Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.031
Filtrar
1.
PLoS One ; 15(7): e0235556, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32614916

RESUMO

To gain a better insight into the selenium nanoparticle (nSe) benefits/toxicity, this experiment was carried out to address the behavior of bitter melon seedlings to nSe (0, 1, 4, 10, 30, and 50 mgL-1) or bulk form (selenate). Low doses of nSe increased biomass accumulation, while concentrations of 10 mgL-1 and above were associated with stem bending, impaired root meristem, and severe toxicity. Responses to nSe were distinct from that of bulk in that the nano-type exhibited a higher efficiency to stimulate growth and organogenesis than the bulk. The bulk form displayed higher phytotoxicity than the nano-type counterpart. According to the MSAP-based analysis, nSe mediated substantial variation in DNA cytosine methylation, reflecting the epigenetic modification. By increasing the concentration of nSe, the expression of the WRKY1 transcription factor linearly up-regulated (mean = 7.9-fold). Transcriptions of phenylalanine ammonia-lyase (PAL) and 4-Coumarate: CoA-ligase (4CL) genes were also induced. The nSe treatments at low concentrations enhanced the activity of leaf nitrate reductase (mean = 52%) in contrast with the treatment at toxic concentrations. The toxic concentration of nSe increased leaf proline concentration by 80%. The nSe supplement also stimulated the activities of peroxidase (mean = 35%) and catalase (mean = 10%) enzymes. The nSe-treated seedlings exhibited higher PAL activity (mean = 39%) and soluble phenols (mean = 50%). The nSe toxicity was associated with a disrupted differentiation of xylem conducting tissue. The callus formation and performance of the explants originated from the nSe-treated seedlings had a different trend than that of the control. This experiment provides new insights into the nSe-associated advantage/ cytotoxicity and further highlights the necessity of designing convincing studies to introduce novel methods for plant cell/tissue cultures and agriculture.


Assuntos
Metilação de DNA/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Momordica charantia/metabolismo , Nanopartículas/toxicidade , Selênio/química , Citosina/metabolismo , Momordica charantia/efeitos dos fármacos , Momordica charantia/crescimento & desenvolvimento , Nanopartículas/química , Nitrato Redutase/genética , Nitrato Redutase/metabolismo , Fenóis/metabolismo , Fenilalanina Amônia-Liase/genética , Fenilalanina Amônia-Liase/metabolismo , Folhas de Planta/enzimologia , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Prolina/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação para Cima/efeitos dos fármacos
2.
Sheng Wu Gong Cheng Xue Bao ; 36(6): 1162-1169, 2020 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-32597065

RESUMO

In recent years, selenium nanoparticles (SeNPs) have been widely used in many fields such as nanotechnology, biomedicine and environmental remediation due to their good electrical conductivity, photothermal properties and anticancer properties. In this study, the cell-free supernatant, whole cell and the cell-free extracts of the strain Cupriavidus sp. SHE were used to synthesize SeNPs, and several methods were applied to analyze the crystal structure and surface functional groups of the nanoparticles. Finally, Pseudomonas sp. PI1 (G⁺) and Escherichia coli BL21 (G⁻) were selected to investigate the antibacterial properties of SeNPs. Cell-free supernatant, whole cell and cell-free extracts of the strain could synthesize SeNPs. As for the cell-free supernatant, selenite concentration of 5 mmol/L and pH=7 were favorable for the synthesis of SeNPs. TEM images show that the average size of nanospheres synthesized by the supernatant was 196 nm. XRD analysis indicates the hexagonal crystals structure of SeNPs. FTIR and SDS-PAGE confirmed the proteins bound to the surfaces of SeNPs. SeNPs synthesized by cell-free supernatant showed no antimicrobial activities against Pseudomonas sp. PI1 and Escherichia coli BL21 (DE3). These results suggest that proteins played an important role in biotransformation of SeNPs in an eco-friendly process, and SeNPs synthesized in this study were non-toxic and biologically compatible, which might be applied in other fields in the future.


Assuntos
Cupriavidus , Nanopartículas , Selênio , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Cupriavidus/metabolismo , Ácido Selenioso/análise , Selênio/química , Selênio/farmacologia
3.
Arch Microbiol ; 202(8): 2233-2243, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32533206

RESUMO

Selenium nanoparticles (SeNPs) are attractive nanomaterials for application in medical diagnosis, because their toxicities are lower than the elemental selenium which is a functional element and essential for human. In the current study, SeNPs synthesis capability of a novel soil originated indigenous Bacillus isolate was investigated. In this context, effects of processing conditions (SeO2 concentration, pH, temperature, and time), and yeast extract supplementation on the synthesis of SeNPs have been tested. In addition, nanoparticles were characterized and antioxidant capacity was determined. The cell-free supernatant of the bacterium, which was obtained after the cultivation of the isolate in nutrient broth at 33 °C for 24 h, was used for the synthesis. During the synthesis color change from light yellow to red-orange was an indication of the formation of SeNPs. Effect of SeO2 concentration was tested on the formation of nanoparticles and at concentrations higher than 10 mM, there was no formation of nanoparticles. The best production was achieved at 6.4 mM concentration, at pH 9 and 33 °C in 72 h. Field emission scanning electron microscopy (FESEM) images revealed that SeNPs were spherical in shape having the diameters between 31 and 335 nm, and the average diameter was determined to be 126 nm. Energy dispersive X-ray spectroscopy analysis confirmed the presence of elemental selenium. SeNPs possessed significant antioxidant activity that the scavenging capacity was up to 56.5 ± 5% (IC50 322.8 µg/mL).


Assuntos
Bacillus/efeitos dos fármacos , Bacillus/metabolismo , Meios de Cultura/farmacologia , Nanopartículas/química , Selênio/química , Antioxidantes/análise , Microscopia Eletrônica de Varredura , Nanopartículas/ultraestrutura
4.
Food Chem ; 331: 127378, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32593797

RESUMO

Selenium nanoparticles (Se0NPs) have been well-characterized; however, whether processing affects their physicochemical and functional properties remains unknown. Here, chitosan (low and high molecular weight; CS(L) and CS(H), respectively) was used to stabilize Se0NPs, and the effects of heating (37 â„ƒ, 70 â„ƒ, and 95 â„ƒ), freeze-drying-rehydration, and freeze-thawing on CS-Se0NPs physicochemical stability, Se release, antioxidant capacity, and antibacterial activity were evaluated. The results demonstrated that all treatments could cause CS-Se0NPs aggregation and Se release to varying degrees. Aggregation of CS-Se0NPs decreased their antibacterial activity, while Se release increased their antioxidant capacity with negligible effects on antibacterial activities. None of the CS-Se0NPs could tolerate freeze-thawing. CS(H)-Se0NPs exhibited better rehydration and heating stability than CS(L)-Se0NPs, although "rod-like" triclinic crystalline Se in CS(H)-Se0NPs, produced by 95℃ heating, decreased both antioxidant and antibacterial activities. Thus, these results provide a theoretical basis for the development and suitable application of CS-Se0NPs.


Assuntos
Antibacterianos/farmacologia , Quitosana/química , Nanopartículas/química , Selênio/química , Antibacterianos/química , Antioxidantes/química , Antioxidantes/farmacologia , Liofilização , Peso Molecular , Tamanho da Partícula , Selênio/farmacocinética , Difração de Raios X
5.
Med Hypotheses ; 143: 109878, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32464491

RESUMO

Selenium (Se) is a ubiquitous element akin to sulfur (S) existing in the Earth crust in various organic and inorganic forms. Selenium concentration varies greatly depending on the geographic area. Consequently, the content of selenium in food products is also variable. It is known that low Se is associated with increased incidence of cancer and heart diseases. Therefore, it is advisable to supplement diet with this element albeit in a proper form. Although blood increased concentrations of Se can be achieved with various pharmacological preparations, only one chemical form (sodium selenite) can offer a true protection. Sodium selenite, but not selenate, can oxidize thiol groups in the virus protein disulfide isomerase rendering it unable to penetrate the healthy cell membrane. In this way selenite inhibits the entrance of viruses into the healthy cells and abolish their infectivity. Therefore, this simple chemical compound can potentially be used in the recent battle against coronavirus epidemic.


Assuntos
Antivirais/uso terapêutico , Infecções por Coronavirus/prevenção & controle , Suplementos Nutricionais , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Selênio/química , Selenito de Sódio/uso terapêutico , Antioxidantes , Betacoronavirus , Coagulação Sanguínea/efeitos dos fármacos , Hemostasia , Humanos , Isomerases de Dissulfetos de Proteínas/metabolismo , Compostos de Sulfidrila
6.
Chin J Nat Med ; 18(3): 169-177, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32245586

RESUMO

The objective of this study was to verify the protective effect of Bifidobacterium longum (BL) and the synergistical effect of Selenium and BL on alcohol plus high fat diet (HFD) induced hepatic injury in mice. We also want to explore the mechanism of Selenium-enriched Bifidobacterium longum (SeBL). C57BL/6 mice were treated with alcohol plus HFD with or without different dosage of BL or SeBL for 4 weeks. Serum levels of ALT, AST, TC, TG, LDL-C, HDL-C, FFAs, TNF-α, IL-6 and IL-1ß, hepatic MDA level, SOD activity, the mRNA levels of AMPK, PPAR-α and SREBP1 were invested. SeBL inhibited lipid accumulation in hepatocytes; reduced serum AST and ALT levels; improved dyslipidemia; decreased serum FFAs, TC, TG and LDL-C levels. SeBL also inhibited alcohol plus HFD-induced hepatocyte oxidative stress through decrease in hepatic MDA levels and increase in SOD activity. SeBL also regulated lipid metabolism related genes such as AMPK, PPAR-α and SREBP1. Although BL had similar effect as SeBL, SeBL is more effective than BL. SeBL protected mice from alcohol plus HFD-induced hepatic injury in mice because of its inhibitory effect on hepatocellular oxidative stress, lipogenesis and inflammation. Selenium enhanced the protective effect of BL.


Assuntos
Bifidobacterium longum , Fígado Gorduroso Alcoólico/terapia , Hepatopatia Gordurosa não Alcoólica/terapia , Estresse Oxidativo , Probióticos/uso terapêutico , Selênio/química , Animais , Dieta Hiperlipídica/efeitos adversos , Suplementos Nutricionais , Etanol/efeitos adversos , Metabolismo dos Lipídeos , Fígado/efeitos dos fármacos , Fígado/fisiopatologia , Testes de Função Hepática , Masculino , Camundongos Endogâmicos C57BL
7.
Int J Nanomedicine ; 15: 2287-2302, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32280221

RESUMO

Background: Mitochondrial dysfunction played a vital role in the pathogenesis of various diseases, including acute lung injury (ALI). However, few strategies targeting mitochondria were developed in treating ALI. Recently, we fabricated a porous Se@SiO2 nanoparticles (NPs) with antioxidant properties. Methods: The protective effect of Se@SiO2 NPs was assessed using confocal imaging, immunoblotting, RNA-seq, mitochondrial respiratory chain (MRC) activity assay, and transmission electron microscopy (TEM) in airway epithelial cell line (Beas-2B). The in vivo efficacy of Se@SiO2 NPs was evaluated in a lipopolysaccharide (LPS)-induced ALI mouse model. Results: This study demonstrated that Se@SiO2 NPs significantly increased the resistance of airway epithelial cells under oxidative injury and shifted lipopolysaccharide-induced gene expression profile closer to the untreated controls. The cytoprotection of Se@SiO2 was found to be achieved by maintaining mitochondrial function, activity, and dynamics. In an animal model of ALI, pretreated with the NPs improved mitochondrial dysfunction, thus reducing inflammatory responses and diffuse damage in lung tissues. Additionally, RNA-seq analysis provided evidence for the broad modulatory activity of our Se@SiO2 NPs in various metabolic disorders and inflammatory diseases. Conclusion: This study brought new insights into mitochondria-targeting bioactive NPs, with application potential in curing ALI or other human mitochondria-related disorders.


Assuntos
Lesão Pulmonar Aguda/tratamento farmacológico , Mitocôndrias/efeitos dos fármacos , Nanopartículas/química , Selênio/farmacologia , Dióxido de Silício/farmacologia , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/patologia , Animais , Antioxidantes/química , Antioxidantes/farmacologia , Linhagem Celular , Citoproteção , Modelos Animais de Doenças , Células Epiteliais/metabolismo , Humanos , Lipopolissacarídeos/toxicidade , Pulmão/efeitos dos fármacos , Pulmão/patologia , Camundongos , Mitocôndrias/metabolismo , Nanopartículas/uso terapêutico , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Porosidade , Selênio/química , Dióxido de Silício/química
8.
Chemosphere ; 251: 126347, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32169700

RESUMO

Currently, exploring effective measures to reduce multiple toxic metals accumulation in rice grains is an urgent issue to be tackled. Pot experiments were thus conducted to explore the effects and mechanisms of foliar spraying with composite sols of silicon (Si) and selenium (Se) during tillering to booting stage on diminishing cadmium (Cd) and lead (Pb) translocation to rice grains and affiliated physiological and biochemical responses in rice seedlings grown in Cd + Pb-polluted soils (positive control). Results showed that Cd and Pb contents in leaves or grains were distinctly below the positive control by the sols. Compared to the positive control, transcriptions of Cd transporter-related genes including OsLCT1, OsCCX2, OsHMA2 and OsPCR1 genes in leaves, and OsLCT1, OsCCX2, TaCNR2 and OSPCR1 in peduncles were downregulated by the increasing sols. Meanwhile, Se-binding protein 1 was evidently upregulated, together to retard Cd and Pb translocation to rice grains. The sols not only upregulated transcriptions of Lhcb1, RbcL, and OsBTF3 genes and production of psbA, Lhcb1 and RbcL proteins, but also increased the chlorophylls contents and RuBP carboxylase activities in the leaves, improving photosynthesis. The sols restrained ROS production from NADPH oxidases, but activated glutathione peroxidase, alleviating oxidative stress and damage. Additionally, Se was significantly enriched and was existed as selenomethionine in the rice grains. However, Pb transporter-related genes remain to be specified. Thus, the composite sols have potential to reduce Cd and Pb accumulation, mitigate oxidative damage, and promote photosynthesis and organic Se enrichment in rice plants under Cd and Pb combined pollution.


Assuntos
Cádmio/toxicidade , Chumbo/toxicidade , Oryza/fisiologia , Poluentes do Solo/toxicidade , Antioxidantes/metabolismo , Cádmio/análise , Clorofila/metabolismo , Poluição Ambiental , Chumbo/análise , Oryza/química , Estresse Oxidativo/efeitos dos fármacos , Fotossíntese , Folhas de Planta/metabolismo , Plântula/efeitos dos fármacos , Selênio/química , Selênio/metabolismo , Silício/química , Silício/metabolismo , Solo/química , Poluentes do Solo/análise
9.
Chemosphere ; 252: 126475, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32200180

RESUMO

Iron-impregnated food waste biochar (Fe-FWB) was synthesized for Se(Ⅵ) removal from aqueous solution. The effect and interactive effects of different parameters including pyrolysis time, temperature, and Fe concentration were explored using response surface methodology (RSM) to enhance conditions to achieve the highest Se(Ⅵ) removal using Fe-FWB. Pyrolysis time was not significant for Se(Ⅵ) adsorption capacity of Fe-FWB, but temperature and Fe concentration were found to be significant. The highest adsorption was achieved at 3.47 h and 495.0 °C with an Fe concentration of 0.44 M. Fe-FWB synthesized under optimum conditions were used to investigate the kinetic, equilibrium, and thermodynamic adsorption of Se(Ⅵ). Se(Ⅵ) adsorption reached equilibrium within 6 h, and both pseudo-second order and pseudo-first order models were suitable for describing kinetic Se(Ⅵ) adsorption. The Freundlich model was found to suitably fit the equilibrium adsorption data than the Langmuir model. The highest adsorption capacity of Fe-FWB for Se(Ⅵ) was 11.7 mg g-1. Se(Ⅵ) adsorption on Fe-FWB was endothermic and spontaneous. The enthalpy change for Se(Ⅵ) adsorption was 54.4 kJ mol-1, and the entropy change was negative at 15-35 °C. The increment of solution pH from 3 to 11 decreased the Se(Ⅵ) adsorption from 19.2 to 7.4 mg g-1. The impact of interfering anions on Se(Ⅵ) adsorption followed the lineup: HCO3- > HPO42- > SO42- > NO3-. When compared to some adsorbents, the adsorption capacity of Se(Ⅵ) onto Fe-FWB was comparable even at neutral pH and the Fe-FWB was granular. These results indicate that Fe-FWB has prospective application in the removal of Se(Ⅵ) from aqueous solutions.


Assuntos
Selênio/química , Poluentes Químicos da Água/química , Adsorção , Ânions , Carvão Vegetal/química , Alimentos , Concentração de Íons de Hidrogênio , Ferro , Cinética , Estudos Prospectivos , Selênio/análise , Temperatura , Termodinâmica , Água , Poluentes Químicos da Água/análise
10.
PLoS One ; 15(3): e0229886, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32130283

RESUMO

Halophiles are the organisms that thrive in extreme high salt environments. Despite the extensive studies on their biotechnological potentials, the ability of halophilic prokaryotes for the synthesis of nanoparticles has remained understudied. In this study, the archaeal and bacterial halophiles from a solar saltern were investigated for the intracellular/extracellular synthesis of silver and selenium nanoparticles. Silver nanoparticles were produced by the archaeal Haloferax sp. (AgNP-A, intracellular) and the bacterial Halomonas sp. (AgNP-B, extracellular), while the intracellular selenium nanoparticles were produced by the archaeal Halogeometricum sp. (SeNP-A) and the bacterial Bacillus sp. (SeNP-B). The nanoparticles were characterized by various techniques including UV-Vis spectroscopy, XRD, DLS, ICP-OES, Zeta potentials, FTIR, EDX, SEM, and TEM. The average particle size of AgNP-A and AgNP-B was 26.34 nm and 22 nm based on TEM analysis. Also, the characteristic Bragg peaks of face-centered cubic with crystallite domain sizes of 13.01 nm and 6.13 nm were observed in XRD analysis, respectively. Crystallographic characterization of SeNP-A and SeNP-B strains showed a hexagonal crystallite structure with domain sizes of 30.63 nm and 29.48 nm and average sizes of 111.6 nm and 141.6 nm according to TEM analysis, respectively. The polydispersity index of AgNP-A, AgNP-B, SeNP-A, and SeNP-B was determined as 0.26, 0.28, 0.27, and 0.36 and revealed high uniformity of the nanoparticles. All of the synthesized nanoparticles were stable and their zeta potentials were calculated as (mV): -33.12, -35.9, -31.2, and -29.34 for AgNP-A, AgNP-B, SeNP-A, and SeNP-B, respectively. The nanoparticles showed the antibacterial activity against various bacterial pathogens. The results of this study suggested that the (extremely) halophilic prokaryotes have great potentials for the green synthesis of nanoparticles.


Assuntos
Antibacterianos/química , Extremófilos/química , Nanopartículas Metálicas/química , Células Procarióticas/química , Antibacterianos/farmacologia , Bacillus/química , Bactérias/efeitos dos fármacos , Bactérias/patogenicidade , Halobacteriaceae/química , Humanos , Nanopartículas Metálicas/administração & dosagem , Tamanho da Partícula , Selênio/química , Prata/química
11.
J Immunol Res ; 2020: 2714257, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32149156

RESUMO

Pseudorabies is an important infectious disease of swine, and immunization using attenuated pseudorabies virus (aPrV) vaccine is a routine practice to control this disease in swine herds. This study was to evaluate a saline solution containing ginseng stem-leaf saponins (GSLS) and sodium selenite (Se) as a vaccine adjuvant for its enhancement of immune response to aPrV vaccine. The results showed that aPrV vaccine diluted with saline containing GSLS-Se (aP-GSe) induced significantly higher immune responses than that of the vaccine diluted with saline alone (aP-S). The aP-GSe promoted higher production of gB-specific IgG, IgG1, and IgG2a, neutralizing antibody titers, secretion of Th1-type (IFN-γ, IL-2, IL-12), and Th2-type (IL-4, IL-6, IL-10) cytokines, and upregulated the T-bet/GATA-3 mRNA expression when compared to aP-S. In addition, cytolytic activity of NK cells, lymphocyte proliferation, and CD4+/CD8+ ratio was also significantly increased by aP-GSe. More importantly, aP-GSe conferred a much higher resistance of mice to a field virulent pseudorabies virus (fPrV) challenge. As the present study was conducted in mice, further study is required to evaluate the aP-GSe to improve the vaccination against PrV in swine.


Assuntos
Adjuvantes Imunológicos , Panax/química , Saponinas/farmacologia , Selênio/farmacologia , Células Th1/efeitos dos fármacos , Células Th1/imunologia , Células Th2/efeitos dos fármacos , Células Th2/imunologia , Vacinas/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Biomarcadores , Relação CD4-CD8 , Citocinas/metabolismo , Feminino , Expressão Gênica , Imunoglobulina G/imunologia , Camundongos , Vacinas contra Pseudorraiva/imunologia , Saponinas/química , Selênio/química , Soluções , Baço/efeitos dos fármacos , Baço/imunologia , Baço/metabolismo , Suínos , Subpopulações de Linfócitos T/efeitos dos fármacos , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Células Th1/metabolismo , Células Th2/metabolismo
12.
Chemosphere ; 250: 126105, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32092562

RESUMO

The effect of trace metals, namely tungsten and selenium, on the production of acids and alcohols through gas fermentation by a CO-enriched anaerobic sludge in a continuous gas-fed bioreactor was investigated. The CO-enriched sludge was first supplied with a tungsten-deficient medium (containing selenium) and in a next assay, a selenium-deficient medium (containing tungsten) was fed to the bioreactor, at a CO gas flow rate of 10 mL/min. In the absence of tungsten (tungstate), an initial pH of 6.2 followed by a pH decrease to 4.9 yielded 7.34 g/L acetic acid as the major acid during the high pH period. Subsequently, bioconversion of the acids at a lower pH of 4.9 yielded only 1.85 g/L ethanol and 1.2 g/L butanol in the absence of tungsten (tungstate). A similar follow up assay in the same bioreactor with two consecutive periods at different pH values (i.e., 6.2 and 4.9) with a selenium deficient medium yielded 6.6 g/L acetic acid at pH 6.2 and 4 g/L ethanol as well as 1.88 g/L butanol at pH 4.9. The results from the microbial community analysis showed that the only known CO fixing microorganism able to produce alcohols detected in the bioreactor was Clostridium autoethanogenum, both in the tungsten and the selenium deprived media, although that species has so far not been reported to be able to produce butanol. No other solventogenic acetogen was detected.


Assuntos
Microbiota , Selênio/química , Tungstênio/química , Eliminação de Resíduos Líquidos/métodos , 1-Butanol , Ácido Acético , Anaerobiose , Reatores Biológicos , Butanóis , Clostridium , Etanol , Fermentação , Esgotos
13.
Int J Nanomedicine ; 15: 115-124, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32021168

RESUMO

Background: Selenium is an essential trace element that is critical for many biological processes. Selenium nanoparticles (SeNPs) have shown more promise than other forms of selenium due to their low cytotoxicity and high bioavailability. Methods: In this work, a one-step method was demonstrated for fabricating bovine serum albumin (BSA) stabilized SeNPs using ascorbic acid as the reductant. Human dermal fibroblasts were used to assess mammalian cytotoxicity, and Staphylococcus aureus and Escherichia coli were used to assess antibacterial performance. Results: These SeNPs demonstrated increased fibroblast growth and reduced Staphylococcus aureus growth with a fibroblast IC50 value (>681 µg/mL) 1 order of magnitude higher than that for bacteria at day 1. Conclusion: This study demonstrated the promise of this synthesis process in achieving controllable selenium nanoparticle sizes without the use of strong basic solvents for improved antibacterial properties.


Assuntos
Antibacterianos/farmacologia , Nanopartículas/química , Selênio/farmacologia , Antibacterianos/química , Ácido Ascórbico/química , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Escherichia coli/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Química Verde , Humanos , Tamanho da Partícula , Selênio/química , Soroalbumina Bovina/química , Staphylococcus aureus/efeitos dos fármacos
14.
Int J Nanomedicine ; 15: 1187-1203, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32110016

RESUMO

Background: Selenium (Se) is an indispensable trace element required for animals and human beings, whereas Se-deficiency can accelerate the development of acute gastric injury induced by over-consumption of alcohol. Selenium nanoparticles (SeNPs), as a special Se-supplement with favorable properties and unique bioactivities, are expected to play a passive role in gastroprotection. To the best of our knowledge, the gastroprotective potential of SeNPs is unknown and also, a rapid preparation of orally stable SeNPs available for prospective commercial application in the clinic is needed. Thus, SeNPs-embedded chitosan microspheres (SeNPs-CM) were developed to deliver SeNPs, and their gastroprotective potential was evaluated. Results: Herein, a rapid, eco-friendly and economic preparation process, composed of synthesis of SeNPs decorated by chitosan (CS), purification of CS-SeNPs by ultra-filtration (UF) and spray-drying of the purified CS-SeNPs, was introduced to prepare SeNPs-CM. The uniformly distributed SeNPs with a nanosize range of 60 nm were loaded into CS-microspheres, and they could be released from the microspheres in gastric conditions. In addition, SeNPs-CM were safer than selenite in terms of Se dose, with a LD50 of around 8-fold of that of selenite, and it could efficiently enhance the Se retention in Se-deficient Wistar rats. Furthermore, SeNPs-CM pre-treatment might significantly attenuate the ethanol-induced gastric mucosal damage, based on histological evaluation. It might be partly attributed to the systematic antioxidant activities of SeNPs-CM, reflected by the reduction in lipid peroxidation, the augmentation in antioxidant enzymatic activity as well as decreasing aggressive nitric oxides (NO). Conclusion: SeNPs-CM could be taken into consideration as a prospective Se-supplement for the oral delivery of SeNPs, with prominent gastroprotective effect against ethanol-induced mucosal injury.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Mucosa Gástrica/efeitos dos fármacos , Microesferas , Nanopartículas/administração & dosagem , Selênio/farmacologia , Administração Oral , Animais , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Quitosana/química , Etanol/toxicidade , Mucosa Gástrica/metabolismo , Masculino , Nanopartículas/química , Ratos Wistar , Selênio/administração & dosagem , Selênio/química , Selênio/farmacocinética , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/tratamento farmacológico , Ultrafiltração/métodos
15.
Arch Microbiol ; 202(5): 1203-1209, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32077990

RESUMO

Selenium nanoparticles (Se NPs) were synthesized using Saccharomyces cerevisiae yeast. Influences of different amounts of sodium selenite (5.0, 10.0, 15.0, 20.0, and 25 µg) were evaluated on growth of yeast during incubation at 32 °C, during 4 days. UV-Vis spectroscopy results have shown that synthesized Se NPs had broad emission peak (λmax) in the wavelength around 350 nm which demonstrated that formation of Se NPs occurred in intracellular manner. Physico-chemical characteristics of the synthesized Se NPs using dynamic light scattering particle-size analyzer indicated that the fabricated Se NPs had particle size, polydispersity index, and zeta potential ranging from 75 to 709 nm, 0.189 to 0989, and -7.06 to -10.3 mV, respectively. Obtained results revealed that intracellular Se NPs with minimum particle size (75 nm), maximum zeta potential (-10.3 mV), and antioxidant activity (48.5%) were synthesized using minimum amount of selenium salt (5 µg). However, most uniform Se NPs were formed using maximum amount of selenium salt (25 µg). Results also indicated that by increasing amount of sodium selenite in the culture media, from 5.0 to 25 µg, antioxidant activity of the formed Se NPs decreased from 48.5 to 20.8, respectively.


Assuntos
Biotecnologia/métodos , Microbiologia Industrial/métodos , Nanopartículas/química , Saccharomyces cerevisiae/metabolismo , Selênio/química , Meios de Cultura , Tamanho da Partícula
16.
Dalton Trans ; 49(7): 2209-2217, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32003374

RESUMO

Photothermal therapy (PTT) is a promising treatment for tumors due to its efficiency and non-invasiveness. However, during the PTT treatment, reactive oxygen species (ROS) are produced in response to hyperthermia and thus harm the neighboring normal cells. In this work, a multifunctional theranostic agent (Se@SiO2@Au-PEG/DOX NCs) was exploited to solve this problem by introducing selenium, which can efficiently prevent normal cells from oxidative damage by scavenging reactive oxygen species during photothermal therapy. In addition, the Se@SiO2@Au-PEG/DOX nanocomposites (NCs) not only exhibited excellent properties of combined chemo-thermal synergistic therapy, but also showed no appreciable toxicity towards normal tissues due to the protective effect for continuous release of selenium. Thus, the fabricated Se@SiO2@Au-PEG/DOX NCs provide an integrated solution to overcome the limitations of selenium and PTT, and demonstrate great prospects as a safe and highly reliable theranostic agent.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Doxorrubicina/farmacologia , Fotoquimioterapia , Nanomedicina Teranóstica , Células A549 , Animais , Antibióticos Antineoplásicos/síntese química , Antibióticos Antineoplásicos/química , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Doxorrubicina/síntese química , Doxorrubicina/química , Liberação Controlada de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Ouro/química , Ouro/farmacologia , Humanos , Camundongos , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Selênio/química , Selênio/farmacologia , Dióxido de Silício/química , Dióxido de Silício/farmacologia
17.
Environ Health ; 19(1): 14, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-32028962

RESUMO

BACKGROUND: Prenatal exposure to environmental contaminants can have deleterious effects on child development. While psychomotor, cognitive and behavioural outcomes have been investigated in relation to chronic exposure, the associations with visual functions remains unclear. The present study's aim was to assess the associations of prenatal exposure to legacy persistent organic pollutants and heavy metals with visual acuity in Canadian infants. The potential protective effects of selenium against mercury toxicity were also examined. METHODS: Participants (mean corrected age = 6.6 months) were part of the Maternal-Infant Research on Environmental Chemicals (MIREC) study. Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), lead and mercury were measured in maternal blood during pregnancy, as well as in the cord blood. The Teller acuity card test (TAC) (n = 429) and the visual evoked potentials in a sub-group (n = 63) were used to estimate behavioural and electrophysiological visual acuity, respectively. Multivariable linear regression models were used to investigate the relationship between exposure to each contaminant and visual acuity measures, while controlling for potential confounders. Breastmilk selenium, which was available for about half of the TAC and VEP samples, was also taken into account in the mercury models as exploratory analyses. RESULTS: We observed no significant associations between exposure to any contaminants and TAC. Analyses revealed a negative trend (p values < 0.1) between cord blood lead and mercury and electrophysiological visual acuity, whereas PCB and PBDE showed no association. When adding breastmilk selenium concentration to the mercury models, this association became statistically significant for cord concentrations (ß = - 3.41, 95% CI = - 5.96,-0.86), but also for blood levels at 1st and 3rd trimesters of pregnancy (ß = - 3.29, 95% CI = - 5.69,-0.88). However, further regression models suggested that this change in estimates might not be due to adjustment for selenium, but instead to a change in the study sample. CONCLUSIONS: Our results suggest that subtle, but detectable alterations of infant electrophysiological visual acuity can be identified in a population prenatally exposed to low mercury concentrations. Compared to behavioural visual acuity testing, electrophysiological assessment may more sensitive in detecting visual neurotoxicity in relation with prenatal exposure to mercury.


Assuntos
Poluentes Ambientais/sangue , Exposição Materna , Fármacos Neuroprotetores/sangue , Acuidade Visual/fisiologia , Canadá , Feminino , Sangue Fetal/química , Éteres Difenil Halogenados/sangue , Humanos , Lactente , Chumbo/sangue , Masculino , Mercúrio/sangue , Leite Humano/química , Fármacos Neuroprotetores/química , Bifenilos Policlorados/sangue , Gravidez , Selênio/sangue , Selênio/química , Acuidade Visual/efeitos dos fármacos
18.
Environ Sci Pollut Res Int ; 27(8): 7886-7900, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31889272

RESUMO

Fipronil (FIP) is a highly effective, broad-use insecticide that belongs to the phenylpyrazole chemical group. It is extensively used in the agriculture and veterinary medicine for controlling a wide variety of pests. Though FIP showed lower toxicity in vertebrates than in insects, it was recognized to have a variety of toxic effects in mammals. The present study was undertaken to evaluate FIP-induced alterations in the blood biochemical markers and oxidative stress parameters in male albino mice via oral sub-acute toxicity exposure. The possible ameliorative effect of the pretreatment with selenium plus α-tocopherol (vitamin E) against the harmful effects of FIP was also investigated. Mice in FIP-test groups were exposed to different sublethal doses, i.e., 1.43, 2.87, and 4.78 mg active ingredient (AI)/kg body weight (b.w.), equal to 1/100, 1/50, and 1/30 LD50 of FIP, respectively, for 28 days. Mice in the amelioration groups were orally administered with selenium + vitamin E (0.3 mg + 22.5 mg/kg b.w., respectively) 14 days prior to exposure to the higher dose (4.78 mg/kg) of FIP for another 14 days. Fipronil exposure at medium and high doses showed lowered values of red blood cell count (RBC), hematocrit (HCT), hemoglobin (HGB), white blood cell (WBC), and platelet (PLT) counts after 28-day exposure, compared to the control. All three doses caused significant increases in levels of liver-function biomarkers, i.e., aspartate amino transaminase (AST), alanine amino transaminase (ALT), alkaline phosphatase (ALP), cholesterol, and bilirubin levels compared to the control. Levels of biomarkers related to kidney functions, i.e., urea, uric acid, and creatinine, increased significantly than these of the control. Likewise, the oxidative stress indices, i.e., hydrogen peroxide (H2O2) and malondialdehyde (MDA), significantly increased at the higher and medium doses, while antioxidant enzymes, catalase (CAT) and superoxide dismutase (SOD), decreased significantly. On the other hand, prior administration of selenium + vitamin E in the FIP-exposed mice led to restore values of most hematological parameters nearly to these of the control. Also, the levels of AST, total protein, and creatinine seemed to be restored to the control values. Interestingly, pretreatment with selenium + vitamin E restored the levels of antioxidant enzymes, CAT and SOD, to the control values, whereas, oxidative stress indices, H2O2 and MDA, remained significantly high. It is our thought that the sublethal dose less than 1.43 mg/kg b.w. of commercial formulation of FIP (COACH® 200 SC) could be considered as no-observed-adverse-effect-level(NOAEL) under our present experimental conditions at short-term toxicity study. On the other hand, the higher sublethal doses, 4.78 and 2.87 mg/kg b.w., induced significant adverse effects in biomarkers and may be deleterious to human health following long-term exposure.


Assuntos
Pirazóis/química , Selênio , Animais , Antioxidantes , Humanos , Peróxido de Hidrogênio , Peroxidação de Lipídeos , Fígado , Masculino , Camundongos , Estresse Oxidativo , Selênio/química , Vitamina E/química
19.
Chemosphere ; 246: 125794, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31918102

RESUMO

Environmental contamination by heavy metals, such as lead (Pb), can lead to severe immune dysfunction. MicroRNAs (miRNAs) are involved in regulating immunity. Whether Pb can regulate neutrophil apoptosis through miRNA, and whether selenium (Se) can antagonize this response are still unknown. We treated neutrophils with 12.5 µM (CH3OO)2Pb and 1 µM Na2SeO3 for 3 h, after which apoptosis was evaluated using acrideine orange/ethidium bromide (AO/EB) dual fluorescent staining and flow cytometry. The results showed that neutrophil apoptosis was significantly increased following Pb exposure, and that this response was prevented upon Se addition. Pb up-regulates miR-16-5p and leads to the subsequent down-regulation of the target genes phosphoinositide-3-kinase regulatory subunit 1 (PiK3R1), insulin-like growth factor 1 receptor (IGF1R), and phosphatidylinositol 3 kinase (Pi3K)-protein kinase B (AKT), followed by activation of the tumor protein P53 (P53)-B-cell lymphoma-2 (Bcl-2)/Bcl-2-Associated X protein (Bax)-cytochrome c (Cytc)-Caspase 9 (mitochondrial apoptotic pathway) and the tumor necrosis factor receptor superfamily member 6 (Fas)-Fas-associated death domain protein (Fadd)-Caspase 8 (death receptor pathway). Pb also triggered oxidative stress and indirectly activated the mitochondrial apoptotic pathway. We conclude that miR-16-5p plays a key role in the apoptosis of neutrophils exposed to Pb by down-regulating the expression of PiK3R1 and IGFR1, thereby activating the mitochondrial apoptotic pathway and death receptor pathway. Se can prevent Pb-induced apoptosis.


Assuntos
Poluentes Ambientais/toxicidade , Chumbo/toxicidade , MicroRNAs/metabolismo , Neutrófilos/efeitos dos fármacos , Fosfatidilinositol 3-Quinase/metabolismo , Substâncias Protetoras/metabolismo , Receptor IGF Tipo 1/metabolismo , Selênio/metabolismo , Animais , Apoptose/efeitos dos fármacos , Galinhas/metabolismo , Galinhas/fisiologia , Chumbo/metabolismo , MicroRNAs/genética , Mitocôndrias/metabolismo , Neutrófilos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Selênio/química , Proteína Supressora de Tumor p53
20.
Artigo em Inglês | MEDLINE | ID: mdl-31903843

RESUMO

In order to treat selenium pollution, the study presents the use of potassium ferrate (K2FeO4) as an environmentally friendly agent for in situ removal of Se(IV) from aqueous media. Batch experiments were carried out to evaluate the influences of various factors including dosage of K2FeO4, ex-situ and in-situ adsorption, initial pH, and adsorption isotherms. The results showed that increasing dosage of K2FeO4 benefited the removal of total selenium with the efficiency up to 97.0% and Se(IV) removal significantly depended on pH, and as the pH increases, the decrease in Se(IV) adsorption efficiency is a general trend of pH dependence. The X-ray powder diffraction, Fourier transformed infrared spectrometer and high-resolution X-ray photoelectron spectroscopy analysis indicated that Se(IV) was removed from the aqueous solution by adsorbing on the surface of the decomposition products of K2FeO4 which are ferric oxide nanoparticles, and the selenium adsorbed on the generated ferric oxide nanoparticles existed in the forms of Se(IV) and Se(VI). Se(IV) and Se(VI) were adsorbed to the decomposition products of K2FeO4 by forming an inner-sphere complexes and an outer-sphere complexes, respectively.


Assuntos
Compostos Férricos/química , Compostos de Ferro/química , Nanopartículas/química , Compostos de Potássio/química , Selênio/análise , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Concentração de Íons de Hidrogênio , Oxirredução , Espectroscopia Fotoeletrônica , Selênio/química , Poluentes Químicos da Água/química , Difração de Raios X
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA