Fig. 4

Effects of curcumin on the UPM-induced production of ROS in nasal fibroblasts. ROS were quantified by flow cytometry with DCF-DA. Each value in the graph represents the mean ± SEM of three independent experiments. *p < 0.05, **p < 0.01, and ***p < 0.001 vs. 0 μg/mL of UPM or 0 μM of curcumin; #p < 0.05 and ###p < 0.001 vs. 25 μg/mL of UPM. UPM: urban particulate matter; ROS: reactive oxygen species; DCF-DA: 2′,7′-dichlorofluorescin diacetate; SEM: standard error of the mean