Study On The Mechanism Of Aster For Treating PM 2.5 Lung Injury Based On Network Pharmacology

Objective:In recent years,although the prevention and control of haze has been effective,it still threatens people’s health.PM 2.5,as the main component of hazy weather,can enter the lungs with people’s breathing due to its small particle size,leading to lung inflammation and endangering human health.It is therefore of great importance to find drugs that can prevent and treat lung damage caused by PM 2.5.Aster as the main ingredient of the Chinese herbal medicine Lung Ning Granules,which is useful in treating viral colds,chronic bronchitis and acute respiratory infections,it can be considered for the prevention or treatment of lung damage caused by PM 2.5.To explore the main compounds and possible mechanisms of action of aster in the treatment of PM 2.5-induced lung damage based on network pharmacology;and to perform molecular docking as well as validation in animal experiments.Methods:Network pharmacology study:The TCMSP database was searched for OB>30%and DL>0.18 to find the main chemical constituents and the corresponding target information of the revertant herb,and the obtained target information was converted into the corresponding Gene Symbol for storage in the Uniprot database.Targets related to PM 2.5-induced lung damage were retrieved using Gene Cards,OMIM databases,and unduplicated results from both databases were saved.The drug and disease related targets were imported into Venny software,Venn diagrammed and the intersecting targets were saved.The saved intersecting targets were imported into Cytoscape 3.7.2software to construct network diagrams of the links between drugs,diseases and targets,and to perform protein interaction analysis through the STRING database.The key targets of PM 2.5-induced lung damage were ranked in terms of magnitude,and the network topology parameters of the active ingredients and targets were analysed using the network analyser tool.The enrichment analysis of GO function and KEGG pathway was carried out through the Metascape platform,with the help of an online tool to draw bar graphs for visual analysis.The core active ingredients with high correlation were screened for molecular docking with Auto Dock 4.2 and the docking results were analysed.Experimental animal study:Collected and processed the ambient air sampling filter membranes provided by the Dalian Environmental Protection Bureau and prepare them into PM 2.5 suspension mixes and set aside.The SPF-rated SD rats were randomly divided into a blank control group,a model group,and two experimental groups（with different doses of Feining particles）,with 7 rats in each group.In the experimental group,the doses of 16g·kg^-1 and 32g·kg^-1 were administered of Feining particles（aster）twice daily,starting three days earlier.On the third day,PM 2.5 suspension was given to both the model group and the experimental group at a concentration of 10mg·kg^-1 for 7consecutive days.The pathomorphological changes in lung tissue were observed using HE staining and the levels of TNF-αand IL-6 in rat lung tissue as well as serum were measured by ELISA.Western Blot assay was used to detect the expression of HIF-1αin rat lung tissue homogenates.Results:Network pharmacology study:The study retrieved 19 active compound components of aster,the main components being quercetin,luteolin and asteroside C.Aster and PM 2.5 cause lung damage with 29 common targets,The results of the PPI protein interaction network indicate that TP53,PTGS2,TNF,IL6,VEGFA,HMOX1,EGFR,CXCL8,IL10 and PTENT are potential key targets.GO analysis yielded 2788entries related to biological processes,184 entries related to molecular functions and126 entries related to cellular components.Analysis of the KEGG pathway revealed major involvement in diabetic complications AGEs-RAGE signalling pathway,liposomes and atherosclerosis,chemical carcinogenesis-reactive oxygen species,cellular senescence,HIF-1 and TNF signalling pathway.The active ingredients quercetin and luteolin were molecularly docked to the key targets IL and TNF and both proved to have good binding activity.Experimental animal study:Compared with the blank control group,the lung tissue of SD rats in the model group showed mucosal epithelial hyperplasia,severe inflammatory infiltration,partial loss of alveoli and fibrosis under HE staining microscopy;the TNF-αand IL-6 contents in lung tissue and serum were significantly increased,and the difference was statistically significant（P﹤0.05）.Compared to the model group,the lung tissue status of the experimental group improved,with reduced capillary wall thickening,less proliferation of alveolar septa and more structural integrity observable microscopically.In contrast,the high dose group showed better improvement in lung tissue than the low dose group.The decrease in TNF-αand IL-6levels and HIF-1αexpression in lung tissue homogenates and serum was more pronounced in the high-dose group,and the difference was statistically significant（P﹤0.05）.Results:Aster contains quercetin and luteolin,the main components of Aster,which can exert anti-inflammatory,anti-viral,cellular ageing and immunomodulatory effects through a variety of pathways.Regulation of the HIF-1 signalling pathway and its role as a possible mechanism for treating PM 2.5-induced lung injury,providing ideas and references for subsequent studies.Aster improves lung histopathological changes in rats with PM 2.5-induced damage and reduces inflammatory factor levels in lung tissue homogenates and serum,which may be related to the regulation of HIF-1 signaling pathway.