Jin-Hee Han

The vesicular γ-aminobutyric acid (GABA) transporter (VGAT; SLC32A1) plays an essential role in inhibitory neurotransmission by transporting GABA into synaptic vesicles. Given the involvement of impaired GABAergic inhibition in epilepsy, identifying potential VGAT-targeting compounds remains an important objective for investigating the regulation of GABAergic neurotransmission. This study aimed to establish a computational workflow to curate vigabatrin-like compounds and prioritize candidates for further investigation as potential VGAT modulators. A 182-record SwissSimilarity collection was processed through sequential filters comprising removal of endogenous metabolites, radiolabeled tracers, and the reference compound; an independent two-dimensional fingerprint similarity assessment; drug-likeness evaluation; structural-alert screening; and database-verified pharmacological classification. Selected compounds were subsequently evaluated using molecular docking, molecular dynamics (MD) simulations, and steered molecular dynamics (SMD). The initial collection contained 108 compounds (59.3%) corresponding to endogenous metabolites, GABA-shunt-related molecules, stereoisomers, or radiolabeled derivatives. Subsequent structure-based analyses provided complementary predictions of ligand–VGAT interaction patterns, complex stability, and resistance to ligand displacement. Among the compounds examined, DB12444, DB04235, and DB17839 exhibited comparatively strong force responses under the applied pulling protocol, supporting their prioritization for further investigation. This analysis establishes a multi-stage framework that integrates chemical curation, independently assessed structural similarity, and structure-based simulations to prioritize vigabatrin-similar compounds. The resulting computational evidence can guide experimental selection of candidate VGAT modulators.

This study aimed to optimize fermentation conditions for maximizing ellagic acid accumulation/release from Juglans mandshurica (Manchurian walnut) fruit extract using Weissella confusa. A 20% ethanol extract was fermented across a central composite design spanning temperature (26.59–43.41 °C), pH (2.98–8.02), and time (3.91–24.09 h), and response surface methodology was used to determine the optimal conditions. The predicted optimum was 36.61 °C, initial pH 6.70, and 24.09 h, under which the ellagic acid yield reached 64.05 µg/mL, experimentally validated at this single optimum condition using three independent replicate fermentations (n = 3), giving 64.04 ± 0.95 µg/mL by HPLC. Antioxidant activity at the optimized condition was evaluated using total phenolic content, DPPH, and ABTS radical scavenging assays. The fermented extract showed markedly enhanced radical scavenging activity, with DPPH inhibition reaching 85.47% at 400 μg/mL and ABTS exceeding 99.99%, while the total phenolic content was 141.41 ± 2.32 mg gallic acid equivalents (GAE)/g. These results indicate that W. confusa-mediated fermentation enhances the ellagic acid content and antioxidant potential of J. mandshurica extract, presumably through enzymatic hydrolysis of ellagitannins involving tannase and β-glucosidase, although these enzyme activities were not directly measured. This approach offers a sustainable strategy for developing functional ingredients with natural antioxidant properties for food and nutraceutical applications.

Epilepsy is a chronic neurological disorder in which current antiseizure medications are limited by incomplete seizure control and variable therapeutic responses, highlighting the need to identify new bioactive candidates. Passiflora incarnata (P. incarnata) has demonstrated neuropharmacological and anticonvulsant properties. However, the individual phytochemicals and molecular mechanisms underlying these effects remain incompletely characterized. In this study, we integrated network pharmacology with cellular validation to identify epilepsy-relevant phytochemicals of P. incarnata and evaluate their neuroprotective effects. Eleven phytochemicals underwent target prediction and were compared with epilepsy-associated genes, yielding 147 common targets. Protein–protein interaction analysis identified 134 interacting proteins and 590 interactions, with GABA_A receptor subunits prominently represented among the top hub genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses further identified GABA-related functions and neuroactive ligand–receptor signaling. Integration of compound–target functional profiling with structural analysis prioritized the luteolin-derived flavonoid lineage, leading to the selection of orientin, a C-glycosylflavone constituent of P. incarnata, and luteolin, its structurally related core flavone scaffold, for experimental validation. In differentiated SH-SY5Y cells, pretreatment with orientin or luteolin attenuated L-glutamic acid-induced cellular injury in the presence of glycine, as evidenced by improved cell viability and reduced lactate dehydrogenase release. Both compounds also markedly reduced glutamate-induced intracellular Ca²⁺ accumulation. Notably, thapsigargin substantially reversed these Ca²⁺-lowering effects, suggesting a potential role for ER-associated Ca²⁺ regulatory mechanisms. The predicted GABAergic targets were not directly validated, and the cellular findings demonstrate neuroprotection against glutamate-induced excitotoxicity rather than direct GABA_A receptor modulation or antiseizure efficacy. Collectively, these findings demonstrate the utility of network pharmacology-guided prioritization for identifying bioactive constituents of P. incarnata and support orientin as a neuroprotective candidate for further mechanistic and in vivo investigation.

Persistent malaria transmission remains a considerable challenge in Indonesia despite national elimination efforts, with the Menoreh Hills representing a residual transmission hotspot characterized by ecological and socio-behavioral complexity. This highland region, spanning the boundaries of the Kulon Progo, Purworejo, and Magelang districts presents a complex eco-epidemiological setting in which malaria transmission persists despite substantial reductions in incidence. Spatial analyses consistently reveal micro-foci and cross-district clusters, underscoring the structural and ecological interconnectedness of the Menoreh Hills, including Anopheles mosquito habitats. Anopheles mosquitoes exhibit ecological adaptability and behavioral plasticity that may contribute to residual transmission. This region features a heterogeneous landscape of secondary forests, agricultural lands, and rural settlements that foster diverse vector species and habitats, occupational exposure, and sustained human-vector contact associated with Plasmodium transmission. Hypnozoite-mediated relapse in P. vivax, prolonged gametocyte carriage in P. falciparum, and asymptomatic or submicroscopic infections may contribute to residual transmission. Surveillance is complicated by fragmented governance, variable funding, high human mobility across district borders, and logistical constraints imposed by rugged topography. This review emphasizes the necessity of strengthening integrated malaria surveillance systems that combine entomological, serological, genomic, and spatial data to enable early detection and targeted interventions. Cross-sectoral collaboration, community engagement, and adaptive, location-specific strategies addressing socio-ecological determinants alongside biological and environmental drivers are essential to interrupt persistent transmission in complex residual foci such as the Menoreh Hills.

Plasmodium infection induces extensive remodeling of host erythrocytes through parasite-exported proteins that interact with host cell components . Among these, tryptophan-rich antigens (TRAgs) are conserved across Plasmodium species and have been proposed as vaccine candidates, but their molecular functions remain largely unexplored. In this study, we characterized Plasmodium knowlesi tryptophan-rich antigen 40.1 (PkTRAg40.1) to investigate its localization, biochemical properties, host interactions, and immunogenicity. Recombinant PkTRAg40.1 showed no detectable binding to intact human erythrocytes in flow cytometry-based binding assays. Biochemical characterization demonstrated that native PkTRAg40.1 was predominantly associated with detergent-resistant insoluble fractions and was detected as multiple higher-molecular-weight forms. Protease protection assays further showed that native PkTRAg40.1 was accessible to protease under the experimental conditions tested. Consistent with these observations, immunofluorescence assays revealed that PkTRAg40.1 colocalized with skeleton-binding protein 1 (PkSBP1), supporting its localization to Sinton and Mulligan’s clefts (SMCs), parasite-derived membranous structures. Pull-down assays and MALDI-TOF/MS identified spectrin alpha as a host binding partner, and biolayer interferometry confirmed its specific interaction with the spectrin alpha α12–16 fragment (K _D = 4.71 ± 0.62 μM). Serological analysis of P. knowlesi patient samples revealed that PkTRAg40.1 is immunogenic, exhibiting 50% sensitivity and 92.9% specificity, and also displayed cross-reactivity with sera from Plasmodium vivax -infected patients. Collectively, these findings identify PkTRAg40.1 as a TRAg associated with parasite-derived membranous structures that interacts with the host erythrocyte cytoskeleton, thereby expanding current understanding of the molecular functions of Plasmodium TRAgs.

Glucose acquisition is essential for the long-term survival of adult Clonorchis sinensis within the host bile duct. Although several glucose transporter-related proteins have been identified in C. sinensis, the molecular and functional properties of facilitative glucose transport proteins, including the protein designated as glucose transporter protein 5 (CsGTP5) in this study, have not been characterized. In this study, CsGTP5 was cloned from adult C. sinensis and functionally analyzed using the Xenopus laevis oocyte expression system. The CsGTP5 open reading frame comprised 1,575 bp and encoded a 524-amino-acid protein with 12 predicted transmembrane domains, consistent with the topology of facilitative glucose transporter-like proteins. CsGTP5-expressing oocytes showed significantly increased uptake of [3 H] deoxy-D-glucose compared with water-injected control oocytes, whereas no significant uptake was observed for other tested substrates, including arginine, α-ketoglutarate, p-aminohippurate, taurocholate, and tetraethylammonium. CsGTP5-mediated [3 H] deoxy-D-glucose uptake increased in a time-dependent manner and was not affected by replacement of extracellular Na+ with Li+ or choline, indicating sodium-independent transport. Uptake was saturable, with an apparent Km of 4.0 mM and a Vmax of 300.0 pmol/oocyte/h. Competition assays showed that deoxy-D-glucose and glucose strongly inhibited CsGTP5-mediated uptake, whereas other monosaccharides had little effect. Molecular docking analysis further supported the predicted glucose-recognition capacity of CsGTP5. These findings demonstrate that CsGTP5 mediates sodium-independent deoxy-D-glucose uptake in a heterologous oocyte expression system and provide a basis for further investigation of its physiological role in C. sinensis.

Background: Acetylcholinesterase (AChE) is a key therapeutic target in neurological disorders, and the discovery of novel inhibitors with improved efficacy and pharmacokinetic properties remains a significant challenge. Methods: In this study, an integrated computational and experimental approach was employed to identify potential AChE inhibitors. A machine learning-based model was developed to predict bioactive compounds from large chemical libraries, followed by Blood–Brain Barrier (BBB) permeability screening to ensure Central Nervous System (CNS) suitability. The shortlisted compounds were further evaluated using molecular docking, molecular dynamics simulations, and MM-PBSA binding free-energy calculations to assess their interaction profiles and stability. Selected top-ranked compounds were subjected to in vitro biological evaluation for AChE inhibitory activity. Results: The results demonstrated that several screened compounds, including Z1498348710 and Z1824281875, exhibited notable inhibition with AChE activity reduced to approximately 75% and 72%, respectively, compared to the control. Other compounds such as Z29542160, Z105150208, Z94570687, and Z94570675 showed moderate inhibitory effects, maintaining AChE activity in the range of 82–86%. In comparison, the reference inhibitors Donepezil and Neostigmine bromide displayed significantly stronger inhibition, reducing AChE activity to approximately 20% and 18%, respectively. Conclusions: Overall, the identified compounds demonstrated moderate AChE inhibitory activity while exhibiting favorable predicted physicochemical and computational profiles. These findings suggest that they represent promising starting points for medicinal chemistry optimization and future development as CNS-active AChE inhibitors.

Objectives: This scoping review synthesizes molecular evidence on Plasmodium genetic diversity and multiplicity of infection (MOI) in Southeast Asia and describes variation by species and epidemiological setting.Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines, we searched PubMed, Scopus, ProQuest, and EBSCO for English language, open-access obersvational studies published between January 1, 2015 until October 11,2025. Included studies involved laboratory-confirmed human malaria and reported MOI and genetic diversity data derived from appropriate molecular genotyping methods. Findings were summarized by species, geography, markers, and clinical categories.Results: Sixteen studies were included, comprising 1,609 genotyped Plasmodium falciparum infections, 1,526 Plasmodium vivax infections, 37 Plasmodium malariae infections, and 188 human Plasmodium knowlesi infections. P. falciparum exhibited marked heterogeneity, with polyclonal infection rates ranging from 3.9% to 73.9% and mean MOI ranging from 1.05 to 4.9. P. vivax consistently showed high diversity, with polyclonal infection rates ranging from 16.9% to 71.4% and mean MOI ranging from 1.1 to 1.91, alongside expected heterozygosity values of 0.66–0.87. P. malariae displayed low MOI, whereas P. knowlesi showed polyclonal infection rates ranging from 7.3% to 21% and mean MOI ranging from 1.04 to 1.06. No data were available for Plasmodium ovale.Conclusion: P. falciparum and P. vivax remain genetically diverse across Southeast Asia, with heterogeneous transmission patterns, particularly in border regions. Limited data on P. malariae, human P. knowlesi, and P. ovale highlight the need for standardized molecular surveillance to support targeted elimination efforts.

Plasmodium falciparum remains a major cause of mortality in malaria-endemic regions, and strain-specific immunity limits vaccine efficacy. The 6-cysteine proteins Pf12 and Pf41 are proposed blood-stage vaccine candidates, yet their diversity and antigenicity in asymptomatic carriers are poorly defined. Genetic variation and natural selection pressure were analyzed in 172 P. falciparum isolates from asymptomatic individuals in Tanzania. Genomic DNA extracted from dried blood spots was amplified by PCR and subsequently sequenced to evaluate genetic diversity. IgG responses to recombinant Pf12 and Pf41 were quantified using a protein microarray. Statistical analyses included Spearman’s correlation to assess antibody associations and unpaired t-tests to compare IgG levels between parasite-positive and parasite-negative individuals. Both genes exhibited low nucleotide diversity (pf12 π = 0.00042 ± 0.00007; pf41 π = 0.00061 ± 0.00004) and negative Tajima’s D values suggest that both genes are under selective constraints, consistent with purifying or directional selection. Neutrality test indicated an excess of rare variants consistent with recent population expansion. Haplotype network showed limited regional differentiation, supporting strong conservation. Pf12 and Pf41 elicited high IgG seropositivity (97.7% and 98.3%), with strongly correlated antibody levels (ρ = 0.721, p < 0.001). A predominant Pf41 substitution, S232R (47.8%), and rare Asn/His variants (0.6%) were detected. Overall, both proteins display limited polymorphism and robust IgG recognition, features consistent with exposure-driven immunity. These findings highlight conserved merozoite antigens that warrant further investigations for their biological relevance and vaccine potential, particularly to determine their functional role in protective immunity.