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1.
Food Chem ; 305: 125457, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505414

RESUMO

Taking into account a growing market and small number of articles related to honeydew honey, a metabolomic approach associated with multivariate analysis and modelling was proposed to discriminate five varieties of honey. Advanced analytical techniques were used for determination of 20 elements, 14 carbohydrates and stable carbon isotope ratio. No chemical marker has been found within sugar compounds, but several elements (Ba, Ca, Mg, Sr, Mn, Al, Co, Ni, Se) were marked as characteristic of honey type and allow classification of three botanical origins (Abies alba, Quercus frainetto, Quercus ilex). Sugars turanose, trehalose, arabinose and raffinose, elements Ba, Sr, P, Cd and Se, and δ13C values of honey, have different concentrations in honeys of the same botanical origin but harvested in different season. In addition to a confirmation of authenticity in terms of production, the values of δ13C of protein could be a good indicator of botanical origin.

2.
J Environ Manage ; 246: 63-70, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174031

RESUMO

Intensive use of pesticides requires innovative approaches for their removal from the environment. Here we report the method for degradation of dimethoate in water using non-thermal plasma needle and analyze kinetics of dimethoate removal and possible degradation pathways. The effects of dimethoate initial concentration, plasma treatment time, Argon flow rate and the presence of radical promoters on the effectiveness of proposed method are evaluated. With argon flow rate of 0.5 slm (standard litres per minute) 1 × 10-4 M dimethoate can be removed within 30 min of treatment. Using UPLC analysis it was confirmed that one of the decomposition products is dimethoate oxo-analogue omethoate, which is in fact more toxic than dimethoate. However, the overall toxicity of contaminated water was reduced upon the treatment. The addition of H2O2 as a free radical promoter enhances dimethoate removal, while K2S2O8 results with selective conversion to omethoate. Using mass spectrometry in combination with the theoretical calculations, possible degradation pathways were proposed. The feasibility of the proposed method for dimethoate degradation in real water samples is confirmed. The proposed method is demonstrated as a highly effective approach for dimethoate removal without significant accumulation of undesirable toxic products and secondary waste.


Assuntos
Dimetoato , Praguicidas , Peróxido de Hidrogênio , Cinética , Água
3.
Food Chem ; 274: 629-641, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30372988

RESUMO

Concerning the particular nutritive value of honeydew honey compared to blossom honey, and small number of studies defining botanical origin of honeydew honey, comprehensive analysis of phenolic profile of 64 honeydew honey samples of specific botanical origin was performed. Two advanced techniques of liquid chromatography hyphenated with mass spectrometry were used for identification of a total of 52 compounds and quantification of 25 of them. Pattern recognition analysis applied on data on phenolic compounds content confirmed that quercetin, naringenin, caffeoylquinic acid, hydroxyphenylacetic acid, apigenin and genistein, could be considered as potential markers of botanical origin of honeydew honey. Spectroscopic and electrochemical approaches were applied for the evaluation of the antioxidant capacity. Quercus sps. samples, Quercus frainetto and Quercus ilex, showed high biological activity and specific chemical composition. Additionally, cyclic voltammetry profiles were used for characterization and natural clustering of honeydew honey for the first time.


Assuntos
Antioxidantes/química , Mel/análise , Fenóis/análise , Quercus/química , Cromatografia Líquida de Alta Pressão , Análise por Conglomerados , Técnicas Eletroquímicas , Espectrometria de Massas , Valor Nutritivo , Análise de Componente Principal , Quercus/metabolismo
4.
Food Chem ; 271: 469-478, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30236704

RESUMO

UV-C irradiation is widely used in the food industry. However, the health effects from dietary exposure to the irradiated pesticide residues retained in foodstuffs are underestimated. In this study, technical chlorpyrifos (TCPF) and its oil in water (EW) and emulsifiable concentrate (EC) formulations were irradiated by UV-C, and their photodegradation products were subjected to toxicity assessment, including determination of acetylcholinesterase (AChE) activity, genotoxicity and oxidative stress using human blood cells as a model system. Toxicity studies were performed using the chlorpyrifos concentrations in the range of those proposed as the maximum residue levels in plant commodities. TCPF, EW and EC photodegradation products induced DNA damage and oxidative stress, and their genotoxicity did not decrease as a function of irradiation time. Irradiated TCPF and EC are more potent AChE inhibitors than irradiated EW. Accordingly, the application of UV-C irradiation must be considered when processing the plants previously treated with chlorpyrifos formulations.


Assuntos
Clorpirifos/efeitos da radiação , Clorpirifos/toxicidade , Raios Ultravioleta , Acetilcolinesterase , Inibidores da Colinesterase , Humanos , Inseticidas/efeitos da radiação , Inseticidas/toxicidade , Estresse Oxidativo
5.
Metallomics ; 10(7): 1003-1015, 2018 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-29978878

RESUMO

The present paper deals with investigation of the interaction between selected simple structure Au(iii) ([AuCl4]-, [AuCl2(dmso)2]+, [AuCl2(bipy)]+) and Pt(ii) ([PtCl2(dmso)2]) complexes with Na/K-ATPase as the target enzyme, using an experimental and theoretical approach. Reaction stoichiometries and binding constants for these enzyme/complex systems were determined, while kinetic measurements were used in order to reveal the type of inhibition. Based on the results obtained by quantum mechanical calculations (electrostatic surface potential (ESP), volume and surface of the complexes) the nature of the investigated complexes was characterized. By using the solvent accessible surface area (SASA) applied on specific inhibitory sites (ion channel and intracellular domains) the nature of these sites was described. Docking studies were used to determine the theoretical probability of the non-covalent metal binding site positions. Inhibition studies implied that all the investigated complexes decreased the activity of the enzyme while the kinetic analysis indicated an uncompetitive mode of inhibition for the selected complexes. Docking results suggested that the main inhibitory site of all these complexes is located in the ion translocation pathway on the extracellular side in the E2P enzyme conformation, similar to the case of cardiac glycosides, specific Na/K-ATPase inhibitors. Also, based on our knowledge, the hydrolyzed forms of [AuCl4]- and [PtCl2(dmso)2] complexes were investigated for the first time by theoretical calculations in this paper. Thereby, a new inhibitory site situated between the M2 and M4 helices was revealed. Binding in this site induces conformational changes in the enzyme domains and perturbs the E1-E2P conformational equilibrium, causing enzyme inhibition.

6.
J Biol Inorg Chem ; 23(5): 689-704, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29644470

RESUMO

In recent years, the search for effective anticancer compounds based on transition metal complexes has been the focus of medical investigations. The synergy between the ruthenium(II) and N-alkylphenothiazine counter-ions (chlorpromazine hydrochloride, thioridazine hydrochloride and trifluoperazine dihydrochloride, respectively) through the formation of three different complexes (1-3) was investigated. We explored whether the selected counter-ions and complexes might affect redox homeostasis and genome integrity of normal human blood cells, and induce an inhibition of Na+/K+-ATPase and AChE at pharmacologically relevant doses. Our results have shown that counter-ions and complexes did not affect the activity of Na+/K+-ATPase, while AChE activity was inhibited in a dose-dependent manner. All investigated compounds disturbed the viability and redox homeostasis of lymphocytes. Complexes 1 and 2 displayed potent cytotoxic and prooxidant action while complex 3 behaved as a weaker genotoxic inducer. Still, the tested complexes appeared to be less genotoxic and more cytostatic than the corresponding counter-ions. The effects of selected complexes were also tested in PC12 and U2OS cancer cells with special attention being given to the ability of phenothiazines to affect dopamine D2 receptors. Using the confocal laser scanning microscopy, we observed that all the complexes reduced cell viability. Although all investigated complexes have been bound to the dopamine receptor D2-eGFP, only complex 3 reduced its surface density and increased its lateral mobility in investigated cell lines. Albeit the role of alternative targets for complex 3 cannot be ruled out, its effects should be further examined as potential treatment strategy against cancer cells that overexpress D2.

7.
Curr Med Chem ; 25(3): 324-335, 2018 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-28595554

RESUMO

BACKGROUND: Sulphur is an abundant element in biological systems, which plays an important role in processes essential for life as a constituent of proteins, vitamins and other crucial biomolecules. The major source of sulphur for humans is plants being able to use inorganic sulphur in the purpose of sulphur-containing amino acids synthesis. Sulphur-containing amino acids include methionine, cysteine, homocysteine, and taurine. Methionine and cysteine are classified as proteinogenic, canonic amino acids incorporated in protein structure. Sulphur amino acids are involved in the synthesis of intracellular antioxidants such as glutathione and N-acetyl cysteine. Moreover, naturally occurring sulphur-containing ligands are effective and safe detoxifying agents, often used in order to prevent toxic metal ions effects and their accumulation in human body. METHODS: Literature search for peer-reviewed articles was performed using PubMed and Scopus databases, and utilizing appropriate keywords. RESULTS: This review is focused on sulphur-containing amino acids - methionine, cysteine, taurine, and their derivatives - glutathione and N-acetylcysteine, and their defense effects as antioxidant agents against free radicals. Additionally, the protective effects of sulphur-containing ligands against the toxic effects of heavy and transition metal ions, and their reactivation role towards the enzyme inhibition are described. CONCLUSION: Sulphur-containing amino acids represent a powerful part of cell antioxidant system. Thus, they are essential in the maintenance of normal cellular functions and health. In addition to their worthy antioxidant action, sulphur-containing amino acids may offer a chelating site for heavy metals. Accordingly, they may be supplemented during chelating therapy, providing beneficial effects in eliminating toxic metals.


Assuntos
Aminoácidos/farmacologia , Antioxidantes/farmacologia , Radicais Livres/antagonistas & inibidores , Metais Pesados/antagonistas & inibidores , Enxofre/farmacologia , Animais , Humanos
8.
Curr Med Chem ; 24(30): 3283-3309, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28685687

RESUMO

BACKGROUND: Acetylcholinesterase (AChE) is involved in the termination of impulse transmission by rapid hydrolysis of the neurotransmitter acetylcholine in numerous cholinergic pathways in the central and peripheral nervous systems. The enzyme inactivation leads to acetylcholine accumulation, hyperstimulation of nicotinic and muscarinic receptors, and disrupted neurotransmission. Hence, acetylcholinesterase inhibitors, interacting with the enzyme as their primary target, are applied as relevant drugs for different neurodegenerative diseases (such as Alzheimer's and Parkinson's) as well as toxins. At the same time, there are increasing evidence that in non-neuronal context, AChE is involved in the regulation of cell proliferation, differentiation, apoptosis and cell-cell interaction. An irregular expression of AChE has been found in different types of tumors, suggesting the involvement of AChE in the regulation of tumor development. Having all this in mind, there is a possibility that some AChE inhibitors could be used as anti-cancer agents. OBJECTIVE: This contribution will discuss a broad range of possible application of different AChE inhibitors as drugs, from well-known anti-Alzheimer's disease drugs to their use in cancer treatment in future. Emphasis will be put on various known AChE inhibitors classes, whose application as drugs could be controversy, as well as on newly investigated natural products, which can also modulate AChE activity. CONCLUSION: It is not clear a patient treated for neurodegenerative condition prone to increased risk for some types of cancer and vice versa. This is necessary to keep in mind during rational drug design process for all therapies, which are based on AChE as a target molecule.


Assuntos
Acetilcolinesterase/metabolismo , Doença de Alzheimer/tratamento farmacológico , Inibidores da Colinesterase/uso terapêutico , Neoplasias/tratamento farmacológico , Acetilcolinesterase/química , Doença de Alzheimer/metabolismo , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Produtos Biológicos/uso terapêutico , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Desenho de Drogas , Humanos , Neoplasias/metabolismo , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/metabolismo
9.
J Biol Inorg Chem ; 22(6): 819-832, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28432453

RESUMO

The in vitro effects of oxo-bridged binuclear gold(III) complexes, i.e., [(bipy2Me)2Au2(µ-O)2][PF6]2 (Auoxo6), Au2[(bipydmb-H)2(µ-O)][PF6] (Au2bipyC) and [Au2(phen2Me)2(µ-O)2](PF6)2 (Au2phen) on Na/K-ATPase, purified from the porcine cerebral cortex, were investigated. All three studied gold complexes inhibited the enzyme activity in a concentration-dependent manner achieving IC50 values in the low micromolar range. Kinetic analysis suggested an uncompetitive mode of inhibition for Auoxo6 and Au2bipyC, and a mixed type one for Au2phen. Docking studies indicated that the inhibitory actions of all tested complexes are related to E2-P enzyme conformation binding to ion channel and intracellular part between N and P sub-domain. In addition, Au2phen was able to inhibit the enzyme by interacting with its extracellular part as well. Toxic effects of the gold(III) complexes were evaluated in vitro by following lactate dehydrogenase activity in rat brain synaptosomes and incidence of micronuclei and cytokinesis-block proliferation index in cultivated human lymphocytes. All investigated complexes turned out to induce cytogenetic damage consisting of a significant decrease in cell proliferation and an increase in micronuclei in a dose-dependent manner. On the other hand, lactate dehydrogenase activity, an indicator of membrane integrity/viability, was not affected by Auoxo6 and Au2bipyC, while Au2phen slightly modified its activity.


Assuntos
Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Ouro/química , Compostos Organometálicos/química , Compostos Organometálicos/farmacologia , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Adulto , Inibidores Enzimáticos/efeitos adversos , Inibidores Enzimáticos/metabolismo , Humanos , Cinética , Masculino , Simulação de Acoplamento Molecular , Compostos Organometálicos/efeitos adversos , Compostos Organometálicos/metabolismo , Conformação Proteica , ATPase Trocadora de Sódio-Potássio/química , ATPase Trocadora de Sódio-Potássio/metabolismo , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/metabolismo
10.
Arh Hig Rada Toksikol ; 68(1): 1-8, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28365670

RESUMO

Undecylprodigiosin pigment (UPP) is reported to display cytotoxic activity towards various types of tumours. Nevertheless, its efficacy in modifying the cellular response to ionising radiation is still unknown. In this study, the radiomodulating effects of UPP were investigated. The effects of UPP were assessed in vitro by treating cultures of human peripheral blood with UPP and ionising radiation using two treatment regimens, the UPP pre-irradiation treatment and UPP post-irradiation treatment. The activity of UPP was investigated evaluating its effects on the radiation-induced micronuclei formation, cell proliferation, and induction of apoptosis. The redox modulating effects of UPP were examined measuring the catalase activity and the level of malondialdehyde, as a measure of oxidative stress. The results showed that UPP effects on cellular response to ionising radiation depend on its concentration and the timing of its administration. At low concentration, the UPP displayed radioprotective effects in γ-irradiated human lymphocytes while at higher concentrations, it acted as a radiosensitiser enhancing either mitotic catastrophe or apoptosis depending on the treatment regimen. The UPP modified redox processes in cells, particularly when it was employed prior to γ-irradiation. Our data highlight the importance of further research of the potential of UPP to sensitize tumour cells to radiation therapy by inhibiting pathways that lead to treatment resistance.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Neoplasias/radioterapia , Prodigiosina/toxicidade , Radioterapia/efeitos adversos , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/efeitos da radiação , Adulto , Relação Dose-Resposta a Droga , Humanos , Masculino , Fatores de Tempo
11.
Metallomics ; 9(3): 292-300, 2017 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-28181616

RESUMO

Na/K-ATPase is emerging as an important target for a variety of anticancer metal-based drugs. The interactions of Na/K-ATPase (in its E1 state) with three representative and structurally related cytotoxic gold(iii) complexes, i.e. [Au(bipy)(OH)2][PF6], bipy = 2,2'-bipyridine; [Au(pydmb-H)(CH3COO)2], pydmb-H = deprotonated 6-(1,1-dimethylbenzyl)-pyridine and [Au(bipydmb-H)(OH)][PF6], bipyc-H = deprotonated 6-(1,1-dimethylbenzyl)-2,2'-bipyridine, are investigated here in depth using a variety of spectroscopic methods, in combination with docking studies. Detailed information is gained on the conformational and structural changes experienced by the enzyme upon binding of these gold(iii) complexes. The quenching constants of intrinsic enzyme fluorescence, the fraction of Trp residues accessible to gold(iii) complexes and the reaction stoichiometries were determined in various cases. Specific hypotheses are made concerning the binding mode of these gold(iii) complexes to the enzyme and the likely binding sites. Differences in their binding behaviour toward Na/K-ATPase are explained on the ground of their distinctive structural features. The present results offer further support to the view that Na/K-ATPase may be a relevant biomolecular target for cytotoxic gold(iii) compounds of medicinal interest and may thus be involved in their overall mode of action.


Assuntos
Antineoplásicos/química , Antineoplásicos/metabolismo , Compostos de Ouro/química , Compostos de Ouro/metabolismo , ATPase Trocadora de Sódio-Potássio/química , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Sítios de Ligação , Simulação de Acoplamento Molecular , Conformação Proteica , Espectrofotometria Ultravioleta , Suínos
12.
Exp Toxicol Pathol ; 69(1): 55-62, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27843060

RESUMO

It is known that some bacterial species are more resilient to different kinds of irradiation due to the naturally developed protective mechanisms and compounds such as pigments. On the other hand, reasoned tissue engineering using plasma remains a critical task and requires very precise control of plasma parameters in order to mitigate its potential detrimental effects. Here we isolated a natural protective agent, microbially produced undecylprodigiosin ((5'Z)-4'-methoxy-5'-[(5-undecyl-1H-pyrrol-2-yl)methylene]-1H,5'H-2,2'-bipyrrole), and investigated its effects on human blood cells independently and in combination with plasma. Two approaches were applied; the first, undecylprodigiosin (UP pigment) was added to the blood cultures, which then were exposed to plasma (pre-treatment); and the second- the blood cultures were exposed to plasma and then treated with pigment (post-treatment). The interactions of plasma and UP pigment with blood cells were investigated by conducting a series of biological tests providing the information regarding their genotoxicity, cytotoxicity and redox modulating activities. The exposure of cells to plasma induced oxidative stress as well as certain genotoxic and cytotoxic effects seen as elevated micronuclei incidence, decreased cell proliferation and enhanced apoptosis. In blood cultures treated with UP pigment alone, we found that both cytotoxic and protective effects could be induced depending on the concentration used. The highest UP pigment concentration increased lipid peroxidation and the incidence of micronuclei by more than 70% with maximal suppression of cell proliferation. On the contrary, we found that the lowest UP pigment concentration displayed protective effects. In combined treatments with plasma and UP pigment, we found that UP pigment could provide spatial shielding to plasma exposure. In the pre-treatment approach, the incidence of micronuclei was reduced by 35.52% compared to control while malondialdehyde level decreased by 36% indicating a significant mitigation of membrane damage induced by plasma. These results open perspectives for utilizing UP pigment for protection against overexposures in the field of plasma medicine.


Assuntos
Antioxidantes/farmacologia , Células Sanguíneas/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Prodigiosina/análogos & derivados , Protetores contra Radiação/farmacologia , Células Sanguíneas/efeitos da radiação , Dano ao DNA/efeitos dos fármacos , Humanos , Técnicas In Vitro , Peroxidação de Lipídeos/efeitos dos fármacos , Prodigiosina/farmacologia
13.
J Inorg Biochem ; 161: 27-36, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27235271

RESUMO

In vitro influence of five synthesized functionalized hexavanadates (V6) on commercial porcine cerebral cortex Na(+)/K(+)-ATPase activity has been studied. Dose dependent Na(+)/K(+)-ATPase inhibition was obtained for all investigated compounds. Calculated half maximal inhibitory concentration IC50 values, in mol/L, for Na(+)/K(+)-ATPase were 7.6×10(-5), 1.8×10(-5), 2.9×10(-5), 5.5×10(-5) for functionalized hexavanadates (V6) with tetrabutylammonium (TBA) [V6-CH3][TBA]2, [V6-NO2][TBA]2, [V6-OH][TBA]2 and [V6-C3][TBA]2 respectively. [V6-OH][Na]2 inhibited Na(+)/K(+)-ATPase activity up to 30% at maximal investigated concentration 1×10(-3)mol/L. This reactivity has been interpreted using a study of the non-covalent interactions of functionalized hexavanadate hybrids through Cambridge Structural Database (CSD) analysis. Bibliographic searching has led to 18 different structures and 99 contacts. We have observed that C-H⋯O contacts consolidate the structures. We have also performed density functional theory (DFT) calculations and have determined electrostatic potential values at the molecular surface on a series of functionalized V6. These results enlightened their chemical reactivity and their potential biological applications such as the inhibition of the ATPase.


Assuntos
Inibidores Enzimáticos , ATPase Trocadora de Sódio-Potássio , Vanadatos , Animais , Cristalografia por Raios X , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , ATPase Trocadora de Sódio-Potássio/química , Suínos , Vanadatos/síntese química , Vanadatos/química
14.
Curr Drug Metab ; 16(3): 168-90, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26279325

RESUMO

Myeloperoxidase (MPO) is an important member of the haem peroxidase - cyclooxygenase superfamily. This enzyme is physiologically expressed in circulating neutrophils, monocytes and some tissue macrophages including microglia. MPO plays an essential role in the antimicrobial and antiviral system of humans. The microbicidal activity of MPO exists due to its capability to oxidize halide and pseudohalide ions (CI(-), Br(-), I(-) and SCN(-)) by H2O2, thereby producing respective hypohalous acids (HOX). During the phagocytosis of pathogens, azurophilic granules release their content together with MPO into phagolysosomes. On the other hand, MPO can be discharged outside the phagocytes. Due to this, tissue damage during inflammation is greatly promoted by MPO-derived oxidants. Regarding its activity, MPO is a key factor in a great number of conditions within the group of cardiovascular diseases, inflammatory diseases, neurodegenerative diseases, kidney diseases and immune-mediated diseases. Therefore, MPO and its downstream inflammatory pathways might be attractive targets for both prognostic and therapeutic intervention in the prophylaxis of all mentioned illnesses. Nowadays, structure and reaction mechanism of MPO are known, which enable rational strategy in the development of specific MPO inhibitors that still preserve MPO activity during host defense from bacteria, but hinder pathophysiologically persistent activation of MPO. Various methods for MPO activity inhibition and unfavorable effects of MPO-derived oxidants remodeling will be discussed. Emphasis will be put on various known inhibitors, as well as on newly investigated natural products, which can also inhibit MPO activity.


Assuntos
Inibidores Enzimáticos/farmacologia , Peroxidase/antagonistas & inibidores , Biomarcadores , Inibidores Enzimáticos/química , Modelos Moleculares , Peroxidase/metabolismo , Conformação Proteica
15.
Toxicol Lett ; 233(1): 29-37, 2015 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-25562544

RESUMO

Although primary toxic action of organophosphorous insecticides is associated with acetylcholinesterase inhibition, later studies suggest that oxidative stress may be responsible for induced organophosphates toxicity. These studies mostly include thio forms, while the effects of their metabolites/degradation products have been less investigated. Therefore, this paper studies the toxic effects of diazinon degradation products, diazoxon and 2-isopropyl-6-methyl-4-pyrimidinol, and compares them with the toxic potential of the parent compound. The toxicity induced by various concentrations of the investigated compounds was in vitro evaluated by the activities of acetylcholinesterase, ATPases, antioxidant defense enzymes and lactate dehydrogenase, and malondialdehyde level in rat brain synaptosomes. Diazinon inhibited acetylcholinesterase and Na(+)/K(+)-ATPase in dose-dependent manner, while the inhibition of ecto-ATPase activity was less than 15% at all investigated concentrations. It did not demonstrate noteworthy prooxidative properties causing increase (up to 10%) in antioxidant enzymes activity and malondialdehyde level, as a marker of lipid peroxidation. Diazinon oxidation product, diazoxon was found as the most toxic investigated compound. Beside the expected strong inhibitory effect on acetylcholinesterase, it induced dose-dependent and almost complete inhibition of Na(+)/K(+)-ATPase and ecto-ATPase at the highest investigated concentration (0.1mM). Increasing diazoxon concentrations activated catalase (up to 30%), superoxide dismutase (up to 50%), glutathione peroxidase (up to 30%), and significantly increased malondialdehyde level (up to 50%). The investigated hydrolysis product of diazinon, 2-isopropyl-6-methyl-4-pyrimidinol did not remarkably alter the activities of acetylcholinesterase, Na(+)/K(+)-ATPase, catalase, glutathione peroxidase and lipid peroxidation level (up to about 10%). Although this diazinon metabolite has been known as non toxic, it induced superoxide dismutase stimulation up to 30%. Finally, even high concentrations of both diazinon and its metabolites did noticeably affect lactate dehydrogenase activity as a marker of synaptosomal integrity. The changes in investigated biochemical parameters in rat brain synaptosomes could serve as indicators of toxicity due to the exposure to thio organophosphates and/or their break-down products.


Assuntos
Encéfalo/efeitos dos fármacos , Diazinon/toxicidade , Síndromes Neurotóxicas/patologia , Estresse Oxidativo/efeitos dos fármacos , Sinaptossomos/efeitos dos fármacos , Acetilcolinesterase/metabolismo , Adenosina Trifosfatases/antagonistas & inibidores , Adenosina Trifosfatases/metabolismo , Animais , Encéfalo/metabolismo , Catalase/metabolismo , Inibidores da Colinesterase/toxicidade , Relação Dose-Resposta a Droga , Glutationa Peroxidase/metabolismo , Inseticidas/toxicidade , L-Lactato Desidrogenase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Malondialdeído/metabolismo , Compostos Organofosforados/toxicidade , Pirimidinas/toxicidade , Ratos , Ratos Wistar , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , ATPase Trocadora de Sódio-Potássio/metabolismo , Superóxido Dismutase/metabolismo , Sinaptossomos/metabolismo
16.
J Med Biochem ; 34(2): 215-222, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28356834

RESUMO

BACKGROUND: Cortical stab injury (CSI) induces changes in the activity, expression and cellular distribution of specific ectonucleotidases at the injury site. Also, several experimentally induced neuropathologies are associated with changes in soluble ectonucleotidase activities in the plasma and serum, whilst various insults to the brain alter purine compounds levels in cerebrospinal fluid, but also in serum, indicating that insults to the brain may induce alterations in nucleotides release and rate of their hydrolysis in the vascular system. Since adenine nucleotides and adenosine regulate diverse cellular functions in the vascular system, including vascular tone, platelet aggregation and inflammatory responses of lymphocytes and macrophages, alterations of ectonucleotidase activities in the vascular system may be relevant for the clinical outcome of the primary insult. METHODS: We explored ectonucleotidase activities using specific enzyme assays and determined adenine nucleotides concentrations by the UPLC method in the rat serum after cortical stab injury. RESULTS: At 4-h post-injury, ATP and AMP hydrolysis increased by about 60% and 40%, respectively, while phosphodiesterase activity remained unchanged. Also, at 4-h post-injury a marked decrease in ATP concentration and more than 2-fold increase in AMP concentration were recorded. CONCLUSIONS: CSI induces rapid up-regulation of nucleotide catabolizing soluble ectonucleotidases in rat serum, which leads to the observed shift in serum nucleotide levels. The results obtained imply that ectonucleotidases and adenine nucleotides participate in the communication between the brain and the vascular system in physiological and pathological conditions and thereby may be involved in the development of various human neuropathologies.

17.
J Inorg Biochem ; 140: 228-35, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25173578

RESUMO

Na(+)/K(+)-ATPase is in charge of maintaining the ionic and osmotic intracellular balance by using ATP as an energy source to drive excess Na(+) ions out of the cell in exchange for K(+) ions. We explored whether three representative cytotoxic gold(III) compounds might interfere with Na(+)/K(+)-ATPase and cause its inhibition at pharmacologically relevant concentrations. The tested complexes were [Au(bipy)(OH)2][PF6] (bipy=2,2'-bipyridine), [Au(py(dmb)-H)(CH3COO)2] (py(dmb)-H=deprotonated 6-(1,1-dimethylbenzyl)-pyridine), and [Au(bipy(dmb)-H)(OH)][PF6] (bipy(dmb)-H=deprotonated 6-(1,1-dimethylbenzyl)-2,2'-bipyridine). We found that all of them caused a pronounced and similar inhibition of Na(+)/K(+)-ATPase activity. Inhibition was found to be non-competitive and reversible. Remarkably, treatment with cysteine resulted in reversal or prevention of Na(+)/K(+)-ATPase inhibition. It is very likely that the described effects may contribute to the overall cytotoxic profile of these gold complexes.


Assuntos
Antineoplásicos/farmacologia , Ouro/química , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Antineoplásicos/química , Humanos , Técnicas In Vitro , Cinética , Linfócitos/efeitos dos fármacos , Masculino , Testes para Micronúcleos , Espectrofotometria Ultravioleta
18.
Mol Cell Endocrinol ; 388(1-2): 58-68, 2014 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-24662727

RESUMO

In this study the in vivo effects of estradiol in regulating Na(+)/K(+)-ATPase function in rat heart was studied. Adult male Wistar rats were treated with estradiol (40µg/kg, i.p.) and after 24h the animals were sacrificed and the heart excised. Following estradiol administration, cardiac Na(+)/K(+)-ATPase activity, expression of the α1 subunit, and phosphorylation of the α1 subunit were significantly increased. These animals also had significantly decreased levels of digoxin-like immunoreactive factor(s). Na(+) levels were also significantly reduced but to a level that was still within the normal physiological range, highlighting the ability of the Na(+)/K(+)-ATPase to balance the ionic composition following treatment with estradiol. Estradiol treated rats also showed increased phosphorylation of protein kinase B (Akt), and extracellular-signal-regulated kinase 1/2 (ERK1/2). We therefore suggest a role for Akt and/or ERK1/2 in estradiol-mediated regulation of cardiac Na(+)/K(+)-ATPase expression and activity in rat heart.


Assuntos
Estradiol/fisiologia , Miocárdio/enzimologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Cardenolídeos/sangue , Membrana Celular/enzimologia , Colesterol/sangue , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Expressão Gênica , Masculino , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-jun/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Ratos Wistar , Saponinas/sangue , Transdução de Sinais , ATPase Trocadora de Sódio-Potássio/genética
19.
Curr Neuropharmacol ; 11(3): 315-35, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-24179466

RESUMO

Acetylcholinesterase is involved in the termination of impulse transmission by rapid hydrolysis of the neurotransmitter acetylcholine in numerous cholinergic pathways in the central and peripheral nervous systems. The enzyme inactivation, induced by various inhibitors, leads to acetylcholine accumulation, hyperstimulation of nicotinic and muscarinic receptors, and disrupted neurotransmission. Hence, acetylcholinesterase inhibitors, interacting with the enzyme as their primary target, are applied as relevant drugs and toxins. This review presents an overview of toxicology and pharmacology of reversible and irreversible acetylcholinesterase inactivating compounds. In the case of reversible inhibitors being commonly applied in neurodegenerative disorders treatment, special attention is paid to currently approved drugs (donepezil, rivastigmine and galantamine) in the pharmacotherapy of Alzheimer's disease, and toxic carbamates used as pesticides. Subsequently, mechanism of irreversible acetylcholinesterase inhibition induced by organophosphorus compounds (insecticides and nerve agents), and their specific and nonspecific toxic effects are described, as well as irreversible inhibitors having pharmacological implementation. In addition, the pharmacological treatment of intoxication caused by organophosphates is presented, with emphasis on oxime reactivators of the inhibited enzyme activity administering as causal drugs after the poisoning. Besides, organophosphorus and carbamate insecticides can be detoxified in mammals through enzymatic hydrolysis before they reach targets in the nervous system. Carboxylesterases most effectively decompose carbamates, whereas the most successful route of organophosphates detoxification is their degradation by corresponding phosphotriesterases.

20.
J Inorg Biochem ; 124: 35-41, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23591145

RESUMO

The in vitro influence of gold(III) complexes, H[AuCl4], [Au(DMSO)2Cl2]Cl and [Au(bipy)Cl2]Cl (bipy = 2,2'-bipyridine), upon commercially available Na(+)/K(+) ATPase activity, purified from porcine brain cortex, was investigated. Additionally, the complexes were tested on human lymphocytes, and incidence of micronuclei and cell proliferation index was determined. Concentration-dependent inhibition of the enzyme for all three compounds was obtained, but with differing potencies. Calculated IC50 from Hill analysis were (in M): 5.75×10(-7), 5.50×10(-6) and 3.98×10(-5), for H[AuCl4], [Au(DMSO)2Cl2]Cl and [Au(bipy)Cl2]Cl, respectively, while Hill coefficient values, n, were above 1 in all cases. This inhibition can be prevented using -SH donating ligands such as L-Cys and glutathione, and these ligands can also cause a recovery of the enzyme activity after the induced inhibition. Kinetic analysis demonstrated that each of the studied gold(III) complexes affects Na(+)/K(+) ATPase reducing maximum enzymatic velocity, Vmax, but not significantly changing the affinity for the substrate (KM value), implying a noncompetitive mode of the interaction. Furthermore, among investigated gold(III) complexes, the [Au(bipy)Cl2]Cl complex exhibits a strong cytotoxic effect on human lymphocytes, which suggests its potential for use in antitumor therapy.


Assuntos
Proliferação de Células/efeitos dos fármacos , Citotoxinas/farmacologia , Compostos de Ouro/farmacologia , Linfócitos/enzimologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Células Cultivadas , Feminino , Humanos , Linfócitos/citologia , Masculino , Suínos
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