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1.
Environ Monit Assess ; 192(6): 381, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32430726

RESUMO

Brazil is one of the largest consumers of pesticides in the world. The high rainfall rate and inadequate soil use and management promote the transfer of these compounds to the aquatic system. The aim of this study was to identify and quantify pesticides present in epilithic biofilms in order to evaluate the effectiveness of this matrix as a bioindicator able to discriminate areas and periods with different inputs of pesticides. Among the 25 pesticides analyzed in the biofilms, 20 compounds were detected. The epilithic biofilms picked up pesticides independent of their polarities, even in the period of lower use. The frequency and median concentration of five herbicides (2,4-D, atrazine, desethyl-atrazine, simazine, nicosulfuron), three fungicides (carbendazim, epoxiconazole, tebuconazole), and one insecticide (imidacloprid) were highest in biofilms sampled in summer crops during the growing period. Biofilms collected in the upper region of the catchment, where genetically modified soybean and corn cultivated in a no-tillage system prevail, the highest frequency and median concentration of three herbicides (2,4-D, thifensulfuron, isoproturon), four fungicides (carbendazim, epoxiconazole, tebuconazole, metconazole), and one insecticide (imidacloprid) were observed. Despite the excessive amounts of pesticides used in the catchment, the median values of all pesticides in the epilithic biofilm were considered low. The lower diversity and concentration of pesticides observed in the autumn/winter season is representative of lower use of pesticides, barriers to pesticide transfer from soil to water, and the biofilm's resilience capacity to decompose pesticides.


Assuntos
Agricultura , Biofilmes , Praguicidas , Bioacumulação , Biomarcadores , Brasil , Monitoramento Ambiental , Praguicidas/farmacocinética , Movimentos da Água
2.
Chemosphere ; 248: 126024, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32004891

RESUMO

Root uptake, translocation, and subcellular distribution of six pesticides (dinotefuran, thiamethoxam, imidacloprid, imazethapyr, propiconazole, and chlorpyrifos) with Kow ranging from -0.549 to 4.7 were investigated in wheat to study transportation and accumulation of pesticides. The root bioconcentration factor (RCF) of pesticides decreased with water solubility (R2 = 0.6121) and increased with hydrophobicity (when the pH-adjusted log Kow > 2, R2 = 0.925), respectively. The translocation of neutral pesticides from roots to shoots increased positively with water solubility (R2 > 0.6484) but decreased with hydrophobicity (R2 > 0.8039). The subcellular fraction concentration factor (SFCF) increased linearly with hydrophobicity of the tested pesticides (R2 > 0.958). The log RCF was positively correlated with log SFCF in root cell walls (R2 = 0.9894) and organelles (R2 = 0.9786). Transportation of the pesticides from roots to stems and stems to leaves was adversely affected by the log SFCF of cell walls and organelles of roots (R2 > 0.7997) and stems (R2 > 0.6666), respectively. Hydrophobicity-dependent SFCF is a factor governing accumulation of pesticides in roots after uptake and their subsequent upward translocation.


Assuntos
Praguicidas/farmacocinética , Triticum/efeitos dos fármacos , Triticum/metabolismo , Transporte Biológico , Parede Celular/efeitos dos fármacos , Parede Celular/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Praguicidas/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/metabolismo , Solubilidade , Triticum/citologia , Triticum/crescimento & desenvolvimento
3.
Obesity (Silver Spring) ; 27(11): 1865-1873, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31689012

RESUMO

OBJECTIVE: Persistent organic pollutants (POPs) are lipophilic environmental toxicants that accumulate in adipose tissue. Weight loss leads to mobilization and increased redistribution of these toxicants. Many are obesogens and endocrine disruptors. Increased exposure could pose long-term health risks. The study objective was to measure the changes in serum concentrations of lipophilic POPs during significant weight loss. METHODS: This study enrolled 27 patients at a university hospital in a longitudinal, 6-month, observational study examining changes in POP blood levels after bariatric surgery. The primary outcome was the changes in the concentrations of 24 polychlorinated biphenyls (PCBs), 9 organochlorine pesticides (OCPs), 11 polybrominated diphenyl ethers, 2,2',4,4',5,5'-hexabromobiphenyl, and 4 perfluorochemicals (PFCs). RESULTS: Older adults (those born before 1976) had baseline levels of PCBs, OCPs, and PFCs that were two- to fivefold higher than younger adults (those born after 1976). Older adults had greater increases in PCBs, OCPs, and polybrominated diphenyl ethers associated with weight loss. Conversely, younger adults had greater increases in PFCs associated with weight loss. On average, blood POP levels increased as weight loss occurred. CONCLUSIONS: Although weight loss is considered beneficial, the release and redistribution of POPs to other lipid-rich organs such as the brain, kidneys, and liver warrant further investigation. Interventions should be considered to limit organ exposure to POPs when weight loss interventions are planned.


Assuntos
Tecido Adiposo/metabolismo , Cirurgia Bariátrica , Poluentes Ambientais/sangue , Poluentes Ambientais/farmacocinética , Obesidade Mórbida/cirurgia , Tecido Adiposo/química , Adulto , Fatores Etários , Análise Química do Sangue , Exposição Ambiental/análise , Poluentes Ambientais/análise , Feminino , Seguimentos , Éteres Difenil Halogenados/análise , Éteres Difenil Halogenados/sangue , Éteres Difenil Halogenados/farmacocinética , Humanos , Hidrocarbonetos Clorados/análise , Hidrocarbonetos Clorados/sangue , Hidrocarbonetos Clorados/farmacocinética , Fígado/química , Fígado/metabolismo , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/sangue , Obesidade Mórbida/metabolismo , Praguicidas/análise , Praguicidas/sangue , Praguicidas/farmacocinética , Bifenilos Policlorados/análise , Bifenilos Policlorados/sangue , Bifenilos Policlorados/farmacocinética , Período Pós-Operatório , Distribuição Tecidual , Perda de Peso/fisiologia
4.
Chem Res Toxicol ; 32(11): 2281-2294, 2019 11 18.
Artigo em Inglês | MEDLINE | ID: mdl-31674768

RESUMO

Ecological risk assessment is carried out for chemicals such as pesticides before they are released into the environment. Such risk assessment currently relies on summary statistics gathered in standardized laboratory studies. However, these statistics extract only limited information and depend on duration of exposure. Their extrapolation to realistic ecological scenarios is inherently limited. Mechanistic effect models simulate the processes underlying toxicity and so have the potential to overcome these issues. Toxicokinetic-toxicodynamic (TK-TD) models operate at the individual level, predicting the internal concentration of a chemical over time and the stress it places on an organism. TK-TD models are particularly suited to addressing the difference in exposure patterns between laboratory (constant) and field (variable) scenarios. So far, few studies have sought to predict sublethal effects of pesticide exposure to wild mammals in the field, even though such effects are of particular interest with respect to longer term exposure. We developed a TK-TD model based on the dynamic energy budget (DEB) theory, which can be parametrized and tested solely using standard regulatory studies. We demonstrate that this approach can be used effectively to predict toxic effects on the body weight of rats over time. Model predictions separate the impacts of feeding avoidance and toxic action, highlighting which was the primary driver of effects on growth. Such information is relevant to the ecological risk posed by a compound because in the environment alternative food sources may or may not be available to focal species. While this study focused on a single end point, growth, this approach could be expanded to include reproductive output. The framework developed is simple to use and could be of great utility for ecological and toxicological research as well as to risk assessors in industry and regulatory agencies.


Assuntos
Peso Corporal/efeitos dos fármacos , Poluentes Ambientais/farmacocinética , Poluentes Ambientais/toxicidade , Modelos Biológicos , Praguicidas/farmacocinética , Praguicidas/toxicidade , Animais , Relação Dose-Resposta a Droga , Ecotoxicologia , Poluentes Ambientais/sangue , Feminino , Masculino , Especificidade de Órgãos , Praguicidas/sangue , Ratos , Medição de Risco , Distribuição Tecidual , Toxicocinética
5.
J Colloid Interface Sci ; 556: 650-657, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31499436

RESUMO

HYPOTHESIS: Nonionic surfactants are used as adjuvants in agri-sprays to stabilise pesticides, but what happens when pesticide-loaded micelles are brought into direct contact with plant leaves? As pesticide solubilisation dehydrates the micellar shell and increases the effective hydrophobicity of the surfactant, we hypothesise that these micelles would uptake plant waxes and alter the amount of pesticide solubilized as a result of the re-equilibrating process. EXPERIMENTS: The solubility of the pesticide cyprodinil (CP) and its effect on the shape of hexaethylene glycol monododecyl ether (C12E6) micelles were studied using changes in cloud point, nuclear magnetic resonance (NMR), cryogenic transmission electron microscopy (Cryo-TEM) and small-angle neutron scattering (SANS). Similarly, the solubility of wheat leaf waxes was examined, as was the effect of adding leaf waxes to pre-dissolved cyprodinil in micellar C12E6. FINDINGS: Wax solubilisation caused pesticide release and shell hydration, and shortened the length of the cylindrical micelles of the CP loaded C12E6. Temperature increase led to a significant rise in the amount of the dissolved waxes, increased pesticide release, increased micellar length, and caused shrinkage and dehydration of the shell. This study indicates that agrochemical sprays are capable of dissolving leaf waxes, and may trigger pesticide release from surfactant micelles upon contact with plant surfaces.


Assuntos
Micelas , Praguicidas , Folhas de Planta/parasitologia , Pirimidinas , Triticum/parasitologia , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/farmacologia , Praguicidas/química , Praguicidas/farmacocinética , Praguicidas/farmacologia , Pirimidinas/química , Pirimidinas/farmacocinética , Pirimidinas/farmacologia , Solubilidade , Ceras
6.
Arch Toxicol ; 93(10): 2849-2862, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31428841

RESUMO

Human biomonitoring provides information about chemicals measured in biological matrices, but their interpretation remains uncertain because of pharmacokinetic (PK) interactions. This study examined the PKs in blood from Long-Evans rats after a single oral dose of 0.4 mg/kg bw of each pesticide via a mixture of the 17 pesticides most frequently measured in humans. These pesticides are ß-endosulfan; ß-hexachlorocyclohexane [ß-HCH]; γ-hexachlorocyclohexane [γ-HCH]; carbofuran; chlorpyrifos; cyhalothrin; cypermethrin; diazinon; dieldrin; diflufenican; fipronil; oxadiazon; pentachlorophenol [PCP]; permethrin; 1,1-dichloro-2,2bis(4-chlorophenyl)ethylene [p,p'-DDE]; 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane [p,p'-DDT]; and trifluralin. We collected blood at 10 min to 48-h timepoints in addition to one sample before gavage (for a control). We used GS-MS/MS to measure the pesticide (parents and major metabolites) concentrations in plasma, determined the PK parameters from 20 sampling timepoints, and analyzed the food, litter, and cardboard in the rats' environment for pesticides. We detected many parents and metabolites pesticides in plasma control (e.g., diethyl phosphate [DEP]; PCP; 3-phenoxybenzoic acid [3-PBA]; 3,5,6-trichloro-2-pyridinol [TCPy], suggesting pre-exposure contamination. The PK values post-exposure showed that the AUC0-∞ and Cmax were highest for TCPy and PCP; ß-endosulfan, permethrin, and trifluralin presented the lowest values. Terminal T1/2 and MRT for γ-HCH and ß-HCH ranged from 74.5 h to 117.1 h; carbofuran phenol presented the shortest values with 4.3 h and 4.8 h. These results present the first PK values obtained through a realistic pattern applied to a mixture of 17 pesticides to assess exposure. This study also highlights the issues of background exposure and the need to work with a relevant mixture found in human matrices.


Assuntos
Exposição Ambiental/análise , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Praguicidas/farmacocinética , Administração Oral , Animais , Monitoramento Biológico , Cromatografia Gasosa , Feminino , Humanos , Ratos , Ratos Long-Evans , Espectrometria de Massas em Tandem
7.
Int J Legal Med ; 133(6): 1763-1784, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31297610

RESUMO

Organophosphorus insecticides, such as parathion-ethyl, quinalphos, chlorpyrifos, chlorfenvinphos or diazinon, are still widely used for pest control on crops. These compounds are extremely toxic to humans, and, even though specific legislation exists that controls the use of these substances, the frequency of toxic and/or fatal events and the existing data suggest that they are still easily accessed and the knowledge associated to the risks is not well-recognized. For these reasons, the determination of the exposure to these compounds, their detection (and of their metabolites as well) in biological samples, is of great importance in clinical and forensic toxicology, and, therefore, the development of techniques for this evaluation is an important task for laboratories. Most confirmatory analyses use blood, serum, plasma and urine as biological samples and are performed by either gas chromatographic-mass spectrometric or liquid chromatographic-mass spectrometric instrumentation, which represents the gold standard in what concerns high sensitivity. This paper will not only address the physical-chemical and toxicological aspects of this class of compounds but also perform a comprehensive and critical review on the analytical methods available for their determination in biological specimens, with special focus on the latest instrumental developments and sample preparation approaches.


Assuntos
Toxicologia Forense/métodos , Intoxicação por Organofosfatos/diagnóstico , Praguicidas/análise , Cromatografia Líquida , Cromatografia Gasosa-Espectrometria de Massas , Conteúdo Gastrointestinal/química , Cabelo/química , Humanos , Rim/química , Extração Líquido-Líquido , Fígado/química , Pulmão/química , Estrutura Molecular , Miocárdio/química , Praguicidas/farmacocinética , Praguicidas/toxicidade , Saliva/química , Extração em Fase Sólida
8.
Anal Chem ; 91(3): 2093-2099, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30628431

RESUMO

Understanding the behavior of pesticide translocation is significant for effectively applying pesticides and reducing pesticide exposures from treated plants. Herein, we applied surface enhanced Raman spectroscopy (SERS) for real-time monitoring of pesticide translocation in tomato plant tissues, including leaves and flowers, following root exposure in hydroponic and soil systems. Various concentrations of the systemic pesticide, thiabendazole, was introduced into hydroponic systems used for growing tomato plants. At selected time intervals, tomato leaves and flowers were picked and thiabendazole was measured directly under a Raman microscope after pipetting gold nanoparticle-containing solution onto the plant tissue. We found that the pesticide signals first appeared along the midrib in the lowest leaves and moved distally to the edge of the leaves. As the concentration of pesticide applied to the root was increased, the time necessary to detect the signal was decreased. The SERS surface mapping method was also able to detect thiabendazole in the trichomes of the leaves. In addition, we found a unique SERS peak at 737 cm-1 on both leaves and flowers at 4 and 6 days following the application of 200 mg/L thiabendazole to the hydroponic system. This peak appears to be coming from adenine-containing materials and may be related to the plant's response to pesticide toxicity, which could be used as a potential marker for monitoring plant responses to stresses. These results demonstrate a successful application of SERS as a rapid and effective way to study the real-time translocation behavior of pesticides in a plant system.


Assuntos
Lycopersicon esculentum/química , Praguicidas/análise , Tiabendazol/análise , Lycopersicon esculentum/metabolismo , Praguicidas/farmacocinética , Análise Espectral Raman , Tiabendazol/farmacocinética , Fatores de Tempo
9.
Chemosphere ; 217: 195-203, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30415117

RESUMO

Total 22 organochlorine pesticides (OCPs) compounds and 31 polychlorinated biphenyls (PCBs) congeners in mangrove sediments and tissues (leaf, branch, root and fruit) of nine species from three Mangrove Reserves of China were studied. The mean concentrations of total DDTs, HCHs, OCPs and PCBs in sediments were 2.84, 0.06, 3.84 and 0.17 ng g-1 dw, while those in tissues were 1.85, 0.22, 9.43 and 1.61 ng g-1 dw, respectively. The elevated OCPs and PCBs levels in mangrove leaves may be caused by atmospheric sedimentation. The biota sediment accumulation factor (BSAF) values of both OCPs (mean: 3.4) and PCBs (mean: 9.9) are generally larger than one, implying mangroves' bioaccumulation and their ability to intercept pollutants. The BSAFs of PCBs in mangrove tissues were negatively correlated with the PCB congener's octanol-water partition coefficients (KOW, R = 0.58, n = 31, p < 0.001), suggesting that lower chlorinated CB congeners are more bioaccumulative in mangroves. In order to better understanding the fate of these organochlorine compounds, the cycling (including the standing accumulation, the annual absorption, the annual net retention, the annual return, and the turnover period) of OCPs and PCBs in the Mangrove Reserves were estimated, and the results indicated that mangroves are playing important roles in retaining OCPs and PCBs.


Assuntos
Avicennia/metabolismo , Hidrocarbonetos Clorados/farmacocinética , Praguicidas/farmacocinética , Bifenilos Policlorados/farmacocinética , China , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Bifenilos Policlorados/análise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/farmacocinética
10.
J Matern Fetal Neonatal Med ; 32(14): 2387-2392, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29463139

RESUMO

BACKGROUND: Organophosphates, pythyreoids, carbamate pesticides and fungicides are heavily used in agriculture. They may have dangerous effects on newborn health especially on immune system and growth via prenatal transmission by placenta or postnatal transmission by breastfeeding. METHODS: In 2015, 144 non-persistent pesticides in 64 milk samples of 32 mothers were studied by OuEChERS method in liquid chromatography/tandem mass spectrometer in neonatal Intensive Care Unit in Adana, a city in Cukurova region which is an important agricultural area in Turkey. RESULTS: Pesticides were detected in milk samples of 11 mothers (34.3%) and 21 (32.8%) of milk samples. In five mothers, fungicides (in 5/10 samples propicanozole-PP, in 4/10 samples bromucanozole-BM), in five mothers, organophosphates (in 10/10 samples primyphosphomethyl-PPM), in one mother, both organophosphates and fungicide (in 1/2 samples PPM and in 1/2 samples buprimate) were detected. However, the estimated daily intakes (EDI) were less than acceptable daily intakes (ADI) for PPM, PP and BM, respectively. CONCLUSIONS: Although pesticides levels in human milk did not exceed the ADIs, we suggest monitoring pesticides in human breast milk especially for newborn health.


Assuntos
Exposição Materna , Leite Humano/química , Praguicidas/análise , Adulto , Agricultura , Estudos de Casos e Controles , Feminino , Humanos , Recém-Nascido , Mães , Praguicidas/farmacocinética , População Rural/estatística & dados numéricos , Turquia , Adulto Jovem
11.
J Agric Food Chem ; 66(43): 11244-11253, 2018 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-30299946

RESUMO

Avermectin (AVM) as a nonsystemic pesticide possesses a low effective utilization rate. Studies of the multifunctional pesticide delivery system for improving biological activity are developing prosperously. In this study, multifunctional avermectin/polysuccinimide with glycine methyl ester nanoparticles (AVM-PGA) were prepared by the self-assembly process. The AVM loading capacity was up to 23.7%. After 24 h of UV irradiation, there was still about 70% of AVM remaining in PGA42 nanocarriers, as opposed to less than 5% of the free-form AVM. The rising ambient pH promoted the release of AVM using an in vitro releasing test, revealing a favorable pH-responsively controlled-release property. The mortality rate of Plutella xylostella with 2.5 µg/mL of AVM content of AVM-PGA42 was 96.3% after 48 h, while that of free AVM was only 51.5%. In addition, the AVM could be detected in stems and all leaves treated with AVM-PGA42 nanoparticles, whereas rare AVM was detected only in treated leaves for the free-form AVM, which achieved the transportation of nanocarriers carrying AVM in rice for the first time. Furthermore, the PGA nanoparticles performed a good growth promoting effect on rice. These results show that the AVM-PGA42 nanopesticides have a great potential application prospect to control the pest and improve the drug utilization efficiency on agriculture.


Assuntos
Ácido Aspártico/análogos & derivados , Ivermectina/análogos & derivados , Nanopartículas , Oryza/química , Peptídeos/química , Praguicidas/química , Animais , Ácido Aspártico/química , Ácido Aspártico/farmacocinética , Ivermectina/química , Ivermectina/farmacocinética , Lepidópteros , Peptídeos/farmacocinética , Praguicidas/farmacocinética , Folhas de Planta/química
12.
J Pharm Biomed Anal ; 161: 20-27, 2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-30142493

RESUMO

In Traditional Chinese Medicine (TCM), crude herbs are processed to obtain the medicinal parts of the plant, from which extracts are prepared for people to take as medicine. However, there is no report on the pesticide residual behavior in Chinese medicines during processing at present, and thus, a systematic study of the effects of different processing factors (PF) on pesticide removal in Chinese medicines and the associated risk of dietary exposure is urgently needed. This study main investigated the dissipation and metabolism of pesticides in Chinese medicine Paeoniae Radix Alba during processing, and the calculated pesticide PFs were also used to assess the risk of dietary exposure. For analyze samples, a simple and high-throughput multiresidue pesticide analysis method was developed and validated for pesticides and their metabolites in P. Radix. based on QuEChERS procedure combined with HPLC-MS/MS. Recoveries at three concentration levels were within 61.37%-117.82% with an associated precision RSD < 15% indicating satisfactory accuracy. TCM processing could be useful for the partial removal of several pesticide residues, with removal rate reaching 98%. The polarity is the dominant variable, which with a high contribution was the effectiveness of the treatment and the concentration factors for pesticides. The hazard quotients of all pesticides were much lower than the safety level, indicating low risk of dietary exposure. Results are of great theoretical and practical value for the scientific evaluation of the safety of Chinese medicines, improvement of the quality and safety level of Chinese medicine.


Assuntos
Medicamentos de Ervas Chinesas/farmacocinética , Paeonia/metabolismo , Praguicidas/farmacocinética , Cromatografia Líquida de Alta Pressão , Substâncias Perigosas/análise , Espectrometria de Massas em Tandem
13.
J Hazard Mater ; 360: 420-427, 2018 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-30138902

RESUMO

Bioaccumulation and biotransformation are critical processes modifying toxicity of easily metabolizable chemicals to aquatic organisms. In this study, tissue-specific accumulation, biotransformation and elimination of a current-use pesticide fipronil in tilapia (Oreochromis niloticus) were quantified by combining in vivo measurements and a newly developed multi-compartmental toxicokinetic model. Waterborne fipronil was taken up via gills and metabolized rapidly and solely to fipronil sulfone. Significant decrease of fipronil residues in liver and intestine during exposure period strongly suggested the induction of metabolism in these two organs. Significant transport of fipronil and fipronil sulfone in the liver-bile-intestine system implied that hepatobiliary excretion and enterohepatic re-absorption played important roles in fipronil metabolism and system circulation of the parent compound and the metabolite. The multi-compartmental model quantitatively described the highly dynamic inter-compartmental transport and rapid branchial clearance of fipronil in fish. Modeling results also suggested that uptake and biotransformation were the stronger driving forces for the inter-compartmental transport of fipronil in fish than the inherent partitioning capacity. Overall, our findings highlight the importance of biotransformation on internal disposition of fipronil in fish, which helps to improve aquatic toxicity assessment of this pesticide.


Assuntos
Modelos Biológicos , Praguicidas/farmacocinética , Praguicidas/toxicidade , Pirazóis/farmacocinética , Pirazóis/toxicidade , Tilápia/metabolismo , Poluentes Químicos da Água/farmacocinética , Poluentes Químicos da Água/toxicidade , Animais , Biotransformação , Brânquias/metabolismo , Mucosa Intestinal/metabolismo , Fígado/metabolismo , Toxicocinética
14.
Expert Opin Drug Metab Toxicol ; 14(7): 739-752, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29886753

RESUMO

INTRODUCTION: Drug transporters are now recognized as major actors of pharmacokinetics. They are also likely implicated in toxicokinetics and toxicology of environmental pollutants, notably pesticides, to which humans are widely exposed and which are known to exert various deleterious effects toward health. Interactions of pesticides with drug transporters are therefore important to consider. Areas covered: This review provides an overview of the interactions of pesticides with membrane drug transporters, i.e. inhibition of their activity, regulation of their expression, and handling of pesticides. Consequences for toxicokinetics and toxicity of pesticides are additionally summarized and discussed. Expert opinion: Some pesticides belonging to several chemical classes, such as organochlorine, pyrethroid, and organophosphorus pesticides, have been demonstrated to interact with various uptake and efflux drug transporters, including the efflux pump P-glycoprotein (P-gp) and the uptake organic cation transporters (OCTs). This provides proof of the concept that pesticide-transporter relationships merit attention. More extensive and systematic characterization of pesticide-transporter relationships, possibly through the use of in silico methods, is however likely required. In addition, consideration of transporter polymorphisms, pesticide mixture effects, and realistic pesticide concentrations reached in humans may help better define the in vivo relevance of pesticide-transporter interactions in terms of toxicokinetics and toxicity.


Assuntos
Poluentes Ambientais/toxicidade , Proteínas de Membrana Transportadoras/metabolismo , Praguicidas/toxicidade , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Animais , Transporte Biológico , Simulação por Computador , Exposição Ambiental/efeitos adversos , Poluentes Ambientais/química , Poluentes Ambientais/farmacocinética , Humanos , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Praguicidas/química , Praguicidas/farmacocinética , Toxicocinética
15.
Mar Pollut Bull ; 131(Pt A): 602-610, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29886987

RESUMO

Trophodynamics and chiral signatures of organochlorine pesticides (OCPs), including dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), and chlordanes in a food web from Zhoushan Fishing Ground, China, were studied. Residues of OCPs in all teleost fishes were within food safety levels. Strong positive correlations were found between trophic levels (TLs) and wet weight concentrations of target chemicals, with trophic magnification factors (TMFs) from 4.17 to 9.77. Lipid contents and TLs significantly correlated, which indirectly affect the bioaccumulation processes of OCPs. The consistently racemic EF values of α-HCH, as well as invariability of the relative proportions of HCH isomers in different marine species implied that HCHs in animals originate directly from the surrounding environment. However, in vivo biotransformation and/or elimination of o,p'-DDT cannot be precluded. TMFs of the individual enantiomers further suggest that the influence of achiral biotransformation is too minor to induce enantioselective biomagnification of chiral OCPs through the studied food web.


Assuntos
Cadeia Alimentar , Hidrocarbonetos Clorados/análise , Hidrocarbonetos Clorados/farmacocinética , Praguicidas/análise , Praguicidas/farmacocinética , Animais , Organismos Aquáticos , Biotransformação , Isótopos de Carbono/análise , Cetáceos/metabolismo , China , Monitoramento Ambiental , Hidrocarbonetos Clorados/química , Lipídeos/análise , Isótopos de Nitrogênio/análise , Praguicidas/química , Estereoisomerismo , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Poluentes Químicos da Água/farmacocinética , Zooplâncton/química , Zooplâncton/efeitos dos fármacos
16.
Environ Pollut ; 240: 670-682, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29775944

RESUMO

Environmental chemicals originating from human activities, such as persistent organic pollutants (POPs), may interfere with the endocrine system of aquatic organisms. The effect of these chemicals on biota and human populations is of high public concern but remains poorly understood, especially in aquatic environments of South America. The aim of this study was to investigate the bioavailability of POPs and the related effects in caged male tilapia (Oreochromis niloticus) in four cascading reservoirs of the Iguaçu River, Southern Brazil. POPs including organochlorine pesticides (OCPs), polychlorinated biphenyl (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined in the reservoir water and tissue samples of tilapia after two months of exposure. The PCB levels in water (14.7 ng L-1) were 14 times higher than the limits permitted by the Brazilian legislation in the Salto Santiago (SS) reservoir. Similarly, concentrations of aldrin and its metabolites (6.05 ng L-1) detected in the water sample of the Salto Osório (SO) reservoir were also above the permitted limits. RT-qPCR analysis revealed different transcript levels of cytochrome P450 enzymes (CYP1A and CYP3A) in the liver among the four groups, with induced activity in tilapia from the SS reservoir. Quantification of the CYP3A mRNA expression and catalytic activity showed higher values for fish caged at the SS reservoir. The fish from this site also had a higher number of eosinophils observed in the testes. Although overt measurements of endocrine disruption were not observed in caged fish, alteration of CYP enzymes with co-occurrence of organochlorine contaminants in water may suggest bioavailability of contaminants from agricultural sources to biota. Additional studies with feral or caged animals for a longer duration may be necessary to evaluate the risks of the waterways to humans and wildlife.


Assuntos
Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP3A/metabolismo , Disruptores Endócrinos/farmacocinética , Fígado/metabolismo , Praguicidas/farmacocinética , Tilápia/metabolismo , Poluentes Químicos da Água/farmacocinética , Animais , Disponibilidade Biológica , Brasil , Disruptores Endócrinos/análise , Peixes , Éteres Difenil Halogenados/análise , Éteres Difenil Halogenados/farmacocinética , Humanos , Hidrocarbonetos Clorados/análise , Hidrocarbonetos Clorados/farmacocinética , Masculino , Praguicidas/análise , Bifenilos Policlorados/análise , Bifenilos Policlorados/farmacocinética , Rios/química , Poluentes Químicos da Água/análise
17.
Chemosphere ; 203: 219-227, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29621678

RESUMO

The dissipation, partitioning dynamics and biouptake was measured for selected hazardous current-used pesticides (conazole fungicides: epoxiconazole, flusilazole, tebuconazole; prochloraz, chlorpyrifos, pendimethalin) and for a transformation product (2-hydroxyatrazine) in agricultural soil and quartz sand as representatives of a real and a worst-case scenario. Dissipation, uptake to Lactuca sativa and the freely dissolved concentration along with the organic carbon-normalized sorption coefficients (Koc) were determined on days 12, 40, and 90 following the application of compounds at three fortification levels (0.1-1.0-10 mg/kg). Conazole fungicides showed similar dissipation patterns and were more persistent in soil than prochloraz, chlorpyrifos and pendimethalin. 2-Hydroxyatrazine showed a concentration-depended decrease in persistency in soil. Lettuce roots were shown to accumulate higher amounts than shoots where the extent of root uptake was driven by compound partitioning. This was evidenced by the ability of freely dissolved concentration (Cfree) to reliably (r2 = 0.94) predict root uptake. Concentration in leaves did not exceed the maximum residue levels (MRLs) for lettuce, which was likely given by the low root-to-shoot translocation factors (TFs) of the tested compounds varying between 0.007 and 0.14. Koc values were in the range of literature values. Sorption to soil was higher than to sand for all compounds, yet following the Koc dynamics compounds did not appear to be sequestered in soil with increasing residence time. From these results, it follows that the tested compounds may persist in soil but since they did not accumulate in lettuce above MRLs, contamination of the food web is unlikely.


Assuntos
Atrazina/análogos & derivados , Alface/metabolismo , Praguicidas/farmacocinética , Poluentes do Solo/análise , Atrazina/análise , Atrazina/farmacocinética , Fungicidas Industriais/análise , Fungicidas Industriais/farmacocinética , Praguicidas/análise , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo
18.
Nat Prod Rep ; 35(5): 434-454, 2018 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-29644346

RESUMO

Covering: up to 2018 Insects live in a world full of toxic compounds such as plant toxins and manmade pesticides. To overcome the effects of these toxins, herbivorous insects have evolved diverse, elaborate mechanisms of resistance, such as toxin avoidance, target-site alteration, and detoxification. These resistance mechanisms are thought to be encoded by the insects' own genomes, and in many cases, this holds true. However, recent omics analyses, in conjunction with classic culture-dependent analyses, have revealed that a number of insects possess specific gut microorganisms, some of which significantly contribute to resistance against phytotoxins and pesticides by degrading such chemical compounds. Here, we review recent advances in our understanding on the symbiont-mediated degradation of natural and artificial toxins, with a special emphasis on their underlying genetic basis, focus on the importance of environmental microbiota as a resource of toxin-degrading microorganisms, and discuss the ecological and evolutionary significance of these symbiotic associations.


Assuntos
Insetos/efeitos dos fármacos , Insetos/microbiologia , Praguicidas/farmacocinética , Simbiose/fisiologia , Toxinas Biológicas/farmacocinética , Animais , Evolução Biológica , Enzimas/genética , Enzimas/metabolismo , Inativação Metabólica/genética , Isotiocianatos/farmacocinética , Oxalatos/farmacocinética , Fenóis/farmacocinética , Simbiose/efeitos dos fármacos , Terpenos/farmacocinética
19.
Int J Mol Sci ; 19(3)2018 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-29538323

RESUMO

Controllable pesticide release in response to environmental stimuli is highly desirable for better efficacy and fewer adverse effects. Combining the merits of natural and synthetic polymers, pH and temperature dual-responsive chitosan copolymer (CS-g-PDMAEMA) was facilely prepared through free radical graft copolymerization with 2-(dimethylamino) ethyl 2-methacrylate (DMAEMA) as the vinyl monomer. An emulsion chemical cross-linking method was used to expediently fabricate pyraclostrobin microcapsules in situ entrapping the pesticide. The loading content and encapsulation efficiency were 18.79% and 64.51%, respectively. The pyraclostrobin-loaded microcapsules showed pH-and thermo responsive release. Microcapsulation can address the inherent limitation of pyraclostrobin that is photo unstable and highly toxic on aquatic organisms. Compared to free pyraclostrobin, microcapsulation could dramatically improve its photostability under ultraviolet light irradiation. Lower acute toxicity against zebra fish on the first day and gradually similar toxicity over time with that of pyraclostrobin technical concentrate were in accordance with the release profiles of pyraclostrobin microcapsules. This stimuli-responsive pesticide delivery system may find promising application potential in sustainable plant protection.


Assuntos
Cápsulas/síntese química , Quitosana/química , Metacrilatos/química , Nylons/química , Praguicidas/farmacocinética , Estrobilurinas/farmacocinética , Animais , Cápsulas/efeitos da radiação , Liberação Controlada de Fármacos , Praguicidas/toxicidade , Estrobilurinas/toxicidade , Raios Ultravioleta , Peixe-Zebra
20.
Regul Toxicol Pharmacol ; 94: 124-143, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29407202

RESUMO

Ecological risk assessments are often limited in their ability to consider metabolic transformations for fish species due to a lack of data. When these types of evaluations are attempted they are often based on parent chemical only, or by assuming similarity to available mammalian metabolic pathways. The metabolism maps for five pesticides (fluazinam, halauxifen-methyl, kresoxim-methyl, mandestrobin, and tolclofos-methyl) were compared across three species. A rapid and transparent process, utilizing a database of systematically collected information for rat, goat, and fish (bluegill or rainbow trout), and using data evaluation tools in the previously described metabolism pathway software system MetaPath, is presented. The approach demonstrates how comparisons of metabolic maps across species are aided by considering the sample matrix in which metabolites were quantified for each species, differences in analytical methods used to identify metabolites in each study, and the relative amounts of metabolites quantified. By incorporating these considerations, more extensive rat and goat metabolism maps were found to be useful predictors of the more limited metabolism of the five pesticides in fish.


Assuntos
Cabras/metabolismo , Oncorhynchus mykiss/metabolismo , Perciformes/metabolismo , Praguicidas/farmacocinética , Aminopiridinas/farmacocinética , Animais , Feminino , Masculino , Redes e Vias Metabólicas , Compostos Organotiofosforados/farmacocinética , Ratos , Especificidade da Espécie , Estrobilurinas/farmacocinética
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