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1.
J Appl Toxicol ; 44(3): 355-370, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37735745

RESUMO

Agriculture commonly utilizes crop protection products to tackle infestations from fungi, parasites, insects, and weeds. Validamycin A, an inhibitor of trehalase, possesses antibiotic and antifungal attributes. Epidemiological evidence has led to concerns regarding a potential link between pesticide usage and neurodegenerative diseases. The fruit fly, Drosophila melanogaster, has been recognized as a reliable model for genetic research due to its significant genetic similarities with mammals. Here, we propose to use D. melanogaster as an effective in vivo model system to investigate the genotoxic risks associated with exposure to validamycin A. In this study, we performed a neurotoxic evaluation of validamycin A in D. melanogaster larvae. Several endpoints were evaluated, including toxicity, intracellular oxidative stress (reactive oxygen species), intestinal damage, larval behavior (crawling behavior, light/dark sensitivity assay, and temperature sensitivity assay), locomotor (climbing) behavior, and neurogenotoxic effects (impaired DNA via Comet assay, enhanced by Endo III and formamidopyrimidine DNA glycosylase [FPG]). The results showed that exposure to validamycin A, especially at higher doses (1 and 2.5 mM), induced DNA impairment in neuroblasts as observed by Comet assay. Both larvae and adults exhibited behavioral changes and produced reactive oxygen species. Most importantly, this research represents a pioneering effort to report neurogenotoxicity data specifically in Drosophila larval neuroblasts, thus underscoring the importance of this species as a testing model in exploring the biological impacts of validamycin A. The in vivo findings from the experiments are a valuable and novel addition to the existing validamycin A neurogenotoxicity database.


Assuntos
Encéfalo , Drosophila melanogaster , Inositol/análogos & derivados , Animais , Drosophila melanogaster/genética , Espécies Reativas de Oxigênio , Larva , DNA , Mamíferos
2.
J Appl Toxicol ; 43(2): 212-219, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-35644834

RESUMO

Plastic waste in different environments has been constantly transforming into microplastic/nanoplastic (MNPLs). As they may coexist with other contaminants, they may behave as vectors that transport various toxic trace elements, including metals. Because the impact of exposure to such matter on health still remains elusive, the abundant presence of MNPLs has lately become a pressing environmental issue. Researchers have been utilizing Drosophila melanogaster as a dynamic in vivo model in genetic research for some time. The fly has also recently gained wider recognition in toxicology and nanogenotoxicity studies. The use of nanoparticles in numerous medical and consumer products raises serious concern, since many in vitro studies have shown their toxic potential. However, there is rather limited in vivo research into nanomaterial genotoxicity using mice or other mammalians owing to high costs and ethical concerns. In this context, Drosophila, thanks to its genetic tractability, short life span, with its entire life cycle lasting about 10 days, and distinct developmental stages, renders this organism an excellent model in testing toxic effects mediated by MNPLs. This review therefore aims to encourage research entities to employ Drosophila as a model in their nanogenotoxicity experiments focusing on impact of MNPLs at the molecular level.


Assuntos
Metais Pesados , Nanoestruturas , Poluentes Químicos da Água , Animais , Camundongos , Microplásticos , Drosophila melanogaster/genética , Plásticos/toxicidade , Metais Pesados/toxicidade , Nanoestruturas/toxicidade , Mamíferos , Poluentes Químicos da Água/toxicidade
3.
Int J Mol Sci ; 25(1)2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38203725

RESUMO

Humans and animals may be exposed on a continuous daily basis to a mixture of environmental contaminants that may act on several organ systems through differing mechanisms [...].


Assuntos
Ecotoxicologia , Humanos
4.
Toxicol Mech Methods ; 33(4): 327-336, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36253933

RESUMO

Propionic acid is a short-chain fatty acid that is the main fermentation product of the enteric microbiome. It is found naturally and added to foods as a preservative and evaluated by health authorities as safe for use in foods. However, propionic acid has been reported in the literature to be associated with both health and disease. The purpose of this work is to better understand how propionic acid affects Drosophila melanogaster by examining some of the effects of this compound on the D. melanogaster hemocytes. D. melanogaster was chosen as a suitable in vivo model to detect potential risks of propionic acid (at five concentrations ranging from 0.1 to 10 mM) used as a food preservative. Toxicity, cellular immune response, intracellular oxidative stress (reactive oxygen species, ROS), gut damage, and DNA damage (via Comet assay) were the end-points evaluated. Significant genotoxic effects were detected in selected cell targets in a concentration dependent manner, especially at two highest concentrations (5 and 10 mM) of propionic acid. This study is the first study reporting genotoxicity data in the hemocytes of Drosophila larvae, emphasizing the importance of D. melanogaster as a model organism in investigating the different biological effects caused by the ingested food preservative product.


Assuntos
Drosophila melanogaster , Conservantes de Alimentos , Animais , Ensaio Cometa , Dano ao DNA , Drosophila melanogaster/efeitos dos fármacos , Drosophila melanogaster/genética , Conservantes de Alimentos/toxicidade , Imunidade Celular/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos
5.
J Appl Toxicol ; 42(3): 450-474, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34486762

RESUMO

The use of graphene and multi-walled carbon nanotubes (MWCNTs) has now become rather common in medical applications as well as several other areas thanks to their useful physicochemical properties. While in vitro testing offers some potential, in vivo research into toxic effects of graphene and MWCNTs could yield much more reliable data. Drosophila melanogaster has recently gained significant popularity as a dynamic eukaryotic model in examining toxicity, genotoxicity, and biological effects of exposure to nanomaterials, including oxidative stress, cellular immune response against two strains (NSRef and G486) of parasitoid wasp (Leptopilina boulardi), phenotypic variations, and locomotor behavior risks. D. melanogaster was used as a model organism in our study to identify the potential risks of exposure to graphene (thickness: 2-18 nm) and MWCNTs in different properties (as pure [OD: 10-20 nm short], modified by amide [NH2 ] [OD: 7-13 nm length: 55 µm], and modified by carboxyl [COOH] [OD: 30-50 nm and length: 0.5-2 µm]) at concentrations ranging from 0.1 to 250 µg/ml. Significant effects were observed at two high doses (100 and 250 µg/ml) of graphene or MWCNTs. This is the first study to report findings of cellular immune response against hematopoiesis and parasitoids, nanogenotoxicity, phenotypic variations, and locomotor behavior in D. melanogaster.


Assuntos
Dano ao DNA , Drosophila melanogaster/efeitos dos fármacos , Grafite/toxicidade , Interações Hospedeiro-Parasita/efeitos dos fármacos , Nanotubos de Carbono/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Animais , Drosophila melanogaster/imunologia , Drosophila melanogaster/parasitologia , Drosophila melanogaster/fisiologia , Imunidade Celular/efeitos dos fármacos , Locomoção/efeitos dos fármacos , Fenótipo
6.
J Appl Toxicol ; 42(11): 1854-1867, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35837816

RESUMO

Boron trioxide nanoparticles (B2 O3 NPs) have recently been widely used in a range of applications including electronic device technologies, acousto-optic apparatus fields, and as nanopowder for the production of special glasses. We propose Drosophila melanogaster as a useful in vivo model system to study the genotoxic risks associated with NP exposure. In this study, we have conducted a genotoxic evaluation of B2 O3 NPs (size average 55.52 ± 1.41 nm) and its ionic form in D. melanogaster. B2 O3 NPs were supplied to third instar larvae at concentrations ranging from 0.1-10 mM. Toxicity, intracellular oxidative stress (reactive oxygen species, ROS), phenotypic alterations, genotoxic effect (via the wing somatic mutation and recombination test, SMART), and DNA damage (via Comet assay) were the end-points evaluated. B2 O3 NPs did not cause any mutagenic/recombinogenic effects in all tested non-toxic concentrations in Drosophila SMART. Negative data were also obtained with the ionic form. Exposure to B2 O3 NPs and its ionic form (at two highest concentrations, 2.5 and 5 mM) was found to induce DNA damage in Comet assay. Additionally, ROS induction in hemocytes and phenotypic alterations were determined in the mouths and legs of Drosophila. This study is the first study reporting genotoxicity data in the somatic cells of Drosophila larvae, emphasizing the importance of D. melanogaster as a model organism in investigating the different biological effects in a concentration-dependent manner caused by B2 O3 NPs and its ionic form. The obtained in vivo results contribute to improvement the genotoxicity database on the B2 O3 NPs.


Assuntos
Drosophila melanogaster , Nanopartículas , Animais , Boro , Dano ao DNA , Drosophila/genética , Drosophila melanogaster/genética , Íons , Larva/genética , Testes de Mutagenicidade , Mutagênicos/toxicidade , Nanopartículas/toxicidade , Estresse Oxidativo , Espécies Reativas de Oxigênio
7.
Adv Exp Med Biol ; 1357: 275-301, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35583649

RESUMO

Nanotechnology is often praised as the future technology that will revolutionize the world as we know it, because nanomaterials (NMs) offer numerous practical applications for a wide range of fields such as medicine, cosmetics, food preservation, paintings, and industry. Produced by nanotechnology, NMs are in the front line of this innovative applied science, while nanoparticles (NPs) refer to materials existing in the natural world and measuring 1-100 nanometers in at least one dimension. The recent surge in the number of endeavors to utilize NMs makes it imperative to identify hazards and risk factors involved as we have yet to know harmful effects of this uncharted territory on the environment and public health. While researchers generally choose to carry out in vitro experiments in an effort to assess toxicity of NMs, in vivo approaches seem to yield better evidence that is more relevant to risk assessment. In that context, Drosophila melanogaster stands out as the most dynamic model organism for biological experiments, since 75% of the genes responsible for human diseases are known to have homologs in D. melanogaster, which facilitates research into various pathologies. This book chapter aims to present the full picture of studies on separate NMs that employed in vivo approaches (toxicity, genotoxicity, internalization, cell uptake, tissue distribution, etc.) using D. melanogaster, attempting to offer an in-depth analysis of risks involved in exposure to NMs, as well as many advantages of other animal models used by nanogenotoxicology studies.


Assuntos
Nanopartículas , Nanoestruturas , Animais , Drosophila , Drosophila melanogaster/genética , Nanopartículas/toxicidade , Nanoestruturas/toxicidade , Nanotecnologia
8.
Int J Mol Sci ; 23(16)2022 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-36012388

RESUMO

New insights into the interactions between nanopesticides and edible plants are required in order to elucidate their impacts on human health and agriculture. Nanopesticides include formulations consisting of organic/inorganic nanoparticles. Drosophila melanogaster has become a powerful model in genetic research thanks to its genetic similarity to mammals. This project mainly aimed to generate new evidence for the toxic/genotoxic properties of different nanopesticides (a nanoemulsion (permethrin nanopesticides, 20 ± 5 nm), an inorganic nanoparticle as an active ingredient (copper(II) hydroxide [Cu(OH)2] nanopesticides, 15 ± 6 nm), a polymer-based nanopesticide (acephate nanopesticides, 55 ± 25 nm), and an inorganic nanoparticle associated with an organic active ingredient (validamycin nanopesticides, 1177 ± 220 nm)) and their microparticulate forms (i.e., permethrin, copper(II) sulfate pentahydrate (CuSO4·5H2O), acephate, and validamycin) widely used against agricultural pests, while also showing the merits of using Drosophila-a non-target in vivo eukaryotic model organism-in nanogenotoxicology studies. Significant biological effects were noted at the highest doses of permethrin (0.06 and 0.1 mM), permethrin nanopesticides (1 and 2.5 mM), CuSO4·5H2O (1 and 5 mM), acephate and acephate nanopesticides (1 and 5 mM, respectively), and validamycin and validamycin nanopesticides (1 and 2.5 mM, respectively). The results demonstrating the toxic/genotoxic potential of these nanopesticides through their impact on cellular internalization and gene expression represent significant contributions to future nanogenotoxicology studies.


Assuntos
Cobre , Permetrina , Animais , Cobre/toxicidade , Drosophila , Drosophila melanogaster , Humanos , Hidróxidos , Inositol/análogos & derivados , Mamíferos , Compostos Organotiofosforados , Permetrina/toxicidade , Fosforamidas
9.
Drug Metab Rev ; 53(4): 604-617, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33989097

RESUMO

The field of nanotechnology has allowed for increasing nanoparticle (NP) exposure to the male reproductive system. Certain NPs have been reported to have adverse consequences on male germ and somatic cells. Germ cells are the bridge between generations and are responsible for the transmission of genetic and epigenetic information to future generations. A number of NPs have negative impacts on male germ and somatic cells which could ultimately affect fertility or the ability to produce healthy offspring. These impacts are related to NP composition, modification, concentration, agglomeration, and route of administration. NPs can induce severe toxic effects on the male reproduction system after passing through the blood-testis barrier and ultimately damaging the spermatozoa. Therefore, understanding the impacts of NPs on reproduction is necessary. This review will provide a comprehensive overview on the current state of knowledge derived from the previous in vivo and in vitro research on effects of NPs on the male reproductive system at the genetic, cellular, and molecular levels.


Assuntos
Nanopartículas , Genitália Masculina , Humanos , Masculino , Nanopartículas/toxicidade , Nanotecnologia , Reprodução
10.
PLoS Pathog ; 15(10): e1008084, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31589659

RESUMO

It is common to find abundant genetic variation in host resistance and parasite infectivity within populations, with the outcome of infection frequently depending on genotype-specific interactions. Underlying these effects are complex immune defenses that are under the control of both host and parasite genes. We have found extensive variation in Drosophila melanogaster's immune response against the parasitoid wasp Leptopilina boulardi. Some aspects of the immune response, such as phenoloxidase activity, are predominantly affected by the host genotype. Some, such as upregulation of the complement-like protein Tep1, are controlled by the parasite genotype. Others, like the differentiation of immune cells called lamellocytes, depend on the specific combination of host and parasite genotypes. These observations illustrate how the outcome of infection depends on independent genetic effects on different aspects of host immunity. As parasite-killing results from the concerted action of different components of the immune response, these observations provide a physiological mechanism to generate phenomena like epistasis and genotype-interactions that underlie models of coevolution.


Assuntos
Drosophila melanogaster/imunologia , Drosophila melanogaster/parasitologia , Hemócitos/imunologia , Interações Hospedeiro-Parasita , Imunidade Humoral/imunologia , Vespas/imunologia , Animais , Drosophila melanogaster/genética , Feminino , Genótipo , Hemócitos/parasitologia , Masculino , Monofenol Mono-Oxigenase/metabolismo , Vespas/genética , Vespas/patogenicidade
11.
J Toxicol Environ Health A ; 84(16): 649-660, 2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-33874844

RESUMO

The abundant presence and extensive use of polystyrene microplastics (PSMPs) has recently become a serious environmental concern, as impact of exposure to these substances on human health remains unknown. While in vitro studies yield data on adverse effect of PSMPs, in vivo approaches are more relevant for risk assessment. Drosophila melanogaster is one of the most genetically and experimentally accessible model organisms used in biology as an in vivo model. D. melanogaster was selected as a representative in vivo model organism to examine the genotoxic potential of PSMPs at 5 concentrations of three different sizes namely 4, 10, or 20 µm. In particular, the wing somatic mutation and recombination test (SMART), a scalable, time-efficient in vivo assay developed to study genotoxicity of various compounds in a rapid manner at low costs was used. The third-instar Drosophila larvae were exposed to PSMPs through food at 5 concentrations ranging from 0.01-10 mM. Viability (lethality), larval length, morphological deformations, locomotor activity (climbing behavior), and genotoxic effects were the end-points measured. Exposure to PSMPs at 4, 10, or 20 µm produced significant morphological defects, impaired climbing behavior, and genotoxicity as evidenced by the SMART test demonstrating induction of somatic recombination. Significant increases were observed in the frequency of total spots, suggesting that PSMPs might induce genotoxic activity predominantly via initiation of somatic DNA recombination in a concentration-dependent manner.


Assuntos
Dano ao DNA , Drosophila melanogaster/efeitos dos fármacos , Microplásticos/toxicidade , Nanopartículas/toxicidade , Poliestirenos/toxicidade , Animais , Relação Dose-Resposta a Droga , Drosophila melanogaster/crescimento & desenvolvimento , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Modelos Animais
12.
J Appl Toxicol ; 41(1): 118-147, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33111384

RESUMO

Nanomaterials (NMs) generally display fascinating physical and chemical properties that are not always present in bulk materials; therefore, any modification to their size, shape, or coating tends to cause significant changes in their chemical/physical and biological characteristics. The dramatic increase in efforts to use NMs renders the risk assessment of their toxicity highly crucial due to the possible health perils of this relatively uncharted territory. The different sizes and shapes of the nanoparticles are known to have an impact on organisms and an important place in clinical applications. The shape of nanoparticles, namely, whether they are rods, wires, or spheres, is a particularly critical parameter to affect cell uptake and site-specific drug delivery, representing a significant factor in determining the potency and magnitude of the effect. This review, therefore, intends to offer a picture of research into the toxicity of different shapes (nanorods, nanowires, and nanospheres) of NMs to in vitro and in vivo models, presenting an in-depth analysis of health risks associated with exposure to such nanostructures and benefits achieved by using certain model organisms in genotoxicity testing. Nanotoxicity experiments use various models and tests, such as cell cultures, cores, shells, and coating materials. This review article also attempts to raise awareness about practical applications of NMs in different shapes in biology, to evaluate their potential genotoxicity, and to suggest approaches to explain underlying mechanisms of their toxicity and genotoxicity depending on nanoparticle shape.


Assuntos
Aberrações Cromossômicas/induzido quimicamente , Sistemas de Liberação de Medicamentos/efeitos adversos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Animais , Humanos , Conformação Molecular , Testes de Mutagenicidade
13.
J Toxicol Environ Health A ; 83(11-12): 456-469, 2020 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-32515692

RESUMO

The biological impact of nanomaterials (NMs) is determined by several factors such as size and shape, which need to be taken into consideration in any type of analysis. While investigators often prefer to conduct in vitro studies for detection of any possible adverse effects of NMs, in vivo approaches yield more relevant data for risk assessment. For this reason, Drosophila melanogaster was selected as a suitable in vivo model to characterize the potential risks associated with exposure nanorods (NRs), nanospheres (NSs), nanowires (NWs) forms of titanium dioxide (TiO2), and their microparticulated (or bulk) form, as TiO2. Third instar larvae (72 hr old larvae) were fed with TiO2 (NRs, NSs, or NWs) and TiO2 at concentrations ranging from 0.01 to 10 mM. Viability (toxicity), internalization (cellular uptake), intracellular reactive oxygen species (ROS) production, and genotoxicity (Comet assay) were the end-points evaluated in hemocyte D. melanogaster larvae. Significant intracellular oxidative stress and genotoxicity were noted at the highest exposure concentration (10 mM) of TiO2 (NRs, NSs, or NWs), as determined by the Comet assay and ROS analysis, respectively. A concentration-effect relationship was observed in hemocytes exposed to the NMs. Data demonstrated that selected forms of TiO2.-induced genotoxicity in D. melanogaster larvae hemocytes indicating this organism is susceptible for use as a model to examine in vivo NMs-mediated effects.


Assuntos
Dano ao DNA , Nanoestruturas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Titânio/toxicidade , Animais , Transporte Biológico , Drosophila melanogaster , Hemócitos/efeitos dos fármacos , Hemócitos/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Larva/efeitos dos fármacos , Larva/metabolismo , Nanosferas/química , Nanosferas/toxicidade , Nanoestruturas/química , Nanotubos/química , Nanotubos/toxicidade , Nanofios/química , Nanofios/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Titânio/química , Titânio/metabolismo
14.
Environ Res ; 166: 10-15, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29807314

RESUMO

Chronic obstructive pulmonary disease (COPD) in humans, describes a group of lung conditions characterised by airflow limitation that is poorly reversible. The airflow limitation usually progresses slowly and is related to an abnormal inflammatory response of the lung to toxic particles. COPD is characterised by oxidative stress and an increased risk of lung carcinoma. The 2-amino-3-methylimidazo [4,5-f]quinoline (IQ) is one of a number of mutagenic/carcinogenic heterocyclic amines found mainly in well-cooked meats which are thus part of the regular diet. Antioxidants are very important in order to protect the cells against oxidative damage. The aim of the present study was to assess the effects of IQ on the level of DNA damage and susceptibility to a potent mutagen in peripheral blood cells of COPD patients. DNA damage and the frequency of micronuclei (MNi) were evaluated using the Comet and micronucleus assays, respectively. Differential expressions of both mRNA and protein of the endogenous antioxidant enzyme catalase were evaluated with quantitative polymerase chain reaction (qPCR) and Western blot analysis, respectively. Furthermore, the effect of bulk and nano forms of quercetin and their combination with IQ were examined. Results of the present study clearly demonstrated that MNi frequency in the peripheral blood lymphocytes exhibited a positive correlation with the DNA damage as evident from the different Comet assay parameters. Increase of the endogenous antioxidant catalase also showed there was a stimulation of this enzyme system by IQ. Whereas, the endogenous antioxidant quercetin significantly reduced oxidative stress in COPD patients and healthy individuals.


Assuntos
Dano ao DNA , Mutagênicos/toxicidade , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Quercetina/farmacologia , Quinolonas/toxicidade , Catalase/análise , Ensaio Cometa , Humanos , Linfócitos , Testes para Micronúcleos , Estresse Oxidativo
15.
J Toxicol Environ Health A ; 81(14): 645-660, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29873610

RESUMO

Graphene and multi-walled carbon nanotubes (MWCNT) are widely used in nanomedicine, and other fields, due to their unique physicochemical properties including high tensile strength, ultra-light weight, thermal and chemical stability, and reliable semi-conductive electronic properties. Although extensive amount of data exist describing their adverse effects including potential genotoxicity, few studies using gene mutation detection approaches in mammalian cells are available, which represents an important gap for risk estimations. The aim of the present study was to determine the effects of graphene or MWCNT [as pure, carboxyl (COOH) functionalized, and amide (NH2) functionalized] on cytotoxicity, intracellular levels of reactive oxygen species, apoptosis, gene expression changes, and gene mutation induction in L5178Y/Tk+/-3.7.2C mouse lymphoma cell line. Although some adverse effects were observed at concentrations of 350 and 450 µg/ml, which are excessive and not environmentally relevant levels, no marked effects were detected at concentrations of 250 µg/ml and lower. This is the first study reporting cytotoxicity, mutagenicity, and gene expression findings in the mouse lymphoma cell line for graphene and different MWCNT forms at high concentrations; however, the biological relevance of these observations needs to be assessed following chronic in vivo exposure.


Assuntos
Grafite/toxicidade , Nanotubos de Carbono/toxicidade , Animais , Linhagem Celular Tumoral , Dano ao DNA , Grafite/química , Camundongos , Testes de Mutagenicidade , Nanotubos de Carbono/química , Testes de Toxicidade
16.
Environ Res ; 136: 300-8, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25460650

RESUMO

The in vitro genotoxic and the soft-agar anchorage independent cell transformation ability of titanium dioxide nanoparticles (nano-TiO2) and its microparticulated form has been evaluated in human embryonic kidney (HEK293) and in mouse embryonic fibroblast (NIH/3T3) cells. Nano-TiO2 of two different sizes (21 and 50 nm) were used in this study. The comet assay, with and without the use of FPG enzyme, the micronucleus assay and the soft-agar colony assay were used. For both the comet assay and the frequency of micronuclei a statistically significant induction of DNA damage, was observed at the highest dose tested (1000 µg/mL). No oxidative DNA damage induction was observed when the comet assay was complemented with the use of FPG enzyme. Furthermore, long-term exposure to nano-TiO2 has also proved to induce cell-transformation promoting cell-anchorage independent growth in soft-agar. Results were similar for the two nano-TiO2 sizes. Negative results were obtained when the microparticulated form of TiO2 was tested, indicating the existence of important differences between the microparticulated and nanoparticulated forms. As a conclusion it should be indicated that the observed genotoxic/tranforming effects were only detected at the higher dose tested (1000 µg/mL) what play down the real risk of environmental exposures to this nanomaterial.


Assuntos
Nanopartículas Metálicas/toxicidade , Mutagênicos/toxicidade , Titânio/toxicidade , Ensaio Cometa , Células HEK293 , Humanos , Testes para Micronúcleos
17.
J Toxicol Environ Health A ; 77(21): 1292-303, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25268556

RESUMO

Two different sizes of zinc oxide nanoparticles (ZnO NP, ≤ 35 nm and 50-80 nm) were tested in the human lymphoblastoid cell line TK6 to increase our knowledge on their genotoxic potential. The comet assay was the system used, and the results obtained showed that the highest concentration tested (100 µg/ml) for the two selected compounds was genotoxic. The percent DNA in tail obtained after treatment with ZnO NP (≤ 35 nm) was significantly higher than that of ZnO NP (50-80 nm) at all concentrations tested. To investigate the nature of the induced genotoxic damage, specific enzymes recognizing oxidized DNA bases were used. Treatments with endonuclease III (Endo III) and formamidopyrimidine DNA glycosylase (FPG) demonstrated that only ZnO NP (50-80 nm) were able to induce significant levels of net oxidative DNA damage. Further DNA repair kinetics studies revealed that DNA damage initially induced was removed in approximately 5 h. DNA damage induced by ZnO NP was repaired more slowly than damage following microparticulated ZnO exposure. No marked differences in repair kinetics of both forms of ZnO NP were observed. Evidence indicates that a high proportion of DNA damage induced by ZnO NP (50-80 nm) correlated with induction of oxidative damage, and that both forms of ZnO NP interfere with mechanisms involved in DNA damage repair.


Assuntos
Dano ao DNA/efeitos dos fármacos , Reparo do DNA/efeitos dos fármacos , Nanopartículas/toxicidade , Óxido de Zinco/toxicidade , Linhagem Celular , Ensaio Cometa , Humanos , Nanopartículas/química , Estresse Oxidativo/efeitos dos fármacos , Óxido de Zinco/química
18.
Environ Toxicol Pharmacol ; 106: 104390, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38367919

RESUMO

Heavy metals are now persistently present in living things' environments, in addition to their potential toxicity. Therefore, the aim of this study was to utilize D. melanogaster to determine the biological effects induced by different heavy metals including cadmium chloride (CdCl2), copper (II) sulfate pentahydrate (CuSO 4.5 H2O), and silver nitrate (AgNO3). In vivo experiments were conducted utilizing three low and environmentally relevant concentrations from 0.01 to 0.5 mM under single and combined exposure scenarios on D. melanogaster larvae. The endpoints measured included viability, reactive oxygen species (ROS) generation and genotoxic effects using Comet assay and the wing-spot test. Results indicated that tested heavy metals were not toxic in the egg-to adult viability. However, combined exposure (CdCl2+AgNO3 and CdCl2+AgNO3+CuSO 4.5 H2O) resulted in significant genotoxic and unfavorable consequences, as well as antagonistic and/or synergistic effects on oxidative damage and genetic damage.


Assuntos
Poluentes Ambientais , Metais Pesados , Animais , Cádmio , Cobre/toxicidade , Drosophila melanogaster/genética , Poluentes Ambientais/toxicidade , Metais Pesados/toxicidade , Dano ao DNA
19.
J Toxicol Environ Health A ; 76(16): 990-1002, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24156722

RESUMO

In this study a genotoxic evaluation of titanium dioxide (TiO2, 2.3 nm), zirconium oxide (ZrO2, 6 nm), aluminum oxide (Al2O3, 16.7 nm) nanoparticles (NP) and their ionic forms was conducted using human peripheral blood lymphocytes and cultured human embryonic kidney (HEK293) cells by means of a modified alkaline comet assay with/without the formamidopyrimidine-DNA glycosylase (Fpg) and endonuclease III (Endo III) enzymes. Modifications to the comet assay by using lesion-specific endonucleases, such as Endo III and Fpg, detect DNA bases with oxidative damage. Both human peripheral blood lymphocytes and cultured embryonic kidney cells were incubated with TiO2, ZrO2, or Al2O3 NP at concentrations of 1, 10, or 100 µg/ml. Our results showed no significant induction in DNA damage by the comet assay with/without the Endo III and Fpg enzymes at all concentrations of ZrO2 and Al2O3. In the case of TiO2 NP only the highest concentration of 100 µg/ml significantly induced a genotoxic response. Data thus indicate that both ZrO2 and Al2O3 NP were not genotoxic in our system and in the case of TiO2 the lowest-observed-adverse-effect level (LOAEL) for genotoxicity was 100 µg/ml. Evidence indicates that these metallic NP are considered safe in light of the fact that no genotoxicity was noted with ZrO2 and Al2O3 and that the highest TiO2 concentration is not environmentally relevant.


Assuntos
Óxido de Alumínio/toxicidade , Rim/citologia , Linfócitos/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Titânio/toxicidade , Zircônio/toxicidade , Óxido de Alumínio/química , Sobrevivência Celular , Células Cultivadas , Ensaio Cometa , Humanos , Nanopartículas Metálicas/química , Titânio/química , Zircônio/química
20.
Toxics ; 11(8)2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37624187

RESUMO

Autophagy is the process through which a body breaks down and recycles its own cellular components, primarily inside lysosomes. It is a cellular response to starvation and stress, which plays decisive roles in various biological processes such as senescence, apoptosis, carcinoma, and immune response. Autophagy, which was first discovered as a survival mechanism during starvation in yeast, is now known to serve a wide range of functions in more advanced organisms. It plays a vital role in how cells respond to stress, starvation, and infection. While research on yeast has led to the identification of many key components of the autophagy process, more research into autophagy in more complex systems is still warranted. This review article focuses on the use of the fruit fly Drosophila melanogaster as a robust testing model in further research on autophagy. Drosophila provides an ideal environment for exploring autophagy in a living organism during its development. Additionally, Drosophila is a well-suited compact tool for genetic analysis in that it serves as an intermediate between yeast and mammals because evolution conserved the molecular machinery required for autophagy in this species. Experimental tractability of host-pathogen interactions in Drosophila also affords great convenience in modeling human diseases on analogous structures and tissues.

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