Mechanism of TGF-β1/Smad signaling pathway in rhein protected diabetic rat′s kidney / 药学实践杂志

ABSTRACT

Objective To study the protective effect of Rhein on the kidney of type 2 diabetic rats induced by high fat diet.Methods A rat model of type 2 diabetes was induced by high fat diet combined with low dose streptozotocin 35 mg/kg.The diabetic rats were randomly divided into diabetes group, Low, middle and high rhein dose groups (50,100,150 mg/kg), metformin group (300 mg/kg) and normal control group.Blood glucose and urine micro albumin were measured at 0, 2, 4 and 8 weeks respectively.Serum creatinine, urea nitrogen, total cholesterol and triglyceride were measured at 8 weeks.HE staining was used to observe the pathological changes of renal tissue.Effects of rhein on the expression of transforming growth factor-β1 and Smad3 protein in renal tissue of diabetic rats were detected with Western Blot.Results The blood glucose and urine micro albumin in model group were significantly higher than those in normal control group.Each rhein dose group exhibited reduced blood glucose and urinary micro albumin in diabetic rats.The high rhein dose group showed significant reduction of blood glucose and urine micro albumin in diabetic rats (P<0.05).Compared with model group, rhein reduced the serum Cr, BUN, TC and TG values in each dose group, most significantly in the high rhein dose group (P<0.05).The obvious pathological changes of renal tissue in model group were observed with most improved changes in the high rhein dose group.The expression of TGF-β1 and Smad3 protein in renal tissue of diabetic rats decreased significantly (P<0.05).Conclusion Rhein has preventive effect on diabetic nephropathy.The mechanism may relate to the improvement of renal function, regulation of blood lipid and down regulation of TGF-β1 and Smad3 protein expression in renal tissue.