Yu-Ping-Feng nasal drops relieve allergic rhinitis via TRPV1/Ca2+/NFAT pathway

Ethnopharmacological relevance: Allergic rhinitis (AR) is a chronic inflammatory disorder of the nasal mucosa mediated by immunoglobulin E (IgE). Yu-Ping-Feng nasal drops (YPFND), a compound derived from traditional Chinese medicine, is extensively utilized in the management of respiratory ailments, including AR. Nonetheless, the precise biological pathways through which YPFND influences AR are yet to be fully elucidated.

Purpose: We aim to investigate the bioactivity of YPFND against AR and its therapeutic potential molecular mechanism.

Methods: We conducted a 14-day randomized controlled trial involving 60 AR patients assigned to control group (10 % YPFND solution, Con group), mometasone furoate group (MFN group), and YPFND group, with nasal symptom outcomes assessed post-treatment. In parallel, an ovalbumin (OVA)- developed AR rat model was established to investigate the effect of YPFND on nasal mucosal inflammation. Nasal tissues and serum were analyzed by ELISA, Western blot, quantitative PCR (qPCR), histology, immunofluorescence and flow cytometry. Chemical constituents of YPFND were identified via LC-MS/MS. Serum proteomics in control and OVA-induced AR rats was analyzed by nano-HPLC-MS/MS with DIA-NN identification and MaxLFQ quantification. Molecular docking and molecular dynamics (MD) simulations were performed to predict the binding affinity of active compounds to the transient receptor potential vanilloid 1 (TRPV1) protein. In vitro, human nasal epithelial cells (HNEpC) were stimulated with interleukin-17 A (IL-17 A) to induce inflammation. The effects of YPFND on TRPV1-mediated CA²⁺ influx and nuclear factor of activated T cells (NFAT) activation were assessed, and TRPV1 specificity was confirmed using the antagonist SB-366791.

Results: LC-MS/MS analysis identified 984 compounds, among which molecular docking revealed nine candidates exhibiting strong binding affinity to TRPV1. Subsequently, MD simulations confirmed the stability of the 5-O-methylvisammioside-TRPV1 complex. Quantitative proteomics quantified 9978 proteins and identified 527 significantly altered proteins (259 upregulated, 268 downregulated) between OVA-induced AR and control rats, enriched in pathways including inflammatory mediator regulation of TRP channels. YPFND significantly alleviated clinical and experimental AR symptoms. In HNEpC, IL-17 A stimulated the expression of TRPV1 and facilitated CA²⁺ influx. YPFND inhibited the IL-17 A-provoked NFAT expression via the TRPV1/CA²⁺ signaling pathway. In addition, YPFND ameliorated airway inflammation by inhibiting the TRPV1/NFAT pathway in AR rats and down-regulated the expression of retinoic acid receptor-related Orphan Receptor gamma t (RORγ-t), further regulating the balance between T helper 17 (Th17) cells and regulatory T (Treg) cells.

Conclusion: Our research elucidates a novel IL-17A/TRPV1/CA²⁺/NFAT signaling cascade as a critical mediator of Th17/Treg disequilibrium in AR. Moreover, it demonstrates that YPFND exerts anti-inflammatory effects by attenuating TRPV1-dependent CA²⁺ influx and its downstream NFAT activation.

Allergic rhinitis; Anti-inflammatory; TRPV1; Th17/Treg balance; YPFND.