[Acupoint injection improves allergic rhinitis by balancing Th17/Treg in allergic rhinitis rats]

To observe the effect of acupoint injection on expression of fork head/winged helix protein 3 (Foxp3), retinoic acid-related orphan receptor γt (RORγt) in nasal mucosa and serum interleukin-17 (IL-17) level in allergic rhinitis (AR) rats, so as to explore its mechanism underlying improvement of AR in terms of balancing Th17/Treg.

Thirty-two SD rats (half male and half female) were randomized into normal control, AR model, acupoint injection and non-acupoint injection groups (n＝8 in each group). The AR model was established by ovalbumin sensitization. In the acupoint injection group, "Yintang" (EX-HN3) and bilateral "Yingxiang"(LI20) were selected for injection of mixture solution of dexamethasone (DEX) and transfer factor and lidocaine (0.1 mL/acupoint), once every 3 days for a total of 4 times. The non-acupoints, located at the mid-point between the "Houhai" (GV1) and "Huantiao"(GB30) on the bilateral hips and the sites 5 cm inferior to the axillary were injected with the same dose of mixture solution as that in the acupoint injection. The AR severity was assessed by cumulative quantification scoring methods (including the numbers of nose-catching and sneezes, and the amount of nasal secretions in 30 min). The expressions of Foxp3 and RORγt in the nasal mucosa were detected by immunohistochemistry. The serum IL-17 content was detected by enzyme linked immunosorbent assay (ELISA)．.

The AR symptom score and serum IL-17 content were significantly higher in the AR model group than those in the normal control group (P<0.05), and significantly down-regulated in the acupoint injection group (not in the non-acupoint group) relevant to the AR model group (P<0.05). Following modeling, the expression levels of nasal Foxp3 protein was significantly down-regulated while that of RORγt protein markedly up-regulated in the AR model group relevant to the normal control group (P<0.05), indicating an imbalance between Foxp3 and RORγt activity(P<0.05). After EA intervention, the increased expression of Foxp3 and the down-regulated expression of RORγt were revised in the acupoint injection group (P<0.05) but not in the non-acupoint group (P>0.05). The percentage of the Foxp3 positive cells and the ratio of Foxp3/RORγt were negatively correlated with the AR symptom score(P<0.05), the expression of RORγt and the content of IL-17 were positively correlated with the symptom score (P<0.05)．.

Acupoint injection is able to improve symptoms of RA rats, which may be related with its function in up-regulating the level of nasal mucosal Foxp3 and suppressing the levels of nasal RORγt and serum IL-17 to correct the imbalance of Th17/Treg.