A Dual Pharmacological Strategy against COVID-19: The Therapeutic Potential of Metformin and Atorvastatin.

Metformin (MET) and atorvastatin (ATO) are promising treatments for COVID-19. This review explores the potential of MET and ATO, commonly prescribed for diabetes and dyslipidemia, respectively, as versatile medicines against SARS-CoV-2. Due to their immunomodulatory and antiviral capabilities, as well as their cost-effectiveness and ubiquitous availability, they are highly suitable options for treating the virus. MET's effect extends beyond managing blood sugar, impacting pathways that can potentially decrease the severity and fatality rates linked with COVID-19. It can partially block mitochondrial complex I and stimulate AMPK, which indicates that it can be used more widely in managing viral infections. ATO, however, impacts cholesterol metabolism, a crucial element of the viral replicative cycle, and demonstrates anti-inflammatory characteristics that could modulate intense immune reactions in individuals with COVID-19. Retrospective investigations and clinical trials show decreased hospitalizations, severity, and mortality rates in patients receiving these medications. Nevertheless, the journey from observing something to applying it in a therapeutic setting is intricate, and the inherent diversity of the data necessitates carefully executed, forward-looking clinical trials. This review highlights the requirement for efficacious, easily obtainable, and secure COVID-19 therapeutics and identifies MET and ATO as promising treatments in this worldwide health emergency.

Natural and Synthetic Coumarins as Potential Drug Candidates Against SARS-CoV-2/CoViD-19.

COVID-19, an airborne disease caused by a betacoronavirus named SARS-- CoV-2, was officially declared a pandemic in early 2020, resulting in more than 770 million confirmed cases and over 6.9 million deaths by September 2023. Although the introduction of vaccines in late 2020 helped reduce the number of deaths, the global effort to fight COVID-19 is far from over. While significant progress has been made in a short period, the fight against SARS-CoV-2/COVID-19 and other potential pandemic threats continues. Like AIDS and hepatitis C epidemics, controlling the spread of COVID-19 will require the development of multiple drugs to weaken the virus's resistance to different drug treatments. Therefore, it is essential to continue developing new drug candidates derived from natural or synthetic small molecules. Coumarins are a promising drug design and development scaffold due to their synthetic versatility and unique physicochemical properties. Numerous examples reported in scientific literature, mainly by in silico prospection, demonstrate their potential contribution to the rapid development of drugs against SARS-CoV-2/COVID-19 and other emergent and reemergent viruses.

Roles of Bothrops jararacussu toxins I and II: Antiviral findings against Zika virus.

Zika virus is the etiologic agent of Zika fever, and has been previously associated with cases of microcephaly, drawing the attention of the health authorities worldwide. However, no vaccine or antiviral are currently available. Phospholipases A2 (PLA2) isolated from snake venoms have demonstrated antiviral activity against several viruses. Here we demonstrated the anti-ZIKV activity of bothropstoxins-I and II (BthTX-I and II) isolated from Bothrops jararacussu venom. Vero E6 cells were infected with ZIKVPE243 in the presence of compounds for 72 h, when virus titers were evaluated. BthTX-I and II presented strong dose-dependent inhibition of ZIKV, with a SI of 149.1 and 1.44 × 105, respectively. These toxins mainly inhibited the early stages of the replicative cycle, such as during the entry of ZIKV into host cells, as shown by the potent virucidal effect, suggesting the action of these toxins on the virus particles. Moreover, BthTX-I and II presented significant activity towards post-entry stages of the ZIKV replicative cycle. Molecular docking analyses showed that BthTX-I and II potentially interact with DII and DIII domains from ZIKV Envelope protein. Our findings show that these PLA2s could be used as useful templates for the development of future antiviral candidate drugs against Zika fever.

Chloroquinolone Carboxamide Derivatives as New Anti-HSV-1 Promising Drugs.

BACKGROUND: Since the emergence of HSV resistant strains, new antiviral agents have emerged and still are urgently needed, especially those with alternative targets. OBJECTIVE: In this work, we evaluated new quinolone derivatives as anti-HSV. METHODS: For this study, cells were infected and treated with different components to evaluate the profile of HSV replication in vitro. In addition, studies were performed to determine the pharmacokinetic toxicity and profile of the compound. RESULTS: Indeed the EC50 values of these promising molecules ranged between 8 µM and 32 µM. We have also showed that all compounds inhibited the expression of ICP27 viral proteins, which gives new insights in the search for new target for antiherpetic therapy. Chlorine in positions C6 and phosphonate in position C1 have shown to be important for viral inhibition. The chloroquinolone carboxamide derivatives fulfilled "Lipinsky Rule of Five" for good oral bioavailability and showed higher intestinal absorption and blood brain barrier penetration, as well as lower toxicity profile. CONCLUSION: Although the inhibition activities of chloroquinolone carboxamide derivatives were lower than acyclovir, they showed different modes of action in comparison to the drugs currently available. These findings encourage us to continue pre-clinical studies for the development of new anti-HSV-1 agents.

Reaching the Final Endgame for Constant Waves of COVID-19.

Despite intramuscular vaccines saving millions of lives, constant devastating waves of SARS-CoV-2 infections continue. The elimination of COVID-19 is challenging, but necessary in order to avoid millions more people who would suffer from long COVID if we fail. Our paper describes rapidly advancing and innovative therapeutic strategies for the early stage of infection with COVID-19 so that tolerating continuing cycles of infection should be unnecessary in the future. These therapies include new vaccines with broader specificities, nasal therapies and antiviral drugs some targeting COVID-19 at the first stage of infection and preventing the virus entering the body in the first place. Our article describes the advantages and disadvantages of each of these therapeutic options which in various combinations could eventually prevent renewed waves of infection. Finally, important consideration is given to political, social and economic barriers that since 2020 hindered vaccine application and are likely to interfere again with any COVID-19 endgame.

Quinacrine, an Antimalarial Drug with Strong Activity Inhibiting SARS-CoV-2 Viral Replication In Vitro.

Quinacrine (Qx), a molecule used as an antimalarial, has shown anticancer, antiprion, and antiviral activity. The most relevant antiviral activities of Qx are related to its ability to raise pH in acidic organelles, diminishing viral enzymatic activity for viral cell entry, and its ability to bind to viral DNA and RNA. Moreover, Qx has been used as an immunomodulator in cutaneous lupus erythematosus and various rheumatological diseases, by inhibiting phospholipase A2 modulating the Th1/Th2 response. The aim of this study was to evaluate the potential antiviral effect of Qx against denominated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Vero E6 cells. The cytotoxicity of Qx in Vero E6 cells was determined by the MTT assay. Afterwards, Vero E6 cells were infected with SARS-CoV-2 at different multiplicities of infections (MOIs) of 0.1 and 0.01 in the presence of Qx (0-30 µM) to determinate the half maximal effective concentration (EC50). After 48 h, the effect of Qx against SARS-CoV-2 was assessed by viral cytotoxicity and viral copy numbers, the last were determined by digital real-time RT-PCR (ddRT-PCR). Additionally, electron and confocal microscopy of Vero E6 cells infected and treated with Qx was studied. Our data show that Qx reduces SARS-CoV-2 virus replication and virus cytotoxicity, apparently by inhibition of viral ensemble, as observed by ultrastructural images, suggesting that Qx could be a potential drug for further clinical studies against coronavirus disease 2019 (COVID-19) infection.

Novel 2019 coronavirus structure, mechanism of action, antiviral drug promises and rule out against its treatment.

In the past two decades, the world has faced several infectious disease outbreaks. Ebola, Influenza A (H1N1), SARS, MERS, and Zika virus have had a massive global impact in terms of economic disruption, the strain on local and global public health. Most recently, the global outbreak of novel coronavirus 2019 (SARS-CoV-2) that causes COVID-19 is a newly discovered virus from the coronavirus family in Wuhan city, China, known to be a great threat to the public health systems. As of 15 April 2020, The Johns Hopkins University estimated that the COVID-19 affected more than two million people, resulting in a death toll above 130,000 around the world. Infected people in Europe and America correspond about 40% and 30% of the total reported cases respectively. At this moment only few Asian countries have controlled the disease, but a second wave of new infections is expected. Predicting inhibitor and target to the COVID-19 is an urgent need to protect human from the disease. Therefore, a protocol to identify anti-COVID-19 candidate based on computer-aided drug design is urgently needed. Thousands of compounds including approved drugs and drugs in the clinical trial are available in the literature. In practice, experimental techniques can measure the time and space average properties but they cannot be captured the structural variation of the COVID-19 during the interaction of inhibitor. Computer simulation is particularly suitable to complement experiments to elucidate conformational changes at the molecular level which are related to inhibition process of the COVID-19. Therefore, computational simulation is essential tool to elucidate the phenomenon. The structure-based virtual screening computational approach will be used to filter the best drugs from the literature, the investigate the structural variation of COVID-19 with the interaction of the best inhibitor is a fundamental step to design new drugs and vaccines which can combat the coronavirus. This mini-review will address novel coronavirus structure, mechanism of action, and trial test of antiviral drugs in the lab and patients with COVID-19.

Falla hepática aguda sobre crónica por exacerbación de hepatitis B asociada a suspensión de la terapia antiviral: reporte de caso / Acute-on-chronic liver failure caused by hepatitis B flare associated with stopping antiviral therapy: case report

El principal objetivo del tratamiento de la infección por virus de la hepatitis B es prevenir la replicación viral, con el fin de evitar las posibles complicaciones asociadas a la infección, como son las exacerbaciones o flares, las cuales pueden llegar a ser tan severas que causan una falla hepática aguda sobre crónica (ACLF). La ACLF se asocia con falla multiorgánica y una alta mortalidad, y puede ser desencadenada por la reactivación de hepatitis virales, infecciones bacterianas y consumo de alcohol, entre otros factores. Aunque la fisiopatología de la ACLF no es clara aún, parece haber una respuesta inflamatoria excesiva asociada con esta condición. El uso de análogos de nucleótidos/nucleósidos en el tratamiento de la hepatitis B crónica reduce el riesgo de morbilidad y mortalidad asociadas a la progresión de la enfermedad hepática, pero la terapia a largo plazo tiene sus limitaciones por el alto costo y por el riesgo asociado al uso indefinido. Debido a esto, en los últimos años se ha venido considerando la interrupción de la terapia en algunos pacientes por parte de las diferentes asociaciones; no obstante, aún no hay consenso en cuanto al mejor momento para hacerlo. Se describe el caso clínico de un paciente con cirrosis compensada por hepatitis B, con HBsAg positivo y HBeAg inicialmente negativo, a quien se le suspendió el tratamiento con entecavir por decisión médica, presentando una ACLF por exacerbación de la hepatitis B, con posterior deterioro y muerte del paciente. Se debe realizar una caracterización adecuada de cada paciente antes de suspender el tratamiento.

The main objective of treating hepatitis B virus infection is to prevent viral replication in order to avoid possible complications, including flares which can become so severe that can cause an acute over chronic liver failure (ACLF). ACLF is associated with multiple organ failure and high mortality, and can be triggered by reactivation of viral hepatitis, bacterial infections and alcohol consumption, among other factors. Although the pathophysiology of ACLF is not yet clear, there appears to be an excessive inflammatory response associated with this condition. The use of nucleotide/nucleoside analogs in chronic hepatitis B reduces the risk of morbidity and mortality related to the progression of the disease, but long-term treatment has its limitations due to the high cost and the risk of indefinite therapy. Due to this, in recent years the stopping of therapy in some patients has been considered by the different associations; however, there is currently no consensus as to the best time to do it. We present a clinical report of a patient with compensated hepatitis B cirrhosis, with positive HBsAg and initially negative HBeAg, who stopped treatment with entecavir by medical instruction, developing ACLF due to exacerbation of hepatitis B, with subsequent deterioration of the patient condition and ultimately death. An adequate characterization of each patient must be carried out before stopping treatment.

Insights into the antiviral activity of phospholipases A2 (PLA2s) from snake venoms.

Viruses are associated with several human diseases that infect a large number of individuals, hence directly affecting global health and economy. Owing to the lack of efficient vaccines, antiviral therapy and emerging resistance strains, many viruses are considered as a potential threat to public health. Therefore, researches have been developed to identify new drug candidates for future treatments. Among them, antiviral research based on natural molecules is a promising approach. Phospholipases A2 (PLA2s) isolated from snake venom have shown significant antiviral activity against some viruses such as Dengue virus, Human Immunodeficiency virus, Hepatitis C virus and Yellow fever virus, and have emerged as an attractive alternative strategy for the development of novel antiviral therapy. Thus, this review provides an overview of remarkable findings involving PLA2s from snake venom that possess antiviral activity, and discusses the mechanisms of action mediated by PLA2s against different stages of virus replication cycle. Additionally, molecular docking simulations were performed by interacting between phospholipids from Dengue virus envelope and PLA2s from Bothrops asper snake venom. Studies on snake venom PLA2s highlight the potential use of these proteins for the development of broad-spectrum antiviral drugs.

Preprocesamiento de los fármacos antivirales candidatos contra COVID-19 en modelos de SARS cov2. Objetivos / Preprocessing of the candidate antiviral drugs against COVID-19 in models of SARS cov2 targets

Although many viral infections are self-limiting, other are real health challenges like COVID-19 since many viruses possess just few drug gable targets to be treated with small drug molecules. Corona virus genome encodes for up to 17 main proteins. Orf1ab encodes for polyprotein. COVID-19 structural proteins are the spike S, membrane M, envelope E and the nucleocapsid N protein while other are non-structural proteins designated as NSP1-13 for non-structural proteins. Among NSP the most important corona virus targets for developing antiviral drugs are the papain-like protease, PDB ID: 6m03 and RNA polymerase NSP12, PDB ID: 6nur. NCBI, NIH Genbank, Uniprot, PDB, DrugBank, ChemSpider databases and bioinformatics editor softwares like ICM Mol soft pro and Swiss Dock were used in addition to the in vitro lab model of viral protease were integrated to retrieve and analyze corona virus targets and to select the candidate ligands in an attempt to evaluate the inhibitory efficacy of different experimental and approved drugs which were further optimized and searched for the highly similar approved drug. This step aims to adopt drug repurposing to speed the development of antiviral drugs and recommend rational in vivo and clinical studies. After COVID-19 targets had been analyzed the drugs that shared > 70% similarity to the binding sites of those targets were reversin, pentagastrin, remdesivir, norfloxacin and nitazoxanide against COVID-19 papain-like protease whereas benzyl glutathione, lopinavir and hydroxymethylglutathione against RNA polymerase. The anti-resistance reversin showed the highest inhibitory efficacy against COVID-19 papain-like protease as indicated by the ligand-protease binding energy with Mol soft pro analysis. The calculated inhibitory binding was -137.30 kJ/mol z > 1.9 as compared with the tetrazapentadecanoate -129.57 kJ/mol z = 4.0, whereas remdesivir, pentagastrin, nitazoxanide and norfloxacin had a moderate antiprotease activity (>- 100 kJ/mol). Norfloxacin shoresults showed a slight consistency between in vitro and in silico models. Although benzyl glutathione is an experimental compound, however it had the highest RNA polymerase inhibiting efficacy with -129 kJ/mol binding energy which is even higher than lopinavir and Favinavir. From the overall results, reversin, oligopeptides, quinolones and antiviral drugs may widen the treatment options for COVID-19 if further evaluated in clinical studies

Clinical Management of Argentine Hemorrhagic Fever using Ribavirin and Favipiravir, Belgium, 2020.

We report a case of Argentine hemorrhagic fever diagnosed in a woman in Belgium who traveled from a disease-endemic area. Patient management included supportive care and combination therapy with ribavirin and favipiravir. Of 137 potential contacts, including friends, relatives, and healthcare and laboratory workers, none showed development of clinical symptoms of this disease.

Safety and Efficacy of 8 Weeks Ledipasvir/Sofosbuvir for Chronic Hepatitis C Genotype 4 in Children Aged 4-10 Years.

OBJECTIVE: To evaluate the safety and efficacy of shortened 8-week regimen of ledipasvir/sofosbuvir (LED/SOF) combination therapy in treatment-naïve children without cirrhosis aged 4-10 years of age with chronic hepatitis C virus (HCV) infection. STUDY DESIGN: This observational single arm prospective study included 30 treatment-naïve children (20 males) with proved chronic HCV fulfilling inclusion criteria. Their body weights ranged from 17 to 26 kg. Four patients were excluded from the study. All the included children received a single oral dose of LED/SOF 45/200 mg for 8 weeks. Body weight, HCV-RNA, complete blood count, and liver function tests were monitored at 0, 2, 4, and 8 weeks and sustained virologic response was evaluated after 12 weeks after treatment (SVR12). The emergence of any side effects was also monitored. RESULTS: The most common risk factor (53.3%) was an parent or sibling with HCV infection. Twenty-nine patients (96.7%) were negative for HCV-RNA by week 2 of treatment and 1 patient became negative by week 4. The end of treatment response and SVR12 were 100%. Transaminases levels declined and returned to normal levels by week 2. Major side effects were fatigue in 90% (27/30) and headache in 76.7% (23/30). Side effects were minimal, tolerable, and did not interfere with daily activity or necessitate treatment discontinuation. CONCLUSIONS: A shortened 8-week regimen of LED/SOF (45/200 mg) is safe and effective with 100% SVR12 in treatment-naïve children with cirrhosis aged 4-10 years with chronic HCV infection genotype 4.

In Silico Studies against Viral Sexually Transmitted Diseases.

Sexually Transmitted Diseases (STDs) refer to a variety of clinical syndromes and infections caused by pathogens that can be acquired and transmitted through sexual activity. Among STDs widely reported in the literature, viral sexual diseases have been increasing in a number of cases globally. This emphasizes the need for prevention and treatment. Among the methods widely used in drug planning are Computer-Aided Drug Design (CADD) studies and molecular docking which have the objective of investigating molecular interactions between two molecules to better understand the three -dimensional structural characteristics of the compounds. This review will discuss molecular docking studies applied to viral STDs, such as Ebola virus, Herpes virus and HIV, and reveal promising new drug candidates with high levels of specificity to their respective targets.

An eye on hepatitis C: a review / O olho na hepatite C: uma revisão

ABSTRACT This review aims to caution ophthalmologists about the ocular consequences leading to the diagnosis of hepatitis C virus infection. In addition, in this context, the effects of old and new drugs are discussed in the ophthalmological setting. The importance of early diagnosis and the curative treatment of the disease has been reported in the national and international literature, demonstrating that its progression has important implications for daily clinical and surgical ophthalmological practice. Despite the scarcity of studies on new direct-acting antiviral drugs, fewer side effects of these drugs have been shown when compared with conventional interferon treatment with or without ribavirin. The ophthalmologist's risk of becoming infected, as demonstrated by the presence of the virus in ocular structures, and the possibility of contamination, is also discussed.

RESUMO Esta revisão objetiva alertar os oftalmologistas sobre as consequências oculares que levam ao diagnóstico da infecção pelo vírus da Hepatite C. Além disso, neste contexto, os efeitos de drogas antigas e novas são discutidos no cenário oftalmológico. A importância do diagnóstico precoce e do tratamento curativo da doença tem sido relatada na literatura nacional e internacional, demonstrando que sua progressão tem implicações importantes para a prática oftalmológica diária. Apesar da escassez de estudos sobre novos medicamentos antivirais de ação direta, foram demonstrados menos efeitos colaterais desses medicamentos quando comparados ao tratamento convencional com interferon, com ou sem ribavirina associado ou não à rivabirina. O risco do oftalmologista de se infectar, como demonstrado pela presença do vírus nas estruturas oculares, e a possibilidade de contaminação, também é discutido.

In vitro comparison of acyclovir, ganciclovir and cidofovir against equid alphaherpesvirus 3 and evaluation of their efficacy against six field isolates / Comparación in vitro de aciclovir, ganciclovir y cidofovir contra alfa-herpesvirus equino 3 y evaluación de la eficacia de los mismos frente a 6 aislamientos de campo del virus

Equid alphaherpesvirus 3 (EHV3) is the etiological agent of equine coital exanthema (ECE), which is a venereal, highly contagious disease, characterized by the formation of papules, vesicles, pustules and ulcers on the external genitalia of mares and stallions. EHV3 remains in a latent state after a successful infection and there are latently infected animals in which the virus is reactivated and generally re-excreted subclinically. There are no available vaccines for this condition and prevention is based on the clinical examination of mares prior to mating, which allows to segregate those showing clinical signs. As this approach does not eliminate the risk of contagion in stallions from subclinically infected mares, there is a need for a specific EHV3 treatment. Nowadays, there exist various antiviral compounds of proven effectiveness for other alphaherpesviruses affecting humans and animals. The aim of the present study was to compare the efficacy of three antiviral compounds, acyclovir, ganciclovir and cidofovir against EHV3 in vitro, and to assess their efficacy against six EHV3 Argentinian field isolates. To determine the efficacy of these compounds in vitro, three parameters were analyzed: reduction of plaque number, reduction of plaque size and reduction of viral production. Additionally, the effectiveness of the three compounds at an optimum concentration previously determined in this study was investigated for the EHV3 field isolates. Based on our results, ganciclovir was the most potent antiviral compound to reduce EHV3 replication in vitro and may thus be a valuable candidate for treatment and prevention of ECE in mares and stallions.

El alfa-herpesvirus equino 3 (EHV3) es el agente etiológico del exantema coital equino (ECE), enfermedad venérea, altamente contagiosa y caracterizada por la aparición de pápulas, vesículas, pústulas y úlceras en los genitales externos de yeguas y padrillos. Luego de la primo-infección, el EHV3 se mantiene en el animal en un estado de latencia a partir del cual puede reactivar y excretarse, generalmente de manera subclínica. No existen vacunas, por lo que la prevención se basa en la detección de las lesiones clínicas previo al servicio, y la segregación de estos animales. Sin embargo, este abordaje no previene la infección del padrillo por parte de yeguas que excretan el virus de manera subclínica, y por lo tanto existe la necesidad de un tratamiento específico contra el EHV3. En la actualidad, existen varios compuestos antivirales de probada eficacia contra herpesvirus humanos y veterinarios. El objetivo de este trabajo es comparar la eficacia de 3 compuestos antivirales, aciclovir, ganciclovir y cidofovir, contra EHV3 in vitro, y evaluar la eficacia de los mismos contra 6 cepas de campo argentinas de EHV3. Para determinar la eficacia de los compuestos in vitro se evaluaron 3 parámetros: reducción del número de placas de lisis, reducción del tamaño de placas de lisis y reducción de la producción de virus. Adicionalmente, la efectividad de los compuestos en una concentración óptima, previamente determinada en este estudio, fue determinada para 6 cepas de campo argentinas de EHV3. De acuerdo con los resultados obtenidos, ganciclovir fue el compuesto más potente en reducir la replicación del EHV3 in vitro, y por lo tanto podría considerarse un potencial candidato para el tratamiento y la prevención del ECE en yeguas y padrillos.

Experimental Dissection of the Lytic Replication Cycles of Herpes Simplex Viruses in vitro.

Herpes simplex viruses type 1 and type 2 (HSV-1 and HSV-2) produce lifelong infections and are highly prevalent in the human population. Both viruses elicit numerous clinical manifestations and produce mild-to-severe diseases that affect the skin, eyes, and brain, among others. Despite the existence of numerous antivirals against HSV, such as acyclovir and acyclovir-related analogs, virus variants that are resistant to these compounds can be isolated from immunosuppressed individuals. For such isolates, second-line drugs can be used, yet they frequently produce adverse side effects. Furthermore, topical antivirals for treating cutaneous HSV infections usually display poor to moderate efficacy. Hence, better or novel anti-HSV antivirals are needed and details on their mechanisms of action would be insightful for improving their efficacy and identifying specific molecular targets. Here, we review and dissect the lytic replication cycles of herpes simplex viruses, discussing key steps involved in cell infection and the processes that yield new virions. Additionally, we review and discuss rapid, easy-to-perform and simple experimental approaches for studying key steps involved in HSV replication to facilitate the identification of the mechanisms of action of anti-HSV compounds.

In vitro comparison of acyclovir, ganciclovir and cidofovir against equid alphaherpesvirus 3 and evaluation of their efficacy against six field isolates.

Equid alphaherpesvirus 3 (EHV3) is the etiological agent of equine coital exanthema (ECE), which is a venereal, highly contagious disease, characterized by the formation of papules, vesicles, pustules and ulcers on the external genitalia of mares and stallions. EHV3 remains in a latent state after a successful infection and there are latently infected animals in which the virus is reactivated and generally re-excreted subclinically. There are no available vaccines for this condition and prevention is based on the clinical examination of mares prior to mating, which allows to segregate those showing clinical signs. As this approach does not eliminate the risk of contagion in stallions from subclinically infected mares, there is a need for a specific EHV3 treatment. Nowadays, there exist various antiviral compounds of proven effectiveness for other alphaherpesviruses affecting humans and animals. The aim of the present study was to compare the efficacy of three antiviral compounds, acyclovir, ganciclovir and cidofovir against EHV3 in vitro, and to assess their efficacy against six EHV3 Argentinian field isolates. To determine the efficacy of these compounds in vitro, three parameters were analyzed: reduction of plaque number, reduction of plaque size and reduction of viral production. Additionally, the effectiveness of the three compounds at an optimum concentration previously determined in this study was investigated for the EHV3 field isolates. Based on our results, ganciclovir was the most potent antiviral compound to reduce EHV3 replication in vitro and may thus be a valuable candidate for treatment and prevention of ECE in mares and stallions.

El asunto Tamiflú/Relenza, la salud pública y algunas lecciones para la decisión y la ética / The Tamiflú/Relenza issue, the public health and some lessons for decision-making and ethics

La gripe española de 1918 provocó millones de muertos y sigue presente en la imaginación popular. Ese recuerdo se reavivó en 2005 con la gripe aviar y en 2009 con la pandemia de gripe A. Como respuesta a la amenaza se promovió el uso de los antivirales Tamiflú (oseltamivir) y Relenza (zanamivir) de los que se hicieron compras millonarias en euros por parte de los gobiernos. Sin embargo, hubo dudas acerca de la efectividad de los antivirales y la presión científica y política obligó a que las compañías farmacéuticas compartieran los datos crudos de los ensayos clínicos de los mismos. El análisis independiente permitió concluir en 2014 que los antivirales tenían una eficacia modesta en el alivio de los síntomas, carecían de impacto sobre complicaciones y muertes, tenían efectos adversos importantes y no modificaban la transmisión-contagio. En este texto se analiza la historia del Tamiflú/Relenza y se deducen las pertinentes lecciones éticas generalizables a todas las crisis de salud pública, como la erosión del crédito de la medicina, de los medicamentos, de los ensayos clínicos, de las autoridades y del proceso de toma de sus decisiones(AU)

The Spanish flu of 1918 caused millions of deaths and is still present in the people's thought. That memory revived in 2005 with the onset of the aviarian influenza and in 2009 with the influenza A pandemic. As a response to these threats, it was encouraged to use antiviral drugs called Tamiflu (Oseltamivir) and Relenza (zanamivir) and governments spent millions of Euros to purchase them. However, the effectiveness of these antiviral drugs was called into question and the scientific and political pressures forced the pharmaceutical companies to share their raw data from the clinical trials of these two drugs. An independent analysis allowed concluding in 2014 that these antiviral drugs had modest effectiveness in releasing the symptoms, had no impact on complications and deaths, caused significant adverse effects and did not change the transmission-contagion relation. This paper analyzed the history of Tamiflu/Relenza and inferred the relevant ethical lessons that may be generalized to all public health crises, such as the erosion of the credit of medicine, of drugs, of clinical trials, of the authorities and of their decision-making process(AU)

Avaliação in vitro da atividade citotóxica de drogas antivirais em fibroblastos caprinos / In vitro evaluation of the citotoxic activity of antiviral drugs in goat fibroblasts

O objetivo deste trabalho foi avaliar o efeito citotóxico das drogas antivirais em cultivos de fibroblastos que foram isolados por explantation da membrana sinovial de caprinos soronegativos para a presença de anticorpos para lentivírus de pequenos ruminantes. As células eram mantidas em cultivo, para posterior utilização nos testes de citotoxicidade, contendo Meio Essencial Mínimo (MEM) acrescido de SFB 10%, antifúngico, antibióticos e glutamina. Para o teste de citotoxicidade das drogas, alíquotas de 0,1mL de fibroblastos, na concentração de 2 x105 células/mL, foram depositadas em microplacas de 96 poços, incubadas por 24 e 48h com posterior troca do meio por outro contendo diluições de 0,005 μM, 0,05 μM, 0,5 μM, 5μM, 50 μM e 500 μM de cada droga, que foram: zidovudina (AZT), estavudina, lamivudina, didanosina, efavirenz, atazanavir e lopinavir. Após 24 h de incubação o meio foi desprezado e acrescentou-se 100 μL de azul de tetrazólio (MTT) a uma concentração de 5 mg/mL. As microplacas foram incubadas por 4 h/37oC. Posteriormente, adicionou-se 100 μL de uma solução de 95% de isopropanol e 5% de ácido fórmico. A análise espectrofotométrica foi medida em um leitor de ELISA a uma absorbância de 600 nm. A partir dos valores das densidades ópticas determinou-se a concentração da droga capaz de reduzir em 50% as células viáveis. Dessa forma, a zidovudina e a didanosina na concentração de 0,05 μM e a estavudina e a lamivudina nas concentrações de 0,5 μM e 500 μM, respectivamente, não apresentaram efeitos tóxicos. Concluindo-se que essas drogas mostram potencial para o desenvolvimento de testes capazes de mensurar sua atividade antiviral frente aos lentivírus de pequenos ruminantes (SRLV – small ruminant lentivirus).

This work evaluates the cytotoxic effect of antiviral drugs on cultured fibroblasts that were isolated by explantation from the synovial membrane of goats that were soronegative to the presence of lentivirus antibodies from small ruminants. The cells were grown in MEM supplemented with 10% fetal bovine serum, an antifungal, antibiotics and glutamine. The drug cytotoxicity assay was performed in 0.1 mL of fibroblasts with 2x105 cells per mL, cultivated in 96 well microplates, incubated for 24h and submitted to dilutions of 0.005 μM, 0.05 μM, 0.5 μM, 5 μM, 50 μM and 500 μM of each of zidovudine, stavudine, lamivudine, didanosine, efavirenz, atazanavir and lopinavir. After incubation for 24 hours the medium was removed and replaced by 100 μL of MTT solution (5 mg/mL) for 4 h at 37ºC. Then, the MTT solution was removed and 100 μL of a solution of 95% isopropanol and 5% of acid formic was added in order to dissolve the crystals. The absorbance was read on a multiwell spectrophotometer at 600 nm. The optical density values were used to determine the concentration of the drug capable of reducing the viable cells by 50%. Zidovudine and the didanosine at a concentration of 0.05 μM and stavudine and lamivudine at concentrations of 0.5 μM and 500 μM had no toxic effect. Therefore, these drugs have potential to develop tests to measure their antiviral activity against small ruminant lentiviruses.