Fig. 2

ROS regulation played a critical role in the preventive effect of ALT against OSCC cells. A–C Representative DCFH-DA fluorescent images in CAL27 and SCC9 cells treated with ALT. Mean optical density analysis of cellular DCFH-DA staining (green fluorescence; a ROS production indicator). Scale bar = 100 µm. D–F Representative DAF-FM DA fluorescent images in CAL27 and SCC9 cells treated with ALT. Mean optical density analysis of cellular DAF-FM DA staining (green fluorescence; an indicator of production of RNS). Scale bar = 100 µm. G–I Representative DCFH-DA fluorescent images in CAL27 and SCC9 cells treated with ALT with or without NAC. For experiments with NAC, the cells were pre-treated as with 5 mM NAC for 2 h. 12 µM ALT was used to treat CAL27 cells, and 8 µM ALT was added to SCC9 cells. Scale bar = 100 µm. (***p < 0.001, ****p < 0.0001 versus the Control group, ^####p < 0.0001 versus the ALT group)