Immunomodulatory Effect of Polysaccharide Extracted from Sanghuangporus baumi Mycelia in LPS-Induced RAW264.7 Macrophages

Sanghuangporus baumi is a kind of medicinal fungus with high activity. The aim of the present study was to investigate the immunoregulatory effects of Sanghuangporus baumi mycelia polysaccharides (SJ) on lipopolysaccharide (LPS)-induced RAW264.7 cells. In this study, Sanghuangporus baumi mycelia polysaccharides (SJ) were taken as the study subjects，and LPS-stimulated RAW264.7 macrophages were used as the cell model. The experiment was divided into three groups: Control group, LPS (model) and LPS+SJ groups. A CCK-8 kit was used to detect the viability of RAW264.7 cells. The effects of SJ on nitric oxide, and cytokines (IL-6, IL-1β, and TNF-α) production in LPS-stimulated RAW264.7 macrophages were measured by enzyme-linked immunoassay assay (ELISA). Furthermore, the effects of SJ on the protein levels of IL-6, TNF-α, IL-1β and inducible nitric oxide synthase (iNOS) were investigated by Western-Blot analysis. The results indicated that SJ increased 20.5%~50% cell viability at different concentrations compared to the control group. SJ at 200 μg/mL potently inhibited the release of nitric oxide and cytokine production in LPS-stimulated RAW264.7 (P<0.001), and compared with the LPS group, the secretion of NO, TNF-α, IL-6 and IL-1β decreased by 21.62%, 29.99%, 35.5% and 50.03%, respectively. Moreover, SJ also reduced LPS-induced protein expression levels of IL-6, TNF-α, IL-1β and iNOS in a dose-dependent fashion (P