Fig. 3.

DBD plasma promotes ROS generation, which induces oxidative stress in keratinocytes. Cells were exposed to DBD plasma for 0, 3, 6, 9, and 12 min. After 24 h, (A) cell viability was assessed by MTT assay. *p < 0.05 indicates a statistically significant difference between the viability of DBD plasma-exposed cells (for 3, 6, 9, and 12 min) and non-exposed cells (0 min). (B) Cell morphology was assessed by an inverted microscope. Scale bars = 20 μm. (C) Cells were stained with DCF-DA, and intracellular ROS levels were detected by flow cytometry. *p < 0.05 indicates a statistically significant difference between the ROS levels in cells exposed to DBD plasma (“3, 6, 9, 12” min) and the ROS levels in non-exposed cells (“0” min). (D) H₂O₂ concentration was assessed using the Amplex® red reagent. *p < 0.05 indicates a statistically significant difference between the H₂O₂ concentration in DBD plasma-exposed cells (“6” and “9” min) and the H₂O₂ concentration in non-exposed cells (“0” min). (E) Superoxide anion production was assessed with a superoxide anion assay kit. *p < 0.05 indicates a statistically significant difference between the superoxide anion concentration in DBD plasma-exposed cells (“6” and “9” min) and the superoxide anion concentration in non-exposed cells (“0” min). (F) Hydroxyl radical production was assessed using the OH580 probe. *p < 0.05 indicates a statistically significant difference between the hydroxyl radical concentration in DBD plasma-exposed cells (“6” and “9” min) and the hydroxyl radical concentration in non-exposed cells (“0” min). (G) NO concentration was detected by measuring the concentration of nitrate and nitrite by a Griess reaction method. *p < 0.05 indicates a statistically significant difference between the NO concentration in DBD plasma-exposed cells (“6” and “9” min) and non-exposed cells (“0” min). (H) The lipid peroxidation was assessed by using the 8-isoprostane detection kit. *p < 0.05 indicates a statistically significant difference between the 8-isoprostane concentration in DBD plasma-exposed cells (“6” and “9” min) and the 8-isoprostane concentration in non-exposed cells (“0” min). (I) DNA damage was reflected by 8-OHdG concentration. *p < 0.05 indicates a statistically significant difference between the 8-OHdG concentration in DBD plasma-exposed cells (“6” and “9” min) and the 8-OHdG concentration in non-exposed cells (“0” min). (J) The protein oxidation was reflected by protein carbonylation. *p < 0.05 indicates a statistically significant difference between the concentrations of carbonylated proteins in DBD plasma-exposed cells (“6” and “9” min) and the concentrations of carbonylated proteins in non-exposed cells (“0” min).