Search Results (1,229)

A novel, uniform acid heteropolysaccharide with a molecular weight of 13.14 kDa was isolated from the fermented broth of the mangrove endophytic fungus Penicillium janthinellum N29, designated as PJ3-1. A structural analysis showed that PJ3-1 is a straight-chain heteropolysaccharide containing GlcN, GlcNAc, Glc and GlcA in the ratio of 12.23:1.79:10.93:1.00. PJ3-1 markedly inhibits α-glucosidase activity and relieves insulin resistance in HepG2 cells. It alleviates lipid peroxidation and upregulates the activities of endogenous antioxidant enzymes. In addition, it also significantly scavenges hydroxyl radicals, ferrous ions, superoxide anions, DPPH radicals and ABTS radicals and enhances reducing power in a dose-dependent manner. Collectively, these findings suggest that PJ3-1 has the potential to serve as a natural antioxidant and hypoglycemic agent for functional food or pharmaceutical applications. Full article

Magnetic heterogeneous Fenton Fe₃O₄/HNT catalysts were successfully synthesized using the solvothermal method. Characterization of Fe₃O₄/HNT composites involved XRD, XPS, FT-IR, SEM, BET and TEM. Results showed uniform anchoring of magnetic Fe₃O₄ nanoparticles on HNTs’ external surface. Under pH conditions close to neutral, the catalyst achieved a naphthalene (NAP) removal efficiency exceeding 98% within 15 min while maintaining a relatively high H₂O₂ utilization rate. The catalyst exhibits significant resistance to common aqueous interferers containing anions (NO₃⁻, Cl⁻, CO₃²⁻) and humic acids. Moreover, the catalyst could be easily isolated from the solution through the use of magnetic separation technology. It displayed remarkable stability and recyclability, maintaining NAP removal efficiency above 80% even after the fifth cycle, in comparison to the initial catalyst. The excellent catalytic performance of this catalyst is attributed to the synergistic effect between HNT and Fe₃O₄. Meanwhile, the diverse Fenton catalytic process of Fe₃O₄/HNT was explained, indicating that hydroxyl radicals (•OH) and superoxide anion radicals (•O₂⁻) were key in eliminating NAP in the Fe₃O₄/HNT-H₂O₂ setup. Full article

Foam cell formation of macrophages is a core pathological event in the progression of atherosclerosis. Investigating the changes in active molecules during macrophage foaming is critical for the early warning and mechanistic research of atherosclerosis. Superoxide anion (O₂^•−) and nitric oxide (NO) are two typical representatives of these active species; evaluating the fluctuations of O₂^•− and NO during macrophage foaming is vital for understanding the early diagnosis and pathological mechanisms of atherosclerosis. Herein, we report a fluorescent probe for the detection of O₂^•− and NO concentration changes based on the quenching effect of the urea bond and trifluoromethanesulfonate group on the fluorophore. MB-ROS features favorable sensitivity, selectivity and biocompatibility, enabling imaging of O₂^•− and NO fluctuations in macrophages. It was further validated in ox-LDL-stimulated foam cell models to visually track abnormal ROS/RNS changes during foam formation. This work offers a reliable chemical imaging tool to uncover redox imbalance underlying early atherosclerotic macrophage foaming. Full article

Red-flowered strawberry possesses both ornamental and edible value, but its short single-flower lifespan severely limits its ornamental potential. In this study, petals of the red-flowered strawberry cultivar ‘140’ were collected at five developmental stages (large bud, half-bloom, full-bloom, initial withering, and withered) to systematically analyze the senescence process from morphological characteristics, physiological, and ethylene-related gene expression perspectives. The results showed that the epidermal cell breakage rate increased continuously during petal senescence, with lower epidermal cells consistently exhibiting higher breakage rates than the upper epidermal cells. Moisture content decreased progressively, while relative electrolyte leakage, malondialdehyde, hydrogen peroxide, and superoxide anion contents increased continuously. Superoxide dismutase, peroxidase, and catalase activities, as well as glutathione content, exhibited unimodal responses, peaking at different stages. Both ethylene and abscisic acid contents increased and then decreased, with ethylene showing greater amplitude and faster rate of change. The ethylene biosynthesis gene FaACO1 and signaling genes FaETR1, FaETR2, FaEIN2, FaEIN7, FaERF13, and FaERF118 were significantly upregulated at full-bloom or initial withering stages, with FaERF118 showing the highest and continuously increasing expression. These findings indicate that water loss, membrane lipid peroxidation, and reactive oxygen species accumulation synergistically drive petal senescence, with the ethylene signaling pathway playing a key regulatory role. Full article

A high-performance Z-scheme Ho₂BiNbO₇/ZnBiTmO₄ heterojunction (HZ) photocatalyst was prepared for the first time using a wet impregnation method. The HZ photocatalyst significantly improved the separation efficiency of the photoinduced electrons and the photoinduced holes; meanwhile, the HZ photocatalyst could effectively broaden the visible light spectrum via a specific mechanism of the Z-scheme heterojunction structure. The experimental results displayed that the HZ photocatalyst had strong catalytic activity when the brilliant green (BLG) was degraded. In particular, the degradation rate of BLG when using the HZ photocatalyst was found to be 99.47%, and the mineralization efficiency of the total organic carbon (TOC) concentration was found to be 98.26% when using the HZ photocatalyst under visible light irradiation (VILIIR). The HZ photocatalyst possessed higher photocatalytic activity compared with Ho₂BiNbO₇, ZnBiTmO₄, or N-doped TiO₂ (N-T). The degradation rate of BLG when using the HZ photocatalyst was 1.27 times higher than that when using Ho₂BiNbO₇, 1.15 times higher than that when employing ZnBiTmO₄, or 2.91 times higher than that when using N-T under VILIIR. The mineralization efficiency of the TOC concentration after catalytic degradation of BLG when employing the HZ photocatalyst was 1.31 times higher than that when employing Ho₂BiNbO₇, 1.19 times higher than that when employing ZnBiTmO₄, or 3.14 times higher than that when using N-T under VILIIR. The experimental generating radicals confirmed that the HZ photocatalyst might produce diverse reactive radicals, which contained superoxide anions (•O₂⁻), hydroxyl radicals (•OH) and photogenerated holes (h⁺) after catalytic degradation of BLG. The descending order of oxidizing capacity for above three radicals was as follows: •OH > •O₂⁻ > h⁺. The descending order of the photocatalytic activity for the four photocatalysts was as follows: HZ > ZnBiTmO₄ > Ho₂BiNbO₇ > N-T. The intermediate degradation products of BLG were detected by employing the HZ photocatalyst during the photocatalytic degradation process of BLG; the reliability, reusability, and stability of the HZ photocatalyst were proven by quintic cyclical degradation experiments of BLG. This study developed the degradation pathways and degradation mechanism of BLG when using the HZ photocatalyst under VILIIR. This work supplies novel thought for the design and manufacture of Z-scheme heterojunction catalysts, and it provides a basis for developing an efficient environmental remediation technique for BLG pollution. Full article

Fresh-cut apples are highly prone to browning during processing and storage. This long-standing problem will cause huge economic losses and restrict the commercial development potential of the fresh-cut fruit industry. In this study, Fuji apples were used as test materials to explore the inhibitory effect and anti-oxidant mechanism of pre-cutting high oxygen treatment (90% O₂, 3 h) combined with post-cutting Withania somnifera extract immersion on the browning of fresh-cut apples. Through the determination of physiological and biochemical indexes and proteomics analysis, the effects of different treatments on the nutritional quality, reactive oxygen species metabolism, membrane lipid peroxidation, anti-oxidant enzyme activity and related protein expression of fresh-cut apples were systematically evaluated. The results showed that after 14 days of storage, the combined treatment group had the lowest browning index of 41.29% and the highest whiteness index of 60.35%, and its color protection effect was significantly better than that of single high oxygen treatment or single extract treatment. The combined treatment could increase the total phenol content to 6.45 mg/g after 7 days of storage, and increase the DPPH free radical scavenging rate to 0.60% after 14 days of storage, significantly enhancing the anti-oxidant capacity. Meanwhile, the combined treatment could maintain higher activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), and maintain the malondialdehyde content at a low level of 0.06 nmol/g after 14 days of storage, effectively delaying the process of membrane lipid peroxidation. However, adverse results were also observed in the study, including the rebound of superoxide anion level (28.16 nmol/g) after 14 days of storage, the highest accumulation of H₂O₂ during the whole storage period, and the significant increase in polyphenol oxidase (PPO) activity (151.14 IU/L) after 14 days of storage, indicating an elevated browning risk under prolonged storage. Proteomics analysis revealed that the combined treatment regulated multiple metabolic pathways, including the up-regulating of glutathione metabolism and pentose phosphate pathway to enhance reactive oxygen species scavenging capacity, as well as the modulation of fatty acid metabolism to preserve cell membrane integrity. Despite the above limitations, the overall browning inhibitory effect of the combined treatment is still better than that of a single treatment, but its pro-oxidant effect and long-term reactive oxygen species regulation effect still need to be further optimized. In summary, pre-cutting high oxygen treatment combined with post-cutting Withania somnifera extract treatment is an effective anti-browning strategy for fresh-cut apples, which can provide a theoretical basis for the development of natural and efficient fresh-cut fruit and vegetable preservation technology. Full article

This study aimed to investigate the effects of luteolin on the growth performance and intestinal health of juvenile Genetically Improved Farmed Tilapia (GIFT, Oreochromis niloticus). A total of 450 juvenile GIFT tilapia (initial body weight 8.12 ± 0.04 g) were randomly assigned to five groups (90 fish per group; three replicate tanks of 30 fish each) and fed diets containing luteolin at 0, 50, 150, 300, or 600 mg/kg (CG, LG50, LG150, LG300, and LG600, respectively) for 56 days. The results showed that with increasing luteolin supplementation, the weight gain rate (WGR) and specific growth rate (SGR) first increased and then decreased; the LG300 group had the highest WGR and SGR (significantly higher than the CG and LG600 groups, p < 0.05) and the lowest feed conversion ratio. Based on broken-line and quadratic polynomial regression analyses of the WGR and SGR, the optimal dietary luteolin supplementation level was determined to be 274.14–303.39 mg/kg. For intestinal antioxidant enzyme activities and oxidative stress, total superoxide dismutase (T-SOD) activity in the LG150 and LG300 groups was significantly higher than in the CG and LG600 groups (p < 0.05), and superoxide anion (O₂⁻) content in the LG300 group was significantly lower than in the CG, LG50, and LG600 groups (p < 0.05). Histological analysis of the intestine revealed that muscular layer thickness was significantly greater in the LG300 group than in the CG group (p < 0.05). Intestinal microbiota analysis indicated that compared with the CG group, the LG300 group showed lower relative abundances of the potential pathogens Plesiomonas and Bosea, whereas it had a higher relative abundance of the potentially beneficial bacteria Bacteroidota and Romboutsia. Intestinal untargeted metabolomics revealed that, compared with the CG group, the beneficial metabolites Chrysoeriol, Laricitrin, and Docosahexaenoylethanolamine were significantly up-regulated, whereas the biotoxins Aplysiatoxin, 17-Debromo- and Pectenotoxin 3 were significantly down-regulated in the LG300 group (p-adjust < 0.05), with the up-regulated metabolites significantly enriched in the flavone and flavonol biosynthesis pathway (p-adjust < 0.05). Collectively, dietary supplementation with an appropriate level (300 mg/kg) of luteolin can effectively improve the growth performance and intestinal health of juvenile GIFT tilapia. Full article

Macropinocytosis is an actin-driven endocytic process mediating nonspecific uptake of extracellular fluid through membrane ruffling. Neutrophil macropinocytosis has been reported only in limited descriptive studies, and its signaling mechanisms have not been defined. Here, we provide a characterization of macropinocytosis in primary human neutrophils and investigate signaling pathways that contribute to the regulation of this process. Quantitative flow cytometry using a high-molecular-weight fluid-phase tracer showed that the diacylglycerol (DAG) mimetic 4β-phorbol 12-myristate 13-acetate (4β-PMA) induces macropinocytic activity in primary human neutrophils. Granulocyte macrophage-colony stimulating factor (GM-CSF) and hepatocyte growth factor (HGF) also promoted fluid-phase uptake. Inhibition of actin polymerization or macropinocytosis reduced tracer uptake, confirming dependence on actin-driven machinery. Scanning electron microscopy revealed dorsal membrane ruffling and cup-like structures after stimulation. Mechanistically, DAG-dependent activation of protein kinase C beta (PKCβ) acted upstream of NADPH oxidase 2 (NOX2)-derived superoxide anion production, driving membrane remodeling. Collectively, these findings define a DAG–PKCβ–NOX2–superoxide signaling axis, as a key regulator of macropinocytosis in primary human neutrophils and provide the first mechanistic framework for its redox-dependent regulation. Full article

Tamarix chinensis Lour. (T. chinensis) is a traditional herb with functions for releasing the exterior to promote the eruption of rashes, among other ailments. However, these function-related pharmacological effects, such as anti-complement, anti-oxidative, and anti-inflammatory, remain unclear. This study aims to reveal the aforementioned effects and the molecular mechanisms of the ethanol extract of T. chinensis (TCE). Our results demonstrated that TCE inhibited classical- and lectin-mediated complement activation, reduced intracellular ROS via NADPH oxidase inhibition, and directly scavenged DPPH radicals and superoxide anions. By using lipopolysaccharide (LPS)-stimulated macrophages, along with LPS-induced acute lung injury (ALI) and endotoxemia mice, the anti-inflammatory activity and the underlying molecular mechanisms of TCE were deeply investigated. In LPS-activated macrophages, it suppressed iNOS, CCL2, IL-6 and IL-1β transcriptionally and translationally. Mechanistically, TCE inhibited NF-κB signaling by blocking IκBα phosphorylation and p65 nuclear translocation, as well as suppresses AP-1 signaling by reducing ERK and JNK phosphorylation. In vivo, TCE lowered serum multiple pro-inflammatory cytokines of endotoxemic mice and alleviated lung injury of ALI mice. Collectively, our results demonstrated that TCE possesses anti-complement and anti-oxidative activities and exerts anti-inflammatory effects through inhibiting NF-κB and AP-1 signaling. These findings provide scientific evidence for supporting the traditional use of T. chinensis. Full article

Canker is a destructive fungal disease that adversely affects plant growth, triggering leaf drop, branch dieback and even plant death. For the blueberry industry, fungal canker reduces blueberry yield and quality. In this study, diseased branches of the ‘Bluegold’ blueberry cultivar collected from open-field plantations in Jilin Province, China, were used to isolate and identify the pathogen, characterize its biological properties, and investigate the physiological and metabolomic responses of blueberry shoots to pathogen infection. Based on morphological characteristics and internal transcribed spacer sequence analysis, the pathogen was preliminarily identified as Diaporthe eres. Biological characterization showed that the optimal temperature and pH for mycelial growth of the isolate were 25 °C and 6, respectively, while light conditions had no significant effect on fungal growth. Pathogenicity results demonstrated that infection by the isolate significantly induced the accumulation of superoxide anions (O₂^.−) and hydrogen peroxide (H₂O₂) in blueberry new shoots, which led to lipid peroxidation and subsequently resulted in significant increases in malondialdehyde content and relative electrical conductivity. Concurrently, the plant’s antioxidant enzyme system was disrupted, and the activities of peroxidase and superoxide dismutase remained significantly elevated throughout the infection period, while catalase activity exhibited an initial increase followed by a gradual decline. Metabolomic analysis identified 541 differentially accumulated metabolites, with key metabolites including ferulic acid, quercetin and kaempferol showing marked abundance changes. These were primarily enriched in pathways closely associated with plant resistance, such as phenylpropanoid biosynthesis and flavonoid biosynthesis. Combined analysis of physiological and metabolomic data showed that reactive oxygen species accumulation and antioxidant enzyme responses were accompanied by significant enrichment of phenylpropanoid and flavonoid metabolism, indicating coordinated antioxidant regulation and secondary metabolic reprogramming in blueberry shoots following pathogen infection. Overall, this study preliminarily identified a D. eres isolate associated with blueberry canker in Jilin Province, and systematically characterized the physiological and metabolic responses of blueberry to pathogen infection, providing a theoretical basis for understanding blueberry—Diaporthe interactions and for developing effective disease management strategies. Full article

Background/Objectives: Since redox balance is critical to colorectal cancer cell survival, and estradiol, a potent antioxidant, correlates with reduced disease incidence, understanding the redox basis of cellular responsiveness to estradiol is essential for advancing therapeutic insight. This study evaluates the adaptive and maladaptive redox responses of colorectal carcinoma cells to estradiol treatment by defining the basal redox set-point as the intracellular balance between pro-oxidants and antioxidants. Methods: Human colorectal cancer cell lines HCT-116 and SW-480 were treated for 24 h with pregnancy-range and pharmacological-range concentrations of estradiol. Redox biomarkers (superoxide anion/O₂^.−, hydrogen peroxide/H₂O₂, nitric oxide/NO, reduced glutathione/GSH and oxidized glutathione/GSSG), cell viability, and basal migration were analyzed. Correlation, network topology, PCA, and Jaccard similarity analyses were applied to characterize basal redox set-points and quantify estradiol-induced changes in redox profiles in the two cell lines. Results: HCT-116 cells exhibited an O₂^.−-centered redox set-point associated with NO and GSH. SW-480 cells displayed a H₂O₂-centered redox set-point associated with NO and GSH. In HCT-116 cells, estradiol triggered a maladaptive response associated with antioxidant activation and reduced proliferation. Conversely, SW-480 cells exhibited an adaptive response characterized by modulation of NO levels and the GSH pool and associated with increased proliferation. Conclusions: These findings identify redox set-point organization as a potential determinant of estradiol responsiveness in colorectal cancer cells. From a clinical perspective, characterizing basal redox set-points in patient-derived tumor cells may enable stratification of colorectal cancer patients by predicted responsiveness to redox-modulating therapies, informing personalized treatment. Full article

Industrial wastewater containing synthetic dyes is difficult to treat because many dyes are chemically stable, highly colored, and resistant to natural degradation. In this study, a Ag₂CO₃/montmorillonite (Ag₂CO₃/MMT) composite photocatalyst was synthesized by an in situ precipitation method using acid-activated MMT as a low-cost clay support. The prepared material was characterized by XRD, FTIR, SEM, BET, and UV–Vis diffuse reflectance spectroscopy to evaluate its structural, morphological, textural, and optical properties. XRD and FTIR confirmed the formation of crystalline Ag₂CO₃ on the MMT support, while SEM analysis showed dispersed Ag₂CO₃ surface particles/deposits on the clay sheets. BET analysis indicated that the composite retained mesoporosity after Ag₂CO₃ deposition, which is beneficial for dye adsorption and diffusion. The photocatalytic performance was evaluated using methylene blue (MB) and methyl orange (MO) under visible-light irradiation. The Ag₂CO₃/MMT composite showed efficient dye decolorization, with faster degradation of cationic MB than anionic MO, mainly due to stronger electrostatic interaction between MB and the negatively charged catalyst surface. Kinetic analysis followed a pseudo-first-order model, with apparent rate constants of 0.036 min⁻¹ for MB and 0.021 min⁻¹ for MO. Operational parameters, including solution pH, irradiation time, and catalyst dosage, strongly influenced photocatalytic efficiency. Reactive species trapping experiments indicated that superoxide radicals (•O₂⁻) and photogenerated holes (h⁺) were the dominant oxidative species. The catalyst retained more than 91% activity after four cycles, indicating good recyclability under the tested conditions. These results suggest that Ag₂CO₃/MMT is a promising visible-light-responsive photocatalyst for dye-contaminated wastewater treatment. Full article

Soil salinization critically restricts melon production, and the seed germination stage is particularly vulnerable to saline–alkali stress (SAS). Although silicon (Si) is known to enhance plant stress tolerance, its role in alleviating SAS-induced inhibition of melon seed germination—particularly under combined neutral and alkaline salt stress—remains insufficiently characterized. Here, using the melon cultivar ‘Xinyinhui’, we simulated SAS with a mixture of NaCl and NaHCO₃ and screened for the optimal Si concentration. We then systematically examined physiological, biochemical, and gene expression responses. SAS significantly inhibited germination (20.4% reduction in germination rate; 56.9% in vigor index) and induced oxidative damage (MDA increased by 9.7%; superoxide anion by 170.6%), suppressed antioxidant enzyme activities (SOD −28.8%, POD −69.4%), and disturbed starch metabolism. Exogenous Si at 1.25 mmol·L⁻¹ effectively alleviated these effects: The germination rate increased from 71.7% to 88.8%, and SOD and POD activities increased by 26.7% and 63.6%, while MDA and superoxide anion decreased by 7.1% and 16.4%. Si also promoted starch degradation, as indicated by a 13.9% reduction in starch content, 8.4% increase in total amylase activity, and 23.2% upregulation of CmBMY expression. In addition, Si significantly improved root morphology: Root surface area, volume, branch number, and tip number increased by 19.8–326.3%, while the average root diameter decreased by 24.4%. These results suggest that exogenous Si alleviates SAS inhibition of melon seed germination through coordinated regulation of antioxidant defense and starch metabolism rather than through a single pathway. Our findings provide a physiological basis for the potential application of Si fertilizer in melon cultivation under saline–alkali conditions. Full article

Developing earth-abundant photocatalysts that operate efficiently under visible light remains a central challenge in sustainable aerobic oxidation chemistry. We synthesized a binuclear cobalt(II) structure (Co₂) in which two redox-active metal centers are bridged by a polypyridine scaffold to integrate light-harvesting and catalytic functions within a single low-nuclearity unit. The complex exhibits a strong absorption band below 450 nm, undergoes facile charge separation upon photoexcitation, and channels molecular oxygen (O₂) toward superoxide radical anion (O₂^•–) under blue-light irradiation. Spectroscopic and mechanistic studies indicate that the polypyridine framework governs photon capture and excited-state delocalization, whereas the proximal Co(II) sites mediate the subsequent single-electron transfer to O₂. Driven by this dual-site synergy, Co₂ selectively oxidizes a broad scope of thioethers to the corresponding sulfoxides in yields exceeding 95%, with no over-oxidation to sulfones detected. The catalyst retains its structural integrity over five successive runs without measurable activity loss. By confining complementary photophysical and redox functions within a discrete bimetallic unit, this work establishes a design strategy for noble-metal-free, visible-light-driven organic transformations. Full article

To address the inherent drawbacks of peroxymonosulfate advanced oxidation processes (PMS-AOPs), including the low efficiency of reactive species production, short radical half-lives, and restricted pollutant degradation performance, sodium salt-assisted modification was adopted to fabricate ZIF-8-derived carbon. In this study, sodium salt-assisted modification was adopted to treat ZIF-8, and the chlorine-doped derived carbon materials HNC-T_x-Cl were prepared for peroxymonosulfate activation and tetracycline degradation in water. Compared with NC-800 fabricated by direct calcination of ZIF-8 at 800 °C, HNC-800-Cl synthesized via NaCl-assisted calcination exhibits more abundant pore structures and richer carbon defects, with a specific surface area of 1115 m²/g and a high graphitic defect ratio I_D/I_G of 1.20. Catalytic tests reveal that HNC-800-Cl achieves 93.39% tetracycline removal within 90 min at a catalyst dosage of 0.05 g L⁻¹ and PMS concentration of 0.1 mM. The system possesses a strong anti-interference ability toward complex water environments, maintaining a favorable degradation performance in the presence of coexisting anions, natural organic matter and actual water matrices. It also exhibits outstanding cycling stability, retaining a removal rate of 80.34% after five recycling runs. Radical quenching experiments and EPR characterization verify that superoxide radical (·O₂⁻) is the dominant reactive species during tetracycline degradation. Both the radical and non-radical pathways are clarified to illustrate the mechanisms of PMS activation and pollutant degradation. This work provides a novel catalytic material strategy to overcome the deficiencies of conventional PMS-AOPs, and offers a new perspective for structural regulation and non-metallic doping modification of ZIF-8-derived carbon materials. Full article