Possible role of glutathione in the antitumor effect of a copper-containing synthetic superoxide dismutase in mice.

The effect of glutathione and a glutathione reductase inhibitor on the antitumor effect of Cu(II)(3,5-diisopropylsalicylate)2 (CuDIPS) was studied. CuDIPS is a low-molecular-weight copper coordination compound that exhibits superoxide dismutase-like activity. CuDIPS had antitumor activity against intraperitoneal Ehrlich ascites carcinoma in Swiss mice. A single ip injection of glutathione partially eliminated the antitumor effect of CuDIPS, whereas a single ip injection of 1,3-bis(2-chloroethyl)-1-nitrosourea enhanced the antitumor effect of CuDIPS. These results are consistent with the hypothesis that CuDIPS exerts part of its antitumor effect by producing H2O2.