["Yingxiang" (LI2) acupoint injection alleviates nasal allergy symptoms in allergic rhinitis rats by regulating Treg/Th17 immune balance].

OBJECTIVES: 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.

METHODS: 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.

RESULTS: 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.

CONCLUSIONS: "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.