Developmental Toxicity Research Articles

The effect of tris (1,3-dichloro-2-propyl) phosphate on the early embryonic heart development of Oryzias melastigma

The flame retardant tri (1, 3-dichloro-2-propyl) phosphate (TDCIPP) is widely present in environmental media and organisms. People have paid much attention to the growth and developmental toxicity of TDCIPP, but there is little information about its cardiotoxicity and potential mechanisms. In this study, marine medaka (Oryzias melastigma) embryos were exposed to TDCIPP solutions (0, 0.05, 0.5, 5, and 50 μg/L) for 21 days to investigate the adverse effects of TDCIPP on cardiac development. The results showed that TDCIPP exposure altered the heart rate at different stages of embryonic development. In addition, 50 μg/L TDCIPP resulted in increased sinus venosus (SV)–bulbus arteriosus (BA) distance, pericardial cysts, and cardiac linearization in newly hatched fish. During embryonic development, the expression level of key genes regulating cardiac development is disturbed. The early stage of cardiac development is the sensitive window period for the toxic effects of TDCIPP. Oxidative stress was observed in newly hatched juveniles, but no significant lipid peroxidation damage was observed. In addition, vitellogenin (VTG) levels in juvenile fish were significantly reduced. Our results show that TDCIPP exposure induces cardiotoxicity in marine medaka embryos, which is induced in the early stages and promotes heart defects by amplifying inflammatory responses at a later stage.

Development of a TBXT-EGFP iPS Cell Model for Screening the Early Developmental Toxicity of Typical Environmental Pollutants

In our daily lives, we are inevitably exposed to a variety of environmental pollutants in numerous ways. Fortunately, recent years have witnessed significant advancements in the field of stem cell toxicology, which have provided new opportunities for research in environmental toxicology. Applying stem cell technology to environmental toxicology, overcomes some of the limitations of traditional screening methods and we can more accurately predict the toxicity of environmental pollutants. However, there are still several aspects of stem cell toxicology models that require improvement, such as increasing the throughput of detection and simplifying detection methods. Consequently, we developed an environmental pollutant toxicity detection model based on TBXT-EGFP iPS cells and screened the developmental toxicity of 38 typical environmental pollutants. Our results indicate that TBBPA-BDBPE, TBBPA-BHEE, DG, and AO2246 may interfere with the expression of TBXT, a critical marker gene for early human embryo development, implying that these environmental pollutants could lead to developmental abnormalities.

Propanil impairs organ development in zebrafish by inducing apoptosis and inhibiting mitochondrial respiration

Propanil, an anilide herbicide, has frequently been detected in surface waters in Europe and the United States, largely due to its use in paddy cultivation areas. Particularly in specific regions like Sri Lanka, propanil is considered a potential cause of certain diseases and toxicities due to its high environmental runoff; however, there has been little research on its developmental toxicity. In the present study, we confirmed the developmental toxicity of propanil in zebrafish embryos exposed to 0, 2, 5, and 6 mg/L based on the LC50 value. Propanil exposure in embryos induced morphological changes, including decreased body length and eye size, and increased the heart and yolk sac edema. It increased the number of apoptotic cells in the brains and eyes of zebrafish larvae by 214 % and 184 %, respectively. Propanil-treated embryos exhibited altered mitochondrial metabolism, reducing basal respiration by 28 %, maximal respiration by 24 %, and ATP production by 38 %. These alterations induced organ defects in transgenic zebrafish models (cmlc2:DsRed, flk1:EGFP, olig2:DsRed, lfabp:DsRed;elastase:EGFP, and insulin:EGFP). It induced cardiovascular toxicity, as confirmed by the reduced atrial area, cerebrovascular intensity, and intersegmental vessels. Additionally, propanil decreased the fluorescence intensity of neurons, liver, and pancreas. Collectively, this study indicates that propanil causes early developmental toxicity through apoptosis and mitochondrial dysfunction. It presents a new perspective on how mitochondrial dysfunction, previously unreported in toxicity studies of other anilide herbicides, may affect developmental toxicity.

Fine particulate matter‑induced cardiac developmental toxicity (Review)

Fine particulate matter‑induced cardiac developmental toxicity (Review)

Hepatotoxicity of N-nitrosodin-propylamine in larval zebrafish by upregulating the Wnt pathway

N-nitrosodin-propylamine is an organic compound mainly used in organic synthesis. As a typical pollutant, the accidental release of N-nitrosodin-propylamine may cause environmental pollution, especially water environment pollution. In the present study, we used the zebrafish model for the first time to evaluate the developmental toxicity of this drug in the liver. Zebrafish larvae fertilized at 72hpf showed a range of toxic responses after 72hpf exposure to the drug. These include increased mortality, delayed absorption of yolk sac nutrients, shorter body length, abnormal liver morphology, gene disruption, and altered expression of various indicators with increasing dose. Studies on the mechanism of toxicity showed that N-nitrosodin-propylamine exposure increased the level of oxidative stress, increased the level of apoptosis in hepatocytes, and up-regulated the transcriptional expression level of Wnt signaling pathway genes. Astaxanthin and IWR-1 can effectively save the liver toxicity in zebrafish caused by N-nitrosodin-propylamine. Our study showed that the drug exposure induced hepatotoxicity in zebrafish larvae through the up-regulation of Wnt signaling pathway, oxidative stress and apoptosis.

Neurotoxicity Assessment of Amicarbazone Using Larval Zebrafish

Amicarbazone (AMZ), a triazolinone herbicide widely applied in agriculture, is known to inhibit photosystem II in target plants, disrupting photosynthesis and causing oxidative stress that leads to weed mortality. Despite its widespread use, the developmental and neurotoxic effects of AMZ on aquatic organisms remain underexplored. This study assesses the impact of AMZ exposure on zebrafish (Danio rerio) embryos/larvae, focusing on developmental toxicity and neurotoxicity. Zebrafish were exposed to AMZ at various concentrations to evaluate survival, malformations, heart rate, and behavior. Significant developmental defects, including reduced survival rates, increased malformations, and decreased heart rates, were observed in zebrafish embryos exposed to AMZ, particularly at higher concentrations. Additionally, behavioral assays revealed decreased locomotor activity, particularly at concentrations of 100 and 200 mg/L. Moreover, AMZ exposure disrupted motor axon formation, oligodendrocyte development, and the expression of key genes involved in neurodevelopment. The downregulation of cholinergic, dopaminergic, and serotonergic signaling pathways was also identified, indicating neurotoxicity. These findings highlight AMZ’s potential to induce both developmental and neurotoxic effects in zebrafish and suggest the need for further research on its long-term ecological impacts.

In Silico, In Vitro, and In Vivo Studies Indicate the Endocrine-Disrupting Effects of Cyproconazole Stereoisomers.

The widespread use of chiral triazole fungicide cyproconazole (CPZ) in agricultural fields has led to frequent detection of CPZ in the environment. The restriction of CPZ in the EU raised wide concerns regarding its potential endocrine-disrupting effects (EDEs). The present study was conducted to evaluate EDEs of CPZ stereoisomers in vitro, in silico, and in vivo. The reporter gene assay indicated that all CPZ stereoisomers were agonists to the human estrogenic receptor α. (2S,3S)-(+)- and (2R,3S)-(-)-CPZ exhibited stronger binding capacities to ERα compared with (2R,3R)-(-)- and (2S,3R)-(+)-CPZ. Our computational studies showed consistent results with reporter gene assay, elucidating the stereoselective binding mode of CPZ to estrogen receptor. In zebrafish embryos, the 96h-lethality of CPZ stereoisomers ordered (2R,3R)-(-)- > (2R,3S)-(-)- > (2S,3S)-(+)- > Rac- > (2S,3R)-(+)-CPZ. Stereoselective developmental toxicity of CPZ was observed while (2R,3S)-(-)-CPZ is the most toxic isomer. The estrogenic hormones were significantly decreased in (2S,3R)-(+)- and (2R,3S)-(-)-CPZ groups and enhanced in (2S,3S)-(+)- and (2R,3R)-(-)-CPZ, along with the gene expression in hypothalamic-pituitary-gonad axis altered. CPZ shows no thyroid hormone activity. These data clarified that CPZ is a new-found endocrine disruptor threatening human health and each stereoisomer of CPZ showed stereoselective EDEs by regulating the nuclear receptor-mediated gene expression.

Comparison of triclosan and triclocarban in triggering immunotoxicity in larval zebrafish

As two efficient broad-spectrum sterilizing agents, triclosan (TCS) and triclocarban (TCC) are widely used, especially during the COVID-19 pandemic. The health risks caused by secondary pollution of TCS and TCC have aroused wide concern. Because of the similar mother nucleus structure and high lipophilicity, it remains unknown about the differences in the effect and mechanism of the toxicity (especially immunotoxicity) between TCS and TCC in organisms in the environment. In this study, we used zebrafish as a model to compare the immunotoxicity and mechanisms between the two pollutants at the same exposure concentration (0.6 µmol/L). The results showed that both TCS and TCC led to a hatching rate below 60% at the time point of 72 hours post fertilization (hpf) and the mortality rates of 40% and 50% at 120 hpf in larval zebrafish, respectively. The zebrafish exposed to TCS and TCC displayed malformations, such as shortened body, swimming sac closure, pericardial edema, yolk cyst deposition, and absorption disorder. Moreover, the developmental abnormalities caused by TCC were significantly severer than those caused by TCS. TCS exposure increased the proliferation rate of innate immune cells to 20% and decreased the number of mature T cells by 35%, while TCC exposure inhibited the differentiation of both innate immune cells and T cells, with the inhibition rates of 25% and 60%, respectively. The results of real-time quantitative PCR (RT-qPCR) and ELISA showed that TCS and TCC exposure up-regulated the expression levels of il-1β, il-6, and tnf-α, while il-10 and IgM exhibited opposite expression patterns. Additionally, both compounds slightly decreased C3 expression. The Pearson correlation analysis showed that the developmental toxicity induced by TCS and TCC had positive and negative correlations with the differentiation of immune cells, respectively. However, the toxicity induced by either TCS or TCC was positively correlated with the expression of pro-inflammatory cytokines. GO function and KEGG pathway enrichment analyses demonstrated that the target molecules of TCS and TCC were enriched in different signaling pathways, and the key network hub genes and the enriched regulatory pathways differed between TCS and TCC. The findings provide compelling evidence that TCS and TCC adopt different mechanisms in triggering immunotoxicity and offer a theoretical reference for the recognition, warning, and management of TCS and TCC-induced health risks.

Synthesis and characterization of two asymmetrical 2-cyclohexylsulfenyl-5-alkylsulfenyl[1,3,4]thiadiazoles and study the impact of substituents on the structural features, thermal behavior, and anti-bacterial activity

Regarding the importance of 1,3,4-thiadiazoles due to versatile biological activity and for investigation of the symmetry impact on thermal behavior and antibacterial activity of 2,5-bisalkylsulfenyl[1,3,4]thiadiazole, two new derivatives viz. 2-cyclohexylsulfenyl-5-cyclopentylsulfenyl[1,3,4]thiadiazole and 2-cyclohexylsulfenyl-5-dodecylsulfenyl[1,3,4]thiadiazole, were synthesized through the nucleophilic substitution reaction appropriate alkyl halide with 5-cyclohexyl-3H-[1,3,4]thiadiazole-2-thione in ethanol under reflux conditions. The chemical structure of the products was elucidated by the physical and spectroscopic techniques. After tedious work, the suitable snow-like crystals of 2-cyclohexylsulfenyl-5-dodecylsulfenyl[1,3,4]thiadiazole for single-crystal X-ray diffraction analysis could be isolated from a mixed solvent, namely ethanol and water in volume ratio of 9:1. Then, the influence of symmetry and cyclic or non-cyclic aliphatic substituents on the important structure parameters of the 2,5-bisalkylsulfenyl[1,3,4]thiadiazole derivatives were negligible, however, those structure characteristics were different for 5–cyclohexylsulfenyl–3H–[1,3,4]thiadiazole–2–thione, due to its thione structure. TGA/DTA study demonstrated the effect of the symmetry and van der Waals interaction on thermal stability, and the robust influence of the pseudo hydrogen bonding NH with C = S on the melting and crystallization phase transitions was revealed by DSC analysis. The pharmacokinetics, drug-likeness, medicinal chemistry friendliness, and toxicology of three derivatives of bis-alkylsulfenyl[1,3,4]thiadiazole were evaluated by two prediction tools of SwissADME and T.E.S.T tools predicted good pharmacokinetics, drug-likeness, and anti-toxicant properties in developmental toxicity for the bis-alkylsulfenyl[1,3,4]thiadiazoles and 5–cyclohexylsulfenyl–3H–[1,3,4]thiadiazole–2–thione. Finally, the in vitro antibacterial activity of two new 2-cyclohexylsulfenyl-5-cyclopentylsulfenyl[1,3,4]thiadiazole and 2-cyclohexylsulfenyl-5-dodecylsulfenyl[1,3,4]thiadiazole against S. aureus and E. coli, confirmed them as promising anti-bacterial agent. All obtained results proved that the physicochemical, thermal, pharmacokinetic, and biological properties of 2,5-bisalkylsulfenyl[1,3,4]thiadiazoles can be tuned by selecting appropriate substituents.

Zaluzanin-D enriched Vernonia arborea extract mediated copper oxide nanoparticles synthesis and their anti-oxidant, anti-inflammatory and DNA methylation altering properties.

Metal oxide nanoparticles synthesized with the aid of medicinal plant extracts are showing potential as treatment options for inflammatory diseases. Two key benefits of this synthesis method is: the synthesis process is environmentally benign and the utilization of medicinal plant-derived extracts adds to the medicinal value of the synthesized nanoparticle. Earlier, sesquiterpene lactone zaluzanin-D (ZD) has been isolated from leaves of Vernonia arborea. ZD showed ability to reduce inflammation in activated monocytes. Copper oxide nanoparticles (bCuO-NPs) were synthesized using ZD-enriched leaf extract of V. arborea and characterized by UV-vis spectroscopy, FT-IR, XRD, particle size analyzer, and TEM. Synthesized bCuO-NPs did not show significant toxicity to human monocytic cell lines (THP-1) at the tested concentrations. The bCuO-NPs showed radical scavenging ability indicating anti-oxidant properties. Flow cytometry experiments proved the capability of bCuO-NPs to reduce intracellular ROS in peroxide-activated THP-1 cells. The NPs also showed a significant ability to reduce inflammatory adhesion in PMA-activated THP-1 cells. In the DNA methylation studies, bCuO-NPs behaved similarly to ZD and prevented DNA hypomethylation at the MMP-9 promoter region. These properties strongly indicate the ability of bCuO-NPs to reduce inflammation in the activated monocytes. Furthermore, in zebrafish (Danio rerio) embryos, the developmental toxicity of bCuO-NPs was assessed. The studies indicated the reduced toxicity and compatibility of the NPs with biological organisms. Based on the results, it can be concluded that the bCuO-NPs produced from ZD-enriched leaf extract have significant anti-oxidant capabilities and the ability to reduce inflammation in monocytic cell lines. Overall, reduced in vitro and in vivo toxicity, along with its antioxidant and anti-inflammatory properties, makes bCuO-NPs a potential candidate for anti-inflammatory drugs.

Study of combined multiple exposure and reproductive / developmental toxicity of 2-ethylhexanoic acid by screening method

Introduction. According to the normative and methodological documents of the Russian Federation, chemicals introduced into economic activities are subject to mandatory toxicological assessment and hygienic regulation. To substantiate the value of the hygienic standard of 2-ethylhexanoic acid, the production of which is planned in the country, additional test on its reproductive toxicity was required. The aim of the research was to determine the no-observed adverse effect levels of the 2-ethylhexanoic acid for maternal and reproductive toxicities in combined multiple exposure and the reproduction/developmental toxicity screening test (OECD 422). Materials and methods. The study was performed in accordance with the requirements of the OECD Test Guideline 422 «Combined repeated dose toxicity study with the reproduction/developmental toxicity screening test». Results. During the experiment no animal deaths or clinical symptoms of the toxic effect of 2-ethylhexanoic acid were observed at all tested doses (250, 500 and 1000 mg/kg b.w.). The assessment of behavioural responses using the open field method showed no differences in animals from experimental and control group. Histological examination indicated the acid at doses of 500 and 1000 mg/kg b.w. to cause significant changes in bladder (increased sclerosis in the submucosa), lungs (increased proportion of emphysematous altered parenchyma), adrenal gland (increased cell alterations and lipomatous inclusions), thyroid gland (increased loci of interfollicular tissue) in males and females’ rats. The total weight of offspring in the experimental groups was found to be statistically dose-dependent reduced on days 4 and 13 after birth compared with the control. Limitations. The study had no limitations. Conclusion. 2-Ethylhexanoic acid has no effect on the reproductive function in experimental animals. Developmental toxicity, expressed in a decrease in the total weight of offspring, was observed at the level of general toxic effects and is not specific. NOAELs were established at the level of 250 mg/kg b.w. for general toxic effect, > 1000 mg/kg b.w. for reprotoxic effect.

VERMEER FCM: A tool integrating exposure and hazard modelling for chemicals migrating from food contact materials

A new tool, VERMEER FCM, was developed to support the risk assessment of single organic chemicals migrating from plastic food contact materials (FCM). The freely available tool is integrated into MERLIN-Expo and has been designed in line with Regulation (EU) No 10/2011 for plastic FCM. Overall, the tool consists of three modules that allow (i) to model the migration of chemicals into food, (ii) to predict toxicological endpoints relevant to risk assessment of FCM chemicals, and (iii) to automatically check whether the chemical of interest is included in Regulation (EU) No 10/2011. To apply the VERMEER FCM tool, users need to provide information regarding the chemical(s) of interest, the FCM, the food and other parameters (e.g. contact time and temperature). The three modules can be run either separately or in combination. Migration is predicted by a recently developed migration model, whereas hazard predictions for genotoxicity, subchronic toxicity, reproductive and developmental toxicity and carcinogenicity are provided by QSAR models selected from the publicly available VEGA HUB. The major novelty of the tool is that it combines information on hazard and exposure (i.e. migration) with regulatory information. Several case studies were performed to demonstrate the application of the tool.

Exploring Saffron's Therapeutic Potential: Insights on Phytochemistry, Bioactivity, and Clinical Implications.

Saffron, derived from the Crocus sativus plant, has been revered for centuries for its culinary, medicinal, and cultural significance. This review provides a comprehensive overview of saffron's chemical constituents and phytochemistry, elucidating its rich profile of bioactive compounds. Emphasis is placed on exploring the bio-accessibility, bioavailability, and bioactivity of saffron's phytochemicals, laying the foundation for understanding its pharmaceutical significance. The pharmaceutical importance of saffron and its phytochemicals is thoroughly examined, focusing on their diverse therapeutic properties. These include anticancer, antidiabetic, antioxidant, antimicrobial, anti-inflammatory, antinociceptive, anticonvulsant, antidepressant, learning and memory enhancement, cardiovascular, and antihypertensive properties. Such multifaceted pharmacological activities underscore saffron's potential as a valuable medicinal resource. Clinical studies investigating the efficacy and safety of saffron in various health conditions are synthesized, providing insights into its clinical applications. Moreover, toxicity assessments in animal models, encompassing acute, subacute, subchronic, and developmental toxicity, are discussed to delineate the safety profile of saffron and its bioactive constituents. Finally, recent advances and future perspectives in saffron research are highlighted, underscoring emerging trends and potential avenues for further exploration. This review serves as a comprehensive resource for researchers, clinicians, and stakeholders interested in harnessing the therapeutic potential of saffron while ensuring its safe and effective utilization in healthcare settings.

Tri-iso-butyl phosphate (TiBP) exposure induces neurotoxicity by triggering oxidative stress accompanied by neurotransmitter system disruptions and apoptosis in zebrafish larvae

The current research sheds light on the biological toxicity of organophosphate flame retardants (OPFRs), yet it overlooks the neurotoxicity and potential molecular mechanisms of tris(1,3-dichloro-2-propyl) phosphate (TiBP), a prominent constituent of the OPFRs. To address this, we utilized zebrafish larvae as a model to investigate TiBP's acute toxicity and neurotoxic effects, along with the associated molecular pathways. Our findings revealed that the 96 h and 120 h LC50 values for TiBP were 56.51 mg/L and 48.85 mg/L, respectively. Gradient exposure based on the 120 h LC50 demonstrated that TiBP induced developmental toxicity, characterized by elevated heart rate, reduced body length, and diminished eye distance. Additionally, a decrease in swimming activity was observed in the light test, along with the inhibition of the neuro crest cell development in Tg (HuC:eGFP) and Tg (sox10: eGFP) zebrafish larvae following TiBP exposure, as well as the alterations of neurogenesis and ACh-related genes. Expression of key neurodevelopment genes, including mbpa, gap43, nestin, ngfra, was significantly downregulated. Furthermore, heightened anxiety-like behaviors in open field and phototaxis tests were observed, concomitant with neurotransmitter imbalances. Specifically, there was an increase in DA levels, a decrease in GABA, and an upregulation of AChE activity. These disruptions were primarily mediated through transcriptional dysregulation of neurotransmitter synthesis, transport, and reception. Upon exposure to TiBP, zebrafish larvae exhibited a concentration-dependent increase in both ROS level and apoptosis. An upregulation of antioxidant enzymes and their transcription levels indicated the presence of oxidative stress in the larvae. The induction of ddit3 was congruent with the observed apoptosis, suggesting that it may be triggered by oxidative stress via the ERs-CHOP pathway. In summary, our study indicates that oxidative stress is a pivotal molecular event in the neurotoxicity induced by TiBP, implicating the disruption of the GABAergic, dopaminergic, and cholinergic systems, as well as triggering apoptosis.

Research on the types and toxicity of VOCs released from solvent-based inks in high temperature environment

ABSTRACT During the utilization, blending, transportation, and storage, a significant amount of volatile organic compounds (VOCs) are released from inks, posing risks to both human health and the ecological environment. This study sought to identify the types and structures of VOCs released from four types of solvent-based inks (referred to as CAB, PVB, AKR, and Rs inks) in high-temperature settings and to assess the bioaccumulation factors, developmental toxicity, and acute toxicity of these released VOCs. The findings revealed that all tested inks released substantial amounts of VOCs in high-temperature environments. CAB and PVB inks released fewer types of VOCs with relatively smaller molecular weights, primarily with carboxylic acid groups and hydroxyl groups, while AKR and Rs inks released more types of VOCs with larger molecular weights, including polycyclic aromatic hydrocarbons. Toxicity analysis indicated that although the primary VOCs released from CAB and PVB ink displayed some developmental toxicity, their bioaccumulation factors were below 100. The principal VOCs from AKR ink did not exhibit developmental toxicity. Conversely, the predominant VOCs from Rs ink not only demonstrated developmental toxicity but also had bioaccumulation factors exceeding 100. Additionally, the VOCs released from CAB, PVB, and AKR inks exhibited stronger acute toxicity to luminescent bacteria, while those from Rs ink showed greater acute toxicity to fish. These results offer a scientific foundation for the safe usage of inks and environmental conservation.

Flavor compound geraniol induces inhibited nutrient utilization and developmental toxicity on embryonic–larval zebrafish

AbstractFlavors are widely utilized in the food and oral pharmaceutical industry, particularly in products for children, to enhance palatability and promote ingestion willingness. The complex compositions of flavors potentially induce severer toxicity especially in children. In this study, zebrafish embryos are applied for toxicity screening of flavor and its compounds by immersing in flavor solutions followed by the assessment of morphology of zebrafish larvae. Geraniol is identified as the prominent toxic compound and is considered highly toxic to zebrafish embryo. In further toxicology study, geraniol demonstrates the concentration‐dependent developmental toxicity as the obvious reduction of body and eye lengths, as well as the increased prevalence of tail deformities, pericardial edema, and spine deformation. Zebrafish larvae treated with geraniol exhibit reduction in liver area and exocrine pancreas length, increase in yolk sac area, as well as elevation of triglycerides and total cholesterol, which indicate the inhibited nutrient utilization. Transcriptome analysis reveals that under geraniol treatment, 248 differentially expressed genes (DEGs) are downregulated, whereas 23 DEGs are upregulated, and 110 DEGs are related to metabolic process. Biological processes of lipid metabolism, carbohydrate metabolism, protein hydrolysis, and transmembrane transport, including their involved functional genes, are all downregulated. These findings reveal the developmental toxicity of geraniol by affecting the nutrient utilization‐related organs development and biological processes. This study establishes an efficient screening model for identifying toxic flavor compounds during developing stages, thereby elucidating the potential safety risks of geraniol exposure in zebrafish and providing a comprehensive understanding of its potential toxicity mechanism.

Reproductive and developmental toxicity of α-terpineol in Wistar rats

Alpha-terpineol (α-T) is a type of monoterpenoid alcohol commonly present in essential oils, it contributes to a pleasant floral fragrance similar to that of lilacs. This research aimed to evaluate the impact of α-terpineol on the reproductive functions of both male and female rats, including gonadal activity, mating behavior, conception, conceptus development and parturition. Six male and female Wistar rats per group received α-terpineol through gavage at doses of 0, 75, 150 and 300 mg/kg/day. The study revealed changes in body weight gain inhibition, food consumption, azoospermia, decreased testosterone levels (0.7 ± 1.61 ng/mL, 0.7 ± 2.30 ng/mL) as well as histopathological variations in testis and epididymis among males exposed to doses of 150 and 300 mg/kg/day. Moreover, this exposure led to significantly decreased serum T4 levels in both adult males (21.85 ± 12.68 ng/mL, 16.20 ± 9.15 ng/mL) and dams (11.24 ± 12.37 ng/mL, 9.48 ± 11.74 ng/mL) at the dose range of 150 and 300 mg/kg/day without affecting TSH concentrations. In summary, the present study showed that α-terpineol induced reproductive toxicities in male rats. Therefore, a detailed toxicological assessment is highly recommended.

Acrylamide induces spatiotemporal metabolic profiling disturbance via targeting taurine and hypotaurine metabolism during early zebrafish development

AbstractAcrylamide, an endocrine‐disrupting emerging contaminant from both the environment and food processing, has been linked to cardiac developmental toxicity in zebrafish. However, the mechanisms involved in the cardiac developmental toxicity from long‐term exposure to acrylamide remain unclear. This study provides in‐depth evidence on the metabolic regulation of zebrafish embryos with acrylamide exposure. A comprehensive metabolites analysis of four different acrylamide exposures (0, 0.5, 1.0, and 2.0 mM) at different zebrafish developmental stages (6, 24, 48, 72, 96, and 120 h post fertilization, hpf) was performed. Metabolite changes throughout the zebrafish development (6–120 hpf) were closely associated with taurine and hypotaurine metabolism. The pattern of significantly changed metabolites revealed that acrylamide strongly disrupts taurine and hypotaurine metabolism related to a deficient cardiovascular system. Moreover, acrylamide exposure disrupted the de novo synthesis of taurine via cysteine sulfinic acid decarboxylase during early zebrafish embryogenesis. In addition, taurine supplementation (10 mM) effectively alleviates acrylamide‐induced deficient cardiovascular system. Our results demonstrate that acrylamide exposure has a detrimental effect on early heart development in zebrafish due to the inhibition of de novo synthesis of taurine.

Standardization and optimization of the hiPSC-based PluriLum assay for detection of embryonic and developmental toxicants.

New approach methodologies (NAMs) for predicting embryotoxicity and developmental toxicity are urgently needed for generating human relevant data, while reducing turnover time and costs, and alleviating ethical concerns related to the use of animal models. We have previously developed the PluriLum assay, a NKX2.5-reporter gene 3D model using human-induced pluripotent stem cells (hiPSCs) that are genetically modified to enable the assessment of adverse effects of chemicals on the early-stage embryo. Aiming at improving the predictive value of the PluriLum assay for future screening purposes, we sought to introduce standardization steps to the protocol, improving the overall robustness of the PluriLum assay, as well as a shortening of the assay protocol. First, we showed that the initial size of embryoid bodies (EBs) is crucial for a proper differentiation into cardiomyocytes and overall reproducibility of the assay. When the starting diameter of the EBs exceeds 500 µm, robust differentiation can be anticipated. In terms of reproducibility, exposure to the fungicide epoxiconazole at smaller initial diameters resulted in a larger variation of the derived data, compared to more reliable concentration-response curves obtained using spheroids with larger initialdiameters. We further investigated the ideal length of the differentiation protocol, resulting in a shortening of the PluriLum assay by 24 h to 7 days. Following exposure to the teratogens all-trans and 13-cis retinoic acid, both cardiomyocyte contraction and measurement of NKX2.5-derived luminescence were recorded with a similar or increased sensitivity after 6 days of differentiation when compared to the original 7 days. Finally, we have introduced an efficient step for enzymatic dissociation of the EBs at assay termination. This allows for an even splitting of the individual EBs and testing of additional endpoints other than the NKX2.5-luciferase reporter, which was demonstrated in this work by the simultaneous assessment of ATP levels. In conclusion, we have introduced standardizations and streamlined the PluriLum assay protocol to improve its suitability as a NAM for screening of a large number of chemicals for developmental toxicity testing.

Early developmental anomalies in zebrafish (Danio rerio) embryos induced by the Clematis florida Thunb.

Ethnopharmacological relevanceThe C.florida. is one of the common medicines used by She population in China, with therapeutic effects of promoting blood circulation and anti-inflammatory. According to the acute toxicity grading standard of chemical substances, this herb is a low-toxicity herb. At present, the safety of C.florida., especially its impact on early embryonic development, is still unclear. Aim of the studyThis study investigated the toxic effects of C. florida. on early embryonic development using a zebrafish embryo model. Materials and methodsIn this study, we used zebrafish embryos exposed to C.florida. at early stage to assess the early developmental toxicity by analyzing the developmental toxicity phenotype, oxidative stress, cell apoptosis, total enzyme activity, behavioral trajectory, and gene expression levels. ResultsEmbryos of the zebrafish exposed to different concentrations of C.florida. exhibited multiple organs and systems developmental disorders, including the heart, vessels, brain, bone, liver, and so on. Especially, with the increase of drug concentration, it is observed that the developmental malformations of the cardiovascular structure and function in larvae are becoming increasingly severe. In addition, results show that the abnormalities in embryonic development may be attributed to oxidative stress induced by apoptosis and activation of immune system resulting from an imbalance in the hematopoietic system. ConclusionsThis study provides a comprehensive and detailed summary of the toxic effects of C.florida. on embryonic development, which contributes to a deeper understanding of the potential adverse developmental consequences, and also prompt people to pay considerable attention to its treatment in medicinal practice.