Drug repurposing of nitazoxanide: can it be an effective therapy for COVID-19?

Revisiting the dimensions of universal vaccine with special focus on COVID-19: Efficacy versus methods of designing

Even though the use of SARS-CoV-2 vaccines during the COVID-19 pandemic showed unprecedented success in a short time, it also exposed a flaw in the current vaccine design strategy to offer broad protection against emerging variants of concern. However, developing broad-spectrum vaccines is still a challenge for immunologists. The development of universal vaccines against emerging pathogens and their variants appears to be a practical solution to mitigate the economic and physical effects of the pandemic on society. Very few reports are available to explain the basic concept of universal vaccine design and development. This review provides an overview of the innate and adaptive immune responses generated against vaccination and essential insight into immune mechanisms helpful in designing universal vaccines targeting influenza viruses and coronaviruses. In addition, the characteristics, safety, and factors affecting the efficacy of universal vaccines have been discussed. Furthermore, several advancements in methods worthy of designing universal vaccines are described, including chimeric immunogens, heterologous prime-boost vaccines, reverse vaccinology, structure-based antigen design, pan-reactive antibody vaccines, conserved neutralizing epitope-based vaccines, mosaic nanoparticle-based vaccines, etc. In addition to the several advantages, significant potential constraints, such as defocusing the immune response and subdominance, are also discussed.

Drug repurposing of pyrazolotriazine derivatives as potential anti-SARS-CoV-2 agents: in vitro and in silico studies

The search for new molecules targeting SARS-CoV-2 has been a priority since 2020. The continuous evolution of new mutants increases the need for more research in the area. One way to find new leads is to repurpose existing drugs and molecules against the required target. Here, we present the in vitro and in silico screening of ten previously synthesized and reported compounds as anti-COVID 19 agents. The compounds were screened in vitro against VERO-E6 cells to find their Cytotoxic Concentration (CC50) and their Inhibitory Concentration (IC50). Compounds 1, 2, and 5 revealed a promising anti-SARS-CoV-2 of (IC50 = 2.4, 11.2 and 2.8 µM), respectively while compounds 3 and 7 showed moderate activity of (IC50 = 17.8 and 26.1 µM) compared to Chloroquine which showed an IC50 of 24.9 µM. Among tested compounds, 1 showed the highest selectivity (CC50/IC50) of 192.8. Docking, molecular dynamics and ADME studies were done to investigate potential interactions between compounds and SARS-CoV-2 targets as well as to study the possibility of using them as lead compounds.

Antiviral Chemotherapy in Avian Medicine-A Review

This review article describes the current knowledge about the use of antiviral chemotherapeutics in avian species, such as farm poultry and companion birds. Specific therapeutics are described in alphabetical order including classic antiviral drugs, such as acyclovir, abacavir, adefovir, amantadine, didanosine, entecavir, ganciclovir, interferon, lamivudine, penciclovir, famciclovir, oseltamivir, ribavirin, and zidovudine, repurposed drugs, such as ivermectin and nitazoxanide, which were originally used as antiparasitic drugs, and some others substances showing antiviral activity, such as ampligen, azo derivates, docosanol, fluoroarabinosylpyrimidine nucleosides, and novel peptides. Most of them have only been used for research purposes and are not widely used in clinical practice because of a lack of essential pharmacokinetic and safety data. Suggested future research directions are also highlighted.

Drug Repurposing in the Chemotherapy of Infectious Diseases

Repurposing is a universal mechanism for innovation, from the evolution of feathers to the invention of Velcro tape. Repurposing is particularly attractive for drug development, given that it costs more than a billion dollars and takes longer than ten years to make a new drug from scratch. The COVID-19 pandemic has triggered a large number of drug repurposing activities. At the same time, it has highlighted potential pitfalls, in particular when concessions are made to the target product profile. Here, we discuss the pros and cons of drug repurposing for infectious diseases and analyze different ways of repurposing. We distinguish between opportunistic and rational approaches, i.e., just saving time and money by screening compounds that are already approved versus repurposing based on a particular target that is common to different pathogens. The latter can be further distinguished into divergent and convergent: points of attack that are divergent share common ancestry (e.g., prokaryotic targets in the apicoplast of malaria parasites), whereas those that are convergent arise from a shared lifestyle (e.g., the susceptibility of bacteria, parasites, and tumor cells to antifolates due to their high rate of DNA synthesis). We illustrate how such different scenarios can be capitalized on by using examples of drugs that have been repurposed to, from, or within the field of anti-infective chemotherapy.

'Poly phenolic phytoceutical loaded nano-bilosomes for enhanced caco-2 cell permeability and SARS-CoV 2 antiviral activity': in-vitro and insilico studies

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) predisposed to the emergence of worldwide catastrophe that impels the evolution of safe and effective therapeutic system. Polyphenols as resveratrol (RSV) exhibit a well evidenced antiviral activity. Unfortunately, like most phenolic nutraceuticals, RSV suffers from restrained solubility and massive degradation in GIT and liver which in turn prohibit its clinical use. Herein, PEGylated bilosomes (PBs) contain PEGylated edge activator along with the traditional components as (Span 60, cholesterol and bile salts) were proposed to boost both permeability and bioavailability of RSV. The investigation of the prominent effect of the diverse variables on the characteristics of the vesicles and picking of the optimum formula were conducted via construction of 2³ factorial experiment. The appraisal of the formulae was conducted on the basis of entrapment efficiency percent (EE%), particle size (PS) and zeta potential (ZP). In addition, the spherical shaped optimal formula (F5) exhibited EE% of 86.1 ± 2.9%, PS of 228.9 ± 8.5 nm, and ZP of -39.8 ± 1.3 mV. The sorted optimum formula (F5) exhibited superior dissolution behaviors, and boosted Caco-2 cells cellular uptake by a round 4.7 folds relative to RSV dispersion. In addition, F5 demonstrated a complete in vitro suppression of SARS-CoV-2 at a concentration 0.48 μg/ml with 6.6 times enhancement in antiviral activity relative to RSV dispersion. The accomplished molecular modeling heavily provided proof for the possible interactions of resveratrol with the key residues of the SARS-CoV2 Mpro enzyme. Finally, F5 could be proposed as a promising oral panel of RSV for curation from SARS-CoV-2 infection.

The African Kelleni's roadmap using nitazoxanide and broad-spectrum antimicrobials to abort returning to COVID-19 square one

For over 3.5 years, SARS CoV-2 is continuing to evolve threatening to return all and any improvement the world has made into square one. In this clinically oriented systematic review and perspective, the author explains how the best current medical evidence is strongly supporting the use of the low cost, widely available and very safe nitazoxanide in early management of COVID-19, debates the relevant theoretical studies that negated or doubted this benefit, and suggests an African roadmap to preempt the worst-case scenario if or when a new SARS CoV-2 (sub) variant or even a new respiratory virus causes a new global surge of morbidity and mortality. Kelleni's protocol, including nitazoxanide as an integral component, is continuing to perfectly save lives of patients infected with many viruses, including SARS CoV-2 and the author stresses that respiratory RNA viruses are best managed with early pharmacological treatment. Broad-spectrum antimicrobials as nitazoxanide and azithromycin together with other therapeutics as non-steroidal anti-inflammatory drugs and the antihistaminic loratadine should be considered first to personalize the clinical management of COVID-19 and selected other alarming viral infections.

Immunotoxicity and transcriptome analysis of zebrafish embryos exposure to Nitazoxanide

Nitazoxanide (NTZ) is a broad-spectrum immunomodulatory drug, and little information is about the immunotoxicity of aquatic organisms induced by NTZ. In the present study, reduced body length and decreased yolk sac absorption in the NTZ-treated group were observed. Meanwhile, the number of innate immune cells and adaptive immune cells was substantially reduced upon NTZ exposure, and the migration and retention of macrophages and neutrophils in the injured area were inhibited. Following NTZ stimulation, oxidative stress levels in the zebrafish increased obviously. Mechanistically, RNA-seq, a high-throughput method, was performed to analyze the global expression of differentially expressed genes (DEGs) in zebrafish embryos treated with NTZ. 531 DEGs were identified by comparative transcriptome analysis, including 121 up-regulated and 420 down-regulated genes in zebrafish embryos after NTZ exposure. The transcriptome sequences were further subjected to the Kyoto Encyclopedia of Genes and Genomes (KEGG) and gene ontology (GO) and analysis, showing phototransduction and metabolic pathway, respectively, and were most enriched. In addition, some immune-related genes were inhibited after NTZ exposure. RNA-seq results confirmed by qRT-PCR were used to verify the expression of the 6 selected genes. The other immune-related genes such as two pro-inflammatory cytokines (IL-1β, tnfα) and two chemokines (CXCL8b.3, CXCL-c1c) were further confirmed and were differentially regulated after NTZ exposure. In summary, NTZ exposure could lead to immunotoxicity and increased ROS in zebrafish embryos, this study provides valuable information for future elucidating the molecular mechanism of exogenous stimuli-induced immunotoxicity in aquatic ecosystems.

Investigating the Biological Potency of Nitazoxanide-Based Cu(II), Ni(II) and Zn(II) Complexes Synthesis, Characterization and Anti-COVID-19, Antioxidant, Antibacterial and Anticancer Activities

In this work, the biological potency of nitazoxanide (NTZ) was enhanced through coordination with transition metal ions Cu(II), Ni(II), and Zn(II). Initially, complexes with a ligand-metal stoichiometry of 2:1 were successfully synthesized and characterized by spectroscopic techniques and thermogravimetric methods. Measurement of the infrared spectrum revealed the bidentate nature of the ligand and excluded the possibility of the metal ion-amide group interaction. Nuclear magnetic resonance spectra showed a reduction in the NH- intensity signal and integration, indicating the possibility of enolization and the formation of keto-enol tautomers. To interpret these results, density functional theory was utilized under B3LYP/6-311G** for the free ligand and B3LYP/LANL2DZ for the metal complexes. We used UV-Vis and fluorescence spectroscopy to understand the biological properties of the complexes. This showed stronger interactions of NTZ-Cu(II) and NTZ-Ni(II) with DNA molecules than the NTZ-Zn(II) compound, with a binding constant (Kb) for the copper complex of 7.00 × 105 M-1. Both Cu(II)- and Ni(II)-NTZ had functional binding to the SARS-CoV-2 (6LU7) protease. Moreover, all metal complexes showed better antioxidation properties than the free ligand, with NTZ-Ni(II) having the best IC50 value of 53.45 μg/mL. NTZ-Ni(II) was an effective antibacterial, with a mean inhibitory concentration of 6 μM, which is close to that of ampicillin (a reference drug). The metal complexes had moderated anticancer potencies, with NTZ-Cu(II) having IC50 values of 24.5 and 21.5 against human breast cancer cells (MCF-7) and cancerous cervical tumor cells (HeLa), respectively. All obtained complexes exhibited high selectivity. Finally, the metal ions showed a practical role in improving the biological effectiveness of NTZ molecules.

Quantitation of tizoxanide in multiple matrices to support cell culture, animal and human research

Currently nitazoxanide is being assessed as a candidate therapeutic for SARS-CoV-2. Nitazoxanide is rapidly broken down to its active metabolite tizoxanide upon administration. Unlike many other candidates being investigated, tizoxanide plasma concentrations achieve antiviral levels after administration of the approved dose, although higher doses are expected to be needed to maintain these concentrations across the dosing interval in the majority of patients. Here an LC-MS/MS assay is described that has been validated in accordance with Food and Drug Administration (FDA) guidelines. Fundamental parameters have been evaluated, and these included accuracy, precision and sensitivity. The assay was validated for human plasma, mouse plasma and Dulbecco's Modified Eagles Medium (DMEM) containing varying concentrations of Foetal Bovine Serum (FBS). Matrix effects are a well-documented source of concern for chromatographic analysis, with the potential to impact various stages of the analytical process, including suppression or enhancement of ionisation. Herein a validated LC-MS/MS analytical method is presented capable of quantifying tizoxanide in multiple matrices with minimal impact of matrix effects. The validated assay presented here was linear from 15.6 ng/mL to 1000 ng/mL. The presented assay here has applications in both pre-clinical and clinical research and may be used to facilitate further investigations into the application of nitazoxanide against SARS-CoV-2.

Drug repositioning in the COVID-19 pandemic: fundamentals, synthetic routes, and overview of clinical studies

INTRODUCTION

Drug repositioning is a strategy to identify a new therapeutic indication for molecules that have been approved for other conditions, aiming to speed up the traditional drug development process and reduce its costs. The high prevalence and incidence of coronavirus disease 2019 (COVID-19) underline the importance of searching for a safe and effective treatment for the disease, and drug repositioning is the most rational strategy to achieve this goal in a short period of time. Another advantage of repositioning is the fact that these compounds already have established synthetic routes, which facilitates their production at the industrial level. However, the hope for treatment cannot allow the indiscriminate use of medicines without a scientific basis.

RESULTS

The main small molecules in clinical trials being studied to be potentially repositioned to treat COVID-19 are chloroquine, hydroxychloroquine, ivermectin, favipiravir, colchicine, remdesivir, dexamethasone, nitazoxanide, azithromycin, camostat, methylprednisolone, and baricitinib. In the context of clinical tests, in general, they were carried out under the supervision of large consortiums with a methodology based on and recognized in the scientific community, factors that ensure the reliability of the data collected. From the synthetic perspective, compounds with less structural complexity have more simplified synthetic routes. Stereochemical complexity still represents the major challenge in the preparation of dexamethasone, ivermectin, and azithromycin, for instance.

CONCLUSION

Remdesivir and baricitinib were approved for the treatment of hospitalized patients with severe COVID-19. Dexamethasone and methylprednisolone should be used with caution. Hydroxychloroquine, chloroquine, ivermectin, and azithromycin are ineffective for the treatment of the disease, and the other compounds presented uncertain results. Preclinical and clinical studies should not be analyzed alone, and their methodology's accuracy should also be considered. Regulatory agencies are responsible for analyzing the efficacy and safety of a treatment and must be respected as the competent authorities for this decision, avoiding the indiscriminate use of medicines.

Repurposing Benztropine, Natamycin, and Nitazoxanide Using Drug Combination and Characterization of Gastric Cancer Cell Lines

Gastric cancer (GC) ranked as the fifth most incident cancer in 2020 and the third leading cause of cancer mortality. Surgical prevention and radio/chemotherapy are the main approaches used in GC treatment, and there is an urgent need to explore and discover innovative and effective drugs to better treat this disease. A new strategy arises with the use of repurposed drugs. Drug repurposing coupled with drug combination schemes has been gaining interest in the scientific community. The main objective of this project was to evaluate the therapeutic effects of alternative drugs in GC. For that, three GC cell lines (AGS, MKN28, and MKN45) were used and characterized. Cell viability assays were performed with the reference drug 5-fluororacil (5-FU) and three repurposed drugs: natamycin, nitazoxanide, and benztropine. Nitazoxanide displayed the best results, being active in all GC cells. Further, 5-FU and nitazoxanide in combination were tested in MKN28 GC cells, and the results obtained showed that nitazoxanide alone was the most promising drug for GC therapy. This work demonstrated that the repurposing of drugs as single agents has the ability to decrease GC cell viability in a concentration-dependent manner.

A comprehensive review on pharmacologic agents, immunotherapies and supportive therapeutics for COVID-19

The emergence of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has affected many countries throughout the world. As urgency is a necessity, most efforts have focused on identifying small molecule drugs that can be repurposed for use as anti-SARS-CoV-2 agents. Although several drug candidates have been identified using in silico method and in vitro studies, most of these drugs require the support of in vivo data before they can be considered for clinical trials. Several drugs are considered promising therapeutic agents for COVID-19. In addition to the direct-acting antiviral drugs, supportive therapies including traditional Chinese medicine, immunotherapies, immunomodulators, and nutritional therapy could contribute a major role in treating COVID-19 patients. Some of these drugs have already been included in the treatment guidelines, recommendations, and standard operating procedures. In this article, we comprehensively review the approved and potential therapeutic drugs, immune cells-based therapies, immunomodulatory agents/drugs, herbs and plant metabolites, nutritional and dietary for COVID-19.

Repurposing of Chemotherapeutics to Combat COVID-19

Severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) is a novel strain of SARS coronavirus. The COVID-19 disease caused by this virus was declared a pandemic by the World Health Organization (WHO). SARS-CoV-2 mainly spreads through droplets sprayed by coughs or sneezes of the infected to a healthy person within the vicinity of 6 feet. It also spreads through asymptomatic carriers and has negative impact on the global economy, security and lives of people since 2019. Numerous lives have been lost to this viral infection; hence there is an emergency to build up a potent measure to combat SARS-CoV-2. In view of the non-availability of any drugs or vaccines at the time of its eruption, the existing antivirals, antibacterials, antimalarials, mucolytic agents and antipyretic paracetamol were used to treat the COVID-19 patients. Still there are no specific small molecule chemotherapeutics available to combat COVID-19 except for a few vaccines approved for emergency use only. Thus, the repurposing of chemotherapeutics with the potential to treat COVID-19 infected people is being used. The antiviral activity for COVID-19 and biochemical mechanisms of the repurposed drugs are being explored by the biological assay screening and structure-based in silico docking simulations. The present study describes the various US-FDA approved chemotherapeutics repositioned to combat COVID-19 along with their screening for biological activity, pharmacokinetic and pharmacodynamic evaluation.

Pre-clinical evaluation of antiviral activity of nitazoxanide against SARS-CoV-2

Background

To address the emergence of SARS-CoV-2, multiple clinical trials in humans were rapidly started, including those involving an oral treatment by nitazoxanide, despite no or limited pre-clinical evidence of antiviral efficacy.

Methods

In this work, we present a complete pre-clinical evaluation of the antiviral activity of nitazoxanide against SARS-CoV-2.

Findings

First, we confirmed the in vitro efficacy of nitazoxanide and tizoxanide (its active metabolite) against SARS-CoV-2. Then, we demonstrated nitazoxanide activity in a reconstructed bronchial human airway epithelium model. In a SARS-CoV-2 virus challenge model in hamsters, oral and intranasal treatment with nitazoxanide failed to impair viral replication in commonly affected organs. We hypothesized that this could be due to insufficient diffusion of the drug into organs of interest. Indeed, our pharmacokinetic study confirmed that concentrations of tizoxanide in organs of interest were always below the in vitro EC₅₀.

Interpretation

These preclinical results suggest, if directly applicable to humans, that the standard formulation and dosage of nitazoxanide is not effective in providing antiviral therapy for Covid-19.

Funding

This work was supported by the Fondation de France “call FLASH COVID-19”, project TAMAC, by “Institut national de la santé et de la recherche médicale” through the REACTing (REsearch and ACTion targeting emerging infectious diseases), by REACTING/ANRS MIE under the agreement No. 21180 (‘Activité des molécules antivirales dans le modèle hamster’), by European Virus Archive Global (EVA 213 GLOBAL) funded by the European Union's Horizon 2020 research and innovation program under grant agreement No. 871029 and DNDi under support by the Wellcome Trust Grant ref: 222489/Z/21/Z through the COVID-19 Therapeutics Accelerator”.

Robust antiviral activity of commonly prescribed antidepressants against emerging coronaviruses: in vitro and in silico drug repurposing studies

During the current coronavirus disease 2019 (COVID-19) pandemic, symptoms of depression are commonly documented among both symptomatic and asymptomatic quarantined COVID-19 patients. Despite that many of the FDA-approved drugs have been showed anti-SARS-CoV-2 activity in vitro and remarkable efficacy against COVID-19 in clinical trials, no pharmaceutical products have yet been declared to be fully effective for treating COVID-19. Antidepressants comprise five major drug classes for the treatment of depression, neuralgia, migraine prophylaxis, and eating disorders which are frequently reported symptoms in COVID-19 patients. Herein, the efficacy of eight frequently prescribed FDA-approved antidepressants on the inhibition of both SARS-CoV-2 and MERS-CoV was assessed. Additionally, the in vitro anti-SARS-CoV-2 and anti-MERS-CoV activities were evaluated. Furthermore, molecular docking studies have been performed for these drugs against the spike (S) and main protease (M^pro) pockets of both SARS-CoV-2 and MERS-CoV. Results showed that Amitriptyline, Imipramine, Paroxetine, and Sertraline had potential anti-viral activities. Our findings suggested that the aforementioned drugs deserve more in vitro and in vivo studies targeting COVID-19 especially for those patients suffering from depression.

Favipiravir and/or nitazoxanide: a randomized, double-blind, 2×2 design, placebo-controlled trial of early therapy in COVID-19 in health workers, their household members, and patients treated at IMSS (FANTAZE)

BACKGROUND

The 2020 pandemic of SARS-CoV-2 causing COVID-19 disease is an unprecedented global emergency. COVID-19 appears to be a disease with an early phase where the virus replicates, coinciding with the first presentation of symptoms, followed by a later 'inflammatory' phase which results in severe disease in some individuals. It is known from other rapidly progressive infections such as sepsis and influenza that early treatment with antimicrobials is associated with a better outcome. The hypothesis is that this holds for COVID-19 and that early antiviral treatment may prevent progression to the later phase of the disease.

METHODS

Trial design: Phase IIA randomised, double-blind, 2 × 2 design, placebo-controlled, interventional trial.

RANDOMISATION

Participants will be randomised 1:1 by stratification, with the following factors: gender, obesity, symptomatic or asymptomatic, current smoking status presence or absence of comorbidity, and if the participant has or has not been vaccinated.

BLINDING

Participants and investigators will both be blinded to treatment allocation (double-blind).

DISCUSSION

We propose to conduct a proof-of-principle placebo-controlled clinical trial of favipiravir plus or minus nitazoxanide in health workers, their household members and patients treated at the Mexican Social Security Institute (IMSS) facilities. Participants with or without symptomatic COVID-19 or who tested positive will be assigned to receive favipiravir plus nitazoxanide or favipiravir plus nitazoxanide placebo. The primary outcome will be the difference in the amount of virus ('viral load') in the upper respiratory tract after 5 days of therapy. Secondary outcomes will include hospitalization, major morbidity and mortality, pharmacokinetics, and impact of antiviral therapy on viral genetic mutation rate. If favipiravir with nitazoxanide demonstrates important antiviral effects without significant toxicity, there will be a strong case for a larger trial in people at high risk of hospitalization or intensive care admission, for example older patients and/or those with comorbidities and with early disease.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04918927 . Registered on June 9, 2021.

QSAR, homology modeling, and docking simulation on SARS-CoV-2 and pseudomonas aeruginosa inhibitors, ADMET, and molecular dynamic simulations to find a possible oral lead candidate

Background

In seek of potent and non-toxic iminoguanidine derivatives formerly assessed as active Pseudomonas aeruginosa inhibitors, a combined mathematical approach of quantitative structure-activity relationship (QSAR), homology modeling, docking simulation, ADMET, and molecular dynamics simulations were executed on iminoguanidine derivatives.

Results

The QSAR method was employed to statistically analyze the structure-activity relationships (SAR) and had conceded good statistical significance for eminent predictive model; (GA-MLR: Q² _LOO = 0.8027; R ² = 0.8735; R ² _ext = 0.7536). Thorough scrutiny of the predictive models disclosed that the Centered Broto-Moreau autocorrelation - lag 1/weighted by I-state and 3D topological distance-based autocorrelation-lag 9/weighted by I-state oversee the biological activity and rendered much useful information to realize the properties required to develop new potent Pseudomonas aeruginosa inhibitors. The next mathematical model work accomplished here emphasizes finding a potential drug that could aid in curing Pseudomonas aeruginosa and SARS-CoV-2 as the drug targets Pseudomonas aeruginosa. This involves homology modeling of RNA polymerase-binding transcription factor DksA and COVID-19 main protease receptors, docking simulations, and pharmacokinetic screening studies of hits compounds against the receptor to identify potential inhibitors that can serve to regulate the modeled enzymes. The modeled protein exhibits the most favorable regions more than 90% with a minimum disallowed region less than 5% and is simulated under a hydrophilic environment. The docking simulations of all the series to the binding pocket of the built protein model were done to demonstrate their binding style and to recognize critical interacting residues inside the binding site. Their binding constancy for the modeled receptors has been assessed through RMSD, RMSF, and SASA analysis from 1-ns molecular dynamics simulations (MDS) run.

Conclusion

Our acknowledged drugs could be a proficient cure for SARS-CoV-2 and Pseudomonas aeruginosa drug discovery, having said that extra testing (in vitro and in vivo) is essential to explain their latent as novel drugs and manner of action.

Supplementary Information

The online version contains supplementary material available at 10.1186/s43141-022-00362-z.

Tizoxanide Promotes Apoptosis in Glioblastoma by Inhibiting CDK1 Activity

The antiparasitic drug nitazoxanide (NTZ) has received considerable attention for its potential in cancer therapy. In this study, we demonstrate that tizoxanide (TIZ), an active metabolite of NTZ, exhibits antiglioma activity in vitro and in vivo by inducing G2/M cell cycle arrest and apoptosis. In vitro, TIZ dose-dependently inhibited the proliferation of U87, U118, and A172 human glioblastoma (GBM) cells at 48 h with IC₅₀ values of 1.10, 2.31, and 0.73 µM, respectively. Treatment with TIZ (1 and 10 µM) also dose-dependently inhibited the colony formation of these GBM cells and accumulated ROS damage in the nucleus. In silico target fishing combined with network pharmacological disease spectrum analyses of GBM revealed that cycle-dependent kinase 1 (CDK1) is the most compatible target for TIZ and molecular docking by Molecule Operating Environment (MOE) software confirmed it. Mechanistically, TIZ inhibited the phosphorylation of CDK1 at Thr161 and decreased the activity of the CDK1/cyclin B1 complex, arresting the cell cycle at the G2/M phase. TIZ may induce apoptosis via the ROS-mediated apoptotic pathway. In vivo, TIZ suppressed the growth of established subcutaneous and intracranial orthotopic xenograft models of GBM without causing obvious side effects and prolonged the survival of nude mice bearing glioma. Taken together, our results demonstrated that TIZ might be a promising chemotherapy drug in the treatment of GBM.

Thiazole-based SARS-CoV-2 protease (COV Mpro ) inhibitors: Design, synthesis, enzyme inhibition, and molecular modeling simulations

As an attempt to contribute to the efforts of combating the pandemic virus severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) responsible for COVID‐19, new analogs of the repurposed drug nitazoxanide which showed promising inhibitory efficacy on a viral protease enzyme were designed, synthesized and evaluated for their inhibitory activity on the main protease of the SARS‐CoV‐2 virus, using the COV2‐3CL protease inhibition assay. The obtained results showed that the N‐(substituted‐thiazol‐2‐yl)cinnamamide analogs 19, 20, and 21 were the most active compounds with IC₅₀ values of 22.61, 14.7, 21.99 µM, respectively, against the viral protease compared to the reference drugs, nitazoxanide, and lopinavir. Molecular modeling studies showed binding interactions of 19, 20, and 21 with hydrogen bonds to Gln189 and Glu166, arene–arene interaction between the thiazole moiety and His41, and other hydrophobic interactions between the ethene spacer moiety and Asn142. Moreover, an extra arene–arene interaction between substituted benzo[d]thiazole and His41 was observed regarding compounds 19 and 21. Surface mapping and flexible alignment proved the structural similarity between the new drug candidates and nitazoxanide. Compliance of the new compounds to Lipinski's rule of five was investigated and absorption, distribution, metabolism, excretion, and toxicology data were predicted. The newly synthesized compounds are promising template ligands for further development and optimization.

Drug Sensitivity of Vaccine-Derived Rubella Viruses and Quasispecies Evolution in Granulomatous Lesions of Two Ataxia-Telangiectasia Patients Treated with Nitazoxanide

A strong association between rubella virus (RuV) and chronic granulomas, in individuals with inborn errors of immunity, has been recently established. Both the RA27/3 vaccine and wild-type RuV strains were highly sensitive to a broad-spectrum antiviral drug, nitazoxanide (NTZ), in vitro. However, NTZ treatment, used as a salvage therapy, resulted in little or no improvements of RuV-associated cutaneous granulomas in patients. Here, we report investigations of possible causes of treatment failures in two ataxia-telangiectasia patients. Although a reduction in RuV RNA in skin lesions was detected by real-time RT-PCR, live immunodeficiency-related vaccine-derived rubella viruses (iVDRV) were recovered from granulomas, before and after the treatments. Tizoxanide, an active NTZ metabolite, inhibited replications of all iVDRVs in cultured A549 cells, but the 50% and 90% inhibitory concentrations were 10–40 times higher than those for the RA27/3 strain. There were no substantial differences in iVDRV sensitivities, neither before nor after treatments. Analysis of quasispecies in the E1 gene, a suspected NTZ target, showed no effect of NTZ treatments on quasispecies’ complexity in lesions. Thus, failures of NTZ therapies were likely due to low sensitivities of iVDRVs to the drug, and not related to the emergence of resistance, following long-term NTZ treatments.

Mechanism of Action of Small-Molecule Agents in Ongoing Clinical Trials for SARS-CoV-2: A Review

Since the first reports from December 2019, COVID-19 caused an overwhelming global pandemic that has affected 223 countries, seriously endangering public health and creating an urgent need for effective drugs to treat SARS-CoV-2 infection. Currently, there is a lack of safe, effective, and specific therapeutic drugs for COVID-19, with mainly supportive and symptomatic treatments being administered to patients. The preferred option for responding to an outbreak of acute infectious disease is through drug repurposing, saving valuable time that would otherwise be lost in preclinical and clinical research, hastening clinical introduction, and lowering treatment costs. Alternatively, researchers seek to design and discover novel small-molecule candidate drugs targeting the key proteins in the life cycle of SARS-CoV-2 through an in-depth study of the infection mechanism, thus obtaining a number of candidate compounds with favorable antiviral effects in preclinical and clinical settings. There is an urgent need to further elucidate the efficacy and mechanism of action of potential anti-SARS-CoV-2 small-molecule drugs. Herein, we review the candidate small-molecule anti-SARS-CoV-2 drugs in ongoing clinical trials, with a major focus on their mechanisms of action in an attempt to provide useful insight for further research and development of small-molecule compounds against SARS-CoV-2 infection.

RdRp inhibitors and COVID-19: Is molnupiravir a good option?

Rapid changes in the viral genome allow viruses to evade threats posed by the host immune response or antiviral drugs, and can lead to viral persistence in the host cells. RNA-dependent RNA polymerase (RdRp) is an essential enzyme in RNA viruses, which is involved in RNA synthesis through the formation of phosphodiester bonds. Therefore, in RNA viral infections such as SARS-CoV-2, RdRp could be a crucial therapeutic target. The present review discusses the promising application of RdRp inhibitors, previously approved or currently being tested in human clinical trials, in the treatment of RNA virus infections. Nucleoside inhibitors (NIs) bind to the active site of RdRp, while nonnucleoside inhibitors (NNIs) bind to allosteric sites. Given the absence of highly effective drugs for the treatment of COVID-19, the discovery of an efficient treatment for this pandemic is an urgent concern for researchers around the world. We review the evidence for molnupiravir (MK-4482, EIDD-2801), an antiviral drug originally designed for Alphavirus infections, as a potential preventive and therapeutic agent for the management of COVID-19. At the beginning of this pandemic, molnupiravir was in preclinical development for seasonal influenza. When COVID-19 spread dramatically, the timeline for development was accelerated to focus on the treatment of this pandemic. Real time consultation with regulators took place to expedite this program. We summarize the therapeutic potential of RdRp inhibitors, and highlight molnupiravir as a new small molecule drug for COVID-19 treatment.

Clinical features and mechanistic insights into drug repurposing for combating COVID-19

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) emerged from Wuhan in China before it spread to the entire globe. It causes coronavirus disease of 2019 (COVID-19) where mostly individuals present mild symptoms, some remain asymptomatic and some show severe lung inflammation and pneumonia in the host through the induction of a marked inflammatory 'cytokine storm'. New and efficacious vaccines have been developed and put into clinical practice in record time, however, there is a still a need for effective treatments for those who are not vaccinated or remain susceptible to emerging SARS-CoV-2 variant strains. Despite this, effective therapeutic interventions against COVID-19 remain elusive. Here, we have reviewed potential drugs for COVID-19 classified on the basis of their mode of action. The mechanisms of action of each are discussed in detail to highlight the therapeutic targets that may help in reducing the global pandemic. The review was done up to July 2021 and the data was assessed through the official websites of WHO and CDC for collecting the information on the clinical trials. Moreover, the recent research papers were also assessed for the relevant data. The search was mainly based on keywords like Coronavirus, SARS-CoV-2, drugs (specific name of the drugs), COVID-19, clinical efficiency, safety profile, side-effects etc.This review outlines potential areas for future research into COVID-19 treatment strategies.

Nitazoxanide Exerts Immunomodulatory Effects on Peripheral Blood Mononuclear Cells from Type 2 Diabetes Patients

BACKGROUND

Type 2 diabetes (T2D) is a low-grade inflammatory condition with abnormalities in the immune response mediated by T lymphocytes and macrophages. Drug repositioning for immunomodulatory molecules is an attractive proposal for treating T2D. Nitazoxanide (NTZ) is a broad-spectrum drug with promising immunomodulatory effects. Thus, we investigated the immunomodulatory effect of NTZ on peripheral blood mononuclear cells (PBMCs) from patients with T2D.

METHODS

Fifty patients with T2D were selected, and the proliferative response of T lymphocytes and the M1/M2 ratio of macrophages post cell culture were evaluated by flow cytometry, as well as measuring the concentration of cytokines by ELISA and the relative expression of microRNAs (miRNAs) related to the immune response by real-time PCR.

RESULTS

NTZ exerts an inhibitory effect on the cell proliferation of T lymphocytes stimulated with anti-CD3 and anti-CD28 antibodies without modifying cell viability, and significant decreases in the supernatant concentrations of interleukin (IL)-1β, IL-2, IL-6, IL-10, and IL-12. Furthermore, NTZ negatively regulates the relative expression of miR-155-5p without changes in miR-146a-5p. The M1/M2 ratio of monocytes/macrophages decreased the M1 and increased the M2 subpopulation by NTZ.

CONCLUSIONS

Our results suggest that NTZ exerts immunomodulatory effects on PBMCs from T2D patients, and shows potential alternative therapeutic benefits.

Delineating a potent antiviral activity of Cuphea ignea extract loaded nano-formulation against SARS-CoV-2: In silico and in vitro studies

The outbreak of coronavirus disease-2019, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a worldwide emerging crisis. Polyphenols are a class of herbal metabolites with a broad-spectrum antiviral activity. However, most polyphenols encounter limited efficacy due to their poor solubility and degradation in neutral and basic environments. Thus, the effectiveness of their pharmaceutical application is critically dependent on the delivery systems to overcome the aforementioned drawbacks. Herein, Polyphenols-rich Cuphea ignea extract was prepared and its constituents were identified and quantified. Molecular docking was conducted for 15 compounds in the extract against SARS-CoV-2 main protease, among which rutin, myricetin-3-O-rhamnoside and rosmarinic acid depicted the most promising antiviral activity. Further, a self-nanoemulsifying formulation, composed of 10% oleic acid, 40% tween 20 and propylene glycol 50%, was prepared to improve the solubility of the extract components and enable its concurrent delivery permitting combined potency. Upon dilution with aqueous phases, the formulation rapidly Formsnanoemulsion of good stability and excellent dissolution profile in acidic pH when compared to the crude extract. It inhibited SARS-CoV-2 completely in vitro at a concentration as low as 5.87 μg/mL presenting a promising antiviral remedy for SARS-CoV-2, which may be attributed to the possible synergism between the extract components.

Drug-based therapeutic strategies for COVID-19-infected patients and their challenges

Emerging epidemic-prone diseases have introduced numerous health and economic challenges in recent years. Given current knowledge of COVID-19, herd immunity through vaccines alone is unlikely. In addition, vaccination of the global population is an ongoing challenge. Besides, the questions regarding the prevalence and the timing of immunization are still under investigation. Therefore, medical treatment remains essential in the management of COVID-19. Herein, recent advances from beginning observations of COVID-19 outbreak to an understanding of the essential factors contributing to the spread and transmission of COVID-19 and its treatment are reviewed. Furthermore, an in-depth discussion on the epidemiological aspects, clinical symptoms and most efficient medical treatment strategies to mitigate the mortality and spread rates of COVID-19 is presented.

Coronavirus Disease (COVID-19) Control between Drug Repurposing and Vaccination: A Comprehensive Overview

Respiratory viruses represent a major public health concern, as they are highly mutated, resulting in new strains emerging with high pathogenicity. Currently, the world is suffering from the newly evolving severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This virus is the cause of coronavirus disease 2019 (COVID-19), a mild-to-severe respiratory tract infection with frequent ability to give rise to fatal pneumonia in humans. The overwhelming outbreak of SARS-CoV-2 continues to unfold all over the world, urging scientists to put an end to this global pandemic through biological and pharmaceutical interventions. Currently, there is no specific treatment option that is capable of COVID-19 pandemic eradication, so several repurposed drugs and newly conditionally approved vaccines are in use and heavily applied to control the COVID-19 pandemic. The emergence of new variants of the virus that partially or totally escape from the immune response elicited by the approved vaccines requires continuous monitoring of the emerging variants to update the content of the developed vaccines or modify them totally to match the new variants. Herein, we discuss the potential therapeutic and prophylactic interventions including repurposed drugs and the newly developed/approved vaccines, highlighting the impact of virus evolution on the immune evasion of the virus from currently licensed vaccines for COVID-19.

Races of small molecule clinical trials for the treatment of COVID-19: An up-to-date comprehensive review

The coronavirus disease‐19 (COVID‐19) pandemic has become a global threat since its first outbreak at the end of 2019. Several review articles have been published recently, focusing on the aspects of target biology, drug repurposing, and mechanisms of action (MOAs) for potential treatment. This review gathers all small molecules currently in active clinical trials, categorizes them into six sub‐classes, and summarizes their clinical progress. The aim is to provide the researchers from both pharmaceutical industries and academic institutes with the handful information and dataset to accelerate their research programs in searching effective small molecule therapy for treatment of COVID‐19.

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.

Candidate antiviral drugs for COVID-19 and their environmental implications: a comprehensive analysis

Emerging from Wuhan, China, SARS-CoV-2 is the new global threat that killed millions of people, and many are still suffering. This pandemic has not only affected people but also caused economic crisis throughout the world. Researchers have shown good progress in revealing the molecular insights of SARS-CoV-2 pathogenesis and developing vaccines, but effective treatment against SARS-CoV-2-infected patients are yet to be found. Several vaccines are available and used in many countries, while many others are still in clinical or preclinical studies. However, this involves a long-term process, considering the safety procedures and requirements and their long-term protection capacity and in different age groups are still questionable. Therefore, at present, the drug repurposing of the existing therapeutics previously designed against other viral diseases seems to be the only practical approach to mitigate the current situation. The safety of most of these therapeutic agents has already been tested. Recent clinical reports revealed promising therapeutic efficiency of several drugs such as remdesivir, tenofovir disoproxil fumarate, azithromycin, lopinavir/ritonavir, chloroquine, baricitinib, and cepharanthine. Besides, plasma therapies were used to treat patients and prevent fatal outcomes. Thus, in this article, we have summarized the epidemiological and clinical data from several clinical trials conducted since the beginning of the pandemic, emphasizing the efficiency of the known agents against SARS-CoV-2 and their harmful side effects on the human body as well as their environmental implications. This review shows a clear overview of the current pharmaceutical perspective on COVID-19 treatment.

Efficacy of Ceftazidime and Cefepime in the Management of COVID-19 Patients: Single Center Report from Egypt

The purpose of this study was to explore the value of using cefepime and ceftazidime in treating patients with COVID-19. A total of 370 (162 males) patients, with RT-PCR-confirmed cases of COVID-19, were included in the study. Out of them, 260 patients were treated with cefepime or ceftazidime, with the addition of steroids to the treatment. Patients were divided into three groups: Group 1: patients treated with cefepime (124 patients); Group 2: patients treated with ceftazidime (136 patients); Group 3 (control group): patients treated according to the WHO guidelines and the Egyptian COVID-19 management protocol (110 patients)/ Each group was classified into three age groups: 18–30, 31–60, and >60 years. The dose of either cefepime or ceftazidime was 1000 mg twice daily for five days. Eight milligrams of dexamethasone were used as the steroidal drug. Careful follow-ups for the patients were carried out. In vitro and in silico M^pro enzyme assays were performed to investigate the antiviral potential of both antibiotics. The mean recovery time for Group 1 was 12 days, for Group 2 was 13 days, and for Group 3 (control) was 19 days. No deaths were recorded, and all patients were recovered without any complications. For Group 1, the recovery time was 10, 12, and 16 days for the age groups 18–30, 30–60, and >60 years, respectively. For Group 2, the recovery time was 11, 13, and 15 days for the age groups 18–30, 30–60, and >60 years, respectively. For Group 3 (control), the recovery time was 15, 16, and 17 days for the age groups 18–30, 30–60, and >60 years, respectively. Both ceftazidime and cefepime showed very good inhibitory activity towards SARS CoV-2′s M^pro, with IC₅₀ values of 1.81 µM and 8.53 µM, respectively. In conclusion, ceftazidime and cefepime are efficient for the management of moderate and severe cases of COVID-19 due to their potential anti-SARS CoV-2 activity and low side effects, and, hence, the currently used complex multidrug treatment protocol can be replaced by the simpler one proposed in this study.

Molecular Insights of SARS-CoV-2 Infection and Molecular Treatments

The coronavirus disease emerged in December 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome-related coronavirus 2 (SARS-CoV-2) and its rapid global spread has brought an international health emergency and urgent responses for seeking efficient prevention and therapeutic treatment. This has led to imperative needs for illustration of the molecular pathogenesis of SARS-CoV-2, identification of molecular targets or receptors, and development of antiviral drugs, antibodies, and vaccines. In this study, we investigated the current research progress in combating SARS-CoV-2 infection. Based on the published research findings, we first elucidated, at the molecular level, SARS-CoV-2 viral structures, potential viral host-cell-invasion and pathogenic mechanisms, main virus-induced immune responses, and emerging SARS-CoV-2 variants. We then focused on the main virus- and host-based potential targets, summarized and categorized effective inhibitory molecules based on drug development strategies for COVID-19, that can guide efforts for the identification of new drugs and treatment for this problematic disease. Current research and development of antibodies and vaccines were also introduced and discussed. We concluded that the main virus entry route- SARS-CoV-2 spike protein interaction with ACE2 receptors has played a key role in guiding the development of therapeutic treatments against COVID-19, four main therapeutic strategies may be considered in developing molecular therapeutics, and drug repurposing is likely to be an easy, fast and low-cost approach in such a short period of time with urgent need of antiviral drugs. Additionally, the quick development of antibody and vaccine candidates has yielded promising results, but the wide-scale deployment of safe and effective COVID-19 vaccines remains paramount in solving the pandemic crisis. As new variants of the virus begun to emerge, the efficacy of these vaccines and treatments must be closely evaluated. Finally, we discussed the possible challenges of developing molecular therapeutics for COVID-19 and suggested some potential future efforts. Despite the limited availability of literatures, our attempt in this work to provide a relatively comprehensive overview of current SARS-CoV-2 studies can be helpful for quickly acquiring the key information of COVID-19 and further promoting this important research to control and diminish the pandemic.

Analysing the impact of the two most common SARS-CoV-2 nucleocapsid protein variants on interactions with membrane protein in silico

As the body of scientific research focusing on the severe acute respiratory syndrome coronavirus 2 or SARS-CoV-2 continues to grow, several mutations have been reported as very common across the globe. In this study, we analysed the SARS-CoV-2 nucleocapsid protein (N protein) with respect to the widely observed 28881-28883 GGG to AAC variant. One of the major functions of the SARS-CoV-2 nucleocapsid protein is virion packaging through its interactions with the membrane protein (M protein). Our goal was to investigate, using in silico studies, the interaction between the mutant nucleocapsid protein and the M protein and how it differed from that of wild type N-M protein interaction. The results showed significant differences in interactions between the two. The mutant protein was predicted to form 3 salt bridges with the M protein, while the wild type only formed 2. The mutant protein was also predicted to display less temperature sensitivity than its wild type counterpart.

Potential drug development and therapeutic approaches for clinical intervention in COVID-19

While the vaccination is now available to many countries and will slowly dissipate to others, effective therapeutics for COVID-19 is still illusive. The SARS-CoV-2 pandemic has posed an unprecedented challenge to researchers, scientists, and clinicians and affected the wellbeing of millions of people worldwide. Since the beginning of the pandemic, a multitude of existing anti-viral, antibiotic, antimalarial, and anticancer drugs have been tested, and some have shown potency in the treatment and management of COVID-19, albeit others failed to leave any positive impact and a few also became controversial as they showed mixed clinical outcomes. In the present article, we have brought together some of the candidate therapeutic drugs being repurposed or used in the clinical trials and discussed their clinical efficacy and safety for COVID-19.

Early COVID-19 therapy with azithromycin plus nitazoxanide, ivermectin or hydroxychloroquine in outpatient settings significantly improved COVID-19 outcomes compared to known outcomes in untreated patients

In a prospective observational study (pre-AndroCoV Trial), the use of nitazoxanide, ivermectin and hydroxychloroquine demonstrated unexpected improvements in COVID-19 outcomes when compared to untreated patients. The apparent yet likely positive results raised ethical concerns on the employment of further full placebo controlled studies in early-stage COVID-19. The present analysis aimed to elucidate, through a comparative analysis with two control groups, whether full placebo-control randomized clinical trials (RCTs) on early-stage COVID-19 are still ethically acceptable. The Active group (AG) consisted of patients enrolled in the Pre-AndroCoV-Trial (n = 585). Control Group 1 (CG1) consisted of a retrospectively obtained group of untreated patients of the same population (n = 137), and Control Group 2 (CG2) resulted from a precise prediction of clinical outcomes based on a thorough and structured review of indexed articles and official statements. Patients were matched for sex, age, comorbidities and disease severity at baseline. Compared to CG1 and CG2, AG showed reduction of 31.5-36.5% in viral shedding (p < 0.0001), 70-85% in disease duration (p < 0.0001), and 100% in respiratory complications, hospitalization, mechanical ventilation, deaths and post-COVID manifestations (p < 0.0001 for all). For every 1000 confirmed cases for COVID-19, at least 70 hospitalizations, 50 mechanical ventilations and five deaths were prevented. Benefits from the combination of early COVID-19 detection and early pharmacological approaches were consistent and overwhelming when compared to untreated groups, which, together with the well-established safety profile of the drug combinations tested in the Pre-AndroCoV Trial, precluded our study from continuing employing full placebo in early COVID-19.

Telaprevir is a potential drug for repurposing against SARS-CoV-2: computational and in vitro studies

Drug repurposing is an important approach to the assignment of already approved drugs for new indications. This technique bypasses some steps in the traditional drug approval system, which saves time and lives in the case of pandemics. Direct acting antivirals (DAAs) have repeatedly repurposed from treating one virus to another. In this study, 16 FDA-approved hepatitis C virus (HCV) DAA drugs were studied to explore their activities against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) human and viral targets. Among the 16 HCV DAA drugs, telaprevir has shown the best in silico evidence to work on both indirect human targets (cathepsin L [CTSL] and human angiotensin-converting enzyme 2 [hACE2] receptor) and direct viral targets (main protease [Mpro]). Moreover, the docked poses of telaprevir inside both hACE2 and Mpro were subjected to additional molecular dynamics simulations monitored by calculating the binding free energy using MM-GBSA. In vitro analysis of telaprevir showed inhibition of SARS-CoV-2 replication in cell culture (IC50 = 11.552 μM, CC50 = 60.865 μM, and selectivity index = 5.27). Accordingly, based on the in silico studies and supported by the presented in vitro analysis, we suggest that telaprevir may be considered for therapeutic development against SARS-CoV-2.

Lipid polymer hybrid nanocarriers as a combinatory platform for different anti-SARS-CoV-2 drugs supported by computational studies

The COVID-19 pandemic caused by SARS-CoV-2 has demonstrated the potential of emergent pathogens to severely damage public health and global economies. As a consequence of the pandemic, millions of people have been forced into self-isolation, which has negatively affected the global economy. More efforts are needed to find new innovative approaches that could fundamentally change our understanding and management of this disaster. Herein, lipid polymer hybrid nanoparticles (LPH NPs) were utilized as a platform for the delivery of azithromycin or niclosamide in combination with piroxicam. The obtained systems were successfully loaded with both azithromycin and piroxicam (LPH_Azi–Pir) with entrapment efficiencies (EE%) of 74.23 ± 8.14% and 51.52 ± 5.45%, respectively, or niclosamide and piroxicam (LPH_Nic–Pir) with respective EE% of 85.14 ± 3.47% and 48.75 ± 4.77%. The prepared LPH NPs had a core–shell nanostructure with particle size ≈ 125 nm and zeta potential ≈ −16.5 irrespective of drug payload. A dose-dependent cellular uptake of both LPH NPs was observed in human lung fibroblast cells. An enhanced in vitro antiviral efficacy of both LPH_Azi–Pir and LPH_Nic–Pir was obtained over the mixed solution of the drugs. The LPH NPs of azithromycin or niclosamide with piroxicam displyed a promising capability to hinder the replication of SARS-CoV-2, with IC₅₀ of 3.16 and 1.86 μM, respectively. These results provide a rationale for further in vivo pharmacological as well as toxicological studies to evaluate the potential activity of these drugs to combat the COVID-19 outbreak, especially the concept of combination therapy. Additionally, the molecular docking of macrolide bioactive compounds against papain-like protease (PDB ID:6wuu) was achieved. A ligand-based study, especially rapid overlay chemical structure (ROCS), was also examined to identify the general pharmacophoric features of these compounds and their similarity to reported anti-SARS-CoV-2 drugs. Molecular dynamic simulation was also implemented.

Drug repurposing approach to combat SARS-CoV-2: lipid polymer hybrid nanoparticles (LPH) for the delivery of azithromycin or niclosamide in combination with piroxicam.

A comparative analysis of parechovirus protein structures with other picornaviruses

Parechoviruses belong to the genus Parechovirus within the family Picornaviridae and are non-enveloped icosahedral viruses with a single-stranded RNA genome. Parechoviruses include human and animal pathogens classified into six species. Those that infect humans belong to the Parechovirus A species and can cause infections ranging from mild gastrointestinal or respiratory illness to severe neonatal sepsis. There are no approved antivirals available to treat parechovirus (nor any other picornavirus) infections. In this parechovirus review, we focus on the cleaved protein products resulting from the polyprotein processing after translation comparing and contrasting their known or predicted structures and functions to those of other picornaviruses. The review also includes our original analysis from sequence and structure prediction. This review highlights significant structural differences between parechoviral and other picornaviral proteins, suggesting that parechovirus drug development should specifically be directed to parechoviral targets.

Early use of nitazoxanide in mild COVID-19 disease: randomised, placebo-controlled trial

Background

Nitazoxanide is widely available and exerts broad-spectrum antiviral activity in vitro. However, there is no evidence of its impact on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

Methods

In a multicentre, randomised, double-blind, placebo-controlled trial, adult patients presenting up to 3 days after onset of coronavirus disease 2019 (COVID-19) symptoms (dry cough, fever and/or fatigue) were enrolled. After confirmation of SARS-CoV-2 infection using reverse transcriptase PCR on a nasopharyngeal swab, patients were randomised 1:1 to receive either nitazoxanide (500 mg) or placebo, three times daily, for 5 days. The primary outcome was complete resolution of symptoms. Secondary outcomes were viral load, laboratory tests, serum biomarkers of inflammation and hospitalisation rate. Adverse events were also assessed.

Results

From June 8 to August 20, 2020, 1575 patients were screened. Of these, 392 (198 placebo, 194 nitazoxanide) were analysed. Median (interquartile range) time from symptom onset to first dose of study drug was 5 (4–5) days. At the 5-day study visit, symptom resolution did not differ between the nitazoxanide and placebo arms. Swabs collected were negative for SARS-CoV-2 in 29.9% of patients in the nitazoxanide arm versus 18.2% in the placebo arm (p=0.009). Viral load was reduced after nitazoxanide compared to placebo (p=0.006). The percentage viral load reduction from onset to end of therapy was higher with nitazoxanide (55%) than placebo (45%) (p=0.013). Other secondary outcomes were not significantly different. No serious adverse events were observed.

Conclusions

In patients with mild COVID-19, symptom resolution did not differ between nitazoxanide and placebo groups after 5 days of therapy. However, early nitazoxanide therapy was safe and reduced viral load significantly.

This was the first study to evaluate the effect of early nitazoxanide therapy in mild COVID-19. Nitazoxanide did not accelerate symptom resolution after 5 days of therapy, but did reduce viral load significantly with no serious adverse events.https://bit.ly/37i75pr

Quantitation of tizoxanide in multiple matrices to support cell culture, animal and human research

Currently nitazoxanide is being assessed as a candidate therapeutic for SARS-CoV-2. Unlike many other candidates being investigated, tizoxanide (the active metabolite of nitazoxanide) plasma concentrations achieve antiviral levels after administration of the approved dose, although higher doses are expected to be needed to maintain these concentrations across the dosing interval in the majority of patients. Here an LC-MS/MS assay is described that has been validated in accordance with Food and Drug Administration (FDA) guidelines. Fundamental parameters have been evaluated, and these included accuracy, precision and sensitivity. The assay was validated for human plasma, mouse plasma and Dulbeccos Modified Eagles Medium (DMEM) containing varying concentrations of Foetal Bovine Serum (FBS). Matrix effects are a well-documented source of concern for chromatographic analysis, with the potential to impact various stages of the analytical process, including suppression or enhancement of ionisation. Therefore, a robustly validated LC-MS/MS analytical method is presented capable of quantifying tizoxanide in multiple matrices with minimal impact of matrix effects. The validated assay presented here was linear from 15.6ng/mL to 1000ng/mL. Accuracy and precision ranged between 102.2% and 113.5%, 100.1% and 105.4%, respectively. The presented assay here has applications in both pre-clinical and clinical research and may be used to facilitate further investigations into the application of nitazoxanide against SARS-CoV-2.

Strong Inhibitory Activity and Action Modes of Synthetic Maslinic Acid Derivative on Highly Pathogenic Coronaviruses: COVID-19 Drug Candidate

In late December 2019, a novel coronavirus, namely severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), escaped the animal-human interface and emerged as an ongoing global pandemic with severe flu-like illness, commonly known as coronavirus disease 2019 (COVID-19). In this study, a molecular docking study was carried out for seventeen (17) structural analogues prepared from natural maslinic and oleanolic acids, screened against SARS-CoV-2 main protease. Furthermore, we experimentally validated the virtual data by measuring the half-maximal cytotoxic and inhibitory concentrations of each compound. Interestingly, the chlorinated isoxazole linked maslinic acid (compound 17) showed promising antiviral activity at micromolar non-toxic concentrations. Thoughtfully, we showed that compound 17 mainly impairs the viral replication of SARS-CoV-2. Furthermore, a very promising SAR study for the examined compounds was concluded, which could be used by medicinal chemists in the near future for the design and synthesis of potential anti-SARS-CoV-2 candidates. Our results could be very promising for performing further additional in vitro and in vivo studies on the tested compound (17) before further licensing for COVID-19 treatment.

Chemotherapy vs. Immunotherapy in combating nCOVID19: An update

The nCOVID-19 pandemic initiated its course of contagion from the city of Wuhan and now it has spread all over the globe. SARS-CoV-2 is the causative virus and the infection as well as its symptoms are distributed across the multi-organ perimeters. Interactions between the host and virus governs the induction of ‘cytokine storm’ resulting various immunopathological consequences leading to death. Till now it has caused tens of millions of casualties and yet no credible cure has emerged to vision. This article presents a comprehensive overview on the two most promising remedial approaches that are being attempted for the management, treatment, and plausible cure of nCOVID-19. In this context, chemotherapeutic approach primarily aims to interrupt the interactions between the host and the virus causing inhibition of its entry into the host cell and/or its proliferation and suppressing the inflammatory milieu in the infected patients. On the other side, immunotherapeutic approaches aim to modulate the host immunity by fine tuning the inflammatory signaling cascades to achieve phylaxis from the virus and restoring immune-homeostasis. Considering most of the path-breaking findings, combinatorial therapy involving of chemotherapeutics as well as vaccine could usher to be a hope for all of us to eradicate the crisis

Evolution of COVID-19 Pregnancies Treated With Nitazoxanide in a Third-Level Hospital

Background

Nitazoxanide shows adequate in vitro activity against coronavirus. The aim of this study was to describe the behavior of coronavirus disease 2019 (COVID-19) in pregnant women treated with nitazoxanide.

Methodology

This cross-sectional study included the files of COVID-19 positive pregnant women treated with nitazoxanide 500 mg every 6 hours, levofloxacin every 12 hours, and clarithromycin 500 mg every 12 hours.

Results

The data of 51 women (mean age: 27.4 ± 7.2 years) were analyzed. Eleven (21.56%) patients had to receive medical attention in the intensive care unit. There were 22 (43.13%) preterm deliveries, 21 by cesarean and one by vaginal delivery. The medical attention of this population was as follows: 31 cesareans, five vaginal deliveries, nine still pregnant, two requiring manual vacuum aspiration, two ectopic pregnancies, one requiring curettage, and one requiring hysterotomy. There were seven (13.72%) cases of preeclampsia, and there were two (3.92%) deaths.

Conclusion

Nitazoxanide prescription could be an option against COVID-19 in pregnancy due to its safety profile.

Human respiratory viral infections: Current status and future prospects of nanotechnology-based approaches for prophylaxis and treatment

Respiratory viral infections are major cause of highly mortal pandemics. They are impacting socioeconomic development and healthcare system globally. These emerging deadly respiratory viruses develop newer survival strategies to live inside host cells and tricking the immune system of host. Currently, medical facilities, therapies and research -development teams of every country kneel down before novel corona virus (SARS-CoV-2) which claimed ~2,828,629 lives till date. Thus, there is urgent requirement of novel treatment strategies to combat against these emerging respiratory viral infections. Nanocarriers come under the umbrella of nanotechnology and offer numerous benefits compared to traditional dosage forms. Further, unique physicochemical properties (size, shape and surface charge) of nanocarriers provide additional advantage for targeted delivery. This review discusses in detail about the respiratory viruses, their transmission mode and cell invasion pathways, survival strategies, available therapies, and nanocarriers for the delivery of therapeutics. Further, the role of nanocarriers in the development of treatment therapy against SARS-CoV-2 is also overviewed.

DrugRepV: a compendium of repurposed drugs and chemicals targeting epidemic and pandemic viruses

Viruses are responsible for causing various epidemics and pandemics with a high mortality rate e.g. ongoing SARS-CoronaVirus-2 crisis. The discovery of novel antivirals remains a challenge but drug repurposing is emerging as a potential solution to develop antivirals in a cost-effective manner. In this regard, we collated the information of repurposed drugs tested for antiviral activity from literature and presented it in the form of a user-friendly web server named ‘DrugRepV’. The database contains 8485 entries (3448 unique) with biological, chemical, clinical and structural information of 23 viruses responsible to cause epidemics/pandemics. The database harbors browse and search options to explore the repurposed drug entries. The data can be explored by some important fields like drugs, viruses, drug targets, clinical trials, assays, etc. For summarizing the data, we provide overall statistics of the repurposed candidates. To make the database more informative, it is hyperlinked to various external repositories like DrugBank, PubChem, NCBI-Taxonomy, Clinicaltrials.gov, World Health Organization and many more. ‘DrugRepV’ database (https://bioinfo.imtech.res.in/manojk/drugrepv/) would be highly useful to the research community working to develop antivirals.

Effect of a combination of nitazoxanide, ribavirin, and ivermectin plus zinc supplement (MANS.NRIZ study) on the clearance of mild COVID-19

This trial compared the rate and time of viral clearance in subjects receiving a combination of nitazoxanide, ribavirin, and ivermectin plus Zinc versus those receiving supportive treatment. This non-randomized controlled trial included 62 patients on the triple combination treatment versus 51 age- and sex-matched patients on routine supportive treatment. all of them confirmed cases by positive reverse-transcription polymerase chain reaction of a nasopharyngeal swab. Trial results showed that the clearance rates were 0% and 58.1% on the 7th day and 13.7% and 73.1% on the 15th day in the supportive treatment and combined antiviral groups, respectively. The cumulative clearance rates on the 15th day are 13.7% and 88.7% in the supportive treatment and combined antiviral groups, respectively. This trial concluded by stating that the combined use of nitazoxanide, ribavirin, and ivermectin plus zinc supplement effectively cleared the SARS-COV2 from the nasopharynx in a shorter time than symptomatic therapy.

Human Astroviruses: A Tale of Two Strains

Since the 1970s, eight closely related serotypes of classical human astroviruses (HAstV) have been associated with gastrointestinal illness worldwide. In the late 2000s, three genetically unique human astrovirus clades, VA1-VA3, VA2-VA4, and MLB, were described. While the exact disease associated with these clades remains to be defined, VA1 has been associated with central nervous system infections. The discovery that VA1 could be grown in cell culture, supports exciting new studies aimed at understanding viral pathogenesis. Given the association of VA1 with often lethal CNS infections, we tested its susceptibility to the antimicrobial drug, nitazoxanide (NTZ), which we showed could inhibit classical HAstV infections. Our studies demonstrate that NTZ inhibited VA1 replication in Caco2 cells even when added at 12 h post-infection, which is later than in HAstV-1 infection. These data led us to further probe VA1 replication kinetics and cellular responses to infection in Caco-2 cells in comparison to the well-studied HAstV-1 strain. Overall, our studies highlight that VA1 replicates more slowly than HAstV-1 and elicits significantly different cellular responses, including the inability to disrupt cellular junctions and barrier permeability.

A review of potential suggested drugs for coronavirus disease (COVID-19) treatment

The latest pandemic, coronavirus disease-2019 (COVID-19), is associated with high prevalence and easy transmission, which is expanding globally with no conventional treatment or vaccine. The new virus revealed 79% and 50% genomic similarities with severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), respectively. Accordingly, since the disease resists testing and adopting new therapeutics, repositioning pre-existing drugs may present a fast and attractive strategy with known safety, characteristics, and dosage used. However, they are not specific and targeted. Therefore, several drugs have been investigated for their efficacy and safety in the treatment of COVID-19; most of them are undergoing clinical trials. This article summarizes clinical investigations of potential therapeutic drugs used as COVID-19 therapy. Subsequently, it prepares a pattern of results and therapeutic targets to help further experiment designs. We have investigated drugs as classified in the following three groups; 1) The drugs which computationally showed effectiveness (in silico) but needed further lab confirmations; 2) Emetine, Teicoplanin, and Nelfinavir have shown effectiveness in vitro; 3) The drugs currently under clinical trial.

A review on possible mechanistic insights of Nitazoxanide for repurposing in COVID-19

The global pandemic of Coronavirus Disease 2019 (COVID-19) has brought the world to a grinding halt. A major cause of concern is the respiratory distress associated mortality attributed to the cytokine storm. Despite myriad rapidly approved clinical trials with repurposed drugs, and time needed to develop a vaccine, accelerated search for repurposed therapeutics is still ongoing. In this review, we present Nitazoxanide a US-FDA approved antiprotozoal drug, as one such promising candidate. Nitazoxanide which is reported to exert broad-spectrum antiviral activity against various viral infections, revealed good in vitro activity against SARS-CoV-2 in cell culture assays, suggesting potential for repurposing in COVID-19. Furthermore, nitazoxanide displays the potential to boost host innate immune responses and thereby tackle the life-threatening cytokine storm. Possibilities of improving lung, as well as multiple organ damage and providing value addition to COVID-19 patients with comorbidities, are other important facets of the drug. The review juxtaposes the role of nitazoxanide in fighting COVID-19 pathogenesis at multiple levels highlighting the great promise the drug exhibits. The in silico data and in vitro efficacy in cell lines confirms the promise of nitazoxanide. Several approved clinical trials world over further substantiate leveraging nitazoxanide for COVID-19 therapy.