Protective Effect of Platycodin D on Allergic Rhinitis in Mice through DPP4/JAK2/STAT3 Pathway Inhibition.

Background: Allergic Rhinitis (AR) is an inflammatory condition characterized by nasal mucosa remodeling, driven by Immunoglobulin E (IgE). Platycodin D (PLD) exhibits a wide range of bioactive properties.

Aim: The aim of this work was to investigate the potential protective effects of PLD on AR, as well as the underlying mechanisms.

Methods: The anti-allergic and anti-inflammatory potential of PLD was investigated in an ovalbumin-sensitized AR mouse model and human nasal mucosa cells (HNEpC) challenged with interleukin-13 combined with PLD. Our assessment included an examination of nasal symptoms, tissue pathology, and goblet cell hyperplasia. The levels of IgE, Interferon-gamma (IFN-γ), and interleukin-4 in the serum were detected using Enzyme-linked Immunosorbent Assay (ELISA). Furthermore, quantitative Real-time Polymerase Chain Reaction (RT-PCR) and ELISA were employed to determine the expressions of IL-1β, Tumor Necrosis Factor-alpha (TNF-α), and IL-6 in in vivo and in vitro settings. Western blot analysis was conducted to investigate the changes in DPP4/JAK2/STAT3 in vivo and in vitro.

Results: Our results demonstrated that oral administration of PLD significantly ameliorated nasal symptoms in AR mice, improved histopathological changes in the nasal mucosa, raised the level of IFN-γ, and reduced IgE as well as IL-4 levels in the serum. PLD inhibited the expressions of IL-1β, IL-6, TNF-α, and DPP4 in in vivo and in vitro settings. Notably, PLD modulated the changes in DPP4, p-JAK2, and p-STAT3 induced by IL-13 in HNEpC cells and AR mice.

Conclusion: The findings suggested the potential of PLD as a therapeutic agent for the treatment of AR.