Antitumor activity in mice of orally administered polysaccharide from Kefir grain.

The antitumor activity of a water-soluble polysaccharide (KGF-C), isolated from the Kefir grain, was studied in the mice subcutaneously inoculated with Ehrlich carcinoma (EC) or Sarcoma 180 (S-180). The growth of EC and S-180 solid tumor was inhibited by 40-59% and 21-81%, respectively, by oral administration of KGF-C as compared with the unadministered mice. The tumor growth was similarly inhibited by intraperitoneal administration. The mechanism of the antitumor activity of KGF-C was considered to be host-mediated because of the lack of direct in vitro effect on tumor cells.