Cytotoxicity of fullerenols on Tetrahymena pyriformis

With the increasing use of fullerenes and their derivatives in a variety of fields, the toxicity and effects of fullerenes on humans and the environment have received considerable attention. In this study, the cytotoxicity of fullerene derivative, C60(OH)x, on Tetrahymena pyriformis was investigated. Cell growth inhibition was evaluated by counting with an optical microscope, and the generation time was calculated. It was indicated that the fullerenols caused a dose-dependent growth inhibition of the cells. The morphologic change in the damaged macronucleus of cells was observed using a fluorescent microscope. Superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and glutathione reductase (GR) levels were also measured for Tetrahymena pyriformis, using conventional methods. The results showed that fullerenols could reduce GSH-PX and GR activities. But no noticeable difference in SOD activity was observed between the treated groups and the control group. This indicated that the antiproliferative effect of fullerenols might be mediated by the reduction in the activities of GSH-PX and GR of cells and the destruction of the macronucleus.