The effects of DA-6034 on NF-kappaB activity induced by lipopolysaccharide or tumor necrosis factor alpha in a human colonic epithelial cell line.

BACKGROUND/AIMS: DA-6034, a synthetic derivative of eupatilin, has shown a potent anti-inflammatory effect in experimental rat models with inflammatory bowel disease (IBD). Nuclear factor kappaB (NF-kappaB) is known to play a central role in regulating inflammatory responses in patients with IBD, and is an important target for therapeutic intervention. We, therefore, examined the effects of DA-6034 on NF-kappaB activity and proinflammatory cytokines production in the human colonic cell line.

METHODOLOGY

HT-29 cells were stimulated with either lipopolysaccharide (LPS) or tumor necrosis factor alpha (TNF-alpha). After pretreatment with different doses of DA-6034, the influence of DA-6034 on NF-kappaB activity was determined by an electrophoretic mobility shift assay (EMSA). The effect of DA-6034 on inhibitory protein kappaBalpha (IkappaBalpha) activity was determined by immunoblotting. TNF-alpha and interlukin 8 (IL-8) messenger RNA expression, which are regulated by NF-kappaB, were assayed by RT-PCR. The production of TNF-alpha or IL-8 proteins was measured by ELISA.

RESULTS

DA-6034 inhibited NF-kappaB activity and prevented IkappaBalpha degradation in HT-29 cells after stimulation with either LPS or TNF-alpha. Furthermore, the production of TNF-alpha or IL-8 proteins decreased significantly after DA-6034 pretreatment.

CONCLUSIONS

These observations suggest that DA-6034 produces an anti-inflammaotory effect through inhibition of NF-kappaB activity by the prevention of I B degradation.