Characterization and protective effect of Polygonatum sibiricum polysaccharide against cyclophosphamide-induced immunosuppression in Balb/c mice

In this study, the polysaccharide from Polygonatum sibiricum (PSP) was evaluated for the immunomodulatory activity by the cyclophosphamide (Cy)-induced immunosuppressed-model in vivo. The PSP has been analyzed in order to identify a variety of chemical properties such as monosaccharide compositions and structural confirmation. The results show that the main components of PSP were galactose and rhamnose. The PSP could significantly stimulate neutral red phagocytosis of RAW264.7 macrophages. Compared with the cyclophosphamide group, PSP accelerated recovery of spleen and thymus indexes, and enhanced T cell and B cell proliferation responses as well as peritoneal macrophage phagocytosis. In addition, PSP treatment restored the levels of IL-2, TNF-α, IL-8 and IL-10 in the serum of the Cy-treated mice in a dose-dependent manner. Therefore, PSP played an important role in the protection against immunosuppression in the Cy-treated mice and could be used as a potential immunostimulant agent.