Objective To investigate the expression transforming growth factor?1(TGF-?1),Smad7 and connective tissue growth factor(CTGF) in rats with renal tubulointerstitial fibrosis and the effects of Gypenosides(GPs) treatment on expression of TGF-?,Smad7 and CTGF.Methods Unilateral ureteral Obstruction(UUO) rat animal models were used and the rats were divided into GPs group(Gypenosides 200 mg?Kg~(-1)?d~(-1) by gastric gavage from 3d before the obstruction to 14 days after the induction),model group and sham operated group.The expression of TGF-?1,Smad7 and CTGF in the obstructed kidneys was assessed by RT-PCR,immunohistochemistry and HE staining methods after 3,7,and 14d respectively.The degree of tubulointerstitial damage was scored by Masson staining methods.Results Compared with the sham operated group,the expressions of TGF-?1,CTGF mRNA and protein were markedly increased in UUO group,and the expression of Smad7 mRNA and protein was markedly decreased(all P