Figure 2. Effects of n-TiO₂, n-SiO₂, n-ZnO, n-CeO₂ on extracellular oxyradical production by mussel hemocytes.

A) Total oxyradical production; B) Superoxide anion (O₂ ⁻) production. Hemocytes were exposed for 30 min to different concentrations of n-oxides (1, 5, 10 µg/ml) and total extracellular oxyradical production was evaluated as cytochrome c reduction as described in Methods (A). In a parallel set of samples, superoxide dismutase-SOD (300 Units/ml) was included to allow specific evaluation of superoxide (O₂ ⁻) generation (B). Data, representing the mean±SD of four experiments in triplicate, were analysed by ANOVA followed by Tukey’s post hoc test. *  =  P≤0.01, all treatments vs controls.