Effect of combination therapy of glycyrrhizin acid and prostaglandin E1 on renal interstitial fibrosis in rats

Objective To investigate the effect of glycyrrhizin acid(GA) and prostaglandin E1(PGE1) on renal interstitial fibrosis(RIF) in rats.Methods Rat models of unilateral ureteral obstruction(UUO) were established by ligating left ureteral.120 rats were randomly divided into 5 groups: sham group,model group,GA group,PGE1 group and GA+PGE1 group.8 rats in each group were sacrificed at days 7,14 and 21 after operation.The serum level of creatinine(CREA) was determined,and the histopathological examination of renal tissue were observed by HE staining under optical microscope.The serum levels of transforming growth factor β1(TGF-β1) and connective tissue growth factor(CTGF) were detected by ELISA.The expressions of CTGF and TGF-β1 in renal tissue were observed by immunohistochemical staining.Results In model group,histopathological scores,levels of serum CREA,TGF-β1 and CTGF,and the expressions of TGF-β1 and CTGF were all significantly increased than those in sham group on days 14 and 21 after operation(P0.01).In GA+PGE1 group,the degree of renal interstitial damage,and serum contents and expressions of TGF-β1 and CTGF were remarkably reduced compared with those in other treatment groups(P0.01).Conclusion GA and PGE1 have potent preventive effect on RIF in UUO rats,which may be related to down-regulation of TGF-β1 and CTGF.