copper oxide
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Genotoxická aktivita dvojjadrových [Cu2(RCOO)4(N-oxide)2] komplexov (R = 2-chlórfenoxymetyl) bola testovaná voči kmeňom Salmonella typhimurium (TA97, TA100 a TA102) Amesovou metódou in vitro a porovnávaná s aktivitou volných N-oxidov - 4-nitrochinolín-N-oxidom, 4-nitropyridín-N-oxidom a 2-metyl-4-nitropyridín-N-oxidom. Komplexáciou 4-nitrochinolín-N-oxidu s bis(2-chlórfenoxyacetáto)meďnatým fragmentom bol redukovaný jeho mutagénny účinok (9-krát, vzťahované na obsah N-oxidu). V prípade 4-nitropyridín-N-oxidu, 2-metyl-4-mtropyridín-N-oxidu a ich bis(N-oxid)-tetrakis (2-chlórfenoxyacetáto)mednatých komplexov nebol tento fenomén pozorovaný.
Using Ames method in vitro, the genotoxic activity of binuclear [Cu2(RCOO)4(N-oxide)2] complexes (R = 2-chlorophenoxymethyl) was tested against the strains of Salmonella typhimurium (TA97, TA100 and TA102) and compared to that of the free N-oxides - 4-nitroquinoline N-oxide, 4-nitropyridine N-oxide and 2-methyl-4-mtiopyridine N-oxide. Complexation of 4-nitroquinohne N-oxide with bisC2-chlorophenoxyacetato)copper(II) fragment reduced its mutagenic effect (9-times, correlated with N-oxide content). In the case of 4-nitropyridine N-oxide, 2-methyl-4-nitropyridine N-oxide and their bis(N-oxide)tetrakis(2-chlorophenoxyacetato)copper(II) complexes this phenomenon was not observed.
- MeSH
- 4-nitrochinolin-1-oxid aplikace a dávkování MeSH
- chlorfenoly analogy a deriváty aplikace a dávkování MeSH
- měď analogy a deriváty aplikace a dávkování MeSH
- organokovové sloučeniny aplikace a dávkování MeSH
- Salmonella typhimurium MeSH
- techniky in vitro MeSH
- testy genotoxicity MeSH
- testy toxicity MeSH
In parallel to technological advances and ever-increasing use of nanoparticles in industry, agriculture and consumer products, the potential ecotoxicity of nanoparticles and their potential accumulation in ecosystems is of increasing concern. Because scientific reports raise a concern regarding nanoparticle toxicity to plants, understanding of their bioaccumulation has become critical and demands more research. Here, the synthesis of isotopically-labeled nanoparticles of silver, copper and zinc oxide is reported; it is demonstrated that while maintaining the basic properties of the same unlabeled ("regular") nanoparticles, labeled nanoparticles enable more sensitive tracing of nanoparticles within plants that have background elemental levels. This technique is particularly useful for working with elements that are present in high abundance in natural environments. As a benchmark, labeled and unlabeled metal nanoparticles (Ag-NP, Cu-NP, ZnO-NP) were synthesized and compared, and then exposed in a series of growth experiments to Arabidopsis thaliana; the NPs were traced in different parts of the plant. All of the synthesized nanoparticles were characterized by TEM, EDS, DLS, ζ-potential and single particle ICP-MS, which provided essential information regarding size, composition, morphology and surface charge of nanoparticles, as well as their stability in suspensions. Tracing studies with A. thaliana showed uptake/retention of nanoparticles that is more significant in roots than in shoots. Single particle ICP-MS, and scanning electron micrographs and EDS of plant roots showed presence of Ag-NPs in particular, localized areas, whereas copper and zinc were found to be distributed over the root tissues, but not as nanoparticles. Thus, nanoparticles in any natural matrix can be replaced easily by their labeled counterparts to trace the accumulation or retention of NPs. Isotopically-labeled nanoparticles enable acquisition of specific results, even if there are some concentrations of the same elements that originate from other (natural or anthropogenic) sources.
Druhá část sdělení o problematice stopových prvků v kritických stavech je věnována mědi a selenu. Kuprémie po krátkém poklesu po traumatu stejně jako u systémové infekce stoupá. Ceruloplasmin, na který je v plazmě vázána, je reaktantem akutní fáze. Deficit mědi vyžadující úhradu vzniká při rozsáhlých popálených plochách, ztrátách sekretů zažívacího traktu a negativní bilanci při hemodialýze. Protože je měď nezbytná pro utilizaci železa při tvorbě transferinu a hemoglobinu, vede její nedostatek k hypochromní anémii. Je uvedeno doporučené dávkování mědi při výše uvedených ztrátách. Selen má řadu funkcí významných pro přežití kritických stavů, mezi které patří ochrana před organickými peroxidy, přeměna tyroxinu v aktivní trijodtyronin, zlepšení odpovědí na glukokortikoidy, kontrola glykémie, inhibice adhezních molekul a vliv na funkci T lymfocytů. Selenémie je při systémovém zánětu snížená a s tíží stavu (např. s rozvojem sepse) progresivně dále klesá. Práce referuje o řadě klinických pokusů se suplementací různě vysokých dávek selenu, podávaných maximálně po dobu dvou týdnů. Mortalita významně klesla zatím v jen jednom rozsáhlém klinickém pokusu, mezi dalšími jednotlivě uváděnými pozitivními výsledky jsou např. zlepšení skóre víceorgánové dysfunkce (SOFA), úprava nízkých hodnot cholesterolu, prealbuminu, glutathionperoxidázy, pokles C-reaktivního proteinu. Jsou diskutovány optimální terapeutické dávky. Pro měď i selen jsou uvedeny i toxické projevy předávkování, které se samy mohou stát příčinou kritických stavů.
The second part of the communication on the issue of trace elements in critically ill patients is devoted to copper and selenium. After a short decrease in trauma, as well as in systemic inflammation, plasmatic level of copper increases. The copper is bound on ceruloplasmin, which is an acute phase reactant. Copper deficiency requiring substitution occurs in extensive burns, losses from the gastrointestinal tract or in negative balance during haemodialysis. Copper is necessary for the utilization of iron in the formation of haemoglobin and transferrin and therefore the insufficient level results to hypochromic anaemia. The authors present the recommended doses for copper supplementation in the aforementioned losses. Selenium possesses a number of functions important for the surviving of critical illness, including protection from the organic peroxides, the conversion of thyroxine to active triiodothyronine, improvement in response to glucocorticoids, glycaemic control, inhibition of adhesion molecules and the effect on the function of T-lymphocytes. The level of selenium is reduced in systemic inflammation and it falls progressively depending on the severity of condition (e.g. sepsis). The article reports a number of clinical trials with different regimens of supplementation with high doses of selenium, administered for maximal period of two weeks. The mortality rate has dropped significantly so far in one large clinical trial only. Some other trial have reported positive results in some outcomes: SOFA score improvement in patients with multiple organ dysfunctions, elevation of previously low cholesterol, praealbumin and glutathione peroxidase levels, and reduction in C-reactive protein values. The optimal therapeutic doses are discussed in detail. The toxic effects of copper and selenium overdose, which can cause a critical condition per se, are mentioned.
- MeSH
- dítě MeSH
- enterální výživa normy MeSH
- klinické zkoušky jako téma statistika a číselné údaje MeSH
- kritický stav * terapie MeSH
- lidé MeSH
- měď * analýza metabolismus nedostatek normy otrava škodlivé účinky terapeutické užití MeSH
- nutriční podpora * normy MeSH
- oxidační stres fyziologie MeSH
- parenterální výživa normy MeSH
- perioperační období MeSH
- rány a poranění patofyziologie terapie MeSH
- selen * analýza aplikace a dávkování metabolismus nedostatek normy otrava škodlivé účinky terapeutické užití MeSH
- stopové prvky analýza metabolismus nedostatek normy otrava škodlivé účinky terapeutické užití MeSH
- zánět patofyziologie MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
Flavonoids are considered beneficial, but they may exhibit pro-oxidative effects likely due to metal reducing properties. For the first time, 24 structurally related flavonoids were compared for copper reduction, and modulation of the copper-triggered Fenton reaction and lysis of erythrocytes. The vast majority of flavonoids reduced cupric ions; their behaviour ranged from progressive gradual reduction through bell-shaped, neutral, to a blockade of spontaneous reduction. Similarly, different behaviours were observed with the Fenton reaction. Flavone was the only flavonoid that potentiated copper-triggered haemolysis (155 ± 81 % at twice the amount of Cu2+), while 18 flavonoids were at least partly protective in some concentrations. Only 5-hydroxyflavone did not reduce Cu2+ and behaved as an antioxidant in both assays (reduction of 60 ± 10 % and 88 ± 1%, respectively, at an equimolar ratio with Cu2+). In conclusion, relatively subtle structural differences resulted in very different anti/prooxidant behaviour depending on the model.
The rapid dissolution of copper oxide (CuO) nanoparticles (NPs) with release of ions is thought to be one of the main factors modulating their toxicity. Here we assessed the cytotoxicity of a panel of CuO NPs (12 nm ± 4 nm) with different surface modifications, i.e., anionic sodium citrate (CIT) and sodium ascorbate (ASC), neutral polyvinylpyrrolidone (PVP), and cationic polyethylenimine (PEI), versus the pristine (uncoated) NPs, using a murine macrophage cell line (RAW264.7). Cytotoxicity, reactive oxygen species (ROS) production, and cellular uptake were assessed. The cytotoxicity results were analyzed by the benchmark dose (BMD) method and the NPs were ranked based on BMD20values. The PEI-coated NPs were found to be the most cytotoxic. Despite the different properties of the coating agents, NP dissolution in cell medium was only marginally affected by surface modification. Furthermore, CuCl2(used as an ion control) elicited significantly less cytotoxicity when compared to the CuO NPs. We also observed that the antioxidant, N-acetylcysteine, failed to protect against the cytotoxicity of the uncoated CuO NPs. Indeed, the toxicity of the surface-modified CuO NPs was not directly linked to particle dissolution and subsequent Cu burden in cells, nor to cellular ROS production, although CuO-ASC NPs, which were found to be the least cytotoxic, yielded lower levels of ROS in comparison to pristine NPs. Hierarchical cluster analysis suggested, instead, that the toxicity in the current in vitro model could be explained by synergistic interactions between the NPs, their dissolution, and the toxicity of the coating agents.
- MeSH
- antioxidancia MeSH
- buněčná smrt účinky léků MeSH
- buněčné linie MeSH
- kovové nanočástice chemie toxicita MeSH
- makrofágy metabolismus MeSH
- měď chemie farmakokinetika toxicita MeSH
- myši MeSH
- povrchové vlastnosti MeSH
- reaktivní formy kyslíku metabolismus MeSH
- rozpustnost MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
HPLC determination of a background level of 8 oxodG and 2-dG in rat liver after addition of copper to perfusate was developed. The reversed phase analytical column Purospher® STAR C18e with 50 mmol L1 phosphate buffer, pH 5.5 and methanol (92:8, v/v) mobile phase was applied for the analysis. The validation of the HPLC method according to linearity, accuracy and precision was carried out. Oxidative DNA damage (expressed as concentration ratio of 8-oxodG/106 2-dG) was determined by the simultaneous measuring of 2-dG with UV detection followed by coulochemical detection of 8 oxodG. The procedure using a model of liver damage caused by intoxication with copper and ischemia / reperfusion with addition of various concentrations of CuSO4 to the perfused rat livers was tested. The aim of this study was to decide whether the toxicity of copper in liver perfusates is related to protein oxidation and oxidative DNA damage. The high contribution to the DNA damage can be related to the physical liver manipulation during harvest and reperfusion as well as to artefacts induced during the sample preparation (time-consuming sample handling during DNA isolation and extraction). The obtained results pointed out that the DNA damage occurred already during liver handling even before application of CuSO4, whereby concentration of CuSO4 higher than 0.03 mmol L1 caused a total liver damage, which led to a complete stop of the flow of the perfusate.
- MeSH
- biologické markery MeSH
- deoxyguanosin chemie MeSH
- elektrochemické techniky * metody využití MeSH
- krysa rodu rattus MeSH
- měď * toxicita MeSH
- nemoci jater * MeSH
- oxidační stres MeSH
- poškození DNA * MeSH
- spektrofotometrie metody využití MeSH
- vysokoúčinná kapalinová chromatografie * metody využití MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
