Influence of Salvianolic Acid B on Expression of MMP-2 in Renal Fibrosis Rats

Objective:To investigate the effect of salvianolic acid B(SA-B)on renal interstitial fibrosis in rats and its mechanisms.Methods:Thirty six male sprague-dawley rats were randomly divided into sham group,model group and SA-B treatment group.Rat models of renal interstitial fibrosis were established with unilateral ureteral ligation(UUO)Meanwhile,the rats in SA-B treatment group were treated with SA-B at a dose of 1.25 mg/kg daily.After 14 and 21 days of UUO,6 rats in each group were sacrificed respectively and the obstructed kidney were collected for HE staining and methenamine silver(PASM)stain to check the histological changes of renal interstitial tissues.Hydroxyproline(Hyp)content of kidney was assayed with jamall's method.The protein expressions of MMP-2 and TIMP-2 in renal tissues were detected with Western blot,and the activities of MMP-2 were detected by gelatin zymography.Results:Serum creatinine(Scr),blood urea nitrogen(BUN)and Hyp in the model group were significantly higher than those in the sham group.Moreover,in the model group,tubules lumen were widened and the basement membranes were thickened than that in sham group.There was no significant difference in glomerular damage between the the model group and sham group.Many inflammatory cells infiltrated in the renal interstitium parallels the extent of fibrogenesis.The tubular epithelial cells were karyorrhexis or karyolysis,some tubulars were atrophy.The protein expression and activity of MMP-2 and protein expression of TIMP-2 in kidney tissue were significantly up-regulated in the model group.After intervention with SA-B,the renal pathological status in the treatment group was significantly alleviated,the expression and activity of MMP-2 were significantly down-regulated,and the level of TIMP-2 in renal tissues decreased significantly.Conclusion:SA-B can alleviate renal interstitial fibrosis and improve the renal function by inhibiting MMP-2 and TIMP-2 expressions in UUO rats.