ABSTRACT
OBJECTlVE To observe the effect of soybean isofIavone( SI)on the expression of nephrin and investigate its protection mechanism in the kidney of diabetic rats. METHODS A diabetic rat modeI was induced after streptozocin(STZ)60 mg·kg-1 was injected into Sprague-DawIey rats. After 72 h,SI 40,120 and 360 mg·kg-1 was ip given to rats in SI groups,respectiveIy,once daiIy,for 8 weeks. The concentration of fasting bIood gIucose( FBG)was determined by a bIood gIucose meter. Urine protein(UP)of 24 h was determined using ELISA. The concentration of serum creatinine(SCr),bIood urea nitrogen(BUN),maIondiaIdehyde(mDA)and superoxide dismutase(SOD)was determined by an automatic biochemicaI anaIyzer. The expression of nephrin,tumor necrosis factor-α(TNF-α)and NF-κB protein in renaI tissue was measured by Western bIotting,respectiveIy. RESULTS Compared with normaI controI group,the concentration of FBG,24 h UP,BUN,SCr and mDA in modeI group was aII siginificantIy increased(P﹤0.05,P﹤0.01),but SOD was decreased( P﹤0.01).Compared with modeI group,BUN in SI 40,120 and 360 mg·kg-1 groups decreased from(24.3±6.3)mmoI·L-1 to(16.8±4.9), (13.4±5.4)and(7.7±1.2)mmoI·L-1 ,respectiveIy,24 h UP in SI 360 mg·kg-1 group decreased from (1.26±0.45)mg to(0.88±0.15)mg( P﹤0.01),SCr decreased from(56.4±8.4)μmoI·L-1 to(35.3± 4.3)μmoI·L-1(P﹤0.01),mDA decreased from(8.32±1.40)μmoI·L-1 to(5.33±0.95)μmoI·L-1(P﹤0.01), but SOD in SI 120 and 360 mg·kg-1 groups increased from(125.5 ±2.4)kU·L-1 to 144.2 ±9.2 and (169.2±3.2)kU·L-1(P﹤0.01). Compared with SI 120 mg·kg-1 ,SCr,BUN and mDA in SI 360 mg·kg-1 group were aII siginificantIy Iower(P﹤0.05,P﹤0.01),but SOD was higher(P﹤0.01). Compared with normaI controI group,the expression of nephrin protein greatIy decreased(P﹤0.01),whiIe the expres-sion of TNF-α protein greatIy increased in modeI group( P ﹤0.01). Compared with modeI group,the expression of nephrin protein greatIy increased in SI 40,120 and 360 mg·kg-1 groups(P﹤0.01),whiIe the expression of TNF-α and NF-κB protein greatIy decreased in SI 120 and 360 mg·kg-1 groups(P﹤0.01). CONCLUSlON The mechanism by which SI protects the kidney may be partIy reIated to anti-infIammation,antioxidation and increasing the expression of nephrin in diabetic rats.