Abstract

Background/Aims
The nuclear factor-κB (NF-κB) is associated with expression of proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-8 (IL-8). DA-6034, a derivative of flavonoid, has shown a potent anti-inflammatory effect in IBD animal model. The aim of this study was to characterize the anti-inflammatory activity of DA-6034 in terms of regulation of NF-κB. Methods: HT-29 cells were stimulated with lipopolysaccharide (LPS) or TNF-α alone or pretreated with DA-6034. The influence of DA-6034 on NF-κB DNA binding activity and inhibitory protein κB (IκB) activity was determined using an electrophoretic mobility shift assay (EMSA) and Western blot analysis. The RT-PCR method was used to determine the degree of gene expression of TNF-α and IL-8. Production of TNF-α and IL-8 protein was measured by ELISA. Results: DA-6034 prevented NF-κB activation stimulated with LPS and TNF-α and inhibited LPS- and TNF-α-induced IκB degradation. LPS-induced TNF-α mRNA expression and TNF-α-induced IL-8 mRNA expression were significantly decreased by DA-6034 pretreatment as compared to the absence of DA-6034 pretreatment. Conclusions: These results suggest that the inhibitory effect of DA-6034 on the production of TNF-α in LPS-stimulated and IL-8 in TNF-α-stimulated HT-29 cells may involve transcription regulation by suppression of NF-κB activation by interfering with IκB degradation. (Intest Res 2005; 3:38-47)

• Keywords: IBD, DA-6034, NF-κB, IκB