A novel compound 2-(4-{2-[(phenylthio)acetyl]carbonohydrazonoyl}phenoxy)acetamide downregulates TSLP through blocking of caspase-1/NF-κB pathways.

Thymic stromal lymphopoietin (TSLP) is regarded as the main factor responsible for the pathogenesis of allergic disorders such as atopic dermatitis, chronic obstructive pulmonary diseases, and allergic rhinitis. As part of our continuing search for novel anti-inflammatory compounds, 2-(4-{2-[(phenylthio)acetyl]carbonohydrazonoyl}phenoxy)acetamide (PA) was analyzed. In the present study, we examined how PA regulates the mRNA expression and production of TSLP in the human mast cell line, HMC-1 cells. Computer-aided docking simulation, enzyme-linked immunosorbent assay, quantitative polymerase chain reaction, caspase-1 assay, and Western blotting were used to investigate the effects of PA. PA decreased the mRNA expression and production of TSLP in HMC-1 cells. PA (1μM) inhibited the TSLP production up to 87.710±5.201%. PA also improved the activation and phosphorylation of nuclear factor-κB as well as the degradation and phosphorylation of IκBα. Caspase-1 activation was up-regulated in activated HMC-1 cells, whereas caspase-1 activation was down-regulated by PA. Finally, PA inhibited ear swelling response induced by phorbol myristate acetate in mice. These results indicate that PA would be effective to treat inflammatory and atopic disorders through the down-regulations of TSLP.