Fig. 4

VB1 treatment induces DNA damage by increasing ROS. a A375 (left panel) and Sk-Mel-28 (right panel) cells were treated with 0–20 μM VB1 for 48 h, and western blotting was then performed for the indicated antibodies. b A375 and Sk-Mel-28 cells were treated with 10 μM VB1 for 0–48 h, and γH2AX was stained by immunofluorescence and calculated. The results represent the mean (n = 5) ± SD of each group, and an asterisk (*) indicates a significant difference using one-way ANOVA (p < 0.05). c A375 and Sk-Mel-28 cells were treated with 10 μM VB1 for 0–48 h, and γH2AX was stained by immunofluorescence. Representative images of staining of γH2AX. d A375 and Sk-Mel-28 cells were treated with 20 μM VB1 for 0–12 h. The levels of ROS were measured by DCF fluorescence with flow cytometry. The relative ROS levels were analyzed using the GraphPad Prism software (histogram). e A375 and Sk-Mel-28 cells were pretreated with 5 mmol/L N-acetylcysteine (NAC) for 1 h, and then, exposed to 20 μM VB1 for another 6 h. The levels of ROS were measured by DCF fluorescence with flow cytometry. The relative ROS levels were analyzed using the GraphPad Prism software (histogram). The results represent the mean (n = 4) ± SD of each group, and an asterisk (*) indicates a significant difference using one-way ANOVA (p < 0.05)