Effects of a protein-bound polysaccharide from a basidiomycetes against hepatocarcinogenesis induced by 3'-methyl-4-dimethylaminoazobenzene in rats.

: PSK, extracted from mycelia of a strain of Coriolus versicolor, was administered to groups of 20 male Wistar rats before and during treatment with 3'-methyl-4-dimethylaminoazobenzene (3-MDAB). After 24 weeks, the survival rates were significantly higher in the groups given PSK before or with the 3-MDAB than in groups not given PSK or given PSK after 12 weeks of 3-MDAB treatment. Blood alpha-fetoprotein levels, determined every four weeks, increased in all groups after 3-MDAB treatment, but were significantly lower in the groups given PSK before or with the 3-MDAB than in the other groups. The results indicate that PSK had a suppressive effect on 3-MDAB-induced hepatocarcinogenesis.