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1.
J Environ Sci (China) ; 110: 140-149, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34593185

RESUMO

Maintaining a residual disinfectant/oxidant (e.g., chlorine and chlorine dioxide), is a generally used strategy to control microbial contaminants and bacterial regrowth in distribution systems. Secondarily oxidant, such as hypobromous acid (HOBr), can be formed during chlorination of bromide-containing waters. The decay of oxidants and formation of disinfection byproducts (DBPs) due to the interaction between oxidants and selected metal oxides were studied. Selected metal oxides generally enhanced the decay of these halogen-containing oxidants via three pathways: (1) catalytic disproportionation to yield an oxidized form of halogen (i.e., halate) and reduced form (halide for chlorine and bromine or chlorite for chlorine dioxide), (2) oxygen formation, and (3) oxidation of a metal in a reduced form (e.g., cuprous oxide) to a higher oxidation state. Cupric oxide (CuO) and nickel oxide (NiO) showed significantly strong abilities for the first pathway, and oxygen formation was a side reaction. Cuprous oxide can react with oxidants via the third pathway, while goethite was not involved in these reactions. The ability of CuO on catalytic disproportionation of HOBr remained stable up to four cycles. In chlorination process, bromate formation tends to be important (exceeding 10 µg/L) when initial bromide concentration is above 400 µg/L in the presence of dissolved organic matter. Increasing initial bromide concentrations increased the formation of DBPs and calculated cytotoxicity, and the maximum was observed at pH 8.6 during chlorination process. Therefore, the possible disinfectant loss and DBP formation should be carefully considered in drinking water distribution systems.


Assuntos
Desinfetantes , Água Potável , Poluentes Químicos da Água , Purificação da Água , Cloro , Desinfetantes/análise , Desinfecção , Halogenação , Oxidantes , Óxidos , Poluentes Químicos da Água/análise
2.
J Environ Manage ; 300: 113692, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34509127

RESUMO

Several thousands of highly persistent per- and polyfluoroalkyl substances (PFAS) exist and it is therefore challenging to analytically determine a larger spectrum of these compounds simultaneously in one sample. It is even more difficult to efficiently remove mobile PFAS in wastewater treatment plants (WWTPs) to protect the receiving waters. The total oxidizable precursor (TOP) assay is an approach that enables the detection of the total PFAS content in a sample via oxidation of precursors, followed by subsequent analysis of the perfluoroalkyl acid (PFAA) concentration before and after oxidative processes. Activated carbon combined with a preceding ozonation step is considered a promising tool for the removal of micropollutants but considering PFAS removal efficiencies in effluents for this process combination more information is required. The focus of the study was to implement and assess the TOP assay with ozone as oxidizing agent to estimate the total PFAS content in a WWTP effluent. Additionally, granular activated carbon (GAC) and powdered activated carbon (PAC) with a preceding ozonation step was tested for the removal efficiencies for 22 PFAS. For the TOP assay the obtained accordance in molarity using spiked tap water as quality control was 95.2% (15 mg O3/L) and 99.1% (6 mg O3/L). Applying the TOP assay, an estimated total PFAS content of 840 ng/L was determined in the respective effluent, which was 91.1% higher than obtained by target PFAS analysis, implying the presence of unknown precursors not included in common monitoring. While all treatment techniques that included ozone or a preceding ozonation step solely transformed precursors and long-chain perfluoroalkyl acids (PFAA, i.e., >C9) to shorter congeners, PAC was the only tested water treatment application that was able to remove 19.3% of the total PFAS molarity.


Assuntos
Ozônio , Poluentes Químicos da Água , Purificação da Água , Carvão Vegetal , Oxidantes , Águas Residuárias/análise , Poluentes Químicos da Água/análise
3.
Int J Mol Sci ; 22(17)2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34502054

RESUMO

Equol (7-hydroxy-3-(4'-hydroxyphenyl)-chroman, EQ), one of the major intestinally derived metabolites of daidzein, the principal isoflavane found in soybeans and most soy foods, has recently attracted increased interest as a health-beneficial compound for estrogen-dependent diseases. However, based on its structure with two p-substituted phenols, this study aimed to examine whether EQ is a substrate for tyrosinase and whether it produces o-quinone metabolites that are highly cytotoxic to melanocyte. First, the tyrosinase-catalyzed oxidation of EQ was performed, which yielded three EQ-quinones. They were identified after being reduced to their corresponding catechols with NaBH4 or L-ascorbic acid. The binding of the EQ-quinones to N-acetyl-L-cysteine (NAC), glutathione (GSH), and bovine serum albumin via their cysteine residues was then examined. NAC and GSH afforded two mono-adducts and one di-adduct, which were identified by NMR and MS analysis. It was also found that EQ was oxidized to EQ-di-quinone in cells expressing human tyrosinase. Finally, it was confirmed that the EQ-oligomer, the EQ oxidation product, exerted potent pro-oxidant activity by oxidizing GSH to the oxidized GSSG and concomitantly producing H2O2. These results suggest that EQ-quinones could be cytotoxic to melanocytes due to their binding to cellular proteins.


Assuntos
Equol/metabolismo , Melanócitos/efeitos dos fármacos , Oxidantes/toxicidade , Quinonas/toxicidade , Cisteína/análogos & derivados , Cisteína/metabolismo , Glutationa/metabolismo , Células HEK293 , Humanos , Monofenol Mono-Oxigenase/metabolismo , Oxidantes/metabolismo , Ligação Proteica , Quinonas/metabolismo , Soroalbumina Bovina/metabolismo
4.
Int J Mol Sci ; 22(16)2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34445561

RESUMO

Among numerous contaminants, the ubiquitous occurrence of nonsteroidal anti-inflammatory drugs (NSAIDs) in the environment and their plausible harmful impact on nontarget organisms have made them one of the most important areas of concern in recent years. Crop plants can also potentially be exposed to NSAIDs, since the concentration of these pharmaceuticals is constantly rising in the surface water and soil. Our goal was to evaluate the stress response of two crop plants, maize and tomato, to treatment with selected NSAIDs, naproxen and diclofenac. The focus of the research was on the growth response, photosynthetic efficiency, selected oxidative stress factors (such as the H2O2 level and the rate of lipid peroxidation) as well as the total phenolic content, which represents the non-enzymatic protectants against oxidative stress. The results indicate that susceptibility to the NSAIDs that were tested is dependent on the plant species. A higher sensitivity of tomato manifested in growth inhibition, a decrease in the content of the photosynthetic pigments and a reduction in the maximum quantum efficiency of PSII and the activity of PSII, which was estimated using the Fv/Fm and Fv/F0 ratios. Based on the growth results, it was also possible to reveal that diclofenac had a more toxic effect on tomato. In contrast to tomato, in maize, neither the content of the photosynthetic pigments nor growth appeared to be affected by DFC and NPX. However, both drugs significantly decreased in maize Fv and Fm, which are particularly sensitive to stress. A higher H2O2 concentration accompanied, in most cases, increasing lipid peroxidation, indicating that oxidative stress occurred in response to the selected NSAIDs in the plant species that were studied. The higher phenolic content of the plants after NSAIDs treatment may, in turn, indicate the activation of defense mechanisms in response to the oxidative stress that is triggered by these drugs.


Assuntos
Diclofenaco/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Lycopersicon esculentum/efeitos dos fármacos , Naproxeno/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Zea mays/efeitos dos fármacos , Anti-Inflamatórios não Esteroides/farmacologia , Peróxido de Hidrogênio/farmacologia , Lycopersicon esculentum/crescimento & desenvolvimento , Lycopersicon esculentum/metabolismo , Oxidantes/farmacologia , Fenóis/farmacologia , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
5.
Ultrason Sonochem ; 77: 105702, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34375945

RESUMO

2-picoline is a very important pyridine derivative with significant applications though it is also poisonous and harmful having considerable adverse influence on aquatic life, environment and organisms. The need for developing effective treatment methodologies for 2-Picoline directed the current work focusing on degradation of 2-Picoline using the combination of ultrasound and advanced oxidants such as hydrogen peroxide (H2O2), potassium persulphate (KPS), Fenton's reagent, and Peroxymonosulphate (PMS) along with the use of Titanium oxide (TiO2) as catalyst. Ultrasonic bath having 8 L capacity and operating frequency of 40 ± 2 kHz has been used. The effect of parameters like power, initial pH, temperature, time and initial concentration of 2-Picoline were studied to establish best operating conditions which were further used in the combination treatment approaches of ultrasound with oxidising agents. The chemical oxygen demand (COD) reduction for the optimized approaches of ultrasound in combination with oxidizing agents was also determined. Degradation experiments were performed using oxidising agents also in absence of ultrasound to investigate the individual treatment capacity of the oxidants and also the synergetic index for the combination. Kinetic study demonstrated that second order model suited for all the treatment approaches except US/Fenton where first order model fitted better. Ultrasound in combination with Fenton reagent demonstrated a substantial synergy for the degradation of 2-Picoline compared to other treatment approaches showing highest degradation of 97.6 %, synergetic index as 5.71, cavitational yield of 1.82 × 10-5 mg/J and COD removal of 82.4 %.


Assuntos
Oxidantes/química , Picolinas/química , Ondas Ultrassônicas , Concentração de Íons de Hidrogênio , Cinética , Temperatura
6.
Water Res ; 203: 117495, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34388496

RESUMO

This study investigated the effects of thirteen (photo/electro) chemical oxidation processes on the formation potential (FP) of N-nitrosodimethylamine (NDMA) during the chloramination of ranitidine in reverse osmosis (RO) permeate and brine. The NDMA-FP varied significantly depending on the pretreatment process, initial pH, and water matrix types. At higher initial pH values (> 7.0), most pretreatments did not reduce the NDMA-FP, presumably because few radical species and more chloramine-reactive byproducts were generated. At pH < 7.0, however, electrochemical oxidation assisted by chloride and Fe2+/H2O2, catalytic wet peroxide oxidation and peroxydisulfate-induced pretreatments removed up to 85% of NDMA-FP in the RO brine. Ultraviolet (UV) irradiation or prechlorination alone did not reduce the NDMA-FP effectively, but combined UV/chlorine treatment effectively reduced the NDMA-FP. In contrast, after UV irradiation (2.1 mW cm-2 for 0.5 h) in the presence of H2O2 and chloramine, NDMA formation increased substantially (up to 26%) during the post-chloramination of the RO permeate. Mass spectrometric analysis and structural elucidation of the oxidation byproducts indicated that compared with the reactive nitrogen species generated by UV/NH2Cl, sulfate radicals and (photo/electro)chemically generated reactive chlorine species were more promising for minimizing NDMA-FP. Unlike, the hemolytic •OH driven by UV/H2O2, the •OH from Fe(IV)-assisted pretreatments showed a significant synergistic effect on NDMA-FP reduction. Overall, the results suggest the need for a careful assessment of the type of radical species to be used for treating an RO water system containing amine-functionalized compounds.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Dimetilnitrosamina , Peróxido de Hidrogênio , Oxidantes , Ranitidina , Água , Poluentes Químicos da Água/análise
7.
Water Res ; 203: 117557, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34418644

RESUMO

Liquid sludge often contains odorous and toxic hydrogen sulfide and high levels of FeII compounds (e.g., iron sulfides), due to the extensive use of iron salts for hydrogen sulfide control in sewers and for enhanced primary treatment and phosphate removal in wastewater treatment plants. We proposed and verified that dosing appropriate chemical oxidants in the sulfide-iron-laden sludge can be a simple and cost-effective strategy to remove hydrogen sulfide, phosphate, and emerging organic contaminants, and to improve sludge dewaterability simultaneously. Among the seven oxidants investigated, H2O2, ClO2 and NaClO2 were the more cost-effective oxidants than others to control hydrogen sulfide release from the liquid sludge. Dosing these three oxidants also improved sludge dewaterability and removed dissolved phosphate from the liquid sludge, with H2O2 performing the best. Hydrogen sulfide was removed via both direct oxidation by the dosed oxidants and indirect oxidation by the FeIII that was in-situ formed from oxidation of the FeII compounds in the sludge. The in-situ formed FeIII also precipitated/adsorbed the soluble phosphate into the solid form (FePO4). Fenton-like reactions occurred between H2O2 and the FeII compounds in the sludge, and hydroxyl radicals (HO•) were generated. HO• oxidized hydrogen sulfide, destructed refractory organic emerging contaminants and sludge extracellular polymeric compounds (EPSs), and improved the sludge dewaterability. The formation of HO• can be enhanced by hydrogen sulfide and the sludge EPSs present in the sludge through providing more available FeII for the Fenton-like reactions. This study demonstrates the importance of selecting and dosing suitable oxidants to the sulfide-iron-laden sludge with due consideration for the multiple benefits in engineering practices. The same principles may be also used in formulating a dual oxidant-iron strategy to treat sulfide-iron-laden sewage, sludge, and sediments for simultaneous abatement of various pollutants.


Assuntos
Sulfeto de Hidrogênio , Esgotos , Peróxido de Hidrogênio , Ferro , Oxidantes , Oxirredução , Fosfatos , Sulfetos , Eliminação de Resíduos Líquidos
8.
Sci Total Environ ; 790: 148195, 2021 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-34380254

RESUMO

In recent years, there has been increasing interest in using of advanced oxidation processes in water and wastewater decontamination. As a new oxidants peracids, mainly peracetic acid (PAA) and peracid salts, i.e. peroxymonosulfate (PMS) and persulfate (PS) are used. The degradation process of organic compounds takes place with the participation of radicals, including hydroxyl (•OH) and sulfate (SO4•-) radicals derived from the peracids activation processes. Peracids can be activated in homogeneous systems (UV radiation, d-electron metal ions, e.g. Fe2+, Co2+, Mn2+, base, ozonolysis, thermolysis, radiolysis), or using heterogeneous activation (metals with zero oxidation state, metal oxides, quinones, activated carbon, semiconductors). As a result of oxidation, products of a lower mass than the parent compounds, less toxic, and more susceptible to biodegradation are formed. An important task is to investigate the effect of the peracid activation method and matrix composition on the efficiency of contamination removal. The article presents the latest information about the application of peracids in the removal of organic micropollutants of emerging concern (mainly focuses on endocrine disrupted compounds). The most important information on peracetic acid, peroxymonosulfate and persulfate salts, and methods of their activation are presented. Current uses of these oxidants in organic micropollutants removal are also described. Information was collected on the factors influencing the oxidation process and the effectiveness of pollutant removal. This paper compares PAA, PMS and PS-based processes for the first time in terms of kinetics and efficiency.


Assuntos
Ácido Peracético , Poluentes Químicos da Água , Oxidantes , Oxirredução , Peróxidos , Sais , Poluentes Químicos da Água/análise
9.
Life Sci ; 284: 119911, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34450167

RESUMO

AIM: Male reproductive toxicity is becoming of growing significance due to clinical chemotherapy usage. Methotrexate (MTX) is an anti-folate used on a large scale for different tumors and autoimmune conditions. Despite its wide clinical use, MTX is associated with severe testicular intoxication. The exact underlying mechanism is unclear. METHODS: Our study was conducted to explore the pathogenesis mechanism of MTX-induced testicular damage and the potential testicular protective effects of apocynin (APO) on testicular injury induced by single i.p. MTX (20 mg/kg). APO was administered orally (100 mg/kg) for ten days. RESULTS: As compared to rats given MTX alone, co-administration of MTX with APO demonstrated multiple beneficial effects evidenced by a marked increase in testosterone, FSH, and LH and significantly restored testes histopathological alterations. Mechanistically, APO restored antioxidant status through up-regulation of Nrf2, cytoglobin, PPAR-γ, SIRT1, AKT, and p-AKT, while effectively lowering Keap-1. Moreover, APO significantly attenuated inflammation by down-regulating NF-κB-p65, iNOS, and TLR4 expressions confirmed by in-silico evidence. Additionally, network pharmacology analysis, a bioinformatics approach, was used to decipher various cellular processes' molecular mechanisms. SIGNIFICANCE: The current investigation proves the beneficial effects of APO in MTX-associated testicular damage through activation of cytoglobin, Keap-1/Nrf2/AKT, PPAR-γ, SIRT1, and suppressing of TLR4/NF-κB-p65 signal. Our data collectively encourage extending the investigation to the clinical setting to explore APO effects in MTX-treated patients.


Assuntos
Acetofenonas/farmacologia , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Metotrexato/efeitos adversos , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Testículo/patologia , Receptor 4 Toll-Like/metabolismo , Acetofenonas/química , Animais , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Inflamação/patologia , Interleucina-6/metabolismo , Masculino , Simulação de Acoplamento Molecular , Óxido Nítrico/metabolismo , Oxidantes/metabolismo , Estresse Oxidativo/efeitos dos fármacos , PPAR gama/metabolismo , Peroxidase/metabolismo , Mapas de Interação de Proteínas/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Sirtuína 1/metabolismo , Testículo/efeitos dos fármacos , Testículo/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
10.
Nutrients ; 13(8)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34444799

RESUMO

Neonates with preterm, gastrointestinal dysfunction and very low birth weights are often intolerant to oral feeding. In such infants, the provision of nutrients via parenteral nutrition (PN) becomes necessary for short-term survival, as well as long-term health. However, the elemental nutrients in PN can be a major source of oxidants due to interactions between nutrients, imbalances of anti- and pro-oxidants, and environmental conditions. Moreover, neonates fed PN are at greater risk of oxidative stress, not only from dietary sources, but also because of immature antioxidant defences. Various interventions can lower the oxidant load in PN, including the supplementation of PN with antioxidant vitamins, glutathione, additional arginine and additional cysteine; reduced levels of pro-oxidant nutrients such as iron; protection from light and oxygen; and proper storage temperature. This narrative review of published data provides insight to oxidant molecules generated in PN, nutrient sources of oxidants, and measures to minimize oxidant levels.


Assuntos
Nutrição Enteral , Oxidantes , Nutrição Parenteral , Antioxidantes , Atrofia , Cisteína , Glutationa/metabolismo , Humanos , Recém-Nascido , Recém-Nascido de muito Baixo Peso , Peroxidação de Lipídeos , Hepatopatias , Estresse Oxidativo , Nutrição Parenteral Total , Nascimento Prematuro , Espécies Reativas de Oxigênio , Vitaminas
11.
Molecules ; 26(15)2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34361786

RESUMO

Silver birch, Betula pendula Roth, is one of the most common trees in Europe. Due to its content of many biologically active substances, it has long been used in medicine and cosmetics, unlike the rare black birch, Betula obscura Kotula. The aim of the study was therefore to compare the antioxidant properties of extracts from the inner and outer bark layers of both birch trees towards the L929 line treated with acetaldehyde. Based on the lactate dehydrogenase test and the MTT test, 10 and 25% concentrations of extracts were selected for the antioxidant evaluation. All extracts at tested concentrations reduced the production of hydrogen peroxide, superoxide anion radical, and 25% extract decreased malonic aldehyde formation in acetaldehyde-treated cells. The chemical composition of bark extracts was accessed by IR and HPLC-PDA methods and surprisingly, revealed a high content of betulin and lupeol in the inner bark extract of B. obscura. Furthermore, IR analysis revealed differences in the chemical composition of the outer bark between black and silver birch extracts, indicating that black birch may be a valuable source of numerous biologically active substances. Further experiments are required to evaluate their potential against neuroinflammation, cancer, viral infections, as well as their usefulness in cosmetology.


Assuntos
Antioxidantes/farmacologia , Betula/química , Casca de Planta/química , Extratos Vegetais/farmacologia , Acetaldeído/antagonistas & inibidores , Acetaldeído/farmacologia , Animais , Antioxidantes/química , Antioxidantes/isolamento & purificação , Betula/classificação , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Peróxido de Hidrogênio/antagonistas & inibidores , Malondialdeído/antagonistas & inibidores , Camundongos , Oxidantes/antagonistas & inibidores , Oxidantes/farmacologia , Triterpenos Pentacíclicos/química , Triterpenos Pentacíclicos/isolamento & purificação , Casca de Planta/classificação , Extratos Vegetais/química , Polônia , Superóxidos/antagonistas & inibidores , Triterpenos/química , Triterpenos/isolamento & purificação
12.
Water Res ; 202: 117353, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34246989

RESUMO

Cell-viability of cyanobacteria declines from development to decay stage during a successive bloom. Potassium permanganate (KMnO4) has demonstrated to be a superior pre-oxidant to treat high-viability cyanobacteria compared to other common oxidants (e.g., chlorine), but whether it is feasible to treat low-viability cyanobacteria is unknown. Here, effects of KMnO4 on membrane integrity, cyanotoxin fate and extracellular organic matters (EOMs) removal of high- and low-viability cyanobacteria were compared. Results showed that cell-viability of cyanobacteria could affect oxidant decay (kdecay), membrane damage (kloss), and cyanotoxins release (ki) and degradation (ke) during KMnO4 oxidation, similar to chlorination. However, unlike chlorination, initial low dosages of KMnO4 (0.5 and 1 mg L-1) minimized membrane damage for low-viability cyanobacteria (< 27%), and continuously decrease extracellular cyanotoxins, extracellular organic matters (EOMs), and aromatic compounds to some degrees (P<0.05). High dosages of KMnO4 (> 2 mg L-1) caused severe membrane destruction (> 89%) for low-viability cyanobacteria, leading to a fast increase of extracellular cyanotoxins within 1 h. However, total/extracellular cyanotoxins were oxidized to below the safety guideline of 1 µg L-1 after being dosed with sufficient oxidant exposure. EOMs and aromatic compounds were also reduced by 5-18% (P<0.05). Additionally, KMnO4-assisted coagulation significantly improved the removal of low-viability cyanobacteria (2-5 fold). Consequently, KMnO4 could be a promising pre-oxidant to treat low-viability cyanobacteria at decay stage of a successive bloom.


Assuntos
Cianobactérias , Purificação da Água , Cloro , Halogenação , Oxidantes , Oxirredução , Permanganato de Potássio
13.
Acta Biomed ; 92(3): e2021100, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34212935

RESUMO

PURPOSE: Glycemic control is important in order to avoid LDLs increased susceptibility to oxidation in diabetic patients. This study assess the relationship between diabetes control with serum prooxidant-antioxidant balance (PAB), oxidized LDL cholesterol (oxLDLc), homocysteine and vitamin D levels in patients with type 2 diabetes. MATERIAL AND METHODS: This was a cross-sectional study on three groups including 80 subjects as well (WGC) and poor (PGC) glycemic control and 40 healthy subjects. Presence of nephropathy and retinopathy were determined using IDF criteria. HbA1c level was determined with columnar chromatography using BioSystems kit. Serum PAB, homocysteine, oxLDLc and vitamin D levels were measured by the standard tests. RESULTS: There was a significant association between PAB with PGC (P< 0.001), diabetic retinopathy (P< 0.01) and nephropathy (P< 0.01) in type 2 diabetic patients. Moreover, the results showed that vitamin D serum levels was significantly lower in PGC patients (P< 0.01), and diabetic patients with retinopathy (P< 0.01). Multiple linear regression analysis revealed that the vitamin D deficiency can predict the HbA1c variations by 77.7% (ß=- 0.775) in subjects with type 2 diabetes mellitus (P<0.001). CONCLUSIONS: There was a significant association between prooxidant-antioxidant balance and vitamin D serum levels with diabetic complications.


Assuntos
Diabetes Mellitus Tipo 2 , Deficiência de Vitamina D , Estudos Transversais , Diabetes Mellitus Tipo 2/complicações , Controle Glicêmico , Humanos , Oxidantes , Deficiência de Vitamina D/complicações
14.
Int J Mol Sci ; 22(14)2021 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-34299235

RESUMO

The allergenic and inflammatory potential of proteins can be enhanced by chemical modification upon exposure to atmospheric or physiological oxidants. The molecular mechanisms and kinetics of such modifications, however, have not yet been fully resolved. We investigated the oligomerization and nitration of the grass pollen allergen Phl p 5 by ozone (O3), nitrogen dioxide (NO2), and peroxynitrite (ONOO-). Within several hours of exposure to atmospherically relevant concentration levels of O3 and NO2, up to 50% of Phl p 5 were converted into protein oligomers, likely by formation of dityrosine cross-links. Assuming that tyrosine residues are the preferential site of nitration, up to 10% of the 12 tyrosine residues per protein monomer were nitrated. For the reaction with peroxynitrite, the largest oligomer mass fractions (up to 50%) were found for equimolar concentrations of peroxynitrite over tyrosine residues. With excess peroxynitrite, the nitration degrees increased up to 40% whereas the oligomer mass fractions decreased to 20%. Our results suggest that protein oligomerization and nitration are competing processes, which is consistent with a two-step mechanism involving a reactive oxygen intermediate (ROI), as observed for other proteins. The modified proteins can promote pro-inflammatory cellular signaling that may contribute to chronic inflammation and allergies in response to air pollution.


Assuntos
Phleum/metabolismo , Proteínas de Plantas/metabolismo , Rinite Alérgica Sazonal/metabolismo , Alérgenos/química , Cinética , Nitratos/metabolismo , Dióxido de Nitrogênio/química , Óxidos de Nitrogênio , Oxidantes , Ozônio/química , Ácido Peroxinitroso/química , Proteínas de Plantas/análise , Poaceae/metabolismo , Pólen/metabolismo , Proteínas/química , Rinite Alérgica Sazonal/fisiopatologia
15.
J Hazard Mater ; 418: 126355, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34329014

RESUMO

Landfill leachate is produced from garbage decomposition with highly toxic and bio-refractory compounds, which poses serious harm to environmental security and human health. Thus, it is urgent to treat landfill leachate properly. Persulfate (PS) oxidation has attracted extensive attentions in terms of fast reaction speed, non-selectivity to target pollutants and thorough oxidation. In recent years, PS oxidation has been widely adopted for landfill leachate purification. However, the related results have been rarely summarized. In this review, the treatment of landfill leachate by PS oxidation system is discussed systematically including oxidants, activation modes and oxidation mechanisms. In addition, the current situation of PS oxidation system and other coupled systems for landfill leachate treatment is also summarized. Finally, the challenges and future research directions of landfill leachate treatment based on PS oxidation process are proposed. Meaningfully, this review will provide valuable references for the development of landfill leachate treatment process, promoting the application of advanced oxidation technology in landfill leachate treatment.


Assuntos
Resíduos de Alimentos , Poluentes Químicos da Água , Humanos , Oxidantes , Oxirredução , Tecnologia , Poluentes Químicos da Água/análise
16.
Rev Port Cardiol (Engl Ed) ; 40(7): 489-497, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34274095

RESUMO

BACKGROUND: Contrast-induced nephropathy (CIN) is a life-threatening complication after primary percutaneous coronary intervention (p-PCI). Oxidative stress and inflammation may play an important role in the development of CIN. OBJECTIVE: We aimed to assess the relationship between total oxidant status, total antioxidant capacity, high-sensitivity C-reactive protein (hs-CRP), gamma-glutamyltransferase and uric acid (UA) in the development of CIN in patients presenting with ST-elevation myocardial infarction (STEMI). METHODS: This prospective cohort study consisted of 341 patients with STEMI. Patients were divided into two groups: those with and those without CIN. Predictors of CIN were determined by multivariate regression analyses. RESULTS: Multivariate regression analysis showed that initial glucose level, contrast media volume/glomerular filtration ratio (eGFR) ratio, hs-CRP, UA and oxidative status index were associated with the development of CIN in patients with STEMI. CONCLUSION: The main finding of this study is that increased oxidative stress and inflammation parameters were associated with the development of CIN in patients with STEMI. Other independent predictors of CIN were contrast media volume/eGFR ratio, initial glucose level, UA and hs-CRP.


Assuntos
Intervenção Coronária Percutânea , Infarto do Miocárdio com Supradesnível do Segmento ST , Antioxidantes , Humanos , Oxidantes , Intervenção Coronária Percutânea/efeitos adversos , Estudos Prospectivos , Fatores de Risco , Infarto do Miocárdio com Supradesnível do Segmento ST/cirurgia
17.
Molecules ; 26(14)2021 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-34299619

RESUMO

Radioiodine labeling of peptides and proteins is routinely performed by using various oxidizing agents such as Chloramine T, Iodobeads, and Iodogen reagent and radioactive iodide (I-), although some other oxidizing agents were also investigated. The main objective of the present study was to develop and test a novel reagent, inorganic monochloramine (NH2Cl), for radioiodine labeling of new chemical entities and biomolecules which is cost-effective, easy to make and handle, and is selective to label amino acids, peptides, and proteins. The data presented in this report demonstrate that the yields of the non-radioactive iodine labeling reactions using monochloramine are >70% for an amino acid (tyrosine) and a cyclic peptide (cyclo Arg-Gly-Asp-d-Tyr-Lys, cRGDyK). No evidence of the formation of N-chloro derivatives in cRGDyK was observed, suggesting that the reagent is selective in iodinating the tyrosine residue in the biomolecules. The method was successfully translated into radioiodine labeling of amino acid, a peptide, and a protein, Bovine Serum Albumin (BSA).


Assuntos
Radioisótopos do Iodo/química , Cloraminas/química , Marcação por Isótopo/métodos , Oligopeptídeos/química , Oxidantes/química , Peptídeos Cíclicos/química , Compostos Radiofarmacêuticos/química , Compostos de Tosil/química
18.
J Hazard Mater ; 419: 126492, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34323717

RESUMO

Occurrence of successive cyanobacterial blooms in source waters can continuously impair drinking water quality. Previous studies have separately investigated potassium permanganate (KMnO4) to treat high-viability cyanobacteria at just one stage of either development or maintenance. However, maintenance stage exhibited significantly higher cell-density and extracellular organic matters (EOMs) than development stage, which may result in a different KMnO4 oxidation pattern. In this study, kinetics of oxidant decay, membrane integrity loss, and toxin degradation of high-viability cyanobacteria at both stages were compared. Results showed that cyanobacteria at maintenance stage became more resistant to KMnO4 oxidation than that at development stage, since elevated cell-density and more proteins involved in EOMs resulted in lower oxidant exposure at this stage. Meanwhile, elevated cyanobacterial biomass became the main competitors to decrease toxin degradation efficiency at maintenance stage, leading to incapacity to degrade extracellular toxin to below safety guideline of 1 µg L-1. Consequently, comparing with the best strategy for development stage (6 mg min L-1, no membrane damage), a higher oxidant exposure (12 mg min L-1) was recommended to treat cyanobacteria at maintenance stage even with slight membrane damage (19%), since it degraded extracellular toxin to below safety guideline and achieved the highest removal ratio of EOMs. Overall, this study demonstrated that stage of cyanobacteria can strongly affect KMnO4 oxidation pattern, and it is necessary for water supplies to optimize KMnO4 treatments depending on bloom stage.


Assuntos
Cianobactérias , Microcystis , Purificação da Água , Oxidantes , Oxirredução , Permanganato de Potássio
19.
Free Radic Biol Med ; 172: 633-651, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34246778

RESUMO

The heme peroxidase family generates a battery of oxidants both for synthetic purposes, and in the innate immune defence against pathogens. Myeloperoxidase (MPO) is the most promiscuous family member, generating powerful oxidizing species including hypochlorous acid (HOCl). Whilst HOCl formation is important in pathogen removal, this species is also implicated in host tissue damage and multiple inflammatory diseases. Significant oxidant formation and damage occurs extracellularly as a result of MPO release via phagolysosomal leakage, cell lysis, extracellular trap formation, and inappropriate trafficking. MPO binds strongly to extracellular biomolecules including polyanionic glycosaminoglycans, proteoglycans, proteins, and DNA. This localizes MPO and subsequent damage, at least partly, to specific sites and species, including extracellular matrix (ECM) components and plasma proteins/lipoproteins. Biopolymer-bound MPO retains, or has enhanced, catalytic activity, though evidence is also available for non-catalytic effects. These interactions, particularly at cell surfaces and with the ECM/glycocalyx induce cellular dysfunction and altered gene expression. MPO binds with higher affinity to some damaged ECM components, rationalizing its accumulation at sites of inflammation. MPO-damaged biomolecules and fragments act as chemo-attractants and cell activators, and can modulate gene and protein expression in naïve cells, consistent with an increasing cycle of MPO adhesion, activity, damage, and altered cell function at sites of leukocyte infiltration and activation, with subsequent tissue damage and dysfunction. MPO levels are used clinically both diagnostically and prognostically, and there is increasing interest in strategies to prevent MPO-mediated damage; therapeutic aspects are not discussed as these have been reviewed elsewhere.


Assuntos
Oxidantes , Peroxidase , Humanos , Ácido Hipocloroso , Inflamação , Oxirredução , Peroxidase/metabolismo
20.
Int J Mol Sci ; 22(14)2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34299170

RESUMO

Previous research has shown that a perinatal obesogenic, high-fat diet (HFD) is able to exacerbate ozone-induced adverse effects on lung function, injury, and inflammation in offspring, and it has been suggested that mitochondrial dysfunction is implicated herein. The aim of this study was to investigate whether a perinatal obesogenic HFD affects ozone-induced changes in offspring pulmonary oxidant status and the molecular control of mitochondrial function. For this purpose, female Long-Evans rats were fed a control diet or HFD before and during gestation, and during lactation, after which the offspring were acutely exposed to filtered air or ozone at a young-adult age (forty days). Directly following this exposure, the offspring lungs were examined for markers related to oxidative stress; oxidative phosphorylation; and mitochondrial fusion, fission, biogenesis, and mitophagy. Acute ozone exposure significantly increased pulmonary oxidant status and upregulated the molecular machinery that controls receptor-mediated mitophagy. In female offspring, a perinatal HFD exacerbated these responses, whereas in male offspring, responses were similar for both diet groups. The expression of the genes and proteins involved in oxidative phosphorylation and mitochondrial biogenesis, fusion, and fission was not affected by ozone exposure or perinatal HFD. These findings suggest that a perinatal HFD influences ozone-induced responses on pulmonary oxidant status and the molecular control of mitophagy in female rat offspring.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Pulmão/patologia , Mitocôndrias/patologia , Mitofagia , Oxidantes/metabolismo , Ozônio/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal/patologia , Animais , Animais Recém-Nascidos , Feminino , Perfilação da Expressão Gênica , Pulmão/metabolismo , Masculino , Fenômenos Fisiológicos da Nutrição Materna , Mitocôndrias/metabolismo , Fosforilação Oxidativa , Estresse Oxidativo , Gravidez , Efeitos Tardios da Exposição Pré-Natal/etiologia , Ratos , Ratos Long-Evans
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