Environmental Toxicology Studies Research Articles

Emamectin benzoate-induced toxicity affects intestinal epithelial integrity involving apoptosis

The frequency presence of emamectin benzoate in agricultural production highlights the need for studying their toxicity against human intestinal epithelial barrier (IEB). Herein, we combined a Caco-2 cell model with transcriptome analysis to assess the intestinal toxicity of emamectin benzoate and its disease-causing potential. Results showed that the half maximal inhibitory concentration (IC50) of emamectin benzoate on Caco-2 cell viability after 24, 48, and 72 h of exposure were 18.1, 9.9, and 8.3 μM, respectively. Emamectin benzoate exposure enhanced the Caco-2 monolayer paracellular permeability, damaged the IEB, and increased cellular apoptosis. Key driver gene analysis of 42 apoptosis - related DEGs, identified 10 genes (XIAP, KRAS, MCL1, NRAS, PIK3CA, CYCS, MAPK8, CASP3, FADD, and TNFRSF10B) with the strongest correlation with emamectin benzoate - induced apoptosis. Transcriptomics identified 326 differentially expressed genes (DEGs, 204 upregulated and 122 downregulated). The functional terms of neurodegeneration - multiple diseases was enriched with the most number of DEGs, and the Parkinson disease pathway had the highest enrichment degree. Our findings provided support for environmental toxicology studies and the health risk assessment of emamectin benzoate.

Bringing Artificial Intelligence (AI) into Environmental Toxicology Studies: A Perspective of AI-Enabled Zebrafish High-Throughput Screening.

The booming development of artificial intelligence (AI) has brought excitement to many research fields that could benefit from its big data analysis capability for causative relationship establishment and knowledge generation. In toxicology studies using zebrafish, the microscopic images and videos that illustrate the developmental stages, phenotypic morphologies, and animal behaviors possess great potential to facilitate rapid hazard assessment and dissection of the toxicity mechanism of environmental pollutants. However, the traditional manual observation approach is both labor-intensive and time-consuming. In this Perspective, we aim to summarize the current AI-enabled image and video analysis tools to realize the full potential of AI. For image analysis, AI-based tools allow fast and objective determination of morphological features and extraction of quantitative information from images of various sorts. The advantages of providing accurate and reproducible results while avoiding human intervention play a critical role in speeding up the screening process. For video analysis, AI-based tools enable the tracking of dynamic changes in both microscopic cellular events and macroscopic animal behaviors. The subtle changes revealed by video analysis could serve as sensitive indicators of adverse outcomes. With AI-based toxicity analysis in its infancy, exciting developments and applications are expected to appear in the years to come.

Influence of para-substituted benzaldehyde derivatives with different push/pull electron strength groups on the conformation of human serum albumin and toxicological effects in zebrafish

Excessive intake of benzaldehyde and its derivatives can cause irreversible damage to living organisms. Hence, benzaldehyde derivatives with different para-substitutions of push/pull electronic groups were chosen to investigate the effect of different substituent properties on the structure of human serum albumin (HSA). The binding constants, number of binding sites, major interaction forces, protein structural changes, and binding sites of benzaldehyde (BzH) and its derivatives (4-BzHD) with HSA in serum proteins were obtained based on multispectral and molecular docking techniques. The mechanism of BzH/4-BzHD interaction on HSA is mainly static quenching and is accompanied by the formation of a ground state complex. BzH/4-BzHD is bound to HSA in a 1:1 stoichiometric ratio. The interaction forces for the binding of BzH/4-BzHD to HSA are mainly hydrogen bonding and hydrophobic interaction, which are also accompanied by a small amount of electrostatic interactions. The effect of BzH/4-BzHD on HSA conformation follows: 4-Diethylaminobenzaldehyde (4-DBzH) > 4-Nitrobenzaldehyde (4-NBzH) > 4-Hydroxybenzaldehyde (4-HBzH) > 4-Acetaminobenzaldehyde (4-ABzH) > BzH, which means that the stronger push/pull electronic strength of the para-substituted benzaldehyde derivatives has a greater effect on HSA conformation. Furthermore, the concentration-lethality curves of different concentrations for BzH/4-BzHD on zebrafish verified above conclusion. This work provides a scientific basis for the risk assessment of benzaldehyde and its derivatives to the ecological environment and human health and for the environmental toxicological studies of benzaldehyde derivatives with different strengths of push/pull electron substitution.

Extracellular Vesicles in Environmental Toxicological Studies: Association between Urinary Concentrations of Phthalate Metabolites and Exosomal miRNA Expression Profiles.

Phthalates are chemical compounds, mainly used as additives in plastics, which are known to induce harmful impacts to the environment and human health due to their ability to act as hormone-mimics. Few studies have been reported on the relationship between human exposure to phthalates and the level of circulating microRNAs (miRs), especially those miRs encapsulated in extracellular vesicles/exosomes or exosome-like vesicles (ELVs). We examined the relationship of ELV-miR expression patterns and urine of adult men with five phthalate metabolites (i.e., mono isobutyl phthalate, mono-n-butyl phthalate, mono benzyl phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, mono-(2-ethylhexyl) phthalate) to identify potential biomarkers and relevant pathways. We found significant positive associations which were further confirmed by multivariable analysis. Overall, our analyses showed that the Σ phthalate metabolite concentration was associated with a significant increase in the expression level of two miRs found in ELV: miR-202 and miR-543. Different pathways including cancer and immune-related responses were predicted to be involved in this relationship. Analyzing the specific downstream target genes of miR-202 and miR-543, we identified the phosphatase and tensin homolog (PTEN) as the key gene in several converging pathways. In summary, the obtained results demonstrate that exposure to environmental phthalates could be related to altered expression profiles of specific ELV-miRs in adult men, thereby demonstrating the potential of miRs carried by exosomes to act as early effect biomarkers.

Using Electroporation to Improve and Accelerate Zebrafish Embryo Toxicity Testing.

Zebrafish have emerged as a useful model for biomedical research and have been used in environmental toxicology studies. However, the presence of the chorion during the embryo stage limits cellular exposure to toxic elements and creates the possibility of a false-negative or reduced sensitivity in fish embryo toxicity testing (FET). This paper presents the use of electroporation as a technique to improve the delivery of toxic elements inside the chorion, increasing the exposure level of the toxins at an early embryo stage (<3 h post-fertilization). A custom-made electroporation device with the required electrical circuitry has been developed to position embryos between electrodes that provide electrical pulses to expedite the entry of molecules inside the chorion. The optimized parameters facilitate material entering into the chorion without affecting the survival rate of the embryos. The effectiveness of the electroporation system is demonstrated using Trypan blue dye and gold nanoparticles (AuNPs, 20-40 nm). Our results demonstrate the feasibility of controlling the concentration of dye and nanoparticles delivered inside the chorion by optimizing the electrical parameters, including pulse width, pulse number, and amplitude. Next, we tested silver nanoparticles (AgNPs, 10 nm), a commonly used toxin that can lower mortality, affect heart rate, and cause phenotypic defects. We found that electroporation of AgNPs reduces the exposure time required for toxicity testing from 4 days to hours. Electroporation for FET can provide rapid entry of potential toxins into zebrafish embryos, reducing the time required for toxicity testing and drug delivery experiments.

Environmental and human toxicology studies on explosive chemicals leaking from submerged munitions

AbstractThis review provides an overview of 15 years of munitions research by the Institute of Toxicology and Pharmacology for Natural Scientists, University Medical School Schleswig‐Holstein, Kiel, Germany. As early as 2009, it was possible to detect the TNT metabolite 4‐ADNT in a quantity of 250 ng/g (wet weight) in blue mussels collected directly on munition items in the Kolberger Heide dumping area (Bight of Kiel, Baltic Sea, Germany). Based on these results, biomonitoring with blue mussels was established, in which uncontaminated mussels were exposed at certain distances from munition items and then retrieved after a few weeks in order to then be analyzed in the laboratory for energetic compounds (EC) including TNT and metabolites thereof. In following studies – in addition to mussels – also fish, sediments, water samples and passive samplers from specific locations were examined for the presence of EC. The study areas included dumping site regions from both the Baltic Sea and the North Sea, and were then extended to appropriate shipwrecks in the North Sea. The field studies were completed with laboratory investigations, which dealt with the development of a molecular biomarker as a kind of “early warning system” and with aspects of microbial degradation of EC. Finally, risk assessments for the marine environment and the human seafood consumer were carried out. The sections below are based on results from more than 10 scientific research projects and more than 20 publications in primary international research journals.

Liver Injury Induced by Exposure to Polystyrene Microplastics Alone or in Combination with Cadmium in Mice Is Mediated by Oxidative Stress and Apoptosis.

Microplastics (MPs) have been considered an emerging environmental pollutant which, when combined with toxic metals, enter the circulatory system of mammals and eventually cause damage. Therefore, it is important to study the toxicity of the mixture of MPs and heavy metals for evaluating risk assessment of mammals. In the present study, the toxicological effects of different concentrations of polystyrene (PS)-MPs alone or in combination with cadmium chloride (CdCl2) during chronic exposure (8 weeks) were evaluated using intragastric administration in mice. Using comparative analysis, it was revealed that PS-MPs alone or in combination with Cd could destroy the normal structural morphology of liver tissue and increase the levels of two biochemical indicators of liver damage, thereby inducing changes in antioxidant and hyperoxide capacities. In addition, PS-MPs and/or Cd activated the antioxidant signaling pathway Nrf2-Keap1 and affected the endogenous apoptosis signaling pathway p53-Bcl-2/Bax, thus promoting apoptosis. These findings suggested that exposure to MPs alone or in combination with Cd led to adverse effects on the liver. Furthermore, it was revealed that co-exposure to MPs and Cd reduced Cd toxicity, thereby highlighting the possibility MPs may act as carriers of other toxic substances and coordinate with them. Therefore, evaluating the synergistic or anti-agonistic effects of MPs on the toxicity and bioavailability of xenobiotics is in the future critical in environmental toxicological studies.

Sex blind: bridging the gap between drug exposure and sex-related gene expression in Danio rerio using next-generation sequencing (NGS) data and a literature review to find the missing links in pharmaceutical and environmental toxicology studies.

The sex of both humans and Danio rerio has previously been shown to affect the way individuals respond to drug exposure. Genes which allow identification of sex in juvenile zebrafish show potential to reveal these confounding variables between sex in toxicological and preclinical trials but the link between these is so far missing. These sex-specific, early expressed genes where expression is not altered by drug exposure must be carefully selected for this purpose. We aimed to discover genes which can be used in pharmaceutical trials and environmental toxicology studies to uncover sex-related variations in gene expression with drug application using the model organism Danio rerio. Previously published early sex determining genes from King et al. were evaluated as well as additional genes selected from our zebrafish Next-generation sequencing (NGS) data which are known from previously published works not to be susceptible to changes in expression with drug exposure. NGS revealed a further ten female-specific genes (vtg1, cyp17a1, cyp19a1a, igf3, ftz-f1, gdf9, foxl2a, Nr0b1, ipo4, lhcgr) and five male related candidate genes (FKBP5, apobb1, hbaa1, dmrt1, spata6) which are also expressed in juvenile zebrafish, 28 days post fertilisation (dpf). Following this, a literature review was performed to classify which of these early-expressed sex specific genes are already known to be affected by drug exposure in order to determine candidate genes to be used in pharmaceutical trials or environmental toxicology testing studies. Discovery of these early sex-determining genes in Danio rerio will allow identification of sex-related responses to drug testing to improve sex-specific healthcare and the medical treatment of human patients.

Synthesis of a new sulfonated-hexachlorobiphenyl standard for environmental analysis, ecotoxicological, and toxicological studies

Sulfonated-polychlorinated biphenyls (sulfonated-PCBs) are a newly discovered class of PCB metabolites. They were observed for the first time in polar bear serum and lately, in soil, together with hydroxy-sulfonated-PCBs. Their presence is ubiquitous in soils, and their estimated physical chemical properties show high mobility in water, compared to the parent compounds. However, no single pure standards exist so far and therefore their quantification in the environmental matrices is not accurate. Additionally, pure standards are needed to experimentally determine their physical chemical properties, as well as the ecotoxicological and toxicological characteristics. In the present work, the challenging goal of preparing a polychlorinated biphenyl monosulfonic acid was achieved exploring different synthetic approaches, along which the selection of the starting material resulted in a crucial point. Using PCB-153 (2,2′-4,4′-5,5′-hexachloro-1,1′-biphenyl) the synthesis afforded, as the major species, a side compound. On the contrary, the use of PCB-155 (2,2′-4,4′-6,6′-hexachloro-1,1′-biphenyl), a symmetric hexachlorobiphenyl derivative showing chlorine atoms at all the ortho positions, gave the target sulfonated-PCB compound. In this case, sulfonation was successfully carried out through a two-step procedure, involving chlorosulfonylation and the subsequent hydrolysis of the chlorosulfonyl intermediate.

State of the art of poecilid fish ( Pisces: Poeciliidae) in México

ABSTRACT&#x0D; Objective: To present a review about the knowledge of the fish of the family poecilidade in Mexico.&#x0D; Design/methodology/approach: The present review was carried out through the search and bibliographic compilation of literature, as well as in the consultation of articles in different databases, for its subsequent analysis.&#x0D; Results: Mexico has a great diversity of poeciliids with 105 species registered, 64 are endemic, most are in some category of protection, distributed throughout the national territory, mainly in the Usumacinta River basin. In this area, their reproductive biology and feeding have been studied, which vary according to the species. Their culture in Mexico, focuses on the commercialization of ornamental species both native and exotic.&#x0D; &#x0D; &#x0D; &#x0D; &#x0D; &#x0D; Limitations on study/implications: The poecilid fishes are a well study group; however, the information about the mexican species is scattered and in different areas are limited.&#x0D; Findings/conclusions: Mexico is the country with the greatest diversity of poecilid fish worldwide, most of which are in some category of protection, and are a group well distributed throughout the national territory, with potential as environmental indicators and toxicological studies.

ASSESSMENT OF LIVER FUNCTION MARKERS IN AMIETOPHRYNUS MACULATUS AND PTYCHADENA PUMILIO AS A BIOMONITORING TOOL OF HEAVY METALS POLLUTION IN SELECTED AREAS OF LAGOS STATE.

The sensitivity of African amphibians Amietophrynus maculatus and Ptychadena pumiliowere exploited in determining oxidative stress induced by heavy metals pollution in selected areas of Lagos state.Lead (Pb), cadmium (Cd), manganese (Mn), chromium (Cr), zinc (Zn) and Nickel (Ni) which is one of the factors that contribute to amphibian population decline.The mean levels of Total protein (TP), Aspartate Aminotransferases (AST) Alanine Aminotransferases (ALT) and Alkaline Phosphatase (ALP) induced in the liver of both sampled animalsin five selected locations in Lagos State (Ibafo, Iwaya, Makoko 1, Makoko 2 and Unilag) were assessed for their sensitivity to pollution as a biomomitoring tool in heavy metals polluted environment.Three healthy matured A.maculatus (79.00 ± 5.00g) and P. pumilio(62.00 ± 5.00g)were randomly collected from three points of eachselected locations.The resultsshowed thatthe highest mean values for TP, AST, ALT and ALP detected in the animals were 55.43 g/L, 71.67 U/L, 19.00U/L and 31.00 U/L respectively. AST detected in both animals sampled from all the selected locationswere the only consistent liver function markers.Additionally, Makoko 2 and Ibafolocations were the most polluted relative to the other selected sites as indicated in both amphibians sampled. Therefore, the role of these liver function test parameters in the sampled animals and their sensitivity could be a good battery of heavy metals pollution monitoring tools in assessing the environmental health as an early warning signalin environmental toxicology studies.

Human health risk assessment of cinnamate UV absorbers: In vitro and in silico investigations

Organic UV absorbers (UVAs) are contaminants of emerging concern. Environmental persistence and potential toxicological enrichment studies of UVAs have attracted international concern. It is important to study the toxicity mechanism of UVAs. This study is the first to report the toxicological mechanism of two cinnamate UV absorbers (CUVAs), 2-ethyl 4-methoxycinnamate (OMC) and isoamyl 4-methoxycinnamate (IMC) based on cellular models and molecular models. Cellular models demonstrated that the CUVAs-induced apoptosis might be associated with cellular mitochondrial damage pathways. The results of molecular models showed that OMC and IMC could affect the binding between major proteins and enzymes in the mitochondrial damage pathway and contaminants, ultimately leading to apoptosis. The cellular-molecular models showed that IMC and OMC have dose–effect relationships on cytotoxicity. The composite model is more informative than a single model. This study further indicate that UVAs causes toxicology effects that have implications for the environment and human health.

Evaluating Different Extraction Approaches for GC-MS Based Metabolomics Analysis of the Giant Pandas' Fur.

Giant pandas in zoo captivity are situated in residential areas, where environmental pollutants and anthropogenic factors have an impact on their health. Hair metabolomics has been applied in numerous environmental toxicological studies. Therefore, the panda fur metabolome could be a reliable approach to reflect endogenous and exogenous metabolic changes related to environmental exposure. However, there is no established extraction protocol to study the fur metabolome of pandas. The aim of this research was to optimize the extraction of panda fur metabolome for high-throughput metabolomics analysis using gas chromatography-mass spectrometry. Fur samples were collected from five pandas. Eight different extraction methods were investigated and evaluated for their reproducibility, metabolite coverage, and extraction efficiency, particularly in relation to the biochemical compound classes such as amino acids, tricarboxylic acid cycle derivatives, fatty acids, and secondary metabolites. Our results demonstrated that HCl + ACN were the superior extraction solvents for amino acid and secondary metabolite extraction, and NaOH + MeOH was ideal for fatty acid extraction. Interestingly, the metabolomic analysis of panda fur was capable of discriminating the longitudinal metabolite profile between black and white furs. These extraction protocols can be used in future study protocols for the analysis of the fur metabolome in pandas.

Variability of Microcystin-LR Standards Available from Seven Commercial Vendors.

Microcystins (MCs) are a large group of heptapeptide cyanobacterial toxins commonly produced in harmful algal blooms (HABs) and associated with adverse health effects in wildlife, livestock, pets, and humans. MC chemical standards are extracted from cyanobacteria biomass rather than produced synthetically and are used in water assessment methods and toxicological studies. MC standards are generally supplied in less than 1 mg quantities, and verification of the mass can only be accomplished by analytical chemistry methods using a certified reference of the specific MC for comparison. Analytical quantification of MCs in environmental samples and toxicology studies using accurate doses of test chemicals administered to experimental animals rely on the availability and accuracy of chemical standards. To check the accuracy and purity of available standards, seven individual microcystin-LR (MCLR) standards were purchased from separate commercial vendors and analyzed to determine the actual mass supplied and identify the presence of potential contaminants. To determine the effect of varying toxin mass in toxicological studies, each MCLR standard was administered to CD-1 mice in doses based on mass purchased, by a single 40 µg/kg intraperitoneal injection. The measured mass purchased varied from the vendor label mass by more than 35% for two of the seven MCLR standards. Contaminants, including trifluoroacetic acid (TFA), were identified in four of the seven samples. Comparative in vivo hepatotoxicity between vendor samples closely reflected the actual amount of MCLR present in each standard and demonstrated the toxicological impact of varying cyanotoxin mass.

A novel color-coded sensor array for visual recognition and traceability investigation of multiple antibiotics

To combat the serious environmental menace originating from over-consumption of antibiotics in human therapy and farming industry, studies have been devoted to developing diverse technologies for antibiotics monitoring. Herein, a novel color-coded array was constructed by Ln-MOF (Ln = Eu, Tb, and Gd) fluorescent carriers for qualitative and quantitative analyses of antibiotics based on a cross-responsive mechanism. The distinct morphology identification of 10 nitro-antibiotics was obtained after processing by linear discriminant analysis (LDA) and hierarchical cluster analysis (HCA), and concentration distributions were assessed within a range of 0–12 ppm (the detection limits all as low as ppb). Aid by the proposed array, the spiked antibiotics in lake water were successfully determined with a satisfactory recovery of 90.8%−110.8%. Notably, unknown speciation and concentration of multiple antibiotics in specific water samples can be determined, which further confirmed its admirable traceability. This research opens up a possibility to monitor environmental behavior and toxicology studies of antibiotics.

DEFENSE ANTIOXIDANTS AND LIPID PERIOXIDATION IN AMIETOPHRYNUS MACULATUS AND PTYCHADENA PUMILIO AS A POLLUTION BIO-MONITORING TOOL IN SELECTED AREAS OF LAGOS STATE

The sensitivity of African amphibians; Amietophrynus maculatus and Ptychadena pumilio were exploited in determining oxidative stress induced by heavy metals pollution; lead (Pb), cadmium (Cd), manganese (Mn), chromium (Cr), zinc (Zn) and nickel (Ni), which is one of the factors that may have contributed to amphibian population decline. The study investigated the overall mean concentration of the selected heavy metals in the heart, liver, kidney and activities of Superoxide dismutase (SOD), Catalase (CAT) and Glutathione (GSH) as well as the level of lipid peroxidation product; malondialdehyde (MDA), in the liver of the sampled animals in five selected locations in Lagos State (Ibafo, Iwaya, Makoko 1, Makoko 2 and Unilag). Three healthy and matured P. pumilio (62.00 ± 5.00g) and A.maculatus (79.00 ± 5.00g) were randomly collected from three points of each selected locations. The results showed that the overall mean concentration (mg/kg) of the selected heavy metals in descending order in A. maculates and P. pumilio were as follows: Heart (Zn &gt;Mn&gt;Pb/Ni &gt; Cr &gt; Cd; Zn &gt;Mn&gt;Pb&gt; Ni &gt; Cd &gt; Cr), Liver (Zn &gt;Mn&gt;Pb&gt; Cd &gt; Ni &gt; Cr; Zn &gt;Mn&gt;Pb&gt; Cd &gt; Cr &gt; Ni) and Kidney (Zn &gt;Mn&gt;Pb&gt; Cd &gt; Cr &gt; Ni; Zn &gt;Mn&gt;Pb&gt; Cd &gt; Cr &gt; Ni) respectively. In addition, the overall range of antioxidant activities (U/mg) in A. maculates and P. pumilio sampled in the various locations varied significantly (P &lt; 0.05) as follows; SOD (4.42-42.70; 5.14-30.62); CAT 10.84-17.82; 7.94-19.72); GSH (3.74-33.11; 4.42-12.17) and MDA (0.01-0.05;0.01-0.05) respectively. GSH was most depleted in both animals sampled from Ibafo. Therefore the sensitivity of the amphibians and the role of these biomarkers could be a good battery of monitoring tools in assessing the environmental health in environmental toxicology studies

Neuroendocrine pathways at risk? Simvastatin induces inter and transgenerational disruption in the keystone amphipod Gammarus locusta.

The primary focus of environmental toxicological studies is to address the direct effects of chemicals on exposed organisms (parental generation - F0), mostly overlooking effects on subsequent non-exposed generations (F1 and F2 - intergenerational and F3 transgenerational, respectively). Here, we addressed the effects of simvastatin (SIM), one of the most widely prescribed human pharmaceuticals for the primary treatment of hypercholesterolemia, using the keystone crustacean Gammarus locusta. We demonstrate that SIM, at environmentally relevant concentrations, has significant inter and transgenerational (F1 and F3) effects in key signaling pathways involved in crustaceans' neuroendocrine regulation (Ecdysteroids, Catecholamines, NO/cGMP/PKG, GABAergic and Cholinergic signaling pathways), concomitantly with changes in apical endpoints, such as depressed reproduction and growth. These findings are an essential step to improve hazard and risk assessment of biological active compounds, such as SIM, and highlight the importance of studying the transgenerational effects of environmental chemicals in animals' neuroendocrine regulation.

Multi-omics reveals the regulatory mechanisms of zinc exposure on the intestine-liver axis of golden pompano Trachinotus ovatus

Metal zinc (Zn) has been the focus of many environmental toxicological studies, but there are limited studies on its potential dietary molecular toxicity and physiology. The present study was the first to use multi-omics-based approaches to explore the fish intestine-liver axis under dietary Zn exposure. Golden pompano Trachinotus ovatus were exposed to different dietary concentrations (78.4, 134.6, and 161.4 mg/kg as the control, low-dose Zn, and high-dose Zn groups, respectively) of Zn for 4-week. Low-dose Zn exposure significantly promoted the fish growth, whereas the high-dose Zn exposure reduced the fish growth. Co-analysis of 16S diversity, metagenome and transcriptome showed that the low-dose Zn enriched the intestinal microflora and changed the dominant microflora abundances (Proteobacteria, Fusobacteria, Firmicutes and Bacteroidetes), as well as activated the growth hormone metabolism in the liver. Meanwhile, the high-dose of Zn caused the intestinal microbiota dysbiosis, activated the Type VI secretion systems (T6SSs), and further triggered the oxidative stress response, immunity, and antiviral function of the liver. Multi-omics revealed the interference of long-term Zn dietary exposure on the intestine-liver axis. There was an apparent homeostasis of Zn accumulation in the fish tissues, but the window of dietary Zn nutritional requirements versus toxicity appeared to be narrow for the golden pompano. These results provided new insight into the adverse effects and regulatory mechanisms of dietary Zn requirements and toxicity in marine fish.

Characterization of ATPases in the gill of freshwater mussel (Unio tigridis) and effects of ionic and nanoparticle forms of aluminium and copper

Mussels are often used to monitor the aquatic systems for different ecological aims, as they are one of the best bioindicator animals. However, the characterization of biomarkers should be known before using them in environmental monitoring and toxicology studies. There is no study to our knowledge on the characterization of Na-ATPase and Ca-ATPase in tissues of freshwater mussel (Unio tigridis). Thus, this study was undertaken to characterize the optimum working conditions of Na-ATPase and Ca-ATPase in the gill of mussels, determining the highest levels of parameters (Na+, Mg2+, Ca2+, ATP, pH, temperature, enzyme amount, incubation time) to obtain maximum activity. The present study also aimed to investigate in vitro effects of ionic and nanoparticle (Al2O3, CuO) forms of aluminium and copper (0, 30, 90, 270 μg/L) on the activities of Na-ATPase and Ca-ATPase. Data showed that there was no ouabain-sensitive ATPase activity in the gill up to 10 mM ouabain concentrations. Na-ATPase and Ca-ATPase activities in the gill of control mussels were 5.124 ± 0.373 and 3.750 ± 0.211 μmol Pi/mg pro./h, respectively. Exposure to different concentrations of nanoparticles did not alter significantly (P > 0.05) the activities of Na-ATPase and Ca-ATPase in vitro, whereas the same concentrations of ionic aluminium and copper significantly decreased (P < 0.05) the enzyme activities. Data emphasized that there were different modes of action between ionic and nanoparticle forms of aluminium and copper. Data also suggested that in vivo studies should also be carried out to estimate better the effects of nanoparticle and ionic forms of metals on ATPases of U. tigridis.

Effect of polystyrene microplastics and temperature on growth, intestinal histology and immune responses of brine shrimp Artemia franciscana

Microplastics pollution and seawater temperature rise have been the major environmental issues, threatening the survival and biodiversity of marine organisms. This study evaluated the combined effect of temperature and polystyrene microplastics (MP) on Artemia, a filter-feeding crustacean that is widely used for environmental toxicology studies. Brine shrimp Artemia franciscana were exposed to three MP concentrations (0, 0.2, and 2.0 mg/L) and three temperatures (22, 26, and 30 °C) for 14 d. In general, higher MP concentration and temperature led to a decreased survival rate and growth. Two-way ANOVA analysis indicated that the survival rate of Artemia was significantly impacted by both MP concentration and temperature (P 0.05). Growth of Artemia was significantly impacted by temperature (P<0.05), and with a significant interaction between two factors (P<0.05). Furthermore, the enzymatic activity, intestinal histological analyses, and immune gene expression were determined for Artemia reared at 30 °C with three MP concentrations (0, 0.2, and 2.0 mg/L). The results showed that 2.0 mg/L MP resulted in reduced Artemia intestinal microvilli and exfoliated epithelia cells, significantly increased acid phosphatase (ACP) activity (P<0.05) and immune-related gene ADRA1B and CREB3 expression, revealing that higher MP concentration could induce oxidative and immunological stress on Artemia at 30 °C. Overall, our study suggests that MP and temperature have combined adverse effect on Artemia, especially at relatively high temperature and polystyrene MP concentration. These findings are important to understand the potential ecological risks posed by these two factors on the organisms in marine environment.