Effect of bile acids on Nuclear factor-κB (NF-κB) expression. (a) SEG-1 cells were treated for 18 hours with 50–300 μM DCA (left) or with 100 μM DCA, CDCA, or TCA (right). Cellular nuclear protein was subjected to Western blotting for NF-κB p65 and β-actin. (b) SEG-1 cells were transfected with the NF-κB luciferase reporter plasmid, incubated for 24 hours, then treated for an additional 18 hours with 50 – 300 μM DCA (left) or with 100 μM DCA, CDCA, or TCA (right). Luciferase activity for NF-κB reporter plasmid was measured and normalized to beta-galactosidase activity. Values shown represent the means ± SD of triplicate experiments.