Theaflavin-3,3-Digallate Plays a ROS-Mediated Dual Role in Ferroptosis and Apoptosis via the MAPK Pathway in Human Osteosarcoma Cell Lines and Xenografts

Figure 2

TF3 induced cell death in OS cell lines. OS cells were treated with 0.05% DMSO (vehicle control) or the indicated concentration (160 μM) of TF3 for 24 h. (a) TEM was used to examine the ultrastructure of MG63 and HOS cells. The mitochondria of cells in the TF3 (160 μM) group seemed to be shrunken, with dense membranes and diminished or absent cristae. (b) Merged images of JC-1 staining illustrating the differences in MMP between the TF3 (160 μM) and control groups. The cells were also counterstained with Hoechst 33342 solution. Red fluorescence: polymers and normal MMP; green fluorescence: monomers and low MMP. (c–e) A CCK-8 assay was performed to measure the viability of HOS and MG-63 cells incubated with TF3 (160 μM) for 24 h in the presence of 2 mM NAC, 2 μM Fer-1, or 20 μM z-VAD-FMK. The data are presented as the (). , , , and vs. the vehicle control group.

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