Preliminary Study On The Therapeutic Effect And Mechanism Of Phytolaccae Radix Crude Extract On Diabetic Nephropathy Rats

Objective: By observing the effects of Phytolaccae Radix crude extract on body weight,serum creatinine and 24-hour urinary protein and the expression of TNF-ɑ,IL-1β,VEGF,Nephrin and p-p38 MAPK protein in kidney tissue of diabetic nephropathy rats,and to explore the therapeutic effect of Phytolaccae Radix crude extract and its possible mechanism.Methods: Sixty-five SPF male SD rats weighing 180～220 g were randomly divided into normal control group and diabetic nephropathy group.The model of type 1 diabetic nephropathy was established by intraperitoneal injection of STZ,which was randomly divided into model group,high-dose Phytolacca acinosa group,medium-dose Phytolacca acinosa,low-dose Phytolacca acinosa and losartan potassium group.After each group was given corresponding drugs for 4 weeks,the body weight,24-hour urine,blood samples and kidney tissues of each group were collected,and 24-hour urinary protein and serum creatinine were detected.The kidney tissues were stained by HE and Masson.Immunohistochemical method was used to detect TNF-ɑ and IL-1β in rat kidney.The expressions of VEGF,p-p38 MAPK and Nephrin protein in kidney tissue of rats in each group were detected by western blotting.Results: 1.The weight of rats in the model group was the lowest,and the weight of middle,high of Phytolacca acinosa and losartan potassium groups were significantly higher than that of the model group(P<0.05).The weight of Phytolacca acinosa high dose group and losartan potassium group were higher than that of Phytolacca acinosa low dose group(P<0.05).2.24-hour urinary protein: the 24-hour urinary protein of rats in model group was the highest,while 24-hour urinary protein of normal control group.Phytolacca acinosa group and losartan potassium group were significantly lower than that of model group(P<0.05).The 24-hour urinary protein of Phytolacca acinosa high-dose group and losartan potassium group were lower than that of Phytolacca acinosa low-dose group(P<0.05).3.Serum creatinine: The serum creatinine of model rats were the highest,while that of normal control group.Phytolacca acinosa group and losartan potassium group was significantly lower than that of model group(P<0.05).Serum creatinine in high-dose Phytolacca acinosa group and losartan potassium group were lower than that in low-dose Phytolacca acinosa group(P<0.05).4.HE and Masson staining results: the pathological changes of kidney tissue in diabetic nephropathy rats were different.The pathological characteristics of kidney in model group were glomerular mesangial cells and mesangial matrix hyperplasia,some proximal convoluted tubules were vacuolated and expanded,renal tubular basement membrane was thickened,inflammatory cells were infiltrated,and some proximal convoluted tubules were protein tubular.The comprehensive score of kidney tissue in high dose Phytolacca acinosa group and losartan potassium group were lower than that in model group(P<0.05).5.Immunohistochemical results showed that TNF-ɑ and IL-1β were expressed in glomerular and renal tubular epithelial cells of kidney,and TNF-ɑ and IL-1β were most expressed in kidney tissue of model group,while the expressions of Phytolacca acinosa high dose group and Losartan potassium group were significantly lower than those of model group(P<0.05).6.Western Blot results: compared with the model group,the relative expression of VEGF and p-p38 MAPK in kidney tissue of rats in each dose group of Phytolacca acinosa and losartan potassium group decreased significantly(P<0.05).while the relative expression of Nephrin protein increased significantly(P<0.05).Conclusion: The Phytolaccae Radix crude extract has therapeutic effect on diabetic nephropathy rat model,and its mechanism may be related to reducing the expression of pp38 MAPK protein in kidney tissue and the production of TNF-ɑ,IL-1β and VEGF.