Antitumor activity of dinitrosyl iron complexes with glutathione

The antitumor dose-dependent effect of binuclear dinitrosyl iron complexes with glutathione as NO donors on a solid tumor in the mouse, Lewis lung carcinoma, was detected. The complexes being injected at doses of 21, 42, 105 mg/kg daily for 10 days blocked completely the development of the tumor for the first week after tumor cell implantation into animals. After that, the part of tumor cells which remained in intact alive state began to grow at a rate equal to that for control animals. The effect was proposed to be caused via formation of an antinitrosative defense system in the cells as a response to NO attack on cells. It was also hypothesized that this system can be inactivated by higher doses of dinitrosyl iron complexes. Data were obtained which were in line with the hypothesis.