Fig. 1

Cell viability (a) and intracellular ROS levels (b) in normal human dermal fibroblasts (NHDFs). Cell toxicity test in NHDFs was assayed by MTT assay. Intracellular ROS levels were determined by measuring the oxidative conversion of DFH-DA to the DCF. Fibroblasts were harvested and incubated with 50 μM DCFH-DA at 37 °C for 30 min in the dark. The fluorescence intensity was monitored by an Infinite® F200 PRO. The results are mean ± standard deviation (SD) (n = 3). *P < 0.05, **P < 0.01 vs. pollutant-untreated control. #P < 0.05, ##P < 0.01 vs. pollutant-treated control