ABSTRACT
BACKGROUND: There Is an emerging field to put Into practice new strategies for developing molecules with antimicrobial properties. In this line, several metals and metalloids are currently being used for these purposes, although their cellular effect(s) or target(s) in a particular organism are still unknown. Here we aimed to investigate and analyze Au3+ toxicity through a combination of biochemical and molecular approaches. RESULTS: We found that Au3+ triggers a major oxidative unbalance in Escherichia coli, characterized by decreased intracellular thiol levels, increased superoxide concentration, as well as by an augmented production of the antioxidant enzymes superoxide dismutase and catalase. Because ROS production is, in some cases, associated with metal reduction and the concomitant generation of gold-containing nanostructures (AuNS), this possibility was evaluated in vivo and in vitro. CONCLUSIONS: Au3+ is toxic for E. coli because it triggers an unbalance of the bacterium's oxidative status. This was demonstrated by using oxidative stress dyes and antioxidant chemicals as well as gene reporters, RSH concentrations and AuNS generation.
Subject(s)
Oxidation-Reduction/drug effects , Oxidative Stress/drug effects , Escherichia coli/drug effects , Metal Nanoparticles/toxicity , Gold/toxicityABSTRACT
Background: Although nanoparticles (NPs) have many advantages, it has been proved that they may be absorbed by and have toxic effects on the human body. Recent research has tried to evaluate and compare the nanotoxicity of gold nanoparticles (AuNPs) produced by two types of microorganisms in vitro by two different methods. AuNPs were produced by Bacillus cereus and Fusarium oxysporum, and their production was confirmed by visible spectral, transmission electron microscope, and X-ray diffraction (XRD) analyses. The human fibroblast cell line CIRC-HLF was treated with AuNPs, and the induced nanotoxicity was measured using direct microscopic and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Results: The results showed that the produced AuNPs had a maximum absorbance peak around 510530 nanometer (nm), with spherical, hexagonal, and octagonal shapes and average sizes around 2050 nm. The XRD results confirmed the presence of GNPs in the microbial culture supernatants. An MTT assay showed that GNPs had dose-dependent toxic effects, and microscopic analysis showed that GNPs induced cell abnormalities in doses lower than the determined half-maximal inhibitory concentrations (IC50s). Conclusions: In conclusion, the biologically produced AuNPs had toxic effects in the cell culture, and direct techniques such as microscopic evaluation instead of indirect methods such as MTT assay were more useful for assessing the nanotoxicity of the biologically produced AuNPs. Thus, the use of only MTT assay for nanotoxicity evaluation of AuNPs is not desirable.
Subject(s)
Nanoparticles/metabolism , Nanoparticles/toxicity , Gold/metabolism , Gold/toxicity , Spectrophotometry , Bacillus cereus/metabolism , Cells, Cultured , Gold Compounds/metabolism , Gold Compounds/toxicity , Toxicity Tests , Surface Plasmon Resonance , Nanotechnology , Microscopy, Electron, Transmission , Metal Nanoparticles/toxicity , Fusarium/metabolismABSTRACT
El uso creciente de nanomateriales en productos industriales y de consumo ha incrementado la preocupación mundial respecto a sus posibles efectos adversos en los sistemas biológicos. Como consecuencia de la falta de un marco legislativo y la ausencia de un consenso sobre los protocolos experimentales, las investigaciones ecotoxicológicas se llevan a cabo a un ritmo mucho más lento que la producción de nuevas nanopartículas. Por esta razón, existe una necesidad creciente de realizar estudios que aporten conocimiento sobre el riesgo de estos contaminantes emergentes de propiedades únicas. El objetivo del presente trabajo fue evaluar la frecuencia de micronúcleos (FMN) en eritrocitos de ejemplares juveniles de pacú (Piaractus mesopotamicus) expuestos a nanopartículas de plata (Nano-Ag) a las concentraciones de 0 μg·L-1 (control); 2,5 μg·L-1; 10 μg·L-1; y 25 μg·L-1, durante 24 horas. Se observó que la FMN se incrementó significativamente (p<0,01) en la concentración de 25 μg·L-1, mientras que no hubo diferencias significativas entre los grupos expuestos a 2,5 y 10 μg·L-1 y el control. Estos resultados sugieren que los eventos aneugénicos o clastogénicos podrían representar un posible mecanismo de toxicidad de Nano-Ag en esta especie.
The growing use of nanomaterials in consumer and industrial products has aroused global concern about possible adverse effects on biological systems. Due to the lack of a regulation framework and the absence of a consensus on the experimental protocols, ecotoxicological investigations are carried out much slower than the production of new nanoparticles. For this reason, there is a growing need for studies that provide knowledge about the risk of these emerging contaminants of unique properties. The objective of the present study was to evaluate the frequency of micronuclei (FMN) in erythrocytes of juvenile Piaractus mesopotamicus exposed to silver nanoparticles (nano-Ag; Nanotek SA) at concentrations of 0 μg·L-1 (control); 2.5 μg·L-1; 10 μg·L-1; and 25 μg·L-1, for 24 hours (n = 10 per treatment). The FMN show a significant increase (p <0.01) in fish exposed to 25 μg·L-1 of Nano-Ag, while there were no significant differences among the groups exposed to 2.5 and 10 μg·L-1 with the control. These results suggest that the aneugenics or clastogenics events may represent a possible mechanism of toxicity of Nano-Ag in this specie.
Subject(s)
Metal Nanoparticles/toxicity , Micronucleus Tests/methods , Microscopy, Electron, Transmission/methods , Mutagenicity Tests/statistics & numerical dataABSTRACT
Background: Circulatory power (CP) and ventilatory power (VP) are indices that have been used for the clinical evaluation of patients with heart failure; however, no study has evaluated these indices in patients with coronary artery disease (CAD) without heart failure. Objective: To characterize both indices in patients with CAD compared with healthy controls. Methods: Eighty-seven men [CAD group = 42 subjects and healthy control group (CG) = 45 subjects] aged 40–65 years were included. Cardiopulmonary exercise testing was performed on a treadmill and the following parameters were measured: 1) peak oxygen consumption (VO2), 2) peak heart rate (HR), 3) peak blood pressure (BP), 4) peak rate-pressure product (peak systolic HR x peak BP), 5) peak oxygen pulse (peak VO2/peak HR), 6) oxygen uptake efficiency (OUES), 7) carbon dioxide production efficiency (minute ventilation/carbon dioxide production slope), 8) CP (peak VO2 x peak systolic BP) and 9) VP (peak systolic BP/carbon dioxide production efficiency). Results: The CAD group had significantly lower values for peak VO2 (p < 0.001), peak HR (p < 0.001), peak systolic BP (p < 0.001), peak rate-pressure product (p < 0.001), peak oxygen pulse (p = 0.008), OUES (p < 0.001), CP (p < 0.001), and VP (p < 0.001) and significantly higher values for peak diastolic BP (p = 0.004) and carbon dioxide production efficiency (p < 0.001) compared with CG. Stepwise regression analysis showed that CP was influenced by group (R2 = 0.44, p < 0.001) and VP was influenced by both group and number of vessels with stenosis after treatment (interaction effects: R2 = 0.46, p < 0.001). Conclusion: The indices CP and VP were lower in men with CAD than healthy controls. .
Fundamento: Os índices da Potência Circulatória (PC) e Potência Ventilatória (PV) têm sido utilizados para avaliação clínica de pacientes com insuficiência cardíaca, mas nenhum estudo avaliou esses índices em pacientes com Doença Arterial Coronariana (DAC). Objetivo: Caracterizar ambos os índices em pacientes com DAC comparados a indivíduos saudáveis. Métodos: Oitenta e sete homens [grupo DAC = 42 sujeitos e, grupo controle (GC) = 45 sujeitos] com idade entre 45 e 65 anos foram incluídos. Um Teste de Exercício Cardiopulmonar (TECP) foi realizado em esteira e as seguintes variáveis foram obtidas: 1) consumo de oxigênio (VO2) pico; 2) Frequência Cardíaca (FC) pico; 3) Pressão Arterial (PA) pico; 4) duplo produto pico (PA sistólica pico x FC pico); 5) pulso de oxigênio pico (VO2 pico dividido pela FC pico); 6) eficiência ventilatória para o consumo de oxigênio (OUES); 7) eficiência ventilatória para a produção de dióxido de carbono (VE/VCO2 slope); 8) PC (VO2 pico x PA sistólica pico); e 9) PV (PA sistólica pico dividido pelo VE/VCO2 slope). Resultados: O grupo DAC apresentou valores significativamente menores das seguintes variáveis no pico do exercício: VO2 (p < 0,001), FC (p < 0,001), PA sistólica (p < 0,001), duplo produto (p < 0,001), pulso de oxigênio (p = 0,008), OUES (p < 0,001), PC (p < 0,001) e PV (p < 0,001), e valores significativamente maiores de PA diastólica (p = 0,004) e VE/VCO2 slope (p < 0,001) em relação ao GC. Uma análise de regressão pelo método stepwise mostrou que a PC foi influenciada pelo grupo (R2 = 0,44, p < 0,001) e a PV tanto pelo grupo quanto pelo número de vasos com estenose pós tratamento (efeito de interação: R2 = 0,46, p < 0,001). Conclusion: Os índices da PC e PV foram menores em homens com DAC comparados ao GC, podendo dessa forma ser utilizados na caracterização dessa população. .
Subject(s)
Animals , Humans , Aluminum Oxide/toxicity , Cell Adhesion Molecules/metabolism , Cell Adhesion/drug effects , Endothelium, Vascular/drug effects , Metal Nanoparticles/toxicity , Cells, Cultured , Cell Adhesion Molecules/genetics , Dose-Response Relationship, Drug , E-Selectin/genetics , E-Selectin/metabolism , Endothelium, Vascular/metabolism , Endothelium, Vascular/ultrastructure , Gene Expression/drug effects , Intercellular Adhesion Molecule-1/genetics , Intercellular Adhesion Molecule-1/metabolism , Microscopy, Electron, Transmission/methods , Monocytes/drug effects , Monocytes/metabolism , Monocytes/ultrastructure , Particle Size , RNA, Messenger/metabolism , Swine , Vascular Cell Adhesion Molecule-1/genetics , Vascular Cell Adhesion Molecule-1/metabolismABSTRACT
Silver nanoprticles (SNPs) are invested in medical, industrial and environmental applications. Little if any, is known about the morphometric alterations induced by the toxicity of SNPs. The aim of the present work is to find out the effect of variable size of SNPs on different morphometric parameters. Adult healthy male mice (BAL/C) were subjected to (10 nm, 20 nm, 40 nm 60 nm and 100 nm) SNPs for 35 days. Silver NPs caused non-significant decline on the average weight, significant decline in food consumption, increase in water intake, unilateral blindness, tanning fur color and cholestasis together with a decrease in the relative ratio of the liver, kidney and spleen weight to body weight. Mice subjected to 10 nm and 20 nm were more affected than mice receiving larger nanoparticles. These findings may indicate that SNPs could induce morphometric alterations that are size related wheresmaller SNPs have more impact than the larger ones.
Poco se sabe acerca de las alteraciones morfométricas inducidas por la toxicidad de las nanopartículas de plata (NPP). El objetivo fue investigar el efecto del tamaño variable de las NPP en diferentes parámetros morfométricos. Ratones machos adultos sanos (BAL/C) fueron sometidos a diferentes NPP de diferentes tamaños durante 35 días (10 nm, 20 nm, 40 nm 60 nm y 100 nm, respectivamente). Las NPP causaron una disminución no significativa del peso promedio, una disminución significativa en el consumo de alimentos, un aumento de la ingesta de agua, ceguera unilateral, cambios en el color de piel y colestasis junto con una disminución en el tamaño promedio del hígado, riñón y el peso del bazo, en relación al peso corporal. Los ratones sometidos a 10 nm y 20 nm fueron más afectados que los ratones que recibieron las nanopartículas más grandes. Estos resultados pueden indicar que las NPP podrían inducir alteraciones morfométricas que están relacionadas con el tamaño, en las cuales las NPP más pequeñas tienen un mayor impacto que las más grandes.
Subject(s)
Animals , Male , Mice , Silver/toxicity , Spleen/drug effects , Metal Nanoparticles/toxicity , Kidney/drug effects , Liver/drug effects , Organ Size/drug effects , Time Factors , Body Weight/drug effects , Mice, Inbred BALB CABSTRACT
Gold nanoparticles have diverse applications and are being used in food and cosmetic industry, for drug delivery and in the diagnosis and treatment of cancer. However there is a need to study their biochemical mode of action. In this study, in vivo effect of gold nanoparticles on the activities of the two antioxidant enzymes — superoxide dismutase (SOD) and indoleamine 2,3-dioxygenase (IDO) was investigated in various tissues of rats. Rats were injected with 20 μg/kg body wt of 20 nm gold nanoparticles for three consecutive days through intraperitoneal route. The animals were sacrificed by CO2 asphyxiation 24 h after the last dose of gold nanoparticles. Results showed that treatment with gold nanoparticles caused no significant change in SOD activity in most of the tissues, except kidneys. In kidneys, gold nanoparticles caused a significant increase in SOD activity, when compared to the activity in control rats. However, treatment with gold nanoparticles altered the expression pattern of SOD activity in various tissues. For example, in control rats highest SOD activity was demonstrated in heart and least in kidneys and spleen. But, in gold nanoparticles treated rats, maximum SOD activity was observed in liver and the lowest in spleen. Gold nanoparticles caused no significant change in IDO activity in the studied tissues.
Subject(s)
Animals , Gold/chemistry , Heart/drug effects , Heart/physiology , Indoleamine-Pyrrole 2,3,-Dioxygenase/metabolism , Kidney/drug effects , Kidney/enzymology , Liver/drug effects , Liver/enzymology , Lung/drug effects , Lung/enzymology , Male , Metal Nanoparticles/toxicity , Rats , Rats, Wistar , Spleen/drug effects , Spleen/enzymology , Superoxide Dismutase/metabolismABSTRACT
Nanoparticles of silver have many important applications and are among the most commonly used nanomaterials. They are increasingly used in a variety of both medical and consumer products which includes: spectrally selective coating for solar energy absorption and intercalation material for electrical batteries, as optical receptors, polarizing filters, catalysts in chemical reaction and bio-labeling. Nanosilver [Ag-NP] has both antibacterial and antiviral activity. Yet, the knowledge about the systemic toxicity of nanosilver is relatively limited. The aim of work: To evaluate the potential toxicity of small size 10nm silver nanoparticles using two different doses [0.1 ml and 0.4 ml] focusing on the ultrastructural changes occurring in mice hepatocytes. This study was performed using three groups of mice. The animals of the first group were given a daily intravenous injection of 0.1 ml of silver nanoparticles for 28 consecutive days. The second group was treated with 0.4 ml of silver nanoparticles for 28 consecutive days. The third group served as a control group in which the animals did not receive any vehicle. The study was focused on the ultrastructure of the liver. Ultrastructure observations of liver cells of mice Treated with any of the two doses [0.1 and 0.4 ml] of 10 nm Ag-NP indicated severe accumulation of dark deposits of Ag-NP in the cytoplasm and the cell organelles. Our study revealed that nanosilver used in doses of 0.1 and 0.4 ml led to deposits in the cells and induced damage of cell components especially the nucleus, mitochondria and chromatin
Subject(s)
Male , Animals, Laboratory , Metal Nanoparticles/toxicity , Cytotoxicity Tests, Immunologic/methods , Liver/cytology , Liver/ultrastructure , MiceABSTRACT
En los últimos años, la evolución en el desarrollo de productos elaborados a partir de nanotecnología ha experimentado un espectacular crecimiento. En particular, las nanopartículas de oro han despertado gran interés en los sectores biomédico y alimentario, donde se ha descrito su utilización en el tratamiento frente al cáncer o como parte integrante de envases resistentes a la abrasión, con propiedades antimicrobianas. Por tanto, se cree que la exposición humana a las nanopartículas de oro aumentará considerablemente en los próximos años, pudiendo tener esto repercusiones sobre la salud. En este marco, el estudio de la toxicología de las nanopartículas ha revelado que su toxicidad depende de multitud de factores. Además, en la bibliografía hay cierta controversia en torno a los posibles efectos citotóxicos inducidos por las nanopartículas de oro. Diversos estudios de exposición in vitro han destacado su inocuidad en algunas líneas celulares, mientras que otros trabajos demostraron respuesta citotóxica. La siguiente revisión tiene por objeto describir las propiedades más relevantes de las nanopartículas de oro considerando sus potenciales aplicaciones en medicina y en la industria de los alimentos, así como examinar su posible toxicidad, con especial énfasis en los estudios de citotoxicidad in vitro disponibles hasta el momento.
In the recent years, the development of nanotechnology-based products has experienced a spectacular growth. Especially, gold nanoparticles have awoken a great interest in the biomedical and food sector, where their applications in cancer treatment as well as their incorporation in abrasion resistant and antimicrobial packaging have been described. Therefore, it is believed that human exposure to gold nanoparticles will increase considerably in the next few years, which may arise possible human health hazards. Hence, toxicology studies on nanoparticles revealed that their toxicity depends on various factors. Furthermore, there is some controversy regarding to gold nanoparticle-induced cytotoxicity. Several in vitro studies have reported that gold nanoparticles are innocuous, while some investigations have demonstrated a cytotoxic response after the exposure to these. The aim of this review is to describe the most relevant properties of gold nanoparticles according to their possible applications in medicine and in food industry, as well as to provide information about their possible toxic effects, taking into account the cytotoxic in vitro studies published at present.