Fig. 2.

(A) Cell toxicity determined by the MTT assay after 24 h of treatment with different concentrations of DHS (1, 2.5, 5, 7.5, 10, 15, 30, 60 and 90 μM) in LF1 cells. (B) Effect on DNA synthesis evaluated by BrdU incorporation in LF1 cells seeded on coverslips, and treated with increasing concentration of DHS as indicated. Representative images of BrdU-positive cells are showed in the panel (Scale bar = 10 μm). (C) Analysis of BrdU incorporation in LF1 cells treated with different concentration of DHS as indicated. (D) Analysis of BrdU incorporation of 30 μM DHS or RSV at different time (1, 3, 6, 24 h). All results are expressed as mean ± SD from three independent experiments; values are expressed as percentage of BrdU-stained positive cells (*p ≤ 0.05; **p ≤ 0.01 compared to control cells).