Search Results (11,862)

Current treatments for ulcerative colitis (UC) often fail to adequately address its multifactorial pathogenesis, which involves oxidative stress, barrier dysfunction, and gut microbiota dysbiosis. This study evaluated the therapeutic potential and multi-targeting mechanism of a ginseng, salvia root, and notoginseng oral solution (GSNS) in a mouse model of colitis induced by dextran sulfate sodium (DSS). Based on high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) technology, 25 major bioactive components were identified. Following the induction of colitis with 3.5% DSS in C57BL/6J mice, the animals were treated with the GSNS (40, 80, or 160 mg/kg/day) or 5-Amino Salicylic Acid (5-ASA). The therapeutic efficacy was assessed via disease activity, histopathological staining, cytokines and oxidative stress analysis, and a barrier integrity test. Combined data from Western blot, qPCR, immunohistochemistry, electron microscopy, and 16S rRNA sequencing indicate that the therapeutic effect of the GSNS against colitis is attributable to its dual role in dampening pro-inflammatory cytokines and potentiating antioxidant defenses via the Nrf2/HO-1 signaling pathway. It also upregulated Occludin expression, repaired tight junctions, and was associated with beneficial alterations in the gut microbiota, as evidenced by increased Prevotellaceae and suppressing Escherichia-Shigella. These findings demonstrated that the GSNS exerts a multi-target effect against colitis by synergistically enhancing antioxidant defense, repairing the intestinal barrier, and modulating microbial ecology, supporting its potential as a promising natural compound-based candidate for DSS-induced colitis treatment. Full article

Antimicrobial resistance (AMR) threatens global health, particularly through the rise of multidrug-resistant tuberculosis (MDR-TB) and other critical bacterial infections such as methicillin-resistant Staphylococcus aureus (MRSA). Rifamycins remain frontline antibiotics but are increasingly undermined by resistance. Here, we introduce a click-enabled platform for the synthesis of C8-functionalized rifamycins, which can be converted in a single additional step into efficacious 3′-hydroxy-5′-aminobenzoxazinorifamycins (bxRifs) and enzymatically into 25-deacetylated rifamycins (deAcRifs), providing access to novel antibacterial scaffolds that expand beyond the scope of traditional C8 modifications. Accordingly, we establish a modular strategy for late-stage analog development of the complex natural product rifamycin S, wherein azido and alkyne functionalities are installed via tailored core chemistry and converted into 1,2,3-triazoles through copper(I)-catalyzed click chemistry. Another key feature of this work is the development of systematic HPLC purification methods, enabling the isolation of analytically pure compounds despite structural complexity. The resulting analogs exhibit distinct antibacterial profiles, notably against Gram-positive bacteria including MRSA and Streptococcus mutans, informing structure–activity relationships and offering a foundation for further optimization. This approach supports the rapid diversification of rifamycin scaffolds to combat the escalating threat of AMR, while also establishing a foundation for future discovery through bioorthogonal applications. Full article

Background/Objectives: Meloxicam (MLX) is a nonsteroidal anti-inflammatory drug (NSAID) recommended for treating acute and chronic pain in dogs, frequently administered prophylactically to mitigate postoperative pain; however, its utility is limited by characteristic NSAID-associated adverse effects, such as gastrointestinal side effects. Nanosystems offer the potential to minimize adverse effects by sustaining drug release. Therefore, this study assessed the pharmacokinetics of MLX nanoencapsulation in female dogs undergoing ovariohysterectomy using a population pharmacokinetic (PopPK) modeling approach. Methods: MLX-loaded polymeric nanocapsules (NC-MLX) were prepared using the nanoprecipitation method and characterized by zeta potential, pH, mean diameter, particle size distribution, and drug content. Dogs received 0.2 mg/kg of either NC-MLX or free MLX orally, 4 h before surgery, and plasma samples were analyzed using an HPLC-PDA method. Pharmacokinetics were characterized by non-compartmental analysis and PopPK modeling. Several compartmental structures, variability models, and residual error models were explored, and relevant covariates were investigated. Results: NC-MLX had an average diameter of 326 ± 13 nm, a zeta potential of −26.2 ± 6.4 mV, and drug loading of 99.47% ± 0.01%. NC-MLX showed a significant increase in the t_1/2 (36.99 ± 17.26 h) of MLX compared to the free drug (15.22 ± 4.4 h). The best-fitting PopPK model was a two-compartment model with double extravascular first-order absorption rate constants (Ka₁ and Ka₂), including a lag time for Ka₂ and linear elimination, describing the second peak observed in several animals. The nanoformulation was a significant covariate for Tlag₂, delaying the time for absorption (1.22 and 2.55 h for free MLX and NC-MLX, respectively) and increasing V₂ (0.134 and 0.402 L/kg for free MLX and NC-MLX, respectively). External model validation showed that the final PopPK model accurately predicted plasma concentrations, with MPE% and RMSE values below 15%. Conclusions: Our findings suggest that NC-MLX alters MLX absorption and distribution profiles, supporting its potential as an alternative for postoperative pain management in dogs. Full article

Background: Red/blue- light-emitting diode (LED)-assisted withering provides a controllable spectral input to steer tea quality, yet metabolite-level evidence linking spectrum composition to quantitative taste phenotypes in white tea remains insufficient. Methods: Fresh leaves were withered under supplemental red/blue LEDs—S0, S1, S2, S3, S4, and S5—and the resulting white teas were evaluated by quantitative descriptive analysis (QDA), untargeted metabolomics, weighted gene co-expression network analysis (WGCNA), and high-performance liquid chromatography (HPLC) quantification of caffeine, gallic acid, and eight catechin monomers. Results: Red/blue-mixed spectrum enhanced the overall sensory quality relative to the incandescent lamp; S3 maximized sweetness and freshness, whereas S4 minimized bitterness and astringency and achieved the highest overall score. Untargeted metabolomics showed the largest deviation for S0 vs. S4. A total of 18 common metabolites were identified between the S0 and light-supplemented withering treatments, dominated by saccharides and related derivatives. WGCNA linked a saccharide-centered module to higher sweetness/freshness/smoothness and a lipid-oxylipin-centered module to stronger bitterness/astringency. HPLC independently confirmed that S4 contained the lowest catechins and caffeine, supporting its reduced bitter/astringent attributes. Conclusions: Overall, the application of mixed red-blue spectra offered a promising approach to enhancing the palatability of white tea by coordinately intensifying saccharide metabolism while simultaneously suppressing key bitter and astringent components. Our study provided a scientific basis for standardizing white tea processing to enhance sensory quality. Full article

Mycotoxins are the most frequently occurring natural contaminant in food and feed products. Through the deployment of diverse agricultural strategies or biological, chemical, or physical treatments of crop products, mycotoxin contamination remains a persistent issue for the agricultural sector and food/feed industry. We previously suggested that halophytes, thanks to their high antioxidant activity, could protect animal cell lines from mycotoxin contamination. Here, a hydroalcoholic extract of Calystegia soldanella L. leaves was evaluated for in vitro total antioxidant capacity (TAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH)-quenching bioassays, as well as anti-inflammatory (ELISA measurement of IL-8 secretion), ROS-inhibiting production (CellROX Green assay), and calcium influx restoration (fluorescent probe Fura2-QBT assay) activities in two animal cells upon mycotoxin intoxication. C. soldanella extract displayed high antioxidant activities (DPPH IC₅₀ < 80 μg·mL⁻¹ and TAC of 90 mg AAE·g⁻¹ DW. Moreover, it exhibited a significant protective action on renal (MDBK) and intestinal (IPEC-J2) cells against zearalenone (ZEA) or T2-toxin contamination, restoring about 75% of cell viability (MTS bioassay) at 1 μg·mL⁻¹. This effect was accompanied by strong anti-inflammatory, ROS-inhibition, and membrane integrity restoration activities. A bio-guided study revealed that the fraction of C. soldanella extract eluted from C18-bound silica with 60% methanol was the most active one. Upon HPLC and 1D- and 2D-NMR analyses, major compounds identified in this fraction were flavonol-type flavonoids, including quercetin-3-O-glucose (X1), quercetin-3-O-rutinoside (X2), and quercetin-3-O-glucose-6″-acetate (X3). Enriched sub-fractions containing these compounds largely contributed to the cytoprotective effects of C. soldanella, supporting its potential use as a food/feed ingredient. Full article

White Analytical Chemistry (WAC) provides a holistic framework for evaluating analytical methods by balancing analytical performance, environmental sustainability, and practical efficiency. Existing WAC assessment tools offer structured evaluation but often lack flexibility or comprehensiveness. To bridge this gap, we introduce the Whiteness Evaluation for Chemical Analysis (WECA) tool as a dynamic, web-based application that enables customizable, context-aware assessment of analytical methods. WECA allows users to select 2–4 criteria per RGB domain (Red: analytical performance; Green: environmental impact; Blue: practical efficiency), assign user-defined weights, and visualize results through an intuitive color-coded interface. The tool calculates a composite WECA score (%) that reflects overall method “whiteness”. Three case studies, covering HPLC-DAD, micellar electrokinetic chromatography, and electrochemical sensing, demonstrate WECA’s applicability and its ability to highlight method strengths and weaknesses across diverse analytical scenarios. WECA represents a step toward more adaptable, transparent, and visually intuitive method evaluation in alignment with the evolving principles of WAC. Full article

Background: Traditionally, wild jujube (Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chou) has been used to nourish the heart, calm the spirit, and arrest spontaneous sweating. Modern research confirms its broad pharmacological activities, including antioxidant, anti-inflammatory, neuroprotective, and cognitive-enhancing effects. This study aims to isolate and characterize the structure of jujube polysaccharides and evaluate their protective effects against oxidative stress damage in neural stem cells (NSCs). Methods: We successfully isolated and purified a novel pectin polysaccharide (ZJP-2) from wild jujube. Its structure was characterized in detail using high-performance liquid chromatography coupled with multi-angle laser light scattering and refractive index detection (HPLC-MALS-RI), high-performance anion exchange chromatography (HPAEC), gas chromatography–mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) spectroscopy. Results: Structural analysis revealed that ZJP-2 is a pectin heteropolysaccharide with a molecular weight of approximately 67.93 kDa. Its monosaccharide composition primarily includes galac-turonic acid (GalA), arabinose (Ara), rhamnose (Rha), galactose (Gal), and glucose (Glc). The backbone consists of α-GalA and rhamnose-galacturonic acid-I (RG-I) domains linked by (1→4)-glycosidic bonds. NMR spectroscopy further confirmed its glycosidic bond types. In activity assessment, our study demonstrated that ZJP-2 significantly alleviated DMNQ-induced oxidative stress damage in C17.2 neural stem cells. Its protective effect was achieved by reducing intracellular reactive oxygen species (ROS) levels and upregulating the mRNA expression of antioxidant genes associated with the signaling axis (p < 0.05). Moreover, ZJP-2 suppressed DMNQ-induced overexpression of Nestin and NeuN (p < 0.05), contributing to the maintenance of NSCs’ undifferentiated state and functional homeostasis. Conclusions: In conclusion, ZJP-2 possesses distinct structural characteristics and significant neuroprotective potential, supporting its development as a natural functional food or dietary supplement for preventing oxidative stress-related neural damage. Full article

(1) Background: Bioactive peptides from marine and plant sources show neuroprotective potential, yet how their combination ratios affect memory regulation via the gut–brain axis remains unclear. This study investigated the effects of different ratios of marine peptide QMDDQ (Glutamine-Methionine-Aspartate-Aspartate-Glutamine) and plant peptide AGLPM (Alanine-Glycine-Leucine-Proline-Methionine) on scopolamine-induced memory impairment in mice. (2) Methods: Cognitive function was assessed using the Morris water maze and novel object recognition tests. Nissl staining, microplate-based assays for acetylcholine (ACh) content and acetylcholinesterase (AChE) activity, Western blotting for neurotrophic factors, LC-MS/MS-based intestinal peptide profiling, and HPLC-based brain amino acid analysis were performed. (3) Results: The 1:1 ratio most effectively restored learning and memory, regulated hippocampal cholinergic function, mitigated neuronal damage, and elevated BDNF, NGF, and NTF-3 expression. In the gut, peptides were hydrolyzed into glutamate- and proline-rich fragments, which influenced brain amino acid balance by elevating glutamate and proline levels while reducing NH₃-related signaling. (4) Conclusions: These results highlight the ratio-dependent efficacy of QMDDQ-AGLPM combinations and provide evidence for a gut peptide remodeling-brain metabolic link relevant to cognitive impairment. Full article

This study aims to evaluate the interspecific variation in polyphenolic profiles and biological activities of acorn flours from three native Tunisian Quercus L. species (Q. ilex L., Q. suber L., and Q. canariensis Willd.). Q. canariensis extracts are the richest in total phenolic, flavonoid and hydrolysable tannin contents. Six phenolic compounds were identified by HPLC-DAD analysis. Chlorogenic acid was the dominant compound in Q. canariensis and Q. ilex acorns. Whereas in Q. suber, caffeic acid was the main component and, along with trans-ferulic acid, was exclusive to this species. Hyperoside was notably identified in Q. canariensis. The UHPLC-DAD-MS analysis of hydrolysable tannins revealed twelve compounds. Acorns of Q. canariensis and Q. suber were dominated by ellagitannins, whereas Q. ilex contained mainly gallotannins. To our knowledge, these compounds are identified for the first time in Tunisian acorns. Q. canariensis exhibited the strongest antioxidant potential with DPPH, ABTS and FRAP assays, as well as the highest antibiofilm and anti-α-amylase activities. All extracts inhibited ATCC pathogenic bacterial strains while largely sparing the beneficial probiotic Limosilactobacillus fermentum. This result indicates a selective antibacterial effect not previously reported for Quercus acorns. Q. canariensis may represent a potential source of functional food ingredient, nutraceuticals, and pharmaceuticals, which remains to be confirmed through in vivo investigations. Full article

Objectives: The aim of the work was to present a method for routine determination of antiarrhythmic drugs, propafenone (PPF), its two metabolites, 5-hydroxypropafenone (5OHPPF) and N-depropylpropafenone (NDPPF), mexiletine (MEX), amiodarone (AD) and desethylamiodarone (DEAD) in serum. Methods: A simple isocratic HPLC-UV system with a manual injector was applied. The separations were performed at ambient temperature on Supelcosil LC-CN column (150 × 4.6 mm, 5 μm). Two analytical procedures (A and B) were used: (A) for AD and (B) for PPF/MEX. The mobile phase for (A) was a mixture of: CH₃OH:CH₃CN:H₂O:0.5M KH₂PO₄ (200:100:194:6 v/v + 0.1 mL 85% H₃PO₄ per 500 mL). The slightly acidified serum sample was extracted with hexane and the analytes were detected at 240 nm. The mobile phase for (B) was a mixture of: CH₃CN:H₂O:0.5M KH₂PO₄ (185:310:5 v/v + 0.1 mL 85% H₃PO₄ per 500 mL). The alkalized serum sample was extracted with diisopropyl ether, then back extracted into 0.01M HCl and finally the analytes were detected at 210 nm. Results: The method was calibrated with adequate selectivity and specificity in the range of 20–4000 ng/mL for AD, DEAD and MEX, 10–4000 ng/mL for PPF and 10–500 ng/mL for 5OHPPF and NDPPF. For all analytes, precision and accuracy fulfilled EMA requirements, i.e., ≤15% (≤20% for LLOQ), ensuring the reliability of the measurements. Conclusions: The method can be suitable for laboratories equipped with basic HPLC apparatus as an economical alternative to the LC-MS/MS technique. Full article

Parkinson’s disease (PD) is characterized by progressive degeneration of nigrostriatal dopaminergic neurons, leading to motor dysfunction and compensatory postsynaptic dopamine receptor alterations. Valproic acid (VPA), a histone deacetylase inhibitor, has shown neuroprotective properties; however, its dose-dependent effects on dopaminergic integrity and dopamine D2 receptor (D2R) regulation remain unclear. Adult male Wistar rats received VPA (200 or 400 mg/kg, p.o.) or vehicle for 20 days prior to unilateral 6-hydroxydopamine (6-OHDA) lesioning. Motor performance was evaluated using the beam balance test, exploratory behavior in the open field, striatal dopamine levels by PLC-electrochemical detection, and D2R protein expression by Western blot. The 6-OHDA lesion induced marked motor deficits, reduced striatal dopamine content, and significantly increased D2R expression. VPA at 200 mg/kg produced only minor, non-significant effects. In contrast, VPA at 400 mg/kg preserved motor performance, attenuated dopamine depletion, and normalized striatal D2R expression. These findings demonstrate a clear dose-dependent neuroprotective effect of VPA and indicate that stabilization of postsynaptic D2R expression accompanies preservation of dopaminergic terminals in the 6-OHDA rat model. Full article

Imidazole dipeptides (IDPs), including carnosine, anserine, and balenine, are functional food ingredients found in meats. They have been reported to exhibit high antioxidant activity. 2-Oxo-imidazole dipeptides (2-oxo-IDPs) are present in trace amounts in various tissues and show notably higher antioxidant activity compared with IDPs. Trace amounts of 2-oxo-IDPs are also present in commercial IDP reagents, suggesting that they affect the antioxidant activity of IDPs. Trace amounts of 2-oxo-IDPs were detected in IDP reagents from various manufacturers by HPLC. Some reagents with trace amounts of 2-oxo-IDPs exhibited higher antioxidant activity in a DPPH radical-scavenging assay compared with high-purity IDP reagents devoid of 2-oxo-IDPs. Therefore, it is important to use highly purified IDP reagents to measure antioxidant activity accurately. The antioxidant activity of highly purified IDPs and 2-oxocarnosine (2-oxo-Car) was evaluated through their ability to protect protein and DNA from ROS. 2-Oxo-Car markedly inhibited the protein and DNA degradation by ClO⁻ and ONOO⁻ compared with IDPs. Moreover, 2-oxo-Car was not cytotoxic, even at high concentrations, and suppressed pyocyanin-induced ROS generation in C2C12 cells compared with IDPs and glutathione. Overall, 2-oxo-IDPs are effective antioxidants and are equivalent or superior to known water-soluble antioxidants, such as glutathione and vitamin C. Full article

In recent years, sustainability and the concept of a circular economy have grown in importance within almost all industrial sectors. Especially in the chemical industry, recycling of polymer waste streams has become an important pathway to avoid plastic waste being landfilled or incinerated. Additionally, traditional carbon sources, such as fossil fuels, can be substituted with streams of recycled polymer. For example, polyethylene terephthalate (PET), which is utilized in plastic bottles and textiles, may be recycled via glycolysis. This depolymerization yields the monomer bis(2-hydroxyethyl) terephthalate (BHET). This study focuses on the thermal behavior and stability of BHET, both in pure form as well as in the presence of ethylene glycol (EG), as it results from PET glycolysis. For this, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), high-performance liquid chromatography (HPLC), powder X-ray diffraction (PXRD), and thermogravimetry (TG) were utilized. The results exhibited pure BHET polymerizing to PET at temperatures above 120 °C, while further increasing temperatures increased the reaction kinetics. Additionally, no reaction was observed in BHET/EG mixtures at any temperature investigated, which can be attributed to the presence of EG shifting the equilibrium of the reaction towards the BHET, thus inhibiting polymerization. Based on these results and the determined BHET/EG (solubility) phase diagram, potential purification strategies based on crystallization are proposed. Full article

This study evaluated the effect of freezing and frozen storage at three temperatures (−20, −30, −40 °C) on hop (Humulus lupulus L.) secondary metabolites and antioxidant capacity. These temperatures were selected based on the glass transition temperature (T_g’) of the maximally freeze-concentrated matrix. Cones were analyzed after freezing (t₀) and up to 360 days (t₃₆₀) by high-performance liquid chromatography with ultraviolet diode-array detection (HPLC-UV/DAD) for bitter acids, prenylflavonoids and phenolic acids, and by the Folin–Ciocalteu, ABTS the radical cation scavenging assay (ABTS) and the ferric-reducing antioxidant power assay (FRAP) assays for total phenolic content and antioxidant activity. Confocal laser scanning microscopy (CLSM) at t₃₆₀ was used to relate microstructural damage to metabolite retention. Freezing at −40 °C ensured the highest retention of bitter acids, phenolic acids (gallic, syringic, vanillic, caffeic, chlorogenic), and antioxidant capacity, whereas xanthohumol and 8-prenylnaringenin reached their maximum levels at −30 and −20 °C, respectively. During frozen storage, changes in metabolite profiles were mainly driven by storage time rather than temperature; over 360 days, α-acids, colupulone, xanthohumol and selected phenolic acids increased, while most other compounds declined. Multivariate analysis and CLSM elucidated the relationships between process conditions, tissue structure and metabolite profiles, enabling the selection of freezing and storage temperatures to optimally preserve different targets of hop bioactives and overall indicating −40 °C as the most effective. Full article