Regulation of the oxidative processes as a possible mechanism of iron nanoparticles antitumor action.

Abstract

e23160 Background: It has been shown that metal nanoparticles (NPs) can inhibit a tumor growth. Oxidative processes play important roles in tumor development and growth. The aim of this study was to determine parameters of oxidative stress in the blood of tumor-bearing animals depending on the antitumor effect of iron NPs (30-50 nm). Methods: Male rats with transplantable lymphosarcoma (LS) in the main group (n = 21) were treated with eight i.p. injections of iron NPs (total doses of 10 mg/kg bw), the control LS rats (n = 20) received saline i.p. The activity of catalase, superoxide dismutase (SOD), content of glutathione (GSH) and malondialdehyde (MDA) in the red blood cells (RBC) and ceruloplasmin oxidase activity (CP) and MDA content in blood plasma were measured. These parameters were analyzed in rats with complete tumor regression (n = 12) after NPs treated and in cases of tumor growth (n = 9). Results: In RBC of control group the level of GSH and catalase activity were increased compared to healthy rats by 24% and 14.3% (p < 0.05), respectively. In spite of activation of the given antioxidant system components, the MDA content in RBC was increased by 45% (p < 0.01) compared to normal values. In plasma of control group we observed an increase in MDA by 167.4% (p < 0.01) and a decrease in CP by 36.8% (p < 0.001). In the main group there was a decrease in blood MDA level and the antioxidant system reorganization. The degree of changes depended on the antitumor effect of NPs: rats with tumor growth showed a tendency to the decreasing MDA in RBC and normalization of plasma MDA; MDA in rats with LS regression was similar to normal values. In the main group the CP activity did not differ from the values in healthy rats. GSH increased in animals with tumor growth by 218.6% and in the animals with the effect - by 69% compared to normal values (p < 0.01). SOD activity in the rats with LS growth increased by 42% and in the rats with LS regression it decreased by 30% (p < 0.01). Conclusions: The data suggest the relationship between antitumor effect and modulating action on oxidative processes in LS rats treated by iron NPs. Iron NPs improved efficiency of antioxidant system in blood and contributed to suppression of oxidative stress associated with tumor growth.