Figure 2: Effect of DHEA on the inhibition of proliferation 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 20 μg/cm2 of PM10 (P) for 72 h. Cell proliferation was evaluated by crystal violet staining. Nontreated cells showed 100% of proliferation. The results are expressed as mean ± SD of three separate experiments. compared with nontreated cells, and compared with particles-treated cells.