Should ACE2 be given a chance in COVID-19 therapeutics: A semi-systematic review of strategies enhancing ACE2

Food-Derived Up-Regulators and Activators of Angiotensin Converting Enzyme 2: A Review

Angiotensin-converting enzyme 2 (ACE2) is a key enzyme in the renin-angiotensin system (RAS), also serving as an amino acid transporter and a receptor for certain coronaviruses. Its primary role is to protect the cardiovascular system via the ACE2/Ang (1-7)/MasR cascade. Given the critical roles of ACE2 in regulating numerous physiological functions, molecules that can upregulate or activate ACE2 show vast therapeutic value. There are only a few ACE2 activators that have been reported, a wide range of molecules, including food-derived compounds, have been reported as ACE2 up-regulators. Effective doses of bioactive peptides range from 10 to 50 mg/kg body weight (BW)/day when orally administered for 1 to 7 weeks. Protein hydrolysates require higher doses at 1000 mg/kg BW/day for 20 days. Phytochemicals and vitamins are effective at doses typically ranging from 10 to 200 mg/kg BW/day for 3 days to 6 months, while Traditional Chinese Medicine requires doses of 1.25 to 12.96 g/kg BW/day for 4 to 8 weeks. ACE2 activation is linked to its hinge-bending region, while upregulation involves various signaling pathways, transcription factors, and epigenetic modulators. Future studies are expected to explore novel roles of ACE2 activators or up-regulators in disease treatments and translate the discovery to bedside applications.

Natural Products as a Potential Source of Promising Therapeutics for COVID-19 and Viral Diseases

Background

A global pandemic has recently been observed due to the new coronavirus disease, caused by SARS-CoV-2. Since there are currently no antiviral medicines to combat the highly contagious and lethal COVID-19 infection, identifying natural sources that can either be viricidal or boost the immune system and aid in the fight against the disease can be an essential therapeutic support.

Methods

This review was conducted based on published papers related to the herbal therapy of COVID-19 by search on databases including PubMed and Scopus with herbal, COVID-19, SARS-CoV-2, and therapy keywords.

Results

To combat this condition, people may benefit from the therapeutic properties of medicinal plants, such as increasing their immune system or providing an antiviral impact. As a result, SARS-CoV-2 infection death rates can be reduced. Various traditional medicinal plants and their bioactive components, such as COVID-19, are summarized in this article to assist in gathering and debating techniques for combating microbial diseases in general and boosting our immune system in particular.

Conclusion

The immune system benefits from natural products and many of these play a role in activating antibody creation, maturation of immune cells, and stimulation of innate and adaptive immune responses. The lack of particular antivirals for SARS-CoV-2 means that apitherapy might be a viable option for reducing the hazards associated with COVID-19 in the absence of specific antivirals.

Is the prognosis of non-hypertensive, COVID-19 patients treated with renin-angiotensin-aldosterone system inhibitors more uncertain?

Previous studies suggested that ongoing treatment with renin-angiotensin-aldosterone system (RAAS) inhibitor drugs may alter the course of SARS-CoV-2 infection and promote the development of more severe forms of the disease. The authors conducted a comparative, observational study to retrospectively analyze data collected from 394 patients admitted to ICU due to SARS-CoV-2 pneumonia. The primary aim of the study was to establish an association between the use of RAAS inhibitor drugs and mortality in the ICU. The secondary aims of the study were to establish an association between the use of RAAS inhibitor drugs and clinical severity at ICU admission, the need for tracheal intubation, total days of mechanical ventilation, and the ICU length of stay. The authors found no statistically significant difference in ICU mortality between patients on RAAS inhibitor drugs at admission and those who were not (31.3% versus 26.2% mortality, p-value 0.3). However, the group of patients taking RAAS inhibitor drugs appeared to be more critical at ICU admission, and this difference became statistically significant in the subgroup of non-hypertensive patients. ICU mortality in the subgroup of non-hypertensive patients treated with RAAS inhibitor drugs also tended to be higher. Overexpression of the angiotensin-converting enzyme 2 (ACE2) in human cells, induced by RAAS inhibitor drugs, promotes viral entry-replication of SARS-CoV-2 and alters the basal balance of the RAAS, which may explain the findings observed in the present study. These phenomena may be amplified in non-hypertensive patients treated with RAAS inhibitor therapy.

Alamandine: A promising treatment for fibrosis

Angiotensin (Ang) II, the main active member of the renin angiotensin system (RAS), is essential for the maintenance of cardiovascular homeostasis. However, hyperactivation of the RAS causes fibrotic diseases. Ang II has pro-inflammatory actions, and moreover activates interstitial fibroblasts and/or dysregulates extracellular matrix degradation. The discovery of new RAS pathways has revealed the complexity of this system. Among the RAS peptides, alamandine (ALA, Ala¹ Ang 1-7) has been identified in humans, rats, and mice, with protective actions in different pathological conditions. ALA has similar effects to its well-known congener, Ang-(1-7), as a vasodilator, anti-inflammatory, and antifibrotic. Its protective role against cardiovascular diseases is well-reviewed in the literature. However, the protective actions of ALA in fibrotic conditions have been little explored. Therefore, in this article, we review the ability of ALA to modulate the inflammatory process and collagen deposition, to serve as an antioxidant, and to mediate protection against functional disorders. In this scenario, we also explore ALA as a promising therapy for pulmonary fibrosis after COVID-19 infection.

Connecting the dots between inflammatory cascades of obesity and COVID-19 in light of mortal consequences-a review

Obesity is a term that has recently been referred to describe a condition in which a person has become a diseased vessel. Obesity's internal pathology is too mysterious as it has a close resemblance with fatal diseases pathology. Obesity and coronavirus disease 2019 (COVID-19) are simultaneous epidemics declared by many organizations after observing their rampage in the recent world. Oxidative stress, cytokine storm, interleukin, and their contribution to the internal adipocyte environment implicated in the cascades of inflammatory pathology are portrayed here. Major determinants like angiotensin-converting enzyme 2 (ACE2) and renin-angiotensin-aldosterone system (RAAS) axis are highly sensitive molecular factors. Data from various countries suggested a clinical overview of how greater body mass index (BMI) is related to greater COVID-19 risk. It also gives insight into how obese individuals are obligately getting admitted and combating COVID-19 in intensive care unit including children less than 13 years of age under ultimate therapeutic options. There are numerous studies currently taking place for finding a cure for obesity which are mainly focused on natural resources and novel therapies like photobiomodulation (PBM) consisting of laser treatment, infrared treatment, etc. as current pharmacological treatments are reported to have fatal adverse effects. Finally, it is discussed how attenuating obesity will be a solution for future combat strategy. This review gives light on the areas of coagulation, inflammatory parameters, cardiometabolic complications, endothelial dysfunctions, immunological infirmity due to COVID-19 in obese individuals. A conceptual outline about correlation between the inflammatory pathophysiological steps triggering the aggravation of fatal consequences has been drawn in this review.

Effect of Preexisting Asthma on the Risk of ICU Admission, Intubation, and Death from COVID-19: A Systematic Review and Meta-Analysis

Background

The Centers for Disease Control and Prevention (CDC) identifies asthma as a comorbidity in COVID-19 that increases the risk of severity and death. However, research has shown that asthma is not associated with increased severity and death, thus making the consequences of asthma in COVID-19 unclear.

Methods

We searched the electronic databases PubMed, WHO COVID-19 database, and Taylor and Francis Online for studies that compared the medical outcomes of COVID-19 between patients with and without asthma, from the emergence of SARS-CoV-2 in December 2019 to the 3^rd of September 2021, excluded duplicates, reviews, editorials, and case reports, and screened the titles, abstracts, and full texts. The quality of the included studies was assessed using the Newcastle–Ottawa Scale (NOS) for nonrandomized studies. Rates of intensive care unit (ICU) admission, intubation, and death among patients with and without asthma were compiled and meta-analysis was conducted using a random-effects model.

Results

Nineteen studies with a total of 289,449 participants met the inclusion criteria. COVID-19 patients with asthma had no significant association with increased risk of ICU admission, intubation, and death as compared with those without asthma ((odds ratio (OR) = 1.25, confidence interval (CI) = 0.90–1.74, I² = 82%, X² = 55.13, p < 0.01), (OR = 0.89, CI = 0.59–1.34, I² = 91%, X² = 110.82, p < 0.01), and (OR = 0.90, 95% CI = 0.63–1.27, I² = 88%, X² = 146.96, p < 0.01)), respectively.

Conclusion

Preexisting asthma did not significantly increase the risk of poorer prognosis and death from COVID-19.

A Systematic Review of the Global Intervention for SARS-CoV-2 Combating: From Drugs Repurposing to Molnupiravir Approval

The rising outbreak of SARS-CoV-2 continues to unfold all over the world. The development of novel effective antiviral drugs to fight against SARS-CoV-2 is a time cost. As a result, some specific FDA-approved drugs have already been repurposed and authorized for COVID-19 treatment. The repurposed drugs used were either antiviral or non-antiviral drugs. Accordingly, the present review thoroughly focuses on the repurposing efficacy of these drugs including clinical trials experienced, the combination therapies used, the novel methods followed for treatment, and their future perspective. Therefore, drug repurposing was regarded as an effective avenue for COVID-19 treatment. Recently, molnupiravir is a prodrug antiviral medication that was approved in the United Kingdom in November 2021 for the treatment of COVID-19. On the other hand, PF-07321332 is an oral antiviral drug developed by Pfizer. For the treatment of COVID-19, the PF-07321332/ritonavir combination medication is used in Phase III studies and was marketed as Paxlovid. Herein, we represented the almost history of combating COVID-19 from repurposing to the recently available oral anti-SARS-CoV-2 candidates, as a new hope to end the current pandemic.

Adverse events and Breakthrough infections associated with COVID-19 vaccination in the Indian population

Vaccines against COVID‐19 provide immunity to deter severe morbidities associated with the infection. However, it does not prevent infection altogether in all exposed individuals. Furthermore, emerging variants of SARS‐CoV‐2 impose a threat concerning the competency of the vaccines in combating the infection. This study aims to determine the variability in adverse events and the extent of breakthrough infections in the Indian population. A retrospective study was conducted using a pre‐validated questionnaire encompassing social, demographic, general health, the status of SARS‐CoV‐2 infection, vaccination, associated adverse events, and breakthrough infections in the Indian population. Informed consent and ethical approval were obtained as per Indian Council of Medical Research (ICMR) guidelines. Participants, who provided the complete information, were Indian citizens, above 18 years, and if vaccinated, administered with either Covishield or Covaxin, were considered for the study. Data have been compiled in Microsoft Excel and analyzed for statistical differences using STATA 11. The responses from 2051 individuals fulfilling the inclusion criteria were analyzed. Among 2051, 1119 respondents were vaccinated and 932 respondents were non‐vaccinated. Among 1119 vaccinated respondents, 7 were excluded because of missing data. Therefore, out of 1112 vaccinated, 413 experienced adverse events with a major fraction of younger individuals, age 18–40 years, getting affected (74.82%; 309/413). Furthermore, considerably more females than males encountered adverse consequences to vaccination (p < 0.05). Among vaccinated participants, breakthrough infections were observed in 7.91% (88/1112; 57.96% males and 42.04% females) with the older age group, 61 years and above (odds ratio, 3.25 [1.32–8.03]; p = 0.011), and males were found to be at higher risk. Further research is needed to find the age and sex‐related factors in determining vaccine effectiveness and adverse events.

Significant higher adverse events following COVID‐19 vaccination in females in comparison to males.

Breakthrough infections among Indian population was found to be 7.91%.

Older people and males were found to be at high risk for getting breakthrough infections.

The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) Pandemic: Are Africa's Prevalence and Mortality Rates Relatively Low?

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the cause of coronavirus disease 19 (COVID-19), has been rapidly spreading since December 2019, and within a few months, it turned out to be a global pandemic. The disease affects primarily the lungs, but its pathogenesis spreads to other organs as well. However, its mortality rates vary, and in the majority of infected people, there are no serious consequences. Many factors including advanced age, preexisting health conditions, and genetic predispositions are believed to exacerbate outcomes of COVID-19. The virus contains several structural proteins including the spike (S) protein with subunits for binding, fusion, and internalization into host cells following interaction with host cell receptors and proteases (ACE2 and TMPRSS2, respectively) to cause the subsequent pathology. Although the pandemic has spread into all countries, most of Africa is thought of as having relatively less prevalence and mortality. Several hypotheses have been forwarded as reasons for this and include warmer weather conditions, vaccination with BCG (i.e., trained immunity), and previous malaria infection. From genetics or metabolic points of view, it has been proposed that most African populations could be protected to some degree because they lack some genetic susceptibility risk factors or have low-level expression of allelic variants, such as ACE2 and TMPRSS2 that are thought to be involved in increased infection risk or disease severity. The frequency of occurrence of α-1 antitrypsin (an inhibitor of a tissue-degrading protease, thereby protecting target host tissues including the lung) deficiency is also reported to be low in most African populations. More recently, infections in Africa appear to be on the rise. In general, there are few studies on the epidemiology and pathogenesis of the disease in African contexts, and the overall costs and human life losses due to the pandemic in Africa will be determined by all factors and conditions interacting in complex ways.

Dysregulated Bradykinin: Mystery in the Pathogenesis of COVID-19

The COVID-19 pandemic is rapidly spreading, and health care systems are being overwhelmed with the huge number of cases, with a good number of cases requiring intensive care. It has become imperative to develop safe and effective treatment strategies to improve survival. In this regard, understanding the pathogenesis of COVID-19 is highly important. Many hypotheses have been proposed, including the ACE/angiotensin-II/angiotensin receptor 1 pathway, the complement pathway, and the angiotensin-converting enzyme 2/mitochondrial assembly receptor (ACE2/MasR) pathway. SARS-CoV-2 binds to the ACE2 on the cell surface, downregulating the ACE2, and thus impairs the inactivation of bradykinin and des-Arg9-bradykinin. Bradykinin, a linear nonapeptide, is extensively distributed in plasma and different tissues. Kininogens in plasma and tissue are the main sources of the two vasoactive peptides called bradykinin and kallidin. However, the role of the dysregulated bradykinin pathway is less explored in the pathogenesis of COVID-19. Understanding the pathogenesis of COVID-19 is crucial for the development of new effective treatment approaches which interfere with these pathways. In this review, we have tried to explore the interaction between SARS-CoV-2, ACE2, bradykinin, and its metabolite des-Arg9-bradykinin in the pathogenesis of COVID-19.

The Interaction Between Pulmonary Fibrosis and COVID-19 and the Application of Related Anti-Fibrotic Drugs

COVID-19 is a highly contagious respiratory disease, which mainly affects the lungs. Critically ill patients are easily complicated by cytokine storms, acute respiratory distress syndrome (ARDS), and respiratory failure, which seriously threaten their lives. Pulmonary fibrosis (PF) is a common interstitial lung disease, and its pathogenesis may involve the participation of a variety of immune cells and inflammatory factors. Current studies have shown that patients with COVID-19 may be complicated by pulmonary fibrosis, and patients with pulmonary fibrosis may also be at higher risk of contracting COVID-19 than healthy people. Pulmonary fibrosis is an important risk factor leading to the aggravation of COVID-19 disease. COVID-19 complicated by cytokine storm and ARDS mechanism pathways are similar to the pathogenesis of pulmonary fibrosis. The potential interaction between pulmonary fibrosis and COVID-19 can cause acute exacerbation of the patient’s condition, but the potential mechanism between the two has not been fully elucidated. Most of the drug treatment programs for COVID-19-related pulmonary fibrosis are currently formulated about the relevant guidelines for idiopathic pulmonary fibrosis (IPF), and there is no clear drug treatment program recommendation. This article aims to summarize the relevant mechanism pathways of COVID-19 and pulmonary fibrosis, explore the interrelationships and possible mechanisms, and discuss the value and risks of existing and potential COVID-19-related pulmonary fibrosis treatment drugs, to provide reference for anti-fibrosis treatment for patients.

SIT1 transporter as a potential novel target in treatment of COVID-19

Studies published earlier this year demonstrated the association of the solute carrier SLC6A20 gene with the risk and severity of COVID-19. The SLC6A20 protein product (Sodium-dependent Imino Transporter 1 (SIT1)) is involved in the transport of amino acids, including glycine. Here we summarized the results of recent studies demonstrating the interaction of SIT1 with the ACE2 receptor for SARS-CoV-2 as well as an observed association of SLC6A20 with the risk and traits of Type 2 diabetes (T2D). Recently, it was also proposed that SLC6A20 represents the novel regulator of glycine levels and that glycine has beneficial effects against the proinflammatory cytokine secretion induced by SARS-CoV-2 infection. Ivermectin, as a partial agonist of glycine-gated chloride channels, was also recently suggested to interfere with the COVID-19 cytokine storm by inducing the activation of glycine receptors. Furthermore, plasma glycine levels are found to be decreased in diabetic patients. Thus, further clinical trials are warranted to confirm the potential favorable effects of targeting the SIT1 transporter and glycine levels in the treatment of COVID-19, particularly for the severe case of disease associated with hyperglycemia, inflammation, and T2D. These findings suggest that SIT1 may potentially represent one of the missing pieces in the complex puzzle observed between these two pandemic diseases and the potential novel target for their efficient treatment.

Similarities between COVID-19 and systemic sclerosis early vasculopathy: A "viral" challenge for future research in scleroderma

OBJECTIVE

To review similarities between COVID-19 and systemic sclerosis (SSc) early vasculopathy to provide novel insights into both diseases.

METHODS

A narrative review of the literature supplemented with expert opinion.

RESULTS

There is clear evidence that the endothelium is at the centre stage in SSc and COVID-19, with endothelial cell activation/injury and dysfunction creating the crucial evolving step in the pathogenesis of both diseases. The angiotensin system has also been implicated in the early stages of both COVID-19 and SSc. Autoptic studies provide novel insights into the effects of SARS-CoV-2 on the endothelium. Normal endothelium and endothelial dysfunction in COVID-19 and SSc are discussed. It is debated whether SARS-CoV-2 infection triggers autoimmunity with production of autoantibodies which is of mechanistic interest because other viral illnesses are potentially involved in endothelial dysfunction and in SSc pathogenesis.

CONCLUSION

COVID-19 is due to a direct assault of SARS-CoV-2 on the vascular system as an acute infection, whereas SSc remains a chronic/sub-acute autoimmune disease of largely unknown etiology Further study and exploration of the SARS-CoV-2 pathogenic mechanisms might provide further useful milestones in the understanding of the early SSc pathogenesis.

Vitamin D and immuno-pathology of COVID-19: many interactions but uncertain therapeutic benefits

Introduction: COVID-19 pandemic has caused huge loss of human lives and extensive socio-economic damages. The immuno-pathology of this disease is neither clearly understood nor there are effective drugs for severe cases of COVID-19. Repurposing of available drugs for the treatment of COVID-19 is imperative.Areas Covered: This review has gathered the evidence from PubMed, Google Scholar, WHO, and other reliable websites on COVID-19 and summarized the existing knowledge of the immuno-pathology of COVID-19. We elucidated how vitamin D through its diverse actions on immune effector cells, epithelial cells, or renin-angiotensin-aldosterone system could have a modulatory role on the pathogenic mechanisms of COVID-19. The epidemiological evidence associating vitamin D deficiency with the severity and incidence of COVID-19 is also presented. However, the evidence of clinical benefit to patients of COVID-19 from randomized controlled trials with vitamin D has not come as yet.Expert opinion: It is now established that fatality of COVID-19 is primarily determined by hyperactivation of the host's innate immune system in response to SARS-CoV-2 invasion, and thus the research on the immuno-modulatory and other roles of vitamin D against viral infections should be pursued vigorously. This would be also useful for future pandemics caused by other novel viruses.

COVID-19: Vaccine Delivery System, Drug Repurposing and Application of Molecular Modeling Approach

The acute respiratory syndrome coronavirus (SARS-CoV-2) has spread across the world, resulting in a pandemic COVID-19 which is a human zoonotic disease that is caused by a novel coronavirus (CoV) strain thought to have originated in wild or captive bats in the initial COVID outbreak region. The global COVID-19 outbreak started in Guangdong Province, China's southernmost province. The global response to the COVID-19 pandemic has been hampered by the sheer number of infected people, many of whom need intensive care before succumbing to the disease. The epidemic is being handled by a combination of disease control by public health interventions and compassionate treatment for those who have been impacted. There is no clear anti-COVID-19 medication available at this time. However, the need to find medications that can turn the tide has led to the development of a number of investigational drugs as potential candidates for improving outcomes, especially in the severely and critically ill. Although many of these adjunctive medications are still being studied in clinical trials, professional organizations have attempted to define the circumstances in which their use is deemed off-label or compassionate. It is important to remind readers that new information about COVID-19's clinical features, treatment options, and outcomes is released on a regular basis. The mainstay of treatment remains optimized supportive care, and the therapeutic effectiveness of the subsequent agents is still being studied.

Evaluation of Dual Inhibitory Effect of Anagliptin, Ramipril, and Lisinopril on Angiotensin-Converting Enzyme and DPP-4 Activities

BACKGROUND

We previously tested two angiotensin-converting enzyme (ACE) inhibitors and two dipeptidyl peptidase-4 (DPP-4) inhibitors for dual enzyme inhibitory effect. Only two DPP-4 inhibitors, linagliptin and sitagliptin, were able to inhibit ACE.

OBJECTIVE

In the present study, we investigated if other inhibitors of ACE or DPP-4 could simultaneously inhibit the activities of both DPP-4 and ACE.

METHODS

Forty Sprague Dawley rats were used. The control group received saline only. The other three groups were treated with anagliptin, ramipril, or lisinopril. Two different doses were tested, separated with a 6-day drug-free interval. Angiotensin II (ang II) levels, the activities of ACE, and DPP-4 were measured from blood samples at baseline and days 1, 10, and 14. After the oral glucose challenge, levels of the active form of glucagon-like peptide-1 (GLP-1) were measured.

RESULTS

Regardless of the dose, anagliptin did not show any inhibitory effect on the activity of ACE or ang II levels. For ramipril and lisinopril, only a high dose of lisinopril was able to produce a modest reduction of the DPP-4 activity, but it was not enough to inhibit the inactivation of GLP-1.

CONCLUSION

It seems that while most ACE inhibitors cannot affect DPP-4 activity, inhibitors of DPP-4 vary in their effect on ACE activity. The selection of DPP-4 inhibitors under different clinical situations should take into account the action of these drugs on ACE.

Can Resveratrol-Inhaled Formulations Be Considered Potential Adjunct Treatments for COVID-19?

The pandemic caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) has led to an extraordinary threat to the global healthcare system. This infection disease, named COVID-19, is characterized by a wide clinical spectrum, ranging from asymptomatic or mild upper respiratory tract illness to severe viral pneumonia with fulminant cytokine storm, which leads to respiratory failure. To improve patient outcomes, both the inhibition of viral replication and of the unwarranted excessive inflammatory response are crucial. Since no specific antiviral drug has been proven effective for the treatment of patients and the only upcoming promising agents are monoclonal antibodies, inexpensive, safe, and widely available treatments are urgently needed. A potential anti-inflammatory molecule to be evaluated, which possesses antiviral activities in several experimental models, is the polyphenol resveratrol. This compound has been shown to inhibit SARS-CoV-2 replication in human primary bronchial epithelial cell cultures and to downregulate several pathogenetic mechanisms involved in COVID-19 severity. The use of resveratrol in clinical practice is limited by the low bioavailability following oral administration, due to the pharmacokinetic and metabolic characteristics of the molecule. Therefore, topical administration through inhaled formulations could allow us to achieve sufficiently high concentrations of the compound in the airways, the entry route of SARS-CoV-2.

Renin-angiotensin-aldosterone system blockers and region-specific variations in COVID-19 outcomes: findings from a systematic review and meta-analysis

BACKGROUND AND AIMS

Coronavirus disease 2019 (COVID-19) has been observed to cause a high mortality in people with cardiometabolic diseases. Renin-angiotensin-aldosterone system (RAAS) blockers enhance the expression of ACE2, the binding receptor of SARS-CoV-2, and can enhance viral infectivity. We aim to provide a pooled estimate of the effect of RAAS blockers on COVID-19 outcomes.

METHODS

A literature search was performed using MEDLINE/PubMed, Google Scholar and preprint servers. All clinical studies analyzing the effect of RAAS blockers on clinical outcomes in COVID-19 patients were included in this study. Newcastle-Ottawa scale was used for quality assessment of studies. MOOSE checklist was followed. Mortality and severity outcomes were recorded as pooled odds ratio (OR) with 95% Confidence Intervals (CIs) and level of heterogeneity (I 2). Odds of mortality was the primary outcome. Odds of severity, hospitalization, intensive care unit (ICU) admission, mechanical ventilation (MV), steroid use and acute kidney injury were the secondary outcomes. Severity outcomes were chosen depending upon the definition used by respective authors. Country-specific variations and effects of individual class of RAAS blockers were also explored.

RESULTS

In total 47 published studies were included in the final analysis, with a total of 26,432 patients from 31 studies in mortality analysis and 20,127 patients from 23 studies in severity analysis. No increased risk of mortality [Pooled OR 0.91 (0.65-1.26), I 2 = 89%] or severity [Pooled OR 1.08 (0.79-1.46), I 2 = 88%] was seen with RAAS blockers. The drug class was protective in hypertension [pooled OR 0.63 (0.46-0.86), I 2 = 58%]. Severity of COVID-19 outcomes was high for Europeans [Pooled OR 2.08 (1.52-2.85), I 2 = 77%] and US patients [Pooled OR 1.87 (1.62-2.17)]. Nearly 4 times higher risk of hospitalization and 2 times higher risk of ICU admission and MV were observed in US patients. Class-wise, angiotensin receptor blocker use was associated with 1.6 times higher odds of severity, mainly in Europeans.

CONCLUSION

RAAS blockers are not associated with increased mortality in COVID-19 patients and should be continued in hypertensives. US and European patients are at higher risk of severe outcomes. Pharmacogenetic differences may explain the ethnicity-related variations.

PLAIN LANGUAGE SUMMARY

Effect of RAAS-blocking medicines on COVID-19 Background and aims: Higher deaths have been observed in COVID-19 patients who have other long-term diseases such as heart disease, diabetes, and high blood pressure. Many of these patients are prescribed a class of medicines called RAAS blockers (ramipril, telmisartan, etc). We studied whether the use of these medicines worsens the course of COVID-19 disease in these patients or causes excess deaths.Methods: We conducted a pooled analysis of 47 observational studies on the use of RAAS blocker drugs in COVID-19 patients.Results: We found that RAAS blockers do not cause excess deaths in patients with COVID-19. On the contrary, they have benefits if prescribed to those with high blood pressure. We also found that whereas European and US patients of COVID-19 taking these medicines had higher disease severity, this was not the case for Chinese patients.Conclusion: Theremay be some genetic and other factors responsible for differences by ethnicity.

COVID-19 and pulmonary fibrosis: therapeutics in clinical trials, repurposing, and potential development

In 2019, an unprecedented disease named coronavirus disease 2019 (COVID-19) emerged and spread across the globe. Although the rapid transmission of COVID-19 has resulted in thousands of deaths and severe lung damage, conclusive treatment is not available. However, three COVID-19 vaccines have been authorized, and two more will be approved soon, according to a World Health Organization report on December 12, 2020. Many COVID-19 patients show symptoms of acute lung injury that eventually leads to pulmonary fibrosis. Our aim in this article is to present the relationship between pulmonary fibrosis and COVID-19, with a focus on angiotensin converting enzyme-2. We also evaluate the radiological imaging methods computed tomography (CT) and chest X-ray (CXR) for visualization of patient lung condition. Moreover, we review possible therapeutics for COVID-19 using four categories: treatments related and unrelated to lung disease and treatments that have and have not entered clinical trials. Although many treatments have started clinical trials, they have some drawbacks, such as short-term and small-group testing, that need to be addressed as soon as possible.

Mesenchymal Stem Cells for the Compassionate Treatment of Severe Acute Respiratory Distress Syndrome Due to COVID 19

Mesenchymal stem cells (MSC) have received particular attention due to their ability to inhibit inflammation caused by cytokine storm induced by COVID-19. In this way some patients have been treated successfully. The aim of this study was to evaluate the safety and describe the clinical changes after IV administration of allogeneic human umbilical cord MSC (ahUCMSC), in patients with bilateral pneumonia caused by COVID-19, complicated with severe ARDS, as compassionate treatment. This was a pilot, open-label, prospective, longitudinal study. Five patients that did not improve in their clinical conditions after 48 hours of receiving the standard medical management used by the Medical Center and with persistent PaO2/FiO2 less than 100 mmHg were enrolled. ahUCMSC were infused IV, at dose of 1x10⁶ per Kg of body weight over 15 minutes. Patients were monitored after the infusion to detect adverse event. Pa02/FiO2, vital signs, D-dimer, C reactive protein and total lymphocytes were monitored for 21 days after the infusion or until the patient was discharged from the hospital. Descriptive statistics were used with means or medians and standard deviation or interquartile range according to the type of variable. The Wilcoxon’s rank-sum was used for stationary samples. Adverse events occurred in three patients and were easily and quickly controlled. Immediately after the infusion of ahUCMSC, constant rise of PaO2/FiO2 was observed in all patients during the first 7 days, with statistical significance. Three patients survived and were extubated on the ninth day post-infusion. Two patients died at 13 and 15 days after infusion. The infusion of ahUCMSC in patients with severe ARDS caused by COVID-19, was safe, and demonstrated its anti-inflammatory capacity in the lungs, by improving the respiratory function expressed by PaO2 / FiO2, which allowed the survival of 3 patients, with extubation at 9 days.

Coronavirus disease 2019 and the natural agents: Is there a role for the primary care?

Coronavirus disease 2019 (COVID-19) is a newly discovered RNA virus that belongs to corona virus group. It leads to an infectious state manifested as fever, loss of smell and taste sensations, cough, myalgia, fatigue and headache. The condition may become more serious as difficulty in breathing, chest pain and even death. Until successful vaccine is developed, complimentary and herbal medicine can be used as alternative prevention measure against COVID-19 in high-risk populations. This is because the none of the traditional agents used in the treatment protocols had proven effective results. In addition, recent studies reported that dietary supplements and herbal agents may have effective antioxidant and anti-inflammatory properties that may contribute efficiently to amelioration of the effects of COVID-19. This review sheds light on the possible role of the natural agents in the management of COVID-19 with reference to the role of the primary care in this issue.

Risk prediction of COVID-19 incidence and mortality in a large multi-national hemodialysis cohort: implications for management of the pandemic in outpatient hemodialysis settings

Background

Experiences from the first wave of the 2019 coronavirus disease (COVID-19) pandemic can aid in the development of future preventive strategies. To date, risk prediction models for COVID-19-related incidence and outcomes in hemodialysis (HD) patients are missing.

Methods

We developed risk prediction models for COVID-19 incidence and mortality among HD patients. We studied 38 256 HD patients from a multi-national dialysis cohort between 3 March and 3 July 2020. Risk prediction models were developed and validated, based on predictors readily available in outpatient HD units. We compared mortality among patients with and without COVID-19, matched for age, sex and diabetes.

Results

During the observational period, 1259 patients (3.3%) acquired COVID-19. Of these, 62% were hospitalized or died. Mortality was 22% among COVID-19 patients with odds ratios 219.8 [95% confidence interval (CI) 80.6–359] to 342.7 (95% CI 60.6–13 595.1), compared to matched patients without COVID-19. Since the first wave of the pandemic affected most European countries during the study, the risk prediction model for incidence of COVID-19 was developed and validated in European patients only [N = 22 826 area under the ROC curve(AUC)_Dev 0.64, AUC_Val 0.69]. The model for prediction of mortality was developed in all COVID-19 patients (AUC_Dev 0.71, AUC_Val 0.78). Angiotensin receptor blockers were independently associated with a lower incidence of COVID-19 in European patients.

Conclusions

We identified modifiable risk factors for COVID-19 incidence and outcome in HD patients. Our risk prediction tools can be readily applied in clinical practice. This can aid in the development of preventive strategies for future waves of COVID-19.

ACE2/Ang-(1-7)/Mas1 axis and the vascular system: vasoprotection to COVID-19-associated vascular disease

The two axes of the renin-angiotensin system include the classical ACE/Ang II/AT1 axis and the counter-regulatory ACE2/Ang-(1-7)/Mas1 axis. ACE2 is a multifunctional monocarboxypeptidase responsible for generating Ang-(1-7) from Ang II. ACE2 is important in the vascular system where it is found in arterial and venous endothelial cells and arterial smooth muscle cells in many vascular beds. Among the best characterized functions of ACE2 is its role in regulating vascular tone. ACE2 through its effector peptide Ang-(1-7) and receptor Mas1 induces vasodilation and attenuates Ang II-induced vasoconstriction. In endothelial cells activation of the ACE2/Ang-(1-7)/Mas1 axis increases production of the vasodilator's nitric oxide and prostacyclin's and in vascular smooth muscle cells it inhibits pro-contractile and pro-inflammatory signaling. Endothelial ACE2 is cleaved by proteases, shed into the circulation and measured as soluble ACE2. Plasma ACE2 activity is increased in cardiovascular disease and may have prognostic significance in disease severity. In addition to its enzymatic function, ACE2 is the receptor for severe acute respiratory syndrome (SARS)-coronavirus (CoV) and SARS-Cov-2, which cause SARS and coronavirus disease-19 (COVID-19) respectively. ACE-2 is thus a double-edged sword: it promotes cardiovascular health while also facilitating the devastations caused by coronaviruses. COVID-19 is associated with cardiovascular disease as a risk factor and as a complication. Mechanisms linking COVID-19 and cardiovascular disease are unclear, but vascular ACE2 may be important. This review focuses on the vascular biology and (patho)physiology of ACE2 in cardiovascular health and disease and briefly discusses the role of vascular ACE2 as a potential mediator of vascular injury in COVID-19.

Network Pharmacology Integrated Molecular Docking Reveals the Anti-COVID-19 and SARS Mechanism of Fufang Banlangen Keli

Purpose

Fufang Banlangen Keli (FBK) has been recommended for its clinical treatment of Coronavirus disease 2019 (COVID-19) and severe acute respiratory syndrome (SARS), but the mechanism of action is unclear. So, using network pharmacology and molecular docking, we studied the active components and mechanism of FBK in the treatment of COVID-19 and SARS.

Methods

The Encyclopedia of Traditional Chinese Medicine and Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform were used to screen the active components by oral bioactivity and drug likeness. Then, PharmMapper and SwissTargetPrediction databases were used to screen potential target genes of active components; the related target genes of COVID-19 and SARS were obtained from the GeneCards database. The intersection of the active components and disease-related targets was performed by the Venny2.1.0 database. The DAVID6.8 database and KOBAS3.0 database were used to get gene ontology (GO) function enrichment and Kyoto Encyclopedia of Genes and Genomes pathway annotation of gene targets. The “components-targets-pathways (C-T-P)” network of FBK was conducted by Cytoscape3.6.1 software. The top active components, angiotensin-converting enzyme 2 (ACE2) and SARS-CoV-2 3 Cl, were imported into AutoDock and PyMOL for molecular docking.

Results

From the FBK, a total of 28 active components and 73 gene targets were screened through network pharmacology. Twenty pathways were analyzed, including pathways in cancer, nod-like receptor signaling pathway, and pancreatic cancer, etc. ( P < 0.05). A total of 337 items were obtained by GO functional enrichment analysis ( P < 0.05), including 257 items for biological process, 38 items for cell composition, and 42 items for molecular function. Furthermore, molecular docking studies were performed to study potential binding between the key gene targets and selected active components.

Conclusion

Based on network pharmacology and molecular docking technology, qingdainone, (2Z)-2-(2-oxoindolin-3-ylidene) indolin-3-one, sinensetin, and acacetin in FBK were verified to bind to ACE2 and SARS-COV-2 3 Cl, so as to treat COVID-19 and SARS.

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.

The Contribution of Endothelial Dysfunction in Systemic Injury Subsequent to SARS-Cov-2 Infection

SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) infection is associated, alongside with lung infection and respiratory disease, to cardiovascular dysfunction that occurs at any stage of the disease. This includes ischemic heart disease, arrhythmias, and cardiomyopathies. The common pathophysiological link between SARS-CoV-2 infection and the cardiovascular events is represented by coagulation abnormalities and disruption of factors released by endothelial cells, which contribute in maintaining the blood vessels into an anti-thrombotic state. Thus, early alteration of the functionality of endothelial cells, which may be found soon after SARS-CoV-2 infection, seems to represent the major target of a SARS CoV-2 disease state and accounts for the systemic vascular dysfunction that leads to a detrimental effect in terms of hospitalization and death accompanying the disease. In particular, the molecular interaction of SARS-CoV-2 with the ACE2 receptor located in the endothelial cell surface, either at the pulmonary and systemic level, leads to early impairment of endothelial function, which, in turn, is followed by vascular inflammation and thrombosis of peripheral blood vessels. This highlights systemic hypoxia and further aggravates the vicious circle that compromises the development of the disease, leading to irreversible tissue damage and death of people with SARS CoV-2 infection. The review aims to assess some recent advances to define the crucial role of endothelial dysfunction in the pathogenesis of vascular complications accompanying SARS-CoV-2 infection. In particular, the molecular mechanisms associated with the interaction of SARS CoV-2 with the ACE2 receptor located on the endothelial cells are highlighted to support its role in compromising endothelial cell functionality. Finally, the consequences of endothelial dysfunction in enhancing pro-inflammatory and pro-thrombotic effects of SARS-CoV-2 infection are assessed in order to identify early therapeutic interventions able to reduce the impact of the disease in high-risk patients.

Of Cross-immunity, Herd Immunity and Country-specific Plans: Experiences from COVID-19 in India

India has witnessed a high number of COVID-19 cases, but mortality has been quite low, and most cases have been asymptomatic or mild. In early April, we had hypothesized a low COVID-19 mortality in India, based on the concept of cross-immunity. The presence of cross-immunity is presumed to lead to a milder course of disease and allow the time necessary for the development of adaptive immunity by the body to eliminate the virus. Evidence supporting our hypothesis has started showing up. Multiple studies have shown the generation of different T cell subsets and B cells responding to epitopes of viral proteins, especially of the spike protein, as a part of adaptive immunity against SARS-CoV-2. Cross-reactive T-cells have been demonstrated in patients who have been previously exposed to endemic coronaviruses. The interplay of cross-immunity and herd immunity is apparent in the COVID-19 scenario in India from the presence of a large number of asymptomatic or mild cases, a low infection-fatality ratio and a generally flat curve of percentage positivity of cases with respect to total testing, both in periods of strict lock-down and step-wise unlocking. It seems that cross-immunity resulted in faster generation of herd immunity. Although the initial restrictive measures such as lockdown prevented the rapid spread of the outbreak, further extension of such measures and overly expensive ones such as enhanced testing in India will result in a huge burden on the health economics as well as the society. Hence, we propose a restructuring of the health services and approach to COVID-19. The restructured health services should move away from indiscriminate testing, isolation and quarantine, and instead, the emphasis should be on improving facilities for testing and management of only critical COVID cases and the replacement of complete lockdowns by the selective isolation and quarantine of susceptible persons such as the aged and those with co-morbidities. In the process of describing India-specific plans, we emphasize why the development of country-specific plans for tackling epidemics is important, instead of adopting a "one policy fits all" approach.

miR-98 Regulates TMPRSS2 Expression in Human Endothelial Cells: Key Implications for COVID-19

The two main co-factors needed by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to enter human cells are angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2). Here, we focused on the study of microRNAs that specifically target TMPRSS2. Through a bioinformatic approach, we identified miR-98-5p as a suitable candidate. Since we and others have shown that endothelial cells play a pivotal role in the pathogenesis of the coronavirus disease 2019 (COVID-19), we mechanistically validated miR-98-5p as a regulator of TMPRSS2 transcription in two different human endothelial cell types, derived from the lung and from the umbilical vein. Taken together, our findings indicate that TMPRSS2 represents a valid target in COVID-19 treatment, which may be achieved by specific non-coding-RNA approaches.

Science unites a troubled world: Lessons from the pandemic

European Journal of Pharmacology has published a special issue entitled Therapeutic targets and pharmacological treatment of COVID-19 that contains more than 30 manuscripts. Scientists from around the world contributed both review articles and original manuscripts that are remarkable in their diversity. Each contribution offers a unique perspective on the current approaches of the discipline called pharmacology. Yet the contributions share an enthusiasm to put forward a fresh viewpoint and make a positive difference by the exchange of ideas during the troubled times of this pandemic. What other enterprise but science can unite so many diverse cultures and nationalities in global uncertainty and discord, and mobilize an effective response against a common enemy. The efforts of science are in stark contrast to those of populism that has introduced division and a self-serving attitude that are not simply ill-matched to tackle the pandemic, but foster its spread and severity. We trust that the readers of European Journal of Pharmacology will discover new ideas and concepts in our special COVID-19 series as members of the scientific community and shared world.