SW inhibits growth and induces apoptosis of A549 cells. (A) Dose-dependent effects of SW on cell viability. A549 cells were treated with various concentrations of SW (20, 40, 60 and 80%) for 4 h, and Cell Counting kit-8 assay was used to measure cell viability. (B) Time-dependent effects of SW on cell viability. The cells were treated with 25% SW for various durations (2, 4, 6 and 8 h), and cell viability was measured as in (A). (C) Dose-dependent effects of SW on cell apoptosis. A549 cells were treated as in (A); subsequently, cell apoptosis was assessed by Annexin V-FITC/PI staining. (a) Control, and (b) 20%, (c) 40%, (d) 60% and (e) 80% SW groups. (D) Time-dependent effects of SW on cell apoptosis. A549 cells were treated as in (B), and cell apoptosis was measured as in (C). (a) Control, and (b) 2 h, (c) 4 h, (d) 6 h and (e) 8 h SW groups. (E) Percentage of apoptotic cells in (C). (F) Percentage of apoptotic cells in (D). Data are presented as the means ± standard error of the mean, n=5. ***P<0.001 vs. the control group. FITC, fluorescein isothiocayanate; PI, propidium iodide; SW, seawater.