Search Results (525)

As a non-volatile diterpenoid, oridonin represents the major bioactive compound in the medicinal plant Isodon rubescens (Hemsl.) Hara. This compound exhibits a broad range of pharmacological activities, including potent anticancer effects against various tumor types, as well as antibacterial and anti-inflammatory properties. Although the pharmacological properties of oridonin have been extensively characterized, its exact tissue-level distribution in leaves has yet to be elucidated. In this study, histochemical staining, desorption electrospray ionization mass spectrometry imaging (DESI–MSI), and dichloromethane-targeted extraction coupled with high-performance liquid chromatography (HPLC) were employed to determine the cellular distribution of oridonin in I. rubescens leaves. Histochemical staining with Hydrochloric acid–vanillin (HCl–vanillin) revealed intense fluorescence signals exclusively in peltate glandular trichomes, with no detectable fluorescence in mesophyll cells. DESI–MSI analysis showed that the characteristic ion signal of oridonin (m/z = 387.15) exhibited a punctate distribution pattern closely matching the spatial arrangement of glandular trichomes. Quantitative HPLC analysis demonstrated that oridonin content in glandular trichome extracts accounted for 77.44% of that in whole-leaf extracts, whereas mesophyll extracts contained only 10.20%, suggesting that glandular trichomes serve as the primary storage site. Furthermore, bioactivity assays revealed that glandular trichome-enriched extracts exhibited significant antibacterial activity against Bacillus subtilis, Micrococcus luteus, and Staphylococcus aureus, and showed cytotoxic effects on A549 human lung adenocarcinoma cells, with activity levels positively correlated with oridonin content. These convergent lines of evidence provide evidence that glandular trichomes are the main accumulation and storage sites of oridonin in I. rubescens leaves, and that trichome-stored oridonin constitutes the primary material basis for the antibacterial and cytotoxic activities of this plant. This study provides a cellular-level basis for the quality evaluation and breeding of high-oridonin I. rubescens varieties. Full article

This study investigated the interactions between phenolic compounds from Israeli and Chilean white wines and human serum carrier proteins, including human serum albumin (HALB), gamma-globulin (HGLO), and fibrinogen (HFB), to characterize their antioxidant capacity and serum protein-binding behavior under controlled experimental conditions. The analyzed wines included Israeli Chardonnay (ICR), Chilean Chardonnay (CCR), Israeli Sauvignon Blanc (ISB), and Chilean Sauvignon Blanc (CSB). HPLC and FTIR fingerprinting revealed cultivar- and region-dependent differences in phenolic composition, with Chardonnay wines showing stronger protein-binding behavior and Sauvignon Blanc samples displaying high antioxidant efficiency relative to their phenolic content. ICR exhibited the highest total binding capacity, 46.44%, and the strongest albumin interaction, with a binding constant (Kb) of 8.44 × 10⁴ M⁻¹ and a Gibbs free energy (ΔG) value of −35.03 kJ/mol. Empirical fluorescence quenching kinetics demonstrated that white wine phenolics establish stable physical complexes with human serum proteins, displaying a distinct preferential affinity for HALB as the protein showing the strongest apparent interaction among the proteins tested. Two- and three-dimensional fluorescence spectroscopy confirmed substantial quenching of the intrinsic tryptophan and tyrosine residues, indicating meaningful microenvironmental alterations within the protein’s active transport sites. These empirical interactions were closely mirrored by complementary molecular docking simulations, which provided a structural visualization of the physical binding interactions. ICR also showed the highest antioxidant capacity, with DPPH and CUPRAC values of 1.66 and 2.91 mmol TE/L, respectively. Ethanol control showed negligible effects, indicating that the observed bioactivity was mainly associated with the polyphenolic matrix. Among the investigated samples, Chardonnay showed higher apparent protein-binding capacity, whereas Sauvignon Blanc showed relatively high antioxidant efficiency in relation to its phenolic content. Full article

Polycyclic aromatic hydrocarbons (PAHs) are hazardous contaminants formed during incomplete combustion and frequently detected in smoked, grilled, roasted, and fried meat products. Their formation is influenced by temperature, smoking duration, fuel type, fat content, and the distance from the heat source. Available studies indicate that traditionally smoked and charcoal-grilled products contain higher PAH concentrations than raw or less processed meat. Under Regulation (EU) 2023/915, the maximum permitted levels are 2 µg/kg for benzo[a]pyrene (BaP) and 12 µg/kg for the sum of four marker PAHs (PAH4) in standard smoked meat products, while derogation limits of 5 and 30 µg/kg, respectively, apply to certain traditionally smoked products. Chromatographic methods enable sensitive PAH determination, with limits of detection of 0.003–0.200 µg/kg reported for high-performance liquid chromatography with fluorescence detection (HPLC–FLD) of meat products. Literature data indicate that PAH formation can be reduced through indirect smoking, appropriate fuel selection, smoke purification, prevention of fat dripping, and antioxidant-rich marinades. Overall, effective PAH control requires optimized processing technologies, sensitive analytical monitoring, and compliance with regulatory standards while preserving product quality and traditional practices. Unlike reviews focusing on individual aspects, this review integrates current knowledge on PAH formation, occurrence, health risks, analytical determination, legislation, and mitigation within a single meat-focused framework. Full article

Enrofloxacin residues in foods pose potential risks to food safety and public health, creating demand for rapid, sensitive, and matrix-compatible screening methods. All-inorganic CsPbBr₃ quantum dots (QDs) are promising fluorescent probes because of their strong photoluminescence, but their poor stability in polar media greatly restricts their practical use in food analysis. Herein, ZIF-8-confined and APTES-passivated CsPbBr₃ QDs were developed as an ethanol-compatible fluorescent sensor for enrofloxacin detection in foods. Unlike reported CsPbBr₃@ZIF-8 systems mainly used for metal-ion sensing in aqueous media, this work integrates ZIF-8-confined in-situ growth with APTES-assisted silane passivation to improve the stability and applicability of CsPbBr₃ QDs in ethanol-based food extracts. ZIF-8 provided a confined microenvironment, while the APTES-derived silane layer further enhanced fluorescence stability. The sensor exhibited a distinct turn-off fluorescence response toward enrofloxacin, with a linear range of 0.1–25.0 mg·L⁻¹ and a limit of detection of 0.058 mg·L⁻¹, mainly attributed to electron transfer with CsPbBr₃@ZIF-8. The method was successfully applied to honey, milk, fish, and shrimp samples, achieving recoveries of 85.2–106.8%. Results obtained for aquatic products showed no significant difference from HPLC analysis (p > 0.05), demonstrating the potential of this sensor for rapid enrofloxacin residue screening in complex food matrices. Full article

Background/Objectives: Filipendula ulmaria (L.) Maxim. (meadowsweet) is a medicinal plant traditionally used for its antioxidant and anti-inflammatory effects. There is also some data indicating its anticancer potential; however, its impact on colorectal cancer cells remains poorly understood. Here we investigated the cytotoxic and pro-apoptotic effects of an aqueous F. ulmaria extract on human LoVo colorectal cancer cells and analyzed some of the mechanisms underlying it. Methods: LoVo colorectal cancer cells were treated with the aqueous extract and analyzed for intracellular reactive oxygen species (ROS), mitochondrial membrane potential, DNA damage, lysosomal alterations, apoptosis-related mechanisms, and antioxidant activity. Phytochemical profiling was performed by HPLC-TOF/MS. Results: The extract elevated intracellular ROS levels, disrupted mitochondrial membrane potential, and induced DNA damage in LoVo cells. Activation of crucial caspases, along with increased p53 levels, confirmed engagement of both extrinsic and intrinsic apoptotic pathways. Changes in lysosomal fluorescence were also observed, indicating alterations in lysosomal properties. In chemical assays (FRAP, TAC, DPPH, ABTS, and superoxide scavenging), the extract demonstrated robust antioxidant capacity comparable to or exceeding that of ascorbic acid. Phytochemical profiling by HPLC-TOF/MS revealed a rich presence of bioactive flavonoids, phenolic acids, and coumarins. Altogether, our findings indicate that the extract’s cytotoxicity against colon cancer cells arises from a multifaceted mechanism involving oxidative stress, organelle dysfunction, and apoptosis induction. Conclusions: These results highlight F. ulmaria aqueous extract as a promising candidate for colorectal cancer phytotherapy as a form of supportive treatment and warrant further preclinical validation. Full article

Background: Carcinogenic polycyclic aromatic hydrocarbons (PAHs), particularly benzo[a]pyrene (BaP) and the EFSA-recommended PAH4 index (benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene, and chrysene), can accumulate in human breast milk following maternal exposure. Aim: This study aimed to determine BaP and PAH4 levels in breast milk samples of lactating mothers in Hungary and to evaluate demographic, lifestyle, dietary, and environmental predictors of these carcinogenic PAHs. Methods: Breast milk samples (n = 50) were analyzed using high-performance liquid chromatography with fluorescence detection (HPLC/FLD). Due to the right-skewed distribution of PAH concentrations, BaP and PAH4 values were log10-transformed before statistical analysis. Associations between log10-transformed PAH concentrations and maternal variables were assessed using t-tests, Pearson correlation, and multivariable linear regression. Results: BaP was detected in 32 of 50 samples (64%), whereas PAH4 was detectable in 44 of 50 samples (88%). Frequent milk consumption was independently associated with higher log10-transformed PAH4 concentrations in multivariable analysis. Samples collected during the heating season tended to show higher carcinogenic PAH levels compared to those obtained outside the heating period. Other demographic and lifestyle factors showed no consistent independent associations. Conclusions: Lifestyle and environmental factors, particularly dietary habits and seasonal exposure, contribute to carcinogenic PAH levels in breast milk among Hungarian mothers. Identifying modifiable determinants may support strategies to reduce infant exposure. Full article

Among the non-classical platinum complexes, Pt(IV) prodrugs are most promising as versatile scaffolds for structural modification and fine tuning of their activation-by-reduction mechanism of action and the resulting anticancer activity. Herein, four new asymmetrically disubstituted pyrenebutyrate complexes of Pt(IV) (2–5) were synthesized and thoroughly studied. In this series, the second axial ligand was derived from dicarboxylic acids of different length—4 and 5 C-atoms, or replacement of the C-atom in the middle with either O- or S-atom. The structural effects on reduction kinetics, lipophilicity and cellular internalization of the complexes were monitored by NMR, HPLC, fluorescence and ICP-MS measurements. Their cytotoxicity was tested on a panel of cancer cell lines and mechanistic insights were obtained from proteome analysis and microscope imaging. The data indicate that all complexes, especially complex 3, represent a promising class of Pt(IV) prodrugs, exhibiting significantly higher cytotoxic activity than cisplatin in all tested models, including a cisplatin-resistant line. This was explained with a stronger and more integrated apoptotic response than cisplatin: pronounced Bax upregulation (3.6-fold), maximal cleaved caspase-3 (4-fold), activation of both intrinsic and extrinsic pathways, and effective p53 Ser15/Ser46 phosphorylation. The consistent rank order of potency (3 > 4 > 5 ≈ 2 ≫ cisplatin) suggests that subtle ligand modifications can substantially enhance efficacy, possibly by improving cellular uptake or altering DNA binding. Full article

Marine medicinal algae represent a valuable reservoir of bioactive metabolites for anticancer drug discovery, yet the efficient identification of target-relevant compounds from chemically complex marine matrices remains challenging. In this study, an integrated cathepsin B-oriented strategy was developed to discover, prioritize, isolate, and validate antitumor metabolites from the brown alga Sargassum polycystum. Affinity ultrafiltration LC-MS was first applied to screen CTSB-binding constituents from the crude extract, followed by molecular docking, molecular dynamics simulation, and gray relational analysis for multidimensional candidate prioritization. Seven CTSB-binding metabolites were characterized, including chlorogenic acid, caffeic acid, cynarin, loliolide, taxifolin, senkyunolide H, and dihydroactinidiolide, with binding degrees of 73.99–85.61% at 2.5 U/mL CTSB. Molecular docking showed predicted binding affinities ranging from −6.3 to −9.4 kcal/mol, compared with −10.2 kcal/mol for the positive control CA-074Me. Integrated computational and biological evaluation identified caffeic acid, cynarin, and taxifolin as the top-ranked candidates. Preparative recovery was then achieved using counter-current chromatography combined with semi-preparative HPLC, and the isolated compounds were structurally identified by LC-MS/MS and NMR. Cellular assays in NCI-H1975 cells suggested that these metabolites reduced CTSB-associated enzymatic activity and intracellular CTSB-related fluorescence signals to different extents, with phenolic acid-type compounds exhibiting comparatively stronger effects. At the extract level, S. polycystum dose-dependently suppressed NCI-H1975 xenograft tumor growth, with inhibition rates of 48.78%, 36.58%, and 22.86% in the high-, middle-, and low-dose groups, respectively, without evident hepatorenal histopathological toxicity. This effect was associated with reduced CTSB, Ki-67, and Bcl-2 staining, increased Bax staining, enhanced apoptosis, and ultrastructural alterations in tumor tissues. Overall, this study provides a practical CTSB-oriented workflow for discovering antitumor metabolites from marine medicinal algae and supports further investigation of S. polycystum as a potential source of anti-NSCLC candidates. Full article

Mycotoxins are toxic secondary metabolites produced primarily by molds of the genera Aspergillus, Fusarium, and Penicillium. These widespread food and feed contaminants can cause significant risks to human and animal health. The aim of this study was to compare the performance of reference chromatographic methods (high-performance liquid chromatography coupled with either fluorescence detection (HPLC-FLD) or tandem mass spectrometry (HPLC-MS/MS)) with two commercially available rapid tests from two manufacturers. To that end, 90 randomly selected grain samples (barley n = 10, wheat n = 21, triticale n = 10, maize n = 49) collected in 2025 were analyzed for deoxynivalenol (DON), zearalenone (ZEN), ochratoxin A (OTA), and the sum of T-2 and HT-2 toxins. None of the samples exceeded the maximum levels established by the European Union (EU); however, widespread contamination with one or more mycotoxins was observed. Results showed that although rapid test strips offer advantages such as low cost, short analysis time, and operational simplicity, their considerably higher limits of detection and quantification values make them unsuitable for advanced laboratory analysis. Therefore, HPLC-FLD and HPLC-MS/MS remain the gold-standard methods for reliable, sensitive, and precise mycotoxin determination. Full article

Background/Objectives: Teriflunomide is an active metabolite of leflunomide and acts as a selective and reversible inhibitor of dihydroorotate dehydrogenase, a key enzyme in de novo pyrimidine biosynthesis. It exhibits immunomodulatory activity by reducing the proliferation of activated T and B lymphocytes and is widely used in the treatment of rheumatoid arthritis and relapsing multiple sclerosis. This study aimed to develop a rapid, accurate, and simple high-performance liquid chromatography (HPLC) method with fluorometric detection for quantifying teriflunomide in human plasma. Methods: Plasma samples were prepared by liquid–liquid extraction followed by pre-column derivatization with NBD-Cl. Teriflunomide was derivatized with 4-chloro-7-nitrobenzofurazan (NBD-Cl) and separated using a reversed-phase C18 column (5 µm, 4.6 × 150 mm) at 30 °C with isocratic elution. The mobile phase consisted of acetonitrile and 0.1% orthophosphoric acid (80:20, v/v) at a flow rate of 1.1 mL/min. Fluorescence detection was performed at λex = 465 nm and λem = 535 nm. The method meets European Medicines Agency (EMA) guidelines for bioanalytical validation and was successfully applied to pharmacokinetic studies, including AUC_0–t, AUC_0–∞, C_max, T_max, and t_½. Results: Teriflunomide showed a retention time of 2.55 ± 0.01 min. The method exhibited linearity in the range of 0.01–30 ng/mL (r² = 0.9998), with a limit of detection and quantification of 0.003 and 0.01 ng/mL, respectively. The relative standard deviation was 3.27%. Conclusions: This work introduces a novel, cost-effective, and highly sensitive HPLC with fluorescence detection (HPLC-FL) method for the determination of teriflunomide in human plasma, providing an efficient alternative to LC-MS/MS for routine pharmacokinetic and bioequivalence studies. Full article

Background/Objectives: Aromatic L-amino acid decarboxylase deficiency (AADC-D; OMIM #608643) is a rare autosomal recessive neurometabolic disorder caused by pathogenic variants in the DDC gene, leading to impaired of monoamine neurotransmitter biosynthesis. AADC, a pyridoxal-5′-phosphate (PLP)-dependent enzyme, catalyzes the conversion of L-dopa and 5-hydroxytryptophan (5-HTP) to dopamine and serotonin, respectively. Early diagnosis remains challenging due to the limited specificity of current biochemical approaches. This study aimed to evaluate plasma AADC enzyme activity using these physiological substrates by High-Performance Liquid Chromatography (HPLC)-based method and assess its potential utility in the biochemical diagnosis of AADC deficiency. Methods: Plasma AADC activity was quantified using physiological substrates (L-dopa and 5-HTP) by HPLC with electrochemical and fluorescence detection. Sanger sequencing of the DDC gene was performed in two suspected patients to identify pathogenic variants. Results: Two genetically confirmed AADC-D patients demonstrated reduced enzyme activity. Using L-dopa as substrate, enzyme activity in patients was 12.4 and 26.1 pmol/min/mL, both below the published reference interval (36–129 pmol/min/mL). Using 5-HTP as substrate, enzyme activity was 1.5 and 5.1 pmol/min/mL; Patient 1 showed activity below the reference interval (2.0–7.1 pmol/min/mL), while Patient 2 demonstrated activity within the lower range of reported values. Reduced enzyme activity was consistent with the clinical features and molecular findings with identification of pathogenic variants in the DDC gene (c.175G>A and c.714+4A>T). Conclusions: Plasma AADC activity measurement demonstrates potential as a functional biochemical biomarker that augments molecular genetic testing in the biochemical evaluation of AADC deficiency. Further studies involving larger patient cohorts are required to further evaluate its diagnostic performance and broader clinical applicability. Full article

Bacterial infections pose a serious threat to human health, and antibiotics remain the first-line therapeutic agents in clinical practice. However, the vast majority of antibiotics lack the ability to penetrate cell membranes, which severely limits the number of clinically available options for treating intracellular bacterial infections. Developing efficient intracellular antibiotic delivery strategies is therefore of considerable clinical significance, both for reducing antibiotic dosage and for expanding the repertoire of drugs applicable to intracellular infections. To address this challenge, we constructed a protein-based delivery platform mediated by a cell-penetrating miniprotein for efficient intracellular antibiotic delivery. In this system, bovine serum albumin (BSA), which possesses broad antibiotic-binding capability, was employed as the drug carrier, while the cell-penetrating miniprotein ZF5.3, which is capable of endosomal escape, served as the transmembrane delivery mediator. ZF5.3 was conjugated to BSA via a bioorthogonal reaction, and ceftriaxone (CRO) was selected as the model antibiotic to construct a nanoscale delivery system. The binding interaction between CRO and BSA was characterized using UV-Vis, HPLC, and molecular docking techniques. The assembly of the ZF5.3–BSA delivery platform was confirmed by UV-Vis absorption spectroscopy and gel electrophoresis. Intracellular delivery efficiency was evaluated by confocal fluorescence imaging and flow cytometry, and the results demonstrated that ZF5.3 conjugation enhanced intracellular protein delivery efficiency by over 5-fold. Fluorescence co-localization analysis revealed that ZF5.3-mediated cargo is mainly distributed in the cytoplasm and does not completely co-localize with lysosomal markers, suggesting its ability to effectively escape from lysosomes. An intracellular infection model using Staphylococcus aureus was established. Colony-forming unit (CFU) counting experiments confirmed that the delivery system significantly enhanced the intracellular antibacterial activity of ceftriaxone. CCK8 cytotoxicity assays confirmed that the system is non-toxic to cells. Full article

4-Chlorophenoxyacetic acid (4-CPA), a synthetic auxin analog, is employed in agriculture both as a plant growth regulator and as a constituent of herbicide formulations. Consequently, the establishment of simple and rapid detection methods is essential for effective environmental monitoring. This study reports the first development of a homogeneous fluorescence polarization immunoassay (FPIA) for the determination of 4-CPA. The monoclonal antibody (M1), raised against 4-CPA, was evaluated as a recognition element. Furthermore, two fluorescently labeled 4-CPA tracers—with ethylenediamine fluorescein thiocarbamate and aminohexylaminocarbonylfluorescein—were synthesized and purified, and their structures were unequivocally confirmed by high-performance liquid chromatography coupled with high-resolution mass spectrometric detection (HPLC-HRMS). Optimal concentrations of monoclonal antibodies and tracers were established, yielding a limit of detection of 1.2 ng/mL. The assay demonstrated a broad dynamic range of 2.3–300 ng/mL and a rapid analysis time of 15 min. Validation via the standard addition method in authentic open water samples resulted in recovery rates of 98–112%. To address the cross-reactivity with the prevalent herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), two novel strategies were devised and successfully implemented. The first approach involves the concurrent execution of two separate FPIAs—one for 2,4-D and one for 4-CPA—followed by the mathematical resolution of two analyte concentrations from the two measured binding values. The second strategy entails the preliminary selective removal of 2,4-D from sample matrices using affinity chromatography columns with immobilized anti-2,4-D antibodies prior to FPIA for 4-CPA. These proposed methodologies appear highly promising for overcoming the inherent limitations of traditional immunoassays when faced with significant cross-reactivity among structurally analogous compounds. Full article

For agricultural films, spectral matching, UV protection, and environmental durability are essential for efficient crop production. A self-cleaning silane-crosslinked red/blue dual-emission carbon dot/polyvinyl alcohol composite film (KH/RB-CQDs/PVA) was fabricated via a covalent anchoring strategy. RB-CQDs were synthesized by a two-step hydrothermal method using o-phenylenediamine: initial blue-emitting carbon cores formed, then phosphoric acid-assisted secondary treatment covalently bridged residual precursor-derived red fluorophores onto cores through pyrophosphate bonds, as evidenced by TEM, XPS, ³¹P NMR, HPLC-MS and DFT. This rigid bridging suppressed excessive core growth and energy transfer while spatially separating dual emission, endowing excellent photostability (>95% fluorescence retention after 50 min UV and 30 d storage). Subsequently, KH-560 was employed to construct a robust covalent crosslinked network anchoring RB-CQDs in PVA and forming rough Si-O-Si surface structures, confirmed by SEM and XPS. The resulting film exhibited 16.16% quantum yield, 291% tensile strength enhancement, 95% UV shielding, and <1% contaminant residue. Chlorophyll fluorescence kinetics, gas-exchange analyses, and photosynthetic response curves demonstrated that KH/RB-CQDs/PVA increased the potato net photosynthetic rate by 55.46% and tuber yield by 76% through synergistic optimization of photosystem II electron transport and RuBisCO-mediated carbon assimilation. This work provides a molecular design principle for high-performance intelligent agricultural films. Full article

Natural food pigments such as curcumin and β-carotene are valued for their coloring properties and health-promoting bioactivities, including antioxidant and anticancer effects. However, both compounds are susceptible to light-induced degradation, which can compromise their stability and functional integrity. This study investigated changes in the photostability and bioactivity of curcumin and β-carotene under fluorescent light irradiation, focusing on their interactions with the porphyrin photosensitizers zinc protoporphyrin (ZnPP) and protoporphyrin IX (PPIX). Spectral and HPLC analyses revealed significant pigment degradation, with β-carotene exhibiting greater instability than curcumin. ZnPP and PPIX accelerated the bleaching of both pigments in a concentration-dependent manner, with ZnPP consistently showing stronger destabilizing effects. Functional assays further demonstrated that the antioxidant activity of curcumin was altered by light exposure. Co-irradiation with ZnPP or PPIX significantly reduced the scavenging activity of curcumin against DPPH, ABTS, and AAPH radicals. In HCT-116 colon cancer cells, irradiation alone slightly enhanced the cytotoxic activity of curcumin, whereas co-irradiation with ZnPP or PPIX significantly attenuated this effect. These findings indicate that porphyrin photosensitizers accelerate pigment degradation and impair functional properties under light exposure, highlighting the importance of pigment–photosensitizer interactions during food storage and processing. Full article