Fig. 2

α-Mangostin induced ER stress in MBA-MB-231 cells. a MDA-MB-231 cells were treated with 0, 1, 2, and 4 μM α-mangostin for 24 h, and then the relative expression levels of CHOP, BIP, ATF6, IRE1, and PERK were analyzed by western blot and were quantified densitometrically with the software ImageJ and calculated according to the reference bands of GAPDH. Data represented the mean ± SD of three independent experiments. *p < 0.05, **p < 0.01. b The relative expression levels of CHOP, BIP, ATF6, IRE1 and PERK in cells treated with/without 4 μm α-mangostin followed 24 h incubation with/without 4PBA were analyzed by western blot and quantified. Data represented the mean ± SD of three independent experiments. *p < 0.05, **p < 0.01. c Cells were treated with different concentrations of α-mangostin (0, 1, 2, and 4 μM). After 24 h, cells were stained with JC-1 and analyzed by flow cytometry. Histogram showed cells treated with DMSO alone (red), 1 μM α-mangostin (blue), 2 μM α-mangostin (pink) and 4 μM α-mangostin (green). For comparison, the control group (red histogram) was merged into every histogram. The corresponding bar graph showed the mean green fluorescence intensity, which was measured with excitation/emission: 488/525 nm by flow cytometer. Data represented the mean ± SD of three independent experiments. **p < 0.01