Potent Antiviral Activity Research Articles

Identification of cepharanthine as an effective inhibitor of African swine fever virus replication

ABSTRACT African swine fever virus (ASFV) causes highly contagious swine disease, African swine fever (ASF), thereby posing a severe socioeconomic threat to the global pig industry and underscoring that effective antiviral therapies are urgently required. To identify safe and efficient anti-ASFV compounds, a natural compound library was screened by performing an established cell-based ELISA in an ASFV-infected porcine alveolar macrophage (PAM) model. In total, 6 effective anti-ASFV compounds with low cytotoxicity were identified. Cepharanthine (CEP), a bisbenzylisoquinoline alkaloid, was the most potent inhibitor effect with an IC50 of 0.3223 μM. To further investigate the mechanism through which CEP inhibits ASFV replication, transcriptome profiles were generated in PAMs treated with CEP and/or infected with ASFV. ASFV infection dramatically altered immune response-associated gene expression. CEP treatment upregulated the expression of cholesterol biosynthesis-related genes, regardless of infection status. According to time-of-addition experiments, CEP primarily exerts its antiviral effect during the early stages of ASFV infection, specifically by inhibiting viral entry. Transcriptomic analysis suggested that CEP blocks ASFV entry through the clathrin-mediated endocytosis pathway by increasing EHD2 gene expression in macrophages. Disrupting EHD2 with small interfering RNA promoted ASFV entry into clathrin-positive vesicles. Finally, the protective effect of CEP in vivo was evaluated using ASFV-infected pigs. CEP could provide partial protection against ASFV infection, as indicated by an increase in survival time from 9.67 days to 16.67 days. Our findings imply that CEP exhibits potential antiviral activity against ASFV infection in PAMs, positioning it as a promising therapeutic strategy for ASF.

Exploring bifunctional molecules for anti-SARS-CoV-2 and anti-inflammatory activity through structure-based virtual screening, SAR investigation, and biological evaluation.

As new variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue to emerge, they raise increasing concerns about the efficacy of neutralizing antibodies and vaccines. This situation underscores the urgent need for specific drugs against the coronavirus disease 2019 (COVID-19). Given that COVID-19 is particularly associated with substantial inflammation, the development of novel, effective antiviral and anti-inflammatory agents represents a promising research direction. In this study, we virtually screened a library consisting of 2900 anti-inflammatory small molecules for their inhibitory effects on the 3-chymotrypsin-like protease (3CLpro) of SARS-CoV-2 and selected 23 promising candidates for further testing using a fluorescence resonance energy transfer (FRET) assay. The results indicated that Gnetol had the most potent inhibitory effect against SARS-CoV-2 3CLpro. Further structural modifications led to the identification of compounds 38 and 39, which displayed superior inhibitory activity. Compound 39 showed good selectivity for host proteases. Subsequently, Gnetol and its structural analogs, which demonstrated SARS-CoV-2 3CLpro inhibitory activity, were tested for their anti-inflammatory effects. Among these, Piceatannol and compound 39 exhibited enhanced anti-inflammatory effects, with compound 39 alone showing the most potent antiviral and anti-inflammatory activity. Thus, our study has explored a new research strategy for discovering antiviral and anti-inflammatory bifunctional molecules. The discovery of Gnetol and its structural analogs has provided new lead candidates for the development of COVID-19 therapeutics.

Lithospermic acid inhibits dengue virus infection through binding with envelope proteins

The dengue virus has emerged as a global pandemic, highlighting the urgent need for the immediate development of antiviral therapeutics. Lithospermum erythrorhizon, a medicinal plant commonly used in China for various ailments including viral infections, inflammation, rheumatism, and cancer, showed promising antiviral properties in our research. Specifically, both the ethanol extract of Lithospermum erythrorhizon and its active component, lithospermic acid, demonstrated significant inhibitory effects on Dengue virus (DENV) replication in Vero cells, with EC50 values of 6.50 μg/mL(95% CI: 2.25 to 18.98)and 15.00 μM(95% CI: 12.13 to 18.07), respectively. Notably, lithospermic acid exhibited potent antiviral activity across multiple cell lines against DENV, impeding virus replication and specifically impeding the expression of viral E and NS3 proteins during the early stages of DENV infection. Experimental assays involving RNase digestion and sucrose density gradient analysis confirmed that lithospermic acid did not directly inactivate DENV but rather interfered with viral processes. Furthermore, the compound was found to bind to the E protein of DENV, effectively inhibiting viral infection and mitigating the cytopathic effects induced by DENV. Collectively, these findings underscore the potential of lithospermic acid as a promising candidate for the development of therapeutic strategies targeting DENV infection.

Multi-protomics analysis identified host cellular pathways perturbed by tick-borne encephalitis virus infection

Tick-borne encephalitis virus (TBEV) represents a pivotal tick-transmitted flavivirus responsible for severe neurological consequences in Europe and Asia. The emergence of TBEV genetic mutations and vaccine-breakthrough infections, along with the absence of effective vaccines and specific drugs for other tick-borne flaviviruses associated with severe encephalitis or hemorrhagic fever, underscores the urgent need for progress in understanding the pathogenesis and intervention strategies for TBEV and related flaviviruses. Here we elucidate cellular alterations in the proteome, phosphoproteome, and acetylproteome upon TBEV infection. Our findings reveal a substantial impact of TBEV infection on the innate immune response, ribosomal biogenesis, autophagy, and DNA damage response (DDR). Mechanically, the non-structural protein NS5 of TBEV impedes DNA damage repair by interacting with SIRT1 to suppress the deacetylation of KAP1 and Ku70. Additionally, the precursor membrane protein prM induces autophagy via associating with AKT1 while constrains autolysosome formation through binding to VPS11. Inhibitors targeting DDR, as well as specific kinases, exhibit potent antiviral activity, suggesting the dysregulated pathways and kinases as potential targets for antiviral intervention. These results from our study contribute to elucidating the pathogenesis and offers insights for developing effective antiviral drugs against TBEV and other tick-borne flaviviruses.

Machine learning-aided identification of natural compounds targeting Marburg virus VP40 with potential antiviral activity

Marburg virus infection poses a significant threat to humans due to its high fatality rate. The application of in-silico drug design to target the essential protein target of the virus has been proven to be a fundamental technique to inhibit viral growth. Here, VP40 (a matrix protein) was used as an essential protein target of Marburg, and 2569 natural compounds were screened using the molecular docking and neural network-based DeepPurpose architecture. The top 138 compounds that exhibited a binding score of −8 kcal/mol in molecular docking were used in the best DeepPurpose model to predict the IC50. The best model in DeepPurpose was composed of Morgan and CNN-based encoding for protein and ligand, respectively. The top three compounds, NPL130 (CHEMBL2087156), NPL313 (CHEMBL76073), and NPL371 (CHEMBL54440), were selected from the machine learning model, and molecular dynamics simulation was performed for their best complex along with the control compound complex, Nilotinib (CHEMBL255863). Protein showed less than 0.3 nm of deviation in the complex formed with control and NPL130 compounds. Control had shown the best average MM/GBSA binding energy of −36.97 kcal/mol with the lowest standard deviation of 1.86. A stable complex was indicated by the negative binding free energies of −20 to −25 kcal/mol for all three hits. The free energy landscape showed that, along with the control compound, NPL130 had the biggest conformational space with the lowest free energy. Overall, this study proposed NPL130 as a potential hit compound to target Marburg viral growth.

MiRNA-431-5p enriched in EVs derived from IFN-β stimulated MSCs potently inhibited ZIKV through CD95 downregulation

BackgroundZika virus (ZIKV) primarily spreads through mosquito bites and can lead to microcephaly in infants and Guillain-Barre syndrome in adults. It is noteworthy that ZIKV can persist in the semen of infected males for extended periods and can be sexually transmitted. Infection with ZIKV has severe pathological manifestations on the testicular tissues of male mice, resulting in reduced sperm motility and fertility. However, there are no approved prophylactic vaccines or therapeutics available to treat Zika virus infection.MethodsUsing a male type I and II interferon receptor-deficient (ifnar1(-/-) ifngr1(-/-)) C57BL/6 (AG6) mouse model infected with ZIKV as a representative model, we evaluated the degree of testicular damage and viral replication in various organs in mice treated with EVs derived from MSC-stimulated with IFN-β (IFNβ-EVs) and treated with controls. We measured testicle size, detected viral load in various organs, and analyzed gene expression to assess treatment efficacy.ResultsOur findings demonstrated that intravenous administration of IFNβ-EVs effectively suppressed ZIKV replication in the testes. Investigation with in-depth RNA sequencing analysis found that IFN-β treatment changed the cargo miRNA of EVs. Notably, miR-431-5p was identified to be significantly enriched in IFNβ-EVs and exhibited potent antiviral activity in vitro. We showed that CD95 was a direct downstream target for miR-431-5p and played a role in facilitating ZIKV replication. miR-431-5p effectively downregulated the expression of CD95 protein, consequently promoted the phosphorylation and nuclear localization of NF-kB, which resulted in the activation of anti-viral status, leading to the suppression of viral replication.ConclusionsOur study demonstrated that the EVs produced by IFNβ-treated MSCs could effectively convey antiviral activity.

Potential antiviral activity of rhamnocitrin against influenza virus H3N2 by inhibiting cGAS/STING pathway in vitro.

Influenza remains a serious issue for public health and it's urgent to discover more effected drugs against influenza virus. Rhamnocitrin, as a flavonoid, its effect on influenza virus infection remains poorly explored. In this study, rhamnocitrin showed antiviral effect and anti-apoptosis on influenza virus A/Aichi/2/1968 (H3N2) in MDCK cells and A549 cells. In addition, molecular docking revealed that rhamnocitrin have good binding activity with the target proteins cGAS and STING, molecular dynamic simulation and surface plasmon resonance showed that rhamnocitrin could form a stable complex with the above proteins. Moreover, the qPCR and western blot assays further verified that rhamnocitrin could reduce type I IFN and proinflammatory cytokines production by inhibiting the cGAS/STING pathway. Taken together, the results suggest that rhamnocitrin could be a potential anti-viral agent against influenza.

PLNC8 αβ Potently Inhibits the Flavivirus Kunjin and Modulates Inflammatory and Intracellular Signaling Responses of Alveolar Epithelial Cells.

PLNC8 αβ is a cationic antimicrobial peptide that previously has been reported to express both antibacterial and antiviral properties. This study aimed to further elucidate the antiviral effects of PLNC8 αβ and its impact on virus-induced cytotoxicity and inflammatory signaling in human alveolar epithelial cells (A549) infected with the flavivirus Kunjin. Complementary in silico analyses using molecular dynamics (MD) simulation were conducted to investigate the mechanism of action of PLNC8 αβ by studying the interaction of PLNC8 α and β with models of a flavivirus membrane and a eukaryotic plasma membrane, respectively. Our findings demonstrated that PLNC8 αβ significantly reduces both extracellular and intracellular viral loads, as confirmed by plaque reduction assays and RT-PCR. The peptide also mitigated virus-induced cytotoxicity and inflammation. Notably, PLNC8 αβ modulated the virus-induced dysregulation of key signaling and inflammatory genes, such as TLR9, TLR3, NOD2, FOS, JUN, IL6, and CXCL8. MD simulation revealed that PLNC8 αβ exhibits higher binding affinity for a flavivirus membrane model compared to a model of the plasma membrane, likely due to stronger electrostatic interactions with anionic phospholipids. This selective interaction possibly accounts for a potent antiviral activity of PLNC8 αβ combined with a minimal cytotoxicity toward human cells. Overall, PLNC8 αβ shows significant promise as an antiviral agent against flavivirus infections and warrants further exploration for peptide-based antiviral therapies.

Synergistic Integration of α-Ag2WO4 into PLA/PBAT for the Development of Electrospun Membranes: Advancing Structural Integrity and Antimicrobial Efficacy.

The rising resistance of various pathogens and the demand for materials that prevent infections drive the need to develop broad-spectrum antimicrobial membranes capable of combating a range of microorganisms, thereby enhancing safety in biomedical and industrial applications. Herein, we introduce a simple and efficient technique to engineer membranes composed of polylactic acid (PLA) and polybutylene adipate terephthalate (PBAT) biopolymers and α-Ag2WO4 particles using an electrospinning technique. The corresponding structural, thermal, mechanical, and antimicrobial properties were characterized. X-ray diffraction (XRD) patterns confirmed the integration of crystalline α-Ag2WO4 within the polymer matrix. Scanning electron microscopy (SEM) and Raman confocal microscopy revealed uniformly dispersed α-Ag2WO4 particles in the electrospun fibers, influencing their diameter and surface roughness. Thermal analysis indicated adjustments in the thermal stability and crystallinity of the composites with an increasing α-Ag2WO4 content. Dynamic mechanical analysis (DMA) highlighted variations in storage modulus and glass transition temperatures due to interactions between α-Ag2WO4 and polymer chains, with tensile tests showing an increase in elastic modulus and ultimate tensile strength as the α-Ag2WO4 content increased. Antimicrobial assessments revealed that PLA/PBAT membranes with α-Ag2WO4 showed pronounced antibacterial activity, forming inhibition halos across all samples against Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, and Mycobacterium smegmatis (a surrogate for Mycobacterium tuberculosis). These membranes also exhibited potent antiviral activity against bacteriophage phi 6, a surrogate for SARS-CoV-2, suggesting potential applications in combating infections caused by enveloped viruses. The antimicrobial activities are attributed to the generation of reactive oxygen species (ROS) and the controlled release of Ag+ ions. This work underscores the multifaceted capabilities of α-Ag2WO4-enhanced PLA/PBAT membranes in combating bacterial and viral growth, where both durability and microbial resistance are critical. Taken together, our findings provide a solution for obtaining advanced materials to be applied in a wide range of industrial applications, such as filtration systems, food preservation, antimicrobial coatings, protective textiles, and cleaning products.

Structure-Based Design of Covalent SARS-CoV-2 Papain-like Protease Inhibitors.

The COVID-19 pandemic is caused by SARS-CoV-2, a highly transmissible and pathogenic RNA betacoronavirus. Like other RNA viruses, SARS-CoV-2 continues to evolve with or without drug selection pressure, and many variants have emerged since the beginning of the pandemic. The papain-like protease, PLpro, is a cysteine protease that cleaves viral polyproteins as well as ubiquitin and ISG15 modifications from host proteins. Leveraging our recently discovered Val70Ub binding site in PLpro, we designed covalent PLpro inhibitors by connecting cysteine reactive warheads to the biarylphenyl PLpro inhibitors via flexible linkers. Several leads displayed potent enzymatic inhibition (IC50 = 0.1-0.3 μM) and antiviral activity (EC50 = 0.09-0.96 μM). Fumaramide inhibitors Jun13567 (15), Jun13728 (16), and Jun13714 (18) showed favorable in vivo pharmacokinetic properties with intraperitoneal injection. The X-ray crystal structure of PLpro with Jun13567 (15) validated our design strategy, revealing covalent conjugation between the catalytic Cys111 and the fumaramide warhead. The results suggest these covalent PLpro inhibitors are promising SARS-CoV-2 antiviral drug candidates.

Molecular Docking Simulations of Protoporphyrin IX, Chlorin e6, and Methylene Blue for Target Proteins of Viruses Causing Skin Lesions: Monkeypox and HSV

Background: The replication of monkeypox in the skin is critical to understanding its pathogenesis and spread. p37, a highly conserved 37 kDa peripheral membrane protein encoded by the F13L gene in Orthopoxvitidae is a validated target for anti-poxviral medication like tecovirimat, the first FDA-approved anti-poxviral drug that was approved in 2018. The detailed recognition mechanism of tecovirimat on p37 of monkeypox has not been fully clarified. As p37, HSV-1 gD and HSV-2 gD proteins of HSV are viral envelope glycoproteins identified as ligands for the human nectin-1 as a functional receptor of permissive cells. The use of non-damaging light for microbial inactivation (MI) has been documented for different virus like HSV, where photosensitizers (PSs) are used as lightresponsive agents which could generate antiviral responses primarily by oxidation. In addition, some PSs could elicit antiviral responses in a light-independent way by interacting within the viral-cell recognition sites. Objective: This paper aims to evaluate the formation of complexes between the latest structural data available on the range of monkeypox and HSV-1/2 envelope proteins with the approved PSs protoporphyrin IX, chlorin e6, and methylene blue. Methods: Ligands and receptors preparation, and molecular docking analyses were performed with Chimera and the Autodock Vina Software. Molecular docking and molecular dynamics simulation (MD) analyses for a 100 ns trajectory were also performed for the p37 – Methylene blue complex. Results: PSs studies were found to form complexes into the patch regions of recognition between HSV-1/2 gD and human receptors, while MB was found to form a complex with the p37 protein into de pocket region where tecovirimat acts. MD simulation showed stability in the interaction of MB with the pocket region of the p37 protein. Conclusion: The molecular mechanisms of potential dual antiviral activity for these complexes were clarified showing that MI with the use of these PSs could be further evaluated for viral skin lesions produced by monkeypox and HSV.

Uncovering the Potent Antiviral Activity of the Sesterterpenoids from the Sponge Ircinia Felix Against Human Adenoviruses: from the Natural Source to the Total Synthesis.

Human Adenovirus (HAdV) infections in immunocompromised patients can result in disseminated diseases with high morbidity and mortality rates due to the absence of available treatments for these infections. The sponge Ircinia felix was selected for the significant anti-HAdV activity displayed by its organic extracts. Its chemical analysis yielded three novel sesterterpene lactams, ircinialactams J-L, along with three known sesterterpene furans which structures were established by a deep spectrometric analysis. Ircinialactam J displayed significant antiviral activity against HAdV without significant cytotoxicity, showing an effectiveness 11 times greater than that of the standard treatment, cidofovir®. Comparison of the antiviral evaluation results of the isolated compounds allowed us to deduce some structure-activity relationships. Mechanistic assays suggest that ircinialactam J targets an early step of the HAdV replicative cycle before HAdV genome reaches the nucleus of the host cell. The first total synthesis of ircinialactam J was also accomplished to prove the structure and to provide access to analogues. Key steps are a regio- and stereoselective construction of the trisubstituted Z-olefin at Δ7 by iron-catalyzed carbometallation of a homopropargylic alcohol, a stereoselective methylation to generate the stereogenic center at C18, and the formation of the (Z)-Δ20 by stereoselective aldol condensation to introduce the tetronic acid unit. Ircinialactam J is a promising chemical lead to new potent antiviral drugs against HAdV infections.

Antipathogenic Activity of Betainized Polyethyleneimine Sprays Without Toxicity.

Background/Objectives: The design of alternative antipathogenic sprays has recently attracted much attention due to the limitations of existing formulations, such as toxicity and low and narrow efficacy. Polyethyleneimine (PEI) is a great antimicrobial polymer against a wide range of pathogens, but toxicity limits its use. Here, betainized PEI (B-PEI) was synthesized to decrease the toxicity of PEI and protonated with citric acid (CA), boric acid (BA), and HCl to improve antimicrobial activity. Methods: Cytotoxicity of the PEI-based solutions was determined on L929 fibroblast cells. Antibacterial/fungal activity of PEI-based antipathogenic sprays was investigated by microtiter and disc diffusion assays, in addition to bacterial viability and adhesion % of common bacteria and fungi on the PEI-treated masks. Furthermore, the antiviral effect of the PEI-based solutions was determined against SARS-CoV-2 virus. Results: The biosafe concentration of PEI was determined as 1 μg/mL with 75 ± 11% cell viability, but B-PEI and its protonated forms had great biocompatibility even at 1000 μg/mL with more than 85% viability. The antibacterial/fungal effect of non-toxic B-PEI was improved by protonation with BA and HCl with 2.5-10 mg/mL minimum bactericidal/fungicidal concentrations (MBCs/MFCs). Bacterial/fungal viability and adhesion on the mask was almost eliminated by using 50 μL with 5-10 mg/mL of B-PEI-BA. Both protonated bare and betainized PEI show potent antiviral activity against SARS-CoV-2 virus. Conclusions: The toxicity of PEI was overcome by using betainized forms of PEI (B-PEI). Furthermore, the antimicrobial and antiviral efficacy of PEI and B-PEI was improved by protonation with CA, BA, and HCl of amine groups on B-PEI. B-PEI-BA spray solution has great potential as an antipathogenic spray with broad-spectrum antimicrobial potency against harmful bacteria, fungi, and viruses without any toxicity.

EDP-938 Has a High Barrier to Resistance in Healthy Adults Experimentally Infected with Respiratory Syncytial Virus.

EDP-938 is an oral once-daily RSV nucleoprotein (N) inhibitor with potent antiviral activity. In a human RSV challenge trial, EDP-938 significantly reduced viral load and symptom severity. During antiviral development, it is critical to understand the propensity for resistance to develop. In vitro studies of EDP-938 suggest a higher barrier to resistance as compared to RSV fusion inhibitors. We evaluated the development of viral resistance to EDP-938 in a human challenge trial. A subset of the 124 participants with RSV infection were chosen for genetic analysis; 159 nasal wash samples from 48 participants were analyzed using next-generation sequencing of the N gene of RSV. Of the 48 participant sampled, 37 were from EDP-938-treated and 11 were placebo-treated participants, representing 45% and 26% of the participants, respectively. The effects of treatment-emergent mutations on viral load, EDP-938 efficacy, and viral fitness were evaluated. Two of the 37 EDP-938-treated participants with samples sequenced had treatment-emergent mutations: N:L139I and N:E112G. From in vitro analysis, N:L139I reduced sensitivity to EDP-938 by approximately 10-fold, while N:E112G had no effect. However, N:L139I was associated with a reduction in viral fitness, suggesting clinical resistance is associated with fitness costs. Neither of these variants were associated with reduced viral clearance. In human RSV infections treated with EDP-938, emergence of RSV variants with reduced sensitivity to EDP-938 occurred in only 1 participant and was associated with reduced viral fitness. EDP-938's high barrier to resistance highlights its robust mechanism of action. NCT03691623.

RpIFN-λ1 alleviates the clinical symptoms of porcine epidemic diarrhea

Porcine epidemic diarrhea (PED), caused by the porcine epidemic diarrhea virus (PEDV), primarily affects the jejunum and ileum of pigs. Interferons, glycoproteins with high species specificity and potent antiviral activity, are crucial in defending against viral infections. Unlike other interferons, interferon-lambda (IFN-λ) mainly acts on mucosal epithelial cells and exhibits robust antiviral activity at mucosal surfaces. However, the high cost limits the use of naturally extracted interferons in farming. In this study, we expressed recombinant porcine interferon-lambda 1 (rpIFN-λ1) in eukaryotic cells, demonstrating effective antiviral activity against PEDV in Vero E6 and IPI-FX cells. In vivo, rpIFN-λ1 alleviated clinical symptoms and intestinal damage, enhanced antioxidant capacity, reduced inflammation, and significantly improved the survival rate of piglets following PEDV infection. Both in vitro and in vivo studies confirmed that rpIFN-λ1 upregulated interferon-stimulated genes (ISGs) via the JAK-STAT pathway, thereby exerting antiviral effects. In conclusion, rpIFN-λ1 significantly inhibited PEDV replication and alleviated clinical symptoms. The selectivity of rpIFN-λ1 for intestinal cells and its ability to reduce viral shedding suggest that this agent is a promising antiviral for enteric viruses such as PEDV. Our findings highlight rpIFN-λ1 as a cost-effective, efficient, and novel strategy for antiviral treatment of PEDV.

Coumarin-imidazopyridine hybrids and their first-in-class ZnII metal complexes as potent dual entry and replication inhibitors of Zika viral infection

In this study, we synthesized and characterized a series of coumarin-imidazopyridine hybrid ligands (HL1-HL4) and their corresponding Zn(II) complexes (C1-C4). The ligands were synthesized via a two-step process in 56–90 % yields. The resulting ligands, were utilized to form Zn(II) complexes, characterized by conductivity measurements, HRMS, IR, 1H NMR spectroscopy and X-ray diffractions. Biological evaluations revealed that these compounds exhibited potent antiviral activity against Zika virus (ZIKV), with EC50 values ranging from 0.55 to 4.8 µM and SI of up to 1490. Notably, the complexes (the first-in-class Zn(II) anti-ZIKV complexes) generally displayed enhanced activity compared to their respective ligands, with some compounds outperforming the reference antiviral, ribavirin. The Time of Addition assay suggested that while some compounds interfere with both viral entry (with a virucidal component) and replication phases, other only acted in replication phases. These results together with molecular modeling studies on ZIKV Envelope protein and ZIKV NS2B-NS3 offered insights for their mode of actions and further optimizations.

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.

An in-depth exploration of ethnomedicinal applications, phytochemical profiles, and pharmacological potentials: unveiling Withania somnifera

Researchers have extensively studied Withania somnifera (L.) Dunal, a woody shrub renowned for its multifaceted medicinal attributes such as antibacterial, anti-inflammatory, adaptogenic, aphrodisiac, and tonifying properties, because of its medicinal and traditional values. However, comprehensive information about its medicinal uses and pharmacological implications is scattered across various sources. Thus, this study aims to provide a comprehensive review of its ethnomedicinal uses, phytochemistry, and pharmacological attributes, consolidating information from diverse data sources. Systematic investigations have revealed the presence of diverse phytochemicals in W. somnifera, including major alkaloids, withanolides, flavonoids, tannins, oils, phytosterols, and amino acids. Extracts, fractions, and bioactive compounds derived from W. somnifera exhibited potent antibacterial, anti-inflammatory, anti-aging, anti-analgesic, anti-cancer, antivenom, anti-fungal, and anti-viral activities. W. somnifera serves as a valuable source of phytochemicals with diverse biological activities, offering significant therapeutic benefits globally. However, further studies are needed to assess potential side effects. Additionally, while several isolated compounds have demonstrated notable bioactivities, future research should focus on elucidating their mechanistic features to facilitate their integration into drug discovery endeavors.

Synthesis and Anticancer Activity Assessment of Zelkovamycin Analogues.

The zelkovamycin family is a class of cyclic octapeptides with potent antibacterial and antiviral activity. Due to their unique chemical structures and excellent bioactivity, zelkovamycins have consistently attracted the interest of synthetic chemists. However, only the total synthesis of zelkovamycin and zelkovamycin G has been reported until now. The current work presents, for the first time, the synthesis of zelkovamycin analogues, along with their anticancer activity assessment. Firstly, the corresponding chain peptide based on the amino acid sequence of zelkovamycin H was synthesized using the Fmoc solid-phase peptide strategy. This was followed by cyclization under high dilution conditions to obtain compound 21, and its structure was elucidated by NMR analysis. The results confirm that compound 21 is not the natural product of zelkovamycin H. We deduced that during the synthesis of peptide 12, the D-Abu residue epimerized to the L-Abu form, leading to the formation of peptide 20, which blocked our efforts during the synthesis of zelkovamycin H. Two more analogues, 22 and 23, were synthesized by changing the structure of amino acid residues using the same strategy. The anticancer activity of analogues 21-23 against Huh-7 cells was evaluated in vitro; however, their IC50 values were >50 μM.

Inhibition of fish rhabdovirus demonstrates application prospect of two methylimidazole phenylpropanoid-based small molecules in aquaculture

Aquaculture faces significant challenges, notably spring viremia of carp (SVC) caused by spring viremia of carp virus (SVCV), which is particularly devastating due to its high mortality rates and rapid transmission among fish populations. This study introduces two novel methylimidazole phenylpropanoid-based small molecules, LML1013 and LML1014, synthesized for combating SVCV in aquaculture environments. Comprehensive in vitro and in vivo evaluations demonstrated that these compounds have potent antiviral activities against SVCV. They effectively inhibited SVCV replication in epithelioma papulosum cyprinid (EPC) cells and significantly reduced mortality rates in infected juvenile common carp. Further analyses revealed that daily administration of these compounds not only blocked SVCV replication but also stimulated the innate immune responses of the fish, thereby enhancing their overall resistance to viral infection. Notably, the antiviral efficacy was observed in a dose- and time-dependent manner without inducing cytotoxic effects, emphasizing their therapeutic potential. The stability of LML1013 and LML1014 in aquacultural water and their ability to prevent horizontal viral transmission were also confirmed, further supporting their feasibility as treatment options in aquaculture. Overall, the development of LML1013 and LML1014 provides a promising strategy for controlling SVCV outbreaks and enhancing the sustainability of fish farming operations. This approach offers significant implications for improving aquaculture biosecurity and effectively managing viral disease threats.