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1.
J Mol Model ; 27(11): 323, 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34643800

RESUMO

The world has face the COVID-19 pandemic which has already caused millions of death. Due to the urgency in fighting the virus, we study five residues of free amino acids present in the structure of the SARS-CoV-2 spike protein (S). We investigated the spontaneous interaction between amino acids and silver ions (Ag+), considering these ions as a virucide chemical agent for SARS-CoV-2. The amino acid-Ag+ systems were investigated in a gaseous medium and a simulated water environment was described with a continuum model (PCM) the calculations were performed within the framework of density functional theory (DFT). Calculations related to the occupied orbitals of higher energy showed that Ag+ has a tendency to interact with the nitrile groups (-NH). The negative values of the Gibbs free energies show that the interaction process between amino acids-Ag+ in both media occurs spontaneously. There is a decrease in Gibbs free energy from the amino acid-Ag+ interactions immersed in a water solvation simulator.


Assuntos
Aminoácidos/química , Antivirais/química , Teoria da Densidade Funcional , Prata/química , Glicoproteína da Espícula de Coronavírus/química , Aminoácidos/metabolismo , Antivirais/metabolismo , Sítios de Ligação , Cátions Monovalentes , Expressão Gênica , Humanos , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , SARS-CoV-2/química , Prata/metabolismo , Glicoproteína da Espícula de Coronavírus/antagonistas & inibidores , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismo , Eletricidade Estática , Termodinâmica
2.
Chem Commun (Camb) ; 57(70): 8726-8729, 2021 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-34396382

RESUMO

SilE and SilB are both proteins involved in the silver efflux pump found in Gram-negative bacteria such as S. typhimurium. Using model peptides along with NMR and CD experiments, we show how SilE may store silver ions prior to delivery and we hypothesize for the first time the interplay between SilB and SilE.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas de Transporte/metabolismo , Fragmentos de Peptídeos/metabolismo , Prata/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/química , Sítios de Ligação , Proteínas de Transporte/química , Farmacorresistência Bacteriana , Ressonância Magnética Nuclear Biomolecular , Fragmentos de Peptídeos/química , Ligação Proteica , Salmonella typhimurium/química
3.
Carbohydr Polym ; 269: 118346, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34294353

RESUMO

In the present study, the novel Ag/cellulose nanocrystal (CNC)-doped CeO2 quantum dots (QDs) with highly efficient catalytic performance were synthesized using one pot co-precipitation technique, which were then applied in the degradation of methylene blue and ciprofloxacin (MBCF) in wastewater. Catalytic activity against MBCF dye was significantly reduced (99.3%) for (4%) Ag dopant concentration in acidic medium. For Ag/CNC-doped CeO2 vast inhibition domain of G-ve was significantly confirmed as (5.25-11.70 mm) and (7.15-13.60 mm), while medium- to high-concentration of CNC levels were calculated for G + ve (0.95 nm, 1.65 mm), respectively. Overall, (4%) Ag/CNC-doped CeO2 revealed significant antimicrobial activity against G-ve relative to G + ve at both concentrations, respectively. Furthermore, in silico molecular docking studies were performed against selected enzyme targets dihydrofolate reductase (DHFR), dihydropteroate synthase (DHPS), and DNA gyrase belonging to folate and nucleic acid biosynthetic pathway, respectively to rationalize possible mechanism behind bactericidal potential of CNC-CeO2 and Ag/CNC-CeO2.


Assuntos
Antibacterianos/farmacologia , Celulose/química , Cério/química , Corantes/química , Pontos Quânticos/química , Prata/farmacologia , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/efeitos da radiação , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Catálise/efeitos da radiação , Celulose/síntese química , Celulose/metabolismo , Celulose/efeitos da radiação , Cério/metabolismo , Cério/efeitos da radiação , Ciprofloxacina/química , DNA Girase/química , DNA Girase/metabolismo , Di-Hidropteroato Sintase/química , Di-Hidropteroato Sintase/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologia , Luz , Azul de Metileno/química , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Ligação Proteica , Pontos Quânticos/metabolismo , Pontos Quânticos/efeitos da radiação , Prata/química , Prata/metabolismo , Prata/efeitos da radiação , Staphylococcus aureus/efeitos dos fármacos , Tetra-Hidrofolato Desidrogenase/química , Tetra-Hidrofolato Desidrogenase/metabolismo , Poluentes Químicos da Água/química , Purificação da Água/métodos
4.
Ecotoxicol Environ Saf ; 220: 112371, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34052759

RESUMO

Uptake of most metal nanoparticles (NPs) in organisms is assumed to be mainly driven by the bioavailability of the released ions, as has been verified in controlled and short-term exposure tests. However, the changeability of NPs and the dynamic processes which NPs undergo in the soil environment, bring uncertainty regarding their interactions with soil organisms over a long period of time. To assess the potential impacts of long-term exposure scenarios on the toxicokinetic of metal NPs, earthworms Eisenia fetida were exposed to soils spiked with pristine Ag-NP, aged Ag-NP (Ag2S-NP) and ionic Ag for nine months, and results were compared to those from a similar short-term (28 days) experiment, conducted under similar conditions. Overall, there were no statistical differences between long-term accumulation patterns in earthworms exposed to pristine Ag-NP and AgNO3, while for Ag2S-NP, the amount of Ag internalized after 9 months was five times lower than for the other treatments. Average Ag concentrations in soil pore water in all treatments did not change over time, however the soil pH decreased and electrical conductivity increased in all treatments. Metallothionein concentrations in exposed earthworms were not statistically different from levels in untreated earthworms. Finally, the short-term toxicokinetic models predicted the bioaccumulation in earthworms exposed to Ag-NP, AgNO3 after nine months on the whole. Although the bioaccumulation for Ag2S-NPs was somewhat under-predicted, the rate of accumulation of Ag2S-NPs is much lower than that of Ag-NPs or AgNO3 and thus potentially of lower concern. Nevertheless, better understanding about the exposure kinetics of Ag2S-NP would help to address potential nano-specific toxicokinetic and toxicodynamics, also of other sulfidized metal NPs.


Assuntos
Íons/metabolismo , Nanopartículas Metálicas , Oligoquetos/metabolismo , Prata/metabolismo , Poluentes do Solo/metabolismo , Solo/química , Animais , Bioacumulação , Disponibilidade Biológica , Transporte Biológico , Metalotioneína , Compostos de Prata/metabolismo , Toxicocinética , Água
5.
Sci Rep ; 11(1): 10356, 2021 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-33990673

RESUMO

Due to the increasing demand for eco-friendly, cost-effective and safe technologies, biosynthetic metal nanoparticles have attracted worldwide attention. In this study, silver nanoparticles (AgNPs) were extracellularly biosynthesized using the culture supernatants of Aspergillus sydowii. During synthesis, color change was preliminarily judge of the generation of AgNPs, and the UV absorption peak at 420 nm further confirms the production of AgNPs. Transmission electron microscopy and X-ray diffraction were also used to identify the AgNPs. The results shows that AgNPs has crystalline cubic feature and is a polydisperse spherical particle with size between 1 and 24 nm. Three main synthesis factors (temperature, pH and substrate concentration) were optimized, the best synthesis conditions were as follows 50 °C, 8.0 and 1.5 mM. In the biological application of AgNPs, it shows effective antifungal activity against many clinical pathogenic fungi and antiproliferative activity to HeLa cells and MCF-7 cells in vitro. Our research finds a new path to biosynthesis of AgNPs in an eco-friendly manner, and bring opportunity for biomedical applications in clinic.


Assuntos
Antifúngicos/farmacologia , Antineoplásicos/farmacologia , Aspergillus/metabolismo , Química Verde/métodos , Prata/farmacologia , Antifúngicos/síntese química , Antineoplásicos/síntese química , Aspergillus/química , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Células MCF-7 , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Transmissão , Prata/química , Prata/metabolismo
6.
Cells ; 10(3)2021 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-33808775

RESUMO

Graphene oxide-silver nanoparticle (GO-AgNPs) nanocomposites have drawn much attention for their potential in biomedical uses. However, the potential toxicity of GO-AgNPs in animals and humans remains unknown, particularly in the developing fetus. Here, we reported the GO-AgNP-mediated cytotoxicity and epigenetic alteration status in caprine fetal fibroblast cells (CFFCs). In brief, the proliferation and apoptosis rate of GO-AgNP-treated CFFCs (4 and 8 µg/mL of GO-AgNPs) were measured using the cell-counting kit (CCK-8) assay and the annexin V/propidium iodide (PI) assay, respectively. In addition, the oxidative stress induced by GO-AgNPs and detailed mechanisms were studied by evaluating the generation of reactive oxygen species (ROS), superoxide dismutase (SOD), lactate dehydrogenase (LDH), malondialdehyde (MDA), and caspase-3 and abnormal methylation. The expression of pro- and anti-apoptotic genes and DNA methyltransferases was measured using reverse transcription followed by RT-qPCR. Our data indicated that GO-AgNPs cause cytotoxicity in a dose-dependent manner. GO-AgNPs induced significant cytotoxicity by the loss of cell viability, production of ROS, increasing leakage of LDH and level of MDA, increasing expression of pro-apoptotic genes, and decreasing expression of anti-apoptotic genes. GO-AgNPs incited DNA hypomethylation and the decreased expression of DNMT3A. Taken together, this study showed that GO-AgNPs increase the generation of ROS and cause apoptosis and DNA hypomethylation in CFFCs. Therefore, the potential applications of GO-AgNPs in biomedicine should be re-evaluated.


Assuntos
Fibroblastos/metabolismo , Nanopartículas Metálicas , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Prata/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Humanos , Malondialdeído/metabolismo , Metilação/efeitos dos fármacos , Prata/metabolismo
7.
mBio ; 12(2)2021 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-33820823

RESUMO

Gram-negative bacteria utilize the resistance-nodulation-cell division (RND) superfamily of efflux pumps to expel a variety of toxic compounds from the cell. The Escherichia coli CusA membrane protein, which recognizes and extrudes biocidal Cu(I) and Ag(I) ions, belongs to the heavy-metal efflux (HME) subfamily of RND efflux pumps. We here report four structures of the trimeric CusA heavy-metal efflux pump in the presence of Cu(I) using single-particle cryo-electron microscopy (cryo-EM). We discover that different CusA protomers within the trimer are able to bind Cu(I) ions simultaneously. Our structural data combined with molecular dynamics (MD) simulations allow us to propose a mechanism for ion transport where each CusA protomer functions independently within the trimer.IMPORTANCE The bacterial RND superfamily of efflux pumps mediate resistance to a variety of biocides, including Cu(I) and Ag(I) ions. Here we report four cryo-EM structures of the trimeric CusA pump in the presence of Cu(I). Combined with MD simulations, our data indicate that each CusA protomer within the trimer recognizes and extrudes Cu(I) independently.


Assuntos
Microscopia Crioeletrônica , Proteínas de Escherichia coli/química , Escherichia coli/metabolismo , Transporte de Íons , Proteínas de Membrana Transportadoras/química , Metais Pesados/metabolismo , Sítios de Ligação , Transporte Biológico , Cobre/metabolismo , Escherichia coli/genética , Escherichia coli/ultraestrutura , Proteínas de Escherichia coli/ultraestrutura , Proteínas de Membrana Transportadoras/ultraestrutura , Simulação de Dinâmica Molecular , Ligação Proteica , Prata/metabolismo
8.
Molecules ; 26(4)2021 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-33672102

RESUMO

Macroalgae are sources of bioactive compounds that are interesting from both a chemical and a medical point of view. Although their use in biomedicine has increased significantly in recent years, tests conducted to date have been mostly related to species from temperate latitudes, with the potential application of Antarctic biodiversity being minor. The wide variety of algae species present on Antarctic coastal areas can be a source of new antioxidants. Bearing this in mind, the brown macroalgae Desmarestia antarctica (DA) and the red Iridaea cordata (IC) were selected for the preparation of aqueous extracts with the aim of analyzing their antioxidant activity. This analysis was performed by determining reducing power, total phenolic content, and 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity. Furthermore, both extracts were employed to synthesize gold and silver nanoparticles. The nanomaterials were fully characterized by means of UV-Visible spectroscopy, transmission electron microscopy, Z potential measurements, and Fourier transform infrared spectroscopy, which confirmed the formation of stable, spherical nanoparticles with mean diameters of 13.7 ± 3.1 and 17.5 ± 3.7 nm for Ag@DA and Ag@IC and 12.6 ± 1.9 and 12.3 ± 1.6 nm for Au@DA and Au@IC. Antioxidant assays were performed after the synthesis of the nanomaterials to evaluate their possible synergistic effect with the extracts. The results suggest that polysaccharides and proteins may play a key role in the process of reduction and stabilization. Finally, for the sake of comparison, the results obtained for the Antarctic macroalgae Desmarestia menziesii and Palmaria decipiens have also been considered in the present work.


Assuntos
Antioxidantes/farmacologia , Ouro/metabolismo , Nanopartículas Metálicas/química , Feófitas/química , Rodófitas/química , Prata/metabolismo , Regiões Antárticas , Antioxidantes/síntese química , Antioxidantes/química , Compostos de Bifenilo/antagonistas & inibidores , Ouro/química , Tamanho da Partícula , Picratos/antagonistas & inibidores , Prata/química
9.
Int J Mol Sci ; 22(4)2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33670100

RESUMO

Silver-based materials are widely used in clinical medicine. Furthermore, the usage of silver containing materials and devices is widely recommended and clinically approved. The impact on human health of the increasing use of silver nanoparticles in medical devices remains understudied, even though Ag-containing dressings are known to release silver into the bloodstream. In this study, we detected a widespread and sometimes significant silver accumulation both in healthy and sick liver biopsies, levels being statistically higher in patients with various hepatic pathologies. 28 healthy and 44 cirrhotic liver samples were investigated. The median amount of 0.049 ppm Ag in livers was measured in cirrhotic livers while the median was 0.0016 ppm for healthy livers (a more than 30-fold difference). The mean tissue concentrations of essential metals, Fe and Zn in cirrhotic livers did not differ substantially from healthy livers, while Cu was positively correlated with Ag. The serum levels of gamma-glutamyl transpeptidase (GGTP) was also positively correlated with Ag in cirrhotic livers. The increased Ag accumulation in cirrhotic livers could be a side effect of wide application of silver in clinical settings. As recent studies indicated a significant toxicity of silver nanoparticles for human cells, the above observation could be of high importance for the public health.


Assuntos
Cobre/metabolismo , Cirrose Hepática/metabolismo , Transplante de Fígado , Fígado/metabolismo , Prata/metabolismo , Adulto , Feminino , Humanos , Cirrose Hepática/cirurgia , Masculino , Pessoa de Meia-Idade
10.
Sci Total Environ ; 768: 144659, 2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-33736311

RESUMO

The widespread use of silver nanoparticles (Ag NPs) has raised substantial health risks, but little is known about the epigenetic toxicity induced by Ag+ and Ag NPs. This study characterized physiological and lncRNA profiles to explore the toxic effects and epigenetic mechanisms in Tetrahymena thermophila on exposure to Ag+ (in the form of AgNO3) and different Ag NPs for 24 h. The Ag NPs studied varied in size (10 nm and 80 nm) and surface coating (citrate and polyvinylpyrrolidone). We found that both Ag+ and Ag NPs elicited strong growth-inhibiting effects on T. thermophila. The toxicity was mainly caused by high reactive oxygen species (ROS) levels, leading to lipid peroxidation and mitochondrial dysfunction. To combat the oxidative stress, the protist activated an antioxidative response, increasing the activity of glutathione peroxidase and other antioxidants. Notably, 1250 lncRNAs were differentially expressed under Ag+ or Ag NPs exposure relative to the non-exposure control, which were clustered into 15 expression modules in weighted gene co-expression network analysis. These gene modules exhibited toxicant-specific expression patterns, potentially playing regulatory roles, via their co-expressed mRNAs, to inhibit cell growth, activate cell membrane cation channel, and promote oxidoreductase activity. This research illuminates how post-transcriptional mechanisms of a ciliated protozoan regulate responses to Ag+ and Ag NPs toxicities.


Assuntos
Nanopartículas Metálicas , Tetrahymena thermophila , Epigênese Genética , Nanopartículas Metálicas/toxicidade , Estresse Oxidativo , Prata/metabolismo , Prata/toxicidade , Tetrahymena thermophila/genética
11.
Endocr Regul ; 55(1): 52-60, 2021 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-33600664

RESUMO

Objectives. The application of nanoparticles is experiencing a rapid growth, but it faces a problem of their toxicity, especially adverse effects on female reproduction. Food and medicinal plants and their isoflavones can be protectors against environmental stressors, but their ability to abate the adverse effects of nanoparticles has not been studied yet. In the present study, we examined the effect of silver (AgNPs) and titanium dioxide (titania, TiO2NPs) nanoparticles alone or in combination with plant phytoestrogens/antioxidants (resveratrol, diosgenin, and quercetin) on accumulation of nanoparticles, and progesterone release by cultured porcine ovarian granulosa cells.Methods. Porcine granulosa cells were incubated in the presence of AgNPs or TiO2NPs (0.1, 1, 10 or 100 µg/ml) alone or in combination with resveratrol, diosgenin or quercetin (10 µg/ml) for 48 h. The accumulation of tested nanoparticles by granulosa cells was assessed under light microscope. Progesterone concentration in culture media was measured by ELISA kit.Results. Cells accumulated both AgNPs and TiO2NPs in a dose-dependent manner. AgNPs, but not TiO2NPs, at highest dose (100 µg/ml) resulted in a destruction of cell monolayer. Both Ag-NPs and TiO2NPs reduced progesterone release. Resveratrol, diosgenin, and quercetin promoted accumulation of both AgNPs and TiO2NPs in ovarian cells and inhibited the progesterone output. Furthermore, resveratrol and diosgenin, but not quercetin, prevented the suppressive action of both AgNPs, and TiO2NPs on progesterone release.Conclusions. These observations (1) demonstrate accumulation of AgNPs and TiO2NPs in ovarian cells, (2) confirm the toxic impact of AgNPs, and TiO2NPs on these cells, (3) confirm the inhibitory effects of plant polyphenols/phytoestrogens on ovarian steroidogenesis, (4) show the ability of these isoflavones to increase the accumulation of AgNPs and TiO2NPs, and (5) show their ability to reduce the suppressive effect of AgNPs and TiO2NPs on ovarian progesterone release. The suppressive effect of AgNPs and TiO2NPs on ovarian functions should be taken into account by their exposition. However, these adverse effects could be mitigated by some plant isoflavones.


Assuntos
Células da Granulosa/metabolismo , Isoflavonas/farmacologia , Nanopartículas Metálicas/toxicidade , Prata/metabolismo , Titânio/metabolismo , Animais , Células Cultivadas , Diosgenina/farmacologia , Feminino , Células da Granulosa/efeitos dos fármacos , Progesterona/metabolismo , Quercetina/farmacologia , Resveratrol/farmacologia , Prata/toxicidade , Suínos , Titânio/toxicidade
12.
Molecules ; 26(4)2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-33562781

RESUMO

The nanomaterial industry generates gigantic quantities of metal-based nanomaterials for various technological and biomedical applications; however, concomitantly, it places a massive burden on the environment by utilizing toxic chemicals for the production process and leaving hazardous waste materials behind. Moreover, the employed, often unpleasant chemicals can affect the biocompatibility of the generated particles and severely restrict their application possibilities. On these grounds, green synthetic approaches have emerged, offering eco-friendly, sustainable, nature-derived alternative production methods, thus attenuating the ecological footprint of the nanomaterial industry. In the last decade, a plethora of biological materials has been tested to probe their suitability for nanomaterial synthesis. Although most of these approaches were successful, a large body of evidence indicates that the green material or entity used for the production would substantially define the physical and chemical properties and as a consequence, the biological activities of the obtained nanomaterials. The present review provides a comprehensive collection of the most recent green methodologies, surveys the major nanoparticle characterization techniques and screens the effects triggered by the obtained nanomaterials in various living systems to give an impression on the biomedical potential of green synthesized silver and gold nanoparticles.


Assuntos
Ouro/química , Ouro/metabolismo , Química Verde/métodos , Nanopartículas , Prata/química , Prata/metabolismo , Materiais Biocompatíveis/química , Materiais Biocompatíveis/metabolismo
13.
Sci Rep ; 11(1): 770, 2021 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-33436966

RESUMO

Silver is a poisonous but precious heavy metal that has widespread application in various biomedical and environmental divisions. Wide-ranging usage of the metal has twisted severe environmental apprehensions. Henceforth there is a cumulative call for the progress of modest, low-cost and, the ecological method for remediation of silver. In the present study, Bacillus cereus was isolated from contaminated soil. Various experimental factors like the amount of AgNO3, inoculum size, temperature, time, and pH were improved by using central composite design (CCD) grounded on response surface methodology (RSM). Optimized values for AgNO3 (1 mM) 10 ml, inoculum size (Bacillus cereus) 8.7 ml, temperature 48.5 °C, time 69 h, and pH 9 showed in the form of optimized ramps. The formed nanoparticles stayed characterized by UV-visible spectrophotometer, Scanning Electron Microscopy, Fourier transform infra-red spectrometry, particle size analyzer, and X-ray diffraction. The particle size ranges from 5 to 7.06 nm with spherical form. The antimicrobial effectiveness of synthesized nanoparticles was tested contrary to five multidrug resistant microbial strains, Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, Salmonella enterica, Porteus mirabilis by disc diffusion method. The minimum inhibitory concentrations and minimum lethal concentrations were detected by the broth macro dilution method. 2,2-diphenyl-1-picrylhydrazyl-hydrate (DPPH) was used to check the free radical scavenging ability of biogenic silver nanoparticles. Similarly, anti-radical activity was checked by 2,2'-Azino-Bis-3-Ethylbenzothiazoline-6-Sulfonic Acid (ABTS) with varying time intervals. Catalytic potential of biosynthesized silver nanoparticles was also investigated.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Bacillus cereus/metabolismo , Nanopartículas Metálicas/química , Prata/metabolismo , Bacillus cereus/efeitos dos fármacos , Bacillus cereus/crescimento & desenvolvimento , Catálise , Tamanho da Partícula , Prata/química , Difração de Raios X
14.
Environ Sci Pollut Res Int ; 28(17): 21900-21909, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33410076

RESUMO

The current investigation pointed to report the negative impacts of silver nanoparticles [Ag]NPs that synthesized by leaf extract of Moringa oleifera on oxidative stress biomarkers of Oreochromis niloticus, as well as the role of different Selenium type to antagonistic that toxicity. Fish were exposed to [Ag]NPs (1.95 and 3.9 ppm) as sublethal concentrations alongside 0.1 ppm of Se bulk and 0.1 ppm biosynthesized [Se]NPs selenium nanoparticles antagonistic effect for 2 and 4 weeks. Lipid peroxidation (LPO), DNA fragmentation, total antioxidant capacity (TAOC), catalase (CAT), and superoxide dismutase (SOD) were evaluated as oxidative stress biomarkers,. A significant increase (p < 0.05) in LPO and DNA fragmentation and a significant decrease (p < 0.05) in TAOC, CAT, and SOD were found in [Ag]NPs exposed groups when compared with the control one. Biosynthesized [Se]NPs and Se bulk showed a positive role in [Ag]NPs detoxification. Our investigation suggested that [Ag]NPs showed a toxic effect on oxidative stress biomarkers. However, Se-NP addition gives a good recovery of oxidative biomarkers more than Se bulk in detoxification of [Ag]NPs.


Assuntos
Ciclídeos , Nanopartículas Metálicas , Selênio , Animais , Biomarcadores/metabolismo , Ciclídeos/metabolismo , Fígado/metabolismo , Nanopartículas Metálicas/toxicidade , Estresse Oxidativo , Selênio/metabolismo , Prata/metabolismo , Prata/toxicidade
15.
Andrologia ; 53(3): e13982, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33469996

RESUMO

Silver nanoparticles (SNPs) can pass from the cell membrane and testicular blood barrier due to their small size, and by increasing oxidative stress they cause disorder in the male reproductive system. Kombucha is a traditional fermented drink with detoxification and potent antioxidant properties. We aimed to examine the protective effect of Kombucha against the damages due to SNPs on the testis tissue. In this experimental study, NMRI mice were randomly separated into four groups (n = 6), namely control (distilled water), SNPs (500 mg/kg), Kombucha extract (9 ml/kg) and SNPs + Kombucha, and were treated with gavage for 35 days. A significant decrease in testosterone level and total antioxidant capacity, and a significant increase in malondialdehyde concentration was observed in the SNPs group in comparison with the control group. Histological studies on the testis of mice treated with SNPs showed vacuolation, decrease in generational epithelium thickness, seminiferous tubules diameter, testis volume and the number of spermatozoa in lumen of the seminiferous tubule and increase in the volume of interstitial space while the mentioned parameters were improved in the SNPs + Kombucha group compared to the SNPs group. Kombucha reduces the adverse effects of SNPs on testis tissue and improves the function of the male reproductive system.


Assuntos
Nanopartículas Metálicas , Prata , Animais , Antioxidantes/metabolismo , Masculino , Nanopartículas Metálicas/toxicidade , Camundongos , Estresse Oxidativo , Túbulos Seminíferos , Prata/metabolismo , Prata/toxicidade , Espermatozoides , Testículo/metabolismo
16.
Anal Sci ; 37(2): 275-281, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32863333

RESUMO

Chiral enantiomer recognition is important but facing tough challenges in the direct quantitative determination for complex samples. In this work, via chosing nitrogen-doped silicon quantum dots (N-SiQD) as optical nanoprobe and constructing N-SiQD/silver (N-SiQD/Ag NPs) complex, ß-D-GOx as model enzyme and glucose enantiomers as analytes, a fluorescent and colorimetric dual-signal chiral sensing strategy was proposed herein for chiral recognition based on specific enzyme-catalyzed reaction. N-SiQD can exhibit intense fluorescence, while it can be quenched by Ag NPs owing to the formation of N-SiQD/Ag NPs. In the presence of glucose isomer, D-glucose is catalytically hydrolyzed by ß-D-GOx to form H2O2 owing to the specific enzyme catalyzed reaction between D-glucose and ß-D-GOx, and H2O2 can etch Ag NPs from the N-SiQD/Ag NPs probe to change the solution color from brown to colorless and restore the N-SiQD fluorescence; while these phenomena cannot be caused by L-glucose, a dual-signal sensing method was thus constructed for recognizing glucose enantiomers. It is believed that the chiral enantiomers recognition strategy via enzyme catalysis has great application for selective and quantificational detection of enantiomers in the complex sample system.


Assuntos
Colorimetria , Corantes Fluorescentes/metabolismo , Glucose Oxidase/metabolismo , Glucose/metabolismo , Prata/metabolismo , Corantes Fluorescentes/química , Glucose/química , Glucose Oxidase/química , Estrutura Molecular , Nanopartículas/química , Prata/química , Estereoisomerismo
17.
Chemosphere ; 263: 127961, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32829223

RESUMO

Standardized experimental approaches for the quantification of the bioaccumulation potential of nanomaterials in general and in (benthic) invertebrates in particular are currently lacking. We examined the suitability of the benthic freshwater amphipod Hyalella azteca for the examination of the bioaccumulation potential of nanomaterials. A flow-through test system that allows the generation of bioconcentration and biomagnification factors was applied. The feasibility of the system was confirmed in a 2-lab comparison study. By carrying out bioconcentration and biomagnification studies with gold, titanium dioxide and silver nanoparticles as well as dissolved silver (AgNO3) we were able to assess the bioaccumulation potential of different types of nanomaterials and their exposure pathways. For this, the animals were examined for their total metal body burden using inductively coupled mass spectroscopy (ICP-MS) and for the presence of nanoparticulate burdens using single-particle ICP-MS. The role of released ions was highlighted as being very important for the bioavailability and bioaccumulation of metals from nanoparticles for both examined uptake paths examined (bioconcentration and biomagnification). In 2018 a tiered testing strategy for engineered nanomaterials was proposed by Handy et al. that may allow a waiver of bioaccumulation fish studies using inter alia invertebrates. Data gained in studies carried out with invertebrates like the developed Hyalella azteca test may be included in this proposed tiered testing strategy.


Assuntos
Anfípodes/metabolismo , Nanopartículas Metálicas/análise , Poluentes Químicos da Água/metabolismo , Animais , Bioacumulação , Peixes/metabolismo , Água Doce/química , Invertebrados/metabolismo , Prata/metabolismo , Titânio , Poluentes Químicos da Água/análise
18.
Mar Genomics ; 56: 100808, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32778401

RESUMO

Shewanella sp. Arc9-LZ is a bacterium capable of synthesizing silver nanoparticles in darkness. It was isolated from the marine sediment from the Arctic Ocean (158°01'12"W; 84°28'38"N) collected during the 9th Chinese National Arctic Expedition in 2018. Here, we describe the complete genome of Shewanella sp. Arc9-LZ. The complete genome of Shewanella sp. Arc9-LZ is composed of a circular chromosome of 4,911,031 bp with G + C content of 41.61 mol%. The genome encodes 4040 protein-coding genes (CDSs), 104 tRNAs, and 35 rRNAs. The rRNAs contain 14 copies of 5S rRNA gene, 11 copies of 16S rRNA gene, and 10 copies of 23S rRNA gene. Based on the KEGG, COG, NR, Swiss-Prot, TCDB, and CAZy analysis, a total of 64 genes belonging to 9 kinds are related to the AgNPs synthesis. These genes are involeved in the synthesis of riboflavin, b-type cytochrome, c-type cytochrome, coenzyme Q, NADPH dehydrogenase, cytochrome c reductase, cytochrome c oxidase, nitroreductase, and nitrate reductase.


Assuntos
Genoma Bacteriano , Shewanella/genética , Prata/metabolismo , Organismos Aquáticos/genética , Regiões Árticas , Escuridão , Nanopartículas Metálicas/química , Oceanos e Mares , Sequenciamento Completo do Genoma
19.
Ecotoxicol Environ Saf ; 208: 111427, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33049449

RESUMO

This study aimed to determine the in vivo effect of silver nanoparticles (AgNPs) on the concentration of sex steroids (progesterone - P4, estradiol - E2, testosterone - T) and thyroid hormones (thyroxine - T4, triiodothyronine - T3) in the blood plasma as well as the messenger ribonucleic acid (mRNA) and protein expression of HSD3ß, CYP17A1 and CYP19A1 enzymes and steroid hormone concentrations in chicken ovarian follicles. AgNPs did not affect serum steroid hormone levels, but increased T3 levels depending on the size and concentration of AgNPs. At the level of ovarian tissues, AgNPs: (i) affected the levels of E2 and T in prehierachical follicles; (ii) reduced the expression of CYP19A1 mRNA and protein and consequently diminished E2 concentration in small white follicles; and (iii) increased the expression of CYP17A1 mRNA in large white follicles, without changing its protein expression. The results indicate that AgNPs affect chicken ovarian steroidogenesis. The effects of AgNPs depend on exposure time, the type of follicle and the degree of its development and are associated with the modulation of steroidogenic gene expression and E2 and T synthesis. Prehierachical follicles seem to be more susceptible to AgNPs than preovulatory ones. In conclusion, AgNPs by targeting the chicken ovary may indirectly influence the selection processes of prehierarchical follicles to the pre-ovulatory hierarchy and disturb the ovarian steroidogenesis. Furthermore, AgNPs may affect thyroid hormone metabolism in different ways by size which in turn may influence energy homeostasis of the target cells.


Assuntos
Nanopartículas Metálicas/toxicidade , Folículo Ovariano/fisiologia , Prata/toxicidade , Hormônios Tireóideos/fisiologia , Animais , Aromatase , Galinhas/metabolismo , Estradiol/metabolismo , Feminino , Hormônios Esteroides Gonadais/metabolismo , Folículo Ovariano/efeitos dos fármacos , Ovário/metabolismo , Progesterona/metabolismo , RNA Mensageiro/metabolismo , Prata/metabolismo , Esteroide 17-alfa-Hidroxilase/metabolismo , Testosterona/metabolismo , Hormônios Tireóideos/metabolismo , Tri-Iodotironina/metabolismo
20.
Biotechnol Lett ; 43(1): 307-316, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32944816

RESUMO

OBJECTIVES: To assess the extracellular synthesis of silver nanoparticles using marine derived fungi Aspergillus brunneoviolaceus with their antibacterial and antioxidant activities. RESULTS: The biosynthesis of silver nanoparticles was estimated by the change in color from light yellow to dark brown within 36 h as the reaction progressed. UV-Visible spectroscopy exhibited its stability at 411 nm; ATR-FTIR spectroscopy depicted the functional group responsible for its production; X-Ray Diffraction denoted its crystalline FCC structure resembling the peaks in XRD pattern, corresponding to [111], [200], [220], [311] and [222] planes; TEM imaging revealed its spherical morphology with the particle size ranging from 0.72 to 15.21 nm and Tauc's plot analysis that disclosed its band gap energy as 2.44 eV that manifested the potential of AgNPs to be semiconductors. The characterization data henceforth, confirmed the efficient production of silver nanoparticles. The biosynthesized AgNPs expressed strong antibacterial activity against two Gram-positive and three Gram-negative bacteria. They also proved to possess higher antioxidative potentials by showing their potent radical scavenging activity against DPPH (2, 2-diphenyl-1-picrylhydrazyl). CONCLUSIONS: The study unfolds the prospect for further utilization of this mycogenically synthesized AgNPs as antibacterial, antioxidative and anticancer agents.


Assuntos
Antibacterianos , Antioxidantes , Aspergillus/química , Nanopartículas Metálicas/química , Prata , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Antioxidantes/química , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Organismos Aquáticos/química , Bactérias/efeitos dos fármacos , Produtos Biológicos/química , Compostos de Bifenilo/metabolismo , Picratos/metabolismo , Prata/química , Prata/metabolismo
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