Figure 1.

Effect of siramesine on viability of various cell lines. Cells were incubated with increasing concentrations of siramesine (0–45 μM) for 8–48 h. The pancaspase inhibitor Z-VAD-FMK (20 μM), the cathepsin inhibitor E-64d (10 μM) and the lipophilic antioxidant α-tocopherol (0.3 mM) were applied 2 h before siramesine treatment. After incubation with siramesine, the cells were stained with annexin V and propidium iodide (PI), followed by flow cytometric analysis. Live cells were defined as annexin V/PI double-negative cells. Experiments were performed in duplicate; the bars represent mean±S.D. (a) Effect of siramesine on viability of various cell lines after 8 h of incubation with siramesine. (b) Effect of lower siramesine concentrations on viability of HaCaT cells at later time points (12–48 h). S, siramesine; T, α-tocopherol