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1.
Chembiochem ; 24(8): e202200749, 2023 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-36779388

RESUMO

The mitochondrion, an essential organelle involved in cellular respiration, energy production, and cell death, is the main cellular source of reactive oxygen species (ROS), including superoxide. Mitochondrial diseases resulting from uncontrolled/excess ROS generation are an emerging public health concern and there is current interest in specific mitochondriotropic probes to get information on in-situ ROS production. As such, nitrones vectorized by the triphenylphosphonium (TPP) cation have recently drawn attention despite reported cytotoxicity. Herein, we describe the synthesis of 13 low-toxic derivatives of N-benzylidene-1-diethoxyphosphoryl-1-methylethylamine N-oxide (PPN) alkyl chain-grafted to a pyridinium, triethylammonium or berberinium lipophilic cation. These nitrones showed in-vitro superoxide quenching activity and EPR/spin-trapping efficiency towards biologically relevant free radicals, including superoxide and hydroxyl radicals. Their mitochondrial penetration was confirmed by 31 P NMR spectroscopy, and their anti-apoptotic properties were assessed in Schwann cells treated with hydrogen peroxide. Two pyridinium-substituted PPNs were identified as potentially better alternatives to TPP nitrones conjugates for studying mitochondrial oxidative damage.


Assuntos
Mitocôndrias , Superóxidos , Superóxidos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Mitocôndrias/metabolismo , Apoptose , Cátions/metabolismo , Espectroscopia de Ressonância de Spin Eletrônica/métodos
2.
Redox Biol ; 56: 102450, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36030628

RESUMO

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant disorder characterized by progressive muscle weakness. Adenine nucleotide translocator 1 (ANT1), the only 4q35 gene involved in mitochondrial function, is strongly expressed in FSHD skeletal muscle biopsies. However, its role in FSHD is unclear. In this study, we evaluated ANT1 overexpression effects in primary myoblasts from healthy controls and during Xenopus laevis organogenesis. We also compared ANT1 overexpression effects with the phenotype of FSHD muscle cells and biopsies. Here, we report that the ANT1 overexpression-induced phenotype presents some similarities with FSHD muscle cells and biopsies. ANT1-overexpressing muscle cells showed disorganized morphology, altered cytoskeletal arrangement, enhanced mitochondrial respiration/glycolysis, ROS production, oxidative stress, mitochondrial fragmentation and ultrastructure alteration, as observed in FSHD muscle cells. ANT1 overexpression in Xenopus laevis embryos affected skeletal muscle development, impaired skeletal muscle, altered mitochondrial ultrastructure and led to oxidative stress as observed in FSHD muscle biopsies. Moreover, ANT1 overexpression in X. laevis embryos affected heart structure and mitochondrial ultrastructure leading to cardiac arrhythmia, as described in some patients with FSHD. Overall our data suggest that ANT1 could contribute to mitochondria dysfunction and oxidative stress in FSHD muscle cells by modifying their bioenergetic profile associated with ROS production. Such interplay between energy metabolism and ROS production in FSHD will be of significant interest for future prospects.


Assuntos
Distrofia Muscular Facioescapuloumeral , Translocador 1 do Nucleotídeo Adenina/genética , Translocador 1 do Nucleotídeo Adenina/metabolismo , Humanos , Desenvolvimento Muscular , Músculo Esquelético/metabolismo , Distrofia Muscular Facioescapuloumeral/genética , Distrofia Muscular Facioescapuloumeral/patologia , Mioblastos/metabolismo , Espécies Reativas de Oxigênio/metabolismo
3.
Molecules ; 27(14)2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35889385

RESUMO

In order to discover new 31P NMR markers for probing subtle pH changes (<0.2 pH unit) in biological environments, fifteen new conformationally constrained or sterically hindered α-aminophosphonates derived from diethyl(2-methylpyrrolidin-2-yl)phosphonate were synthesized and tested for their pH reporting and cytotoxic properties in vitro. All compounds showed near-neutral pKas (ranging 6.28−6.97), chemical shifts not overlapping those of phosphorus metabolites, and spectroscopic sensitivities (i.e., chemical shifts variation Δδab between the acidic and basic forms) ranging from 9.2−10.7 ppm, being fourfold larger than conventional endogenous markers such as inorganic phosphate. X-ray crystallographic studies combined with predictive empirical relationships and ab initio calculations addressed the inductive and stereochemical effects of substituents linked to the protonated amine function. Satisfactory correlations were established between pKas and both the 2D structure and pyramidalization at phosphorus, showing that steric crowding around the phosphorus is crucial for modulating Δδab. Finally, the hit 31P NMR pH probe 1b bearing an unsubstituted 1,3,2-dioxaphosphorinane ring, which is moderately lipophilic, nontoxic on A549 and NHLF cells, and showing pKa = 6.45 with Δδab = 10.64 ppm, allowed the first clear-cut evidence of trans-sarcolemmal pH gradients in normoxic Dictyostelium discoideum cells with an accuracy of <0.05 pH units.


Assuntos
Dictyostelium , Organofosfonatos , Concentração de Íons de Hidrogênio , Fósforo , Força Próton-Motriz
4.
Free Radic Biol Med ; 184: 99-113, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35398201

RESUMO

Chronic mountain sickness (CMS) is a high-altitude (HA) maladaptation syndrome characterised by elevated systemic oxidative-nitrosative stress (OXNOS) due to a free radical-mediated reduction in vascular nitric oxide (NO) bioavailability. To better define underlying mechanisms and vascular consequences, this study compared healthy male lowlanders (80 m, n = 10) against age/sex-matched highlanders born and bred in La Paz, Bolivia (3600 m) with (CMS+, n = 10) and without (CMS-, n = 10) CMS. Cephalic venous blood was assayed using electron paramagnetic resonance spectroscopy and reductive ozone-based chemiluminescence. Nutritional intake was assessed via dietary recall. Systemic vascular function and structure were assessed via flow-mediated dilatation, aortic pulse wave velocity and carotid intima-media thickness using duplex ultrasound and applanation tonometry. Basal systemic OXNOS was permanently elevated in highlanders (P = <0.001 vs. lowlanders) and further exaggerated in CMS+, reflected by increased hydroxyl radical spin adduct formation (P = <0.001 vs. CMS-) subsequent to liberation of free 'catalytic' iron consistent with a Fenton and/or nucleophilic addition mechanism(s). This was accompanied by elevated global protein carbonylation (P = 0.046 vs. CMS-) and corresponding reduction in plasma nitrite (P = <0.001 vs. lowlanders). Dietary intake of vitamins C and E, carotene, magnesium and retinol were lower in highlanders and especially deficient in CMS + due to reduced consumption of fruit and vegetables (P = <0.001 to 0.028 vs. lowlanders/CMS-). Systemic vascular function and structure were also impaired in highlanders (P = <0.001 to 0.040 vs. lowlanders) with more marked dysfunction observed in CMS+ (P = 0.035 to 0.043 vs. CMS-) in direct proportion to systemic OXNOS (r = -0.692 to 0.595, P = <0.001 to 0.045). Collectively, these findings suggest that lifelong exposure to iron-catalysed systemic OXNOS, compounded by a dietary deficiency of antioxidant micronutrients, likely contributes to the systemic vascular complications and increased morbidity/mortality in CMS+. TRIAL REGISTRY: ClinicalTrials.gov; No: NCT01182792; URL: www.clinicaltrials.gov.


Assuntos
Doença da Altitude , Altitude , Doença da Altitude/metabolismo , Espessura Intima-Media Carotídea , Doença Crônica , Espectroscopia de Ressonância de Spin Eletrônica , Radicais Livres , Humanos , Ferro , Masculino , Análise de Onda de Pulso
5.
Methods Mol Biol ; 2275: 65-85, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34118032

RESUMO

The mitochondrion can be considered as the metabolic powerhouse of the cell, having a key impact on energy production, cell respiration, and intrinsic cell death. Mitochondria are also the main source of endogenous reactive oxygen species , including free radicals (FR), which are physiologically involved in signaling pathways but may promote cell damage when unregulated or excessively formed in inappropriate locations. A variety of chronic pathologies have been associated with FR-induced mitochondrial dysfunctions , such as cancer, age-related neurodegenerative diseases, and metabolic syndrome.In recent years drug design based on specific mitochondria-targeted antioxidants has become a very attractive therapeutic strategy and, among target compounds, nitrones have received growing attention because of their specific affinity toward FR. Here, we describe protocols dealing with the preparation, mitochondria permeation assessment, electron paramagnetic resonance (EPR) spin trapping setting, and antiapoptotic properties evaluation of a series of new linear nitrones vectorized by a triphenylphosphonium cation and labeled with a diethoxyphosphoryl moiety as 31P nuclear magnetic resonance (NMR) reporter with antioxidant property.


Assuntos
Antioxidantes/síntese química , Mitocôndrias/química , Óxidos de Nitrogênio/química , Compostos Organofosforados/síntese química , Células 3T3 , Animais , Antioxidantes/química , Antioxidantes/farmacocinética , Espectroscopia de Ressonância de Spin Eletrônica , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Camundongos , Estrutura Molecular , Compostos Organofosforados/química , Compostos Organofosforados/farmacocinética , Isótopos de Fósforo/química , Fosforilação , Ratos , Detecção de Spin
6.
Food Chem ; 350: 129222, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33607411

RESUMO

The reaction pathways were investigated by which a fungoid chitosan (CsG) may protect against photooxidative decay of model solutions and a sulphite-free white wine. Samples containing CsG were dark incubated for 2 days before exposure to fluorescent lighting for up to 21 days in the presence of wine like (+)-catechin and/or iron doses. In both systems CsG at winemaking doses significantly reduced the photoproduction of acetaldehyde and, to a better extent, glyoxylic acid, two key reactive aldehydes implicated in wine oxidative spoilage. After 21 days, CsG was two-fold more effective than sulphur dioxide in preventing glyoxylic acid formation and minimizing the browning of white wine. Among the antioxidant mechanisms involved in CsG protective effect, iron chelation, and hydrogen peroxide quenching were demonstrated. Besides, the previously unreported tartrate displacement from the [iron(III)-tartrate] complex was revealed as an additional inhibitory mechanism of CsG under photo-Fenton oxidation conditions.


Assuntos
Aldeídos/química , Quitosana/química , Processos Fotoquímicos , Vinho/análise , Antioxidantes/química , Catequina/química , Glioxilatos/química , Oxirredução , Dióxido de Enxofre/química , Tartaratos/química
7.
Antioxidants (Basel) ; 10(2)2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-33573143

RESUMO

Tamanu oil from Calophyllum inophyllum L. has long been used in traditional medicine. Ethanol extraction was found the best strategy for recovering bioactive compounds from the resin part of Tamanu oil, yielding two neutral and acidic resins fractions with high phenolics, flavonoids and pyranocoumarins concentrations. A further cascade of LPLC/HPLC separations of neutral and acidic resin fractions allowed identifying fifteen metabolites, and among them, calanolide D and 12-oxocalanolide A (both in neutral fraction) were first identified from a natural source. All these extracts, subfractions and isolated metabolites demonstrated increased free radical scavenging, antioxidant, anti-inflammatory, antimicrobial and antimycobacterial activity compared to Tamanu oil and its de-resinated lipid phase. Overall, these results could promote resinous ethanol-soluble Tamanu oil extracts as a useful multifaceted and renewable medicinal resource.

8.
Food Chem ; 285: 67-76, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30797377

RESUMO

The efficacy against oxidative degradation in model and sulphite-free white wines of two commercial, insoluble chitosans (one being approved for winemaking) were investigated by electron paramagnetic resonance (EPR). Both compounds at various doses significantly inhibited the formation of α-(4-pyridyl-1-oxide)-N-t-butylnitrone (4-POBN)-1-hydroxyethyl adducts under normal wine storage conditions. Pre-incubation with 2 g/L chitosan followed by filtration had a better effect than adding 50 mg/L sulphur dioxide to the experimental Chardonnay wine on the release of 4-POBN adducts after 6 days of incubation with 100 µM iron(II). In a relevant photooxidative system acetaldehyde formation was significantly reduced after 6 days of incubation. Parallel EPR tests were performed to assess the importance of metal chelation (iron and copper) versus direct scavenging of hydroxyl radicals on the effect of chitosan. The present data support the potentiality of using biocompatible chitosan as a healthier complement and/or alternative to sulphur dioxide against white wine oxidative spoilage.


Assuntos
Antioxidantes/química , Quitosana/química , Sulfitos/química , Quelantes/química , Espectroscopia de Ressonância de Spin Eletrônica , Compostos Ferrosos/química , Radical Hidroxila/química , Piridinas/química , Marcadores de Spin , Vinho/análise
9.
J Physiol ; 597(2): 611-629, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30397919

RESUMO

KEY POINTS: Chronic mountain sickness (CMS) is a maladaptation syndrome encountered at high altitude (HA) characterised by severe hypoxaemia that carries a higher risk of stroke and migraine and is associated with increased morbidity and mortality. We examined if exaggerated oxidative-inflammatory-nitrosative stress (OXINOS) and corresponding decrease in vascular nitric oxide bioavailability in patients with CMS (CMS+) is associated with impaired cerebrovascular function and adverse neurological outcome. Systemic OXINOS was markedly elevated in CMS+ compared to healthy HA (CMS-) and low-altitude controls. OXINOS was associated with blunted cerebral perfusion and vasoreactivity to hypercapnia, impaired cognition and, in CMS+, symptoms of depression. These findings are the first to suggest that a physiological continuum exists for hypoxaemia-induced systemic OXINOS in HA dwellers that when excessive is associated with accelerated cognitive decline and depression, helping identify those in need of more specialist neurological assessment and targeted support. ABSTRACT: Chronic mountain sickness (CMS) is a maladaptation syndrome encountered at high altitude (HA) characterised by severe hypoxaemia that carries a higher risk of stroke and migraine and is associated with increased morbidity and mortality. The present cross-sectional study examined to what extent exaggerated systemic oxidative-inflammatory-nitrosative stress (OXINOS), defined by an increase in free radical formation and corresponding decrease in vascular nitric oxide (NO) bioavailability, is associated with impaired cerebrovascular function, accelerated cognitive decline and depression in CMS. Venous blood was obtained from healthy male lowlanders (80 m, n = 17), and age- and gender-matched HA dwellers born and bred in La Paz, Bolivia (3600 m) with (CMS+, n = 23) and without (CMS-, n = 14) CMS. We sampled blood for oxidative (electron paramagnetic resonance spectroscopy, HPLC), nitrosative (ozone-based chemiluminescence) and inflammatory (fluorescence) biomarkers. We employed transcranial Doppler ultrasound to measure cerebral blood flow (CBF) and reactivity. We utilised psychometric tests and validated questionnaires to assess cognition and depression. Highlanders exhibited elevated systemic OXINOS (P < 0.05 vs. lowlanders) that was especially exaggerated in the more hypoxaemic CMS+ patients (P < 0.05 vs. CMS-). OXINOS was associated with blunted cerebral perfusion and vasoreactivity to hypercapnia, impaired cognition and, in CMS+, symptoms of depression. Collectively, these findings are the first to suggest that a physiological continuum exists for hypoxaemia-induced OXINOS in HA dwellers that when excessive is associated with accelerated cognitive decline and depression, helping identify those in need of specialist neurological assessment and support.


Assuntos
Doença da Altitude , Disfunção Cognitiva , Depressão , Estresse Nitrosativo , Estresse Oxidativo , Adulto , Idoso , Doença da Altitude/sangue , Doença da Altitude/metabolismo , Doença da Altitude/fisiopatologia , Circulação Cerebrovascular , Doença Crônica , Disfunção Cognitiva/sangue , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/fisiopatologia , Depressão/sangue , Depressão/metabolismo , Depressão/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos
10.
J Ethnopharmacol ; 207: 251-267, 2017 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-28669771

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: According to Saharian traditional medicine, Anvillea radiata Coss. & Dur. (Asteraceae) has been valued for treating a variety of ailments such as gastro-intestinal, liver and pulmonary diseases, and has gained awareness for its beneficial effect on postprandial hyperglycemia. However, to best of our knowledge, no detailed study of the antidiabetic curative effects of this plant has been conducted yet. AIM OF THE STUDY: To determine the hypoglycemic and antidiabetic effect of dietary supplementation with Anvillea radiata extracts on high-fat-diet (HFD)-induced obesity and insulin resistance in C57BL/6J mice in relation with antioxidant, anti-inflammatory, pancreatic beta-cells and skeletal muscle protection, and digestive enzyme inhibiting properties. MATERIALS AND METHODS: Six extracts (water soluble and organic) from aerial parts of the plant were analyzed phytochemically (total phenolic and flavonoid content) and screened for in vitro superoxide (by chemiluminescence) and hydroxyl radical (by electron paramagnetic resonance spin-trapping) scavenging, antioxidant (DPPH, TRAP and ORAC assays), xanthine oxidase, metal chelating, α-amylase and α-glucosidase inhibitory property, and protective effects on copper-induced lipoprotein oxidation. Then selected hydroalcoholic and aqueous extracts were assessed for toxicity in normal human lung fibroblasts and A549 cancer cells using FMCA and MTT assays. Two water-soluble extracts having the best overall properties were assessed for their (i) protective effect at 1-15µg/mL on metabolic activity of rat insulinoma-derived INS-1 cells exposed to hyperglycemic medium, and (ii) acute hypoglycemic effect on 16-weeks HFD-induced diabetic mice. Then diabetic mice were administered HFD supplemented by extracts (up to 150mg/kg/day) for 12 additional weeks using standard diet as control and the antidiabetic drug, metformin (150mg/kg), as positive control. Then the antidiabetic, anti-inflammatory and antioxidant activity of extracts were determined. RESULTS: Of the highly efficient polyphenolics-enriched hydroalcoholic and ethyl acetate extracts, the lyophilized aqueous (AQL) and butanol extracts were not toxic in cells (≤ 400µg/mL) or when given orally in normal mice (≤ 2000mg/kg), exerted a dose-dependent hypoglycemic action in diabetic mice, which was maximal at the dose of 150mg/kg. Upon administering this dose for 12 weeks, both extracts significantly ameliorated body weight control capacity, recovery of plasma glucose and insulin level, reduced oxidative stress in blood, myocardial and skeletal muscles, and improved hyperlipidemic and inflammatory status. Moreover, diabetes-related complications were optimally ameliorated by oral therapy based on halved doses (75mg/kg) of a mixture of AQL and metformin. CONCLUSIONS: Current investigation supports the traditional medicinal usage of Anvillea radiata and suggests that both readily accessible and low-cost bio-extracts have the potency to develop an antihyperglycemic, antihyperlipidemic and protective agent against beta-cells and muscle dysfunction at doses compatible with the common practices of indigenous people for the management of metabolic disorders.


Assuntos
Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Asteraceae/química , Hipoglicemiantes/farmacologia , Extratos Vegetais/farmacologia , 1-Butanol/química , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/isolamento & purificação , Antioxidantes/administração & dosagem , Antioxidantes/isolamento & purificação , Linhagem Celular , Linhagem Celular Tumoral , Diabetes Mellitus Experimental/tratamento farmacológico , Dieta Hiperlipídica , Relação Dose-Resposta a Droga , Feminino , Humanos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/isolamento & purificação , Medicina Tradicional , Metformina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Ratos , Água/química
11.
Talanta ; 170: 119-127, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28501147

RESUMO

Myeloperoxidase (MPO) is a key enzyme derived from leukocytes which is associated with the initiation and progression of many inflammatory diseases. Increased levels of MPO may contribute to cellular dysfunction and tissues injury by producing highly reactive oxidants such as hypochlorous acid (HOCl). Myeloperoxidase-generated HOCl is therefore considered as a relevant biomarker of oxidative stress-related damage and its quantitation is of great importance to the study of disease progression. In this context, the current study describes a rapid, sensitive and homogeneous fluorescence-based method for detecting the MPO chlorination activity in biological samples. This assay utilizes 7-hydroxy-2-oxo-2H-chromene-8-carbaldehyde oxime as a selective probe for HOCl detection, and is adapted to 96-well microplates to allow high-throughput quantitation of active MPO. The ability of the method to monitor HOCl release was further investigated in hyperglycemic streptozotocin-treated diabetic rats. The data proved that the present assay has a reliable performance when quantitating the active MPO in the plasma of diabetic animals, a feature of inflammatory disease found concomitant with an elevation of protein carbonyls levels and lipid peroxidation and which was negatively correlated with the ratio of reduced-to-oxidized glutathione.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Ensaios Enzimáticos/métodos , Ácido Hipocloroso/metabolismo , Estresse Oxidativo , Peroxidase/metabolismo , Animais , Células HL-60 , Halogenação , Humanos , Masculino , Peroxidase/sangue , Ratos , Espectrometria de Fluorescência
12.
Eur J Pharmacol ; 794: 162-172, 2017 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-27743884

RESUMO

The NADPH oxidase proteins catalyse the formation of superoxide anion which act as signalling molecules in physiological and pathological processes. Nox1-dependent NADPH oxidase is expressed in heart, lung, colon, blood vessels and brain. Different strategies involving Nox1 inhibition based on diphenylene iodonium derivatives are currently tested for colorectal cancer therapy. Here, after peptides screening on Nox1-dependent NADPH oxidase assay in HT-29 cells, we identify a peptide (referred to as NF02), cell-active, that potently block Nox1-dependent reactive oxygen species generation. Study of DEPMPO adduct formation by electron paramagnetic resonance showed that NF02 has no superoxide scavenging activity and no impact on cellular reactive oxygen species-producing enzymes such xanthine oxidase. NF02 was not cytotoxic, inhibited reactive oxygen species production of reconstituted Nox1/Noxo1/Noxa1 complex in HEK293 and did not decrease Nox2 dependent cellular NADPH oxidase reactive oxygen species production. Finally, NF02 inhibited cell migration and invasion of colorectal cancer cells which is consistent with the described impact of Nox1 inhibitors on cell migration. NF02 peptide is a new NADPH oxidase inhibitor specific for Nox1 over Nox2 and xanthine oxidase which might represent a useful Nox1 tool with potential therapeutic insights.


Assuntos
Movimento Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , NADPH Oxidases/antagonistas & inibidores , Oligopeptídeos/farmacologia , Sequência de Aminoácidos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/química , Humanos , NADPH Oxidase 1 , NADPH Oxidases/metabolismo , Invasividade Neoplásica , Oligopeptídeos/química
13.
Chembiochem ; 18(3): 300-315, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-27885767

RESUMO

There is increasing interest in measuring pH in biological samples by using nitroxides with pH-dependent electron paramagnetic resonance (EPR) spectra. Aiming to improve the spectral sensitivity (ΔaX ) of these probes (i.e., the difference between the EPR hyperfine splitting (hfs) in their protonated and unprotonated forms), we characterized a series of novel linear α-carboxy, α'-diethoxyphosphoryl nitroxides constructed on an amino acid core and featuring an (α or α')-C-H bond. In buffer, the three main hfs (aN , aH , and aP ) of their EPR spectra vary reversibly with pH and, from aP or aH titration curves, a two- to fourfold increase in sensitivity was achieved compared to reference imidazoline or imidazolidine nitroxides. The crystallized carboxylate 10 b (pKa ≈3.6), which demonstrated low cytotoxicity and good resistance to bioreduction, was applied to probe stomach acidity in rats. The results pave the way to a novel generation of highly sensitive EPR pH markers.


Assuntos
Aminoácidos/química , Espectroscopia de Ressonância de Spin Eletrônica , Óxidos de Nitrogênio/química , Organofosfonatos/química , Células A549 , Animais , Sobrevivência Celular/efeitos dos fármacos , Cristalografia por Raios X , Ácido Gástrico/química , Mucosa Gástrica/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Masculino , Simulação de Dinâmica Molecular , Óxidos de Nitrogênio/toxicidade , Organofosfonatos/síntese química , Fosforilação , Ratos , Ratos Sprague-Dawley
14.
Eur J Med Chem ; 119: 197-217, 2016 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-27162124

RESUMO

A series of new hybrid 2-(diethoxyphosphoryl)-N-(benzylidene)propan-2-amine oxide derivatives with different aromatic substitution (PPNs) were synthesized. These molecules were evaluated for their EPR spin trapping potential on eleven different radicals and NO-donation properties in vitro, cytotoxicity and vasoprotective effect on precontracted rat aortic rings. A subfamily of the new PPNs featured an antioxidant moiety occurring in natural phenolic acids. From the experimental screening of these hydroxyphenyl- and methoxyphenyl-substituted PPNs, biocompatible nitrones 4d, and 4g-4i deriving from caffeic, gallic, ferulic and sinapic acids, which combined improved EPR probing of ROS formation, vasorelaxant action and antioxidant potency, might be potential drug candidate alternatives to PBN and its analogues.


Assuntos
Aorta/efeitos dos fármacos , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Óxido Nítrico/química , Óxidos de Nitrogênio/química , Óxidos de Nitrogênio/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Aorta/fisiologia , Compostos de Bifenilo/química , Bovinos , Linhagem Celular Tumoral , Radicais Livres/química , Interações Hidrofóbicas e Hidrofílicas , Óxido Nítrico/metabolismo , Fosforilação , Picratos/química , Carbonilação Proteica/efeitos dos fármacos , Ratos , Detecção de Spin , Superóxidos/química , Vasodilatação/efeitos dos fármacos
15.
Methods Mol Biol ; 1265: 135-47, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25634273

RESUMO

(31)P nuclear magnetic resonance (NMR) is a unique technique to monitor noninvasively the energetics of living systems at real time through the detection of a variety of phosphorylated metabolites. Using adequately designed α-aminophosphonates as external probes, we have shown earlier that (31)P NMR can also give access simultaneously to the accurate pH of cytosolic and acidic compartments in normal and stressed cultured cells or isolated perfused organs, a feature that was not possible using endogenous inorganic phosphate as the probe. More recently, we obtained a series of derivatives of these new pH probes that incorporate a triphenylphosphonium cation as a specific vector to the mitochondrion. Here, we describe the synthesis, (31)P NMR pH titrating properties in buffers, and application in cultures of the green alga Chlamydomonas reinhardtii of two of these mitochondria-targeted pH probes in comparison with one nonvectorized, yet still informative α-aminophosphonate.


Assuntos
Citosol/metabolismo , Concentração de Íons de Hidrogênio , Mitocôndrias/metabolismo , Ressonância Magnética Nuclear Biomolecular/métodos , Chlamydomonas reinhardtii/química , Chlamydomonas reinhardtii/metabolismo
16.
Nanotoxicology ; 9(6): 696-705, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25325158

RESUMO

The broad range of applications of cerium oxide (CeO2) nanoparticles (nano-CeO2) has attracted industrial interest, resulting in greater exposures to humans and environmental systems in the coming years. Their health effects and potential biological impacts need to be determined for risk assessment. The aims of this study were to gain insights into the molecular mechanisms underlying the genotoxic effects of nano-CeO2 in relation with their physicochemical properties. Primary human dermal fibroblasts were exposed to environmentally relevant doses of nano-CeO2 (mean diameter, 7 nm; dose range, 6 × 10(-5)-6 × 10(-3) g/l corresponding to a concentration range of 0.22-22 µM) and DNA damages at the chromosome level were evaluated by genetic toxicology tests and compared to that induced in cells exposed to micro-CeO2 particles (mean diameter, 320 nm) under the same conditions. For this purpose, cytokinesis-blocked micronucleus assay in association with immunofluorescence staining of centromere protein A in micronuclei were used to distinguish between induction of structural or numerical chromosome changes (i.e. clastogenicity or aneuploidy). The results provide the first evidence of a genotoxic effect of nano-CeO2, (while not significant with micro-CeO2) by a clastogenic mechanism. The implication of oxidative mechanisms in this genotoxic effect was investigated by (i) assessing the impact of catalase, a hydrogen peroxide inhibitor, and (ii) by measuring lipid peroxidation and glutathione status and their reversal by application of N-acetylcysteine, a precusor of glutathione synthesis in cells. The data are consistent with the implication of free radical-related mechanisms in the nano-CeO2-induced clastogenic effect, that can be modulated by inhibition of cellular hydrogen peroxide release.


Assuntos
Cério/toxicidade , Dano ao DNA , Fibroblastos/efeitos dos fármacos , Mutagênicos/toxicidade , Nanopartículas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Pele/efeitos dos fármacos , Células Cultivadas , Cério/química , Coloides , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Mutagênicos/química , Nanopartículas/química , Tamanho da Partícula , Cultura Primária de Células , Pele/metabolismo , Pele/patologia , Propriedades de Superfície
17.
Cardiovasc Pathol ; 23(6): 344-50, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25151067

RESUMO

We present here the results of our inter-disciplinary examination of the mummified heart of Blessed Anne-Madeleine Remuzat (1696-1730). This organ has been examined in the context of a canonization process. This analysis is related to important aspects of the early history of anatomy in Europe, that of "Holy autopsies", and to the relationship between anatomical investigations, Catholic theology, and religious/medical customs. According to anatomical, genetic, toxicological, and palynological analyses, it has been shown that this organ has not been naturally ("miraculously") conserved but embalmed using myrtle, honey, and lime. Moreover, a right ventricle dilatation has been diagnosed, that may represent a post-tuberculosis condition and may have played a role in the cause of death of this religious figure.


Assuntos
Catolicismo/história , Coração , Anatomia/história , Autopsia/história , DNA Mitocondrial/genética , DNA Mitocondrial/isolamento & purificação , Embalsamamento/história , Feminino , França , Coração/anatomia & histologia , Coração/diagnóstico por imagem , História do Século XVIII , Humanos , Múmias/história , Miocárdio/química , Pólen , Religião e Medicina , Tomografia Computadorizada por Raios X
18.
Phytother Res ; 28(10): 1423-46, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24831562

RESUMO

Many studies have shown that a large number of terpenoids and aromatic compounds contained in essential oils have significant anticancer activities, both on cell lines and on tumors in animals. The activity of these constituents is related to the activation of cell death (apoptosis) induced by the caspases proteins in cancer cells, with minor modifications of healthy cells. Many phenomena seem to occur, among which are as follows: overexpression and regulation of liver detoxification enzymes, changes in the membrane potential of cancer cells and mitochondria, production of free radicals in cancer cells, inhibition of angiogenesis, and modification of tumor-inducing genes. These active essential oil constituents appear to act synergistically with conventional chemotherapy and radiotherapy, and some clinical studies in humans are beginning to be realized. In this review, we discuss about the antitumoral activity of 13 essential oil components selected among the most studied in the literature, with a focus on their possible mode of action. We also report current data on the anticancer properties of several total essential oils.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Caspases/metabolismo , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sinergismo Farmacológico , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Potenciais da Membrana/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Neoplasias/patologia
19.
J Transl Med ; 12: 38, 2014 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-24507657

RESUMO

BACKGROUND: Although reperfusion injury has been shown to be responsible for cardiomyocytes death after an acute myocardial infarction, there is currently no drug on the market that reduces this type of injury. TRO40303 is a new cardioprotective compound that was shown to inhibit the opening of the mitochondrial permeability transition pore and reduce infarct size after ischemia-reperfusion in a rat model of cardiac ischemia-reperfusion injury. METHODS: In the rat model, the therapeutic window and the dose effect relationship were investigated in order to select the proper dose and design for clinical investigations. To evaluate post-ischemic functional recovery, TRO40303 was tested in a model of isolated rat heart. Additionally, TRO40303 was investigated in a Phase I randomized, double-blind, placebo controlled study to assess the safety, tolerability and pharmacokinetics of single intravenous ascending doses of the compound (0.5 to 13 mg/kg) in 72 healthy male, post-menopausal and hysterectomized female subjects at flow rates from 0.04 to 35 mL/min (EudraCT number: 2010-021453-39). This work was supported in part by the French Agence Nationale de la Recherche. RESULTS: In the vivo model, TRO40303 reduced infarct size by 40% at 1 mg/kg and by 50% at 3 and 10 mg/kg given by intravenous bolus and was only active when administered before reperfusion. Additionally, TRO40303 provided functional recovery and reduced oxidative stress in the isolated rat heart model.These results, together with pharmacokinetic based allometry to human and non-clinical toxicology data, were used to design the Phase I trial. All the tested doses and flow rates were well tolerated clinically. There were no serious adverse events reported. No relevant changes in vital signs, electrocardiogram parameters, laboratory tests or physical examinations were observed at any time in any dose group. Pharmacokinetics was linear up to 6 mg/kg and slightly ~1.5-fold, hyper-proportional from 6 to 13 mg/kg. CONCLUSIONS: These data demonstrated that TRO40303 can be safely administered by the intravenous route in humans at doses expected to be pharmacologically active. These results allowed evaluating the expected active dose in human at 6 mg/kg, used in a Phase II proof-of-concept study currently ongoing.


Assuntos
Infarto do Miocárdio/tratamento farmacológico , Oximas/efeitos adversos , Oximas/uso terapêutico , Secoesteroides/efeitos adversos , Secoesteroides/uso terapêutico , Animais , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Voluntários Saudáveis , Humanos , Técnicas In Vitro , Lipossomos , Masculino , Infarto do Miocárdio/sangue , Infarto do Miocárdio/complicações , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão Miocárdica/sangue , Traumatismo por Reperfusão Miocárdica/complicações , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/patologia , Estresse Oxidativo/efeitos dos fármacos , Oximas/sangue , Oximas/farmacologia , Ratos , Secoesteroides/sangue , Secoesteroides/farmacologia , Sus scrofa , Pesquisa Translacional Biomédica
20.
J Med Chem ; 56(6): 2487-99, 2013 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-23437893

RESUMO

A series of mitochondria targeted α-aminophosphonates combining a diethoxyphosphoryl group and an alkyl chain-connected triphenylphosphonium bromide tail were designed and synthesized, and their pH-sensitive (31)P NMR properties and biological activities in vitro and in vivo were evaluated. The results showed a number of these mito-aminophosphonates exhibiting pKa values fitting the mitochondrial pH range, short relaxation, and chemical shift parameters compatible with sensitive (31)P NMR detection, and low cytotoxicity on green algae and murine fibroblasts cell cultures. Of these, two selected compounds demonstrated to distribute at NMR detectable levels within the cytosolic and mitochondrial sites following their perfusion to isolated rat livers, with no detrimental effects on cell energetics and aerobic respiration. This study provided a new molecular scaffold for further development of in situ spectroscopic real-time monitoring of mitochondrion/cytosol pH gradients.


Assuntos
Mitocôndrias/química , Mitocôndrias/metabolismo , Organofosfonatos/síntese química , Organofosfonatos/metabolismo , Células 3T3 , Animais , Técnicas de Química Sintética , Chlamydomonas reinhardtii/efeitos dos fármacos , Citosol/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Fígado/citologia , Espectroscopia de Ressonância Magnética , Camundongos , Organofosfonatos/química , Organofosfonatos/toxicidade , Perfusão , Permeabilidade , Ratos
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