2-Bromopalmitate depletes lipid droplets to inhibit viral replication.

The global impact of emerging viral infections emphasizes the urgent need for effective broad-spectrum antivirals. The cellular organelle, lipid droplet (LD), is utilized by many types of viruses for replication, but its reduction does not affect cell survival. Therefore, LD is a potential target for developing broad-spectrum antivirals. In this study, we found that 2-bromopalmitate (2 BP), a previously defined palmitoylation inhibitor, depletes LD across all studied cell lines and exerts remarkable antiviral effects on different coronaviruses. We comprehensively utilized 2 BP, alongside other palmitoylation inhibitors such as cerulenin and 2-fluoro palmitic acid (2-FPA), as well as the enhancer palmostatin B and evaluated their impact on LD and the replication of human coronaviruses (hCoV-229E, hCoV-Oc43) and murine hepatitis virus (MHV-A59) at non-cytotoxic concentrations. While cerulenin and 2-FPA exhibited moderate inhibition of viral replication, 2 BP exhibited a much stronger suppressive effect on MHV-A59 replication, although they share similar inhibitory effects on palmitoylation. As expected, palmostatin B significantly enhanced viral replication, it failed to rescue the inhibitory effects of 2 BP, whereas it effectively counteracted the effects of cerulenin and 2-FPA. This suggests that the mechanism that 2 BP used to inhibit viral replication is beyond palmitoylation inhibition. Further investigations unveil that 2 BP uniquely depletes LDs, a phenomenon not exhibited by 2-FPA and cerulenin. Importantly, the depletion of LDs was closely associated with the inhibition of viral replication because the addition of oleic acid to 2 BP significantly rescued LD depletion and its inhibitory effects on MHV-A59. Our findings indicate that the inhibitory effects of 2 BP on viral replication primarily stem from LD disruption rather than palmitoylation inhibition. Intriguingly, fatty acid (FA) assays demonstrated that 2 BP reduces the FA level in mitochondria while concurrently increasing FA levels in the cytoplasm. These results highlight the crucial role of LDs in viral replication and uncover a novel biological activity of 2 BP. These insights contribute to the development of broad-spectrum antiviral strategies. IMPORTANCE: In our study, we conducted a comparative investigation into the antiviral effects of palmitoylation inhibitors including 2-bromopalmitate (2-BP), 2-fluoro palmitic acid (2-FPA), and cerulenin. Surprisingly, we discovered that 2-BP has superior inhibitory effects on viral replication compared to 2-FPA and cerulenin. However, their inhibitory effects on palmitoylation were the same. Intrigued by this finding, we delved deeper into the underlying mechanism of 2-BP's potent antiviral activity, and we unveiled a novel biological activity of 2-BP: depletion of lipid droplets (LDs). Importantly, we also highlighted the crucial role of LDs in viral replication. Our insights shed new light on the antiviral mechanism of LD depletion paving the way for the development of broad-spectrum antiviral strategies by targeting LDs.

Recombinant porcine interferon delta 8 inhibits swine acute diarrhoea syndrome coronavirus infection in vitro and in vivo.

Swine acute diarrhoea syndrome coronavirus (SADS-CoV), which originates from zoonotic transmission of bat coronaviruses in the HKU2 lineage, causes severe illness in pigs and carries a high risk of spreading to humans. At present, there are no licenced therapeutics for the treatment of SADS-CoV. In this study, we examined the effectiveness of recombinant porcine interferon delta 8 (IFN-δ8) against SADS-CoV both in vitro and in vivo. In vitro experiments showed that IFN-δ8 inhibited SADS-CoV proliferation in a concentration-dependent manner, with complete inhibition occurring at a concentration of 5 µg/mL. In vivo experiments demonstrated that two 50 µg/kg doses of IFN-δ8 injected intraperitoneally protected piglets against lethal challenge, blocked viral shedding, attenuated intestinal damage, and decreased the viral load in the jejunum and ileum. Further findings suggested that IFN-δ8 inhibited SADS-CoV infection by increasing the expression of IFN-stimulated genes. These results indicate that IFN-δ8 shows promise as a biological macromolecule drug against SADS-CoV infection.

Molecular Research on Coronavirus: Pathogenic Mechanisms, Antiviral Drugs, and New Vaccines.

Since the COVID-19 outbreak in 2019, five coronaviruses have been found to infect humans, including SARS-CoV (severe acute respiratory syndrome coronavirus) [...].

Structural Basis for Coronaviral Main Proteases Inhibition by the 3CLpro Inhibitor GC376.

The main protease (Mpro) of coronaviruses participates in viral replication, serving as a hot target for drug design. GC376 is able to effectively inhibit the activity of Mpro, which is due to nucleophilic addition of GC376 by binding covalently with Cys145 in Mpro active site. Here, we used fluorescence resonance energy transfer (FRET) assay to analyze the IC50 values of GC376 against Mpros from six different coronaviruses (SARS-CoV-2, HCoV-229E, HCoV-HUK1, MERS-CoV, SARS-CoV, HCoV-NL63) and five Mpro mutants (G15S, M49I, K90R, P132H, S46F) from SARS-CoV-2 variants. The results showed that GC376 displays effective inhibition to various coronaviral Mpros and SARS-CoV-2 Mpro mutants. In addition, the crystal structures of SARS-CoV-2 Mpro (wide type)-GC376, SARS-CoV Mpro-GC376, MERS-CoV Mpro-GC376, and SARS-CoV-2 Mpro mutants (G15S, M49I, S46F, K90R, and P132H)-GC376 complexes were solved. We found that GC376 is able to fit into the active site of Mpros from different coronaviruses and different SARS-CoV-2 variants properly. Detailed structural analysis revealed key molecular determinants necessary for inhibition and illustrated the binding patterns of GC376 to these different Mpros. In conclusion, we not only proved the inhibitory activity of GC376 against different Mpros including SARS-CoV-2 Mpro mutants, but also revealed the molecular mechanism of inhibition by GC376, which will provide scientific guidance for the development of broad-spectrum drugs against SARS-CoV-2 as well as other coronaviruses.

Tree Species-Dependent Inactivation of Coronaviruses and Enteroviruses on Solid Wood Surfaces.

The ongoing challenge of viral transmission, exemplified by the Covid pandemic and recurrent viral outbreaks, necessitates the exploration of sustainable antiviral solutions. This study investigates the underexplored antiviral potential of wooden surfaces. We evaluated the antiviral efficacy of various wood types, including coniferous and deciduous trees, against enveloped coronaviruses and nonenveloped enteroviruses like coxsackie virus A9. Our findings revealed excellent antiviral activity manifesting already within 10 to 15 min in Scots pine and Norway spruce, particularly against enveloped viruses. In contrast, other hardwoods displayed varied efficacy, with oak showing effectiveness against the enterovirus. This antiviral activity was consistently observed across a spectrum of humidity levels (20 to 90 RH%), while the antiviral efficacy manifested itself more rapidly at 37 °C vs 21 °C. Key to our findings is the chemical composition of these woods. Resin acids and terpenes were prevalent in pine and spruce, correlating with their antiviral performance, while oak's high phenolic content mirrored its efficacy against enterovirus. The pine surface absorbed a higher fraction of the coronavirus in contrast to oak, whereas enteroviruses were not absorbed on those surfaces. Thermal treatment of wood or mixing wood with plastic, such as in wood-plastic composites, strongly compromised the antiviral functionality of wood materials. This study highlights the role of bioactive chemicals in the antiviral action of wood and opens new avenues for employing wood surfaces as a natural and sustainable barrier against viral transmissions.

Anti-Coronavirus Potential of Polyether Ionophores: The New Application of Veterinary Antibiotics in Livestock.

Coronaviruses have consistently posed a major global concern in the field of livestock industry and public health. However, there is currently a lack of efficient drugs with broad-spectrum antiviral activity to address the challenges presented by emerging mutated strains or drug resistance. Additionally, the method for identifying multitarget drugs is also insufficient. Aminopeptidase N (APN) and 3C-like proteinase (3CLpro) represent promising targets for host-directed and virus-directed strategies, respectively, in the development of effective drugs against various coronaviruses. In this study, maduramycin ammonium demonstrated a broad-spectrum antiviral effect by targeting both of the proteins. The binding domains 4 Å from the ligand of both target proteins shared a structural similarity, suggesting that screening and designing drugs based on these domains might exhibit broad-spectrum and highly effective antiviral activity. Furthermore, it was identified that the polyether ionophores' ability to carry zinc ion might be one of the reasons why they were able to target APN and exhibit antiviral effect. The findings of this experiment provide novel perspectives for future drug screening and design, while also offering valuable references for the utilization of polyether ionophores in the management of livestock health.

Profiling of coronaviral Mpro and enteroviral 3Cpro specificity provides a framework for the development of broad-spectrum antiviral compounds.

The main protease from coronaviruses and the 3C protease from enteroviruses play a crucial role in processing viral polyproteins, making them attractive targets for the development of antiviral agents. In this study, we employed a combinatorial chemistry approach-HyCoSuL-to compare the substrate specificity profiles of the main and 3C proteases from alphacoronaviruses, betacoronaviruses, and enteroviruses. The obtained data demonstrate that coronavirus Mpros exhibit overlapping substrate specificity in all binding pockets, whereas the 3Cpro from enterovirus displays slightly different preferences toward natural and unnatural amino acids at the P4-P2 positions. However, chemical tools such as substrates, inhibitors, and activity-based probes developed for SARS-CoV-2 Mpro can be successfully applied to investigate the activity of the Mpro from other coronaviruses as well as the 3Cpro from enteroviruses. Our study provides a structural framework for the development of broad-spectrum antiviral compounds.

Antimalarials and macrolides: a review of off-label pharmacotherapies during the first wave of the SARS-CoV-2 pandemic

Abstract We critically analyzed clinical trials performed with chloroquine (CQ) and hydroxychloroquine (HCQ) with or without macrolides during the first wave of COVID-19 and discussed the design and limitations of peer-reviewed studies from January to July 2020. Seventeen studies were eligible for the discussion. CQ and HCQ did not demonstrate clinical advantages that justified their inclusion in therapeutic regimens of free prescription for treatment or prophylactic purposes, as suggested by health authorities, including in Brazil, during the first wave. Around August 2020, robust data had already indicated that pharmacological effects of CQ, HCQ and macrolides as anti-SARS-CoV-2 molecules were limited to in vitro conditions and largely based on retrospective trials with low quality and weak internal validity, which made evidence superficial for decision-making. Up to that point, most randomized and nonrandomized clinical trials did not reveal beneficial effects of CQ or HCQ with or without macrolides to reduce lethality, rate of intubation, days of hospitalization, respiratory support/mechanical ventilation requirements, duration, type and number of symptoms, and death and were unsuccessful in increasing virus elimination and/or days alive in hospitalized or ambulatory patients with COVID-19. In addition, many studies have demonstrated that side effects are more common in CQ-or HCQ-treated patients.

Electrocardiograma en pacientes con SARS-CoV-2: guía rápida para interpretación / Electrocardiogram in patients with SARS-CoV-2: quick guide for interpretation

Conscientes de la emergencia sanitaria mundial desencadenada por el COVID-19 y la imperiosa necesidad de tomar decisiones tanto tempranas como efectivas, nuestro grupo desarrolló esta guía dirigida a la interpretación rápida y enfocada del electrocardiograma convencional de 12 derivaciones en pacientes con infección por SARS-CoV-2 en quienes se plantea inicio de tratamiento farmacológico. Dadas las alternativas terapéuticas que se están implementando de manera precoz para tener un impacto en la sobrevida de los pacientes, es imperioso limitar el número de efectos adversos que se pueden desencadenar en el desarrollo del tratamiento intrahospitalario como ambulatorio. Somos a su vez conscientes de que la coyuntura actual demanda toma de decisiones costo-efectivas y ágiles en el menor tiempo posible. Por lo anterior, gestamos esta guía rápida para facilitarle al personal médico involucrado en el manejo de estos pacientes (internistas, cardiólogos, intensivistas, infectologos, etc.) la interpretación y valoración de los tópicos más relevantes en electrocardiografía para limitar el número de posibles complicaciones en sus pacientes. El objetivo de dicha guía es acortar tiempos de atención, inicio temprano de terapia farmacológica basado en su juicio clínico y limitar al máximo posibles complicaciones y/o efectos adversos que retrasen el punto crítico terapéutico infeccioso. Esperamos facilitar a ustedes y su grupo de trabajo la toma de decisiones, basado en el uso costo-efectivo del electrocardiograma. No obstante, es importante recordar que toda decisión médica es un ejercicio riguroso, científico e integral basado en cada caso en particular. El electrocardiograma la ayudará a reforzar sus decisiones, así como a seguir a los pacientes que puedan presentar posibles complicaciones. Lo invitamos a que guarde esta guía rápida en sus dispositivos digitales y en cada momento que considere inicio de terapia farmacológica valore lo que en ella se indica.

Safety alert for hospital environments and health professional: chlorhexidine is ineffective for coronavirus

SUMMARY An alarming fact was revealed by recent publications concerning disinfectants: chlorhexidine digluconate is ineffective for disinfecting surfaces contaminated by the new coronavirus. This is a finding that requires immediate disclosure since this substance is widely used for the disinfection of hands and forearms of surgeons and auxiliaries and in the antisepsis of patients in minimally invasive procedures commonly performed in hospital environments. The objective of this study is to compare the different disinfectants used for disinfection on several surfaces, in a review of worldwide works. Scientific studies were researched in the BVS (Virtual Health Library), PubMed, Medline, and ANVISA (National Health Surveillance Agency) databases. The following agents were studied: alcohol 62-71%, hydrogen peroxide 0.5%, sodium hypochlorite 0.1%, benzalkonium chloride 0.05-0.2%, povidone-iodine 10%, and chlorhexidine digluconate 0.02%, on metal, aluminum, wood, paper, glass, plastic, PVC, silicone, latex (gloves), disposable gowns, ceramic, and Teflon surfaces. Studies have shown that chlorhexidine digluconate is ineffective for inactivating some coronavirus subtypes, suggesting that it is also ineffective to the new coronavirus.

RESUMO Um dado alarmante revelado por publicações a respeito dos agentes desinfetantes: o digluconato de clorexidina é ineficaz para desinfecção de superfícies contaminadas por coronavírus. Trata-se de uma constatação que reclama imediata divulgação, uma vez que essa substância é amplamente usada para degermação de mãos e antebraços dos cirurgiões e auxiliares e na antissepsia dos pacientes, em procedimentos minimamente invasivos, comumente em ambientes hospitalares. O objetivo deste trabalho foi comparar os diferentes desinfetantes usados para desinfecção em diversas superfícies em revisão de trabalhos mundiais. Foram pesquisados trabalhos científicos na BVS (Biblioteca Virtual de Saúde), PubMed, Medline e Anvisa (Agência Nacional de Vigilância Sanitária). Foram estudados os seguintes agentes: álcool 62-71%, peróxido de hidrogênio 0,5%, hipoclorito de sódio 0,1%, cloreto de benzancônio 0,05-0,2%, iodo povidina 10% e digluconato de clorexidina 0,02%, em superfícies de metal, alumínio, madeira, papel, vidro, plástico, PVC, silicone, látex (luvas), avental descartável, cerâmica e teflon. Os estudos demonstraram que o digluconato de clorexidina é ineficaz para a inativação de alguns subtipos de coronavírus, sugerindo que também seja ineficaz contra o novo coronavírus.

Tratamiento farmacológico de la infección COVID-19 en adultos. Actualización / Pharmacological interventions for adults with COVID-19 infection: Rapid synthesis (Up to date)

La enfermedad respiratoria aguda COVID-19 es la causante de la pandemia que actualmente amenaza la salud de los seres humanos. Al 5 de abril, se ha propagado la infección se ha propagado a 208 países, se han reportado 1'273.709 casos confirmados de la infección, 69.456 muertes y 262.486 pacientes recuperados. En Colombia, se reportan 1.485 casos confirmados, 35 muertes, 88 recuperados y 1.362 casos activos, de los cuales 50 se encuentran en condición crítica. Se incluyeron 19 nuevos estudios que cumplieron criterios de elegibilidad, cuatro revisiones sistemáticas, dos ensayos clínicos, y 13 estudios observacionales. En total, esta síntesis rápida incluye 36 estudios, dos guías de práctica clínica, seis revisiones sistemáticas, cinco ensayos clínicos, y 23 estudios observacionales. La evidencia disponible sobre tratamientos farmacológicos para el control de la infección COVID-19 es aún limitada y de baja calidad. Se identifican siete grupos de tratamientos usados en pacientes con infección COVID-19. Se detallan a continuación junto con la evidencia clínica disponible de su eficacia y seguridad: Antivirales, Interferón, Cloroquina e hidroxicloroquina, Corticosteroides, Oxigenoterapia, Reanimación con líquidos endovenosos y otros tratamientos.