Search Results (13,723)

In silico prediction of ADME parameters, Lipinski’s Rule of Five, toxicity, or the reliability level of the predicted biological activity of a given structure against a specific pathogen are an integral part of modern drug discovery to accelerate the identification of promising lead compounds while reducing development costs and toxicity risks. In this context, multivariate statistical methods such as Principal Component Analysis (PCA) play an important role in the evaluation of large chemical and biological datasets, facilitating the identification of structural similarities, physicochemical trends, or predictions of pharmacological behavior. Natural products remain one of the most important sources of structurally diverse bioactive scaffolds, serving as inspiration for the development of novel therapeutics. Buchenavianines are a rare class of piperidine-flavonoid alkaloids isolated from tropical woody species of the genus Buchenavia (Combretaceae). Scientific interest in buchenavianines was initially stimulated by the discovery of potent anti-HIV activity in extracts of Buchenavia capitata, which demonstrated their ability to interfere with viral replication pathways and highlighted their potential as antiviral drug candidates. Studies have suggested that buchenavianines may possess anti-inflammatory, antioxidant, and anticancer potential; therefore they represent important lead compounds for medicinal chemistry in the development of a new generation of drugs. PCA showed that the first two principal components explained 92.7% of the total variance (PC1 = 56%, PC2 = 36.7%), indicating that the selected descriptors adequately captured the variability among the studied buchenavianines. This study underscores the importance of these secondary metabolites as lead compounds in modern medicinal chemistry and drug discovery. Full article

Background: Persistent infection with high-risk human papillomavirus (hrHPV) is the principal cause of cervical intraepithelial neoplasia (CIN). Cytokines regulate antiviral immunity and tissue remodeling, and cytokine profiling may provide additional information about the biology of cervical lesions. Objective: To characterize cytokine profiles in cervical mucus and serum across grades of cervical intraepithelial neoplasia. Methods: The study included 90 women aged 18–80 years: 30 HPV-negative women with negative cytology (Control) and 60 HPV-positive women with histologically confirmed low-grade (LSIL, n = 30; Gr-1) or high-grade (HSIL, n = 30; Gr-2) squamous intraepithelial lesions. Participants were also stratified by minor (grade 1) or major (grade 2) colposcopic findings. An exploratory subgroup of 15 women with HPV16/18-positive HSIL received antiviral and immunomodulatory therapy. Concentrations of 27 cytokines (pg/mL)—FGF, eotaxin, G-CSF, GM-CSF, IFN-γ, IL-1ra, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12(p70), IL-13, IL-15, IL-17A, IP-10, MCP-1, MIP-1α, MIP-1β, PDGF-BB, RANTES, TNF-α, and VEGF—were measured in serum and cervical mucus using the Bio-Plex Pro Human Cytokine 27-plex assay (Bio-Rad, USA) on a Luminex 200 platform. Statistical analyses were performed using SPSS version 23.0 and Microsoft Excel 365. Results are reported as medians and interquartile ranges [Q1–Q3]. A two-sided p-value < 0.05 was considered statistically significant. Results: Exploratory multivariate analyses identified IL-1β, IP-10, MCP-1, and FGF as the cytokines most strongly associated with lesion severity and colposcopic findings. In cervical mucus, HSIL was associated with the highest IL-1β concentration (0.83 pg/mL [0.18–4.91] vs. 0.30 pg/mL [0.04–0.69] in controls; p < 0.001) and the lowest IP-10 concentration (3.07 pg/mL [1.02–13.16] vs. 25.12 pg/mL [5.01–42.40]; p < 0.001). The highest mucus FGF concentration was observed in LSIL (1.73 pg/mL [1.33–2.27] vs. 0.32 pg/mL [0.17–0.59] in controls; p < 0.001), whereas MCP-1 was lower in LSIL than in HSIL (2.38 pg/mL [1.57–3.54] vs. 5.38 pg/mL [3.12–10.55]; p < 0.05). Similar patterns were observed in serum, except that IL-1β was lower than in controls. After treatment, HPV was undetectable in 10 women and remained detectable in 5. The overall cytokine profile changed only modestly. Among the five women with persistent HPV infection, cervical mucus MCP-1 was lower after treatment than before treatment (0.09 pg/mL [0.01–0.41] vs. 0.37 pg/mL [0.08–0.73]; p < 0.01). Conclusions: These findings show associations between lesion severity, colposcopic findings, and compartment-specific cytokine patterns. Because the study was cross-sectional and the treatment subgroup was small and uncontrolled, the results should be considered exploratory and require longitudinal validation. Full article

Occult hepatitis B infection (OBI) is defined by detectable hepatitis B virus (HBV) DNA in liver tissue in the absence of hepatitis B surface antigen (HBsAg) and remains insufficiently characterized in low-endemic European settings. This study aimed to determine the prevalence of OBI using direct HBV DNA detection in liver tissue in a real-world cohort of patients undergoing diagnostic liver biopsy. This observational study included consecutive HBsAg-negative patients who underwent liver biopsy between 2020 and 2023. HBV DNA in liver tissue was quantified by real-time PCR, and clinical and serological data were collected. A total of 86 patients were included. OBI was identified in 4 patients (4.7%). All OBI cases were anti-HBc-positive, and two were also anti-HBs-positive. No cases of seronegative OBI were detected. OBI was observed across different underlying liver disease etiologies, including viral, metabolic, autoimmune, and cholestatic conditions. In conclusion, OBI was infrequent in this cohort and consistently associated with anti-HBc seropositivity. These findings suggest that anti-HBc may help identify individuals with prior HBV exposure in whom occult infection can be detected in liver tissue in low-prevalence settings. Full article

Porcine epidemic diarrhea virus (PEDV) is a major pathogen affecting the global swine industry, causing severe diarrhea, dehydration, and high mortality in neonatal piglets. Due to the continuous emergence of viral variants, the protective efficacy of currently available vaccines remains suboptimal, highlighting the urgent need for effective antiviral agents. In this study, we investigated the anti-PEDV activity of muscone in vitro. Our results demonstrated that muscone inhibits PEDV replication in a dose-dependent manner and exerts its antiviral effect primarily during the early stages of viral infection. Further mechanistic studies revealed that muscone acts mainly by interfering with viral entry into host cells. Specifically, Western blot analysis and confocal microscopy showed that muscone treatment led to the degradation of caveolin-1, suggesting that muscone may block PEDV entry by disrupting caveolin-mediated endocytosis. Collectively, our findings provide clear evidence that muscone possesses potent anti-PEDV activity in vitro and offer mechanistic insights into its mode of action, thereby establishing muscone as a promising lead compound for the development of novel antiviral strategies against PEDV. Full article

Viral infections remain a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT), particularly in patients with delayed immune reconstitution or prolonged immunosuppression. Although antiviral drugs have substantially reduced the incidence of viral disease, their use is limited by toxicity, resistance, and the inability to restore long-term antiviral immunity. Adoptive transfer of virus-specific T cells represents a targeted immunotherapeutic strategy to re-establish pathogen-specific immune responses while minimizing the risk of graft-versus-host disease (GvHD). This review focuses on the development and clinical application of adoptive virus-specific T cell therapy after allogeneic HSCT, with particular emphasis on cytomegalovirus (CMV). We summarize the evolution of adoptive antiviral T cell therapy, compare current manufacturing and selection strategies, and critically review available clinical evidence regarding efficacy, persistence, safety, and alloreactivity. In addition to CMV-directed products, we discuss approaches targeting Epstein–Barr virus (EBV), adenovirus (AdV), and other clinically relevant pathogens in the context of multipathogen-specific T cell products and third-party donor approaches. We further address current knowledge on immune monitoring, factors influencing antiviral immune reconstitution, as well as practical challenges that still limit broader clinical use. Finally, we discuss emerging strategies to improve product standardization, availability, and integration of adoptive T cell therapy with modern antiviral prophylaxis and graft-engineering approaches. Full article

Influenza in pregnancy is associated with a higher risk of severe respiratory disease and adverse maternal and perinatal outcomes, particularly later in gestation. This narrative review synthesizes evidence on epidemiology, pathophysiology, placental and fetal consequences, clinical presentation, diagnosis, antiviral management, and vaccination. Pregnancy involves dynamic immune adaptation together with reduced respiratory reserve, increased oxygen consumption, and cardiovascular changes that may amplify the effects of influenza pneumonia. Placental and fetal consequences appear to be mediated predominantly by maternal hypoxemia, fever, systemic inflammation, and hemodynamic disturbance; transplacental viral transmission is rare. Therefore, adverse fetal and neonatal outcomes are more closely linked to the severity and timing of maternal illness, placental dysfunction, and prematurity than to direct fetal infection. Prompt recognition is essential, and antiviral treatment should not await laboratory confirmation when influenza is suspected. Oseltamivir remains the preferred antiviral therapy and should be initiated as early as possible, including in patients presenting after 48 h with progressive or severe disease. Seasonal inactivated or recombinant influenza vaccination is the cornerstone of prevention, protecting both the mother and the infant through transplacental transfer of influenza-specific IgG. This integrated perspective supports vaccination, early diagnosis, and timely treatment to reduce maternal and perinatal risk. Full article

Herpes simplex virus type 1 (HSV-1) and varicella–zoster virus (VZV) are clinically important alphaherpesviruses that establish lifelong latent infections and remain significant causes of morbidity despite the availability of antiviral drugs. The emergence of drug resistance and the inability of current therapies to eliminate latent virus reservoirs underscore the need for novel antiviral agents with alternative mechanisms of action. In the present study, we evaluated the antiviral activity of an ethanolic extract prepared from commercial cinnamon bark marketed as Cinnamomum cassia and cinnamaldehyde, a well-known constituent of cinnamon tested here as a purified compound, against HSV-1 and VZV in vitro. Antiviral activity was assessed using plaque reduction assays, time-of-addition experiments, and quantitative real-time PCR for viral DNA accumulation and specific viral immediate-early transcript levels. Both the C. cassia extract and cinnamaldehyde inhibited HSV-1 and VZV replication in a dose-dependent manner while exhibiting relatively low cytotoxicity. Nonlinear dose–response analysis yielded IC₅₀ values of 3.44 and 2.80 µg/mL for the C. cassia extract against HSV-1 and VZV, respectively, and 0.961 and 1.50 µg/mL for cinnamaldehyde. Time-of-addition experiments demonstrated that antiviral activity was greatest when treatment was maintained throughout infection or initiated after viral entry, whereas pretreatment of cells or direct incubation with virus particles produced minimal effects. Both agents markedly reduced intracellular production of infectious progeny viruses and decreased viral DNA accumulation and the abundance of the specific immediate-early transcripts examined. These findings support a predominantly post-entry antiviral effect of both materials, rather than a primary effect on viral attachment or direct virion inactivation. Collectively, these results support further investigation of these agents as promising natural inhibitors of HSV and VZV infections. Full article

Hepatitis A virus (HAV) infection is a major cause of acute viral hepatitis worldwide. However, no effective antiviral therapy is currently available. HAV manipulates host secretory pathways, including the endosomal sorting complex required for transport (ESCRT)-dependent pathways, to facilitate viral propagation. Nevertheless, whether HAV also utilizes alternative secretory pathways remains unclear. Here, we provide evidence suggesting that an ESCRT-independent pathway may contribute to extracellular HAV RNA levels in Huh7 cells infected with HAV genotype IB (HM175-18f) and genotype IIIA (HA11-1299). Treatment with the ESCRT-independent pathway inhibitor GW4869 significantly reduced extracellular HAV RNA levels. GW4869 did not significantly affect HAV subgenomic RNA replication. These results suggest that the neutral sphingomyelinase 2 (nSMase2)-dependent ESCRT-independent pathway may contribute to extracellular HAV RNA levels rather than intracellular HAV RNA replication. Consistent with these findings, knockdown of sphingomyelin phosphodiesterase 3, which encodes SMase2, also significantly reduced extracellular HAV RNA levels. These findings suggest that an nSMase2-dependent ESCRT-independent extracellular vesicle pathway may contribute to extracellular HAV RNA levels. Full article

The pursuit of efficient approaches for the production of promising antiviral and cytostatic pharmaceuticals is a crucial direction in medical biotechnology, especially after the COVID-19 pandemic. Modified nucleosides and nucleotides represent a highly promising class of chemicals for the development of drugs against cancer and viral infections. Being an alternative to traditional chemical synthesis, cascades of nucleic exchange enzymes offer single-step synthesis of such compounds with exceptional stereo- and regioselectivity. Furthermore, employing thermostable enzymes for such cascades offers the advantages of increased substrate solubility, lower solution viscosity, prevention of contamination, and simplified biocatalyst purification via thermal denaturation. The first biocatalyst for two distinct cascade pathways of nucleotide and nucleoside synthesis is ribokinase. In this article, we report improving the activity of ribokinase from Thermus sp. 2.9 (TspRK) for the cascade synthesis of modified nucleosides and nucleotides. We have employed a rational design approach, including Boltz-2 modeling and sequence conservation analysis. We have engineered two mutants, T244I and N272H, achieving a 3-fold increase in ribose phosphorylation rate (k_cat). Improving the enzymatic activity of a thermostable ribokinase will serve as the basis for further optimization of cascade synthesis of pharmaceutical modified nucleosides and nucleotides. Full article

Background/Objectives: The Elecsys HCV Duo immunoassay simultaneously detects HCV core antigen (HCV Ag) and anti-HCV antibodies in a single sample. We evaluated its clinical performance against a standard-of-care reference algorithm of anti-HCV antibody and HCV RNA testing. Methods: We retrospectively analyzed 1332 residual serum or plasma samples tested with reference HCV RNA assays and the Alinity i Anti-HCV assay. Samples were classified as reference-positive, indicating current or past HCV infection (n = 166; 88 RNA+/Ab+ with active infection and 78 RNA−/Ab+ with resolved or treated infection), or reference-negative (n = 1166; RNA−/Ab−), including 1000 randomly selected blood donor samples. All specimens were tested with the Elecsys HCV Duo (cobas^® e 801, Roche Diagnostics). Positive and negative percent agreements (PPA and NPA) were calculated against the combined reference standard. Results were further analyzed by infection status and viral load. No HCV RNA+/anti-HCV− (window-period) specimens were available. Results: Overall agreement was high (PPA 98.8% [164/166; 95% CI, 95.7–99.9%]; NPA 99.9% [1165/1166; 95% CI, 99.5–100.0%]). Agreement of the anti-HCV component with the Alinity i Anti-HCV assay was identical (PPA 98.8%, NPA 99.9%). The HCV Duo Ag component showed a PPA of 60.2% (95% CI, 49.2–70.5%) and NPA of 99.0% (95% CI, 98.3–99.5%) against HCV RNA detection. The Ag module was also reactive in 12 of 78 (15.4%) RNA−/Ab+ specimens, all from previously treated patients; thus, 53 of 65 (81.5%) dual Ag/Ab-reactive specimens had detectable HCV RNA. HCV Ag positivity was highest at HCV RNA ≥10⁶ IU/mL (77.4%, 41/53), compared with 32.1% (9/28) at 10⁴–10⁶ IU/mL and 42.9% (3/7) at <10⁴ IU/mL. Receiver operating characteristic analysis of the Ag component yielded an area under the curve of 0.920 (95% CI, 0.904–0.934). Conclusions: The Elecsys HCV Duo demonstrated high overall agreement with the reference methods, supporting its potential as a single-step screening test for HCV infection. Most, but not all, dual Ag/Ab-reactive specimens were viremic, so this result may help prioritize anti-HCV-positive individuals for linkage to care; however, the assay does not replace HCV RNA testing, which remains necessary to confirm active infection, particularly in Ag-negative or previously treated individuals. Because no window-period specimens were included, the potential of the assay for earlier detection of acute infection could not be evaluated. Full article

The present study describes the development and validation of a simple, rapid, and reliable RP-HPLC method for the simultaneous estimation of acyclovir and doxepin hydrochloride in bulk and topical cream formulation using an Analytical Quality by Design (AQbD) approach. The combination of acyclovir, an antiviral agent, and doxepin, an antipruritic and anti-inflammatory drug, offers a combined topical approach for the management of herpes-associated skin conditions. The method development was guided by a predefined Analytical Target Profile (ATP), followed by systematic risk assessment to identify critical quality attributes (CQAs) and critical method parameters (CMPs). The central composite design (CCD) was employed to optimize key chromatographic variables, including mobile phase composition and flow rate. The chromatographic separation was achieved on a C18 column using an isocratic mobile phase of acetonitrile and water (40:60 v/v) at a flow rate of 1.0 mL/min, with UV detection at 240 nm. The retention times were found to be 2.58 min for acyclovir and 4.64 min for doxepin hydrochloride, indicating efficient separation with good peak symmetry. The method was validated according to ICH Q2(R2) guidelines and demonstrated excellent linearity over the concentration ranges of 2–10 µg/mL (acyclovir) and 12–28 µg/mL (doxepin hydrochloride), with correlation coefficients greater than 0.997. The method exhibited high precision (%RSD < 2%), accuracy (recovery within 99–101%), and good sensitivity with low LOD and LOQ values. The robustness studies confirmed the reliability of the method under small, deliberate variations in chromatographic conditions. The developed cream formulation showed uniform drug content and satisfactory in vitro drug release, with a sustained release profile reaching approximately 96% over 24 h. In conclusion, the proposed AQbD-based RP-HPLC method is suitable for routine quantitative analysis and quality control of acyclovir and doxepin hydrochloride in combined topical formulations. Full article

The rapid expansion of aquaculture has increased the demand for sustainable strategies to improve animal performance and control infectious diseases while reducing reliance on conventional chemotherapeutics. Medicinal plants have attracted increasing interest because their bioactive compounds can influence host physiology and exert activities against a broad range of pathogens. These effects involve both direct pathogen inhibition and modulation of host defense, including immune responses, inflammation, apoptosis, and intestinal homeostasis. However, their application is constrained by incomplete mechanistic understanding, species- and dose-dependent efficacy, and inconsistent standardization of plant materials and formulations. This review summarizes recent advances in the use of medicinal plants in aquaculture, with emphasis on growth promotion and antiviral, antibacterial, antiparasitic, and antifungal activities. We examine the mechanisms underlying these effects, including nutritional regulation, microbiota, immune responses, and direct effects on pathogens. We also discuss major challenges in dose optimization, species-specific responses, mechanistic validation, and plant–microbiota interactions, and highlight the need for standardized evaluation and multi-omics approaches to support their safe and consistent application in sustainable aquaculture. Full article

Background and Aim: Hepatitis delta virus (HDV) infection is among the most aggressive forms of chronic viral hepatitis: fibrosis advances quickly, and cirrhosis, hepatocellular carcinoma (HCC) and hepatic decompensation develop more often than with other hepatitis viruses. Metabolic dysfunction-associated steatotic liver disease (MASLD) is now the leading chronic liver disorder worldwide, and it may add to liver damage when it occurs alongside viral hepatitis. To date, however, data on hepatic steatosis in patients with chronic HDV infection remain scarce. We therefore aimed to describe the frequency of hepatic steatosis, assessed by the controlled attenuation parameter of transient elastography (FibroScan), in patients with chronic HBV infection and persistent anti-HDV seropositivity, and to examine whether it was associated with liver fibrosis. Methods: A total of 125 patients with chronic HBV infection and anti-HDV antibodies documented for at least six months were enrolled in this cross-sectional study between March and September 2024. HDV-RNA was tested in all participants. FibroScan provided liver stiffness measurement (LSM, kPa) and the controlled attenuation parameter (CAP, dB/m). We used CAP ≥ 248 dB/m to identify steatosis and LSM ≥ 12.5 kPa to identify cirrhosis. Because cardiometabolic risk factors were not systematically recorded, the criteria for MASLD could not be applied, and steatosis is reported as CAP-defined hepatic steatosis. Multivariable logistic regression was used to look for factors linked to LSM-defined advanced fibrosis (LSM ≥ 9.5 kPa), with sensitivity analyses accounting for ALT elevation. Results: The mean age was 39.0 years, and 74.4% (n = 93) of patients were male. HDV-RNA was detectable in 68.0% (n = 85). Of the 85 patients previously treated with pegylated interferon-alpha, 26 (30.6%) had a sustained virological response (SVR). Median LSM was 10.1 kPa (IQR 9.1–10.7) and median CAP 218 dB/m (IQR 211–239); cirrhosis was present in 15.2% (n = 19). CAP-defined steatosis was found in 24.0% (n = 30). Patients with and without steatosis were similar in age, sex, HDV-RNA status, liver stiffness, cirrhosis rate and SVR rate (36.4% vs. 28.6%, p = 0.593). After adjustment, detectable HDV-RNA was associated with advanced fibrosis (adjusted odds ratio [aOR] 4.89, 95% CI 2.13–11.26, p < 0.001), including after further adjustment for ALT. No significant association was found for steatosis (aOR 0.82, 95% CI 0.32–2.12, p = 0.684), although the confidence interval was wide. Conclusions: About one in four anti-HDV-positive patients had CAP-defined hepatic steatosis. Detectable HDV-RNA was associated with LSM-defined advanced fibrosis, whereas no significant association with steatosis was found; the precision of this estimate was limited, and the exploratory cirrhosis analysis was underpowered. Whether steatosis in this setting reflects metabolic dysfunction, and whether it affects long-term outcomes, warrants prospective study with full metabolic phenotyping. Full article

Peniadenisteroid A, also known as striasteroid C, is a unique marine-derived natural steroidal alkaloid with a characteristic adenine–steroid hybrid scaffold, in which an adenine moiety is bound to the C-3 position of the steroid skeleton. This natural metabolite displays evident antiviral activity through neuraminidase inhibition, with an IC₅₀ value of 6.15 μM. In this work, the C-3 epimer, (3S)-peniadenisteroid A, was successfully synthesized in eight steps with an overall yield of 3.9%. Biological screening results revealed that the intermediate (3S)-P6 exhibited prominent inhibitory activity against cellular nitric oxide (NO) production, while both (3S)-peniadenisteroid A and peniadenisteroid A presented weak anti-inflammatory effects. Further mechanistic studies indicated that (3S)-P6 exerts significant anti-inflammatory bioactivity by negatively regulating the STAT3/NF-κB and HIF-1α signaling pathways. Moreover, network pharmacology combined with molecular docking predicted Heat Shock Protein 90α (HSP90α) as the putative binding target of (3S)-P6. Overall, this study completes the synthesis and biological evaluation of (3S)-peniadenisteroid A, highlighting that intermediate (3S)-P6 is a valuable lead compound for further anti-inflammatory drug discovery. Full article

Coinfection between hepatitis viruses and human immunodeficiency virus (HIV) significantly increases liver disease and AIDS progression. This retrospective cross-sectional study evaluated the prevalence and genetic diversity of hepatitis B (HBV) and C viruses (HCV) among people living with HIV (PLWH) in Venezuela’s Capital District. A total of 420 serum samples collected between 2022 and 2025 were tested for serological and molecular markers, including whole-genome HBV sequencing via next-generation sequencing (NGS) to characterize viral genotype distribution and mutations. Seroprevalences for HBsAg, anti-HBc, and anti-HCV were 2.9%, 20%, and 4.0%, respectively. HBV exposure was significantly higher in older men, with no differences between treatment-naïve and treated patients. Occult HBV infection (OBI) prevalence decreased compared to 2014 data (seropositive: 7% vs. 16%, seronegative: 0.9% vs. 20%). This decline, along with the higher HBV exposure among older adults, may be partially attributed to the universal HBV vaccination introduced in Venezuela in 1998, as well as modifications in antiretroviral therapy affecting HBV replication. Notably, key vaccine- and diagnostic-escape mutations were detected in OBI cases, highlighting clinical and public health concerns. Increased HCV prevalence appears to be linked to rising intravenous drug use in the country. HBV phylogenetic analysis revealed genotype F3 as predominant, followed by F1b (Cosmopolitan clade), while HCV showed genotype 1a to be the most frequent, followed by 1b and 3a. These findings underscore the success of immunization efforts but highlight the urgent need for continuous molecular surveillance and updated public health policies, including targeted harm-reduction programs, to control viral hepatitis in vulnerable populations. Full article