NA phytochemicals and target prediction. A total of 201 phytochemicals identified in NA (108 in CL and 93 in EO) were collected with CAS ID (Chemical Abstracts Service registry number) and PubChem CID (Supplementary file 1). The possible targets of the NA phytochemicals were determined using similarity ensemble approach (SEA). The scope of potential targets of NA was narrowed from 5187 to 1052 based on the Tanimoto Coefficient (Tc max ≥ 0.6) (Supplementary file 2). Further duplicate entries and genes not found in humans were removed, and the number of targets for analysis gradually decreased from 1052 to 262.
PPI network analysis and module identification. The PPI network was created using NetworkAnalyst 3.0 as an undirected network, i.e., edges having no direction. The target genes/proteins were represented as ‘nodes,’ and the interaction between any two genes/proteins was represented by ‘edge.’ The network analysis revealed the interaction of 163 nodes via 604 edges (Figure 2). In the network, 42 nodes showed a degree of one, while 121 nodes showed a degree more than one. Out of 121 nodes, 39 nodes had ≥ ten connections to other nodes. We also found “betweenness” ranging from 2.5 to 2617.62 for 94 nodes in the constructed network. The results indicate that the constructed network was abundant in the hub proteins (high degree, i.e., number of connections with other nodes) and bottleneck proteins (high betweenness, i.e., number of shortest routes passing through a node), which suggests that they may be important proteins27,28. Based on the results, proteins having the high degree in the PPI network showed the high betweenness. As hub proteins contribute to many interactions and hold the network together29, they play a crucial role in regulating signaling pathways as well as transcription. Therefore, hub proteins may serve as potential therapeutic targets or biomarkers.
The constructed PPI network was further clustered into modules, which contain proteins with similar functions. A network module is a subnetwork in which nodes are more closely linked to each other than rest of the network. Identifying the modules within the network is important as it might help in detecting the hidden structural information. Seven highly connected independent modules were observed, out of which only Module 1 showed a significant P-value (P ≤ .001) (Table 1). Thus, the PPI network of Module 1 was extracted for further analysis (Figure 3). The particulars of topological parameters, i.e., closeness centrality, betweenness centrality, eccentricity, and degree, have been shown in Table 2, highlighting the importance of each target in the network.
Table 1
Identification of modules of the PPI network
Modules
|
Targets
|
Size
|
P-value
|
Module 1
|
AKT1, AURKA, AURKB, BCL2, CCND1, CRYAB, CSNK2A1, CYP19A1, DNMT1, EP300, ESR1, ESR2, FABP3, FOS, GSK3B, HDAC1, HDAC2, HDAC3, HDAC8, HDAC9, IL2, JUN, KDM2A, MAP3K8, MCL1, MMP1, MMP13, MMP2, MMP9, NFE2L2, NFKB1, NR3C1, NR4A1, PLK1, PLK4, PPARD, PPARG, RELA, RXRA, SMAD3, SRC, SREBF2, TERT, TOP1, TOP2A
|
45
|
0.0000291
|
Module 2
|
ALK, AXL, EGFR, ERBB2, FYN, IGF1R, INSR, MET, MYLK, PDGFRB, PIK3R1, PTK2, PTPN1, PTPN2, PTPN6, STAT1, STAT3, SYN1, TLR2
|
19
|
0.303
|
Module 3
|
ABCB1, ABCG2, ACHE, ALOX5, APEX1, APP, CCNA1, CCNA2, CDK1, CDK4, DYRK1A, ELAVL1, EPHB4, NOS3, NUAK1, PIM1, VCP
|
17
|
0.889
|
Module 4
|
ABCB11, CYP3A4, NR1H2, NR1H3, NR1H4, PPARA, RARB, RARG, RXRB, RXRG, SPHK1
|
11
|
0.789
|
Module 5
|
ACP1, DAPK1, FASN, FLT3, FLT4, IKBKG, KDR, TEK, TPT1
|
9
|
0.476
|
Module 6
|
HDAC6, MAPK14, MAPT, PKN1, RPS6KA3
|
5
|
0.67
|
Module 7
|
CDK2, MIF, MPG, P4HB, PGD
|
5
|
1
|
Table 2
Properties of network Module 1
Name
|
Betweenness Centrality
|
Closeness Centrality
|
Eccentricity
|
Clustering Coefficient
|
Degree
|
Topological Coefficient
|
AKT1
|
0.019
|
0.537
|
3
|
0.378
|
10
|
0.313
|
AURKA
|
0.006
|
0.458
|
3
|
0.400
|
5
|
0.447
|
AURKB
|
0.001
|
0.419
|
4
|
0.000
|
2
|
0.604
|
BCL2
|
0.012
|
0.440
|
3
|
0.167
|
4
|
0.346
|
CCND1
|
0.011
|
0.550
|
3
|
0.667
|
10
|
0.424
|
CRYAB
|
0.003
|
0.440
|
3
|
0.333
|
3
|
0.452
|
CSNK2A1
|
0.021
|
0.543
|
3
|
0.422
|
10
|
0.366
|
CYP19A1
|
0.000
|
0.415
|
4
|
1.000
|
2
|
0.780
|
DNMT1
|
0.003
|
0.478
|
3
|
0.400
|
5
|
0.457
|
EP300
|
0.095
|
0.677
|
2
|
0.391
|
23
|
0.285
|
ESR1
|
0.068
|
0.629
|
3
|
0.395
|
20
|
0.310
|
ESR2
|
0.000
|
0.454
|
3
|
0.900
|
5
|
0.520
|
FABP3
|
0.001
|
0.383
|
4
|
0.000
|
2
|
0.563
|
FOS
|
0.060
|
0.603
|
3
|
0.368
|
17
|
0.286
|
GSK3B
|
0.059
|
0.543
|
3
|
0.200
|
11
|
0.282
|
HDAC1
|
0.151
|
0.688
|
3
|
0.313
|
25
|
0.270
|
HDAC2
|
0.038
|
0.603
|
3
|
0.417
|
16
|
0.313
|
HDAC3
|
0.052
|
0.620
|
3
|
0.399
|
18
|
0.298
|
HDAC8
|
0.008
|
0.444
|
3
|
0.200
|
6
|
0.313
|
HDAC9
|
0.010
|
0.512
|
3
|
0.476
|
7
|
0.377
|
IL2
|
0.000
|
0.506
|
3
|
1.000
|
5
|
0.545
|
JUN
|
0.125
|
0.657
|
3
|
0.329
|
22
|
0.268
|
KDM2A
|
0.000
|
0.444
|
3
|
1.000
|
3
|
0.611
|
MAP3K8
|
0.000
|
0.427
|
3
|
0.333
|
3
|
0.600
|
MCL1
|
0.002
|
0.376
|
4
|
0.000
|
2
|
0.500
|
MMP1
|
0.000
|
0.449
|
3
|
0.833
|
4
|
0.558
|
MMP13
|
0.000
|
0.449
|
3
|
0.833
|
4
|
0.558
|
MMP2
|
0.000
|
0.440
|
4
|
1.000
|
3
|
0.656
|
MMP9
|
0.000
|
0.500
|
3
|
0.900
|
5
|
0.518
|
NFE2L2
|
0.000
|
0.423
|
4
|
1.000
|
2
|
0.611
|
NFKB1
|
0.025
|
0.595
|
2
|
0.505
|
14
|
0.339
|
NR3C1
|
0.019
|
0.557
|
3
|
0.485
|
12
|
0.360
|
NR4A1
|
0.032
|
0.512
|
3
|
0.333
|
10
|
0.332
|
PLK1
|
0.033
|
0.524
|
3
|
0.422
|
10
|
0.370
|
PLK4
|
0.001
|
0.431
|
4
|
0.333
|
4
|
0.510
|
PPARD
|
0.001
|
0.500
|
3
|
0.786
|
8
|
0.500
|
PPARG
|
0.006
|
0.530
|
3
|
0.639
|
9
|
0.397
|
RELA
|
0.081
|
0.667
|
2
|
0.385
|
22
|
0.285
|
RXRA
|
0.022
|
0.595
|
2
|
0.505
|
14
|
0.331
|
SMAD3
|
0.053
|
0.603
|
3
|
0.375
|
16
|
0.297
|
SRC
|
0.013
|
0.537
|
3
|
0.439
|
12
|
0.342
|
SREBF2
|
0.000
|
0.458
|
3
|
0.667
|
4
|
0.516
|
TERT
|
0.000
|
0.484
|
3
|
0.800
|
5
|
0.500
|
TOP1
|
0.001
|
0.431
|
3
|
0.500
|
4
|
0.433
|
TOP2A
|
0.013
|
0.530
|
3
|
0.429
|
8
|
0.366
|
Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. GO enrichment analysis was done on 45 target genes of Module 1, and the GO terms with P ≤ .01 were selected and represented on the graph as − log P values (Figure 4). The results showed that these 45 target genes are involved in various biological processes like negative regulation of apoptotic process, aging, regulation of signal transduction by p53 class mediator, histone H3 deacetylation, positive regulation of transcription from RNA polymerase II promoter, negative regulation of cell growth, etc. (Figure 4a). In addition, these processes are associated with molecular functions such as transcription factor binding, NF-kappa B binding, protein kinase activity, DNA binding, protein homodimerization activity, etc. (Figure 4b). These processes occur in different cellular components like nucleoplasm, nucleus, cytosol, spindle microtubule, nuclear chromosome, etc. (Figure 4c).
KEGG pathway enrichment analysis was also done to explore the target’s role (Supplementary file 3). The top 30 enriched pathways have been shown in Figure 5. The results showed that the targets were highly enriched in Pathways in cancer, Endocrine resistance, IL-17 signaling pathway, Apoptosis, Cell cycle, Wnt signaling pathway, Longevity regulating pathway- multiple species, etc. In addition, pathways related to the T2DM and its complications were also observed, including, PI3K-Akt signaling pathway, Insulin resistance, TNF signaling pathway, AGE-RAGE signaling pathway in diabetic complications, FoxO signaling pathway, NF-kappa B signaling pathway, Jak-STAT signaling pathway, MAPK signaling pathway, HIF-1 signaling pathway, Non-alcoholic fatty liver disease (NAFLD), etc. These results suggest that NA herbal formulation may exert therapeutic effects by regulating these pathways.
Gene-disease association network. A gene-disease association network constructed for the 45 target genes of Module 1 showed 424 nodes and 611 edges (Figure 6). The degree and betweenness of the resultant diseases ranged from 11 to 1 and 9700.68 to 0, respectively. The diseases with betweenness ≥ 50 were considered significant (Supplementary file 4). The results showed that besides diabetic conditions, NA could be explored in other disease conditions like neoplasms, leukemia, carcinoma, obesity, hypertensive disease, atherosclerosis, osteoporosis, liver cirrhosis, fatigue, heatstroke, depressive and anxiety disorders.
Identification of T2DM genes and corresponding NA phytochemicals. A list of 579 genes related to T2DM was identified using various databases as described in methodology (Supplementary file 5). Out of 45 genes, 18 were common among Module 1 and the T2DM related gene list (Table 3). The NA phytochemicals targeting these 18 gene targets were identified as curcumin, quercetin, (2S)-Eriodictyol 7-O-beta-D-glucopyranoside, arachidic acid, bis-(4-hydroxycinnamoyl)methane, bisdemethoxycurcumin, calebin A, demethoxycurcumin, dihydrocurcumin, letestuianin B, corilagin, indole-3-acetic acid, chebulinic acid, tauroursodeoxycholic acid, Go-Y022, epigallocatechin gallate, eriodictyol, glycocholic acid, naringenin, naringenin 7-O-beta-D-glucoside, beta-carotene, and quercetin-3-O-glucoside. The results also showed that AKT1, BCL2, CYP19A1, ESR1, IL2, MCL1, NR4A1, and RXRA are the targets of EO, while EP300, HDAC1, JUN, NFKB1, NR3C1, PPARD, and PPARG are the targets of CL. However, GSK3B, MMP2, and MMP9 are the common targets of both CL and EO.
Table 3
Nisha Amalaki gene targets related to Type 2 diabetes mellitus
Target gene
|
Protein Description
|
UniProt ID
|
Associated pathways
|
Relevant phytochemical(s)
|
Herb
|
AKT1
|
RAC-alpha serine/threonine-protein kinase
|
P31749
|
Insulin resistance, PI3K-Akt signaling pathway, AGE-RAGE signaling pathway in diabetic complications, AMPK signaling pathway, HIF-1 signaling pathway, FoxO signaling pathway, MAPK signaling pathway, TNF signaling pathway
|
Quercetin
|
EO
|
Ellagic acid
|
EO
|
BCL2
|
Apoptosis regulator Bcl-2
|
P10415
|
Apoptosis, AGE-RAGE signaling pathway in diabetic complications, HIF-1 signaling pathway, NF-kappa B signaling pathway, PI3K-Akt signaling pathway, Jak-STAT signaling pathway
|
Epigallocatechin gallate
|
EO
|
CYP19A1
|
Aromatase
|
P11511
|
Metabolic pathways, Ovarian steroidogenesis, Steroid hormone biosynthesis
|
Naringenin 7-O-beta-D-glucoside
|
EO
|
Naringenin
|
EO
|
Eriodictyol
|
EO
|
(2S)-Eriodictyol 7-O-beta-D-glucopyranoside
|
EO
|
EP300
|
Histone acetyltransferase p300
|
Q09472
|
FoxO signaling pathway, HIF-1 signaling pathway, Jak-STAT signaling pathway, Pathways in cancer, Cell cycle, cAMP signaling pathway, Notch signaling pathway
|
Calebin A
|
CL
|
Curcumin
|
CL
|
Letestuianin B
|
CL
|
Demethoxycurcumin
|
CL
|
1,7-bis(4-hydroxy-3-methoxyphenyl)-1,4,6-heptatrien-3-one
|
CL
|
Dihydrocurcumin
|
CL
|
Go-Y022
|
CL
|
ESR1
|
Estrogen receptor
|
P03372
|
Endocrine resistance, Pathways in cancer, Thyroid hormone signaling pathway, Estrogen signaling pathway
|
Naringenin
|
EO
|
GSK3B
|
Glycogen synthase kinase-3 beta
|
P49841
|
PI3K-Akt signaling pathway, Non-alcoholic fatty liver disease (NAFLD), Insulin resistance, Pathways in cancer, Wnt signaling pathway, Cell cycle, Thyroid hormone signaling pathway
|
Demethoxycurcumin
|
CL
|
bis-(4-hydroxycinnamoyl) methane
|
CL
|
Bisdemethoxycurcumin
|
CL
|
Quercetin
|
EO
|
Ellagic acid
|
EO
|
HDAC1
|
Histone deacetylase 1
|
Q13547
|
Pathways in cancer, Cell cycle, Notch signaling pathway, Thyroid hormone signaling pathway, Longevity regulating pathway - multiple species
|
bis-(4-hydroxycinnamoyl) methane
|
CL
|
Bisdemethoxycurcumin
|
CL
|
IL2
|
Interleukin-2
|
P60568
|
PI3K-Akt signaling pathway, Pathways in cancer, Jak-STAT signaling pathway, Inflammatory bowel disease (IBD), HTLV-I infection
|
Quercetin-3-O-glucoside
|
EO
|
JUN
|
Transcription factor AP-1
|
P05412
|
AGE-RAGE signaling pathway in diabetic complications, MAPK signaling pathway, Non-alcoholic fatty liver disease (NAFLD), Pathways in cancer, TNF signaling pathway, Apoptosis, Endocrine resistance
|
Demethoxycurcumin
|
CL
|
Curcumin
|
CL
|
Calebin A
|
CL
|
bis-(4-hydroxycinnamoyl) methane
|
CL
|
Bisdemethoxycurcumin
|
CL
|
1,7-bis(4-hydroxy-3-methoxyphenyl)-1,4,6-heptatrien-3-one
|
CL
|
Go-Y022
|
CL
|
MCL1
|
Induced myeloid leukemia cell differentiation protein
|
Q07820
|
Jak-STAT signaling pathway, PI3K-Akt signaling pathway, Apoptosis, MicroRNAs in cancer
|
Corilagin
|
EO
|
Indole-3-acetic acid
|
EO
|
Chebulinic acid
|
EO
|
MMP2
|
72 kDa type IV collagenase
|
P08253
|
AGE-RAGE signaling pathway in diabetic complications, Endocrine resistance, Estrogen signaling pathway, Pathways in cancer, GnRH signaling pathway
|
bis-(4-hydroxycinnamoyl) methane
|
CL
|
Bisdemethoxycurcumin
|
CL
|
Epigallocatechin gallate
|
EO
|
Quercetin
|
EO
|
MMP9
|
Matrix metalloproteinase-9
|
P14780
|
Endocrine resistance, Estrogen signaling pathway, IL-17 signaling pathway, Pathways in cancer, TNF signaling pathway
|
Demethoxycurcumin
|
CL
|
Calebin A
|
CL
|
Curcumin
|
CL
|
Letestuianin B
|
CL
|
bis-(4-hydroxycinnamoyl) methane
|
CL
|
1,7-bis(4-hydroxy-3-methoxyphenyl)-1,4,6-heptatrien-3-one
|
CL
|
Bisdemethoxycurcumin
|
CL
|
Dihydrocurcumin
|
CL
|
Go-Y022
|
CL
|
Quercetin
|
EO
|
NFKB1
|
Nuclear factor NF-kappa-B p105 subunit
|
P19838
|
Insulin resistance, AGE-RAGE signaling pathway in diabetic complications, Apoptosis, PI3K-Akt signaling pathway, MAPK signaling pathway, Longevity regulating pathway, NF-kappa B signaling pathway, Non-alcoholic fatty liver disease (NAFLD), Pathways in cancer, TNF signaling pathway
|
Demethoxycurcumin
|
CL
|
Calebin A
|
CL
|
Curcumin
|
CL
|
Dihydrocurcumin
|
CL
|
1,7-bis(4-hydroxy-3-methoxyphenyl)-1,4,6-heptatrien-3-one
|
CL
|
Go-Y022
|
CL
|
Letestuianin B
|
CL
|
NR3C1
|
Glucocorticoid receptor
|
P04150
|
HIF-1 signaling pathway, FoxO signaling pathway, Thyroid hormone signaling pathway, Notch signaling pathway, Estrogen signaling pathway
|
Glycocholic acid
|
CL
|
Tauroursodeoxycholic acid
|
CL
|
NR4A1
|
Nuclear receptor subfamily 4 group A member 1
|
P22736
|
PI3K-Akt signaling pathway, MAPK signaling pathway
|
beta-carotene
|
EO
|
PPARD
|
Peroxisome proliferator-activated receptor delta
|
Q03181
|
PPAR signaling pathway, Wnt signaling pathway, Pathways in cancer
|
Arachidic acid
|
CL
|
PPARG
|
Peroxisome proliferator-activated receptor gamma
|
P37231
|
PPAR signaling pathway, AMPK signaling pathway, Longevity regulating pathway
|
Arachidic acid
|
CL
|
RXRA
|
Retinoic acid receptor RXR-alpha
|
P19793
|
Non-alcoholic fatty liver disease (NAFLD), PI3K-Akt signaling pathway, PPAR signaling pathway, Thyroid hormone signaling pathway, Adipocytokine signaling pathway, Pathways in cancer
|
beta-carotene
|
EO
|
EO, Emblica officinalis; CL, Curcuma longa
|
M-T-P network analysis. To visualize and construct an M-T-P network, the metabolites, potential targets, and associated pathways were imported into Cytoscape v3.8.2. The network contained 148 nodes and 578 edges with a network density of 0.053 (Supplementary file 6). Next, the M-T-P network using the T2DM related metabolites, potential targets, and associated pathways was constructed using Cytoscape v3.8.2 (Figure 7). The network showed 63 nodes and 197 edges with an average clustering coefficient of 0.088 and network density of 0.084. In this network, phytochemicals like bisdemethoxycurcumin, bis-(4-hydroxycinnamoyl) methane, and demethoxycurcumin showed the highest degree, each having ten targets suggesting that these compounds may be the significant phytochemicals of NA in treating T2DM. It was followed by curcumin, 1,7-bis(4-hydroxy-3-methoxyphenyl)-1,4,6-heptatrien-3-one, calebin A, and quercetin which had a degree equal to 8. The network analysis showed that one metabolite could correspond to multiple targets, and one target could correspond to multiple metabolites and pathways. Thus, the network reflected the features of the synergetic relationships between the multiple metabolites, targets, and pathways of NA. Based on the M-T-P network, a proposed schematic diagram was drawn outlining the target proteins and pathways involved in T2DM (Figure 8).