Immunoactivities and antineoplastic activities of Saccharomyces cerevisiae mannoprotein

The alkaline extract Saccharomyces cerevisiae mannoprotein (ASMP), hot water extract S. cerevisiae mannoprotein (WSMP) and deproteinized water extract S. cerevisiae mannoprotein (DWSMP) showed significant immunomodulatory activities in this study. Effect of each polysaccharide on the proliferation of T lymphocytes induced by Con A was measured in vitro, and the lymphocyte proliferation induced by WSMP and DWSMP were significantly increased compared with Con A group (p < 0.01). The polysaccharide ASMP, WSMP and DWSMP could stimulate T cell-mediate immunity through delayed-type hypersensitivity, and the phagocytic ratio was significantly increased by WSMP and DWSMP (p < 0.05). Based on these results, the ASMP, WSMP and DWSMP suggested as the supplement for immune enhancement. The inhibition ratio of HepG2, HL-60 and Eca109 cells was observed and compared with control, the result indicated that hot water extract mannoprotein isolated from S. cerevisiae could be considered as an effective natural antitumor source, but alkali extract mannoprotein had not found distinct inhibition activity.