RESUMO
Objective To explore the effect of Yizheng Recipe on pyroptosis of alveolar epithelium in rats with recurrent respiratory tract infection(RRTI)based on HMGB1/TLR4/NF-κB signal pathway.Methods SD rats were firstly grouped into normal group and model group.In the model group,the RRTI rat model of spleen-Qi deficiency and lung- Qi deficiency was induced by fatigue combined with diet disorder and shavings and tobacco leaf smoking.Then,the rats in the model group were grouped into:RRTI model group(gavaged with normal saline 0.5 mL·100 g-1·d-1)and Yupingfeng Powder control treatment group(gavaged with Yupingfeng Powder suspension 0.5 mL·100 g-1·d-1),Yizheng Recipe high,medium and low-dose treatment groups(gavaged with Yizheng Recipe 0.75,0.5,0.25 mL·100 g-1·d-1),the normal group(gavaged with normal saline 0.5 mL·100 g-1·d-1).The general activities of the rats were observed and the pulmonary function of the rats was detected by the AniRes2005 animal pulmonary function analysis system;the expression of inflammatory factors in rat serum was detected by ELISA;HE,PAS and TUNEL staining were applied to detect the pathological changes of lung tissue;Western blot was applied to detect cell pyroptosis and the expression of HMGB1/TLR4/NF-κB signaling pathway-related proteins.Results Compared with the normal group,the lung function of the RRTI model group was weakened;the inflammatory response increased,and the lung tissue damage,edema and apoptosis were obviously increased;meantime,the pyroptosis was aggravated,and the HMGB1/TLR4/NF-κB pathway was activated(P<0.05).Compared with the RRTI model group,the Yupingfeng Powder control treatment group and the Yizheng Recipe high-dose,medium-dose and low-dose treatment groups all had different degrees of remission in lung function;inflammatory response reduced,the lung tissue damage,edema and apoptosis reduced;meantime,the pyroptosis and HMGB1/TLR4/NF-κB pathway were inhibited(P<0.05).Yizheng Recipe high-dose treatment group and Yupingfeng Powder control treatment group had similar curative effect on RRTI model rats(P>0.05);and Yizheng Recipe was dose-dependent in treating RRTI model rats(P<0.05).Conclusion Yizheng Recipe may inhibit the pyroptosis of alveolar epithelial cells in RRTI model rats by reducing the inflammatory response,and then protecting the lung tissue from damage,this process may be related to the HMGB1/TLR4/NF-κB pathway.