[Studies on antioxidant effects of Hypsizigus marmoreus. II. Effects of Hypsizigus marmoreus for antioxidant activities of tumor-bearing mice].

The in vivo effect of Hypsizigus marmoreus on the plasma antioxidant status of tumor-bearing mice was examined. Female DBA/2 mice treated with subcutaneous injection of 3-methylcholanthrene were fed on a basal diet (CE-2) or CE-2 containing 5% fruit bodies of the mushroom for 76 weeks. Antioxidant activities (AOA) of mice with tumor were significantly higher than those of mice without tumor. The high levels of AOA were attributable to the increase of high molecular weight AOA in the plasma. A similar increase in plasma AOA was also observed in sarcoma-180 solid tumor-bearing mice. The mushroom feeding exhibited a potent antitumor effect and caused a significant decrease in lipid peroxide levels (as thiobarbituric acid reactive substances; TBARS). These results suggest that the increase of AOA in the plasma of tumor-bearing mice is one of the mechanism of cancer preventive effects and also suggest that Hypsizigus marmoreus might play a role in decreasing TBARS by controlling AOA induction.