Immunomodulatory and antioxidant activity of a Siraitia grosvenorii polysaccharide in mice

The aim of this present study was to investigate the immunomodulatory and antioxidant activities of Siraitia grosvenorii polysaccharide (SGP) using a mouse model. The roles of regulation of SGP were investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, fluorescence method and ELISA method. The chemical structures were analyzed by Fourier transform infrared spectroscopy (FTIR) and gas chromatography (GC). The results show that SGP promoted the proliferation of spleen cells and regulated the level of reactive oxygen species (ROS) in vitro. Furthermore, it significantly raised spleen and thymus indices and superoxidase dismutase activity and regulated the cytokine levels of spleen and thymus in mice in vivo. These findings suggest that SGP possesses immunomodulatory and antioxidant effects.