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1.
Ecotoxicol Environ Saf ; 193: 110345, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32092578

RESUMO

Many areas of the world are affected simultaneously by salinity and heavy metal pollution. Halophytes are considered as useful candidates in remediation of such soils due to their ability to withstand both osmotic stress and ion toxicity deriving from high salt concentrations. Quinoa (Chenopodium quinoa Willd) is a halophyte with a high resistance to abiotic stresses (drought, salinity, frost), but its capacity to cope with heavy metals has not yet been fully investigated. In this pot experiment, we investigated phytoextraction capacity, effects on nutrient levels (P and Fe), and changes in gene expression in response to application of Cr(III) in quinoa plants grown on saline or non-saline soil. Plants were exposed for three weeks to 500 mg kg-1 soil of Cr(NO3)3·9H2O either in the presence or absence of 150 mM NaCl. Results show that plants were able tolerate this soil concentration of Cr(III); the metal was mainly accumulated in roots where it reached the highest concentration (ca. 2.6 mg g-1 DW) in the presence of NaCl. On saline soil, foliar Na concentration was significantly reduced by Cr(III). Phosphorus translocation to leaves was reduced in the presence of Cr(III), while Fe accumulation was enhanced by treatment with NaCl alone. A real-time RT-qPCR analysis was conducted on genes encoding for sulfate, iron, and phosphate transporters, a phytochelatin, a metallothionein, glutathione synthetase, a dehydrin, Hsp70, and enzymes responsible for the biosynthesis of proline (P5CS), glycine betaine (BADH), tocopherols (TAT), and phenolic compounds (PAL). Cr(III), and especially Cr(III)+NaCl, affected transcript levels of most of the investigated genes, indicating that tolerance to Cr is associated with changes in phosphorus and sulfur allocation, and activation of stress-protective molecules. Moderately saline conditions, in most cases, enhanced this response, suggesting that the halophytism of quinoa could contribute to prime the plants to respond to chromium stress.


Assuntos
Chenopodium quinoa/efeitos dos fármacos , Chenopodium quinoa/metabolismo , Cromo/toxicidade , Salinidade , Poluentes do Solo/toxicidade , Biodegradação Ambiental , Transporte Biológico/efeitos dos fármacos , Chenopodium quinoa/genética , Cromo/farmacocinética , Expressão Gênica/efeitos dos fármacos , Íons/metabolismo , Ferro/metabolismo , Chumbo/metabolismo , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Prolina/biossíntese , Plantas Tolerantes a Sal/efeitos dos fármacos , Plantas Tolerantes a Sal/genética , Plantas Tolerantes a Sal/metabolismo , Sódio/metabolismo , Cloreto de Sódio/farmacologia , Poluentes do Solo/farmacocinética , Estresse Fisiológico , Enxofre/metabolismo , Tocoferóis/metabolismo
2.
Ecotoxicol Environ Saf ; 193: 110357, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32105946

RESUMO

Trace metal elements are significant stressors in urban areas. Their harmful effects on physiological parameters are demonstrated, but current laboratory studies are not representative of wild chronic exposure to a trace metal cocktail. Calcium can reduce the accumulation and toxicity of several metals, but soil acidification in cities leads to a decrease in bioavailability of this element. The objective of this study was to investigate the accumulation and toxicity of a trace metal cocktail representative of urban exposure on passerine birds, and test the importance of calcium availability on these toxic effects. We exposed zebra finches (Taeniopygia guttata) to a cocktail of seven metals and one metalloid in drinking water, with or without calcium supplementation. We monitored the concentration of metals in the blood and feathers, and their effects on oxidative status and telomere length. The metal cocktail led to higher concentration of all elements in the feathers, and of arsenic and lead in the blood. Birds with a higher concentration of cadmium, arsenic and lead in the feathers had shorter telomeres, but no impact of the cocktail was detected on oxidative status. Birds of the 'calcium' group and the 'calcium and metal' group accumulated higher concentrations of zinc, chromium and nickel in feathers. The 'calcium and metal' group also accumulated lower concentrations of arsenic and lead in feathers compared to the 'metal' group. Our results suggest that chronic exposure to a cocktail of metals at low concentrations has deleterious effects on birds, which can be limited through calcium intake.


Assuntos
Cálcio/farmacologia , Metais Pesados/toxicidade , Animais , Arsênico/sangue , Arsênico/farmacocinética , Cádmio/farmacocinética , Cálcio/administração & dosagem , Cromo/farmacocinética , Cidades , Suplementos Nutricionais , Plumas/química , Tentilhões , Chumbo/sangue , Chumbo/farmacocinética , Masculino , Metais Pesados/sangue , Níquel/farmacocinética , Encurtamento do Telômero/efeitos dos fármacos , Oligoelementos/farmacocinética , Oligoelementos/toxicidade , Zinco/análise
3.
Ecotoxicol Environ Saf ; 192: 110303, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32061991

RESUMO

Chromium (Cr) concentration has been increasing substantially in the environment due to industrial and anthropogenic factors. Plants can absorb Cr and undergo unrestrained oxidation cascades, resulting in cell injury. The ameliorative role of biogenic copper nanoparticles to relieve wheat plants from Cr stress by supporting their growth is still unclear. The present work aims at the biosynthesis and characterization of copper nanoparticles (CuNPs) from a native Klebsiella pneumoniae strain, followed by assessment of wheat growth and physiological responses to CuNPs mixed in Cr-rich soil. The taxonomic rank of K. pneumoniae SN35 was established by the 16 S rRNA gene sequence analysis. The properties of biogenic CuNPs were elucidated by using UV-vis spectroscopy, FTIR, XRD, SEM, and TEM. It was found that 19.01-47.47 nm spherical shaped CuNPs were stabilized by different functional groups produced extracellularly by the strain SN35. The XRD data revealed the crystalline nature of CuNPs as a face-centered cubic structure. Different concentrations of CuNPs (0, 25, 50 and 100 mg kg-1 of soil) were added into the soil mixed with 3.5 mg kg-1 K2Cr2O7 and the pots were placed in a growth chamber for 30 days. The results revealed that the CuNPs, at 25 and 50 mg kg-1 of soil, augmented plant growth, biomass, and cellular antioxidants contents, whereas decreased the reactive oxygen species and Cr translocation from soil to roots and shoots as compared to control plants. Overall, the results revealed that the soil amendment of CuNPs could immobilize the Cr in the soil to prevent its translocation to the upper plant parts and support wheat growth by relieving cellular oxidative stress.


Assuntos
Cromo/farmacocinética , Cobre/química , Klebsiella pneumoniae/metabolismo , Nanopartículas Metálicas/química , Poluentes do Solo/farmacocinética , Triticum/crescimento & desenvolvimento , Antioxidantes/metabolismo , Disponibilidade Biológica , Biomassa , Cromo/química , Recuperação e Remediação Ambiental , Klebsiella pneumoniae/classificação , Klebsiella pneumoniae/genética , Estresse Oxidativo , Poluentes do Solo/química , Triticum/metabolismo
4.
Chemosphere ; 238: 124663, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31472343

RESUMO

Ochrobactrum anthropi DE2010 is a microorganism isolated from Ebro Delta microbial mats and able to resist high doses of chromium(III) due to its capacity to tolerate, absorb and accumulate this metal. The effect of this pollutant on O. anthropi DE2010 has been studied assessing changes in viability and biomass, sorption yields and removal efficiencies. Furthermore, and for the first time, its capacity for immobilizing Cr(III) from culture media was tested by a combination of High Angle Annular Dark Field (HAADF) Scanning Transmission Electron Microscopy (STEM) imaging coupled to Energy Dispersive X-ray spectroscopy (EDX). The results showed that O. anthropi DE2010 was grown optimally at 0-2 mM Cr(III). On the other hand, from 2 to 10 mM Cr(III) microbial plate counts, growth rates, cell viability, and biomass decreased while extracellular polymeric substances (EPS) production increases. Furthermore, this bacterium had a great ability to remove Cr(III) at 10 mM (q = 950.00 mg g-1) immobilizing it mostly in bright polyphosphate inclusions and secondarily on the cellular surface at the EPS level. Based on these results, O. anthropi DE2010 could be considered as a potential agent for bioremediation in Cr(III) contaminated environments.


Assuntos
Biodegradação Ambiental , Cromo/farmacocinética , Ochrobactrum anthropi/metabolismo , Biomassa , Cromo/metabolismo , Viabilidade Microbiana , Ochrobactrum anthropi/crescimento & desenvolvimento , Espectrometria por Raios X
5.
Chemosphere ; 239: 124760, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31518923

RESUMO

Plant growth and yield are adversely affected by the uptake of toxic hexavalent chromium (Cr(VI)) from soil. The present study describes a facile technique to minimize the uptake of Cr(VI) by chickpea (Cicer arietinum) plant from soil using microporous activated carbon microfiber (ACF). Simultaneously, nano-sized carbon nanofibers (CNFs), grown over the ACF substrate, are used as an efficient carrier of the Cu micronutrient from soil to root, shoot and leaf of the plants. Adsorption, seed germination and plant growth experiments are performed in Cr-stressed medium. The ACF, used as the adsorbent for Cr(VI) in metal-stressed soil (100 mg Cr kg-1 of soil) shows the metal loading of ∼23 mg g-1. Cr(VI) up to 50 mg L-1 concentration causes no stress during germination of chickpea seeds in Murashige and Skoog (MS) medium. A dose of 500 mg-mixture (treatment) per kg-soil increases root and shoot lengths by 52 and 11%, respectively than the control, during plant growth in the metal-stressed soil, attributed to an effective translocation of Cu-CNF through plant cells. Whereas Cr uptake by plant decrease to ∼46%, Cu uptake increase up to ∼120% in comparison to control by the mixture treatment. Protein and chlorophyll contents also significantly increased (*p < 0.05) with the application of treatment. The data clearly show that the mixture of ACF and Cu-CNF can be successfully used for the simultaneous scavenging of Cr(VI) from soil by adsorption over ACF and increased uptake of Cu by plants using the CNFs as the micronutrient carrier.


Assuntos
Cromo/farmacocinética , Cicer/crescimento & desenvolvimento , Nanofibras/química , Poluentes do Solo/farmacocinética , Adsorção , Carvão Vegetal/química , Clorofila/metabolismo , Cromo/isolamento & purificação , Cicer/efeitos dos fármacos , Cicer/metabolismo , Cobre/farmacocinética , Recuperação e Remediação Ambiental/métodos , Germinação , Folhas de Planta , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Solo/química , Poluentes do Solo/isolamento & purificação
6.
Part Fibre Toxicol ; 16(1): 33, 2019 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-31451117

RESUMO

BACKGROUND: Allergic reactions to tattoos are amongst the most common side effects occurring with this permanent deposition of pigments into the dermal skin layer. The characterization of such pigments and their distribution has been investigated in recent decades. The health impact of tattoo equipment on the extensive number of people with inked skin has been the focus of neither research nor medical diagnostics. Although tattoo needles contain high amounts of sensitizing elements like nickel (Ni) and chromium (Cr), their influence on metal deposition in skin has never been investigated. RESULTS: Here, we report the deposition of nano- and micrometer sized tattoo needle wear particles in human skin that translocate to lymph nodes. Usually tattoo needles contain nickel (6-8%) and chromium (15-20%) both of which prompt a high rate of sensitization in the general population. As verified in pig skin, wear significantly increased upon tattooing with the suspected abrasive titanium dioxide white when compared to carbon black pigment. Additionally, scanning electron microscopy of the tattoo needle revealed a high wear after tattooing with ink containing titanium dioxide. The investigation of a skin biopsy obtained from a nickel sensitized patient with type IV allergy toward a tattoo showed both wear particles and iron pigments contaminated with nickel. CONCLUSION: Previously, the virtually inevitable nickel contamination of iron pigments was suspected to be responsible for nickel-driven tattoo allergies. The evidence from our study clearly points to an additional entry of nickel to both skin and lymph nodes originating from tattoo needle wear with an as yet to be assessed impact on tattoo allergy formation and systemic sensitization.


Assuntos
Cromo/farmacocinética , Corantes/toxicidade , Hipersensibilidade/etiologia , Linfonodos/efeitos dos fármacos , Níquel/farmacocinética , Pele/efeitos dos fármacos , Tatuagem/efeitos adversos , Animais , Corantes/farmacocinética , Humanos , Hipersensibilidade/imunologia , Hipersensibilidade/metabolismo , Técnicas In Vitro , Tinta , Linfonodos/imunologia , Linfonodos/metabolismo , Nanopartículas/metabolismo , Nanopartículas/toxicidade , Agulhas , Tamanho da Partícula , Pele/imunologia , Pele/metabolismo , Suínos , Distribuição Tecidual , Titânio/farmacocinética , Titânio/toxicidade
7.
Food Chem ; 298: 125032, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260968

RESUMO

A dietary fibre prepared from sugarcane stalk was compared with psyllium husk and wheat dextrin. In contrast to the other dietary fibres, sugarcane fibre was found to contain significant amounts of insoluble dietary fibre (73-86%), lignin (18.66-20.23%), and rare minerals such as chromium (0.67-2.54 mg/100 g) and manganese (1.07-2.34 mg/100 g). Analysis of the ethanol extract also detected compounds with antioxidant activity. Characterisation of five sugarcane fibres prepared from selected strains, harvest periods (growth or storage phase), and processing conditions showed these factors influenced the final composition. Furthermore, using in vitro digestion, we found that potassium, magnesium, chromium, and zinc in were bioaccessible in sugarcane samples. Also, sodium was shown to bind to the sugarcane fibre potentially indicating bile salt binding activity. Results from this study support the use of sugarcane as a source of dietary fibre in functional foods.


Assuntos
Dextrinas/química , Fibras na Dieta/análise , Plantago/química , Saccharum/química , Triticum/química , Antioxidantes/análise , Cromo/análise , Cromo/farmacocinética , Dextrinas/análise , Fibras na Dieta/metabolismo , Indústria de Processamento de Alimentos/métodos , Lignina/análise , Metais/análise , Metais/farmacocinética
8.
Toxicol Lett ; 314: 133-141, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31325633

RESUMO

Hexavalent chromium (Cr(VI)) compounds are classified as carcinogenic to humans. Whereas chromium measurements in urine and plasma attest to the last few hours of total chromium exposure (all oxidation states of chromium), chromium in red blood cells (RBC) is attributable specifically to Cr(VI) exposure over the last few days. Before recommending Cr in RBC (CrIE) as a biological indicator of Cr(VI) exposure, in vivo studies must be undertaken to assess its reliability. The present study examines the kinetics of Cr(VI) in rat after a single intravenous dose of ammonium dichromate. Chromium levels were measured in plasma, red blood cells and urine. The decay of the chromium concentration in plasma is one-phase-like (with half-life time of 0.55 day) but still measurable two days post injection. The excretion of urinary chromium peaks between five and six hours after injection and shows large variations. Intra-erythrocyte chromium (CrIE) was very constant up to a minimum of 2 days and half-life time was estimated to 13.3 days. Finally, Cr(III) does not interfere with Cr(VI) incorporation in RBC. On the basis of our results, we conclude that, unlike urinary chromium, chromium levels in RBC are indicative of the amount of dichromate (Cr(VI)) in blood.


Assuntos
Carcinógenos Ambientais/administração & dosagem , Carcinógenos Ambientais/metabolismo , Cromo/administração & dosagem , Cromo/sangue , Eritrócitos/metabolismo , Administração Intravenosa , Animais , Biomarcadores/sangue , Biomarcadores/urina , Carga Corporal (Radioterapia) , Carcinógenos Ambientais/farmacocinética , Carcinógenos Ambientais/toxicidade , Cromo/farmacocinética , Cromo/toxicidade , Masculino , Modelos Biológicos , Oxirredução , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Especificidade da Espécie , Toxicocinética
9.
Environ Sci Pollut Res Int ; 26(15): 15406-15413, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30941713

RESUMO

In soil, vanadium (V) contamination is commonly concomitant with chromium (Cr) contamination, which poses potential risks to humans, animals, and plants due to the transfer of toxic metals and the increase in their concentrations via the food chain or through direct exposure. This study applied a multi-step column leaching process using low-molecular-weight organic acids (LMWOAs) to treat V-contaminated soil from a smelter site that contains 2015.1 mg V kg-1 and 1060.3 mg Cr kg-1. After leaching three times with an equivalent solution/soil ratio of 0.3 mL/g using 1.0 M oxalic acid solution, the total removal rates reached 77.2% and 7.2% for V and Cr, respectively, while the removal rates of the extractable fractions reached 118.6% and 99.2% due to the reduction in residual fraction (F4) of toxic metals. Simultaneously, the distribution and redistribution of geochemical fractions of V and Cr were determined with a sequential extraction technique, and the greater proportion of potential mobile fractions of V (65.1%) may increase its leaching from soil relative to Cr (7.1%). In addition, a lower pH of the leaching agent increased the efficiency of the leaching process to an extent. Compared with batch extraction with a typical solution to soil ratio of 10 mL/g, multi-step column leaching used less agent and hence produced less wastewater. This strategy could reduce the mobilization and bioavailability of toxic metals, and potentially enhance in situ soil flushing for the remediation of V- and Cr- contaminated soil.


Assuntos
Cromo/isolamento & purificação , Recuperação e Remediação Ambiental/métodos , Ácido Oxálico/química , Poluentes do Solo/isolamento & purificação , Vanádio/isolamento & purificação , Disponibilidade Biológica , China , Cromo/análise , Cromo/farmacocinética , Recuperação e Remediação Ambiental/instrumentação , Concentração de Íons de Hidrogênio , Malatos/química , Metalurgia , Peso Molecular , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/farmacocinética , Tartaratos/química , Vanádio/análise , Vanádio/farmacocinética , Águas Residuárias
10.
Ecotoxicol Environ Saf ; 171: 84-91, 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-30597320

RESUMO

In this study, we estimated the toxicity risks from river sediments that were affected by multiple pollutants in the Haihe River Basin. We used a range of methods to determine the concentrations, bioavailability, and toxicity of a range of metals and contaminants in sediments and sediment porewater and then assessed the ecological risks and toxicity using various multivariate statistical approaches. We found that more than 70% of the samples were toxic. The concentrations of non-ionic ammonia (0.168-9.295 mg L-1) were generally high in the sediment porewater, while the concentrations of bioavailable chromium (Cr) and polycyclic aromatic hydrocarbons (PAHs) were also high in the porewater samples from NW01 and NW02, respectively. We used the toxic unit (TU) approach, based on the bioavailable pollutant concentrations, to determine the toxicity of PAHs, heavy metals, and non-ionic ammonia in river sediments and sediment porewater. We found that non-ionic ammonia was the main source of toxicity for Daphnia magna, and that Cr and zinc were toxic for Pseudokirchneriella subcapitata and Chironomus dilutus. By combining various indexes, we identified the main contributors to the toxicity in sediments collected from rivers affected by multiple pollutants.


Assuntos
Amônia/toxicidade , Cromo/toxicidade , Sedimentos Geológicos/química , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Poluentes Químicos da Água/toxicidade , Amônia/análise , Amônia/farmacocinética , Animais , Disponibilidade Biológica , China , Chironomidae/efeitos dos fármacos , Clorofíceas/efeitos dos fármacos , Cromo/análise , Cromo/farmacocinética , Daphnia/efeitos dos fármacos , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/farmacocinética , Medição de Risco , Rios/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/farmacocinética , Zinco/análise , Zinco/farmacocinética , Zinco/toxicidade
11.
Toxicol Ind Health ; 35(2): 145-158, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30654724

RESUMO

The populations of wild animals are declining in many parts of the world in response to man-made alterations in the environment. Environmental contamination due to heavy metals discharge from industry may contribute to the decline of wild animal populations by impacting their reproduction, growth, and development. In the leather tanning industry, chromium (Cr) is used as a basic component, but it is a potent toxicant that can affect many of the physiological functions of animals. In the current study, we investigated the reproductive toxicity of industrial Cr in female small Indian mongooses inhabiting a tannery area. Adult female specimens were live trapped from February 2015 to January 2016. Blood and other body tissues (ovaries, kidneys and liver) of the captured specimens were collected along with soil and water samples from the environment for analysis. The Cr concentrations were found significantly ( p < 0.0001) increased compared to control in the environment, blood, and all body tissues of the animals. Estradiol and progesterone levels were found to be significantly decreased in comparison with control ( p < 0.0001), along with reduced ovarian weights, while follicle stimulating hormone (FSH) and luteinizing hormone levels were found significantly ( p < 0.0001) elevated. Light microscopy revealed significantly decreased in comparison with control ovarian follicle numbers ( p < 0.0001) and diameters, vacuolization of the oocytes, and a significantly higher percentage of atretic follicles inside the ovary. We conclude that Cr discharged from the tanneries is absorbed by the exposed female small Indian mongoose, leading to ovarian dysfunction with potential impairment of reproductive function.


Assuntos
Cromo/toxicidade , Poluição Ambiental/efeitos adversos , Herpestidae/fisiologia , Folículo Ovariano , Curtume , Animais , Peso Corporal/efeitos dos fármacos , Cromo/análise , Cromo/farmacocinética , Feminino , Folículo Ovariano/efeitos dos fármacos , Folículo Ovariano/patologia , Paquistão , Progesterona/sangue , Distribuição Tecidual
12.
Food Chem ; 277: 347-352, 2019 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-30502156

RESUMO

There is limited research concentrating on the effects of gut microbiota on the bioaccessibility and speciation of chromium (Cr) in vegetables. In this study, the physiologically based extraction test (PBET) and the unified BARGE method (UBM), were combined with the simulator of human intestinal microbial ecosystems (SHIME) to determine the bioaccessibility and speciation of Cr from vegetables. The results showed that the Cr bioaccessibility was the highest in the gastric phase. The Cr bioaccessibility from the water spinach was the highest, and was 1.6-3.4 and 1.1-1.8 times that of leaf lettuce and celery, respectively. The Cr bioaccessibilities of the UBM method were slightly greater than those of the PBET method. Additionally, the gut microbiota increased the Cr bioaccessibility and reduced more toxic Cr(VI) to less toxic Cr(III) from vegetables. Therefore, our study reveals the possible health risks of consuming Cr-contaminated vegetables based on the bioaccessibility and speciation of Cr.


Assuntos
Cromo/farmacocinética , Microbioma Gastrointestinal , Verduras/química , Adulto , Apium/química , Fezes/microbiologia , Contaminação de Alimentos/análise , Humanos , Intestinos/efeitos dos fármacos , Intestinos/microbiologia , Alface/química , Masculino , Modelos Teóricos , Spinacia oleracea/química , Verduras/classificação
13.
ACS Appl Mater Interfaces ; 11(2): 1907-1916, 2019 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-30566326

RESUMO

Multifunctional theranostic nanoplatforms greatly improve the accuracy and effectiveness in tumor treatments. Much effort has been made in developing advanced optical imaging-based tumor theranostic nanoplatforms. However, autofluorescence and irradiation damage of the conventional fluorescence imaging technologies as well as unsatisfied curative effects of the nanoplatforms remain great challenges against their wide applications. Herein, we constructed a novel core-shell multifunctional nanoplatform, that is, chromium-doped zinc gallogermanate (ZGGO) near-infrared (NIR) persistent luminescent nanoparticles (PLNPs) as a core and zeolitic imidazolate framework-8 (ZIF-8) as a shell (namely ZGGO@ZIF-8). The ZGGO@ZIF-8 nanoplatform possessed dual functionalities of the autofluorescence-free NIR PersL imaging as well as the pH-responsive drug delivery, thus it has high potential in tumor theranostics. Notably, the loading content of doxorubicin (DOX) in ZGGO@ZIF-8 (LC = 93.2%) was quite high, and the drug release of DOX-loaded ZGGO@ZIF-8 was accelerated in an acidic microenvironment such as tumor cells. The ZGGO@ZIF-8 opens up a new material system in the combination of PLNPs with metal-organic frameworks and may offer new opportunities for the development of advanced multifunctional nanoplatforms for tumor theranostics, chemical sensing, and optical information storage.


Assuntos
Doxorrubicina , Estruturas Metalorgânicas , Nanopartículas , Neoplasias , Zeolitas , Cromo/química , Cromo/farmacocinética , Cromo/farmacologia , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/farmacologia , Doxorrubicina/química , Doxorrubicina/farmacocinética , Doxorrubicina/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Células MCF-7 , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacocinética , Estruturas Metalorgânicas/farmacologia , Nanopartículas/química , Nanopartículas/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia , Zeolitas/química , Zeolitas/farmacocinética , Zeolitas/farmacologia , Zinco/química , Zinco/farmacocinética , Zinco/farmacologia
14.
Adv Nutr ; 9(4): 505-506, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30032219

RESUMO

Two oxidation states of chromium are considered to be biologically and environmentally relevant based on their stability in the presence of water and oxygen. Compounds containing chromium(6 + ) are mutagenic and carcinogenic when inhaled and potentially when ingested orally in large quantity as well. Chromium as the trivalent will be the focus of this work as it was proposed to be an essential element for mammals ∼60 y ago; however, in the last 2 decades its status has been questioned. Chromium has been postulated to be involved in regulating carbohydrate and lipid (and potentially also protein) metabolism by enhancing insulin's efficacy (1). However, in 2014, the European Food Safety Authority found no convincing evidence that chromium is an essential element (2). Dietary chromium apparently is absorbed via passive diffusion and the extent of absorption is low (∼1%). Chromium is maintained in the bloodstream bound to the protein transferrin. It is generally believed to be delivered to tissues by transferrin via endocytosis (1). No unambiguous animal model of chromium deficiency has been established (2). One limitation in characterizing chromium deficiency in humans is the lack of an accepted biomarker of chromium nutritional status. Attempts to identify a glucose tolerance factor have not provided a chemically defined functional compound that conforms with the proposed physiologic role of chromium as a facilitator of insulin action in vivo.


Assuntos
Cromo/fisiologia , Animais , Metabolismo dos Carboidratos/fisiologia , Cromo/farmacocinética , Cromo/farmacologia , Dieta , Endocitose , Humanos , Insulina/fisiologia , Metabolismo dos Lipídeos/fisiologia , Estado Nutricional , Recomendações Nutricionais , Transferrina/metabolismo
15.
Chemosphere ; 210: 597-606, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30031343

RESUMO

Toxic chromium [(Cr(VI)] in food chain has created an alarming situation for human life and ecosystems. The present study through a greenhouse pot experiment aims to (a) investigate the ability of organic matter in reducing Cr uptake by lettuce (Lactuca sativa L.) from a sandy loam soil irrigating with Cr(VI)-water, (b) to provide a way for the restriction of Cr transfer from contaminated soils and irrigation water to plants/crops and (c) to contribute to the better management of soil (land) and water use, without reduction of the agricultural production. Since soil and groundwater contamination by Cr is a potential risk in a worldwide scale, due to industrial activities and/or natural processes, organic carbon may play a key role in the mobility of added Cr(VI) to soil via irrigation water, in a significant way. The cultivation of lettuce, using organic matter in the form of leonardite (10 and 30 wt%) and Cr(VI)-irrigation water (100, 200 and 300 mgL-1), showed that the uptake of Cr in both shoots and roots increased with increasing concentration of Cr in the irrigation water. The highest Cr values in shoots (average = 10 mg/kg) and in roots (average = 28 mg/kg) were recorded in those plants cultivated in soil after the addition of Cr(VI)- water without organic matter, whereas the lowest Cr values in shoots (average = 0.44 mg/kg) and in roots (average = 0.7 mg/kg) were recorded in those plants cultivated in soil with addition of 30 wt% organic matter. The used leonardite as organic matter that is an oxidized form of lignite, due to its high content of humic acid is considered to be a useful organic fertilizer that provides possibilities for combining food production with soil protection. Therefore, the application of the natural organic material leonardite, as a land management technique, seems to be a cost-effective method consistent to related protocols for the protection of the soil quality.


Assuntos
Cromo/farmacocinética , Substâncias Húmicas , Alface/metabolismo , Água/química , Água Subterrânea/química , Minerais/economia , Minerais/farmacologia , Oxirredução , Raízes de Plantas/química , Brotos de Planta/química , Solo , Água/farmacologia
16.
Acta Biomater ; 69: 332-341, 2018 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-29355718

RESUMO

Remodeling of calcium phosphate bone cements is a crucial prerequisite for their application in the treatment of large bone defects. In the present study trivalent chromium ions were incorporated into a brushite forming calcium phosphate cement in two concentrations (10 and 50 mmol/mol ß-tricalcium phosphate) and implanted into a femoral defect in rats for 3 and 6 month, non-modified brushite was used as reference. Based on our previous in vitro findings indicating both an enhanced osteoclastic activity and cytocompatibility towards osteoprogenitor cells we hypothesized a higher in vivo remodeling rate of the Cr3+ doped cements compared to the reference. A significantly enhanced degradation of the modified cements was evidenced by micro computed tomography, X-ray and histological examinations. Furthermore the formation of new bone tissue after 6 month of implantation was significantly increased from 29% to 46% during remodeling of cements, doped with the higher Cr3+ amount. Time of flight secondary ion mass spectrometry (ToF-SIMS) of histological sections was applied to investigate the release of Cr3+ ions from the cement after implantation and to image their distribution in the implant region and the surrounding bone tissue. The relatively weak incorporation of chromium into the newly formed bone tissue is in agreement to the low chromium concentrations which were released from the cements in vitro. The faster degradation of the Cr3+ doped cements was also verified by ToF-SIMS. The positive effect of Cr3+ doping on both degradation and new bone formation is discussed as a synergistic effect of Cr3+ bioactivity on osteoclastic resorption on one hand and improvement of cytocompatibility and solubility by structural changes in the calcium phosphate matrix on the other hand. STATEMENT OF SIGNIFICANCE: While biologically active metal ions like strontium, magnesium and zinc are increasingly applied for the modification of ceramic bone graft materials, the present study is the first report on the incorporation of low doses of trivalent chromium ions into a calcium phosphate based biomaterial and testing of its performance in bone defect regeneration in vivo. Chromium(III)-doped calcium phosphate bone cements show improved cytocompatibility and both degradation rate and new bone formation in vivo are significantly increased compared to the reference cement. This important discovery might be the starting point for the application of trivalent chromium salts for the modification of bone graft materials to increase their remodelling rate.


Assuntos
Cimentos para Ossos , Fosfatos de Cálcio , Cromo , Osteogênese/efeitos dos fármacos , Tíbia , Microtomografia por Raio-X , Animais , Cimentos para Ossos/química , Cimentos para Ossos/farmacocinética , Cimentos para Ossos/farmacologia , Fosfatos de Cálcio/química , Fosfatos de Cálcio/farmacocinética , Fosfatos de Cálcio/farmacologia , Cromo/química , Cromo/farmacocinética , Cromo/farmacologia , Masculino , Ratos , Ratos Wistar , Tíbia/diagnóstico por imagem , Tíbia/lesões , Tíbia/metabolismo
17.
Chemosphere ; 193: 793-799, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29175407

RESUMO

Chromium (Cr) contamination in soil is a growing concern in sustainable agricultural production and food safety. Remediation of Cr from contaminated soils is a challenging task which may not only help in sustaining agriculture but also in minimizing adverse environmental impacts. Pot culture experiments were performed with the application of varied concentration of Cr+6 to assess the Chromium accumulation potential of Lemongrass and to study the impact of toxic concentration of Cr+6 on morphological, physiological and biochemical parameters of the plant. The results showed an increasing accumulation trend of Chromium with increasing Chromium concentrations in both root and shoot of 60 days old Lemongrass plants, while the protein and chlorophyll contents decreased. Similarly, accumulation of Cr increased the levels of proline and antioxidant enzymes indicating the enhanced damage control activity. The potentiality of the plant with the capacity to accumulate and stabilize Cr compound in Cr contaminated soil by phytoremediation process has been explored in the present investigation.


Assuntos
Biodegradação Ambiental , Cromo/farmacocinética , Cromo/toxicidade , Cymbopogon/metabolismo , Solo/química , Antioxidantes/metabolismo , Clorofila/metabolismo , Cromo/análise , Cymbopogon/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Poluentes do Solo/análise , Poluentes do Solo/farmacologia
18.
J Environ Manage ; 206: 715-730, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-29156430

RESUMO

In the current industrial scenario, chromium (Cr) as a metal is of great importance, but poses a major threat to the environment. Phytoremediation provides an environmentally sustainable, ecofriendly, cost effective approach for environmental cleanup of Cr. This review presents the current status of phytoremediation research with particular emphasis on cleanup of Cr contaminated soil and water systems. It gives a detailed account of the work done by different authors on the Cr bioavailability, uptake pathway, toxicity and storage in plants following the phytoextraction mechanism. This paper also describes recent findings related to Cr localization in hyperaccumulator plants. It gives an insight into the processes and mechanisms that allow plants to remove Cr from contaminated sites under varying conditions. These detailed knowledge of changes in plant metabolic pool in response to Cr stress would immensely help understand and improve the phytoextraction process. Further, this review provides a detailed understanding of Cr uptake and detoxification mechanism by plants that can be applied in developing a suitable approach for a better applicability of the process.


Assuntos
Cromo , Plantas , Poluentes do Solo , Biodegradação Ambiental , Cromo/farmacocinética , Cromo/toxicidade , Solo , Poluentes do Solo/farmacocinética , Poluentes do Solo/toxicidade
19.
J Appl Toxicol ; 38(3): 351-365, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29064106

RESUMO

The current US Environmental Protection Agency (EPA) reference dose (RfD) for oral exposure to chromium, 0.003 mg kg-1  day-1 , is based on a no-observable-adverse-effect-level from a 1958 bioassay of rats exposed to ≤25 ppm hexavalent chromium [Cr(VI)] in drinking water. EPA characterizes the confidence in this RfD as "low." A more recent cancer bioassay indicates that Cr(VI) in drinking water is carcinogenic to mice at ≥30 ppm. To assess whether the existing RfD is health protective, neoplastic and non-neoplastic lesions from the 2 year cancer bioassay were modeled in a three-step process. First, a rodent physiological-based pharmacokinetic (PBPK) model was used to estimate internal dose metrics relevant to each lesion. Second, benchmark dose modeling was conducted on each lesion using the internal dose metrics. Third, a human PBPK model was used to estimate the daily mg kg-1 dose that would produce the same internal dose metric in both normal and susceptible humans. Mechanistic research into the mode of action for Cr(VI)-induced intestinal tumors in mice supports a threshold mechanism involving intestinal wounding and chronic regenerative hyperplasia. As such, an RfD was developed using incidence data for the precursor lesion diffuse epithelial hyperplasia. This RfD was compared to RfDs for other non-cancer endpoints; all RfD values ranged 0.003-0.02 mg kg-1  day-1 . The lowest of these values is identical to EPA's existing RfD value. Although the RfD value remains 0.003 mg kg-1  day-1 , the confidence is greatly improved due to the use of a 2-year bioassay, mechanistic data, PBPK models and benchmark dose modeling.


Assuntos
Bioensaio , Testes de Carcinogenicidade/métodos , Cromo/toxicidade , Poluentes Ambientais/toxicidade , Neoplasias Intestinais/induzido quimicamente , Modelos Biológicos , Administração Oral , Animais , Bioensaio/normas , Calibragem , Testes de Carcinogenicidade/normas , Cromo/administração & dosagem , Cromo/farmacocinética , Relação Dose-Resposta a Droga , Poluentes Ambientais/administração & dosagem , Poluentes Ambientais/farmacocinética , Feminino , Humanos , Neoplasias Intestinais/patologia , Masculino , Camundongos , Nível de Efeito Adverso não Observado , Ratos , Padrões de Referência , Medição de Risco , Especificidade da Espécie , Estados Unidos , United States Environmental Protection Agency
20.
Plant Physiol Biochem ; 118: 653-666, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28810231

RESUMO

Chromium-induced toxicity and mechanisms of cell death involved in plants are yet to be fully elucidated. To understand the events of these processes, the stress response of the soybean plant using trivalent and hexavalent chromium compounds, namely, basic chromium sulphate (BCS) and potassium dichromate (K2Cr2O7) was investigated. The leaf surface morphology for stomatal aperture, wax deposition and presence of trichomes for chromium accumulation was examined by SEM-EDAX and light microscopy. The leaf mesophyll cell integrity was identified by trypan blue staining; chlorophyll autofluorescence, ROS generation and mitochondrial function were studied by fluorescence microscopy using different dyes. Isolated chloroplasts were analysed for micronutrients and total chromium content by AAS. Elevated Cr level and decreased Fe, Cu and Zn content in chloroplast revealed the active transportation of highly soluble Cr6+ species resulting in poor absorption of micronutrients. Cr accumulation as Cr(V) in chloroplast was noticed at g = 1.98 of electron paramagnetic resonance signal. Plants grown in Cr(VI) amended soil showed chemical modification of biological macromolecules in the chloroplast as observed from fourier transform infra-red (FTIR) spectra; the chloroplast DNA damage was confirmed by DAPI staining. Cr(VI)-treated plants showed significant reduction in the levels of various biochemical parameters. The results altogether clearly indicate that Cr(VI)-induced reactive oxygen species (ROS) production leads to oxidative stress-associated changes in the organelles, particularly in chloroplast, resulting in cell death.


Assuntos
Cloroplastos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Dicromato de Potássio , Espécies Reativas de Oxigênio/metabolismo , Soja/metabolismo , Transporte Biológico Ativo/efeitos dos fármacos , Cromo/farmacocinética , Cromo/farmacologia , Dicromato de Potássio/farmacocinética , Dicromato de Potássio/farmacologia
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