The dual impact of ACE2 in COVID-19 and ironical actions in geriatrics and pediatrics with possible therapeutic solutions

Exploring the Mystery of Angiotensin-Converting Enzyme II (ACE2) in the Battle against SARS-CoV-2

COVID-19 is the newly born pandemic caused by the SARS-CoV-2 virus, which is the recently emerged betacoronavirus that crosses the species barrier. It predominantly infects pneumocytes of the respiratory tract, but due to the presence of angiotensin-converting enzyme II (ACE2) on other cells like surface enterocytes of the upper esophagus and colon, these are also considered as the primary sites of infection. ACE2 receptor served as a cellular entry point for SARS-CoV-2. The expression of the ACE2 receptors is regulated by several factors such as age, tobacco smoking, inflammatory signaling, ACE inhibitors, angiotensin receptor blockers, and comorbidities (chronic obstructive pulmonary disease (COPD), tuberculosis, cerebrovascular disease, coronary heart disease, hypertension, and diabetes). Therefore, scientists are trying to explore the in-depth knowledge of ACE2 and considered it as a potential indirect target for COVID-19 therapeutics. In this focused review, we discussed in detail ACE2 expressions and regulation by different factors in the primary or vulnerable sites of SARS-CoV-2 infections. Clinical trials of rhACE2 in COVID-19 patients are ongoing, and if the outcome of the trials proves positive, it will be a breakthrough for the management of COVID-19. Finally, we suggest that targeting the ACE2 (a master regulator) in a balanced way could serve as a potential option against the management of COVID-19.

Clinical factors associated with death in 3044 COVID-19 patients managed in internal medicine wards in Italy: results from the SIMI-COVID-19 study of the Italian Society of Internal Medicine (SIMI)

During the COVID-19 2020 outbreak, a large body of data has been provided on general management and outcomes of hospitalized COVID-19 patients. Yet, relatively little is known on characteristics and outcome of patients managed in Internal Medicine Units (IMU). To address this gap, the Italian Society of Internal Medicine has conducted a nationwide cohort multicentre study on death outcome in adult COVID-19 patients admitted and managed in IMU. This study assessed 3044 COVID-19 patients at 41 referral hospitals across Italy from February 3rd to May 8th 2020. Demographics, comorbidities, organ dysfunction, treatment, and outcomes including death were assessed. During the study period, 697 patients (22.9%) were transferred to intensive care units, and 351 died in IMU (death rate 14.9%). At admission, factors independently associated with in-hospital mortality were age (OR 2.46, p = 0.000), productive cough (OR 2.04, p = 0.000), pre-existing chronic heart failure (OR 1.58, p = 0.017) and chronic obstructive pulmonary disease (OR 1.17, p = 0.048), the number of comorbidities (OR 1.34, p = 0.000) and polypharmacy (OR 1.20, p = 0.000). Of note, up to 40% of elderly patients did not report fever at admission. Decreasing PaO₂/FiO₂ ratio at admission was strongly inversely associated with survival. The use of conventional oxygen supplementation increased with the number of pre-existing comorbidities, but it did not associate with better survival in patients with PaO₂/FiO₂ ratio < 100. The latter, significantly benefited by the early use of non-invasive mechanical ventilation. Our study identified PaO₂/FiO₂ ratio at admission and comorbidity as the main alert signs to inform clinical decisions and resource allocation in non-critically ill COVID-19 patients admitted to IMU.

COVID-19 and the pituitary

BACKGROUND

Despite COVID-19 being identified as severe respiratory viral infection, progressively many relevant endocrine manifestations have been reported greatly contributing to the severity of the clinical presentation. Systemic involvement in COVID-19 is due to the ubiquitous expression of angiotensin-converting enzyme 2 (ACE2) receptor, responsible for the entry in the cells of SARS-CoV-2, Several reports in humans and animal models showed a significant ACE2 mRNA expression in hypothalamus and pituitary cells. Moreover, higher mortality and poorer outcomes have been widely described in COVID-19 patients with obesity, diabetes and vertebral fractures, which are all highly prevalent in subjects with pituitary dysfunctions.

AIM

To review the main endocrine manifestations of COVID-19 with their possible implications for pituitary diseases, the possible direct and indirect involvement of the pituitary gland in COVID-19, the impact of COVID-19 on the management of established pituitary diseases which can be already at increased risk for worse outcomes and on neurosurgical activities as well as vaccination.

CONCLUSIONS

Our review underlines that there could be a specific involvement of the pituitary gland which fits into a progressively shaping endocrine phenotype of COVID-19. Moreover, the care for pituitary diseases need to continue despite the restrictions due to the emergency. Several pituitary diseases, such as hypopituitarism and Cushing disease, or due to frequent comorbidities such as diabetes may be a risk factor for severe COVID-19 in affected patients. There is the urgent need to collect in international multicentric efforts data on all these aspects of the pituitary involvement in the pandemic in order to issue evidence driven recommendations for the management of pituitary patients in the persistent COVID-19 emergency.

Efficiency of antiviral treatment in COVID-19

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is responsible for generating a global effort to discover urgent therapeutic solutions to limit the human damage caused by COVID-19. In the period of April to June 2020, 105 patients diagnosed with COVID-19 met the conditions for inclusion in the present study. They were treated with antiviral therapy according to local guidelines: D group (53 cases), treated with darunavir/ritonavir (DRV/r); and K group (52 cases), treated with lopinavir/ritonavir (LPV/r). Patients from the K group required 7.5 days of hospitalization less compared to those from the D group (P<0.001). The blood oxygen saturation values recorded in the groups were statistically different [K group (94.02±3.12%) vs. D group (92.13±4.24%), P=0.010]. The percentage of patients with unsatisfactory clinical evolution were non-significantly higher in the D group compared with the K group [20 (37.74%) vs. 12 (23.08%), P=0.157]. We did not note statistically significant differences between the two groups tracked considering the values for the Brescia-COVID Respiratory Severity Scale (BCRSS) of the patients with unsatisfactory clinical evolution, nor of the chest CT' evolution after 10 days of therapy. We did not register significant adverse effects after antiviral therapy in the two groups. Antiviral therapy with LPV/r had some favorable results compared to DRV/r in patients with COVID-19. Both therapies were well tolerated.

Persistently Increased Systemic ACE2 Activity Is Associated With an Increased Inflammatory Response in Smokers With COVID-19

Background: Tobacco smoking is known to be involved in the pathogenesis of several cardiopulmonary diseases. Additionally, smokers are highly susceptible to infectious agents due to weakened immunity. However, the progression of lung injury based on SARS-CoV-2-mediated COVID-19 pathogenesis amongst smokers and those with pre-existing pulmonary diseases is not known. We determined the systemic levels and activity of COVID-19 associated proteins, cytokine/chemokines, and lipid mediators (lipidomics) amongst COVID-19 patients with and without a history of smoking to understand the underlying susceptible factor in the pathogenesis of COVID-19.

Methods: We obtained serum from healthy (CoV−), COVID-19 positive (CoV+), and COVID-19 recovered (CoV Rec) subjects with and without a history of smoking. We conducted a Luminex multiplex assay (cytokine levels), LC/MS (eicosanoids or oxylipin panel), and ACE2 enzymatic activity assays on the serum samples to determine the systemic changes in COVID-19 patients.

Results: On comparing the levels of serum ACE2 amongst COVID-19 (positive and recovered) patients and healthy controls, we found a pronounced increase in serum ACE2 levels in patients with COVID-19 infection. Furthermore, ACE2 enzyme activity was significantly increased amongst COVID-19 patients with a smoking history. Also, we analyzed the levels of Angiotensin 1–7 (Ang1–7) peptide, the product of enzymatic action of ACE2, in the serum samples. We found significantly high levels of Ang1–7 in the serum of both CoV+ and CoV Rec patients. Our data further demonstrated a smoking-induced increase in serum furin and inflammatory cytokine [IFN_γ(p = 0.0836), Eotaxin (p < 0.05), MCP-1 (p < 0.05), and IL-9 (p = 0.0991)] levels in COVID-19 patients as compared to non-smoking controls. Overall, our results show that smoking adversely affects the levels of systemic inflammatory markers and COVID-19 associated proteins, thus suggesting that COVID-19 infection may have severe outcomes amongst smokers.

The Computational Intervention of Macrolide Antibiotics in the Treatment of COVID-19

BACKGROUND

The spike (S) glycoprotein of SARS corona virus (SARS-CoV-2) and human Angiotensin- converting enzyme 2 (ACE2), are both considered the key factors for the initiation of virus infection. The present work is an effort for computational target to block the spike proteins (S) and ACE2 receptor proteins with Macrolide antibiotics like Azithromycin, (AZM), Clarithromycin (CLAM) and Erythromycin (ERY) along with RNA-dependent RNA polymerase (RdRp).

METHODS

Three-dimensional structure of the SARS-CoV-2RdRp was built by the SWISS-MODEL server, the generated structure showed 96.35% identity to the available structure of SARS-Coronavirus NSP12 (6NUR), for model validity, we utilized the SWISS-model server quality parameters and Ramachandran plots.

RESULTS

These compounds were able to block the residues (Arg553, Arg555, and Ala558) surrounding the deep grove catalytic site (Val557) of RdRp and thus plays an important role in tight blocking of enzyme active site. Reference drug Remdesivir was used to compare the docking score of antibiotics with RdRp. Docking value exhibited good binding energy (-7.7 up to -8.2 kcal/mol) with RdRp, indicating their potential as a potent RdRp inhibitor. Interaction of CLAM and ERY presented low binding energy (-6.8 and -6.6) with the ACE2 receptor. At the same time, CLAM exhibited a good binding affinity of -6.4 kcal/mol, making it an excellent tool to block the attachment of spike protein to ACE2 receptors. Macrolides not only affected the attachment to ACE2 but also blocked the spike proteins further, consequently inhibiting the internalization in the host cell. Three Alkyl bonds between Arg555, Ala558, and Met542 by CLAM and two Alkyl bonds of Arg624 and Lys621 by ERY plays an important role for RdRp inactivation, that can prevent the rise of newly budded progeny virus. These macrolides interacted with the main protease protein in the pocket responsible for the dimerization and catalytic function of this protein. The interaction occurred with residue Glu166, along with the catalytic residues (Tyr343, and His235) of Endoribonuclease (NSP15) protein.

CONCLUSION

The present study gives three-way options either by blocking S proteins or ACE2 receptor proteins or inhibiting RdRp to counter any effect of COVID-19 by macrolide and could be useful in the treatment of COVID-19 till some better option available.

Multi-Omics Approach in the Identification of Potential Therapeutic Biomolecule for COVID-19

COVID-19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It has a disastrous effect on mankind due to the contagious and rapid nature of its spread. Although vaccines for SARS-CoV-2 have been successfully developed, the proven, effective, and specific therapeutic molecules are yet to be identified for the treatment. The repurposing of existing drugs and recognition of new medicines are continuously in progress. Efforts are being made to single out plant-based novel therapeutic compounds. As a result, some of these biomolecules are in their testing phase. During these efforts, the whole-genome sequencing of SARS-CoV-2 has given the direction to explore the omics systems and approaches to overcome this unprecedented health challenge globally. Genome, proteome, and metagenome sequence analyses have helped identify virus nature, thereby assisting in understanding the molecular mechanism, structural understanding, and disease propagation. The multi-omics approaches offer various tools and strategies for identifying potential therapeutic biomolecules for COVID-19 and exploring the plants producing biomolecules that can be used as biopharmaceutical products. This review explores the available multi-omics approaches and their scope to investigate the therapeutic promises of plant-based biomolecules in treating SARS-CoV-2 infection.

Anti-TNF-α agents Modulate SARS-CoV-2 Receptors and Increase the Risk of Infection Through Notch-1 Signaling

Although millions of patients with underlining conditions are treated primarily with anti-TNF-α agents, little is known about the safety of this standard therapy during the coronavirus disease-2019 (COVID-19) pandemic. In this study, we investigated the effect of anti-TNF-α monoclonal antibodies on the cellular entry mechanism of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and increasing the risk of COVID-19 development. We focused on the expression of angiotensin-converting enzyme II (ACE2), type II transmembrane serine proteases (TMPRSS2)/TNF-α converting enzyme (TACE) ratio. We also investigated the involvement of Notch-1 signaling and its downstream influence on IL-6, myeloid cell leukemia sequence-1(MCL-1) in the anti-TNF-α mode of action and increased the susceptibility to Mycobacterium avium subspecies paratuberculosis (MAP) infection. Surprisingly, anti-TNF-α downregulated ACE2 expression by 0.46-fold and increased TMPRSS2/TACE ratio by 44% in THP-1 macrophages. Treatment of macrophages with rIL-6 also downregulated ACE2 and increased TMPRSS2/TACE ratio by 54%. Interestingly, anti-TNF-α treatment upregulated Notch-1, IL-6, and MCL-1 by 1.3, 1.2, and 1.9-fold, respectively, and increased viability and burden of MAP infection in macrophages. Blocking Notch signaling doubled ACE2 expression, decreased TMPRSS2/TACE ratio by 38%, and reduced MAP viability by 56%. In a small group of patients, ACE2 level was significantly lower in the plasma from rheumatoid arthritis (RA) patients on anti-TNF-α treatment compared to healthy control. The data in this critical study demonstrated that through Notch-1/IL-6 signaling, anti-TNF-α agents decreased ACE2 expression and shedding through TMPRSS2/TACE modulation and increased the susceptibility to infection. Overall, this study warns against anti-TNF-α therapy in some patients with underlining inflammatory conditions during the COVID-19 pandemic. The findings should impact current guidelines regarding treatment decisions of patients on anti-TNF-α during the COVID-19 pandemic.

Severe acute respiratory syndrome-coronavirus-2: Current advances in therapeutic targets and drug development

The current pandemic of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has quickly emerged as a global health concern with government bodies worldwide taking drastic control measures. Understanding the virology of SARS-CoV-2, its molecular mechanisms, and its pathogenesis are required for a targeted therapeutic approach. In this review, we highlight the current molecular and drug advances that target SARS-CoV-2 at the genome level. We also summarize studies that therapeutically target the host angiotensin-converting enzyme 2 and proteases. Finally, we summarize antibody-mediated therapeutic approaches, as well as recent trends in vaccine development. Hence, the purpose of this study is to investigate different molecular targets in SARS-CoV-2 pathogenesis and their usefulness in developing strategies for drug development.

Disparities in COVID-19 severities and casualties across ethnic groups around the globe and patterns of ACE2 and PIR variants

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) mediated Coronavirus disease-19 (COVID-19) has affected millions of individuals around all corners of the globe. Symptoms and severities of infection with this highly contagious virus vary among individuals and there is disparity in the number of COVID-19-related casualties across different ethnic groups. The primary receptor for SARS-CoV-2 entry into the host cells is angiotensin-converting enzyme 2 (ACE2). Certain variants of ACE2 are known to be associated with COVID-19 comorbidities such as hypertension, cardiovascular complications, diabetes, chronic lung disease, etc. In this study, we looked into the geographic distribution of disease-associated variants of ACE2 as well as closely located PIR gene to explore any possible correlation with the disparities in COVID-19 severities and casualties across ethnic groups. Frequencies of the ACE2 variants associated with COVID-19 comorbidities are higher in the European and the admixed American populations. These variants are also present with stronger pairwise linkage disequilibrium (LD) in the European and the admixed American populations. On the other hand, the variants with protective role are more prevalent in the East and the South Asian populations. Strong pairwise LD exists among the activity modifying (modifier) variants of the PIR and ACE2 genes only in the European super-population. Absence of these PIR variants in the South Asian population may contribute to the overall lower COVID-19 case fatality rates (CFR) despite the dense population in this region.

Phytochemicals from Plant Foods as Potential Source of Antiviral Agents: An Overview

To date, the leading causes of mortality and morbidity worldwide include viral infections, such as Ebola, influenza virus, acquired immunodeficiency syndrome (AIDS), severe acute respiratory syndrome (SARS) and recently COVID-19 disease, caused by the SARS-CoV-2 virus. Currently, we can count on a narrow range of antiviral drugs, especially older generation ones like ribavirin and interferon which are effective against viruses in vitro but can often be ineffective in patients. In addition to these, we have antiviral agents for the treatment of herpes virus, influenza virus, HIV and hepatitis virus. Recently, drugs used in the past especially against ebolavirus, such as remdesivir and favipiravir, have been considered for the treatment of COVID-19 disease. However, even if these drugs represent important tools against viral diseases, they are certainly not sufficient to defend us from the multitude of viruses present in the environment. This represents a huge problem, especially considering the unprecedented global threat due to the advancement of COVID-19, which represents a potential risk to the health and life of millions of people. The demand, therefore, for new and effective antiviral drugs is very high. This review focuses on three fundamental points: (1) presents the main threats to human health, reviewing the most widespread viral diseases in the world, thus describing the scenario caused by the disease in question each time and evaluating the specific therapeutic remedies currently available. (2) It comprehensively describes main phytochemical classes, in particular from plant foods, with proven antiviral activities, the viruses potentially treated with the described phytochemicals. (3) Consideration of the various applications of drug delivery systems in order to improve the bioavailability of these compounds or extracts. A PRISMA flow diagram was used for the inclusion of the works. Taking into consideration the recent dramatic events caused by COVID-19 pandemic, the cry of alarm that denounces critical need for new antiviral drugs is extremely strong. For these reasons, a continuous systematic exploration of plant foods and their phytochemicals is necessary for the development of new antiviral agents capable of saving lives and improving their well-being.

In silico inquest reveals the efficacy of Cannabis in the treatment of post-Covid-19 related neurodegeneration

Coronavirus (SARS-CoV-2), the causative agent of the Covid-19 pandemic has proved itself as the deadliest pathogen. A major portion of the population has become susceptible to this strain. Scientists are pushing their limits to formulate a vaccine against Covid-19 with the least side effects. Although the recent discoveries of vaccines have shown some relief from the covid infection rate, however, physical fatigue, mental abnormalities, inflammation and other multiple organ damages are arising as post-Covid symptoms. The long-term effects of these symptoms are massive. Patients with such symptoms are known as long-haulers and treatment strategy against this condition is still unknown. In this study, we tried to explore a strategy to deal with the post-Covid symptoms. We targeted three human proteins namely ACE2, Interleukin-6, Transmembrane serine protease and NRP1 which are already reported to be damaged via Covid-19 proteins and upregulated in the post-Covid stage. Our target plant in this study is Cannabis (popularly known as 'Ganja' in India). The molecular docking and simulation studies revealed that Cannabidiol (CBD) and Cannabivarin (CVN) obtained from Cannabis can bind to post-Covid symptoms related central nervous system (CNS) proteins and downregulate them which can be beneficial in post-covid symptoms treatment strategy. Thus we propose Cannabis as an important therapeutic plant against post-Covid symptoms.Communicated by Ramaswamy H. Sarma.

Pathological Findings in COVID-19 as a Tool to Define SARS-CoV-2 Pathogenesis. A Systematic Review

Introduction: The World Health Organization declared the COVID-19 pandemic in March 2020. COVID-19 still represents a worldwide health emergency, which causesa severe disease that has led to the death of many patients. The pathophysiological mechanism of SARS-CoV-2 determining the tissue damage is not clear and autopsycan be auseful tool to improve the knowledge of this infection and, thus, it can help achieve a timely diagnosis and develop an appropriate therapy. This is an overview of the main post-mortem findings reporting data on the infection effects on several organs. Methods: A systematic literature search was conducted in the PubMed database searching for articles from 1 January to August 31, 2020. Thearticles were selected identifying words/concepts in the titles and/or abstracts that indicated the analysis of the morphological/pathological tissue injuries related to SARS-CoV-2 disease by several investigations. Results: A total of 63 articles were selected. The main investigated tissue was the lung showing a diffuse alveolar damage (DAD) frequently associated with pulmonary thrombotic microangiopathy. Inflammatory findings and vascular damage were observed in other organs such as heart, liver, kidney, brain, spleen, skin and adrenal gland. The immunohistochemical analysis showed tissue inflammatory cells infiltrates. The virus presence was detected by several investigations such as RT-PCR, immunohistochemistry and electron microscope, showing the effect ofSARS-CoV-2not exclusively in the lung. Discussion: The evidence emerging from this review highlighted the importance of autopsy to provide a fundamental base in the process of understanding the consequences ofSARS-CoV-2 infection. COVID-19 is strictly related to a hyper inflammatory state that seems to start with DAD and immuno-thrombotic microangiopathy. Massive activation of the immune system and microvascular damage might also be responsible for indirect damage to other organs, even if the direct effect of the virus on these tissues cannot be excluded.

Sex differences in the mortality rate for coronavirus disease 2019 compared to other causes of death

Men are more likely than women to die due to coronavirus disease 2019 (COVID-19). This paper sets out to examine whether the magnitude of the sex differences in the COVID-19 mortality rate are unusual when compared to other common causes of death. In doing so, we aim to provide evidence as to whether the causal pathways for the sex differences in the mortality rate of COVID-19 likely differ from those for other causes of death. We found that sex differences in the age-standardized COVID-19 mortality rate were substantially larger than for the age-standardized all-cause mortality rate and most other common causes of death. These differences were especially large in the oldest age groups.

One Sentence Summary

The sex difference in the mortality rate of coronavirus disease 2019 is substantially larger than for other common causes of death.

Repurposing FDA-approved drugs to fight COVID-19 using in silico methods: Targeting SARS-CoV-2 RdRp enzyme and host cell receptors (ACE2, CD147) through virtual screening and molecular dynamic simulations

Background

Different approaches have been proved effective for combating the COVID-19 pandemic. Accordingly, in silico drug repurposing strategy, has been highly regarded as an accurate computational tool to achieve fast and reliable results. Considering SARS-CoV-2's structural proteins and their interaction the host's cell-specific receptors, this study investigated a drug repurposing strategy aiming to screen compatible inhibitors of FDA-approved drugs against viral entry receptors (ACE2 and CD147) and integral enzyme of the viral polymerase (RdRp).

Methods

The study screened the FDA-approved drugs against ACE2, CD147, and RDRP by virtual screening and molecular dynamics (MD) simulation.

Results

The results of this study indicated that five drugs with ACE2, four drugs with RDRP, and seven drugs with CD147 achieved the most favorable free binding energy (ΔG < −10). This study selected these drugs for MD simulation investigation whose results demonstrated that ledipasvir with ACE2, estradiol benzoate with CD147, and vancomycin with RDRP represented the most favorable ΔG. Also, paritaprevir and vancomycin have good binding energy with both targets (ACE2 and RdRp).

Conclusions

Ledipasvir, estradiol benzoate, and vancomycin and paritaprevir are potentially suitable candidates for further investigation as possible treatments of COVID-19 and novel drug development.

Flavonoids against the SARS-CoV-2 induced inflammatory storm

The disease severity of COVID-19, especially in the elderly and patients with co-morbidities, is characterized by hypercytokinemia, an exaggerated immune response associated with an uncontrolled and excessive release of proinflammatory cytokine mediators (cytokine storm). Flavonoids, important secondary metabolites of plants, have long been studied as therapeutic interventions in inflammatory diseases due to their cytokine-modulatory effects. In this review, we discuss the potential role of flavonoids in the modulation of signaling pathways that are crucial for COVID-19 disease, particularly those related to inflammation and immunity. The immunomodulatory ability of flavonoids, carried out by the regulation of inflammatory mediators, the inhibition of endothelial activation, NLRP3 inflammasome, toll-like receptors (TLRs) or bromodomain containing protein 4 (BRD4), and the activation of the nuclear factor erythroid-derived 2-related factor 2 (Nrf2), might be beneficial in regulating the cytokine storm during SARS-CoV-2 infection. Moreover, the ability of flavonoids to inhibit dipeptidyl peptidase 4 (DPP4), neutralize 3-chymotrypsin-like protease (3CL^pro) or to affect gut microbiota to maintain immune response, and the dual action of angiotensin-converting enzyme 2 (ACE-2) may potentially also be applied to the exaggerated inflammatory responses induced by SARS-CoV-2. Based on the previously proven effects of flavonoids in other diseases or on the basis of newly published studies associated with COVID-19 (bioinformatics, molecular docking), it is reasonable to assume positive effects of flavonoids on inflammatory changes associated with COVID-19. This review highlights the current state of knowledge of the utility of flavonoids in the management of COVID-19 and also points to the multiple biological effects of flavonoids on signaling pathways associated with the inflammation processes that are deregulated in the pathology induced by SARS-CoV-2. The identification of agents, including naturally occurring substances such as flavonoids, represents great approach potentially utilizable in the management of COVID-19. Although not clinically investigated yet, the applicability of flavonoids against COVID-19 could be a promising strategy due to a broad spectrum of their biological activities.

An Energy-Resolved Optical Non-invasive Device Detects Essential Electrolyte Balance in Humans at Point-of-Care

Regular monitoring of electrolyte balance is essential for patients suffering from chronic kidney disease (CKD), particularly those undergoing dialysis. In the context of the recent COVID-19 pandemic, more severe forms of infection are observed in elderly individuals and patients having co-morbidities like CKD. The repeated blood tests for the monitoring of electrolyte balance predispose them not only to COVID-19 but also other to hospital-acquired infections (HAI). Therefore, a non-invasive method for easy detection of essential electrolyte (K+ and Na+) levels is urgently needed. In this study, we developed an optical emission spectroscopy-based non-invasive device for simultaneous monitoring of salivary Na+ and K+ levels in a fast and reliable way. The device consisted of a closed spark chamber, micro-spectrometer, high voltage spark generator, electronic circuits, optical fiber, and an indigenously developed software based on the LabVIEW platform. The optical emission originating from the biological sample (i.e., saliva) due to recombination of ions energized by impingement of electrons returning from high voltage spark provides necessary information about the concentration of electrolytes. A small-scale clinical trial on 30 healthy human subjects shows the potential of the indigenously developed device in determining salivary Na + and K+ concentration. The low-cost, portable, point-of-care device requires only 2 mL of sample, and can simultaneously measure 1.0-190.0 mM Na+, and 1.0-270.9 mM K+ . To our understanding, the present work will find its relevance in combating COVID-19 morbidities, along with regular CKD patient-care.

SARS-CoV-2 Immuno-Pathogenesis and Potential for Diverse Vaccines and Therapies: Opportunities and Challenges

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is a novel coronavirus that emerged from Wuhan, China in late 2019 causing coronavirus disease-19 (COVID-19). SARS-CoV-2 infection begins by attaching to angiotensin-converting enzyme 2 receptor (ACE2) via the spike glycoprotein, followed by cleavage by TMPRSS2, revealing the viral fusion domain. Other presumptive receptors for SARS-CoV-2 attachment include CD147, neuropilin-1 (NRP1), and Myeloid C-lectin like receptor (CLR), each of which might play a role in the systemic viral spread. The pathology of SARS-CoV-2 infection ranges from asymptomatic to severe acute respiratory distress syndrome, often displaying a cytokine storm syndrome, which can be life-threatening. Despite progress made, the detailed mechanisms underlying SARS-CoV-2 interaction with the host immune system remain unclear and are an area of very active research. The process's key players include viral non-structural proteins and open reading frame products, which have been implicated in immune antagonism. The dysregulation of the innate immune system results in reduced adaptive immune responses characterized by rapidly diminishing antibody titers. Several treatment options for COVID-19 are emerging, with immunotherapies, peptide therapies, and nucleic acid vaccines showing promise. This review discusses the advances in the immunopathology of SARS-CoV-2, vaccines and therapies under investigation to counter the effects of this virus, as well as viral variants.

Is There a Relationship between COVID-19 and Hyponatremia?

Nowadays, humanity faces one of the most serious health crises, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. The severity of coronavirus disease 2019 (COVID-19) pandemic is related to the high rate of interhuman transmission of the virus, variability of clinical presentation, and the absence of specific therapeutic methods. COVID-19 can manifest with non-specific symptoms and signs, especially among the elderly. In some cases, the clinical manifestations of hyponatremia may be the first to appear. The pathophysiological mechanisms of hyponatremia among patients with COVID-19 are diverse, including syndrome of inappropriate antidiuretic hormone secretion (SIADH), digestive loss of sodium ions, reduced sodium ion intake or use of diuretic therapy. Hyponatremia may also be considered a negative prognostic factor in patients diagnosed with COVID-19. We need further studies to evaluate the etiology and therapeutic management of hyponatremia in patients with COVID-19.

Genetic Diversity of SARS-CoV2 and Environmental Settings: Possible Association with Neurological Disorders

The new coronavirus (CoV), called novel coronavirus disease 2019 (COVID-19), belongs to the Coronaviridae family which was originated from the sea market in Wuhan city in China, at the end of the year 2019. COVID-19 and severe acute respiratory syndrome (SARS) are belonging to the same family (Coronaviridae). The current outbreak of COVID-19 creates public concern and threats all over the world and now it spreads out to more than 250 countries and territories. The researchers and scientists from all over the world are trying to find out the therapeutic strategies to abate the morbidity and mortality rate of the COVID-19 pandemic. The replication, spreading, and severity of SARS-CoV2 depend on environmental settings. Noteworthy, meteorological parameters are considered as crucial factors that affect respiratory infectious disorders, although the controversial effect of the meteorological parameter is exposed against COVID-19. Besides, COVID-19 accelerates the pathogenesis of the neurological disorders. However, the pathogenic mechanisms between COVID-19 and neurological disorders are still unclear. Hence, this review is focused on the genomics and ecology of SARS-CoV2 and elucidated the effects of climatic factors on the progression of COVID-19. This review also critically finds out the vulnerability between COVID-19 and neurological disorders based on the latest research data.

Vitamin C Inhibits Angiotensin-Converting Enzyme-2 in Isolated Rat Aortic Ring

AIMS

The study aimed to assess the inhibitory effect of Vitamin C on angiotensin-converting enzyme 2.

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which uses angiotensin-converting enzyme 2 (ACE-II) as the first route to infect human cells. Accordingly, agents with potential inhibition of ACE-II receptors might be effective in the prevention and management of COVID-19.

OBJECTIVE

The goal of this work was to assess the possible inhibitory effect of ACE-II on ascorbic acid using an ex vivo approach based on the inhibition of diminazene-induced vasorelaxation.

MATERIALS AND METHODS

In the present study, diminazene was used as a known specific inhibitor of ACE-II. Then, the vasorelaxant effect of ascorbic acid on diminazene-induced relaxation was examined using isolated aortic rings. All experiments of this study were evaluated on isolated aortic rings precontracted by epinephrine.

RESULTS

The results confirmed that diminazene-induced vasorelaxation in a dose-dependent manner. More interestingly, ascorbic acid inhibited diminazene-induced vasorelaxation in a dose-dependent manner.

CONCLUSION

This investigation provides valuable experimental proof of the efficacy of ascorbic acid (Vitamin C) on inhibiting ex vivo vascular angiotensin-converting enzyme II, which is known among the pharmacological targets of anti-COVID-19 drugs.

Age-Related Differences in the Expression of Most Relevant Mediators of SARS-CoV-2 Infection in Human Respiratory and Gastrointestinal Tract

Background: Clinical features of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection seem to differ in children compared to that in adults. It has been hypothesized that the lower clinical severity in children could be influenced by differential expression of the main host functional receptor to SARS-CoV-2, the angiotensin-converting enzyme 2 (ACE2), but data are still conflicting. To explore the origin of age-dependent clinical features of coronavirus disease 2019 (COVID-19), we comparatively evaluated the expression in children and adult subjects of the most relevant mediators of the SARS-CoV-2 infection: ACE2, angiotensin-converting enzyme 1 (ACE1), transmembrane serine protease-2 (TMPRSS2), and neuropilin-1 (NRP1), at upper respiratory tract and small intestine level. Methods: The expression of ACE2, ACE1, TMPRSS2, and NRP1 in nasal epithelium and in small intestine epithelium was investigated by quantitative real-time PCR analysis. Results: We found no differences in ACE2, ACE1, and TMPRSS2 expression in the nasal epithelium comparing children and adult subjects. In contrast, nasal epithelium NRP1 expression was lower in children compared to that in adults. Intestinal ACE2 expression was higher in children compared to that in adults, whereas intestinal ACE1 expression was higher in adults. Intestinal TMPRSS2 and NRP1 expression was similar comparing children and adult subjects. Conclusions: The lower severity of SARS-CoV-2 infection observed in children may be due to a different expression of nasal NRP1, that promotes the virus interaction with ACE2. However, the common findings of intestinal symptoms in children could be due to a higher expression of ACE2 at this level. The insights from these data will be useful in determining the treatment policies and preventive measures for COVID-19.

Effects of the Na+/H+ Ion Exchanger on Susceptibility to COVID-19 and the Course of the Disease

The Na⁺/H⁺ ion exchanger (NHE) pumps Na⁺ inward the cell and H⁺ ion outside the cell. NHE activity increases in response to a decrease in intracellular pH, and it maintains intracellular pH in a narrow range. Patients with obesity, diabetes, and hypertension and the elderly are prone to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. The angiotensin II (Ang II) level is high in chronic diseases such as diabetes, hypertension, and obesity. Ang II is the main stimulator of NHE, and an increased Ang II level causes prolonged NHE activation in these patients. The long-term increase in NHE activity causes H⁺ ions to leave the cell in patients with diabetes, hypertension, and obesity. Increasing H⁺ ions outside the cell lead to an increase in oxidative stress and reactive oxygen species. H⁺ ion flows into the cell due to the increased oxidative stress. This vicious circle causes intracellular pH to drop. Although NHE is activated when intracellular pH decreases, there is prolonged NHE activation in chronic diseases such as aforementioned. Novel coronavirus disease 2019 (COVID-19) progression may be more severe and mortal in these patients. SARS-CoV-2 readily invades the cell at low intracellular pH and causes infection. The renin-angiotensin system and NHE play a vital role in regulating intracellular pH. The reduction of NHE activity or its prolonged activation may cause susceptibility to SARS-CoV-2 infection by lowering intracellular pH in patients with diabetes, hypertension, and obesity. Prolonged NHE activation in these patients with COVID-19 may worsen the course of the disease. Scientists continue to investigate the mechanism of the disease and the factors that affect its clinical progression.

Multi-Omics Approach in the Identification of Potential Therapeutic Biomolecule for COVID-19

COVID-19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It has a disastrous effect on mankind due to the contagious and rapid nature of its spread. Although vaccines for SARS-CoV-2 have been successfully developed, the proven, effective, and specific therapeutic molecules are yet to be identified for the treatment. The repurposing of existing drugs and recognition of new medicines are continuously in progress. Efforts are being made to single out plant-based novel therapeutic compounds. As a result, some of these biomolecules are in their testing phase. During these efforts, the whole-genome sequencing of SARS-CoV-2 has given the direction to explore the omics systems and approaches to overcome this unprecedented health challenge globally. Genome, proteome, and metagenome sequence analyses have helped identify virus nature, thereby assisting in understanding the molecular mechanism, structural understanding, and disease propagation. The multi-omics approaches offer various tools and strategies for identifying potential therapeutic biomolecules for COVID-19 and exploring the plants producing biomolecules that can be used as biopharmaceutical products. This review explores the available multi-omics approaches and their scope to investigate the therapeutic promises of plant-based biomolecules in treating SARS-CoV-2 infection.

Exploring the Multifaceted Therapeutic Potential of Withaferin A and Its Derivatives

Withaferin A (WA), a manifold studied, C28-steroidal lactone withanolide found in Withania somnifera. Given its unique beneficial effects, it has gathered attention in the era of modern science. Cancer, being considered a "hopeless case and the leading cause of death worldwide, and the available conventional therapies have many lacunae in the form of side effects. The poly pharmaceutical natural compound, WA treatment, displayed attenuation of various cancer hallmarks by altering oxidative stress, promoting apoptosis, and autophagy, inhibiting cell proliferation, reducing angiogenesis, and metastasis progression. The cellular proteins associated with antitumor pathways were also discussed. WA structural modifications attack multiple signal transduction pathways and enhance the therapeutic outcomes in various diseases. Moreover, it has shown validated pharmacological effects against multiple neurodegenerative diseases by inhibiting acetylcholesterinases and butyrylcholinesterases enzyme activity, antidiabetic activity by upregulating adiponectin and preventing the phosphorylation of peroxisome proliferator-activated receptors (PPARγ), cardioprotective activity by AMP-activated protein kinase (AMPK) activation and suppressing mitochondrial apoptosis. The current review is an extensive survey of various WA associated disease targets, its pharmacokinetics, synergistic combination, modifications, and biological activities.

Severe Acute Respiratory Syndrome Coronavirus-2 Induces Cytokine Storm and Inflammation During Coronavirus Disease 19: Perspectives and Possible Therapeutic Approaches

The new coronavirus outbreak was first identified in Wuhan, China, in December 2019, and has turned out to be a global health emergency, affecting millions of people worldwide. Coronavirus disease 19 (COVID-19), caused by the SARS-CoV-2 virus, can manifest with flu-like symptoms and can be complicated by severe pneumonia with acute respiratory distress syndrome (ARDS); however a large percentage of infected individuals do not have symptoms but contribute to the spread of the disease. Severe acute respiratory syndrome coronavirus-2 infection has become a global public health emergency since no available treatment seems effective and it is hard to manage the several complications caused by an intense release of cytokines. This paper reviews the current options on drugs used to reduce the deadly effects of the cytokine storm.

COVID-19 Outbreak: Pathogenesis, Current Therapies, and Potentials for Future Management

At the end of 2019, a novel coronavirus (CoV) was found at the seafood market of Hubei province in Wuhan, China, and this virus was officially named coronavirus diseases 2019 (COVID-19) by World Health Organization (WHO). COVID-19 is mainly characterized by severe acute respiratory syndrome coronavirus-2 (SARS-CoV2) and creates public health concerns as well as significant threats to the economy around the world. Unfortunately, the pathogenesis of COVID-19 is unclear and there is no effective treatment of this newly life-threatening and devastating virus. Therefore, it is crucial to search for alternative methods that alleviate or inhibit the spread of COVID-19. In this review, we try to find out the etiology, epidemiology, symptoms as well as transmissions of this novel virus. We also summarize therapeutic interventions and suggest antiviral treatments, immune-enhancing candidates, general supplements, and CoV specific treatments that control replication and reproduction of SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV).