FIG. 4.

Effect of NAC on pyocyanin-dependent IL-8 release. A549 cells were treated for 2 h with the indicated concentration of NAC and then stimulated for 24 h with (hatched bars) and without (solid bars) 50 μM pyocyanin. At the end of the incubation, IL-8 in the medium was measured by ELISA. Values were normalized to total cell protein and represent the average ± standard deviation (error bar) of triplicate samples (P < 0.05 for all concentrations of NAC in pyocyanin-treated cells). Similar results were seen in two other independent experiments.