Effect of isosecotanapartholide isolated from Artemisia princeps Pampanini on IL‑33 production and STAT‑1 activation in HaCaT keratinocytes.

The present study aimed to investigate the anti‑inflammatory effect and mechanism of action of isosecotanapartholide (ISTP), isolated from Artemisia princeps Pampanini extract (APE). The effects of ISTP and APE on the proliferation of human keratinocytes following stimulation by tumor necrosis factor‑α/interferon‑γ were assessed. ISTP and APE downregulated the expression levels of signal transducer and activator of transcription‑1 (STAT‑1), and reduced interleukin‑33 (IL‑33) production. ISTP and APE inhibited the mRNA expression levels of thymus and activation‑regulated chemokine (TARC/CCL17) in a dose‑dependent manner. Western blot analysis demonstrated that ISTP and APE dose‑dependently inhibited protein expression levels of intercellular adhesion molecule‑1 and phosphorylation of STAT‑1. The results of the present study indicate that ISTP may inhibit TARC/CCL17 production in human epidermal keratinocytes via the STAT‑1 signaling pathway and may be associated with the inhibition of IL‑33 production. The current study indicated that ISTP is an active component in APE and may be a potential therapeutic agent for the treatment of inflammatory skin disorders.