Abstract: 【Objective】 Liquid chromatograph-mass spectrometer (LC-MS) and network pharmacology were used to explore the active ingredients of Echinacea purpurea (EP),targets and potential mechanism of EP against Porcine epidemic diarrhea virus (PEDV),so as to provide a theoretical basis for the further development of new anti-PEDV therapeutic drugs. 【Method】 A PEDV-infected IPEC-J2 cell model was constructed,and the cell model was treated with EP extracts of different concentrations.The mRNA transcription level of PEDV N protein was detected by Real-time quantitative PCR,and the effect of EP extract on PEDV replication was analyzed.The chemical constituents in EP were qualitatively analyzed by LC-MS.TCMSP,SwissTargetPrediction,NCBI databases were used to search the active ingredients of EP and the molecular targets related to anti-PEDV effects.The intersection targets of EP and PEDV were obtained and entered into the STRING database to construct protein-protein interaction (PPI) network and screen the key targets.The "EP-active ingredient-intersection target" network was constructed,and GO function and KEGG signal pathways of intersection targets were analyzed using the DAVID database to predict the core components,key targets and potential mechanisms of the anti-PEDV effect of EP.Finally,molecular docking was used to verify the binding ability of the main core components and key targets. 【Result】 In vitro results showed that compared with control group,EP extract significantly inhibited PEDV N protein mRNA transcription levels.LC-MS detection showed that EP contained 81 chemical components such as betaine,ellagic acid and cichoriic acid,and the highest classification proportion was mainly phenols,terpenoids and flavonoids.Based on network pharmacological screening,18 medicinal active ingredients such as ellagic acid,(+)-catechin and matrine in EP might exert anti-PEDV effects on 144 targets.The important core components of EP against PEDV included kaempferol,urushetin,luteolin,etc.The key targets included tumor protein 53 (TP53),interleukin-6 (IL-6),steroid receptor coactivator (SRC),mitogen-activated protein kinase 1 (MAPK1),etc.,mainly involved in Th17 cell differentiation,NOD-like receptor signaling pathway,FoxO signaling pathway,etc.,which involved in cellular immunity,apoptosis,cell cycle and other processes.The molecular docking results showed that the binding energy of ellagic acid with TP53,IL-6,SRC and MAPK1 was all less than －29.308 kJ/mol,among which ellagic acid had the strongest affinity with MAPK1. 【Conclusion】This study demonstrated that the anti-PEDV effect of EP was based on the synergistic action of multiple components, multiple targets, and multiple pathways. EP mainly used kaempferol, urushetin, luteolin and other core components to act on TP53, IL-6, SRC, MAPK1 and other targets, and regulated signaling pathways such as Th17 cell differentiation, NOD-like receptor and FoxO to treat PEDV.

Key words: Porcine epidemic diarrhea virus (PEDV); Echinacea purpurea; LC-MS; network pharmacology