Anti-HCV, nucleotide inhibitors, repurposing against COVID-19. Life Sci. 2020;248:117477. [PMID: 32119961 PMCID: PMC7089605 DOI: 10.1016/j.lfs.2020.117477]

Synergistic Effects of Natural Compounds Toward Inhibition of SARS-CoV-2 3CL Protease

The biggest challenge in medical management and control of the COVID-19 pandemic is the nonavailability of the treatment molecules. While vaccines and other biotherapeutic products for managing COVID-19 have reached the market, a small-molecule cure is yet to be developed. This is relevant because the cost of production, storage, and ease of distribution of a small-molecule drug are significantly more favorable than those of biologics. In this paper, we present a multicompound approach, where two drug molecules are administered concurrently to offer an effective therapy for COVID-19. The co-action of the two compounds, each derived from natural origins, has been demonstrated against the 3CL protease, already recognized as a potential drug target for inhibiting SARS-CoV-2. The pair of compounds pursued in this study are flavonoid and naphthalene scaffold. Individually, they offer ∼30 to 35% inhibition at 10 μM. Comprehensive docking and molecular dynamics simulations elucidate that these compounds exhibit excellent binding in the process, which however quickly deteriorates, and the ligand is separated from the binding site. This suggests that while the ligands initially bind with the protease, they are unable to maintain it for an extended period. However, the simulation showed that a simultaneous docked complex of both the compounds together with the protein boosts the stronger binding for a sufficient time. The enzyme assay exhibited 97 and 85% inhibition activity when both compounds were used together at 100 and 50 μM, respectively. Later, a multiconcentration assay was used to determine the coinhibitory activity, and it was observed that the compounds have ∼20 to 30% inhibition activity even at lower concentrations of 0.5 and 1 μM. Surface plasmon resonance was used to measure the binding of the compounds, and when used together, the compounds had a 10-fold greater binding affinity. Thus, the results demonstrate a synergistic mechanism between the two compounds that enhances the inhibition activity against SARS-CoV-2 3CL protease.

Insight from nanomaterials and nanotechnology towards COVID-19

The pandemic coronavirus disease 2019 (COVID-19) becomes one of the most dreadful disease in the history of mankind in the entire world. The covid-19 outbreak started from Wuhan city of China and then rapidly transmitted throughout the world causing mass destruction and seldom. This sporadical disease has taken many lives due to sudden outbreak and no particular vaccines were available at the early wave. All the vaccines developed are mostly targeted to spike protein of the virus which involves the encapsulation of mRNA and nanoparticles. Nanotechnology intervention in fighting against the covid-19 is one way to tackle the disease from different angles including nano coating mask, nano diagnostic kits, nano sanitizer, and nano medicine. This article highlights the intervention of nanotechnology and its possible treatment against the covid-19. It is high time to come together all the units of material science and biological science to fight against the dreadful COVID-19. As an alternative strategy, a multidisciplinary research effort, consisting of classical epidemiology and clinical methodologies, drugs and nanotechnology, engineering science and biological apprehension, can be adopted for developing improved drugs exhibiting antiviral activities. The employment of nanotechnology and its allied fields can be explored to detect, treat, and prevent the covid-19 disease.

De novo design of novel protease inhibitor candidates in the treatment of SARS-CoV-2 using deep learning, docking, and molecular dynamic simulations

The main protease of SARS-CoV-2 is a critical target for the design and development of antiviral drugs. 2.5 M compounds were used in this study to train an LSTM generative network via transfer learning in order to identify the four best candidates capable of inhibiting the main proteases in SARS-CoV-2. The network was fine-tuned over ten generations, with each generation resulting in higher binding affinity scores. The binding affinities and interactions between the selected candidates and the SARS-CoV-2 main protease are predicted using a molecular docking simulation using AutoDock Vina. The compounds selected have a strong interaction with the key MET 165 and Cys145 residues. Molecular dynamics (MD) simulations were run for 150ns to validate the docking results on the top four ligands. Additionally, root-mean-square deviation (RMSD), root-mean-square fluctuation (RMSF), and hydrogen bond analysis strongly support these findings. Furthermore, the MM-PBSA free energy calculations revealed that these chemical molecules have stable and favorable energies, resulting in a strong binding with Mpro's binding site. This study's extensive computational and statistical analyses indicate that the selected candidates may be used as potential inhibitors against the SARS-CoV-2 in-silico environment. However, additional in-vitro, in-vivo, and clinical trials are required to demonstrate their true efficacy.

Structure-based drug repurposing against COVID-19 and emerging infectious diseases: methods, resources and discoveries

To attain promising pharmacotherapies, researchers have applied drug repurposing (DR) techniques to discover the candidate medicines to combat the coronavirus disease 2019 (COVID-19) outbreak. Although many DR approaches have been introduced for treating different diseases, only structure-based DR (SBDR) methods can be employed as the first therapeutic option against the COVID-19 pandemic because they rely on the rudimentary information about the diseases such as the sequence of the severe acute respiratory syndrome coronavirus 2 genome. Hence, to try out new treatments for the disease, the first attempts have been made based on the SBDR methods which seem to be among the proper choices for discovering the potential medications against the emerging and re-emerging infectious diseases. Given the importance of SBDR approaches, in the present review, well-known SBDR methods are summarized, and their merits are investigated. Then, the databases and software applications, utilized for repurposing the drugs against COVID-19, are introduced. Besides, the identified drugs are categorized based on their targets. Finally, a comparison is made between the SBDR approaches and other DR methods, and some possible future directions are proposed.

Phospholipids dock SARS-CoV-2 spike protein via hydrophobic interactions: a minimal in-silico study of lecithin nasal spray therapy

Understanding the physical and chemical properties of viral infections at molecular scales is a major challenge for the scientific community more so with the outbreak of global pandemics. There is currently a lot of effort being placed in identifying molecules that could act as putative drugs or blockers of viral molecules. In this work, we computationally explore the importance in antiviral activity of a less studied class of molecules, namely surfactants. We employ all-atoms molecular dynamics simulations to study the interaction between the receptor-binding domain of the SARS-CoV-2 spike protein and the phospholipid lecithin (POPC), in water. Our microsecond simulations show a preferential binding of lecithin to the receptor-binding motif of SARS-CoV-2 with binding free energies significantly larger than [Formula: see text]. Furthermore, hydrophobic interactions involving lecithin non-polar tails dominate these binding events, which are also accompanied by dewetting of the receptor binding motif. Through an analysis of fluctuations in the radius of gyration of the receptor-binding domain, its contact maps with lecithin molecules, and distributions of water molecules near the binding region, we elucidate molecular interactions that may play an important role in interactions involving surfactant-type molecules and viruses. We discuss our minimal computational model in the context of lecithin-based liposomal nasal sprays as putative mitigating therapies for COVID-19.

Screening Potential Drugs for COVID-19 Based on Bound Nuclear Norm Regularization

The novel coronavirus pneumonia COVID-19 infected by SARS-CoV-2 has attracted worldwide attention. It is urgent to find effective therapeutic strategies for stopping COVID-19. In this study, a Bounded Nuclear Norm Regularization (BNNR) method is developed to predict anti-SARS-CoV-2 drug candidates. First, three virus-drug association datasets are compiled. Second, a heterogeneous virus-drug network is constructed. Third, complete genomic sequences and Gaussian association profiles are integrated to compute virus similarities; chemical structures and Gaussian association profiles are integrated to calculate drug similarities. Fourth, a BNNR model based on kernel similarity (VDA-GBNNR) is proposed to predict possible anti-SARS-CoV-2 drugs. VDA-GBNNR is compared with four existing advanced methods under fivefold cross-validation. The results show that VDA-GBNNR computes better AUCs of 0.8965, 0.8562, and 0.8803 on the three datasets, respectively. There are 6 anti-SARS-CoV-2 drugs overlapping in any two datasets, that is, remdesivir, favipiravir, ribavirin, mycophenolic acid, niclosamide, and mizoribine. Molecular dockings are conducted for the 6 small molecules and the junction of SARS-CoV-2 spike protein and human angiotensin-converting enzyme 2. In particular, niclosamide and mizoribine show higher binding energy of −8.06 and −7.06 kcal/mol with the junction, respectively. G496 and K353 may be potential key residues between anti-SARS-CoV-2 drugs and the interface junction. We hope that the predicted results can contribute to the treatment of COVID-19.

Potential of Marine Terpenoids against SARS-CoV-2: An In Silico Drug Development Approach

In an emergency, drug repurposing is the best alternative option against newly emerged severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. However, several bioactive natural products have shown potential against SARS-CoV-2 in recent studies. The present study selected sixty-eight broad-spectrum antiviral marine terpenoids and performed molecular docking against two novel SARS-CoV-2 enzymes (main protease or M^pro or 3CL^pro) and RNA-dependent RNA polymerase (RdRp). In addition, the present study analysed the physiochemical-toxicity-pharmacokinetic profile, structural activity relationship, and phylogenetic tree with various computational tools to select the 'lead' candidate. The genomic diversity study with multiple sequence analyses and phylogenetic tree confirmed that the newly emerged SARS-CoV-2 strain was up to 96% structurally similar to existing CoV-strains. Furthermore, the anti-SARS-CoV-2 potency based on a protein-ligand docking score (kcal/mol) exposed that the marine terpenoid brevione F (-8.4) and stachyflin (-8.4) exhibited similar activity with the reference antiviral drugs lopinavir (-8.4) and darunavir (-7.5) against the target SARS-CoV-M^pro. Similarly, marine terpenoids such as xiamycin (-9.3), thyrsiferol (-9.2), liouvilloside B (-8.9), liouvilloside A (-8.8), and stachyflin (-8.7) exhibited comparatively higher docking scores than the referral drug remdesivir (-7.4), and favipiravir (-5.7) against the target SARS-CoV-2-RdRp. The above in silico investigations concluded that stachyflin is the most 'lead' candidate with the most potential against SARS-CoV-2. Previously, stachyflin also exhibited potential activity against HSV-1 and CoV-A59 within IC₅₀, 0.16-0.82 µM. Therefore, some additional pharmacological studies are needed to develop 'stachyflin' as a drug against SARS-CoV-2.

Potential Novel Thioether-Amide or Guanidine-Linker Class of SARS-CoV-2 Virus RNA-Dependent RNA Polymerase Inhibitors Identified by High-Throughput Virtual Screening Coupled to Free-Energy Calculations

SARS-CoV-2, or severe acute respiratory syndrome coronavirus 2, represents a new pathogen from the family of Coronaviridae that caused a global pandemic of COVID-19 disease. In the absence of effective antiviral drugs, research of novel therapeutic targets such as SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) becomes essential. This viral protein is without a human counterpart and thus represents a unique prospective drug target. However, in vitro biological evaluation testing on RdRp remains difficult and is not widely available. Therefore, we prepared a database of commercial small-molecule compounds and performed an in silico high-throughput virtual screening on the active site of the SARS-CoV-2 RdRp using ensemble docking. We identified a novel thioether-amide or guanidine-linker class of potential RdRp inhibitors and calculated favorable binding free energies of representative hits by molecular dynamics simulations coupled with Linear Interaction Energy calculations. This innovative procedure maximized the respective phase-space sampling and yielded non-covalent inhibitors representing small optimizable molecules that are synthetically readily accessible, commercially available as well as suitable for further biological evaluation and mode of action studies.

Sensitive Determination of SARS-COV-2 and the Anti-hepatitis C Virus Agent Velpatasvir Enabled by Novel Metal-Organic Frameworks

Herein, we report on the electrochemical determination of velpatasvir (VLP) as the main constituent of Epclusa, a SARS-COV-2 and anti-hepatitis C virus (HCV) agent, using a novel metal-organic framework (MOF). The NH2-MIL-53(Al) MOF was successfully modified with 5-bromo-salicylaldehyde to synthesize 5-BSA=N-MIL-53(Al) MOF. The synthesized MOF has been characterized using Fourier transform infrared spectroscopy, X-ray powder diffraction, scanning electron microscopy, cyclic voltammetry, square wave voltammetry, and electrochemical impedance spectroscopy. The modified MOF showed higher electrochemical activity and response than the bare NH2-MIL-53(Al) MOF. Compared to the bare carbon paste electrode (CPE), the 5-BSA=N-MIL-53(Al)/CPE platform was shown to enhance the electrochemical oxidation and detection of the anti-SARS-COV-2 and anti-HCV agent. Under optimized conditions, the 5-BSA=N-MIL-53(Al)/CPE platform showed a linear range of 1.11 × 10-6 to 1.11 × 10-7 and 1.11 × 10-7 to 25.97 × 10-6 M Britton-Robinson buffer (pH 7) with a detection limit and limit of quantification of 8.776 × 10-9 and 2.924 × 10-8 M, respectively. Repeatability, storage stability, and reproducibility in addition to selectivity studies and interference studies were conducted to illustrate the superiority of the electrode material. The study also included a highly accurate platform for the determination of VLP concentrations in both urine and plasma samples with reasonable recovery.

Hybrid In Silico Approach Reveals Novel Inhibitors of Multiple SARS-CoV-2 Variants

The National Center for Advancing Translational Sciences (NCATS) has been actively generating SARS-CoV-2 high-throughput screening data and disseminates it through the OpenData Portal (https://opendata.ncats.nih.gov/covid19/). Here, we provide a hybrid approach that utilizes NCATS screening data from the SARS-CoV-2 cytopathic effect reduction assay to build predictive models, using both machine learning and pharmacophore-based modeling. Optimized models were used to perform two iterative rounds of virtual screening to predict small molecules active against SARS-CoV-2. Experimental testing with live virus provided 100 (∼16% of predicted hits) active compounds (efficacy > 30%, IC50 ≤ 15 μM). Systematic clustering analysis of active compounds revealed three promising chemotypes which have not been previously identified as inhibitors of SARS-CoV-2 infection. Further investigation resulted in the identification of allosteric binders to host receptor angiotensin-converting enzyme 2; these compounds were then shown to inhibit the entry of pseudoparticles bearing spike protein of wild-type SARS-CoV-2, as well as South African B.1.351 and UK B.1.1.7 variants.

Mapping the footprints of COVID-19 pandemic

The new member of the coronavirus family created havoc in the world in few days of its discovery and was declared as a pandemic by March 2020. The enveloped, single-stranded RNA virus was first identified in a patient with dry cough, pain, and weakness for the past1 week with unknown etiology in Wuhan. The coronavirus soon spread across the globe in the next few weeks. To curb the spread of coronavirus, stringent measures such as lockdown and social distancing were enforced resulted in a declining of cases in various countries. However, unlocking, relaxation of preventive measures, and changing human behaviors led to a drastic increase in the number of COVID-19 cases resulting in the second wave of transmission. This resulted in reimposing of lockdown measures in countries such as Nepal, Italy, France, Netherland, and Germany. At present, the virus has affected over 110.7 million peoples and over 2.4 million deaths across the world, with India having the second-highest number of COVID-19 cases, following the United States of America. Furthermore, a cross-sectional view of the disease states several new strains being reported across the globe at one end and at another end there is rolling out of vaccine against COVID-19. There is still uncertainty related to curbing of the pandemic as effect of vaccine on new strains is undetermined. Thus, it is important to understand the transforming epidemiology of the virus as it helps in planning necessary steps for physicians and policymakers. The present review summarizes the updated information primarily about the epidemiology of COVID-19, from initiation to the present scenario.

Drug repurposing: Misconceptions, challenges, and opportunities for academic researchers

[Figure: see text].

Surface plasmon resonance approach to study drug interactions with SARS-CoV-2 RNA-dependent RNA polymerase highlights treatment potential of suramin

The SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) is essential for virus replication, therefore it is a promising drug target. Here we present a surface plasmon resonance approach to study the interaction of RdRp with drugs in real time. We monitored the effect of favipiravir, ribavirin, sofosbuvir triphosphate PSI-7409 and suramin on RdRp binding to RNA immobilized on the chip. Suramin precluded interaction of RdRp with RNA and even displaced RdRp from RNA.

Functionalized Dendrimer Platforms as a New Forefront Arsenal Targeting SARS-CoV-2: An Opportunity

The novel human coronavirus SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) has caused a pandemic. There are currently several marketed vaccines and many in clinical trials targeting SARS-CoV-2. Another strategy is to repurpose approved drugs to decrease the burden of the COVID-19 (official name for the coronavirus disease) pandemic. as the FDA (U.S. Food and Drug Administration) approved antiviral drugs and anti-inflammatory drugs to arrest the cytokine storm, inducing the production of pro-inflammatory cytokines. Another view to solve these unprecedented challenges is to analyze the diverse nanotechnological approaches which are able to improve the COVID-19 pandemic. In this original minireview, as promising candidates we analyze the opportunity to develop biocompatible dendrimers as drugs themselves or as nanocarriers against COVID-19 disease. From the standpoint of COVID-19, we suggest developing dendrimers as shields against COVID-19 infection based on their capacity to be incorporated in several environments outside the patients and as important means to stop transmission of SARS-CoV-2.

Recent progress in the development of potential drugs against SARS-CoV-2

SARS-CoV-2, a newly emerged and highly pathogenic coronavirus, is identified as the causal agent of Coronavirus Disease (2019) (COVID-19) in the late December 2019, in China. The virus has rapidly spread nationwide and spilled over to the other countries around the globe, resulting in more than 120 million infections and 2.6 million deaths until the time of this review. Unfortunately, there are still no specific drugs available against this disease, and it is very necessary to call upon more scientists to work together to stop a further spread. Hence, the recent progress in the development of drugs may help scientific community quickly understand current research status and further develop new effective drugs. Herein, we summarize the cellular entry and replication process of this virus and discuss the recent development of potential viral based drugs that target bio-macromolecules in different stages of the viral life cycle, especially S protein, 3CLPro, PLPro, RdRp and helicase.

Computational Design and Analysis of a Multi-epitope Against Influenza A virus

Influenza A viruses are among the most studied viruses, however no effective prevention against influenza infection has been developed. So, designing an effective vaccine against Influenza A virus is a critical issue in the field of medical biotechnology. For this reason, to combat this disease, we have designed a novel multi-epitope vaccine candidate based on the several conserved and potential linear B-cell and T-cell binding epitopes by using the in silico approach. This vaccine consists of an ER signal conserved sequence, the PADRE conserved epitope and two conserved epitopes of Influenza matrix protein 2. T-cell binding epitopes from Matrix protein 2 were predicted by in silico tools of epitope prediction. The selected epitopes were joined by flexible linkers and physicochemical properties, toxicity, and allergenecity were investigated. The designed vaccine was antigenic, immunogenic, and non-allergenic with suitable physicochemical properties and has higher solubility. The final multi-epitope construct was modeled, confirmed by different programs and the molecular interactions with immune receptors were considered. The molecular docking assay indicated the interactions with immune-stimulatory toll-like receptor 3 (TLR3) and major histocompatibility complex class I (MHCI). The HADDOCK and H DOCK servers were used to make docking analysis, respectively. The docking analysis indicated a strong and stable binding interaction between the vaccine construct with major histocompatibility complex (MHC) class I and toll-like receptor 3. Overall, the findings suggest that the current vaccine may be a promising vaccine to prevent Influenza infection.

Identification of SARS-CoV-2 RNA-dependent RNA polymerase inhibitors from the major phytochemicals of Nigella sativa: An in silico approach

The coronavirus disease 2019 (COVID-19), which emerged in December 2019, continues to be a serious health concern worldwide. There is an urgent need to develop effective drugs and vaccines to control the spread of this disease. In the current study, the main phytochemical compounds of Nigella sativa were screened for their binding affinity for the active site of the RNA-dependent RNA polymerase (RdRp) enzyme of the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). The binding affinity was investigated using molecular docking methods, and the interaction of phytochemicals with the RdRp active site was analyzed and visualized using suitable software. Out of the nine phytochemicals of N. sativa screened in this study, a significant docking score was observed for four compounds, namely α-hederin, dithymoquinone, nigellicine, and nigellidine. Based on the findings of our study, we report that α-hederin, which was found to possess the lowest binding energy (–8.6 kcal/mol) and hence the best binding affinity, is the best inhibitor of RdRp of SARS-CoV-2, among all the compounds screened here. Our results prove that the top four potential phytochemical molecules of N. sativa, especially α-hederin, could be considered for ongoing drug development strategies against SARS-CoV-2. However, further in vitro and in vivo testing are required to confirm the findings of this study.

Comparative MD Study of Inhibitory Activity of Opaganib and Adamantane-Isothiourea Derivatives toward COVID-19 Main Protease Mpro

In this study, the inhibitory potency of four adamantly- isothiourea derivatives (compounds 1 [4-bromobenzyl (Z)-N'-(adamantan-1-yl)-4-phenylpiperazine-1-carbothioimidate], 2 [3,5-bis(trifluoromethyl)benzyl (Z)-N'-(adamantan-1-yl)-4-phenylpiperazine-1-carbothioimidate], 3 [4-bromobenzyl (Z)-N-(adamantan-1-yl)morpholine-4-carbothioimidate] and 4 [3,5-bis(trifluoromethyl)benzyl (Z)-N-(adamantan-1-yl)morpholine-4-carbothioimidate]) was evaluated against SARS-CoV-2 targeted proteins. The investigated compounds 1-4 possess a similar structure to opaganib, which is used in studies like a potential drug for COVID-19 treatment. Since examined adamantly-isothiourea derivatives (1-4) shown broad-spectrum of antibacterial activity and significant in vitro cytotoxic effects against five human tumor cell lines and shown similarity in structure with opaganib, it was of interest to study their inhibitory potency toward some SARS-CoV-2 proteins such as SARS-CoV-2 main protease Mpro and mutation of SARS-CoV-2 Spike (S) Protein D614G. The inhibitory potency of studied compounds is examined using molecular docking and molecular dynamic simulations. The results of molecular docking simulations indicate compound 1 as the most prominent candidate of inhibition of SARS-CoV-2 main protease Mpro (▵Gbind=11.24 kcal/mol), while almost the same inhibition potency of all studied compounds is exhibited toward D614G. Regarding the results obtained by molecular dynamic simulations, compounds 1 and 4 possess similar inhibitory potency toward SARS-CoV-2 main protease Mpro as opaganib (▵Gbind ≈ 40 kcal/mol).

"Bucket brigade" using lysine residues in RNA-dependent RNA polymerase of SARS-CoV-2

The RNA-dependent RNA polymerase (RdRp) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a promising drug target for coronavirus disease 2019 (COVID-19) because it plays the most important role in the replication of the RNA genome. Nucleotide analogs such as remdesivir and favipiravir are thought to interfere with the RNA replication by RdRp. More specifically, they are expected to compete with nucleoside triphosphates, such as ATP. However, the process in which these drug molecules and nucleoside triphosphates are taken up by RdRp remains unknown. In this study, we performed all-atom molecular dynamics simulations to clarify the recognition mechanism of RdRp for these drug molecules and ATP that were at a distance. The ligand recognition ability of RdRp decreased in the order of remdesivir, favipiravir, and ATP. We also identified six recognition paths. Three of them were commonly found in all ligands, and the remaining three paths were ligand-dependent ones. In the common two paths, it was observed that the multiple lysine residues of RdRp carried the ligands to the binding site like a "bucket brigade." In the remaining common path, the ligands directly reached the binding site. Our findings contribute to the understanding of the efficient ligand recognition by RdRp at the atomic level.

In silico identification of promising inhibitor against RNA-dependent RNA polymerase target of SARS-CoV-2

The severe acute respiratory syndrome is a viral respiratory disease recognised as COVID-19, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Formerly, no precise remedies are available, and many studies regarding COVID-19 prevention and treatment are under development. Several targets for the design of drugs are identified, and studies are in headway to explore the potential target. RNA-dependent RNA polymerase (RdRp) protein identified as a promising target against SARS-CoV-2 infection for the drug design due to its significant role in viral replication. The present study focuses on identifying the binding effect of previously known RdRp inhibitors with RdRp of SARS-CoV-2 using molecular docking and molecular dynamics simulation approaches. Molecular docking and binding free energy calculations against RdRp enzyme identified suramin as a potential compound that showed the highest docking score of -7.83 Kcal/mole and binding energy of -80.83 Kcal/mole as a comparison to other compounds. Further, molecular dynamics simulation studies were moreover showed the stable binding behaviour of suramin docked complex in the protein active site. Thus, the study concludes that suramin might be helpful as a potential inhibitor against RNA-dependent RNA polymerase of SRAS-CoV-2. However, further investigation is needed to assess the possible effect of inhibitors on RdRp through in vitro and in vivo experiments.

Recent challenges facing patients with preexisting chronic liver disease in the era of the COVID-19 pandemic

COVID-19 pandemic has resulted in a growing number of beds in common hospital wards and intensive care units being occupied by COVID-19 patients and the majority of medical and nursing staff being dedicated to their care. The present review summarizes the impact of COVID-19 on patients with underlying chronic liver diseases (CLD). Deferrals of all non-urgent activities in healthcare facilities, including a decrease in liver-clinic visits for patients with CLD, inadequate hepatocellular carcinoma (HCC) surveillance, and postponement of liver transplant activities are the most important consequences. Delays in viral hepatitis elimination programs were also reported, leading to future development of advanced CLD and HCC. Patients with chronic hepatitis B (CHB) and C without cirrhosis are not at risk for a more severe COVID-19 infection course. However, CHB status must be known in patients who are going to receive immunosuppression for preventing disease flare. In addition, checking for drug-drug interactions and potential hepatotoxicity reactions from agents administered to treat both SARS-CoV-2 and CLD are required. Patients with nonalcoholic fatty liver disease appeared to be at a high risk for severe COVID-19, even after adjustment for comorbidities. Patients with cirrhosis may develop decompensation, acute-on-chronic liver failure, or severe COVID-19. The mortality rate is worse in patients with high model for end-stage liver disease score, regardless of the etiology of cirrhosis.

Drug repurposing against coronavirus disease 2019 (COVID-19): A review

Since December 2019, severe acute respiratory syndrome coronavirus 2 has been found to be the culprit in the coronavirus disease 2019 (COVID-19), causing a global pandemic. Despite the existence of many vaccine programs, the number of confirmed cases and fatalities due to COVID-19 is still increasing. Furthermore, a number of variants have been reported. Because of the absence of approved anti-coronavirus drugs, the treatment and management of COVID-19 has become a global challenge. Under these circumstances, drug repurposing is an effective method to identify candidate drugs with a shorter cycle of clinical trials. Here, we summarize the current status of the application of drug repurposing in COVID-19, including drug repurposing based on virtual computer screening, network pharmacology, and bioactivity, which may be a beneficial COVID-19 treatment.

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Mechanism of SARS-CoV-2 infection and drug targets were reviewed.

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Drug repurposing against COVID-19 based on computer virtual screening, network pharmacology, bioactivity were summarized.

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The use of drug repurposing in COVID-19 was addressed.

Neurological complications of COVID-19: from pathophysiology to rehabilitation. An overview

OBJECTIVE

To evaluate how the SARS-COV2 is able to affect the nervous system, the main neurological manifestation, and the treatment used, including neurorehabilitation.

METHODS

Studies performed during the current year that fulfilled inclusion criteria were selected from PubMed, Scopus, Cochrane, and Web of Sciences databases. The search combined the terms "Covid 19," "rehabilitation/treatment," and "neurological complications."

RESULTS

The exact route by which SARS-CoV-2 can penetrate the CNS is still unknown, although a possible retrograde transynaptic pathway from peripheral nerve endings, and/or through the olfactory bulb, have been suggested. An early management of COVID-19 by a multiprofessional team is fundamental to avoid long term sequaele. Rehabilitation is recommended to improve respiratory and cardiac function, as well as to avoid long term neurological complications.

CONCLUSIONS

As no specific conclusions in term of prognosis and treatment could be done, research and consensus paper are needed to provide NeuroCovid patients with the best treatment options, including neurorehabilitation.

Drug repurposing studies targeting SARS-CoV-2: an ensemble docking approach on drug target 3C-like protease (3CLpro)

The COVID-19 pandemic has been responsible for several deaths worldwide. The causative agent behind this disease is the Severe Acute Respiratory Syndrome - novel Coronavirus 2 (SARS-CoV-2). SARS-CoV-2 belongs to the category of RNA viruses. The main protease, responsible for the cleavage of the viral polyprotein is considered as one of the hot targets for treating COVID-19. Earlier reports suggest the use of HIV anti-viral drugs for targeting the main protease of SARS-CoV, which caused SARS in the year 2002-2003. Hence, drug repurposing approach may prove to be useful in targeting the main protease of SARS-CoV-2. The high-resolution crystal structure of the main protease of SARS-CoV-2 (PDB ID: 6LU7) was used as the target. The Food and Drug Administration approved and SWEETLEAD database of drug molecules were screened. The apo form of the main protease was simulated for a cumulative of 150 ns and 10 μs open-source simulation data was used, to obtain conformations for ensemble docking. The representative structures for docking were selected using RMSD-based clustering and Markov State Modeling analysis. This ensemble docking approach for the main protease helped in exploring the conformational variation in the drug-binding site of the main protease leading to the efficient binding of more relevant drug molecules. The drugs obtained as top hits from the ensemble docking possessed anti-bacterial and anti-viral properties. This in silico ensemble docking approach would support the identification of potential candidates for repurposing against COVID-19.Communicated by Ramaswamy H. Sarma.

Isolation of Antibodies Against the Spike Protein of SARS-CoV from Pig Serum for Competitive Immunoassay

Several endemic corona viruses (eCoVs) have been reported to be the most common etiologic agents for the seasonal common cold and also cause pneumonia. These eCoVs share extensive sequence homology with SARS-CoV-2, and immune responses to eCoVs can cross-react with SARS-CoV-2 antigens. Based on such cross-reactivity of antigens among eCoVs, the IgG antibodies against the spike protein (SP) of severe acute respiratory syndrome coronavirus (SARS-CoV) were isolated from pig serum using magnetic beads immobilized with SARS-CoV SP and a protein-A column. The selectivity of the isolated antibodies was tested using different types of antigens, such as SARS-CoV-2 nucleoprotein (NP), influenza A virus (Beijing type), influenza B virus (Tokio and Florida types), human hepatitis B virus surface antigen (HBsAg), and bovine serum albumin (BSA). From the selectivity test, the anti-SP antibodies isolated from pig serum had sufficient selectivity to other kinds of viral antigens, and the apparent binding constant of the isolated antibodies was approximately 1.5 × 10^-8 M from the surface plasmon resonance (SPR) measurements. Finally, the isolated anti-SP antibodies were applied to the immunoassay of SP using competitive immunoassay configuration. The feasibility of the detection as well as the quantitative analysis of the SARS-CoV viral culture fluid was determined using four viral culture samples, namely, SARS-CoV, SARS-CoV-2, MERS-CoV, and CoV-229E.

Adverse Cardiovascular Effects of Anti-COVID-19 Drugs

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or COVID-19 infection is the cause of the ongoing global pandemic. Mortality from COVID-19 infection is particularly high in patients with cardiovascular diseases. In addition, COVID-19 patients with preexisting cardiovascular comorbidities have a higher risk of death. Main cardiovascular complications of COVID-19 are myocardial infarction, myocarditis, acute myocardial injury, arrhythmias, heart failure, stroke, and venous thromboembolism. Therapeutic interventions in terms of drugs for COVID-19 have many cardiac adverse effects. Here, we review the relative therapeutic efficacy and adverse effects of anti-COVID-19 drugs.

Metaheuristics for multiple sequence alignment: A systematic review

The Multiple Sequence Alignment (MSA) is a key task in bioinformatics, because it is used in different important biological analysis, such as function and structure prediction of unknown proteins. There are several approaches to perform MSA and the use of metaheuristics stands out because of the search ability of these methods, which generally leads to good results in a reasonable amount of time. This paper presents a Systematic Literature Review (SLR) on metaheuristics for MSA, compiling relevant works published between 2014 and 2019. The results of our SLR show the constant interest in this subject, due to the several recent publications that use different metaheuristics to obtain more accurate alignments. Moreover, the final results of our SLR show a multi-objective and hybrid approaches trends, which generally leads these methods to achieve even better results. Thus, we show in this work how the use of metaheuristics to perform MSA still remains an important and promising open research field.

Camphor, Artemisinin and Sumac Phytochemicals as inhibitors against COVID-19: Computational approach

Covid-19 is an emerging infectious disease caused by coronavirus SARS-CoV-2. Due to the rapid rise in deaths resulted from this infection all around the world, the identification of drugs against this new coronavirus is an important requirement. Among the drugs that can fight this type of infection; natural products are substances that serve as sources of beneficial chemical molecules for the development of effective therapies. In this study, Camphor, Artemisinin and 14 Sumac phytochemicals were docked in the active site of SARS-CoV-2 main protease (PDB code: 6LU7). We have also performed molecular dynamic simulation at 100 ns with MM-GBSA/PBSA analysis for the structures with the best affinity in the binding site of the studied enzyme (Hinokiflavone and Myricetin) after docking calculations to consider parameters like RMSD, covariance, PCA, radius of gyration, potential energy, temperature and pressure. The result indicates that Hinokiflavone and Myricetin are the structures with best affinity and stability in the binding site of the studied enzyme and they respect the conditions mentioned in Lipinski's rule and have acceptable ADMET proprieties; so, these compounds have important pharmacokinetic properties and bioavailability, and they could have more potent antiviral treatment of COVID-19 than the other studied compounds.

Larvicidal activity and in silico studies of cinnamic acid derivatives against Aedes aegypti (Diptera: Culicidae)

Cinnamic acid derivatives (CAD's) represent a great alternative in the search for insecticides against Aedes aegypti mosquitoes since they have antimicrobial and insecticide properties. Ae. aegypti is responsible for transmitting Dengue, Chikungunya, and Zika viruses, among other arboviruses associated with morbimortality, especially in developing countries. In view of this, in vitro analyses of n-substituted cinnamic acids and esters were performed upon 4th instar larvae (L4) of Ae. aegypti, as well as, molecular docking studies to propose a potential biological target towards this mosquitoes species. The larvicide assays proved that n-substituted ethyl cinnamates showed a more pronounced activity than their corresponding acids, in which p-chlorocinnamate (3j) presented a LC₅₀ value of 8.3 µg/mL. Thusly, external morphologic alterations (rigid and elongated body, curved bowel, and translucent or darkened anal papillae) of mosquitoes' group exposed to compound 3j, were observed by microscopy. In addition, an analytical method was developed for the quantification of the most promising analog by using high-performance liquid chromatography with UV detection (HPLC-UV). Molecular docking studies suggested that the larvicide action is associated with inhibition of acetylcholinesterase (AChE) enzyme. Therefore, expanding the larvicidal study with the cinnamic acid derivatives against the vector Ae. aegypti is important for finding search for more effective larvicides and with lower toxicity, since they have already shown good larvicidal properties against Ae. aegypti.

Efficacy and safety of sofosbuvir plus daclatasvir or ravidasvir in patients with COVID-19: A randomized controlled trial

Only a few treatments are approved for coronavirus disease‐2019 (COVID‐19) infections, with continuous debate about their clinical impact. Repurposing antiviral treatments might prove the fastest way to identify effective therapy. This trial aimed to evaluate the efficacy and safety of sofosbuvir (SOF) plus daclatasvir (DCV) or ravidasvir (RDV) added to standard care (SOC) for patients with moderate and severe COVID‐19 infection. Multicentre parallel randomized controlled open‐label trial. One hundred and twenty eligible patients with moderate and severe COVID‐19 infection were randomized to one of the study arms. Ten days of treatment with SOF plus DCV or RDV in addition to the standard of care compared to SOC. Follow up in 7 days. Sum of the counted symptoms at 7 and 10 days, mean change in oxygen saturation level, viral negativity, and rate of intensive care unit (ICU) admission. Compared to SOC, the SOF‐DCV group experienced a significantly lower sum of the counted symptoms (fever, headache, generalized aches, or respiratory distress) combined with no evidence of deterioration (ICU admission and mechanical ventilation) on Days 7 and 10 of treatment. Oxygen saturation also significantly improved among the SOF‐DCV group compared to SOC starting from Day 4. The study also showed positive trends regarding the efficacy of SOF‐DCV with a lower incidence of mortality. On the other hand, adding SOF‐RDV to SOC did not show significant improvements in endpoints. The results support the efficacy and safety of SOF‐DCV as an add‐on to SOC for the treatment of moderate to severe COVID‐19 infections.

Virtual screening-driven drug discovery of SARS-CoV2 enzyme inhibitors targeting viral attachment, replication, post-translational modification and host immunity evasion infection mechanisms

The novel coronavirus SARS-CoV2, the causative agent of the pandemic disease COVID-19, emerged in December 2019 forcing lockdown of communities in many countries. The absence of specific drugs and vaccines, the rapid transmission of the virus, and the increasing number of deaths worldwide necessitated the discovery of new substances for anti-COVID-19 drug development. With the aid of bioinformatics and computational modelling, ninety seven antiviral secondary metabolites from fungi were docked onto five SARS-CoV2 enzymes involved in viral attachment, replication, post-translational modification, and host immunity evasion infection mechanisms followed by molecular dynamics simulation and in silico ADMET prediction (absorption, distribution, metabolism, excretion and toxicity) of the hit compounds. Thus, three fumiquinazoline alkaloids scedapin C (15), quinadoline B (19) and norquinadoline A (20), the polyketide isochaetochromin D1 (8), and the terpenoid 11a-dehydroxyisoterreulactone A (11) exhibited high binding affinities on the target proteins, papain-like protease (PLpro), chymotrypsin-like protease (3CLpro), RNA-directed RNA polymerase (RdRp), non-structural protein 15 (nsp15), and the spike binding domain to GRP78. Molecular dynamics simulation was performed to optimize the interaction and investigate the stability of the top-scoring ligands in complex with the five target proteins. All tested complexes were found to have dynamic stability. Of the five top-scoring metabolites, quinadoline B (19) was predicted to confer favorable ADMET values, high gastrointestinal absorptive probability and poor blood-brain barrier crossing capacities.Communicated by Ramaswamy H. Sarma.

Targeting SARS-COV-2 non-structural protein 16: a virtual drug repurposing study

Non-Structural Protein 16 (nsp-16), a viral RNA methyltransferase (MTase), is one of the highly viable targets for drug discovery of coronaviruses including SARS-CoV-2. In this study, drug discovery of SARS-CoV-2 nsp-16 has been performed by a virtual drug repurposing approach. First, drug shape-based screening (among FDA approved drugs) with a known template of MTase inhibitor, sinefungin was done and best compounds with high similarity scores were selected. In addition to the selected compounds, 4 nucleoside analogs of anti-viral (Raltgravir, Maraviroc and Favipiravir) and anti-inflammatory (Prednisolone) drugs were selected for further investigations. Then, binding energies and interaction modes were found by molecular docking approaches and compouds with lower energy were selected for further investigation. After that, Molecular dynamics (MD) simulation was carried to test the potential selected compounds in a realistic environment. The results showed that Raltegravir and Maraviroc among other compounds can bind strongly to the active site of the protein compared to sinefungin, and can be potential candidates to inhibit NSP-16. Also, the MD simulation results suggested that the Maraviroc and Raltegravir are more effective drug candidates than Sinefungin for inhibiting the enzyme. It is concluded that Raltegravir and Maraviroc which may be used in the treatment of COVID-19 after Invitro and invivo studies and clinical trial for final confirmation of drug effectiveness. Communicated by Ramaswamy H. Sarma.

Computational investigation on Andrographis paniculata phytochemicals to evaluate their potency against SARS-CoV-2 in comparison to known antiviral compounds in drug trials

The outbreak due to SARS-CoV-2 (or Covid-19) is spreading alarmingly and number of deaths due to infection is aggressively increasing every day. Due to the rapid human to human transmission of Covid-19, we are in need to find a potent drug at the earliest by ruling-out the traditional time-consuming approach of drug development. This is only possible if we use reliable computational approaches for screening compounds from chemical space or by drug repurposing or by finding the phytochemicals and nutraceuticals from plants as they can be immediately used without the need for carrying out drug-trials to test safety and efficacy. A number of plant products were routinely suggested as drugs in traditional Indian and Chinese medicine. Here using molecular docking approach, and combined molecular dynamics and MM-GBSA based free energy calculations approach, we study the potency of the four selected phytochemicals namely andrographolide (AGP1), 14-deoxy 11,12-didehydro andrographolide (AGP2), neoandrographolide (AGP3) and 14-deoxy andrographolide (AGP4) from A. paniculata plant against the four key targets including three non-structural proteins (3 L main protease (3CLpro), Papain-like proteinase (PLpro) and RNA-directed RNA polymerase (RdRp)) and a structural protein (spike protein (S)) of the virus which are responsible for replication, transcription and host cell recognition. The therapeutic potential of the selected phytochemicals against Covid-19 were also evaluated in comparison with a few commercially available drugs. The binding free energy data suggest that AGP3 could be used as a cost-effective drug-analog for treating covid-19 infection in developing countries.Communicated by Ramaswamy H. Sarma.

CoViTris2020 and ChloViD2020: a striking new hope in COVID-19 therapy

Designing anticoronavirus disease 2019 (anti-COVID-19) agents is the primary concern of medicinal chemists/drug designers nowadays. Repurposing of known active compounds against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a new effective and time-saving trend in anti-COVID-19 drug discovery. Thorough inhibition of the coronaviral-2 proteins (i.e., multitarget inhibition) is a possible powerful favorable strategy for developing effectively potent drugs for COVID-19. In this new research study, I succeeded to repurpose the two antioxidant polyhydroxy-1,3,4-oxadiazole compounds CoViTris2020 and ChloViD2020 as the first multitarget coronaviral protein blockers with extremely higher potencies (reach about 65 and 304 times, for CoViTris2020, and 20 and 93 times, for ChloViD2020, more potent than remdesivir and favipiravir, respectively). These two 2,5-disubstituted-1,3,4-oxadiazoles were computationally studied (through molecular docking in almost all SARS-CoV-2 proteins) and biologically assessed (through a newly established robust in vitro anti-COVID-19 assay) for their anticoronaviral-2 bioactivities. The data obtained from the docking investigation showed that both ligands promisingly exhibited very strong inhibitory binding affinities with almost all docked enzymes (e.g., they displayed extremely lower binding energies of - 12.00 and - 9.60 kcal/mol, respectively, with the SARS-CoV-2 RNA-dependent RNA polymerase "RdRp"). The results of the biological assay revealed that CoViTris2020 and ChloViD2020 significantly displayed very high anti-COVID-19 activities (anti-SARS-CoV-2 EC50 = 0.31 and 1.01 μM, respectively). Further in vivo/clinical studies for the development of CoViTris2020 and ChloViD2020 as anti-COVID-19 medications are required. In brief, the ascent of CoViTris2020 and ChloViD2020 as the two lead members of the novel family of anti-COVID-19 polyphenolic 2,5-disubstituted-1,3,4-oxadiazole derivatives represents a promising hope in COVID-19 therapy. CoViTris2020 and ChloViD2020 inhibit SARS-CoV-2 life cycle with surprising EC50 values of 0.31 and 1.01 μM, respectively. CoViTris2020 strongly inhibits coronaviral-2 RdRp with exceptionally lower inhibitory binding energy of - 12.00 kcal/mol.

A comprehensive review of COVID-19 in India: A frequent catch of the information

The arrival of novel health crisis by a novel member of coronavirus group named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by World Health Organization took the whole world in global emergency by affecting 206 countries. The virus infects 206 countries with 86,839,226 confirmed cases, 61,565,949 recoveries, and 1,876,243 deaths as on January 6, 2021. Evidence pointed out the fact that virus might first originated in bats in China and it took only 2 months to spread over almost every country of the world. SARS-CoV-2 belongs to beta coronavirus and is enveloped, positive sense, and single-stranded RNA virus. The treatment would be difficult as SARS-CoV-2 is an RNA virus and thus the mutation rate is higher in comparison with the DNA viruses. The virus infection also leads to generation of effective protective immune response of tumor necrosis factor, interleukin (IL)-1β, IL-6, IL-8, granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, and so on that may help in virus elimination. The speed of the global spread of the current pandemic is of major concern and it has created a significant threat to economic and human health across the world. In India, the infection spreads with an infection and fatality rates of the disease are 1.7% and 2.8%, respectively. By this review, we want to emphasize the actual situation and major factors associated with COVID-19 pandemic, its significance, destructions, important findings, treatments, and preventive measures taken by all nations to provide better cure without having much loss.

Exploring peptide studies related to SARS-CoV to accelerate the development of novel therapeutic and prophylactic solutions against COVID-19

Recent advances in peptide research revolutionized therapeutic discoveries for various infectious diseases. In view of the ongoing threat of the COVID-19 pandemic, there is an urgent need to develop potential therapeutic options. Intense and accomplishing research is being carried out to develop broad-spectrum vaccines and treatment options for corona viruses, due to the risk of recurrent infection by the existing strains or pandemic outbreaks by new mutant strains. Developing a novel medicine is costly and time consuming, which increases the value of repurposing existing therapies. Since, SARS-CoV-2 shares significant genomic homology with SARS-CoV, we have summarized various peptides identified against SARS-CoV using in silico and molecular studies and also the peptides effective against SARS-CoV-2. Dissecting the molecular mechanisms underlying viral infection could yield fundamental insights in the discovery of new antiviral agents, targeting viral proteins or host factors. We postulate that these peptides can serve as effective components for therapeutic options against SARS-CoV-2, supporting clinical scientists globally in selectively identifying and testing the therapeutic and prophylactic agents for COVID-19 treatment. In addition, we also summarized the latest updates on peptide therapeutics against SARS-CoV-2.

Identifying compounds that prevent the binding of the SARS-CoV-2 S-protein to ACE2

We investigated compounds selected by molecular docking to identify a specific treatment for COVID-19 that decreases the interaction between angiotensin-converting enzyme 2 (ACE2) and the receptor-binding domain (RBD) of SARS-CoV-2. Five compounds that interact with ACE2 amino acids Gln24, Asp30, His34, Tyr41, Gln42, Met82, Lys353, and Arg357 were evaluated using specific binding assays for their effects on the interaction between ACE2 with RBD. The compound labeled ED demonstrated favorable ACE2-binding, with an IC₅₀ of 31.95 μM. ED cytotoxicity, evaluated using PC3 cells in an MTT assay, was consistent with the low theoretical toxicity previously reported. We propose that ED mainly interacts with His34, Glu37, and Lys353 in ACE2 and that it has an inhibitory effect on the interaction of ACE2 with the RBD of the S-protein. We recommend further investigation to develop ED into a potential drug or adjuvant in COVID-19 treatment.

Expression of SARS-CoV-2-related receptors in cells of the neurovascular unit: implications for HIV-1 infection

BACKGROUND

Neurological complications are common in patients affected by COVID-19 due to the ability of SARS-CoV-2 to infect brains. While the mechanisms of this process are not fully understood, it has been proposed that SARS-CoV-2 can infect the cells of the neurovascular unit (NVU), which form the blood-brain barrier (BBB). The aim of the current study was to analyze the expression pattern of the main SARS-CoV-2 receptors in naïve and HIV-1-infected cells of the NVU in order to elucidate a possible pathway of the virus entry into the brain and a potential modulatory impact of HIV-1 in this process.

METHODS

The gene and protein expression profile of ACE2, TMPRSS2, ADAM17, BSG, DPP4, AGTR2, ANPEP, cathepsin B, and cathepsin L was assessed by qPCR, immunoblotting, and immunostaining, respectively. In addition, we investigated if brain endothelial cells can be affected by the exposure to the S1 subunit of the S protein, the domain responsible for the direct binding of SARS-CoV-2 to the ACE2 receptors.

RESULTS

The receptors involved in SARS-CoV-2 infection are co-expressed in the cells of the NVU, especially in astrocytes and microglial cells. These receptors are functionally active as exposure of endothelial cells to the SARS CoV-2 S1 protein subunit altered the expression pattern of tight junction proteins, such as claudin-5 and ZO-1. Additionally, HIV-1 infection upregulated ACE2 and TMPRSS2 expression in brain astrocytes and microglia cells.

CONCLUSIONS

These findings provide key insight into SARS-CoV-2 recognition by cells of the NVU and may help to develop possible treatment of CNS complications of COVID-19.

Clinical diagonal translation of nanoparticles: Case studies in dendrimer nanomedicine

Among the numerous nanomedicine formulations, dendrimers have emerged as original, efficient, carefully assembled, hyperbranched, polymeric nanoparticles based on synthetic monomers. Dendrimers are used either as nanocarriers of drugs or as drugs themselves. When used as drug carriers, dendrimers are considered 'best-in-class agents', modifying and enhancing the pharmacokinetic and pharmacodynamic properties of the active entities encapsulated or conjugated with the dendrimers. When used as drugs themselves, dendrimers represent a novel category of "first-in-class" drugs. The purpose of this original review is to analyse the different strategies involved in the development, application, and impact of dendrimers as drugs. We examine a selection of nanoparticles that use multifunctional elements and demonstrate clinical multifunctionality, and we extend these principles to applications in dendrimer nanomedicine design. Finally, for practical consideration, the concepts of vertical and diagonal translation are introduced as potential strategies to facilitate dendrimer development.

Ribavirin Aerosol in the Treatment of SARS-CoV-2: A Case Series

Ribavirin is an inosine monophosphate dehydrogenase inhibitor with demonstrated activity against coronaviruses, including SARS-CoV-2. Five hospitalized patients with COVID-19 (confirmed by positive tests for SARS-CoV-2) received treatment with ribavirin for inhalation solution (ribavirin aerosol) as part of a compassionate use program. Patients included four men and one woman, with an age range of 29–72 years. Patients were managed according to international and Italian treatment guidelines for COVID-19. In addition, therapy with ribavirin aerosol 100 mg/mL was administered for 30 min twice daily for 6 days (i.e., 12 doses) in all patients. In order to address concerns about a possible increase in viral dispersal with the use of a nebulizer, healthcare providers remained outside the patient room during ribavirin aerosol administration. Pretreatment chest computed tomography (CT) scans showed pseudonodular areas of parenchymal thickening in the upper right lobe with associated ground glass opacities, multiple areas of parenchymal consolidation in both lower lobes with associated ground glass opacities, bilateral parenchymal thickening and multiple associated ground glass areas, or focal ground glass areas in the upper lobes bilaterally, which were almost completely resolved (three patients) or moderately cleared (one patient) on imaging at the end of ribavirin treatment. For a fifth patient, CT scans showed a stable pulmonary picture at the end of ribavirin treatment. No adverse reactions to ribavirin treatment were observed in any of the five patients. All patients recovered fully, and nasopharyngeal swabs obtained after hospital discharge tested negative for SARS-CoV-2. Ribavirin aerosol appears to be efficacious in the treatment of patients with COVID-19. A controlled trial of ribavirin aerosol is ongoing and will provide additional data across a broader patient population.

Putative Repurposing of Lamivudine, a Nucleoside/Nucleotide Analogue and Antiretroviral to Improve the Outcome of Cancer and COVID-19 Patients

Lamivudine, also widely known as 3TC belongs to a family of nucleotide/nucleoside analogues of cytidine or cytosine that inhibits the Reverse Transcriptase (RT) of retroviruses such as HIV. Lamivudine is currently indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection or for chronic Hepatitis B (HBV) virus infection associated with evidence of hepatitis B viral replication and active liver inflammation. HBV reactivation in patients with HBV infections who receive anticancer chemotherapy can be a life-threatening complication during and after the completion of chemotherapy. Lamivudine is used, as well as other antiretrovirals, to prevent the reactivation of the Hepatitis B virus during and after chemotherapy. In addition, Lamivudine has been shown to sensitize cancer cells to chemotherapy. Lamivudine and other similar analogues also have direct positive effects in the prevention of cancer in hepatitis B or HIV positive patients, independently of chemotherapy or radiotherapy. Recently, it has been proposed that Lamivudine might be also repurposed against SARS-CoV-2 in the context of the COVID-19 pandemic. In this review we first examine recent reports on the re-usage of Lamivudine or 3TC against the SARS-CoV-2, and we present docking evidence carried out in silico suggesting that Lamivudine may bind and possibly work as an inhibitor of the SARS-CoV-2 RdRp RNA polymerase. We also evaluate and propose assessment of repurposing Lamivudine as anti-SARS-CoV-2 and anti-COVID-19 antiviral. Secondly, we summarize the published literature on the use of Lamivudine or (3TC) before or during chemotherapy to prevent reactivation of HBV, and examine reports of enhanced effectiveness of radiotherapy in combination with Lamivudine treatment against the cancerous cells or tissues. We show that the anti-cancer properties of Lamivudine are well established, whereas its putative anti-COVID effect is under investigation. The side effects of lamivudine and the appearance of resistance to 3TC are also discussed.

Efficacy and safety of sofosbuvir/velpatasvir versus the standard of care in adults hospitalized with COVID-19: a single-centre, randomized controlled trial

Objectives

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the COVID-19 pandemic. The majority of patients experience asymptomatic to mild self-limited disease, but some cases progress to respiratory and multi-organ failure. However, so far, no approved antiviral therapy has been available for treatment of COVID-19. Sofosbuvir/velpatasvir (SOF/VEL) is an approved anti-HCV drug that is capable of suppressing other families of positive-sense RNA viruses with conserved polymerase and may be effective against SARS-CoV-2. This study was conducted to evaluate the efficacy of the SOF/VEL combination in addition to the national standard of care versus the national standard of care alone (hydroxychloroquine and lopinavir/ritonavir as well as supportive care) in patients with moderate to severe COVID-19 infection.

Methods

This single-centre, randomized, open-labelled, prospective clinical trial was done in patients with moderate to severe COVID-19 admitted to Farabi Hospital in Kermanshah Province, Iran. Eligible patients were randomly assigned in a 1:1 ratio to the SOF/VEL arm (SOF/VEL plus the national standard of care) or the control arm (the national standard of care alone). The main outcome of the study was the mortality on Day 28 after randomization. Secondary outcomes were time from the start of medication to clinical improvement, hospital length of stay, need for mechanical ventilation, duration of mechanical ventilation and conversion of RT–PCR results from positive to negative from the time of randomization to discharge. Adverse events were evaluated in all patients who started their assigned treatment.

Results

Between 11 April and 8 June 2020, 80 patients were recruited and randomly assigned into the SOF/VEL (n = 40) and control (n = 40) arms. The primary outcome was not significantly different between the two arms (P = 1.00). Secondary outcomes, including time to clinical improvement, hospital length of stay, need for mechanical ventilation, duration of mechanical ventilation and RT–PCR conversion, were not significantly different between arms either (P > 0.05). SOF/VEL treatment and the national standard of care were tolerated similarly.

Conclusions

Although treatment with SOF/VEL was safe, adding SOF/VEL to the standard of care did not improve the clinical status or reduce mortality in patients with moderate to severe COVID-19. However, larger randomized clinical trials including more parameters are needed for accurate estimation of the efficacy of SOF/VEL.

PLIP 2021: expanding the scope of the protein-ligand interaction profiler to DNA and RNA

With the growth of protein structure data, the analysis of molecular interactions between ligands and their target molecules is gaining importance. PLIP, the protein–ligand interaction profiler, detects and visualises these interactions and provides data in formats suitable for further processing. PLIP has proven very successful in applications ranging from the characterisation of docking experiments to the assessment of novel ligand–protein complexes. Besides ligand–protein interactions, interactions with DNA and RNA play a vital role in many applications, such as drugs targeting DNA or RNA-binding proteins. To date, over 7% of all 3D structures in the Protein Data Bank include DNA or RNA. Therefore, we extended PLIP to encompass these important molecules. We demonstrate the power of this extension with examples of a cancer drug binding to a DNA target, and an RNA–protein complex central to a neurological disease. PLIP is available online at https://plip-tool.biotec.tu-dresden.de and as open source code. So far, the engine has served over a million queries and the source code has been downloaded several thousand times.

A dossier on COVID-19 chronicle

The dissemination of the 2019 novel coronavirus (2019-nCoV) is presenting the planet with a new health emergency response or threat to health. The virus emerged in bats and was disseminated to humans in December 2019 via still unknown intermediate species in Wuhan, China. It is disseminated by inhalation or breaks out with infected droplets and the incubation period is between 2 and 14 days. The symptoms usually include high body temperature, cough, sore throat, dyspnea, low energy or tiredness, and weakness. The condition is moderate in most people; but in the elderly and those with comorbidities, it advances to pneumonia, acute respiratory distress syndrome (ARDS), and multiple organ failure. Popular research work includes normal/low WBC with upraised C-reactive protein (CRP). Treatment is generally supportive and requires home seclusion of suspected persons and rigorous infection control methods at hospitals. The Covid-19 has lower fatality than SARS and MERS. Among the proposed therapeutic regimen, hydroxychloroquine, chloroquine, remdisevir, azithromycin, toclizumab, and cromostat mesylate have shown promising results, and the limited benefit was seen with lopinavir-ritonavir treatment in hospitalized adult patients with severe COVID-19. Early development of the SARS-CoV-2 vaccine started based on the full-length genome analysis of severe acute respiratory syndrome coronavirus. Several subunit vaccines, peptides, nucleic acids, plant-derived, and recombinant vaccines are under pipeline. Research work, development of new medicines and vaccines, and efforts to reduce disease morbidity and mortality must be encouraged to improve our position in the fight against this disease and to protect human life.

Computational Chemistry to Repurposing Drugs for the Control of COVID-19

Thus far, in 2021, 219 countries with over 175 million people have been infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 is a positive sense, single-stranded RNA virus, and is the causal agent for coronavirus disease (COVID-19). Due to the urgency of the situation, virtual screening as a computational modeling method offers a fast and effective modality of identifying drugs that may be effective against SARS-CoV-2. There has been an overwhelming abundance of molecular docking against SARS-CoV-2 in the last year. Due to the massive volume of computational studies, this systematic review has been created to evaluate and summarize the findings of existing studies. Herein, we report on computational articles of drugs which target, (1) viral protease, (2) Spike protein-ACE 2 interaction, (3) RNA-dependent RNA polymerase, and (4) other proteins and nonstructural proteins of SARS-CoV-2. Based on the studies presented, there are 55 identified natural or drug compounds with potential anti-viral activity. The next step is to show anti-viral activity in vitro and translation to determine effectiveness into human clinical trials.

Efficacy of combined Sofosbuvir and Daclatasvir in the treatment of COVID-19 patients with pneumonia: a multicenter Egyptian study

BACKGROUND

Limited experimental and clinical evidence suggests a potential role for sofosbuvir/daclatasvir in treating COVID19. We aim to evaluate the efficacy of generic sofosbuvir/daclatasvir in treating COVID-19 patients with pneumonia.

RESEARCH DESIGN AND METHODS

This multicenter prospective study involved 174 patients with COVID-19. Patients were randomized into two groups. Group A (96 patients) received sofosbuvir (400 mg)/daclatasvir (60 mg) for 14 days in combination with conventional therapy. Group B (78 patients) received conventional therapy alone. Clinical, laboratory, and radiological data were collected at baseline, after 7, 14, and 28 days of therapy. Primary endpoint was rate of clinical/virological cure.

RESULTS

A lower mortality rate was observed in group (A) (14% vs 21%, P = 0.07). After 1 month of therapy, no differences were found in rates of ICU admission, oxygen therapy, or ventilation. Additionally, a statistically significant shorter duration of hospital stay (9% vs 12%, P < 0.01) and a faster achievement of PCR negativity at day 14 (84% versus 47%, P < 0.01) were noticed in group (A).

CONCLUSION

Adding sofosbuvir/daclatasvir to conventional therapy of COVID-19 is promising. Their use is associated with shorter hospital stay, faster PCR negativity and may be reduced mortality.

Potential Inhibition of COVID-19 RNA-dependent RNA Polymerase by Hepatitis C Virus Non-nucleoside Inhibitors: An In-silico Perspective

Background:

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a novel member of the genus betacoronavirus in the Coronaviridae family. It has been identified as the causative agent of coronavirus disease 2019 (COVID-19), spreading rapidly in Asia, America and Europe. Like some other RNA viruses, RNA replication and transcription of SARS-CoV-2 rely on its RNA-dependent RNA polymerase (RdRP), which is a therapeutic target of clinical importance. Crystal structure of SARS-CoV-2 was solved recently (PDB ID 6M71) with some missing residues.

Objective:

We used SARS-CoV-2 RdRP as a target protein to screen for possible chemical molecules with potential anti-viral effects.

Methods:

Here we modelled the missing residues 896-905 via homology modelling and then analysed the interactions of Hepatitis C virus allosteric non-nucleoside inhibitors (NNIs) in the reported NNIs binding sites in SARS-CoV-2 RdRP.

Results:

We found that MK-3281, filibuvir, setrobuvir and dasabuvir might be able to inhibit SARS-CoV-2 RdRP based on their binding affinities in the respective binding sites.

Conclusion:

Further in vitro and in vivo experimental research will be carried out to evaluate their effectiveness in COVID-19 treatment in the near future.

Targeting SARS-CoV-2 nonstructural protein 15 endoribonuclease: an in silico perspective

The newly emerged human coronavirus, SARS-CoV-2, had begun to spread last year and sparked worldwide. In this study, molecular docking is utilized to test some previously approved drugs against the SARS-CoV-2 nonstructural protein 15 (Nsp15). We screened 23 drugs, from which three (saquinavir, valrubicin and aprepitant) show a paramount predicted binding affinity (-9.1, -9.6 and -9.2 kcal/mol, respectively) against SARS-CoV-2 Nsp15. Moreover, saquinavir and aprepitant make nonbonded interactions with Leu201 in the active site cavity of Nsp15, while the drug valrubicin interacts with Arg199 and Leu201. This binding pattern may be effective against the targeted protein, leading to Nsp15 blockage and virus abolition. Additionally, the pharmacological properties of the screened drugs are known since they have been approved against different viruses.