OBJECTIVETo study the effect and mechanism of Coicis Semen oil (Kanglaite injection, KLT) on renal interstitial fibrosis induced by unilateral ureteral obstruction (UUO).

METHODFifty-four male SD rats were randomly divided into 3 groups, 6 in each group, the sham operated group, the model group, and the KLT group. Renal interstitial fibrosis model was established in rats by UUO. After administration of KLT (15 mL x kg(-1) x d(-1)) for 3, 7 and 14 days, the dynamic histological changes of renal interstitial tissues were observed and renal damage including tubular impairment and interstitial fibrosis were quantified on HE and Masson stained tissue sections. The expression of alpha-smooth muscle actin (alpha-SMA) and transforming growth factor-beta1 (TGF-beta1) were measured by immunohistochemistry staining sections. The protein expression of p-Smad2 and Smad7 were detected by Western blot respectively.

RESULTThe degree of tubular damage in KLT group was much lower than that in UUO group (P < 0.05). The expression of alpha-SMA and TGF-beta1 was decreased in both UUO group and KLT group, while it was significantly lower in KLT group at every time point. The protein expression of p-Smad2 was obviously decreased while the protein expressions of Smad7 was obviously increased in KLT group, compared with the UUO group (P < 0.05).

CONCLUSIONCoicis Semen oil could attenuate the tubulo-interstitial fibrosis, probable by intervening the TGF-beta/Smads signal transduction pathway of UUO rats.