[Effect of heat-sensitive moxibustion at "Feishu" (BL13) on immunoinflammatory response in allergic rhinitis rats based on PI3K/AKT signaling pathway].

Abstract

Objective: To observe the effect of heat-sensitive moxibustion at "Feishu" (BL13) on immunoinflammatory response in rats with allergic rhinitis (AR) based on phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, so as to explore its underlying mechanism.

Methods: Thirty-two male SD rats were randomly divided into a blank group (6 rats) and a modeling group (26 rats). In the modeling group, AR model was prepared using systemic and local attack sensitization method with ovalbumin. The successfully-modeled rats were randomized into a model group (6 rats), a medication group (6 rats) and a moxibustion group (14 rats). In the moxibustion group, the suspending moxibustion was operated at bilateral "Feishu" (BL13), 40 min each time, once daily, for 21 consecutive days; during which, the temperature of the body and tail was recorded. During intervention, if the temperature of the body and tail increased by >1 ℃, the heat-sensitive reaction at the point was determined in the rats of the moxibustion group, and these rats were collected in a heat-sensitive moxibustion group (8 rats involved and 6 rats of them were randomly collected to ensure the sample-size consistency); and those without heat-sensitive moxibustion reaction were assigned to a traditional moxibustion group (6 rats). In the medication group, fluticasone propionate nasal spray was applied, 8 μL on each side, once daily and for 21 days. The behavioral score for AR symptoms after modeling and intervention, and the content of serum immunoglobulin E (IgE) after modeling were observed. After intervention, the histological morphology of the nasal mucosa was observed using HE staining, the positive expression of thymic stromal lymphopoietin (TSLP) in the nasal mucosa was detected using immunohistochemistry, the levels of IgE, interleukin (IL)-4, IL-5, IL-13 and interferon-γ (IFN-γ) were detected by ELISA, and the protein expression of the member 4 of tumor necrosis factor receptor superfamily (OX40), phosphorylated protein kinase B (p-AKT), phosphorylated phosphatidylinositol 3-kinase (p-PI3K) in nasal mucosa was detected by Western blotting.

Results: After modeling, the behavioral score of AR symptoms and serum IgE level in the modeling group were higher than those of the blank group (P<0.01), suggesting the success of AR modeling. After intervention, compared with the blank group, the behavioral score of AR symptoms was increased (P<0.01)；the nasal mucosa structure was disordered, the inflammatory infiltration was severe; the positive expression of TSLP in the nasal mucosa increased (P<0.01), the levels of serum IgE, IL-4, IL-5, and IL-13 elevated (P<0.01), and the level of IFN-γ decreased (P<0.01); and the protein expression of OX40, p-AKT, and p-PI3K in the nasal mucosa increased (P<0.05) in the model group. Compared with the model group, the behavioral score of AR symptoms was reduced (P<0.01); the nasal mucosa structure, inflammatory infiltration, and vascular dilation were ameliorated to varying degrees; the positive expression of TSLP in the nasal mucosa decreased (P<0.01); the content of serum IgE, IL-4, IL-5, and IL-13 decreased (P<0.05), and that of IFN-γ increased (P<0.05) in the medication, traditional moxibustion, and heat-sensitive moxibustion groups. Compared with the model group, the protein expression of p-AKT was reduced in the medication and traditional moxibustion groups (P<0.05), the protein expression of OX40, p-AKT, and p-PI3K in the nasal mucosa decreased in the heat-sensitive moxibustion group (P<0.05). When compared with the medication group, the positive expression of TSLP in the nasal mucosa was reduced (P<0.05) in the heat-sensitive moxibustion group. In comparison with the traditional moxibustion group, the content of serum IL-13 was reduced and the content of IFN-γ elevated in the heat-sensitive moxibustion and the medication groups (P<0.05), the protein expression of p-PI3K reduced in the medication group (P<0.05), and the positive expression of TSLP and the protein expression of OX40 and p-PI3K in the nasal mucosa were reduced in the heat-sensitive moxibustion group (P<0.05).

Conclusion: Heat-sensitive moxibustion at "Feishu" (BL13) can alleviate the symptoms of AR rats, ameliorate the inflammatory infiltration and telangiectasia of nasal mucosa, and inhibit immunoinflammatory response, which may be obtained by regulating PI3K/AKT signal pathway.