Mimicking of superoxide dismutase activity by protein-bound polysaccharide of Coriolus versicolor QUEL, and oxidative stress relief for cancer patients.
The protein-bound polysaccharide of Coriolus versicolor QUEL (PS-K) has been found to express antioxidant activity as an "ion-radical scavenger" in diamine oxidation reactions. The mode of this expression was examined to determine whether the drug functioned as a simple radical scavenger or mimicked the action of superoxide dismutase (SOD). The latter was confirmed in both enzymatic and nonenzymatic superoxide anion radical (O2-.) producing systems in vitro. The SOD mimetic activity of PS-K was demonstrated by quantitative analysis of hydrogen peroxide as the end product of O2-., its formation being assisted catalytically by SOD or PS-K. Analysis by electron spin resonance also confirmed the SOD mimetic activity of PS-K in a xanthine-xanthine oxidase reaction. Relative SOD activity with PS-K was approximately 1/8,000 in a KO2-O2-.-producing system. The SOD mimetic activity of PS-K resisted treatment by 0.7N HCl, 0.7N NaOH, boiling for 30 minutes in a double water bath, and digestion by pronase. Fractionation according to differences in molecular mass caused no significant increase in relative SOD activity within a certain range of molecular mass, indicating that there is no definite molecule expressing SOD mimetic activity. Tumor-bearing rats and human patients with digestive tract cancer who suffered from oxidative stress were relieved by a single intraperitoneal administration of PS-K or a 1-day peroral prescription.
Kariya
K
K
Molecular Biology Laboratory, Kitasato University School of Medicine, Kanagawa, Japan.
Nakamura
K
K
Nomoto
K
K
Matama
S
S
Saigenji
K
K
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D001487:Basidiomycota; D002279:Carcinoma 256, Walker / Q000188:drug therapy / Q000378:metabolism; D004067:Digestive System Neoplasms / Q000188:drug therapy / Q000378:metabolism; D016166:Free Radical Scavengers; D006801:Humans; D007155:Immunologic Factors / Q000494:pharmacology; D011509:Proteoglycans / Q000494:pharmacology*; D051381:Rats; D013482:Superoxide Dismutase / Q000378:metabolism*
D000970:Antineoplastic Agents; D000975:Antioxidants; D016166:Free Radical Scavengers; D007155:Immunologic Factors; D011509:Proteoglycans; C010770:polysaccharide-K; D013482:Superoxide Dismutase