Abstract
To investigate the immunomodulatory activity and explore the mechanism of Paulownia tomentosa flower polysaccharides (PTFP). PTFP was orally administrated to mice for seven successive days before and after Newcastle disease vaccination. The results demonstrated that compared with the vaccine control (VC) group, PTFP enhanced the inhibition of hemagglutination assay antibody titers, promoted the antigen-specific immunoglobulin (Ig)G, IgG1, IgG2a, and IgG2b antibodies responses, enhanced proliferation of spleen T and B lymphocytes, increased the secretions of interferon-gamma and interleukin-10 cytokines of spleen lymphocytes, and promoted the activation of natural killer cells. Therefore, PTFP, as an effective immunopotentiator, could induce a mixed T-helper (Th)1 and Th2 immune responses and an innate immune response.