Concentration and time-dependence of cytotoxicity induced by RKA182, FBEG100 and ARS in HL-60 cells. (A) Cells were exposed to the indicated concentrations of RKA182 (black circles), FBEG100 (white circles) or ARS (gray circles) for 24 h, and cytotoxicity was determined by quantification of cellular ATP content. Data are expressed relative to the ATP content of cells exposed only to vehicle (methanol, 0.5%). (B–C) Cells were exposed to 100 μmol/L of RKA182, FBEG100 or ARS for the indicated times, and cytotoxicity was determined by quantification of cellular ATP (B) or LDH (C) contents. Data are expressed relative to the ATP or LDH content of cells exposed only to vehicle at the corresponding timepoints. All data represent mean + SD, n = 3.