OBJECTIVETo investigate the effect and mechanism of Erigeron Injection (EI) on renal interstitial fibrosis in rats.

METHODSUnilateral ureteral obstruction (UUO) model rats were taken as the subject of study. Thirty-six Sprague-Dawley rats were randomly divided into the control group (A), the UUO model group (B) and the treatment group (C) treated with intraperitoneal injection of EI 5 mL/kg per day from 24 h before to 9 days after the operation. On the 10th day of UUO, rats were killed and their kidneys were processed to paraffin sections with HE, PAS and picro-sirius-red staining. The pathological change of renal tubular interstitial tissue and relative cortical/interstitial volume (C/I) as well as the relative content of collagen (RC) were observed by light microscope. The expression of transforming growth factor beta1 (TGF-beta1), alpha-smooth muscle actin (alpha-SMA) and collagen I in the renal mesenchyma were examined by immunohistochemistry.

RESULTSMarked renal interstitial fibrosis changes were found in Group B and C, but the changes were milder in Group C. C/I and RC were higher in Groups B and C as compared with those in Group A (P < 0.01), but they were much lower in Group C than in Group B (P < 0.01). The expression of TGF-beta1, alpha-SMA and collagen I were higher in Group B and C than those in Group A (P < 0.05), but they were lower in Group C than in Group B (P < 0.05).

CONCLUSIONEI could ameliorate renal interstitial fibrosis in rats, which might be partially realized by down-regulating the expression of TGF-beta1 to prevent the renal epithelial cell differentiation and reducing the synthesis of collagen I.