Research Article |
Corresponding author: Raden Bayu Indradi ( bayu.indradi@unpad.ac.id ) Academic editor: Georgi Momekov
© 2022 Raden Bayu Indradi, Dian Ayu Eka Pitaloka, Suryani Suryani.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Indradi RB, Pitaloka DAE, Suryani (2022) Network pharmacology to uncover potential anti-inflammatory and immunomodulatory constituents in Curcuma longa rhizome as complementary treatment in COVID-19. Pharmacia 69(4): 995-1003. https://doi.org/10.3897/pharmacia.69.e89799
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The immune status of patients plays an essential role in COVID-19. Herbal medicine with immunomodulatory and anti-inflammatory effect could have potential as a complementary therapeutic along with modern medicine. This study aims to investigate the anti-inflammatory and immunomodulatory constituents of Curcuma longa (C. longa) and its possible mechanisms in COVID-19. We systematically sorted the biochemical of C. longa rhizome from literature and repository. Next, we investigated targets related to COVID-19 in the selected active phytochemical constituents and analyzed the possible mechanisms against COVID-19 and performed molecular docking with four essential target proteins in COVID-19 for further verification. Ten active phytochemical constituents of C. longa were predicted to interact with four protein targets. The epidermal growth factor was the most interacted protein targeted by Calebin A, curcumin, cyclocurcumin, demethoxycurcumin, turmeronol a, turmeronol b, caffeic acid, and quercetin. Interferon-gamma was performed as the most critical protein targeted by 4-hydroxycinnamic acid. Curcumin was also predicted to interact with toll-like receptor 4 and Ar-turmerone with angiotensin II receptor type 2. We also reported four signaling pathways associated with target proteins-active phytochemical constituents against COVID-19: cytokine-cytokine receptor interaction, toll-like receptor signaling pathway, Jak-STAT signaling pathway, and PI3K-Akt signaling pathway. In conclusion, multi compounds in C. longa might act synergistically against COVID-19 by affecting the inflammatory and immune responses, and other pathological processes through multiple targets and pathways.
anti-inflammatory, Curcuma longa, immunomodulatory, COVID-19
It has been highlighted that the emergence of coronavirus disease 2019 (COVID-19) pandemic in the world, including in Indonesia, posed a new challenge on the efforts to control this infectious disease. According to the latest data, the number of COVID-19 infection cases in Indonesia was estimated to be 6,088,460, total deaths of 156,737 per July 1, 2022 (
The integrative treatment between modern and traditional medicines is useful for COVID-19 that currently has no specific treatment. Since the immune status of patients plays an essential role in COVID-19 infection, a herbal medicine, which has an immunomodulatory effect, could have the potential as a preventive measure and complementary therapeutic agent for patients with COVID-19 (
Network pharmacology is based on high-throughput omics data analysis and network database retrieval, which combines systems biology with multidirectional pharmacology. It focuses on pattern changing from a single protein target and a single drug to multiple protein target and multiple drugs (
In this study, we applied a network pharmacology to investigate the active anti-inflammatory and immunomodulatory constituents of C. longa rhizome and their possible molecular mechanism & synergism effect of various compounds as complementary treatment against COVID-19. Firstly, we selected chemical compounds of C. longa rhizome via public websites and the COVID-19 related target proteins. Next, the extracted overlapping target proteins were discovered as target proteins for analyzing anti-COVID-19 properties. Finally, pathway enrichment analysis was performed to reveal the mechanisms of the most potent constituents against COVID-19. We also performed the molecular docking analysis to validate the interaction between the respective constituents and potential targets.
Our protocol involved five main steps: (1) finding active phytochemical ingredients of C. longa rhizome from the literature database and public repository; (2) finding known targets and candidate genes related to COVID-19; (3) developing gene ontology and pathway analysis; (4) constructing different types of molecule-target networks and analyzing these networks; (5) performing molecular docking.
Phytochemical components of C. longa were collected from Dr. Duke’s Phytochemical and Ethnobotanical Databases (
We identified the potential target of selected phytochemical components using PharmMapper (
COVID-19 related human gene annotations were downloaded from National Center for Biotechnology Information (NCBI) (https://www.ncbi.nlm.nih.gov/gene/), and a total of 165 targets were obtained. We merged the selected phytochemical component targets of C. longa and COVID-19 related targets using Venny 2.1 (https://bioinfogp.cnb.csic.es/tools/venny/) to identify the targets of C. longa related to COVID-19. Overlapped targets were considered as C. longa targets related to COVID-19.
To identify the significant cluster of COVID-19 related targets, protein-protein interaction (PPI) data from COVID-19 related targets were gained from STRING (
Network constructions were visualized using Cytoscape v.3.8.2 for the following networks: 1) network between C. longa phytochemical components – common target and 2) network among C. longa common targets, COVID-19 related targets, and pathways. The nodes represent targets, compounds, and pathways, while edges represent interactions.
We performed GO- and KEGG- enrichment analysis using The Database for Annotation, Visualization, and Integrated Discovery, DAVID v.6.8 (
We performed molecular docking for each selected phytochemical constituent which was found potential against COVID-19 using AutoDock Vina (
We firstly acquired the phytochemical constituents and corresponding targets of the COVID-19-related C. longa. We collected a total of 39 phytochemical components of C. longa rhizome from two databases (Suppl. material
A total of 165 COVID-19 targets were obtained from NCBI (Suppl. material
PPI network has been widely used to identify many different interactions of the protein targets in the context of a complex disease. There was a total of 116 nodes and 429 interactions lines in the STRING PPI network. Due to the complexity of the original network obtained from the STRING database, we imported the PPI data into Cytoscape to explore the importance of potential targets in the protein networks and the main cluster in this network. We used ClusterONE to obtain the significant cluster. The highest cluster with lowest p-value contained 27 nodes (27 targets) and 181 edges (interactions) with a network density of 0,516 (Fig.
To further explore the underlying mechanisms of C. longa as a therapy against COVID-19, we performed GO-enrichment analysis with the 27 COVID-19 related targets from significant cluster identified by DAVID (Fig.
From KEGG analysis, we obtained a total of 32 pathways which four of them were related to COVID-19: cytokine-cytokine receptor interaction, toll-like receptor signaling pathway, Jak-STAT signaling pathway, and PI3K-Akt signaling pathway. All this pathway showed a low p-value (<0.0001) and considered as an important pathway of C. longa anti-inflammatory and immunomodulatory activity against COVID-19.
We create network between C. longa target of COVID-19, other COVID-19 related target, and pathway to understand the interaction (Fig.
Network between C. longa common targets of COVID-19 (blue diamonds, upper left side) – other COVID-19 related targets (green diamonds, upper right side) – pathways (red arrows, down side). Yellow diamond depicts targets included in significant cluster for COVID-19. Red edges represent direct interaction while blue edges represent indirect interaction of C. longa COVID-19 related targets from significant cluster with pathways.
The main active phytochemical constituents in C. longa, namely Quercetin, Ar-turmerone, 4-hydroxycinnamic acid, calebin A, curcumin, cyclocurcumin, demethoxycurcumin, turmeronol A, turmeronol B, and caffeic acid were used to dock with IFNG, AGTR2, EGFR, and TLR4 respectively. Protein rigid used in the docking and water molecules were removed in preparation step before running. It is generally believed that the lower the binding energy of ligand and receptor, the more stable the conformation and the greater the possibility of action. The molecular docking results showed that the binding energies of the main phytochemical constituents in C. longa were predicted interact with COVID-19 related targets based on comparison to the native ligand (energy & amino acid residues) (Table
Molecular docking result of found compound that predicted interact with COVID-19 targets.
Protein | Ligand | Binding Energy | Hydrogen Bond | Residue |
---|---|---|---|---|
EGFR | Native ligand | -8.8 | 4 | LYS645, LYS745, CYS797, MET793 |
Calebin A | -6.9 | 5 | LYS745, THR790, THR854, ASP855, MET793 | |
Curcumin | -7.2 | 4 | LYS745, MET793, ARG841, THR854 | |
Cyclocurcumin | -7.9 | 3 | LYS745, MET793, THR854 | |
Demethoxycurcumin | -7.5 | 5 | LYS745, MET793, THR854, ARG841, ASN842 | |
Turmeronol a | -6.7 | 4 | LYS745, MET793, THR854, GLN791 | |
Turmeronol b | -6.7 | 4 | LYS745, LYS745, THR854, GLN791 | |
Caffeic acid | -6.1 | 5 | LYS745, MET793, THR854, MET793, MET793 | |
Quercetin | -7.9 | 6 | LYS745, LYS745, LYS745, MET793, THR854, THR854 | |
TLR4 | Native ligand | -4.4 | 4 | ASN173, GLU142, GLY147, HIS148 |
Curcumin | -5.7 | 3 | ASN173, GLU169, GLU142 | |
AGTR2 | Native ligand | -6.0 | 3 | ARG2, ARG182, LYS215 |
Ar-Turmerone | -6.4 | 1 | ARG182 | |
IFNG | Native ligand | -2.3 | 3 | ASN69, SER71, ASP72 |
4-Hydroxycinnamic acid | -1.5 | 1 | ASN26 |
Until now, people around the world are still actively fighting against COVID-19, and herbal medicine has played an important role in the complementary therapy of this disease. The result of our network analysis provides insights into the identification of active constituents of C. longa for COVID-19, identification of protein target related to COVID-19, active constituents-target interaction, and signaling pathway associated with target proteins of active constituents in C. longa.
Ten active constituents of C. longa rhizome were predicted to interact with six common protein targets of COVID-19. We found that among these active constituents, curcumin appears in two pairs of active constituents-target interaction as seen in the Fig.
The proposed mechanism of action of multi compounds in C. longa rhizome on trans-signaling pathways (JAK/STAT, PI3K/Akt, and TLR) and their interaction with target proteins against COVID-19. JAK/STAT, The Janus kinase (JAK)/signal transducer and activator of transcription (STAT); PI3K, Phosphatidylinositol-3-kinase (PI3K); MAPK, Mitogenactivated protein kinase; NF-KB, Nuclear Factor kappa-light-chain-enhancer of activated B cells; TLR, Toll-Like receptor; 4HA, 4-Hydroxycinnamic acid; CC, Cyclocurcumin; CA, Caffeic acid; DC, demetoxycurcumin. The figure was created using Biorender (https://biorender.com/).
Numerous studies have been reported in curcumin as a potential treatment for COVID-19. Nanocurcumin was reported to modulate pro-inflammatory cytokines in patients with COVID-19. Patients showed high mRNA expression and secretion of IL-1β, IL-6, TNF-α, and IL-18 but showed a significant reduction in IL-6 and IL-1β after treatment with nano curcumin (Valizadeh et al. 2020). The previous study also demonstrated that the number of Th17 cells, gene expression, and serum Th17-mediated factors levels (IL-17, IL-21, IL-23, and GM-CSF) were significantly reduced in the group of patients with COVID-19 treated with nano curcumin (
IFNG played a vital role in COVID-19, although based on our result, it is only targeted by the 4-hydroxycinnamic acid of C. longa. A recent study reported that IFNG had driven differentiation of immature secretory cells into the largely ACE2+ ciliated cells in patients with COVID-19. ACE2 has upregulated in epithelial cells at least partially through IFNG signaling by immune cells in the patients with moderate COVID-19. Cytotoxic T lymphocytes displayed the characteristic transcriptional profile of high expression of IFNG and TNF together with genes encoding for cytotoxic receptors (KLRB1, KLRC1, and KLRD1) (
Ar-turmerone, as one of the bioactive compounds in C. longa rhizome, was predicted to interact with AGTR2, and this result is in line with our previous idea. AGTR2 belongs to the G-protein coupled receptor one family and functions as a receptor for angiotensin II (
EGFR is the most interacted protein targeted by active constituents of C. longa. A total of 8/10 was predicted to interact with this target protein. EGFR is known to have a role in processing the membrane form of IL-6Rα into its soluble form sIL-6Rα. Complex sIL-6Rα-IL-6 leads to activation of the Jak-STAT signaling pathway via gp130, with it being important for complete activation of the NF-κB signaling pathway (
Toll-like receptor (TLR) is also one of the signaling pathways regulated by active constituents of C. longa. As a component of innate immunity, it plays an important role in activating innate immunity, regulating cytokine expression, indirectly activating the adaptive immune system, and recognizing pathogen‐associated molecular patterns (PAMPs) (
The network pharmacology analysis has identified ten candidates of bioactive compounds in C. longa against COVID-19 infection, this was obtained based on its binding to the six target proteins. The possible mechanism of bioactive compounds in C. longa against COVID-19 has been known in this study, that four pathways are targeted to control infection COVID-19. However, this study still has limitations, the effectiveness, and the mechanism of bioactive compounds in C. longa against COVID-19 needs to be re-validated through in vitro analysis, that is directly effect of bioactive compound to the virus which will support the result of the pathway analysis. The pharmacological effect in inhibiting the pathological process from COVID-19 by C. longa compound also could be validated through in vivo analysis. The in vitro and in vivo analysis could be the further research from this study.
The mechanism of multi compounds in C. longa rhizome were firstly investigated through network pharmacology. The finding of this research suggested 10 compounds (curcumin, turmeronol A, turmeronol B, cyclocurcumin, calebin A, 4-Hydroxycinnamic acid, ar-turmerone, caffeic acid, demetoxycurcumin, quercetin) were connected to 4 considered significant target proteins (EGFR, TLR4, IFNG, and AGTR2). The promising mechanism of C. longa rhizome against COVID-19 were connected to 4 pathways (cytokine-cytokine receptor interactions, P13K/Akt, JAK/STAT, and TLR4 signaling pathways) and blocking the activation of these pathway. Overall, multi compounds in C. longa rhizome might act synergistically against COVID-19 by affecting the inflammatory and immune responses, cell apoptosis, and other pathological processes through multiple targets and pathways.
The data underpinning the analysis reported in this paper are deposited at Figshare data repository at https://doi.org/10.6084/m9.figshare.21184429.v1.
Datasets of Network Pharmacology Process
Data type: datasets
Explanation note: This supplementary file contain raw datasets and results used for Network Pharmacology Process.