Superoxide Research Articles

"Naringenin: A Promising Immunomodulator for Anti-Inflammatory, Neuroprotective, and Anti-Cancer Applications".

Inflammatory, immune, and neurodegenerative diseases constitute a category of persistent and debilitating conditions affecting millions worldwide, with inter-twined pathophysiological pathways. Recent research has spotlighted naturally occurring compounds like naringenin for potential therapeutic applications across multiple ailments. This review offers an encompassing exploration of naringenin's anti-inflamma-tory, immune-protective, and neuroprotective mechanisms, elucidating its pharmacological targets, signal transduction pathways, safety profile, and insights from clinical investigations. Data for this review were amassed through the scrutiny of various published studies via search engines such as PubMed and Google Scholar. Content from reputable publishers including Bentham Science, Taylor and Francis, Nature, PLOS ONE, among others, was referenced. Naringenin exhibits substantial anti-inflammatory effects by restraining the NF-κB signaling pathway. It activates Nrf2, renowned for its anti-inflammatory properties, inducing the release of hemeoxynase-1 by macrophages. Furthermore, naringenin treatment downregulates the expression of Th1 cytokines and inflammatory mediators. It also impedes xanthine oxidase, counteracts reactive oxygen species (ROS), scavenges superoxide radicals, mitigates the accessibility of oxygen-induced K+ erythrocytes, and reduces lipid peroxidation. Naringenin's antioxidant prowess holds promise for addressing neurological conditions. Extensive research has been undertaken to establish the anti-inflammatory, immunomodulatory, and neuroprotective attributes of naringenin across various medical domains, lending credence to its pharmacological utility. The principal obstacle to naringenin's adoption as a therapeutic agent remains the dearth of in vivo data. Efforts should focus on rendering naringenin delivery patient-friendly, economically viable, and technologically advanced.

The degradation of tetrabromobisphenol A by metal-free graphene oxide in the dark

Brominated flame retardants (BFRs) such as tetrabromobisphenol A (TBBPA) were widely detected in the environment. The ease of synthesis of graphene-based materials (GBMs) makes it an excellent metal-free carbon-based catalyst for the reductive debromination of TBBPA. Here we explore the complete debromination of TBBPA from the aqueous environment in the dark using metal-free graphene oxide (GO) and reduced GO (rGO). More importantly, radical scavenger experiments reveal the formation of superoxide radicals and singlet oxygen from the surface of GBMs leading to the debromination of TBBPA. GO shows an enhanced catalytic activity due to enriched O-functional groups on the surface than rGO, as observed by cyclic voltammetry and electrochemical impedance spectroscopy. In addition, the TBBPA degradation pathway was proposed with BPA as the end product and by-products were identified by mass spectroscopy. The complete TBBPA degradation was observed within 240 mins of reaction time (kobs = 8.6×10−3 min−1), which was significantly more efficient than the catalytic activity of other metal-based catalysts. Our study thus provides a new insight into the debromination mechanisms of TBBPA which would exhibit potential for future efficient catalyst development.

Antioxidant and Emulsifying Activity of the Exopolymer Produced by Bacillus licheniformis.

The exopolymer (ESPp) was obtained from Bacillus licheniformis IDN-EC, composed of a polyglutamic acid and polyglycerol phosphate chain O-substituted with αGal moieties (αGal/αGlcNH2 3:1 molar ratio) and with a 5000 Da molecular weight. The cytotoxicity activity of EPSp was determined by reducing the MTT (3-[4,5-dimethyl-thiazol-2-yl]-2,5-diphenyltetrazolium bromide) to formazan on HeLa cells. This EPS did not show cytotoxicity against the tested cell line. The ESPp presented great advantages as an antioxidant with free radical scavenging activities (1,1-diphenyl-2-picryl-hydrazyl radical (DPPH),hydroxyl radical (OH), and superoxide anion (O2-)) (65 ± 1.2%, 98.7 ± 1.9%, and 97 ± 1.7%), respectively. Moreover, EPSp increased the enzyme activity for catalase (CAT) and glutathione peroxidase (GSH-Px) in HeLa cells (CAT, 2.6 ± 0.24 U/mL; and GSH-Px, 0.75 ± 0.3 U/L). The presence of ESPp showed a significant protective effect against H2O2 in the cell line studied, showing great viability (91.8 ± 2.8, 89.9 ± 2.9, and 93.5 ± 3.6%). The EPSp presented good emulsifying activity, only for vegetable oils, olive oil (50 ± 2.1%) and sesame (72 ± 3%). Sesame was effective compared to commercials products, Triton X-100 (52.38 ± 1.6%), Tween 20 (14.29 ± 1.1%), and sodium dodecyl sulphate (SDS) (52.63 ± 1.6%). Furthermore, the EPS produced at 0.6 M has potential for environmental applications, such as the removal of hazardous materials by emulsification whilst resulting in positive health effects such as antioxidant activity and non-toxicity. EPSp is presented as a good exopolysaccharide for various applications.

The application of PAHs-Degrading Pseudomonas aeruginosa to mitigate the phytotoxic impact of pyrene on barley (Hordeum vulgare L.) and broad bean (Vicia faba L.) plants

Mitigating the negative impacts of polycyclic aromatic hydrocarbons (PAHs) is an urgent need due to their toxicity and persistence in the environment. This study investigated the use of Pseudomonas aeruginosa ASU-B6 to detoxify pyrene (PY). The bacterium P. aeruginosa ASU-B6 is capable of degrading PY by 92% as a sole carbon source after 15 days of incubation with phthalate being the major metabolic product. In this regard, the impact of pyrene (PY), P. aeruginosa ASU-B6 (ASU-B6), the bacterial strain combined with pyrene (ASU-B6/PY) and the metabolites produced after pyrene degradation (PY-metabolites) on the germination and physiological attributes of Hordeum vulgare and Vicia faba seedlings were studied. A single application of PY or ASU-B6 showed a toxic effect on the germination of both tested seeds. Interestingly, broad bean seedlings exhibited less sensitivity to PY stress in terms of growth and metabolism compared to barley. Notably, ASU-B6 inhibited fresh and dry weight of shoots and roots of barley and, to a lesser extent, reduced the germination of broad beans compared to the control. However, the combined PY-metabolites and ASU-B6/PY showed a mutual ameliorative effect on seedlings growth, alleviating the phytotoxic impact of each component. Pyrene reduced the virulence of ASU-B6 by inhibiting the production of pyocyanin pigment, while bacteria ameliorated pyrene toxicity through its degradation. Heatmap and principal component analyses highlighted that increasing the contents of hydrogen peroxide, superoxide anion, hydroxyl radical, and lipid peroxidation positively correlated to the toxicity of PY or ASU-B6. However, improving the antioxidant system which buffers the oxidative stress induced by different combinations of PY and ASU-B6 enhanced the growth of germinated seedlings corresponding to PY or ASU-B6. This study reflected the role of ASU-B6 in ameliorating PY-phytotoxicity. In addition, the application of ASU-B6 strain is recommended as a prospective candidate for remediation of PAHs-contaminated environment with a positive impact on the plant growth and metabolic products.

Precursor effect on the hydrothermal synthesis of pure ZnO nanostructures and enhanced photocatalytic performance for norfloxacin degradation

The indiscriminate production and use of antibiotics have caused an environmental imbalance. Therefore, advanced oxidative processes such as photocatalysis have been proposed to eliminate the presence of such emerging pollutants. On the other hand, the use of photocatalytic processes requires the development of highly efficient photocatalysts. This paper introduces photocatalysts based on ZnO nanostructures with different morphologies and grown by low-temperature hydrothermal synthesis. The choice of zinc precursor resulted in significant variations in both the morphology and size of the ZnO particles. Morphologies, such as, dumbbell-like structures, nanogranules, and ellipsoidal particles were obtained by altering the zinc precursor in a slightly alkaline medium, and parameters such as photocatalyst dosage, initial concentration of antibiotic Norfloxacin (NOR), and pH in photocatalysis were thoroughly investigated. The reactive species responsible for NOR degradation were photogenerated holes, superoxide radicals, and hydroxyl radicals, with the latter showing a greater contribution. Degradation pathways are also proposed, and intermediate products were identified by LC-MS. Thirteen degradation products, of which six were reported for the first time, were detected. Among the synthesized morphologies, nanogranules exhibited superior photocatalytic activity, achieving 100% NOR degradation after 70 min under UV-C light and excellent reusability after three cycles (97%). The results surpass those from previous studies, since the simple and efficient photocatalysts employed led to shorter degradation times.

Integrated Cyano Groups into the Skeleton of Conjugated Polymers to Activate Molecular Oxygen for Boosting Photocatalytic H2O2 Efficiency.

Conjugated polymers (CPs) have shown promising potential in the field of hydrogen peroxide (H2O2) photosynthesis. However, a deeper understanding of the interactions between building units and specific functional groups within the molecular skeleton is necessary to elucidate the mechanisms driving H2O2 generation. Herein, a series of typical donor-acceptor (D-A) conjugated polymers (B-B, B-CN, B-DCN) were synthesized by introducing different amounts of cyano groups (-CN) into the molecular skeleton. The strong electron withdrawing properties of cyano can greatly promote the effective separation and transfer of photogenerated charges between building units, resulting in an impressive efficiency of H2O2 generation (2128.5 μmol g-1 h-1) for B-DCN, representing a 96-fold enhancement compared to B-B. More importantly, experimental results and theoretical calculations further revealed that the introduction of -CN can markedly reduce the adsorption energy (Ead) of O2, while serving as an active site to induce the conversion of crucial intermediate superoxide anions (.O2-) into singlet oxygen (1O2), achieving dual-channel H2O2 generation (O2→.O2-→H2O2, O2→.O2-→1O2→H2O2). This work provides valuable insights into the design of efficient H2O2 photosynthesis materials.

Carbon cloth core with a PEDOT decorated TiO2 shell for degradation of emerging organic contaminants and enhanced vanadium redox flow batteries

In this study, carbon cloth (CC) was enrobed with a TiO2 layer (CC@TiO2) and then decorated with poly(3,4-ethylenedioxythiophene) (PEDOT, CC@TiO2-PEDOT). The XRD, Raman, XPS, and EDS results confirmed the successful preparation of the targeted materials, and SEM images revealed the targeted morphology. According to the UV–vis and PL analysis, the CC@TiO2-PEDOT exhibits wide and strong photoabsorption across the UV–vis spectrum, and the photogenerated charge carriers have a long lifespan and low recombination rate. The photocatalytic assessment revealed that CC@TiO2-PEDOT was more efficient than CC@TiO2 and CC@PEDOT in degrading both benzotriazole and 2-hydroxybenzothiazole, however, 2-hydroxybenzothiazole was more stable than benzotriazole. The superoxide anion radicals, holes, and/or hydroxyl radicals of CC@TiO2-PEDOT played pivotal roles in the photocatalytic degradation of benzotriazole. After the photocatalytic process, the benzotriazole solution was safe to use. The CC@TiO2 and CC@TiO2-PEDOT exhibited a superior performance as a potential cathode for vanadium redox flow batteries (VRFBs) and effectively mitigated the parasitic influence of the hydrogen evolution reaction (HER). CC@TiO2 and CC@TiO2-PEDOT displayed significantly smaller peak separation of 94 and 62 mV, at a scan rate of 5 mV/s, respectively, and a higher suppression for HER in comparison to CC or CC@PEDOT. The performance of the CC@TiO2 and CC@TiO2-PEDOT electrodes manifests their high reversibility for the V(II)/V(III) redox reaction. This research underscores the multifaceted potential of CC@TiO2-PEDOT as a promising material for addressing water purification challenges and advancing VRFBs for sustainable energy applications.

N-graphyne surrounded Bi2S3/BiOBr composites: In-situ ultrasound-assisted synthesis and superior photocatalytic activity

In this work, a collection of N-graphyne surrounded Bi2S3/BiOBr composites are firstly synthesized by sonochemical method. The as-prepared ternary composites are composed of nanosheets with average thickness around 25 nm. And, the best absorbability of N-graphyne-Bi2S3/BiOBr composites to rhodamine B is confirmed to be 445.0 mg/g, which is 1.36 folds larger than that of Bi2S3/BiOBr (327.5 mg/g). Moreover, the optimal N-graphyne-Bi2S3/BiOBr composites achieve a 1.17-, 1.68-, and 1.19-folds enhancements towards the visible-light driven photocatalytic degradation of rhodamine B, tetracycline, and methylene blue compared to Bi2S3/BiOBr, respectively. And, it is established that the primary active species in photocatalytic degradation process is superoxide radical (O2–). In addition, under UV–Vis light, the highest NH3 generation rate of N-graphyne-Bi2S3/BiOBr composites in water (i.e., 1.400 μmol⋅gcat−1⋅h−1) is 3.7 times higher than that of Bi2S3/BiOBr. Additionally, the stability of N-graphyne-Bi2S3/BiOBr composites is confirmed by 89 % retention of Rhodamine B degradation efficiency and no obvious change of XRD patterns in the fifth cycle compared to that of the first cycle. Furthermore, the tests of photo-current, the photoluminescence spectra, Tafel plots, Mott-Schottky curves, electrochemical impedance, etc. are methodically adopted to explore the photocatalytic mechanism. To put it succinctly, this work puts forwards a new path for the develop of effective BiOBr-based ternary photocatalysts.

The coupling effect promotes superoxide radical production in the microalgal-fungal symbiosis systems: Production, mechanisms and implication for Hg(II) reduction

Redox transformation of mercury (Hg) is critical for Hg exchange at the air-water interface. However, the superoxide radicals (O2•─) contribution of microalgal-fungal symbiotic systems in lake water to Hg(II) reduction is mainly unknown. Here, we studied the enhanced potential for O2•─ production by the coupling effect between microalgae and fungi. The relationships between microenvironment, microorganisms, and O2•─ production were also investigated. Furthermore, the implication of O2•─ for Hg(II) reduction was explored. The results showed that the coupling effect of microalgae and fungi enhanced O2•─ generation in the symbiotic systems, and the O2•─ generation peaked on day 4 in the lake water at 160.51 ± 13.06–173.28 ± 18.21 μmol/kg FW (fresh weight). In addition, O2•− exhibited circadian fluctuations that correlated with changes in dissolved oxygen content and redox potential on the inter-spherical interface of microalgal-fungal consortia. Partial least squares path modeling (PLS-PM) indicates that O2•─ formation was primarily associated with microenvironmental factors and microbial metabolic processes. The experimental results suggest that O2•─ in the microalgal-fungal systems could mediate Hg(II) reduction, promoting Hg conversion and cycling. The findings highlight the importance of microalgae and fungal symbiotic systems in Hg transformation in aquatic environments.

VvLBD39, a grape LBD transcription factor, regulates plant response to salt and drought stress

Grape (Vitis vinifera L.), as an important deciduous perennial fruit tree, constantly confronts various abiotic stresses such as salinity and drought. The lateral organ boundaries domain (LBD) proteins are a class of plant-specific transcription factors that play pivotal roles in regulating plant growth and responding to abiotic stress. However, the biological function of the LBD transcription factor in grape remains poorly understood. Here, we cloned and characterized the VvLBD39 gene from grape, which contained a highly conserved LBD domain and localized to the cell nucleus. qRT-PCR analyses showed that the expression of VvLBD39 was downregulated upon exposure to NaCl, polyethylene glycol 6000 (PEG6000) and abscisic acid (ABA) treatments, respectively. Overexpression of VvLBD39 in grape calli and Arabidopsis resulted in hypersensitivity to PEG6000 and NaCl stress. Moreover, VvLBD39-overexpressing transgenic tobacco exhibited decreased tolerance to drought and salt stress, as well as insensitivity to exogenous ABA. After drought and salt stress treatments, the chlorophyll content, root length and antioxidant enzyme activity of the transgenic tobacco were lower than those of the wild-type (WT). Conversely, malonic dialdehyde (MDA) content, electronic conductivity, hydrogen peroxide (H2O2) content and superoxide anion (O2-) productivity were markedly elevated in the transgenic tobacco compared to the WT. Further investigations found that VvLBD39 had a negative impact on stomatal closure, ABA biosynthesis and ABA signaling under drought and salt treatments. In addition, the expression of genes related to reactive oxygen species (ROS) scavenging and stress response were significantly downregulated in VvLBD39 transgenic tobacco. Taken together, these results indicated that VvLBD39 functions as a negative regulator of salt and drought tolerance, making it a promising target for drought and salt resistance breeding.

ZIF-67/melamine-derived cobalt encapsulated in N-doped CNTs for periodate activation toward tetracycline degradation

Advance oxidation processes (AOPs) based on periodate (PI) offer new methods for removing pollutants, but the activation of PI by carbon nanotubes and its composites has been rarely reported. In this study, N-doped carbon nanotubes encapsulated cobalt (Co@NCNTs) was synthesized through melamine assisted ZIF–67 pyrolysis, and it was used to activate PI for the tetracycline (TC) degradation. Effects of experimental parameters including catalyst dosage, periodate concentration, initial pH, and temperature were investigated. The results show that this system exhibited excellent activation performance under wide pH (4–10) with a low reaction activation energy (Ea = 8.874 kJ/mol). Radical quenching experiments manifested that iodate radical (IO3) played a main role in the TC elimination, followed by superoxide radical (O2−), singlet oxygen (1O2), and hydroxyl radicals (OH). Additionally, it is found that IO4− is not converted into toxic iodine species (I2, HOI) but nontoxic iodate (IO3−), indicating that no secondary pollution occurred. Finally, possible TC degradation pathways were proposed based on the results of high-performance liquid chromatography mass spectrometry (HPLC-MS) analysis. This article provides a novel approach for the activation PI to remove pollutants and a theoretical support for practical applications.

Bio-inspired multimimimetic synergistic strategies Cs3Bi2Br9/ZnS organosilicon antifouling flexible films: Coupled micro/nanostructured surfaces, fluorescence, and reactive oxygen species mechanisms

Constructing multifaceted bio-inspired environmentally friendly films combining the synergistic advantages of multiple bionics can improve the static antifouling effect of antifouling-releasing silicones and mitigate the toxicity to marine ecology. In this work, based on the multiple anti-fouling mechanisms of fluorescent corals, designed Cs3Bi2Br9/ZnS/PDMS (CZP) flexible fluorescent films with surface microstructures and interpenetrating network Moreover, the blue fluorescence in the CZP films can be maintained for a long time in seawater environment (attributed to bismuth-based chalcogenides), and the formation of the heterostructure of Cs3Bi2Br9/ZnS (CBB/ZS) improves the ability of releasing reactive oxygen species (hydroxyl radical, superoxide radical, and singlet-linear oxygen).The CZP films obtained excellent antifouling effect under static conditions with antimicrobial rate up to 90.51 % and anti-algae adhesion to diatoms up to 96.60 %, which was attributed to the synergistic effect of the fluorescence functionality, micronized structure, and free radical release. Consequently, this work provides a promising avenue for the development of marine antifouling silicon-based films for efficient and environmentally friendly applications.

Trans-membrane piezoelectric activation of peroxymonosulfate for effective control of waterborne antibiotic resistance dissemination

Increasing prevalence of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) constitutes an emerging water safety issue globally. However, the effectiveness of current water treatment techniques in the control of ARGs dissemination remains controversial. Here, we develop a dual-zone strategy based on piezoelectric membrane filtration to efficiently eliminate waterborne antibiotic resistance. Following complete ARB inactivation and effective ARGs reduction in the retentate near the membrane surface (zone 1), a subsequent trans-membrane process (zone 2) further promotes ARGs elimination in the permeate, due to boosted interactions between ARGs and reactive oxygen species (ROS) generated from piezoelectric peroxymonosulfate activation and minimized ROS competition from inactivated ARB within piezocatalytic channels. The abundance of ARGs was largely reduced to ~1.0 × 103 copies·mL−1 in the permeate from ~5.0 × 106 copies·mL−1 in the feed solution. The singlet oxygen (1O2) is demonstrated to be primarily responsible for ARB inactivation, while 1O2, hydroxyl radical (•OH), sulfate radical (SO4·−) and superoxide radical (·O2−) can all participate in ARGs degradation. Our work demonstrates that the piezoelectric membrane-based dual-zone strategy has great potential to control the risk of ARGs dissemination.

Single-Atom Iron Catalysts with Core-Shell Structure for Peroxymonosulfate Oxidation.

The chemical tolerance of ketoenamine covalent organic frameworks (COFs) is excellent; however, the tight crystal structure and low surface area limit their applications in the field of catalysis. In this work, a porous single-atom iron catalyst (FeSAC) with a core-shell structure and high surface area was synthesized by using Schiff base COF nanospheres as the core and ketoenamine COF nanosheets growth on the surfaces. Surface defects were created using sodium cyanoborohydride etching treatment to increase specific surface area. The dye degradation experiments by peroxymonosulfate (PMS) catalyzed by the FeSAC proved that methylene blue can be degraded with a degradation rate constant of 0.125 min-1 under the conditions of 0.1 g L-1 catalyst dosage and 0.05 g L-1 peroxymonosulfate. The FeSAC/PMS system effectively degrades various pollutants in the pH range of 4-10 with over 80% efficiency for four cycles and can be recovered by soaking in iron salt solution. Free radical quenching experiments confirmed that singlet oxygen and superoxide radicals are the main active species for catalysis.

Assessing the antioxidant capacity of Ganoderma-infused white tea via electrochemical sensing techniques

This study presents a novel electrochemical method for assessing the antioxidant capacity of Ganoderma-infused white tea using carbon black-gold nanoparticle (CB-AuNP) modified glassy carbon electrodes and in situ generated superoxide radicals. The CB-AuNP nanocomposite was characterized using scanning electron microscopy and cyclic voltammetry, revealing an increased electrochemical active surface area of 0.158 cm2, which is 2.2 times larger than that of the bare glassy carbon electrode. Optimal conditions for superoxide radical generation were established using the xanthine oxidase-hypoxanthine system (0.10 U/mL XOD, 0.5 mM HX, 10 minutes incubation). The antioxidant capacity of Ganoderma-infused white tea was evaluated using cyclic voltammetry and chronoamperometry, and expressed as Trolox equivalent antioxidant capacity (TEAC). The proposed method demonstrated a strong linear relationship between TEAC values and Ganoderma extract concentration (R2 = 0.9995), with TEAC values ranging from 0.54 ± 0.03–2.85 ± 0.12 mM Trolox/g tea for 0.1–1.0 % w/v Ganoderma-infused white tea. The method exhibited good agreement with conventional spectrophotometric assays (DPPH, ABTS, and FRAP), showing strong correlations (R > 0.997) for all three assays. The practical applicability of the method was validated using commercial tea products, revealing a positive correlation between antioxidant capacity and Ganoderma polysaccharide content (R = 0.9958). The proposed electrochemical method offers a rapid, sensitive, and reliable approach for assessing the antioxidant capacity of functional tea products, with potential applications in quality control and product development.

Binary metal–organic framework composites as environmentally friendly photocatalysts: Green synthesis and visible light-assisted pollutant degradation

Green synthesis of MOF-on-MOF is an effective method to prepare the environmentally friendly photocatalyst using metal–organic frameworks (MOFs). Herein, ZIF-8 was synthesized on MIL-100 (Fe) (ZM composites) with different weight percent ratios of ZIF-8 and denoted as ZM21, ZM11 and ZM12. They were investigated as environmentally friendly photocatalysts for the degradation of Methylene Blue (MB) using visible light. XRD, FT-IR, SEM, EDX, and DRS were used to characterize the synthesized materials (ZIF-8, MIL-100, ZM21, ZM11, and ZM12). The ZM11 composite had the highest dye degradation ability. The MB photocatalytic degradation for the ZIF-8, MIL-100, ZM21, ZM11, and ZM12 were 12.59%, 31.27%, 29.45%, 86.3, and 31.51%, respectively. MB degradation by ZM11 composite followed the first-order kinetic model. The effective radical for the MB photocatalytic degradation was the superoxide radical (•O2–). The ZM11 composite had the ability of 76% dye removal from water after 3 cycles of MB degradation.

Facile construction of a bifunctional Eu-MOF for selective fluorescence sensing and visible light photocatalysis of tetracycline

Contamination detection and removal are important steps in environmental monitoring and cleanup. In this study, europium metal-organic framework structures (Eu-MOF) were designed and prepared that can act as fluorescent probes and photocatalysts for the detection and removal of tetracycline (TC) antibiotics. Eu-MOF was generated by a one-step solvothermal method using europium ion as the metal ion and terephthalic acid as the organic ligand source. The red fluorescence of Eu-MOF is selectively enhanced by TC due to the antenna effect. Eu-MOF, which has a linear range of 0.5–60 μM, can be utilized as a fluorescent probe for tetracycline detection based on this phenomena. In particular, Eu-MOF was found to be able to effectively photocatalyze the degradation of TC, with tetracycline removal rates of about 70 % and 55 % after 180 min of irradiation under ultraviolet light (UV) light and simulated visible light, respectively. The photocatalytic ability of Eu-MOF originated from the generation of hydroxyl radicals (•OH), superoxide radicals (•O2−) and electron holes (h+) under light irradiation. This study innovatively proposed a bifunctional Eu-MOF for TC fluorescence detection and photocatalytic degradation, which provides a novel method for the quick and easy identification and elimination of pharmaceutical contaminants. It can also provide some reference value for the construction of ratiometric fluorescent probes and heterojunction photocatalysts and their application in the treatment of water pollution.

Signaling by Neutrophil G Protein-Coupled Receptors that Regulate the Release of Superoxide Anions.

In human peripheral blood, the neutrophil granulocytes (neutrophils) are the most-abundant white blood cells. These professional phagocytes are rapidly recruited from the bloodstream to inflamed tissues by chemotactic factors that signal danger. Neutrophils, which express many receptors that are members of the large family of G protein-coupled receptors (GPCRs), are critical for the elimination of pathogens and inflammatory insults, as well as for the resolution of inflammation leading to tissue repair. Danger-signaling molecular patterns such as the N-formylated peptides that are formed during bacterial and mitochondrial protein synthesis and recognized by formyl peptide receptors (FPRs) and free fatty acids recognized by free fatty acid receptors (FFARs) regulate neutrophil functions. Short peptides and short chain fatty acids activate FPR1 and FFA2R, respectively, while longer peptides and fatty acids activate FPR2 and GPR84, respectively. The activation profiles of these receptors include the release of reactive oxygen species (ROS) generated by the NADPH oxidase. Activation of the oxidase and the production of ROS are processes that are regulated by proinflammatory mediators, including TNFα and GM-CSF. The receptors have signaling and functional similarities, although there are also important differences, not only between the two closely related neutrophil FPRs, but also between the FPRs and the FFARs. In neutrophils, these receptors never walk alone, and additional mechanistic insights into the regulation of the GPCRs and the novel regulatory mechanisms underlying the activation of NADPH oxidase advance our understanding of the role of receptor transactivation in the regulation of inflammatory reactions.

Mechanisms Mediating the Combined Toxicity of Paraquat and Maneb in SH-SY5Y Neuroblastoma Cells.

Epidemiological and experimental studies have demonstrated that combined exposure to the pesticides paraquat (PQ) and maneb (MB) increases the risk of developing Parkinson's disease. However, the mechanisms mediating the toxicity induced by combined exposure to these pesticides are not well understood. The aim of this study was to investigate the mechanism(s) of neurotoxicity induced by exposure to the pesticides PQ and MB isolated or in association (PQ + MB) in SH-SY5Y neuroblastoma cells. PQ + MB exposure for 24 and 48 h decreased cell viability and disrupted cell membrane integrity. In addition, PQ + MB exposure for 12 h decreased the mitochondrial membrane potential. PQ alone increased reactive oxygen species (ROS) and superoxide anion generation and decreased the activity of mitochondrial complexes I and II at 12 h of exposure. MB alone increased ROS generation and depleted intracellular glutathione (GSH) within 6 h of exposure. In contrast, MB exposure for 12 h increased the GSH levels, the glutamate cysteine ligase (GCL, the rate-limiting enzyme in the GSH synthesis pathway) activity, and increased nuclear Nrf2 staining. Pretreatment with buthionine sulfoximine (BSO, a GCL inhibitor) abolished the MB-mediated GSH increase, indicating that MB increases GSH synthesis by upregulating GCL, probably by the activation of the Nrf2/ARE pathway. BSO pretreatment, which did not modify cell viability per se, rendered cells more sensitive to MB-induced toxicity. In contrast, treatment with the antioxidant N-acetylcysteine protected cells from MB-induced toxicity. These findings show that the combined exposure of SH-SY5Y cells to PQ and MB induced a cytotoxic effect higher than that observed when cells were subjected to individual exposures. Such a higher effect seems to be related to additive toxic events resulting from PQ and MB exposures. Thus, our study contributes to a better understanding of the toxicity of PQ and MB in combined exposures.

Mitigating heat-induced yield loss in peanut: Insights into 24-epibrassinolide-mediated improvement in antioxidant capacity, photosynthesis, and kernel weight

Context or problemAs global temperatures steadily increase, the frequent occurrence of extreme high-temperature events has significantly hampered peanut (Arachis hypogaea L.) production in low-latitude regions. Objective or research questionPreviously, 24-epibrassinolide (EBR) was identified as a substance capable of mitigating abiotic stress damage in plants. However, it remains unclear whether and by what mechanisms EBR can diminish the yield loss caused by heat stress in peanuts. MethodsDuring the flowering phase, two distinct peanut cultivars, Qinghua7 (heat-resistant type) and Shanhua101 (heat-sensitive type) were exposed to a 10-day heat stress treatment (+4.2 ℃). EBR or water was sprayed on the 1st, 3rd, and 5th days of heating, and water-sprayed natural peanuts was used as control, to assess the effect of EBR on antioxidant capacity, photosynthetic performance, and yield in heat-stressed peanuts. ResultsEBR application increased activities of superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase in heat-stressed peanut leaves. Simultaneously, EBR decreased hydrogen peroxide and superoxide anion production, along with a reduction in malondialdehyde content. Additionally, EBR notably alleviated the oxidation damage to chloroplast membranes and grana lamella under heat stress. Thus, an increase in maximum photochemical efficiency, comprehensive performance index, rubisco activity, net photosynthetic rate, and biomass accumulation was observed in heat-stress peanuts. Synergistic enhancement provided by EBR on antioxidant capacity and photosynthetic performance resulted in improved plant growth, kernel weight, and effective pods per plant, led to a reduction in yield loss for heat-stressed cultivars Qinghua7 and Shanhua101 by 26.92 % and 55.18 %, respectively. ConclusionsThe application of EBR enhanced the antioxidant capacity of peanut leaves. This, in turn, mitigated oxidative damage to chloroplast membranes, resulting in improved photosynthetic performance. Ultimately, this intervention led to a reduction in yield loss for heat-stressed peanuts, achieved through an increase in kernel weight. Implications or significanceThe foliar spraying of EBR holds significant promise in crop production, offering a broad application prospect. This practice is beneficial for enhancing the heat resistance of peanuts and potentially other field crops, equipping them to better withstand the increasingly severe climate challenges anticipated in the future.