Figure 3: Effect of DHEA on ROS production induced by particles. Cells were treated with 1 (D1), 10 (D10), and 100 μM (D100) of DHEA alone or in combination with 10 μg/cm2 of TiO2 NPs (T) or PM10 (P) for 48 h. H2O2 (500 μM) was used as a positive control. ROS concentration was evaluated using H2DCFDA by flow cytometry. In (a), continuous lines correspond to control cells without treatment, and dashed lines correspond to treated cells. Histograms match to one representative experiment of three performed in an independent way. In (b), fluorescence intensity was calculated through multiplying the number of events by the mean of the fluorescence intensity value. The results are expressed as mean ± SD of three separate experiments. compared with nontreated cells, and compared with particles-treated cells.