Effects Of Rosmarinic Acid On Interstitial Fibrosis In Rat Kidney With Unilateral Ureteral Obstruction

Objective By observing the effects of rosmarinic acid（RA）on interstitial fibrosis in themodel of rat kidney with unilateral ureteral obstruction（UUO），its probable mechanismwill be explored，and then will be provided theoretical basis for protection and control ofrenal interstitial fibrosis.Methods The healthy and clean Sprague-Dawley（SD）male rats were randomly dividedinto four groups：Sham-operation group（SOR，n=5）；unilateral ureteral obstruction modelgroup（UUO，n=5）；UUO with enalapril treatment group（UUO+EN，n=5）；UUO withrosmarinic acid treatment group（UUO+RA，n=5）.After the one week of the adaptabilityfeeding，copy the UUO model，and then gastric perfusion treatment for two weeks.Ratswere sacrificed at day14respectively after the surgery.The renal pathology changes ofobstructed kidneys were observed by HE stain and Masson stain.The expression for bFGFwas examined by immunohistochemistry.The protein expression for TGF-β1and CTGFwere detected by immunohistochemistry and ELISA.The immunohistochemistry wasanalysed semi-quantitative by IPP6.0.Results1.Renal pathology：（1）the naked eyes observation that:Group SOR rats kidneysize，shape normal and dark red；the ligation kidneys of model group rats obviouslyenlarged，color grey red，capsule obvious thickening，cystic sexy，hydronephrosis，pelvisexpansion and the renal thinning；Group UUO+RA and UUO+EN these changes differentrace reduce.（2）HE staining：①Group SOR has no obvious anomaly；②Group UUO thattubular epithelial cells degeneration，necrosis，tubular expansion or atrophy，interstitialinflammatory cell infiltration，renal interstitial fiber material proliferation and so on.③Compared with Group UUO，Group UUO+RA and Group UUO+EN exhibited obviousattenuation of these morphological lesions.2.Masson staining：Group SOR that interstitialcollagen fibers were not obvious；Group UUO renal interstitial collagen fibers with largeproliferation（compared with Group SOR P＜0.05）；Group UUO+RA and UUO+EN renalinterstitial collagen fibers positive staining area compared to Group UUO were signicantly decreased（P＜0.05），but also exceed Group SOR（P＜0.05），between the two treatmentgroups，the difference was not statistically significan（tP＞0.05）.3.Immunohistochemicaldetection of renal tissue prompted that：①Compared with Group SOR，the expression ofTGF-β1、CTGF and bFGF in the tubulointerstitum were significantly increased in GroupUUO（P＜0.05）.②The expression of TGF-β1、CTGF and bFGF in the tubulointerstitumwere all significantly reduced in Group UUO+RA and Group UUO+EN compared toGroup UUO（P＜0.05）.4.Renal tissue by ELISA detection showed that：①Group UUO、UUO+RA and UUO+EN of TGF-β1and CTGF expression level in renal tissue comparedwith Group SOR significantly with increasing（P＜0.05）.②Group UUO+RA andUUO+EN of TGF-β1and CTGF expression level compared with Group UUO significantlywith reducing（P＜0.05）.③Group UUO+RA of TGF-β1expression compared with GroupUUO+EN significantly with reducing（P＜0.05）.Conclution1.Unilateral ureteral obstruction of rats is the ideal animal models of renalinterstitial fibrosis.2.Rosmarinic acid has certain resistance to renal interstitial fibrosis，itsmechanism may be related to directly or indirectly inhibit the expression of TGF-β1、CTGFand bFGF.