Characterization and immunoenhancement activities of Eucommia ulmoides polysaccharides

The aim of this study is to investigate the physicochemical properties, monosaccharide composition and immunomodulatory effects of Eucommia ulmoides Oliv. polysaccharide. The average molecular weight (Mw) of EUPS was 11.4632 × 105 Da. The monosaccharide components of EUPS were glucose, fructose, mannose, fucose, galactose and arabinose with a relative mass of 36.6%, 16.6%, 14.2%, 15.7%, 9.5% and 7.4%, respectively. In in vitro experiments, EUPS (1.2–75 μg/mL) treatment of dendritic cells (DC) increased their surface expression of MHC I/II, CD80, CD40, and CD86 and indicated that EUPS induced DC maturation. Furthermore, EUPS also significantly enhanced lymphocyte proliferation and significantly enhanced cytokine (IL-4 and IFN-γ) production. In in vivo experiments, our data showed that EUPS could significantly enhance the FMDV-specific IgG, IgG1, IgG2a, and IgG2b antibody titers and T cell proliferation. Together, these results suggest that EUPS is a strong immunostimulant.