TGFB1 and Ureteral obstruction: Compared with group S, the expression of TGF-β1 mRNA and protein in the kidney tissue of rats in groups C and E increased significantly, but the level of TGF-β1 mRNA and protein in the kidney tissue of rats in group E was lower than those in group C. Once again, it was proved that ursolic acid can reduce the level of renal interstitial fibrosis after unilateral ureteral obstruction.