OBJECTIVETo explore the protective effects of bicyclol against renal interstitial fibrosis and possible mechanisms of the protection.

METHODSEighty-one Sprague-Dawley (SD) rats were randomly assigned to a sham-operated group and UUO groups with and without bicyclol treatment. A rat model of renal interstitial fibrosis was prepared by unilateral ureteral obstruction (UUO). Renal tissues were examined by hematoxylin & eosin and Masson staining on 7, 14 and 21 days. Immunhistochemistry was used for determining plasminogen activator inhibitor-1(PAI-1) expression in the renal interstitium. PAI-1 mRNA expression in renal tissues was semi-quantitatively determined by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTSThe relative areas of renal interstitial fibrosis in the bicyclol-treated UUO group 7, 14 and 21 days after operation were (9.6 ± 0.6)%, (16.8 ± 0.8)% and (33.6 ± 1.6)% respectively, which were significantly lower than those in the untreated UUO group [13.0 ± 0.7)%, (25.8 ± 1.5)% and (53.2 ± 2.5)% respectively] (P<0.05). The levels of protein and mRNA expression of PAI-1 in the bicyclol-treated UUO group decreased significantly compared with those in the untreated UUO group 7, 14 and 21 days after operation (P<0.05).

CONCLUSIONSBicyclol can alleviate renal interstitial injury and renal interstitial fibrosis caused by UUO in rats, possibly through a downregulation of renal PAI-1 expression.