Chronic exposure to environmental levels of cis-bifenthrin: Enantioselectivity and reproductive effects on zebrafish (Danio rerio)

Long-term exposure to aryl hydrocarbon receptor agonist neburon induces reproductive toxicity in male zebrafish (Danio rerio)

Neburon is a phenylurea herbicide that is widely used worldwide, but its toxicity is poorly studied. In our previous study, we found that neburon has strong aryl hydrocarbon receptor (AhR) agonist activity, but whether it causes reproductive toxicity is not clear. In the present study, zebrafish were conducted as a model organism to evaluate whether environmental concentrations of neburon (0.1, 1 and 10 µg/L) induce reproductive disorder in males. After exposure to neburon for 150 days from embryo to adult, that the average spawning egg number in high concentration group was 106.40, which was significantly lower than 193.00 in control group. This result was mainly due to the abnormal male reproductive behavior caused by abnormal transcription of genes associated with reproductive behavior in the brain, such as secretogranin-2a. The proportions of spermatozoa in the medium and high concentration groups were 82.40% and 83.84%, respectively, which were significantly lower than 89.45% in control group. This result was mainly caused by hormonal disturbances and an increased proportion of apoptotic cells. The hormonal disruption was due to the significant changes in the transcription levels of key genes in the hypothalamus-pituitary-gonadal axis following neburon treatment. Neburon treatment also significantly activated the AhR signaling pathway, causing oxidative stress damage and eventually leading to a significant increase in apoptosis in the exposed group. Together, these data filled the currently more vacant profile of neburon toxicity and might provide information to assess the ecotoxicity of neburon on male reproduction at environmentally relevant concentrations.

Immuno-antioxidative reno-modulatory effectiveness of Echinacea purpurea extract against bifenthrin-induced renal poisoning

This study was conducted to evaluate the ameliorative, anti-inflammatory, antioxidant, and chemical detoxifying activities of Echinacea purpurea ethanolic extract (EEE) against bifenthrin-induced renal injury. Adult male albino rats (160-200 g) were divided into four groups (10 rats each) and orally treated for 30 days as follows: (1) normal control; (2) healthy animals were treated with EEE (465 mg/kg/day) dissolved in water; (3) healthy animals were given bifenthrin (7 mg/kg/day) dissolved in olive oil; (4) animals were orally administered with EEE 1-h prior bifenthrin intoxication. The obtained results revealed that administration of the animals with bifenthrin caused significant elevations of serum values of urea, creatinine, ALAT and ASAT, as well as renal inflammatory (IL-1β, TNF-α & IFN-γ), apoptotic (Caspase-3) and oxidative stress (MDA and NO) markers coupled with a marked drop in the values of renal antioxidant markers (GSH, GPx, and SOD) in compare to those of normal control. Administration of EEE prior to bifenthrin resulted in a considerable amelioration of the mentioned deteriorated parameters near to that of control; moreover, the extract markedly improved the histological architecture of the kidney. In conclusion, Echinacea purpurea ethanolic extract has promising ameliorative, antioxidant, anti-inflammatory, renoprotective, and detoxifying efficiencies against bifenthrin-induced renal injury.

Bifenthrin Diminishes Male Fertility Potential by Inducing Protein Defects in Mouse Sperm

A synthetic pyrethroid pesticide, bifenthrin, has been commonly used as an effective exterminator, although the rise in its usage has raised concerns regarding its effects on the environment and public health, including reproduction, globally. The current study investigated the function-related molecular disparities and mechanisms in bifenthrin-exposed sperm cells and the underlying mechanism. Therefore, epididymal spermatozoa were released, and various concentrations of bifenthrin were treated (0.1, 1, 10, and 100 μM) to evaluate their effects on sperm. The findings showed that although bifenthrin had no effect on sperm viability, various other sperm functions (e.g., motility, spontaneous acrosome reaction, and capacitation) related to male fertility were decreased, commencing at a 1 µM treatment. Molecular studies revealed nine differentially expressed sperm proteins that were implicated in motile cilium assembly, sperm structure, and metabolic processes. Furthermore, bifenthrin affected sperm functions through abnormal diminution of the expression of specific sperm proteins. Collectively, these findings provide greater insights into how bifenthrin affects male fertility at the molecular level.

Integrated Studies on Male Reproductive Toxicity of Bis(2-ethylhexyl)-tetrabromophthalate: in Silico, in Vitro, ex Vivo, and in Vivo

Bis(2-ethylhexyl)tetrabromophthalate (TBPH) has been widely detected in the environment and organisms; thus, its toxic effects on male reproduction were systematically studied. First, we found that TBPH can stably bind to the androgen receptor (AR) based on in silico molecular docking results and observed an antagonistic activity, but not agonistic activity, on the AR signaling pathway using a constructed AR-GRIP1 yeast assay. Subsequently, we validated the adverse effects on male germ cells by observing inhibited androgen production and proliferation in Leydig cells upon in vitro exposure and affected general motility and motive tracks of zebrafish sperm upon ex vivo exposure. Finally, the in vivo reproductive toxicity was demonstrated in male zebrafish by reduced mating behavior in F0 generation when paired with unexposed females and abnormal development of their offspring. In addition, reduced sperm motility and impaired germ cells in male zebrafish were also observed, which may be related to the disturbed homeostasis of sex hormones. Notably, the specifically suppressed AR in the brain provides further evidence for the antagonistic effects as above-mentioned. These results confirmed that TBPH affected male reproduction through a classical nuclear receptor-mediated pathway, which would be helpful for assessing the ecological and health risks of TBPH.

A review on aquatic toxins - Do we really know it all regarding the environmental risk posed by phytoplankton neurotoxins?

Aquatic toxins are potent natural toxins produced by certain cyanobacteria and marine algae species during harmful cyanobacterial and algal blooms (CyanoHABs and HABs, respectively). These harmful bloom events and the toxins produced during these events are a human and environmental health concern worldwide, with occurrence, frequency and severity of CyanoHABs and HABs being predicted to keep increasing due to ongoing climate change scenarios. These contexts, as well as human health consequences of some toxins produced during bloom events have been thoroughly reviewed before. Conversely, the wider picture that includes the non-human biota in the assessment of noxious effects of toxins is much less covered in the literature and barely covered by review works. Despite direct human exposure to aquatic toxins and related deleterious effects being responsible for the majority of the public attention to the blooms' problematic, it constitutes a very limited fraction of the real environmental risk posed by these toxins. The disruption of ecological and trophic interactions caused by these toxins in the aquatic biota building on deleterious effects they may induce in different species is paramount as a modulator of the overall magnitude of the environmental risk potentially involved, thus necessarily constraining the quality and efficiency of the management strategies that should be placed. In this way, this review aims at updating and consolidating current knowledge regarding the adverse effects of aquatic toxins, attempting to going beyond their main toxicity pathways in human and related models' health, i.e., also focusing on ecologically relevant model organisms. For conciseness and considering the severity in terms of documented human health risks as a reference, we restricted the detailed revision work to neurotoxic cyanotoxins and marine toxins. This comprehensive revision of the systemic effects of aquatic neurotoxins provides a broad overview of the exposure and the hazard that these compounds pose to human and environmental health. Regulatory approaches they are given worldwide, as well as (eco)toxicity data available were hence thoroughly reviewed. Critical research gaps were identified particularly regarding (i) the toxic effects other than those typical of the recognized disease/disorder each toxin causes following acute exposure in humans and also in other biota; and (ii) alternative detection tools capable of being early-warning signals for aquatic toxins occurrence and therefore provide better human and environmental safety insurance. Future directions on aquatic toxins research are discussed in face of the existent knowledge, with particular emphasis on the much-needed development and implementation of effective alternative (eco)toxicological biomarkers for these toxins. The wide-spanning approach followed herein will hopefully stimulate future research more broadly addressing the environmental hazardous potential of aquatic toxins.

Zebrafish as model organisms for toxicological evaluations in the field of food science

Food safety has long been an area of concern. The selection of stable and efficient model organisms is particularly important for food toxicology studies. Zebrafish (Danio rerio) are small model vertebrates, and 70% of human genes have at least one zebrafish ortholog. Zebrafish have advantages as model organisms due to their short life cycle, strong reproductive ability, easy rearing, and low cost. Zebrafish embryos have the advantage of being sensitive to the breeding environment and thus have been used as biosensors. Zebrafish and their embryos have been widely used for food toxicology assessments. This review provides a systematic and comprehensive summary of food toxicology studies using zebrafish as model organisms. First, we briefly introduce the multidimensional mechanisms and structure-activity relationship studies of food toxicological assessment. Second, we categorize these studies according to eight types of hazards in foods, including mycotoxins, pesticides, antibiotics, heavy metals, endocrine disruptors, food additives, nanoparticles, and other food-related ingredients. Finally, we list the applications of zebrafish in food toxicology studies in line with future research prospects, aiming to provide a valuable reference for researchers in the field of food science.

Bifenthrin disrupts cytochrome c oxidase activity and reduces mitochondrial DNA copy number through oxidative damage in pool barb (Puntius sophore)

Bifenthrin (BF), a synthetic pyrethroid is used worldwide for both agricultural and non-agricultural purposes due to its high insecticidal activity and low toxicity in mammals. However, its improper usage implies a possible risk to aquatic life. The Study was aimed to correlate the association of BF toxicity with mitochondrial DNA copy number variation in edible fish Punitus sophore. The 96-h LC 50 of BF in P. sophore was 3.4 μg/L, fish was treated with sub-lethal doses (0.34 μg/L,0.68 μg/L) of BF for 15 days. The activity and expression level of cytochrome c oxidase (Mt-COI) were measured to assess mitochondrial dysfunction caused by BF. Results showed BF reduced the level of Mt-COI mRNA in treated groups, hindered complex IV activity and increased ROS generation leading to oxidative damage. mtDNAcn was decreased in the muscle, brain and liver after BF treatment. Furthermore, BF induced neurotoxicity in brain and muscle cells through the inhibition of AchE activity. The treated groups showed elevated level of malondialdehyde (MDA) and an imbalance of antioxidant enzymes activity. Molecular docking and simulation analysis also predicted that BF binds to the active sites of the enzyme and restricts the fluctuation of active sites' residues. Hence, outcome of the study suggests reduction of mtDNAcn could be a potential biomarker to assess Bifenthrin induced toxicity in aquatic ecosystem.

Prolonged exposure of azocyclotin induced inter- and transgenerational endocrine disruption on Danio rerio linked to transcriptomic and DNA methylomic alterations

The transgenerational effect assessment linked to epigenetic analysis of environmental pollutants on eco (toxico)logical relevant species is regarded as a potential future risk-assessment tool. As an organotin acaricide widely used in China, azocyclotin can lead to endocrine disrupting effect on directly exposed environmental organisms, but whether it has transgenerational negative impact remains unknown. In order to illustrate this issue, in the present study, zebrafish, an aquatic model animal, was exposed to azocyclotin at less than μg/L level in a time span of embryonic stage to adult stage. Subsequently, the developmental and reproductive endocrine disrupting effects of azocyclotin on exposed F0 and unexposed offspring (F1 and F2) were evaluated. Result indicated that parentally exposed to 0.36 μg/L azocyclotin induced embryonic toxicity to unexposed offspring, and significantly (p < 0.05) reduced body weight (by 8.5%-13.9%), whole body length (by 4.8%-14.3%), hepatosomatic index (by 15.6%-24.3%), gonadosomatic index (by 5.3%-17.1%), egg production (by 19.5%-25.4%), estradiol content (47.0%-65.0%) and proportion of mature germ cells (by 29.3%-41.0% and 39.2%-47.7% for late oocytes and spermatozoa, respectively) in adults of F0 and offspring. Additionally, azocyclotin decreased the contents of 5-methycytosine in gonads of unexposed offspring (by 9.9%-38.6%, p < 0.05), led to genome-wide gene up-regulated expression bias and genomic DNA hypomethylation tendency in unexposed offspring. Moreover, based on the level of differentially methylated cytosine in promoter regions/gene body regions, it was found totally 5331/11,170 (in F1) and 3808/7507 (in F2) differentially expressed genes were closely related with differentially methylated genes (r > 0.6). The present study provided a primary evidence that prolonged exposure to low dose azocyclotin induced inter- and transgenerational endocrine disrupting effects on zebrafish probably linked to transcriptomic and DNA methylomic alterations.

Deep Eutectic Solvents for Extraction and Preconcentration of Organic and Inorganic Species in Water and Food Samples: A Review

Deep eutectic solvents (DESs) have been developed as green solvents and these are capable as alternatives to conventional solvents used for the extraction of organic and inorganic species from food and water samples. The continuous generation of contaminated waste and increasing concern for the human health and environment have compelled the scientific community to investigate more ecological schemes. In this concern, the use of DESs have developed in one of the chief approach in the field of chemistry. These solvents have appeared as a capable substitute to conventional hazardous solvents and ionic liquids. The DESs has distinctive properties, easy preparation and components availability. It is not only used in scienctific fields but also used in quotidian life. There are many advantages of DESs in analytical chemistry, they are largely used for extraction and determination of inorganic and organic compounds from different samples. In previous a few years, several advanced researches have been focused on the separation and preconcentration of low level of pollutants using DESs as the extractants. This review summarizes the use of DESs in the separation and preconcentration of organic and inorganic species from water and food samples using various microextraction processes.

Gut microbiota dysbiosis involves in host non-alcoholic fatty liver disease upon pyrethroid pesticide exposure

A growing body of evidence has demonstrated the significance of the gut microbiota in host health, while the association between gut microbiota dysbiosis and multiple diseases is yet elusive in the scenario of exposure to widely used pesticides. Here, we show that gut microbiota dysbiosis involves in host's abnormal lipid metabolism and consequently the non-alcoholic fatty liver disease in Xenopus laevis upon exposure to cis-bifenthrin, one of the most prevalent pyrethroid insecticides in the world. With the guidance of gut microbiota analysis, we found that cis-bifenthrin exposure significantly perturbed the gut microbial community, and the specific taxa that served as biomarkers were identified. Metabolomics profiling and association analysis further showed that a significant change of intestinal metabolites involved in lipid metabolic pathways were induced along with the microbiota dysbiosis upon exposure to cis-bifenthrin. Detailed investigation showed an altered functional regulation of lipids in the liver after cis-bifenthrin exposure and the accumulation of lipid droplets in hepatocytes. Specifically, a change in deoxycholic acid alters bile acid hepatoenteral circulation, which affects lipid metabolism in the liver and ultimately causes the development of fatty liver disease. Collectively, these findings provide novel insight into the gut microbiota dysbiosis upon pesticide exposure and their potential implication in the development of chronic host diseases related to liver metabolic syndrome.

Lipid Metabolic Disorder Induced by Pyrethroids in Nonalcoholic Fatty Liver Disease of Xenopus laevis

Pyrethroids, an effective and widely used class of pesticides, have attracted considerable concerns considering their frequent detection in environmental matrices. However, their potential health risks to amphibians remain unclear. In our study, female Xenopus laevis were exposed to 0, 0.06, and 0.3 μg/L typical pyrethroid, cis-bifenthrin (cis-BF), for 3 months. Elevated activities of both aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were observed, indicating an ongoing liver injury. Furthermore, exposure to cis-BF led to hyperlipidemia and lipid accumulation in the liver of Xenopus. The targeted lipidomic analysis further revealed that treatment with cis-BF perturbed liver steroid homeostasis, as evidenced by the enriched lipids in the steroid biosynthesis pathway. Consistent with the targeted lipidomic result, treatment with cis-BF changed the liver transcriptome profile with induction of 808 and 1230 differentially expressed genes. Kyoto Encyclopedia of Genes and Genomes analysis underlined the adverse effects of cis-BF exposure on steroid biosynthesis, primary bile acid biosynthesis, and the PPAR signaling pathway in the Xenopus liver. Taken together, our study revealed that exposure to cis-BF at environmentally relevant concentrations resulted in lipid metabolic disorder associated with nonalcoholic fatty liver disease of X. laevis, and our results provided new insight into the potential long-term hazards of pyrethroids.

Pyrethroid bioaccumulation in wild fish linked to geographic distribution and feeding habit

The accumulation of pyrethroid insecticides in aquatic food webs has attracted increased research attention. Fish are key species in aquatic food webs, directly connecting invertebrates and human consumption. However, little is known about the bioaccumulation of pyrethroids in wild fish species. In this study, 19 species of wild fish were collected from 11 sites in the Pearl River, China, and the levels of seven pyrethroids in the fish were determined. Linear mixed-effects models were applied to estimate the means of pyrethroid concentrations, in which sample site and fish species were set as random effects. The concentrations of Σ₇ pyrethroids in fish ranged from 4.99 to 50.82 ng/g. Permethrin and bifenthrin were present at the highest concentration (8.89 ± 1.47 ng/g) and frequency (100%) in fish muscle, respectively. The composition patterns of pyrethroids varied in fish organs. Fish species contributed a higher proportion of the variance than geographic distribution (28.6% vs. 26.4%). The pyrethroids in carnivorous fish (23.5 ± 2.9 ng/g) were significantly higher than in omnivorous (14.6 ± 1.9 ng/g) and phytophagous fish (16.0 ± 4.7 ng/g). To our knowledge, this is the first report examining the effect of feeding habits on pyrethroid bioaccumulation in wild fish. The results can provide evidence for the risk of pyrethroid pollution in aquatic ecosystems.

Multi-walled carbon nanotubes impact on the enantioselective bioaccumulation and toxicity of the chiral insecticide bifenthrin to zebrafish (Danio rerio)

The effects of different multi-walled carbon nanotubes on the enantioselective bioaccumulation and toxicity of the chiral pesticide bifenthrin to zebrafish were investigated in this work. The results showed that MWCNTs and MWCNTs-COOH did not affect the preferential bioaccumulation of 1R-cis-BF in zebrafish following exposure to cis-BF enantiomers for 28 days, but which increased cis-BF accumulation amount by 1.03-1.48 times. Further research demonstrated that the genes related to immunity, endocrine activity and neurotoxicity showed enantioselective expression in different zebrafish tissues, and sex-specific differences were observed. The levels of c-fos, th, syn2a, 17β-hsd and cc-chem were expressed as 1.09-2.84 times higher in females and males treated with 1R-cis-BF than in the 1S-cis-BF-treated groups. However, in the presence of MWCNTs or MWCNTs-COOH, c-fos, th, syn2a, 17β-hsd and cc-chem levels were expressed as 1.53-14.92 times higher in females and males treated with 1S-cis-BF than in 1R-cis-BF-treated groups, which indicated that enantioselective expression was altered. The effects of different types of MWCNTs on the enantioselective bioaccumulation and toxicity of BF in zebrafish have little difference. In summary, the presence of MWCNTs or MWCNTs-COOH increased the impact of BF on zebrafish. Therefore, the risks posed by coexisting nanomaterials and chiral pesticides in aquatic environments should be considered.

Reproductive toxicity due to herbicide exposure in freshwater organisms

Excessively used pesticides in agricultural areas are spilled into aquatic environments, wherein they are suspended or sedimented. Owing to climate change, herbicides are the fastest growing sector of the pesticide industry and are detected in surface water, groundwater, and sediments near agricultural areas. In freshwater, organisms, including mussels, snails, frogs, and fish, are exposed to various types and concentrations of herbicides. Invertebrates are sensitive to herbicide exposure because their defense systems are incomplete. At the top of the food chain in freshwater ecosystems, fish show high bioaccumulation of herbicides. Herbicide exposure causes reproductive toxicity and population declines in freshwater organisms and further contamination of fish used for consumption poses a risk to human health. In addition, it is important to understand how environmental factors are physiologically processed and assess their impacts on reproductive parameters, such as gonadosomatic index and steroid hormone levels. Zebrafish is a good model for examining the effects of herbicides such as atrazine and glyphosate on embryonic development in freshwater fish. This review describes the occurrence and role of herbicides in freshwater environments and their potential implications for the reproduction and embryonic development of freshwater organisms.

Effects of penconazole enantiomers exposure on hormonal disruption in zebrafish Danio rerio (Hamilton, 1822)

PEN is a widely used triazole fungicide, usually used to control grape white rot. In the process of agricultural use, PEN will be scattered to the soil and water environment, which brings certain environmental safety risks. In this study, we used a 200-μg/L solution of Rac-PEN, (+)-PEN, and (-)-PEN to perform a 28-day exposure test on zebrafish. The results showed that long-term low-dose PEN exposure did not significantly change the growth factor K and the number of spawning of zebrafish. However, the content of four important hormones vitellogenin, 17β-estradiol, testosterone, and 11-ketotestosterone in zebrafish has changed significantly. Furthermore, we measured the expression of hypothalamus-pituitary-gonads-liver (HPGL) axis-related genes, and the results showed that the expressions of related genes in the brain, gonads, and liver all changed significantly. Combining the above results, we can conclude that PEN has obvious endocrine disrupting effect on zebrafish, and has gender-specific endocrine effects. Meanwhile, Rac-PEN and (+)-PEN had stronger effects on the endocrine system of zebrafish than (-)-PEN.

Stage Dependent Enantioselective Metabolism of Bifenthrin in Embryos of Zebrafish (Danio rerio) and Japanese Medaka (Oryzias latipes)

Bifenthrin (BF) is a widely used pyrethroid that has been frequently detected in surface waters. Previous studies indicated that BF had antiestrogenic activity in zebrafish embryos but estrogenic activity in posthatch fish. To determine whether age-related differences in metabolism contribute to the endocrine effects in developing fish, embryos from zebrafish and Japanese medaka were exposed to BF before and after liver development. Since the commercial mixture of BF is an isomer-enriched product containing two enantiomers (1R-cis-BF and 1S-cis-BF), enantioselective metabolism was also evaluated. The estrogenic metabolite, 4-hydroxybifenthrin (4-OH-BF) was identified in zebrafish embryos, and formation was higher in animals after liver development (>48 hpf). Treatments with β-glucuronidase indicated that 4-OH-BF underwent conjugation in embryos. Formation was reduced by cotreatment of the cytochrome P450 (CYP450) inhibitor, ketoconazole. Formation of 4-OH-BF was greater when treated with 1R-cis-BF compared to the S-enantiomer. However, metabolites were not observed in medaka embryos. These data indicate enantioselective oxidation of BF to an estrogenic metabolite occurs in zebrafish embryos and, since it is increased after liver development, may partially explain estrogenic activity observed in older animals. The lack of activity in medaka suggests species-specific effects with BF metabolism and may influence risk assessment strategies in wildlife.

New Trend in the Extraction of Pesticides from the Environmental and Food Samples Applying Microextraction Based Green Chemistry Scenario: A Review

This review focused on the green microextraction methods used for the extraction of pesticides from the environmental and food samples. Microextraction techniques have been explored and applied in various fields of analytical chemistry since its beginning, as evinced by the numerous reviews published. The success of any technique in science and technology is measured by the simplicity, environmentally friendly, and its applications; and the microextraction technique is highly successive. Deliberations were attentive to studies where efforts have been made to validate the methods through the inter-laboratory comparison study to assess the analytical performance of microextraction techniques against conventional methods. Succinctly, developed microextraction methods are shown to impart significant benefits over conventional techniques. Provided that the analytical community continues to put forward attention and resources into the growth and validation of the microextraction technique, a promising future for microextraction is forecasted.

Neurobehavioral, physiological and inflammatory impairments in response to bifenthrin intoxication in Oreochromis niloticus fish: Role of dietary supplementation with Petroselinum crispum essential oil

This study was conceptualized in order to assess the 96-h LC₅₀ of bifenthrin (BF) in O. niloticus and also to measure the biochemical, behavioral, and molecular responses of the fish suchronically exposed to a sub-lethal concentration of the insecticide. The role of Petroselinum crispum essential oil (PEO) supplementation in mitigating the resulted neurotoxic insult was also investigated. The acute toxicity study revealed that the 96-h LC₅₀ of BF is 6.81 μg/L, and varying degrees of behavioral changes were recorded in a dose-dependent manner. The subchronic study revealed reduction of dissolved oxygen and increased ammonia in aquaria of BF-exposed fish. Clinical signs revealed high degree of discomfort and aggressiveness together with reductions in survival rate and body weight gain. The levels of monoamines in brain, and GABA and amino acids in serum were reduced, together with decreased activities of Na⁺/K⁺-ATPase and acetylcholine esterases (AchE). The activities of antioxidant enzymes were also diminshed in the brain while oxdative damage and DNA breaks were elevated. Myeloperoxidase (MPO) activity in serum increased with overexpression of the pro-inflammatory cytokines in the brain tissue. BF also upregulated the expression of brain-stress related genes HSP70, Caspase-3 and P53. Supplemention of PEO to BF markedly abrogated the toxic impacts of the insecticide, specially at the high level. These findings demonstrate neuroprotective, antioxidant, genoprotective, anti-inflammatory and antiapoptic effects of PEO in BF-intoxicated fish. Based on these mechanistic insights of PEO, we recommend its use as an invaluable supplement in the fish feed.

Developmental toxicity and neurotoxicity of penconazole enantiomers exposure on zebrafish (Danio rerio)

Penconazole is a widely used chiral triazole bactericide that may adversely affect the environment. It contains two corresponding enantiomers and there may be differences in toxicity between the isomers. Therefore, in this study, we exposed zebrafish embryos to different concentrations of the penconazole enantiomer to study the developmental toxicity and neurotoxicity of penconazole on zebrafish and the difference in toxicity between enantiomers. The results showed that penconazole exposure caused adverse effects on zebrafish embryos, such as autonomous motor abnormalities, heart rate slowing, and increased deformity, resulting in significant developmental toxicity. Meanwhile, also caused the zebrafish larvae to slow movement, the neurotransmitter content and nervous system related gene expression significantly changed, which proved that penconazole also caused neurotoxicity to zebrafish. Interestingly, our results also clearly show that (+)-penconazole is significantly more toxic to zebrafish than (-)-penconazole at the same concentration, whether it is developmental toxicity or neurotoxicity, which suggests that we should focus on (+)-penconazole more when conducting toxicological studies on penconazole.

Bifenthrin impairs the functions of Leydig and Sertoli cells in mice via mitochondrion-endoplasmic reticulum dysregulation

Bifenthrin (BF) is a synthetic insecticide that is widely used in fields, resulting in an increase in its exposure to animals. However, reports on the toxic effects of BF on mammalian species and the underlying mechanism are still lacking. Here, we elucidated the mechanism underlying the toxic effects of BF on mouse reproduction using cell lines of immature mouse Leydig (TM3) and Sertoli (TM4) cells, which are constituent cells of testes. Our results show that BF suppressed the proliferation and viability of TM3 and TM4 cells. Additionally, treatment with BF induced cell cycle arrest, apoptotic cell death, and DNA fragmentation. Mitochondrial dysfunction and disruption of calcium homeostasis were observed in BF-treated TM3 and TM4 cells. Further, bifenthrin modulated unfolded protein response and mitochondrion-associated membrane and mitogen-activated protein kinase (MAPK)/phosphoinositide 3-kinase (PI3K) signaling pathways. The expression of the mRNAs related to cell cycle progression, steroidogenesis, and spermatogenesis was downregulated by BF, suggestive of testicular toxicity. Taken together, these results demonstrate the intracellular mechanism of action of BF to involve antiproliferative and apoptotic effects and testicular dysfunction in mouse testis.

Deep eutectic solvent-based dispersive liquid-liquid micro-extraction of pesticides in food samples

Deep eutectic solvents are versatile, green and new generation solvents that can be used during dispersive liquid-liquid micro-extraction techniques for pesticides. They have tunable physico-chemical properties that can be easily changed by varying the ratios of hydrogen bond donors and hydrogen bond acceptors in their structures. Deep eutectic solvents are non-flammable, chemically and thermally stable solvents with low vapour pressure. Thus, they have characteristics that are similar to those of ionic liquids. However, they have simpler synthetic procedures, less expensive and are more biodegradable than ionic liquids. One of the limitations of deep eutectic solvents is their toxicity to the environment but they are less toxic than ionic liquids. This paper gives a focused and comprehensive recent review on the applications of deep eutectic solvents during dispersive liquid-liquid micro-extraction of pesticides in food samples for the period starting from 2016 to 2020. Emphasis was placed on the modifications done to the deep eutectic solvent-based dispersive liquid-liquid micro-extraction techniques in order to enhance their greenness during pesticide pre-concentration in food samples. In addition, hyphenated dispersive liquid-liquid micro-extraction techniques were also reviewed and lastly, the paper outlined the challenges associated with the use of DESs during the DLLME techniques.

Metal oxide nanoparticles facilitate the accumulation of bifenthrin in earthworms by causing damage to body cavity

In this study, we explored the influence of two metal oxide nanoparticles, nano CuO and nano ZnO (10, 50, 250 mg/kg), on accumulation of bifenthrin (100 μg/kg) in earthworms (Eisenia fetida) and its mechanism. The concentrations of bifenthrin in earthworms from binary exposure groups (bifenthrin + CuO and bifenthrin + ZnO) reached up to 23.2 and 28.9 μg/g, which were 2.65 and 3.32 times of that in bifenthrin exposure group without nanoparticles, respectively, indicating that nanoparticles facilitated the uptake of bifenthrin in earthworms. The contents of biomarkers (ROS, SOD, and MDA) in earthworms indicated that nanoparticles and bifenthrin caused damage to earthworms. Ex vivo test was utilized to investigate the toxic effects of the pollutants to cell membrane of earthworm coelomocytes and mechanism of increased bifenthrin accumulation. In ex vivo test, cell viability in binary exposure groups declined up to 30% and 21% compared to the control group after 24 h incubation, suggesting that coelomocyte membrane was injured by the pollutants. We conclude that nanoparticles damage the body cavity of earthworms, and thus lead to more accumulation of bifenthrin in earthworms. Our findings provide insights into the interactive accumulation and toxicity of nanoparticles and pesticides to soil organisms.