Objective:To investigate the effect of astragalus polysaccharide(APS)on macrophage phagocytosis of P.aerugino-sa and its related mechanism.Methods:The effect of APS on the activity of macrophages was detected by CCK-8 assay.The effect of APS on macrophage phagocytosis related signal pathways were detected by Western blot.Gentamicin protection test and flow cytometry were employed to evaluate the effect of APS on macrophage phagocytosis of P.aeruginosa.Then the macrophages were pretreated with the inhibitors of TLR4,NF-κB,STAT3,MAPK and PI3K to assess the mechanism mediating APS on macrophage phagocytosis.Results:APS promotes the activity of macrophages,and significantly promoted the phagocytosis of P.aeruginosa by macrophages.Fur-thermore,macrophage phagocytosis of P.aeruginosa was significantly inhibited by TLR4 inhibitors(TAK242)and PI3K inhibitors(LY294002),but not affected by NF-κB,STAT3 and MAPK inhibitors.Conclusion:APS has no toxicity on macrophages,and can promote the phagocytosis of macrophages to P.aeruginosa,the underlying mechanism may be related to TLR4/PI3K pathway.

Objective:To investigate the effect of astragalus polysaccharide(APS)on macrophage phagocytosis of P.aerugino-sa and its related mechanism.Methods:The effect of APS on the activity of macrophages was detected by CCK-8 assay.The effect of APS on macrophage phagocytosis related signal pathways were detected by Western blot.Gentamicin protection test and flow cytometry were employed to evaluate the effect of APS on macrophage phagocytosis of P.aeruginosa.Then the macrophages were pretreated with the inhibitors of TLR4,NF-κB,STAT3,MAPK and PI3K to assess the mechanism mediating APS on macrophage phagocytosis.Results:APS promotes the activity of macrophages,and significantly promoted the phagocytosis of P.aeruginosa by macrophages.Fur-thermore,macrophage phagocytosis of P.aeruginosa was significantly inhibited by TLR4 inhibitors(TAK242)and PI3K inhibitors(LY294002),but not affected by NF-κB,STAT3 and MAPK inhibitors.Conclusion:APS has no toxicity on macrophages,and can promote the phagocytosis of macrophages to P.aeruginosa,the underlying mechanism may be related to TLR4/PI3K pathway.