Figure 5.

Cytotoxicity of RKA182, FBEG100 and ARS in HepG2 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) Cells were pretreated (gray bars) or not (black bars) with the caspase inhibitor Z.VAD.FMK (100 μmol/L, 1 h) and exposed to RKA182, FBEG100 or ARS for a further 24 h. Cytotoxicity was determined by quantification of cellular ATP content. IC₅₀ values were calculated from concentration-response curves. Unpaired t test, N.S. no statistically significant increase in IC₅₀ value with Z.VAD.FMK pretreatment. Data represent mean + SD, n = 3.