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The aim of this study was to determine the sources of superoxide anion radical (O₂⁻•) in rat heart homogenate under conditions of surgical trauma inflicted against the background of an experimental model of posttraumatic stress disorder (PTSD). Materials and methods. The experiments were conducted on 42 white Wistar rats weighing (220±10) g, divided into 6 groups: Group 1 – intact animals; Group 2 – rodents with PTSD modeled by reproducing single prolonged stress (SPS); Group 3 – rats that underwent a sham operation; Group 4 – animals that underwent laparotomy; Group 5 – rats that underwent a sham operation after SPS modeling; Group 6 – animals that underwent laparotomy after reproducing SPS. The rate of O₂⁻• generation in the heart homogenate was studied using a spectrophotometric test with nitroblue tetrazolium. Results. The modeling of PTSD (SPS) and surgical trauma leads to a significant increase in oxidative stress in the rat heart, evidenced by an elevated rate of O₂⁻• generation involving NADPH-dependent electron transport chains (ETC) in microsomes, NO synthase, the mitochondrial respiratory chain, and leukocyte NADPH oxidase. In the post-laparotomy period following SPS, the oxidative stress enhanced significantly and was manifested through increased O₂⁻• generation by NADPH-dependent microsomal and NO synthase ETC by 72.3%, by NADH-dependent mitochondrial ETC by 72.9%, and leukocyte NADPH oxidase by 80.9% compared to intact control. When compared to group 2, these indicators rose by 29.6%, 24.4%, and 26.8%, respectively. Group 4 demonstrated an even more pronounced increase in O₂⁻• generation, reaching 54.0%, 54.6%, and 62.9% respectively. Furthermore, O₂⁻• production rates from all sources in group 4 were likely higher than those in group 5 by 29.8%, 21.2%, and 21.5% , respectively. Conclusions. The combined effect of laparotomy and experimental PTSD synergistically enhances O₂⁻• production in the heart homogenate from various sources, significantly exceeding the levels observed with either laparotomy or SPS alone.

Given the importance of molecular structure in pharmacological activity and interaction with biological receptors, we conducted a study on the 3,4-dihydroxybenzaldehyde hydrazone derivative of 5-methoxy-indole carboxylic acid (5MICA) and a newly synthesised analogue bearing a 2-methoxy-4-hydroxyphenyl ring using single-crystal X-ray diffraction. We studied the ability of the two compounds to scavenge hypochlorite ions using luminol-enhanced chemiluminescence and their potential to modulate oxidative damage induced by iron on the biologically significant molecules lecithin and deoxyribose in order to evaluate possible antioxidant and prooxidant effects. The X-ray study revealed highly conserved geometry and limited rotation and deformation freedom of the respective indole and phenyl fragments. Interestingly, a conformational difference between the two independent molecules in the asymmetric unit of 3b was found. The X-ray study revealed a combination of hydrogen bonding interactions, short contacts, and π–π stacking stabilizing the specific three-dimensional packing of the molecules of 3a and 3b in the crystal structures. The three-dimensional packing of the molecules of 3b produced a zigzag layering projected along the c-axis. Both compounds effectively decreased luminol-dependent chemiluminescence in model systems with KO2-produced superoxide. They displayed opposite effects when applied in a xanthine/xanthine oxidase system. The hydrazones of 5MICA do not trigger a prooxidant effect or subsequent toxicity under conditions of iron-induced oxidative stress. The 3,4-dihydroxy-substituted derivative demonstrated excellent radical scavenging properties in all model systems, making it the lead compound for the development of compounds with combined neuroprotective and antioxidant properties. [ABSTRACT FROM AUTHOR]

Cyanobacteria are among the oldest organisms colonizing Earth. Their great biodiversity and ability to biosynthesize secondary metabolites through a variety of routes makes them attractive resources for biotechnological applications and drug discovery. In this pioneer study, four filamentous cyanobacteria (Cephalothrix lacustris LEGE 15493, Leptolyngbya boryana LEGE 15486, Nodosilinea nodulosa LEGE 06104 and Leptothoe sp. LEGE 11479) were explored for their anti-inflammatory potential in cell and cell-free in vitro bioassays, involving different inflammatory mediators and enzymes. Extracts of different polarities were sequentially prepared and chemically characterized for their content of phycobiliproteins (PBPs) and carotenoids. HPLC-PDA analysis of the acetone extracts revealed β-carotene to be the dominant carotenoid (18.4–44.3 mg/g) and zeaxanthin as the dominant xanthophyll (52.7–192.9 mg/g), with Leptothoe sp. LEGE 11479 and Nodosilinea nodulosa LEGE 06104, respectively, being the richest strains. The PBP profile was in accordance with the color presented by the aqueous extracts, with Leptolyngbya boryana LEGE 15486 being the richest in phycocyanin (204.5 μg/mg) and Leptothoe sp. LEGE 11479 the richest in phycoerythrin (78.5 μg/mg). Aqueous extracts were more effective in superoxide anion radical scavenging, while acetone ones were more effective in scavenging nitric oxide radical (●NO) and in inhibiting lipoxygenase. Acetone extracts also reduced ●NO production in lipopolysaccharide-stimulated RAW 264.7 macrophages, with the mechanistic study suggesting a downregulation of the inducible nitric oxide synthase expression. Nodosilinea nodulosa LEGE 06104 and Leptothoe sp. LEGE 11479 acetone extracts presented the lowest IC50 values for the mentioned assays, pointing them out as promising resources for the development of new multi-target anti-inflammatory therapies. [ABSTRACT FROM AUTHOR]

In this work, biocorrosion of D16T and AMg6 aluminum alloys under the influence of microscopic fungi was studied. It has been shown that micromycetes produce reactive oxygen species – superoxide anion-radical, hydrogen peroxide, which initiate biocorrosion of metals. The composition products of biocorrosion of D16T and AMg6 after exposure of the alloys on the lawn of a consortium of micromycetes was determined by energy-dispersive X-ray spectroscopy. An X-ray phase study of alloy biocorrosion products was carried out. Scanning electron microscopy and X-ray diffraction analysis show the formation of nanosized and submicron copper clusters. A physicochemical mechanism of biocorrosion of aluminum alloys by microscopic fungi is proposed. An assumption is made about the mechanism of operation of the «zerovalent metal – hydrogen peroxide» systems, which can trigger a cascade of reactions leading to the destructive oxidation of metals. The paper attempts to explain the role of microfungal community biofilms as the main factor in the mycological corrosion of metals.

Soybean (Glycine max) is a valuable crop in agricultural production. Our previous study showed that extract from the cyanobacterium strain Desmonostoc alborizicum is toxic as demonstrated by sequencing the mcyD and mcyG genes of the microcystin synthetase (mcy) cluster. We hypothesized that bioactive compounds from Desmonostoc alborizicum would enhance the defense responses of soybean to cowpea aphids (Aphis craccivora Koch), a severe pest of leguminous crops. Results showed that inoculation with cowpea aphid affected oxidative stress in soybean leaves. A potent production of superoxide anion radical (O2·−) was observed in 30 aphids 12 h post infestation (hpi), while the highest amount of hydrogen peroxide (H2O2) was observed in 30 aphids 96 hpi without treatment of cyanobacteria extract. Results of enzymatic antioxidants (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)) showed that they were intensely stored to decrease the toxic effects of reactive oxygen species (ROS). The highest generation of SOD and CAT was observed in 30 and 20 aphids 96 hpi and 24 hpi with treatment of cyanobacteria extract, while the highest amount of GPx (36.95 nkat mg−1 protein) was observed in aphids 96 hpi, respectively, without treatment of cyanobacteria extract. When exposed to cyanobacteria extract, the production of O2·− and H2O2, as well as the activity of GPx, were significantly reduced, leading to a substantial decrease in oxidative damage. However, the activity of SOD and CAT showed a remarkable increase in the leaves infested with cowpea aphids when treated with cyanobacteria extract. This suggests that the application of cyanobacteria extract may have a novel impact on the antioxidative response of soybean plants in the context of their interaction with cowpea aphids. Incorporating the effect of cyanobacteria extract into current research data can enhance our understanding of the soybean–aphid interaction. [ABSTRACT FROM AUTHOR]

A study is performed of the micromycete biocorrosion of electrical copper M1E and fiberglass FR4 with copper coating, which are used in the production of printed circuit boards. The structure of the surfaces of corroded samples is studied via optical and electron microscopy. Energy dispersive X-ray spectroscopy is used to perform a qualitative and semi-quantitative analysis of chemical elements present in the composition of corrosion products after exposing samples to a bed of micromycetes. An X-ray phase analysis of the products of copper biocorrosion is performed. It is established that microorganisms adhere to the metal surface at the initial stage of micromycetic corrosion, and colonies of them develop. It is suggested that reactive oxygen species (superoxide anion-radical and hydrogen peroxide) participate in the biocorrosion of copper and the functioning of the zerovalent copper–hydrogen peroxide system, triggering a cascade of reactions that result in the destructive oxidation of copper. The role of biofilms of the microscopic fungal colony as the main factor in the mycological corrosion of copper is explained. [ABSTRACT FROM AUTHOR]

Given the importance of molecular structure in pharmacological activity and interaction with biological receptors, we conducted a study on the 3,4-dihydroxybenzaldehyde hydrazone derivative of 5-methoxy-indole carboxylic acid (5MICA) and a newly synthesised analogue bearing a 2-methoxy-4-hydroxyphenyl ring using single-crystal X-ray diffraction. We studied the ability of the two compounds to scavenge hypochlorite ions using luminol-enhanced chemiluminescence and their potential to modulate oxidative damage induced by iron on the biologically significant molecules lecithin and deoxyribose in order to evaluate possible antioxidant and prooxidant effects. The X-ray study revealed highly conserved geometry and limited rotation and deformation freedom of the respective indole and phenyl fragments. Interestingly, a conformational difference between the two independent molecules in the asymmetric unit of 3b was found. The X-ray study revealed a combination of hydrogen bonding interactions, short contacts, and π–π stacking stabilizing the specific three-dimensional packing of the molecules of 3a and 3b in the crystal structures. The three-dimensional packing of the molecules of 3b produced a zigzag layering projected along the c-axis. Both compounds effectively decreased luminol-dependent chemiluminescence in model systems with KO2-produced superoxide. They displayed opposite effects when applied in a xanthine/xanthine oxidase system. The hydrazones of 5MICA do not trigger a prooxidant effect or subsequent toxicity under conditions of iron-induced oxidative stress. The 3,4-dihydroxy-substituted derivative demonstrated excellent radical scavenging properties in all model systems, making it the lead compound for the development of compounds with combined neuroprotective and antioxidant properties.

To examine the effects of membrane charge, the electrolyte species and glycosyl on the distribution of negatively charged radical of superoxide anion (·O2−) around the cell membrane, different phospholipid bilayer systems containing ·O2− radicals, different electrolytes and phospholipid bilayers were constructed through Charmm-GUI and Amber16. These systems were equilibrated with molecular dynamics by using Gromacs 5.0.2 to analyze the statistical behaviors of ·O2− near the lipid membrane under different conditions. It was found that in the presence of potassium rather than sodium, the negative charge of the phospholipid membrane is more likely to rarefy the superoxide anion distribution near the membrane surface. Further, the presence of glycosyl significantly reduced the density of ·O2− near the phospholipid bilayer by 78.3% compared with that of the neutral lipid membrane, which may have a significant contribution to reducing the lipid peroxidation from decreasing the ·O2− density near the membrane. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID-19) poses a serious threat to human health. To date, predicting the course of chronic diseases in individuals who suffered from a coronavirus infection is a topical issue. Osteoarthritis is a chronic degenerative disease of the joints. It was demonstrated that this disease can be caused by different factors, namely, the effect of oxidative stress, hypercholesterolemia, increased aggrecan-degrading activity of specific proteinases against the background of a disorder of particular endocytic pathway, etc. Therefore, the aim of this work was to analyze the expression of the OLR1, ACAN, and LRP1 genes in the synovial membrane cells in patients with osteoarthritis after SARS-CoV2 infection. The study involved 60 men aged 50 to 55. The volunteers were divided into the following groups: the first group (n = 20), conditionally healthy individuals; the second group (n = 20), patients with knee joint osteoarthritis of II–III degree; the third group consisted of 20 patients with knee joint osteoarthritis of II–III degree who recovered from COVID-19. A concentration of cholesterol in the human blood plasma was determined by the enzymatic method using a diagnostic reagent kit. The intensity of superoxide anion radical generation in the synovial fluid was measured by the accumulation of XTT-formazan. The level of expression of the OLR1, ACAN, and LRP1 genes in the synovial membrane cells of knee joints was determined using quantitative real-time RT-PCR. An increase in the expression level of the OLR1 gene was found to a greater extent in the synovial membrane cells in patients with osteoarthritis who recovered from COVID-19 as compared with the group of patients with knee joint osteoarthritis against the background of a more intensive increase in both the cholesterol concentration in the blood plasma and the activation of free radical processes (an increase in the content of superoxide anion radical) in the synovial fluid of patients with osteoarthritis after SARS-CoV2 infection. This can be associated with an increase in system-wide inflammation as a result of the organism's response to a virus. At the same time, a more significant decrease in the level of the ACAN gene expression in the synovial membrane cells in patients with osteoarthritis who recovered from COVID-19 was demonstrated as compared with the group of patients with knee joint osteoarthritis. This indicates a more powerful activation of destructive processes in the cells after infection and can also be mediated by a decrease in the expression level of the LRP1 gene, which, in turn, can cause a further progression of the disease. Understanding of clear mechanisms for the formation of a more severe course of osteoarthritis and possible development of complications in patients with post-COVID-19 syndrome on the example of the functioning of both the LOX1/ox-LDL system and LRP1-endocytic pathway requires further studies. [ABSTRACT FROM AUTHOR]

Cyanobacteria are among the oldest organisms colonizing Earth. Their great biodiversity and ability to biosynthesize secondary metabolites through a variety of routes makes them attractive resources for biotechnological applications and drug discovery. In this pioneer study, four filamentous cyanobacteria (Cephalothrix lacustris LEGE 15493, Leptolyngbya boryana LEGE 15486, Nodosilinea nodulosa LEGE 06104 and Leptothoe sp. LEGE 11479) were explored for their anti-inflammatory potential in cell and cell-free in vitro bioassays, involving different inflammatory mediators and enzymes. Extracts of different polarities were sequentially prepared and chemically characterized for their content of phycobiliproteins (PBPs) and carotenoids. HPLC-PDA analysis of the acetone extracts revealed β-carotene to be the dominant carotenoid (18.4–44.3 mg/g) and zeaxanthin as the dominant xanthophyll (52.7–192.9 mg/g), with Leptothoe sp. LEGE 11479 and Nodosilinea nodulosa LEGE 06104, respectively, being the richest strains. The PBP profile was in accordance with the color presented by the aqueous extracts, with Leptolyngbya boryana LEGE 15486 being the richest in phycocyanin (204.5 μg/mg) and Leptothoe sp. LEGE 11479 the richest in phycoerythrin (78.5 μg/mg). Aqueous extracts were more effective in superoxide anion radical scavenging, while acetone ones were more effective in scavenging nitric oxide radical (●NO) and in inhibiting lipoxygenase. Acetone extracts also reduced ●NO production in lipopolysaccharide-stimulated RAW 264.7 macrophages, with the mechanistic study suggesting a downregulation of the inducible nitric oxide synthase expression. Nodosilinea nodulosa LEGE 06104 and Leptothoe sp. LEGE 11479 acetone extracts presented the lowest IC50 values for the mentioned assays, pointing them out as promising resources for the development of new multi-target anti-inflammatory therapies.

Plasma-activated tap water (PATW) is a new technology for obtaining a high concentration of active aqueous plasma substances by discharging underwater. Commonly plasma-activated water (PAW) is realized by activating deionized water or distilled water, which has problems such as high cost, a small discharge area, and insufficient dissolution of active substances. This paper reports the development of a dielectric barrier discharge array to generate a high concentration of active aqueous plasma substances. The device can realize a uniform, stable, and large-area discharge in a large volume of tap water, and it has the advantages of low cost, high integration, and reusability. Using the device to treat 1000 mL of tap water for 1 h can reduce the pH of the tap water from 8.10 to 2.54, and the logarithmic value of killing E. coli is greater than 5.0. We sprayed PATW onto clothes to sterilize the bacteria when people were through the disinfection door and verified that the PATW had a good sterilization effect. The short-lived substances, singlet oxygen, and superoxide anion radicals played a key role in the sterilization process by PATW. [ABSTRACT FROM AUTHOR]

The intensity of drought-induced oxidative processes by the degree of superoxide anion radical generation and the activity of NADPH oxidase in soybean associated with different activity and virulence of Bradyrhizobium strains were studied. The importance of active Bradyrhizobium japonicum for the formation of effective symbiosis with soybean to improve the realization of the adaptive potential of plants during drought and post-stress period has been established. Increased NADPH oxidase activity in nodules (by 3.5 – 4.7 times), as well as excessive production of superoxide radical in nodules (by 1.5 – 2 times) and roots (from 113 to 323%) of soybean in symbiosis with efficient Bradyrhizobium strains were observed during drought. However, the development of oxidative processes in effective soybean-rhizobial symbioses slowed down after exposure to stress. This indicates the adaptation of soybean plants associated with active Bradyrhizobium strains to growing conditions. In symbiotic systems with ineffective Bradyrhizobium strains, a significant increase in NADPH oxidase activity in nodules (by 3.3 – 6.0 times) and intensification of superoxide radical formation in nodules (by 2 – 3 times) and roots (from 260 to 330%) recorded both under drought and post-stress period. This indicates a significant development of oxidative processes and the inability to realize the adaptive potential of soybean plants in symbiosis with ineffective Bradyrhizobium strains. Thus, excessive formation of the superoxide radical and an increase in the activity of NADPH oxidase indicate the appearance of oxidative processes, which are a typical reaction in response to drought in soybean-rhizobial symbioses of varying efficiency. At the same time, the development of oxidative processes depends on the ability of soybean plants in symbiosis with Bradyrhizobium japonicum to realize their adaptive potential in during drought and post-stress period.

Opuntia plants are abundant but still underexplored edible resources of the Algerian region. This work chemically characterizes extracts of different parts of the fruit of the commercial Opuntia ficus-indica (L.) Mill. and the wild Opuntia stricta (Haw.) Haw. growing in Bejaia, and evaluates their anti-inflammatory potential through different cell and cell-free bioassays. The LC-ESI-UHR-QqTOF-MS/MS analysis enabled the identification of 18 compounds, with azelaic acid and 1- O -vanilloyl- β - d -glucose reported here for the first time. Aqueous extracts of seeds were the most effective in scavenging superoxide anion radical (IC 50 = 111.08 μg/mL) and presented the best anti-inflammatory potential in LPS-stimulated macrophages (IC 50 = 206.30 μg/mL). The pulp of O. stricta suggested potential for addressing post-inflammatory hyperpigmentation, with piscidic and eucomic acids predicted with the strongest binding affinity towards tyrosinase, exhibiting higher scoring values than the reference inhibitor kojic acid. This pioneer study brings valuable perspectives for the pharmacological, nutritional and economic valorization of the wild O. stricta for functional foods. • Phytochemical composition of Opuntia sp. fruits was investigated. • Multiple phenolic compounds were reported in Opuntia stricta for the first time. • Opuntia stricta consumption brings multiple benefits for human's health. • We suggest the economic exploitation of the wild Opuntia stricta for humans consumption. [ABSTRACT FROM AUTHOR]

Oxidative stress is an important pathophysiological mechanism in the development of numerous cardiovascular disorders, but few studies have examined the levels of oxidative stress in adults with congenital heart disease (CHD). The objective of this study was to investigate oxidative stress levels in adults with CHD and the association with inflammation, exercise capacity and endothelial function. To this end, 36 adults with different types of CHD and 36 age- and gender-matched healthy controls were enrolled. Blood cell counts, hs-CRP, NT-proBNP, fasting glucose, cholesterol levels, iron saturation and folic acid concentrations were determined in venous blood samples. Levels of superoxide anion radical in whole blood were determined using electron paramagnetic resonance spectroscopy in combination with the spin probe CMH. Physical activity was assessed with the IPAQ-SF questionnaire. Vascular function assessment (EndoPAT) and cardiopulmonary exercise testing were performed in the patient group. Superoxide anion radical levels were not statistically significantly different between adults with CHD and the matched controls. Moreover, oxidative stress did not correlate with inflammation, or with endothelial function or cardiorespiratory fitness in CHD; however, a significant negative correlation with iron saturation was observed. Overall, whole blood superoxide anion radical levels in adults with CHD were not elevated, but iron levels seem to play a more important role in oxidative stress mechanisms in CHD than in healthy controls. More research will be needed to improve our understanding of the underlying pathophysiology of CHD. [ABSTRACT FROM AUTHOR]

This paper presents an experimental study of biocorrosion of D16T and AMg6 aluminum alloys. The determining role of reactive oxygen species in aluminum biocorrosion by a consortium of molds has been shown. A model has been proposed according to which the initiators of corrosion damage to the metal surface are superoxide anion radical and hydrogen peroxide released via the activity of micromycetes. It has been assumed that the initiation and development of biocorrosion occurs, among other things, as a result of the process of reductive activation of oxygen and the Fenton decomposition of hydrogen peroxide. A conclusion has been made about the mechanism of the occurrence of intergranular and pitting corrosion of aluminum alloys interacting with microscopic fungi. [ABSTRACT FROM AUTHOR]

The activity towards superoxide anion radical (O2·−) generated in an enzymatic model system upon reduction of nitro blue tetrazolium (NBT test), as well as during non-enzymatic oxidation of adrenaline in an alkaline media, was revealed for water-soluble quaternary ammonium salts bearing 2,6-di-tert-butylphenol and pyridine moiety. An increased activity of superoxide dismutase of the Russian sturgeon liver homogenate in the presence of these salts was found. A moderate Fe2+-chelating activity relative to the EDTA standard is characteristic of these salts. Their inhibitory effect was demonstrated in model systems of non-enzymatic oxidation of cis-octadec-9-enoic acid and lipids of the Russian sturgeon liver homogenate. The highest gross antioxidant activity was found for a water-soluble quaternary ammonium salt containing the ortho-pyridinyl moiety. [ABSTRACT FROM AUTHOR]

Mosses are pioneer plants in post-technogenic areas. Therefore, the question of adaptive reactions of mosses from these habitats represents a scientific interest. The research is devoted to the study of adaptive changes in the metabolism of the dominant moss species Bryum caespiticium Hedw., collected in the devastated territories of the Novoyavorivsk State Mining and Chemical Enterprise (SMCE) “Sirka (Sulfur)” exposed to hyperthermia and insolation, which cause oxidative stress in plants. The influence of these stressors on the activity and thermal stability of antioxidant enzymes, hydrogen peroxide content, anion radical generation and accumulation of prooxidant components in moss shoots was studied. The activity and thermal stability of peroxidase and superoxide dismutase (SOD) were analysed forB. caespiticium moss from different locations of northern exposure at the sulfur mining dump No 1 in summer and autumn. We established the dependence of the activity of antioxidant enzymes of moss on the intensity of light and temperature on the experimental plots of the dump No 1. In summer, the highest activity and thermal stability rates of peroxidase and SOD were observed. Under the conditions of the experiment in shoots of В. caespiticium from the northern peak of the dump under the influence of 2 hours temperature action (+ 42 ºС) the most significant increase in peroxidase activity was found by 1.78 times and SOD by 1.89 times, as well as increase in its thermal stability by 1.35–1.42 times, respectively. The increase in peroxidase and SOD activity, as well as the increase in their thermal stability caused by hyperthermia were negated by pre-processing with a protein biosynthesis inhibitor cyclohexamide, which may indicate the participation of the protein-synthesizing system in this process. The effect of increasing the thermal stability of enzymes can be considered as a mechanism of adaptation of the protein-synthesizing system to the action of high temperatures. Increase in the activity and thermal stability of antioxidant enzymes is caused primarily by changes in the expression of stress protein genes, which control the synthesis of specific adaptogens and protectors. The obtained results indicate that the extreme conditions of the anthropogenically transformed environment contribute to the development of forms with the highest potential abilities. The mechanism of action of high temperatures is associated with the development of oxidative stress, which is manifested in the intensification of lipid peroxidation and the generation of superoxide anion radical. It was found that temperature stress and high insolation caused an increased generation of superoxide anion radical as the main inducers of protective reactions in the samples of B. caespiticium from the experimental transect of the sulfur mining heap. It is known that the synthesis of Н2О2 occurs under stress and is a signal to start a number of molecular, biochemical and physiological processes of cells, including adaptation of plants to extreme temperatures. It is shown that high temperatures initiate the generation of hydrogen peroxide. Increased reactive oxygen species (ROS) formation, including Н2О2, under the action of extreme temperatures, can cause the activation of signaling systems. Therefore, the increase in the content of Н2О2 as a signaling mediator is a component of the antioxidant protection system. It is determined that adaptive restructuring of the metabolism of the moss В. caespiticium is associated with the accumulation of signaling prooxidant components (diene and triene conjugates and dienketones). The increase in primary lipid peroxidation products, detected by us, under the action of hyperthermia may indicate the intensification of free radical oxidation under adverse climatic conditions in the area of the sulfur production dump, which leads to the intensification of lipid peroxidation processes. The accumulation of radical and molecular lipid peroxidation products are signals for the activation of protective systems, activators of gene expression and processes that lead to increased resistance of plants.

This work describes the differential quenching of molecular oxygen and superoxide anion radical (O2˙–) by (metallo)‐quercetin (QCR) complexes. The in situ complexes were more reactive with molecular oxygen than preformed complexes. By adjusting the potential range, it was determined that Cu2+ complexes exhibited similar superoxide anion radical (O2˙–) quenching ability as free QCR. The Fe3+ complexes were less reactive than free QCR or Cu2+ complexes. The data indicate that metal ions significantly modulated reactivity of QCR with O2˙– or molecular oxygen, and may regulate antioxidant activity and reactive oxygen species levels in a complex biological setting. [ABSTRACT FROM AUTHOR]

• A series of 28 substituted ferrocenylmethylaniline derivatives were synthesized and their in vitro antioxidant activities against superoxide anion radicals were measured. • Compound FMA23 showed almost the same activity compared to the reference standard α-tocopherol. • The toxicity prediction investigations of the five most potent compounds were accessed for the toxicity properties. • Molecular docking study of compound FMA23 with glutathione reductase enzyme (PDB ID: 1XAN) showed less interaction with the neighboring residues of its active site. • A QSAR equation was developed allowing prediction of the antioxidant activities of similar structures. The superoxide anion radical scavenging activities of a series of twenty-eight ferrocenylmethylaniline derivatives were measured in an in vitro study followed by in silico studies which included quantitative structure-activity relationship (QSAR), toxicity prediction, molecular docking studies, and molecular dynamics simulations. Multilinear regression analysis was employed to establish a quantitative correlation between the scavenging activity of superoxide anion radicals and various structural properties. The QSAR model obtained underwent validation, demonstrating statistical significance with a squared fitting correlation coefficient (R2) of 0.934, an adjusted squared correlation coefficient (R2 adj) value of 0.849, and a cross-validation coefficient (Q2) value of 0.873. Additionally, the calculated Fisher ratio (F) value of 36.525 indicates the model's strong predictability. Toxicity perdition studies demonstrated that among the five most potent compounds, FMA27 and FMA12 were predicted to be non-toxic. The molecular Docking study revealed that compound FMA23 exhibited the least activity against the glutathione reductase enzyme, with the highest inhibitory concentration recorded at 4.16 × 10–6 M and the lowest docking scores observed at −7.34 kcal.mol-1. Interactions between the compound and the amino acid residues of glutathione reductase were primarily hydrophobic and π-cation in nature. Analysis of root mean square deviation (RMSD), radius of gyration (Rg), and root mean square fluctuation (RMSF), from molecular dynamics study, revealed stable fluctuations in protein backbone conformations, consistent compactness of the complex, and minimal fluctuations in most protein residues, respectively. [Display omitted] [ABSTRACT FROM AUTHOR]

The pressing need for highly efficient antibacterial strategies arises from the prevalence of microbial biofilm infections and the emergence of rapidly evolving antibiotic-resistant strains of pathogenic bacteria. Photodynamic therapy represents a highly efficient and compelling antibacterial approach, offering promising prospects for effective control of the development of bacterial resistance. However, the effectiveness of many photosensitizers is limited due to the reduced generation of reactive oxygen species (ROS) in hypoxic microenvironment, which commonly occur in pathological conditions such as inflammatory and bacteria-infected wounds. Herein, we designed and prepared two phenothiazine-derived photosensitizers (NB-1 and NB-2), which can effectively generate superoxide anion radicals (O 2 ●–) through the type I process. Both photosensitizers demonstrate significant efficacy in vitro for the eradication of broad-spectrum bacteria. Moreover, NB-2 possesses distinct advantages including strong membrane binding and strong generation of O 2 ●–, rendering it an exceptionally efficient antibacterial agent against mature biofilms. In addition, laser activated NB-2 could be applied to treat MRSA -infected wound in vivo , which offers new opportunities for potential practical applications. • Two cationic phenothiazine-derived probes (NB-1 and NB-2) are synthesized as photosensitizers. • NB-1 and NB-2 can generate superoxide radical through the Type-I process. • NB-2 with a higher hydrophobicity demonstrates enhanced membrane binding capability and superior antibacterial effect. • NB-2 demonstrates remarkable efficacy in eradicating mature biofilms and treating MRSA -infected wounds in vivo. [ABSTRACT FROM AUTHOR]

[Display omitted] • The defect level of graphite felt was improved by CeO 2. • Cu 2 PO 4 exhibited better catalytic performance than Cu x O. • P-doped Cu 2 PO 4 /EGF electrodes efficiently removed SMX over a pH range of 5.6–11. • Phosphorus doping promoted the production of O 2 –. Non-metallic atom doping is a good strategy to promote the cathode performance in the electro-Fenton process. Therefore, a mixed-valence copper (I and II) phosphate (Cu 2 PO 4) catalyst on P-doped etched graphite felt (EGF), with a strip-groove rough surface, was prepared in this study. The P-doped Cu 2 PO 4 /EGF electrode completely removed sulfamethoxazole (SMX) from contaminated water within 90 min over a wide pH range of 5.6–9 and removed 99.6% of SMX at pH 11. Quenching experiments showed that the main reactive oxygen species (ROS) was O 2 –. According to density functional theory calculations, the adsorption reaction energy (E P = −2.149) of P atoms doped on the EGF surface was lower than that of pyrrolic nitrogen atoms (E N = −0.434), indicating that they were more conducive to oxygen adsorption. Finally, we investigated the mechanism of P-doped Cu 2 PO 4 /EGF adsorption and the catalytic production of O 2 – from O 2. Four main degradation pathways were identified based on the intermediates identified during degradation. Toxicity analysis of the intermediates showed that electro-Fenton degradation reduced the ecotoxicity of SMX. The enhanced electrocatalytic activity obtained by P doping of heterogeneous catalysts provides a new method for preparing efficient and stable composite electrodes for pollutant degradation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Charge transfer complexes between nano-TiO 2 and malonic acid (TiO 2 -MoA CTCs) were synthesized for the first time. • TiO 2 -MoA CTCs calcined at 270 °C showed a very high surface area (between 306 and 324 m2.g−1). • TiO 2 -MoA-270 CTCs highly absorbed along the visible light spectrum. • TiO 2 -MoA CTCs s how ∼ 100 % degradation of tetracycline under low-power visible light. • TiO 2 -MoA CTCs are an efficient source of photogenerated •O 2 – radicals. Charge transfer complexes (CTCs) between nano-TiO 2 and chelating ligands are among the most promising alternatives for photocatalytic applications, such as environmental remediation. However, the development of CTCs based on nano-TiO 2 modified with malonic acid (MoA) has not yet been investigated in detail. In this study, TiO 2 -MoA CTCs, synthesized via sol–gel route, were tested for tetracycline (antibiotic) and chlorophenol (pesticide) photocatalytic degradation with, and without, scavengers of reactive oxidizing species, under low-power visible light (26 W). The TiO 2 -MoA CTCs were thoroughly characterized. TGA-MS and FTIR analyses revealed malonic acid bonded to the TiO 2 surface, while the PL and EPR analyses proved the generation of extrinsic oxygen vacancies due to calcination process of the xerogels. CTCs based on nano-TiO 2 strongly bonded to malonic acid, and highly sensitive to visible light, have been synthesized by sol–gel method, followed by calcination at 270 °C in air. The as-prepared CTCs showed very high surface areas (between 180.9 and 323.9 m2.g−1), presence of F+ color centers in the calcined CTCs due to extrinsic oxygen vacancies and high photocatalytic activity, degrading approximately 100 % of the tetracycline after 6 h. In addition, it has been proved that the TiO 2 -MoA CTCs are efficient sources of •O 2 – radicals. The findings of this research can be generalized to the synthesis, via sol–gel, of other CTCs between TiO 2 and bidentate ligands, such as dicarboxylic acids, and explored for air purification and hydrogen production. [ABSTRACT FROM AUTHOR]

Cyanobacteria are ancient and prolific microorganisms for which the current knowledge remains limited. The present work constitutes the first report on the presence of the cyanobacteria Tolypothrix sp. LEGE 221228, Nostoc sp. LEGE 221229, Scytonema sp. LEGE 221230 and Drouetiella sp. LEGE 221231 in the volcanic crater lake in Chichonal (Chiapas-Mexico), and in the characterization of their pigments profile and antioxidant potential, through the application of biorefinery approaches. The identification of cyanobacteria species was achieved through advanced morphology-based methods for cyanobacterial taxonomy. The HPLC-PDA analysis of the cyanobacteria acetone extracts revealed β-carotene, echinenone and chlorophyll- a as the main pigments. Drouetiella sp. LEGE 221231 presented the highest β-carotene concentration (63.67 μg/mL), total carotenoids (87.92 μg/mL) and chlorophylls (20.88 μg/mL), closely followed by Tolypothrix sp. LEGE 221228 (with 51.37, 75.14 and 14.88 μg/mL, respectively), this being the first report on the carotenoid and chlorophylls profile of these strains. Aqueous extracts revealed the highest content of phycoerythrin in Tolypothrix sp. LEGE 221228 (50.61 mg/g) and of phycocyanin in Nostoc sp. LEGE 221229 (57.66 mg/g), standing out in superoxide anion radical scavenging, while the acetonic ones were more effective in scavenging nitric oxide radical. For both, Tolypothrix sp. LEGE 221228 was the most effective, presenting the lowest IC 50 (53.75 and 57.68 μg/mL, respectively). Overall, the present study enriches the knowledge on biodiversity of cyanobacteria from underexplored environments, enhancing their potential biotechnological applications as producers of added value secondary metabolites with interest in food, pharmaceutical and cosmetic industries. • Extremophile cyanobacteria were isolated from the volcanic crater lake in Chichonal. • Four strains were identified by 16S rRNA and morphological analysis. • β-carotene, echinenone and chlorophyll- a were the dominant carotenoids and chlorophyll. • Carotenoid- rich extracts are more effective in scavenging free radicals of nitrogen. • Tolypothrix sp. LEGE 221228 stood-out in scavenging physiologic free radicals. [ABSTRACT FROM AUTHOR]

The intensity of drought-induced oxidative processes by the degree of superoxide anion radical generation and the activity of NADPH oxidase in soybean associated with different activity and virulence of Bradyrhizobium strains were studied. The importance of active Bradyrhizobium japonicum for the formation of effective symbiosis with soybean to improve the realization of the adaptive potential of plants during drought and post-stress period has been established. Increased NADPH oxidase activity in nodules (by 3.5 - 4.7 times), as well as excessive production of superoxide radical in nodules (by 1.5 - 2 times) and roots (from 113 to 323%) of soybean in symbiosis with efficient Bradyrhizobium strains were observed during drought. However, the development of oxidative processes in effective soybean-rhizobial symbioses slowed down after exposure to stress. This indicates the adaptation of soybean plants associated with active Bradyrhizobium strains to growing conditions. In symbiotic systems with ineffective Bradyrhizobium strains, a significant increase in NADPH oxidase activity in nodules (by 3.3 - 6.0 times) and intensification of superoxide radical formation in nodules (by 2 - 3 times) and roots (from 260 to 330%) recorded both under drought and post-stress period. This indicates a significant development of oxidative processes and the inability to realize the adaptive potential of soybean plants in symbiosis with ineffective Bradyrhizobium strains. Thus, excessive formation of the superoxide radical and an increase in the activity of NADPH oxidase indicate the appearance of oxidative processes, which are a typical reaction in response to drought in soybean-rhizobial symbioses of varying efficiency. At the same time, the development of oxidative processes depends on the ability of soybean plants in symbiosis with Bradyrhizobium japonicum to realize their adaptive potential in during drought and post-stress period. [ABSTRACT FROM AUTHOR]

Cyclic voltammetry (CV) assays were performed to measure superoxide anion radical (O2-) scavenging activities of six novel N-ferrocenylmethyl-N-(nitrophenyl)-acetamides and N-fer­rocenylmethyl-N-(cyanophenyl)acetamides (FMA1-FMA6), followed by molecular docking simulations and in silico toxicity prediction. The obtained values of IC50 from CV assays indicated that all studied compounds showed promising scavenging activity against O.2- radicals, with the compounds FMA1, FMA3, and FMA4 possessing the most significant potency. A molecular docking study revealed that all compounds interact with amino acid residues of glutathione reductase via hydrogen bonding and hydrophobic interactions. The compound FMA4 was the most inactive compound against the glutathione reductase enzyme having the highest inhibitory concentration of 2.61 µM and the lowest docking score of -31.85 kJ/mol. Toxicity studies demonstrated that among six studied compounds, FMA4, FMA5, and FMA6 are predicted to be nontoxic.

Plasma-activated tap water (PATW) is a new technology for obtaining a high concentration of active aqueous plasma substances by discharging underwater. Commonly plasma-activated water (PAW) is realized by activating deionized water or distilled water, which has problems such as high cost, a small discharge area, and insufficient dissolution of active substances. This paper reports the development of a dielectric barrier discharge array to generate a high concentration of active aqueous plasma substances. The device can realize a uniform, stable, and large-area discharge in a large volume of tap water, and it has the advantages of low cost, high integration, and reusability. Using the device to treat 1000 mL of tap water for 1 h can reduce the pH of the tap water from 8.10 to 2.54, and the logarithmic value of killing E. coli is greater than 5.0. We sprayed PATW onto clothes to sterilize the bacteria when people were through the disinfection door and verified that the PATW had a good sterilization effect. The short-lived substances, singlet oxygen, and superoxide anion radicals played a key role in the sterilization process by PATW.

Oxidative stress is an important pathophysiological mechanism in the development of numerous cardiovascular disorders, but few studies have examined the levels of oxidative stress in adults with congenital heart disease (CHD). The objective of this study was to investigate oxidative stress levels in adults with CHD and the association with inflammation, exercise capacity and endothelial function. To this end, 36 adults with different types of CHD and 36 age- and gender-matched healthy controls were enrolled. Blood cell counts, hs-CRP, NT-proBNP, fasting glucose, cholesterol levels, iron saturation and folic acid concentrations were determined in venous blood samples. Levels of superoxide anion radical in whole blood were determined using electron paramagnetic resonance spectroscopy in combination with the spin probe CMH. Physical activity was assessed with the IPAQ-SF questionnaire. Vascular function assessment (EndoPAT) and cardiopulmonary exercise testing were performed in the patient group. Superoxide anion radical levels were not statistically significantly different between adults with CHD and the matched controls. Moreover, oxidative stress did not correlate with inflammation, or with endothelial function or cardiorespiratory fitness in CHD; however, a significant negative correlation with iron saturation was observed. Overall, whole blood superoxide anion radical levels in adults with CHD were not elevated, but iron levels seem to play a more important role in oxidative stress mechanisms in CHD than in healthy controls. More research will be needed to improve our understanding of the underlying pathophysiology of CHD.

Antioxidant activity of new compounds with 1,3-diazin-2,6-dione and pyrrolidine fragments in comparison with 2,6-di-tert-butyl-4-mercaptophenol has been studied in the model system of adrenaline autooxidation in alkaline medium in DPPH, NBT, and CUPRAC tests. In the series of studied compounds, a leader has been revealed, which shows moderate antiradical activity toward DPPH radical, prevents accumulation of toxic products of adrenaline quinoid oxidation, and exhibits higher efficiency as one-electron Cu2+ reducing reagent as compared with known antioxidants, trolox and 2,6-di-tert-butyl-4-mercaptophenol. [ABSTRACT FROM AUTHOR]

Trapping activity of new hydroxy derivatives of chalcones toward electrochemically generated superoxide anion radical () in a xanthine/xanthine oxidase enzymatic system upon reduction of nitro blue tetrazolium and during non-enzymatic quinoid oxidation of adrenaline in alkaline medium has been studied. Antiradical activity of new hydroxy derivatives of chalcones toward has been established for the first time. Reaction with electrochemically generated and higher antiradical activity under adrenaline autooxidation conditions in alkaline medium has been revealed for chalcone containing 2,6-di-tert-butylphenol fragment. Chalcone with two non-shielded OH groups showed the highest trapping activity in xanthine/xanthine oxidase enzymatic system and SOD-protective activity. The inhibiting activity of hydroxy derivatives of chalcones toward agrees well with in silico prediction and indicates their ability to decrease probability of oxidative stress development. Correlation has been found between the ability of the studied chalcones to consume superoxide anion radical and inhibiting activity in model systems of peroxide oxidation of oleic acid and tilapia liver lipids. [ABSTRACT FROM AUTHOR]

The selenoprotein thioredoxin reductase 1 (TrxR1; TXNRD1) participates in multiple cellular processes and is regarded as a cellular target in anti-tumor drug discovery and development. TrxR1 has been reported to reduce menadione to menadiol and to produce superoxide anion radicals. However, the details of TrxR1-mediated menadione reduction have rarely been studied. In this study, we found that wild-type TrxR1 could reduce menadione in a less efficient way, but the U498C mutant variant supported high-efficiency menadione reduction in a Sec-independent manner. Meanwhile, the site-directed mutagenesis results showed that Cys64 mutant increased the K m values and decreased the catalytic efficiency, which was associated with a charge-transfer complex between FAD-Cys64. Mass spectrometry (MS) revealed that in NADPH pre-reduced TrxR1 but not oxidized TrxR1, the highly active Sec498 of wild-type TrxR1 was arylated by menadione and strongly impaired the DTNB reducing activity in a dose-dependent manner. TrxR1 reduced menadione more efficiently than glutathione reductase (GR), and interestingly menadione did not inhibit the GSSG reducing activity of GR. In summary, our results demonstrate that TrxR1 catalyzes the reduction of menadione in a Sec-independent manner, which highly depend on Cys498 instead of N-terminal redox motif, and the Sec498 of TrxR1 is the primary target of menadione. The interaction between menadione and TrxR1 revealed in this study may provide a valuable reference for the development of anticancer drugs targeting selenoprotein TrxR1. [Display omitted] • Mutation of Sec498 to Cys498 enhances both NADPH oxidation and superoxide production in TrxR1 mediated menadione reduction. •Menadione modifies the highly reactive Sec498 of TrxR1, thereby inhibiting the reduction activity of TrxR1. •Sec-containing TrxR1 is more reactive than yeast glutathione reductase in menadione reduction and interaction. [ABSTRACT FROM AUTHOR]

Mosses are pioneer plants in post-technogenic areas. Therefore, the question of adaptive reactions of mosses from these habitats represents a scientific interest. The research is devoted to the study of adaptive changes in the metabolism of the dominant moss species Bryum caespiticium Hedw., collected in the devastated territories of the Novoyavorivsk State Mining and Chemical Enterprise (SMCE) “Sirka (Sulfur)” exposed to hyperthermia and insolation, which cause oxidative stress in plants. The influence of these stressors on the activity and thermal stability of antioxidant enzymes, hydrogen peroxide content, anion radical generation and accumulation of prooxidant components in moss shoots was studied. The activity and thermal stability of peroxidase and superoxide dismutase (SOD) were analysed forB. caespiticiummoss from different locations of northern exposure at the sulfur mining dump No 1 in summer and autumn.We established the dependence of the activity of antioxidant enzymes of moss on the intensity of light and temperature on the experimental plots of the dump No 1. In summer, the highest activity and thermal stability rates of peroxidase and SOD were observed. Under the conditions of the experiment in shoots of В. caespiticium from the northern peak of the dump under the influence of 2 hours temperature action (+ 42 ºС) the most significant increase in peroxidase activity was found by 1.78 times and SOD by 1.89 times, as well as increase in its thermal stability by 1.35–1.42 times, respectively. The increase in peroxidase and SOD activity, as well as the increase in their thermal stability caused by hyperthermia were negated by pre-processing with a protein biosynthesis inhibitor cyclohexamide, which may indicate the participation of the protein-synthesizing system in this process. The effect of increasing the thermal stability of enzymes can be considered as a mechanism of adaptation of the protein-synthesizing system to the action of high temperatures. Increase in the activity and thermal stability of antioxidant enzymes is caused primarily by changes in the expression of stress protein genes, which control the synthesis of specific adaptogens and protectors. The obtained results indicate that the extreme conditions of the anthropogenically transformed environment contribute to the development of forms with the highest potential abilities. The mechanism of action of high temperatures is associated with the development of oxidative stress, which is manifested in the intensification of lipid peroxidation and the generation of superoxide anion radical. It was found that temperature stress and high insolation caused an increased generation of superoxide anion radical as the main inducers of protective reactions in the samples of B. caespiticium from the experimental transect of the sulfur mining heap. It is known that the synthesis of Н2О2 occurs under stress and is a signal to start a number of molecular, biochemical and physiological processes of cells, including adaptation of plants to extreme temperatures. It is shown that high temperatures initiate the generation of hydrogen peroxide. Increased reactive oxygen species (ROS) formation, including Н2О2, under the action of extreme temperatures, can cause the activation of signaling systems. Therefore, the increase in the content of Н2О2 as a signaling mediator is a component of the antioxidant protection system. It is determined that adaptive restructuring of the metabolism of the moss В. caespiticium is associated with the accumulation of signaling prooxidant components (diene and triene conjugates and dienketones). The increase in primary lipid peroxidation products, detected by us, under the action of hyperthermia may indicate the intensification of free radical oxidation under adverse climatic conditions in the area of the sulfur production dump, which leads to the intensification of lipid peroxidation processes. The accumulation of radical and molecular lipid peroxidation products are signals for the activation of protective systems, activators of gene expression and processes that lead to increased resistance of plants. [ABSTRACT FROM AUTHOR]

Nanoplastics (NPs) is a novel plastic contaminant that could be taken up by cells and lead to severe biotoxicity toxicity, NPs in cells can cause oxidant damage by inducing reactive oxygen species (ROS) production and lead to acute inflammation. As a major ROS which related to many kinds of physiological and pathological processes, superoxide anion radical (O 2 •−) could be utilized as a signal of oxidant damage effected by NPs exposure in vivo. To detect the toxic damage mechanism of NPs, a fluorescence probe Bcy-OTf has been developed to monitor O 2 •− fluctuations content in cells and aquatic organisms after exposure to NPs. The probe has a high sensitivity (LOD = 20 nM) and a rapid responsive time (within 6 min), and it has high selectivity and low cytotoxicity to analysis the levels of the endogenous O 2 •−. Endogenous O 2 •− induced by NPs in living cells, Daphnia magna and larval zebrafish were analyzed. Moreover, the results confirmed the key role of MAPK and NF-κB pathway in NPs stimulation mechanisms in cells. This study indicated that Bcy-OTf can precisely assess the fluctuations of endogenous O 2 •−, which has potential for applying in further analysis mechanisms of NPs biological risks. Fluorescent probe Bcy-OTf for evaluating the nanoplastics-induced redox imbalance in cells, zebrafish, and daphnia magna. [Display omitted] • Bcy-OTf is highly sensitive and selective for measuring endogenous O 2.•−. • Bcy-OTf was used to determine O 2.•− in daphnia magna and larval zebrafish under the NPs. • O 2.•− levels increased with NPs concentration or exposure duration. • Bcy-OTf can be used as a promising tool to assess O 2.•− fluctuations and NPs risk analysis. [ABSTRACT FROM AUTHOR]

Introduction: The aim of work is to assess the usefulness of oxidative stress parameters in the differential diagnosis of dementia of the Alzheimer's type and dementia of the Alzheimer's type with coexisting depression. Methods: The study involved three groups of people: patients with Alzheimer's disease (AD) (AD; N=27), patients with Alzheimer's disease and depression (D) (AD+D; N=30), and a control group that consisted of people without dementia and without depression (C; N=24). The assessment of cognitive functioning was carried out using among alia, Auditory Verbal Learning Test and Verbal Fluency Test. Furthermore, we determined the activity of superoxide dismutase (SOD-1) and superoxide anion radical. Results: Multiple models with different combinations of independent variables showed that SOD together with Rey delayed recall were the best significant predictors of AD with the area under curve (AUC) of 0.893 (p = 0.001) and superoxide anion radical (O2•−) together with verbal fluency – sharp objects were the best significant predictors of AD +D diagnosis with the AUC of 0.689 (p = 0.034). Conclusion: This study confirmed the value of neuropsychological diagnosis and analysis of oxidative stress markers in the diagnosis of AD and major depressive disorder (MDD) in the course of AD. The combination of the use of biochemical markers and neuropsychological tests seems particularly important for differential diagnosis. [ABSTRACT FROM AUTHOR]

Fluorescent imaging of cellular superoxide anion radical (O 2 •-) is of great significance to investigate reactive oxygen species-related pathophysiological processes and drug metabolism. However, the application of this technique is far away from maximum partially due to the lack of suitable probes. In this work, we propose a new strategy for design of near-infrared (NIR) O 2 •- fluorescent probes in which p -cresol is used as a self-immolative linker to conjugate the NIR fluorophore DDAO (9H-1,3-Dichloro-7-hydroxy-9,9-dimethylacridine-2-one) with the O 2 •--sensing group (i.e., trifluoromethanesulfonate). The introduction of self-immolative linker effectively increases the self-stability of these probes under physiological conditions. Importantly, the electron-withdrawing halogen substituents on the linker greatly enhance the sensitivity of the probes to O 2 •-. As such, the representative probe DLS4 exhibits high self-stability over a broad range of pHs (5.0–8.5), high selectivity as well as excellent sensitivity to O 2 •- with a detection limit (LOD) of 7.3 nM and 720-fold fluorescence enhancement upon reaction with O 2 •-. Moreover, DLS4 enables imaging of O 2 •- generation in PMA-stimulated RAW 264.7 cells and HeLa cells, and the fluorescence intensities are proportional to the PMA concentrations. In addition, the doxorubicin-induced cytotoxicity of H9c2 cells was also evaluated using DLS4. The present study provides a novel strategy for molecular design of small-molecule O 2 •- fluorescent probes and the resulting probes show great potential as reliable tools to study the development and progression of O 2 •--related diseases and drug metabolism in various systems. [Display omitted] • Near-infrared fluorescent O 2.•- probes with self-immolative linkers were synthesized. • The self-immolative linker enhances self-stability and sensitivity of the probes. • The probe DLS4 exhibits excellent sensitivity and specificity to O 2.•-. • Cellular imaging of endogenous O 2.•- from two cell lines has been achieved using DLS4. • Doxorubicin-induced cytotoxicity of H9c2 cells was reasonably evaluated using DLS4. [ABSTRACT FROM AUTHOR]

A novel in-situ N-doped carbon nanoparticles (NCNs) was prepared through direct pyrolysis of N-rich polyaniline (PANI) without using external N-containing precursor and the as-prepared materials were employed as metal-free peroxydisulfate (PDS) activator for bisphenol A (BPA) degradation. The catalyst derived from PANI carbonization at 900 °C (NCNs-9) displayed the excellent catalytic activity to activate PDS, resulting in 96.0% BPA degradation efficiency within 20 min. The catalytic activity of NCNs was closely related to their structure-composition, and higher graphitic N content and larger BET surface area were beneficial to the generation of reactive oxygen species (ROS). The quenching tests and electron paramagnetic resonance (EPR) demonstrated that BPA degradation in PDS/NCNs system was accomplished via non-radical (1O 2) and radical (·OH, SO 4 ·−, and O 2 ·−) pathways, in which O 2 ·− was the main ROS. The origin of O 2 ·− was the conversion of dissolved oxygen and the activation of PDS. The possible degradation pathways of BPA were also proposed. This study might provide inspirations to design in-situ N-doped carbon nanoparticles as the PDS activator for efficient degradation of persistent organic compound via advanced oxidation processes (AOPs). [ABSTRACT FROM AUTHOR]

Cytochrome bc 1 , also known as mitochondrial complex III, is considered to be one of the important producers of reactive oxygen species (ROS) in living organisms. Under physiological conditions, a certain level of ROS produced by mitochondrial electron transport chain (ETC) might be beneficial and take part in cellular signaling. However, elevated levels of ROS might exhibit negative effects, resulting in cellular damage. It is well known that inhibiting the electron flow within mitochondrial complex III leads to high production of ROS. However, superoxide production by cytochrome bc 1 in a non-inhibited system remained controversial. Here, we propose a novel method for ROS detection in ETC hybrid system in solution comprising bacterial cytochrome bc 1 and mitochondrial complex IV. We clearly show that non-inhibited cytochrome bc 1 generates ROS and that adaptive and pathogenic mitochondrial mutations suppress and enhance ROS production, respectively. We also noted that cytochrome bc 1 produces ROS in a rate-dependent manner and that the mechanism of ROS generation changes according to the rate of operation of the enzyme. This dependency has not yet been reported, but seems to be crucial when discussing ROS signaling originating from mitochondria. Image 1 • System composed of ETC proteins enables highly sensitive detection of ROS. • Cytochrome bc 1 produces measurable level of O 2.•- in non-inhibited conditions • High activity of cytochrome bc 1 correlates with high O 2.•- production rate • Adaptive/disease-related mutations suppress/enhance O 2.•- generation • Q o site can act as a trigger in energy pathway via feedback loop-like mechanism. [ABSTRACT FROM AUTHOR]

We have recently found that penicillamine, a classic copper-chelating thiol-drug for Wilson's disease, can delay tetrachlorohydroquinone (TCHQ) autooxidation via a previously unrecognized redox-activity. However, its underlying molecular mechanism remains not fully understood. In this study, we found, interestingly and unexpectedly, that superoxide dismutase (SOD) can significantly shorten the delay of TCHQ autooxidation by penicillamine, but not by ascorbate; SOD can also markedly increase the yields of the oxidized form of penicillamine. Similar effects were observed with a recently-developed specific and sensitive superoxide anion radical (O 2 •-) probe CT-02H, which was also employed to successfully measure O 2 •- generated from both TCHQ and TCHQ/penicillamine systems for the first time. More importantly, addition of extra O 2 •- (KO 2 /18-crown-6) can further prolong the delaying effects by penicillamine and slow down penicillamine consumption. Taken together, an unexpected critical role of O 2 •- in TCHQ/penicillamine interaction was proposed: O 2 •- may regenerate penicillamine, thereby continuously reducing TCSQ•- to TCHQ and finally delaying TCHQ autooxidation; In contrast, if O 2 •- were eliminated, which can not only markedly change the reaction equilibrium, accelerate the rate of interaction, and ultimately shorten the delay of TCHQ autooxidation by penicillamine, but can also accelerate penicillamine oxidation to form its corresponding disulfide solely via redox reaction without any minor nucleophilic reaction. These findings not only further support our previously-proposed redox mechanism for the protection against TCHQ-induced cytotoxicity by penicillamine, but also reveal a new mode of action for O 2 •- in the inhibition of haloquinoids-induced toxicity by thiol antioxidants. Image 1 • O 2.•- generated from TCHQ autooxidation are detected by O 2 •--probe CT-02H. • SOD can shorten the delay of TCHQ autooxidation by penicillamine. • SOD inhibits the minor nucleophilic reaction between TCHQ and penicillamine. • Extra O 2.•- can prolong the delay of TCHQ autooxidation by penicillamine. • Two O 2.•--generating pathways were observed for TCHQ/penicillamine. [ABSTRACT FROM AUTHOR]

The interaction of the oxazine dye gallocyanine with reactive oxygen ( Н2О2) and halogen (HOCl) species has been studied by spectrophotometry, mass spectrometry, and spectrofluorimetry. It has been shown that gallocyanine reacts with HOCl and (but not with Н2О2) to form fluorescent products. It has been found using the inhibition assay that, both in the xanthine/xanthine oxidase system and in activated human blood neutrophils, the main contribution to the conversion of gallocyanine to a fluorophore comes from its reaction with The results obtained suggest that gallocyanine can act as a fluorogenic chemosensor and be used for estimating the activation of neutrophils and the NADPH-dependent production of superoxide anion radical by neutrophils and other blood cells, as well as for testing antioxidant drugs designed with the aim to correct diseases associated with oxidative stress. [ABSTRACT FROM AUTHOR]

Aspergillus flavus (A. flavus) is a kind of ubiquitous pathgenic fungi, of which an early and accurate detection and inhibition mehtod is essential to reduce its resulted damage of Afatoxions. Here real-time monitoring superoxide anions (O2•−) released from cinnamaldehyde-treated A. flavus was performed for the first time by an electrochemical enzyme-free biomimetic O2•− sensor to offer not only a facile and reliable approach to monitor the effect of inhibiting methods against A. flavus growth, but also a highly sensitive analytical tool to detect A. flavus, thus holding great promise for the sensor to continuously real-time monitor A. flavus released from infection or/and contamination of food in A. flavus-related biological researches and clinic diagnosis of some fatal diseases.

L-Ascorbic acid (AsA) plays an important role in plants and animals. In plants, GDP-D-mannose pyrophosphorylase (GMP) is essential in the AsA biosynthetic pathway. However, little is known about the genes encoding GMP in soybean and here we report genetic and functional analysis of the GmGMP1 (Glycine max GDP-D-mannose pyrophosphorylase 1) gene in this species. GmGMP1 encoded a GDP-mannose pyrophosphorylase and exhibited higher transcript levels in the leaf than in the root, stem, flower, and seed. Transcript of this gene was ubiquitous in the vegetative and reproductive organs, and was induced by abiotic stress and light. Increasing expression of GmGMP1 in Arabidopsis and soybean through an overexpressing approach caused pronounced enhancement of AsA content, and was implicated in lowering the superoxide anion radical content and lipid peroxidation levels in Arabidopsis, and conferring tolerance to osmotic and high salt stresses during seed germination. The present study represents the first systematic determination of soybean genes encoding GDP-mannose pyrophosphorylase and provides useful evidence for the functional involvement of GmGMP1 in control of AsA content and conferring tolerance to osmotic and salt stress.

Royal jelly is natural bee product, traditionally used in medicine for antitumor, anti-inflammatory, antioxidant, antibiotic and many other beneficial properties. The aim of this study was to determine biological effects of royal jelly samples originating from Serbia on normal human fibroblast (MRC-5) and colorectal cancer (HCT-116 and SW-480) cells. MTT cell viability assay was used to determine cytotoxic activity, and NBT test was used for determination of superoxide anion radical concentration. Parameters of cell energy status were determined using LDH and ATP colorimetric methods. Relative expression of mRNA of apoptosis and biotransformation genes was monitored by qPCR method. Royal jelly affected cell viability, caused oxidative stress appearance and elevated parameters of energy status in cancer cell lines. The relative expression of genes whose proteins are included in biotransformation of xenobiotics were changed with notable suppression of CYP1A1, while increased expression of apoptosis genes was noted in tested cell lines. Royal jelly demonstrated cell selective effect and could be prospective in anticancer therapy.

Water pollution by dyes is a major health and environmental issue. Photosensitive organic dyes produce hydrated electrons, eaq−, singlet oxygen, 1O2, and superoxide anion radicals, O2·−. O2·− catalyzes H2O2 transformation into hydroxyl radicals ·OH, which can be used to degrade wastewater under sunlight. Here, we measured eaq−, 1O2, O2·− and ·OH generated under visible light irradiation of photosensitive organic dyes in the presence of the auxiliary Fe3+, the 1,5-diphenylcarbazide molecular probe, the NH2OH molecular probe and the dimethyl sulphoxide probe. Results show that single photosensitive organic dyes are not degraded in the visible light/H2O2 system. However, they were degraded when mixed in a certain proportion to produce a brown coloration, a phenomenon named the 'color-mixing effect.' Likewise, the average yields of O2·− in single photosensitive organic dye solutions were lower, of 0.015 (ΔA510), than that in mixed brown solutions, of 0.113. The color-mixing effect is explained mainly by higher ·OH generation from increased O2·− production. Findings imply that sunlight irradiation is a promising way to clean colorful and dye-containing wastewater. [ABSTRACT FROM AUTHOR]

This paper reports that pre-incubation of a neutrophil suspension in the presence of a near-null magnetic field produced using a system of magnetic shields (a residual constant magnetic field not greater than 20 nT) results in a considerable decrease in the intensity of neutrophil lucigenin-dependent chemiluminescence. The addition of the NADPH oxidase inhibitor diphenyliodonium to the incubation medium reduced the chemiluminescence intensity in both the experimental and the control samples (geomagnetic field). It should be noted that the differences observed between the groups, which were caused by the exposure to a near-null magnetic field, are almost the same both at lower (2.5, 5, and 10 μM) and higher (50 and 100 μM) diphenyliodonium concentrations. In contrast, the addition of 2,4-dinitrophenol, an uncoupler of oxidative phosphorylation in mitochondria, in concentrations starting from 5 μM and up to 200 μM almost completely eliminated the difference between the control and experimental samples, which was observed at low inhibitor concentrations, or in its absence. [ABSTRACT FROM AUTHOR]

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• Cyclic voltammetry (CV) techniques were employed to assess the scavenging activity of N'-Ferrocenylmethyl-N'- phenylpropionohydrazide (NFPP) towards the superoxide anion radical (O 2. −). • IC50 of the studied compound was calculated and compared with ascorbic acid. • Binding parameters such as binding constant and energy of NFPP with DNA and (O 2. −) were calculated using the same technique. • Molecular docking was performed with DNA (PDB ID: 5VY6) and the enzyme NOX1 (PDB ID: 7CFZ) to support the experimental results. Overactivation of the NOX results in an excess production of ROS, which is linked to oxidative stress and deoxyribonucleic acid (DNA) damage. Free radical formation is a physiological event mainly coming from cellular respiration. Inflammatory diseases, cardiovascular diseases, and cancer are only some illnesses that this could trigger. Therefore, chemicals that can block NADPH oxidase (NOX) are essential in maintaining a healthy level of oxidative stress. However, interacting with DNA can alter its shape and slow replication, protecting cells from death. In this study, cyclic voltammetry (CV) techniques were employed to assess the scavenging activity of N'-Ferrocenylmethyl-N'- phenylpropionohydrazide (NFPP) towards the superoxide anion radical (O 2. −). Additionally, the DNA binding modes and binding free energies of NFPP were investigated. To support the experimental results, molecular docking was performed with DNA (PDB ID: 5VY6) and the enzyme NOX1 (PDB ID: 7CFZ). The results were consistent between the two approaches, showing that the chemical investigated had an IC50 lower than that of ascorbic acid (AA) and a spontaneous form of binding with (O 2. −) and DNA due to the negative sign of binding energies. Minor groove binding with two conventional hydrogen bonds was the type of interaction with the DNA. The binding energy between NFPP and NADPH exhibited a significant correlation with the experimental findings, indicating a strong affinity and a reduced inhibition concentration compared to ascorbic acid. [Display omitted] [ABSTRACT FROM AUTHOR]

Cyanobacteria have been recognized for their advantageous impact on plant growth and development. The application of certain techniques has the potential to enhance various aspects of plant development, including growth, yield, proximate content (such as protein and carbohydrate levels), as well as the ability to withstand abiotic stresses such as herbicide exposure. The current investigation focused on examining the influence of bioactive compounds derived from the cyanobacterium Neowestiellopsis persica strain A1387 on enhancing the antioxidant and anyimicrobial activity of wheat plants in their defense against the plant pathogenic Sunn pest. The findings of the study indicate that the levels of H 2 O 2 and GP x in wheat plants that were infected with aphids were significantly elevated compared to the treatments where aphids and cyanobacteria extract were present. The confirmation of these results was achieved through the utilization of confocal and fluorescent microscope tests, respectively. Furthermore, the findings indicated that the constituents of the cyanobacterial extract augmented the plant's capacity to withstand stress by enhancing its defense mechanisms. In a broader context, the utilization of cyanobacterial extract demonstrated the ability to regulate the generation and impact of oxygen (O 2) and hydrogen peroxide (H 2 O 2), while concurrently enhancing the functionality of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GP x) enzymes within wheat plants. This facilitation enabled the plants to effectively manage oxidative stress. Moreover, the findings of the antibacterial activity assessment conducted on the extract derived from cyanobacteria demonstrated notable susceptibility. The bacteria that exhibited the highest sensitivity to the extract of cyanobacterium Neowestiellopsis persica strain A1387 were staphylococcus aureus and pseudomonas aeruginosa. Conversely, salmonella typhi demonstrated the greatest resistance to the aforementioned extract. The potential impact of cyanobacteria extract on the antioxidative response of wheat plants to sunn pest infestation represents a novel contribution to the existing body of knowledge on the interaction between wheat plants and aphids. [ABSTRACT FROM AUTHOR]