Abstract: Aim The expression of NF-κB activation and the effect of antioxidant (N-acetylcys-teine, NAC)on NF-κB activity in human airway epithelial cell was assessed.Methods Using the TNF-α, the airway epithelial cell strains of normal subject(16HBE)and tumor patient (H292)was activated and using Western-Blot and ELISA the expression of NF-κB and IL-8 were detected.Results It was found that the activity of NF-κB could be stimulated by the TNF-α and increase with the amount of TNF-α with the peak occurring at 2 to 4 hours after stimulation and then decreasing at six hours.At the same time, the level of IL-8 was elevated, but decreased with inhibition of NF-κB activity by NAC, that means the action of NAC has a dose-dependent effect.Conclusion NAC not only blocks the signal transmission activated by NF-κB, but also anticipates the transcription modulation of expression of many cell factors and inflammatory mediums.It suggests that NAC may play a role in the anti-inflammatory treatment of respiratory diseases.

Key words: N-acetylcysteine, airway epithelial cell, NF-κB, IL-8, TNF-α