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1.
Ecotoxicol Environ Saf ; 210: 111868, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33421720

RESUMO

Psychiatric drugs are among the leading medications prescribed for humans, with their presence in aquatic environments raising concerns relating to potentially harmful effects on non-target organisms. Nortriptyline (NTP) is a selective serotonin-norepinephrine reuptake inhibitor antidepressant, widely used in clinics and found in environmental water matrices. In this study, we evaluated the toxic effects of NTP on zebrafish (Danio rerio) embryos and early larval stages. Developmental and mortality analyses were performed on zebrafish exposed to NTP for 168 h at concentrations ranging from 500 to 46,900 µg/L. Locomotor behaviour and acetylcholinesterase (AChE) activity were evaluated by exposing embryos/larvae to lower NTP concentrations (0.006-500 µg/L). The median lethal NTP concentration after 168 h exposure was 2190 µg/L. Although we did not identify significant developmental changes in the treated groups, lack of equilibrium was already visible in surviving larvae exposed to ≥ 500 µg/L NTP. The behavioural analyses showed that NTP was capable of modifying zebrafish larvae swimming behaviour, even at extremely low (0.006 and 0.088 µg/L) environmentally relevant concentrations. We consistently observed a significant reduction in AChE activity in the animals exposed to 500 µg/L NTP. Our results highlight acute toxic effects of NTP on the early-life stages of zebrafish. Most importantly, exposure to environmentally relevant NTP concentrations may affect zebrafish larvae locomotor behaviour, which in turn could reduce the fitness of the species. More studies involving chronic exposure and sensitive endpoints are warranted to better understand the effect of NTP in a more realistic exposure scenario.


Assuntos
Inibidores da Captação Adrenérgica/toxicidade , Antidepressivos Tricíclicos/toxicidade , Nortriptilina/toxicidade , Inibidores Seletivos de Recaptação de Serotonina/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra , Acetilcolinesterase/metabolismo , Animais , Comportamento Animal/efeitos dos fármacos , Embrião não Mamífero/efeitos dos fármacos , Larva/efeitos dos fármacos , Locomoção/efeitos dos fármacos
2.
Genet Mol Biol ; 41(1): 145-153, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29658968

RESUMO

This study aimed to assess the feasibility of comet and cytogenetic tests as tools for evaluating genomic instability in seeds of Oryza sativa L. (rice) and Phaseolus vulgaris (beans) L. from gene banks. Rice and beans were exposed to methyl methanesulfonate (MMS) as a reference DNA damaging agent. Seeds of two accessions of rice and beans were obtained from Embrapa Rice and Beans - Brazil. Seed groups were imbibed in three concentrations of MMS for three periods of time to carry out cytogenetic tests, and for one period for the comet test. At concentrations of 10 and 15 mg/L, MMS induced cytotoxic and/or mutagenic effects in the meristematic cells of roots from all the accessions of both species. In the comet test, MMS induced genotoxic effects at all the concentrations in the evaluated accessions of rice and beans, except in one accession of beans at the lowest concentration (5 mg/L). Both species showed sensitivity to MMS. The comet test can be proposed for the measurement of genomic instability in accessions of rice and beans in gene banks, as being more sensitive than the cytogenetic tests used.

3.
Mutagenesis ; 29(3): 215-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24618992

RESUMO

Aneuploidies are numerical genetic alterations that lead to changes in the normal number of chromosomes due to abnormal segregation during cell division. This type of alteration can occur spontaneously or as a result of exposure to mutagenic agents. The presence of these agents in the environment has increased concern about potential damage to human health. Rotenone, derived from plants of the genera Derris and Lonchocarpus, is a product that is used all over the world as a pesticide and piscicide. Before establishing its potential and efficiency for these purposes, it is essential to know more about the possible adverse effects that it may cause. The current work aimed to evaluate the mutagenic potential of rotenone using fish from the species Oreochromis niloticus, as well as to help in understanding its action mechanism. Our results showed the mutagenic potential of rotenone evidenced by increased formation of micronuclei and nuclear buds at low doses of exposure. The use of fluorescence in situ hybridisation technique made it possible to measure the aneugenic potential of the substance, probably due to its impairment of mitotic spindle formation.


Assuntos
Aneugênicos/toxicidade , Ciclídeos/genética , Testes para Micronúcleos/métodos , Rotenona/toxicidade , Aneuploidia , Animais , Brasil , Fragmentação do DNA/efeitos dos fármacos , Feminino , Pesqueiros , Água Doce , Humanos , Hibridização in Situ Fluorescente , Masculino , Praguicidas/toxicidade , Fuso Acromático/efeitos dos fármacos
4.
Eur J Appl Physiol ; 112(3): 941-50, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21706313

RESUMO

Physical training induces beneficial adaptations, but exhausting exercise increases reactive oxygen species, which can cause muscular injuries with consequent inflammatory processes, implying jeopardized performance and possibly overtraining. Acute strenuous exercise almost certainly exceeds the benefits of physical activity; it can compromise performance and may contribute to increased future risk of cardiovascular disease (CVD) in athletes. Polymorphisms in the muscle-type creatine kinase (CK-MM) gene may influence performance and adaptation to training, while many potentially significant genetic variants are reported as risk factors for CVD. Therefore, we investigated the influence of polymorphisms in CK-MM TaqI and NcoI, methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) and C-reactive protein (CRP G1059C) genes on exercise-induced damage and inflammation markers. Blood samples were taken immediately after a race (of at least 4 km) that took place outdoors on flat tracks, and were submitted to genotyping and biochemical evaluation of aspartate aminotransferase (AST), CK, CRP and high-sensitivity CRP (hs-CRP). CK-MM TaqI polymorphism significantly influenced results of AST, CK and hs-CRP, and an association between MTHFR C677T and A1298C with CRP level was found, although these levels did not exceed reference values. The results indicate that these polymorphisms can indirectly influence performance, contribute to higher susceptibility to exercise-induced inflammation or protection against it, and perhaps affect future risks of CVD in athletes.


Assuntos
Proteína C-Reativa/metabolismo , Creatina Quinase Forma MM/genética , Desoxirribonucleases de Sítio Específico do Tipo II/metabolismo , Exercício Físico/fisiologia , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Polimorfismo de Fragmento de Restrição/fisiologia , Polimorfismo de Nucleotídeo Único/fisiologia , Adolescente , Adulto , Atletas , Proteína C-Reativa/análise , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/genética , Feminino , Frequência do Gene , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Fragmento de Restrição/genética , Fatores de Risco , Adulto Jovem
5.
Eur J Appl Physiol ; 112(1): 183-92, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21516340

RESUMO

Physical training induces beneficial adaptations, but exhausting exercise increases reactive oxygen species, which can cause muscular injuries with consequent inflammatory processes, implying jeopardized performance and possibly overtraining. Acute strenuous exercise almost certainly exceeds the benefits of physical activity; it can compromise performance and may contribute to increased future risk of cardiovascular disease (CVD) in athletes. Polymorphisms in the muscle-type creatine kinase (CK-MM) gene may influence performance and adaptation to training, while many potentially significant genetic variants are reported as risk factors for CVD. Therefore, we investigated the influence of polymorphisms in CK-MM TaqI and NcoI, methylenetetrahydrofolate reductase (MTHFR C677T and A1298C) and C-reactive protein (CRP G1059C) genes on exercise-induced damage and inflammation markers. Blood samples were taken immediately after a race (of at least 4 km) that took place outdoors on flat tracks, and were submitted to genotyping and biochemical evaluation of aspartate aminotransferase (AST), CK, CRP and high-sensitivity CRP (hs-CRP). CK-MM TaqI polymorphism significantly influenced results of AST, CK and hs-CRP, and an association between MTHFR C677T and A1298C with CRP level was found, although these levels did not exceed reference values. Results indicate that these polymorphisms can indirectly influence performance, contribute to higher susceptibility to exercise-induced inflammation or protection against it, and perhaps affect future risks of CVD in athletes.


Assuntos
Proteína C-Reativa/genética , Creatina Quinase Forma MM/genética , Exercício Físico/fisiologia , Metilenotetra-Hidrofolato Desidrogenase (NADP)/genética , Esforço Físico/genética , Polimorfismo de Nucleotídeo Único/genética , Adolescente , Adulto , Creatina Quinase Forma MM/sangue , Feminino , Humanos , Masculino , Metilenotetra-Hidrofolato Desidrogenase (NADP)/sangue , Pessoa de Meia-Idade , Corrida/fisiologia , Adulto Jovem
6.
Artigo em Inglês | MEDLINE | ID: mdl-36554372

RESUMO

The use of microbial insecticides and their toxins in biological control and transgenic plants has increased their presence in the environment. Although they are natural products, the main concerns are related to the potential impacts on the environment and human health. Several assays have been performed worldwide to investigate the toxicity or adverse effects of these microbial products or their individual toxins. This overview examines the published data concerning the knowledge obtained about the ecotoxicity and environmental risks of these natural pesticides. The data presented show that many results are difficult to compare due to the diversity of measurement units used in the different research data. Even so, the products and toxins tested present low toxicity and low risk when compared to the concentrations used for pesticide purposes. Complementary studies should be carried out to assess possible effects on human health.


Assuntos
Bacillus thuringiensis , Produtos Agrícolas , Inseticidas , Praguicidas , Plantas Geneticamente Modificadas , Bacillus thuringiensis/genética , Proteínas de Bactérias/genética , Produtos Agrícolas/toxicidade , Ecotoxicologia , Endotoxinas , Proteínas Hemolisinas/toxicidade , Inseticidas/toxicidade , Controle Biológico de Vetores/métodos , Praguicidas/toxicidade , Plantas Geneticamente Modificadas/toxicidade
7.
Artigo em Inglês | MEDLINE | ID: mdl-33626334

RESUMO

Obesity is a global health problem with high prevalence and defined by a high body mass index (BMI). Several comorbidities affecting the central nervous system (CNS) are associated with obesity (e.g., neurodegenerative diseases, cognitive deficit, and psychobehavioral disturbs). The zebrafish (Danio rerio) has been considered a suitable model organism to investigate the neurobehavioral features of various human diseases. Here, we verify the impact of a high-fat diet (HFD) on the CNS by specifically assessing the effects of short-term HFD on anxiety-like responses, aggression, social preference, and memory, which are essential behaviors for survival and reproduction. Animals were separated in three experimental groups. The standard diet group (SD) received 7.5 mg/fish of dry food, while HFD groups received 5 mg/fish dry food plus 7.5 (HFD-7.5) or 15 mg/fish (HFD-15) of chicken egg yolk daily. Dietary fat content (w/w) was approximately 6.5%, 16.9%, and 21.1%, respectively. We performed behavioral tests and morphometric analyses after two weeks of HFD. In comparison to SD animals, HFD groups showed typical obesogenic responses with increases in BMI, abdominal length, and body weight. HFD individuals also showed increased aggression and anxiety-like behaviors in the mirror-induced aggression and novel tank diving tests, respectively. Interestingly, HFD did not change the social preference behavior, mean swimming speed or spontaneous activity levels, while the HFD-15 group showed cognitive deficits in the inhibitory avoidance test. Collectively, this "proof-of-concept" study is the first report to characterize the effects of short-term HFD on different behavioral domains of zebrafish with high degree of face validity. Moreover, our data reinforce the growing utility of zebrafish to explore the neurobehavioral basis of obesity, providing clinically translatable data, complementing the existing rodent models and supporting future mechanistic studies.


Assuntos
Agressão/fisiologia , Ansiedade/fisiopatologia , Comportamento Animal/fisiologia , Disfunção Cognitiva/fisiopatologia , Dieta Hiperlipídica/efeitos adversos , Peixe-Zebra , Animais , Índice de Massa Corporal , Modelos Animais de Doenças , Feminino , Masculino , Natação/fisiologia , Aumento de Peso/fisiologia
8.
Environ Health ; 9: 21, 2010 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-20444272

RESUMO

BACKGROUND: Normal cellular metabolism is well established as the source of endogenous reactive oxygen species which account for the background levels of oxidative DNA damage detected in normal tissue. Hydrogen peroxide imposes an oxidative stress condition on cells that can result in DNA damage, leading to mutagenesis and cell death. Several potentially significant genetic variants related to oxidative stress have already been identified, and angiotensin I-converting enzyme (ACE) inhibitors have been reported as possible antioxidant agents that can reduce vascular oxidative stress in cardiovascular events. METHODS: We investigate the influences of haptoglobin, manganese superoxide dismutase (MnSOD Val9Ala), catalase (CAT -21A/T), glutathione peroxidase 1 (GPx-1 Pro198Leu), ACE (I/D) and gluthatione S-transferases GSTM1 and GSTT1 gene polymorphisms against DNA damage and oxidative stress. These were induced by exposing leukocytes from peripheral blood of healthy humans (N = 135) to hydrogen peroxide (H2O2), and the effects were tested by comet assay. Blood samples were submitted to genotyping and comet assay (before and after treatment with H2O2 at 250 microM and 1 mM). RESULTS: After treatment with H2O2 at 250 microM, the GPx-1 polymorphism significantly influenced results of comet assay and a possible association of the Pro/Leu genotype with higher DNA damage was found. The highest or lowest DNA damage also depended on interaction between GPX-1/ACE and Hp/GSTM1T1 polymorphisms when hydrogen peroxide treatment increased oxidative stress. CONCLUSIONS: The GPx-1 polymorphism and the interactions between GPX-1/ACE and Hp/GSTM1T1 can be determining factors for DNA oxidation provoked by hydrogen peroxide, and thus for higher susceptibility to or protection against oxidative stress suffered by healthy individuals.


Assuntos
Ensaio Cometa , Dano ao DNA/genética , Peróxido de Hidrogênio/farmacologia , Leucócitos/efeitos dos fármacos , Polimorfismo Genético/efeitos dos fármacos , Adolescente , Adulto , Catalase/genética , Dano ao DNA/efeitos dos fármacos , Feminino , Genótipo , Glutationa Peroxidase/genética , Glutationa Transferase/genética , Haptoglobinas/genética , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Peptidil Dipeptidase A/genética , Polimorfismo Genético/genética , Superóxido Dismutase/genética , Adulto Jovem , Glutationa Peroxidase GPX1
9.
Am J Hum Biol ; 22(6): 807-12, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20878976

RESUMO

OBJECTIVES: Reactive oxygen species account for the background levels of oxidatively damaged DNA in normal tissues. Physical exercise increases oxygen consumption and can cause oxidative stress. This stress can also involve deficient antioxidant defenses, which can be influenced by certain genetic polymorphisms. Because regular exercise is a known inducer of antioxidant enzymes, the objective of this study was to compare, by comet assay, differences in the DNA damage between apparently healthy individuals and trained aerobic sportsmen carrying the same single nucleotide polymorphisms of manganese superoxide dismutase (Val9Ala), catalase (-21A/T), glutathione peroxidase 1 (Pro198Leu), before and after exposing leukocytes from peripheral blood to hydrogen peroxide (H2O2). METHODS: Athletes were compared with nonathletes after a situation that promotes reactive oxygen species increase (a race). Blood samples were submitted to genotyping and comet assay, and the athletes and nonathletes were paired according to their gender, age, and MnSOD, CAT, and GPx-1 genotypes. RESULTS: For nonathletes, there was a positive correlation between H2O2 concentrations and DNA damage levels. For athletes, these correlations showed differences between sexes, indicating that running may impose higher oxidative stress on the DNA of women than of men. Significant differences appeared for nonathletes in the comparisons between younger and older age groups after treatment with H2O2 at 250 µM. CONCLUSIONS: This suggests that, for individuals carrying the same genotypes of antioxidant enzymes' genes, the effect of H2O2-induced oxidative stress depends mainly on age and physical training. It also suggests that aerobic physical training can reduce oxidative damages to DNA, preventing related diseases in older people.


Assuntos
Exercício Físico/fisiologia , Peróxido de Hidrogênio/farmacologia , Leucócitos/metabolismo , Estresse Oxidativo , Aptidão Física/fisiologia , Adolescente , Adulto , Fatores Etários , Atletas , Catalase/genética , Dano ao DNA , Feminino , Genótipo , Glutationa Peroxidase/genética , Humanos , Leucócitos/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Fatores Sexuais , Superóxido Dismutase/genética , Glutationa Peroxidase GPX1
10.
Toxicol Lett ; 333: 242-250, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32841739

RESUMO

The Buccal Micronucleus Cytome Assay (BMCyt) has become an important biomonitoring tool for assessing cytogenetic damage in many studied populations. Each laboratory applies protocols that vary according to the method of collecting and preparing samples. Besides, Brazil is a country of great territorial extensions that received immigrants from various parts of the world with different genetic backgrounds. Therefore, the present study aimed to evaluate the inter-laboratory variation in scoring the same set of slides using the more comprehensive scoring criteria, to standardize the BMCyt protocol, to observe the basal alterations in populations of different Brazilian regions and to compare it with other places around the world. Our results showed that a valuable number of laboratories participated, ten laboratories from different regions of the country, for the validation of the BMCyt in human biomonitoring studies, resulting in the 804 healthy individuals. This was possible because we observed: a range of measures needs to be considered, such as the baseline frequency of DNA damage and cell death in non-exposed individuals; age when grouped showed an influence on DNA damage, although when evaluated by group we did not see an influence; association between smoking habit and all endpoints of the BMCyt (except karyolytic cells) was evident; the basal MN frequency, in the majority of groups, follows those around the world; and the BMCyt was confirmed as a good health status biomarker. We emphasize the need for constant discussions on the parameters of cell death due to greater difficulty among the analyzers.


Assuntos
Bioensaio/normas , Núcleo Celular/genética , Células Epiteliais/ultraestrutura , Laboratórios/normas , Micronúcleos com Defeito Cromossômico , Testes para Micronúcleos/normas , Mucosa Bucal/citologia , Adolescente , Adulto , Bioensaio/métodos , Brasil , Morte Celular/genética , Núcleo Celular/ultraestrutura , Dano ao DNA , Feminino , Humanos , Masculino , Micronúcleos com Defeito Cromossômico/estatística & dados numéricos , Testes para Micronúcleos/métodos , Pessoa de Meia-Idade , Mucosa Bucal/ultraestrutura , Adulto Jovem
11.
Genet Mol Biol ; 32(1): 138-43, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21637659

RESUMO

Lake Paranoá is a tropical reservoir for the City of Brasilia, which became eutrophic due to inadequate sewage treatment associated with intensive population growth. At present, two wastewater treatment plants are capable of processing up to 95% of the domestic sewage, thereby successfully reducing eutrophization. We evaluated both genotoxic and cytotoxic parameters in several fish species (Geophagus brasiliensis, Cichla temensis, Hoplias malabaricus, Astyanax bimaculatus lacustres, Oreochromis niloticus, Cyprinus carpio and Steindachnerina insculpita) by using the micronucleus (MN) test, the comet assay and nuclear abnormality assessment in peripheral erythrocytes. The highest frequencies of MN were found in Cichla temensis and Hoplias malabaricus, which were statistically significant when compared to the other species. However, Steindachnerina insculpita (a detritivorous and lake-floor feeder species) showed the highest index of DNA damage in the comet assay, followed by C. temensis (piscivorous). Nuclear abnormalities, such as binucleated, blebbed, lobed and notched cells, were used as evidence of cytotoxicity. Oreochromis niloticus followed by Hoplias malaricus, ominivorous/detritivotous and piscivorous species, respectively, presented the highest frequency of nuclear abnormalities, especially notched cells, while the herbivorous Astyanax bimaculatus lacustres showed the lowest frequency compared to the other species studied. Thus, for biomonitoring aquatic genotoxins under field conditions, the food web should also be considered.

12.
Bull Environ Contam Toxicol ; 83(4): 570-4, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19588065

RESUMO

The environmental toxicology of chemical pesticides have increased interest in the development and use of microbial pest control agents. In the present study four new Brazilian strains of Bacillus and one fungus were tested to evaluate the acute oral toxicity and clearance of these microbials in C57BL6 mice. No mortality was observed after exposure for any of the microorganisms tested. Clearance was significant after 30 days but for one strain of B. thuringiensis and one of B. sphaericus this time was not enough to completely eliminate the spores.


Assuntos
Bacillus/patogenicidade , Praguicidas/toxicidade , Animais , Brasil , Feminino , Fungos/patogenicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Controle de Pragas/métodos
13.
Artigo em Inglês | MEDLINE | ID: mdl-31585628

RESUMO

Loss of genetic integrity can occur during the long-term conservation of seeds. We have studied these effects in seeds of rice (Oryza sativa L.) and common bean (Phaseolus vulgaris L.) exposed to accelerated aging (elevated temperature and moisture) conditions. Tests of first count, germination, and germination speed index were performed to measure physiological quality; cytogenetic tests and comet assay were used to evaluate genetic integrity. With aging, we observed a decrease in mitotic index and an increase in the frequency of chromosomal alterations in root cells of imbibed seeds, as well as increased DNA damage (comet assay) in dry and imbibed seed embryos of both species. The comet assay can be a useful technique for measuring genetic integrity in seed conservation programs.


Assuntos
Genes de Plantas , Oryza/genética , Phaseolus/genética , Preservação Biológica/métodos , Banco de Sementes , Sementes/genética , Cromossomos de Plantas/ultraestrutura , Ensaio Cometa , Análise Citogenética , Dano ao DNA , Regulação da Expressão Gênica de Plantas , Germinação , Umidade , Índice Mitótico , Raízes de Plantas/citologia , Especificidade da Espécie , Temperatura , Fatores de Tempo
14.
PLoS Negl Trop Dis ; 13(8): e0007624, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31398198

RESUMO

BACKGROUND: The use of synthetic insecticides is one of the most common strategies for controlling disease vectors such as mosquitos. However, their overuse can result in serious risks to human health, to the environment, as well as to the selection of insecticidal resistant insect strains. The development of efficient and eco-friendly insect control is urgent, and essential oils have been presented as potential alternatives to synthetic insecticides. Moreover, nanoencapsulation techniques can enhance their efficiency by protecting from degradation and providing a controlled release rate. RESULTS: We assessed the potential of chitosan nanoparticles in encapsulating Siparuna guianensis essential oil, and maintaining its efficiency and prolonging its activity for the control of Aedes aegypti larvae. The encapsulation was characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), with an encapsulation efficiency ranging from 84.8% to 88.0%. Toxicity studies have demonstrated efficacy against mosquito larvae over 50% for 19 days with 100% mortality during the first week. This persistent action is presumably due to the enhanced contact and slow and maintained release conferred by chitosan nanoparticles. Furthermore, the exposure of aquatic non-target organisms (e.g. embryos and small adult fishes) revealed adequate selectivity of these nanoparticles. CONCLUSIONS: The encapsulation of S. guianensis essential oil in chitosan nanoparticles showed promising potential as a larvicide control alternative and should be considered within strategies for fighting Ae. aegypti.


Assuntos
Aedes/efeitos dos fármacos , Quitosana/química , Larva/efeitos dos fármacos , Laurales/química , Nanopartículas/química , Óleos Voláteis/farmacologia , Aedes/crescimento & desenvolvimento , Animais , Brasil , Controle de Insetos/métodos , Inseticidas/farmacologia , Larva/crescimento & desenvolvimento , Microscopia Eletrônica de Varredura , Mosquitos Vetores/efeitos dos fármacos , Extratos Vegetais/farmacologia
15.
Sci Total Environ ; 618: 101-111, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29127867

RESUMO

Wildfire is very common in Brazilian savannas, and its effects on water, soil and aquatic/soil organisms are poorly understood. In this study, we observed the effects of fire, especially of ashes, on surface soil and subsurface water in a typical Brazilian savanna (Cerrado sensu strictu) for one year. Soil analyses (pH, organic matter content, potential acidity, K, Ca, Mg and P) and subsurface water analyses (NO3-, PO43- Mg2+, Ca2+ and K+) were assessed. We evaluated the ecotoxicological effects of ashes on three different endpoints and species, in fish Danio rerio (embryonic development), aquatic snail Biomphalaria glabrata (reproduction) and a soil species Enchytraeus sp. (reproduction). We found a higher amount of exchangeable cations and organic matter content in short-term fire effects on soil, but the higher availability of nutrients did not affect the soil pH in field plots. The effects of ashes on soil and subsurface water did not persist for one-year post-fire, except for organic matter content in burned areas. No toxic effects were observed on hatching success and incidences of developmental abnormalities in D. rerio embryos. However, ash input had adverse effects on reproduction in snails and enchytraeids. We reported a statistically significant decrease in snail eggs exposed to the 50g.L-1 and 100g.L-1 of ashes after four weeks (p<0.05, Dunnett's test and Tukey test). Enchytraeus sp. reproduction was negatively influenced by the natural soil, which presents high acidity, and also when exposed directly to the ashes from burned area, suggesting that pH and other ash compounds may limit the growth of enchytraeids. More studies in burned areas are strongly encouraged, addressing the potential important routes of exposure to ashes in order to understand the impact of intense fires on soil and aquatic biota in tropical savannas.


Assuntos
Biota , Pradaria , Solo/química , Água/química , Incêndios Florestais , Animais , Brasil , Ecotoxicologia
16.
Aquat Toxicol ; 191: 219-225, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28866281

RESUMO

The increasing use of nanotechnology in the last decade has raised concerns about the impact of nanoparticles in the environment. In particular, the potential harmful effects of iron oxide nanoparticles (IONPs) in aquatic organisms have been poorly addressed. We analyze here the toxic effects induced by IONPs in zebrafish using a combination of classical (genotoxicity, oxidative stress) and molecular (transcriptomic) methodologies. Adult animals were exposed for 96h to five sub-lethal IONP concentrations, ranging from 4.7 to 74.4mg/L. Comet and micronucleus assays revealed a significant number of DNA lesions induced by IONPs at all concentrations tested. Conversely, the thiobarbituric acid reactive substances (TBARS) test detected only a mild oxidative damage in liver cells (∼1.5-fold increase of malondialdehyde concentrations) and only at the two higher IONP concentrations tested. Microarray analysis of liver samples identified 953 transcripts (927 unique genes) differentially expressed between controls and IONP-exposed samples. Subsequent functional analysis identified genes related to cation/metal ion binding, membrane formation, and morphogenesis among the transcripts overrepresented upon IONP treatments, whereas mRNAs encompassing genes associated with RNA biogenesis, translation, ribosomes, and several metabolic processes became underrepresented in treated samples. Taken together, these results indicate considerable genotoxic effects of IONPs combined with general negative effect on cell growth and on the ability of the cell produce new proteins. On the contrary, IONPs showed only a limited capacity to induce oxidative stress. To our knowledge, this is the first study on IONPs toxicity using such an integrative approach in an aquatic organism.


Assuntos
Nanopartículas Metálicas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Animais , Análise por Conglomerados , Dano ao DNA/efeitos dos fármacos , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Compostos Férricos/química , Fígado/diagnóstico por imagem , Fígado/efeitos dos fármacos , Fígado/metabolismo , Malondialdeído/metabolismo , Nanopartículas Metálicas/química , Transcriptoma/efeitos dos fármacos , Poluentes Químicos da Água/química , Microtomografia por Raio-X
17.
Artigo em Inglês | MEDLINE | ID: mdl-27153811

RESUMO

Several studies have shown high toxicity of the veterinary pharmaceutical ivermectin (a semisynthetic avermectin) for aquatic invertebrates however, few data is found for fish species. The present study evaluated the toxicity of ivermectin, to embryos, juveniles, and adults of zebrafish at different levels of biological organization including developmental, behavioural and biochemical. Toxicity tests were performed based on OECD protocols and mortality and behavioural changes were assed for all stages. Biochemical responses were assessed in adults and embryos and included cholinesterases (ChEs), catalase (CAT) (only in embryos), glutathione-S-Transferase (GST), lactate dehydrogenase (LDH) and vitellogenin (VTG) like proteins (only in embryos). Genotoxicity was evaluated in adults. Results showed a higher sensitivity of juvenile and adults of zebrafish (96h-LC10 values of 14.0 and 55.4µg/L, respectively). For embryos a 96h-LC10 of 147.1µg/L was calculated, moreover developmental anomalies and hatching inhibition were observed only at high concentrations (>400µg/L), whereas biochemical and behavioural responses occurred at lower concentrations (<60µg/L). Behavioural responses (lethargy) occurred in all life stages. Biochemical responses were observed including the inhibition of GST in adults and changes in ChE, CAT, LDH activities and VTG levels in embryos. Ivermectin did not show to be genotoxic for adult fish. The species sensitivity distribution analysis, based on fish and invertebrate species, indicated a Hazardous Concentration for 5% of the population (HC5) value of 0.057µg/L; suggesting high sensitivity of both groups to ivermectin and a high risk of this compound to aquatic ecosystems.


Assuntos
Ivermectina/toxicidade , Estágios do Ciclo de Vida , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/crescimento & desenvolvimento , Animais , Comportamento Animal/efeitos dos fármacos , Biomarcadores/metabolismo , Relação Dose-Resposta a Droga , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Desenvolvimento Embrionário/efeitos dos fármacos , Monitoramento Ambiental/métodos , Dose Letal Mediana , Locomoção/efeitos dos fármacos , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Testes para Micronúcleos , Medição de Risco , Natação , Peixe-Zebra/genética , Peixe-Zebra/metabolismo
18.
Eur J Cancer Prev ; 25(4): 299-305, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26287697

RESUMO

Pequi (Caryocar brasiliense Camb.), a fruit from Brazil's central region, was evaluated for its chemopreventive effects on preneoplastic liver lesions induced by the carcinogen diethylnitrosamine (DEN) in mice. BALB/c mice, 14 days of age, received an intraperitoneal injection at 10 µg/g of DEN. The mice received either of two doses of pequi oil (100 or 400 mg/kg) daily from the age of 30 days and were killed at the age of 189 days. Stereological parameters, including the volume density (Vv) and the total volume (Vtot) of the lesions (preneoplastic and adenomas), were measured and the expression of cytokeratins CK8/18 was evaluated. The total volume of lesions and adenomas was reduced by 51% in the group treated with the carcinogen and 400 mg/kg of pequi oil administered daily by an oral gavage for 25 consecutive weeks. In addition, some mice in this group did not develop lesions. Among the remaining preneoplastic lesions in this group, the number of remodelled profiles increased by 2.4-fold in the 400-mg pequi oil-treated mice relative to the 100-mg-treated mice. Our results show that pequi oil exerts a hepatoprotective effect against DEN-induced development of preneoplastic lesions and adenoma in mice and the potential for its use in the prevention of liver cancer.


Assuntos
Dietilnitrosamina/toxicidade , Modelos Animais de Doenças , Ericales/química , Neoplasias Hepáticas Experimentais/prevenção & controle , Fitoterapia , Óleos de Plantas/farmacologia , Lesões Pré-Cancerosas/prevenção & controle , Animais , Carcinógenos/toxicidade , Neoplasias Hepáticas Experimentais/induzido quimicamente , Neoplasias Hepáticas Experimentais/patologia , Camundongos , Camundongos Endogâmicos BALB C , Lesões Pré-Cancerosas/induzido quimicamente , Lesões Pré-Cancerosas/patologia
19.
Environ Sci Pollut Res Int ; 23(18): 18362-8, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27282368

RESUMO

This study aims to evaluate the effects of maghemite nanoparticles (γ-Fe2O3) coated with meso-2, 3-dimercaptosuccinic acid (DMSA) stabilizer on the survival and reproduction of the aquatic snail Biomphalaria glabrata. The cumulative means of egg masses and eggs per individual in the control group at the end of 4 weeks were 18.8 and 326.7, respectively. These values at the concentration of 1 mg/L were 17.2 and 291.6; at 10 mg/L, they were 19.6 and 334.4 ,and at 100 mg/L, they were 14.3 and 311.1. Results showed no significant differences between the tested and the control groups at the level of p < 0.05. Exposure of embryos for 10 days showed absence of mortality, malformation, or hatching delay. X-ray microtomography confirmed the presence of nanoparticles in exposed individuals and showed the complete elimination of the nanoparticles after 30 days in clean water. In the studied conditions, it is clear that γ-Fe2O3 coated with stabilizing DMSA did not alter the fecundity or the fertility of the snail B. glabrata after 4 weeks of exposure, and accumulation was not present after 30 days in clean water.


Assuntos
Biomphalaria/efeitos dos fármacos , Compostos Férricos/farmacologia , Nanopartículas Metálicas/química , Animais , Compostos Férricos/química , Fertilidade/efeitos dos fármacos , Reprodução/efeitos dos fármacos
20.
Environ Mol Mutagen ; 39(1): 18-21, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11813292

RESUMO

In Brazil, environmental contamination by mercury occurs mainly as a result of gold mining activities, especially in the Amazon region. In this area, human contamination results mainly from consumption of fish. Treatment of current symptoms of acute or chronic mercury contamination is normally carried out by increasing its excretion through metal scavenger compounds. In Japan, human contamination by mercury, which causes Minamata disease, has been successfully treated by the metal scavenger thiola (N-2 mercaptopropionylglycine). Its effects are based on its capacity to couple with the metal, facilitating its excretion. The possible clastogenic or anticlastogenic effect of thiola was evaluated by the in vivo micronucleus study in bone marrow erythrocytes of mice and also in human lymphocytes in vitro through chromosomal aberration analysis. In both experiments, different concentrations of thiola were used. Treatments with bleomycin (BLM), cyclophosphamide (CP), and also treatments combining these drugs with thiola were carried out with the purpose of studying the anticlastogenicity of thiola, considering its antioxidant properties. Thiola did not induce a significant increase in the micronucleus frequency in polychromatic erythrocytes of mice nor show any protective effect on the damage caused by bleomycin and cyclophosphamide in these cells. At a high dose, thiola showed a cytotoxic effect, significantly decreasing the relative proportion of polychromatic erythrocytes. In human lymphocytes, the tested drug did not increase the frequency of chromosomal aberration and also did not have any protective effect on the damage caused by BLM and CP.


Assuntos
Testes para Micronúcleos , Tiopronina/farmacologia , Animais , Bleomicina/farmacologia , Aberrações Cromossômicas , Ciclofosfamida/farmacologia , Feminino , Humanos , Linfócitos/efeitos dos fármacos , Masculino , Intoxicação por Mercúrio/tratamento farmacológico , Camundongos
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