Figure 3: Glutathione (GSH) measurement in A549 cells unexposed (control) and exposed to increasing concentrations (1–100 μg/mL) of Cd-SiO2NPs, CdCl2, SiO2NPs after 48 h. GSH levels were affected by all tested materials: the GSH depletion in A549 cells was not dose-dependent after Cd-SiO2NP or CdCl2 treatments, while was dose-depended after SiO2NP treatments. Data are mean ± DS of three separate experiments each carried out in six replicates. * significant difference from control.