SW-induced growth inhibition and apoptosis depend on ROS. (A) Effects of NAC (150 mg/kg) pretreatment on SW-induced apoptosis in rats (TUNEL staining; magnification, ×10). (B) Effects of NAC (5 mM) on SW-induced apoptosis of A549 cells (Annexin V-FITC/PI staining). (a) Control, (b) SW, (c) NAC and (d) NAC + SW groups. (C) Number of apoptotic cells per field in (A). (D) Percentage of apoptotic cells in (B). (E-G) Effects of NAC (5 mM) on the expression of the apoptosis-associated proteins caspase-3 and p-JNK in A549 cells. (H) Effects of NAC on SW-induced cell growth inhibition (Cell Counting kit-8 assay). Data are presented as the means ± standard error of the mean, n=5. ***P<0.001 vs. the control group; #P<0.05 and ##P<0.01 vs. the SW group; ^P<0.05, ^^P<0.01 and ^^^P<0.001 vs. the NAC group. FITC, fluorescein isothiocyanate; JNK, c-Jun N-terminal kinae; NAC, N-acetyl-L-cysteine; p-JNK, phosphorylated-JNK; PI, propidium iodide; ROS, reactive oxygen species; SW, seawater.