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Water Research Feb 2024Molecular oxygen as a green, non-toxic, and inexpensive oxidant has displayed numerous advantages compared with other oxidants for more sustainable and environmentally... (Review)
Review
Molecular oxygen as a green, non-toxic, and inexpensive oxidant has displayed numerous advantages compared with other oxidants for more sustainable and environmentally benign pollutant degradation. Molecular oxygen activation stands as a groundbreaking approach in advanced oxidation processes, offering efficient environmental remediation with minimal environmental impact with the production of high-oxidation reactive oxygen species (ROS). The adaptability and energy efficiency of molecular oxygen activation significantly contribute to the progression of sustainable water remediation technologies. This review meticulously explores the principles and mechanisms of molecular oxygen activation, shedding light on the diverse ROS production pathways. Subsequently, this review comprehensively details contemporary activation approaches, including photocatalytic activation, electrocatalytic activation, piezoelectric activation, and photothermal activation, explicating their distinct activation mechanisms. Additionally, it delves into the promising applications of molecular oxygen activation in the degradation of water pollutants, primary air pollutants, and volatile organic compounds, providing an in-depth analysis of the associated degradation pathways and mechanisms. Moreover, this review also addresses the imminent challenges and emerging opportunities in environmental remediation. It is envisioned that this comprehensive analysis will spur ongoing exploration and innovation in the use of molecular oxygen activation for environmental remediation and beyond.
Topics: Reactive Oxygen Species; Environmental Restoration and Remediation; Environmental Pollutants; Air Pollutants; Oxidants; Oxygen
PubMed: 38159543
DOI: 10.1016/j.watres.2023.121075 -
Molecular Metabolism Jan 2024Energy-intensive kidney reabsorption processes essential for normal whole-body function are maintained by tubular epithelial cell metabolism. Although tubular metabolism...
OBJECTIVE
Energy-intensive kidney reabsorption processes essential for normal whole-body function are maintained by tubular epithelial cell metabolism. Although tubular metabolism changes markedly following acute kidney injury (AKI), it remains unclear which metabolic alterations are beneficial or detrimental. By analyzing large-scale, publicly available datasets, we observed that AKI consistently leads to downregulation of the mitochondrial pyruvate carrier (MPC). This investigation aimed to understand the contribution of the tubular MPC to kidney function, metabolism, and acute injury severity.
METHODS
We generated tubular epithelial cell-specific Mpc1 knockout (MPC TubKO) mice and employed renal function tests, in vivo renal C-glucose tracing, mechanistic enzyme activity assays, and tests of injury and survival in an established rhabdomyolysis model of AKI.
RESULTS
MPC TubKO mice retained normal kidney function, displayed unchanged markers of kidney injury, but exhibited coordinately increased enzyme activities of the pentose phosphate pathway and the glutathione and thioredoxin oxidant defense systems. Following rhabdomyolysis-induced AKI, compared to WT control mice, MPC TubKO mice showed increased glycolysis, decreased kidney injury and oxidative stress markers, and strikingly increased survival.
CONCLUSIONS
Our findings suggest that decreased renal tubular mitochondrial pyruvate uptake hormetically upregulates oxidant defense systems before AKI and is a beneficial adaptive response after rhabdomyolysis-induced AKI. This raises the possibility of therapeutically modulating the MPC to attenuate AKI severity.
Topics: Mice; Animals; Monocarboxylic Acid Transporters; Acute Kidney Injury; Oxidation-Reduction; Rhabdomyolysis; Oxidants
PubMed: 38056691
DOI: 10.1016/j.molmet.2023.101849 -
American Journal of Physiology.... May 2024Fatty acid oxidation (FAO) releases the energy stored in fat to maintain basic biological processes. Dehydrogenation is a major way to oxidize fatty acids, which needs... (Review)
Review
Fatty acid oxidation (FAO) releases the energy stored in fat to maintain basic biological processes. Dehydrogenation is a major way to oxidize fatty acids, which needs NAD to accept the released H from fatty acids and form NADH, which increases the ratio of NADH/NAD and consequently inhibits FAO leading to the deposition of fat in the liver, which is termed fatty liver or steatosis. Consumption of alcohol (ethanol) initiates simple steatosis that progresses to alcoholic steatohepatitis, which constitutes a spectrum of liver disorders called alcohol-associated liver disease (ALD). ALD is linked to ethanol metabolism. Ethanol is metabolized by alcohol dehydrogenase (ADH), microsomal ethanol oxidation system (MEOS), mainly cytochrome P450 2E1 (CYP2E1), and catalase. ADH also requires NAD to accept the released H from ethanol. Thus, ethanol metabolism by ADH leads to increased ratio of NADH/NAD, which inhibits FAO and induces steatosis. CYP2E1 directly consumes reducing equivalent NADPH to oxidize ethanol, which generates reactive oxygen species (ROS) that lead to cellular injury. Catalase is mainly present in peroxisomes, where very long-chain fatty acids and branched-chain fatty acids are oxidized, and the resultant short-chain fatty acids will be further oxidized in mitochondria. Peroxisomal FAO generates hydrogen peroxide (HO), which is locally decomposed by catalase. When ethanol is present, catalase uses HO to oxidize ethanol. In this review, we introduce FAO (including α-, β-, and ω-oxidation) and ethanol metabolism (by ADH, CYP2E1, and catalase) followed by the interaction between FAO and ethanol metabolism in the liver and its pathophysiological significance.
Topics: Humans; Catalase; NAD; Cytochrome P-450 CYP2E1; Hydrogen Peroxide; Fatty Liver; Ethanol; Liver Diseases, Alcoholic; Fatty Acids
PubMed: 38573193
DOI: 10.1152/ajpgi.00281.2023 -
Clinical Oral Investigations Aug 2023The objective of the study is to evaluate the bleaching potential of 6% hydrogen peroxide (6% HP) gels containing NF_TiO or NbO irradiated with a violet LED light and...
OBJECTIVES
The objective of the study is to evaluate the bleaching potential of 6% hydrogen peroxide (6% HP) gels containing NF_TiO or NbO irradiated with a violet LED light and the effects on enamel mineral content and surface morphology.
METHODS
Particles were synthesized, and experimental gels were chemically analyzed by preliminary and accelerated stability tests, pH, and HP decomposition rate. Bovine enamel blocks were treated with 6% HP gels containing (n = 10): 5% NF_TiO, 5% NbO, 2.5% NF_TiO + 2.5% NbO or without particles (6% HP), irradiated or not with LED, and the control was treated with 35% HP. Color (∆E) and whitening index (∆WID) variations, surface microhardness (SH), average roughness (∆Ra), Ca-P concentration (EDS), and enamel morphology (SEM) were assessed. Bleaching was performed in 3 sessions of 30 min and 7-day intervals. Data were submitted to two- (pH, decomposition rate, ∆E, and ∆WID) or three-way ANOVA and Bonferroni (SH), Kruskal-Wallis (∆Ra), and Dunnet tests (α = 0.05).
RESULTS
No changes in the gel's color, odor, or translucency were observed. The pH (6 to 6.5) remained stable over time, and light irradiation boosted the HP decomposition rate. NF_TiO and NbO-containing gels displayed higher ∆E and ΔWID when light-irradiated (p < 0.05). NbO and NbO + NF_TiO decreased enamel SH (p < 0.05), but no SH changes were found among groups (p > 0.05). No differences among groups were noted in ∆Ra, Ca-P content, and enamel morphology after treatments (p > 0.05).
CONCLUSION
Experimental light-irradiated 6% HP gels containing NF_TiO or NbO were chemically stable and exhibited bleaching potential comparable with 35% HP.
CLINICAL RELEVANCE
Low-concentrated HP gels containing NF_TiO or NbO and light-irradiated stand as a possible alternative to in-office bleaching.
Topics: Animals; Cattle; Tooth Bleaching; Tooth Bleaching Agents; Hydrogen Peroxide; Hypochlorous Acid; Gels
PubMed: 37369816
DOI: 10.1007/s00784-023-05113-z -
Journal of the American Chemical Society Sep 2023The cytochrome P450 (CYP) AspB is involved in the biosynthesis of the diketopiperazine (DKP) aspergilazine A. Tryptophan-linked dimeric DKP alkaloids are a large family...
The cytochrome P450 (CYP) AspB is involved in the biosynthesis of the diketopiperazine (DKP) aspergilazine A. Tryptophan-linked dimeric DKP alkaloids are a large family of natural products that are found in numerous species and exhibit broad and often potent bioactivity. The proposed mechanisms for C-N bond formation by AspB, and similar C-C bond formations by related CYPs, have invoked the use of a ferryl-intermediate as an oxidant to promote substrate dimerization. Here, the parallel application of steady-state and transient kinetic approaches reveals a very different mechanism that involves a ferric-superoxide species as a primary oxidant to initiate DKP-assembly. Single turnover kinetic isotope effects and a substrate analog suggest the probable nature and site for abstraction. The direct observation of CYP-superoxide reactivity rationalizes the atypical outcome of AspB and reveals a new reaction manifold in heme enzymes.
Topics: Superoxides; Dimerization; Iron; Cytochrome P-450 Enzyme System; Oxidants; Diketopiperazines; Dipeptides; Electrolytes; Catalysis
PubMed: 37611404
DOI: 10.1021/jacs.3c04542 -
Journal of Biochemical and Molecular... Nov 2023The influence of modern lifestyle, diet, exposure to chemicals such as phytosanitary substances, together with sedentary lifestyles and lack of exercise play an... (Review)
Review
The influence of modern lifestyle, diet, exposure to chemicals such as phytosanitary substances, together with sedentary lifestyles and lack of exercise play an important role in inducing reactive stress (RS) and disease. The imbalance in the production and scavenging of free radicals and the induction of RS (oxidative, nitrosative, and halogenative) plays an essential role in the etiology of various chronic pathologies, such as cardiovascular diseases, diabetes, neurodegenerative diseases, and cancer. The implication of free radicals and reactive species injury in metabolic disturbances and the onset of many diseases have been accumulating for several decades, and are now accepted as a major cause of many chronic diseases. Exposure to elevated levels of free radicals can cause molecular structural impact on proteins, lipids, and DNA, as well as functional alteration of enzyme homeostasis, leading to aberrations in gene expression. Endogenous depletion of antioxidant enzymes can be mitigated using exogenous antioxidants. The current interest in the use of exogenous antioxidants as adjunctive agents for the treatment of human diseases allows a better understanding of these diseases, facilitating the development of new therapeutic agents with antioxidant activity to improve the treatment of various diseases. Here we examine the role that RS play in the initiation of disease and in the reactivity of free radicals and RS in organic and inorganic cellular components.
Topics: Humans; Antioxidants; Oxidants; Oxidative Stress; Reactive Oxygen Species; Free Radicals; Biomarkers
PubMed: 37437103
DOI: 10.1002/jbt.23455 -
Surface and intra-pulpal temperature variation during tooth whitening photoactivated with LED/laser.Dental Materials Journal Sep 2023This study evaluated the variation of surface and intra-pulpal temperature, during bleaching protocol, using LED/laser. The 35% (HP35), 15% (HP15) and 6% (HP6) gels were...
This study evaluated the variation of surface and intra-pulpal temperature, during bleaching protocol, using LED/laser. The 35% (HP35), 15% (HP15) and 6% (HP6) gels were used associated with LED/laser applied every 1 min for 30 min in a human canine. The evaluation of surface temperature variation (∆Ts) was performed using a pHmeter and the intra-pulpal temperature variation (∆Ti) was performed using a digital thermometer, at times of 1-, 5-, 10- 15- and 30-min. Statistical analysis was performed using the two-way repeated measures ANOVA test and Bonferroni post-hoc test was used at a significance level of 5%. HP35 and HP15 showed greater temperature variation than HP6 up to 10 min of surface evaluation, showing no differences between them. In the intra-pulpal evaluation, no group showed differences throughout the procedure.
Topics: Humans; Tooth Bleaching; Temperature; Hydrogen Peroxide; Light; Tooth Bleaching Agents; Lasers
PubMed: 37460305
DOI: 10.4012/dmj.2023-017 -
Environmental Science & Technology Jul 2023Volatile organic compounds (VOCs) harm the environment and human health and have been of wide concern and purified efficiently by catalytic oxidation. Spinel oxides,... (Review)
Review
Volatile organic compounds (VOCs) harm the environment and human health and have been of wide concern and purified efficiently by catalytic oxidation. Spinel oxides, mainly composed of transition metal elements with low price and extensive sources, have been widely investigated as efficient and stable catalysts for VOCs oxidation due to their adjustable element composition, flexible structure, and high thermal/chemical stability. However, it is necessary to dissect the design of the spinel in a targeted way to satisfy the removal of different types of VOCs. This article systematically summarizes the recent advances regarding the application of spinel oxides for VOCs catalytic oxidation. Specifically, the design strategies of spinel oxides were first introduced to clarify their effect on the structure and properties of the catalyst. Then the reaction mechanism and degradation pathway of different kinds of VOCs on the spinel oxides were in detail summarized, and the characteristic requirements of the spinel oxides for various VOCs purification were analyzed. Furthermore, the practice applications were also discussed. Finally, the prospects were proposed to guide the rational design of spinel-based catalysts for VOCs purification and intensify the understanding of reaction mechanisms.
Topics: Humans; Oxides; Volatile Organic Compounds; Oxidation-Reduction; Aluminum Oxide; Catalysis
PubMed: 37313598
DOI: 10.1021/acs.est.2c09861 -
Journal of Environmental Sciences... Nov 2024Groundwater contamination near landfills is commonly caused by leachate leakage, and permeable reactive barriers (PRBs) are widely used for groundwater remediation....
Groundwater contamination near landfills is commonly caused by leachate leakage, and permeable reactive barriers (PRBs) are widely used for groundwater remediation. However, the deactivation and blockage of the reactive medium in PRBs limit their long-term effectiveness. In the current study, a new methodology was proposed for the in situ regeneration of PRB to remediate leachate-contaminated groundwater. CO coupled with oxidants was applied for the dispersion and regeneration of the fillers; by injecting CO to disperse the fillers, the permeability of the PRB was increased and the oxidants could flow evenly into the PRB. The results indicate that the optimum filler proportion was zero-valent iron (ZVI)/zeolites/activated carbon (AC) = 3:8:10 and the optimum oxidant proportion was COD/NaSO/HO/Fe = 1:5:6:5; the oxidation system of Fe/HO/SO has a high oxidation efficiency and persistence. The average regeneration rate of zeolites was 72.71%, and the average regeneration rate of AC was 68.40%; the permeability of PRB also increased. This technology is effective for the remediation of landfills in China that have large contaminated areas, an uneven pollutant concentration distribution, and a long pollution duration. The purification mode of long-term adsorption and short-time in situ oxidation can be applied to the remediation of long-term high-concentration organically polluted groundwater, where pollution sources are difficult to cut off.
Topics: Groundwater; Water Pollutants, Chemical; Environmental Restoration and Remediation; Carbon Dioxide; Oxidants; China; Oxidation-Reduction
PubMed: 38844316
DOI: 10.1016/j.jes.2023.08.002 -
Naunyn-Schmiedeberg's Archives of... Oct 2023Reactive oxygen species (ROS) are produced in the mitochondrial respiratory pathway and cellular metabolism. They are responsible for creating oxidative stress and lipid... (Review)
Review
Reactive oxygen species (ROS) are produced in the mitochondrial respiratory pathway and cellular metabolism. They are responsible for creating oxidative stress and lipid peroxidation. In living organisms, there is a balance between oxidative stress and the antioxidant system, but some factors such as medicines disturb the balance and cause many problems. These effects can impact bacterial death and division and also in humans can induce therapeutic or adverse reactions. Web of Science and Pubmed databases were used for searching. This review focuses on the oxidant and antioxidant effects of different classes of antibacterial agents and the mechanisms of oxidative stress. Some of these agents have beneficial effects on killing bacteria due to their antioxidant or oxidant effects. However, some of their side effects may be due to their oxidative effects. Based on the results of this review, minocycline is an antioxidant, but aminoglycosides, chloramphenicol, glycopeptides, antituberculosis drugs, fluoroquinolones, and sulfamethoxazole agents have oxidant effects. Furthermore, cephalosporins, penicillins, metronidazole, and macrolides have both oxidant and antioxidant effects in different studies. It is concluded that some antibacterial agents have oxidant and other antioxidant effects. These activities may affect their therapeutic effects or side effects. Some antioxidants can prevent the adverse effects of antibacterial agents. Clarifying the exact oxidant and antioxidant effects of some antimicrobial agents needs more research projects.
Topics: Humans; Antioxidants; Anti-Bacterial Agents; Oxidants; Oxidative Stress; Reactive Oxygen Species
PubMed: 37083711
DOI: 10.1007/s00210-023-02490-w