3.1.Data Preparation
Combine the search results in TCMSP and BATMAN-TCM to obtain 208 components of astragalus-angelica compound (Figure 1). Screened with OB ≥ 30% and DL ≥ 0.18, and calculated the percentage of active ingredients in astragalus-angelica compound that meet the requirements and the final inclusion percentage (Figure 2). A total of 22 components were obtained (Table 1), including 2 components of angelica and 20 components of astragalus. There are 634 core prediction targets, including 93 prediction targets of angelica and 541 prediction targets for astragalus, and 58 common targets for the two (Figure 3).
Table 1 The top 10 components of OB value in Astragalus-Angelica Compound
Mol_ID
|
Component Name
|
OB (%)
|
DL
|
MOL000398
|
isoflavanone
|
109.99
|
0.3
|
MOL000378
|
7-O-methylisomucronulatol
|
74.69
|
0.3
|
MOL000392
|
formononetin
|
69.67
|
0.21
|
MOL000433
|
fa
|
68.96
|
0.71
|
MOL000438
|
(3R)-3-(2-hydroxy-3,4-dimethoxyphenyl)chroman-7-ol
|
67.67
|
0.26
|
MOL000380
|
(6aR,11aR)-9,10-dimethoxy-6a,11a-dihydro-6H-benzofurano[3,2-cchromen-3-ol
|
64.26
|
0.42
|
MOL000211
|
mairin
|
55.38
|
0.78
|
MOL000371
|
3,9-di-O-methylnissolin
|
53.74
|
0.48
|
MOL000239
|
jaranol
|
50.83
|
0.29
|
MOL000354
|
isorhamnetin
|
49.6
|
0.31
|
3.2.Network Construction
After further screening, 142 common potential targets of astragalus and angelica compound-DN were obtained, corresponding to 18 active ingredients (Figure 4). In the figure, the red nodes represent astragalus and angelica, the purple nodes represent components, and the blue nodes represent gene targets. The degree of freedom of a node represents the number of edges connected to the node in the network. There are a total of 14 components with more than 10 targets, including MOL000098 quercetin (122), MOL000422 kaempferol (51), MOL000354 isorhamnetin (27), MOL000358 β-sitosterol (27), MOL000449 bean sterols (23), MOL000371 3,9-dioxymethyl nisolin (21), these compounds may play an important role in the pathogenesis and treatment of DN. In addition, the number of target points of the 18 components are all ≥3, indicating the complexity of the mechanism of astragalus-angelica compound in the treatment of DN.
Import 142 common targets into STRING, and all can be queried, as shown in Figure 5 (the thickness of the line in the figure represents the strength of the force), and the result is imported into Cytoscape 3.7.2 software to gather the PPI network of the astragalus-angelica compound against DN.Perform cluster analysis on the PPI network, extract the targets with DC values greater than 1 times the median and 2 times the median in turn, and use the CytoHubba plug-in to screen out the top 10 drugs in the number of nodes (Figure 6).
GO analysis from the David database, the screening results of P<0.05, obtained 502 biological processes (BP), 45 cell composition (CC), 96 molecular functions (MF). Sorted by the degree of significance from small to large, GO analysis results show that the BP of astragalus and angelica compound-DN-gene is significantly enriched in drug response, negative regulation of apoptosis process, positive regulation of RNA polymerase II promoter transcription, and deficiency Oxygen response, positive regulation of gene expression,inflammatory response, response to estradiol, aging, etc. MF is mainly enriched in enzyme binding, protein binding,transcription factor binding,protein isomerization activity, RNA polymerase II transcription factor activity, steroid hormone receptor, protein kinase binding, cytokine activity, etc. CC is mainly enriched in the extracellular space, extracellular zone, cytoplasm, mitochondria, fossa, nucleoplasm, extracellular matrix, plasma membrane, etc. (Table 2). Use the BINGO plug-in for analysis, and the results are shown in Figure 7.
Table 2 Biological Process of Astragalus-angelica Compound,DN and targets (top 10)
Category
|
Gene function
|
Count
|
P-Value
|
BP
|
response to drug
|
30
|
1.05X10-22
|
BP
|
negative regulation of apoptotic process
|
34
|
4.97X10-22
|
BP
|
positive regulation of transcription from RNA polymerase II promoter
|
42
|
1.68X10-18
|
BP
|
positive regulation of transcription, DNA-templated
|
32
|
2.31X10-18
|
BP
|
response to hypoxia
|
20
|
2.55X10-16
|
BP
|
positive regulation of gene expression
|
23
|
3.38X10-16
|
BP
|
cellular response to hypoxia
|
16
|
2.27X10-15
|
BP
|
inflammatory response
|
25
|
8.71X10-15
|
BP
|
response to estradiol
|
15
|
2.50X10-14
|
BP
|
aging
|
18
|
3.54X10-14
|
MF
|
enzyme binding
|
32
|
5.35X10-24
|
MF
|
protein binding
|
120
|
1.28X10-16
|
MF
|
identical protein binding
|
32
|
7.18X10-14
|
MF
|
transcription factor binding
|
21
|
2.29X10-13
|
MF
|
protein heterodimerization activity
|
20
|
1.01X10-8
|
MF
|
RNA polymerase II transcription factor activity, ligand-activated sequence-specific DNA binding
|
8
|
1.58X10-8
|
MF
|
steroid hormone receptor activity
|
9
|
1.86X10-8
|
MF
|
protein homodimerization activity
|
24
|
3.29X10-8
|
MF
|
protein kinase binding
|
17
|
9.26X10-8
|
MF
|
cytokine activity
|
12
|
2.45X10-7
|
CC
|
extracellular space
|
48
|
1.42X10-19
|
CC
|
membrane raft
|
16
|
5.96X10-11
|
CC
|
extracellular region
|
39
|
2.06X10-10
|
CC
|
cytosol
|
58
|
3.83X10-10
|
CC
|
mitochondrion
|
32
|
1.96X10-8
|
CC
|
caveola
|
9
|
3.46X10-8
|
CC
|
nucleoplasm
|
45
|
1.13X10-6
|
CC
|
extracellular matrix
|
13
|
3.09X10-6
|
CC
|
plasma membrane
|
56
|
6.49X10-6
|
CC
|
nucleus
|
67
|
9.72X10-6
|
According to P<0.05 and combined with related literature, the KEGG enrichment analysis pathway was screened, and 120 pathways related to DN were obtained. Sort by the number of target genes contained in the pathway, and select pathways with a number of genes> 20 (Figure 8), including cancer pathway, PI3K-Akt signaling pathway, proteoglycan in cancer, HIF-1 signaling pathway, and tumor necrosis factor signaling pathway, etc. There are 43 disease-related pathways, including type 1 diabetes, type 2 diabetes, pancreatic cancer, rheumatoid arthritis, hepatitis B, hepatitis C, non-alcoholic fatty liver, cancer pathway, tuberculosis, etc.; inflammation-related pathways such as TNF signaling pathway, nuclear transcription Factor-κB (NF-κB) signaling pathway; in addition, there are hypoxia inducible factor-1 (HIF-1) signaling pathway, insulin resistance, cyclic adenosine monophosphate (cAMP) signaling pathway, etc. Astragalus-angelica compound may act on these pathways to treat DN.
3.3.Molecular Docking
Among the 18 main active ingredients, select the top 5 target proteins (IL-6, TP53, VEGFA, TNF, MARK1) in the PPI network and degree>10 in the "Astragalus and Angelica compound-component-DN target interaction network". The active ingredients (quercetin, kaempferol, isorhamnetin, etc.) were molecularly docked using AutoDock Vina software, as shown in Table 3.
It is generally believed that the greater the absolute value of the docking score during molecular docking, the stronger the affinity of the compound to the target and the more stable the conformation. An absolute value greater than 4.25 indicates a certain binding activity, greater than 5.0 indicates a good binding activity, and greater than 7.0 indicates a strong binding activity [12]. The molecular docking results showed that the binding ability of quercetin, kaempferol, and isorhamnetin to TP53 was stronger, and the binding energy of each active ingredient was stronger than that of captopril. The binding energy of β-sitosterol and stigmasterol to IL-6 is higher than that of benazepril, captopril and irbesartan. The binding ability of each active ingredient with VEGFA is low, but they are all stronger than captopril. Quercetin, formononetin, mullein, kaempferol and TNF have stronger affinity than Invokana, benazepril and captopril. Comprehensive analysis shows that the docking scores of quercetin and TP53 and stigmasterol and IL-6 have the largest absolute value among the five targets. The targets TP53, IL-6, VEGFA, TNF, and MARK1 respectively have the strongest affinity with quercetin, stigmasterol, kaempferol, and ivy saponins. After processing and optimization with PyMoL software, the specific binding site pattern of the target protein and the molecule can be seen (Figure 9). The yellow line is the hydrogen bond interaction force between the two, which is the main force that promotes the binding of the molecule to the active site.
Table 3 Docking Results of Core Target Protein and Main Active Components
Compound\Affinity(kcal/mol)
|
TP53(3dcy)
|
IL-6(4cni)
|
VEGFA(4kzn)
|
TNF(4twt)
|
MAPK1(6q7s)
|
quercetin
|
-8.3
|
-6.7
|
-5.6
|
-7.9
|
-5.9
|
Jaranol
|
-7.6
|
-6.7
|
-5.3
|
-7.2
|
-5.3
|
hederagenin
|
-7.9
|
-6.8
|
-5.3
|
-4.7
|
-5.9
|
isorhamnetin
|
-8.1
|
-6.8
|
-5.5
|
-7.3
|
-5.8
|
beta-sitosterol
|
-7.2
|
-8.2
|
-5.2
|
-5.3
|
-5.4
|
3,9-di-O-methylnissolin
|
-7.5
|
-6.7
|
-5
|
-7.2
|
-5.1
|
7-O-methylisomucronulatol
|
-7.4
|
-6.7
|
-5
|
-6.5
|
-6
|
(6aR,11aR)-9,10-dimethoxy-6a,11a-dihydro-6H-benzofurano[3,2-c]chromen-3-ol
|
-8.2
|
-5.9
|
-4.8
|
-5.6
|
-5.4
|
Bifendate
|
-7.6
|
-6.5
|
-5.2
|
-6.9
|
-5.2
|
formononetin
|
-7.4
|
-6.6
|
-4.8
|
-7.5
|
-5.3
|
Calycosin
|
-7.4
|
-6.9
|
-5.1
|
-7.9
|
-5.4
|
kaempferol
|
-8.1
|
-6.6
|
-5.6
|
-8
|
-5.7
|
1,7-Dihydroxy-3,9-dimethoxy pterocarpene
|
-7.4
|
-7
|
-5.2
|
-7.5
|
-6
|
Stigmasterol
|
-7.6
|
-8.3
|
-5.2
|
-5.7
|
-5.7
|
Benazepril
|
-8.4
|
-6.8
|
-6
|
-7.2
|
-6.2
|
Irbesartan
|
-9.3
|
-7.9
|
-5.7
|
-9.1
|
-7
|
Captopril
|
-6
|
-4.3
|
-3.5
|
-5.7
|
-3.8
|
Invokana
|
-9
|
-8.4
|
-6.3
|
-7.4
|
-6.7
|