Relieve Lead Poisoning And Anti-chronic Renal Failure Activities Of Extracellular Polysaccharides From Lachnum Sp.

In this study,the physicochemical properties and the immune activities of the extracellular polysaccharide and its dipeptide derivative polysaccharide(LEP240-RH)were studied.Furthermore,we also studied the renal protective effect of LEP240 on mice with chronic renal failure.In addition,the protective effects of LEP281 on liver and kidney in mice induced by lead poisoning were evaluated.The extracellular polysaccharide of Lachnum YM240 was isolated and purified to obtain homogenous polysaccharide.After dipeptide(constitute of arginine and histidine)modification,the physicochemical properties and the immune activity in vitro of LEP240and LEP240-RH were studied.The results showed that the degree of graft(DG)of the polysaccharide dipeptide derivative of Lachnum was 12.86%,and the molecular weights of LEP240 and LEP240-RH were 4.26×10~5 Da and 1.45×10~5 Da,respectively.The structural characteristics of LEP240 and LEP240-RH were analyzed by FT-IR and NMR.The results showed that a new C-N bond was formed in LEP-RH,indicating that the polysaccharide was successful modified.Scanning electron microscopy(SEM)results showed that the extracted polysaccharide exists in block form with a smooth surface and closely aligned particles;LEP240-RH has morphed into a long strip and the distribution was relatively loose,showing as irregular particles.Rheological studies of LEP240 and LEP240-RH at the same concentration indicated that LEP240 and LEP240-RH have similar shear thinning behavior and can form a gel structure.The results of thermal characterization(DSC)indicated that LEP240-RH has better thermal stability than LEP240.LEP240 has two decomposition processes during temperature increase,while LEP240-RH has three decomposition reactions,indicating that the modified polysaccharide has new chemical bonds formation.In addition,the results of immunization experiments in vitro showed that treatment with higher doses(200?g/mL)of LEP240 and LEP240-RH stimulated the proliferation of RAW264.7 macrophages and increased cytokines(IL-2,IL-6 and TNF-The secretion of?),and LEP-RH showed better effect.Moreover,the present study was also investigated the liver and kidney protective efficacy of LEP281 polysaccharide against Pb-induced toxicity in mice.The results showed that LEP281 reduced the weight loss which caused by Pb.Biochemical analysis demonstrated that treatment with LEP281 could improve the antioxidant levels(CAT,GSH-Px and MDA)and tissue damage in liver and kidney tissues of mice.Histopathological observations indicated that LEP281 could attenuate liver and kidney cell injury induced by Pb.To confirmed the protective mechanism of liver and kidney,the levels of key proteins'(caspase-3,Bax,Bcl-2,TGF-?1 and?-SMA)expression which related to apoptosis of liver and kidney cells were quantified by Western blot.The results showed that high dose of LEP281(200 mg/kg)can protect and repaired lead-induced liver and kidney damage by regulating apoptosis.The chronic renal failure(CRF)was constructed by feeding adenine to evaluate the renal protective effect of LEP240.Histopathology analysis indicated that LEP240 could decrease the expression of collagen in CRF mice to reduce renal fibrosis area.In addition,the results of mRNA and western experiments of TGF-?,?-SMA,Smad3 and p-Smad3expression suggested that the effect of improving kidney function may be conferred through TGF/Smad pathway.