Chrysin inhibits lipopolysaccharide-induced inflammatory responses of macrophages via JAK-STATs signaling pathway

QI Shimei; LI Qiang; JIANG Qi; QI Zhilin; ZHANG Yao

doi:10.3969/j.issn.1673-4254.2018.03.02

Abstract：Objective To investigate the mechanism of chrysin in regulating lipopolysaccharide(LPS)-induced inflammation in RAW264.7 cells.Methods RAW264.7 cells were treated with different concentrations(0,5,10,20,40,60,80,100,150,and 200 μg/mL)of chrysin for 24 h,and the cell viability was measured using CCK-8.RAW264.7 cells were pre-treated with 10,30,or 60 μg/mL chrysin for 2 h before stimulation with LPS for different times.The levels of TNF-α,IL-6 and MCP-1 were detected by ELISA, and Western blotting was used to detect the phosphorylation of JAK-1, JAK-2, STAT-1 and STAT-3. The level of reactive oxygen species in RAW264.7 cells was detected by CM-H2DCFDA fluorescence probe.The effect of ROS on LPS-induced JAK-STATs signal and the inflammatory response of RAW264.7 cells was detected by ROS scavenger NAC. The transcription factors STAT-1 and STAT-3 nuclear translocation were observed by laser confocal microscopy. Results Chrysin below 60 μg/mL did not significantly affect the viability of RAW264.7 cells.At 10,30,and 60 μg/mL,chrysin dose-dependently inhibited the expression of iNOS induced by LPS. Chrysin treatment also inhibited LPS-induced phosphorylation of JAK-STATs, nuclear translocation of STAT1 and STAT3, release of TNF-α, IL-6 and MCP-1, and the production of ROS in RAW264.7 cells;ROS acted as an upstream signal to mediate the activation of JAK-STATs signaling pathway.Conclusion Chrysin blocks the activity of JAK-STATs mediated by ROS to inhibit LPS-induced inflammatory response in RAW264.7 cells.