-
Water Research Aug 2023Concerns over human health risks associated with chemical contaminants (micropollutants) in drinking waters are rising due to the increased use of reclaimed water or... (Review)
Review
Concerns over human health risks associated with chemical contaminants (micropollutants) in drinking waters are rising due to the increased use of reclaimed water or water supplies impacted by upstream wastewater discharges. Ultraviolet (UV)-driven advanced oxidation processes (UV-AOPs) using radiation sources that emit at 254 nm have been developed as advanced treatments to degrade contaminants, while those UV-AOPs can be improved towards higher radical yields and lower byproduct formation. Several previous studies have suggested that Far-UVC radiation (200-230 nm) is a promising radiance source to drive UV-AOPs because the direct photolysis of micropollutants and production of reactive species from oxidant precursors can both be improved. In this study, we summarize from the literature the photodecay rate constants of five micropollutants by direct UV photolysis, which are higher at 222 than 254 nm. We experimentally determine the molar absorption coefficients at 222 and 254 nm of eight oxidants commonly used in water treatment and present the quantum yields of the oxidant photodecay. Our experimental results also show that the concentrations of HO, Cl, and ClO generated in the UV/chlorine AOP can be increased by 5.15-, 15.76-, and 2.86-fold, respectively, by switching the UV wavelength from 254 to 222 nm. We also point out the challenges of applying Far-UVC for micropollutant abatement in water treatment, including the strong light screening effect of matrix components (e.g., carbonate, nitrate, bromide, and dissolved organic matter), the formation of byproducts via new reaction pathways, and the needs to improve the energy efficiency of the Far-UVC radiation sources.
Topics: Humans; Water Pollutants, Chemical; Wastewater; Oxidation-Reduction; Chlorine; Oxidants; Water Purification; Ultraviolet Rays; Hydrogen Peroxide
PubMed: 37290191
DOI: 10.1016/j.watres.2023.120169 -
Ulusal Travma Ve Acil Cerrahi Dergisi =... Feb 2024The aim of this study was to quantify serum levels of elafin, a serine protease inhibitor, and to assess its effects on histopathological and biochemical parameters in...
BACKGROUND
The aim of this study was to quantify serum levels of elafin, a serine protease inhibitor, and to assess its effects on histopathological and biochemical parameters in hepatic ischemia-reperfusion injury.
METHODS
Forty female Wistar albino rats were divided into five groups: Group 1 served as the control group. Liver ischemia was induced for 30 minutes in the other four groups. An additional 1-hour, 2-hour, and 3-hour reperfusion was induced in Groups 3, 4, and 5, respectively. At the end of the experiment, intracardiac blood samples were obtained for biochemical examination, and tissue samples from the liver were taken for histopathological examination. Levels of elafin, ischemia-modified albumin (IMA), total antioxi-dant status (TAS), and total oxidant status (TOS) were also examined.
RESULTS
Serum elafin levels decreased beginning from Group 2, with the lowest level reached in Group 5 (p<0.01). The IMA level was the lowest in the control group and the highest in Group 5 (p<0.01). TOS, aspartate aminotransferase (AST), and alanine amino-transferase (ALT) levels were lowest in the control group and highest in Group 5 (p<0.01). Group 5 had the highest IMA/albumin ratio, although no significant differences were found between these four groups. The lowest TAS level was found in the control group, but a stable and significant increase was not detected in the other groups. No significant differences were found between the groups in terms of alkaline phosphatase (ALP) and albumin levels. A negative correlation was observed between serum elafin levels and AST, ALT, and TOS levels (p<0.01). The number of Grade 1 histopathological results was found to be higher in the groups with reperfusion (Groups 3, 4, 5). In histopathological subgroup analysis, while the elafin level was lower in Grade 1 group, AST, ALT, and TOS levels were higher (p<0.01). Additionally, the IMA/albumin ratio was found to be higher in the Grade 1 group (p=0.02).
CONCLUSION
In hepatic ischemia-reperfusion injury, elafin levels decreased as the reperfusion time increased. As the reperfusion time increased, both hepatocyte damage and oxidant capacity increased, with a negative correlation observed between these findings and elafin levels. Therefore, elafin may play a protective role in hepatic ischemia-reperfusion injury and could assist clinicians in assessing liver injury.
Topics: Animals; Female; Rats; Biomarkers; Elafin; Liver; Liver Diseases; Oxidants; Rats, Wistar; Reperfusion Injury; Serum Albumin
PubMed: 38305656
DOI: 10.14744/tjtes.2024.32728 -
Toxicology Sep 2023Levetiracetam (LEV) is an anticonvulsant for epilepsy. The toxic effects of this medication in tissues have been associated with redox state imbalance, which can lead to...
Levetiracetam (LEV) is an anticonvulsant for epilepsy. The toxic effects of this medication in tissues have been associated with redox state imbalance, which can lead to salivary gland dysfunction. Therefore, the current work investigated the effects of LEV on the biochemical, functional, and redox parameters of the parotid and submandibular glands in rats. For this, male Wistar rats (Rattus norvegicus albinus) were randomly divided into 3 groups (n = 10/group): Control (0.9% saline solution), LEV100 (100 mg/kg), and LEV300 (300 mg/kg). After 21 consecutive days of intragastric gavage treatments, pilocarpine stimulated saliva secretion was collected for salivary biochemical analysis. The extracted salivary glands were utilized for histomorphometry and redox state analyses. Our results showed that LEV300 increased plasma hepatotoxicity markers and reduced salivary amylase activity and the acinar surface area of the parotid gland. Total oxidant capacity and oxidative damage to lipids and proteins were higher in the parotid gland, while total antioxidant capacity and uric acid levels were reduced in the submandibular gland of the LEV100 group compared to Control. On the other hand, total oxidant capacity, oxidative damage to lipids and proteins, total antioxidant capacity, and uric acid levels were lower in both salivary glands of the LEV300 group compared to Control. Superoxide dismutase and glutathione peroxidase activities were lower in the salivary glands of treated animals compared to Control. In conclusion our data suggest that treatment with LEV represents a potentially toxic agent, that contributes to drug-induced salivary gland dysfunction.
Topics: Rats; Male; Animals; Rats, Wistar; Antioxidants; Levetiracetam; Uric Acid; Salivary Glands; Oxidation-Reduction; Proteins; Oxidants; Lipids
PubMed: 37572749
DOI: 10.1016/j.tox.2023.153615 -
From Oxidized Fatty Acids to Dimeric Species: In Vivo Relevance, Generation and Methods of Analysis.Molecules (Basel, Switzerland) Nov 2023The occurrence of free fatty acids (FFAs) and the generation of reactive oxygen species (ROS) such as hydroxyl radicals (HO) or hypochlorous acid (HOCl) is... (Review)
Review
The occurrence of free fatty acids (FFAs) and the generation of reactive oxygen species (ROS) such as hydroxyl radicals (HO) or hypochlorous acid (HOCl) is characteristic of inflammatory diseases, for instance, rheumatoid arthritis. Unsaturated fatty acids react with ROS yielding a variety of important products such as peroxides and chlorohydrins as primary and chain-shortened compounds (e.g., aldehydes and carboxylic acids) as secondary products. These modified fatty acids are either released from phospholipids by phospholipases or oxidatively modified subsequent to their release. There is increasing evidence that oligomeric products are also generated upon these processes. Fatty acid esters of hydroxy fatty acids (FAHFAs) are considered as very important products, but chlorinated compounds may be converted into dimeric and (with smaller yields) oligomeric products, as well. Our review is structured as follows: first, the different types of FFA oligomers known so far and the mechanisms of their putative generation are explained. Industrially relevant products as well as compounds generated from the frying of vegetable oils are also discussed. Second, the different opinions on whether dimeric fatty acids are considered as "friends" or "foes" are discussed.
Topics: Fatty Acids; Fatty Acids, Unsaturated; Phospholipids; Fatty Acids, Nonesterified; Hypochlorous Acid
PubMed: 38067577
DOI: 10.3390/molecules28237850 -
Journal of the American Chemical Society Dec 2023The practical catalytic enantioselective -dihydroxylation of olefins that utilize earth-abundant first-row transition metal catalysts under environmentally friendly...
The practical catalytic enantioselective -dihydroxylation of olefins that utilize earth-abundant first-row transition metal catalysts under environmentally friendly conditions is an important yet challenging task. Inspired by the -dihydroxylation reactions catalyzed by Rieske dioxygenases and non-heme iron models, we report the biologically inspired -dihydroxylation catalysis that employs an inexpensive and readily available mononuclear non-heme manganese complex bearing a tetradentate nitrogen-donor ligand and aqueous hydrogen peroxide (HO) and potassium peroxymonosulfate (KHSO) as terminal oxidants. A wide range of olefins are efficiently oxidized to enantioenriched -diols in practically useful yields with excellent -dihydroxylation selectivity and enantioselectivity (up to 99% ee). Mechanistic studies, such as isotopically O-labeled water experiments, and density functional theory (DFT) calculations support that a manganese(V)-oxo-hydroxo (HO-Mn═O) species, which is formed via the water-assisted heterolytic O-O bond cleavage of putative manganese(III)-hydroperoxide and manganese(III)-peroxysulfate precursors, is the active oxidant that effects the -dihydroxylation of olefins; this is reminiscent of the frequently postulated iron(V)-oxo-hydroxo (HO-Fe═O) species in the catalytic arene and alkene -dihydroxylation reactions by Rieske dioxygenases and synthetic non-heme iron models. Further, DFT calculations for the mechanism of the HO-Mn═O-mediated enantioselective -dihydroxylation of olefins reveal that the first oxo attack step controls the enantioselectivity, which exhibits a high preference for -dihydroxylation over epoxidation. In this study, we are able to replicate both the catalytic function and the key chemical principles of Rieske dioxygenases in mononuclear non-heme manganese-catalyzed enantioselective -dihydroxylation of olefins.
Topics: Dioxygenases; Hydrogen Peroxide; Manganese; Oxidation-Reduction; Alkenes; Stereoisomerism; Iron; Oxidants; Catalysis; Water
PubMed: 38064642
DOI: 10.1021/jacs.3c09508 -
Environmental Science & Technology Nov 2023Chlorine photolysis is an advanced oxidation process that relies on the combination of direct chlorination by free available chlorine, direct photolysis, and reactive...
Chlorine photolysis is an advanced oxidation process that relies on the combination of direct chlorination by free available chlorine, direct photolysis, and reactive oxidants to transform contaminants. In waters that contain bromide, free available bromine and reactive bromine species can also form. However, little is known about the underlying mechanisms or formation potential of disinfection byproducts (DBPs) under these conditions. We investigated reactive oxidant generation and DBP formation under dark conditions, chlorine photolysis, and radical-quenched chorine photolysis with variable chlorine (0-10 mg-Cl/L) and bromide (0-2,000 μg/L) concentrations, as well as with free available bromine. Probe loss rates and ozone concentrations increase with chlorine concentration and are minimally impacted by bromide. Radical-mediated processes partially contribute to the formation targeted DBPs (i.e., trihalomethanes, haloacetic acids, haloacetonitriles, chlorate, and bromate), which increase with increasing chlorine concentration. Chlorinated novel DBPs detected by high-resolution mass spectrometry are attributable to a combination of dark chlorination, direct halogenation by reactive chlorine species, and transformation of precursors, whereas novel brominated DBPs are primarily attributable to dark bromination of electron-rich formulas. The formation of targeted and novel DBPs during chlorine photolysis in waters with elevated bromide may limit treatment applications.
Topics: Disinfection; Chlorine; Bromides; Disinfectants; Bromine; Photolysis; Water Purification; Water Pollutants, Chemical; Halogenation; Chlorides; Oxidants
PubMed: 37363941
DOI: 10.1021/acs.est.3c00431 -
Free Radical Biology & Medicine Nov 2023Skeletal muscle is crucial for maintaining human health and overall quality of life. Acute exercise introduces a multifaceted intracellular stress, with numerous... (Review)
Review
Skeletal muscle is crucial for maintaining human health and overall quality of life. Acute exercise introduces a multifaceted intracellular stress, with numerous post-translational modifications believed to underpin the health benefits of sustained exercise training. Reactive oxygen species (ROS) are posited to serve as second messengers, triggering cytoprotective adaptations such as the upregulation of enzymatic scavenger systems. However, a significant knowledge gap exists between the generation of oxidants in muscle and the exact mechanisms driving muscle adaptations. This review delves into the current research on subcellular redox biochemistry and its role in the physiological adaptations to exercise. We propose that the subcellular regulation of specific redox modifications is key to ensuring specificity in the intracellular response.
Topics: Humans; Quality of Life; Muscle, Skeletal; Oxidation-Reduction; Oxidants; Adaptation, Physiological
PubMed: 37923089
DOI: 10.1016/j.freeradbiomed.2023.10.404 -
The Science of the Total Environment Feb 2024Pre-oxidation and powdered activate carbon (PAC) are usually used to remove algae and odorants in drinking waterworks. However, the influence of interaction between...
Comparison of four pre-oxidants coupled powdered activated carbon adsorption for odor compounds and algae removal: Kinetics, process optimization, and formation of disinfection byproducts.
Pre-oxidation and powdered activate carbon (PAC) are usually used to remove algae and odorants in drinking waterworks. However, the influence of interaction between oxidants and PAC on the treatment performance are scarcely known. This study systematically investigated the combination schemes of four oxidants (KMnO, NaClO, ClO, and O) and PAC on the inactivation of Microcystis aeruginosa cells and removal of four frequently detected odorants in raw water (diethyl disulfide (DEDS), 2,2'-oxybis(1chloropropane) (DCIP), 2-methylisoborneol (2-MIB) and geosmin (GSM)). O showed highest pseudo-first-order removal rate for all four compounds and NaClO exhibited highest inactivation rates for the cell viability and Chlorophyll a (Chl-a). The Freundlich model fitted well for the adsorption of DEDS and DCIP by PAC. When treated by combined oxidation/PAC, the removal ratio of algae cells and odorants were lower (at least 1.6 times) than the sum of removal ratios obtained in oxidation or PAC adsorption alone. Among these four oxidants, the highest synchronous control efficiency of odorants (52 %) and algae (66 %) was achieved by NaClO/PAC. Prolonging the dosage time interval promoted the removal rates. The pre-PAC/post-oxidation processes possessed comparable efficiency for the removal of odorants and algae cells comparing with pre-oxidation/post-PAC process, but significantly inhibited formation of disinfection byproducts (DBPs), especially for the formation of C-DBPs (for NaClO and ClO), bromate (for O) and chlorate/chlorite (for ClO). This study could provide a better understanding of improving in-situ operation of the combined pre-treatments of oxidation and PAC for source water.
Topics: Oxidants; Disinfection; Charcoal; Odorants; Adsorption; Powders; Chlorophyll A; Water; Water Purification; Water Pollutants, Chemical
PubMed: 38029977
DOI: 10.1016/j.scitotenv.2023.168920 -
Journal of Esthetic and Restorative... Sep 2023To evaluate the effect of smoking on tooth whitening and color change after at-home bleaching.
OBJECTIVES
To evaluate the effect of smoking on tooth whitening and color change after at-home bleaching.
MATERIALS AND METHODS
This prospective clinical study evaluated two groups of participants: NS-non-smokers (n = 24) and S-smokers (n = 16). All subjects were treated with at-home bleaching using 22% carbamide peroxide (CP) for 1 h/day for 14 days. Color coordinates (L*-luminosity, a*-red-green axis and b*-yellow-blue axis) were obtained before bleaching (D0-baseline), 1 day (D1), 15 days (D15), and 1 month (D30) after bleaching. The whiteness index (WI ) and CIEDE2000 color differences (ΔE ) were calculated for S and NS. Color changes between S and NS subjects for specific teeth (CI-Central Incisors, LI-Lateral Incisors, and C-Canines) were analyzed using the Mann-Whitney test (α = 0.05).
RESULTS
There was no significant difference in WI between S and NS subjects at baseline. NS participants showed higher WI than S at D1, D15, and D30 (p < 0.05). NS showed higher ΔWI for CI and C between D0 and the other evaluation times (D1, D15, and D30) compared to S. Smokers showed higher darkening of CI than NS in ΔWI D30-D1 (p < 0.05). Color changes showed similar overall behavior for ΔWI . For all evaluation times, ΔWI and ΔE values were below the corresponding acceptability thresholds.
CONCLUSION
At-home bleaching was effective on smokers and nonsmokers. Smoking negatively affected color stability after bleaching. ΔE and ΔWI were acceptable for both groups.
CLINICAL SIGNIFICANCE
Although smoking negatively affected color stability after bleaching, the observed changes were clinically acceptable.
Topics: Smoking; Prospective Studies; Color; Tooth Bleaching; Tooth Bleaching Agents; Hydrogen Peroxide
PubMed: 36960913
DOI: 10.1111/jerd.13040 -
International Journal of Molecular... Dec 2023Dinitrosyl iron complexes (DNICs) are important physiological derivatives of nitric oxide. These complexes have a wide range of biological activities, with antioxidant...
Dinitrosyl iron complexes (DNICs) are important physiological derivatives of nitric oxide. These complexes have a wide range of biological activities, with antioxidant and antiradical ones being of particular interest and importance. We studied the interaction between DNICs associated with the dipeptide L-carnosine or serum albumin and prooxidants under conditions mimicking oxidative stress. The ligands of these DNICs were histidine residues of carnosine or His39 and Cys34 in bovine serum albumin. Carnosine-bound DNICs reduced the level of piperazine free radicals in the reaction system containing -butyl hydroperoxide (-BOOH), bivalent iron ions, a nitroxyl anion donor (Angeli's salt), and HEPES buffer. The ability of carnosine DNICs to intercept organic free radicals produced from -BOOH decay could lead to this effect. In addition, carnosine DNICs reacted with the superoxide anion radical (O) formed in the xanthine/xanthine oxidase enzymatic system. They also reduced the oxoferryl form of the heme group formed in the reaction of myoglobin with -BOOH. DNICs associated with serum albumin were found to be rapidly destroyed in a model system containing metmyoglobin and t-BOOH. At the same time, these protein DNICs inhibited the -BOOH-induced oxidative degradation of coenzymes Q and Q in rat myocardial homogenate. The possible mechanisms of the antioxidant and antiradical action of the DNICs studied and their role in the metabolism of reactive oxygen and nitrogen species are discussed.
Topics: Rats; Animals; Antioxidants; Histidine; Carnosine; Nitrogen Oxides; Iron; Nitric Oxide; Free Radicals; Superoxides; Oxygen; Serum Albumin
PubMed: 38139065
DOI: 10.3390/ijms242417236