Green Tea Leaves and Rosemary Extracts Selectively Induce Cell Death in Triple-Negative Breast Cancer Cells and Cancer Stem Cells and Enhance the Efficacy of Common Chemotherapeutics

Figure 8

RE is dependent on the production of oxidative stress to induce apoptosis. The addition of N-acetylcysteine (NAC), a known ROS inhibitor, reduced rosemary-induced apoptosis in breast cancer. MDA-MB-231 was treated with concentrations ranging from 0.01 mg/mL to 0.25 mg/mL of both (a) RE with or without NAC and (b) STE with or without NAC. Treatment groups were compared with the negative control DMSO. Graphed results (left) concerning cell viability were obtained using the WST-1 assay. MDA-MB-231 micrographs of STE and RE with or without NAC at 48 hours (right). Absorbance readings of the formazan product were obtained at 450 nm by using a spectrofluorometer. Values are expressed as a mean ± SD from three independent experiments. Statistical calculations were performed by using a two-way ANOVA multiple comparison test. vs control, vs control, and vs control. Fluorescent images were stained with Annexin V (green), PI (red), and Hoechst (blue) at 200x magnification. Scale bar is 100 microns. Images are representative of three independent experiments.

(a)

(b)