aim To investigate the preventive and therapeutic effects of Danzhijiangtang capsule (DZJT) on diabetic nephropathy in rats and its mechanism. Methods Twelve rats were randomly selected as the normal group from 100 male SD rats, the remaining was induced by high fat diet and streptozotocin (34 mg • kg-1, ip), and 65 successful modeling rats were randomly divided into model group, DZJT high, medium, low dose group and pioglitazone group. Gavage was administered for 8 weeks. The blood glucose, renal function and the expression of TGF-β1 in serum were measured. The pathological changes of renal tissue were observed. The expressions of TGF-β1 Smad2, Smad3, Smad7 and CTGF in renal tissues were detected. Results Compared with normal group, the blood glucose of rats in model group significantly increased, renal and glomerular hypertrophy, basement membrane thickening, extracellular matrix increased, and inflammatory cell infiltration, fibrous tissue hyper plasia, kidney pathological score increased significantly; the expression of TGF-β1, SmacB and CTGF in renal tissues increased significantly, and the expression of Smad2 and Smad7 decreased markedly. Compared with model group, the above indicators in each treatment group decreased in different degrees, and the pathological morphology of kidney was improved obviously; TGF-β1, Smad3 and CTGF decreased, while the levels of Smad2 and Smad7 increased. Conclusions The capsule can effectively improve the symptoms of diabetes and alleviate the kidney damage in rats, and its mechanism may be related to the regulation of TGF-β1/Smads signaling pathway and its downstream CTGF expression.