Antitumor activity of acidic mannan fraction from bakers' yeast.

The acidic fraction of bakers' yeast mannan containing mannose (93.6%), nitrogen (1.0%), and phosphorus (0.6%), designated as WAM025, showed a marked antitumor activity against the ascites forms of Ehrlich, sarcoma 180 and Meth A tumors in vivo. Namely, a 100% survival of mice transplanted with Ehrlich or sarcoma 180 ascites tumor, 1 X 10(5) cells/ddY strain mouse, was obtained by the intraperitoneal administration of WAM025, 150 mg/kg/d for 10 d. This effect evoked by WAM025 seems to be attributed to the activation of peritoneal adherent cells in mice, because a significant elevation of lysosomal enzyme level and active oxygen generation was observed on the peritoneal adherent cells obtained from the mannan-administered mice.