Search Results (130)

Recently, essential rose oils and rose products have gained increasing importance in both the cosmetic and food industries, as well as in the composition of medicinal products. We investigated the in vitro antiviral activity of essential oil and floral water from Rosa damascena Mill against herpes simplex virus type 1 (HSV-1) infection in rabbit retinal cells (RRCs). The composition of the main chemical components in the rose essential oil was determined by means of gas chromatographic analysis. The effect on the viral replication cycle was determined using the cytopathic effect (CPE) inhibition assay. The virucidal activity, the effect on the adsorption stage of the virus to the host cell, and the protective effect on healthy cells were evaluated using the endpoint dilution method. The effects were determined as deviation in the viral titer, Δlg, for the treated cells from the one for the untreated viral control. The identified main active components of rose oil are geraniol (28.73%), citronellol (21.50%), nonadecane (13.13%), nerol (5.51%), heneicosane (4.87%), nonadecene (3.93), heptadecane (2.29), farnesol (2.11%), tricosane (1.29%), eicosane (1.01%), and eugenol (0.85%). The results demonstrated that both rose products do not have a significant effect on the virus replication but directly affect the viral particles and reduce the viral titer by Δlg = 3.25 for floral water and by Δlg = 3.0 for essential oil. Significant inhibition of the viral adsorption stage was also observed, leading to a decrease in the viral titers by Δlg = 2.25 for floral water and by Δlg = 2.0 for essential oil. When pretreating healthy cells with rose products, both samples significantly protected them from subsequent infection with HSV-1. This protective effect was more pronounced for the oil (Δlg = 2.5) compared to the one for the floral water (Δlg = 2.0). We used the in silico molecular docking method to gain insight into the mechanism of hindrance of viral adsorption by the main rose oil compounds (geraniol, citronellol, nerol). These components targeted the HSV-1 gD interaction surface with nectin-1 and HVEM (Herpesvirus Entry Mediator) host cell receptors, at N-, C-ends, and N-end, respectively. These findings could provide a structural framework for further development of anti-HSV-1 therapeutics. Full article

Wastewater-based molecular epidemiology enables the surveillance of both symptomatic and asymptomatic individuals in a non-invasive, cost-effective, rapid, and early-detection manner. The use of wastewater analysis to monitor the prevalence of viral pathogens in a given population has increased significantly since the COVID-19 pandemic. These studies typically involve three main steps: viral concentration, nucleic acid extraction, and DNA/RNA quantification. However, the absence of a standardized methodology remains a major limitation, hindering result comparability across studies. Among the available viral concentration techniques, aluminum-based adsorption–precipitation is one of the most commonly used due to its simplicity, efficiency, and low cost. This study evaluates the robustness and variability of the viral concentration and nucleic acid extraction steps by implementing different process controls in wastewater samples across 122 independent experiments. Additionally, correlations between viral recovery efficiencies and relevant physicochemical parameters were also analyzed (n = 600). The results indicate that, despite the overall robustness of the method, the concentration step exhibits the highest variability (CV = 53.82%), which accounted for 53.73% of the overall variability. In addition, our results show that, on average, 0.65 logarithmic units were lost during the viral concentration step. Furthermore, viral recovery rates were influenced by seasonality and sample characteristics, while no significant correlation was observed with pH or conductivity. These findings highlight the importance of process controls, confirming the robustness of the methodology, and identifying key parameters that should be considered in future studies for improved data interpretation. Full article

Bacterial biofilms, characterized by complex structures, molecular communication, adaptability to environmental changes, insensitivity to chemicals, and immune response, pose a big problem both in clinics and in everyday life. The increasing bacterial resistance to antibiotics also led to the exploration of lytic bacteriophages as alternatives. Nevertheless, bacteria have co-evolved with phages, developing effective antiviral strategies, notably modification or masking phage receptors as the first line of defense mechanism. This study investigates viral–host interactions between non-host-specific phages and Pseudomonas aeruginosa, assessing whether bacteria can detect phage particles and initiate protective mechanisms. Using real-time biofilm monitoring via impedance and optical density techniques, we monitored the phage effects on biofilm and planktonic populations. Three Klebsiella phages, Slopekvirus KP15, Drulisvirus KP34, and Webervirus KP36, were tested against the P. aeruginosa PAO1 population, as well as Pseudomonas Pbunavirus KTN6. The results indicated that Klebsiella phages (non-specific to P. aeruginosa), particularly podovirus KP34, accelerated biofilm formation without affecting planktonic cultures. Our hypothesis suggests that bacteria sense phage virions, regardless of specificity, triggering biofilm matrix formation to block potential phage adsorption and infection. Nevertheless, further research is needed to understand the ecological and evolutionary dynamics between phages and bacteria, which is crucial for developing novel antibiofilm therapies. Full article

Polyphenol-rich extracts derived from agricultural by-products exhibit promising antiviral properties. This study evaluated the antiviral potential of extracts from red onion peels, vineyard prunings, olive prunings and chicory leaves against human coronavirus HuCoV-229E. Subcritical water extraction and resin adsorption techniques were applied to produce the extracts. The extracts were further characterised for their bioactive content, and three out of four extracts showed a high polyphenol content (>200 mg/g). The antiviral activity was assessed through viral infectivity and replication inhibition assays in human MRC-5 host cells. The results indicate that chicory leaf and red onion peel extracts demonstrated significant antiviral effects, with effective concentrations (EC₅₀) of 61.43 µg/mL and 10.1 µg/mL, respectively. Olive pruning extract exhibited moderate activity, while vineyard pruning extract showed limited efficacy. These findings suggest that polyphenol-rich agricultural by-products could serve as sustainable sources for antiviral agents, warranting further investigation into their mechanisms of action and potential applications against other coronaviruses, including SARS-CoV-2. Full article

Unexpected mutations in SARS-CoV-2 produce unique variations. While numerous vaccines and antiviral medications are available for SARS-CoV-2, their use in controlling and preventing COVID-19 is restricted in some areas and countries due to accessibility and cost issues. This study investigated polysaccharides produced from two brown seaweed (Padina boergesenii and Sargassum euryphyllum) for their capacity to inhibit SARS-CoV-2. The seaweed polysaccharides were characterized and identified using ultraviolet and visible (UV/VIS) and Fourier transform infrared attenuated total reflectance (FTIR-ATR) spectra. The polysaccharides inhibited SARS-CoV-2 propagation with inhibitory concentration 50% (IC₅₀) values ranging from 24.2 to 29.3 µg/mL and cytotoxicity concentration 50% (CC₅₀) values for Vero-E6 cells ranging from 587.7 to 396.4 µg/mL for P. boergesenii and S. euryphyllum, respectively. P. boergesenii polysaccharide had a more substantial antiviral potential than S. euryphyllum against SARS-CoV-2 and appeared more promising. At a concentration of 575 µL/mL of P. boergesenii polysaccharide, the virucidal mechanism was found to be the most effective, followed by viral adsorption and replication, with viral inhibition percentages of 68.6% ± 0.8, 57.1% ± 1.4, and 37.2 ± 3, respectively, compared to remdesivir as an antiviral drug. Thus, we concluded that brown seaweed alginate polysaccharides efficiently inhibit SARS-CoV-2 from spreading by preventing viral entry. Finally, P. boergesenii polysaccharide looked promising as a potential therapeutic candidate for the treatment of COVID-19. Full article

Porcine reproductive and respiratory syndrome (PRRS) is one of the most serious diseases threatening the swine industry worldwide. However, no satisfactory control strategy has existed until now. In this study, the effectiveness of tylvalosin against PRRSV and the underlying mechanism was investigated. The results showed that in porcine alveolar macrophages (PAMs), tylvalosin can inhibit the replication of the NADC30-like and NADC34-like strains in a dose-dependent manner. It is worth noting that pre-incubation with tylvalosin had no significant inhibitory effect on the NADC30-like strain but did inhibit the NADC34-like strain. Co-incubation of both viruses and tylvalosin or post-incubation with tylvalosin after viral infection inhibited PRRSV. We further analyzed the effect of tylvalosin on different stages of PRRSV replication and found that the stages in the PRRSV life cycle could be blocked by tylvalosin. Tylvalosin has an antiviral effect on all four stages of the NADC34-like strain’s infectious cycle but has no effect against the adsorption phase of the NADC30-like strain. These results demonstrated that tylvalosin suppressed PRRSV infection in PAMs and inhibited PRRSV infection at multiple steps of the viral life cycle. This study will contribute to the clinical prevention and control of PRRS and provide a basis for further exploration of the anti-PRRSV effects of tylvalosin. Full article

This study is a comparative investigation of the activity of unloaded and curcumin-loaded oil-in-water emulsion or chitosan-based capsules on rabbit retinal cells (RRC), coronavirus HCoV-OC43, and virus HSV-1 virus in relation to their potential ophthalmologic applications. The carriers are developed by using well-established experimental procedures. The characterization of their surface properties and stability in simulated ocular fluids (tear fluid, aqueous humor, and vitreous humor) is performed using the dynamic light scattering method and UV–vis spectrophotometry. In vitro tests are performed to determine the cytotoxicity and phototoxicity of pure curcumin (CR) and selected CR-containing carriers on RRC. The effect of the unloaded and CR-loaded carriers on the antiviral activity, the behavior of the extracellular virions, and the influence on viral adsorption is evaluated against coronavirus HCoV-OC43 and HSV-1 virus by using suitable microbiological assays. In accordance with the obtained experimental results, the toxicity of carriers containing CR is significantly reduced compared to pure compound and unloaded carriers. Moreover, the activity of the unloaded carriers can be increased several times by incorporating CR. The experimental results demonstrate that the variation in the properties of even one component of the structural composition can provoke the different activity of the carriers. Full article

Background/Objectives: Advancements in personalized medicine have revolutionized drug delivery, enabling tailored treatments based on genetic and molecular profiles. Non-viral vectors, such as polyurethane (PU)-based systems, offer promising alternatives for gene therapy. This study develops mathematical models to analyze PU degradation, DNA/RNA release kinetics, and cellular interactions, optimizing their application in personalized therapy. Methods: This theoretical study utilized mathematical modeling and numerical simulations to analyze PU-based gene delivery, focusing on diffusion, degradation, and cellular uptake. Implemented in Python 3.9, it employed differential equation solvers and adsorption/internalization models to predict vector behavior and optimize delivery efficiency. Results: This study demonstrated that PU degrades in biological environments following first-order kinetics, ensuring a controlled and predictable release of genetic material. The Higuchi diffusion model confirmed a gradual, sustained DNA/RNA release, essential for efficient gene delivery. Simulations of PU adsorption onto cellular membranes using the Langmuir model showed saturation-dependent binding, while the endocytosis model revealed a balance between uptake and degradation. These findings highlight PU’s potential as a versatile gene delivery vector, offering controlled biodegradability, optimized release profiles, and effective cellular interaction. Conclusions: Our results confirm that PU-based vectors enable controlled biodegradability, sustained DNA/RNA release, and efficient cellular uptake. Mathematical modeling provides a framework for improving PU’s properties, enhancing transport efficiency and therapeutic potential in personalized medicine and gene therapy applications. Full article

Background/Objectives: This study aims to gain insights into the antimicrobial and antiherpetic activity of hyperforin-rich Hypericum perforatum L. (HP) extract using nanostructured lipid carriers (NLCs) as delivery platforms. Methods: Two established NLC specimens, comprising glyceryl behenate and almond oil or borage oil, and their extract-loaded counterparts (HP-NLCs) were utilized. Their minimal bactericidal/fungicidal concentrations (MBC; MFC) were investigated against Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 10145, Klebsiella pneumoniae ATCC 10031, and Candida albicans ATCC 10231. The anti-herpesvirus (HSV-1) potential was evaluated concerning antiviral and virucidal activity and impact on viral adsorption. Results: The borage oil-based extract-loaded nanodispersion (HP-NLC2) exhibited pronounced microbicidal activity against S. aureus (MBC 6.3 mg/mL), K. pneumoniae (MBC 97.7 µg/mL), and C. albicans (MFC < 48.8 µg/mL), unlike the almond oil-containing sample (HP-NLC1), which showed only weak inhibition of the fungal growth. HP-NLC2 was found to be less cytotoxic and to suppress HSV-1 replication slightly more than HP-NLC1, but generally, the effects were weak. Neither the empty lipid nanoparticles nor the HP extract-loaded carriers expressed activity against E. coli, P. aeruginosa, the HSV-1 extracellular virions, or viral adhesion. Conclusions: It could be concluded that both HP-NLC samples revealed only minor antiherpetic potential of the hyperforin-rich extract, but HP-NLC2 demonstrated significant antibacterial and antimycotic activity. Therefore, the latter was featured as a more convenient HP-carrier system for nano-designed dermal pharmaceutical formulations. Such a thorough investigation of hyperforin-determined anti-HSV-1 effects and antibacterial and antimycotic properties, being the first of its kind, contributes to the fundamental knowledge of HP and reveals new perspectives for the utilization, limitations, and therapeutic designation of its non-polar components. Full article

The growing demand for viral vectors as nanoscale therapeutic agents in gene therapy necessitates efficient and scalable purification methods. This study examined the role of nanoscale biomaterials in optimizing viral vector clarification through a model system mimicking real AAV2 crude harvest material. Using lysed HEK293 cells and silica nanoparticles (20 nm) as surrogates for AAV2 crude harvest, we evaluated primary (depth filters) and secondary (membrane-based) filtration processes under different process parameters and solution conditions. These filtration systems were then assessed for their ability to recover nanoscale viral vectors while reducing DNA (without the need for endonuclease treatment), protein, and turbidity. Primary clarification demonstrated that high flux rates (600 LMH) reduced the depth filter’s ability to leverage adsorptive and electrostatic interactions, resulting in a lower DNA removal. Conversely, lower flux rates (150 LMH) enabled >90% DNA reduction by maintaining these interactions. Solution conductivity significantly influenced performance, with high conductivity screening electrostatic interactions, and the model system closely matching real system outcomes under these conditions. Secondary clarification highlighted material-dependent trade-offs. The PES membranes achieved exceptional AAV2 recovery rates exceeding 90%, while RC membranes excelled in DNA reduction (>80%) due to their respective surface charge and hydrophilic properties. The integration of the primary clarification step dramatically improved PES membrane performance, increasing the final flux from ~60 LMH to ~600 LMH. Fouling analysis revealed that real AAV2 systems experienced more severe and complex fouling compared to the model system, transitioning from intermediate blocking to irreversible cake layer formation, which was exacerbated by nanoscale impurities (~10–600 nm). This work bridges nanomaterial science and biomanufacturing, advancing scalable viral vector purification for gene therapy. Full article

Influenza A virus (IAV) is a widespread human respiratory pathogen that contributes significantly to morbidity and mortality worldwide. The adsorption of the virus into the cell surface is the earliest stage of its replication cycle. The key role of N-linked sialic acids (SIAs) as receptors for binding to IAV’s hemagglutinin (HA) has long been acknowledged. The molecular specificity of this interaction is a key factor in host range, pathogenicity, and transmissibility of various IAV subtypes. Along with this, a number of recent studies have introduced significant complexity into the picture of IAV adsorption and revealed a multitude of new molecules on host cell surfaces to serve as receptors and/or co-receptors for IAV attachment. For successful internalization of the adsorbed virus, downstream signal transduction is necessary to activate effector endocytosis mechanisms. In recent years, our understanding of the sophistication and variability of signal transduction pathways in the virus attachment site has significantly expanded, with the help of research techniques like fluorescence imaging of individual viruses in real-time, dominant-negative mutants, siRNA knockdowns, protein kinase selective inhibitors, phosphoproteome profiling, and others. These approaches deepen our knowledge of the molecules involved in the early stages of the IAV life cycle and also serve as the basis for the development of new effective antiviral drugs. In our review, we analyze recent publications on the mechanisms of IAV adsorption, newly discovered receptors for virus attachment, and signal transmission in the site of the adsorbed virion. Besides this, we consider new data on the development of selective inhibitors as antiviral drugs aimed at both viral and cellular factors of IAV adsorption. Full article

Wastewater-based epidemiology (WBE) is a valuable tool for monitoring pathogen spread in communities; however, current protocols mainly target non-enveloped viruses. This study addresses the need for standardized methods to detect both enveloped and non-enveloped viruses by testing four aluminum hydroxide adsorption–precipitation techniques. Wastewater samples were spiked with an enveloped virus surrogate (Φ6 bacteriophage) and a non-enveloped virus surrogate (MS2 coliphage), and viral recovery was assessed using reverse-transcription quantitative PCR (RT-qPCR). The highest recovery for the enveloped virus was achieved with AlCl₃ at pH 3.5, a 15 min flocculation time, and a 3% elution solution concentration. For the non-enveloped virus, optimal recovery was found with AlCl₃ at pH 6.0, no flocculation time, and a 10% elution solution. The best method for recovering both virus types used AlCl₃ at pH 6.0, 15 min flocculation, and a 3% elution solution concentration. This study shows that while optimal conditions vary between virus types, a standardized AlCl₃ flocculation protocol can efficiently recover both, providing a cost-effective approach for outbreak monitoring in Grenada. Full article

Objectives: The industrial production of influenza vaccines is facing significant challenges, particularly in improving virus production efficiency. Despite advances in cell culture technologies, our understanding of the production characteristics of high-yield suspension cell lines remains limited, thereby impeding the development of efficient vaccine production platforms. This study aims to investigate the key features of STAT1 knockout suspension-adapted MDCK cells (susMDCK-STAT1-KO) in enhancing influenza A virus (IAV) production. Methods: Suspension-adapted susMDCK-STAT1-KO cells were compared to suspension-adapted wild-type MDCK cells (susMDCK) for IAV production. Virus quantification, gene expression analysis, and cholesterol deprivation assays were performed. Metabolite profiles, viral RNA quantification, and lipid and dry weight measurements were also conducted to assess the viral replication and release efficiency. Results: The susMDCK-STAT1-KO cells exhibited significantly improved virus adsorption (64%) and entry efficiency (75%) for the H1N1 virus, as well as accelerated viral transcription and replication for both the H1N1 and H9N2 viruses. Virus release was identified as a limiting factor, with a 100-fold higher intracellular-to-extracellular viral RNA ratio. However, the STAT1-KO cells showed a 2.39-fold higher release rate (750 virions/cell/h) and 3.26-fold greater RNA release for the H1N1 virus compared to wild-type cells. A gene expression analysis revealed enhanced lipid metabolism, particularly cholesterol synthesis, as a key factor in viral replication and release. Cholesterol deprivation resulted in reduced viral titers, confirming the critical role of intracellular cholesterol in IAV production. Conclusions: This study demonstrates the enhanced influenza virus production capacity of susMDCK-STAT1-KO cells, with significant improvements in viral yield, replication, and release efficiency. The findings highlight the importance of STAT1-mediated immune modulation and cholesterol metabolism in optimizing virus production. These insights provide a foundation for the development of more efficient vaccine production platforms, with implications for large-scale industrial applications. Full article

 Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been associated with various hematological disorders. Understanding the pathology of erythrocytes (red blood cells) in coronavirus infection may provide insights into disease severity and progression. Objective: To review and analyze the general pathology of erythrocytes in patients infected with SARS-CoV-2, focusing on clinical and laboratory findings across different severity groups. Methods: Patients were classified into four groups based on clinical criteria: Group 1: Regular group (fever, respiratory symptoms, and radiographic evidence of pneumonia). Group 2: Severe group (shortness of breath >30 breaths/min, peripheral blood oxygen saturation <92% at rest, extensive pneumonia, respiratory failure requiring mechanical ventilation, and/or organ failure necessitating intensive care). Group 3: Low saturation group (peripheral blood oxygen saturation <85% at rest). Group 4: Erythroblastosis group (erythroblast count >0.5% among total nucleated blood cells). Clinical laboratory investigations included major routine studies and scanning microspectrophotometry to measure hemoglobin (Hb) spectra in unstained erythrocytes. Results: Erythroblasts were detected in approximately 30% of SARS-CoV-2 patients, predominantly in the severe group. Serum ferritin, C-reactive protein (CRP), and anisocytosis were strongly correlated with disease severity. Microspectrophotometric studies revealed significant changes in hemoglobin adsorption spectra, with an increase in Hb absorbance at 420 nm in severe cases compared to normal controls. Conclusions: Elevated serum ferritin, CRP levels, anisocytosis, and altered hemoglobin absorption at 420 nm wavelength are associated with adverse outcomes in SARS-CoV-2 infection. These findings highlight the potential utility of hematological parameters as markers for disease severity and prognosis in viral infections. Full article

Herpes viruses are highly contagious agents affecting all classes of vertebrates, thus causing serious health, social, and economic losses. Within the One Health concept, novel therapeutics are extensively studied for both veterinary and human control and management of the infection, but the optimal strategy has not been invented yet. Lactic acid bacteria are key components of the microbiome that are known to play a protective role against pathogens as one of the proposed mechanisms involves compounds released from their metabolic activity. Previously, we reported the anti-herpes effect of postmetabolites isolated from Lactobacilli, and here, we confirm the inhibitory properties of another nine products against the phylogenetically distant human Herpes simplex virus-1 (HSV-1) and fish Koi Herpes virus (KHV) in cell cultures. Cytotoxicity, cytopathic effect inhibition, virucidal effect, the influence on the adsorption stage of the virus to the cells, as well as the protective effect of the postmetabolites on healthy cells were evaluated. The inhibitory effect was more pronounced against HSV-1 than against KHV at all studied viral cycle stages. Regarding the intracellular replicative steps, samples S7, S8, and S9 (Mix group) isolated from Ligilactobacillus salivarius (vaginal strain) demonstrated the most distinct effect with calculated selective indices (SIs) in the range between 69.4 and 77.8 against HSV-1, and from 62.2 to 68.4 against KHV. Bioactive metabolites from various LAB species significantly inhibit extracellular HSV-1 and, to a lesser extent, KHV virions. The blockage of viral adsorption to the host cells was remarkable, as recorded by a decrease in the viral titer with Δlg ≥ 5 in the Mix group for both herpes viruses. The remaining postmetabolites also significantly inhibited viral adsorption to varying degrees with Δlg ≥ 3. Most metabolites also exerted a protective effect on healthy MDBK and CCB cells to subsequent experimental viral infection. Our results reveal new horizons for the application of LAB and their postbiotic products in the prevention and treatment of herpes diseases. Full article