Search Results (261)

Background/Objectives: Chronic complications of diabetes mellitus are closely associated with increased oxidative stress and the formation of advanced glycation end products (AGEs). This study aimed to investigate the antioxidant and antiglycation potential of hesperetin-7-O-glucoside (HCD) and diosmetin-7-O-glucoside (DCD) formulations complexed with cyclodextrins, using in vitro and in silico experimental models to evaluate their efficacy in mitigating hyperglycemia-induced molecular damage. Methods: Antioxidant activity was assessed using chemical and erythrocyte-based oxidative stress models, whereas antiglycation activity was evaluated in BSA–fructose, BSA–methylglyoxal, and arginine–methylglyoxal models. Results: Both formulations showed measurable antioxidant effects, with concentration-dependent behavior observed in some of the evaluated assays. In the DPPH assay, HCD and DCD achieved maximum inhibition values of 30.71% and 26.61%, respectively. Furthermore, DCD exhibited higher total antioxidant capacity (102.80 µg vitamin C equivalents/mL) and nitric oxide scavenging activity (37.89%) than HCD. In a cellular model, both formulations (200 µg/mL) significantly reduced AAPH-induced hemolysis, with DCD providing superior protection (7.05% vs. 16.63% for HCD). Under oxidative stress induced by high glucose concentration in erythrocytes, HCD and DCD reduced non-protein thiol levels, and HCD significantly increased catalase enzyme activity. Regarding antiglycation activity, DCD demonstrated superior efficacy relative to HCD in the BSA-fructose system, achieving 43.23% inhibition. DCD also displayed concentration-dependent inhibition of fructosamine formation (up to 47.99%) and BSA glycation by methylglyoxal (up to 45.20%). Both formulations significantly reduced carbonylated protein levels and preserved free thiol groups. In the arginine–methylglyoxal model, DCD and HCD reached 44.03% and 48.82% inhibition, respectively. Molecular docking revealed high binding affinity of both flavonoids to the protein active site (−9.00 kcal/mol for hesperetin-7-O-glucoside and −9.04 kcal/mol for diosmetin-7-O-glucoside), suggesting a structural protective role. Conclusions: The HCD and DCD formulations demonstrated antioxidant and antiglycation activities that may contribute to attenuating molecular alterations associated with chronic hyperglycemia through complementary mechanisms, including antioxidant effects, protection against protein carbonylation, and inhibition of glycation. While these findings highlight the potential of the evaluated formulations, additional mechanistic and in vivo studies are required to establish their pharmacological applicability. Full article

Rapid, point-of-care detection of Escherichia coli O157:H7 remains an unmet clinical need, as culture and molecular methods are slow and poorly suited to decentralized or emergency settings. A label-free, monolithic aptasensor biochip was fabricated in a standard 65 nm CMOS process, featuring three aptamer-functionalized gold sensing pads with matched reference pads for differential readout. A 37-mer DNA aptamer targeting the E. coli O157:H7 lipopolysaccharide was immobilized via thiol–gold self-assembled monolayer chemistry. Binding events were transduced into surface-potential shifts, amplified by an on-chip analog front-end (~100 V/V gain, 101.5 µW), and evaluated using calibration standards, patient specimens, and hospital environmental samples, with fluorescence microscopy for validation. The sensor achieved 47.42 mV/decade sensitivity across 1–10,000 CFU/mL, an IUPAC detection limit near 3.74 CFU/mL, and an empirical LOD of about 11 CFU/mL, with outputs tracking bacterial load and ~5.7% matrix-related deviation. Hospital samples were detectable to 28 CFU/mL. Because the patient-derived and hospital-acquired cohorts (n = 10 and n = 6, respectively) were assembled for pilot analytical and matrix-tolerance characterization rather than for diagnostic-accuracy determination, these results establish detectability and matrix robustness in real clinical and environmental specimens rather than clinical diagnostic sensitivity or specificity, which will require a larger, prospectively enrolled cohort in future work. Sensor kinetics followed Langmuir-type adsorption, saturating within 16–25 min for target pathogens versus slower responses for non-target strains. Selectivity tests against six bacterial species showed discrimination, with cross-reactivity decreasing from related E. coli pathotypes to Enterobacteriaceae to Gram-positive species. Inter-pad variability stayed below 1.5 mV, supporting this compact, low-power platform for scalable, enrichment-free point-of-care pathogen detection. Full article

Gold nanoparticles (AuNPs) are widely used in aptasensors because of their high extinction coefficient and aggregation-dependent color differences. However, recent studies have indicated that nonspecific interactions between target molecules and AuNPs may dominate the detection signal rather than aptamer–target specific binding. This study systematically investigated the interactions between 13 aminoglycoside antibiotics and AuNPs. We found that all aminoglycoside antibiotics interacted strongly with AuNPs, considerably reducing their salt stability. Furthermore, methoxy polyethylene glycol thiol reversed AuNP aggregation induced by aminoglycoside antibiotics, indicating that it occurs at the secondary minimum. Using density functional theory, we analyzed the molecular structures and charge distribution characteristics of the aminoglycoside antibiotics, elucidating that they replace citrate ions on AuNP surfaces via a ligand exchange mechanism, thereby inducing aggregation. Additionally, both aptamer targets and complementary DNA struggled to desorb the aptamer (KAN6-1) from the AuNP surfaces. Our study demonstrates that the label-free colorimetric assay based on aggregation of unmodified citrate–AuNPs is neither suitable for characterizing the binding affinity of aminoglycoside aptamers nor viable for constructing corresponding colorimetric sensors to detect this class of antibiotics. Thus, researchers should incorporate mechanistic verification and rigorous controls when employing this system to ensure reliable results. Full article

Ferulic acid (FA) is a phenolic acid mainly present in wheat bran. It has beneficial health effects, but may affect gluten network formation and the processing quality of wheat-based products. This study investigated the interaction mechanisms between FA and glutenin/gliadin in dough and simulated dough systems. The results show that FA’s effects on both proteins were dose and system dependent. In dough, low-dose FA (≤0.3 g) promoted structural loosening of glutenin, as suggested by β-sheet conversion to β-turns/random coil structures, increased t-g-t disulfide and free thiols, and reduced particle size, whereas high doses promoted reaggregation via microenvironment reshaping, hydrophobic enhancement, cross-linking, and subunit rearrangement. For gliadin, low-dose FA may have altered local charge and hydrogen-bonding environments, while high-dose FA increased the hydrogen-bonding proportion by 45.71% and g-g-g conformation by 60.85%, suggesting enhanced molecular aggregation. In simulated dough, FA promoted stronger structural loosening of glutenin but favored gliadin aggregation, indicating that starch, lipids, water distribution, and other dough components may redirect FA–protein interactions. Molecular docking, as a complementary approach, predicted the preferential binding of FA to gliadin, LMW-GS and HMW-GS at different sites. These findings provide a theoretical basis for regulating phenolic acid–gluten interactions in whole-wheat and functional wheat-based products. Full article

Copper ions (Cu²⁺) and intracellular biothiols are tightly coupled in cellular redox regulation, where copper–thiol coordination governs oxidative stress and metal homeostasis. However, analytical platforms capable of sequentially monitoring Cu²⁺ and biothiols within a single molecular system remain scarce. Herein, we report a coumarin-based fluorescent probe XDP that enables sequential ON–OFF–ON sensing of Cu²⁺ and biothiols through a coordination–competition mechanism. The imine (C=N) site of XDP selectively coordinates Cu²⁺, leading to fluorescence quenching arising from coordination-induced electronic perturbation and enhanced nonradiative decay. The probe exhibits a linear response toward Cu²⁺ over 1–80 μM with a detection limit of 0.108 μM. Subsequent competitive binding of biothiols (GSH, Cys, and Hcy) releases Cu²⁺ from the complex, thereby restoring fluorescence and enabling detection within 1–30 μM with submicromolar sensitivity. XDP also displays a large Stokes shift (135 nm), which minimizes spectral overlap and improves signal reliability. Notably, Cu²⁺ binding triggers a distinct color change that supports naked-eye detection and smartphone-based RGB quantification. The probe further enables visualization of Cu²⁺ and thiol-triggered signal recovery in living cells and zebrafish. This work establishes a versatile analytical platform for probing copper–thiol interactions in environmental and biological systems. Full article

To understand glycan–protein interactions at biological interfaces, designing surfaces modified with structurally controlled glycans is highly important. In particular, naturally occurring glycosaminoglycans (GAGs) possess periodic sugar arrangements that play important roles in protein recognition, highlighting the need for the development of periodic glycopolymer model systems that can serve as GAG mimics for quantitative interaction analysis. In this study, sequence-controlled periodic glycopolymers were synthesized by reversible addition–fragmentation chain-transfer (RAFT) polymerization and immobilized onto gold surfaces to construct glycan-modified interfaces. The synthesized material was a terminally functionalized periodic glycopolymer with the most basic structure, consisting of alternating maltose-containing vinyl ether (MalVE) units and ethyl maleimide (EtMI) units, with a trithiocarbonate group at the ω-terminal. This trithiocarbonate group was converted to a thiol group for immobilization through Au–S bond formation. Structural characterization by ¹H NMR spectroscopy, size exclusion chromatography (SEC), MALDI-TOF mass spectrometry, and UV–vis spectroscopy confirmed the structure as designed. Quartz crystal microbalance (QCM) measurements verified the stable immobilization of thiol-terminated periodic glycopolymers on the gold surface, and allowed for estimation of graft density and quantitative analysis of glycan-protein interactions at the modified interface. The periodic glycopolymer-modified surfaces exhibited selective binding behavior toward concanavalin A (ConA) compared to bovine serum albumin (BSA), with apparent binding constants on the order of 10⁶–10⁷ L mol⁻¹. This enhanced binding behavior indicated that specific and multivalent interactions with proteins also occurred at periodic pendant maltose residues along the main chain. These results demonstrate that the gold surface modified with end-functional periodic glycopolymers synthesized by RAFT polymerization provides a versatile platform for quantitative analysis of glycan-protein interactions and suggests potential applications for periodic glycopolymers as functional materials. Full article

Cadmium is a widespread environmental xenobiotic that poses serious risks to hepatic, renal, and male reproductive functions. Natural compounds such as silymarin, a bioactive extract from Silybum marianum, have gained attention for their protective potential against xenobiotic-induced toxicity. This study investigated whether subchronic oral administration of silymarin (30 mg/kg) mitigates cadmium-induced toxicity (5 mg/kg) in adult rats over six weeks. Twenty-four rats were assigned to four groups: control, cadmium-exposed, silymarin-treated, and co-treated. Biochemical, hematological, oxidative stress, and reproductive parameters were assessed. Sperm quality was evaluated using CASA, and testicular tissues were examined histologically. Cadmium exposure significantly reduced body weight (−30.8%), elevated transaminases (AST, ALT; p < 0.01), increased serum creatinine and total cholesterol, and induced multi-organ oxidative stress, as reflected by elevated malondialdehyde and markedly reduced SOD, CAT, and thiol group levels in testicular, hepatic, and renal tissues (p < 0.01). Sperm concentration dropped from 75.2 to 21.8 × 10⁶/mL, with total motility falling to 35% and progressive motility to 18%, accompanied by severe seminiferous tubule degeneration (Score III in 5 rats). Co-administration of silymarin partially restored these parameters, sperm concentration recovered to 38.5 × 10⁶/mL, total motility improved to 50.2%, and antioxidant enzyme activities and liver/kidney biomarkers showed significant but incomplete recovery (p < 0.05). Molecular docking revealed favorable binding affinities of silybin toward GPx (−8.4 kcal/mol), CAT (−8.3 kcal/mol), and SOD (−6.4 kcal/mol), offering a preliminary computational hypothesis suggesting possible interactions between silybin and antioxidant enzymes, pending experimental validation. Silymarin alone exerted no adverse effects. These findings establish silymarin as a partial but promising multi-organ cytoprotectant against cadmium toxicity, and highlight the need for future studies optimizing dosing strategies, exploring longer treatment durations, and investigating combination approaches with metal chelators or Nrf2-activating agents to achieve complete tissue recovery. Full article

This study focused on the inhibitory effects of wheat bran feruloyl oligosaccharides (FOs) on the formation of AGEs in three bovine serum albumin (BSA)-based non-enzymatic glycation models, namely BSA-fructose, BSA-methylglyoxal (MGO), and BSA-glyoxal (GO). In the BSA-fructose model, FOs at 0.25 mg/mL achieved a 62% inhibition rate of fructosamine, equivalent to approximately 78% of the activity of the positive control aminoguanidine (AG), and reduced fluorescent AGEs by over 50% on day 12. Additionally, FOs suppressed the accumulation of α-dicarbonyl compounds, key intermediates in the glycation pathway. In the BSA-MGO and BSA-GO system, the decreased fluorescence intensity of tryptophan residues indicated that FOs bound to BSA, inducing conformational changes in the protein microenvironment; this binding also inhibited protein carbonyl formation and the loss of thiol groups, thereby modulating the protein glycation process. Compared with their precursors (ferulic acid, FA; xylooligosaccharides, XOS), FOs exhibited comparable or even superior inhibitory activity against specific AGE subtypes, suggesting a synergistic effect between the feruloyl and oligosaccharide moieties. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that FOs reduced the band intensity of 90 kDa AGEs in the glycation system, indicating the inhibition of protein-fructose cross-linking. Fluorescence spectroscopy confirmed that FOs dynamically quenched BSA with a single binding site, and thermodynamic calculations demonstrated that the binding was spontaneous (ΔG < 0), primarily driven by hydrogen bonds and van der Waals forces (ΔH < 0, ΔS < 0). This study systematically investigated the anti-glycation activities of FOs and their precursors. The findings demonstrate that FOs are promising natural glycation inhibitors and provide important theoretical and experimental support for related research. Furthermore, this study establish a basis for the green and high-value utilization of agricultural by-products like wheat bran. Full article

Diabetes mellitus is a growing health concern that causes numerous complications. Glycation produces advanced glycation end-products (AGEs), which promote diabetic complications. Targeting glycation is a strategy for combating the progression of diabetic complications. Pioglitazone enhances insulin sensitivity in patients with type 2 diabetes mellitus, but its impact on glycation remains unclear. This study aims to evaluate whether pioglitazone can inhibit glucose-induced glycation of human serum albumin (HSA), using in vitro assays and in silico tools. Pioglitazone inhibited >70% of early glycation products and >75% of AGEs. The treatment also reduced free lysine modification and improved biochemical markers, including carbonyl and free thiol levels. Pioglitazone exhibited moderate binding affinity for HSA, with a binding constant of 10⁴ M⁻¹. The interaction between pioglitazone and HSA was both spontaneous and entropically favourable. Molecular dynamics simulations revealed that the HSA–pioglitazone complex remained quite stable, with RMSF, RMSD, SASA, R_g, and HSA’s secondary structure showing minimal changes throughout the simulation. The overall binding energy for HSA–pioglitazone complex formation was −30.06 ± 0.31 kcal mol⁻¹, as obtained from MD simulations. The findings suggest that pioglitazone likely interacts with glycation-prone regions of HSA, as indicated by spectroscopic and docking analyses, and contributes to the reduction of glycation. Full article

BisphenolA (BPA) is a common endocrine disruptor that impairs male fertility through oxidative stress and alterations in membrane lipids. This study evaluated the protective effects of Myrtus communis L. essential oil (EOMC) on BPA-induced sperm toxicity in Wistar rats in vitro. BPA significantly decreased sperm motility and viability. It also increased lipid peroxidation, depleted thiols, and reduced the activity of antioxidant enzymes (SOD, CAT-like and GPx-like). Concomitant treatment with low and intermediate doses of EOMC (0.5–1 µL/mL) restored sperm function, reduced oxidative stress, and preserved membrane phospholipids. However, the highest dose (5 µL/mL) further impaired sperm function and disrupted membrane phospholipids. BPA also altered amino acid profiles and accumulated intracellularly, effects partially reversed by EOMC, which redistributed free BPA into the culture medium. Bioavailability analysis revealed selective absorption of α-pinene, while d-limonene and 1,8-cineole were undetectable. Molecular modeling indicated strong binding of BPA to antioxidant enzymes, potentially disrupting their structure and activity. Overall, these results show that EOMC protects sperm from BPA-induced damage in a dose-dependent manner through antioxidant, membrane-stabilizing, and redistribution mechanisms. This highlights its potential application in phytotherapy for male reproductive health. Full article

Heavy metals including mercury (Hg), lead (Pb), cadmium (Cd), and arsenic (As) remain significant global toxins due to their environmental persistence, widespread anthropogenic release, and serious biological effects. This review consolidates current understanding of their natural and industrial sources, environmental cycling, human exposure routes, and population-level vulnerabilities. It covers their toxicokinetics and toxicodynamics, emphasizing species-specific absorption, distribution, and injury mechanisms, including oxidative stress, thiol binding, mitochondrial dysfunction, endocrine disruption, and cancer risk. Clinical signs range from subtle neurocognitive impairment and kidney damage to severe acute poisoning. The review evaluates evidence-based approaches to risk assessment and biomonitoring, such as blood, urine, hair, and speciation tests, noting issues, including unvalidated provoked testing. Treatment focuses on removing exposure, providing nutritional support, and offering supportive care, with chelation therapy reserved for specific cases. It explains the chemistry, pharmacology, and roles of chelating agents—ALA, DMSA, DMPS, Cys, GSH, and physiologic thiols, comparing their effectiveness, limitations, and costs for various metals. Emerging therapies, precision toxicology, and public health strategies are discussed within a prevention-focused context. Unlike prior reviews focused primarily on toxic mechanisms or isolated clinical management, this review integrates mechanistic toxicology, biomarker interpretation and speciation, evidence-based clinical care, and ethical, cost-conscious decision-making within a single translational framework. This narrative review synthesizes foundational and contemporary literature published through 2025, with particular emphasis on studies published since 2000 that inform toxicokinetics, biomarker interpretation, diagnostics, clinical management, and prevention. Full article

The biotransformation of nodularin (NOD) is one of the critical strategies for regulating their biological toxicity. To investigate the effects and mechanisms of the biotransformation pathway, this study synthesized six biotransformation products of nodulein-R (NODR-BTPs) and evaluated their inhibitory effects on protein phosphatase 1 (PP1) through protein phosphatase inhibition assays. The inhibitory effects of NODR-BTPs diminished as the molecular weight and polarity of the introduced biological thiols increased, indicating that biotransformation is an efficient mechanism for modulating the biological toxicity of NODR. Through ligand replacement and molecular docking techniques, the potential regulatory mechanisms underlying the primary interaction processes between NODR-BTPs and PP1 were further elucidated. The introduced biological thiols improved the hydrogen bonding for Glu₂₇₅ ← “Mdhb⁵”and enhanced the electropositive–electronegative interactions between “Mdhb⁵” and PP1. This resulted in an increase in the positive accessible surface area, negative accessible surface area, and polar surface area at the interface of “Mdhb⁵” and PP1. The biothiol moiety subsequently enhanced hydrogen bonds for Arg₉₆ → MeAsp¹ and Arg₉₆ → Glu⁴, thereby affecting the binding of these key interaction sites to PP1. This further diminished interactions between conserved amino acids in PP1 and Mn²⁺ ions, including the ionic bond for Asp₉₂-Mn₁²⁺ and metal bonds for Asp₆₄-Mn₁²⁺ and His₆₆-Mn₁²⁺, leading to increased exposure of Mn²⁺ ions. The regulatory mechanisms facilitated the restoration of PP1 catalytic activity. Full article

The development of oxidation-resistant and regenerable materials remains a major challenge for mercury removal from contaminated waters and industrial effluents. In this study, a zwitterionic mesoporous silica gel functionalized with L-cysteine (SG-3PS-Cys) was synthesized, where the thiol group is covalently anchored to the silica framework, preventing oxidative degradation while preserving –NH₃⁺ and –COO⁻ groups for Hg(II) coordination. Spectroscopic analyses (FTIR, XPS, and ¹³C NMR) confirmed the formation of a stable, thiol-free binding environment in which mercury interacts through carboxylate oxygen atoms, electrostatically stabilized by neighboring ammonium groups. The material exhibited a high surface area (134 m² g⁻¹) and uniform mesoporosity (9.8 nm), achieving a maximum Hg(II) uptake of 82.7 mg g⁻¹ at pH 3 with rapid kinetics and cooperative S-type isotherms. The adsorbent retained 72% of its capacity after five regeneration cycles and maintained 38.7% selectivity toward Hg(II) in multicomponent solutions. DFT-based surface energy distribution analysis supported the zwitterionic coordination mechanism, revealing energetically homogeneous and high-affinity binding domains. Beyond its chemical stability, the material introduces a sustainable route for mercury remediation, linking surface energy, electrostatic effects, and porosity to achieve durable performance under acidic and complex aqueous conditions. These findings provide a mechanistic and design framework for the next generation of non-thiol adsorbents capable of selective and reusable Hg(II) removal in environmentally relevant scenarios. Full article

To achieve the high-value utilization of pine nut resources, a novel zinc supplement was developed in this study. Pine nut protein was enzymatically hydrolyzed to prepare pine nut peptides (PP), which were subsequently chelated with zinc ions to form pine nut peptide–zinc chelate (PZn). Under optimized conditions, the zinc chelation rate of PZn reached 60.18 ± 1.77%. Peptidomic analysis revealed that PZn is composed of a select group of peptides predominantly characterized by low molecular weight (80.65 ± 1.47% < 1 kDa) and enrichment in aspartic acid, glutamic acid, and cysteine, indicating a self-selective chelation process. Comprehensive characterization via multiple techniques confirmed that zinc ions coordinate with carboxyl, hydroxyl, and thiol groups on these peptides, leading to charge neutralization, disruption of hydrogen-bonding networks, and peptide aggregation. Furthermore, bioactivity prediction of the PZn-constituting peptides revealed high intrinsic antioxidant potential, which corroborated the experimental results, showing that PZn exhibited significantly enhanced radical scavenging capacity compared to PP. These findings demonstrate that PZn possesses excellent zinc-binding capability and antioxidant activity, suggesting its potential as a novel zinc supplement, with its efficacy rooted in its specific molecular composition. Full article

Metal nanoparticles (NP) are increasingly used in biomedical applications. Among them, silver NPs (AgNPs) are used as active components in antibacterial coatings for wound dressings, medical devices, implants, cosmetics, textiles, and food packaging. On the other hand, AgNPs can be toxic to humans, depending on the dose and route of exposure, as agents delivering silver to cells. The cysteine residues are the primary molecular targets in such exposures, due to the high affinity of Ag⁺ ions to thiol groups. The Endothelial monocyte-activating polypeptide II (EMAP II), a cleaved C-terminal peptide of the intracellular aminoacyl-tRNA synthetase multifunctional protein AIMP1, contains five cysteines exposed at its surface. This prompted the question of whether they can be targeted by Ag⁺ ions present at the AgNPs surface or released from AgNPs in the course of oxidative metabolism of the cell. We explored the interactions between recombinant EMAP II, tRNA, and AgNPs using UV-Vis and fluorescence spectroscopy, providing insight into the effects of AgNPs dissolution kinetics on interaction EMAP II with tRNA. In addition, the EMAP II fragments binding to intact AgNPs were established by heteronuclear ¹H-¹⁵N HSQC spectra utilizing a paramagnetic probe. Structural analysis of the EMAP II reveal that the 3D structure of protein was destabilized (partially denatured) by the binding of Ag⁺ ions released from AgNPs at the most exposed cysteines. Surprisingly, this effect enhanced tRNA affinity to EMAP II, lowering its $K_d$. The course of the EMAP II/tRNA/AgNP reaction was also modulated by other factors, such as the presence of Mg²⁺ ions and TCEP, a thiol-group protector used to mimic the reducing conditions of the cell. Full article