Influence of Curcumin on Renal Interstitial Fibrosis in Unilateral Ureteral Obstruction Rats

Objective To investigate the effect of curcumin on the expression of TGF-β1、CTGF and its mechanism on renal interstitial fibrosis following unilateral ureteral obstruction(UUO)in rat kidney.Methods Unilateral ureteral obstruction(UUO)rat animal models were used.Male wistar rats were randomly divided into three groups with 8 rats each:sham-operated group(0.9%saline solution),model group(dimethyl sulfoxide),curcumin treatment group(curcumin 100 mg·kg-1·d-1).Sham-operated rats had their ureters exposed and manipulated but not ligated and snipping.Medicines were given intraperitoneally daily two days after the operation.All rats were killed 4 weeks after surgery,and the kidneys were removed.One part of the kidneys was fixed in 10% phosphate-buffered formalin for pathological and immunohistochemical studies after paraffin embedding.Firstly,renal function was examined in each rat by heart puncture.Secondly,the sites and levels of protein expression of TGF-β1、CTGF and ColⅠwere detected by immunohistochemistry staining.Lastly,the degree of tubulointerstitial fibrosis was scored by HE、Masson staining.Results Compared with sham-operated group,the blood uria nitrogen level was significantly increased in model group〔(10.59±1.53)vs(7.08±0.53)mmol/L〕(P0.01),but serum creatinine was normal in each group.Furthermore,the relative area of interstitial fibrosis was also significantly enlarged in the model group(0.319±0.104 vs 0.039±0.007)(P0.01).Meanwhile,compared with sham-operated group,the expressions of TGF-β1、CTGF and ColⅠ protein were significantly up-regulated in their kidney tissue(0.288±0.058 vs 0.005±0.003;0.314±0.044 vs 0.004±0.001;0.062±0.015 vs 0.012±0.002)(P0.01 or 0.05)in model group.After intervention with curcumin,the upregulations of the above-mentioned parameters were all significantly inhibited,and there were significant differences between model group and treatment group(P0.01 or 0.05).Conclusions The effect of curcumin on ameliorating renal interstitial fibrosis may be correlated with its inhibition on over-expressions of TGF-β1 and CTGF in kidney tissue.