Regulation of Th17/Treg immune imbalance by β-sitosterol in an OVA-induced allergic asthma rat model / 中国免疫学杂志

ABSTRACT

Objective:To explore the interventional effect of β-sitosterol on ovalbumin(OVA)-induced allergic asthma rats and its potential mechanism.Methods:SD male rats were randomly divided into normal group(CON),model group(M),positive drug dexamethasone group(DEX,0.075 mg/kg)and β-sitosterol group(Sit,50 mg/kg).A rat model of allergic asthma was estab-lished by intraperitoneal injection of OVA with aluminum hydrogen solution,and nebulized inhalation of OVA to stimulate.Rats were given intragastric administration 30 min before aerosol challenge,and after continuous administration for 7 days,the indicators of cough and asthma and tracheal phenol red excretion were detected.HE staining was used to observe pathological changes of lung tis-sue.Flow cytometry was used to detect reactive oxygen species(ROS)generation,apoptosis level and ratios of Th17 and Treg cells in peripheral blood.Biochemical method was used to detect contents of MDA,and activities of T-SOD and GSH-Px in rat lung tissues.ELISA was used to detect levels of Th17 and Treg-related cytokines(TNF-α,IL-4,IL-6,IL-17A,and IL-35).Results:Compared with model group,β-sitosterol significantly prolonged the incubation period of cough and gasp in rats with allergic asthma,reduced the frequency of cough and gasping,and promoted the excretion of phenol red in trachea;significantly reduced inflammatory infiltration in lung tissue of asthmatic rats;observably reduced MDA content in lung tissue,ROS of primary lung cell and apoptosis levels of asthmatic rats,increased the activities of T-SOD and GSH-Px;markedly reduced proportion of Th17 cells and levels of pro-inflammatory cyto-kines TNF-α,IL-4,IL-6 and IL-17A,increased proportion of Treg cells and levels of anti-inflammatory cytokine IL-35.Conclusion:β-sitosterol can ameliorate airway inflammation and oxidative damage in OVA-induced allergic asthmatic rats,and its mecha-nism may be related to the regulation of β-sitosterol on Th17/Treg immune imbalance and oxidative stress response.