Illicium verum extract suppresses IFN-γ-induced ICAM-1 expression via blockade of JAKSTAT pathway in HaCaT human keratinocytes

  To investigate the anti-inflammatory effects and regulatory mechanisms of Illicium verum extract (IVE) in the human keratinocyte cell line HaCaT.
  In this study, we examined the effect of Illicium Verum Extract on IFN-γ-induced ICAM-1 expression in HaCaT cells. The levels of IFN-γ receptor α (IFN-γRα), phosphorylated Janus kinase 2 (pJak2), phosphorylated signal transducer and activator of transcription 1 (pSTAT1), and suppressor of cytokine signaling 1 (SOCS1) were analyzed by western blot. Expression of intercellular adhesion molecule-1 (ICAM-1) on the HaCaT cells was determined by reverse transcription-polymerase chain reaction, western blot, and cell-surface enzyme-linked immunosorbent assay. The effects of IVE and its constituents on the adherence of T lymphocytes to IFN-γ-treated HaCaT cells were also investigated.
  IVE significantly inhibited IFN-γ-induced mRNA and protein expression of ICAM-1. Illicium Verum Extract inhibited IFN-γ-induced IFN-γRα, pJak2 and pSTAT1 expression in HaCaT cells. The expression of SOCS1 was up-regulated by treatment of IVE. In addition, Illicium Verum Extract and its constituents (p-anisaldehyde and trans-anethole) effectively suppressed IFN-γ-induced adherence of Jurkat T cells to HaCaT cells and ICAM-1 expression on the cell surface.