Hydroxychloroquine in COVID-19: Potential Mechanism of Action Against SARS-CoV-2

Adverse drug reactions associated with COVID-19 management

The emergence of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) outbreak, which causes COVID-19, had a devastating impact on both people's lives and the global economy. During the course of the pandemic, the lack of specific drugs or treatments tailored for COVID-19 led to extensive repurposing of existing drugs in the pursuit of effective treatments. Some drug molecules demonstrated efficacy, while others proved ineffective. In this context, the approach of drug repurposing emerged as a novel strategy for combating COVID-19. Repurposed drugs and biologics have shown effectiveness, leading to improved clinical outcomes among patients with COVID-19. Similarly, It is equally important to assess the risk-benefit ratio associated with drugs and biologics adapted for COVID-19 treatment. Herein, we primarily focus on evaluating adverse drug events linked to repurposed COVID-19 medications, repurposed biologics, and COVID-specific drug molecules.

Deaths induced by compassionate use of hydroxychloroquine during the first COVID-19 wave: an estimate

BACKGROUND

During the first wave of COVID-19, hydroxychloroquine (HCQ) was used off-label despite the absence of evidence documenting its clinical benefits. Since then, a meta-analysis of randomised trials showed that HCQ use was associated with an 11% increase in the mortality rate. We aimed to estimate the number of HCQ-related deaths worldwide.

METHODS AND FINDINGS

We estimated the worldwide in-hospital mortality attributable to HCQ use by combining the mortality rate, HCQ exposure, number of hospitalised patients, and the increased relative risk of death with HCQ. The mortality rate in hospitalised patients for each country was calculated using pooled prevalence estimated by a meta-analysis of published cohorts. The HCQ exposure was estimated using median and extreme estimates from the same systematic review. The number of hospitalised patients during the first wave was extracted from dedicated databases. The systematic review included 44 cohort studies (Belgium: k = 1, France: k = 2, Italy: k = 12, Spain: k = 6, Turkey: k = 3, USA: k = 20). HCQ prescription rates varied greatly from one country to another (range 16-84%). Overall, using median estimates of HCQ use in each country, we estimated that 16,990 HCQ-related in-hospital deaths (range 6267-19256) occurred in the countries with available data. The median number of HCQ-related deaths in Belgium, Turkey, France, Italy, Spain, and the USA was 240 (range not estimable), 95 (range 92-128), 199 (range not estimable), 1822 (range 1170-2063), 1895 (range 1475-2094) and 12739 (3244- 15570), respectively.

CONCLUSIONS

Although our estimates are limited by their imprecision, these findings illustrate the hazard of drug repurposing with low-level evidence.

After the Hurricane: Anti-COVID-19 Drugs Development, Molecular Mechanisms of Action and Future Perspectives

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is a new coronavirus in the Coronaviridae family. The COVID-19 pandemic, caused by SARS-CoV-2, has undoubtedly been the largest crisis of the twenty-first century, resulting in over 6.8 million deaths and 686 million confirmed cases, creating a global public health issue. Hundreds of notable articles have been published since the onset of this pandemic to justify the cause of viral spread, viable preventive measures, and future therapeutic approaches. As a result, this review was developed to provide a summary of the current anti-COVID-19 drugs, as well as their timeline, molecular mode of action, and efficacy. It also sheds light on potential future treatment options. Several medications, notably hydroxychloroquine and lopinavir/ritonavir, were initially claimed to be effective in the treatment of SARS-CoV-2 but eventually demonstrated inadequate activity, and the Food and Drug Administration (FDA) withdrew hydroxychloroquine. Clinical trials and investigations, on the other hand, have demonstrated the efficacy of remdesivir, convalescent plasma, and monoclonal antibodies, 6-Thioguanine, hepatitis C protease inhibitors, and molnupiravir. Other therapeutics, including inhaled medicines, flavonoids, and aptamers, could pave the way for the creation of novel anti-COVID-19 therapies. As future pandemics are unavoidable, this article urges immediate action and extensive research efforts to develop potent specialized anti-COVID-19 medications.

A validated eco-friendly HPLC-FLD for analysis of the first approved antiviral remdesivir with other potential add-on therapies for COVID-19 in human plasma and pharmaceuticals

It is crucial to have a reliable and sensitive method for separating common drugs used in SARS-CoV-2 pneumonia treatment protocols for ongoing treatment and upcoming investigations. This study presents an HPLC-FLD approach to analyze three co-administered medicines - remdesivir (RDV), hydroxychloroquine sulphate (HCQ), and levofloxacin hemihydrate (LVX) - in their pure forms, pharmaceutical preparations, and spiked human plasma. The HPLC-FLD analysis was conducted using a Symmetry® C18 column (100 mm × 4.6 mm ID, 3.5 μm particle size) at 40 °C, with (A) an aqueous mixture of 0.02 M phosphate buffer and 0.2% heptane-1-sulphonic acid sodium solutions (50 : 50) adjusted to pH 3, (B) acetonitrile, and (C) methanol as the mobile phase. The injection volume was 10 μL, and the flow rate was 1.5 mL min-1. The detection was done using a multi-wavelength excitation and emission fluorescence detector, with individual optimization for each drug. The drug separation time was less than 10 minutes, and the method showed sensitive and wide linearity ranges for all medicines, with r2 values of more than 0.999. The impact of the mobile phase pH and flow rate on suitability parameters (retention time and number of theoretical plates) was studied. The method was found to be environmentally friendly based on GAPI and AGREE metrics. The validity of the method was evaluated following ICH and FDA guidelines.

Clinical Characteristics, Diagnosis, and Therapeutics of COVID-19: A Review

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that suddenly emerged at the end of December 2019 and caused coronavirus disease 2019 (COVID-19) continues to afflict humanity, not only seriously affecting healthcare systems but also leading to global social and economic imbalances. As of August 2022, there were approximately 580 million confirmed cases of COVID-19 and approximately 6.4 million confirmed deaths due to this disease. The data are sufficient to highlight the seriousness of SARS-CoV-2 infection. Although most patients with COVID-19 present primarily with respiratory symptoms, an increasing number of extrapulmonary systemic symptoms and manifestations have been associated with COVID-19. Since the outbreak of COVID-19, much has been learned about the disease and its causative agent. Therefore, great effort has been aimed at developing treatments and drug interventions to treat and reduce the incidence of COVID-19. In this narrative review, we provide a brief overview of the epidemiology, mechanisms, clinical manifestations, diagnosis, and therapeutics of COVID-19.

Real-Life Data on Hydroxychloroquine or Chloroquine with or Without Azithromycin in COVID-19 Patients: A Retrospective Analysis in Brazil

BACKGROUND

Despite no evidence showing benefits of hydroxychloroquine and chloroquine with or without azithromycin for COVID-19 treatment, these medications have been largely prescribed in Brazil.

OBJECTIVES

To assess outcomes, including in-hospital mortality, electrocardiographic abnormalities, hospital length-of-stay, admission to the intensive care unit, and need for dialysis and mechanical ventilation, in hospitalized COVID-19 patients who received chloroquine or hydroxychloroquine, and to compare outcomes between those patients and their matched controls.

METHODS

A retrospective multicenter cohort study that included consecutive laboratory-confirmed COVID-19 patients from 37 Brazilian hospitals from March to September 2020. Propensity score was used to select matching controls by age, sex, cardiovascular comorbidities, and in-hospital use of corticosteroid. A p-value <0.05 was considered statistically significant.

RESULTS

From 7,850 COVID-19 patients, 673 (8.6%) received hydroxychloroquine and 67 (0.9%) chloroquine. The median age in the study group was 60 years (46 - 71) and 59.1% were women. During hospitalization, 3.2% of patients presented side effects and 2.2% required therapy discontinuation. Electrocardiographic abnormalities were more prevalent in the chloroquine/hydroxychloroquine group (13.2% vs. 8.2%, p=0.01), and the long corrected QT interval was the main difference (3.6% vs. 0.4%, p<0.001). The median hospital length of stay was longer in the HCQ/CQ + AZT group than in controls (9.0 [5.0, 18.0] vs. 8.0 [4.0, 14.0] days). There was no statistical differences between groups in intensive care unit admission (35.1% vs. 32.0%; p=0.282), invasive mechanical ventilation support (27.0% vs. 22.3%; p=0.074) or mortality (18.9% vs. 18.0%; p=0.682).

CONCLUSION

COVID-19 patients treated with chloroquine or hydroxychloroquine had a longer hospital length of stay, when compared to matched controls. Intensive care unit admission, invasive mechanical ventilation, dialysis and in-hospital mortality were similar.

COVID-19: An Overview of SARS-CoV-2 Variants-The Current Vaccines and Drug Development

The world is presently in crisis facing an outbreak of a health-threatening microorganism known as COVID-19, responsible for causing uncommon viral pneumonia in humans. The virus was first reported in Wuhan, China, in early December 2019, and it quickly became a global concern due to the pandemic. Challenges in this regard have been compounded by the emergence of several variants such as B.1.1.7, B.1.351, P1, and B.1.617, which show an increase in transmission power and resistance to therapies and vaccines. Ongoing researches are focused on developing and manufacturing standard treatment strategies and effective vaccines to control the pandemic. Despite developing several vaccines such as Pfizer/BioNTech and Moderna approved by the U.S. Food and Drug Administration (FDA) and other vaccines in phase 4 clinical trials, preventive measures are mandatory to control the COVID-19 pandemic. In this review, based on the latest findings, we will discuss different types of drugs as therapeutic options and confirmed or developing vaccine candidates against SARS-CoV-2. We also discuss in detail the challenges posed by the variants and their effect on therapeutic and preventive interventions.

<em>In silico</em> screening of potential compounds from begonia genus as 3CL protease (3Cl pro) SARS-CoV-2 inhibitors

Background: The emergence of Coronavirus disease (COVID-19) has been declared a pandemic and made a medical emergency worldwide. Various attempts have been made, including optimizing effective treatments against the disease or developing a vaccine. Since the SARS-CoV-2 protease crystal structure has been discovered, searching for its inhibitors by in silico technique becomes possible. Objective: This study aims to virtually screen the potential of phytoconstituents from the Begonia genus as 3Cl pro-SARS-CoV- 2 inhibitors, based on its crucial role in viral replication, hence making these proteases “promising” for the anti-SARS-CoV-2 target. Methods: In silico screening was carried out by molecular docking on the web-based program DockThor and validated by a retrospective method. Predictive binding affinity (Dock Score) was used for scoring the compounds. Further molecular dynamics on Desmond was performed to assess the complex stability. Results: Virtual screening protocol was valid with the area under curve value 0.913. Molecular docking revealed only β-sitosterol-3-O-β-D-glucopyranoside with a lower docking score of - 9.712 kcal/mol than positive control of indinavir. The molecular dynamic study showed that the compound was stable for the first 30 ns simulations time with Root Mean Square Deviation <3 Å, despite minor fluctuations observed at the end of simulation times. Root Mean Square Fluctuation of catalytic sites HIS41 and CYS145 was 0.756 Å and 0.773 Å, respectively. Conclusions: This result suggests that β-sitosterol-3-O-β-D- glucopyranoside might be a prospective metabolite compound that can be developed as anti-SARS-CoV-2.

Metal-Free Synthesis of Functionalized Quinolines from 2-Styrylanilines and 2-Methylbenzothiazoles/2-Methylquinolines

A facile functionalization of C(sp³)-H bonds and tandem cyclization strategy to synthesize quinoline derivatives from 2-methylbenzothiazoles or 2-methylquinolines and 2-styrylanilines has been developed. This work avoids the requirement for transition metals, offering a mild approach to activation of C(sp³)-H bonds and formation of new C-C and C-N bonds. This strategy features excellent functional group tolerance and scaled-up synthetic capability, thus providing an efficient and environmentally friendly access to medicinally valuable quinolines.

Metabolic Activation of PARP as a SARS-CoV-2 Therapeutic Target-Is It a Bait for the Virus or the Best Deal We Could Ever Make with the Virus? Is AMBICA the Potential Cure?

The COVID-19 pandemic has had a great impact on global health and is an economic burden. Even with vaccines and anti-viral medications we are still scrambling to get a balance. In this perspective, we have shed light upon an extremely feasible approach by which we can control the SARS-CoV-2 infection and the associated complications, bringing some solace to this ongoing turmoil. We are providing some insights regarding an ideal agent which could prevent SARS-CoV-2 multiplication. If we could identify an agent which is an activator of metabolism and is also bioactive, we could prevent corona activation (AMBICA). Some naturally occurring lipid molecules best fit this identity as an agent which has the capacity to replenish our host cells, specifically immune cells, with ATP. It could also act as a source for providing a substrate for host cell PARP family members for MARylation and PARylation processes, leading to manipulation of the viral macro domain function, resulting in curbing the virulence and propagation of SARS-CoV-2. Identification of the right lipid molecule or combination of lipid molecules will fulfill the criteria. This perspective has focused on a unique angle of host-pathogen interaction and will open up a new dimension in treating COVID-19 infection.

COVID-19 and its treatments: lights and shadows on testicular function

PURPOSE

The SARS-CoV-2 pandemic has rapidly spread worldwide and, among the others, the male gender was quickly recognized as an independent risk factor for both the disease and its consequences. Since the possibility of long-term hormonal axis changes and male gamete impairment have been hypothesized but a relatively low levels of evidence has been reached, we focused this narrative mini-review on summarizing key state-of-the-art knowledge on male reproductive effects of COVID-19 as a quick reference for reproductive health specialists.

METHODS

A comprehensive Medline/PubMed and Embase search was performed selecting all relevant, peer-reviewed papers in English published from 2020. Other relevant papers were selected from the reference lists.

RESULTS

Available evidence indicates that the likelihood of direct testicular damage from SARS-CoV-2 is somewhat low, but there are many indirect ways (fever, cytokine imbalance, and drugs) through which the pituitary-gonadal axis and spermatogenesis may be disrupted. These alterations are probably transient, but as available evidence is low quality, it cannot be excluded that previous pathologies or comorbidities might modulate the risk of their persistence. On the other hand, available evidence shows high safety regarding andrological health for available vaccines, although studies are mainly focused on mRNA vaccines.

CONCLUSION

A careful andrological evaluation of men recovering from COVID-19 is highly recommended. Since available evidence is relatively scarce, a careful andrological follow-up and counseling of these patients are mandatory.

A Clinical Insight on New Discovered Molecules and Repurposed Drugs for the Treatment of COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) began churning out incredulous terror in December 2019. Within several months from its first detection in Wuhan, SARS-CoV-2 spread to the rest of the world through droplet infection, making it a pandemic situation and a healthcare emergency across the globe. The available treatment of COVID-19 was only symptomatic as the disease was new and no approved drug or vaccine was available. Another challenge with COVID-19 was the continuous mutation of the SARS-CoV-2 virus. Some repurposed drugs, such as hydroxychloroquine, chloroquine, and remdesivir, received emergency use authorization in various countries, but their clinical use is compromised with either severe and fatal adverse effects or nonavailability of sufficient clinical data. Molnupiravir was the first molecule approved for the treatment of COVID-19, followed by Paxlovid™, monoclonal antibodies (MAbs), and others. New molecules have variable therapeutic efficacy against different variants or strains of SARS-CoV-2, which require further investigations. The aim of this review is to provide in-depth information on new molecules and repurposed drugs with emphasis on their general description, mechanism of action (MOA), correlates of protection, dose and dosage form, route of administration, clinical trials, regulatory approval, and marketing authorizations.

COVID-19: Diabetes Perspective-Pathophysiology and Management

Recent evidence relating to the impact of COVID-19 on people with diabetes is limited but continues to emerge. COVID-19 pneumonia is a newly identified illness spreading rapidly throughout the world and causes many disabilities and fatal deaths. Over the ensuing 2 years, the indirect effects of the pandemic on healthcare delivery have become prominent, along with the lingering effects of the virus on those directly infected. Diabetes is a commonly identified risk factor that contributes not only to the severity and mortality of COVID-19 patients, but also to the associated complications, including acute respiratory distress syndrome (ARDS) and multi-organ failure. Diabetic patients are highly affected due to increased viral entry into the cells and decreased immunity. Several hypotheses to explain the increased incidence and severity of COVID-19 infection in people with diabetes have been proposed and explained in detail recently. On the other hand, 20-50% of COVID-19 patients reported new-onset hyperglycemia without diabetes and new-onset diabetes, suggesting the two-way interactions between COVID-19 and diabetes. A systematic review is required to confirm diabetes as a complication in those patients diagnosed with COVID-19. Diabetes and diabetes-related complications in COVID-19 patients are primarily due to the acute illness caused during the SARS-CoV-2 infection followed by the release of glucocorticoids, catecholamines, and pro-inflammatory cytokines, which have been shown to drive hyperglycemia positively. This review provides brief insights into the potential mechanisms linking COVID-19 and diabetes, and presents clinical management recommendations for better handling of the disease.

Electrochemical sensor based on a ZnO-doped graphitized carbon for the electrocatalytic detection of the antibiotic hydroxychloroquine. Application: tap water and human urine

Abstract

In December 2019, the world experienced a new coronavirus, SARS-CoV-2, causing coronavirus disease 2019 originating from Wuhan.The virus has crossed national borders and now affects more than 200 countries and territories. Hydroxychloroquine has been considered as a drug capable of treating COVID-19. The objective of this work is to establish a simple platform for electrocatalytic detection of hydroxychloroquine in human urine samples and pharmaceutical samples (tablets) using a ZnO@CPE sensor constructed by simple and inexpensive hydrothermal methods using a square wave voltammetry method. The best results are obtained in a PBS electrolyte with irreversible behavior of the hydroxychloroquine complement and controlled by diffusion coupled with absorption phenomena. The ZnO@CPE shifts the oxidation potential of hydroxychloroquine with the formation of a single very intense peak at the position of Epa = 0.5 V/(vs Ag/AgCl) with a shift is ΔEp = 0.1 V(vs Ag/AgCl) compared to the unmodified electrode. The obtained ZnO@CPE hybrid nanocomposite was characterized by different techniques and showed excellent electrocatalytic activity and higher active surface area compared to the bare carbon paste electrode. Under the optimized experimental conditions, the ZnO@CPE sensor showed good analytical performance for the determination of trace amounts of hydroxychloroquine, a wide linearity range from 10^-3 M to 0.8 × 10^-6 M with a very low detection limit in the range of 1.33 × 10^-7 M, satisfactory selectivity, acceptable repeatability and reproducibility. The calculated recovery and coefficient of variation for the two samples analyzed are very satisfactory, ranging from 97.6 to 102% and 1.2 to 2.3% respectively. The proposed applied method and the fabricated sensor offer the possibility to analyze traces of hydroxychloroquine in real human urine and water samples.

Graphical abstract

Strategy for the electro-oxidation reaction of hydroxychloroquine on the electro-catalytic surface of the ZnO@Carbon graphite electrode and real-time detection of hydroxychloroquine.

Molecular docking-based virtual screening: Challenges in hits identification for Anti-SARS-Cov-2 activity

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) requires finding new drugs or repurposing drugs for clinical use. Molecular docking belongs to structure-based drug design providing a fast method for identifying the hit compounds with antiviral activity against SARS-Cov-2. However, the weakness of the docking method is compounded by the limited crystallographic information and comparison drugs due to the novelty of this virus can present challenges in identifying hits of anti-SARS-Cov-2. In the current review, we highlighted several aspects, especially those related to the target structure, docking validation, and virtual hit selection, that need to be considered to obtain reliable docking results. Here, we discussed several cases pertaining to the issue highlighted and approaches that could be used to solve them.

Additively manufactured electrodes for the electrochemical detection of hydroxychloroquine

Although studies have demonstrated the inactivity of hydroxychloroquine (HCQ) towards SARS-CoV-2, this compound was one of the most prescribed by medical organizations for the treatment of hospitalized patients during the coronavirus pandemic. As a result of it, HCQ has been considered as a potential emerging contaminant in aquatic environments. In this context, we propose a complete electrochemical device comprising cell and working electrode fabricated by the additive manufacture (3D-printing) technology for HCQ monitoring. For this, a 3D-printed working electrode made of a conductive PLA containing carbon black assembled in a 3D-printed cell was associated with square wave voltammetry (SWV) for the fast and sensitive determination of HCQ. After a simple surface activation procedure, the proposed 3D-printed sensor showed a linear response towards HCQ detection (0.4-7.5 μmol L^-1) with a limit of detection of 0.04 μmol L^-1 and precision of 2.4% (n = 10). The applicability of this device was shown to the analysis of pharmaceutical and water samples. Recovery values between 99 and 112% were achieved for tap water samples and, in addition, the obtained concentration values for pharmaceutical tablets agreed with the values obtained by spectrophotometry (UV region) at a 95% confidence level. The proposed device combined with portable instrumentation is promising for on-site HCQ detection.

A review of the effects of ATP and hydroxychloroquine on the phase separation of the SARS-CoV-2 nucleocapsid protein

SARS-CoV-2 is the coronavirus causing the ongoing pandemic with > 460 millions of infections and > 6 millions of deaths. SARS-CoV-2 nucleocapsid (N) is the only structural protein which plays essential roles in almost all key steps of the viral life cycle with its diverse functions depending on liquid–liquid phase separation (LLPS) driven by interacting with various nucleic acids. The 419-residue N protein is highly conserved in all variants including delta and omicron, and composed of both folded N-/C-terminal domains (NTD/CTD) as well as three long intrinsically disordered regions (IDRs). Recent results have suggested that its CTD and IDRs are also cryptic nucleic acid–binding domains. In this context, any small molecules capable of interfering in its interaction with nucleic acids are anticipated to modulate its LLPS and associated functions. Indeed, ATP, the energy currency existing at very high concentrations (2–12 mM) in all living cells but absent in viruses, modulates LLPS of N protein, and consequently appears to be evolutionarily hijacked by SARS-CoV-2 to promote its life cycle. Hydroxychloroquine (HCQ) has been also shown to specifically bind NTD and CTD to inhibit their interactions with nucleic acids, as well as to disrupt LLPS. Particularly, the unique structure of the HCQ-CTD complex offers a promising strategy for further design of anti-SARS-CoV-2 drugs with better affinity and specificity. The finding may indicate that LLPS is indeed druggable by small molecules, thus opening up a promising direction for drug discovery/design by targeting LLPS in general.

A Capillary Electrophoresis-Based Method for the Measurement of Hydroxychloroquine and Its Active Metabolite Desethyl Hydroxychloroquine in Whole Blood in Patients with Rheumatoid Arthritis

A capillary electrophoresis method was developed to detect and measure hydroxychloroquine (HCQ) and its active metabolite desethyl hydroxychloroquine (DHCQ) in whole blood in patients with rheumatoid arthritis. The best separation in terms of peak area reproducibility, migration time, peak shape, and resolution of adjacent peaks was obtained in a 60 cm, 75 µm i.d. uncoated fused-silica capillary using a background electrolyte mixture of an aqueous 55 mmol/L TRIS solution brought to pH 2.6 with phosphoric acid and methanol (85:15) and a voltage and a temperature of separation of 20 kV and 30 °C, respectively. Analytes were separated in less than 12 min, with excellent linearity (R² ≥ 0.999) in the concentration range of 0.5–8 µmol/L. The recovery of analytes spiked in whole blood was 99–101% for HCQ and 98–99% for DHCQ. Analysis of five samples from patients with rheumatoid arthritis receiving HCQ 400 mg daily yielded mean steady-state concentrations of 2.27 ± 1.61 and 1.54 ± 0.55 μmol/L for HCQ and DHCQ, respectively, with a HCQ to DHCQ ratio of 1.40 ± 0.77.

Chemistry of polyhalogenated nitrobutadienes, 17: Efficient synthesis of persubstituted chloroquinolinyl-1H-pyrazoles and evaluation of their antimalarial, anti-SARS-CoV-2, antibacterial, and cytotoxic activities

A series of 26 novel 1-(7-chloroquinolin-4-yl)-4-nitro-1H-pyrazoles bearing a dichloromethyl and an amino or thio moiety at C3 and C5 has been prepared in yields up to 72% from the reaction of 1,1-bisazolyl-, 1-azolyl-1-amino-, and 1-thioperchloro-2-nitrobuta-1,3-dienes with 7-chloro-4-hydrazinylquinoline. A new way for the formation of a pyrazole cycle from 3-methyl-2-(2,3,3-trichloro-1-nitroallylidene)oxazolidine (6) is also described. In addition, the antimalarial activity of the synthesized compounds has been evaluated in vitro against the protozoan malaria parasite Plasmodium falciparum. Notably, the 7-chloro-4-(5-(dichloromethyl)-4-nitro-3-(1H-1,2,4-triazol-1-yl)-1H-pyrazol-1-yl)quinoline (3b) and 7-chloro-4-(3-((4-chlorophenyl)thio)-5-(dichloromethyl)-4-nitro-1H-pyrazol-1-yl)quinoline (9e) inhibited the growth of the chloroquine-sensitive Plasmodium falciparum strain 3D7 with EC50 values of 0.2 ± 0.1 µM (85 ng/mL, 200 nM) and 0.2 ± 0.04 µM (100 ng/mL, 200 nM), respectively. Two compounds (3b and 10d) have also been tested for anti-SARS-CoV-2, antibacterial, and cytotoxic activity.

Clinical progress of therapeutics and vaccines: Rising hope against COVID-19 treatment

Cases of deaths due to COVID-19 (COrona VIrus Disease-19) infection are increasing gradually worldwide. Immense research is ongoing to control this pandemic condition. Continual research outcomes are indicating that therapeutic and prophylactic agents are the possible hope to prevent the pandemic from spreading and to combat this increasing death count. Experience gained from previous coronavirus infections (eg., SARS (Severe Acute Respiratory Syndrome), MERS (Middle Ease Respiratory Syndrome), accumulated clinical knowledge during this pandemic, and research helped to identify a few therapeutic agents for emergency treatment of COVID-19. Thereby, monoclonal antibodies, antivirals, broad-spectrum antimicrobials, immunomodulators, and supplements are being suggested for treatment depending on the stage of the disease. These recommended treatments are authorized under medical supervision in emergency conditions only. Urgent need to control the pandemic condition had resulted in various approaches of repurposing the existing drugs, However, poorly designed clinical trials and associated outcomes do not provide enough evidence to fully approve treatments against COVID-19. So far, World Health Organization (WHO) authorized three vaccines as prophylactic against SARS-CoV-2. Here, we discussed about various therapeutic agents, their clinical trials, and limitations of trials for the management of COVID-19. Further, we have also spotlighted different vaccines in research in combating COVID-19.

A multi-targeting drug design strategy for identifying potent anti-SARS-CoV-2 inhibitors

The COVID-19, caused by SARS-CoV-2, is threatening public health, and there is no effective treatment. In this study, we have implemented a multi-targeted anti-viral drug design strategy to discover highly potent SARS-CoV-2 inhibitors, which simultaneously act on the host ribosome, viral RNA as well as RNA-dependent RNA polymerases, and nucleocapsid protein of the virus, to impair viral translation, frameshifting, replication, and assembly. Driven by this strategy, three alkaloids, including lycorine, emetine, and cephaeline, were discovered to inhibit SARS-CoV-2 with EC50 values of low nanomolar levels potently. The findings in this work demonstrate the feasibility of this multi-targeting drug design strategy and provide a rationale for designing more potent anti-virus drugs.

Elements and COVID-19: A Comprehensive Overview of Studies on Their Blood/Urinary Levels and Supplementation with an Update on Clinical Trials

Simple Summary

COVID-19 is a disease caused by the SARS-CoV-2 coronavirus spreading mainly through person-to-person contact. It has caused millions of deaths around the world and lasting health problems in individuals who have survived the disease. This review concisely summarizes certain issues related to COVID-19 with a focus on elements and gives an update on clinical trials where some minerals will be tested/have been tested alone or in combination with drugs, vitamins, or plant extracts/herbal formulations in COVID-19 patients and in those at higher COVID-19 risk.

Abstract

The current report provides a brief overview of the clinical features, hematological/biochemical abnormalities, biomarkers, and AI-related strategies in COVID-19; presents in a nutshell the pharmacological and non-pharmacological therapeutic options; and concisely summarizes the most important aspects related to sociodemographic and behavioral factors as well as comorbidities having an impact on this disease. It also gives a brief outline of the effect of selected elements on immune response and collects data on the levels of micro-/macro-elements and toxic metals in the blood/urine of SARS-CoV-2 infected patients and on supplementation with minerals in COVID-19 subjects. Moreover, this review provides an overview of clinical trials based on the use of minerals alone or in combination with other agents that can provide effective responses toward SARS-CoV-2 infection. The knowledge compiled in this report lays the groundwork for new therapeutic treatments and further research on biomarkers that should be as informative as possible about the patient’s condition and can provide more reliable information on COVID-19 course and prognosis. The collected results point to the need for clarification of the importance of mineral supplementation in COVID-19 and the relationships of the levels of some minerals with clinical improvement.

COVID-19 drugs in aquatic systems: a review

The outbreak of the human coronavirus disease 2019 (COVID-19) has induced an unprecedented increase in the use of several old and repurposed therapeutic drugs such as veterinary medicines, e.g. ivermectin, nonsteroidal anti-inflammatory drugs, protein and peptide therapeutics, disease-modifying anti-rheumatic drugs and antimalarial drugs, antiretrovirals, analgesics, and supporting agents, e.g. azithromycin and corticosteroids. Excretion of drugs and their metabolites in stools and urine release these drugs into wastewater, and ultimately into surface waters and groundwater systems. Here, we review the sources, behaviour, environmental fate, risks, and remediation of those drugs. We discuss drug transformation in aquatic environments and in wastewater treatment systems. Degradation mechanisms and metabolite toxicity are poorly known. Potential risks include endocrine disruption, acute and chronic toxicity, disruption of ecosystem functions and trophic interactions in aquatic organisms, and the emergence of antimicrobial resistance.

Evaluation of SARS-CoV-2 entry, inflammation and new therapeutics in human lung tissue cells

The development of physiological models that reproduce SARS-CoV-2 infection in primary human cells will be instrumental to identify host-pathogen interactions and potential therapeutics. Here, using cell suspensions directly from primary human lung tissues (HLT), we have developed a rapid platform for the identification of viral targets and the expression of viral entry factors, as well as for the screening of viral entry inhibitors and anti-inflammatory compounds. The direct use of HLT cells, without long-term cell culture and in vitro differentiation approaches, preserves main immune and structural cell populations, including the most susceptible cell targets for SARS-CoV-2; alveolar type II (AT-II) cells, while maintaining the expression of proteins involved in viral infection, such as ACE2, TMPRSS2, CD147 and AXL. Further, antiviral testing of 39 drug candidates reveals a highly reproducible method, suitable for different SARS-CoV-2 variants, and provides the identification of new compounds missed by conventional systems, such as VeroE6. Using this method, we also show that interferons do not modulate ACE2 expression, and that stimulation of local inflammatory responses can be modulated by different compounds with antiviral activity. Overall, we present a relevant and rapid method for the study of SARS-CoV-2.

Safety profile of COVID-19 drugs in a real clinical setting

PURPOSE

The coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has affected millions all over the world and has been declared pandemic, as of 11 March 2020. In addition to the ongoing research and development of vaccines, there is still a dire need for safe and effective drugs for the control and treatment against the SARS-CoV-2 virus infection. Numerous repurposed drugs are under clinical investigations whose reported adverse events can raise worries about their safety. The aim of this review is to illuminate the associated adverse events related to the drugs used in a real COVID-19 setting along with their relevant mechanism(s).

METHOD

Through a literature search conducted on PubMed and Google Scholar database, various adverse events suspected to be induced by eight drugs, including dexamethasone, hydroxychloroquine, chloroquine, remdesivir, favipiravir, lopinavir/ritonavir, ivermectin, and tocilizumab, administered in COVID-19 patients in clinical practice and studies were identified in 30 case reports, 3 case series, and 10 randomized clinical trials.

RESULTS

Mild, moderate, or severe adverse events of numerous repurposed and investigational drugs caused by various factors and mechanisms were observed. Gastrointestinal side effects such as nausea, abdominal cramps, diarrhea, and vomiting were the most frequently followed by cardiovascular, cutaneous, and hepatic adverse events. Few other rare adverse drug reactions were also observed.

CONCLUSION

In light of their ineffectiveness against COVID-19 as evident in large clinical studies, drugs including hydroxychloroquine, lopinavir/ritonavir, and ivermectin should neither be used routinely nor in clinical studies. While lack of sufficient data, it creates doubt regarding the reliability of chloroquine and favipiravir use in COVID-19 patients. Hence, these two drugs can only be used in clinical studies. In contrast, ample well-conducted studies have approved the use of remdesivir, tocilizumab, and dexamethasone under certain conditions in COVID-19 patients. Consequently, it is significant to establish a strong surveillance system in order to monitor the proper safety and toxicity profile of the potential anti-COVID-19 drugs with good clinical outcomes.

Interleukin-6 Perpetrator of the COVID-19 Cytokine Storm

COVID-19 has emerged as a global pandemic. It is mainly manifested as pneumonia which may deteriorate into severe respiratory failure. The major hallmark of the disease is the systemic inflammatory immune response characterized by Cytokine Storm (CS). CS is marked by elevated levels of inflammatory cytokines, mainly interleukin-6 (IL-6), IL-8, IL-10, tumour necrosis factor-α (TNF-α) and interferon-γ (IFN-γ). Of these, IL-6 is found to be significantly associated with higher mortality. IL-6 is also a robust marker for predicting disease prognosis and deterioration of clinical profile. In this review, the pivotal role played by IL-6 in the immuno-pathology of COVID-19 has been illustrated. The role of IL-6 as a pleiotropic cytokine executing both pro and anti-inflammatory activities has been reviewed. ADAM 10, a metalloproteinase switches the anti-inflammatory pathway of IL-6 to pro inflammatory hence blocking the action of ADAM 10 could be a new therapeutic strategy to mitigate the proinflammatory action of IL-6. Furthermore, we explore the role of anti-IL6 agents, IL-6 receptor antibodies which were being used for autoimmune diseases but now are being repurposed for the therapy of COVID-19.

In silico study of some selective phytochemicals against a hypothetical SARS-CoV-2 spike RBD using molecular docking tools

Background

This world is currently witnessing a pandemic outbreak of ‘COVID-19′ caused by a positive-strand RNA virus ‘SARS-CoV-2’. Millions have succumbed globally to the disease, and the numbers are increasing day by day. The viral genome enters into the human host through interaction between the spike protein (S) and host angiotensin-converting enzyme-2 (ACE2) proteins. S is the common target for most recently rolled-out vaccines across regions. A recent surge in single/multiple mutations in S region is of great concern as it may escape vaccine induced immunity. So far, the treatment regime with repurposed drugs has not been too successful.

Hypothesis

Natural compounds are capable of targeting mutated spike protein by binding to its active site and destabilizing the spike-host ACE2 interaction.

Materials and methods

A hypothetical mutated spike protein was constructed by incorporating twelve different mutations from twelve geographical locations simultaneously into the receptor-binding domain (RBD) and docked with ACE2 and seven phytochemicals namely allicin, capsaicin, cinnamaldehyde, curcumin, gingerol, piperine and zingeberene. Molecular Dynamic (MD) simulation and Principal Component Analysis (PCA) were finally used for validation of the docking results.

Result

The docking results showed that curcumin and piperine were most potent to bind ACE2, mutated spike, and mutated spike-ACE2 complex, thereby restricting viral entry. ADME analysis also proved their drug candidature. The docking complexes were found to be stable by MD simulation.

Conclusion

This result provides a significant insight about the phytochemicals' role, namely curcumin and piperine, as the potential therapeutic entities against mutated spike protein of SARS-CoV-2.

Comprehensive Consensus Analysis of SARS-CoV-2 Drug Repurposing Campaigns

The current COVID-19 pandemic has elicited extensive repurposing efforts (both small and large scale) to rapidly identify COVID-19 treatments among approved drugs. Herein, we provide a literature review of large-scale SARS-CoV-2 antiviral drug repurposing efforts and highlight a marked lack of consistent potency reporting. This variability indicates the importance of standardizing best practices-including the use of relevant cell lines, viral isolates, and validated screening protocols. We further surveyed available biochemical and virtual screening studies against SARS-CoV-2 targets (Spike, ACE2, RdRp, PLpro, and Mpro) and discuss repurposing candidates exhibiting consistent activity across diverse, triaging assays and predictive models. Moreover, we examine repurposed drugs and their efficacy against COVID-19 and the outcomes of representative repurposed drugs in clinical trials. Finally, we propose a drug repurposing pipeline to encourage the implementation of standard methods to fast-track the discovery of candidates and to ensure reproducible results.

Computational studies reveal Fluorine based quinolines to be potent inhibitors for proteins involved in SARS-CoV-2 assembly

World is witnessing one of the worst pandemics of this century caused by SARS-CoV-2 virus which has affected millions of individuals. Despite rapid efforts to develop vaccines and drugs for COVID-19, the disease is still not under control. Chloroquine (CQ) and Hydroxychloroquine (HCQ) are two very promising inhibitors which have shown positive effect in combating the disease in preliminary experimental studies, but their use was reduced due to severe side-effects. Here, we performed a theoretical investigation of the same by studying the binding of the molecules with SARS-COV-2 Spike protein, the complex formed by Spike and ACE2 human receptor and a human serine protease TMPRSS2 which aids in cleavage of the Spike protein to initiate the viral activation in the body. Both the molecules had shown very good docking energies in the range of -6kcal/mol. Subsequently, we did a high throughput screening for other potential quinoline candidates which could be used as inhibitors. From the large pool of ligand candidates, we shortlisted the top three ligands (binding energy -8kcal/mol). We tested the stability of the docked complexes by running Molecular Dynamics (MD) simulations where we observed the stability of the quinoline analogues with the Spike-ACE2 and TMPRSS2 nevertheless the quinolines were not stable with the Spike protein alone. Thus, although the inhibitors bond very well with the protein molecules their intrinsic binding affinity depends on the protein dynamics. Moreover, the quinolines were stable when bound to electronegative pockets of Spike-ACE2 or TMPRSS2 but not with Viral Spike protein. We also observed that a Fluoride based compound: 3-[3-(Trifluoromethyl)phenyl]quinoline helps the inhibitor to bind with both Spike-ACE2 and TMPRSS2 with equal probability. The molecular details presented in this study would be very useful for developing quinoline based drugs for COVID-19 treatment.

Combination Treatment With Remdesivir and Ivermectin Exerts Highly Synergistic and Potent Antiviral Activity Against Murine Coronavirus Infection

The recent COVID-19 pandemic has highlighted the urgency to develop effective antiviral therapies against the disease. Murine hepatitis virus (MHV) is a coronavirus that infects mice and shares some sequence identity to SARS-CoV-2. Both viruses belong to the Betacoronavirus genus, and MHV thus serves as a useful and safe surrogate model for SARS-CoV-2 infections. Clinical trials have indicated that remdesivir is a potentially promising antiviral drug against COVID-19. Using an in vitro model of MHV infection of RAW264.7 macrophages, the safety and efficacy of monotherapy of remdesivir, chloroquine, ivermectin, and doxycycline were investigated. Of the four drugs tested, remdesivir monotherapy exerted the strongest inhibition of live virus and viral RNA replication of about 2-log10 and 1-log10, respectively (at 6 µM). Ivermectin treatment showed the highest selectivity index. Combination drug therapy was also evaluated using remdesivir (6 µM) together with chloroquine (15 µM), ivermectin (2 µM) or doxycycline (15 µM) - above their IC50 values and at high macrophage cell viability of over 95%. The combination of remdesivir and ivermectin exhibited highly potent synergism by achieving significant reductions of about 7-log10 of live virus and 2.5-log10 of viral RNA in infected macrophages. This combination also resulted in the lowest cytokine levels of IL-6, TNF-α, and leukemia inhibitory factor. The next best synergistic combination was remdesivir with doxycycline, which decreased levels of live virus by ~3-log10 and viral RNA by ~1.5-log10. These results warrant further studies to explore the mechanisms of action of the combination therapy, as well as future in vivo experiments and clinical trials for the treatment of SARS-CoV-2 infection.

COVID-19: Failure of the DisCoVeRy Clinical Trial, and Now-New Hopes?

The DisCoVeRy clinical trial aimed at the evaluation of four treatments for patients suffering from severe to critical COVID-19: Hydroxychloroquine, eventually associated with azithromycin; the combination lopinavir/ritonavir; the combination with the addition of interferon β-1a; remdesivir. The trial was discontinued due to the lack of positive results. Meanwhile, many other potential options have been considered either to target the virus itself, the interactions with the host cells, or the cytokine storm frequently observed during the infection. Several of those options are briefly reviewed. They include vaccines, small molecules, antibodies, and stem cells.

Adenosine triphosphate energy-independently controls protein homeostasis with unique structure and diverse mechanisms

Proteins function in the crowded cellular environments with high salt concentrations, thus facing tremendous challenges of misfolding/aggregation which represents a pathological hallmark of aging and an increasing spectrum of human diseases. Recently, intrinsically disordered regions (IDRs) were recognized to drive liquid-liquid phase separation (LLPS), a common principle for organizing cellular membraneless organelles (MLOs). ATP, the universal energy currency for all living cells, mysteriously has concentrations of 2-12 mM, much higher than required for its previously-known functions. Only recently, ATP was decoded to behave as a biological hydrotrope to inhibit protein LLPS and aggregation at mM. We further revealed that ATP also acts as a bivalent binder, which not only biphasically modulates LLPS driven by IDRs of human and viral proteins, but also bind to the conserved nucleic-acid-binding surfaces of the folded proteins. Most unexpectedly, ATP appears to act as a hydration mediator to antagonize the crowding-induced destabilization as well as to enhance folding of proteins without significant binding. Here, this review focuses on summarizing the results of these biophysical studies and discussing their implications in an evolutionary context. By linking triphosphate with unique hydration property to adenosine, ATP appears to couple the ability for establishing hydrophobic, π-π, π-cation and electrostatic interactions to the capacity in mediating hydration of proteins, which is at the heart of folding, dynamics, stability, phase separation and aggregation. Consequently, ATP acquired a category of functions at ~mM to energy-independently control protein homeostasis with diverse mechanisms, thus implying a link between cellular ATP concentrations and protein-aggregation diseases.

Current and New Drugs for COVID-19 Treatment and Its Effects on the Liver

Corona virus disease (COVID)-19 is caused by the novel severe acute respiratory syndrome coronavirus-2 (commonly referred to as SARS-CoV-2). In March 2020, the World Health Organization declared the COVID-19 outbreak a pandemic. Though the target organ for the virus is primarily the lungs, with the recent understanding of the pathobiology of this disease and the immune dysregulation associated with it, it is now clear that COVID-19 affects multiple organ systems. Several drugs and therapies have been tried or repurposed to combat the wrath posed by this disease. On October 22, 2020, the USA Food and Drug Administration approved remdesivir for use in adults and pediatric patients (12 years of age and older). Several of the drugs being tried against COVID-19 have hepatotoxicity as their potential side effect. This review aims to provide the latest insights on various drugs being used in the treatment of COVID-19 and their effects on the liver.

Efficacy and Safety of Hydroxychloroquine for Hospitalized COVID-19 Patients: A Systematic Review and Meta-Analysis

We systematically reviewed the efficacy and safety of hydroxychloroquine as treatment for hospitalized COVID-19. Randomized controlled trials (RCTs) evaluating hydroxychloroquine as treatment for hospitalized COVID-19 patients were searched until 2nd of December 2020. Primary outcomes were all-cause mortality, need of mechanical ventilation, need of non-invasive ventilation, ICU admission and oxygen support at 14 and 30 days. Secondary outcomes were clinical recovery and worsening, discharge, radiological progression of pneumonia, virologic clearance, serious adverse events (SAE) and adverse events. Inverse variance random effects meta-analyses were performed. Thirteen RCTs (n=18,540) were included. Hydroxychloroquine total doses ranged between 2000 and 12,400 mg; treatment durations were from 5 to 16 days and follow up times between 5 and 30 days. Compared to controls, hydroxychloroquine non-significantly increased mortality at 14 days (RR 1.07, 95%CI 0.92-1.25) or 30 days (RR 1.08, 95%CI 1.00-1.16). Hydroxychloroquine did not affect other primary or secondary outcomes, except SAEs that were significantly higher than the control (RR 1.24, 95%CI 1.05-1.46). Eleven RCTs had high or some concerns of bias. Subgroup analyses were consistent with main analyses. Hydroxychloroquine was not efficacious for treating hospitalized COVID-19 patients and caused more severe adverse events. Hydroxychloroquine should not be recommended as treatment for hospitalized COVID-19 patients.

JAK-STAT Pathway Inhibition and their Implications in COVID-19 Therapy

As the incidence of COVID-19 increases with time, more and more efforts are made to pave a way out for the therapeutic strategies to deal with the disease progression. Inflammation being a significant influencer in COVID-19 patients, it drives our focus onto the signaling cascades of the JAK/STAT pathway. JAK phosphorylation mediated by cytokine receptor activation leads to phosphorylation of STATs that translocate into the nucleus to translate for inflammatory mediators. The SARS-CoV-2 structural proteins like spike, nucleocapsid, membrane and envelope proteins along with the non- structural proteins 1-16 including proteases like 3CL pro and PLpro promote its entry and survival in hosts. The SARS-CoV-2 infection triggers inflammation via the JAK/STAT pathway leading to recruitment of pneumocytes, endothelial cells, macrophages, monocytes, lymphocytes, natural killer cells and dendritic cells progressing towards cytokine storm. This produces various inflammatory markers in the host that determine the disease severity. The JAK/STAT signaling also mediates immune responses via B cell and T cell differentiation.With an attempt to reduce excessive inflammation, JAK/STAT inhibitors like Ruxolitinib, Baricitinib, Tofacitinib have been employed that mediate its actions via suppressors of cytokine signaling, cytokine inducible SH2 containing protein, Protein inhibitor of activated STAT and protein tyrosine phosphatases. Even though they are implicated with multiple adverse effects, the regulatory authorities have supported its use, and numerous clinical trials are in progress to prove their safety and efficacy. On the contrary, the exact mechanism of JAK/STAT inhibition at molecular levels remains speculative for which further investigations are required.

The systemic pro-inflammatory response: targeting the dangerous liaison between COVID-19 and cancer

Inflammation is an established driver of severe SARS-CoV-2 infection and a mechanism linked to the increased susceptibility to fatal COVID-19 demonstrated by patients with cancer. As patients with cancer exhibit a higher level of inflammation compared with the general patient population, patients with cancer and COVID-19 may uniquely benefit from strategies targeted at overcoming the unrestrained pro-inflammatory response. Targeted and non-targeted anti-inflammatory therapies may prevent end-organ damage in SARS-CoV-2-infected patients with cancer and decrease mortality. Here, we review the clinical role of selective inhibition of pro-inflammatory interleukins, tyrosine kinase modulation, anti-tumor necrosis factor agents, and other non-targeted approaches including corticosteroids in their roles as disease-modulating agents in patients with COVID-19 and cancer. Investigation of these therapeutics in this highly vulnerable patient group is posited to facilitate the development of tailored therapeutics for this patient population, aiding the transition of systemic inflammation from a prognostic domain to a source of therapeutic targets.

Could Histamine H1 Receptor Antagonists Be Used for Treating COVID-19?

COVID-19 has rapidly become a pandemic worldwide, causing extensive and long-term health issues. There is an urgent need to identify therapies that limit SARS-CoV-2 infection and improve the outcome of COVID-19 patients. Unbalanced lung inflammation is a common feature in severe COVID-19 patients; therefore, reducing lung inflammation can undoubtedly benefit the clinical manifestations. Histamine H1 receptor (H1 receptor) antagonists are widely prescribed medications to treat allergic diseases, while recently it has emerged that they show significant promise as anti-SARS-CoV-2 agents. Here, we briefly summarize the novel use of H1 receptor antagonists in combating SARS-CoV-2 infection. We also describe the potential antiviral mechanisms of H1 receptor antagonists on SARS-CoV-2. Finally, the opportunities and challenges of the use of H1 receptor antagonists in managing COVID-19 are discussed.

Metabolic N-Dealkylation and N-Oxidation as Elucidators of the Role of Alkylamino Moieties in Drugs Acting at Various Receptors

Metabolic reactions that occur at alkylamino moieties may provide insight into the roles of these moieties when they are parts of drug molecules that act at different receptors. N-dealkylation of N,N-dialkylamino moieties has been associated with retaining, attenuation or loss of pharmacologic activities of metabolites compared to their parent drugs. Further, N-dealkylation has resulted in clinically used drugs, activation of prodrugs, change of receptor selectivity, and providing potential for developing fully-fledged drugs. While both secondary and tertiary alkylamino moieties (open chain aliphatic or heterocyclic) are metabolized by CYP450 isozymes oxidative N-dealkylation, only tertiary alkylamino moieties are subject to metabolic N-oxidation by Flavin-containing monooxygenase (FMO) to give N-oxide products. In this review, two aspects will be examined after surveying the metabolism of representative alkylamino-moieties-containing drugs that act at various receptors (i) the pharmacologic activities and relevant physicochemical properties (basicity and polarity) of the metabolites with respect to their parent drugs and (ii) the role of alkylamino moieties on the molecular docking of drugs in receptors. Such information is illuminative in structure-based drug design considering that fully-fledged metabolite drugs and metabolite prodrugs have been, respectively, developed from N-desalkyl and N-oxide metabolites.

The controversial therapeutic journey of chloroquine and hydroxychloroquine in the battle against SARS-CoV-2: A comprehensive review

Recently, the pandemic outbreak of a novel coronavirus, officially termed as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), indicated by a pulmonary infection in humans, has become one of the most significant challenges for public health. In the current fight against coronavirus disease-2019, the medical and health authorities across the world focused on quick diagnosis and isolation of patients; meanwhile, researchers worldwide are exploring the possibility of developing vaccines and novel therapeutic options to combat this deadly disease. Recently, based on various small clinical observations, uncontrolled case studies and previously reported antiviral activity against SARS-CoV-1 chloroquine (CQ) and hydroxychloroquine (HCQ) have attracted exceptional consideration as possible therapeutic agents against SARS-CoV-2. However, there are reports on little to no effect of CQ or HCQ against SARS-CoV-2, and many reports have raised concerns about their cardiac toxicity. Here, in this review, we examine the chemistry, molecular mechanism, and pharmacology, including the current scenario and future prospects of CQ or HCQ in the treatment of SARS-CoV-2.

An Update on Antiviral Therapy Against SARS-CoV-2: How Far Have We Come?

COVID-19 pandemic has spread worldwide at an exponential rate affecting millions of people instantaneously. Currently, various drugs are under investigation to treat an enormously increasing number of COVID-19 patients. This dreadful situation clearly demands an efficient strategy to quickly identify drugs for the successful treatment of COVID-19. Hence, drug repurposing is an effective approach for the rapid discovery of frontline arsenals to fight against COVID-19. Successful application of this approach has resulted in the repurposing of some clinically approved drugs as potential anti-SARS-CoV-2 candidates. Several of these drugs are either antimalarials, antivirals, antibiotics or corticosteroids and they have been repurposed based on their potential to negate virus or reduce lung inflammation. Large numbers of clinical trials have been registered to evaluate the effectiveness and clinical safety of these drugs. Till date, a few clinical studies are complete and the results are primary. WHO also conducted an international, multi-country, open-label, randomized trials-a solidarity trial for four antiviral drugs. However, solidarity trials have few limitations like no placebos were used, additionally any drug may show effectiveness for a particular population in a region which may get neglected in solidarity trial analysis. The ongoing randomized clinical trials can provide reliable long-term follow-up results that will establish both clinical safety and clinical efficacy of these drugs with respect to different regions, populations and may aid up to worldwide COVID-19 treatment research. This review presents a comprehensive update on majorly repurposed drugs namely chloroquine, hydroxychloroquine, remdesivir, lopinavir-ritonavir, favipiravir, ribavirin, azithromycin, umifenovir, oseltamivir as well as convalescent plasma therapy used against SARS-CoV-2. The review also summarizes the data recorded on the mechanism of anti-SARS-CoV-2 activity of these repurposed drugs along with the preclinical and clinical findings, therapeutic regimens, pharmacokinetics, and drug-drug interactions.

Structural insights into SARS-CoV-2 spike protein and its natural mutants found in Mexican population

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a newly emerged coronavirus responsible for coronavirus disease 2019 (COVID-19); it become a pandemic since March 2020. To date, there have been described three lineages of SARS-CoV-2 circulating worldwide, two of them are found among Mexican population, within these, we observed three mutations of spike (S) protein located at amino acids H49Y, D614G, and T573I. To understand if these mutations could affect the structural behavior of S protein of SARS-CoV-2, as well as the binding with S protein inhibitors (cepharanthine, nelfinavir, and hydroxychloroquine), molecular dynamic simulations and molecular docking were employed. It was found that these punctual mutations affect considerably the structural behavior of the S protein compared to wild type, which also affect the binding of its inhibitors into their respective binding site. Thus, further experimental studies are needed to explore if these affectations have an impact on drug-S protein binding and its possible clinical effect.

COVID-19: Characteristics and Therapeutics

Novel coronavirus (COVID-19 or 2019-nCoV or SARS-CoV-2), which suddenly emerged in December 2019 is still haunting the entire human race and has affected not only the healthcare system but also the global socioeconomic balances. COVID-19 was quickly designated as a global pandemic by the World Health Organization as there have been about 98.0 million confirmed cases and about 2.0 million confirmed deaths, as of January 2021. Although, our understanding of COVID-19 has significantly increased since its outbreak, and multiple treatment approaches and pharmacological interventions have been tested or are currently under development to mitigate its risk-factors. Recently, some vaccine candidates showed around 95% clinical efficacy, and now receiving emergency use approvals in different countries. US FDA recently approved BNT162 and mRNA-1273 vaccines developed by Pfizer/BioNTech and Moderna Inc. for emergency use and vaccination in the USA. In this review, we present a succinct overview of the SARS-CoV-2 virus structure, molecular mechanisms of infection, COVID-19 epidemiology, diagnosis, and clinical manifestations. We also systematize different treatment strategies and clinical trials initiated after the pandemic outbreak, based on viral infection and replication mechanisms. Additionally, we reviewed the novel pharmacological intervention approaches and vaccine development strategies against COVID-19. We speculate that the current pandemic emergency will trigger detailed studies of coronaviruses, their mechanism of infection, development of systematic drug repurposing approaches, and novel drug discoveries for current and future pandemic outbreaks.

G6PD distribution in sub-Saharan Africa and potential risks of using chloroquine/hydroxychloroquine based treatments for COVID-19

Chloroquine/hydroxychloroquine have been proposed as potential treatments for COVID-19. These drugs have warning labels for use in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Analysis of whole genome sequence data of 458 individuals from sub-Saharan Africa showed significant G6PD variation across the continent. We identified nine variants, of which four are potentially deleterious to G6PD function, and one (rs1050828) that is known to cause G6PD deficiency. We supplemented data for the rs1050828 variant with genotype array data from over 11,000 Africans. Although this variant is common in Africans overall, large allele frequency differences exist between sub-populations. African sub-populations in the same country can show significant differences in allele frequency (e.g. 16.0% in Tsonga vs 0.8% in Xhosa, both in South Africa, p = 2.4 × 10^-3). The high prevalence of variants in the G6PD gene found in this analysis suggests that it may be a significant interaction factor in clinical trials of chloroquine and hydroxychloroquine for treatment of COVID-19 in Africans.

Prevention and treatment of COVID-19: Focus on interferons, chloroquine/hydroxychloroquine, azithromycin, and vaccine

The ongoing pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has drawn the attention of researchers and clinicians from several disciplines and sectors who are trying to find durable solutions both at preventive and treatment levels. To date, there is no approved effective treatment or vaccine available to control the coronavirus disease-2019 (COVID-19). The preliminary in vitro studies on viral infection models showed potential antiviral activities of type I and III interferons (IFNs), chloroquine (CQ)/hydroxychloroquine (HCQ), and azithromycin (AZM); however, the clinical studies on COVID-19 patients treated with CQ/HCQ and AZM led to controversies in different regions due to their adverse side effects, as well as their combined treatment could prolong the QT interval. Interestingly, the treatment with type I IFNs showed encouraging results. Moreover, the different preliminary reports of COVID-19 candidate vaccines showcase promising results by inducing the production of a high level of neutralizing antibodies (NAbs) and specific T cell-mediated immune response in almost all participants. The present review aims to summarize and analyze the recent progress evidence concerning the use of IFNs, CQ/HCQ, and AZM for the treatment of COVID-19. The available data on immunization options to prevent the COVID-19 are also analyzed with the aim to present the promising options which could be investigated in future for sustainable control of the pandemic.

COVID-19 and diabetes mellitus: from pathophysiology to clinical management

Initial studies found increased severity of coronavirus disease 2019 (COVID-19), caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in patients with diabetes mellitus. Furthermore, COVID-19 might also predispose infected individuals to hyperglycaemia. Interacting with other risk factors, hyperglycaemia might modulate immune and inflammatory responses, thus predisposing patients to severe COVID-19 and possible lethal outcomes. Angiotensin-converting enzyme 2 (ACE2), which is part of the renin-angiotensin-aldosterone system (RAAS), is the main entry receptor for SARS-CoV-2; although dipeptidyl peptidase 4 (DPP4) might also act as a binding target. Preliminary data, however, do not suggest a notable effect of glucose-lowering DPP4 inhibitors on SARS-CoV-2 susceptibility. Owing to their pharmacological characteristics, sodium-glucose cotransporter 2 (SGLT2) inhibitors might cause adverse effects in patients with COVID-19 and so cannot be recommended. Currently, insulin should be the main approach to the control of acute glycaemia. Most available evidence does not distinguish between the major types of diabetes mellitus and is related to type 2 diabetes mellitus owing to its high prevalence. However, some limited evidence is now available on type 1 diabetes mellitus and COVID-19. Most of these conclusions are preliminary, and further investigation of the optimal management in patients with diabetes mellitus is warranted.

Cardiotoxicity induced by the combination therapy of chloroquine and azithromycin in human embryonic stem cell-derived cardiomyocytes

Combination therapy using chloroquine (CQ) and azithromycin (AZM) has drawn great attention due to its potential anti-viral activity against SARS-CoV-2. However, clinical trials have revealed that the co-administration of CQ and AZM resulted in severe side effects, including cardiac arrhythmia, in patients with COVID-19. To elucidate the cardiotoxicity induced by CQ and AZM, we examined the effects of these drugs based on the electrophysiological properties of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) using multi-electrode arrays. CQ treatment significantly increased the field potential duration, which corresponds to prolongation of the QT interval, and decreased the spike amplitude, spike slope, and conduction velocity of hESC-CMs. AZM had no significant effect on the field potentials of hESC-CMs. However, CQ in combination with AZM greatly increased the field potential duration and decreased the beat period and spike slope of hESC-CMs when compared with CQ monotherapy. In support of the clinical data suggesting the cardiovascular side effects of the combination therapy of CQ and AZM, our results suggest that AZM reinforces the cardiotoxicity induced by CQ in hESC-CMs.

Coronavirus Disease-19: An Interim Evidence Synthesis of the World Association for Infectious Diseases and Immunological Disorders (Waidid)

Coronavirus disease 2019 (COVID-19) is a rapidly evolving, highly transmissible, and potentially lethal pandemic caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). As of June 11 2020, more than 7,000,000 COVID-19 cases have been reported worldwide, and more than 400,000 patients have died, affecting at least 188 countries. While literature on the disease is rapidly accumulating, an integrated, multinational perspective on clinical manifestations, immunological effects, diagnosis, prevention, and treatment of COVID-19 can be of global benefit. We aimed to synthesize the most relevant literature and experiences in different parts of the world through our global consortium of experts to provide a consensus-based document at this early stage of the pandemic.

Involvement of the nervous system in COVID-19: The bell should toll in the brain

The world is fuming at SARS-CoV-2 for being the culprit for causing the devastating COVID-19, claiming millions of lives across the globe in the form of respiratory disorders. But lesser known are its effects on the CNS that are slowly surfacing in the worldwide population. Our review illustrates findings that claim SARS-CoV-2's arrival onto the ACE2 receptors of neuronal and glial cells mainly via CSF, olfactory nerve, trigeminal nerve, neuronal dissemination, and hematogenous pathways. The role of SARS-CoV-2 structural proteins in its smooth viral infectivity of the host cannot be ignored, especially the spike proteins that mediate spike attachment and host membrane fusion. Worth mentioning the nucleocapsid, envelope, and membrane proteins make the proliferation of SARS-CoV-2 much simpler than expected in spreading infection. This has led to catastrophic conditions like seizures, Guillain-Barré syndrome, viral encephalitis, meningoencephalitis, acute cerebrovascular disease, and respiratory failures. Placing a magnifying lens on the lesser-explored CNS consequences of COVID-19, we attempt to shift the focus of our readers onto the new supporting threats to which further studies are needed.