艾灸及艾烟调控TLR4/NF-κB信号通路改善哮喘大鼠气道炎症的作用机制研究OA

Objective To investigate the mechanisms by which moxibustion and moxa smoke improve airway inflammation in asthmatic rats by regulating the Toll-like receptor 4(TLR4)/nuclear factor-κB(NF-κB)signaling pathway.Methods Sixty Sprague‒Dawley(SD)rats were randomly divided into the blank group,model group,dexamethasone group,conventional moxibustion group,smokeless moxibustion group,and moxa smoke inhalation group according to a random number table,with 10 rats in each group.An asthmatic rat model was established by intraperitoneal injection of ovalbumin and aluminum hydroxide suspension.Rats in the blank group received nebulized normal saline,while those in the other groups received nebulized ovalbumin solution for challenge.No intervention was administered to the blank and model groups.The dexamethasone group received an intraperitoneal injection of dexamethasone sodium phosphate acetate injection at 1 mg/kg.In the conventional moxibustion group,moxibustion was performed on Feishu(BL13,bilateral),Dazhui(GV14),and Fengmen(BL12,bilateral)using moxa sticks.The intervention in the smokeless moxibustion group was the same as that in the conventional moxibustion group,except that moxa smoke was rapidly removed during moxibustion.The moxa smoke inhalation group received moxa smoke inhalation intervention.All interventions were initiated on day 15 of the experiment and administered 0.5 h before each nebulization,once daily for 14 consecutive days.Hematoxylin and eosin(HE)staining and periodic acid-Schiff(PAS)staining were used to observe pathological changes in the lung tissues.Enzyme-linked immunosorbent assay(ELISA)was used to detect serum levels of interleukin-4(IL-4),interleukin-5(IL-5),interleukin-13(IL-13),and inducible nitric oxide synthase(iNOS).Western blot and real-time quantitative PCR were used to detect the protein and mRNA expression levels of TLR4 and NF-κB p65 in lung tissues,respectively.Results Compared with the blank group,the model group showed markedly increased inflammatory cell infiltration and mucus secretion in the lung tissues,as well as significantly increased serum levels of IL-4,IL-5,IL-13,and iNOS and protein and mRNA expression levels of TLR4 and NF-κB p65 in the lung tissues(P<0.01).Compared with the model group,the dexamethasone,conventional moxibustion,and smokeless moxibustion groups showed markedly reduced inflammatory cell infiltration and mucus secretion in the lung tissues,as well as significantly decreased serum levels of IL-4,IL-5,IL-13,and iNOS and protein and mRNA expression levels of TLR4 and NF-κB p65 in the lung tissues(P<0.01).Compared with the smokeless moxibustion group,the conventional moxibustion group showed decreased serum levels of IL-4,IL-5,IL-13,and iNOS and decreased protein and mRNA expression levels of TLR4 and NF-κB p65 in the lung tissues(P<0.05).Conclusion Moxibustion and moxa smoke can inhibit airway inflammatory responses in asthmatic rats,and the mechanisms may be related to regulation of the TLR4/NF-κB signaling pathway.