In silico Drug Repurposing of Anticancer Drug 5-FU and Analogues Against SARS-CoV-2 Main Protease: Molecular Docking, Molecular Dynamics Simulation, Pharmacokinetics and Chemical Reactivity Studies

Background

Since the last COVID-19 outbreak, several approaches have been given a try to quickly tackle this global calamity. One of the well-established strategies is the drug repurposing, which consists in finding new therapeutic uses for approved drugs. Following the same paradigm, we report in the present study, an investigation of the potential inhibitory activity of 5-FU and nineteen of its analogues against the SARS-CoV-2 main protease (3CLpro).

Material and Methods

Molecular docking calculations were performed to investigate the binding affinity of the ligands within the active site of 3CLpro. The best binding candidates were further considered for molecular dynamics simulations for 100 ns to gain a time-resolved understanding of the behavior of the guest-host complexes. Furthermore, the profile of druggability of the best binding ligands was assessed based on ADMET predictions. Finally, their chemical reactivity was elucidated using different reactivity descriptors, namely the molecular electrostatic potential (MEP), Fukui functions and frontier molecular orbitals.

Results and Discussion

From the calculations performed, four candidates (compounds 14, 15, 16 and 18) show promising results with respect to the binding affinity to the target protease, 3CLpro, the therapeutic profile of druggability and safety. These compounds are maintained inside the active site of 3CLpro thanks to a variety of noncovalent interactions, especially hydrogen bonds, involving important amino acids such as GLU166, HIS163, GLY143, ASN142, HIS172, CYS145. Molecular dynamics simulations suggest that the four ligands are well trapped within the active site of the protein over a time gap of 100 ns, ligand 18 being the most retained.

Conclusion

In line with the findings reported herein, we recommend that further in-vitro and in-vivo investigations are carried out to shed light on the possible mechanism of pharmacological action of the proposed ligands.

Identification of potential inhibitors of SARS-CoV-2 main protease from Aloe vera compounds: A molecular docking study

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A solution has to be found rapidly against COVD-19.

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From a set of 10 compounds of Aloe vera, 3 potential inhibitors of SARS-CoV-2 main protease were identified.

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The binding affinity of ligand-protein interactions and the Lipinski’s rule of five based-on ADME analysis were used to confirm the best candidate.

SARS-CoV-2 is the pathogen agent of the new corona virus disease that appeared at the end of 2019 in China. There is, currently, no effective treatment against COVID-19. We report in this study a molecular docking study of ten Aloe vera molecules with the main protease (3CLpro) responsible for the replication of coronaviruses. The outcome of their molecular simulation and ADMET properties reveal three potential inhibitors of the enzyme (ligands 6, 1 and 8) with a clear preference of ligand 6 that has the highest binding energy (−7.9 kcal/mol) and fully obeys the Lipinski’s rule of five.

Aloe vera (L.) Burm. F. as a Potential Anti-COVID-19 Plant: A Mini-review of Its Antiviral Activity

Aims: A novel β-coronavirus (2019-nCoV) has become a pandemic affecting hundreds of thousands of people worldwide. Since there is no effective treatment, the need of finding alternative methods which can help to curb this pandemic is urgent. This study aims to review the literature on the virucidal and cytotoxic properties of Aloe vera, one of the most studied plants considered as a nutraceutical in order to propose it as an alternative solution against COVID-19. Methodology: The literature review was based mainly on the COVID-19 resources that have been made freely available to the scientific community but also on the usual databases such as Pubmed and Google scholar. Results: The literature review shows that the plant has antiviral activity on several types of virus (Haemorrhagic Viral Rhobdavirus Septicaemia, Herpes simplex virus type 1, Herpes simplex virus type 2, Varicella-Zoster virus, human immunodeficiency virus, Influenza virus, poliovirus, Cytomegalovirus, Human papillomavirus) including coronavirus SARS-CoV-1. The plant is consumed orally in several forms and is safe. It is possible that  molecules of this plant that have already shown effectiveness on other viruses by some mechanisms such as interaction of virus enzyme, breakdown of the viral envelope etc. could participate in the action of the plant. Also, the presence of minerals such as Zinc, which have shown an effect on SARS-CoV-1, could be involved in the antiviral effect of Aloe vera. Conclusion: Molecular docking of the main molecules of Aloe vera with SARS-CoV-2 protease is in progress and clinical trials are necessary to confirm the activity of Aloe vera on COVID-19.