Developmental toxicity and angiogenic defects of etoxazole exposed zebrafish (Danio rerio) larvae

Alleviatory efficacy of achillea millefolium L. in etoxazole-mediated toxicity in allium cepa L

The application of pesticides may adversely impact a variety of non-target organisms. The use of side-effect-free herbal remedies to protect against the toxicity of harmful pesticides such as etoxazole has gained attention in recent times. The current study aimed to reveal the potential mitigating efficacy of Achillea millefolium L. extract against etoxazole toxicity in Allium cepa L. A. cepa bulbs in the control group were applied with tap water, while bulbs in the treatment groups were applied with etoxazole at dose of 0.5 m/L and two different doses of A. millefolium extract (200 mg/L and 400 mg/L). The impact of the treatments on certain parameters was evaluated. The molecular docking analysis was employed to investigate the potential interactions of etoxazole with DNA species, DNA topoisomerases, tubulin proteins, glutamate-1-semialdehyde aminotransferase, and protochlorophyllide reductase. The phenolic profile of A. millefolium was assessed. Etoxazole exposure reduced rooting percentage, root length, weight gain, mitotic index, and levels of chlorophyll a and chlorophyll b. Conversely, etoxazole treatment led to an increase in chromosomal aberrations and micronuclei occurrence. The most frequently observed chromosomal aberrations induced by etoxazole, which serve as bioindicators of genotoxicity, were fragment, vagrant chromosome, sticky chromosome, unequal chromatin distribution, bridge, reverse polarization, and vacuolated nucleus. The levels of malondialdehyde and antioxidant enzyme (superoxide dismutase and catalase) activities were also elevated. Epidermis cell damage, flattened cell nucleus, thickened cortex cell wall, and thickened conduction tissue were the meristematic cell disorders triggered by etoxazole. Molecular docking studies showed that etoxazole can interact directly with DNA, tubulins, and the enzymes mentioned above. A. millefolium extract was found to contain a substantial quantity of phenolic compounds. A. millefolium extract, when co-administered with etoxazole, attenuated all toxic effects of etoxazole dose-dependently. In conclusion, A. millefolium may potentially serve as a reliable pharmacological shield against the toxicity of pesticides in non-target organisms.

Bifenox induces hepatotoxicity and vascular toxicity in zebrafish embryos via ROS production and alterations in signaling pathways

Existing evidence shows that currently used pesticides pose toxicological risks to exposed wildlife. Chemically, bifenox belongs to diphenyl ethers, a well-known group of herbicides. Its mechanism of action primarily involves inducing lipid peroxidation and blocking protoporphyrinogen oxidases. Toxicity of diphenyl ether herbicides has been elucidated in animal cells; however, in vivo toxicological evaluations of bifenox are required to determine its unexpected effects. This study aimed to determine the negative effects of bifenox, and its effects on higher eukaryotes. We found that early stages of zebrafish embryo exposed to bifenox demonstrated increased mortality and physiological defects, based on the LC50 value. Bifenox severely inhibited blood vessel growth by reducing key elements of complex connectivity; fluorescently tagged transgenic lines (fli1a:EGFP) showed morphological changes. Additionally, transgenic lines that selectively identified hepatocytes (fabp10a:DsRed) showed reduced fluorescence, indicating that bifenox may inhibit liver development. To evaluate the level of oxidative stress, we used 2',7'-dichlorofluorescein diacetate (DCFH-DA) probes in zebrafish embryos to identify the underlying mechanisms causing developmental damage. Our findings demonstrate that exposure to bifenox causes abnormalities in the hepatic and cardiovascular systems during zebrafish embryogenesis. Therefore, this study provides new information for the evaluation of toxicological risks of bifenox in vertebrates.

Toxic effects of the insecticide tolfenpyrad on zebrafish embryos: Cardiac toxicity and mitochondrial damage

Tolfenpyrad, a highly effective and broad-spectrum insecticide and acaricide extensively utilized in agriculture, presents a potential hazard to nontarget organisms. This study was designed to explore the toxic mechanisms of tolfenpyrad on zebrafish embryos. Between 24 and 96 h after exposure of the fertilized embryos to tolfenpyrad at concentrations ranging from 0.001 to 0.016 mg/L (96 h-LC50 = 0.017 mg/L), lethal effects were apparent, accompanied with notable anomalies including pericardial edema, increased pericardial area, diminished heart rate, and an elongated distance between the venous sinus and the arterial bulb. Tolfenpyrad elicited noteworthy alterations in the expression of genes pertinent to cardiac development and apoptosis, with the most pronounced changes observed in the cardiac development-related genes of bone morphogenetic protein 2b (bmp2b) and p53 upregulated modulator of apoptosis (puma). The findings underscore that tolfenpyrad induces severe cardiac toxicity and mitochondrial damage in zebrafish embryos. This data is imperative for a comprehensive assessment of tolfenpyrad risks to aquatic ecosystems, particularly considering the limited knowledge regarding its detrimental impact on aquatic vertebrates.

6-benzylaminopurine causes endothelial dysfunctions to human umbilical vein endothelial cells and exacerbates atorvastatin-induced cerebral hemorrhage in zebrafish

6-benzylaminopurine (6-BA), a multifunctional plant growth regulator, which is frequently used worldwide to improve qualities of various crops, is an important ingredient in production of "toxic bean sprouts." Although there is no direct evidence of adverse effects, its hazardous effects, as well as joint toxicity with other chemicals, have received particular attention and aroused furious debate between proponents and environmental regulators. By use of human umbilical vein endothelial cells (HUVECs), adverse effects of 6-BA to human-derived cells were first demonstrated in this study. A total of 25-50 mg 6-BA/L inhibited proliferation, migration, and formation of tubular-like structures by 50% in vitro. Results of Western blot analyses revealed that exposure to 6-BA differentially modulated the MAPK signal transduction pathway in HUVECs. Specifically, 6-BA decreased phosphorylation of MEK and ERK, but increased phosphorylation of JNK and P38. In addition, 6-BA exacerbated atorvastatin-induced cerebral hemorrhage via increasing hemorrhagic occurrence by 60% and areas by 4 times in zebrafish larvae. In summary, 6-BA elicited toxicity to the endothelial system of HUVECs and zebrafish. This was due, at least in part, to discoordination of MAPK signaling pathway, which should pose potential risks to the cerebral vascular system.

Assessment of toxicity potential of neglected Mithi River water from Mumbai megacity, India, in zebrafish using embryotoxicity, teratogenicity, and genotoxicity biomarkers

The Mithi River begins at Vihar Lake and flows through the industrial hub of the city of Mumbai, India, and merges with the Arabian Sea at Mahim Creek. The current study was carried out to assess the ecotoxicological effects of the Mithi River surface water in zebrafish (Danio rerio) embryos. Water samples were collected from ten sampling sites (S1 to S10) located along the course of the Mithi River. The toxicity of water samples was assessed using a zebrafish embryo toxicity test (ZFET). Water samples were diluted from all sites at 1:0, 1:2, 1:4, 1:8, 1:16, 1:32, 1:64, and 1:128 times. The lowest and highest LDil 20 values for 96 h were estimated as 9.16 and 74.18 respectively for the S2 and S5 sites. The results of embryotoxicity and teratogenicity assays indicated a significant difference (p < 0.0001) between embryos exposed to control and sampling sites (except S1) for various endpoints such as mortality, egg coagulation, pericardial edema, yolk sac edema, tail bend, and skeletal deformities. The histopathological analysis revealed various lesions, ascertaining the toxic effects of water samples. The comet assay revealed significantly higher DNA damage (except S1) in embryos exposed to sites S5 and S6 with OTM values of 4.46 and 2.48 respectively. The results indicated that the Mithi River is polluted with maximum pollution load at the middle stretches. The study further indicated that the pollutants in the Mithi River (except S1) could potentially be hazardous to the aquatic organisms; therefore, continuous biomonitoring of the river is needed for its revival.

Exposure to the herbicide fluridone induces cardiovascular toxicity in early developmental stages of zebrafish

Fluridone is a systemic herbicide used to control a range of invasive aquatic plants in irrigation systems, lake, and reservoirs. Since aquatic herbicides are more likely to have a hazardous impact on ecosystems than terrestrially applied herbicides, a risk assessment is needed to determine whether to expand or limit their use. The aim of this study was to investigate the developmental toxicity of fluridone using zebrafish. Diverse toxicological results were observed for the sub-lethal endpoints, including lack of hatching, reduced heartbeat and disturbed blood circulation through dysmorphic heart, and edema formation. Abnormal apoptosis was observed in the brain and yolk sac of fluridone-exposed larvae. A computational analysis was used to predict chemical properties in non-target organisms and revealed that fluridone was highly relevant in the cardiovascular system. Double transgenic zebrafish (fli1a:EGFP;cmlc2:dsRed) were used to evaluate the effects of fluridone on the cardiovascular system during embryonic development. Ectopic growth of sub-intestinal vessels and sprouting angiogenesis in the hindbrain region were highly inhibited. Additionally, essential genes involved in the VEGF signaling and heart development were differentially expressed in dose-dependent manner. Collectively, our toxicological findings in fluridone exposure highlight defects in the cardiovascular development causing embryonic lethality that could damage aquatic communities and natural ecosystems.

Quantitative assessment of selective degradation behavior of etoxazole in different classes of organisms by compound-specific isotope analysis

In this paper, the stereoselective degradation and quantitative identification of chiral pesticide etoxazole in organisms with different classes of organisms (soil, chlorella algal fluid and mice) were carried out by compound-specific isotope analysis (CSIA). The degradation behavior and stable isotope fractionation effect of etoxazole in soil, chlorella and mice were investigated. The R-etoxazole degraded faster than S-etoxazole in different classes of organisms. The metabolites M1, M2 and M3 were detected in all three substrates. Biodegradation is the main factor for the change of stable isotope ratio of chiral pesticide etoxazole. Furthermore, the relationship between fractionation value of carbon isotope and residual concentration of etoxazole is established by Rayleigh equation, and the biodegradation rate of etoxazole could be calculated by using CSIA without measuring the concentration of etoxazole. Therefore, the use of CSIA can accurately assess the degradation behavior of pesticide pollution in the environment and provide a certain scientific evidence and technical support in the process of environmental remediation.

Triadimenol promotes the production of reactive oxygen species and apoptosis with cardiotoxicity and developmental abnormalities in zebrafish

Various types of fungicides, especially triazole fungicides, are used to prevent fungal diseases on farmlands. However, the developmental toxicity of one of the triazole fungicides, triadimenol, remains unclear. Therefore, we used the zebrafish animal model, a representative toxicological model, to investigate it. Triadimenol induced morphological alterations in the eyes and body length along with yolk sac and heart edema. It also stimulated the production of reactive oxygen species and expression of inflammation-related genes and caused apoptosis in the anterior regions of zebrafish, especially in the heart. The phosphorylation levels of Akt, ERK, JNK, and p38 proteins involved in the PI3K and MAPK pathways, which are important for the development process, were also reduced by triadimenol. These changes led to malformation of the heart and vascular structures, as observed in the flk1:eGFP transgenic zebrafish models and a reduction in the heart rate. In addition, the expression of genes associated with cardiac and vascular development was also reduced. Therefore, we elucidated the mechanisms associated with triadimenol toxicity that leads to various abnormalities and developmental toxicity in zebrafish.

Ethalfluralin induces developmental toxicity in zebrafish via oxidative stress and inflammation

Ethalfluralin, of dinitroaniline herbicide family, is an effective weed controller. Following residue detection in herbicide-treated fields, ethalfluralin was reported to interfere with early stages of implantation in some vertebrate species. However, the role of ethalfluralin in the development of zebrafish embryos has not been elucidated yet. Therefore, in the present study, we investigated the morphological and physiological changes that occur in the embryonic development of zebrafish due to ethalfluralin exposure. Results indicated that ethalfluralin decreased survival rate along with reduction in the hatching ratio and heartbeat. It was observed to cause edema in the heart and yolk sac, and apoptosis in the anterior region of the developing zebrafish larvae; as visualized through acridine orange and TUNEL staining. In addition, ethalfluralin increased the expression of the apoptosis-associated genes including tp53, cyc1, casp8, casp9, and casp3. The Seahorse Mito Stress analysis revealed that ethalfluralin slightly reduced mitochondrial respiration in live zebrafish embryos. Reactive oxygen species (ROS) production was also observed to be elevated in zebrafish larvae in response to ethalfluralin. Treatment with ethalfluralin decreased blood vessel formation in brain and intestine in flk1 transgenic zebrafish embryos. The decrease in angiogenesis related gene expression was specifically observed in vegfc, flt1, and kdrl, and in the intestinal vasculature related genes apoa4a, aqp3, fabp2, and vil1. Moreover, an increase in inflammatory genes such as cox2a, cox2b, cxcl-c1c, il8, mcl1a, mcl1b, and nf-κb was observed using real-time PCR analysis. Collectively, these results indicate that oxidative stress generated by exposure to ethalfluralin induced ROS generation, apoptosis, inflammation and anti-angiogenic effects, and therefore, ethalfluralin may be toxic to the development of zebrafish embryos.

Risk assessment of oxidative stress and multiple toxicity induced by Etoxazole

Etoxazole is among the systemic pesticides with acaricidal and insecticidal characteristics. This paper reports the first evaluation of the toxic effects of Etoxazole on Allium cepa L. Etoxazole solutions were applied to three groups formed from A. cepa bulbs at 0.125 mL/L, 0.25 mL/L and 0.5 mL/L doses, respectively. The control group was treated with tap water throughout the experimental period. The toxic effects of Etoxazole became more apparent as the dose of Etoxazole was increased. The growth-limiting effect was most pronounced in the highest dose group with approximately 29%, 70% and 58.5% reductions in germination percentage, root elongation and weight gain, respectively. The genotoxic effect of Etoxazole was most severe in the 0.5 mL/L dose group. In this group, the mitotic index decreased by 30% compared to the control group, while the micronucleus frequency increased to 45.3 ± 3.74. The most observed aberrations were fragment, vagrant chromosome, sticky chromosome, unequal distribution of chromatin, bridge, reverse polarization and nucleus with vacuoles. The malondialdehyde level showed a gradual increase with increasing Etoxazole doses and reached 2.7 times that of the control group in the 0.5 mL/L Etoxazole applied group. Catalase and Superoxide dismutase activities increased in the groups exposed to 0.125 mL/L and 0.25 mL/L Etoxazole with dose dependence and decreased abruptly in the group treated with 0.5 mL/L Etoxazole. Etoxazole triggered meristematic cell damages, such as epidermis cell damage, thickening of cortex cell walls, flattened cell nucleus and indistinct transmission tissue. Considering the versatile toxicity induced by Etoxazole, we announce that this chemical has the potential to cause serious damage to non-target organisms. It should be noted that the higher the dose of exposure, the more severe the level of damage. This study will be an important reminder to limit the indiscriminate use of this highly risky agrochemical.

Spiromesifen conferred abnormal development in zebrafish embryos by inducing embryonic cytotoxicity via causing oxidative stress

Spiromesifen (SPF) is widely used in agriculture to protect against herbivorous mites, whose residues may be harmful to the environment. However, the toxicity assessment of SPF is insufficient. Here, we investigated the toxicological effects of SPF using zebrafish embryos as an animal model. The results showed that SPF exposure solutions at 10, 20, 30, and 40 μM caused cytotoxicity in zebrafish embryos such as reactive oxygen species (ROS) accumulation, mitochondrial membrane potential decrease, cell division arrest, and apoptosis, which further led to developmental toxicity in zebrafish embryos including delayed hatching, decreased survival rate and spontaneous curling rate, and severe morphological deformities. SPF also induced apoptosis via changes in the expressions of apoptosis-related marker genes, caused immunotoxicity by reducing the number of macrophages and the activity of AKP/ALP and increasing inflammatory factors, and disturbed endogenous antioxidant systems via changes SOD, CAT, and GST activities as well as MDA and GSH contents. Therefore, the potential mechanism that caused embryonic developmental toxicity appeared to be related to the generation of oxidative stress by an elevation in ROS and changes in apoptosis-, immune-, antioxidant-related markers. The antioxidant system and inflammatory response simultaneously participated in and resisted the threat of SPF to prevent tissue damage. Taken together, spiromesifen induced oxidative stress to contribute to developmental toxicity in zebrafish embryos by inducing embryonic cytotoxicity. Our study provides new insight into the toxicity assessment of SPF to non-target organisms.

What can we learn from commercial insecticides? Efficacy, toxicity, environmental impacts, and future developments

Worldwide pesticide usage was estimated in up to 3.5 million tons in 2020. The number of approved products varies among different countries, however, in Brazil, there are nearly 5000 of such products available. Among them, insecticides correspond to a group of mounting importance for controlling crop pests and disease-associated vectors in public health. Unfortunately, resistance to commercially approved insecticides is commonly observed, limiting the use of these products. Thus, the search for more effective and environmentally friendly products is both a challenge and a necessity since several insecticides are no longer allowed in many countries. In this review, we discuss the historical strategies used in the development of modern insecticides, including chemical structure alterations, mechanism of action and their impact on insecticidal activity. The environmental impact of each pesticide class is also discussed, with persistence data and activity on non-target organisms, along with the human toxicological effect. By tracing the historical route of discovery and development of blockbuster pesticides like DDT, pyrethroids and organophosphates, we also aim to categorize and relate the successful chemical alterations and novel pesticide development strategies that resulted in safer alternatives. A brief discussion on the Brazilian registration procedure and a perspective of insecticides currently approved in the country was also included.

A systematic comparison of the developmental vascular toxicity of bisphenol A and its alternatives in vivo and in vitro

Due to the potential toxicity of bisphenol A (BPA), several bisphenols (BPs), including bisphenol F (BPF), bisphenol S (BPS) and bisphenol AF (BPAF), have been gradually used as its main substitutes, and the levels of these alternatives in different environmental media have been constantly increasing. Although some previous studies have shown that bisphenol substitutes have similar or greater acute toxicity and estrogenic effects than BPA, comparative studies on the cardiovascular toxicity of BPs have not been evaluated. In this study, the developmental vascular toxicity of BPA and three predominant substitutes (BPF, BPS and BPAF) were evaluated using zebrafish embryos and human vascular endothelial cells (HUVECs). BP exposure at a sublethal concentration of 1/10 96 h median lethal concentration (96 h-LC₅₀) significantly hindered intersegmental vessel (ISV) growth, delayed common cardinal vein (CCV) remodeling and decreased subintestinal vessels (SIVs) in Tg (fli1:EGFP) zebrafish embryos. Meanwhile, the results of the endothelial tube formation assay showed that in vitro angiogenesis was inhibited by BP exposure. Mechanistically, BP exposure increased oxidative stress characterized by a significant decrease in superoxide dismutase (SOD) and catalase (CAT) activity, accompanied by increased levels of malondialdehyde (MDA) and reactive oxygen species (ROS) in both zebrafish and HUVECs. Therefore, the vascular toxicity and oxidative stress potency of the BPs were compared and evaluated, ranking as follows: BPAF > BPF > BPA > BPS. To the best of our knowledge, the present work, for the first time, systematically provides direct evidence for BPA and its alternatives on developmental vascular toxicity in vitro and in vivo. Therefore, these findings will provide insight into the rational and safe application of BPA substitutes.

In vitro antibacterial and anti-inflammatory effects of Anacardium occidentale L. extracts and their toxicity on PBMCs and zebrafish embryos

This study evaluated the in vitro antimicrobial and immunomodulatory action of crude extracts from Anacardium occidentale L. (cashew tree) leaves and bark, and to determine their toxicity to peripheral-blood mononuclear cells (PBMCs) and to zebrafish embryos and larvae. Chemical analysis of extracts was performed by proton nuclear magnetic resonance (¹H-NMR). The antibacterial activity was evaluated against selected bacteria strains by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Cytotoxicity of the extracts was assessed using resazurin method, while the effect on production of ROS by PMN leukocytes was measured by luminol. Embryotoxicity to zebrafish was assessed using the fish embryo acute toxicity test (FET) and quantification of toxicity marker enzymes (AChE, LDH, and GST). ¹H-NMR results showed anacardic acid as the main component of the extracts. All bacterial species tested were sensitive to the extracts, with MICs ranging from 312.5 to 10,000 μg/mL. Streptococcus mutans and Escherichia coli were the most susceptible species. The extracts promoted cell viability above 75% at concentrations from 1.25 to 80 μg/mL. Both extracts reduced zymosan-induced ROS (p < 0.05) at concentrations of 1, 8, and 80 μg/mL compared to the control. In vivo, there were embryotoxic effects in zebrafish embryos exposed to both extracts through the presence of lethal and sublethal endpoints. The samples also acted by inhibiting the activities of biomarker enzymes. The A. occidentale L. bark and leaf extracts showed antimicrobial potential and modulated ROS production in vitro, but these also showed embryotoxic effects to zebrafish.

Inhibition of hyaluronan secretion by novel coumarin compounds and chitin synthesis inhibitors

Elevated plasma levels of hyaluronic acid (HA) is a disease marker in liver pathology and other inflammatory disorders. Inhibition of HA synthesis with coumarin 4-methylumbelliferone (4MU) has a beneficial effect in animal models of fibrosis, inflammation, cancer and metabolic syndrome. 4MU is an active compound of approved choleretic drug hymecromone with low bioavailability and a broad spectrum of action. New, more specific and efficient inhibitors of hyaluronan synthases (HAS) are required. We have tested several newly synthesized coumarin compounds and commercial chitin synthesis inhibitors to inhibit HA production in cell culture assay. Coumarin derivative compound VII (10'-methyl-6'-phenyl-3'H-spiro[piperidine-4,2'-pyrano[3,2-g]chromene]-4',8'-dione) demonstrated inhibition of HA secretion by NIH3T3 cells with the half-maximal inhibitory concentration (IC50) = 1.69 ± 0.75 μΜ superior to 4MU (IC50 = 8.68 ± 1.6 μΜ). Inhibitors of chitin synthesis, etoxazole, buprofezin, triflumuron, reduced HA deposition with IC50 of 4.21 ± 3.82 μΜ, 1.24 ± 0.87 μΜ and 1.48 ± 1.44 μΜ, respectively. Etoxazole reduced HA production and prevented collagen fibre formation in the CCl4 liver fibrosis model in mice similar to 4MU. Bioinformatics analysis revealed homology between chitin synthases and HAS enzymes, particularly in the pore-forming domain, containing the proposed site for etoxazole binding.

Fluroxypyr-1-methylheptyl ester interferes with the normal embryogenesis of zebrafish by inducing apoptosis, inflammation, and neurovascular toxicity

Fluroxypyr-1-methylheptyl ester (FPMH) is a synthetic auxin herbicide used to regulate the growth of post-emergence broad-leaved weeds. Although acute exposure to FPMH increases the mortality of several fish species in the juvenile stage, the developmental toxicity of FPMH in aquatic vertebrates has not yet been investigated. In the present study, we assessed the developmental toxicity of FPMH using zebrafish models that offer many advantages for studying toxicology. During embryogenesis, survival rates gradually decreased with increasing FPMH concentrations and exposure times. At 120 h post-fertilization, FPMH-exposed zebrafish larvae showed various abnormalities such as small eye size, heart defects, enlarged yolk sac, and shortened body length. The study results confirmed the induction of apoptosis in the anterior body of zebrafish and upregulation of inflammatory gene expression. Further, defects in vascular networks, especially the loss of central arteries and abnormal aortic arch structures, were seen in the fli1:eGFP transgenic zebrafish model. Neurotoxicity of FPMH was examined using mbp:eGFP zebrafish and which displayed compromised myelination following FPMH administration. Our study has demonstrated the mechanisms underlying FPMH toxicity in developing zebrafish that is a representative model of vertebrates.

DNA Damage and Expression Profile of Genes Associated with Nephrotoxicity Induced by Butralin and Ameliorating Effect of Arabic Gum in Female Rats

Nephrotoxicity induced by exposure to environmental pollution, including herbicides, is becoming a global problem. Natural products are the prime alternative scientific research as they express better medicinal activity and minor side effects compared with a variety of synthetic drugs. This study was performed to evaluate the nephroprotective proficiency of Arabic gum against butralin-induced nephrotoxicity. Adult female rats were supplemented with Arabic gum (4.3 g/kg b.wt) and/or butralin (312 mg/L) in drinking water for 30 days. The results found that markers of serum kidney function, oxidative stress biomarkers, DNA damage, and expression of kidney specific genes (Acsm2, Ace, and Ace2) as well as histopathological examination in treated rats were conducted. Butralin-treated rats showed a rise in serum creatinine (41%), BUN (47.3%), and MDA (140.9%) as well as decrease in activity of the antioxidant markers (CAT (-21%); GPx (-70.7%); and TAC (43.2%)) in comparison with the control group. In addition, butralin treatment increased the DNA damage (221%); altered the expression levels of Acsm2, Ace, and Ace2 (-51.6%, 141.6%, and 143% respectively); and elevated histopathological lesions in the kidney tissues. Pretreatment of Arabic gum prevented butralin-prompted degenerative changes of kidney tissues. The results suggested that the protective effect provided by Arabic gum on renal tissues exposed to the herbicide butralin could be attributed to enhancement of antioxidants and increase the free radical scavenging activity in vivo.

Determination of etoxazole in different parts of citrus fruit and its potential dietary exposure risk assessment

In this study, the profile of etoxazole in whole citrus, peel and pulp samples collected from Chongqing, Guangdong and Anhui provinces was monitored and their dietary risk to human had also been assessed. The final residual levels and distributions of etoxazole in citrus samples were detected by using an ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). The results showed that final concentrations of etoxazole in whole citrus, peel, and pulp were ranged at 0.012-0.174, 0.010-0.637, and 0.010-0.011 mg kg^-1, respectively. The assessment of dietary risk suggested that chronic dietary risk of etoxazole in whole fruit and peel were 0.010-0.197% and 0.035-0.951%, respectively. Our findings indicated that the chronic risk of daily consumption of citrus fruit is acceptable at recommended dosage.

Forchlorfenuron (CPPU) causes disorganization of the cytoskeleton and dysfunction of human umbilical vein endothelial cells, and abnormal vascular development in zebrafish embryos

Forchlorfenuron (CPPU) has been used worldwide, to boost size and improve quality of various agricultural products. CPPU and its metabolites are persistent and have been detected frequently in fruits, water, sediments, and organisms in aquatic systems. Although the public became aware of CPPU through the exploding watermelon scandal of 2011 in Zhenjiang, China, little was known of its potential effects on the environment and wildlife. In this study, adverse effects of CPPU on developmental angiogenesis and vasculature, which is vulnerable to insults of persistent toxicants, were studied in vivo in zebrafish embryos (Danio rerio). Exposure to 10 mg CPPU/L impaired survival and hatching, while development was hindered by exposure to 2.5 mg CPPU/L. Developing vascular structure, including common cardinal veins (CCVs), intersegmental vessels (ISVs) and sub-intestinal vessels (SIVs), were significantly restrained by exposure to CPPU, in a dose-dependent manner. Also, CPPU caused disorganization of the cytoskeleton. In human umbilical vein endothelial cells (HUVECs), CPPU inhibited proliferation, migration and formation of tubular-like structures in vitro. Results of Western blot analyses revealed that exposure to CPPU increased phosphorylation of FLT-1, but inhibited phosphorylation of FAK and its downstream MAPK pathway in HUVECs. In summary, CPPU elicited developmental toxicity to the developing endothelial system of zebrafish and HUVECs. This was do, at least in part due to inhibition of the FAK/MAPK signaling pathway rather than direct interaction with the VEGF receptor (VEGFR).

Zebrafish as a Successful Animal Model for Screening Toxicity of Medicinal Plants

The zebrafish (Danio rerio) is used as an embryonic and larval model to perform in vitro experiments and developmental toxicity studies. Zebrafish may be used to determine the toxicity of samples in early screening assays, often in a high-throughput manner. The zebrafish embryotoxicity model is at the leading edge of toxicology research due to the short time required for analyses, transparency of embryos, short life cycle, high fertility, and genetic data similarity. Zebrafish toxicity studies range from assessing the toxicity of bioactive compounds or crude extracts from plants to determining the optimal process. Most of the studied extracts were polar, such as ethanol, methanol, and aqueous solutions, which were used to detect the toxicity and bioactivity. This review examines the latest research using zebrafish as a study model and highlights its power as a tool for detecting toxicity of medicinal plants and its effectiveness at enhancing the understanding of new drug generation. The goal of this review was to develop a link to ethnopharmacological zebrafish studies that can be used by other researchers to conduct future research.

Embryotoxicity of methylparaben to zebrafish (Danio rerio) early-life stages

Methylparaben (MeP) is widely used as preservative in personal care products, food commodities and pharmaceuticals due to its antimicrobial properties. Its widespread use resulted in the contamination of aquatic environment and raised concerns about the potential adverse effects on human health, especially in the developing organisms. The aim of the present study was to evaluate the embryotoxicity of MeP in zebrafish early-life stages applying the benchmark-dose (BMD) methodology to Fish embryo acute toxicity (FET) tests-OECD guideline 236. Toxic effects were studied by daily evaluation of lethal endpoints, hatching rate and sublethal alterations. Zebrafish fertilized eggs were exposed until 96 h post fertilization (hpf) to five concentrations of MeP: 1 mg/L, 10 mg/L, 30 mg/L, 60 mg/L and 80 mg/L. The lethal concentration 50 (LC 50) was 72.67 mg/L. Indeed, BMD confidence interval (lower bound, BMDL-upper bound, BMDU) was 40.8-57.4 mg/L for lethal endpoints and 16-26.5 mg/L for toxicity index, that includes both lethal and sublethal alterations. Zebrafish embryos exposed to MeP developed sublethal alterations including pericardial edema, yolk edema, blood stasis, reduction in blood circulation, reduced heartbeat and notochord curvature. The number of embryos exposed to the highest concentrations of MeP that reported sublethal alterations increased between 24hpf and 48 hpf-72 hpf-96 hpf. Only zebrafish larvae treated with 30 mg/L of MeP showed behavioural changes. This study highlighted the detrimental effects of MeP on zebrafish early-life stages with attention to its developmental toxicity.

In vivo hepatotoxicity screening of different extracts, components, and constituents of Polygoni Multiflori Thunb. in zebrafish (Danio rerio) larvae

Polygonum multiflorum Thunb. (PM) is a traditional Chinese medicine, commonly used to treat a variety of diseases. However, the hepatotoxicity associated with PM hampers its clinical application and development. In this study, we refined the zebrafish hepatotoxicity model with regard to the following endpoints: liver size, liver gray value, and the area of yolk sac. The levels of alanine aminotransferase, aspartate transaminase, albumin, and microRNAs-122 were evaluated to verify the model. Subsequently, this model was used to screen different extracts, components, and constituents of PM, including 70 % EtOH extracts of PM, four fractions from macroporous resin (components A, B, C, and D), and 19 compounds from component D. We found that emodin, chrysophanol, emodin-8-O-β-D-glucopyranoside, (cis)-emodin-emodin dianthrones, and (trans)-emodin-emodin dianthrones showed higher hepatotoxicity compared to other components in PM, whereas polyphenols showed lower hepatotoxicity. To the best of our knowledge, this study is the first to identify that dianthrones may account for the hepatotoxicity of PM. We believe that these findings will be helpful in regulating the hepatotoxicity of PM.

Treatment of agrochemical wastewater by subcritical water oxidation method: chemical composition and ion analysis of treated and untreated samples

This work aimed at offering an effective and environmentally friendly approach to the real wastewater of an industrial agrochemicals production plant containing high amounts of many hazardous compounds that threaten human health. The removal of total organic carbon (TOC) (59.45%) and colour (97.92%) of the wastewater was achieved using subcritical water oxidation method. The fate of the detected compounds was followed by GC-MS analysis. Several pollutants such as phenol, fumaric acid, chlorpyrifos, penconazole, brassilexin, buprofezin, etoxazole, pyriproxyfen and 2-naphthalene-sulphonic acid which are bio-refractory and harmful to human health, were effectively degraded. Inorganic ions exist in the wastewater or formed through the process and their possible effects on the applied method were analysed. The central composite design was used to optimise the method and fully evaluate the single or combined effects of the method parameters on the removal rates. The precision of the applied design models was evaluated employing ANOVA, Regression coefficients and validation analysis. F and P and R² values were obtained as 107.43, <0.0001, and 0.9898, respectively in the TOC removal model and 39.45, <0.0001, and 0.9726 in the colour removal model.[Formula: see text].

Methiothepin Suppresses Human Ovarian Cancer Cell Growth by Repressing Mitochondrion-Mediated Metabolism and Inhibiting Angiogenesis In Vivo

Ovarian cancer is the fifth leading cause of cancer-related deaths in women. Despite treatment, most patients experience relapse and the 5-year survival rate of ovarian cancer is less than 50%. Serotonin has cell growth-promoting functions in a variety of carcinomas, but the effect of serotonin receptor antagonists on ovarian cancer cells is unknown. In this study, it was confirmed that methiothepin, a serotonin receptor antagonist, suppresses the viability of, and induces apoptosis in, ovarian cancer cells. Methiothepin also induces mitochondrial dysfunction, represented by depolarization of the mitochondrial membrane and increased mitochondrion-specific Ca²⁺ levels, and causes metabolic disruption in cancer cells such as decreased ATP production and oxidative phosphorylation. Methiothepin also interferes with vascular development in transgenic zebrafish embryos. Combination treatment with methiothepin improves the anti-cancer effect of paclitaxel, a standard chemotherapeutic agent. In conclusion, this study revealed that methiothepin is a potential novel therapeutic agent for ovarian cancer treatment.