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Inhibition of the SARS-CoV-2 3CLpro main protease by plant polyphenols

Bahun et al., Food Chemistry, doi:10.1016/j.foodchem.2021.131594

Nov 2021

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In Silico and In Vitro study of plant polyphenols identifying quercetin, curcumin, ellagic acid, epigallocatechin gallate, and resveratrol as SARS-CoV-2 3CL^pro inhibitors with IC₅₀ between 11.8µM and 23.4µM. Real-time binding was analyzed with surface plasmon resonance spectroscopy.

39 preclinical studies support the efficacy of curcumin for COVID-19:

17 In Vitro studies Bahun, Bormann, Boseila, Eleraky, Goc, Goc (B), Guijarro-Real, Kandeil, Leka, Marín-Palma, Mohd Abd Razak, Nittayananta, Septisetyani, Singh, Teshima, Wu, Zhang

1 In Vivo animal study Boseila

In Silico studies predict inhibition of SARS-CoV-2 with curcumin or metabolites via binding to the spike Note A, Nag, Moschovou, Kandeil, Singh (B), Boseila (and specifically the receptor binding domain Note B, Kant, Srivastava, Eleraky), M^pro Note C, Moschovou, Kandeil, Srivastava, Naderi Beni, Rajagopal, Rampogu, Sekiou, Singh, Winih Kinasih, Thapa, Bahun, Eleraky, Boseila, RNA-dependent RNA polymerase Note D, Singh (C), Eleraky, ACE2 Note E, Singh (B), Thapa, Alkafaas, nucleocapsid Note F, Hidayah, Suravajhala, and nsp10 Note G, Suravajhala proteins. In Vitro studies demonstrate inhibition of the spike Note A, Mohd Abd Razak (and specifically the receptor binding domain Note B, Goc (B)), M^pro Note C, Bahun, Guijarro-Real, Mohd Abd Razak, Wu, ACE2 Note E, Goc (B), and TMPRSS2 Note H, Goc (B) proteins. In Vitro studies demonstrate efficacy in Calu-3 Note I, Bormann, A549 Note J, Mohd Abd Razak, 293T Note K, Zhang, HEK293-hACE2 Note L, Nittayananta, Wu, 293T/hACE2/TMPRSS2 Note M, Septisetyani, and Vero E6 Note N, Bormann, Eleraky, Kandeil, Leka, Mohd Abd Razak, Nittayananta, Singh, Teshima, Marín-Palma cells. Curcumin is predicted to inhibit the interaction between the SARS-CoV-2 spike protein receptor binding domain and the human ACE2 receptor for the delta and omicron variants Kant, decreases pro-inflammatory cytokines induced by SARS-CoV-2 in peripheral blood mononuclear cells Marín-Palma, and alleviates SARS-CoV-2 spike protein-induced mitochondrial membrane damage and oxidative stress Zhang.

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Study covers quercetin and curcumin.

1. Alkafaas et al., A study on the effect of natural products against the transmission of B.1.1.529 Omicron, Virology Journal, doi:10.1186/s12985-023-02160-6.biomedcentral.com, doi.org.

2. Bahun et al., Inhibition of the SARS-CoV-2 3CLpro main protease by plant polyphenols, Food Chemistry, doi:10.1016/j.foodchem.2021.131594.sciencedirect.com, doi.org.

3. Bormann et al., Turmeric Root and Its Bioactive Ingredient Curcumin Effectively Neutralize SARS-CoV-2 In Vitro, Viruses, doi:10.3390/v13101914.mdpi.com, doi.org.

4. Boseila et al., Throat spray formulated with virucidal Pharmaceutical excipients as an effective early prophylactic or treatment strategy against pharyngitis post-exposure to SARS CoV-2, European Journal of Pharmaceutics and Biopharmaceutics, doi:10.1016/j.ejpb.2024.114279.sciencedirect.com, doi.org.

5. Eleraky et al., Curcumin Transferosome-Loaded Thermosensitive Intranasal in situ Gel as Prospective Antiviral Therapy for SARS-Cov-2, International Journal of Nanomedicine, doi:10.2147/IJN.S423251.dovepress.com, doi.org.

6. Goc et al., Inhibitory effects of specific combination of natural compounds against SARS-CoV-2 and its Alpha, Beta, Gamma, Delta, Kappa, and Mu variants, European Journal of Microbiology and Immunology, doi:10.1556/1886.2021.00022.akjournals.com, doi.org.

7. Goc (B) et al., Phenolic compounds disrupt spike-mediated receptor-binding and entry of SARS-CoV-2 pseudo-virions, PLOS ONE, doi:10.1371/journal.pone.0253489.plos.org, doi.org.

8. Guijarro-Real et al., Potential In Vitro Inhibition of Selected Plant Extracts against SARS-CoV-2 Chymotripsin-Like Protease (3CLPro) Activity, Foods, doi:10.3390/foods10071503.mdpi.com, doi.org.

9. Hidayah et al., Bioinformatics study of curcumin, demethoxycurcumin, bisdemethoxycurcumin and cyclocurcumin compounds in Curcuma longa as an antiviral agent via nucleocapsid on SARS-CoV-2 inhibition, International Conference on Organic and Applied Chemistry, doi:10.1063/5.0197724.aip.org, doi.org.

10. Kandeil et al., Bioactive Polyphenolic Compounds Showing Strong Antiviral Activities against Severe Acute Respiratory Syndrome Coronavirus 2, Pathogens, doi:10.3390/pathogens10060758.mdpi.com, doi.org.

11. Kant et al., Structure-based drug discovery to identify SARS-CoV2 spike protein–ACE2 interaction inhibitors, Journal of Biomolecular Structure and Dynamics, doi:10.1080/07391102.2023.2300060.tandfonline.com, doi.org.

12. Leka et al., In vitro antiviral activity against SARS-CoV-2 of common herbal medicinal extracts and their bioactive compounds, Phytotherapy Research, doi:10.1002/ptr.7463.wiley.com, doi.org.

13. Marín-Palma et al., Curcumin Inhibits In Vitro SARS-CoV-2 Infection In Vero E6 Cells through Multiple Antiviral Mechanisms, Molecules, doi:10.3390/molecules26226900.mdpi.com, doi.org.

14. Mohd Abd Razak et al., In Vitro Anti-SARS-CoV-2 Activities of Curcumin and Selected Phenolic Compounds, Natural Product Communications, doi:10.1177/1934578X231188861.sagepub.com, doi.org.

15. Moschovou et al., Exploring the Binding Effects of Natural Products and Antihypertensive Drugs on SARS-CoV-2: An In Silico Investigation of Main Protease and Spike Protein, International Journal of Molecular Sciences, doi:10.3390/ijms242115894.mdpi.com, doi.org.

16. Naderi Beni et al., In silico studies of anti-oxidative and hot temperament-based phytochemicals as natural inhibitors of SARS-CoV-2 Mpro, PLOS ONE, doi:10.1371/journal.pone.0295014.plos.org, doi.org.

17. Nag et al., Curcumin inhibits spike protein of new SARS-CoV-2 variant of concern (VOC) Omicron, an in silico study, Computers in Biology and Medicine, doi:10.1016/j.compbiomed.2022.105552.sciencedirect.com, doi.org.

18. Nittayananta et al., A novel film spray containing curcumin inhibits SARS-CoV-2 and influenza virus infection and enhances mucosal immunity, Virology Journal, doi:10.1186/s12985-023-02282-x.biomedcentral.com, doi.org.

19. Rajagopal et al., Activity of phytochemical constituents of Curcuma longa (turmeric) and Andrographis paniculata against coronavirus (COVID-19): an in silico approach, Future Journal of Pharmaceutical Sciences, doi:10.1186/s43094-020-00126-x.springeropen.com, doi.org.

20. Rampogu et al., Molecular Docking and Molecular Dynamics Simulations Discover Curcumin Analogue as a Plausible Dual Inhibitor for SARS-CoV-2, International Journal of Molecular Sciences, doi:10.3390/ijms23031771.mdpi.com, doi.org.

21. Sekiou et al., In-Silico Identification of Potent Inhibitors of COVID-19 Main Protease (Mpro) and Angiotensin Converting Enzyme 2 (ACE2) from Natural Products: Quercetin, Hispidulin, and Cirsimaritin Exhibited Better Potential Inhibition than Hydroxy-Chloroquine Against COVID-19 Main Protease Active Site and ACE2, ChemRxiv, doi:10.26434/chemrxiv.12181404.v1.chemrxiv.org, doi.org.

22. Septisetyani et al., Curcumin and turmeric extract inhibited SARS-CoV-2 pseudovirus cell entry and Spike mediated cell fusion, bioRxiv, doi:10.1101/2023.09.28.560070.biorxiv.org, doi.org.

23. Singh et al., Unlocking the potential of phytochemicals in inhibiting SARS-CoV-2 M Pro protein - An in-silico and cell-based approach, Research Square, doi:10.21203/rs.3.rs-3888947/v1.researchsquare.com, doi.org.

24. Singh (B) et al., Computational studies to analyze effect of curcumin inhibition on coronavirus D614G mutated spike protein, The Seybold Report, doi:10.17605/OSF.IO/TKEXJ.ac.in, doi.org.

25. Singh (C) et al., Potential of turmeric-derived compounds against RNA-dependent RNA polymerase of SARS-CoV-2: An in-silico approach, Computers in Biology and Medicine, doi:10.1016/j.compbiomed.2021.104965.sciencedirect.com, doi.org.

26. Srivastava et al., Paradigm of Well-Orchestrated Pharmacokinetic Properties of Curcuminoids Relative to Conventional Drugs for the Inactivation of SARS-CoV-2 Receptors: An In Silico Approach, Stresses, doi:10.3390/stresses3030043.mdpi.com, doi.org.

27. Suravajhala et al., Comparative Docking Studies on Curcumin with COVID-19 Proteins, MDPI AG, doi:10.20944/preprints202005.0439.v3.preprints.org, doi.org.

28. Teshima et al., Antiviral activity of curcumin and its analogs selected by an artificial intelligence-supported activity prediction system in SARS-CoV-2-infected VeroE6 cells, Natural Product Research, doi:10.1080/14786419.2023.2194647.tandfonline.com, doi.org.

29. Thapa et al., In-silico Approach for Predicting the Inhibitory Effect of Home Remedies on Severe Acute Respiratory Syndrome Coronavirus-2, Makara Journal of Science, doi:10.7454/mss.v27i3.1609.ac.id, doi.org.

30. Winih Kinasih et al., Analisis in silico interaksi senyawa kurkuminoid terhadap enzim main protease 6LU7 dari SARS-CoV-2, Duta Pharma Journal, doi:10.47701/djp.v3i1.2904.ac.id, doi.org.

31. Wu et al., Potential Mechanism of Curcumin and Resveratrol against SARS-CoV-2, Research Square, doi:10.21203/rs.3.rs-2780614/v1.researchsquare.com, doi.org.

32. Zhang et al., Computational Discovery of Mitochondrial Dysfunction Biomarkers in Severe SARS-CoV-2 Infection: Unveiling Their Functions and Facilitating Drug Screening, Elsevier BV, doi:10.2139/ssrn.4677176.ssrn.com, doi.org.

a. The trimeric spike (S) protein is a glycoprotein that mediates viral entry by binding to the host ACE2 receptor, is critical for SARS-CoV-2's ability to infect host cells, and is a target of neutralizing antibodies. Inhibition of the spike protein prevents viral attachment, halting infection at the earliest stage.

b. The receptor binding domain is a specific region of the spike protein that binds ACE2 and is a major target of neutralizing antibodies. Focusing on the precise binding site allows highly specific disruption of viral attachment with reduced potential for off-target effects.

c. The main protease or M^pro, also known as 3CL^pro or nsp5, is a cysteine protease that cleaves viral polyproteins into functional units needed for replication. Inhibiting M^pro disrupts the SARS-CoV-2 lifecycle within the host cell, preventing the creation of new copies.

d. RNA-dependent RNA polymerase (RdRp), also called nsp12, is the core enzyme of the viral replicase-transcriptase complex that copies the positive-sense viral RNA genome into negative-sense templates for progeny RNA synthesis. Inhibiting RdRp blocks viral genome replication and transcription.

e. The angiotensin converting enzyme 2 (ACE2) protein is a host cell transmembrane protein that serves as the cellular receptor for the SARS-CoV-2 spike protein. ACE2 is expressed on many cell types, including epithelial cells in the lungs, and allows the virus to enter and infect host cells. Inhibition may affect ACE2's physiological function in blood pressure control.

f. The nucleocapsid (N) protein binds and encapsulates the viral genome by coating the viral RNA. N enables formation and release of infectious virions and plays additional roles in viral replication and pathogenesis. N is also an immunodominant antigen used in diagnostic assays.

g. Non-structural protein 10 (nsp10) serves as an RNA chaperone and stabilizes conformations of nsp12 and nsp14 in the replicase-transcriptase complex, which synthesizes new viral RNAs. Nsp10 disruption may destabilize replicase-transcriptase complex activity.

h. Transmembrane protease serine 2 (TMPRSS2) is a host cell protease that primes the spike protein, facilitating cellular entry. TMPRSS2 activity helps enable cleavage of the spike protein required for membrane fusion and virus entry. Inhibition may especially protect respiratory epithelial cells, buy may have physiological effects.

i. Calu-3 is a human lung adenocarcinoma cell line with moderate ACE2 and TMPRSS2 expression and SARS-CoV-2 susceptibility. It provides a model of the human respiratory epithelium, but many not be ideal for modeling early stages of infection due to the moderate expression levels of ACE2 and TMPRSS2.

j. A549 is a human lung carcinoma cell line with low ACE2 expression and SARS-CoV-2 susceptibility. Viral entry/replication can be studied but the cells may not replicate all aspects of lung infection.

k. 293T is a human embryonic kidney cell line that can be engineered for high ACE2 expression and SARS-CoV-2 susceptibility. 293T cells are easily transfected and support high protein expression.

l. HEK293-hACE2 is a human embryonic kidney cell line with high ACE2 expression and SARS-CoV-2 susceptibility. Cells have been transfected with a plasmid to express the human ACE2 (hACE2) protein.

m. 293T/hACE2/TMPRSS2 is a human embryonic kidney cell line engineered for high ACE2 and TMPRSS2 expression, which mimics key aspects of human infection. 293T/hACE2/TMPRSS2 cells are very susceptible to SARS-CoV-2 infection.

n. Vero E6 is an African green monkey kidney cell line with low/no ACE2 expression and high SARS-CoV-2 susceptibility. The cell line is easy to maintain and supports robust viral replication, however the monkey origin may not accurately represent human responses.

Bahun et al., 14 Nov 2021, peer-reviewed, 10 authors.

In Vitro studies are an important part of preclinical research, however results may be very different in vivo.

This Paper Curcumin All

Inhibition of the SARS-CoV-2 3CLpro main protease by plant polyphenols

Miha Bahun, Marko Jukić, Domen Oblak, Luka Kranjc, Gregor Bajc, Matej Butala, Krištof Bozovičar, Tomaž Bratkovič, Črtomir Podlipnik, Nataša Poklar Ulrih

Food Chemistry, doi:10.1016/j.foodchem.2021.131594

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Conflicts of interest: The authors declare that they have no conflicts of interest. Appendix A. Supplementary material

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