Upper respiratory tract infection is to point to the generic name of acute inflammation of nasal cavity, pharynx and larynx, and its pathogen includes virus, a bacterium, which is often used antibacterial drugs in clinical. But the use of antibiotics in clinical applications has many problems, allergic reactions and drug toxicity. Extensive use of antimicrobial agents can lead to the emergence of resistant bacteria. Serious adverse reactions such as dysbacteriosis, bring new problems to the patient’s clinical treatment and rehabilitation. Therefore, to avoid the abuse of antibiotics in clinical treatment, there is often a tendency to combine Chinese patent medicine and western medicine, so reasonable combination can not only improve the drug efficacy but also reduce the bacterial resistance  . As a conventional Chinese patent medicine in clinical practice, compound Honggencao is mainly used as Honggencao, Jinyinhua, Chuanxinlian, Yuxingcao and Yejuhua, which has the function of clearing heat and detoxifying, relieving pharynx carbuncle  . In clinical practice, compound Honggencao is mainly used for indications such as acute pharyngitis, tonsillitis and enteritis, while the molecular mechanism of upper respiratory tract infection for acute pharyngitis is still unclear and has not been reported. Therefore, this paper will discuss the target prediction and molecular mechanism of network pharmacology in the treatment of upper respiratory tract infection, to provide some theoretical basis for clinical use.
2. Materials and Methods
2.1. Collection and Screening of Chemical Components of Traditional Chinese Medicine
Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) was used to retrieve compound Honggencao, which mainly consists of five parts: Honggencao, Jinyinhua, Chuanxinlian, Yuxingcao and Yejuhua  . The main chemical components of compound Honggencao were screened according to the ADME principle: oral bioavailability (OB) ≥ 30%, class drug resistance (DL) ≥ 0.18, and the corresponding targets of the main chemical components were obtained.
2.2. Construction of the Compound-Target Network
Search and download candidate genes about “upper respiratory tract infection” from the GeneCards database (www.genecards.org). The above candidate genes were compared with the target genes of the main chemical components of compound Honggencao, to select the common target genes. The software Cytoscape 3.6.1 was used to visualise the network diagram of the main chemical components of compound Honggencao—target genes of upper respiratory tract infection.
2.3. Protein Interaction Network Construction
Compound Honggencao main chemical composition corresponds to the upper respiratory tract infection target Genes through the STRING (Search Tool for the Retrieval of Interacting Genes/Proteins, http://sting-db.org) construction of protein interaction network, participate in the system to build protein score (median confidence) > 0.4. The critical genes of upper respiratory tract infection were screened by Molecular Complex Detection (MCODS) v1.4.2.
2.4. Gene Ontology Analysis and Pathway Analysis of Key Gene
Key genes corresponding to the main chemical components of compound Honggencao were used for gene ontology analysis and pathway analysis, including biological process (BP), molecular function (MF) and cellular component (CC). Using R software “org. Hs. Eg. Db”, “clusterProfiler”, “enrichplot” and “ggplot2” package analysis , the adjusted p-value is less than 0.05.
3.1. Chemical Constituents of a Compound
The main chemical components of compound Honggencao were obtained from TCMSP, including a total of 69 parts as shown in Table 1. The corresponding target genes were a total of 1090, and 205 were left after the removal of the duplicates. Six thousand three hundred ninety-one target genes of upper respiratory tract infection were obtained from the GeneCards database. Finally, 186 target genes of compound Honggencao and upper respiratory tract infection were obtained, as shown in Figure 1.
3.2. Construct the Network of Active Compounds of Compound Honggencao—Targets
Based on the above data of active compounds of compound Honggencao and upper respiratory tract infection from GeneCards database, Cytoscape software was used in this study to construct a target network diagram (as shown in Figure 2) related to compound components of Honggencao and upper respiratory tract infection, with 256 nodes and 1079 edges (Figure 2).
3.3. Construction of Protein Interaction Network
A protein interaction network consisting of 186 nodes and 3515 edges was constructed in STING from the compound components corresponding to the targets related to upper respiratory tract infection (Figure 3). MCODSv1.4.2, a plug-in of Cytoscape, was used to analyse and obtain the critical gene network relationships of the main chemical components of compound Honggencao concerning upper respiratory tract infection targets, as shown in Figure 4. There are 56 nodes and 1228 edges.
Figure 1. The targets of compound Honggencao concerning upper respiratory tract infection. (Blue circle shows there are 6391 target genes of upper respiratory tract infection were obtained from the GeneCards database. Yellow circle shows there are 205 genes in compound Honggencao. The intersection of two circles shows there are 186 targets in compound Honggencao are associated with treatment in upper respiratory tract infection.)
Figure 2. Target network of compound Honggencao of active components related to upper respiratory tract infection. (There are compounds in red, traditional Chinese medicine in green, targets in blue.)
Figure 3. Interaction network relationship of potential action targets of compound Honggencao.
Figure 4. Key gene interaction network relationship of compound Honggencao of active components related to upper respiratory tract infection.
Table 1. Basic information of active compounds in compound Honggencao.
3.4. GO Analysis and Pathway Analysis of Essential Genes
Through the study of the critical gene ontology, there were 2567 GO entries, among which BP included 2273 such as response to lipopolysaccharide, response to molecule of bacterial origin and response to oxygen levels. CC contains 103 items including Clinique, clinique microdomain and clinique region. There were 191 MF, including nuclear receptor activity, transcription factor activity, direct ligand regulated sequence-specific DNA binding and cytokine receptor binding. The results are shown in Figure 5 for the top 10 GO analysis. There were 166 pathways involved in pathway analysis, including AGE-RAGE signaling pathway in diabetic complications, PFluid shear stress and atherosclerosis and Human cytomegalovirus infection. The results of GO analysis and KEGG analysis displayed in Figure 5.
Network pharmacology, as a method to investigate the network relationship among drugs, diseases and targets, has been widely used in pharmacology research and is helpful to find the target and molecular mechanism of drug action quickly. We have reported on the molecular mechanism of chemical components of Honggencao based on network pharmacology and found that the pathways of Honggencao were related to Staphylococcus aureus infection and hepatitis B infectious diseases . Du et al. reported that Jinyinghua exhibited the characteristics of multi-molecule, multi-target and multi-pathway in the anti-inflammatory mechanism of its active ingredient based on network pharmacology . Wang et al. also investigated the mechanism of action of Yuxingcao in the treatment of bronchitis based on network pharmacology and found 12 active components and 42 bronchitis targets . In this study, we will further systematically explore the active components and targets of compound Honggencao on upper respiratory tract infection using network pharmacology, and reveal the interaction between the upper respiratory tract infection and the active components of compound Honggencao on upper respiratory tract infection.
Liu Wei found that the serum level of IL-17 in children with recurrent upper respiratory tract infection was significantly higher than that of healthy children. Cox statistical analysis showed that IL-17 was an independent factor in the occurrence of children with upper respiratory tract infection . Our results found that the active component pathway of compound Honggencao included IL-17 signaling pathway. Therefore, combined with the characteristics of IL-17 expression level in the mentioned clinical reports, certain theoretical basis can be provided for the treatment of upper respiratory tract infection by compound Honggencao. Ma et al. reported that in patients treated with Yuxingcao combined with amoxicillin for upper respiratory tract infection, the tumour necrosis factor-a level was significantly lower than that treated with amoxicillin , which was consistent with the pathway of action of the active components of compound Honggencao including tumour necrosis factor signaling pathway in
Figure 5. The top 10 GO analysis and top 20 KEGG pathways of compound Honggencao.
this study. The action pathway of compound Honggencao also included the human cytomegalovirus infection pathway, so in the infantile idiopathic thrombocytopenic purpura cytomegalovirus infection, its precursor infection was mainly the upper respiratory tract infection , which provided a certain theoretical reference for the use of compound red root in the prevention and treatment of the infection with the help of network pharmacology.
In this study, although it found that compound Honggencao had the characteristics of multiple components and multiple targets, and explained its related signal channels in upper respiratory tract infection, the complex network relationship between its drugs and the disease still need to be further verified by experiment and clinic.
Based on the method of network pharmacology, this study explored the potential active components, targets and signaling pathways of compound Honggencao in the treatment of upper respiratory tract infection, providing a certain theoretical basis for the research on the pharmacological direction of molecular signaling pathways and providing a certain theoretical basis for clinical use.
This study was funded by the Study and Development Fund for Sciences and Technology in Chengde City (No. 201701A086 and No. 201701A087).
Consent for Publication
All of the authors consent to the publication of this study in the Journal of Chinese Medicine.
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