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

Background: C fullerene-based nanoformulations are proposed to have a direct toxic effect on tumor cells. Previous investigations demonstrated that C 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 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 fullerene in vitro revealed augmented phagocytic activity and down-regulated reactive nitrogen species generation in these cells. Additionally, cytofluorimetric analysis showed that C 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 fullerene was more pronounced toward malignant phagocytes. At the same time, C fullerenes have the ability to down-regulate the pro-oxidant effect of cisplatin on normal cells. These results indicate that C fullerenes may influence phagocyte metabolism and have both pro-oxidant and antioxidant properties.

Conclusions: The antineoplastic effect of C 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.