Search Results (570)

Background: Metabolic syndrome is characterized by dysregulated glucose metabolism and is a major risk factor for type 2 diabetes mellitus and cardiovascular disease. Although glucose-lowering therapies such as glucagon-like peptide-1 receptor (GLP-1R) agonists are effective, their use may be limited by cost, administration route, side effects and tolerability. Bergamot (Citrus bergamia Risso et Poiteau) extract, rich in flavanones, has shown favorable metabolic effects in clinical studies, although its mechanisms of action remain insufficiently defined. This study aimed to investigate the potential glucose-modulating mechanisms of a standardized phospholipid-formulated bergamot extract (BP) (Vazguard™) in vitro. Methods: GLP-1R activation was assessed in a U2OS cell line expressing cyclic adenosine monophosphate (cAMP)-sensitive Nomad Biosensors™. Dipeptidyl peptidase-4 (DPP4) activity was evaluated using a cell-free enzymatic assay, while Glucose transporter type 4 (GLUT4)-mediated glucose uptake was assessed in CHO-K1 cells stably expressing human GLUT4 using an adenosine triphosphate (ATP)-based readout. Cytotoxicity was also using lactate dehydrogenase (LDH), MTT, and nuclei count assays. Results: BP exhibited a dose-dependent (0.31–5 mg/mL) increase in cAMP biosensor fluorescence, consistent with GLP-1R-associated signaling and a maximal response of approximately 60% relative to the positive control (GLP-1R agonist II). No cytotoxic effects were observed. In contrast, BP showed no inhibitory effect on DPP4 activity and did not alter GLUT4-mediated glucose uptake under the experimental conditions tested. Conclusions: These findings provide novel mechanistic evidence that phospholipid-formulated bergamot extract suggests a possible involvement in GLP-1R-associated signaling in vitro, without detectable effects on DPP4 or GLUT4 pathways under the conditions tested. This suggests a mechanism consistent with weak agonist or allosteric modulation of GLP-1R and supports further investigation of bergamot formulated with phospholipids as potential natural adjuncts in metabolic health management. Full article

Coronavirus disease 2019 continues to pose global health challenges, with the pandemic significantly burdening several economies, healthcare systems, and the social lives of individuals. Furthermore, new cases continue to be reported, underscoring the need for therapeutic strategies targeting conserved regions and host–virus interactions. Building on earlier virtual screening for small molecules, all-atom molecular dynamics simulations and binding-free-energy calculations were performed to elucidate how the two previously identified small molecules (NSC36398 and NSC281245) may affect the dynamic behaviour of the interaction between heat shock 70 kDa protein 8 (HSPA8) and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike glycoprotein. Post-MD analyses refined prior docking predictions, where NSC281245 was found to bind tightly to the complex with limited perturbations at the HSPA8-spike protein interaction surface, whereas NSC36398 appeared to induce allosteric-like domain-level destabilisation effects while maintaining stable polar contacts with the protein. Our findings demonstrate the potential of NSC36398 as a promising modulator for disrupting the HSPA8-spike protein complex, which may serve as a structural lead for designing next-generation inhibitors of host–virus interactions. Full article

GM1 gangliosidosis and Morquio B are rare lysosomal storage disorders (LSDs) with significant unmet medical needs. These disorders result from mutations in the galactosidase beta 1 (GLB1) gene, leading to impaired β-galactosidase (β-Gal) activity and toxic substrate accumulation. The lack of approved disease-modifying therapies for GM1 gangliosidosis and Morquio B, along with the challenges of achieving effective central nervous system delivery, has driven interest in small-molecule pharmacological chaperones (PCs) to restore β-Gal stability and function. Using Gain Therapeutics’ Magellan™ platform, a novel allosteric binding site on β-Gal was identified, enabling the discovery of a new class of Structurally Targeted Allosteric Regulators (STARs). Medicinal chemistry optimization produced a structurally unique STAR compound series, demonstrating broad β-Gal stabilizing effects. The therapeutic potential of these compounds was evaluated in vitro using a canine fibroblast model of GM1 gangliosidosis, where they were shown to significantly reduce toxic GM1 ganglioside accumulation. Immunocytochemistry-based assays confirmed substrate clearance and provided reliable structure–activity relationships, guiding further compound development. Notably, STARs achieved greater substrate clearance than the competitive PC N-nonyl-deoxygalactonojirimycin (NN-DGJ) under the conditions tested, as demonstrated by immunocytochemistry-based assays. While these findings are encouraging, further in vivo studies are required to validate the therapeutic efficacy of these few STAR compounds, particularly in addressing the neurodegenerative aspects of GM1 gangliosidosis. This study underscores the potential of the Magellan platform in identifying STAR molecules and provides a strong foundation for further optimization and preclinical validation in GLB1-related disorders, particularly GM1 gangliosidosis. Full article

Galectin-3 (Gal3) is one of the most pro-inflammatory proteins and a biomarker of inflammatory diseases and cancer. Previous studies showed that Gal3 binds to αv and β1 integrins, but it is unclear how Gal3 binds to integrins. Here, we show that Gal3 bound to soluble αvβ3 and αIIbβ3 integrins in 1 mM Mn²⁺ in cell-free conditions in a glycan-independent manner. Docking simulation predicts that Gal3 binds to the classical RGD-binding site (site 1) of αvβ3, but the predicted Gal3-binding site does not include galactose-binding site. RGDfV or eptifibatide inhibited Gal3 binding to αvβ3 and αIIbβ3, respectively, but lactose, a pan-galectin inhibitor, did not inhibit Gal3 binding to integrins. Point mutations of the predicted site 1 binding interface of Gal3 effectively inhibited Gal3 binding to site 1. Site 2 is involved in pro-inflammatory signaling (e.g., TNF and IL-6 secretion), and we previously showed that pro-inflammatory cytokines (e.g., CCL5 and TNF) bind to site 2 and allosteric integrin activation. Docking simulation predicted that Gal3 binds to site 2 of αvβ3 and α5β1. We found that Gal3 induced allosteric activation of soluble integrins αvβ3, αIIbβ3, and α5β1 in 1 mM Ca²⁺ in cell-free conditions. Point mutations in the predicted site 2 binding interface inhibited Gal3-induced integrin activation, suggesting that Gal3 binding to site 2 is required for Gal3-induced integrin activation. Known anti-inflammatory agents, Ivermectin, NRG1, and FGF1, inhibited integrin activation induced by Gal3 in αvβ3 and αIIbβ3. These findings suggest that Gal3 binding to site 2 may be a potential mechanism of pro-inflammatory and pro-thrombotic action of Gal3. Full article

Neuroinflammation is determinant in the progression of neurodegenerative diseases. One of the main mechanisms underlying this process involves the persistent activation of glial cells. Persistent activation of glial cells induces proinflammatory transcription factors and the release of cytokines, chemokines, and reactive oxygen species that exacerbate cellular dysfunction. This neurotoxic environment promotes neuronal death, while the products of cellular damage feed back into glial activation, establishing a self-sustaining pathogenic cycle that drives neurodegeneration. Alkaloids present in Amaryllidaceae plants support the use of this resource in folk medicine, displaying potent effects as acetylcholinesterase inhibitors and allosteric modulators of nicotinic receptors (nAChR). In this study, a murine microglial cell (IMG) model of LPS-induced inflammation was used to evaluate the involvement of α7 and α4β2 nAChRs in glioprotection and neuroprotection of SH-SY5Y cells against 6-hydroxydopamine (OHDA). GC-MS analysis revealed differences in the alkaloid profile between in vitro cultures with fructose and wild-type Rhodophiala pratensis. Homolycorine-type, norbelladine-type and crinine-type alkaloids produced in vitro reduced LPS-induced inflammation (5 µg/mL), possibly via α7 and α4β2 nAChRs, and showed a protective effect against OHDA-induced oxidative stress (1–3 µg/mL) and inhibited AChE and BuChE (24–78 µg/mL). Full article

Fungal contamination during postharvest storage causes significant food losses, particularly due to Penicillium expansum and Penicillium brevicompactum, highlighting the need for sustainable antifungal alternatives. This study evaluated the antifungal potential of clove essential oil (Syzygium aromaticum) against P. expansum and P. brevicompactum by integrating in vitro assays with in silico analyses. Minimum inhibitory concentrations (MICs) were determined, and effects on fungal growth, membrane integrity, and spore germination were assessed. Molecular docking and molecular dynamics simulations were performed to evaluate the affinity and stability of the five most abundant GC–MS compounds that met predefined ProTox-II toxicity criteria (categories 5–6; LD₅₀ ≥ 2000 mg/kg) toward chitin synthase I (CHS I), a key enzyme in chitin biosynthesis. The oil exhibited strong inhibitory activity, with MIC values of 0.156 µL/mL against P. expansum and 0.312 µL/mL against P. brevicompactum, along with significant morphological and physiological alterations. Computational analyses indicated that trans-β-caryophyllene oxide and α-humulene form stable interactions at both the active and an allosteric site of CHS I, supporting a putative dual inhibitory mechanism. These findings highlight clove essential oil as a promising ecological alternative to synthetic fungicides and underscore the value of computational approaches for elucidating antifungal mechanisms in understudied species. Full article

Cognitive impairment in schizophrenia remains insufficiently addressed by existing treatments. Current FDA-approved therapies primarily modulate neurotransmitter systems, resulting in incomplete symptom control and substantial adverse effects. There is therefore a critical need for therapeutic strategies that more directly address the intracellular signaling mechanisms underlying synaptic dysfunction and cognitive deficits in schizophrenia. Protein phosphatases represent an essential but historically underexplored class of signaling enzymes that regulate phosphorylation-dependent control of synaptic receptor trafficking, plasticity, and neuronal circuit function. Although multiple phosphatases have been implicated in schizophrenia through genetic, post-mortem, and functional studies, their therapeutic targeting has been limited by challenges related to selectivity, cellular permeability, and pleiotropy. Here, we review the etiology of schizophrenia and limitations of current pharmacological approaches, synthesize evidence linking specific protein phosphatases to schizophrenia pathophysiology, and discuss emerging strategies, including allosteric modulation and targeted protein degradation, that may enable selective intervention in phosphatase-driven signaling pathways. We highlight the striatal-enriched tyrosine phosphatase STEP (PTPN5) as a case study illustrating how selective phosphatase modulation can restore synaptic signaling in schizophrenia-relevant models. Full article

The progression of prostate cancer to castration-resistant disease (CRPC) remains a clinical challenge in which oxidative stress intersects with the PI3K/AKT–androgen receptor (AR) axis. Quercetin (QRC) is a redox-active dietary flavonol, yet its mechanistic impact on CRPC is incompletely defined. Here, we tested whether QRC suppresses AR output by directly modulating AKT. C4-2B and 22Rv1 CRPC cell lines were treated with increasing QRC concentrations, with or without enzalutamide (Enz). Proliferation and viability were monitored by IncuCyte imaging and SYTOX Green incorporation. AKT phosphorylation (S473), AR phosphorylation (S210/213), AR abundance and localization, and prostate-specific antigen (PSA) secretion were assessed by immunoblotting, immunofluorescence, and dot blot, respectively. Docking and molecular dynamic simulations were performed to identify and evaluate a putative QRC-binding site on AKT. QRC produced a dose-dependent cytostatic effect (IC₅₀ 24.37 μM in C4-2B; 21.54 μM in 22Rv1) without marked cell death, reduced pAKT(S473) by up to 80%, decreased pAR(S210/213), and diminished nuclear AR and PSA secretion. Simulations suggested a putative druggable allosteric pocket in the AKT1 N-lobe, with G159 emerging as a potential anchor residue. Enz cotreatment with QRC did not produce additive effects, consistent with a model in which QRC acts upstream of ligand-driven AR activation and thereby limits the incremental benefit of AR antagonism under these conditions. These data support QRC as an AKT–AR axis modulator in CRPC and provide a target engagement framework beyond simple ROS scavenging. Full article

Background/Objectives: The emergence of antimicrobial resistance necessitates the development of new and effective antimicrobial agents. In this study, three different series of imidazole-based chalcones (IBC1-25) were designed and synthesised using a sustainable approach, with the aim of identifying compounds with enhanced antimicrobial activity. Methods: A series of monoalkoxy, dialkoxy, and trialkoxy imidazole-based chalcones (IBC1–25) were synthesised and evaluated for their antimicrobial and antifungal activities against a range of microbial strains. Structure-activity relationships were analysed, and molecular docking studies were performed to investigate potential binding interactions with biofilm-associated regulatory proteins. In addition, ADME properties were predicted to assess drug-likeness. Results: Among the monoalkoxy derivatives (IBC1-14), IBC5 exhibited the broadest spectrum of activity, particularly against S. epidermidis. Several dialkoxy analogues (IBC17-21) demonstrated improved potency, with IBC20 showing notably high activity. While IBC22 and IBC25 were largely ineffective, IBC23 and IBC24 displayed significant antibacterial and antifungal activities. Overall, dialkoxy and trialkoxy derivatives exhibited enhanced efficacy, whereas monoalkoxy compounds with bulky or long-chain substituents were generally less active. The presence of multiple alkoxy substituents, such as methoxy and ethoxy groups, on the phenyl ring significantly improved activity, particularly against fungi and Gram-positive bacteria. Molecular docking studies revealed that IBC20 and IBC23 showed favourable binding to the biofilm-associated regulator TcaR, suggesting a potential allosteric inhibition mechanism, while weak interactions were observed with TagF. ADME predictions indicated good oral absorption and compliance with key drug-likeness criteria. Conclusions: The results demonstrate that both the number and type of alkoxy substituents play a critical role in antimicrobial activity. In particular, IBC20 and IBC23 emerge as promising candidates for further development as antimicrobial agents targeting biofilm-associated pathways. Full article

Background: Neurodevelopmental disorders span a wide spectrum of deficits, often with a known or suspected genetic basis. While some genetic determinants may indicate treatment with selective compounds, more often both the molecular cause of the disorder and the mechanism of action for the therapeutic compound are more ambiguously matched. Due to the polypharmacological nature of most neuroactive compounds, measuring gene expression changes following drug perturbation could be an effective strategy to gain insight into shared therapeutic action downstream of diversity in receptor interaction. High-throughput drug discovery platforms have effectively measured changes in gene expression following drug perturbation in cell cultures, but unfortunately, these platforms often lack specificity for neuroactive compounds, fail to capture the developmental influence of cell–cell interactions, and do not accurately model drug metabolism in an intact system. Methods: In this study, we present a high-throughput, low-cost and cell-type-specific approach for capturing transcriptional changes in neural cell populations following neuroactive compound exposure through the combined use of transgenic zebrafish, cell sorting, and bulk RNA-seq. Results: Our system captures unique transcriptional profiles between neuronal and non-neuronal cell populations and demonstrates specific drug responsiveness within our neuronal cell population. We assessed two known positive allosteric modulators (PAMs) of γ-Aminobutyric acid sub-type A receptors (GABA_AR), ivermectin and propofol, as a case study to explore shared pathway and gene expression changes following drug exposure; these chemically distinct agents share a mechanistic signature that dampens the neuronal hyperexcitability characteristic of a broad spectrum of neurodevelopmental disorders. Two shared downregulated genes reflect a core expression module for modulating GABAergic tone: SRC proto-oncogene, non-receptor tyrosine kinase (SRC), and Glutamate decarboxylase 2 (GAD2). Conclusions: We provide this methodology and analysis as a framework for exploring shared changes in gene expression following neuroactive compound exposure in vivo, leading to a more complete and nuanced understanding of therapeutic effects on neurons that can aid in drug repurposing efforts for neurodevelopmental disorders. Full article

Polycystic ovary syndrome (PCOS) is associated with impaired ovarian steroidogenesis and ovulation, which necessitates the development of effective ovulation inducers for PCOS. The aim of the study was to evaluate the effects of allosteric luteinizing hormone receptor agonist TP03 and human chorionic gonadotropin (hCG) on ovarian steroidogenesis, as well as ovulation in prepubertal female rats with dehydroepiandrosterone(DHEA)-induced PCOS. Taking into account differences in progesterone levels, cohorts with high (PCOS(H)) and low (PCOS(L)) progesterone were formed and treated with Follimag and Cetrotide. After 48 h, TP03 (25 mg/kg) or hCG (25 IU/rat) were injected, and hormone levels, gene expression, and ovarian morphology were assessed. The PCOS(H)-cohort exhibited irregular estrous cycles, ovarian cysts, and increased ovarian mass and estradiol levels, but the number of corpora lutea (CL) was maintained. In the PCOS(L)-cohort, ovarian weight was increased, and Star, Cyp11a1, and Adamts1 gene expression as well as the CL number were decreased. In both cohorts, TP03 and hCG increased progesterone levels and the expression of steroidogenesis (Star, Cyp11a1) and ovulation (Cox2, Adamts1, Egr1) genes, as well as inducing CL formation. Thus, TP03, like hCG, stimulates steroidogenesis and ovulation in PCOS-rats with different progesterone levels, which provides the first evidence of the effectiveness of allosteric LHR agonists as ovulation triggers in PCOS. Full article

Background: Fast excitatory transmission in the central nervous system is carried out by AMPA-type glutamate receptors. Neuronal hyperexcitability and epilepsy have been associated with the dysregulation of AMPA receptor function. Modulation of the gating kinetics of AMPA receptor function has been proposed to be a desirable target for therapy, especially when the modulation is transmembrane AMPA receptor regulatory protein (TARP)-dependent and AMPA receptor subunit composition-dependent. Methods: Eight dibenzobarrelene-based heterocycles were characterized for their effects on the human embryonic kidney cells expressing homomeric GluA1 and heteromeric GluA1/2 AMPA receptors, either alone or co-expressed with the TARPγ8 auxiliary subunit, using whole-cell patch-clamp electrophysiological recordings, and the current amplitude and kinetics of desensitization and deactivation were measured after rapid glutamate application. Results: Each chemical evaluated suppressed glutamate-induced currents via AMPA receptors and augmented both desensitization and deactivation, indicating a negative allosteric modulatory effect. The co-expression of TARPγ8 diminished, but did not eradicate, the inhibition and acceleration induced by the compounds. The observations indicate that the chemicals diminish agonist-bound open states and facilitate transitions to non-conducting states while maintaining effectiveness. Conclusions: The present study describes a specific kinetic mechanism by which dibenzobarrelene derivatives impair the function of the AMPA receptor and its dependence on auxiliary proteins. The present study provides a mechanistic understanding of AMPA receptor gating modulation and establishes a pharmacological framework for future investigations in more physiologically relevant systems. Full article

Psoriasis is a chronic, immune-mediated inflammatory skin disease requiring effective long-term systemic treatment. Current options, including using conventional small molecules and biological therapies, are limited by adverse events, suboptimal efficacy, or poor adherence due to inconvenient administration. This highlights an unmet need for safe, convenient, and effective oral self-administered dosage form therapies aligned with patient preferences. This review evaluates the mechanism, safety, and efficacy of next-generation tyrosine kinase 2 (TYK2) inhibitors and compares them to currently available therapeutic options. The pathogenesis of psoriasis is driven by chronic systemic inflammation mediated by the interleukin-23 (IL-23)/Th17/interleukin-17 (IL-17) axis. Selective TYK2 inhibitors, such as deucravacitinib, envudeucitinib, and zasocitinib, act through a unique allosteric mechanism by binding to the regulatory pseudokinase domain (JH2) rather than the enzyme’s catalytic domain. This enables highly selective suppression of IL-23-mediated inflammation while mitigating systemic toxicity seen with nonselective Janus kinase (JAK) inhibitors. Clinical trials (POETYK PSO-1 and PSO-2) and long-term extension studies demonstrate that deucravacitinib provides superior efficacy compared to the first-generation oral small molecule apremilast, with high and sustained response rates. It maintains durable efficacy for up to four years in patients with moderate to severe plaque psoriasis and shows a stable long-term safety profile, with low incidence of major adverse cardiovascular events (MACEs), venous thromboembolism (VTE), serious infections, and malignancies. Selective TYK2 inhibition bridges the therapeutic gap, providing an optimal balance of efficacy and oral convenience. With the potential to improve patient adherence and quality of life, these agents represent a promising option to become a first-line oral systemic therapy for psoriasis. Full article

Aldose Reductase (AR; AKR1B1) is an enzyme that plays a key role in the metabolism of glucose and other carbonyl compounds, and whose hyperactivity contributes to oxidative stress and vascular dysfunction. Despite decades of investigation into this enzyme, inhibitors have failed to translate into clinical application for Diabetic Retinopathy (DR). We argue that these failures might arise from non-selective inhibition, considering the dual roles of AR, which contribute not only to DR pathology but also support retinal health, as AR is an important detoxifying enzyme for aldehydes produced during oxidative stress. Here, we discuss missing structural information, despite more than one hundred crystal structures of AR in complex with inhibitors. Our review bridges this gap by discussing how recent advances in structural biology, e.g., fragment-based drug discovery and MicroED, provide novel ways to selectively modulate AR functions, offering advantages for the detection of weak, allosteric, or conformation-dependent binding events. Despite past challenges, we suggest that therapeutic targeting of AR to find new-generation inhibitors will become more effective once we have a clearer understanding of the requirements for selective inhibition of AR, blocking its pathological impact while preserving its physiological functions. By integrating fragment screening and structural biology, we outline a strategy to reinvigorate AR modulation as a viable retina-specific approach for managing DR, with potentially broader relevance toward multiple diabetic microvascular complications. Full article

Background/Objectives: Parmentiera edulis, traditionally called “cuajilote”, is a medicinal plant used to treat infections, indigestion, kidney problems, and diabetes. Although all parts of the plant are utilized, there is little scientific evidence available on its phytochemical composition to explain its medicinal properties. This exploratory study aims to characterize and identify phytochemicals in hydromethanolic extracts of leaves, stems, and fruits; determine their antioxidant capacity, and evaluate in vitro and in silico inhibition of α-glucosidase and α-amylase, enzymes involved in glycemic control. Methods: Total phenolic and flavonoid contents were determined, and antioxidant capacity was evaluated using different assays. Phenolic acids were tentatively identified by UPLC-qTOF-MS/MS. Enzyme inhibition assays against α-glucosidase and α-amylase were performed in vitro, and molecular docking was used to explore enzyme–ligand interactions. Results: The total phenolic content was significantly higher in the fruit (552.9 mg GAE/100 g dw), while flavonoids were more abundant in leaves (119.84 mg QE/100 g dw). Antioxidant capacity varied among plant parts, depending on the assay used. Caffeic, chlorogenic, coumaric, ferulic, gallic, and quinic acids were identified. The highest concentrations were observed for chlorogenic, ferulic, and quinic acids. Among the analyzed parts, leaf extracts showed the most potent inhibitory effect on α-glucosidase (IC₅₀: 0.85 mg/mL) and α-amylase (IC₅₀: 1.38 mg/mL). Molecular docking revealed that chlorogenic and quinic acids interacted with the catalytic sites of α-amylase (Glu233, Asp197, and Asp300), whereas in α-glucosidase, interactions were observed at allosteric sites. Conclusions: These results suggest that Parmentiera edulis possesses bioactive compounds that could explain its therapeutic use. Full article