Effects of Compound Fo'ercao Mixture on TLR4/MyD88/NF-κB signaling pathway in a rat model of chronic obstructive pulmonary disease
AIM To explore the effect of Compound Fo'ercao Mixture on TLR4/MyD88/NF-κB signaling pathway in a rat model of chronic obstructive pulmonary disease(COPD).METHODS Rats were randomly divided into the blank group(n=10),and the model group(n=50)for the establishment of a rat model of COPD by 12-week cigarette smoke exposure combined with intratracheal injection of LPS.The successful rat models were randomly divided into the model group,the dexamethasone group(0.5 mg/kg)and the low,medium and high dose Compound Fo'ercao Mixture groups(6.8,13.6 and 27.2 g/kg),with 10 rats in each group.After 24 weeks of drug intervention,the rats had their lung function detected by animal lung function meter;their pathological changes of lung tissue observed by HE staining;their serum TNF-α,IL-1β,IL-6,and MDA levels and SOD activity detected by ELISA;their pulmonary mRNA expressions of TLR4,MyD88,NF-κB and caspase-3 detected by RT-qPCR;and their pulmonary protein expressions of TLR4,MyD88,NF-κB and TNF-α detected by Western blot.RESULTS Compared with the blank group,the model group displayed obviously pulmonary ventilation dysfunction,damaged lung tissue and bronchus,decreased SOD activity(P<0.01);increased serum TNF-α,IL-1β,IL-6 and MDA levels(P<0.01);and increased pulmonary expressions of TLR4,MyD88,NF-κB and caspase-3 mRNA and TLR4,MyD88,NF-κB and TNF-α proteins(P<0.01).Compared with the model group,all Compound Fo'ercao Mixture groups shared improvement in lung function indices levels and lung tissue damage;decrease in the levels of serum TNF-α,IL-1β,IL-6 and MDA(P<0.05,P<0.01);and decrease in the pulmonary expressions of TLR4,MyD88,NF-κB and caspase-3 mRNA and TLR4,MyD88,NF-κB and TNF-α protein(P<0.05,P<0.01)in a dose-dependent manner.CONCLUSION Compound Fo'ercao Mixture can improve the lung dysfunction and pathological injury in a rat model of COPD,and its mechanism may be associated with the regulated TLR4/MyD88/NF-κB signaling pathway.