Anti-food Allergic Activity Of Sulfated Polysaccharide From Gracilaria Lemaneiformis

Food allergy is a common allergic disease and food safety issue which has wide concern from government and public,its incidence is increasing year by year,and it has serious impact on the health of allergic people.In order to control the growth of the allergic incidence,the development of new natural active substances which have the preventive or treatment effect on food allergy cause many attentions from more and more scholars.GLSP(sulfated polysaccharide from Gracilaria lemaneiformis)is a sulfated polysaccharide extracted from Gracilaria lemaneiformis,which have several bioactivities such as anti-tumor,anti-virus,and anti-hypoglycemia.Until now,few study on their anti-allergic activity was reported.So investigation of GLSP anti-allergy and mechanisms will be meaningful for the further development of novel function food or anti-allergy drug.The polysaccharide was isolated from Gracilaria lemaneiformis with hot-water extraction,evaporation under reduced pressure,precipitated by ethanol,then was purified by DEAE-cellulose 52 chromatographic column orderly.The average molecular weight of the purified polysaccharide was 152,481 Da.The monosaccharide in polysaccharide is galactose by High Performance Liquid Chromatography(HPLC)analysis,and its content was 87.49%.It has 3,6-anhydrogalactose and SO42-through ftir spectrum FTIR analysis,and the contents are 8.23% and 11.26,respectively.Through the cell model experiments,GLSP had the ability to inhibit the degranulation of Rat Basophilic Leukemia(RBL)-2H3 cells,to suppress the release of histamine and reactive oxygen species(ROS),to decrease the levels of cytokines(interleukin(IL)-4,Tumor Necrosis Factor(TNF)-?).The inhibition of degranulation is connected with the content of SO42-in GLSP.The expression of CD63 and CD203 c in KU812 cells is decreased by GLSP,the inhibition ratio is 49.43%,34.41%,respectively.And the suppression of GLSP is dependent on the inhibition of p38 Mitogen-activated protein kinase(MAPK).According to the experiments of tropomyosin(TM)-sensitized Balb/c mice,GLSP was able to alleviate allergy symptoms,to decrease the levels of histamine and mouse mast cells protease(mMCP)-1,to reduce TM-specific immuneglobulin(IgE)and IgG1 levels,to suppress the production of Th2 cytokines(IL-4 and IL-13)and the expression of GATA-3,and to promote the production of regulatory T cells cytokines(IL-10 and transforming growth factor(TGF)-?)and the expression of Forkhead box(Fox)p3.There is little effect on the production of Th1 cytokines(interferon(IFN)-?)and the expression of T-bet.The anti-allergic effect of GLSP on prevention is better than treatment.In conclusions,GLSP is able to inhibit the activation of mast cells and basiphilics,to alleviate the allergic symptoms,to decrease the TM-specific IgE and IgG1 levels,to promote the regulatory T cells,and to suppress Th2 cells.The p38 Mitogen-activated protein kinase(MAPK)signal pathway can be inhibited by the sulfated polysaccharide from Gracilaria lemaneiformis.The results from experiments in vitro and in vivo suggesting that the anti-food allergic activity of GLSP is dependent on the immnosuppression and the inhibition of p38 MAPK.