C(60) fullerene and its nanocomplexes with anticancer drugs modulate circulating phagocyte functions and dramatically increase ROS generation in transformed monocytes

BACKGROUND: C(60) fullerene-based nanoformulations are proposed to have a direct toxic effect on tumor cells. Previous investigations demonstrated that C(60) fullerene used alone or being conjugated with chemotherapeutic agents possesses a potent anticancer activity. The main aim of this study was to investigate the effect of C(60) fullerene and its nanocomplexes with anticancer drugs on human phagocyte metabolic profile in vitro. METHODS: Analysis of the metabolic profile of phagocytes exposed to C(60) fullerene in vitro revealed augmented phagocytic activity and down-regulated reactive nitrogen species generation in these cells. Additionally, cytofluorimetric analysis showed that C(60) fullerene can exert direct cytotoxic effect on normal and transformed phagocytes through the vigorous induction of intracellular reactive oxygen species generation. RESULTS: Cytotoxic action as well as the pro-oxidant effect of C(60) fullerene was more pronounced toward malignant phagocytes. At the same time, C(60) fullerenes have the ability to down-regulate the pro-oxidant effect of cisplatin on normal cells. These results indicate that C(60) fullerenes may influence phagocyte metabolism and have both pro-oxidant and antioxidant properties. CONCLUSIONS: The antineoplastic effect of C(60) fullerene has been observed by direct toxic effect on tumor cells, as well as through the modulation of the functions of effector cells of antitumor immunity.