Platycodin D suppresses mast cell-mediated allergic inflammation

Mast cell-mediated allergic inflammation is involved in allergic rhinitis (AR). Platycodin D (PLD) is one of the main effective ingredients from the root of Platycodon grandiflorum. It is known to have anti-tumor, anti-inflammatory, and anti-allergic activities. However, the effects of PLD on AR have not yet been fully elucidated. In this study, we evaluated the anti-allergic and anti-inflammatory effects of PLD on phorbol-12-myristate 13-acetate plus calcium inophore (PMACI)-induced human mast cells. In this study, we found that PLD significantly inhibited the expression of TNF-alpha and IL-1 beta and histamine release in the PMACI-stimulated HMC-1 cells; it also inhibited the PMACI-induced caspase-1 activation in HMC-1 cells. Moreover, it inhibited the PMACI-induced I kappa B-alpha degradation and MAPK activation in HMC-1 cells. Taken together, our results showed that PLD inhibits PMACI-induced IL-1 beta expression and caspase-1 activity by suppressing the activation of NF-kappa B signaling pathway and MAPK signaling pathway in HMC-1 cells. Therefore, our data suggest the possible therapeutic application of PLD in the treatment of AR.