Study On The Mechanism Of Fucoidan From Laminaria Japonica Resistance To Renal Failure

Fucoidan is a kind of sulfated heteropolysacchrides from brown algae mainlycomposed of fucose. The chemical composition and bioactivity vary as algae speciesand preparation method. It was showed that fucoidan extracted from Laminariajaponica possessed the activities of healing diabetic nephropathy and delaying chronicrenal failure. However, the acting target and mechanism of fucoidan’s delayingchronic renal failure activity are not clear, which limits its clinical application. Inorder to provide some theory and methodology dependence, this paper investigatedfucoidan’s delaying chronic renal failure activity and its mechanism.Acid extraction and water extraction were employed to extract fucoidan fromLaminaria japonica. A lower molecular weight fucoidan, which was prepared byascorbic and hydrogen peroxide degradation, was separated into different chemicalcomponent by DEAE-Sepharose FF column. By the determination of chemicalcomposition of these fucoidan, it was found that molecular weight and chemicalcomposition of these fucoidan samples were quite different from each. Thus wespeculate their different activity of resistance to renal failure.The fucoidan content in organs of mice after intravenous injection wasdetermined by PMP-HPLC method. The results showed that fucoidan dispersedmostly in kidney after0.5h, while barely existing in other organs. This phenomenaaccords with its obvious acticity of resistance to renal failure of fucoidan. Fucoidanplays its activity of resistance to renal failure by kidney itself, rather than by theendocrine system. By measuring the fucoidan content in organs of mice afterintravenous injection of different dosage of fucoidan, the fucoidan content in kidneyand injection dosage have a good linear relationship.MTT method was used to detect the vitality of rat glomerular mesangial cellHBZY-1. It was found that0.5μg/mL of lipopolysaccharide (LPS) and0-100μg/mLof fucoidan had no significant effect on the cell vitality. Griess method was used to detect the concentration of signal molecule NO in cell culture. It was found thatfucoidan can suppress the NO quantity increase of HBZY-1induced by LPS. UsingELISA method to detect the concentrations of TGF-β1in cell lysis solution, it wasfound that fucoidan can decrease the TGF-β1generation of HBZY-1induced by LPS.Therefore, fucoidan can suppress the inflammatory reaction of HBZY-1induced byLPS, thus delaying the process of kidney disease.The automatic biochemical analyzer was used to test the blood urea nitrogen(BUN) and serum creatinine (Scr) content of glycerol induced acute renal failure(ARF) rat. The results showed that the BUN and Scr content of ARF rats increasedobviously, kidney function was damaged. Fucoidan can reduce BUN and Scr contentand improve the renal function. Immunohistochemical method was used to detectheparanase (HPSE) content in rat kidney, it was showed that heparanase contentincreased significantly in kidneys of ARF rat. Fucoidan can reduce the content ofheparanase to a certain extent, thus to improve the kidney function.The research in this paper showed that the fucoidan of Laminaria japonica canbe accumulated in the kidneys, alleviate kidney inflammation, reduce kidneyheparanase content, so as to delay the progress of renal failure, improve the kidneyfunction. It played a certain role in promoting the mechanism research of fucoidanresistance to renal failure.