Fig. 4.

Effect of α-tocopherol on nuclear factor kappa B (NF-κB) and activator protein-1 (AP-1) activity in A549 and bronchial epithelial cell line (BEAS)-2B cells. Cells were treated for 45 min with or without α-tocopherol and stimulated thereafter for 30 min with 10 ng/ml tumour necrosis factor (TNF)-α. Nuclear extracts were analysed using electrophoretic mobility shift assay (EMSA). Five µg nuclear extract/lane was loaded. Representative autoradiograms of NF-κB (a) and AP-1 (b) activity are shown. The results from unstimulated cells are shown in the left lane of each gel. Control experiment using excess of unlabelled NF-κB or AP-1 verifying that the binding of [³²P]-labelled oligonucleotides was specific are shown to the right in EMSA analysis of A549 cells. Intensity of bands, corresponding to NF-κB, was quantified using an image analysis system (c). Data are expressed as fold increase in intensity versus unstimulated cells. Statistical significance versus cells stimulated with TNF-α alone is indicated (analysis of variance and Dunnet's multiple comparison test n = 5).