Activity of Galidesivir in a Hamster Model of SARS-CoV-2

Coronavirus disease 2019 (COVID-19) has claimed the lives of millions of people worldwide since it first emerged. The impact of the COVID-19 pandemic on public health and the global economy has highlighted the medical need for the development of broadly acting interventions against emerging viral threats. Galidesivir is a broad-spectrum antiviral compound with demonstrated in vitro and in vivo efficacy against several RNA viruses of public health concern, including those causing yellow fever, Ebola, Marburg, and Rift Valley fever. In vitro studies have shown that the antiviral activity of galidesivir also extends to coronaviruses. Herein, we describe the efficacy of galidesivir in the Syrian golden hamster model of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Treatment with galidesivir reduced lung pathology in infected animals compared with untreated controls when treatment was initiated 24 h prior to infection. These results add to the evidence of the applicability of galidesivir as a potential medical intervention for a range of acute viral illnesses, including coronaviruses.

GOCOVRI® (amantadine) extended-release capsules in Parkinson's disease

Amantadine is an old, antiviral compound, which moderately improves motor behavior in Parkinson's disease. Its current resurgence results from an innovative, delayed uptake and extended release amantadine hydrochloride capsule, given at bedtime once daily. It is the only approved compound for reduction of involuntary movements, so called dyskinesia, in fluctuating orally levodopa treated patients. It additionally ameliorates ‘off’-intervals characterized by impaired motor behavior. These beneficial effects result from higher and more continuous brain delivery of amantadine. Future clinical research is warranted on preventive effects of this amantadine capsule combined with enzyme blockers of central monoamine oxidase B and peripheral catechol-O-methyltransferase on motor complications in orally levodopa treated patients, as all these pharmacological principles support the concept of continuous dopamine substitution.

Quantum Mechanical Modeling Unveil the Effect of Substitutions on the Activation Barriers of the Diels-Alder Reactions of an Antiviral Compound 7H-Benzo[a]phenalene

Density functional theory has been utilized for exploring the mechanism of Diels-Alder reaction between 7H-benzo[a]phenalene and maleic anhydride. 7H-Benzo[a]phenalene is an antiviral compound and information available about its cycloaddition reactions with possible reaction path and mechanism is scarce. In order to work on the synthesis of its further potential derivatives, the mechanism of its reaction with all aspects should be well understood. Two novel intermediates involved in this reaction have been reported. Diels-Alder reaction of maleic anhydride has found many applications in the synthesis of wide range of useful products. The major concern of this work is to evaluate the consequences of introducing electron donating and electron withdrawing substituents on the reactivity of maleic anhydride towards 7H-benzo[a]phenalene. Thermodynamic parameters, activation parameters, energies of frontier orbitals, global reactivity indices and global electron density transfer (GEDT) have been determined for all the reactions. Fukui functions are computed for each reactant in order to identify the most reactive sites. All the reactions have been found to proceed via normal electron demand having polar nature. The substituents with opposite electronic properties were expected to affect the reactivity of dienophile in an inverse manner, however, the results are not according to this assumption. Rather, both kinds of substituents increased the activation barrier of the reaction. This behavior has been explained in the light of various parameters such as the stability of reacting species, gap of frontier molecular orbitals etc. Experimental studies reported previously are in agreement with these results.

Letermovir profilaxis allogén vérképző-őssejt transzplantációban: egy hazai centrum gyakorlati tapasztalatai

Összefoglaló. Bevezetés: A humán cytomegalovírus infekció direkt és indirekt szövődményei napjainkban is veszélyeztetik az allogén őssejt-transzplantációval kezelt betegeket. A széles körben alkalmazott preemptív stratégia mellett előnyös lehet a kórokozó reaktivációjának megelőzése profilaktikusan adagolt vírusellenes vegyülettel. A letermovir innovatív hatásmechanizmusú, szűk spektrumú antivirális szer, mely allogén őssejt-transzplantáltak körében végzett, placebo kontrollált klinikai vizsgálatban csökkentette a cytomegalovírus infekciók gyakoriságát és javította a túlélést. A szerzők 23, allogén őssejt-transzplantált beteg retrospektív módon gyűjtött adatait ismertetik, akik a beavatkozás kapcsán letermovir profilaxisban részesültek. A betegek több mint fele akut leukémiában szenvedett, harmaduk aktív betegséggel került transzplantációra, kétharmaduk donora haploidentikus egyezést mutatott. A letermovir adagolása során 2, azt követően további 3 személyben lépett fel cytomegalovírus infekció. Szervi érintettséggel járó cytomegalovírus betegség egyetlen esetben sem alakult ki. A megfigyelési időszak során 2 fő hunyt el, cytomegalovírustól független okok miatt. Az alkalmazhatóságot korlátozó mellékhatást nem észleltek. A letermovir a mindennapi klinikai gyakorlatban is hatékonynak és biztonságosnak bizonyult az őssejt-transzplantáltak cytomegalovírus fertőzésének megelőzésére. Summary. Introduction: Direct and indirect effects of cytomegalovirus infection remain an ongoing threat to patients treated with allogeneic stem cell transplantation. In addition to the widely used preemptive approach, prevention of viral replication with a prophylactically administered antiviral drug seems to be feasible. Letermovir, a narrow-spectrum antiviral compound with an innovative mechanism of action, has been shown to decrease the incidence of cytomegalovirus infection and to improve survival in a placebo-controlled clinical trial recruiting allogeneic stem cell transplant patients. Authors present retrospectively collected data from 23 patients receiving letermovir prophylaxis as a part of their allogeneic stem cell transplantation procedure. More than half of prophylaxed individuals had acute leukemia, a third of them underwent transplantation with an active disease and two third of the cohort had a haploidentical donor. During prophylaxis 2, subsequently further 3 patients developed a cytomegalovirus infection. No organ-specific disease could be detected. Through the observational period 2 patients have died due to causes unrelated to cytomegalovirus. No side effect interfering with drug use could be revealed. In this real-life case series letermovir has been shown to be effective and safe for the prevention of cytomegalovirus infection in allogeneic stem cell transplant patients.

Molecular Study of Antiviral Compound of Indonesian Herbal Medicine as 3CLpro and PLpro Inhibitor in SARS-COV-2

Rapid transmission of COVID-19 disease and the fatal effects of the disease lead researchers to use various way to find potential anti-COVID-19 compounds, including using modern approaches. Molecular docking is one of the methods that can be used to analyse antiviral compounds and its molecular target from Indonesian herbs that are believed to have properties as anti-COVID-19. This study aims to analyse antiviral compounds from 5 herbs that have the potential as inhibitors of PLpro and 3CLpro, which both are a non-structural protein in SARS-CoV-2 by molecular docking approach using PLANTS. Remdesivir triphosphate, the active metabolite of remdesivir, was used as the comparison compound in studies. The results showed docking scores obtained from interactions between natural ligands, remdesivir trifospat, curcumin, demetoksikurkumin, bisdemetoksikurkumin, luteolin, apigenin, kuersetin, kaempferol, formononrtin-7-O-glucoronide, androgafolide, and neoandrogafolide with PLpro are as follows -111,441, -103,827, -103,609, -102,363, -100,27,-79,6655, -78.6901, -80.9337, -79.4686, -82.1124, -79.1789, and -97.2452.Combination between quercetin, neoandrographolide, bisdemethoxycurcumin, demetoxycurcumin, and curcumin showed a synergy effect by reduce its docking score. Meanwhile its interaction with the protein 3CLpro showed docking score for those compounds as follows 64.0074, -86.1811, -81.428, -87.1625, -78.2899, -73.4345,-70,3368, -71.5539, -68.4321, -72.0154, -75.9777 and -93.7746.Combination between andrographolide, neoandrographolide, bisdemethoxycurcumin, demetoxycurcumin and curcumin, also shows synegy effect in 3CLpro allow them to reduce the docking score.This study concludes that curcumin was known as the most potent compound that act as a PLpro inhibitor based on a docking score of -103,609, while in 3CLpro all the compound have a potential to inhibit 3CLpro with demethosxycurcumin and neoandrogafolide as the most potent compound with a docking score -87,126 and -93.7746.

Pharmacological perturbation of intracellular dynamics as a SARS-CoV-2 antiviral strategy

SARS-CoV-2 (CoV2) is the viral agent responsible for the pandemic of the coronavirus disease 2019 (COVID-19). Vaccines are being deployed all over the world with good efficacy, but there is no approved antiviral treatment to date. This is particularly needed since the emergence of variants and the potential immune escape may prolong pandemic spreading of the infection for much longer than anticipated. Here, we developed a series of small molecules and identified RG10 as a potent antiviral compound against SARS-CoV-2 in cell lines and human airway epithelia (HAE). RG10 localizes to endoplasmic reticulum (ER) membranes, perturbing ER morphology and inducing ER stress. Yet, RG10 does not associate with SARS-CoV-2 replication sites although preventing virus replication. To further investigate the antiviral properties of our compound, we developed fluorescent SARS-CoV-2 viral particles allowing us to track virus arrival to ER membranes. Live cell imaging of replication-competent virus infection revealed that RG10 stalls the intracellular virus-ER dynamics. Finally, we synthesized RG10b, a stable version of RG10, that showed increased potency in vitro and in HAE with a pharmacokinetic half-life greater than 2 h. Together, our work reports on a novel fluorescent virus model and innovative antiviral strategy consisting of the perturbation of ER/virus dynamics, highlighting the promising antiviral properties of RG10 and RG10b.

Evaluation of Ribavirin–Poloxamer Microparticles for Improved Intranasal Absorption

Ribavirin is a water-soluble antiviral compound which, owing to its inability to cross the blood–brain barrier, has limited effectiveness in treating viruses affecting the central nervous system. Direct nose-to-brain delivery was investigated for ribavirin in combination with poloxamer 188, an excipient known to enhance the absorption of drug compounds administered intranasally. Composite solid microparticles suitable for intranasal insufflation were prepared by suspending fine crystals of ribavirin in a matrix of poloxamer 188, which were cryogenically milled and characterized to ensure that ribavirin remained stable throughout preparation. In vitro diffusion of ribavirin across a semi-permeable regenerated cellulose membrane showed comparable cumulative drug release after 180 min from both fine solid particles (<20 µm) and 1:1 ribavirin:poloxamer microparticles (d50 = 20 µm); however, the initial release from polymer microparticles was slower, owing to gel formation on the membrane surface. When solid ribavirin was directly deposited on excised olfactory mucosa, either as fine drug particles or 1:1 ribavirin:poloxamer microparticles, permeation was significantly increased from microparticles containing poloxamer 188, suggesting additional interactions between the polymer and olfactory mucosa. These data indicate that for highly water-soluble drugs such as ribavirin or drugs subject to efflux by the nasal mucosa, a formulation of poloxmer-containing microparticles can enhance permeability across the olfactory epithelium and may improve direct nose-to-brain transport.

In silico Screening of Some Compounds Derived from the Desert Medicinal Plant Rhazya stricta for Potential Treatment of COVID -19

The recent emerging SARS-CoV-2 pandemic which was identified as COVID-19 disease has become a global health concern. It resulted in a major pneumonia outbreak worldwide. Currently, there are no approved drugs and several attempts have been made to use computational program approaches in drug repurposing for COVID-19 treatment. The SARS-CoV-2 spike glycoprotein receptor-binding domain (RBD) is vital for binding to the hACE2 receptor, which initiates entry into human cells, and thus is a key target for antiviral compound development. Many herbal natural products have been proved to exert virucidal activity against the vast majority of pathogenic viruses. Rhazya stricta, a folkloric medicinal desert plant of Saudi Arabia was shown to exhibit bactericidal activity against a verity of pathogens including Methicillin-resistant Staphylococcus aureus (MRSA) and some other Multidrug-Resistant Organisms (MDR’s). This study aims to test for antiviral activity of the folkloric medicinal desert plant Rhazya stricta against coronavirus SARS-CoV-2. We identified three non-alkaloid herbal natural compounds Lig230, Lig434, and Lig68 from Rhazya Stricta that bind and interact significantly with RBD (PDB: I.D. 6M0J) by using virtual screening and computer aiding program Autodock vina. Based on the results of docking scores, molecular docking simulations, RMSD, RMSF, and radius of gyration (Rg), the virtually screened antiviral compounds showed good binding interactions and high stability. Lig230 revealed the highest average of interaction energy during MD simulation (− 417.284 kJ/mol) followed by Lig434 (− 366.186 kJ/mol) and the lowest interaction energy was by Lig68 (− 352.5872 kJ/mol). To evaluate the oral bioavailability, a drug-likeness profile was performed by SwissADME and the results revealed that these compounds expected to confront permeability and solubility difficulties if they were introduced orally. In conclusion, the suggested three compounds can serve as potential anti- SARS-CoV-2 and should be furtherly tested in vitro and in vivo.