Figure 4: Intracellular ROS formation in KB cells untreated and treated with Chilean propolis ethanolic extract (80 μg/ml) for 72 hours in the presence or absence of 10 μM SnCl2 or 15 μM SnMP. Each value represents the mean ± SD of three separate experiments performed in duplicate. (*p<0.001 vs. Control; **p<0.001 vs. Propolis; ***p<0.001 vs. Propolis + SnCl2).