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1.
Oxid Med Cell Longev ; 2020: 9260748, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32377313

RESUMO

Parkinson's disease (PD) patients can benefit from antioxidant supplementation, and new efficient antioxidants are needed. The aim of this study was to evaluate the protective effect of selected nitroxide-containing redox nanoparticles (NRNPs) in a cellular model of PD. Antioxidant properties of NRNPs were studied in cell-free systems by protection of dihydrorhodamine 123 against oxidation by 3-morpholino-sydnonimine and protection of fluorescein against bleaching by 2,2-azobis(2-amidinopropane) hydrochloride and sodium hypochlorite. Model blood-brain barrier penetration was studied using hCMEC/D3 cells. Human neuroblastoma SH-SY5Y cells, exposed to 6-hydroxydopamine (6-OHDA), were used as an in vitro model of PD. Cells were preexposed to NRNPs or free nitroxides (TEMPO or 4-amino-TEMPO) for 2 h and treated with 6-OHDA for 1 h and 24 h. The reactive oxygen species (ROS) level was estimated with dihydroethidine 123 and Fluorimetric Mitochondrial Superoxide Activity Assay Kit. Glutathione level (GSH) was measured with ortho-phtalaldehyde, ATP by luminometry, changes in mitochondrial membrane potential with JC-1, and mitochondrial mass with 10-Nonyl-Acridine Orange. NRNP1, TEMPO, and 4-amino-TEMPO (25-150 µM) protected SH-SY5Y cells from 6-OHDA-induced viability loss; the protection was much higher for NRNP1 than for free nitroxides. NRNP1 were better antioxidants in vitro and permeated better the model BBB than free nitroxides. Exposure to 6-OHDA decreased the GSH level after 1 h and increased it considerably after 24 h (apparently a compensatory overresponse); NRNPs and free nitroxides prevented this increase. NRNP1 and free nitroxides prevented the decrease in ATP level after 1 h and increased it after 24 h. 6-OHDA increased the intracellular ROS level and mitochondrial superoxide level. Studied antioxidants mostly decreased ROS and superoxide levels. 6-OHDA decreased the mitochondrial potential and mitochondrial mass; both effects were prevented by NRNP1 and nitroxides. These results suggest that the mitochondria are the main site of 6-OHDA-induced cellular damage and demonstrate a protective effect of NRNP1 in a cellular model of PD.

2.
Molecules ; 25(6)2020 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-32213847

RESUMO

The aim of this study was to characterize the interaction of chosen catechins ((+)-catechin, (-)-epigallocatechin (EGC), and (-)-epigallocatechin gallate (EGCG)) with human erythrocytes and their protective effects against oxidative damage of erythrocytes. Uptake of the catechins by erythrocytes was studied by fluorimetry, their interaction with erythrocyte membrane was probed by changes in erythrocyte osmotic fragility and in membrane fluidity evaluated with spin labels, while protection against oxidative damage was assessed by protection against hemolysis induced by permanganate and protection of erythrocyte membranes against lipid peroxidation and protein thiol group oxidation. Catechin uptake was similar for all the compounds studied. Accumulation of catechins in the erythrocyte membrane was demonstrated by the catechin-induced increase in osmotic resistance and rigidification of the erythrocyte membrane detected by spin labels 5-doxyl stearic acid and 16-doxyl stearic acid. (-)-Epigallocatechin and EGCG inhibited erythrocyte acetylcholinesterase (mixed-type inhibition). Catechins protected erythrocytes against permanganate-induced hemolysis, oxidation of erythrocyte protein thiol groups, as well as membrane lipid peroxidation. These results contribute to the knowledge of the beneficial effects of catechins present in plant-derived food and beverages.

3.
Anal Biochem ; 597: 113698, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32222539

RESUMO

Nitroxides and nitroxide-containing nanoparticles (RNP) are excellent antioxidants. However, they have relatively high reduction potentials, which make them behave like oxidants or show little activity in some antioxidant assays. We found that stable nitroxyl radicals (TEMPO and 4-amino-TEMPO) has low reactivity in the test of scavenging of 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical (ABTS•). As a result, supplementation of blood plasma with nitroxides may decrease its total antioxidant capacity assayed with ABTS•. Nitroxides oxidize Fe2+ and in this way interfere with the ferric-Xylenol Orange assay of peroxides. Nitroxides as well as RNP directly oxidize glutathione and fluorogenic probes used for estimation of reactive oxygen species (ROS) (dihydro-2'7'-dichlorofluorescein diacetate, dihydroethidine and dihydrorhodamine 123) and thus produce artefacts in assays of glutathione and ROS in cell-free and cellular systems. These results point to the necessity of careful interpretation of antioxidant assays concerning nitroxides and RNP or performed in their presence.

4.
Aging (Albany NY) ; 12(2): 1910-1927, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31962290

RESUMO

The study was aimed at evaluation of the role of secondary oxidative stress in the stress-induced premature senescence (SIPS) of human fibroblasts induced by H2O2. Two fibroblast lines were used: lung MRC-5 and ear H8F2p25LM fibroblasts. The lines differed considerably in sensitivity to H2O2 (IC50 of 528 and 33.5 µM, respectively). The cells were exposed to H2O2 concentrations corresponding to IC50 and after 24 h supplemented with a range of antioxidants. Most of antioxidants studied slightly augmented the survival of fibroblasts at single concentrations or in a narrow concentration range, but the results were not consistent among the cell lines. Chosen antioxidants (4-amino-TEMPO, curcumin, caffeic acid and p-coumaric acid) did not restore the level of glutathione decreased by H2O2. Hydrogen peroxide treatment did not induce secondary production of H2O2 and even decreased it, decreased mitochondrial potential in both cell lines and induced changes in the mitochondrial mass inconsistent between the lines. Antioxidant protected mitochondrial potential only in H8F2p25LM cells, but attenuated changes in mitochondrial mass. These results speak against the intermediacy of secondary oxidative stress in the SIPS induced by H2O2 and suggest that the small protective action of antioxidants is due to their effects on mitochondria.

5.
Life Sci ; 227: 212-223, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30928407

RESUMO

AIMS: 3-Bromopyruvate (3-BP), an alkylating agent and a glycolytic inhibitor, is a promising anticancer agent, which can be efficient also against multidrug-resistant cancer cells. The aim of this study was to examine how 3-BP affects the survival and mobility of rat (MAT-LyLu and AT-2) and human (DU-145 and PC-3) metastatic prostate cancer cell lines. MAIN METHODS: Cytotoxicity was estimated with Neutral Red. Cell mobility was analyzed by time-lapse microscopic monitoring of trajectories of individual cells at 5-min intervals for 6h. ATP was estimated with luciferin/luciferase and glutathione (GSH) with o-phthalaldehyde. Actin cytoskeleton was visualized with phalloidin conjugated with Atto-488. KEY FINDINGS: All metastatic prostate cell lines studied were very sensitive to 3-BP (IC50 of 4-26µM). 3-Bromopyruvate drastically reduced cell movement even at concentrations of 5-10µM after 1h treatment. This compound depleted also cellular ATP and GSH, and disrupted actin cytoskeleton. SIGNIFICANCE: The data obtained suggest that 3-BP can potentially be useful for treatment of metastatic prostate cancer and, especially, be efficient in limiting metastasis.


Assuntos
Neoplasias da Próstata/tratamento farmacológico , Piruvatos/farmacologia , Citoesqueleto de Actina/efeitos dos fármacos , Trifosfato de Adenosina/análise , Animais , Linhagem Celular , Linhagem Celular Tumoral/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Glutationa/análise , Humanos , Masculino , Invasividade Neoplásica , Próstata/patologia , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Ratos
6.
Free Radic Res ; 53(2): 170-178, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30362385

RESUMO

An alkylating compound, 3-bromopyruvic acid (3-3-bromopyruvic acid (BP)) is a promising anti-cancer agent, potentially able to act on multidrug-resistant cells. Its action has been attributed mainly to inhibition of glycolysis. This compound induces also oxidative stress at a cellular level. The effects of 3-BP on gene expression have not been studied although they may determine the survival of cells exposed to 3-BP. The aim of this paper was to examine the effect 3-BP on gene expression pattern in breast MCF-7 cancer cells. Detection of the differences in gene expression was performed using microarrays and dysregulated genes were validated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Exposure of cells to 100 µM 3-BP for 6, 12 and 24 increased expression and diminished expression of 39 and 6 genes, respectively. Among the induced genes, 22 belong to general cellular stress response genes, maintenance genes involved in redox homeostasis, responding to oxidative stress (among them metallothioneins, low-molecular-weight thiol homeostasis enzymes and genes coding for NAD(P)H-dependent oxidoreductases operating on complex organic substrates, including aldo-keto reductases). These results demonstrate that transient oxidative stress in cells exposed to 3-BP is followed by antioxidant response.


Assuntos
Antioxidantes/metabolismo , Neoplasias da Mama/genética , Piruvatos/metabolismo , Neoplasias da Mama/metabolismo , Feminino , Humanos , Estresse Oxidativo
7.
Food Chem ; 278: 692-699, 2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-30583431

RESUMO

Studies of 54 antioxidants revealed that 27 of them, mainly polyphenols, generated hydrogen peroxide (H2O2) when added to Dulbecco's modified Eagle's medium (DMEM), other media used for culture of mammalian and yeast cells and phosphate-buffered saline. The most active antioxidants were: propyl gallate (PG), (-)-epigallocatechin gallate (EGCG) and quercetin (Q). Chelex treatment and iron chelators decreased H2O2 generation suggesting that transition metal ions catalyze antioxidant autoxidation and H2O2 production. Green tea also generated H2O2; tea prepared on tap water generated significantly more H2O2 than tea prepared on deionized water. Ascorbic acid decreased H2O2 production although it generated H2O2 itself, in the absence of other additives. Lemon added to the tea significantly reduced generation of H2O2. Hydrogen peroxide generated in the medium contributed to the cytotoxicity of PG, EGCG and Q to human prostate carcinoma DU-145 cells, since catalase increased the survival of the cells subjected to these compounds in vitro.


Assuntos
Antioxidantes/química , Peróxido de Hidrogênio/química , Catalase/metabolismo , Catequina/análogos & derivados , Catequina/química , Catequina/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Peróxido de Hidrogênio/metabolismo , Oxirredução , Polifenóis/química , Galato de Propila/química , Galato de Propila/farmacologia , Quercetina/química , Quercetina/farmacologia , Chá/química , Chá/metabolismo , Elementos de Transição/química
8.
J Nanobiotechnology ; 16(1): 87, 2018 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-30390681

RESUMO

Oxidative stress (OS) and nitrative stress (NS) accompany many diseases, including Alzheimer's disease (AD) and Parkinson's disease (PD). Antioxidants have been proposed to counteract OS/NS in these diseases. Nevertheless, the effects of antioxidants are limited and new, more efficient antioxidants are searched for. Redox-active nanoparticles (RNPs), containing antioxidants create a new therapeutical perspective. This review examines the recent literature describing synthesis and potential applications of cerium oxide RNPs, boron cluster-containing and silica containing RNPs, Gd3N@C80 encapsulated RNPs, and concentrates on nitroxide-containing RNPs. Nitroxides are promising antioxidants, preventing inter alia glycation and nitration, but their application poses several problems. It can be expected that application of RNPs containing covalently bound nitroxides, showing low toxicity and able to penetrate the blood-brain barrier will be more efficient in the treatment of neurodegenerative disease, in particular AD and PD basing on their effects in cellular and animal models of neurodegenerative diseases.


Assuntos
Antioxidantes/química , Nanopartículas/química , Doenças Neurodegenerativas/tratamento farmacológico , Óxidos de Nitrogênio/química , Animais , Antioxidantes/uso terapêutico , Barreira Hematoencefálica/metabolismo , Cério/química , Humanos , Cinética , Nanopartículas/uso terapêutico , Óxidos de Nitrogênio/uso terapêutico , Oxirredução , Estresse Oxidativo , Tamanho da Partícula , Multimerização Proteica , Propriedades de Superfície , Termodinâmica
9.
Food Chem ; 268: 567-576, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30064798

RESUMO

Interaction of metal, especially iron ions with flavanols is considered as an important feature of these compounds and is believed to contribute to their both antioxidant and prooxidant properties. The aim of this study was to examine how Fe2+ binding to form a 4:1 (flavanol:Fe2+) mixtures affects the antioxidant properties of flavanols. ABTS∗ scavenging, protection against fluorescence bleaching induced by AAPH and hypochlorite, protection against lipid peroxidation and protection against hypochlorite-induced hemolysis demonstrated that flavonol-Fe2+ mixtures retain antioxidant properties, although, in most cases, they are lower with respect to the flavanols alone. No superoxide dismutase-like or catalase-like activity of the mixtures was revealed.


Assuntos
Antioxidantes/química , Polifenóis/química , Flavonóis , Peroxidação de Lipídeos
11.
Aging (Albany NY) ; 10(5): 868-901, 2018 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-29779015

RESUMO

Non-enzymatic protein modifications occur inevitably in all living systems. Products of such modifications accumulate during aging of cells and organisms and may contribute to their age-related functional deterioration. This review presents the formation of irreversible protein modifications such as carbonylation, nitration and chlorination, modifications by 4-hydroxynonenal, removal of modified proteins and accumulation of these protein modifications during aging of humans and model organisms, and their enhanced accumulation in age-related brain diseases.


Assuntos
Envelhecimento/metabolismo , Encefalopatias/metabolismo , Encefalopatias/fisiopatologia , Estresse Oxidativo/fisiologia , Processamento de Proteína Pós-Traducional/fisiologia , Animais , Halogenação/fisiologia , Humanos , Carbonilação Proteica/fisiologia
12.
Biomed Res Int ; 2018: 4340871, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29651432

RESUMO

Salivary gland tumors account for 3-6% of tumors of the head and neck. About 80% of salivary gland tumors occur in parotid glands. Oxidative stress (OS) is implicated in the origin, development, and whole-body effects of various tumors. There are no data on the occurrence of OS in the parotid gland tumors. The aim of this study was to ascertain if whole-body OS accompanies parotid gland tumors, based first of all on oxidative modifications of blood serum proteins and other markers of OS in the serum of the patients. The group studied included 17 patients with pleomorphic adenoma, 9 patients with Warthin's tumor, 8 patients with acinic cell carcinoma, and 24 age-matched controls. We found increased concentration of interleukin 4 in patients with acinic cell carcinoma, decreased plasma thiols, increased AOPP concentration, and decreased FRAP of blood serum in all groups of the patients while protein oxidative modifications assessed fluorimetrically, protein carbonyls, protein nitration, malondialdehyde concentration, and serum ABTS⁎-scavenging capacity were unchanged. These data indicate the occurrence of OS in patients with parotid gland tumors and point to various sensitivities of OS markers.


Assuntos
Produtos da Oxidação Avançada de Proteínas/sangue , Biomarcadores Tumorais/sangue , Interleucina-4/sangue , Proteínas de Neoplasias/sangue , Estresse Oxidativo , Neoplasias Parotídeas/sangue , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Parotídeas/patologia , Projetos Piloto
13.
Free Radic Biol Med ; 116: 114-122, 2018 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-29305896

RESUMO

Ribonucleotide reductase (RNR) catalyses the rate limiting step of DNA synthesis utilising a mechanism that requires a tyrosyl radical. We have previously shown that superoxide can quench protein tyrosyl radicals in vitro, either by oxidative addition, or reduction of the radical to tyrosine. Here, we observe that Saccharomyces cerevisiae strains lacking either copper-zincSOD (SOD1) or manganese SOD (SOD2) had decreased RNR activity compared to SOD-competent yeast. When superoxide production was increased by treatment with paraquat, RNR activity was further decreased, with yeast lacking SOD1 being the most sensitive. The growth of yeast lacking SOD1 was also the most sensitive to paraquat treatment. Using expressed recombinant RNR, superoxide addition was not detectable using mass-spectrometry. This suggests that oxidative addition is not the major route of inhibition in our system, but does not rule out reduction by superoxide as a possible mechanism. Our results demonstrate that protection of RNR from inactivation by superoxide is an important function of SOD, particularly cytoplasmic SOD1.


Assuntos
Citoplasma/metabolismo , Ribonucleotídeo Redutases/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/fisiologia , Superóxido Dismutase-1/metabolismo , Superóxido Dismutase/metabolismo , Regulação para Baixo , Microrganismos Geneticamente Modificados , Mutação/genética , Oxirredução , Paraquat/toxicidade , Proteínas de Saccharomyces cerevisiae/genética , Superóxido Dismutase/genética , Superóxido Dismutase-1/genética , Tirosina/metabolismo
14.
Free Radic Res ; 52(3): 335-338, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29092648

RESUMO

TEMPO-phosphate has been introduced as a phosphate analogue to study phosphate transport in erythrocytes. The nitroxide is reduced intracellularly upon entering the cells, the membrane transport being the rate-limiting step of the loss of ESR signal. The use of TEMPO-phosphate is convenient and avoids the hazard of radioactivity. We studied the inhibition of TEMPO-phosphate transport to human erythrocytes by various compounds. DIDS and SITS, inhibitors of Band 3, inhibited the TEMPO-phosphate transport. 1-cyano-4-hydroxycinnamic acid, inhibitor of monocarboxylate transporters, did not affect the permeation of TEMPO-phosphate. The transport of TEMPO-phosphate was inhibited by various polyphenols, especially curcumin, naringin, quercetin, luteolin and kaempferol. Interestingly, 3-bromopyruvic acid, an alkylating agent and potential anticancer agent, induced an apparent enhancement of TEMPO-phosphate transport into erythrocytes.


Assuntos
Transporte Biológico/fisiologia , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Fosfatos/química , Humanos
15.
Food Chem ; 241: 480-492, 2018 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-28958556

RESUMO

Antioxidant properties of five catechins and five other flavonoids were compared with several other natural and synthetic compounds and related to glutathione and ascorbate as key endogenous antioxidants in several in vitro tests and assays involving erythrocytes. Catechins showed the highest ABTS-scavenging capacity, the highest stoichiometry of Fe3+ reduction in the FRAP assay and belonged to the most efficient compounds in protection against SIN-1 induced oxidation of dihydrorhodamine 123, AAPH-induced fluorescein bleaching and hypochlorite-induced fluorescein bleaching. Glutathione and ascorbate were less effective. (+)-catechin and (-)-epicatechin were the most effective compounds in protection against AAPH-induced erythrocyte hemolysis while (-)-epicatechin gallate, (-)-epigallocatechin gallate and (-)-epigallocatechin protected at lowest concentrations against hypochlorite-induced hemolysis. Catechins [(-)-epigallocatechin gallate and (-)-epicatechin gallate)] were most efficient in the inhibition of AAPH-induced oxidation of 2'7'-dichlorodihydroflurescein contained inside erythrocytes. Excellent antioxidant properties of catechins and other flavonoids make them ideal candidates for nanoformulations to be used in antioxidant therapy.


Assuntos
Antioxidantes/química , Catequina/química , Ácido Ascórbico , Flavonoides , Oxirredução , Chá
16.
Oxid Med Cell Longev ; 2017: 7905148, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29181127

RESUMO

Multiple sclerosis (MS) is a disease involving oxidative stress (OS). This study was aimed at examination of the effect of melatonin supplementation on OS parameters, especially oxidative protein modifications of blood serum proteins, in MS patients. The study included 11 control subjects, 14 de novo diagnosed MS patients with the relapsing-remitting form of MS (RRMS), 36 patients with RRMS receiving interferon beta-1b (250 µg every other day), and 25 RRMS patients receiving interferon beta-1b plus melatonin (5 mg daily). The levels of N'-formylkynurenine, kynurenine, dityrosine, carbonyl groups, advanced glycation products (AGEs), advanced oxidation protein products (AOPP), and malondialdehyde were elevated in nontreated RRSM patients. N'-Formylkynurenine, kynurenine, AGEs, and carbonyl contents were decreased only in the group treated with interferon beta plus melatonin, while dityrosine and AOPP contents were decreased both in the group of patients treated with interferon beta and in the group treated with interferon beta-1b plus melatonin. These results demonstrate that melatonin ameliorates OS in MS patients supporting the view that combined administration of interferon beta-1b and melatonin can be more effective in reducing OS in MS patients than interferon beta-1b alone.


Assuntos
Proteínas Sanguíneas/metabolismo , Interferon beta/uso terapêutico , Melatonina/uso terapêutico , Esclerose Múltipla/tratamento farmacológico , Adulto , Feminino , Humanos , Interferon beta/farmacologia , Masculino , Melatonina/farmacologia , Esclerose Múltipla/patologia , Estresse Oxidativo
17.
Acta Biochim Pol ; 64(3): 503-506, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28746421

RESUMO

Main thiols and disulfides were determined in the hemolymph of the Jamaican field cricket Gryllus assimilis at various developmental stages. On the basis of these data, redox potentials of the glutathione, cysteine and homocysteine redox systems were calculated. The concentrations of all thiols studied decreased during development (at a stage of 6 molts) with respect to young crickets, and increased again in adult insects. Redox potentials of the glutathione and cysteine systems increased from values of -131.0±5.6 mV and -86.9±17.1 mV, respectively in young crickets to -58.0±3.6 mV and -36.1±4.2 mV, respectively, at the stage of 6 molts and decreased to values of -110.4±24.8 mV and -66.3±12.2 mV, respectively, in adult insects. Redox potentials of the glutathione and cysteine systems in the hemolymph of young and adult insects were similar to those reported for human plasma.


Assuntos
Dissulfetos/metabolismo , Gryllidae/crescimento & desenvolvimento , Gryllidae/metabolismo , Hemolinfa/metabolismo , Compostos de Sulfidrila/metabolismo , Animais , Cisteína/metabolismo , Glutationa/metabolismo , Dissulfeto de Glutationa/metabolismo , Homocisteína/metabolismo , Ninfa/crescimento & desenvolvimento , Ninfa/metabolismo , Oxirredução
18.
J Neuroimmunol ; 305: 145-153, 2017 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-28284335

RESUMO

Myasthenia gravis (MG) is an autoimmune disease caused by production of antibodies against acetylcholine receptors of the neuromuscular junction (Ab). The aim of this study was to ascertain if oxidative stress accompanies MG by estimation of the several independent parameters of oxidative damage, mainly the levels of oxidative modifications of blood serum proteins. The group studied consisted of 50 MG patients (28 females and 22 males), 24 with ocular MG (OMG) and 26 with generalized MG (GMG), of mean age of 66.7 (30-81)years (y), mean disease duration of 9.5 (0.5-34)y, mean level of Ab of 8.9 (0.1-85)nmol/ml, and 25 age-matched healthy controls. MG patients were stratified into groups according to disease duration (<5y or >5y), Ab level (low, <3 or high, >3nmol/l) as well as symptoms (GMG or OMG). Glycophore fluorescence was increased in OMGa. Dityrosine was increased in both types of MGc, in patients ill <5b and >5cy, with lowc and highc levels of Ab. N-formylkynurenine was increased in OMGa and GMGb, in both disease duration groupsa, in the group of low Aba. Kynurenine was increased in the group with high Aba. Tryptophan fluorescence was decreased in OMGb and GMGc, in patients ill for <5b and >5ay, with lowa and highc Ab. Serum thiol group concentration were decreased in GMGc, in patients ill for >5yb. AOPP level was elevated in OMGa, in patients ill for >5ya with high Aba. Protein carbonyls were increased in both OMGc and GMGc, in patients ill for >5ay, with lowb and highb Ab. FRAP and ABTS• scavenging by fast antioxidants were unchanged, but ABTS• scavenging by slow antioxidants was lower in OMGb and GMGc, in patients ill for >5cy, in patients with lowc and highb Ab (ap<0.05, bp<0.01, cp<0.001). These results demonstrate systemic oxidative stress in MG, suggesting therapeutic use of antioxidants.


Assuntos
Proteínas Sanguíneas/metabolismo , Miastenia Gravis/sangue , Estresse Oxidativo/fisiologia , Adulto , Produtos da Oxidação Avançada de Proteínas/metabolismo , Idoso , Idoso de 80 Anos ou mais , Autoanticorpos/sangue , Benzotiazóis/metabolismo , Progressão da Doença , Feminino , Glicoforinas/metabolismo , Humanos , Cinurenina/metabolismo , Masculino , Pessoa de Meia-Idade , Miastenia Gravis/cirurgia , Carbonilação Proteica , Receptores Colinérgicos/imunologia , Ácidos Sulfônicos/metabolismo , Timectomia , Tirosina/análogos & derivados , Tirosina/metabolismo
19.
Gen Physiol Biophys ; 36(2): 175-186, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28218612

RESUMO

Glycation is the cause of diabetic complications and contributes to the development of other diseases and aging. Numerous exogenous compounds have been tested for their anti-glycating activity. The aim of this study was to answer the question, which endogenous compounds at physiological concentrations can effectively prevent glycation. A set of endogenous compounds has been tested for the ability to protect albumin from glucose-induced glycation in vitro at a concentration of 1 mM and in a physiological concentration range. Only glutathione was found to protect significantly against glycation at physiological concentrations. Glutathione depletion increased the rate of hemoglobin glycation in erythrocytes incubated with high glucose concentrations. These results indicate that the level of glutathione is the main determinant of glycation of intracellular proteins.


Assuntos
Glucose/química , Glucose/metabolismo , Glutationa/sangue , Glutationa/química , Hemoglobinas/química , Hemoglobinas/metabolismo , Adulto , Proteínas Sanguíneas/química , Proteínas Sanguíneas/metabolismo , Células Cultivadas , Feminino , Produtos Finais de Glicação Avançada/sangue , Produtos Finais de Glicação Avançada/química , Humanos , Soroalbumina Bovina/química
20.
Acta Biochim Pol ; 64(1): 195-198, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27991936

RESUMO

Deoxyribose test has been widely used for determination of reactivities of various compounds for the hydroxyl radical. The test is based on the formation of hydroxyl radical by Fe2+ complex in the Fenton reaction. We propose a modification of the deoxyribose test to detect strong iron binding, inhibiting participation of Fe2+ in the Fenton reaction, on the basis of examination of concentration dependence of deoxyribose degradation on Fe2+ concentration, at a constant concentration of a chelating agent.


Assuntos
Desoxirribose/química , Peróxido de Hidrogênio/química , Radical Hidroxila/química , Ferro/química , Sítios de Ligação , Quelantes/química , Técnicas de Laboratório Clínico/métodos , Relação Dose-Resposta a Droga , Quelantes de Ferro/química
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