Safety, tolerability, and outcomes of losartan use in patients hospitalized with SARS-CoV-2 infection: A feasibility study

Losartan Plays a Fungistatic and Fungicidal Activity Against Candida albicans Biofilms: Drug Repurposing for Localized Candidosis

Candidosis is one of the most frequent opportunistic infections and exhibits variable clinical presentations, including oral localized forms. Drugs affecting the renin-angiotensin system targets inhibit secreted aspartic proteases from Candida albicans. The objective of the study was to evaluate whether losartan has antimicrobial action against C. albicans biofilms. Biofilms were treated with losartan or aliskiren (for comparison) for 24 h. Metabolic activity of viable cells and growth inhibition of C. albicans biofilms were assessed using XTT [2,3-Bis(2-Methoxy-4-Nitro-5-Sulfophenyl)-5-[(Phenyl-Amino)Carbonyl]-2H-Tetrazolium Hydroxide] and colony-forming unit assays, respectively. In addition, the cytotoxicity of the drugs on human cells was evaluated using the AlamarBlue assay. Both drugs decreased fungal viability at all concentrations. In addition, all concentrations of losartan inhibited the growth of C. albicans biofilm, ranging from 47% to 88.5%, whereas aliskiren showed inhibition from 1 to 10 mg/mL, which ranged from 16% to 97.6%. Furthermore, at certain concentrations, these drugs maintained the viability of human cells. Losartan and aliskiren have fungistatic and fungicidal action against C. albicans biofilms and are compatible with human cells. Therefore, these antihypertensive drugs can be repurposed to interfere with the metabolism and development of Candida biofilms, which are widely associated with clinical forms of candidosis, including oral localized forms such as denture stomatitis.

Repurposing of RAS-Pathway Mediated Drugs for Intestinal Inflammation Related Diseases for Treating SARS-CoV-2 Infection

Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) is an emerging zoonotic virus, which causes Coronavirus Disease 2019 (COVID-19). Entry of coronaviruses into the cell depends on binding of the viral spike (S) proteins to cellular receptors Angiotensin-converting enzyme 2 (ACE2). The virus-mediated reduction of ACE2/Ang1-7 causes flooding of inflammatory cytokines. A similar scenario of hyper immunologic reaction has been witnessed in the context of Intestinal Inflammatory Diseases (IIDs) with the deregulation of ACE2. This review summarizes several IIDs that lead to such susceptible conditions. It discusses suitable mechanisms of how ACE2, being a crucial regulator of the Renin-Angiotensin System (RAS) signaling pathway, can affect the physiology of intestine as well as lungs, the primary site of SARS-CoV-2 infection. ACE2, as a SARS-CoV-2 receptor, establishes a critical link between COVID-19 and IIDs. Intercessional studies targeting the RAS signaling pathway in patients may provide a novel strategy for addressing the COVID-19 crisis. Hence, the modulation of these key RAS pathway members can be beneficial in both instances. However, it's difficult to say how beneficial are the ACE inhibitors (ACEI)/ Angiotensin II type-1 receptor blockers (ARBs) during COVID-19. As a result, much more research is needed to better understand the relationship between the RAS and SARS-CoV-2 infection.

Pulse oximetry for the diagnosis and management of acute respiratory distress syndrome

The diagnosis of acute respiratory distress syndrome (ARDS) traditionally requires calculation of the ratio of partial pressure of arterial oxygen to fraction of inspired oxygen (PaO2/FiO2) using arterial blood, which can be costly and is not possible in many resource-limited settings. By contrast, pulse oximetry is continuously available, accurate, inexpensive, and non-invasive. Pulse oximetry-based indices, such as the ratio of pulse-oximetric oxygen saturation to FiO2 (SpO2/FiO2), have been validated in clinical studies for the diagnosis and risk stratification of patients with ARDS. Limitations of the SpO2/FiO2 ratio include reduced accuracy in poor perfusion states or above oxygen saturations of 97%, and the potential for reduced accuracy in patients with darker skin pigmentation. Application of pulse oximetry to the diagnosis and management of ARDS, including formal adoption of the SpO2/FiO2 ratio as an alternative to PaO2/FiO2 to meet the diagnostic criterion for hypoxaemia in ARDS, could facilitate increased and earlier recognition of ARDS worldwide to advance both clinical practice and research.

A Review of In Silico Research, SARS-CoV-2, and Neurodegeneration: Focus on Papain-Like Protease

Since the appearance of SARS-CoV-2 and the COVID-19 pandemic, the search for new approaches to treat this disease took place in the scientific community. The in silico approach has gained importance at this moment, once the methodologies used in this kind of study allow for the identification of specific protein-ligand interactions, which may serve as a filter step for molecules that can act as specific inhibitors. In addition, it is a low-cost and high-speed technology. Molecular docking has been widely used to find potential viral protein inhibitors for structural and non-structural proteins of the SARS-CoV-2, aiming to block the infection and the virus multiplication. The papain-like protease (PLpro) participates in the proteolytic processing of SARS-CoV-2 and composes one of the main targets studied for pharmacological intervention by in silico methodologies. Based on that, we performed a systematic review about PLpro inhibitors from the perspective of in silico research, including possible therapeutic molecules in relation to this viral protein. The neurological problems triggered by COVID-19 were also briefly discussed, especially relative to the similarities of neuroinflammation present in Alzheimer's disease. In this context, we focused on two molecules, curcumin and glycyrrhizinic acid, given their PLpro inhibitory actions and neuroprotective properties and potential therapeutic effects on COVID-19.

Acute respiratory distress syndrome in COVID-19: possible mechanisms and therapeutic management

COVID-19 pandemic is a serious concern in the new era. Acute respiratory distress syndrome (ARDS), and lung failure are the main lung diseases in COVID-19 patients. Even though COVID-19 vaccinations are available now, there is still an urgent need to find potential treatments to ease the effects of COVID-19 on already sick patients. Multiple experimental drugs have been approved by the FDA with unknown efficacy and possible adverse effects. Probably the increasing number of studies worldwide examining the potential COVID-19 related therapies will help to identification of effective ARDS treatment. In this review article, we first provide a summary on immunopathology of ARDS next we will give an overview of management of patients with COVID-19 requiring intensive care unit (ICU), while focusing on the current treatment strategies being evaluated in the clinical trials in COVID-19-induced ARDS patients.

Pulmonary fibrosis from molecular mechanisms to therapeutic interventions: lessons from post-COVID-19 patients

Pulmonary fibrosis (PF) is characterised by several grades of chronic inflammation and collagen deposition in the interalveolar space and is a hallmark of interstitial lung diseases (ILDs). Recently, infectious agents have emerged as driving causes for PF development; however, the role of viral/bacterial infections in the initiation and propagation of PF is still debated. In this context, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the current coronavirus disease 2019 (COVID-19) pandemic, has been associated with acute respiratory distress syndrome (ARDS) and PF development. Although the infection by SARS-CoV-2 can be eradicated in most cases, the development of fibrotic lesions cannot be precluded; furthermore, whether these lesions are stable or progressive fibrotic events is still unknown. Herein, an overview of the main molecular mechanisms driving the fibrotic process together with the currently approved and newly proposed therapeutic solutions was given. Then, the most recent data that emerged from post-COVID-19 patients was discussed, in order to compare PF and COVID-19-dependent PF, highlighting shared and specific mechanisms. A better understanding of PF aetiology is certainly needed, also to develop effective therapeutic strategies and COVID-19 pathology is offering one more chance to do it. Overall, the work reported here could help to define new approaches for therapeutic intervention in the diversity of the ILD spectrum.