Mechanism Of Xie-Bai-San On Regulating Treg Cells In Treatment Of Allergic Rhinitis

Objective: This study was designed to explore the therapeutic mechanism of Xie-Bai-San powder on OVA protein induced allergic rhinitis(AR)in mice.Methods:(1)SPF BALB/c mice(female,6 weeks old,25 ± 2g,n = 48)were categorized into normal control group(NC),allergic rhinitis model group(AR),Xie-Bai-San treatment group(XBS group)and dexamethasone treatment group(Dex group).(2)AR group,XBS group and Dex group mice were intraperitoneally injected with ovalbumin(OVA)and aluminum hydroxide adjuvant respectively to establish allergic rhinitis mouse model;then NC group was given 0.9% normal saline,Xie-Bai-San powder and dexamethasone suspension in 0.5% sodium carboxymethyl cellulose solution by gavage respectively.On the 39 th day of modeling,after the last ovalbumin challenge,the behavioral symptoms of mice were observed for 15 minutes,and the times of scratching nose and sneezing were obtained.(3)The eyeball blood of mice was taken on the last day for the serum collection via centrifugation.The levels of Interferon-γ,Interleukin(IL)4,IL-13,Th17 cytokines(IL-17),immunosuppressive factor IL-10,and OVA-s Ig E in sera were detected.(4)HE staining was performed to evaluate the nasal tissue inflammatory cells infiltration,and the ratios of Treg in spleen was assessed by flow cytometry.(5)TNF-α and IL-10 in the tissue of nasal mucosa were examined through ELISA.The nuclear factor E2 related factor 2(Nrf2),heme oxygenase-1(HO-1),phosphorylated Akt(p-Akt),phosphorylated NF-κB p65(p-NF-κB p65),phosphorylated p38(p-p38),phosphorylated IκBα(p-IκBα),phosphorylated JNK(p-JNK)and phosphorylated ERK(p-ERK)were detected by Western blot.Results:(1)The frequencies of sneezing and nose scratching of mice in XBS group was significantly less than that in AR group.(2)HE staining showed that the degrees of congestion and edema of nasal mucosa in XBS group were improved significantly,and the infiltration of inflammatory cell in nasal mucosa was also significantly reduced compared with AR group.(3)Compared with AR group,the level of IL-10 in XBS group was notably up-regulated and returned to the level close to that of normal control;while the concentrations of IL-4,IL-13 and OVA-s Ig E in XBS group wre significantly lower than that in AR group.(4)Compared with NC group,the levels of IL-6 and TNF-α in nasal mucosa of AR mice were significantly elevated,while the expressions of TNF-α and IL-6in nasal mucosa of XBS group and Dex group mice were significantly decreased.(5)Based on the data of flow cytometry,the ratio of Treg in spleen of XBS and Dex group were enhanced than that of AR group.(6)Expressions of p-Akt and p-NF-κB p65 in allergic rhinitis group were higher dramatically than that in NC group(P <0.05).Compared to AR group,Nrf2 protein in nasal mucosa of XBS group and Dex group increased obviously(P <0.05),and the expression of HO-1 in Dex group rised markedly,which indicated that XBS could activate Nrf2/ HO-1 pathway and inhibit Akt and NF-κB signaling pathway.(7)OVA induced allergic rhinitis mice favored a promoted phosphorylation of ERK,p38 and JNK in nasal mucosa,while the expression of p-ERK in nasal mucosa was reversed after intervention with XBS.Conclusion: XBS intervention can relief sympton of allergic rhinitis,The mechanism may induce Treg,promote immune tolerance to allergens,activate Nrf2/ HO-1 oxidative stress pathway and inhibit ERK/NF-κB inflammatory signal pathway in nasal mucosa tissue cells,alleviate the damage of nasal mucosa tissue caused by oxidative stress and inflammatory reaction,and alleviate the symptoms of allergic rhinitis.