Figure 2.

Effect of hemin, SFN, QUE and 3,4HPAA in apoptosis. Cells were incubated with vehicle (0.4% DMSO), 1 μM SFN, 10 μM QUE or 2.6 μM 3,4HPAA in the absence or presence of 10 μM hemin. After 72 h, caspase 3 activity was measured in (A) RKO cells and (B) CCD841 cells; as well as cytochrome c levels in the media of (C) RKO cells; and (D) CCD841 cells. Caspase activity and cytochrome c release were expressed as p-nitroanilide/min/mg of protein, and ng (cytochrome c)/mg of protein, respectively. Values are expressed as mean ± SEM, from three independent culture preparations. For all bars with the same letter, the difference between the means is not statistically significant. Values with different letters indicate significant differences (p < 0.05) between bars (two-way ANOVA, Bonferroni post-test). 3,4HPAA, 3,4-dihydroxyphenylacetic acid; QUE, quercetin; SFN, sulforaphane.