Antiviral Research Articles

Efficient Strategy for Synthesizing Vector-Free and Oncolytic Herpes Simplex Type 1 Viruses.

Synthesizing viral genomes plays an important role in fundamental virology research and in the development of vaccines and antiviral drugs. Herpes simplex virus type 1 (HSV-1) is a large DNA virus widely used in oncolytic virotherapy. Although de novo synthesis of the HSV-1 genome has been previously reported, the synthetic procedure is still far from efficient, and the synthesized genome contains a vector sequence that may affect its replication and application. In the present study, we developed an efficient vector-free strategy for synthesis and rescue of synthetic HSV-1. In contrast to the conventional method of transfecting mammalian cells with a completely synthesized genome containing a vector, overlapping HSV-1 fragments synthesized by transformation-associated recombination (TAR) in yeast were linearized and cotransfected into mammalian cells to rescue the synthetic virus. Using this strategy, a synthetic virus, F-Syn, comprising the complete genome of the HSV-1 F strain, was generated. The growth curve and electron microscopy of F-Syn confirmed that its replication dynamics and morphogenesis are similar to those of the parental virus. In addition, by combining TAR with in vitro CRISPR/Cas9 editing, an oncolytic virus, F-Syn-O, with deleted viral genes ICP6, ICP34.5, and ICP47 was generated. The antitumor effect of F-Syn-O was tested in vitro. F-Syn-O established a successful infection and induced dose-dependent cytotoxic effects in various human tumor cell lines. These strategies will facilitate convenient and systemic manipulation of HSV-1 genomes and could be further applied to the design and construction of oncolytic herpesviruses.

Nanoenabled Antiviral Pesticide for Tobacco Mosaic Virus: Excellent Adhesion Performance and Strong Inhibitory Effect to Alleviate the Damage on Photosynthetic System.

Tobacco mosaic virus (TMV) is a major agricultural threat. Here, a cationic star polymer (SPc) was designed to construct an efficient nanodelivery system for moroxydine hydrochloride (ABOB). ABOB could self-assemble with SPc via a hydrogen bond and van der Waals force, and this complexation reduced the particle size of ABOB from 2406 to 45 nm. With the aid of SPc, the contact angle of ABOB decreased from 100.8 to 79.0°, and its retention increased from 6.3 to 13.8 mg/cm2. Furthermore, the complexation with SPc could attenuate the degradation of ABOB in plants, and the bioactivity of SPc-loaded ABOB significantly improved with a reduction in relative viral expression from 0.57 to 0.17. The RNA-seq analysis revealed that the ABOB/SPc complex could up-regulate the expression of growth- and photosynthesis-related genes in tobacco seedlings, and the chlorophyll content increased by 2.5 times. The current study introduced an efficient nanodelivery system to improve the bioactivity of traditional antiviral agents.

Effectiveness of recently-approved oral antiviral medications on the outcome of patients with mild-to-moderate COVID-19 and preexisting chronic obstructive pulmonary diseases

ABSTRACT Objectives This study assessed the effectiveness of the oral antiviral agents nirmatrelvir – ritonavir (NMV-r) and molnupiravir (MOV) for treating mild-to-moderate coronavirus disease 2019 (COVID-19) in patients with COPD. Methods This retrospective cohort study extracted data from the TriNetX platform and examined 94,984 COVID-19 patients with preexisting COPD from 1 January 2022, to 1 October 2023. Patients receiving NMV-r or MOV (study group) were compared with those not receiving oral antiviral agents (control group) after propensity score matching (PSM). Results After PSM, 7,944 patients were classified into the study and control groups. The primary composite outcome of all-cause hospitalization, or death in 30 days was reported in 458 (5.7%) patients in the study group and 566 (7.1%) patients in the control cohort, yielding a hazard ratio [HR] of 0.79 (95% confidence interval [CI]: 0.70–0.89; Table 2). Compared with the control group, the study group had a significantly lower risk of all-cause hospitalization (HR, 0.87; 95% CI: 0.76–0.99) and death (HR: 0.21, 95% CI: 0.13–0.35). Conclusions This study revealed that oral antivirals – NMV-r or MOV might improve clinical outcomes in patients with preexisting COPD and COVID-19. However, only a small proportion of preexisting COPD patients with COVID-19 received oral antiviral treatment.

Novel Alkynylamide-Based Nonpeptidic Allosteric Inhibitors for SARS-CoV-2 3-Chymotrypsin-like Protease.

Although the coronavirus disease 2019 (COVID-19) crisis has passed, there remains a necessity for continuous efforts toward developing more targeted drugs and preparing for potential future virus attacks. Currently, most of the drugs received authorization for the treatment of COVID-19 have exhibited several limitations, such as poor metabolic stability, formidable preparation, and uncertain effectiveness. It is still significant to develop novel, structurally diverse small-molecule antiviral drugs targeting SARS-CoV-2 3-chymotrypsin-like protease (3CLpro). Herein, we report a class of alkynylamide-based nonpeptidic 3CLpro inhibitors that can be prepared conveniently by our previously developed one-pot synthetic method. The structure-activity relationships of alkynylamides as SARS-CoV-2 3CLpro inhibitors have been carefully investigated and discussed in this study. The two stereoisomers of the resulting molecules exhibit stereoselective interaction with 3CLpro, and the optimized compound (S,R)-4y inhibits 3CLpro with high potency (IC50 = 0.43 μM), low cytotoxicity, and acceptable cell permeability. Compound (S,R)-4y presents as a noncovalent inhibitor of 3CLpro against SARS-CoV-2 by the time-dependent inhibition assay (TDI) and mass spectrometry analysis. The Lineweaver-Burk plots, binding energy, surface plasmon resonance, and molecular docking studies suggest that (S,R)-4y specifically binds to an allosteric pocket of the SARS-CoV-2 3CLpro. These findings provide a novel class of nonpeptidic alkynylamide-based allosteric inhibitors with high selectivity against SARS-CoV-2 3CLpro featured by a simplified one-pot synthesis at room temperature in air.

Antiviral activity of the water extract and ethanol extract of Sorbus commixta against influenza A virus in vitro

Although vaccines and antivirals are currently available, influenza virus infections continually present major threats to human health. Due to genetic diversity and variability of influenza viruses, the development of new antiviral agents against the virus remains as a considerable challenge. In this study, we evaluated the antiviral activity of the water extract and ethanol extract of Sorbus commixta Hedl. (SCH), widely used as a medical herb, against influenza A viruses and identified molecular mechanisms for the antiviral activity. The water extract and ethanol extract of SCH demonstrated virucidal activity against influenza A virus at the noncytotoxic concentrations. In addition, cytopathic effect reduction assay and GFP fluorescence image analysis suggest that SCH extracts have inhibitory activity on multiple stages during influenza virus life cycle. Mechanisms studies showed that SCH extracts inhibited the biological functions of influenza viral surface hemagglutinin and neuraminidase proteins that play critical roles in the viral entry and release steps. SCH extracts not only prevented the receptor binding of influenza viral HA to the cellular receptors but also inhibited the HA-mediated membrane fusion. In addition, SCH extracts suppressed the enzyme activity of the viral neuraminidase. The results together suggest that SCH extracts contain antiviral natural compounds that inhibit multiple influenza viral proteins including the viral surface proteins. Our findings suggest that SCH extracts could be promising resources for the development of novel antiviral agents against influenza A viruses.

Prediction of hepatocellular carcinoma and liver-related events in anti-HDV positive individuals

Chronic hepatitis D (CHD) is the most severe form of chronic viral hepatitis, with a high risk of developing hepatocellular carcinoma (HCC) and liver-related mortality. Risk stratification is needed to guide HCC surveillance strategies and to prioritize treatment with antiviral agents. We conducted a multicenter retrospective cohort of anti-HDV positive individuals managed at sites in the Netherlands and the United Kingdom. We studied the 5-year cumulative incidences of HCC and liver-related events (first of HCC, liver transplantation and liver-related mortality), in the overall cohort and among relevant subgroups. We analyzed 269 anti-HDV positive individuals with a median follow-up of 4.3 years in which 47 first events occurred. The 5-year cumulative incidences of HCC and liver-related events were 3.8% and 15.6% in the overall cohort. The 5-year cumulative incidence of HCC and liver-related events for individuals without cirrhosis was 0% and 0.9% compared to 12% and 41.3% for individuals with cirrhosis (p<0.001). The 5-year cumulative incidence of HCC and liver-related events was 0% and 2.1% among individuals with low PAGE-B scores, compared to 3.2% and 21.1% with intermediate and 25.4% and 45.5% with high risk scores (p<0.001). We found comparable results for the FIB-4 score. Findings were consistent regardless of cirrhosis or detectable HDV RNA (p<0.001). Anti-HDV positive individuals are at high risk of adverse liver-related outcomes. The incidences of HCC was negligible among individuals without cirrhosis and among individuals with low baseline PAGE-B and/or FIB-4 scores. Therefore, these score can be used to guide HCC surveillance strategies and potentially also for treatment prioritization.

Simultaneous Estimation of Atazanavir &amp; Ritonavir in API &amp; Marketed Formulations by Using RP-HPLC

Development and validation of RP-HPLC method for simultaneous estimation of Atazanavir and Ritonavir in their combined tablet dosage form. Atazanavir and Ritonavir are antiviral agents used in treatment of HIV. A simple, precise, rapid, accurate and cost-effective high- performance liquid chromatography (HPLC) method was successfully developed and validated for simultaneous estimation of Atazanavir and Ritonavir in their combined tablet dosage form. The selected mobile phase was Methanol: Phosphate Buffer in proportion 65:35 v/v respectively. The optimized columns used are C18 column, Symmetry and Zodiac column. X bridge C18 (4.6×150 mm, 5 µm) particle size was found to be ideal as it gave good peak shape and resolution at 1ml/min flow for Atazanavir and Ritonavir. In this study, the validation of Atazanavir and Ritonavir in API and marketed formulations were performed keeping in accordance with the parameters like system suitability, specificity, linearity, accuracy, precision (reproducibility &amp; repeatability), robustness. The developed stability indicating method is capable for determination of impurities of Atazanavir and Ritonavir in combined tablet dosage form as well as individual dosage forms also. The method has been successfully validated according to ICH guidelines and the results obtained by using RP – HPLC are rapid, accurate and precise. The proposed methods were successfully applied for the analysis of synthetic mixtures and pharmaceutical formulations of Atazanavir and Ritonavir.

STAT6 promotes innate immunity against BEFV and VSV by inhibiting STUB1 and NIX-mediated MAVS degradation

Signal transducers and activators of transcription 6 (STAT6), an essential member of the STAT protein family, plays vital roles in innate immunity, however, its function in regulating innate immunity through the degradation of MAVS has not been described. In this study, we found that STAT6 suppresses the replication of both bovine ephemeral fever virus (BEFV) and vesicular stomatitis virus (VSV). Further investigations revealed that STAT6 promotes the type I IFN (IFN-I) signaling pathway in the context of BEFV and VSV infection. Moreover, the knockout of STAT6 leads to the degradation of MAVS through both the ubiquitin-proteasome and autophagolysosomal pathways. Mechanistically, STAT6 results in the downregulation of E3 ubiquitin ligase STIP1 homology and Ubox-containing protein 1 (STUB1), inhibits the interaction between STUB1 and MAVS, and reduces STUB1- mediated K48-linked MAVS ubiquitination, thereby inhibiting the MAVS degradation through the ubiquitin-proteasome pathway. Furthermore, STAT6 also suppresses MAVS degradation through the autophagy receptor Bcl2 interacting protein 3 like (NIX)-mediated autophagy pathway. Taken together, our study unveils a novel mechanism by which STAT6 acts as a positive regulator of the type I IFN signaling pathway during BEFV and VSV infection, predominantly by inhibiting MAVS degradation and ultimately suppressing BEFV and VSV infection. These findings provide valuable insights into the regulation of MAVS degradation by STAT6, which may serve as a basis for the design of novel antiviral agents.

Lambda carrageenan displays antiviral activity against the infectious pancreatic necrosis virus (IPNV) by inhibiting viral replication and enhancing innate immunity in salmonid cells

Sulfated polysaccharide lambda carrageenan (λ-CGN) was evaluated for its antiviral effect against IPNV using the in vitro infection model of CHSE-214 salmonid cells. A plaque reduction lysis assay revealed that λ-CGN has an IC50 of 0.9 μg⋅mL−1, CC50 > 128 μg⋅mL−1 and a Selectivity Index (SI) > 142. In comparison, iota, kappa carrageenans and lambda oligo-carrageenan (λ-OC) were less effective than λ-CGN against IPNV. λ-CGN showed no virucidal activity when applied directly to viral particles. Time of addition experiments showed that pre-treatment, co-treatment, and post-treatment with λ-CGN significantly reduced viral RNA copies in the cell supernatant. Additionally, a decrease in intracellular viral RNA was observed with pre-treatment and post-treatment, indicating an impact on different stages of viral replication. Polyacrylamide gel electrophoresis of IPNV genomic RNA in presence of λ-CGN showed a reduction in the level of viral genomic RNA. Confocal microscopy confirmed the intracellular localization of λ-CGN, suggesting that λ-CGN may inhibit the synthesis of IPNV genomic RNA. Moreover, cells pre-treated with λ-CGN showed an increased expression of innate immunity genes CXCL11, IL1β, IFNa, and IRF3. These findings highlight the need for further research to confirm the in vivo pharmacological potential of λ-CGN as a new antiviral agent in salmonids.

Anti-viral Effects of Pavetta indica Methanolic Extract and Acyclovir on Behavioral and Biochemical Parameters in Streptozotocin-induced Alzheimer's Disease in Rats.

Alzheimer's disease is a neurological dysfunction of the brain caused by neurodegeneration and oxidative stress. Some viruses, such as herpes viruses, HSV-1, and HSV-2, are causative agents of Alzheimer's disease and result in β-amyloid peptide and tau protein accumulation in the brain. Some antiviral drugs, such as valacyclovir, acyclovir, and foscarnet, reduce amyloid-beta and P-tau. Pavetta indica leaves are also reported for their antiviral properties. The current study aimed to find out the significance of using Pavetta indica methanolic extract and acyclovir against Alzheimer's disease induced by streptozotocin. Wistar rats received acyclovir and Pavetta indica methanolic extract orally at different dose ranges (50, 150, 450 mg/kg) and (125, 250, 500 mg/kg), respectively. The standard therapy, Rivastigmine (2 mg/kg), was given orally. Intracerebroventricular-streptozotocin produced significant alternations in behavioral assessments, including locomotor activity test, Morris water maze test, and elevated plus maze test. Moreover, intracerebroventricular-streptozotocin ameliorated the antioxidant defense activity by decreasing levels of catalase, superoxide dismutase, and reduced glutathione while enhancing the oxidative stress markers, including malondialdehyde, and total nitrite levels. Finally, the main findings showed that intracerebroventricular-streptozotocin significantly increased the inflammatory marker, tumor necrosis factor-α, and disturbed neurotransmitter mediators, including levels of acetylcholinesterase, glutamate, and γ-amino butyric acid. In a dose-dependent manner, acyclovir and Pavetta indica methanolic extract treatments abrogated the streptozotocin-induced behavioral and neurological abnormalities in rats. The potential therapeutic effects of PIME and acyclovir administration in intracerebroventricular-streptozotocin-treated rats may be attributed to its potential antiviral, antioxidant, and anti-inflammatory effects. The current study suggests that Pavetta indica methanolic extract and acyclovir are promising therapeutic targets against Alzheimer's disease.

Structural investigation, DNA/Mpox/COVID-19 molecular docking, and biological assays of two novel Co(II) and Cu(II) complexes derived from tri- and bi-dentate pyridyl-functionalized phosphoramide ligand [Ph]P(O)[NH-2Py]2

Phosphoramides have recently gained significant attention in medical and pharmaceutical research due to their diverse biological applications, including anticancer and antiviral drugs. Here, novel phosphoramide complexes [Co(II){(O)P[NH-2Py]2[Ph]}2][CoCl4] (1) and [Cu(II){(O)P[O][NH-2Py][Ph]}2{OH2}].2H2O (2) derived from [Ph]P(O)[NH-2Py]2 were synthesized and characterized by FT-IR, CHN elemental analysis and single crystal X-ray diffraction. In these discrete chelate complexes the phosphoramide [Ph]P(O)[NH-2Py]2 moiety acts as a flexible tridentate O,N,N-donor ligand for 1 or bidentate N,O-donor ligand for 2. The metal cation has a hexa-coordinate M(N)4(O)2 environment adopting a distorted octahedral geometry for 1 and a penta-coordinate M(N)2(O)3 environment with a distorted square pyramidal geometry for 2. The supramolecular assemblies have 1D linear arrangements along the [201] axis formed via NH…Cl hydrogen bond interactions for 1 and 2D arrangements parallel to the ab plane formed via classical NH…O and OH…O hydrogen bonds for 2. The in vitro anticancer activity of 1 and 2 was assessed against MDA-MB-231 breast cancer cell line showing a good inhibitory effect for both compounds, especially for the Cu(II) complex 2 with a IC50 of 29 ± 2.1 nmolar. Antioxidant and anti-hemolytic potential of 1 and 2 was experimentally evaluated using the DPPH technique showing suitable performance for both compounds. The binding capacity of 1 and 2 to DNA was investigated using molecular docking simulations showing a good correlation with the experimental in vitro results. The results reveal mixed modes of interactions between the compounds with the DNA receptor confirming a suitable DNA-binding ability for both 1 and 2. In silico molecular docking technique was also employed to provide a detailed prediction of the binding affinity of the studied compounds for SARS-CoV-2 (−6.5 kcal/mol) and Monkeypox (−8.4 kcal/mol)) which competes with current effective drugs.

Mutated Adenovirus Attacks in West Bengal, India: Risk Evaluation of Multi-Country Outbreaks and Mitigation Strategies.

The human adenovirus (HAdV) is beginning to spread rapidly in children through human, surface and animal vectors. Around 12,000 cases were recognised in 2022 in West Bengal and a shocking number of cases arose throughout India and in other under-developed areas. This is going to be a big threat to public health since no vaccine, awareness or protocol policies were introduced. Early detection, immediate isolation and proper policy developments are the key factors in overcoming the situation. Therefore, we performed this rapid review and discussed probable mitigation strategies, updated research on vaccine development, and treatment strategies to control the outbreaks of mutated HAdV. This is a narrative review of publicly available information. Here, we extracted updated information and data using the terms HAdV outbreaks, mutations, species, risks and prevention from Google Scholar and PubMed. We considered relevant articles that have discussed prevention strategies, ongoing research, and antiviral drugs for managing HAdV outbreaks. Early detection from throat swabs, isolation and symptomatic treatments are required to minimise viral infections. A massive test needs to be performed to find the affected people. The cases should be immediately isolated. It is recommended to treat high-touch surfaces with heat- or bleach-containing cleaners to prevent the spread of infection. Oxygen support and many broad-spectrum antivirals have been used to treat HAdV. Several studies showed antibody neutralisation and interactions between the natural killer cell receptor KIR3DS1 and HLA-F in infected cells, indicating possible therapeutic options in the future. HAdV-4 and HAdV-7 vaccines have been limitedly approved for administration to military personnel. Isolation, certain safety measures, broad-spectrum antiviral drugs and further research on new vaccines could be useful to prevent this virus from producing a worldwide pandemic. Also, the authorities should ensure the proper therapeutic interventions and nursing care facilities for the infected children. Patient or public contribution was not relevant to our work.

Synthesis of Thioglycolic Acid-Modified Molybdenum Disulfide Nanosheets for Electrochemical Sensing and Its Application in Molnupiravir Detection

In the modern world, population growth, industrialization, and lifestyle changes have led to a rise in existing and new diseases, increasing global drug consumption. Proper pharmaceutical dosage is vital since drugs are only effective within specific concentration ranges. Therefore, developing reliable analytical methods for drug analysis in pharmaceuticals and biological samples is essential. Electroanalytical methods are particularly advantageous due to their low cost, ease of use, and rapid response. This study introduces a highly sensitive electrochemical sensor based on thioglycolic acid (TA)-decorated metallic phase molybdenum disulfide (MP-MoS2) nanosheets for the selective detection of molnupiravir (MOL), an antiviral drug used in Covid-19 treatment. The TA@MP-MoS2 nanomaterial was characterized using FTIR, TEM, and EIS. Screen-printed carbon electrodes (SPCE) were modified with TA@MP-MoS2 nanosheets to evaluate their electro-chemical and catalytic behaviours towards MOL by cyclic voltammetry (CV) and square wave voltammetry (SWV). The sensor displayed a well-defined electro-oxidation signal for MOL at 0.534 V, with the linear responses in two concentration ranges: 0.50–3.40 μM and 3.40–9.55 μM, and a low detection limit of 22.6 nM. The proposed design that has promising results could be an alternative strategy to fabricate the sensitive sensor for the detection of antiviral agents in real samples.

The antiviral effect and potential mechanism of Houttuynia cordata thunb. (HC) against coxsackievirus A4

Ethnopharmacological relevanceHand, foot, and mouth disease (HFMD) is mainly caused by various of enteroviruses such as enterovirus 71 (EVA71), coxsackievirus A16 (CVA16), CVA6, and CVA10 in infants and children under 5 years old. During the past 5 years, CVA4 has become the dominant pathogen resulting in HFMD in China. However, there are no effective vaccines and antiviral drugs available. Houttuynia cordata Thunb (HC). is a Chinese herbal medicine eaten as vegetables for treating viral infection diseases, but whether HC has anti-CVA4 effect remains unclear. Aim of the studyIn this study, we want to investigate the antiviral activity of HC against CVA4 in vitro and in vivo and elucidate the potential mechanism of HC against CVA4. Materials and methodsMTT assay were used to evaluate the cytotoxicity of HC. Virus titers assay, CPE assay, violet staining and immunofluorescence were used to investigate the antiviral effect of HC against CVA4. A 13-day-old suckling mice model was established to evaluate the therapeutic efficacy of HC against CVA4 infection. Western blot, qRT-PCR and time-of-drug addition assay were performed to elucidate the potential mechanism of HC against CVA4 infection. ResultsMTT assay indicated the cytotoxicity concentration of HC on Vero cells and RD cells were more than 1 mg/ml, suggesting that the low cytotoxicity of HC. In vitro antiviral assay revealed that HC could dose-dependently prevent the CPE, suppress the release of newborn virus, and inhibit the replication of CVA4 by decreasing viral RNA transcription and protein expression with IC50 of 88.96 μg/mL. A time-of-addition assay showed that HC mainly exerted anti-CVA4 effect by inhibiting virus replication at the post-entry stage. In vivo results further demonstrated that HC could effectively prevent the lethal infection of CVA4 by promoting survival, improving clinical symptoms, prolonging the survival time, inhibiting excessive inflammatory responses, and reducing pathological injury in vivo. Mechanistic studies revealed inhibition of p38 MAPK and JNK pathway over-activation may be the primary mechanism of HC against CVA4 infection. ConclusionIn summary, our results for the first time demonstrated that HC not only effectively inhibited CVA4 replication, but also partially protected the lethal infection of CVA4 in vivo. Furthermore, pharmacological mechanism studies revealed that the primary mechanism of HC against CVA4 infection may be associated with its effect of inhibiting over-activation of p38 MAPK and JNK signaling pathways caused by enteroviruses. Our finding indicated that HC might be a potential innovative medicine for treating HFMD.

Establishment of enterically transmitted hepatitis virus animal models using lipid nanoparticle-based full-length viral genome RNA delivery system

BackgroundEnterically transmitted hepatitis viruses, such as hepatitis A virus (HAV) and hepatitis E virus (HEV), remain notable threats to public health. However, stable and reliable animal models of HAV and...

Adjusting susceptibilities of C57BL/6 mice to orthoflaviviruses for evaluation of antiviral drugs by altering the levels of interferon alpha/beta receptor function

The purpose of this study was to optimize the infectivity of four different orthoflaviviruses in mice for evaluating antiviral drugs by using wild-type mice with intact interferon responses, type 1 interferon alpha/beta receptor knockout mice, or by injecting wild type C57BL/6 mice with varying doses of anti-type 1 interferon receptor antibody (MAR1-5A3) to optimize the infectivity and lethality. West Nile virus productively infected wild-type C57BL/6 mice to cause lethality, whereas Usutu virus required a complete absence of type 1 interferon receptor function. Deer tick virus (lineage 2 Powassan virus) and Japanese encephalitis viruses required a dampening of type 1 interferon responses by adjusting the doses of MAR1-5A3 antibody injections. Challenge dose-responsive mortality, weight loss, and viral titers of these two viruses were observed if the type 1 interferon responses were dampened with MAR1-5A3. Conversely, without MAR1-5A3 injections, these disease phenotypes were not viral challenge dose-responsive. From these different interferon-responsive models, the appropriate lethality was identified to determine that 7-deaza-2'-C-methyladenosine has high efficacy for West Nile and Usutu viruses, and low efficacy for deer tick and Japanese encephalitis viruses.

Cholenamide-based, antiviral fluorescent probes targeting oxysterol-binding protein

Oxysterols (OSs) represent a large family of cholesterol-derived molecules, involved in several physiological and pathological processes. Recently, we reported the remarkable antiviral activity against herpes simplex virus 2 (HSV-2) infection of three cholenamide or homocholenamide derivatives, namely PFM067, PFM064, and PFM069, identified by the screening of an in-house library of OS derivatives. With the aim to shed light on the antiviral mechanism of action of this class of molecules, we assumed to exploit the use of cholenamide-based fluorescent probes.Herein, we report that PFM120 and PFM124, two fluorescent tagged version of PFM067 maintain the same antiviral properties against HSV-2 as the parent compound and localize intracellularly inside the endoplasmic reticulum and the cis-Golgi network. Moreover, we also demonstrate that both tagged molecules co-localize with oxysterol-binding protein (OSBP) and are able to induce its re-localization. Finally, we report that PFM120 and PFM124 are endowed with antiviral activity against another OSBP-dependent viral pathogen, i.e. the human rhinovirus (HRV), different in structure and replication strategy from HSV-2.Taken together, these results candidate PFM120 and PFM124 as useful tools to investigate the actual mechanism of action and molecular target(s) of cholenamide-based antivirals and provide a proof of principle to explore them as a promising broad-spectrum class of antiviral agents.

Trends in candidate HCV NAT+ listing and associated impacts on liver transplantation waitlist outcomes

Direct-acting antiviral agents have facilitated the utilization of hepatitis C virus (HCV)+ organs in HCV nucleic acid amplification test (NAT)- recipients. We evaluated trends in HCV NAT+ listing and impact on transplant probability, waitlist mortality, and likelihood of receiving HCV NAT+ organs using the United Network for Organ Sharing dataset of adult patients waitlisted for liver transplantation from 1/2016-9/2023. Multivariable regression models accounting for competing risks were fit to study waitlist outcomes. 21,776 patients were initially listed for HCV NAT+ organs while 45,378 were not. The percentage of waitlisted patients listed for these organs increased significantly from 2016 to 2023 (8.8% to 60.8%, p<0.001). Initial HCV NAT+ listing was associated with a waitlist mortality benefit in 2021-2023 (SHR 0.73, 95% CI 0.68-0.79, p<0.001) and 17% reduced hazard of overall mortality (HR 0.83, 95% CI 0.78-0.89, p<0.001). 16.0% of the total protective effect associated with HCV NAT+ listing on overall survival was mediated through actual receipt of HCV NAT+ organs (TERERI of -0.160 and a PIE of -0.026; p<0.001). Patients not listed for HCV NAT+ organs in the modern era are relatively disadvantaged in terms of waitlist outcomes. While listings have risen over time, there remains center-level and geographic variation.

Dual effects of ipecac alkaloids with potent antiviral activity against foot-and-mouth disease virus as replicase inhibitors and direct virucides

ABSTRACT Foot-and-Mouth Disease (FMD) is a contagious, blistering disease caused by the Foot-and-Mouth Disease virus (FMDV), which affects livestock globally. Currently, no commercial antiviral agent is available for effective disease control. This study investigated the antiviral potential of natural-derived alkaloids against FMDV in BHK-21 cells. Twelve alkaloids were assessed for their antiviral activities at various stages of FMDV infection, including pre-viral entry, post-viral entry, and prophylactic assays, as well as attachment and penetration assays by evaluating cytopathic effect reduction and directed-virucidal effects. The results showed that ipecac alkaloids, cephaeline (CPL) and emetine (EMT), exhibited dual effects with robust antiviral efficacy by reducing cytopathic effect and inhibiting FMDV replication in a dose-dependent manner. Evaluation through immunoperoxidase monolayer assay and RT-PCR indicated effectiveness at post-viral entry stage, with sub-micromolar EC50 values for CPL and EMT at 0.05 and 0.24 µM, respectively, and high selective indices. Prophylactic effects prevented infection with EC50 values of 0.23 and 0.64 µM, respectively. Directed-virucidal effects demonstrated significant reduction of extracellular FMDV, with CPL exhibiting a dose-dependent effect. Furthermore, the replicase (3Dpol) inhibition activity was identified using the FMDV minigenome assay, which revealed strong inhibition with IC50 values of 0.15 µM for CPL and 4.20 µM for EMT, consistent with the decreased negative-stranded RNA production. Molecular docking confirmed the interaction of CPL and EMT with residues in the active site of FMDV 3Dpol. In conclusion, CPL and EMT exhibited promising efficacy through their dual effects and provide an alternative approach for controlling FMD in livestock.

Pongamia pinnata L. seed-derived karanjin as prominent antiviral agent against Newcastle disease virus

Current study aim to explore Karanjin (Kar) isolated from the seeds of Pongamia pinnata as a potential antiviral polyphenol against Newcastle disease virus (NDV) through comprehensive investigations. For the in vitro study, plaque assays, gene and protein expression were used to analyse the inhibitory impact of Kar on NDV, where it reduced NDV replication as shown by a 13-fold suppression of the hemagglutinin-neuraminidase (HN) gene and decrease about 60% in virus activity. In ovo study showed that Kar mitigates NDV effects in chicken embryos. In silico studies involving molecular docking and molecular dynamics simulations showed strong binding between Kar and HN protein of NDV. Kar also influenced glucose metabolism, enhancing antiviral responses, as showed by the upregulation of GLUT1 and HEX genes through RT-qPCR and HPLC analyses. The study contributes valuable insights for future investigations into therapeutic applications of Kar against viral infections.