Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Arch Toxicol ; 97(5): 1285-1298, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36892595

RESUMO

The current approach for the risk assessment of chemicals does not account for the complex human real-life exposure scenarios. Exposure to chemical mixtures in everyday life has raised scientific, regulatory, and societal concerns in recent years. Several studies aiming to identify the safety limits of chemical mixtures determined hazardous levels lower than those of separate chemicals. Following these observations, this study built on the standards set by the real-life risk simulation (RLRS) scenario and investigated the effect of long-term exposure (18 months) to a mixture of 13 chemicals (methomyl, triadimefon, dimethoate, glyphosate, carbaryl, methyl parathion, aspartame, sodium benzoate, EDTA, ethylparaben, butylparaben, bisphenol A and acacia gum) in adult rats. Animals were divided into four dosing groups [0xNOAEL (control), 0.0025xNOAEL (low dose-LD), 0.01xNOAEL (medium dose-MD) and 0.05xNOAEL (high dose-HD) (mg/kg BW/day)]. After 18 months of exposure, all animals were sacrificed, and their organs were harvested, weighed, and pathologically examined. While organ weight tended to be higher in males than in females, when sex and dose were taken into account, lungs and hearts from female rats had significantly greater weight than that of males. This discrepancy was more obvious in the LD group. Histopathology showed that long-term exposure to the chemical mixture selected for this study caused dose-dependent changes in all examined organs. The main organs that contribute to chemical biotransformation and clearance (liver, kidneys, and lungs) consistently presented histopathological changes following exposure to the chemical mixture. In conclusion, exposure to very low doses (below the NOAEL) of the tested mixture for 18 months induced histopathological lesions and cytotoxic effects in a dose and tissue-dependent manner.


Assuntos
Praguicidas , Masculino , Humanos , Ratos , Feminino , Animais , Nível de Efeito Adverso não Observado , Ratos Sprague-Dawley , Praguicidas/toxicidade , Aditivos Alimentares/toxicidade , Tamanho do Órgão
2.
Front Oncol ; 11: 683605, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34262868

RESUMO

PURPOSE: Due to the current practice on colorectal cancer (CRC) management, chemoresistance is most often recognized at the end of the treatment. Therefore, effective and easy-to-use prognostic biomarkers are needed. EXPERIMENTAL DESIGN: We evaluated the prognostic significance of two novel CRC biomarkers: a) micronuclei frequency (MNf) in 55 metastatic CRC (mCRC) and 21 locally advanced rectal cancer (laRC) patients using cytokinesis block micronucleus assay (CBMN assay) and b) telomerase activity (TA) in 23 mCRC and five laRC patients using TRAP-ELISA. Both biomarkers were evaluated in peripheral blood lymphocytes (PBLs) before, at the middle, and at the end of the therapy (approximately 0, 3, and 6 months) for mCRC patients before, at the end of the therapy, and after surgery for laRC patients. RESULTS: Overall, MNf demonstrated significant prognostic value since a decrease of MNf less than 29% between middle and initial MNf measurements can discriminate between progressive and stable/responsive disease with sensitivity of 36% and specificity of 87.0% while being able to identify responsive disease with sensitivity of 72.7% and specificity of 59.3%. On the other hand, TA presented a significant trend of increase (p = 0.07) in patients with progressive disease at the middle measurement. CONCLUSIONS: The findings of this study suggest that the MN frequency may serve as a promising prognostic biomarker for the monitoring of the treatment response of patients with CRC, while TA should be evaluated in a larger group of patients to further validate its significance.

3.
Toxicol Rep ; 8: 988-993, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34026563

RESUMO

The present work assessed the effect of copper (Cu) on cell dynamics and structure of the microalga Porphyridium purpureum (Rhodophyta, Bangiophycidae). Ultrastructure of the microalga was investigated and fluorescence of chlorophyll a and phycoerythrin, and content of reactive oxygen species (ROS) were estimated by flow cytometry. The number of cells did not show statistically significant differences at concentrations of 50 and 100 µg/L of Cu compared to the control, whereas 150 µg/L of Cu inhibited population growth. The fluorescence of chlorophyll a increased following exposure to Cu 100 µg/L and fluorescence of phycoerythrin enhanced by Cu 150 µg/L. There was no alteration in the above indicators at other concentrations. The content of ROS increased with increasing Cu concentration in a dose-dependent manner. The population size structure was also changed by Cu as the number of cells sized 4-6 µm was increased in the presence of Cu, especially with Cu 150 µg/L. Changes in the topography of thylakoids grew larger with Cu concentration.

4.
Toxicol Rep ; 7: 947-954, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32793424

RESUMO

Carbon nanofibers (CNFs) are widely used in consumer products today. In this study, we assessed the effects of CNFs on the digestive system of three freshwater invertebrate species (Gammaridae, Ephemerellidae, and Chironomidae). The aquatic insects Diamesa sp., Drunella cryptomeria, and Gammarus suifunensis were incubated with the CNFs at the concentration of 100 mg/L during the 7-days period. Histological examination of the whole specimens and the longitudinal sections revealed no toxic effects of CNFs. However, a noticeable change in the structure of the CNFs accumulated in the intestines of the aquatic insects was found by Raman spectroscopy. The registered decrease in the relative proportion of amorphous carbon included in the CNF sample was found in the intestines of Diamesa sp. and D. cryptomeria. The registered effect can indicate a biodegradation of amorphous carbon in the digestive tract of these two insect species. In contrast, the decrease of highly structured carbons and the decrease of G-bonds intensity were registered in the digestive tract of G. suifunensis. This observation demonstrates the partial biodegradation of CNFs in the digestive tract of G. suifunensis.

5.
Exp Ther Med ; 19(3): 1626-1632, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32104213

RESUMO

Osteoarthritis (OA) and osteoporosis (OP) are associated skeletal pathologies and have as a distinct feature the abnormal reconstruction of the subchondral bone. OA and OP have been characterized as age-related diseases and have been associated with telomere shortening and altered telomerase activity (TA). This review discusses the role of telomeres and telomerase in OA and OP pathologies and focuses on the usability of telomere length (TL) and the rate of telomere shortening as potential disease biomarkers. A number of studies have demonstrated that telomere shortening may contribute to OA and OP as an epigenetic factor. Therefore, it has been claimed that the measurement of TL of chondrocytes and/or peripheral blood cells may be an appropriate marker for the evaluation of the progression of these diseases. However, there is a need to be perform further studies with larger cohorts, with the aim of obtaining objective results and a better understanding of the association between TL, inflammation and aging, in order to provide further insight into the pathophysiology of degenerative joint diseases.

6.
Toxicol Lett ; 316: 154-170, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31521832

RESUMO

The present study investigates the genotoxic and cytotoxic effects of long term exposure to low doses of a mixture consisting of methomyl, triadimefon, dimethoate, glyphosate, carbaryl, methyl parathion, aspartame, sodium benzoate, EDTA, ethylparaben, buthylparaben, bisphenol A and acacia gum in rats. Four groups of ten Sprangue Dawley rats (5 males and 5 females per group) were exposed for 18 months to the mixture in doses of 0xNOAEL, 0.0025xNOAEL, 0.01xNOAEL and 0.05xNOAEL (mg/kg bw/day). After 18 months of exposure, the rats were sacrificed and their organs were harvested. Micronuclei frequency was evaluated in bone marrow erythrocytes whereas the organs were cytopathologically examined by the touch preparation technique. The exposure to the mixture caused a genotoxic effect identified only in females. Cytopathological examination showed specific alterations of tissue organization in a tissue-type dependent manner. The observed effects were dose-dependent and correlated to various tissue parameters. Specifically, testes samples revealed degenerative and cellularity disorders, liver hepatocytes exhibited decreased glycogen deposition whereas degenerative changes were present in gastric cells. Lung tissue presented increased inflammatory cells infiltration and alveolar macrophages with enhanced phagocytic activity, whereas brain tissue exhibited changes in glial and astrocyte cells' numbers. In conclusion, exposure to very low doses of the tested mixture for 18 months induces genotoxic effects as well as monotonic cytotoxic effects in a tissue-dependent manner.


Assuntos
Metabolismo Energético/efeitos dos fármacos , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Testes para Micronúcleos , Testes de Toxicidade Crônica , Animais , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Masculino , Nível de Efeito Adverso não Observado , Ratos Sprague-Dawley , Medição de Risco , Fatores Sexuais , Fatores de Tempo
7.
Toxicol Lett ; 310: 70-91, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30999039

RESUMO

The aim of the current study was to evaluate the effects of a mixture of thirteen common chemicals on rats, after a one-year exposure to doses around the acceptable daily intake (ADIs), using blood and urinary tests. The influence of low doses of the mixture on weight gain, water consumption, feed consumption and feed efficiency, biochemistry parameters, haematological parameters, blood lymphocytes subsets, serum inflammation profile and urine parameters was evaluated. Our mixture caused a moderate monotonic increase of the males' appetite and a non-monotonic increase of anabolism and a monotonic increase of appetite for the females. Regarding biochemical parameters, the exposure to the test mixture caused non-monotonic increases of AST and ALT, a decrease of PChE in males and plausibly a monotonic biliary obstruction in both sexes. Monocytes significantly increased in low dose groups of both sexes. A significant decrease of all the lymphocytes subclasses and an increased expression of TNF-α protein associated with an increased expression of IFN-γ protein observed in various groups. It became apparent that after twelve months of exposure very low doses of the tested mixture had both non-monotonic and monotonic harmful effects on different levels on rats.


Assuntos
Misturas Complexas/toxicidade , Aditivos Alimentares/toxicidade , Praguicidas/toxicidade , Testes de Toxicidade Crônica , Animais , Regulação do Apetite/efeitos dos fármacos , Biomarcadores/sangue , Biomarcadores/urina , Colestase/induzido quimicamente , Citocinas/sangue , Citocinas/urina , Ingestão de Líquidos/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Hormese , Mediadores da Inflamação/sangue , Mediadores da Inflamação/urina , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Masculino , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Ratos Sprague-Dawley , Medição de Risco , Fatores de Tempo , Aumento de Peso/efeitos dos fármacos
8.
Oncol Lett ; 17(3): 2703-2712, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30854044

RESUMO

Colorectal cancer (CRC) is the third most diagnosed type of cancer affecting males, and the second most diagnosed type of cancer affecting females, and one of the leading causes of cancer-related mortality globally. The estimation of the micronuclei (MN) frequency in peripheral blood lymphocytes (PBLs) from patients with CRC is proposed as a prognostic/predictive easy-to-use biomarker. In this study, we aimed to investigate the effects of systemic treatment on the MN frequency in PBLs from patients with CRC in order to determine the effectiveness of the MN frequency as a biomarker. For this purpose, from 2016 to 2018, we quantified the MN frequency as a prognostic/predictive biomarker in serial samples from 25 patients with metastatic CRC (mCRC) using cytokinesis block micronucleus assay (CBMN assay). The MN frequency in the PBLs of the patients was evaluated before, during the middle and at the end of the therapy (approximately 0, 3 and 6 months). The results revealed a common pattern regarding the fluctuation in the MN frequency. Statistical analysis confirmed that when the disease response was estimated with radiological criteria, a good response was depicted at the MN frequency and vice versa. Consequently, the findings of this study suggest that the MN frequency may serve as a promising prognostic/predictive biomarker for the monitoring of the treatment response of patients with CRC.

9.
Toxicol Rep ; 6: 105-110, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30622904

RESUMO

Effects of technical materials of pesticide active ingredients, belonging to various chemical classes, on erythropoiesis in mouse bone marrow were studied as part of the research on the pesticide mutagenic activity in micronucleus test. The purpose of the present study was to estimate the toxic action of the test substances on the target organ and the validity of the results of the micronucleus assay under conditions of erythropoiesis suppression. It was demonstrated that intragastrically administrated triazole pesticides reached bone marrow (target organ where micronucleus induction was assessed) and exerted an inhibitory effect on erythropoiesis. The effects of triazole pesticides were enhanced in the following order: difenoconazole ≤ tebuconazole < cyproconazole < flutriafol. Furthermore, an association between structural features of molecules and specific target organ activity of the test pesticides was observed. Based on the data on the general toxicity and the results of the evaluation of the effects on erythropoiesis, the maximum tolerated doses (MTDs) of 79 different technical materials of pesticides for CD-1 mice were determined.

10.
Inhal Toxicol ; 30(9-10): 361-369, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30369275

RESUMO

BACKGROUND: The aim of the present study was to identify the composition and reported chemical health hazards of the most common electronic cigarette liquids (e-liquids) in nine European Union (EU) Member States (MS) prior to adoption of the Tobacco Product Directive (TPD). MATERIALS AND METHODS: Within the Horizon2020, EUREST-PLUS study, 122 of the most commonly sold e-liquids in 9 EU MS were randomly selected and purchased. A quantitative and qualitative chemical analysis was performed using a previously validated based gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry method. The most commonly detected compounds were then divided according to the Danger Globally Harmonized System of Classification and Labelling of Chemicals (GHS) and Warning GHS codes. RESULTS: Within our qualitative analysis, 171 different compounds were detected. Discrepancies in measured versus reported nicotine concentration were identified. Forty-one (85.4%) of the most commonly detected compounds were registered with Warning GHS codes, 11 with Danger GHS codes and 9 with both codes. Of the total number of the detected compounds, 293 were attributable to fruits flavor, followed by tobacco flavor (204), nonalcoholic drinks (n = 64), desserts-sweets (n = 50), menthol - mint (n = 42) and alcohol (n = 39). Menthol which is classified as a strong irritant to skin and eye was the most frequently detected compound. CONCLUSION: A large plethora of compounds with varying warning codes was identified in e-cigarette samples. The systematic monitoring and chemical evaluation of e-liquids are warranted, so as to ensure consumer protection.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Aromatizantes/análise , Nicotina/análise , Cromatografia Líquida , Europa (Continente) , Cromatografia Gasosa-Espectrometria de Massas
11.
Int J Mol Med ; 42(1): 405-413, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29717770

RESUMO

Anabolic agents are doping substances which are commonly used in sports. Stanozolol, a 17α­alkylated derivative of testosterone, has a widespread use among athletes and bodybuilders. Several medical and behavioral adverse effects are associated with anabolic androgenic steroids (AAS) abuse, while the liver remains the most well recognized target organ. In the present study, the hepatic effects of stanozolol administration in rats at high doses resembling those used for doping purposes were investigated, in the presence or absence of exercise. Stanozolol and its metabolites, 16­ß­hydroxystanozolol and 3'­hydroxystanozolol, were detected in rat livers using liquid chromatography­mass spectrometry (LC­MS). Telomerase activity, which is involved in cellular aging and tumorigenesis, was detected by examining telomerase reverse transcriptase (TERT) and phosphatase and tensin homolog (PTEN) expression levels in the livers of stanozolol­treated rats. Stanozolol induced telomerase activity at the molecular level in the liver tissue of rats and exercise reversed this induction, reflecting possible premature liver tissue aging. PTEN gene expression in the rat livers was practically unaffected either by exercise or by stanozolol administration.


Assuntos
Envelhecimento/fisiologia , Fígado/fisiologia , Condicionamento Físico Animal , Estanozolol/administração & dosagem , Estanozolol/farmacologia , Telomerase/metabolismo , Animais , Regulação da Expressão Gênica/efeitos dos fármacos , Imuno-Histoquímica , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Metaboloma/efeitos dos fármacos , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Ratos Sprague-Dawley , Estanozolol/análogos & derivados , Telômero/metabolismo
12.
Artigo em Inglês | MEDLINE | ID: mdl-29704990

RESUMO

Imidacloprid (IMI) is a systemic, chloro-nicotinyl insecticide classified in Regulation N° 1272/2008 of the European Commision as "harmful if swallowed and very toxic to aquatic life, with long-lasting effects". IMI is metabolized in vitro both by aldehyde oxidase (AOX) (reduction) and by cytochrome P450s enzymes (CYPs). In the present study, the AOX inhibitor sodium tungstate dihydrate (ST) was used to elucidate the relative contribution of CYP 450 and AOX metabolic pathways on IMI metabolism, in male rabbits exposed to IMI for two months. To evaluate the inhibition effectiveness, various metabolite concentrations in the IMI and IMI + ST exposed groups were monitored. DNA damage was also evaluated in micronucleus (MN) and single cell electrophoresis (SCGC) assays in both groups, along with oxidative stress (OS) with the inflammatory status of the exposed animals, in order to clarify which metabolic pathway is more detrimental in this experimental setting. A significant increase in the frequency of binucleated cells with MN (BNMN, 105%) and micronuclei (MN, 142%) was observed after exposure to IMI (p < 0.001). The increase in the ST co-exposed animals was less pronounced (BNMN 75%, MN 95%). The Cytokinesis Block Proliferation Index (CBPI) showed no significant difference between controls and exposed animals at any time of exposure (p > 0.05), which indicates no cytotoxic effect. Similarly, comet results show that the IMI group exhibited the highest achieved tail intensity, which reached 70.7% over the control groups, whereas in the IMI + ST groups the increase remained at 48.5%. No differences were observed between all groups for oxidative-stress biomarkers. The results indicate that the AOX metabolic pathway plays a more important role in the systemic toxicity of IMI.


Assuntos
Aldeído Oxidase/antagonistas & inibidores , Inseticidas/toxicidade , Mutagênicos/toxicidade , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Compostos de Tungstênio/farmacologia , Animais , Sistema Enzimático do Citocromo P-450/metabolismo , DNA/efeitos dos fármacos , Masculino , Redes e Vias Metabólicas/efeitos dos fármacos , Testes para Micronúcleos , Estresse Oxidativo , Coelhos , Análise de Célula Única
13.
Exp Ther Med ; 13(2): 614-618, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28352339

RESUMO

Anabolic androgenic steroids (AAS) are performance-enhancing drugs commonly abused by atheletes. Stanozolol is a synthetic testosterone-derived anabolic steroid. Although it is well known that AAS have several side-effects, there are only few toxicological studies available on the toxic effects and mechanisms of action of stanozolol. The aim of this study was to investigate the genotoxic effects of stanozolol and to determine its effects on telomerase activity in Sprague-Dawley male rats. For this purpose, 34 male rats were divided into 5 groups as follows: i) the control group (n=5); ii) the propylene glycol (PG)-treated group (n=5); iii) the stanozolol-treated group (n=8); iv) the PG-treated group subjected to exercise (n=8); and v) the stanozolol-treated group subjected to exercise (n=8). PG is used as a solvent control in our study. Stanozolol (5 mg/kg) and PG (1 ml/kg) were injected subcutaneously 5 days/week for 28 days. After 28 days, the animals were sacrificed, and DNA damage evaluation (comet assay) and telomerase activity assays were then performed using peripheral blood mononuclear cells (PBMCs). Telomerase activity was measured by using the TeloTAGGG Telomerase PCR ELISA PLUS kit. The results of this study revealed that stanozolol treatment induced DNA damage, while exercise exerted a protective effect. Stanozolol treatment without exercise stimulation was associated with a significant increase in telomerase activity in the PBMCs.

14.
J Anal Toxicol ; 41(3): 214-223, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-27979929

RESUMO

In this study, we focused on the validation of a method for the simultaneous detection and quantification of cannabinoids, cocaine and opiates in hair as well as on the distribution of the drugs deposition in hair collected from different anatomical body sites. The proposed analytical procedure was validated for various parameters such as selectivity, linearity, limit of quantification, precision, accuracy, matrix effect and recovery. Four hundred and eighty-one samples were collected during 2010-2015 from 231 drug abusers. A 6-h ultrasonic-assisted methanolic extraction was applied for the isolation of the drugs. The analysis was performed in an liquid chromatography-mass spectrometry system for the opiates and cocaine and in a gas chromatography-mass spectrometry system for the cannabinoids. Cocaine was the most frequent detected drug (68.8-80.5%) followed by cannabinoids (47.6-63.3%) and opiates (34.7-46.7%) depending on the body site that the samples were collected. The mean concentrations of Δ9-tetrahydrocannabinol (THC) were 0.63 ± 2.11 for head, 0.54 ± 1.03 for pubic, 0.34 ± 0.51 for axillary and 0.18 ± 0.18 ng/mg for chest hair samples. The values of cocaine were 6.52 ± 15.98, 4.64 ± 10.77, 6.96 ± 38.21 and 3.94 ± 6.35 ng/mg, while the values of 6-monoacetylmorphine (MAM) were 3.33 ± 5.89, 3.06 ± 9.33, 1.37 ± 1.37 and 16.4 ± 1.77 ng/mg for head, pubic, axillary and chest samples, respectively. Differences between the detected concentrations of cocaine and opiates between the hair samples of different anatomical sites, as well as the ratio of drug metabolites to the parent compounds were observed in some cases. Statistically significant differences in the mean detected levels were noticed for morphine and heroin between head and pubic hair and also for cocaine and benzoylecgonine, between head and axillary hair samples. Moreover, the ratio of MAM to morphine and THC to cannabinol seems to correlate statistically with the total opiate or cannabinoid detected concentrations. The above differences could be attributed to several parameters associated with the structure, morphology, growth rate and other characteristics of the collected hair.


Assuntos
Toxicologia Forense/métodos , Cabelo/química , Drogas Ilícitas/análise , Detecção do Abuso de Substâncias/métodos , Analgésicos Opioides/análise , Canabinoides/análise , Cromatografia Líquida , Cocaína/análise , Toxicologia Forense/instrumentação , Cromatografia Gasosa-Espectrometria de Massas , Cabelo/crescimento & desenvolvimento , Humanos , Drogas Ilícitas/farmacocinética , Limite de Detecção , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Detecção do Abuso de Substâncias/instrumentação , Distribuição Tecidual
15.
Bioelectrochemistry ; 113: 9-14, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27607473

RESUMO

The interaction of pesticides with environmental factors, such as pH, may result in alterations of their physicochemical properties and should be taken into consideration in regard to their classification. This study investigates the genotoxicity of methidathion and its alkaline hydrolysis by-products in cultured human lymphocytes, using the square-wave voltammetry (square wave-adsorptive cathodic stripping voltammetry (SW-AdCSV) technique) and the cytokinesis block micronucleus assay (CBMN assay). According to the SW-AdCSV data the alkaline hydrolysis of methidathion results in two new molecules, one non-electro-active and a second electro-active which is more genotoxic than methidathion itself in cultured human lymphocytes, inducing higher micronuclei frequencies. The present study confirms the SW-AdCSV technique as a voltammetric method which can successfully simulates the electrodynamics of the cellular membrane.


Assuntos
Linfócitos/efeitos dos fármacos , Testes para Micronúcleos , Testes de Mutagenicidade , Compostos Organotiofosforados/metabolismo , Compostos Organotiofosforados/toxicidade , Adulto , Membrana Celular/efeitos dos fármacos , Citocinese/efeitos dos fármacos , Eletroquímica , Humanos , Hidrólise , Linfócitos/citologia , Compostos Organotiofosforados/química , Adulto Jovem
16.
Food Chem Toxicol ; 94: 250-9, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27321377

RESUMO

Cypermethrin (CY) is a frequently used class II pyrethroid pesticide, while piperonyl butoxide (PBO) plays a major role in the pesticide formulation of synthetic pyrethroids. Synthetic pyrethroids are metabolized in mammals via oxidation and ester hydrolysis. PBO can prevent the metabolism of CY and enhances its pesticide effect. While this potentiation effect reduces the amount of pesticide required to eliminate insects, it is not clear how this mixture affects mammals. In our in vivo experiment, New Zealand white male rabbits were exposed to low and high doses of CY, PBO, and their combinations, for 4 months. Genotoxicity and cytotoxicity were monitored by measuring binucleated cells with micronuclei (BNMN), micronuclei (MN) and the cytokinesis block proliferation index (CBPI) in lymphocytes. After two months of exposure, a statistically significant increase in the frequency of BNMN was observed for all exposed animals (p < 0.001) in a dose-dependent way. MN were significantly elevated compared to controls (p < 0.001), with high dose groups reaching a 442% increase when co-exposed. BNMN and MN continued to increase after four months. Histopathological examination of lesions showed damage involving inflammation, attaining lymphoplasmatocytic infiltration in the high dose groups. Both CY and PBO cause liver and kidney inflammation and induce genotoxicity.


Assuntos
Inflamação/induzido quimicamente , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Butóxido de Piperonila/toxicidade , Piretrinas/toxicidade , Animais , Rim/patologia , Fígado/patologia , Masculino , Testes para Micronúcleos , Coelhos
17.
Chemosphere ; 149: 108-13, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26855213

RESUMO

The present in-vivo study focuses on the genotoxic effect of the neonicotinoid pesticide imidacloprid (IMI) in rabbits. The purpose of the study was to establish a possible relationship between exposure to the pesticide (dose and duration) and genotoxicity. Furthermore, an analytical method for the simultaneous determination of IMI and its major metabolite 6-chloronicotinic acid (6-ClNA) in blood was developed and validated. The isolation of the two analytes from blood was performed by liquid-liquid extraction with dichloromethane. Analysis was performed by Liquid Chromatography - Atmospheric Pressure Chemical Ionization - Mass Spectrometry (LC-APCI-MS). The method was applied on the determination of IMI and 6-ClNA in serum samples obtained from rabbits fed with the insecticide at two low doses. Furthermore, parameters of genotoxicity and cytotoxicity were evaluated by measuring binucleated cells with micronuclei (BNMN), micronuclei (MN) and the Cytokinesis Block Proliferation Index (CBPI), in lymphocytes of exposed rabbits. The results revealed a genotoxic effect of IMI for both exposed groups. There were statistically significant differences in the frequencies of BNMN and MN between control and exposed groups but there was no dose-dependence, neither time-dependence of the genotoxic effect for the administered doses. This is the first time that long term exposure to IMI in rabbits was studied for the determination of its genotoxic effect. The genotoxic effect of IMI as it is depicted by the current study is in accordance with previous studies.


Assuntos
Dano ao DNA , Imidazóis/toxicidade , Inseticidas/toxicidade , Mutagênicos/toxicidade , Nitrocompostos/toxicidade , Animais , Cromatografia Líquida , Citocinese , Imidazóis/sangue , Inseticidas/sangue , Inseticidas/metabolismo , Extração Líquido-Líquido , Linfócitos/efeitos dos fármacos , Masculino , Espectrometria de Massas , Micronúcleos com Defeito Cromossômico , Mutagênicos/metabolismo , Neonicotinoides , Ácidos Nicotínicos , Nitrocompostos/sangue , Coelhos
18.
Life Sci ; 145: 114-20, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26690741

RESUMO

AIM: The aimof this study is to clarify the effect of cypermethrin (CY) on the oxidative stress (OS) and inflammation status of animals exposed to it and the synergistic role of piperonyl butoxide (PB0). MAIN METHODS: Markers of oxidative stress, such as total antioxidant activity (TAC), protein carbonyls, hemoglobin (Hb), reduced glutathione (GSH), thiobarbituric-acid reactive substances (TBARS), along with the telomerase activity in PBMCs (peripheral blood mononuclear cells) were analyzed. KEY FINDINGS: Oxidative stress markers showed statistically significant differences between groups in TAC (p b 0.001), GSH (p = 0.018) and CAT activity (p = 0.029), which depended on dose and combined effect of both compounds. Telomerase activity also showed a statistically significant difference between all groups (F = 43.48, df=6, 14, p b 0.001)with cypermethrin, piperonyl butoxide and the co-exposed groups being significantly different fromthe control group (p b 0.05). Significance: The observed results for TBARS, GSH, Hb, TAC, Crbnls and CAT from our exposed groups showed altered levels compared to control groups that could be linked to doses and combined effects of each chemical substance (cypermethrin and piperonyl butoxide). Oxidative stress markers suggest that cypermethrin, piperonyl butoxide and the co-exposed groups, induce oxidative stress as well as induction of telomerase activity.


Assuntos
Inflamação/induzido quimicamente , Estresse Oxidativo/efeitos dos fármacos , Praguicidas/toxicidade , Butóxido de Piperonila/toxicidade , Piretrinas/toxicidade , Animais , Inflamação/metabolismo , Masculino , Coelhos , Telomerase/metabolismo
19.
J Anal Toxicol ; 39(4): 262-9, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25681325

RESUMO

The electronic cigarette (e-cig) is an invention of the past few years and its popularity is rapidly growing all over the world. A rapid multicomponent analytical protocol for the analysis of the replacement liquids (e-liquids) of e-cig was developed using gas (GC) and liquid chromatography (LC)-mass spectrometry (MS). GC-MS-based methods were developed for the determination of the main humectants and polycyclic aromatic hydrocarbons (PAHs). For the determination and quantification of nicotine (NIC) and nitrosamines, appropriate LC-MS-based methods were developed. The approbated methods were applied for the analysis of 263 e-liquid samples obtained from the Greek market. The instruments response was linear; the limits of quantification ranged from 0.003 µg/mL for three PAHs to 1.187 µg/mL for glycerol. The precision was <16% for all analytes, while the mean accuracy ranged from 99.1% for NIC to 106.6% for the flavor 2,5-dimethylpyrazine. The measured concentrations of NIC were correlated with the theoretical concentrations as reported by the manufacturers. An analog relation between the concentration of the glycerol and of propylene glycol was noticed. The frequency of detection of flavors ranged from 30.4% for the methyl cyclopentenolone to 5.3% for 3.4-dimethoxybenzaldehyde. Nitrosamines and PAHs were not detected in any sample. Because a similar analytical protocol was not available from the existing literature so far, our study offers the advantage of complete analytical methods for rapid and simultaneous multicomponent identification.


Assuntos
Cromatografia Líquida/métodos , Sistemas Eletrônicos de Liberação de Nicotina/normas , Cromatografia Gasosa-Espectrometria de Massas/métodos , Monoterpenos Acíclicos , Etilenoglicóis/análise , Glicerol/análise , Limite de Detecção , Monoterpenos/análise , Nicotina/análise , Nitrosaminas/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Propilenoglicol/análise , Controle de Qualidade , Reprodutibilidade dos Testes
20.
PLoS One ; 7(2): e31880, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22355401

RESUMO

We assessed the cardiorespiratory and immune response to physical exertion following secondhand smoke (SHS) exposure through a randomized crossover experiment. Data were obtained from 16 (8 women) non-smoking adults during and following a maximal oxygen uptake cycling protocol administered at baseline and at 0-, 1-, and 3- hours following 1-hour of SHS set at bar/restaurant carbon monoxide levels. We found that SHS was associated with a 12% decrease in maximum power output, an 8.2% reduction in maximal oxygen consumption, a 6% increase in perceived exertion, and a 6.7% decrease in time to exhaustion (P<0.05). Moreover, at 0-hours almost all respiratory and immune variables measured were adversely affected (P<0.05). For instance, FEV(1) values at 0-hours dropped by 17.4%, while TNF-α increased by 90.1% (P<0.05). At 3-hours mean values of cotinine, perceived exertion and recovery systolic blood pressure in both sexes, IL4, TNF-α and IFN-γ in men, as well as FEV(1)/FVC, percent predicted FEV(1), respiratory rate, and tidal volume in women remained different compared to baseline (P<0.05). It is concluded that a 1-hour of SHS at bar/restaurant levels adversely affects the cardiorespiratory and immune response to maximal physical exertion in healthy nonsmokers for at least three hours following SHS.


Assuntos
Citocinas/sangue , Exposição Ambiental/efeitos adversos , Exercício Físico/fisiologia , Imunidade Inata/efeitos dos fármacos , Fenômenos Fisiológicos Respiratórios/efeitos dos fármacos , Poluição por Fumaça de Tabaco/efeitos adversos , Adulto , Pressão Sanguínea/efeitos dos fármacos , Cotinina/sangue , Cotinina/urina , Estudos Cross-Over , Feminino , Humanos , Masculino , Testes de Função Respiratória , Método Simples-Cego , Capacidade Vital , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...