Search Results (2,631)

Background: In rheumatoid arthritis (RA), the CD40-CD40L axis plays a key role in immune cell activation and the production of inflammatory mediators. Although the soluble form of CD40 (sCD40) has been identified and investigated in various autoimmune disorders, its significance in RA and its relationship with inflammatory and humoral markers remain to be fully elucidated. Methods: Sixty-two patients with RA, classified according to the 2010 ACR/EULAR criteria, and 31 age- and sex-matched healthy controls were included. Clinical characteristics, disease activity (DAS28-ESR), and acute-phase reactant levels (CRP and ESR) were evaluated in patients with RA. Autoantibodies (RF, ACPA, anti-MCV, and anti-PAD4), serum cytokines, and sCD40 levels were quantified using ELISA and multiplex bead-based assays. Group differences and associations were assessed using nonparametric tests. Multiple linear regression analysis was performed to account for potential confounding variables. Results: Serum sCD40 levels did not differ significantly between patients with RA and healthy controls or among patient subgroups stratified by disease activity or sex. No associations were observed between sCD40 levels and autoantibody seropositivity or titers. sCD40 levels were positively correlated with age (r_s = 0.293, p = 0.02). Notably, after adjustment for age, sCD40 showed a significant negative correlation with IL-2 (r_s = −0.317, p = 0.01). Conclusions: Serum sCD40 does not reflect disease activity or the humoral immune response in RA. Nevertheless, further studies are needed to evaluate its relevance during early stages of the disease and to further characterize its role in cytokine production. Full article

Background/Objectives: Plant-mediated silver nanoparticles (AgNPs) are promising components for oral biomaterials because of their antimicrobial potential; however, their biological behavior depends strongly on the phytochemical matrix, physicochemical characteristics, and exposure concentration. This study aimed to evaluate silver nanoparticles formulations synthesized using turmeric powder-derived Curcuma longa ethanolic and aqueous extracts, with emphasis on physicochemical characterization, antibacterial activity against oral-relevant Gram-positive bacteria, cytocompatibility toward human gingival fibroblasts (HGF-1), and acute in ovo vascular compatibility. Methods: AgCUR-EtOH NPs and AgCUR-H₂O NPs were synthesized using CUR-EtOH and CUR-H₂O extracts as reducing and stabilizing matrices. The resulting formulations were characterized by UV–visible spectroscopy (UV-Vis), dynamic light scattering (DLS), zeta-potential analysis, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined against Streptococcus mutans, Streptococcus oralis, and Staphylococcus aureus. Cytocompatibility was evaluated in HGF-1 human gingival fibroblasts after 24 h exposure to 1–10 µg/mL using complementary viability, lysosomal, mitochondrial, and fluorescence-based assays. Acute vascular irritation was assessed using the hen’s egg test–chorioallantoic membrane (HET-CAM) assay. Results: Both formulations exhibited broad, polydisperse hydrodynamic distributions and negative apparent zeta potentials. AgCUR-H₂O NPs showed a lower Z-average diameter than AgCUR-EtOH NPs under their respective solvent-specific measurement conditions. XRD pattern revealed heterogeneous crystalline compositions dominated by residual AgNO₃, together with weaker contributions consistent with metallic Ag and a possible minor oxidized silver phase. FTIR spectra demonstrated extract-derived organic functional groups and prominent nitrate-associated bands. TEM/EDX confirmed Ag-containing nanostructures with approximate size ranges of 15–175 nm for AgCUR-EtOH NPs and 15–150 nm for AgCUR-H₂O NPs. S. mutans was the most susceptible microorganism, with MIC values of 9 and 7 µg/mL and MBC values of 88 and 62 µg/mL for AgCUR-EtOH NPs and AgCUR-H₂O NPs, respectively. AgCUR-H₂O NPs consistently showed lower MIC and MBC values against all tested strains, but also produced a more pronounced concentration-dependent reduction in HGF-1 viability. At 10 µg/mL, cell viability was 71.88% for AgCUR-EtOH NPs and 52.14% for AgCUR-H₂O NPs. Both formulations showed low acute irritation potential in ovo, with irritation scores of 1.06 and 0.69, respectively. Conclusions: The two CUR-AgNP formulations exhibited distinct physicochemical, antibacterial, and cellular response profiles under the tested conditions. At equivalent concentrations expressed as total dried formulation mass, AgCUR-H₂O NPs yielded lower MIC and MBC values against the tested bacterial strains, whereas AgCUR-EtOH NPs produced a less pronounced reduction in HGF-1 viability. Because the powders were not quantitatively normalized for total silver, extract-derived organic fraction, or residual precursor content, these differences cannot be attributed exclusively to nanoparticle properties or to the extraction solvent and should not be interpreted as evidence of the intrinsic superiority of either formulation. Both formulations showed low acute vascular irritation. Further quantitative compositional, silver-release, and biofilm assessments are required before incorporation into oral biomaterial platforms. Full article

Background: Blood-accessible biomarkers may support future personalization of prostate cancer radiotherapy, but their interpretation depends on sampling timing relative to radiotherapy, androgen deprivation therapy, and post-treatment recovery. We mapped clinical evidence for selected biomarker domains beyond prostate-specific antigen: γ-H2AX/DNA damage response, IL-6/inflammatory mediators, testosterone/endocrine recovery and a prespecified galectin-1/3 immune–stromal domain evaluated as a potential evidence gap. Methods: We conducted a PRISMA-ScR scoping review of PubMed, Scopus, and Web of Science searched on 7 January 2026. Eligible original human studies evaluated soluble serum/plasma analytes or peripheral blood cell-based assays in prostate RT pathways. Data were charted by biomarker domain, treatment context, RT modality/fractionation, assay reporting, sampling schedule, and endpoint linkage. Results: Of 3499 records, 45 studies were included. No eligible study reported repeated circulating galectin-1/3 kinetics anchored to prostate radiotherapy, identifying a distinct clinical evidence gap. The remaining evidence was dominated by testosterone studies (n = 28), followed by IL-6/inflammatory mediators (n = 12) and γ-H2AX/DDR (n = 5). Testosterone studies were mapped as separate RT-only endocrine kinetics and ADT-anchored recovery streams. IL-6 studies mainly used during-RT or early post-RT sampling and linked trajectories to acute toxicity, fatigue, symptoms or inflammatory phenotypes; no included study directly validated serial IL-6/inflammatory trajectories against biochemical control, metastasis-free survival, or overall survival. γ-H2AX studies were characterized by ultra-acute, fraction-anchored sampling. Across domains, baseline definition and sampling timing limited interpretability more than assay platform alone. Conclusions: Evidence maturity was unequal across the selected domains. Testosterone provided the comparatively more developed longitudinal clinical literature, whereas IL-6/inflammatory mediators remained exploratory and were linked mainly to acute toxicity, fatigue, symptoms, and inflammatory phenotypes. γ-H2AX remained predominantly a translational and biodosimetry-oriented marker, while galectin-1/3 represented a hypothesis-generating clinical evidence gap. None of these biomarkers currently supports routine biomarker-guided prostate RT personalization. Future biomarker-embedded studies may benefit from domain-specific sampling considerations, explicit RT/systemic-therapy context stratification, standardized assay reporting, and clinically relevant endpoints. Full article

Background/Objectives: Psoriasis is a chronic, immune-mediated inflammatory skin disorder affecting millions of individuals worldwide. It remains a therapeutic challenge due to the limited skin penetration of many drugs, adverse systemic effects, and the need for long-term management. Transferosomal nanoformulations containing natural products were proposed as a potential therapeutic tool. Methods: Transferosomes containing 20-hydroxyecdysone and resveratrol were prepared using the thin-film hydration method followed by probe ultrasonication, generating several formulation variants differing in composition. The vesicles were characterized by dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA) to determine size, polydispersity index (PDI), and zeta potential. Furthermore, time-domain nuclear magnetic resonance (TD-NMR) relaxation measurements were employed to evaluate local molecular dynamics and membrane fluidity, providing deeper insights into the structural integrity and elasticity of the transferosomal systems. The stability of the nanoformulations was assessed for one month in water and phosphate-buffered saline (PBS). Viability was evaluated in vitro using the MTS assay on human epidermal keratinocyte (HEK) and psoriasis-patient derived human epidermal keratinocyte (PHEK) cell lines, alongside antimicrobial profiling against four representative human skin microbiome strains. Acute toxicity was further examined in vivo using the Danio rerio FET test. Results: The formulations demonstrated high physicochemical stability over the tested period, maintained desirable particle sizes within 100–200 nm, and showed no cytotoxicity toward skin-associated bacteria or in the zebrafish model. Conclusions: The developed nanoformulations present suitable properties in terms of safety and stability and can be considered for potential use in psoriasis treatment. Full article

Background/Objectives. Programmed death-ligand 1 (PD-L1) is a critical immune checkpoint protein that enables tumors to evade immune surveillance by suppressing T cell activation. Monoclonal antibodies are currently used to modulate PD-1/PD-L1 interactions. However, several immune-associated adverse effects were ascribed to those treatments. This led to the necessity for small-molecule alternatives like BMS-202. Methods. In this study, we investigated the temporal dynamics of cell-surface PD-L1 in response to the small-molecule dimerizer BMS-202. Treatment with a non-cytotoxic concentration of BMS-202 at 5 µM triggered a transient reduction in surface PD-L1 concentration, reaching its lowest level at 15 min. In the attempt to characterize the fate of PD-L1 following exposure to the BMS-202 dimerizer, we employed a low-pH wash internalization assay. Results. The results demonstrated a transient increase in intracellular PD-L1 within 5–15 min of compound exposure, followed by rapid recovery of surface PD-L1 levels. These findings suggest that BMS-202-induced changes in surface PD-L1 are acute and reversible, with levels returning to baseline within 24 h post-exposure. Conclusions. These findings reveal a dynamic regulatory mechanism where small-molecule-induced dimerization triggers rapid protein trafficking and transient surface depletion. Understanding these temporal dynamics is essential for the development of next-generation small-molecule immune checkpoint inhibitors. Full article

Background/Objectives: Chronic myeloid leukemia (CML) is a hematological malignancy driven by the constitutively active BCR-ABL1 fusion protein. Although current ABL1 tyrosine kinase inhibitors (TKIs) have improved CML management, resistance remains a major challenge, highlighting the need for novel therapeutic strategies. Methods: A chalcone derivative containing naphthalene and toluene moieties (A) was synthesized from 2-acetonaphthone and p-tolualdehyde and subsequently converted into a novel 4,5-dihydro-1H-pyrazole-1-carbothioamide derivative (B) through reaction with thiosemicarbazide. The cytotoxicity of compounds A and B against K562 CML cells was evaluated using the MTT assay. The active compound was further investigated for cytotoxic selectivity using HL-60 acute myeloid leukemia (AML) cells and healthy PBMCs. Apoptotic effects in K562 cells were analyzed using Annexin V/ethidium homodimer staining, whereas ABL1 inhibitory activity was determined using the ADP-Glo kinase assay. The potential interaction between the active compound and ABL1 was assessed by molecular docking analysis. Results: Compound B displayed potent cytotoxic activity against K562 cells with an IC₅₀ value of 6.92 ± 1.14 µM and demonstrated selectivity toward leukemic cells over PBMCs (SI = 5.4). Treatment with compound B markedly induced apoptosis in K562 cells. In addition, compound B inhibited ABL1 activity in a concentration-dependent manner. Molecular docking studies revealed a favorable binding orientation within the ATP-binding pocket of ABL1. Furthermore, in silico absorption, distribution, metabolism, and excretion (ADME) analysis predicted favorable pharmacokinetic properties for compound B. Conclusions: These findings demonstrate that compound B possesses cytotoxic, pro-apoptotic, and ABL1 inhibitory activities against CML cells and may serve as a promising lead structure for the development of novel therapeutic agents targeting CML. Full article

Background: Atypical hemolytic uremic syndrome (aHUS) is a life-threatening thrombotic microangiopathy driven by uncontrolled activation of the complement alternative pathway, with pregnancy triggering 10–20% of cases (pregnancy-associated aHUS, p-aHUS). Thalassemia, a chronic hemolytic anemia, creates a state of subclinical complement dysregulation; however, its clinical association with p-aHUS has rarely been reported. Methods: This study presents a 27-year-old primigravida with β-thalassemia intermedia requiring transfusions during pregnancy (CD17 heterozygote) who developed severe postpartum hemorrhage (1760 mL) after vaginal delivery. Over postpartum days 0–4, the patient was monitored for hematological and renal parameters. Laboratory investigations included peripheral smear, ADAMTS13 activity assay, direct Coombs test, and sC5b-9 complement level measurement. Results: Over postpartum days 0–4, the patient developed microangiopathic hemolytic anemia (hemoglobin nadir 46 g/L, lactate dehydrogenase peak 3436 U/L), thrombocytopenia (platelet nadir 31 × 10⁹/L), and acute kidney injury (creatinine peak 663 μmol/L). Peripheral smear showed 4% schistocytes. Subsequent detection revealed normal ADAMTS13 activity (90%), negative direct Coombs test, and elevated sC5b-9 (384.95 ng/mL; normal < 340). The diagnosis of p-aHUS was confirmed, and the patient received hemodialysis and recovered within three months. Conclusions: These findings suggest that chronic complement dysregulation secondary to thalassemia, combined with pregnancy-related complement stress and postpartum hemorrhage, may contribute to the development of p-aHUS. Therefore, thalassemia should be considered a potential sensitizing condition for p-aHUS, warranting close monitoring and complement evaluation in such patients. Full article

Toxoplasmosis remains a major global health concern, particularly in immunocompromised individuals and pregnant women, while currently available therapies are associated with significant toxicity and limited efficacy against chronic infection. Drug repurposing represents an attractive strategy for the identification of safer and more effective anti-Toxoplasma gondii agents. This study investigated the antiparasitic potential of loratadine, a second-generation antihistamine, using an integrated in silico, in vitro, and in vivo approach. The anti-T. gondii activity of loratadine was evaluated through β-galactosidase-based proliferation assays, reversibility assays, and experiments using pretreated tachyzoites. In vivo efficacy was assessed in murine models of acute and chronic toxoplasmosis. Disease progression, survival, parasite burden, and cerebral cyst formation were analyzed following treatment. Loratadine inhibited the intracellular proliferation of T. gondii tachyzoites in a concentration-dependent manner and induced partially irreversible effects on parasite viability after drug withdrawal. Pretreatment of extracellular tachyzoites produced limited effects, suggesting that loratadine predominantly acts during the intracellular stage of infection. In the acute toxoplasmosis model, loratadine treatment delayed disease progression, prolonged animal survival, and significantly reduced the number of tachyzoites recovered from the peritoneal cavity. In the chronic infection model, treatment significantly decreased both the number and size of cerebral cysts, although these findings do not demonstrate cyst eradication or direct bradyzoite killing. Despite its measurable biological activity, loratadine exhibited a relatively low in vitro selectivity index, highlighting the need for further optimization. These exploratory findings identify loratadine as a promising lead compound (hit) for further optimization rather than an immediately translatable therapeutic candidate. Additional medicinal chemistry, pharmacokinetic, mechanistic, and confirmatory preclinical studies will be required to determine its potential for anti-T. gondii drug development. Full article

LncRNA NR_003508 has been implicated in lipopolysaccharide (LPS)-induced acute respiratory distress syndrome. Yet, the involvement of LncRNA NR_003508 in Pseudomonas aeruginosa (PA)-induced autophagy remains elusive. This study aims to reveal the underlying mechanisms of LncRNA NR_003508 in PA-induced autophagy, thereby enhancing the basic research content of the pathogenesis of PA infection. Fluorescence in situ hybridization (FISH) probes and q-PCR revealed that PA infection induced macrophage autophagy accompanied by increasing LncRNA NR_003508, suggesting that LncRNA NR_003508 may participate in competing endogenous RNA (ceRNA)-mediated regulatory networks. Concurrently, autophagic clearance of PA requires LncRNA NR_003508. Then, we used the Gene Expression Omnibus (GEO) database to find that LC3 was considered a core protein in PA-infected autophagy. Furthermore, LncRNA NR_003508 promoted the formation of autophagosomes, which played a positive role in PA clearance. Functionally, bioinformatics analysis and luciferase reporter assays demonstrated that LncRNA NR_003508 promotes the conversion of LC3I to LC3II by sponging miR-344i and facilitates p62 degradation by binding to miR-344g-5p. Taken together, our data established that LncRNA NR_003508 enhanced the formation of autophagosomes induced by PA infection via the miR-344i/LC3 and miR-344g-5p/p62 axes, partly boosting the clearance of PA and providing a theoretical basis and experimental support for understanding the mechanisms underlying PA infection. Full article

Sodium–glucose co-transporter 2 (SGLT2) inhibitors confer cardioprotection in patients with and without diabetes; however, whether SGLT2 is expressed in cardiac tissue and how these drugs act locally in the heart remains unclear. We investigated SGLT2 expression and the effects of empagliflozin in human iPSC-derived cardiac cells exposed to diabetogenic conditions. SGLT2 expression and the effects of empagliflozin were assessed in iPSC-derived cardiomyocytes, endothelial cells, and cardiac fibroblasts under acute diabetogenic conditions using protein expression and metabolic activity assays, and in a multicellular 3D cardiac microtissue model using metabolic activity and contraction analyses. SGLT2 was detected in all three iPSC-derived cardiac cell types with nuclear and perinuclear localisation; no membrane-bound expression was observed. Endothelial cell SGLT2 expression was elevated under diabetogenic conditions. Diabetogenic stress reduced metabolic activity in both cardiomyocytes and endothelial cells; empagliflozin partially rescued endothelial cell metabolic activity but had no effect in cardiomyocytes. Empagliflozin reversed diabetogenic stress-induced cardiac fibroblast activation. 3D cardiac microtissues under diabetogenic conditions exhibited prolonged relaxation time, reduced beat rate variability, and reduced metabolic activity. Empagliflozin maintained metabolic activity at levels comparable to those of the control but did not rescue relaxation time or beat rate variability. The responsiveness of non-myocytes (endothelial cells and cardiac fibroblasts) to empagliflozin, in the absence of any effect on cardiomyocytes, suggests that non-myocyte-mediated mechanisms may contribute to the clinically observed cardioprotection of SGLT2 inhibitors. Full article

Oxybaphus himalaicus Edgew. is a traditional Tibetan medicinal plant used to treat nephritis and edema; however, its active constituents and the molecular mechanisms underlying its renoprotective properties remain poorly elucidated. This study investigated the pharmacological activity and mechanism of Boeravinone A (BA), a major constituent of O. himalaicus, in lipopolysaccharide (LPS)-induced acute kidney injury (AKI). A mouse model of LPS-induced AKI and LPS-stimulated RAW264.7 macrophages were used to evaluate the anti-inflammatory and renoprotective effects of BA in vivo and in vitro. Activity-based protein profiling (ABPP) was performed to identify potential molecular targets, followed by validation using isothermal titration calorimetry (ITC), cellular thermal shift assay (CETSA), and drug affinity responsive target stability (DARTS) assays. The functional role of the identified target was further examined using shRNA-mediated knockdown and virtual knockout analysis. BA dose-dependently attenuate LPS-induced renal injury and reduced inflammatory responses. Phosphoglycerate kinase 1 (PGK1) was identified as a direct target of BA. Mechanistically, BA activated the Kelch-like ECH-associated protein 1–nuclear factor erythroid 2-related factor 2 (Keap1–Nrf2) pathway through PGK1, enhanced the expression of antioxidant enzymes such as Nqo1, and reduced the production of pro-inflammatory cytokines, including IL-1β and IL-6. Virtual knockout of PGK1 in macrophages further supported its regulatory role in this pathway. These findings suggest that BA exerts renoprotective effects by targeting PGK1 and activating the Keap1-Nrf2 pathway, thereby reducing oxidative stress and inflammation. This study provides a pharmacological basis for the traditional use of O. himalaicus and supports BA as a potential candidate for mechanism-based intervention in AKI. Full article

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological malignancy that requires novel therapeutic targets and selective repurposed drugs with low systemic toxicity. Here, we evaluated the clinically approved M3 muscarinic receptor antagonist, Darifenacin (DF), against Jurkat and MOLT-4 T-ALL cells, as well as healthy human T lymphocytes, under identical conditions. DF induced selective, concentration-dependent cytotoxicity with IC₅₀ values of 26.7 ± 1.07 µM (Jurkat) and 30.5 ± 1.54 µM (MOLT-4), whereas healthy T lymphocytes exhibited an apparent IC₅₀ of 197.9 ± 1.29 µM, corresponding to a 6.5–7.4-fold therapeutic window. Mechanistically, DF decreased M3 receptor and choline acetyltransferase expression and increased acetylcholinesterase activity. Convergent multi-assay validation confirmed that this cytotoxicity was driven by activation of the intrinsic mitochondrial apoptotic pathway, as evidenced by increased Bax, decreased Bcl-2, and cleavage of the executioner caspase-3. Furthermore, DF induced glycative stress through the accumulation of methylglyoxal (MG) and advanced glycation end products (AGEs), and selectively inhibited lysosomal Cathepsins B and C. Molecular docking predicted highly favorable molecular binding within the catalytic cavities of these proteases. These findings suggest that DF exhibits selective antileukemic activity by simultaneously disrupting cholinergic signaling, inducing glycative stress, inhibiting cathepsins, and triggering apoptosis. Thus, DF emerges as a promising candidate for multi-target drug repurposing in T-ALL therapy. Full article

Curcumin, a natural polyphenol with well-established antioxidant and anti-inflammatory properties, was evaluated for its protective effects against glyphosate (GLY)-induced mammary toxicity. Pregnant mice received GLY (50 or 250 mg/kg/day) with or without curcumin (150 mg/kg/day) by oral gavage; GLY dose-dependently disrupted alveolar architecture, caused marked inflammatory infiltration, and downregulated tight-junction proteins. In parallel, goat mammary epithelial cells (GMECs) were treated with GLY (1 or 7 mM) and curcumin (1 µM) to dissect acute cellular stress pathways. These complementary models address distinct aspects of GLY toxicity: the in vivo system reflects defined oral exposure, whereas the in vitro setting employs high concentrations to probe mechanistic events. Transcriptomic profiling combined with functional assays demonstrated that GLY triggered oxidative stress, endoplasmic reticulum stress, and intracellular Ca²⁺ overload, activated the TNFα/MAPK axis, suppressed STAT3 phosphorylation, and ultimately promoted apoptosis. Curcumin co-treatment alleviated these alterations at both structural and molecular levels. These findings indicate that curcumin can combat GLY-induced mammary injury by restoring cellular homeostasis and inhibiting apoptotic and inflammatory signaling, thereby protecting breast health. Full article

Distinguishing tuberculous spondylodiscitis (TS) from pyogenic spondylodiscitis (PS) remains difficult when presentation is non-specific, blood cultures are negative, or initial biopsy is non-diagnostic. The two entities differ substantially in antimicrobial strategies, resistance testing requirements, public health interventions, and surgical thresholds, yet diagnostic delay is associated with neurological deficits, spinal instability, and permanent deformity. This narrative review maps the non-imaging evidence most useful for frontline differentiation between TS and PS across five domains: epidemiology and risk stratification, clinical presentation, laboratory markers, tissue acquisition and histopathology, and molecular diagnostics. PubMed/MEDLINE was searched from inception to 31 March 2026 using pre-specified Boolean search terms; a secondary Scopus search identified no additional eligible records. Following screening, approximately 90 records were included in this synthesis. Priority was given to comparative TS-versus-PS cohorts, biopsy-yield and culture-negative studies, pathology series, pediatric data, and recent molecular diagnostics literature. Epidemiological TB (tuberculosis) risk, longer symptom duration, constitutional symptoms, deformity, and a less intense acute-phase response increase the probability of TS, whereas healthcare exposure, bacteraemia, recent spinal procedures, and brisk neutrophilic inflammation favor PS. In stable patients, the highest-yield strategy is early blood cultures followed by image-guided biopsy with parallel tissue allocation for bacterial culture, mycobacterial studies, histopathology, and selected molecular assays. No single laboratory marker reliably distinguishes TS from PS without tissue confirmation. Per a 2023 systematic review and meta-analysis, image-guided percutaneous biopsy achieves microbiological confirmation in approximately one-third of cases. Histopathology demonstrating caseating granulomatous inflammation supports TS, although a substantial minority of confirmed cases lack classic features. Supported by cohort prospective data, Xpert MTB/RIF Ultra has the clearest first-line molecular role when TS is plausible and should be requested at the time of first biopsy rather than reserved for salvage testing; broader or targeted next-generation sequencing is best reserved for selected unresolved cases. Imaging differentiation is addressed in the companion manuscript, Part II. Full article

Background/Objectives: The lack of effective antiviral therapies for many viral infections highlights the need for the development of new antiviral agents. The broad antiviral effects of glycopeptide antibiotics (GPAs) and their derivatives have been previously described. In our studies, we investigated the in vitro viral inhibitory activity of newly synthesized GPA derivatives against Zika virus (ZIKV), chikungunya virus (CHIKV), o’nyong-nyong virus (ONNV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods: Antiviral activity (EC50) and cytotoxicity (CC50) of the active compounds were determined using cell-based assays. The mechanism of action of the lead compound was investigated using binding and entry assays, cell-free virion pre-incubation, a virion destabilization assay, a liposome-based capsid protection assay, and molecular docking analysis. Results: Seven of the compounds were able to inhibit ZIKV and two compounds inhibited all four tested viruses. Among them, a teicoplanin pseudoaglycone derivative, compound 7, showed the strongest antiviral activity, inhibiting all four viruses at low micromolar concentrations. Mechanistic studies demonstrated that compound 7 acts during an early stage of ZIKV infection and inhibits low-pH-triggered virus–liposome fusion. Molecular docking analysis suggested potential interactions between compound 7 and the viral envelope protein that could interfere with the conformational rearrangements required for membrane fusion. Conclusions: The present findings demonstrate that hydrophobic GPA derivatives, particularly compound 7, exhibit promising broad-spectrum antiviral activity in vitro. Whether similar mechanisms contribute to the antiviral activity against other viruses remains unknown. The studied GPA derivatives are promising candidates for further pre-clinical and clinical development as broad-spectrum antivirals. Full article