Screening of host-mediated antitumor polysaccharides by crossed immunoelectrophoresis using fresh human serum.

On crossed immunoelectrophoresis, human serum C3 (the third component of complement) converted by antitumor polysaccharides (ATSO [antitumor polysaccharide oral], AB-P [Agaricaus blazei polysaccharide], GU-P [Grifora umbellata polysaccharide], PS-K [polysaccharide Kureha] and zymosan) moved faster than native C3, appearing as the 3rd peak. The ratio of height of the 3rd peak to the alpha 2-macroglobulin (alpha 2-M) peak was linearly proportional to the dose of ATSO. At the dose of 500 micrograms/ml antitumor polysaccharides, the ratios were higher than 0.76, and the ratios for the serum treated with polysaccharide of no antitumor activity (dextran and gum arabic) were less than about 0.52. This ratio readily determined in vivo can be used as a measure for the antitumor activity of polysaccharides.