Experimental Study Of The Immunomodulatory Effects Of Fomes Fomentarius Polysaccharides

Objectives:To investigate the immunomodulatory effects of Fomes fomentarius polysacchafides(FFP) and the underlying mechanisms.Methods:Normal mouse immunocyte metabolic activity was determined with methylthiazolyl tetrazolium(MTT) colorimetry assay,light microscope was applied to examine morphologic changes of mouse peritoneal exudate cells after treated with the FFP in vitro,the amounts of tumor necrosis factorα(TNF-α),interferonγ(INF-γ) and interleukin 2(IL-2) were measured with ELISA assay,macrophage phagocytosis was determined with percentage of phagocytized chicken red blood cells(CRBC),and humoral immunity was evaluated with the production of specific antibody(haemolysin) against sheep red blood cells(SRBC).The immunosuppressed mice were induced by cyclophosphamide(CP,SC.).Immune organs were weighed and indexes of immune organs were derived by calculation.Phagocytosis of mononuclear macrophage was determined by the method of carbon particle clearance test.The immunosuppressed mouse humoral immunity was evaluated with the production of specific antibody(haemolysin) against sheep red blood cells also.And the immunosuppressed mouse cellular immunity was assessed with the mouse delayed type hypersensitivity(DTH) model induced by DNFB.The peripheral leukocyte count was carried out by the method of microscopic counting.Results:It was found that FFP(100,50,25μg/ml)significantly enhanced the splenocyte metabolic activity(P=0.000,P=0.001,P=0.004),and production of cytokines such as TNF-α(P=0.000,P=0.000,P=0.001 ),IFN-γ(P=0.000,P=0.000,P=0.001 ) and IL-2(P=0.002,P=0.002,P=0.023) in normal mice in vitro,compared with control group,with TNF-αlevel being increased most obviously.The polysaccharides markedly promoted the metabolic activity of mouse peritoneal exudate cells (P=0.000,P=0.000,P=0.004) and production of TNF-αby the cells in normal mice in vitro(P=0.000,P=0.000,P=0.000).And the effects were dose-dependent in a certain concentration range.Light microscopic observation showed that the density of mouse peritoneal exudate cells treated with FFP was increased and morphological changes were evident.Cells spread out in round,elliptic,fusiform and irregular shapes.FFP(100,50,25mg/kg)increased the level of serum hemolysin induced by SRBC immunization(P=0.005,P=0.017,P=0.044),and FFP(100,50mg/kg) remarkably potentiated the rate and index of phagocytosis of CRBC by peritoneal macrophages in normal mice in vivo respectively(P=0.000,P=0.002),(P=0.000, P=0.004).FFP(200,100 mg/kg) markedly increased the indexes of thymus and spleen in immunosuppressed mice in vivo respectively(P=0.003,P=0.044),(P=0.010, P=0.038).FFP(200 mg/kg) remarkably promoted the serum clearance of carbon particles in immunosuppressed mice induced by cyclophosphamide,indicating an increase in phagocytic function of macrophages in the mice in vivo(P=0.015). FFP(200,100 mg/kg) increased the level of serum hemolysin induced by SRBC immunization in immunosuppressed mice(P=0.005,P=0.031).FFP(200,100 mg/kg) remarkably increased the swelling degree in DTH in immunosuppressed mice induced by CP in vivo(P=0.003,P=0.029).FFP(200 mg/kg) remarkably increased the swelling rate in DTH in immunosuppressed mice induced by CP in vivo (P=0.017).FFP(200,100 mg/kg) increased the level of peripheral leukocyte count in immunosuppressed mice induced by CP in vivo(P=0.001,P=0.033)Conclusion:1.Fomesfomentarius polysaccharides(FFP) have the capacity of enhancement of immune function in normal mice.The polysaccharides can significantly enhance immunocyte metabolic activity,promote secretion of TNF-α,IFN-γ,and IL-2 by immunocytes in normal mice in vitro,and potentiate mouse humoral immune response in vivo.2.FFP can promote secretion of IFN-γ,and IL-2 by mouse immunocytes in vitro, and increase the level of serum hemolysin(IgM) induced by SRBC immunization in normal mice in vivo,suggesting a mechanism in which potentiated humoral immune response by FFP may be related with their promotion of secretion of IFN-γand IL-2 by mouse immunocytes.3.FFP can markedly promote the metabolic activity of mouse peritoneal exudate cells and production of TNF-αby the cells in vitro.FFP can remarkably potentiate the phagocytosis of mouse peritoneal macrophages in normal mice in vivo.It is suggested that macrophage is one of the target cells for FFP.4.The experimental model of immunosuppressed mice induced by cyclophosphamide(CP,SC.) was established successfully.5.FFP have the capacity of enhancement of immune function in immunosuppressed mice induced by CP in vivo.FFP can markedly increase the indexes of thymus and spleen in immunosuppressed mice,elevate the corrected phagocytic index(α),potentiate the phagocytic function of macrophages,increase the level of serum hemolysin,potentiate DTH,and increase the level of peripheral leukocyte count.It is suggested that FFP enhance obviously the function of cellular and humoral immunity in immunosuppressed mice induced by CP in vivo.6.The preliminary experimental results demonstrate that FFP is a sort of effective immunomodulator.