FIGURE 2.

Effect of pretreatment with rifampicin on cytotoxicity and intracellular ATP content in HepaRG cells. HepaRG cells were pretreated for 72 h with rifampicin and then exposed to drugs for 48 h. Cytotoxicity was assessed by the release of AK. (A–D) Cytotoxicity of erlotinib, imatinib, lapatinib, and sunitinib, respectively. (E–H) Intracellular ATP content of erlotinib, imatinib, lapatinib, and sunitinib, respectively. Data are expressed as % AK release in the presence of 0.5% Triton X (set at 100%) or as % ATP content in the presence of 0.1% DMSO (set at 100%). Data represent the mean ± SEM of at least three independent experiments. ^∗p < 0.05, ^∗∗p < 0.01 or ^∗∗∗p < 0.001 versus DMSO control. ^†p < 0.05, ^††p < 0.01 or ^†††p < 0.001 rifampicin versus respective DMSO pretreatment.