Abstract
The polysaccharide As-I, a β-1, 3 glucan possessing 1, 6-linked side chains, isolated from mycelia of Cochliobolus miyabeanus (Ascomycetes) , inhibited the growth of Sarcoma 180 solid tumor in ICR mice. As-I also inhibited the growth of solid tumors of IMC-carcinoma in CDF1 mice by 32% and that of solid tumors of MM-46 carcinoma in C3H mice by 99.3% at 0.1 mg/kg/d (10 times). However, As-I has no direct cytotoxic activity against tumor cells. The effect of As-I on macrophages was studied, because branched β-1, 3 glucans may stimulate cellular immunity. As-I activated macrophage spreading and phagocytosis of tumor cells. Accordingly, the antitumor activity of As-I might be host-mediated, like that of other β-1, 3 glucans.
