Effect Of Fucoidan On Renal Interstitial Fibrosis In Adenine-induced Chronic Renal Failure In Rats

Background Renal interstitial fibrosis is a collective term for chronic renalfailure(CRF). Studies have unambiguously illustrated a definite importance ofepithelia-mesenchymal transition (EMT) in progressive renal fibrosis. A few ofresearches have suggested that fucoidan improves renal blood and has a renopotectiveeffect. However, the effect of fucoidan on EMT has not been reported.Objective To examine the effect of fucoidan on EMT and renal interstitial fibrosisin the adenine-induced chronic renal failure in rats and elucidate its possiblemechanisms.Methods Sixty-three male Wistar rats were divided into three groups:(1)normalgroup (n=15), (2) CRF group(n=24),(3)CRF+FPS group (n=24). CRF rats free accessto food containing 0.75% adenine. CRF+FPS rats access to food containing 0.75%adenine, as well as FPS 200mg/kg/day, intragastric administration. All the rats weresacrificed at the end of week 2,4,6. The blood was collected for biochemical analysis.Masson stain of renal tissue was performed to grade the extent of renal interstitialfibrosis. Expressions of alpha smooth muscle actin(α-SMA), E-cadherin, monocytechemoattractant protein-1(MCP-1), transforming growth factor-β1(TGF-β1), vascularendothelial growth factor (VEGF) and thrombospondin-1(TSP-1) were detected byimmunohistological method, Western blot or RT-PCR.Results Serum creatinine values of CRF rats reached a significant increase of 3-4 times thoseof normal rats on the fourteenth experimental day. The urinary protein levels in CRF+FPSgroup were evidently lower than that in CRF group, but serum creatinine levels werenot significantly different from that in CRF rats. Furthermore, interstitium and tubularhistopathological changes were lessened in FPS-treated rats. The expressions ofα-SMA, MCP-1, TGF-β1 and TSP-1 in renal tissue were significantly lower inCRF+FPS group compared with the CRF group, respectively. Meanwhile VEGFexpression in renal tissue was significantly higher in CRF+FPS group than in the CRFrats.Conclusions FPS may ameliorate EMT and the renal fibrosis in adenine-inducedchronic renal failure in rats. This effect is probably related to down-regulatedexpressions of TGF-β₁, MCP-1 and TSP-1, and up-regulated expression of VEGF.The exact mechanism still needs to be studied further.