NDGA inhibits NSC-741909-induced apoptosis and caspase-8 and poly-(ADP-ribose) polymerase (PARP) activation. H460 cells were treated with 1 μM NSC-741909 in the presence or absence of 10 mM N-acetyl cysteine (NAC) or 20 μM nordihydroguaiaretic acid (NDGA). Cells treated with solvent (dimethylsulfoxide) or the antioxidants alone were used as controls. (A) Percentage of apoptotic cells was determined by flow cytometry analysis 24 h after treatment. The values shown represent the mean ± SD of three analyses. **p < 0.01, compared with cells treated with NSC-741909 alone. (B) Representative FACS graphs. (C) Whole-cell lysates from H460 cells treated as described above were harvested for Western blot analysis of caspase-8 and PARP activation.