• Journal of Yeungnam Medical Science
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• v.23 no.1
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• pp.26-35
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• 2006

Background: Luteolin, a flavone found in various Chinese herbal medicines is known to possess anti-inflammatory properties through its ability to inhibit various proinflammatory signaling pathways including NF-${\kappa}B$ and p38 MAPK. In this study, we investigated the potential therapeutic effect of luteolin on dextran sodium sulfate (DSS)-induced colitis. Materials and Methods: We used a transgenic mouse model expressing the enhanced green fluorescent protein (EGFP) under the transcriptional control of NF-${\kappa}B$ $cis$-elements. C57BL/6 NF-${\kappa}B^{EGFP}$ mice received 2.5% DSS in their drinking water for six days in combination with daily luteolin administration (1mg/kg body weight, 0.1ml vol, intragastric) or vehicle. NF-${\kappa}B$ activity was assessed macroscopically with a Charge-Coupled Device (CCD) camera and microscopically by confocal analysis. Results: A significant increase in the Disease Activity Index (DAI), histological score (p<0.05), IL-12 p40 secretion in colonic stripe culture (p<0.05) and EGFP expression was observed in luteolin and/or DSS-treated mice compared to water-treated mice. Interestingly, a trend toward a worse colitis (DAI, IL-12p40) was observed in luteolin-treated mice compared to non-treated DSS-exposed mice. In addition, EGFP expression (NF-${\kappa}B$ activity) strongly increased in the luteolin-treated mice compared to control mice. Confocal microscopy showed that EGFP positive cells were primarily lamina propria immune cells. Conclusions: These results suggest that luteolin is not a therapeutic alternative for intestinal inflammatory disorders derived for primary defects in barrier function. Thus, therapeutic intervention targeting these signaling pathways should be viewed with caution.