Attenuation of LPS-induced inflammation by ICT, a derivate of icariin, via inhibition of the CD14/TLR4 signaling pathway in human monocytes

ObjectiveTo evaluate the anti-inflammatory potential of ICT in LPS stimulated human innate immune cells.Background3, 5, 7-Trihydroxy-4'-methoxy-8-(3-hydroxy-3- methylbutyl)–flavone (ICT) is a novel derivative of icariin, the major active ingredient of Herba Epimedii, an herb used in traditional Chinese medicine. We previously demonstrated its anti-inflammatory potential in a murine macrophage cell line as well as in mouse models.MethodsWe measured TNF-α production by ELISA, TLR4/CD14 expression by flow cytometry, and NF-κB and MAPK activation by western blot all in LPS-stimulated PBMC, human monocytes, or THP-1 cells after treatment with ICT.ResultsICT inhibited LPS-induced TNF-α production in THP-1 cells, PBMCs and human monocytes in a dose-dependent manner. ICT treatment resulted in down-regulation of the expression of CD14/TLR4 and attenuated NF-κB and MAPK activation induced by LPS.ConclusionWe illustrate the anti-inflammatory property of ICT in human immune cells, especially in monocytes. These effects were mediated, at least partially, via inhibition of the CD14/TLR4 signaling pathway.

► We illustrated the anti-inflammatory property of ICT in human monocytes. ► These effects were mediated via inhibition of the CD14/TLR4 signaling pathway. ► ICT may provide an alternative candidate for the treatment of inflammatory diseases.