Development of antiviral therapeutics combating coxsackievirus type B3 infection

Enteroviruses comprise highly diverse group of single-stranded positive RNA viruses belonging to Enterovirus genus, Picornaviridae family. They are the most prevalent viruses worldwide highlighted by high resistance to environmental cues. Enteroviruses normally cause seasonal self-limiting infections, but also known as causative infectious agents of encephalitis, myocarditis, poliomyelitis, acute heart failure and sepsis. Enterovirus genetic plasticity contributes to widespread epidemics and sporadic outbreaks (e. g., outbreaks of Enterovirus D68 and Enterovirus 71). Type B Coxsackieviruses of Enterovirus B species is one of commonly identified infectious agents associated predominantly with mild upper respiratory and gastrointestinal illnesses. Nevertheless, Coxsackieviruses B3 infection can result in severe myocarditis leading ultimately to heart failure. The pathogenesis of Coxsackievirus B3-induced myocarditis is well known being mediated by both direct damage due to viral proteases and indirectly via secondary host immune responses. Despite success in preventive vaccination of some enterovirus infections that allowed to control some of them direct antiviral agents for treatment of enteroviral infection particularly Coxsackieviruses B3 myocardial infection are still in demand. In addition, no ongoing clinical trials for therapy or prevention of Coxsackieviruses B3 infection are available. Current treatment strategies are mainly aimed to stabilize patient condition and relieve discomfort condition. It seems that relatively small market for anti-enteroviral drugs prevents pharma industry from developing new drugs. The Coxsackieviruses B3 lifecycle have been extensively studied and potential targets for drug design have been identified. The aim of our review was to describe current state in the field of antiviral drug design combating Coxsackieviruses B3 infection emphasizing direct-acting antivirals, albeit paying some attention to host factor-targeting inhibitors (including compounds from medicinal plant extracts) as well. The following categories of direct Coxsackieviruses B3 inhibitors are discussed in detail: capsid binders (pleconaril and its derivatives), viral 3C protease inhibitors (rupintrivir and its analogs), drugs targeting viral replication (both nucleoside analogs and non-nucleoside inhibitors). Results of drug repurposing screens for amiloride, benzerazide, dibucaine and fluoxetine are also discussed

The influence of biological products and growth regulators on the yield and quality indicators of pea seeds of various varieties

Abstract Peas are an important agricultural crop of great importance in human and animal nutrition. Peas, being a legume crop, help replenish nitrogen reserves in the soil. In field studies of the Federal State Budgetary Scientific Institution of the Federal Scientific Center of Legumes and Goat Crops (Oryol region), the influence of various growth regulators and biological products on the yield and quality indicators of pea seeds of the Nord and Multik varieties was studied. Pea plants are grown on dark gray forest, medium loamy soil of average cultivation. Before sowing, pea seeds were treated with solutions of Kornevin, Albit and Epin-extra by soaking for 5 hours. Solutions of the drugs were used at a concentration of 10-6 M, then dried and treated with Rizotorfin before sowing. Growth rates during the growing season and the yield of pea plants were determined. The content of protein, starch and amylose in starch was determined in the seeds. Research results have shown that the yield of pea plants depends on weather conditions. Under favorable weather conditions, the highest yield was obtained from the pea variety Nord (42.2 c/ha) in the variant with seed treatment with Kornevin, and in the Multik variety (43.0 c/ha) when treated with Rizotorfin. In arid conditions, the highest yield of peas of the Nord variety was obtained using the preparations Epin-extra and Kornevin. The highest yield of peas of the Multik variety was obtained using the preparations Rizotorfin, Kornevin and Epin-Extra. The research results, confirmed by statistical evaluation, showed that bioregulators and growth regulators help stimulate the amount of nitrogen supplied to plants, as well as the synthetic processes of protein synthesis. This contributed to improving the quality of seeds and green mass

ANTIVIRAL PROPERTIES OF VERDAZYLS AND LEUCOVERDAZYLS AND THEIR ACTIVITY AGAINST GROUP B ENTEROVIRUSES

Enteroviruses are non-enveloped viruses of Enterovirus genus, Picornaviridae family, causing a variety of human diseases: from acute respiratory and intestinal infections to more severe pathologies including poliomyelitis, encephalitis, myocarditis, pancreatitis. Currently, no approved direct-acting antiviral drugs for treatment of enterovirus infections exists, whereas vaccination is available only for prevention of poliomyelitis and enterovirus 71 infection. Therefore, it is promising to conduct a search for inhibitors of enteroviruses life cycle in drug development to treat enterovirus infections. Here, antiviral properties of stable free radicals, verdazyls, and their precursors, leucoverdazyls, were investigated. It has been shown that leucoverdazyls vs verdazyls increased the survival of permissive cell culture infected with coxsackievirus. The activity range of the lead leucoverdazyl against RNA-containing and DNA-containing human viruses (in the viral yield reduction assay) and its proposed mechanism of action (time of addition assay) was studied. The lead compound suppressed reproduction of group B enteroviruses in vitro, with modest activity against influenza A virus and no activity against herpes virus type 1 and adenovirus type 5. The maximum decrease in viral titers was observed upon its addition to infected cells during early and middle stages of the virus life cycle. Thus, we concluded that the studied compound has a pronounced inhibitory activity against group B enteroviruses not belonging to the class of capsid binder inhibitors, without virucidal properties. Previously, we described antioxidant properties of leucoverdazyls. It is known that many viral infections are accompanied by production of reactive oxygen species and oxidative stress, and some compounds with antioxidant properties exhibit antiviral potential. Targeted chemical modifications of leucoverdazyls and further studies of leucoverdazyl mechanism of action as well as in vivo animal studies are needed. However, the results obtained may be useful for future development of new antiviral drugs to treat enteroviral infections. © Volobueva A.S. et al., 2023.The work was supported by a grant for young scientists from the St. Petersburg Pasteur Institute

4-Hydroxy-3-nitro-1,4-dihydrotriazolo[5,1-c][1,2,4]triazines: synthesis, antiviral activity, and electrochemical characteristics

A new method for preparation of 4-hydroxy-3-nitro-1,4-dihydrotriazolo[5,1-c][1,2,4]-triazines using 1-nitro-2-morpholinoethylene and 3-diazo-1,2,4-triazoles is proposed. Antiviral activity against the Coxsackie B3 virus and electrochemical transformations of the prepared compounds are studied. © 2022, Springer Science+Business Media LLC.Russian Science Foundation, RSF, (20-13-00142)This work was performed under financial support of the Russian Science Foundation (Project No. 20-13-00142)

Methods of Synthesis and Antiviral Activity of New 4-Alkyl-3-Nitro-1,4-Dihydroazolo[5,1-c][1,2,4]Triazin-4-ols

[Figure not available: see fulltext.] An azo coupling reaction of α-nitro ketones with 5-diazoazoles was used to obtain 4-alkyl-3-nitro-1,4-dihydroazolo[5,1-с][1,2,4]triazines, which were characterized with respect to their antiviral activity against influenza and Coxsackie B3 viruses. © 2021, Springer Science+Business Media, LLC, part of Springer Nature.This study was funded by the Russian Science Foundation (project No. 20-13-00142)

Design of 4-Substituted Sulfonamidobenzoic Acid Derivatives Targeting Coxsackievirus B3

A series of novel 4-substituted sulfonamidobenzoic acid derivatives was synthesized as the structural evolution of 4-(4-(1,3-dioxoisoindolin-2-yl)phenylsulfonamido)benzoic acid, which is the known inhibitor of the enterovirus life cycle. Antiviral properties of prepared compounds were evaluated in vitro using phenotypic screening and viral yield reduction assay. Their capsid binding properties were verified in thermostability assay. We identified two new hit-compounds (4 and 7a) with high activity against the coxsackievirus B3 (Nancy, CVB3) strain with potencies (IC50 values of 4.29 and 4.22 μM, respectively) which are slightly superior to the reference compound 2a (IC50 5.54 μM). Both hits changed the heat inactivation of CVB3 in vitro to higher temperatures, suggesting that they are capsid binders, as 2a is. The results obtained can serve as a basis for further development of the lead compounds for novel drug design to combat enterovirus infection

Conditioned medium of induced mesenchymal stem cells as an activator of differentiation in the osteogenic direction

In the prevailing era, the need for new biologically active substances of peptide nature and their therapeutic impacts are of great interest of the contemporary pharmacology. Hence, this study intends to assess the osteoinductive potential of the conditioned medium concentrate on native mesenchymal stem cells. To gratify the study's aim, this study was carried out on a culture of rat mesenchymal stem cells. To stimulate the differentiation of Mesenchymal stem cells in the osteogenic direction, this study used a complete nutrient medium containing dexamethasone, ascorbic acid, sodium beta-glycerophosphate in the concentrations recommended in the guidelines. Subsequently, the resulting concentrate sample was examined using HPLC-MS / MS mass, spectrometric analysis. Part of the previously obtained concentrate of the conditioned medium was used, to assess the proliferation and differentiation of rat Mesenchymal stem cells in the osteogenic direction by staining for alkaline phosphatase. Given the results of the study, it can be concluded that that most of the identified proteins of the conditioned medium concentrate belong to the group of proteins regulating cellular processes, and groups of proteins were also, found that relate to the organization of the extracellular structure, the processes of cell development, or are directly responsible for the differentiation of Mesenchymal stem cells in the osteogenic direction. Along with this, the concentrate of the conditioned medium does not affect the proliferation rate of Mesenchymal stem cells. Thus, the resulting concentrate of the conditioned medium, can be further used, for the development of therapeutic preparations with osteoinductive and regenerative potential

The stop-flow arm equilibrium pressure in preoperative patients: Stressed volume and correlations with echocardiography

Background: The distending intravascular pressure at no flow conditions reflects the stressed volume. While this haemodynamic variable is recognised as clinically important, there is a paucity of reports of its range and responsiveness to volume expansion in patients without cardiovascular disease and no reports of correlations to echocardiographic assessments of left ventricular filling. Methods: Twenty-seven awake (13 male), spontaneously breathing patients without any history of cardiopulmonary, vascular or renal disease were studied prior to induction of anaesthesia. The no-flow equilibrium pressure in the arm following rapid circulatory occlusion (P arm ) was measured via a radial arterial catheter. Transthoracic echocardiography was used to measure left ventricular end diastolic area and volume as well as the diameter of the inferior vena cava. The P arm and echocardiographic variables were measured before and after administration of 500 mL 0.9% NaCl over 10 minutes. Changes were analysed by paired t test, Pearson's correlation and multiple linear regression. Results: P arm increased overall from 22 ± 5 mm Hg to 25 ± 6 mm Hg (mean difference 3.0 ± 4.5 mm Hg, P = 0.002) following the fluid bolus with corresponding increases in arterial pressure and echocardiographic variables. Variability in the direction of the P arm response reflected concomitant changes in vascular compliance. Only weak correlations were observed between changes in P arm and inferior vena cava diameter indexed to body surface area (R 2  = 0.29, P = 0.01). Conclusion: Preoperative measurements of P arm increased following acute expansion of the intravascular volume. Echocardiography demonstrated poor correlation with P arm

Storm surges as a forcing factor of coastal erosion in the western and eastern Russian Arctic

The evolution of Arctic coasts over the coming decades will be governed by changes in the natural environment caused by the effects of climate warming. Rising temperatures are altering the arctic coastline by reducing sea ice and permafrost thawing, and larger changes are projected to occur as this trend continues. This is an important topic to pursue given the direct impacts to human communities and infrastructure already being felt along Arctic coasts. About half of the Russian Arctic coast is composed of ice-rich permafrost deposits. The mean annual coastal retreat rate is 1-5 m per year, but at single sites can exceed 25 m for some years. In general, the exact processes which affect thermal-erosion coasts and the intensity of these processes are determined by a combination of and interaction between thermal and wave-energy factors. Thermal energy is transmitted to the frozen coast via radiative and sensible heat fluxes from the air and water. Correspondingly, higher air and water temperatures, together with longer durations of ice-free seas and positive air temperatures, affect the stability of frozen coasts. The wave-energy factor acts via the direct mechanical impact of sea waves on the shore. In arctic seas the wind-induces waves are predominate. The effectiveness of this factor is determined by storm-driven sea surge intensity as well as by the length of the stormiest period. Conversely, surge intensity substantially depends on the fetch, which is intrinsically linked to sea-ice extent. The minimum area of sea ice extent in the northern hemisphere during the last 30 years has changed from 6 to 3.5 million square kilometers. In September, 2007, sea ice area achieved its historical minimum for the period of satellite observation (since 1978). Less extensive sea ice creates more open water and longer fetches, allowing stronger wave generation by winds and increasing wave-induced erosion along arctic shores. Therefore, the acceleration of erosion and thermo-abrasion of the coast can be caused by the increase of the air and water temperatures and by the wind-wave activity increases. Coastal dynamics have been observed at key sites in the western and eastern sectors of Russian Arctic. We have calculated annual wave energy variations for the last 30 years. Hindcast analysis has revealed that warming events have not always lead to an increase in wave energy or to acceleration of coastal erosion. For example, in the Arctic regions that we studied, in half of the cases warm periods were characterized on one hand by reduced ice cover and growth of open water area, and, on the other hand, by decreased wind-wave activity. As a result no acceleration in coastal retreat was observed. Furthermore, in the western sector of the Russian Arctic the wave fetch was limited by the presence of islands, while in the eastern one by wave acceleration limit. Thus, expectations of catastrophic acceleration of coastal erosion in Arctic are probably exaggerated

Water-Soluble Fullerene C₆₀ Derivatives Are Effective Inhibitors of Influenza Virus Replication

The influenza virus genome features a very high mutation rate leading to the rapid selection of drug-resistant strains. Due to the emergence of drug-resistant strains, there is a need for the further development of new potent antivirals against influenza with a broad activity spectrum. Thus, the search for a novel, effective broad-spectrum antiviral agent is a top priority of medical science and healthcare systems. In this paper, derivatives based on fullerenes with broad virus inhibiting activities in vitro against a panel of influenza viruses were described. The antiviral properties of water-soluble fullerene derivatives were studied. It was demonstrated that the library of compounds based on fullerenes has cytoprotective activity. Maximum virus-inhibiting activity and minimum toxicity were found with compound 2, containing residues of salts of 2-amino-3-cyclopropylpropanoic acid (CC50 > 300 µg/mL, IC50 = 4.73 µg/mL, SI = 64). This study represents the initial stage in a study of fullerenes as anti-influenza drugs. The results of the study lead us conclude that five leading compounds (1–5) have pharmacological prospects