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1.
Artigo em Inglês | MEDLINE | ID: mdl-34444340

RESUMO

Mancozeb (MZ) and zoxamide (ZOX) are fungicides commonly used in pest control programs to protect vineyards. Their toxic and genotoxic potential were investigated in vitro on HepG2 and A549 cell lines at environmentally relevant concentrations. Cytotoxicity, apoptosis, necrosis and intracellular reactive oxygen species (ROS), comet assay and a micronucleus test with CREST immunofluorescence were used. The expression of a panel of genes involved in apoptosis/necrosis (BAX/BCL2), oxidative stress (NRF2), drug metabolism (CYP1A1) and DNA repair (ERCC1/OGG1) was evaluated by real-time PCR. Both fungicides were cytotoxic at the highest tested concentrations (295.7 and 463.4 µM, respectively); MZ induced necrosis, ZOX did not increase apoptosis but modulated BAX and BCL2 expression, suggesting a different mechanism. Both compounds did not increase ROS, but the induction of CYP1A1 and NRF2 expression supported a pro-oxidant mechanism. The comet assay evidenced MZ genotoxicity, whereas no DNA damage due to ZOX treatment was observed. Positive micronuclei were increased in both cell lines treated with MZ and ZOX, supporting their aneugenic potential. ERCC1 and OGG1 were differently modulated, indicating the efficient activation of the nucleotide excision repair system by both fungicides and the inhibition of the base excision repair system by MZ. Overall, MZ confirmed its toxicity and new ZOX-relevant effects were highlighted.


Assuntos
Fungicidas Industriais , Maneb , Zineb , Amidas , Ensaio Cometa , Dano ao DNA , Fungicidas Industriais/toxicidade , Maneb/toxicidade , Estresse Oxidativo , Espécies Reativas de Oxigênio , Zineb/toxicidade
2.
Nutrients ; 13(7)2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34371895

RESUMO

BACKGROUND: Curcumin, a natural polyphenol and the principal bioactive compound in Curcuma longa, was reported to have anti-inflammatory, anti-cancer, anti-diabetic and anti-rheumatic activity. Curcumin is not only considered for preventive, but also for therapeutic, purposes in cancer therapy, which requires a killing effect on cancer cells. A drawback, however, is the low bioavailability of curcumin due to its insolubility in water. To circumvent this limitation, curcumin was administered in different water-soluble formulations, including liposomes or embedded into nanoscaled micelles. The high uptake rate of micellar curcumin makes it attractive also for cancer therapeutic strategies. Native curcumin solubilised in organic solvent was previously shown to be cytotoxic and bears a genotoxic potential. Corresponding studies with micellar curcumin are lacking. METHODS: We compared the cytotoxic and genotoxic activity of native curcumin solubilised in ethanol (Cur-E) with curcumin embedded in micells (Cur-M). We measured cell death by MTT assays, apoptosis, necrosis by flow cytometry, senolysis by MTT and C12FDG and genotoxicity by FPG-alkaline and neutral singe-cell gel electrophoresis (comet assay). RESULTS: Using a variety of primary and established cell lines, we show that Cur-E and Cur-M reduce the viability in all cell types in the same dose range. Cur-E and Cur-M induced dose-dependently apoptosis, but did not exhibit senolytic activity. In the cytotoxic dose range, Cur-E and Cur-M were positive in the alkaline and the neutral comet assay. Genotoxic effects vanished upon removal of curcumin, indicating efficient and complete repair of DNA damage. For inducing cell death, which was measured 48 h after the onset of treatment, permanent exposure was required while 60 min pulse-treatment was ineffective. In all assays, Cur-E and Cur-M were equally active, and the concentration above which significant cytotoxic and genotoxic effects were observed was 10 µM. Micelles not containing curcumin were completely inactive. CONCLUSIONS: The data show that micellar curcumin has the same cytotoxicity and genotoxicity profile as native curcumin. The effective concentration on different cell lines, including primary cells, was far above the curcumin concentration that can be achieved systemically in vivo, which leads us to conclude that native curcumin and curcumin administered as food supplement in a micellar formulation at the ADI level are not cytotoxic/genotoxic, indicating a wide margin of safety.


Assuntos
Apoptose/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Curcumina/toxicidade , Dano ao DNA , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ensaio Cometa , Curcumina/química , Relação Dose-Resposta a Droga , Composição de Medicamentos , Etanol/química , Humanos , Lipossomos , Micelas , Necrose , Medição de Risco , Solubilidade , Solventes/química
3.
Nutrients ; 13(7)2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34371907

RESUMO

The effect of coffee and cocoa on oxidative damage to macromolecules has been investigated in several studies, often with controversial results. This study aimed to investigate the effect of one-month consumption of different doses of coffee or cocoa-based products containing coffee on markers of DNA damage and lipid peroxidation in young healthy volunteers. Twenty-one volunteers were randomly assigned into a three-arm, crossover, randomized trial. Subjects were assigned to consume one of the three following treatments: one cup of espresso coffee/day (1C), three cups of espresso coffee/day (3C), and one cup of espresso coffee plus two cocoa-based products containing coffee (PC) twice per day for 1 month. At the end of each treatment, blood samples were collected for the analysis of endogenous and H2O2-induced DNA damage and DNA oxidation catabolites, while urines were used for the analysis of oxylipins. On the whole, four DNA catabolites (cyclic guanosine monophosphate (cGMP), 8-OH-2'-deoxy-guanosine, 8-OH-guanine, and 8-NO2-cGMP) were detected in plasma samples following the one-month intervention. No significant modulation of DNA and lipid damage markers was documented among groups, apart from an effect of time for DNA strand breaks and some markers of lipid peroxidation. In conclusion, the consumption of coffee and cocoa-based confectionery containing coffee was apparently not able to affect oxidative stress markers. More studies are encouraged to better explain the findings obtained and to understand the impact of different dosages of these products on specific target groups.


Assuntos
Biomarcadores/sangue , Chocolate , Café , Dano ao DNA , Peroxidação de Lipídeos , Estresse Oxidativo , 8-Hidroxi-2'-Desoxiguanosina/sangue , Chocolate/efeitos adversos , Cromatografia Líquida de Alta Pressão , Café/efeitos adversos , Ensaio Cometa , Estudos Cross-Over , GMP Cíclico/análogos & derivados , GMP Cíclico/sangue , Feminino , Guanina/análogos & derivados , Guanina/sangue , Humanos , Masculino , Espectrometria de Massas em Tandem , Adulto Jovem
4.
Sci Total Environ ; 794: 148489, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34217092

RESUMO

In the present study we evaluated cytotoxic and genotoxic activities of endocrine disrupting compounds (EDCs), including dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), bisphenol A (BPA), and nonylphenol (NP), which have been previously identified in effluents from two paper mills with different paper production technologies (virgin or recycled fibres). Moreover, we evaluated genotoxic activity of the effluents from these two paper mills and compared it to the activity of artificial complex mixtures consisting of the seven EDCs at concentrations detected in corresponding paper mill effluents. None of the EDCs was genotoxic in Salmonella typhimurium (SOS/umuC assay), while all induced DNA damage in human hepatocellular carcinoma (HepG2) cells (comet assay). After 4 h of exposure genotoxic effects were determined at concentrations ≥ 1 µg/L for BBP and DEHP, ≥10 µg/L for DMP, DEP, DBP, and BPA, and ≥100 µg/L for NP, while after 24 h of exposure DNA damage occurred at ≥10 µg/L for DBP, BPA and NP, and ≥100 µg/L for DMP, DEP, BBP and DEHP. The effluents and corresponding artificial mixtures of EDCs from paper mill that uses virgin fibres did not induce DNA damage in HepG2 cells, while the effluents and corresponding artificial mixtures for the paper mill that uses recycled fibres were genotoxic. Genotoxic activity of effluents was significantly higher compared to corresponding artificial mixtures suggesting the presence of further unknown compounds contributing to the effect. Wastewater monitoring based on chemical analysis is limited to determination of targeted compounds and does not take into account possible interactions between chemicals in mixtures. Therefore, it alone cannot provide an adequate information on potential toxic effects required for the assessment of genotoxic activity of real environmental samples and their potential threats to the environment and human health.


Assuntos
Disruptores Endócrinos , Ácidos Ftálicos , Compostos Benzidrílicos/análise , Ensaio Cometa , Dano ao DNA , Dibutilftalato , Disruptores Endócrinos/análise , Disruptores Endócrinos/toxicidade , Humanos , Águas Residuárias
5.
Free Radic Biol Med ; 174: 89-99, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34324980

RESUMO

Although DNA repair is known to impact susceptibility to cancer and other diseases, relatively few population studies have been performed to evaluate DNA repair kinetics in people due to the difficulty of assessing DNA repair in a high-throughput manner. Here we use the CometChip, a high-throughput comet assay, to explore inter-individual variation in repair of oxidative damage to DNA, a known risk factor for aging, cancer and other diseases. DNA repair capacity after H2O2-induced DNA oxidation damage was quantified in peripheral blood mononuclear cells (PBMCs). For 10 individuals, blood was drawn at several times over the course of 4-6 weeks. In addition, blood was drawn once from each of 56 individuals. DNA damage levels were quantified prior to exposure to H2O2 and at 0, 15, 30, 60, and 120-min post exposure. We found that there is significant variability in DNA repair efficiency among individuals. When subdivided into quartiles by DNA repair efficiency, we found that the average t1/2 is 81 min for the slowest group and 24 min for the fastest group. This work shows that the CometChip can be used to uncover significant differences in repair kinetics among people, pointing to its utility in future epidemiological and clinical studies.


Assuntos
Peróxido de Hidrogênio , Leucócitos Mononucleares , Ensaio Cometa , Dano ao DNA , Reparo do DNA , Humanos , Individualidade , Cinética , Linfócitos , Estresse Oxidativo/genética
6.
Artigo em Inglês | MEDLINE | ID: mdl-34266624

RESUMO

The alkaline comet assay has been widely used to determine genotoxicity in human populations exposed to arsenic. The sample sizes of earlier studies were usually small, and inconsistent results were found. Meta-analyses can merge the results of multiple studies of the same type and increase the credibility of the conclusion by increasing the sample size. Thus, to investigate the monitoring effect of alkaline comet assay on genotoxicity for arsenic exposed population, meta-analyses were performed. Thirteen studies were found to meet the inclusion criteria and were included in this study; of them, twelve articles were of medium quality (15-20 points), only one study was of high quality (21-27 points). Meta-analyses showed that the overall estimates of Mean Ratio (MR, defined as the mean value of the response in the exposed group divided by that in the reference group) were 2.81(95 % confidence interval (CI) 1.93-4.10); 2.37(95 % CI, 1.73-3.26), and 1.69(95 %CI, 1.29-2.20) for comet tail length, % tail DNA, and tail moment, respectively. This shows that the level of DNA damage in arsenic exposed population is significantly higher than that in control populations. A meta-analysis of the correlation coefficients showed that the overall estimate was 0.52 (95 %CI, 0.48∼0.56, P<0.05) with all correlation coefficients included, but it changed to 0.24 (95 %CI, 0.17∼0.28, P<0.05) when two abnormal correlation coefficients were excluded, suggesting there was a positive correlation between arsenic load in vivo and DNA damage, but the overall estimate value of coefficients was unstable. Therefore, we conclude that the alkaline comet assay can be used as an effective genotoxic biomonitoring tool for arsenic-exposed populations. However, more and higher-quality studies are still needed to verify its actual application value.


Assuntos
Ensaio Cometa/métodos , Mutagênicos/toxicidade , Arsênio/toxicidade , DNA/metabolismo , Dano ao DNA , Humanos , Publicações
7.
Artigo em Inglês | MEDLINE | ID: mdl-34200547

RESUMO

Pesticides have been considered as potential chemical mutagens; however, little is known about toxic and genotoxic effects during pesticide application in Zamora-Jacona, Michoacan State in Mexico. This study sought to determine DNA damage and cholinesterase activities inhibitions in 54 agricultural workers exposed to complex mixtures of pesticides vs. control group (26 individuals) using Comet assay in peripheral whole blood, micronucleus (MN) test in oral mucosa cells, Cytokinesis-blocked MN assay in lymphocytes (L-CBMNcyt) and measuring AChE and BChE activities in whole blood and plasma samples, respectively. Exposed subjects demonstrated significantly elevated levels of primary (Comet assay: tail intensity, tail length, tail moment, Olive tail moment) and permanent DNA damage (MN assay: in blood/buccal cells; frequencies of nuclear buds, binucleated cells, cells with condensed chromatin, karyorrhexis, pyknosis, and karyolysis). However, inhibition of cholinesterase activities (AChE and BChE) was not observed in the workers. Confounding factors including sex, age, BMI, working exposure period, protection level, smoking habit (cigarettes per day units), alcohol consumption (weekly), medication, were considered in the analysis. These combined techniques demonstrated usefulness in the health hazards risks pesticide exposure assessment and suggested the need for periodic monitoring together with the education and the training of occupational workers for the safe application of potentially harmful pesticides.


Assuntos
Exposição Ocupacional , Praguicidas , Colinesterases , Ensaio Cometa , Análise Citogenética , Dano ao DNA , Humanos , Linfócitos , México , Testes para Micronúcleos , Mucosa Bucal , Exposição Ocupacional/efeitos adversos , Exposição Ocupacional/análise , Praguicidas/toxicidade
8.
Mutat Res Rev Mutat Res ; 787: 108349, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34083037

RESUMO

About 40 million workers are occupationally exposed to crystalline silica (CS) which was classified as a human carcinogen by the IARC. It is assumed that damage of the genetic material via inflammation and reactive oxygen species by CS lead to formation of malignant cells. We conducted a systematic literature search to find out if inhalation of CS containing dusts at workplaces causes damage of the genetic material. Thirteen studies were found eligible for this review, in most of them (n = 9) micronuclei (MN) which reflect structural/numerical chromosomal aberrations were monitored in lymphocytes and/or in exfoliated buccal cells. In 5 investigations DNA damage was measured in blood cells in single cell gel electrophoresis (comet) experiments. Frequently studied groups were potters, stone cutters, miners and construction workers. Results of meta-analyses show that exposure to CS causes formation of MN and DNA breaks, the overall ratio values were in exposed workers 2.06- and 1.96-fold higher than in controls, respectively. Two studies reported increased levels of oxidized guanine, and higher levels of DNA adducts with malondialdehyde indicating that exposure to CS leads to oxidative damage. The exposure of the workers to CS was quantified only in two studies, information concerning the size and chemical structures of the particles is lacking in most investigations. Therefore, it is not possible to use the results to derive occupational exposure limits of workers to CS which vary strongly in different countries. Nevertheless, the evaluation of the current state of knowledge shows that biomonitoring studies in which damage of the genetic material is measured in CS exposed workers can contribute to assess adverse health effects as consequence of DNA instability in specific occupations.


Assuntos
Ensaio Cometa/métodos , Dano ao DNA/fisiologia , Dano ao DNA/genética , Micronúcleos com Defeito Cromossômico , Dióxido de Silício/química
9.
Mutat Res Rev Mutat Res ; 787: 108371, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34083035

RESUMO

The alkaline comet assay, or single cell gel electrophoresis, is one of the most popular methods for assessing DNA damage in human population. One of the open issues concerning this assay is the identification of those factors that can explain the large inter-individual and inter-laboratory variation. International collaborative initiatives such as the hCOMET project - a COST Action launched in 2016 - represent a valuable tool to meet this challenge. The aims of hCOMET were to establish reference values for the level of DNA damage in humans, to investigate the effect of host factors, lifestyle and exposure to genotoxic agents, and to compare different sources of assay variability. A database of 19,320 subjects was generated, pooling data from 105 studies run by 44 laboratories in 26 countries between 1999 and 2019. A mixed random effect log-linear model, in parallel with a classic meta-analysis, was applied to take into account the extensive heterogeneity of data, due to descriptor, specimen and protocol variability. As a result of this analysis interquartile intervals of DNA strand breaks (which includes alkali-labile sites) were reported for tail intensity, tail length, and tail moment (comet assay descriptors). A small variation by age was reported in some datasets, suggesting higher DNA damage in oldest age-classes, while no effect could be shown for sex or smoking habit, although the lack of data on heavy smokers has still to be considered. Finally, highly significant differences in DNA damage were found for most exposures investigated in specific studies. In conclusion, these data, which confirm that DNA damage measured by the comet assay is an excellent biomarker of exposure in several conditions, may contribute to improving the quality of study design and to the standardization of results of the comet assay in human populations.


Assuntos
Ensaio Cometa/métodos , Biomarcadores/sangue , Dano ao DNA/genética , Dano ao DNA/fisiologia , Humanos
10.
Mutat Res Rev Mutat Res ; 787: 108364, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34083043

RESUMO

The purpose of this review is to evaluate the literature on the genotoxicity of cumene (CAS # 98-82-8) and to assess the role of mutagenicity, if any, in the mode of action for cumene-induced rodent tumors. The studies reviewed included microbial mutagenicity, DNA damage/ repair, cytogenetic effects, and gene mutations. In reviewing these studies, attention was paid to their conformance to applicable OECD test guidelines which are considered as internationally recognized standards for performing these assays. Cumene was not a bacterial mutagen and did not induce Hprt mutations in CHO cell cultures. In the primary rat hepatocyte cultures, cumene induced unscheduled DNA synthesis in one study but this response could not be reproduced in an independent study using a similar protocol. In a study that is not fully compliant to the current OECD guideline, no increase in chromosomal aberrations was observed in CHO cells treated with cumene. The weight of the evidence (WoE) from multiple in vivo studies indicates that cumene is not a clastogen or aneugen. The weak positive response in an in vivo comet assay in the rat liver and mouse lung tissues is of questionable significance due to several study deficiencies. The genotoxicity profile of cumene does not match that of a classic DNA-reactive molecule and the available data does not support a conclusion that cumene is an in vivo mutagen. As such, mutagenicity does not appear to be an early key event in cumene-induced rodent tumors and alternate hypothesized non-mutagenic modes-of-action are presented. Further data are necessary to rule in or rule out a particular MoA.


Assuntos
Dano ao DNA/fisiologia , Animais , Células CHO , Ensaio Cometa , Cricetulus , Dano ao DNA/genética , Humanos , Mutagênese/genética , Mutagênese/fisiologia , Testes de Mutagenicidade , Mutação/genética , Ratos
11.
J Toxicol Environ Health A ; 84(18): 761-768, 2021 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-34180377

RESUMO

Dipyrone or metamizole is one of the most frequently used analgesic worldwide. Despite its widespread use, this drug may exert genotoxic and cytotoxic effects on lymphocytes. Therefore, studies with therapeutic agents that may provide protection against these effects are important. The homeopathic compound Canova® (CA) appears to be a beneficial candidate for preventing DNA damage and cellular lethality, since this compound acts as an immunomodulator associated with cytoprotective actions. Hence, the aim of the present investigation was to determine the potential cytoprotective effects of CA using cell line VERO as a model. VERO cells were incubated with sodium dipyrone and subsequently subject to the comet, apoptosis and immunocytochemistry assays. Data demonstrated that sodium dipyrone induced an increase in DNA damage index (DI) employing the comet assay. However, when VERO cells were co-treated with CA at the three concentrations studied, a significant reduction in DI was observed, indicating an antigenotoxic effect attributed to CA. Further dipyrone induced an elevation in %apoptosis at 24 and 48 hr. However, when dipyrone was co-incubated with CA, a significant reduction in %apoptosis was noted at the three concentrations of CA employed. Results from immunocytochemical analysis showed a rise in the expression of caspase 8 and cytochrome C when cells were exposed to dipyrone. In contrast, co-treatment of dipyrone and CA significantly reduced the effect of dipyrone. Therefore, evidence indicated that CA acted as an anticytotoxic and antigenotoxic agent counteracting damage induced by dipyrone.


Assuntos
Venenos de Crotalídeos/farmacologia , Crioprotetores/farmacologia , Dipirona/efeitos adversos , Materia Medica/farmacologia , Extratos Vegetais/farmacologia , Animais , Apoptose , Chlorocebus aethiops , Ensaio Cometa , Imuno-Histoquímica , Células Vero
12.
Exp Parasitol ; 226-227: 108121, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34097889

RESUMO

Cystic echinococcosis (CE), a parasitic larval cystic stage of a small taeniid-type tapeworm (Echinococcus granulosus), causes illness in intermediate hosts and has become a threat to global public health. Currently, chemical compounds recommended by the WHO targeting CE are albendazole and mebendazole, however, none of them shows enhanced efficacy. Novel molecular compounds are urgently required to treat this disease. Our group uncover a drug, termed harmine (HM), that may be capable of treating CE. In this study, we aim to evaluate the anti-parasitic efficacy and the mechanism of DNA damage of HM against E. granulosus. In vitro, the results indicated that, within two and three days of treatment, ABZ killed 30.4% and 35.3% of protoscoleces, whereas HM killed 52.7% and 100% of protoscoleces, respectively. Furthermore, the presence of abnormalities in the internal structure of protoscoleces was examined by ultrastructural images of TEM, and the result showed that there were scattered nucleoli and heterochromatin margination phenomenon by HM treatment. DNA damage of protoscoleces was examined by using the comet assay, and results showed the DNA of protoscoleces was damaged. Moreover, EgATM, EgP53, EgTopo2a and EgRad54 genes were used to support the DNA damage by HM treatment, and results showed that all four genes were upregulated expression. In further, the result of HM treatment was tested by using designed siRNA to inhibit the expression of EgTopo2a and EgRad54. The results demonstrated that the viability was 88.75 ± 2.11% after suppressing the expression of EgTopo2a, which was significantly higher than that for HM alone group (P < 0.01). The viability was 10.11 ± 2.60% after transfected with EgRad54 siRNA, which was significantly lower compared with the HM alone group (P < 0.01). Based on our preliminary data, HM demonstrated significant parasiticidal activity against E. granulosus in vitro without obvious toxicity towards its host cells, suggesting that HM can be a potential anti-echinococcosis drug. HM was found to induce DNA damages of CE by activating the EgATM-EgP53-EgTopo2a signaling pathway. We therefore surmise that DNA damage response may be one of the mechanisms of HM against the parasite.


Assuntos
Antiparasitários/farmacologia , Dano ao DNA/efeitos dos fármacos , Equinococose/tratamento farmacológico , Echinococcus granulosus/efeitos dos fármacos , Harmina/farmacologia , Animais , Antiparasitários/uso terapêutico , Ensaio Cometa , Echinococcus granulosus/genética , Echinococcus granulosus/ultraestrutura , Harmina/uso terapêutico , Microscopia Eletrônica de Transmissão , Inibidores da Monoaminoxidase/farmacologia , RNA Interferente Pequeno/química , RNA Interferente Pequeno/fisiologia , Reação em Cadeia da Polimerase em Tempo Real , Ovinos
13.
Int J Biol Macromol ; 182: 1602-1610, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34033823

RESUMO

Phospholipase A2 Bothropstoxin-I (PLA2 BthTX-I) is a myotoxic Lys49-PLA2 from Bothrops jararacussu snake venom. In order to evaluate the DNA damage caused by BthTX-I, we used the Somatic Mutation and Recombination Test (SMART) in Drosophila melanogaster and Comet assay in HUVEC and DU-145 cells. For SMART, different concentrations of BthTX-I (6.72 to 430 µg/mL) were used and no significant changes in the survival rate were observed. Significant frequency of mutant spots was observed for the ST cross at the highest concentration of BthTX-I due to recombinogenic activity. In the HB cross, BthTX-I increased the number of mutant spots at intermediate concentrations, being 53.75 µg/mL highly mutagenic and 107.5 µg/mL predominantly recombinogenic. The highest concentrations were neither mutagenic nor recombinogenic, which could indicate cytotoxicity in the wing cells of D. melanogaster. In vitro, all BthTX-I concentrations (1 to 50 µg/mL) induced decrease in HUVEC cell viability, as well as in DU-145 cells at concentrations of 10, 25, and 50 µg/mL. The comet assay showed that in HUVEC and DU-145 cells, all BthTX-I concentrations promoted increase of DNA damage. Further studies should be performed to elucidate the mechanism of action of PLA2 BthTX-I and its possible use in therapeutic strategies against cancer.


Assuntos
Bothrops/metabolismo , Venenos de Crotalídeos/toxicidade , Fosfolipases A2/metabolismo , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Ensaio Cometa , Drosophila melanogaster , Células Endoteliais da Veia Umbilical Humana , Humanos , Mutação/genética
14.
J Toxicol Environ Health A ; 84(17): 689-701, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34034641

RESUMO

Nicotiana tabacum is the most cultivated tobacco species in the state of Rio Grande do Sul, Brazil. Workers who handle the plant are exposed to the leaf components during the harvesting process and when separating and classifying the dried leaves. In addition to nicotine, after the drying process, other components may be found including tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons, as well as pesticides residues. The objective of this study was to examine the genotoxicity attributed to the aqueous extract of dried tobacco leaves obtained from tobacco barns using Chinese hamster lung fibroblast cells (V79) as a model system by employing alkaline comet assay, micronucleus (MN) and Ames test. MTT assay was used to assess cytotoxicity and establish concentrations for this study. Data demonstrated cell viability > 85% for concentrations of 0.625-5 mg/ml while the comet assay indicated a significant increase in DNA damage at all concentrations tested. A significant elevation of MN and nuclear buds (NBUD) was found for 5 mg/ml compared to control and other dry tobacco leaves concentrations (0.625-2.5 mg/ml). Mutagenicity was not found using the Salmonella/Microsome test (TA98, TA100, and TA102 strains) with and without metabolic activation. The concentration of inorganic elements was determined employing the PIXE technique, and 13 inorganic elements were detected. Using CG/MS nicotine amounts present were 1.56 mg/g dry tobacco leaf powder. Due to the observed genotoxicity in V79 cells, more investigations are needed to protect the health of tobacco workers exposed daily to this complex mixture of toxic substances present in dry tobacco leaves.


Assuntos
Mutagênicos/toxicidade , Folhas de Planta/química , Tabaco/química , Animais , Linhagem Celular , Ensaio Cometa , Cricetulus , Testes para Micronúcleos , Testes de Mutagenicidade
15.
Toxicol Lett ; 348: 1-9, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-33984417

RESUMO

Nanotechnology-based drugs show superiority over conventional medicines because of increased bioavailability, lower accumulation in non-target tissues, and improved therapeutic index with increased accumulation at target sites. However, it is important to be aware of possible problems related to the toxicity of these products, which have therapeutically superior properties. Accordingly, the present study was designed to investigate the safety profile of amoxicillin nanoparticles (AmxNPs) that we developed to increase the oral bioavailability of amoxicillin (Amx) in poultry. In the first part of the study, the genotoxicity potential of AmxNPs was evaluated using the Ames test and the in vitro comet assay. The results of Ames test showed that none of the tested concentrations of Amx and AmxNPs cause a significant increase in the revertant number of Salmonella typhimurium strains TA98, and TA100, either with or without metabolic activation. Similarly, the comet assay revealed that AmxNPs did not induce DNA damage at any of the concentrations used, whereas high-dose (200 µg/mL) of Amx caused a significant increase in the percentage of DNA in the tail. In the second part of the study, the toxicity potential of AmxNPs on broilers was investigated by measuring biochemical parameters. In vivo results demonstrated that AmxNps did not cause a significant change in biochemical parameters, whereas Amx increased ALT, glucose, and cholesterol levels at certain sampling times. The obtained findings suggest that AmxNPs could be a safe promising potential drug in drug delivery systems.


Assuntos
Amoxicilina/toxicidade , Nanopartículas/toxicidade , Animais , Galinhas , Ensaio Cometa , Dano ao DNA , Sistemas de Liberação de Medicamentos , Avaliação Pré-Clínica de Medicamentos , Camundongos , Polímeros , Salmonella typhimurium/efeitos dos fármacos , Células Swiss 3T3
16.
Artigo em Inglês | MEDLINE | ID: mdl-33865537

RESUMO

Chronic exposure to benzene is a risk factor for hematological malignancies. Gasoline-station workers are exposed to benzene in gasoline, via both inhalation and dermal contact (attendants and managers) or inhalation (workers in the on-site convenience stores and offices). We have studied the exposure of these workers to benzene and the resulting genotoxic and immunotoxic effects. Levels of urinary trans, trans-muconic acid were higher among gasoline-station workers than among office workers with no known exposure to benzene (comparison group). Among the exposed workers, we observed statistically significant biological effects, including elevated DNA damage (comet assay); higher frequencies of micronuclei and nuclear buds (CBMN assay); lower levels of T-helper lymphocytes and naive Th lymphocytes; lower CD4 / CD8 ratio; and higher levels of NK cells and memory Th lymphocytes. Both groups of exposed workers (inhalation and inhalation + dermal routes) showed similar genotoxic and immunotoxic effects.


Assuntos
Benzeno/toxicidade , Gasolina/toxicidade , Sistema Imunitário/efeitos dos fármacos , Exposição Ocupacional , Adulto , Idoso , Poluentes Ocupacionais do Ar/toxicidade , Brasil/epidemiologia , Ensaio Cometa , Estudos Transversais , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/imunologia , Feminino , Humanos , Sistema Imunitário/metabolismo , Imunomodulação/efeitos dos fármacos , Exposição por Inalação/efeitos adversos , Exposição por Inalação/análise , Contagem de Linfócitos , Masculino , Testes para Micronúcleos , Pessoa de Meia-Idade , Testes de Mutagenicidade , Exposição Ocupacional/efeitos adversos , Exposição Ocupacional/análise , Exposição Ocupacional/estatística & dados numéricos , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/imunologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/patologia , Adulto Jovem
17.
Artigo em Inglês | MEDLINE | ID: mdl-33865541

RESUMO

The genotoxic and cytotoxic effects of 2,4-dichlorophenoxyacetic acid (2,4-D) on specimens of Astyanax lacustris were evaluated using different biomarkers. Additionally, this study evaluated the efficiency of an activated carbon filter made from the husks green coconut, which was used as a biosorbent to remove 2,4-D dissolved in the water, and the potential effectiveness of this procedure for the reduction of the toxic effects of this compound on A. lacustris. Three sublethal concentrations of 2,4-D (10, 20, and 40 mg L-1) were tested over 24, 48, and 72 h, and their effects on Astyanax lacustris were evaluated using chromosomal aberration test, the mitotic index, the frequency of micronuclei and nuclear alterations, and the comet assay. Exposure to 2,4-D increased the frequency of chromosomal aberrations, reduced the mitotic index, and caused significant levels of nuclear modification in some of the treatments, in comparison with the negative control. The comet assay revealed DNA damage (classes 1-3) at all 2,4-D concentrations, reaching significant levels in the 20 mg L-1 (48 h) and 40 mg L-1 (72 h) treatments. The coconut husk biosorbent was highly effective for the removal of 2,4-D and the fish exposed to the water decontaminated by this filter had low levels of cellular alteration. The findings of the present study demonstrated, for the first time, the genotoxic and cytotoxic effects of 2,4-D in Astyanax lacustris, as well as suggests the potential application of a biosorbent for the effective decontamination of water contaminated with pesticides.


Assuntos
Ácido 2,4-Diclorofenoxiacético/isolamento & purificação , Ácido 2,4-Diclorofenoxiacético/toxicidade , Materiais Biocompatíveis/farmacocinética , Characidae , Recuperação e Remediação Ambiental/métodos , Absorção Fisico-Química/efeitos dos fármacos , Animais , Materiais Biocompatíveis/química , Characidae/genética , Aberrações Cromossômicas/induzido quimicamente , Aberrações Cromossômicas/veterinária , Cocos/química , Ensaio Cometa , Análise Citogenética/veterinária , Dano ao DNA , Monitoramento Ambiental/métodos , Filtração/instrumentação , Filtração/métodos , Herbicidas/isolamento & purificação , Herbicidas/toxicidade , Testes de Mutagenicidade , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/toxicidade , Purificação da Água/métodos
18.
Artigo em Inglês | MEDLINE | ID: mdl-33865544

RESUMO

Quantum Dots (QDs), are considered as promising tools for biomedical applications. They have potential applications in agricultural industries, novel pesticide formulations, use in bio-labels and devices to aid genetic manipulation and post-harvest management. Since interactions with higher plants are of important environmental and ecological concern we investigated the cytotoxicity and genotoxicity of CdSe QDs in a model plant (Allium cepa) and established relationships between QDs genotoxic activity and oxidative stress. Allium cepa bulbs with intact roots were exposed to three concentrations of CdSe QDs (12.5, 25 and 50 nM). Cell viability and mitotic frequencies was measured for cytotoxicity, and to assess the genotoxicity DNA lesions, chromosome aberrations and micronuclei were evaluated. We report that QDs exerted significant genotoxic effects, associated with oxidative stress. This could be correlated with the retention of Cd in Allium roots as a dose-dependent increase with the highest uptake at 50 nM of CdSe QD. Oxidative stress induced by CdSe QD treatment activated both, antioxidant (SOD, CAT) scavengers and antioxidant (GPOD, GSH) enzymes. Concentrations as low as 25 nM CdSe QDs were cytotoxic and 50 nM CdSe QDs was found to be genotoxic to the plant. These findings enable to determine the concentrations to be used when practical applications using nanodevices of this type on plants are being considered.


Assuntos
Compostos de Cádmio/toxicidade , Cebolas/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Pontos Quânticos/toxicidade , Compostos de Selênio/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Ensaio Cometa , Dano ao DNA , Peroxidação de Lipídeos/efeitos dos fármacos , Testes para Micronúcleos , Testes de Mutagenicidade , Cebolas/genética , Cebolas/crescimento & desenvolvimento , Cebolas/metabolismo , Estresse Oxidativo/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo
19.
Artigo em Inglês | MEDLINE | ID: mdl-33865545

RESUMO

Prednisone (PD) is one of the most commonly used corticosteroids in immunosuppressive therapy for patients with autoimmune diseases and transplants. Chronic use of corticosteroids is associated with several side effects and an increase in neoplasia. Since genotoxic effects are associated with an increased risk of cancer development, this study evaluated the genotoxic and cytotoxic activities of PD using the SMART/wing assay in Drosophila melanogaster and the micronucleus test and comet assay in mouse bone marrow cells. Further, the toxic effects of PD on mouse organ tissues were assessed using histopathological analyses. In the SMART/wing assay, PD showed a significant genotoxic activity at all concentrations tested (0.375, 0.75, 1.5, and 2.0 mg/mL) compared to the negative control (p < 0.05). The micronucleus test and comet assay also showed an elevated genotoxicity of PD at all treatment conditions (24, 48, and 120 h with doses ranging from 0.5 to 1.5 mg/kg) compared to the negative control (p < 0.05). The histopathological analyses did not show toxicity of PD in mouse cells and tissues. Therefore, our results demonstrate that PD is a potent genotoxic immunosuppressant in mice and D. melanogaster cells. Somatic recombination was the primary contributor (46%-82%) to the induced genotoxicity observed in the SMART test.


Assuntos
Dano ao DNA/efeitos dos fármacos , Prednisona/efeitos adversos , Animais , Animais Geneticamente Modificados , Animais não Endogâmicos , Ensaio Cometa , Drosophila melanogaster , Feminino , Masculino , Camundongos , Testes para Micronúcleos , Testes de Mutagenicidade/métodos , Mutagênicos/toxicidade
20.
Food Chem Toxicol ; 152: 112163, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33836211

RESUMO

Comet assay, applied to in vitro, in vivo and ex vivo systems, is a quick, simple, and sensitive method for the detection of genotoxicity. In general, fresh whole blood or peripheral blood mononuclear cells (PBMCs) are used in the assay for the determination of DNA damage and repair. In this study, the effects of storage conditions on genotoxicity assessed by Comet assay in human whole blood and lymphocyte samples, were evaluated. Whole blood and lymphocyte samples were stored at 4 °C for 1, 2, 3, 4, 5 and 7 days; at -20 °C for 1 month and at -80 °C for 3, 6 and 12 months. 1% DMSO was used as cryoprotectant. No significant differences in DNA damage were demonstrated in all of the storage conditions and durations, and the results were similar according to the median values (p < 0.05). According to Spearman or Pearson correlations, an important correlation was found between the DNA damage of the fresh samples and the samples which were kept at -80 °C for 6 months with temperature and time (p < 0.01 for Pearson and p < 0.05 for Spearman). The results of this study indicated that blood and lymphocyte samples stored in +4 °C, -20 °C and -80 °C up to 12 months can be used instead of fresh samples especially in human biomonitoring studies.


Assuntos
Ensaio Cometa/métodos , Dano ao DNA , DNA/sangue , Linfócitos/química , Manejo de Espécimes/métodos , Adulto , Temperatura Baixa , DNA/genética , Humanos , Masculino
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