Luteolin inhibits the nuclear factor-kappa B transcriptional activity in Rat-1 fibroblasts.

Department of Life Science, Division of Molecular and Life Science and School of Environmental Science and Engineering, Pohang University of Science and Technology, San 31 Hyojadong, Nam-Gu, Pohang, Kyungbuk 790-784, South Korea.
Biochemical Pharmacology (Impact Factor: 4.58). 10/2003; 66(6):955-63. DOI: 10.1016/S0006-2952(03)00465-9
Source: PubMed

ABSTRACT Flavonoids are natural polyphenolic compounds that have anti-inflammatory, cytoprotective and anticarcinogenic effects. In this study, we investigated the effects of several flavonoids on nuclear factor-kappa B (NF-kappa B) activation by using luciferase reporter gene assay. Among the flavonoids examined, luteolin showed the most potent inhibition on lipopolysaccharide (LPS)-stimulated NF-kappa B transcriptional activity in Rat-1 fibroblasts. Luteolin did not inhibit either I kappa B alpha degradation or NF-kappa B nuclear translocation, DNA binding or phosphorylation by LPS. However, luteolin prevented LPS-stimulated interaction between the p65 subunit of NF-kappa B and the transcriptional coactivator CBP. In addition, a specific PKA inhibitor that blocked the phosphorylation of CREB and c-Jun by luteolin partially reversed the inhibitory effect of luteolin on NF-kappa B.CBP complex formation and NF-kappa B transcriptional activity by LPS. These data imply that inhibition of NF-kappa B transcriptional activity by luteolin may occur through competition with transcription factors for coactivator that is available in limited amounts. Taken together, this study provides a molecular basis for the understanding of the anti-inflammatory effects of luteolin.

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