Effect of icariin on microglia-mediated neuro-inflammation through Nrf2 signaling pathway

OBJECTIVE To investigate the protective effect of icariin(ICA) on lipopolysaccharide(LPS)-induced BV2 microglia injury,and to clarify the role of nuclear factor erythroid 2-related factor 2(Nrf2) signaling pathway in BV2 microglia-mediated neuroinflammation.METHODS BV2 microglia were randomly divided into control,ICA(0.1 μmol·L^(-1)),LPS(1 mg·L^(-1)),LPS + ICA(0.01 μmol·L^(-1)),and LPS + ICA(0.1 μmol·L^(-1))groups.BV2 microglia were treated with ICA for 30 min and then treated with LPS for 24 h.MTT assay was used to determine the cells survival rate,Griess kit and ELISA kits were used to detect the contents of NO,IL-1β and IL-18 in the culture supernatant,Western blotting was used to detect the expression of Nrf2,HO-1 and NQO1.Real time RT-PCR was used to detect the expression of Nrf2,HO-1 and NQO1 after ICA addition for 2,6 and 24 h.And immunofluorescence was used to observe the activation of Nrf2.RESULTS ICA reduced LPS-induced NO,IL-1β and IL-18 production in the culture supernatant,and ICA increase LPS-induced mRNA and protein expression of Nrf2 signaling pathway.CONCLUSION ICA protects LPS induced neuroinflammation by regulating Nrf2 signaling pathway.