麦门冬饮子通过调控PAR1/Gαi/cAMP信号通路及TRPV1表达改善阴虚肺热咳嗽的作用机制OA

Objective:To investigate the effects of Maimendong Yinzi(MMDYZ)on cough with Yin deficiency and lung heat syndrome and explore its potential mechanism of action.Methods:Forty-eight Institute of Cancer Research(ICR)mice were randomly divided into a control group,a model group,a Baihe Gujin Tablet(BHGJP)group(1.36 g·kg-1),and low-dose,medium-dose,and high-dose MMDYZ groups(5,10,20 g·kg-1·d-1,based on the weight of crude drug),with eight mice in each group.The mouse model of cough with Yin deficiency and lung heat syndrome was prepared by a combination of smoke exposure,nasal drip of lipopolysaccharide(LPS),intragastric gavage with thyroxine,and capsaicin atomization.After successful modeling,drug interventions were administered for seven days.During modeling,the mice were observed for changes in general status,anal temperature,fecal water content,and water intake.After medication,the above indicators were evaluated again,along with assessments of spontaneous activity,cough sensitivity,lung function,lung index,and tracheal phenol red secretion.Bronchoalveolar lavage fluid(BALF)was analyzed for cell differential counts,and the level of cyclic adenosine monophosphate(cAMP),cyclic guanosine monophosphate(cGMP),tumor necrosis factor-α(TNF-α),and interleukin-6(IL-6)in serum was measured via enzyme linked immunosorbent assay(ELISA).Lung injury was assessed via hematoxylin-eosin(HE)staining.Network pharmacology was employed to predict the potential mechanism of MMDYZ in alleviation cough with Yin deficiency and lung heat syndrome.Western blot(WB)was used to measure protease-activated receptor1(PAR1)and GTPhase αi subunit(Gαi)protein expressions in lung tissue.ELISA was used to determine lung cAMP content,and immunohistochemistry(IHC)was employed to evaluate transient receptor potential vanilloid subtype 1(TRPV1)expression.Results:Compared with the control group,the model group exhibited significantly increased water intake and anal temperature and significantly decreased fecal water content(P<0.05).The total distance traveled in 5 min and the central zone duration were reduced,while standing frequency significantly increased(P<0.05).Cough sensitivity and enhanced pause(PenH)were elevated.Peak expiratory flow(PEF)significantly declined(P<0.05).BALF neutrophil(NEU)and white blood cell(WBC)counts rose.Serum cAMP and cAMP/cGMP ratio significantly increased,and cGMP significantly decreased(P<0.05).Serum TNF-α and IL-6 levels were significantly elevated(P<0.05).The lung injury was obvious,and the lung index was significantly elevated(P<0.05).Compared with the model group,the medium-dose and high-dose MMDYZ groups and the BHGJP group showed significantly improved indicators mentioned above.Additionally,network pharmacology suggested that MMDYZ might alleviate cough with Yin deficiency and lung heat syndrome via cAMP,hypoxia inducible factor-1(HIF-1),and TNF signaling pathways.WB,ELISA,and IHC revealed that,compared with the control group,the model group exhibited significantly upregulated PAR1,Gαi,and TRPV1 expressions and significantly downregulated cAMP in lung tissue(P<0.05).Compared with the model group,MMDYZ reduced PAR1(P<0.01),Gαi(P<0.05),and TRPV1(P<0.01)while increasing cAMP level(P<0.01).Conclusion:MMDYZ may alleviate cough with Yin deficiency and lung heat syndrome by modulating the PAR1/Gαi/cAMP pathway and TRPV1 expression.