<p>(A) <i>O. majorana</i> extract induces an activation of caspase 8 but not caspase 9 in MDA-MB-231 cells. MDA-MB-231 cells were incubated with various concentrations of the extract for 24 h. The caspase activation induced by the OME was assayed as described under <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0056649#s2" target="_blank">Materials and methods</a>. The relative caspase 8 and 9 activity was normalized to the number of viable cells per well and is expressed as fold of induction compared to the control. (B) Western blot analysis showing an increase in cellular TNF-α protein in the MDA-MB-231 cells treated with OME. Whole cell protein were extracted from OME-treated cells or vehicle (ethanol)-treated cells and subjected to Western blot analysis, as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0056649#s2" target="_blank">Materials and Methods</a>, for TNF-α and β-actin (loading control) proteins. (C) Immunofluorescence staining for TNF-α in OME-treated MDA-MB- 231cells. Cells were treated with 150 and 300 µg/mL of the extract for 24 h, fixed, permeabilized, and then processed for immunofluorescence using antibodies against TNF-α protein. DAPI was used as a nuclear stain. (*<i>p</i><0.05 and **<i>p</i><0.005).</p
