“Yingxiang” (LI2) acupoint injection alleviates nasal allergy symptoms in allergic rhinitis rats by regulating Treg/Th17 immune balance

To observe the effect of “Yingxiang” (LI2) acupoint injection on T-helper 17 (Th17) cell, regulatory T (Treg) cell, and related cytokine expressions in allergic rhinitis (AR) rats, so as to explore its possible mechanism in improving AR.

Twenty-four SD rats were randomly divided into normal, model, and acupoint injection groups (n=8) . The AR model was established using ovalbumin sensitization. The rats of acupoint injection group received injection of a mixture solution of dexamethasone and lidocaine (0.05 mL/acupoint) at bilateral LI2, once every 3 d for a total of 4 times. Nasal allergy symptom scores were recorded; histopathological changes in the nasal mucosa were observed via HE staining; flow cytometry was used to detect the percentage of Th17 and Treg in peripheral blood; the levels of serum allergen-specific immunoglobulin E (sIgE) , interleukin (IL)-10 and IL-17A were detected by ELISA; the mRNA and protein expression levels of forkhead transcription factor p3 (Foxp3) and retinoic acid orphan receptor γt (RORγt) in nasal mucosa were detected by real-time fluorescence quantitative PCR and Western blot, respectively.

Following modeling, the symptom scores, Th17/CD4⁺ T cell ratio in peripheral blood, serum contents of sIgE and IL-17A, and RORγt mRNA and protein expression levels in nasal mucosa were significantly increased (P<0.01) , while the Treg/CD4⁺ T cell ratio, serum IL-10 content, and Foxp3 mRNA and protein expression levels in nasal mucosa were significantly decreased (P<0.01) . After acupoint injection intervention, the modeling induced increase and decrease of indexes mentioned above were completely reversed (P<0.01) . HE staining revealed thickened nasal mucosa, disordered epithelial arrangement, partial cilia loss, and massive inflammatory cell infiltration in the model group, which were markedly improved in the acupoint injection group.

“Yingxiang” acupoint injection can effectively alleviate nasal allergy symptoms in AR rats, which may be related to its function in regulating Treg/Th17 immune balance and suppressing inflammatory responses.