Effects Of Puerarin On Receptor For Advanced Glycation End Products In Renal Cortex Of Streptozotocin-induced Diabetic Rats

Objective and BackgroundDiabetic nephropathy(DN)is a major microvascular complication in long-standing diabetic patients who eventually undergo renal dialysis or transplantation.It cause disability,shorten life expectancy,and reduce quality of life.As is diabetes itself,the pathogenesis of diabetic nephropathy is still unclear.Studies have revealed that advanced glycation end products(AGEs)and the receptor for AGEs(RAGE) interactions have been implicated in the development of diabetic nephropathy.Therefore,limiting RAGE expression might be an intriguing concept to modulate DN in diabetic patients.It was found that radix puerariae could decrease the level of blood glucose and the activity of aldose reductase in red blood cells,inhibit the formation of glycation products significantly.Puerarin is an isoflavonoid derived from radix puerariae.Recent studies have revealed that puerarin can reduce the excretory rate of urinary albumin and is beneficial to diabetic patients who have earlier nephropathy.It has also revealed that puerarin can inhibit non-enzyme glycosylation.The aim of the present study was to determine whether puerarin affects expression of RAGE mRNA in renal cortex of streptozotocin-induced diabetic rats,and its influence on earlier diabetic nephropathy.Research Design and MethodsWe induced Diabetic rats by an intraperitoneal injection of STZ in SD rats.The criterion of diagnosis of diabetes was the consecutive blood glucose level≥16.7 mmol/L.30 male SD rats were randomly divided into 3 groups,diabetes adding puerarin group(n=11,intraperitoneal injection puerarin 100mg/kg.d),diabetes adding placebo group(n=11)and normal control group(n=8).The body weight and blood glucose were measured every two weeks.8 weeks later,all rats were killed and the expression of RAGE mRNA was quantified in renal cortex by reverse transcription-polymerase chain reaction(RT-PCR)respectively.Results1.The RAGE mRNA expression was increased in renal cortex of diabetic rats.RAGE/β-actin ratio of diabetic group was significantly higher than that of the control(P＜0.01).2.After treatment with puerarin,RAGE mRNA expression decreased significantly and RAGE/β-actin ratio was obviously lower than that of diabetes adding placebo group.Conclusions1.The high expression of RAGE mRNA may participate in the renal damage of diabetic rats.2.Puerarin can decrease the level of blood glucose and showed some renal protective effect on diabetic nephropathy,partly through inhibition of excessive expression of RAGE mRNA in renal cortex.