ABSTRACT
AIM:To investigate the immunomodulatory effect of astragalus saponin(AS)on macrophages and explore the mechanism of its immunomodulation.METHODS:By adding different concentrations of AS into cultured mouse peritoneal macrophages in vitro,the influence of AS on the synthesis of nitro oxide(NO)was detected by NO kit(enzymatic method).MTT assay was used to determine the cytotoxicity of macrophages induced by AS.The morphological changes of macrophages were observed under transmission electron microscope.LSCM and specificity fluorescent probe Fluo-3/AM were applied to observe the change of Ca2+ in macrophages induced by AS.RESULTS:AS significantly increased NO synthesis,enhanced the effects of mouse peritoneal macrophages on killing carcinoma cells.Cell surface projection exhibited multiplication,becoming thickening and growth longer via transmission electron microscope.Increase in intracellular Ca2+ in macrophages was also observed.CONCLUSION:AS enhances the immune function of macrophages by increasing NO synthesis and enhancing cytotoxicity.The increased intracellular Ca2+ may be the mechanism of immunomodulatory effect of AS.