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1.
Aquat Toxicol ; 235: 105814, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33933832

RESUMO

Microplastics (MPs, <5 mm) have been frequently detected in aquatic ecosystems, representing both health and ecological concerns. However data about the combined effects of MPs and other contaminants is still limited. This study aimed to evaluate the impact of MPs and the heavy metal copper (Cu) on zebrafish (Danio rerio) larvae development and behavior. Zebrafish embryos were subchronically exposed to MPs (2 mg/L), two sub-lethal concentrations of Cu (60 and 125 µg/L) and binary mixtures of MPs and Cu using the same concentrations, from 2-h post fertilization until 14 days post fertilization. Lethal and sub-lethal responses (mortality, hatching, body length) were evaluated during the embryogenesis period, and locomotor, avoidance, anxiety and shoaling behaviors, and acetylcholinesterase (AChE) activity were measured at 14 dpf. The results showed that survival of larvae was reduced in groups exposed to MPs, Cu and Cu+MPs. Regarding the behavioral patterns, the higher Cu concentration and mixtures decreased significantly the mean speed, the total distance traveled and the absolute turn angle, demonstrating an adverse effect on swimming competence of zebrafish larvae. Exposure to MPs and Cu, alone or combined, also affected avoidance behavior of zebrafish, with larvae not reacting to the aversive stimulus. There was a significant inhibition of AChE activity in larvae exposed to all experimental groups, compared to the control group. Moreover, a higher inhibition of AChE was noticed in larvae exposed to MPs and both Cu+MPs groups, comparatively to the Cu alone groups. Our findings demonstrate the adverse effects of MPs, alone or co-exposed with Cu, on fish early life stages behavior. This study highlights that MPs and heavy metals may have significant impacts on fish population fitness by disrupting locomotor and avoidance behaviors.


Assuntos
Cobre/toxicidade , Microplásticos/toxicidade , Poluentes Químicos da Água/toxicidade , Acetilcolinesterase , Animais , Comportamento Animal/efeitos dos fármacos , Ecossistema , Larva/efeitos dos fármacos , Metais Pesados , Plásticos , Natação , Peixe-Zebra/fisiologia
2.
Ecotoxicol Environ Saf ; 217: 112239, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33892344

RESUMO

Neurotransmission related signals are involved in the control of response to toxicants. We here focused on the tyramine and the glutamate related signals to determine their roles in regulating nanoplastic toxicity in Caenorhabditis elegans. In the range of µg/L, exposure to nanopolystyrene (100 nm) increased the expression of tdc-1 encoding a tyrosine decarboxylase required for synthesis of tyramine, and decreased the expression of eat-4 encoding a glutamate transporter. Both TDC-1 and EAT-4 could act in the neurons to regulate the nanopolystyrene toxicity. Meanwhile, neuronal RNAi knockdown of tdc-1 induced a susceptibility to nanopolystyrene toxicity, and neuronal RNAi knockdown of eat-4 induced a resistance to nanopolystyrene toxicity. In the neurons, TYRA-2 functioned as the corresponding receptor of tyramine and acted upstream of MPK-1 signaling to regulate the nanopolystyrene toxicity. Moreover, during the control of nanopolystyrene toxicity, GLR-4 and GLR-8 were identified as the corresponding glutamate receptors, and acted upstream of JNK-1 signaling and DBL-1 signaling, respectively. Our results demonstrated the crucial roles of tyramine and glutamate related signals in regulating the toxicity of nanoplastics in organisms.


Assuntos
Caenorhabditis elegans/fisiologia , Microplásticos/toxicidade , Animais , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Ácido Glutâmico/metabolismo , Intestinos , Neurônios/metabolismo , Poliestirenos/toxicidade , Interferência de RNA , Receptores de Amina Biogênica/metabolismo , Transdução de Sinais , Tiramina/metabolismo
3.
Ecotoxicol Environ Saf ; 217: 112243, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33915449

RESUMO

Microplastic contamination has been considered as a global environmental problem in marine ecosystem. Due to small size (< 5 mm) in overlapping with that of microalgae, microplastics can easily be ingested by a wide range of marine copepods both in the laboratory and in situ. Although many studies have reported adverse effects of microplastics on marine copepods, it still lacks a systematic overview about the bioavailability of microplastics and their potential ecological consequences. As copepods dominate zooplankton biomass and provide an essential trophic link in marine ecosystem, this review indicates the bioavailability and toxicity of microplastics in such taxon depend on the shape, size, abundance, and properties of plastics. Also, ours is purposed to tease out the possible molecular mechanisms behind. Microplastic ingestion is prevalent; they impede food intake, block the digestive tract, and cause physiological stress in copepods (e.g., immune responses, metabolism disorders, energy depletion, behavioral alterations, growth retardation, and reproduction disturbance). Notably, in response to microplastic exposure, the copepods show both species- and stage-specificity. Furthermore, microplastics can serve as vectors of organic contaminants (e.g., triclosan, chlorpyrifos, and dibutyl phthalate) and thus increase their toxicity in marine copepods, consequently aggravating the adverse impacts of microplastics in marine ecosystem. Given that most previous studies have partially used pristine microplastics and their short-term exposure might have undervalued their negative effects, more multigenerational mechanistic researches (for example, via an integration of omics-based technology and phenotypic trait analysis) are urgently required for numerous marine copepods exposed to environmental-characteristics plastics as demonstrated by aged microplastics at environmentally realistic concentrations and added with other environmental pollutants; thus it will not only provide mechanistic insights into the biological impacts of microplastics, but also help make the seawater-benchmark setting and ecological assessment for microplastic pollution in marine environment.


Assuntos
Copépodes/fisiologia , Microplásticos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Disponibilidade Biológica , Biomassa , Copépodes/efeitos dos fármacos , Ecossistema , Monitoramento Ambiental , Microalgas , Plásticos/análise , Reprodução , Água do Mar , Zooplâncton
4.
Fish Shellfish Immunol ; 113: 154-161, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33862235

RESUMO

Abundant microplastics was found in aquatic ecosystem and aquatic organisms, which raised many concerns in public. Silver carp (Hypophthalmichthys molitrix), a species filter-feeding planktivorous fish, feed on particle between 4 and 85 µm in size, and the respiratory process works together with feeding mechanism when filtering plankton from water. The aim of this study was to assess the physiological response of silver carp exposed to 5 µm polystyrene microspheres during 48 h of exposure followed by 48 h of depuration through the gill histology, and oxidative stress biomarkers in intestine. The results revealed that microplastics can pass through the whole digestive tract of silver carp and be excreted by feces. Low microplastic concentration (80 µg/L) induced oxidative stress and up-regulation of TUB84 and HSP70 gene in intestine, and silver carp have ability to recover after the exposure to microplastic was removed. High microplastic concentration (800 µg/L) definitely cause significant damage to gills and intestines, in this situation, far beyond the possibility of fish own repair, and even when the threaten removed, silver carp can't recovery soon. Our studies assessed the dosage-effect relationship with physiological stress on silver carp when exposure to microplastics.


Assuntos
Carpas , Microplásticos/toxicidade , Estresse Oxidativo , Poliestirenos/toxicidade , Testes de Toxicidade Aguda/veterinária , Poluentes da Água/toxicidade , Animais , Biomarcadores/metabolismo , Relação Dose-Resposta a Droga , Intestinos/efeitos dos fármacos , Microesferas , Material Particulado/toxicidade
5.
Aquat Toxicol ; 235: 105821, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33826974

RESUMO

Owing to the increasing usage of plastics, their debris is continuously deposited in marine environments, resulting in deleterious effects on aquatic organisms. Although it is known that microplastics disturb the cellular redox status, knowledge of molecular in marine cladocerans is still lacking. In the present study, we investigated the acute toxicity of different-sized polystyrene (PS) beads (0.05, 0.5, and 6-µm diameter), ingestion and egestion patterns, their distribution in the tissues, and their effects on the antioxidant systems in the brackish water flea Diaphanosoma celebensis. All different-sized PS beads showed no mortality at the concentrations used in this study. After 48 h of exposure to PS beads of different sizes, all microbeads were retained in the digestive tract, but the retention time varied according to the bead size. In particular, the group that was exposed to 0.05-µm beads showed widely distributed fluorescence (e.g., in the embryo, and probably in lipid droplets as well as the digestive tract). The transcriptional level and enzyme activities of antioxidants were modulated depending on the size of the PS beads, and lipid peroxidation was induced in groups exposed to 0.05 and 0.5-µm beads. These findings suggest that the size of PS beads is an important factor for cellular toxicity, and can induce size-dependent oxidative stress in this species. This study provides a better understanding of the molecular modes of action of microplastics in marine zooplankton.


Assuntos
Cladóceros/fisiologia , Poliestirenos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/farmacologia , Organismos Aquáticos , Cladóceros/efeitos dos fármacos , Ingestão de Alimentos , Microplásticos/toxicidade , Plásticos , Poliestirenos/análise , Águas Salinas , Sifonápteros , Zooplâncton
6.
Aquat Toxicol ; 235: 105827, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33882407

RESUMO

Toxicity tests using the model organism Caenorhabditis elegans have shown that exposure to small microplastics such as polystyrene (PS) beads lead to high body burdens and dietary restrictions that in turn inhibit reproduction. Pharyngeal pumping is the key mechanism of C. elegans for governing the uptake of food and other particles and can be easily monitored by determining the pumping rates. In this study, pharyngeal pumping of C. elegans was examined in response to increasing quantities of food bacteria (E. coli: 106-1010 cells ml-1) and synthetic particles (107-109 beads ml-1) of similar size (1 µm). While the average pumping rate of C. elegans exposed to E. coli depended on the density of the bacterial cells, this was not the case for the synthetic beads. At 107 items ml-1, bacterial cells and synthetic beads triggered a basic stimulation of the pumping rate, independent of the nutritional value of the particle. At quantities >107 items ml-1, however, the nutritional value was essential to maximize the pumping rate, as it was upregulated only by E. coli cells, which can be chemosensorially recognized by C. elegans. Given the unselective uptake of all particles in the size range of bacteria, restricting the pumping rates for particles with low nutritional value to a basic rate, prevents the nematodes from wasting energy by high-frequency pumping, but still allows a food-quality screening at low food levels.


Assuntos
Caenorhabditis elegans/fisiologia , Microplásticos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Bactérias , Escherichia coli/fisiologia , Comportamento Alimentar/efeitos dos fármacos , Alimentos , Nematoides/fisiologia , Plásticos , Poliestirenos/análise
7.
Nat Commun ; 12(1): 2358, 2021 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-33883554

RESUMO

Global warming has driven a loss of dissolved oxygen in the ocean in recent decades. We demonstrate the potential for an additional anthropogenic driver of deoxygenation, in which zooplankton consumption of microplastic reduces the grazing on primary producers. In regions where primary production is not limited by macronutrient availability, the reduction of grazing pressure on primary producers causes export production to increase. Consequently, organic particle remineralisation in these regions increases. Employing a comprehensive Earth system model of intermediate complexity, we estimate this additional remineralisation could decrease water column oxygen inventory by as much as 10% in the North Pacific and accelerate global oxygen inventory loss by an extra 0.2-0.5% relative to 1960 values by the year 2020. Although significant uncertainty accompanies these estimates, the potential for physical pollution to have a globally significant biogeochemical signal that exacerbates the consequences of climate warming is a novel feedback not yet considered in climate research.


Assuntos
Aquecimento Global , Microplásticos/toxicidade , Modelos Biológicos , Oxigênio/análise , Água do Mar/análise , Poluentes Químicos da Água/toxicidade , Zooplâncton/efeitos dos fármacos , Zooplâncton/fisiologia , Animais , Simulação por Computador , Ecossistema , Microplásticos/farmacocinética , Oceanos e Mares , Poluentes Químicos da Água/farmacocinética
8.
Ecotoxicol Environ Saf ; 217: 112217, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33862431

RESUMO

Microplastics are widespread in freshwater environments, their biological effects and combined effects of other pollutants have attracted extensive attention. In this study, we investigated the adsorption properties of heavy metals onto polystyrene (PS) microplastics as well as the bioavailability and toxicity of microplastics and heavy metals by hydroponic wheat seedlings experiment. Results showed that PS microplastics (0.5 µm, 100 mg/L) had no significant effect on wheat seedlings growth, photosynthesis, and reactive oxygen species (ROS) content. However, PS microplastics could adsorb copper and cadmium, with a predominantly chemisorption. The accumulation of copper and cadmium in wheat seedlings reduced in the presence of PS microplastics, which meant the toxic effect by heavy metals might be mitigated. Compared with single heavy metals treatments, the combination of PS microplastics and heavy metals increased chlorophyll content, enhanced photosynthesis and reduced the accumulation of ROS. These findings suggest that PS microplastics (0.5 µm, 100 mg/L) have a mitigating effect on the bioavailability and toxicity of copper and cadmium.


Assuntos
Cádmio/toxicidade , Cobre/toxicidade , Microplásticos/toxicidade , Poluentes do Solo/toxicidade , Triticum/fisiologia , Adsorção , Disponibilidade Biológica , Transporte Biológico , Clorofila , Hidroponia , Metais Pesados/toxicidade , Microplásticos/metabolismo , Fotossíntese , Plásticos , Poliestirenos , Plântula/efeitos dos fármacos , Plântula/fisiologia , Poluentes do Solo/metabolismo
9.
Ecotoxicol Environ Saf ; 217: 112199, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33864982

RESUMO

Environmental aging of ubiquitous microplastics (MP) occurs through the action of biotic and abiotic factors, and aged MP exhibit different physicochemical properties and environmental behavior from virgin MP. This study aimed to investigate the aged micro-sized polystyrene (mPS) and polyvinyl chloride (mPVC), and the heavy metals copper (Cu) and cadmium (Cd), and examine the effects of their combined toxicities on microalga Chlorella vulgaris. Results showed that the presence of MP inhibited cell growth as compared with the control, the inhibition rate (I) decreased as concentrations of MP rose and aged MP exhibited stronger inhibition of cells than did virgin MP. The largest I was achieved in each culture with the MP concentration of 0.01 g/L, in which aged mPS with the maximal of 36.84% (Iaged mPS) followed by aged mPVC (Iaged mPVC = 30.03%), virgin mPS (Ivirgin mPS = 29.10%) and virgin mPVC (Ivirgin mPVC = 16.72%). Addition of the heavy metals Cu2+ and Cd2+ significantly inhibited cell growth, and toxicity increased with concentrations in a range of 0.5-2.0 mg/L; the maximum I values were 19.50% (ICu) and 85.14% (ICd), respectively. The combined toxicity of aged MP + Cu or aged MP + Cd was less than that of individual heavy metals. In particular, as compared with the maximal ICd of 85.14% achieved by single Cd2+, the toxicity of Cd2+ was greatly reduced when combined with aged mPS and mPVC, with the I value decreased to 27.55% (Iaged mPS) and 32.51% (Iaged mPVC), respectively. Both single and combined treatments caused cell damage to the microalga, accompanied by increased superoxide dismutase (SOD) and intracellular malonaldehyde (MDA) content.


Assuntos
Chlorella vulgaris/metabolismo , Metais Pesados/toxicidade , Microplásticos/toxicidade , Poluentes Químicos da Água/toxicidade , Disponibilidade Biológica , Cádmio/toxicidade , Chlorella vulgaris/efeitos dos fármacos , Cobre/toxicidade , Malondialdeído/farmacologia , Metais Pesados/metabolismo , Microalgas/metabolismo , Microplásticos/metabolismo , Plásticos , Poliestirenos/toxicidade , Cloreto de Polivinila , Superóxido Dismutase/metabolismo , Poluentes Químicos da Água/metabolismo
10.
Int J Mol Sci ; 22(4)2021 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-33672484

RESUMO

Polystyrene (PS) nanoplastic exposure has been shown to affect the viability of neuronal cells isolated from mouse embryonic brains. However, the viability of mouse embryonic fibroblasts (MEFs) was not affected although PS nanoplastics accumulated in the cytoplasm. It is currently unknown whether MEFs do not respond to PS nanoplastics or their cellular functions are altered without compromising viability. Here, we found that PS nanoplastics entered the cells via endocytosis and were then released into the cytoplasm, probably by endosomal escape, or otherwise remained in the endosome. Oxidative and inflammatory stress caused by intracellular PS nanoplastics induced the antioxidant response pathway and activated the autophagic pathway. However, colocalization of the autophagic marker LC3B and PS nanoplastics suggested that PS nanoplastics in the cytoplasm might interfere with normal autophagic function. Furthermore, autophagic flux could be impaired, probably due to accumulation of PS nanoplastic-containing lysosomes or autolysosomes. Intriguingly, the level of accumulated PS nanoplastics decreased during prolonged culture when MEFs were no longer exposed to PS nanoplastics. These results indicate that accumulated PS nanoplastics are removed or exported out of the cells. Therefore, PS nanoplastics in the cytoplasm affect cellular functions, but it is temporal and MEFs can overcome the stress caused by PS nanoplastic exposure.


Assuntos
Embrião de Mamíferos/patologia , Fibroblastos/patologia , Microplásticos/toxicidade , Nanopartículas/toxicidade , Poliestirenos/toxicidade , Estresse Fisiológico , Animais , Autofagia/efeitos dos fármacos , Citoplasma/efeitos dos fármacos , Citoplasma/metabolismo , Endocitose/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Espaço Intracelular/metabolismo , Camundongos , Estresse Fisiológico/efeitos dos fármacos
11.
Sci Total Environ ; 779: 146454, 2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-33744565

RESUMO

Current studies simply focus on the toxicity of nano-plastics, while the correlation between their toxicity and bio-distribution, as well as intestinal microorganisms is still blank. Therefore, we systematically evaluated the toxicity based on the accumulation characteristics of nano-plastics in C. elegans. Meanwhile, for the first time, human fecal microbiota was transplanted into the gut of C. elegans and found that nano-plastics can through the intestinal barrier to the whole body after oral intake and can't be drastically excreted until die, thus causing toxic effects; while human fecal microbiota transplantation can significantly improve the living state via activating PMK-1/SKN-1 pathway to promote the production of intracellular glutathione, and exogenous glutathione addition can also markedly protect nematodes against nano-plastics induced toxicity. Our results not only provide a fully understand between the accumulation characteristic and health risk of nano-plastics, but also take C. elegans and intestinal flora into the field of toxicity evolution of nanomaterials.


Assuntos
Caenorhabditis elegans , Transplante de Microbiota Fecal , Microplásticos/toxicidade , Animais , Proteínas de Caenorhabditis elegans
12.
Environ Toxicol Pharmacol ; 84: 103615, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33607259

RESUMO

Marine and land plastic debris biodegrades at micro- and nanoscales through progressive fragmentation. Oceanographic model studies confirm the presence of up to ∼2.41 million tons of microplastics across the Atlantic, Pacific, and Indian subtropical gyres. Microplastics distribute from primary (e.g., exfoliating cleansers) and secondary (e.g., chemical deterioration) sources in the environment. This anthropogenic phenomenon poses a threat to the flora and fauna of terrestrial and aquatic ecosystems as ingestion and entanglement cases increase over time. This review focuses on the impact of microplastics across taxa at suggested environmentally relevant concentrations, and advances the groundwork for future ecotoxicological-based research on microplastics including the main points: (i) adhesion of chemical pollutants (e.g., PCBs); (ii) biological effects (e.g., bioaccumulation, biomagnification, biotransportation) in terrestrial and aquatic organisms; (iii) physico-chemical properties (e.g., polybrominated diphenyl ethers) and biodegradation pathways in the environment (e.g., chemical stress, heat stress); and (iv) an ecotoxicological prospect for optimized impact assessments.


Assuntos
Poluentes Ambientais/toxicidade , Microplásticos/toxicidade , Animais , Organismos Aquáticos/efeitos dos fármacos , Ecotoxicologia , Monitoramento Ambiental , Humanos , Água do Mar
13.
Aquat Toxicol ; 233: 105772, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33618324

RESUMO

Besides the adverse biological effects induced by microplastics (MPs), the effects associated with sorption of ambient pollutants on MPs are considered as an emerging environmental problem as MPs act as a mediator of pollutants. The present study examines the combined effects of nano(micro)plastics (NMPs) and arsenic (As) by exposing the marine rotifer Brachionus plicatilis to MP particles at the micro-scale (6 µm) and nano-scale (nanoplastics, NPs) (50 nm) along with As. In vivo toxicity, bioaccumulation, and biochemical reactions were used to examine the effects of combined exposure. The results of in vivo experiments showed that As toxicity increased with NP exposure, whereas toxicity was alleviated by MPs, indicating a different mode of action between NPs and MPs in combination with As. The highest level of As bioaccumulation was detected in NP + As groups, and followed by MP + As and As-only exposure groups, whereas no significant difference between groups was shown for As metabolites. In addition, the activity of several ATP-binding cassette proteins that confer multixenobiotic resistance, which is responsible for efflux of As, was activated by As but significantly inhibited by NP exposure, supporting the findings of in vivo experiments. Our results show that the effects of combining exposure to As with NP and MPs differ depending on particle size and provide an in-depth understanding of both environmental pollutants.


Assuntos
Arsênico/toxicidade , Microplásticos/toxicidade , Nanopartículas/toxicidade , Rotíferos/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Arsênico/metabolismo , Bioacumulação , Disponibilidade Biológica , Microplásticos/metabolismo , Modelos Teóricos , Nanopartículas/metabolismo , Rotíferos/metabolismo , Natação , Poluentes Químicos da Água/metabolismo
14.
Ecotoxicol Environ Saf ; 213: 112041, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33601174

RESUMO

Awareness of risks posed by widespread presence of nanoplastics (NPs) and bioavailability and potential to interact with organic pollutants has been increasing. Inhalation is one of the more important pathways of exposure of humans to NPs. In this study, combined toxicity of concentrations of polystyrene NPs and various phthalate esters (PAEs), some of the most common plasticizers, including dibutyl phthalate (DBP) and di-(2-ethyl hexyl) phthalate (DEHP) on human lung epithelial A549 cells were investigated. When co-exposed, 20 µg NPs/mL increased viabilities of cells exposed to either DBP or DEHP and the modulation of toxic potency of DEHP was greater than that of DBP, while the 200 µg NPs/mL resulted in lesser viability of cells. PAEs sorbed to NPs decreased free phase concentrations (Cfree) of PAEs, which resulted in a corresponding lesser bioavailability and joint toxicity at the lesser concentration of NPs. The opposite effect was observed at the greater concentration of NPs, which may result from the dominated role of NPs in the combined toxicity. Furthermore, our data showed that oxidative stress and inflammatory reactions were mechanisms for combined cytotoxicities of PAEs and NPs on A549 cells. Results of this study emphasized the combined toxic effects and mechanisms on human lung cells, which are helpful for assessing the risk of the co-exposure of NPs and organic contaminants in humans.


Assuntos
Poluentes Ambientais/toxicidade , Microplásticos/toxicidade , Ácidos Ftálicos/toxicidade , Poliestirenos/toxicidade , Células A549 , China , Dibutilftalato/toxicidade , Dietilexilftalato , Ésteres , Humanos , Pulmão , Estresse Oxidativo , Plastificantes
15.
Ecotoxicol Environ Saf ; 212: 112012, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33550074

RESUMO

Microplastics (MPs) considered as a new persistent environmental pollutant could enter into the circulatory system and result in decrease of sperm quantity and quality in mice. However, the effects of Polystyrene MPs (PS MPs) on the ovary and its mechanism in rats remained unclear. In this present study, thirty-two healthy female Wistar rats were exposed to different concentrations of 0.5 µm PS MPs dispersed in deionized water for 90 days. Using hematoxylin-eosin (HE) staining, the number of growing follicles was decreased compared to the control group. In addition, the activity of glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD) were decreased while the expression level of malondialdehyde (MDA) was increased in ovary tissue. Confirmed by immunohistochemistry, the integrated optical density of NLRP3 and Cleaved-Caspase-1 had been elevated by 13.9 and 14 in granulosa cells in the 1.5 mg/kg/d group. Furthermore, compared to the control group, the level of AMH had been decreased by 23.3 pg/ml while IL-1ß and IL-18 had been increased by 32 and 18.5 pg/ml in the 1.5 mg/kg/d group using the enzyme-linked immune sorbent assay (ELISA). Besides, the apoptosis of granulosa cells was elevated measured by terminal deoxyribonucleotide transferase-mediated nick end labeling (TUNEL) staining and flow cytometry. Moreover, western blot assays showed that the expressions of NLRP3/Caspase-1 signaling pathway related factors and Cleaved-Caspase-3 were increased. These results demonstrated that PS MPs could induce pyroptosis and apoptosis of ovarian granulosa cells via the NLRP3/Caspase-1 signaling pathway maybe triggered by oxidative stress. The present study suggested that exposure to microplastics had adverse effects on ovary and could be a potential risk factor for female infertility, which provided new insights into the toxicity of MPs on female reproduction.


Assuntos
Apoptose/efeitos dos fármacos , Caspase 1/metabolismo , Microplásticos/toxicidade , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Ovário/efeitos dos fármacos , Poliestirenos/toxicidade , Piroptose/efeitos dos fármacos , Animais , Feminino , Células da Granulosa/efeitos dos fármacos , Células da Granulosa/metabolismo , Células da Granulosa/patologia , Interleucina-18/metabolismo , Interleucina-1beta/metabolismo , Malondialdeído/metabolismo , Ovário/metabolismo , Ovário/patologia , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Transdução de Sinais
17.
Ecotoxicol Environ Saf ; 211: 111899, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33453641

RESUMO

The presence of microplastics and arsenic in soil can endanger crop growth; therefore, their effects on the properties of rhizosphere soil should be evaluated. Large (10-100 µm) and small (0.1-1 µm) polystyrene (PSMP) and polytetrafluorethylene (PTFE) particles were added to soil with different arsenic concentrations (1.4, 24.7, and 86.3 mg kg-1) to investigate the combined effect of microplastics and arsenic pollution on rice rhizosphere soil. After the addition of PSMP and PTFE, pH, arsenic (V) and arsenic (III) in the soil were observed to decrease. The interaction of arsenic with PSMP and PTFE resulted in this phenomenon, leading to a decrease of arsenic bioavailability in the soil. PSMP, PTFE, and arsenic reduced the abundance of Proteobacteria, increased the abundance of Chloroflexi and Acidobacteria, and inhibited soil urease, acid phosphatase, protease, dehydrogenase, and peroxidase activity via affecting the tertiary structure of the enzyme. PSMP, PTFE, and arsenic also reduced the available nitrogen and phosphorus content in the soil. Arsenic increased the soil organic matter content, whereas PSMP and PTFE reduced the organic matter content. Furthermore, microplastics inhibited the effects of arsenic on the microbial and chemical properties of the rhizosphere soil. This study revealed the effects of microplastic and arsenic pollution on rice rhizosphere microorganisms and nutrients, and elucidated the mechanism by which these pollutants retard crop growth in the designed growth medium.


Assuntos
Arsênico/toxicidade , Microplásticos/toxicidade , Poluentes do Solo/toxicidade , Arsênico/análise , Poluição Ambiental , Nitrogênio , Nutrientes , Oryza/crescimento & desenvolvimento , Plásticos , Rizosfera , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise
18.
Aquat Toxicol ; 231: 105723, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33385845

RESUMO

Microplastics (MPs) as complex synthetic pollutants represent a growing concern for the aquatic environment. Previous studies examined the toxicity of MPs, but infrequently used a natural particle control such as kaolin. The cause of toxicity, either the physical structure of the particles or chemical components originating from the MPs, has rarely been resolved. Moreover, the ecotoxicological assessment of biodegradable plastics has received little attention. To narrow down the main driver for toxicity of irregular biodegradable MPs, we conducted a series of 28-days sediment toxicity tests with the freshwater oligochaete Lumbriculus variegatus and recorded the number of worms and dry weight as endpoints. Therefore, MPs containing several biodegradable polymers were either mixed with the sediment or layered on the sediment surface with concentrations from 1 to 8.4% sediment dw-1. Kaolin particles were evaluated in parallel as particle control. Furthermore, aqueous leachates and methanolic extracts as MP equivalents as well as solvent-treated, presumably pure MPs were investigated after mixing them into the sediment. Our results reveal that MP mixed with the sediment induced stronger adverse effects than layered MP. Kaolin particles caused no adverse effects. In contrast, they enhanced dry weight in both applications. The impact of aqueous leachates was comparable to the control without MPs, whereas methanolic extracts affected the worm number at the highest concentration with 100% mortality. Solvent-treated, presumably pure MP resulted in mostly higher worm numbers when compared to untreated MPs mixed into the sediment. This study demonstrates that MPs mixed into the sediment affect L. variegatus more than MPs that are layered on the sediment surface. Kaolin as a natural, fine-sized particle control created somewhat favorable conditions for the worm. The main driver for toxicity, however, proved to be chemicals associated with the plastic product and its previous content.


Assuntos
Água Doce/química , Microplásticos/toxicidade , Oligoquetos/efeitos dos fármacos , Testes de Toxicidade , Animais , Biodegradação Ambiental , Sedimentos Geológicos/química , Tamanho da Partícula , Solventes/química , Poluentes Químicos da Água/toxicidade
19.
Aquat Toxicol ; 231: 105737, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33422861

RESUMO

Increasing global research has identified microplastics (MPs) to be impacting marine organisms. The present work aimed at investigating the physiological and behavioral effects of thirty-six juvenile Sparus aurata exposed to control, virgin and weathered MPs enriched diets during a 21-day period under controlled conditions. Physiological effects were assessed in liver and brain using the following biomarkers: activities of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GRd), the detoxifying enzyme glutathione S-transferase (GST) and malondialdehyde (MDA) as indicative of lipid peroxidation. Individuals were recorded for behavior analysis (i.e. social interactions and feeding behavior). Results revealed an increase in cellular stress from control to weathered fish groups, with the virgin group showing intermediate levels in all quantified biomarkers. Significant differences were found in the liver for all biomarkers except for MDA, suggesting that exposure time to MPs in this experiment is long enough to trigger the activation of antioxidant enzymes but not to produce cell damage by lipid peroxidation. In brain tissue samples, fish from the weathered group presented significantly higher values for CAT and SOD, highlighting its function as primary antioxidants. Regarding behavioral effects, results showed that the two MPs enriched groups were significantly bolder during social interactions and, although no significantly, tended to be more active during feeding. In conclusion, MPs which have been weathered in marine environmental conditions produces a higher physiological response than virgin MPs but also, a physiological response is variable depending on the tissue analyzed. In addition, a short period to MP exposure seems to affect overall social and feeding behavior but, further research is needed to assess long-term effects of MP ingestion and its potential consequences on fish populations.


Assuntos
Comportamento Animal , Ingestão de Alimentos , Microplásticos/toxicidade , Dourada/fisiologia , Animais , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Catalase/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Malondialdeído/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Análise de Componente Principal , Superóxido Dismutase/metabolismo , Poluentes Químicos da Água/toxicidade
20.
Ecotoxicol Environ Saf ; 208: 111718, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396049

RESUMO

Plastics enter in terrestrial natural system primarily by agricultural purposes, while acid rain is the result of anthropogenic activities. The synergistic effects of microplastics and acid rain on plant growth are not known. In this study, different sizes of polyethylene terephthalate (PET) and acid rain are tested on Lepidium sativum, in two separate experimental sets. In the first one we treated plants only with PET, in the second one we used PET and acid rain together. In both experimentations we analyzed: i) plant biometrical parameters (shoot height, leaf number, percentage inhibition of seed germination, fresh biomass), and ii) oxidative stress responses (hydrogen peroxide; ascorbic acid and glutathione). Results carried out from our experiments highlighted that different sizes of polyethylene terephthalate are able to affect plant growth and physiological responses, with or without acid rain supplied during acute toxicity (6 days). SHORT DESCRIPTION: This study showed that different sizes of PET microplastics affect physiological and biometrical responses of Lepidum sativum seedlings, with or without acid rain; roots and leaves responded differently.


Assuntos
Chuva Ácida/toxicidade , Lepidium sativum/efeitos dos fármacos , Microplásticos/toxicidade , Polietilenotereftalatos/toxicidade , Poluentes Químicos da Água/toxicidade , Lepidium sativum/crescimento & desenvolvimento , Lepidium sativum/metabolismo , Lepidium sativum/fisiologia , Microplásticos/química , Estresse Oxidativo/efeitos dos fármacos , Tamanho da Partícula , Folhas de Planta/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Polietilenotereftalatos/química , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/fisiologia , Poluentes Químicos da Água/química
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