[Acupoint injection inhibiting abnormal secretion of mucin and inflammatory reaction of nasal mucosa in rats with allergic rhinitis through the p38 mitogen-activated protein kinase pathway].

Objectives: To observe the effects of acupoint injection on the expression of p38 mitogen-activated protein kinase (MAPK), phosphorylated (p)-p38 MAPK, mucin 5 subtype AC (MUC5AC) in the nasal mucosa, and serum inflammatory factors of rats with allergic rhinitis, so as to explore the mechanism of acupoint injection in improving inflammatory reactions in the nasal mucosa of rats with allergic rhinitis.

Methods: SD rats were randomly divided into the normal group, model group, acupoint injection group, and non-acupoint group, with 7 rats in each group. The allergic rhinitis rat model was established using ovalbumin sensitization. Intervention was performed by injecting dexamethasone and 1% lidocaine mixture (0.05 mL) into the bilateral "Yingxiang"(LI20) and "Yintang"(GV24) acupoints, with injection at non-acupoints for non-acupoint group as the control, once every 3 days for a total of 4 times. Allergic symptoms in the rat nose were evaluated using a cumulative scoring method；histopathological changes in the nasal mucosa were observed after HE staining；serum histamine (HA), interleukin (IL)-6, IL-8, and tumor necrosis factor-alpha (TNF-α) contents were detected using ELISA；real-time fluorescent quantitative PCR was used to detect the expression of MUC5AC mRNA in the nasal mucosa；Western blot was used to detect the expression of p38 MAPK, p-p38 MAPK, and MUC5AC protein in the nasal mucosa.

Results: Compared with the normal group, nasal allergic symptom score, serum HA, IL-6, IL-8, and TNF-α contents, nasal mucosal p38 MAPK, p-p38 MAPK proteins expression, MUC5AC mRNA and protein expression were significantly increased(<0.01) in the model group. Compared with the model group and non-acupoint group, nasal allergic symptom score, serum HA, IL-6, IL-8, and TNF-α contents, nasal mucosal p38 MAPK and p-p38 MAPK proteins expression, MUC5AC mRNA and protein expression were significantly reduced (<0.01, <0.05) in the acupoint injection group.

Conclusions: Acupoint injection can reduce nasal allergic symptom, and MUC5AC secretion in rats with allergic rhinitis, alleviate nasal mucosal inflammatory reactions, and its mechanism of action may be related to the inhibition of p38 MAPK phosphorylation, thereby reducing the release of inflammatory factors.