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1.
Talanta ; 236: 122884, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34635264

RESUMO

This work describes (Z)-N-((Z)-2-(1,3,3-trimethylindolin-2ylidene)ethylidene)quinoline-8-amine (LYSO-QF), a high-performing and biocompatible dye comprised of quinoline and Fisher aldehyde moieties linked via an imine vinyl backbone with lysosome targeting ability that can be used to quantitatively detect the mercury ion (Hg2+) in biosystems and the natural environment. This is achieved by forming three different tetrameric, trimeric and dimeric complexes between Hg2+ and LYSO-QF with the limit of detection (LOD) of 11 nm. The complexes formed were analyzed with the aid of time-dependent density functional theory (TD-DFT) calculations. The concentration dependence of the Hg2+ complex fluorescence emission changes from grey-green to jade green and then to red as the different types of complex are formed. The favorable sensor properties of the LYSO-QF probe are demonstrated by monitoring different Hg2+ concentrations in buffer solutions, HeLa cells, zebrafish model samples and several different types of water sample. Experiments with Whatman paper strips demonstrate that the cost-effective LYSO-QF also has considerable potential for use in on-site Hg2+ detection with the naked eye.


Assuntos
Complexos de Coordenação , Mercúrio , Quinolinas , Aldeídos , Animais , Células HeLa , Humanos , Lisossomos , Peixe-Zebra
2.
Sci Total Environ ; 802: 149826, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34455281

RESUMO

The aim of the present study was to evaluate the enantioselective bioaccumulation, metabolism, and toxic effects of metolachlor and S-metolachlor in zebrafish. Five-month-old zebrafish were exposed to metolachlor and S-metolachlor for 28 days, then transferred to clean water and purified for 7 days. In the uptake phase, S-metolachlor was preferentially accumulated at low concentrations, while metolachlor was preferentially accumulated at high concentrations. The two chemicals were metabolized by >70% in zebrafish on the first day and showed same metabolic process. At the accumulation endpoint, S-metolachlor had no significant inhibitory effect on the enzymes activities of superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) and developmental indicators of zebrafish. However, 300 µg/L metolachlor significantly inhibited the enzymes activities of SOD, CAT and GST and affected the liver development. The preferential enrichment of metolachlor at the high concentration may be the reason for its higher toxicity to zebrafish. Further research demonstrated that metolachlor significantly altered the expression of hypothalamic-pituitary-gonadal (HPG) axis-related genes, including gnrh2, gnrh3, lhß, 17ßhsd and cyp19a, thereby reducing the levels of testosterone (T) in females and sex hormones (estradiol and testosterone) in males. S-metolachlor increased the levels of estradiol (E2) in females by altering the expression of HPG axis-related genes such as fshß, cyp17, 17ßhsd and cyp19a. The mechanism of metolachlor and S-metolachlor on the endocrine disrupting effects of zebrafish is different, which may be sex-specific. 7 days after transferring the exposed zebrafish to clean water, most of the enzymes activities, sex hormone levels and related gene expression levels returned to normal, which may be related to the rapid metabolism of the two chemicals.


Assuntos
Poluentes Químicos da Água , Peixe-Zebra , Acetamidas , Animais , Bioacumulação , Feminino , Masculino , Estereoisomerismo , Poluentes Químicos da Água/toxicidade
3.
Sci Total Environ ; 802: 149914, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34474293

RESUMO

The increasing production and application of graphene oxide (GO, a popular carbon nanomaterial), makes their release into aqueous environment inevitably. The capability of GO to enhance the toxicity of background contaminants has been widely concerned. However, the effect of GO on heavy metal accumulation in fish embryos remains unclear. Here, we show that GO-promoted chromium (Cr) uptake by zebrafish embryos with multiple effects. The adsorption accelerated the aggregation and settlement of Cr6+-adsorbed GO and decreased the Cr6+ concentration in the upper water, which enhanced the interaction of chorions and contaminants (Cr6+, GO and Cr6+-adsorbed GO). In the presence of GO, the Cr content in chorions and intra-chorion embryos was increased by four times and 57% respectively, compared to that of the single Cr6+ exposure. Furthermore, GO+Cr6+ increased the oxygen consumption rates, embryonic acid extrusion rates and ATP production, induced more serious oxidative stress, and disturbed amino acid metabolism, fatty acid metabolism and TCA cycle. These findings provide new insights into the effect of GO on heavy metal bioaccumulation and toxicity during embryogenesis.


Assuntos
Grafite , Poluentes Químicos da Água , Adsorção , Animais , Cromo/toxicidade , Metabolismo Energético , Grafite/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra
4.
Talanta ; 237: 122919, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34736655

RESUMO

Diazepam (DZP) was routinely prescribed to a large population troubled with anxiety disorders. However, due to the overuse and misuse, DZP and its chlorination disinfection byproduct 2-methylamino-5-chlorobenzophenone (MACB) caused environmental pollution and can be detected ubiquitously in drinking water in Beijing, China. However, little information is known about the metabolic dynamics of MACB. Here, we established desorption electrospray ionization mass spectrometry (DESI-MS) imaging method to visually and quantitatively assess the distribution and metabolism of MACB in zebrafish. The results showed that MACB specifically accumulated in spinal cord particularly in female zebrafish. Meanwhile, the accumulation of MACB could pass through the blood-brain barrier (BBB) and induced microglial phagocytosis of neurons. Therefore, the intervention strategies should be explored to restrict the release of such substances, eliminating the potential risks for both human beings and the eco-environment.


Assuntos
Espectrometria de Massas por Ionização por Electrospray , Peixe-Zebra , Animais , Diazepam , Desinfecção , Feminino , Halogenação , Humanos
5.
Spectrochim Acta A Mol Biomol Spectrosc ; 265: 120320, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34509890

RESUMO

Hydrogen peroxide (H2O2) plays pivotal roles in various biological functions and pharmacological activities. High selectivity and sensitivity remain challenges for fluorescent probes to detection of H2O2 with a large stokes shift. Herein, a new "turn-on" fluorescent probe (DCM-C) was designed based on the mechanism of intramolecular charge transfer (ICT). In PBS buffer (10 mM, pH 7.4, with 20% DMSO, v/v), DCM-C exhibited high selectivity and sensitivity for H2O2 over other interfering analytes with a large stokes shift (187 nm), and the detection limit was as low as 35.5 nM. In addition, the probe was effective for detecting exogenous and endogenous H2O2 in living cells, and identifying stained in cytoplasm. Moreover, the probe has been used successfully for determining H2O2 in zebrafish by fluorescence imaging.


Assuntos
Corantes Fluorescentes , Peróxido de Hidrogênio , Animais , Fluorescência , Células HeLa , Humanos , Peixe-Zebra
6.
Sci Total Environ ; 802: 149938, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34525687

RESUMO

Deltamethrin (DM), a type II pyrethroid insecticide, is widely used to control agricultural pests. However, its excessive use exerts a detrimental effect on the ecological environment and human health, indicating the need to study its potential risks in detail. In the present study, zebrafish embryos were exposed to varying concentrations of DM (0.1, 1, 10, and 25 µg/L) for 96 h to assess the alterations in the transcript levels of proteins of the estrogenic and dopaminergic pathways. In addition, its effect on zebrafish locomotor activity was studied. The mRNA expression of cyp19a1b, erα, erß2, fshr, gnrh2, gnrhr3, vtg3, dat, and dr1 significantly changed after exposing the embryos to DM. Deltamethrin at 10 and 25 µg/L significantly reduced the average swimming speed of zebrafish larvae. In addition, embryos injected with zebrafish estrogen receptor α (erα) and ß (erß) morpholinos and co-exposed to 25 µg/L DM for 96 h showed reduced expression of vtg3 mRNA compared to embryos exposed to 25 µg/L DM only. The locomotor activity of erα and erß knockdown zebrafish following DM exposure was increased significantly when compared with that of larvae exposed to 25 µg/L DM only. Our results demonstrated that DM altered the locomotor activity of zebrafish larvae and the transcript levels of the components of estrogenic and dopaminergic pathways; erα and erß knockdown weakened these effects.


Assuntos
Piretrinas , Peixe-Zebra , Animais , Embrião não Mamífero , Humanos , Larva , Nitrilas , Piretrinas/toxicidade , Receptores de Estrogênio/genética
7.
Environ Pollut ; 292(Pt B): 118440, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34740738

RESUMO

This study focused on the short-term whole organism bioassays (WOBs) on fish (Danio rerio) and crustaceans (Gammarus fossarum and Daphnia magna) to assess the negative biological effects of water from the major European River Sava and the comparison of the obtained results with in vitro toxicity data (ToxCast database) and Risk Quotient (RQ) methodology. Pollution profiles of five sampling sites along the River Sava were assessed by simultaneous chemical analysis of 562 organic contaminants (OCs) of which 476 were detected. At each sampling site, pharmaceuticals/illicit drugs category was mostly represented by their cumulative concentration, followed by categories industrial chemicals, pesticides and hormones. An exposure-activity ratio (EAR) approach based on ToxCast data highlighted steroidal anti-inflammatory drugs, antibiotics, antiepileptics/neuroleptics, industrial chemicals and hormones as compounds with the highest biological potential. Summed EAR-based prediction of toxicity showed a good correlation with the estimated toxicity of assessed sampling sites using WOBs. WOBs did not exhibit increased mortality but caused various sub-lethal biological responses that were dependant relative to the sampling site pollution intensity as well as species sensitivity. Exposure of G. fossarum and D. magna to river water-induced lower feeding rates increased GST activity and TBARS levels. Zebrafish D. rerio embryo exhibited a significant decrease in heartbeat rate, failure in pigmentation formation, as well as inhibition of ABC transporters. Nuclear receptor activation was indicated as the biological target of greatest concern based on the EAR approach. A combined approach of short-term WOBs, with a special emphasis on sub-lethal endpoints, and chemical characterization of water samples compared against in vitro toxicity data from the ToxCast database and RQs can provide a comprehensive insight into the negative effect of pollutants on aquatic organisms.


Assuntos
Rios , Poluentes Químicos da Água , Animais , Bioensaio , Croácia , Daphnia , Monitoramento Ambiental , Medição de Risco , Água , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Peixe-Zebra
8.
Chemosphere ; 287(Pt 3): 132352, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34826958

RESUMO

Diffusive gradient in thin films (DGT) for organics has received considerable attention for studying the chemical dynamics of various organic pollutants in the environment. This review investigates current limitations of DGT for organics and identifies several research gaps for future studies. The application of a protective outer filter membrane has been recommended for most DGT applications, however, important questions regarding longer lag times due to significant interaction or adsorption of specific groups of compounds on the outer membrane remain. A modified DGT configuration has been developed that uses the diffusive gel as the outer membrane without the use of an extra filter membrane, however use of this configuration, while largely successful, remains limited. Biofouling has been a concern when using DGT for metals; however, effect on the performance of DGT for organics needs to be systemically studied. Storage stability of compounds on intact DGT samplers has been assessed in select studies and that data is synthesized here. DGT has been used to describe the kinetic desorption of antibiotics from soils and biosolids based on the soil/biosolid physical-chemical characteristics, yet applications remain limited and requires further research before wide-scale adoption is recommended. Finally, DGT for organics has been rarely, albeit successfully, combined with bioassays as well as in vivo bioaccumulation studies in zebrafish. Studies using DGT combined with bioassays to predict the adverse effects of environmental mixtures on aquatic or terrestrial biota are discussed here and should be considered for future research.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Animais , Bioensaio , Difusão , Monitoramento Ambiental , Poluentes Químicos da Água/análise , Peixe-Zebra
9.
Chemosphere ; 287(Pt 4): 132434, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34606890

RESUMO

Fluoxetine (FLU), a selective serotonin reuptake inhibitor, is commonly found in aquatic environments. Ultraviolet (UV) photolysis is widely used to remove certain pharmaceuticals from water and wastewater. The present study aimed to investigate the toxicity of FLU and its transformed products formed during UV photolysis by using zebrafish embryos (Danio rerio) as a model. The degradation rates of FLU for five days were approximately 63.6% ± 2.14%, 84.6% ± 0.99%, and 97.5% ± 0.25% after 15, 30, and 60 min of UV irradiation, respectively. Furthermore, the degradation mechanism was explored using LC-MS measurements and density flooding theory (DFT) theoretical calculations. Comprehensive toxicity preassessment of FLU and its degradation products was carried out using the T.E.S.T. software. The effects of physiological and biochemical parameters and neuron- and apoptosis-related gene expression were examined in zebrafish embryos exposed to non-irradiated (0-min) and irradiated (15, 30- and 60-min) solutions from 4 h post-fertilization (hpf) to 120 hpf. The hatching time of zebrafish embryos exposed to the non-irradiated solution (0-min) and irradiated solution (60-min) was delayed, their heart rate at 48 and 72 hpf increased, and their body length at 120 hpf decreased. Significant differences were found between the non-irradiated (0-min) and UV-irradiated (15- or 30-min) groups. A dynamic response involving acetylcholinesterase (AChE) and superoxide dismutase (SOD) activity was also observed in the non-irradiated and UV-irradiated groups. During the UV treatment experiments, the expression levels of neuron-related and apoptosis-related genes were significantly reduced over time alongside the formation of FLU degradation products. Overall, this study provides new concepts to remove and assess the toxicity of emerging contaminants in aquatic environments and highlights the need to consider the formation and persistence of toxic transformation products.


Assuntos
Poluentes Químicos da Água , Peixe-Zebra , Acetilcolinesterase , Animais , Antidepressivos , Embrião não Mamífero , Fluoxetina/toxicidade , Água , Poluentes Químicos da Água/toxicidade
10.
Environ Pollut ; 292(Pt A): 118307, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34626713

RESUMO

Municipal sewage treatment plants (STPs) have been regarded as an important source of organic contaminants in aquatic environment. To assess the impact of STPs on occurrence and toxicity of STP-associated contaminants in receiving waterways, a novel passive sampler modified from polar organic chemical integrative sampler (m-POCIS) was deployed at the inlet and outlet of a STP and several upstream and downstream sites along a river receiving STP effluent in Guangzhou, China. Eighty-seven contaminants were analyzed in m-POCIS extracts, along with toxicity evaluation using zebrafish embryos. Polycyclic musks were the predominant contaminants in both STP and urban waterways, and antibiotics and current-use pesticides (e.g., neonicotinoids, fiproles) were also ubiquitous. The m-POCIS extracts from downstream sites caused significant deformity in embryos, yet the toxicity could not be explained by the measured contaminants, implying the presence of nontarget stressors. Sewage treatment process substantially reduced embryo deformity, chemical oxygen demand, and contamination levels of some contaminants; however, concentrations of neonicotinoids and fiproles increased after STP treatment, possibly due to the release of chemicals from perturbed sludge. Source identification showed that most of the contaminants found in urban waterways were originated from nonpoint runoff, while cosmetics factories and hospitals were likely point sources for musks and antibiotics, respectively. Although the observed embryo toxicity could not be well explained by target contaminants, the present study showed a promising future of using passive samplers to evaluate chemical occurrence and aquatic toxicity concurrently. Zebrafish embryo toxicity significantly decreased after sewage treatment, but higher toxicity was observed for downstream samples, demonstrating that urban runoff may produce detrimental effects to aquatic life, particularly in rainy season. These results highlight the relevance of monitoring nonpoint source pollution along with boosting municipal sewage treatment infrastructure.


Assuntos
Esgotos , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Compostos Orgânicos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Peixe-Zebra
11.
Environ Pollut ; 292(Pt A): 118296, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34627961

RESUMO

Cellular transport of metal nanoparticles (NPs) is critical in determining their potential toxicity, but the transformation of metal ions released from the internalized NPs is largely unknown. Cu-based NPs are the only metallic-based NPs that are reported to induce higher toxicity compared with their corresponding ions, likely due to their unique cellular turnover. In the present study, we developed a novel gold core to differentiate the particulate and ionic Cu in the Cu2O microparticles (MPs), and the kinetics of bioaccumulation, exocytosis, and cytotoxicity of Au@Cu2O MPs to zebrafish embryonic cells were subsequently studied. We demonstrated that the internalized MPs were rapidly dissolved to Cu ions, which then undergo lysosome-mediated exocytosis. The uptake rate of smaller MPs (130 nm) was lower than that of larger ones (200 nm), but smaller MPs were dissolved much quickly in cells and therefore activated the exocytosis more quickly. The rapid release of Cu ions resulted in an immediate toxic action of Cu2O MPs, while the cell deaths mainly occurred by necrosis. During this process, the buffering ability of glutathione greatly alleviated the Cu toxicity. Therefore, although the turnover of intracellular Cu at a sublethal exposure level was hundred times faster than the basal values, labile Cu(I) concentration increased by only 2 times at most. Overall, this work provided new insights into the toxicity of copper NPs, suggesting that tolerance to Cu-based NPs depended on their ability to discharge the released Cu ions.


Assuntos
Nanopartículas Metálicas , Peixe-Zebra , Animais , Cobre/toxicidade , Íons , Nanopartículas Metálicas/toxicidade , Metais
12.
Environ Pollut ; 292(Pt A): 118317, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34634407

RESUMO

Neonicotinoids have been often detected in aquatic environment with high concentrations; however, little is known about their risk and fate to/in fish. This study systematically investigated the bio-uptake, tissue distribution and metabolism of neonicotinoids in zebrafish, taking clothianidin (CLO) as an example. The results revealed the uptake and elimination kinetics of CLO in whole fish and different tissues was very similar, and its bioconcentration factor (<1) indicates the low bioaccumulation potential in zebrafish. The highest accumulative tissues for CLO were found to be intestine and liver. Eight biotransformation products were identified in intestine and liver, and the metabolic pathways were found to be N-demethylation and nitro-reduction. The metabolic kinetics of two products (desmethyl clothianidin and clothianidin urea) revealed the metabolism of CLO mainly occurred in liver and intestine. This suggested that the hepatobiliary system played an important role in the metabolism and elimination of CLO. This study provides a comprehensive evaluation of the toxicokinetics of CLO in zebrafish, and these results can contribute to its ecological risk assessment.


Assuntos
Inseticidas , Animais , Guanidinas/toxicidade , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Tiazóis , Distribuição Tecidual , Peixe-Zebra
13.
Sci Total Environ ; 804: 150228, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34798747

RESUMO

Silver nanoparticles (AgNPs) released into the environment are subject to environmental transformation processes before accumulating in aquatic organisms and transferring along the food chain. Lack of understanding on how environmental transformation affects trophic transfer of AgNPs hinders accurate prediction of the environmental risks of these widely present nanomaterials. Here we discover that pristine AgNPs as well as their sulfidation products (Ag2S-NPs) and dissolution products (Ag+) tend to be accumulated in Daphnia magna and subsequently transferred to zebrafish. In D. magna, Ag+ exhibits the highest bioaccumulation potential whereas Ag2S-NPs show the lowest bioaccumulation. Surprisingly, the biomagnification factor of Ag+ along the D. magna-zebrafish food chain appears to be significantly lower relative to AgNPs and Ag2S-NPs, likely due to the limited release of Ag from D. magna to zebrafish during digestion. Moreover, AgNPs and their transformation products mainly accumulate in the internal organs, particularly intestine, of zebrafish. Adsorption of AgNPs on the surface of the intestinal cell membrane mitigates depuration of AgNPs and, at least in part, leads to the larger biomagnification factor of AgNPs, relative to their transformation products. This research highlights the necessity of considering environmental transformation processes of nanomaterials in assessing their bioavailability and risk.


Assuntos
Nanopartículas Metálicas , Poluentes Químicos da Água , Animais , Daphnia , Cadeia Alimentar , Íons , Prata , Peixe-Zebra
14.
Sci Total Environ ; 803: 149858, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34482148

RESUMO

Brevetoxins (PbTx) are a well-recognized group of neurotoxins associated with harmful algal blooms, and specifically recurrent "Florida Red Tides," in marine waters that are linked to impacts on both human and ecosystem health including well-documented "fish kills" and marine mammal mortalities in affected coastal waters. Understanding mechanisms and pathways of PbTx toxicity enables identification of relevant biomarkers to better understand these environmental impacts, and improve monitoring efforts, in relation to this toxin. Toward a systems-level understanding of toxicity, and identification of potential biomarkers, high-resolution magic angle spinning nuclear magnetic resonance (HRMAS NMR) was utilized for metabolic profiling of zebrafish (Danio rerio) embryos, as an established toxicological model, exposed to PbTx-2 (the most common congener in marine waters). Metabolomics studies were, furthermore, complemented by an assessment of the toxicity of PbTx-2 in embryonic stages of zebrafish and mahi-mahi (Coryphaena hippurus), the latter representing an ecologically and geographically relevant marine species of fish, which identified acute embryotoxicity at environmentally relevant (i.e., parts-per-billion) concentrations in both species. HRMAS NMR analysis of intact zebrafish embryos exposed to sub-lethal concentrations of PbTx-2 afforded well-resolved spectra, and in turn, identification of 38 metabolites of which 28 were found to be significantly altered, relative to controls. Metabolites altered by PbTx-2 exposure specifically included those associated with (1) neuronal excitotoxicity, as well as associated neural homeostasis, and (2) interrelated pathways of carbohydrate and energy metabolism. Metabolomics studies, thereby, enabled a systems-level model of PbTx toxicity which integrated multiple metabolic, molecular and cellular pathways, in relation to environmentally relevant concentrations of the toxin, providing insight to not only targets and mechanisms, but potential biomarkers pertinent to environmental risk assessment and monitoring strategies.


Assuntos
Ecossistema , Peixe-Zebra , Animais , Humanos , Espectroscopia de Ressonância Magnética , Toxinas Marinhas , Metabolômica , Oxocinas
15.
J Colloid Interface Sci ; 607(Pt 1): 16-23, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34492349

RESUMO

The exploration of carbon dots (CDs) with high quantum yield, facile synthesis path and satisfying output for their multiple applications remains a challenge. Thus, a silicon-doped orange-emitting carbon dots (O-CDs) is synthesized via a one-step hydrothermal method o-phenylenediamine and ethyl orthosilicate as raw materials. The O-CDs exhibits a bright and non-excitation-dependent emission peaking at 580 nm, and the corresponding quantum yield could be greatly boosted from 39.2 % to 64.1 % by silicon doping. The obtained O-CDs possess good biocompatibility and promising luminescence stability with varying solvents, ionic concentrations and temperatures. Its bio-imaging ability is performed by incubating zebrafish embryos with O-CDs aqueous solution, and clear in-vivo fluorescent images are obtained. Furthermore, due to its high-efficient and specific pH-sensitive emission with excellent dispersibility, the O-CDs can be used as a fluorescent ink for dual-model data encry/decryption in both hand-writing and stamp printing. Therefore, the as-prepared O-CDs show the potential as promising candidate for biomedical diagnosis, data encryption, and anti-counterfeiting.


Assuntos
Citrus sinensis , Pontos Quânticos , Animais , Carbono , Corantes Fluorescentes , Concentração de Íons de Hidrogênio , Luminescência , Silício , Peixe-Zebra
16.
Sci Total Environ ; 804: 149920, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34509837

RESUMO

Enormous production of cosmetic products and its indiscriminate use tends to discharge into the aquatic environment and might threaten non-target organisms inhabiting aquatic ecosystems. In the present study, developmental toxicity of 4-methylbenzylidene camphor (4-MBC), a widely used organic UV filter in personal care products has been evaluated using zebrafish embryo-larval stages. Waterborne exposure induced developmental toxicity and deduced 2.71 mg/L as 96 h LC50 whereas embryos exposed to sub-lethal concentrations (50 and 500 µg/L) caused a significant delay in hatching rate, heart rate, reduced larval length, and restricted hatchlings motility besides the axial curvature. Chronic exposure to 10 dpf resulted in significant decrease in SOD activity at 500 µg/L with no changes in CAT level besides a significant increase in GST enzyme at 5 µg/L concentration in 5 dpf sampled larvae. However, all the three enzymes were significantly elevated in 10 dpf larvae indicating differential oxidative stress during the stages of development. Similar trend is noticed for acetylcholine esterase enzyme activity. A concentration dependent increase in malondialdehyde content was noted in larvae sampled at 5 and 10 dpf. In addition, multixenobiotic resistance (MXR) activity inhibition, and elevated oxidative tissue damage were noticed at 5 dpf with no significant changes in 10 dpf larvae. Furthermore, immunoblot analysis confirms 4-MBC induced apoptosis in zebrafish larvae with promoted cleaved Caspase-3, Bax and inhibited Bcl-2 proteins expression. Subsequently, docking studies revealed the binding potential of 4-MBC to zebrafish Abcb4 and CYP450 8A1 proteins with the binding energy of -8.1 and -8.5 kcal/mol representing target proteins interaction and toxicity potentiation. Our results showed that 4-MBC exposure triggers oxidative stress at sub-lethal concentrations leading to apoptosis, deformities and locomotion perturbations in developing zebrafish.This is first of its kind in systematically demonstrating developmental toxicity of 4-MBC and the information shall be used for aquatic toxicity risk assessment.


Assuntos
Poluentes Químicos da Água , Peixe-Zebra , Animais , Cânfora/análogos & derivados , Ecossistema , Embrião não Mamífero , Larva , Estresse Oxidativo , Poluentes Químicos da Água/toxicidade
17.
Sci Total Environ ; 804: 150185, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34509844

RESUMO

Lead induced neurotoxicity has been extensively investigated. However, the potential connections between early-life lead exposure and the frequently observed aberrant neurobehavior in juveniles and adults remain unclear. In this study, zebrafish model was used to explore the immediate and long-term effects of early-life exposure to environmental levels of lead on the central nervous system, and the cellular and molecular mechanisms underlying the consequent abnormal neurobehavior. Lead exposed zebrafish larvae exhibited neurologic damage and defective neurobehavior. Consistent with clinical studies, despite being raised in lead-free conditions, the juvenile and adult fish experienced lead exposure earlier, presented ADHD-like symptoms, and the adult fish exhibited remarkably affected vitality and shoaling behavior. Their anxiety levels were elevated, whereas their social interaction, as well as learning and memory were strongly depressed. The expression profiles of key genes involved in neurodevelopment and neurotransmitter systems were significantly modulated, in similar patterns as in the larval stage. Notably, the density of neurons was decreased and varicosities in neuronal axons were frequently observed in the lead-exposed groups. It's tempting to speculate that the disruption of early neurodevelopment as well as the prolonged modulation of neuromorphic and neurotransmitter systems contribute to the lead-induced neurobehavioral disorders observed in juveniles and adulthood.


Assuntos
Chumbo , Peixe-Zebra , Animais , Sistema Nervoso Central , Larva , Chumbo/toxicidade
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 264: 120270, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34438115

RESUMO

Hypochlorite plays a significant role in physiological processes, particularly regulation of lysosomal functions, and is involved in various diseases. Thus, it is crucial to develop highly sensitive and selective molecule tools to detect HClO in lysosomes. Herein, a novel 2H-benzo[h]chromene-pyridine derivative (1) was synthesized through condensation reaction, which exhibited a notable deep-red emission at 640 nm in pure water. This deep-red emission was specifically quenched by adding ClO-. The response of probe 1 toward ClO- was rapid (within 10 s), sensitive (detection limit of 0.012 µM), and effective over a wide range of pH (1.0-12.0). Due to the existence of morpholine as the lysosome-targeting unit, the probe was successfully utilized to monitor lysosomal ClO-. Moreover, the probe 1 was also applied to detecting ClO- in zebrafish.


Assuntos
Corantes Fluorescentes , Ácido Hipocloroso , Animais , Humanos , Lisossomos , Imagem Óptica , Água , Peixe-Zebra
19.
Spectrochim Acta A Mol Biomol Spectrosc ; 264: 120265, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-34455378

RESUMO

A new long-wavelength fluorescent probe 1 that could specifically identify H2S has been successfully synthesized and applied for imaging H2S in zebrafish. Probe 1 was readily prepared by featuring nitrobenzene as the recognition unit coupled to resorufin. The fluorescence off-on response is based on the fact that H2S can reduce the nitro group to an amino group, followed by the 1,6-rearrangement-elimination and the release of resorufin. By evaluating the application abilities of probe 1 in vivo and vitro, it is shown that probe 1 has high sensitivity and selectivity to H2S, low background fluorescence interference, with a low detection limit of 17.30 µM. Notably, the occurrence of the reaction can be observed by the naked eye, and the color of the solution changes from yellow to pink. More importantly, it is the first time that using paper chips as carrier to detect H2S, which lays a foundation for the practical application of detecting H2S. The excellent analysis and application capabilities of probe 1 make it an effective tool for further application in practice.


Assuntos
Sulfeto de Hidrogênio , Animais , Corantes Fluorescentes , Células HeLa , Humanos , Imagem Óptica , Oxazinas , Peixe-Zebra
20.
Sci Total Environ ; 805: 150366, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-34818752

RESUMO

The frequent detection of polychlorinated diphenyl ethers (PCDEs) in aquatic systems has aroused widespread concerns, however, their potential hazard to aquatic ecosystems has been poorly understood. Here the acute toxicity of 12 PCDE congeners was evaluated in three model aquatic organisms representing different trophic levels following OECD test guidelines, including green algae (Scenedesmus obliquus), water flea (Daphnia magna), and zebrafish (Danio rerio). Dose-dependent increases in growth inhibition and mortality were observed for all tested PCDE congeners. Most of the PCDE congeners, in particular 3,3',4,4'-tetra-CDE, were highly toxic to the three aquatic organisms with EC50 or LC50 values below 1 mg L-1. Their toxicities were generally comparable with those of certain polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Moreover, D. magna was the most sensitive species among the three aquatic organisms. In addition, the EC50 or LC50 values had an extremely significant correlation with the n-octanol-water partition coefficient (logKow) of the PCDE congeners. The established quantitative structure-property relationship (QSPR) models indicated that the molecular polarizability (α) could significantly influence the acute toxicity of PCDEs on Daphnia magna and Danio rerio, and the energy of the lowest unoccupied molecular orbital (ELUMO) is the key factor of the acute toxicity of PCDEs in Scenedesmus obliquus. In addition, even at environmental levels, 3,3',4,4'-tetra-CDE could induced seveve oxidative damages in the three aquactic species. These findings would contribute to the understanding of adverse effects of PCDEs in aquatic organisms.


Assuntos
Scenedesmus , Poluentes Químicos da Água , Animais , Organismos Aquáticos , Daphnia , Ecossistema , Éteres Difenil Halogenados/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra
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