Effects of Astragalus Polysaccharides on Expression of iNOS Gene and Production of NO in Mous Peritoneal Macrophages

To study the effects of astragalus polysaccharides(APS) on the inducible nitric oxide synthase(iNOS) gene expression and nitric oxide(NO) secretion of mouse peritoneal macrophages in vivo,Kunming mice were intraperitoneally administered with 1mL saline,5mg / kg,25mg / kg,50mg / kg,100 mg / kg,200mg / kg APS twice daily for 7days.Peritoneal macrophages of mice were separated and expression level of iNOS gene in the cells was detected by QRT-PCR.After incubation for 24h,the content of NO in the culture supernatant,as well as phgocytic power of peritoneal macrophages were determined by using nitrate reductase and neutral red respectively.The results showed that,compared with the saline group,APS(50mg / kg,100mg / kg and 200mg / kg) significantly increased the expression of iNOS gene,the production of NO and phagocytosis of neutral red of peritoneal macrophages were dose-dependent.The results suggest that increasing the production of NO via up-regulation of iNOS gene expression is one of the mechanisms of APS to enhance the functions of macrophage.