PSK as a chemopreventive agent.

摘要: PSK, a protein-bound polysaccharide preparation obtained from cultured mycelia of the CM-101 strain Coriolus versicolor belonging to basidiomycetes, is biological response modifier capable exhibiting diverse activities. This agent has been used clinically for treatment postoperative cancer patients in Japan by oral use. In this paper, chemopreventive aspects PSK were reviewed. Oral administration reduced incidence tumor and/or prolonged survival period following chemical carcinogen-induced, radiation-induced, and spontaneously developed animal models: rat gastrointestinal induced 1,2-dimethylhydrazine; hepatoma 3'-methyl-dimethylaminobenzene; mouse thymic lymphoma whole-body irradiation; spontaneous mammary tumor; so on. did not interact inhibit drug-metabolizing enzymes had no effect on Ames test. On other hand, scavenged active oxygen through induction manganese superoxide dismutase, prevented increase frequency anticancer agent-induced sister chromatid exchange, suppressed fetal deformation transplacental injection teratogen, suggesting an initiation or promotion process carcinogenesis. Also, regulated cytokine production enhanced antitumor activity effector cells such as killer T-cells natural cells, growth after development malignant cells. Thus, seems act at multiple steps during carcinogenesis rather than particular step. The main mechanism may be antiteratogenic attributed radical trapping, preventive effects against chromosome injury, immunomodulative modulation cell function.(ABSTRACT TRUNCATED AT 250 WORDS)