Search Results (8,336)

Background/Objectives: The emergence of methicillin-resistant Staphylococcus aureus (MRSA) necessitates innovative strategies to overcome conventional resistance mechanisms. This study investigated the potential of the natural flavonolignan silibinin (SIL) as an antivirulence agent against S. aureus, with a particular emphasis on its putative multi-target antibacterial activity and its capacity to potentiate the effects of ciprofloxacin (CIP). Methods: The antibacterial and antivirulence properties of SIL were assessed using both in vitro and in silico approaches. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined, and its synergistic interaction with CIP was evaluated using checkerboard assays. Inhibition of biofilm formation, as well as disruption of established biofilms, was assessed using an MTT-based viability assay. Staphyloxanthin (STX) inhibition was examined through pigment extraction and spectrophotometric quantification of pathway intermediates. Molecular docking studies were conducted to predict the binding affinities of the compounds to key bacterial targets, while safety was evaluated through haemolytic and cytotoxicity assays. Results: SIL exhibited weak to moderate direct antibacterial activity (MICs of 256–512 µg/mL), which is characteristic of many natural product scaffolds. Notably, SIL potentiated the activity of CIP, reducing its MIC by up to fourfold against selected resistant strains of S. aureus. SIL significantly inhibited biofilm formation and disrupted established mature biofilms in a strain-dependent manner. In vitro metabolic profiling and in silico analyses provided mechanistic insights into the effects of SIL on STX biosynthesis. Precursor accumulation data suggest inhibition at the diapophytoene desaturase (CrtN) catalytic step, representing a potential mechanism not previously reported for flavonolignans. Molecular docking studies further predicted favourable binding affinities for CrtM and other key targets. Importantly, SIL exhibited no haemolytic activity and low cytotoxicity in macrophages at synergistic concentrations. Conclusions: This study provides evidence that SIL functions as a dual-action agent, potentiating ciprofloxacin efficacy while reducing STX production and inhibiting biofilm formation, thereby impairing key virulence mechanisms of S. aureus. These findings, together with its favourable safety profile, provide a strong rationale for the development of silibinin-based topical adjuvants to combat drug-resistant Staphylococcus infections in humans. Full article

Siponimod, a selective sphingosine 1-phosphate (S1P) receptor modulator, represents a next-generation therapeutic drug for active secondary progressive multiple sclerosis. This study conducted in-depth forced degradation studies of siponimod in solid state subjected to acidic, alkaline, oxidative, photolytic, and thermal conditions, in compliance with ICH guidelines Q1A (R2) and Q3A (R2). An HPLC method was developed to quantify siponimod and separate its degradation products (DPs). The DPs were characterized using LC-HRMS/MS and LC-MSⁿ techniques. Moreover, the toxicological profiles of siponimod and its DPs were evaluated through the in silico tools ProTox 3.0 and ADMETlab 3.0, with molecular docking and dynamics simulations assessing their binding to the S1P1 receptor. Siponimod was stable to light but degraded under acidic, alkaline, oxidative, and thermal stress, producing five products: DP-1 (acidic), DP-2/3 (oxidative), DP-4 (hydrolytic), and DP-5 (thermal). The toxicity prediction suggested that neither siponimod nor its DPs exhibited carcinogenic or mutagenic potential, and the molecular modeling analysis revealed that DP-2 and DP-3 demonstrated favorable binding affinities, with stable dynamic profiles and thermodynamic properties that closely resembled those of siponimod. As far as we know, this is the first study on the structural elucidation of the DPs of siponimod by LC-HRMS/MS and LC-MSⁿ. Full article

Background/Objectives: Haemoadsorption has recently emerged as an extracorporeal treatment option for sepsis, septic shock, intoxications, and cardiac surgery to modulate dysregulated inflammatory responses or remove a wide range of circulating molecules. To ensure appropriate clinical use of the CytoSorb^® haemoadsorber, it is essential to understand the extent to which specific drugs are adsorbed by the device. Methods: We conducted a systematic literature review using the PubMed and Ovid MEDLINE database to identify studies on drug binding to the CytoSorb^® haemoadsorber, including both in vivo and in vitro studies. Publications in English language, available up to 31 December 2025 that reported or enabled calculation of percentage of drug removal, CytoSorb^® clearance or half-life during CytoSorb^® therapy were included. Records were screened, eligibility and quality were assessed, and data were extracted independently by two reviewers. Results: We found that 26 studies reported on the binding of 56 drugs to CytoSorb^®, with most available information relating to antibiotics used in the treatment of sepsis and septic shock. CytoSorb^® appears to remove vancomycin and linezolid but not meropenem, although data for other antibiotics are insufficient to assess clinical relevance. Data on the removal of anticoagulant and antithrombotic drugs with CytoSorb^® before and during cardiac surgery indicate that using this procedure to reduce complications associated with apixaban and ticagrelor is feasible and safe. The available evidence on the use of CytoSorb^® for drug poisoning is of very low quality. Conclusions: Although the number of studies on drug binding to the CytoSorb^® is increasing, the review is limited by the marked heterogeneity among the included studies. It is advised to use therapeutic drug monitoring whenever possible during CytoSorb^® treatment. Research of binding of drugs to CytoSorb^® is crucial for its safe and effective clinical use, but adequate methodology is necessary. Full article

Hyperthermic intraperitoneal chemotherapy (HIPEC) for colorectal peritoneal metastases relies primarily on DNA-damaging agents whose efficacy depends on sustained cytotoxic exposure. Whether brief treatment can induce durable transcriptional remodeling remains unclear. Mithramycin A (MA) is a GC-rich DNA-binding agent with transcriptional regulatory activity involving chromatin-associated pathways. Here, we investigated the molecular and functional consequences of a single 90-min HIPEC-mimetic MA exposure in colorectal cancer models. RNA sequencing revealed extensive and coordinated transcriptional remodeling, affecting a substantial fraction of expressed genes and producing a response qualitatively distinct from mitomycin C. MA selectively suppressed key chromatin-associated regulatory factors, including DNMT1, JARID2, and HDAC4, while coordinately activating canonical cyclin-dependent kinase inhibitors CDKN1A, CDKN1C, and CDKN2C. Gene set enrichment analysis demonstrated enrichment of G2/M checkpoint pathways and suppression of oncogenic gene networks. These molecular changes translated into sustained inhibition of clonogenic growth and activation of caspase-dependent apoptosis following drug washout, with hyperthermia potentiating apoptotic signaling. Collectively, these findings indicate that brief MA exposure induces selective modulation of chromatin regulators and durable transcriptional reorganization, supporting modulation of chromatin regulatory networks as a potential therapeutic strategy for HIPEC-based colorectal cancer therapy. Full article

Helicobacter pylori urease is a key virulence factor and a validated target for anti-infective strategies. In this study, a comprehensive computational workflow was applied to identify potential urease inhibitors through a drug repurposing approach. A curated library was first filtered using permeability-related descriptors and multiparametric scoring. The resulting compounds were evaluated through ensemble and consensus docking across multiple protein conformations and docking engines, followed by XP rescoring, metal–ligand distance analysis, and molecular dynamics simulations. Binding stability and thermodynamic profiles were further assessed using MM-GBSA and well-tempered metadynamics. This integrative strategy led to the identification of several candidate compounds exhibiting favorable docking scores, stable coordination with the catalytic Ni²⁺ center, and consistent binding behavior during molecular dynamics simulations. Notably, selected compounds showed improved relative binding free energy profiles compared to reference inhibitors within the applied computational framework. Overall, this study provides a robust computational pipeline for urease inhibitor identification and highlights repurposed compounds as promising candidates for further experimental validation. Full article

We utilized molecular dynamics (MD) simulations to explore the interaction of the RGD peptide with the αvβ3 integrin receptor, a key process for targeted drug delivery to tumors. The goal of these simulations was to model the transport of boron atoms by the RGD peptide and to characterize the binding event between this vector and its receptor. The study focused on the interaction processes and spatial arrangements of the solvated RGD–integrin system. Simulations were run for 100 ns to achieve relaxed-state configurations. Our model featured two RGD peptides: one pre-localized within the integrin’s binding site and another initially positioned externally. The external peptide was observed to diffuse freely and subsequently bind to the αvβ3 integrin. This spontaneous binding event provides valuable insights into the pharmacological specificity and mechanisms of the RGD–integrin interaction, informing the design of effective drug delivery systems. Full article

Background: Hepatitis B virus (HBV) infection continues to be a major public health concern, especially in sub-Saharan Africa, where widespread epidemics and restricted availability of long-term antiviral therapies result in higher mortality and morbidity rates. Drug repurposing represents a strategic approach to accelerate the discovery of effective therapies by leveraging agents with demonstrated antiviral and immunomodulatory activity. Product Nkabinde (PN) is a patented African polyherbal formulation initially developed for the treatment of HIV. Recent experimental studies demonstrate PN’s potent anti-HIV activity and significant immunomodulatory effects in human immune cells, implicating host-directed mechanisms relevant to chronic viral infections. This study combines an integrative application of network pharmacology and molecular docking to evaluate the repurposing potential of PN as a multi-target agent in HBV. Method: Bioactive components of PN were screened, and compound-associated targets were intersected with HBV-associated genes (proteins) to construct a protein–protein interaction (PPI) network. Topological analysis identified 10 hub targets (STAT1, STAT3, SRC, HCK, EGFR, SYK, PIK3CA, PIK3CB, PIK3R1, and PTPN11). Gene Ontology and KEGG pathway enrichment were performed with an FDR cut-off < 0.05. Significantly enriched pathways included JAK–STAT signaling, chemokine signaling, EGFR-TKI resistance, PI3K complex signaling, and viral infection pathways, particularly those related to Kaposi sarcoma virus and HSV-1, indicating immunoregulatory and antiviral roles. Molecular docking was performed using AutoDock Vina 1.1.2 to evaluate binding affinity and interaction mode of key PN phytochemicals against the hub proteins, and results were compared to their respective co-crystallized ligands. Results: Molecular docking indicated that major phytochemicals from PN exhibited significant binding affinities across all 10 hub host targets, typically outperforming or closely matching their respective co-crystallized ligands. The strongest contacts were observed for β-sitosterol–PIK3CB (−14.2 kcal/mol) and oleanolic acid–SYK (−14.0 kcal/mol), which were significantly stronger than the co-crystallized ligands (−7.9 and −8.3 kcal/mol, respectively), indicating robust stabilization within catalytic and regulatory pockets. Procyanidin B2 toward HCK (−10.5 vs. −7.9 kcal/mol) and PIK3CA (−9.5 vs. −7.3 kcal/mol), quercetin toward PIK3R1 (−10.6 vs. −8.2 kcal/mol) and PTPN11 (−9.2 vs. −7.5 kcal/mol), rutin toward SRC (−10.5 vs. 7.8 kcal/mol), and diosgenin toward EGFR (−9.4 vs. 8.4 kcal/mol). Procyanidin B2 maintained robust multi-hydrogen bonding networks, demonstrating significant binding, despite STAT1 and STAT3 docking showing identical affinities to co-crystals. Conserved hydrogen bonds, π–cation interactions, and significant hydrophobic packing at ATP-binding clefts and regulatory domains supported these interaction patterns, indicating competitive suppression of host signaling nodes taken over by HBV. Conclusions: Together, these results demonstrate that the components of PN possess strong multitarget binding capabilities across the PI3K/AKT, JAK–STAT, SRC-family kinase, EGFR, and SYK pathways, supporting their potential repurposing as host-directed HBV therapeutics with the ability to impede immune evasion, viral persistence, and HBV-associated oncogenic progression. Full article

Drug resistance remains a major challenge in epilepsy, and overexpression of ATP-binding cassette transporters, particularly P-glycoprotein (P-gp), at the blood–brain barrier (BBB) has been consistently implicated in limiting central nervous system drug exposure. Genetic experimental models suitable for investigating molecular regulation and functional alterations of P-gp in epilepsy remain scarce. This study evaluated P-gp expression and functional alterations in the Wistar Audiogenic Rat (WAR), a genetic model of epilepsy exhibiting phenotypic heterogeneity. WAR animals were classified into refractory epilepsy (WAR-RE) or temporal lobe epilepsy (WAR-TLE) phenotypes and compared with non-epileptic Wistar controls. Fexofenadine, a well-established in vivo P-gp probe substrate, was administered orally, and plasma pharmacokinetic parameters were determined. P-gp expression at the BBB was assessed by immunohistochemistry in hippocampal regions. WAR-RE animals exhibited significantly increased systemic exposure to fexofenadine, characterized by higher area under the curve and prolonged half-life, alongside reduced apparent clearance, compared with control animals (p < 0.05). In contrast, WAR-TLE animals showed greater interindividual variability without statistically significant differences. Immunohistochemical analysis revealed increased P-gp expression in hippocampal microvessels in both WAR phenotypes. These findings demonstrate that the WAR model displays molecular upregulation of P-gp at the BBB, accompanied by functional alterations in the disposition of a prototypical P-gp substrate. Although direct brain drug concentrations were not assessed, the integration of systemic pharmacokinetics with transporter expression supports the use of WAR as a genetic proof-of-concept model for studying P-gp regulation and transporter-mediated drug disposition in epilepsy. This model provides a valuable molecular framework for future investigations addressing transporter modulation and mechanisms underlying pharmacoresistance. Full article

Oxidative stress is intrinsically linked to mental disorders, involving an imbalance between reactive species and antioxidant defenses, where catalase is an essential, ubiquitous antioxidant enzyme. The pleiotropic effects of antipsychotic drugs, used for schizophrenia and mood disorders, are not fully elucidated at the molecular level. This study characterized the binding of a highly effective but potentially dangerous antipsychotic, clozapine (CLZ), to commercial bovine liver catalase (BLC). Using various spectroscopic methods under simulated physiological conditions, we found a moderate binding affinity of CLZ for BLC (K_a = 1.4 × 10⁻⁵ M⁻¹), subtly influencing the protein’s secondary and tertiary structures and slightly increasing its thermal stability. CLZ efficiently protected BLC against free-radical-induced oxidation and preserved its catalytic activity for decomposing toxic hydrogen peroxide. The effect of CLZ on BLC antioxidant activity was dual: no significant effect at lower, physiologically relevant concentrations, but significant inhibition at saturating, toxic drug concentrations. Molecular docking and molecular dynamics results indicated the presence of two specific binding sites within BLC monomers, one located near its active site. In conclusion, our in vitro results indicate that CLZ’s specific binding to BLC can be both beneficial and potentially harmful, and that this effect is dose-dependent. Full article

Pharmacological inhibition of the nucleoside transporter hENT1 is a promising therapeutic target across a range of diseases, including cardiovascular disorders, neurodegenerative conditions, and cancer. However, current inhibitors lack drug-like properties, necessitating the development of new inhibitors with improved pharmacological profiles. We employed a dual-pharmacophore virtual screening protocol to identify putative hENT1 inhibitors from a library of over 2 million compounds, followed by structure-based molecular docking. To validate the inhibition effect of the lead compounds, we established a functional assay using gemcitabine (GEM)-induced cytotoxicity as a readout of hENT transport activity using eight cancer cell lines. H292 was the optimal cancer cell line for the validation assay based on its high GEM sensitivity (IC50 = 28 nM) and the concentration-dependent cytotoxicity inhibition of the reference inhibitor NBTI, a hENT1 inhibitor. Of the 19 candidate compounds, two leads (compounds 2 and 3) demonstrated potency comparable to NBTI, increasing GEM IC50 values by 2.2- and 2.9-fold at 5 µM, respectively. Both compounds were non-cytotoxic to normal fibroblasts, exhibited favorable ADME properties, displayed superior docking scores of −12.63 and −12.49 kcal/mol compared to NBTI (−9.06 kcal/mol), and displayed a novel vertical binding orientation within the hENT1 binding pocket distinct from NBTI’s horizontal mode. This study established a validated non-radioactive, gemcitabine-based functional assay for hENT inhibitor discovery and identified two putative inhibitors with therapeutic potential for cancer chemosensitization, pain management, and cardio- and neuroprotection. The non-radioactive functional assay overcomes the limitations of traditional radiolabeled methods, enabling scalable, broader screening applications. Full article

Background/Objectives: Protein kinases play a crucial role in cancer initiation, progression, and therapeutic resistance by regulating signalling pathways involved in tumour growth and survival. Consequently, they represent major targets in anticancer drug discovery. Among heterocyclic scaffolds explored in kinase inhibitor design, benzimidazole has emerged as a privileged structure due to its strong hydrogen-bonding capability and structural resemblance to purine moieties. Triazole motifs are also widely incorporated into bioactive molecules because of their metabolic stability, favourable electronic properties, and ability to establish key interactions within kinase active sites. This review aims to summarise and critically discuss benzimidazole- and triazole-based kinase inhibitors, both as individual scaffolds and as hybrid systems, with emphasis on their kinase targets and multitarget potential. Methods: The relevant literature was surveyed from major scientific databases focusing on studies describing the synthesis, biological evaluation, and molecular modelling of benzimidazole- and triazole-containing kinase inhibitors. Results: Numerous studies demonstrate that both benzimidazole and triazole scaffolds exhibit significant kinase inhibitory activity against oncogenic targets, including EGFR, cyclin-dependent kinases (CDKs), and components of the PI3K/Akt/mTOR signalling pathway. Hybrid molecules combining these pharmacophores frequently enhance binding interactions and facilitate the development of multitarget kinase inhibitors. Structure–activity relationship trends indicate that pharmacophore accessibility, substitution patterns, and linker architecture influence inhibitory potency and selectivity. Conclusions: Overall, benzimidazole- and triazole-based scaffolds represent promising platforms for developing next-generation multitarget anticancer agents and provide valuable insights for the rational design of improved kinase inhibitors. Full article

Background: Lung cancer recurrence and metastasis are major causes of cancer-related mortality, but the molecular determinants underlying these processes remain incompletely understood. This study aimed to identify key regulators of lung cancer progression through integrative analyses of bulk and single-cell transcriptomic datasets. Methods: Bulk transcriptomic and single-cell RNA sequencing data from multiple cohorts were integrated to identify genes associated with survival, recurrence, and metastasis. Tumor microenvironment features were further analyzed to prioritize core progression-related genes. ANLN was subsequently evaluated in independent single-cell datasets, followed by functional validation using CRISPR–Cas9-mediated gene knockout in lung cancer cells. Network-based drug prediction and molecular docking were performed to identify candidate compounds targeting ANLN-related programs. Results: ANLN was identified as a core progression-related gene associated with poor prognosis. ANLN was upregulated in recurrent and metastatic lung tumors and correlated with worse overall survival. Single-cell analyses showed that ANLN was predominantly expressed in epithelial and proliferating tumor cells and was associated with microenvironment remodeling, enhanced proliferative and migratory programs, and progression toward an invasive phenotype. These findings were validated in an independent single-cell dataset capturing the transition from in situ to invasive lung cancer. Functional experiments showed that ANLN deletion reduced proliferation and promoted apoptosis in lung cancer cells. Drug prediction and molecular docking identified several candidate compounds, among which Trifluridine and Monobenzone showed favorable binding potential and pro-apoptotic effects in lung cancer cells. Conclusions: ANLN is a potential regulator of lung cancer recurrence and metastasis and marks a conserved invasion-prone epithelial state. ANLN-associated pathways may represent potential therapeutic targets in lung cancer. Full article

The ATP-binding cassette subfamily G member 2 (ABCG2), also known as breast cancer resistance protein (BCRP), is an efflux transporter expressed in key pharmacokinetic tissues and biological barriers. It regulates exposure to many endogenous compounds, drugs, and environmental toxins. Genetic variability in ABCG2 has been recognised as an important contributor to interindividual variability in drug response, especially in terms of efficacy and toxicity. This narrative review summarises current knowledge on the clinical relevance of ABCG2 genetic variants, with a focus on their effects on pharmacokinetics, adverse drug reactions and drug–drug–gene interactions, as well as their potential implementation in personalised therapy. A literature search was performed in PubMed, Scopus and the Clinical Pharmacogenomics Database (ClinPGx), with an emphasis on clinically relevant studies and available pharmacogenomic guidelines. The most investigated ABCG2 variant, c.421C>A (rs2231142; p.Gln141Lys), is consistently associated with reduced transporter activity and increased systemic exposure to several substrate drugs, including statins, allopurinol and anticancer agents, which may influence both treatment response and the risk of toxicity. Although growing evidence supports the clinical relevance of ABCG2 genotyping, its routine implementation remains limited. Integration of ABCG2 variability into polygenic models and clinical decision-support tools may further improve individualised treatment, particularly in patients with multimorbidity and polypharmacy. Full article

Background: Rett Syndrome (RTT) is a progressive neurodevelopmental disorder caused by MECP2 gene mutations. MeCP2 protein binding to methylated DNA is involved in normal brain development and function. T158M is a common RTT-associated mutation, where a threonine is replaced with a methionine, affecting protein function and stability. RTT has recently been identified as a neurometabolic disorder, with metformin emerging as a potential candidate drug. Metformin is a safe and accessible drug, commonly used for Type 2 diabetes. Our team previously studied the regulatory role of metformin on the expression of RTT-related genes/proteins using in vitro and in vivo approaches. However, the phenotypical and behavioral impact of metformin in transgenic mice carrying the common T158M mutation was not explored. Methods: Wild type (WT) and mutant Mecp2^T158M (Mecp2^tm4.1Bird) male mice were subjected to daily intraperitoneal injection of metformin for 20 days. The control mice received a daily intraperitoneal injection of the solvent. The main RTT-like phenotypical criteria were assessed daily. Behavioral tests included the open field test and elevated plus maze. Results: Behavioral tests indicated no significant effect of metformin on the anxiety levels, locomotion, and exploratory behaviors in the hemizygous male Mecp2^T158M mice, despite our observation of increased anxiety levels in the WT counterparts. In hemizygous male Mecp2^T158M mice, metformin treatment showed beneficial effects on RTT-like phenotypes, including breathing irregularities, gait abnormalities, hindlimb clasping, and overall total score. The positive effect of metformin was also observed on the body weight in the hemizygous male Mecp2^T158M mice. Conclusions: Our findings provide evidence for potential therapeutic effects of metformin for MeCP2-associated neurological disorders. Full article

Theaflavin-3,3′-digallate (TF3), a flavan-3-ol derivative found in black tea, exhibits anti-tumor activity, but its mechanism of action in hepatocellular carcinoma (HCC) remains to be elucidated. Here we systematically delineate how TF3 targets Pin1 to suppress HCC through an integrated approach combining computational simulations, enzyme assay and cell-based assays. TF3 spontaneously occupies the active site of Pin1 with a docking score of −8.9 kcal/mol, inhibiting its PPIase activity (IC₅₀ = 60.33 μmol/L) and yielding a binding constant (K_a) of 3.1 × 10⁵ mol/L. Drug affinity responsive target stability (DARTS) assays further corroborated that TF3 directly engages Pin1 within HCC cells. Functionally, TF3 potently suppressed the viability of HepG2, SK-Hep-1 and Huh-7 cells in both dose- and time-dependent manners (IC₅₀ = 61.22, 14.09 and 69.85 μmol/L at 24 h, respectively), and exhibited a modest selectivity window against the viability of L02 and THLE-2 cells (IC₅₀ = 133.43 and 90.29 μmol/L at 24 h, respectively). In addition, TF3 triggers mitochondrial-mediated apoptosis, evidenced by ROS accumulation, loss of mitochondrial membrane potential, an elevated Bax/Bcl-2 ratio, cytochrome c release and enhanced PARP cleavage, and induces G₂/M phase arrest. It also robustly inhibits HCC cell proliferation, invasion and migration, coinciding with downregulation of proteins governing cell cycle progression and invasive behavior. Transcriptome profiling coupled with enrichment analysis discovered that TF3 treatment differentially regulated 5009 genes, which were prominently enriched in pathways linked to apoptosis, cell cycle control, MAPK and PI3K/AKT signaling pathways. Western blotting analysis revealed that TF3 selectively suppresses phosphorylation of p38 and the PI3K/AKT cascade, activating JNK phosphorylation. In summary, our findings indicate that TF3 suppresses HCC proliferation by targeting Pin1, with attendant modulation of the MAPK and PI3K/AKT pathways, thereby presenting a potential candidate for targeted HCC therapy. Full article