Anti-inflammatory Effects of Morchella Esculenta Polysaccharide and Its Derivatives in Fine Particulate Matter-Treated NR8383 Cells.

Fine particulate matter (PM2.5) exposure could cause many acute and chronic respiratory diseases. In this study the protective effects of polysaccharide from Morchella esculenta (FMP-1) and its derivatives against PM2.5-induced inflammation were evaluated. By flow cytometry and ELISA analysis, sulfated polysaccharide SFMP-1 showed the best protective effect in reducing PM2.5-induced cell death, cell apoptosis and production of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β), which was accompanied by a diminished level in reactive oxygen species (ROS) formation caused by PM2.5 in rat alveolar macrophage NR8383 cells. Furthermore, the mechanism was studied by immunofluorescence, qRT-PCR and western blotting. SFMP-1 could down-regulate the expression of inducible NO synthesis (iNOS) and cyclooxygenase-2 (COX-2) at both mRNA and protein levels in PM2.5-treated cells. The PM2.5-induced phosphorylation of nuclear factor-kappa B (NF-κB) was also reduced through suppressing nuclear translation of the NF-κB and inhibiting the degradation and phosphorylation of IκBα. These results indicated that SFMP-1 could protect NR8383 cells from PM2.5-induced inflammation by inhibiting NF-κB activation.