Figure 4.

Exposure to PQQ triggers intracellular ROS accumulation. Three cancer cell lines, A549 cells (panel A), Neuro-2A cells (panel B) and HCC-LM3 cells (panel C) were exposed to different doses of PQQ at 4h, 12h and 24h. The generation of ROS was quantitatively measured by the flow cytometer using H₂DCFDA dye. Separate cell cultures treated with 500 µM of H₂O₂ 15 minutes prior to the assessment were used as positive controls. All values are showed as means ± SEM from three-independent experiments.*p < 0.05 as compared with control group; **p < 0.01 as compared with control group.