Euonymus alatus extract attenuates LPS-induced NF-κB activation via IKKβ inhibition in RAW 264.7 cells

Aim of the studyThe present study was performed to investigate the underlying mechanisms of anti-inflammatory effects with the extract of Euonymus alatus (EEA), and specially focused on nuclear factor κB (NF-κB) signaling pathway by targeting the IκB kinase β (IKKβ).Materials and methodsThe effect of EEA for IKKβ activity was analyzed using an immobilized metal affinity for phosphochemicals (IMAP)-based time-resolved fluorescence resonance energy transfer (TR-FRET) assay. The effect of EEA on lipopolysaccharide (LPS)-induced NF-κB activation in murine macrophage RAW 264.7 cells with western blotting and immunofluorescent staining was evaluated.ResultsIKKβ studies based on IMAP-TR-FRET showed that EEA possesses a potent IKKβ inhibitory activity with IC50 value of 11.83 μg/ml. EEA (10, 30 μg/ml) also attenuated the LPS-induced IκBα phosphorylation/degradation, NF-κB translocation and subsequent NO synthesis in RAW 264.7 cells.ConclusionsThese results suggest that EEA abrogates LPS-induced NF-κB signaling pathway by targeting the IKKβ in RAW 264.7 cells and these properties may provide a molecular basis for understanding the inhibitory effects of EEA on LPS-mediated inflammation.

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