Search Results (2,499)

Conventional hydrogen peroxide (HP) tooth whitening treatments frequently induce structural deterioration of enamel, necessitating the development of biocompatible and highly efficient alternatives. This in vitro study investigated the application of a novel functional biomaterial, the Type I aggregation-induced emission (AIE) photosensitizer CPTQ, for peroxide-free photodynamic tooth whitening. Under white-light irradiation (25 mW/cm²), CPTQ (12.5 μM) demonstrated rapid degradation of representative chromogenic molecules (crystal violet, malachite green, and rhodamine B). Extracted human teeth stained with both model pigments and complex beverage mixtures (coffee, tea, and fruit juices) were allocated into four treatment groups: negative control (NC), CPTQ, 7.5% HP, and 30% HP (n = 6 per group). Colorimetric parameters (ΔE₀₀, Δa*, Δb*, and ΔL*) and enamel-related endpoints—including surface morphology, roughness, mineral composition (Ca/P), and microhardness—were evaluated over 6 h and analyzed using one-way ANOVA. For pigment-stained teeth, the photodynamic whitening efficiency of CPTQ was comparable to that of 30% HP (ΔE₀₀, p > 0.05) during the 6 h treatment period. At 1.5 h, the ΔE₀₀ value in the CPTQ group (23.35 ± 2.32) was significantly greater than those in the NC group (15.70 ± 1.78, p < 0.05) and the 7.5% HP group (15.02 ± 1.63, p < 0.05). For beverage-stained teeth, the whitening efficiency (ΔE₀₀) of CPTQ was significantly greater than that of the control group at 1.5 h (6.22 ± 2.09 vs. 1.82 ± 0.56, p < 0.01) and was significantly greater than that of 7.5% HP at 4.5 h (10.94 ± 2.82 vs. 7.56 ± 1.78, p < 0.05). Crucially, unlike the change observed after 30% HP treatments, CPTQ treatment resulted in no statistically significant differences from NC in preserved enamel surface integrity, including morphology assessed by SEM, surface roughness (R_a and S_a, both p > 0.05), mineral composition (Ca and P, both p > 0.05), and microhardness (ΔH_V, p > 0.05). Mechanistic investigations using reactive oxygen species (ROS) scavengers (TBA and DABCO) suggested that hydroxyl radicals generated via the Type I photodynamic pathway are the primary drivers of pigment degradation, reducing ΔE₀₀ from 12.56 to 1.09 upon •OH inhibition. CPTQ achieved measurable in vitro whitening through a predominantly Type I ROS-mediated mechanism while causing limited changes in the evaluated enamel surface endpoints. Full article

The antioxidant activity of polyphenolic scaffolds and the selectivity of enzyme inhibition can be significantly modified through structural modification. The antioxidant properties and the multi-target enzyme inhibitory properties of resveratrol and three structurally different analogs (oxyresveratrol, 3′,5′-dimethoxyresveratrol and triacetylresveratrol) were comparatively assessed to clarify the structure-activity relationships. The antioxidant activity was measured using complementary electron-transfer assay, radical-scavenging assay, and metal chelating assay, whereas the enzyme inhibition was evaluated against hCA I and hCA II, GST, AChE, BChE, and α-glycosidase, as well as α-amylase enzymes. Oxyresveratrol showed the best antioxidant behavior in most of the assays, which is in line with the occurrence of the extra additional hydroxyl groups, which increases the ability to donate electrons. Conversely, acetylation significantly minimized radical scavenging action and enhanced enzyme inhibition abilities. The strongest inhibitory activity of triacetylresveratrol was exhibited against hCA I (IC₅₀: 49.50 nM), hCA II (IC₅₀: 46.50 nM), BChE (IC₅₀: 46.20 nM), and against α-glycosidase, whereas, 3′,5′-dimethoxyresveratrol showed the strongest inhibition ability against AChE (IC₅₀: 13.86 nM). Comparatively, resveratrol exhibited a relatively high GST inhibition (IC₅₀: 463.54 nM), which showed the role of the free phenolic groups in the enzyme interaction. These results reveal that hydroxylation positively impacts the antioxidant activity, but acetylation and methoxylation regulate selectivity and the enzymes inhibition potency. The observed differences in biological profiles between the derivatives provide mechanistic insight of activity changes based on functional groups and the selection of resveratrol multi-target therapeutic derivatives in oxidative stress-linked and metabolic diseases. Full article

The present work is a first attempt to develop, on a lab scale, herbal-infused Debina white wines containing typical or lower sulphur dioxide and to evaluate their antioxidant potential and volatile profile. Two different herbal-infused wines were prepared by adding (a) saffron plus mastic, and (b) mountain tea. During storage, all herbal-infused wines exhibited higher antioxidant capacity than the respective control ones, indicating their higher storage capability. In particular, they exhibited higher levels of free SO₂ and aminothiols, substrates of white wine oxidation. Moreover, they exhibited higher antioxidant activity as determined by the Folin, FRAP, and the scavenging of hydroxyl radicals methods. Volatile profile of herbal-infused and control wines was determined semi-quantitatively using HS-SPME coupled with GC×GC-TOF-MS methodology. Herbal-infused wines exhibited enriched volatile profiles containing volatiles originating from the herbals used. These include safranal from saffron, monoterpenes from mastic, and β-thujene, camphene, and β-ocimene from mountain tea. All herbal-infused wines exhibited satisfactory organoleptic quality, with sensory properties differentiated from the respective control ones. Full article

Fe/Zn-modified TiO₂ photocatalysts were synthesized by the sol–gel method to investigate the influence of Fe loading, Zn loading, and calcination temperature on the degradation of food-industry pollutants. A 2³ factorial design combined with Response Surface Methodology was employed to optimize the synthesis parameters. The catalysts were characterized by N₂ adsorption–desorption, SEM/EDS, X-ray diffraction coupled with Rietveld refinement and point of zero charge analyses. The materials exhibited mesoporous structures with type IV isotherms, while Fe/Zn modification altered the crystalline phase composition and surface charge of TiO₂. Low metal loading stabilized the anatase phase, whereas higher Fe contents promoted the formation of hematite and rutile. Photocatalytic performance was evaluated through the discoloration and degradation of Red 40 and Tartrazine under natural sunlight and the degradation of cheese whey under artificial irradiation. F10Z2-400 exhibited the highest activity toward Red 40 (99.85% discoloration and 77.02% COD removal), whereas T-400 showed the best performance for tartrazine (86.25% discoloration and 87.61% COD removal). For cheese whey, F10Z10-400 achieved the highest degradation (41.01% COD removal). Reactive-species scavenging indicated that hydroxyl radicals made the predominant contribution to the discoloration of both dyes, followed by superoxide radicals and photogenerated holes. Kinetic analyses indicated that the Behnajady–Modirshahla–Ghanbery model best described the degradation process. RSM identified calcination temperature as the most influential synthesis parameter and showed that the effects of Fe and Zn loading were pollutant-dependent. No single catalyst formulation provided the best performance for all evaluated matrices. Full article

Coconut meat (solid endosperm) is a valuable oilseed product with significant nutritional and functional properties, yet the quality changes during maturation remain unclear. This study investigated the effects of maturity on nutrients, antioxidant and α-amylase inhibitory activities, and volatile organic compounds in coconut meat of the Wenye No. 3 variety at 8, 10, and 12 months after pollination (named CM-8, CM-10 and CM-12, respectively). Results showed that moisture content decreased from 81.15% to 61.73%, while fat (8.61% to 17.53%), protein (0.60% to 1.29%), and total soluble sugars (2.13% to 4.84%) increased from CM-8 to CM-12. Total phenolic content declined with maturity, whereas ABTS scavenging activity was significantly higher at CM-12 than at CM-10, and hydroxyl radical scavenging activity was similarly elevated at CM-10 and CM-12. α-Amylase inhibitory activity peaked at CM-10 (20.4%). Phosphorus, magnesium, zinc, and copper peaked at CM-12. Lauric acid predominated at all stages, with unsaturated fatty acids transiently increasing at CM-10. GC-IMS identified 31 volatile compounds, with esters and alcohols dominating in CM-8 and CM-10, while aldehydes accumulated in CM-12. These findings provide theoretical guidance for staged harvesting and graded utilization of coconut in the processing industry. Full article

Biochar-supported rare earth oxides are herein assessed as heterogeneous catalysts for the UV-assisted Catalytic Wet Peroxide Oxidation (UV-CWPO) treatment of pharmaceuticals under mild conditions. Catalysts were synthesized by two different pyrolysis methods (activated carbon-assisted oxygen-limited pyrolysis in a muffle furnace, and inert-gas pyrolysis in a tubular furnace under nitrogen flow), and characterized by XRD, SEM, and N₂ adsorption–desorption isotherms. Their performance in assisting 385 nm UVA-LED CWPO treatment of acetaminophen (ACE), diclofenac (DCF), and metamizole (MTZ) was assessed under circumneutral pH conditions. The biochar-supported cerium-loaded catalyst prepared by oxygen-limited pyrolysis reported the highest activity, achieving 80% ACE and 70% DCF removals within 120 min of treatment, whereas MTZ was completely removed in less than 10 min, with only 16% of the removal attributable to adsorption. Superoxide radicals dominated the degradation mechanism, and photogenerated holes and hydroxyl radicals contributed moderately. Catalyst stability (minimal activity loss and negligible cerium leaching) was confirmed over five consecutive reuses. Degradation efficiency decreased ≈12–18% because of radical scavenging losses caused by the content of inorganic ions and organic matter in tap, river, and WWTP effluent waters. Treated effluents addressed lower toxicity than untreated solutions, reinforcing the environmental safety of this treatment strategy. Full article

In this work, we report the fabrication of a relatively efficient, cheap, and stable silicon-based photocatalyst for water purification. Silicon-nickel composites were fabricated by mixing and grinding metallurgical silicon with commercial nickel nanoparticles. Experiments demonstrate a significant improvement in methylene blue degradation under UV—and especially under solar—conditions. About half of the contaminants were degraded after 100 min. Theoretical modeling demonstrates the effects of impurities in subsurface layers on absorbance and on the release of hydroxyl radicals from silicon. Full article

This study proposes a self-condensing water-electrode plasma device in which ambient water vapor is condensed on a cooled needle-tip electrode within a strong electric-field region, forming continuously renewed water droplets, Taylor cones, or water-film interfaces that participate in the discharge process. The effects of ambient humidity, needle-tip temperature, and applied voltage on the self-condensation behavior were investigated. The discharge modes at different applied voltages and discharge gaps, the generation of reactive species, and the inactivation efficacy against Staphylococcus aureus were also analyzed. The results showed that increasing ambient humidity, decreasing the needle-tip temperature, and increasing the applied voltage all promoted water condensation at the needle tip. The electric field shortened the droplet formation time and reduced the droplet detachment size. As the applied voltage increased, the device sequentially underwent water condensation, electrospray, stable Taylor-cone, water-film discharge, and bare-electrode discharge stages, while the boundary voltage of each stage increased with the discharge gap. The ozone concentration remained below the instrument’s limit of detection during discharge with the self-condensing water electrode, whereas hydroxyl-radical generation was significantly enhanced. Compared with a conventional metal electrode, the self-condensing water electrode exhibited greater inactivation of S. aureus at the same applied voltage, with a more pronounced advantage under low-voltage conditions. These findings demonstrate that introducing a self-condensing water interface can regulate the local discharge morphology and reactive-species composition, providing a new strategy for developing low-temperature plasma sterilization technologies with low ozone production and high bactericidal activity. Full article

To realize the high-value valorization of cold-pressed walnut meal, walnut oligopeptides were fabricated via synchronous dual-enzyme hydrolysis combined with activated carbon decolorization and membrane separation purification. We optimized the overall preparation process and systematically characterized the products, including their amino acid profile, in vitro antioxidant capacity, cytoprotective effects against H₂O₂-triggered oxidative injury in PC12 cells, and regulatory activity toward acetylcholinesterase (AChE). The optimal hydrolysis conditions were identified as pH 10.0, total enzyme dosage of 11,000 U/g, a trypsin-to-alkaline protease ratio of 2.1:1, solid–liquid ratio of 1:26, temperature of 51 °C and reaction duration of 4 h, which produced a hydrolysis degree of 33.02%. The optimized decolorization parameters were pH 5.2, activated carbon dosage of 2.3%, treatment at 58 °C for 43 min, with a peptide recovery rate reaching 83.35%. Cold-pressed walnut meal is rich in glutamic acid, arginine and aspartic acid, which lay the molecular foundation for the bioactive properties of the derived oligopeptides. In vitro tests demonstrated that the oligopeptides possessed strong scavenging ability against hydroxyl, DPPH and superoxide anion radicals (clearance rates of 90.18%, 81.72% and 85.80%, respectively), and maintained 73.21% of antioxidant activity after simulated gastrointestinal digestion. Moreover, walnut oligopeptides at 0.8 mg/mL showed no cytotoxicity and afforded a 79.88% protective effect against oxidative damage. The peptides significantly boosted SOD and GSH-Px activities, lowered MDA accumulation, and strongly suppressed AChE activity, performing better than donepezil hydrochloride. This efficient, eco-friendly technique achieves high-value utilization of walnut processing by-products. The obtained oligopeptides possess great potential as natural antioxidants and neuroprotective ingredients for functional food development. Full article

The mycelium of Phallus rubrovolvatus contains abundant metabolites with broad application prospects in functional foods and pharmaceuticals. However, how carbon and nitrogen substrate availability regulate the accumulation dynamics of mycelial metabolites remains under-explored. In this study, the supply levels of carbon (glucose) and nitrogen (peptone) were optimized to select high-biomass mycelia. Integrating nutritional activity assays with metabolomics and redundancy analysis, the regulatory mechanisms governing carbon–nitrogen metabolic flux were deciphered. The results demonstrated that mycelial nutritional content and antioxidant capacity exhibited a progressive upward trend under three distinct modes: carbon-driven, nitrogen-driven, and carbon–nitrogen synergistic-driven regimes. In the optimal carbon–nitrogen synergistic-driven group, the contents of total soluble sugars, reducing sugars, flavonoids, total phenolics, and soluble proteins increased by 72.06%, 160.80%, 52.47%, 113.69%, and 8.21%, respectively, compared with the control group. Meanwhile, the scavenging rates of superoxide anion, hydroxyl, ABTS, and DPPH free radicals increased by 14.12%, 24.09%, 14.77%, and 66.47%, respectively, compared with the control group. Differentially accumulated metabolites were significantly enriched in amino acid metabolism, energy metabolism, and secondary metabolite biosynthesis pathways. Carbon and nitrogen substrates reshaped intracellular metabolic flux, cooperatively regulating nutrient synthesis and intracellular redox equilibrium. This work reveals a cascade-linking relationship in which nutrient supply triggers metabolic remodeling, regulates oxidative balance, and drives pathway response. It provides theoretical support for the precision fermentation and industrial upgrade of P. rubrovolvatus, while offering a valuable reference paradigm for the high-value exploitation of other rare edible and medicinal fungi. Full article

Background/Objectives: Medicinal and aromatic plants are important sources of phenolic compounds with antioxidant properties. This study evaluated the total phenolic content (TPC) and antioxidant activity of 19 commercially available medicinal herb and spice products of reported Mount Athos provenance and investigated the influence of extraction solvent on these properties. Methods: Extracts were prepared by ultrasound-assisted extraction using water, 50% aqueous methanol, or 50% aqueous acetone. TPC was determined using the Folin–Ciocalteu assay, while antioxidant activity was evaluated using DPPH, ABTS, FRAP, and a qualitative supercoiled plasmid DNA relaxation assay. Solvent effects were assessed using Friedman and post hoc Wilcoxon signed-rank tests, and associations between TPC and antioxidant activity were examined using correlation and regression analyses. Results: TPC and antioxidant activity varied considerably among botanical products and extraction conditions, with Origanum spp. generally exhibiting among the highest TPC values and strong antioxidant responses. Aqueous acetone yielded significantly higher TPC than aqueous methanol and water. Both aqueous organic solvents produced greater DPPH inhibition than water, whereas aqueous methanol produced greater ABTS activity than water; no significant solvent effect was observed for FRAP. TPC was positively associated with antioxidant activity, particularly ABTS and FRAP, explaining up to 78% of its variability. Several extracts also preserved the supercoiled plasmid DNA form under hydroxyl radical-generating conditions, although this observation requires quantitative confirmation. Conclusions: Medicinal herbs and spices of Athonite provenance exhibit considerable phytochemical and antioxidant variability. Extraction solvent influences phenolic recovery and antioxidant activity in an assay-dependent manner, with no single solvent being uniformly superior. These findings provide baseline data supporting further phytochemical characterization and quantitative evaluation of the antioxidant and DNA-protective properties of these botanical materials. Full article

Background/Objectives: The oxidation of low-density lipoprotein (LDL) is a crucial step in atherogenesis. Beta-Caryophyllene (BCP) is a natural compound with established anti-oxidative and anti-inflammatory properties as shown in animal and cell culture studies. We examined whether BCP can impede LDL oxidation in an in vitro model. Methods: The anti-oxidative effect of BCP was evaluated in different concentrations (0, 25, 50, 100, and 150 µg/mL) with regard to scavenging reactive oxygen species (ROS) during LDL oxidation, which was initiated by the addition of copper chloride (CuCl₂) in a concentration of 10 µmol/L. Lipid hydroperoxides (LPO), malondialdehyde (MDA), dienes, cell viability, and reactions of BCP with ROS according to Gibbs free energies were applied to determine the oxidation state of LDL. Results: Our findings indicated that BCP is highly efficient in inhibiting LDL oxidation in a dose-dependent manner in this in vitro model. The lipid hydroperoxide content in oxLDL was significantly lower in the presence of 100 µg/mL BCP compared to oxLDL without BCP (p < 0.0001). This corresponds to the MDA levels, which were significantly lower in the presence of 100 µg/mL BCP compared to oxLDL without BCP (p = 0.0393). Furthermore, a dose-dependent inhibition of diene formation in the LDL particle was observed in the presence of ascending BCP concentrations which corresponds to a decrease in the cytotoxicity of oxLDL in EA.hy926 cells in the presence of increasing concentrations of BCP. Moreover, BCP’s anti-oxidant effectiveness exceeds that of the widely recognized anti-oxidant spermidine at equivalent concentrations. Our quantum chemical calculations showed that the reactions between BCP and hydroxyl radicals, hydroperoxyl radicals, or hydrogen peroxide are exergonic. We therefore conclude that BCP impedes the oxidation of LDL by its capability to scavenge (at least) these three reactive oxygen species. Conclusions: Our results indicate that BCP impedes the oxidation of LDL in vitro and therefore presumably has the potential to serve as an appropriate therapeutic agent to prevent atherogenesis and related (cardio)vascular diseases by balancing vascular oxidative stress. For this purpose, more prospective clinical studies in humans are required to assess the potential atheroprotective and health-promoting effects of BCP. Full article

Pharmaceutical pollutants have emerged as a critical class of aquatic micropollutants due to their continuous release, persistence, and potential impacts on ecosystems and human health. Conventional wastewater treatment systems are often insufficient to achieve complete removal, necessitating the development of advanced oxidation processes (AOPs), such as Fenton and Fenton-like systems. These processes rely on the generation of reactive oxygen species (ROS), including hydroxyl radicals (•OH), superoxide species, singlet oxygen, and, in some heterogeneous systems, high-valent iron-oxo intermediates, which collectively enable the degradation of structurally diverse and recalcitrant pharmaceutical compounds. Recent advances have highlighted the pivotal role of nanomaterials as catalysts in enhancing Fenton-based processes. Nanostructured catalysts, including iron-based nanoparticles (NPs), metal oxides, carbon-based materials, and bimetallic composites, offer high surface area, tunable redox properties, and improved electron transfer, leading to enhanced catalytic efficiency and mineralization rates. Importantly, the integration of green synthesis approaches using plant extracts, microorganisms, and biopolymers provides environmentally benign routes for nanomaterial fabrication while introducing functional surface groups that improve catalytic performance. Mechanistically, pharmaceutical degradation in Fenton systems involves complex pathways driven by multiple ROS species, including •OH, superoxide radicals, and singlet oxygen, leading to the formation of intermediate products and eventual mineralization. However, challenges such as NP aggregation, metal leaching, incomplete mineralization, and potential toxicity of intermediates remain critical considerations. This review critically evaluates the occurrence of pharmaceutical pollutants, the fundamentals of Fenton and Fenton-like processes, and the design and application of green-synthesized nanomaterials as efficient catalysts. It further explores degradation mechanisms, operational parameters, and sustainability considerations, highlighting future directions for scalable, environmentally responsible water treatment technologies. Full article

Atmospheric oxidation capacity is a key parameter for measuring the atmosphere’s self-cleaning ability. Its strength directly affects the degradation rate of pollutants such as methane, carbon monoxide, and nitrogen oxides, and has a profound impact on regional air quality, ecosystem health, and even global climate chemistry processes. Against the backdrop of increasing global anthropogenic emissions and rapid climate system changes, quantitatively assessing the spatiotemporal evolution of atmospheric oxidation capacity is particularly important. This study systematically simulated and assessed the atmospheric oxidation capacity of Guangdong Province in October 2017 based on the Weather Research and Forecasting with Chemistry model (WRF-Chem). To more scientifically quantify atmospheric oxidation capacity, this study examined a new observational index, AOC_TOX (the rate atmospheric oxidants being reduced), and compared it to the traditionally used index AOC_ODT (the rate atmospheric reductants being oxi32dized). The results show that the AOC_TOX and AOC_ODT indices exhibit a high degree of consistency in both temporal variation trends and spatial distribution patterns. Temporally, the diurnal variation characteristics of the AOC_TOX and AOC_ODT indices are highly consistent, with 24 h averages of 1.8 × 10⁷ cm⁻³ s⁻¹ and 2.0 × 10⁷ cm⁻³ s⁻¹, respectively, showing minimal difference. Spatially, the high-value and low-value regions of both indices significantly overlap. This result demonstrates the internal consistency of the new AOC_TOX index in characterizing atmospheric oxidation capacity. Furthermore, by analyzing the contributions of different oxidants, this study clarifies that hydroxyl radicals (OH) are the main driving force of atmospheric oxidation capacity during the day, while nitrate radicals (NO₃) play a dominant role at night. Finally, simulation analysis further reveals that human activity emissions are a key factor regulating the spatial pattern of regional atmospheric oxidation capacity. Full article

A novel sulfated α-glucan (VpG), with an ultra-high molecular weight of approximately 2250 kDa and a sulfation degree of 18.6%, was previously isolated from Volutharpa ampullacea perryi and shown to alleviate dextran sulfate sodium (DSS)-induced ulcerative colitis in mice. However, the underlying mechanisms remain unclear. In the present study, we further characterized the structural features of VpG using scanning electron microscopy (SEM), atomic force microscopy (AFM) and UV-Vis spectroscopy, and evaluated its immunomodulatory effects in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. SEM revealed a dense, porous surface with co-existing filamentous and flake-like structures, while AFM imaging showed that VpG adopted an irregular branched chain-like conformation. In functional assays, VpG significantly inhibited the production of pro-inflammatory cytokines, inducible nitric oxide synthase (iNOS) and toll-like receptor 4 (TLR4) in a dose-dependent manner. Flow cytometric analysis revealed that VpG downregulated LPS-induced expression of the M1 surface marker CD80, while Western blotting showed that VpG suppressed the phosphorylation of p38, ERK1/2, and JNK1/2/3, indicating blockade of the MAPK signaling pathway. In addition, VpG exhibited potent radical scavenging activity against hydroxyl and superoxide anion radicals, which is associated with its anti-inflammatory activity. Collectively, these findings indicate that VpG exerts its anti-inflammatory effects through the inhibition of M1 macrophage polarization and suppression of MAPK activation, with its antioxidant capacity potentially contributing to the overall effect. This study provides a mechanistic basis for understanding the anti-inflammatory action of VpG and supports its potential as a therapeutic candidate for ulcerative colitis. Full article