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Drosophila melanogaster is one of the crucial in vivo models in terms of analyzing the toxicity of various unknown chemicals. Every part of the fly serves as a model in metabolic and therapeutic approaches. Genotoxic and teratogenic compounds are exposed to Drosophila through the oral route. Further, the toxicity of genotoxic compounds is analyzed in Drosophila's gut, hemolymph, and phenotype. The toxicity of teratogen compounds is also analyzed using a Drosophila embryo. The current chapter summarizes several techniques that are used to detect the genotoxicity and teratogenicity of any unknown compound in this model., (© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

For aquatic ecosystem Daphnia magna is evolving as a model organism to check the teratogenicity of numerous compounds. D. magna can be easily cultured in the laboratory, and the teratogen effect of several compounds can be easily studied. The developmental stages are well studied in D. magna. All the developmental stages are transparent so the defect can be easily accessed. So, the postembryonic developmental changes can be easily studied after the exposure with teratogen. More importantly, D. magna also have a swimming behavioral phenotype. The behavioral defect can be easily accessed after teratogen exposure. The current chapter summarizes numerous protocols associated with embryo and adult staining and adult behavioral assays that can be used to access the teratogenicity of any unknown compound., (© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Salvia lachnostachys Benth is native to Brazil and has anti-inflammatory, anti-arthritic, cytotoxic, antitumor, and antihyperalgesic activities. The population, including pregnant women, consume this plant to treat pain, inflammation, flu, spasms, insomnia, and depression, mainly. There are no safety reports on the use of this plant during pregnancy. The present study aimed to evaluate the effects of S. lachnostachys ethanolic extract (EESl) on reproductive performance, embryofetal development, and DNA integrity of pregnant female mice. Pregnant females were randomly divided into three experimental groups (n = 10): The Control group was treated with a vehicle, and treatment groups were administered with EESl at 100 and 1000 mg/kg, respectively. Treatment occurred by gavage throughout the gestational period until day 18. Afterward, reproductive performance, embryofetal development, and DNA integrity parameters were evaluated. The results indicated that EESl did not alter any reproductive performance parameters. However, it changed embryofetal outcome through reduced placental weight (EESl 100 mg/kg), decreased fetal weight (EESl 100 and 1000 mg/kg), and increased frequency of small for gestational age fetuses (EESl 1000 mg/kg). In addition, EES1 increased the frequency of external, visceral, and skeletal malformations. Because of the above, it is considered that EESl is not maternotoxic, does not alter reproductive performance, but does alter embryofetal development. Its use in the gestational period is not indicated due to its teratogenic potential., (© 2023. The Author(s).)

Isotretinoin (13-cis-retinoic acid), a derivative of vitamin A, is used in the treatment of severe acne resulting in sebum suppression induced by sebocyte apoptosis. Isotretinoin treatment is associated with several adverse effects including teratogenicity, hepatotoxicity, and dyslipidemia. Isotretinoin's effects on endocrine systems and its potential role as an endocrine disruptor are not yet adequately investigated. This review presents clinical, endocrine, and molecular evidence showing that isotretinoin treatment adversely affects the pituitary-ovarian axis and enhances the risk of granulosa cell apoptosis reducing follicular reserve. Isotretinoin is associated with pro-apoptotic signaling in sebaceous glands through upregulated expression of p53, forkhead box O transcription factors (FOXO1, FOXO3), and tumor necrosis factor-related apoptosis inducing ligand (TRAIL). Two literature searches including clinical and experimental studies respectively support the hypothesis that isotretinoin's toxicological mode of action on the pituitary-ovarian axis might be caused by over-expressed p53/FOXO1 signaling resulting in gonadotropin suppression and granulosa cell apoptosis. The reduction of follicular reserve by isotretinoin treatment should be especially considered when this drug will be administered for the treatment of acne in post-adolescent women, in whom fertility may be adversely affected. In contrast, isotretinoin treatment may exert beneficial effects in states of hyperandrogenism, especially in patients with polycystic ovary syndrome., (Copyright © 2021. Published by Elsevier Inc.)

In this review, we explore evidence that hypoxia in the developing human fetus can lead not only to the more commonly accepted disruptive-type defects, but also patterns of anomalies that suggest that hypoxia can exert a more classic teratogenic effect, using the brain as one example. We review neuropathology in the context of intrauterine hypoxia, particularly as it relates to carbon monoxide poisoning, in utero strokes, and homozygous alpha-thalassemia. In general, the associated brain injuries resemble those seen with other causes of hypoxic-ischemic injury. Fetal strokes during development usually lead to loss of brain tissue in areas that do not follow a typical embryologic pattern, and therefore are considered disruptions. However, there is also evidence that fetal brain ischemia can cause more classically recognized patterns of abnormal embryonic neuronal migration and organization such as polymicrogyria, cortical dysplasia, or dysgenesis, including select types of focal cortical dysplasia. This study summarizes available literature and evidence to raise clinicians' awareness regarding the association between hypoxia and congenital anomalies, including brain malformations., (© 2021 Wiley Periodicals LLC.)

Amitriptyline is a tricyclic antidepressant commonly prescribed in humans for pain and sleep disorders and in non-human primates for self-injurious behaviors. Here, we report a clinical case on the teratogenic effect of maternal-fetal amitriptyline exposure., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Aim: To systematically identify studies of implementing risk management measures when prescribing teratogenic medicines for women of childbearing age and studies reporting risk perceptions of teratogenic medications., Methods: MEDLINE, CINAHL, Scopus, EMBASE, and International Pharmaceutical Abstracts were searched. Studies were included in the risk management section if they reported any of the following risk management measures: teratogenic counseling, contraceptive counseling, pregnancy testing before starting treatment, pregnancy testing during treatment, use of contraception before starting treatment, and use of contraception during treatment. Studies were included in the perceptions section if they reported perceived teratogenic risk as numerical value., Results: Fifty-five studies were included in the risk management section and seven studies were included in the perceptions sections. Prevalence of risk management measures varied as follows: teratogenic counseling (9.5%-99.3%), contraceptive counseling (6.1%-98%), pregnancy testing before starting treatment (0%-95.1%), pregnancy testing during treatment (12.7%-100%), contraception use before starting treatment (15.7%-94%), and contraception use during treatment (1.7%-100%). A proper estimation of the teratogenic risk was reported for thalidomide (by general practitioners and obstetric/gynecologists), for etretinate (by pregnant women), and for misoprostol (by pregnant and nonpregnant women). An under-estimation was reported for warfarin and retinoids (by general practitioners and obstetric/gynecologists). And over-estimation was reported for thalidomide, valproate, lithium, isotretinoin, phenytoin, warfarin and etretinate by different populations., Conclusion: Considerable variation in the implementation of risk management measures when prescribing teratogenic medicines to women of childbearing age is reported in the literature. A common tendency to over-estimate the risk of teratogenic medications was evident., (© 2020 The Authors. Birth Defects Research published by Wiley Periodicals LLC.)

Human induced pluripotent stem cells (hiPSC) were used to develop an assay format that may deliver information on teratogenicity of drugs. A human pluripotent stem cell scorecard panel was used to monitor the expression of 96 marker genes that are indicative of the stem cell state or differentiation into the ectoderm, mesoderm and endoderm lineages. We selected a human episomal iPS cell line for the assay based on karyotype stability, initial pluripotency, differentiation capacity and overall gene expression variability. The assay is based on embryoid body formation and was developed to be simply automated. In this proof of concept study, we used eight reference compounds (valproic acid, all-trans-retinoic acid, thalidomide, methotrexate, hydroxyurea, ascorbic acid, penicillin G and ibuprofen) to test the technical performance of the assay (readout stability) in concentration-response and time-course experiments. We also found that each compound affected marker gene expression in a different way. Various forms of data analysis identified 19 out of 96 early developmental genes as potential predictive markers for teratogenicity. Machine-learning models were run to exemplify how the assay will be developed further. The preliminary results from these analyses suggest that the assay could be suitable for the pre-screening of candidate pharmaceutical compounds. The approach presented here points a way towards development of a human cell-based assay that could replace the murine EST currently used to screen for early indications of potential teratogenicity of drug candidates., (Copyright © 2020 F. Hoffmann - La Roche Ltd. Published by Elsevier Inc. All rights reserved.)

There is a great need for novel in vitro methods to predict human developmental toxicity to comply with the 3R principles and to improve human safety. Human-induced pluripotent stem cells (hiPSC) are ideal for the development of such methods, because they are easy to retrieve by conversion of adult somatic cells and can differentiate into most cell types of the body. Advanced three-dimensional (3D) cultures of these cells, so-called embryoid bodies (EBs), moreover mimic the early developing embryo. We took advantage of this to develop a novel human toxicity assay to predict chemically induced developmental toxicity, which we termed the PluriBeat assay. We employed three different hiPSC lines from male and female donors and a robust microtiter plate-based method to produce EBs. We differentiated the cells into cardiomyocytes and introduced a scoring system for a quantitative readout of the assay-cardiomyocyte contractions in the EBs observed on day 7. Finally, we tested the three compounds thalidomide (2.3-36 µM), valproic acid (25-300 µM), and epoxiconazole (1.3-20 µM) on beating and size of the EBs. We were able to detect the human-specific teratogenicity of thalidomide and found the rodent toxicant epoxiconazole as more potent than thalidomide in our assay. We conclude that the PluriBeat assay is a novel method for predicting chemicals' adverse effects on embryonic development.

The first pharmaceutical retinoids approved by the U.S. Food and Drug Administration were given black-box warnings against their use in pregnancy due to potential teratogenic effects. These first- and second-generation retinoids were initially formulated for oral dosing and are structurally very similar to vitamin A, which has beneficial effects on skin as well as plays a vital role in driving healthy embryogenesis. Some of these early retinoids have since been reformulated for topical application, which has resulted in their diminished potential for systemic exposures. Additionally, rational drug design has been applied to create today's third-generation retinoids (adapalene, tazarotene, and bexarotene). These compounds include aromatic rings within their molecular cores to provide structural rigidity that contrasts with the flexible aliphatic backbone of vitamin A and the earlier generations of retinoids, and thus limits their off-target activity. As a result of these design features, the teratogenic potential in animals of the third-generation retinoids and those reformulated for topical use is generally less than seen with oral administration of earlier generations of retinoids. The available, but limited, epidemiologic data further show little-to-no teratogenic potential associated with real-life use of these compounds in humans. Given the paucity of epidemiologic data available at this time, however, it is recommended that the use of topical retinoids during pregnancy be avoided. However, in circumstances when inadvertent exposure in pregnancy may occur, the available data provide some reassurance that adverse pregnancy outcomes are unlikely., (© 2020 Wiley Periodicals LLC.)

Pregnant women are an especially vulnerable population, given the sensitivity of a developing fetus to chemical exposures. However, prescribing behavior for the gravid patient is guided on limited human data and conflicting cases of adverse outcomes due to the exclusion of pregnant populations from randomized, controlled trials. These factors increase risk for adverse drug outcomes and reduce quality of care for pregnant populations. Herein, we propose the application of artificial intelligence to systematically predict the teratogenicity of a prescriptible small molecule from information inherent to the drug. Using unsupervised and supervised machine learning, our model probes all small molecules with known structure and teratogenicity data published in research-amenable formats to identify patterns among structural, meta-structural, and in vitro bioactivity data for each drug and its teratogenicity score. With this workflow, we discovered three chemical functionalities that predispose a drug towards increased teratogenicity and two moieties with potentially protective effects. Our models predict three clinically-relevant classes of teratogenicity with AUC = 0.8 and nearly double the predictive accuracy of a blind control for the same task, suggesting successful modeling. We also present extensive barriers to translational research that restrict data-driven studies in pregnancy and therapeutically "orphan" pregnant populations. Collectively, this work represents a first-in-kind platform for the application of computing to study and predict teratogenicity., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)

Ethnopharmacological Relevance: Endopleura uchi (Huber) Cuatrec is a plant species from the Brazilian Amazon. The barks of this tree are used in folk medicine - mainly as a decoction - for dyslipidemia, uterine infection, fibroids, polycystic ovary, menstrual disorders, as a contraceptive and abortive agent, among others. However, the data available about its developmental toxicity are still insufficient., Aim of the Study: This study aimed to evaluate the reproductive toxicity and teratogenic effects in embryos from zebrafish treated with the hydroethanolic extract from the barks of Endopleura uchi (EEu)., Materials and Methods: Both sexes of zebrafish (Danio rerio) were treated with EEu either through immersion (1.2, 2.5, and 5 mg/L) or orally (75, 200, and 500 mg/kg) over 21 consecutive days. Next, we assessed their fertility and gonads' histopathology; in their embryos were assessed teratogenesis, lethalities, and heart rate during daily observations (24, 48, 72, and 96 hpf)., Results: The phytochemical analysis of EEu through HPLC/MS shows bergenin as the major compounds. After 21 days of treatment were detected minor histopathological changes in parental fishes, such as atretic oocytes, interstitial fibrosis, and decreased the percentage of early vitellogenic oocytes, but without impairing the reproduction of treated animals. However, in the embryos was observed significantly increased frequency of malformation in all the groups treated through immersion, and in the group treated orally with the highest concentration (500 mg/kg)., Conclusion: Based on the results, EEu caused no adverse effects in the progenitors on both treatments (immersion and oral). However, it was observed that the concentrations 1.2, 2.5, and 5 mg/L (immersion), and the dose 500 mg/kg (oral) caused malformations in the offspring (F1 generation). These results emphasize the need for attention when using preparations from E. uchi, mainly for pregnant women. Further studies are needed to compare its effects with the extract's primary compound (bergenin)., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Rhopalurus junceus is the most common scorpion in Cuba and the venom is often used as a natural product for anti-cancer therapy. Despite this, no study has been published concerning its toxicological profile. The aim of the study was characterizing the short-term, subchronic toxicity and the teratogenic potential of Rhopalurus junceus scorpion venom by oral route in mice. Short-term oral toxicity was test in both sexes NMRI mice that received 100 mg/kg/day of scorpion venom extract for 28 days. For the subchronic study, mice were administered with three doses (0.1, 10, and 100 mg/kg) by oral route for 90 days. Teratogenic potential was tested in pregnant mice administered from day 6-15 post conception. Significant differences were observed in body weight and food intake of animal treated for short-term and subchronic assays. Variations in serum urea and cholesterol were observed after 90 days oral treatment. Spontaneous findings not related to the treatment were reveal in histology evaluation. Exposure in pregnant mice did not produce maternal toxicity. Signs of embryo-fetal toxicity were not observed. The current study provides evidence that exposure to low or moderate dose of Rhopalurus junceus scorpion venom by oral route did not affect health of animals and has low impact on reproductive physiology., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Purpose: Bayesian hierarchical models (BHMs) have been used to identify adverse drug reactions, allowing information sharing amongst adverse reactions and drugs expected to have similar properties. This study evaluated the use of BHMs in the routine signal detection analyses of potential first-trimester teratogens, where these models have not previously been applied., Methods: Data on 15 058 malformed foetuses exposed to first trimester medications (1995-2011) from 13 European congenital anomaly (CA) registries were analysed. The proportion of each CA in women taking a specific medication was compared with the proportion of that CA in all other women in the dataset (55 CAs × 523 medications). BHMs were grouped by either medications or CAs or by both simultaneously, and the results compared with analysing each medication-CA combination separately and adjusting for multiplicity using a double false discovery rate (FDR) procedure. The proportions of "high-risk" medications (medications which have been shown to carry a moderate to high risk of foetal malformations) identified as potential signals were compared, as well as the total number of potential signals requiring follow up (the effective workload)., Results: BHMs identified more high-risk medications than the double FDR method, but the effective workload was larger. A BHM grouping both medications and CAs, for example, identified 23% of high-risk medications compared with 14% by the double FDR; however, there was an increase from 16 to 71 potential signals requiring follow up., Conclusion: For comparable effective workloads, BHMs did not outperform the double FDR, which is comparatively straightforward to implement and is therefore recommended for continued use in teratogenic signal detection analyses., (© 2020 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons Ltd.)

The objective of this work was to evaluate whether tetracycline (TC) in environmentally relevant concentrations was able to induce alterations to embryonic development and teratogenic effects in oocytes and embryos of Cyprinus carpio. For this purpose, an embryolethality study was conducted and the lethal concentration 50 (LC 50 ) and effective concentration 50 of malformations (EC 50 ) were calculated, and with these data the teratogenic index (TI) was determined. The main alterations to embryonic development and the teratogenic effects produced by TC on embryos of C. carpio were determined using the Kimmel and Hersem scale adapted for Cyprinus carpio. LC 50 and EC 50 were respectively 500.08 and 145.3 μg L -1 .TC was shown to be teratogenic with teratogenic index of 3.44, and the main malformations identified in concentrations of 90-900 μg L -1 were malformation in tail, modified chorda structure, pericardical edema, scoliosis and malformations of the heart. A significant decrease in concentration-dependent in Kimmel and Hersem score was observed. The results allow us to conclude that TC at environmentally relevant concentrations is capable of inducing embryotoxic and teratogenic effects, generating risk in the integrity of the common carp C. Carpio., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Pluripotent stem cells recapitulate many aspects of embryogenesis in vitro. Here, we established a novel culture system to differentiate human embryonic stem cell aggregates (HESCA), and evaluated its utility for teratogenicity assessment. Culture of HESCA with modulators of developmental signals induced morphogenetic and molecular changes associated with differentiation of the paraxial mesoderm and neuroectoderm. To examine impact of teratogenic exposures on HESCA differentiation, 18 compounds were tested, for which adequate information on in vivo plasma concentrations is available. HESCA treated with each compound were examined for gross morphology and transcript levels of 15 embryogenesis regulator genes. Significant alterations in the transcript levels were observed for 94% (15/16) of the teratogenic exposures within 5-fold margin, whereas no alteration was observed for 92% (11/12) of the non-teratogenic exposures. Our study demonstrates that transcriptional changes in HESCA serve as predictive indicator of teratogenicity in a manner comparable to in vivo exposure levels., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objective: To study the teratogenic effect caused by Xanthoceras sorbifolia Bunge seed on SD rats., Methods: The experiments were performed in the groups of 2. 0, 4. 0 and 8. 0 g/kg, purified water negative control group and cyclophosphamide positive control group. On the 6 th to 15 th day of pregnancy, the SPF SD rats were exposed to Xanthoceras sorbifolia Bunge seed. All the rats were sacrificed on the day before delivery. Examination were performed on the bones stained by alizarin red and internal organs fixed with Bouins fluid., Results: Maternal body weight, weight gain, uterine fetal weight, net weigh, bed number, corpus luteum number, absorbing births number, live births number, still birth number and percentage and the abnormal rate of appearance, bone, internal organs of each dose group of Xanthoceras sorbifolia, there was no statistical significant difference between Bunge seed groups and negative control group., Conclusion: Under the conditions of this experiment, the Xanthoceras sorbifolia Bunge seed had no maternal toxicity to pregnant SD rats, no teratogenic and developmental toxicity to fetal rats. No Observed Adverse Effect Level of maternal toxicity and the minimum teratogenic dose of fetal rats is >8. 0 g/kg.

The spin-trap free radical scavenger N -tert-butyl-α-phenylnitron (PBN) ameliorated effects of several teratogens involving reactive oxygen species (ROS). We investigated for the first time whether PBN could ameliorate teratogenesis induced by a DNA hypomethylating hematological therapeutic 5-azacytidine (5azaC). At days 12 and 13 of gestation, Fisher rat dams were pretreated by an i.v. injection of PBN (40 mg/kg) and 1 h later by an i.p. injection of 5azaC (5mg/kg). Development was analyzed at gestation day 15 in embryos and day 20 in fetuses. PBN alone did not significantly affect development. PBN pretreatment restored survival of 5azaC-treated dams' embryos to the control level, restored weight of embryos and partially of fetuses, and partially restored crown-rump lengths. PBN pretreatment converted limb adactyly to less severe oligodactyly. PBN pretreatment restored global DNA methylation level in the limb buds to the control level. Cell proliferation in limb buds of all 5azaC-treated dams remained significantly lower than in controls. In the embryonic liver, PBN pretreatment normalized proliferation diminished significantly by 5azaC; whereas in embryonic vertebral cartilage, proliferation of all 5azaC-treated dams was significantly higher than in PBN-treated dams or controls. Apoptotic indices significantly enhanced by 5azaC in liver and cartilage were not influenced by PBN pretreatment. However, PBN significantly diminished ROS or reactive nitrogen species markers nitrotyrosine and 8-hydroxy-2'deoxyguanosine elevated by 5azaC in embryonic tissues, and, therefore, activity of this DNA hypomethylating agent was associated to the activation of free radicals. That pretreatment with PBN enhanced proliferation in the liver and not in immature tissue is interesting for the treatment of 5azaC-induced hepatotoxicity and liver regeneration.

The assays in this study utilize mouse embryonic stem cells (mESCs) and zebrafish embryos to evaluate the potential developmental toxicity of industrial and pharmaceutical chemicals. A set of eleven chemicals of known mammalian in vivo teratogenicity were tested in the assays and correlations to mammalian data. Using mESCs, proliferation, differentiation, and cytotoxicity of the chemicals were measured. In zebrafish embryos, lethality and the lowest effect level concentrations for morphological malformations were determined. Clustering of the assays based on frequency of affected assays resulted in a ranking of the test compounds that correlated to in vivo rodent data (R = 0.88, P < 0.001). We conclude that the combination of ESC- and zebrafish-based assays provides a valuable platform for the prioritization of pharmaceutical and industrial chemicals for further testing of developmental toxicity in rodents., (Copyright © 2018 Elsevier Inc. All rights reserved.)

MicroRNAs (miRNAs) are a class of small noncoding RNAs that modulate the expression of virtually all genes. miRNAs have been implicated in the regulation of a broad range of cellular and physiologic processes. Dysregulation of miRNAs has been found to be associated with a variety of diseases and disorders, including teratogenesis. One of the important strategies to reveal miRNA function in teratogenesis is the manipulation of their expression levels and patterns in specific regions in the developing embryos. The combination of microinjection technology with the whole embryo culture (WEC) system provides an excellent platform for the mechanistic study of the roles of miRNAs in teratogenesis. Here we describe an approach to investigating and manipulating miRNAs in cultured mouse embryos and present protocols for whole embryo culture, microinjection of miRNA mimics or inhibitors, validation of the efficacy of microRNA modulation in embryos, and assessment of the teratogen-induced apoptosis.

Pharmaceuticals are chemical compounds which are used to preserve human and animal health. Once administered, these compounds are metabolized or can remain unaltered until excreted. Therefore, a mixture of pharmaceuticals and their metabolites enters municipal sewers and wastewater treatment plants where, depending on their polarity, water solubility, and persistence, they cannot be completely removed or transformed during the treatment process, so that unaltered pharmaceuticals and/or their metabolites can enter surface water. As a result, in recent years concern has grown about trace concentrations and the risk they pose to ecosystems, considering the annual increase in pharmaceutical production and use at world level.This chapter reviews the frog embryo teratogenesis assay-Xenopus (FETAX). Originally developed during the mid-1980s as a test for detecting the developmental toxicity of pure chemical products and complex mixtures in the laboratory, in recent years it has been used to evaluate the mechanisms of action, biotransformation, and detoxification of xenobiotics as well as in ecotoxicology studies using alternative species and in situ monitoring.

The objective of this study was to provide in ovo evidence for the proposed role of kynurenine formamidase of l-tryptophan to NAD + pathway in embryo yolk sac membranes as a primary target for organophosphorus insecticide (OPI) teratogens in OPI-induced NAD-associated avian teratogenesis. Slices prepared from yolk sac membranes or embryo livers of chicken eggs treated with the OPI dicrotophos and/or methyl parathion were incubated with l-tryptophan. Yolk sac membrane slices metabolized l-tryptophan in the pathway to NAD + before that function was established in livers. OPI interfered in ovo with the second step of l-tryptophan to NAD + biosynthesis by inhibiting kynurenine formamidase. Its inhibition due to the teratogen dicrotophos occurred in yolk sac membranes during the period of embryo highest susceptibility to OPI teratogens in contrast to delayed and lower inhibition caused by the nonteratogen methyl parathion. Both OPI affected liver kynurenine formamidase in a similar manner. The onsets of liver enzyme inhibition, however, were delayed by about two days and occurred at the time of the reduced embryo susceptibility to teratogens. The early disruption of l-tryptophan metabolism and higher inhibition of kynurenine formamidase in yolk sac membranes may be the factors that determine action of OPI as teratogens in chicken embryos., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

In previous publications, we described the population incidence of abnormalities in zebrafish larvae exposed to toxicants. Here, we examine the phenomenon of clustering or co-occurrence of abnormalities in individual larva. Our aim is to see how this clustering can be used to assess the specificity and severity of teratogenic effect. A total of 11,214 surviving larvae, exposed continuously from 1 day postfertilization (dpf) to one of 60 toxicants, were scored at 5 dpf for the presence of eight different abnormal phenotypes. These were as follows: pericardial edema, yolk sac edema, dispersed melanocytes, bent tail, bent trunk, hypoplasia of Meckel's cartilage, hypoplasia of branchial arches, and uninflated swim bladder. For 43/60 compounds tested, there was a concentration-dependent increase in the severity score (number of different abnormalities per larva). Statistical analysis showed that abnormalities tended to cluster (i.e., to occur in the same larva) more often than expected by chance alone. Yolk sac edema and dispersed melanocytes show a relatively strong association with one another and were typically the first abnormalities to appear in single larvae as the concentration of compound was increased. By contrast, hypoplastic branchial arches and hypoplastic Meckel's cartilage were only frequently observed in the most severely affected larvae. We developed a metric of teratogenicity (TC 3/8 ), which represents the concentration of a compound that produces, on average, 3/8 abnormalities per larva. On this basis, the most teratogenic compounds tested here are amitriptyline, chlorpromazine hydrochloride, and sodium dodecyl sulfate; the least teratogenic is ethanol. We find a strong correlation between TC 3/8 and LC 50 of the 43 compounds that showed teratogenic effects. When we examined the ratio of TC 3/8 to LC 50 , benserazide hydrochloride, copper (II) nitrate trihydrate, and nicotine had the highest specific teratogenicity, while aconitine, hesperidin, and ouabain octahydrate had the lowest. We conclude that analyzing the clustering of abnormalities per larva can provide an enriched teratogenic dataset compared with simple measurement of the population frequency of abnormalities.

Thalidomide causes Thalidomide Embryopathy (TE), but is largely used to treat several conditions. Investigations with Cereblon, a thalidomide target protein encoded by CRBN gene, have helped to understand thalidomide therapeutic and teratogenic properties. We sequenced CRBN-thalidomide binding region in 38 TE individuals and 136 Brazilians without congenital anomalies, and performed in silico analyses. Eight variants were identified, seven intronic and one in 3'UTR. TE individuals had rare variants in higher frequency than the non-affected group (p=0.04). The genotype rs1620675 CC was related to neurological anomalies in TE individuals (p=0.004). Bioinformatics analysis suggested this genotype leads to potential alterations in splicing sites and binding to transcription factors. Comparison of the Cereblon-thalidomide binding domains in mammals demonstrated that CRBN is highly conserved across species. All the variants require evaluation in functional assays in order to understand their role in Cereblon-thalidomide binding and complex interactions that lead to TE., (Copyright © 2016 Elsevier Inc. All rights reserved.)

In spite of extensive research and persistent arguments, the mechanism of aluminum (Al) toxicity is still obscure. It is firmly established that aluminum is a potent neurotoxicant. So, the aim based on is aluminum damage chicken heart, as well as the vitelline circulation. In the first 3 days of incubation (D0-D2), 1.0, 2.0, or 4.0 mg aluminum chloride/0.3 ml avian saline was injected into the center of each viable fertilized egg yolk (AL1, AL2, and AL3 groups, respectively). Control eggs were either uninjected (AL0) or injected (ALS, 0.3 ml saline). Crown rump length was significantly decreased, while, embryonic mortalities, growth delay, as well as congenital heart defects were increased in the eggs injected 2.0 or 4.0 mg of Al. Although no relationship is clear about the embryonic mortality induced by Al in chicken embryos to the dose concentration, the higher mortality occurs in early developmental stages in developing chick embryos. Furthermore, chick embryos exposed to 4.0 mg/Al showed a high incidence of defects of ventricular septation and ventricular myocardium. Configuration and density of branched vitelline vessels were also significantly deteriorated after injection with 4.0 mg/Al. It concluded that Al is a cardiac teratogen for a chick in a dose-dependent way. These data highlight a novel approach for aluminum in congenital cardiovascular defects. Therefore, further research is needed to explain the teratogenicity of Al on the embryonic heart development.

Angiogenesis, the formation of new blood vessels, is essential for tumor growth, stabilization and progression. Angiogenesis inhibitors are now widely used in the clinic; however, there are relatively few published studies on the mechanism of their presumed teratogenic effects. To address this issue, we screened a variety of angiogenesis inhibitors in developing zebrafish and chicken embryo models to assess for developmental defects and potential teratogenic effects. We confirmed previous reports that sunitinib, sorafenib and TNP-470 are teratogenic and demonstrate that axitinib, pazopanib, vandetanib, and everolimus are also teratogens in these models. A dose response study identified the drugs inhibit HUVEC cell proliferation in vitro, and also target the developing blood vessels of embryos in vivo. This provides further evidence for the potential risk of fetal toxicity when using these drugs in a clinical setting, and emphasizes the importance of the development and maintenance of the vasculature in the embryo. We conclude that angiogenesis inhibitors, regardless of the molecular target, are teratogenic when exposed to chicken embryos.

Previous studies have shown that N(1),N(12)-bis(all-trans-retinoyl)spermine (RASP), a retinoid analog, inhibits RNase P activity and angiogenesis in the chicken embryo chorioallantoic membrane, demonstrates anti-tumor activity on prostate cancer cells, and acts as anti-inflammatory agent, being more effective and less toxic than all-trans retinoic acid. In an attempt to further characterize the biological profile of RASP, we tested its effects on organ toxicity and teratogenicity by daily oral gavage of RASP at a level of 50 mg/Kg of body weight in two generations of rats. We found that this compound does not induce changes to the body growth, the appearance of physical features, and the animal's reflexes. Additionally, no substantial histopathological lesions were found in brain, heart, lung, thymus, liver, thyroid gland, adrenal gland, pituitary gland, kidneys, spleen, skin, femora, prostate, testis, epididymis, vagina, uterus, and ovaries of RASP-treated animals. These results suggest RASP, as a promising lead compound for the treatment of several dermatological disorders and certain cancer types, has apparently minimal toxic side-effects as revealed in this two-generation reproduction study in rats., (© 2016 Wiley Periodicals, Inc.)

The foetal outcomes of 2,635 pregnancies recorded in the Australian Pregnancy Register were studied. In at least the initial 4months of 515 pregnancies, there had been no intrauterine exposure to antiepileptic drugs, though the women involved in 264 of these pregnancies took antiepileptic drugs in later pregnancies. Compared with these 515 drug-unexposed pregnancies, foetal malformations risks were increased more than five-fold in association with valproate monotherapy, and more than doubled in association with carbamazepine monotherapy (p<0.05). There were no statistically significant increases in malformation rates associated with other more commonly used antiepileptic drugs, while the malformation risk in relation to levetiracetam exposure was lower than that in the drug-unexposed pregnancies. The published literature has rather consistently shown raised malformation rates associated with carbamazepine monotherapy, though only once was it statistically significant. There now appears to be enough evidence to make it likely that carbamazepine possesses some teratogenic capacity. This makes it unwise to employ the malformation rate associated with carbamazepine monotherapy as a comparator when assessing the foetal hazards from exposure to newer antiepileptic drugs. Levetiracetam may prove a better comparator if adequate untreated control material is unobtainable., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Mammalian fetal development is easily disrupted by exogenous agents, making it essential to test new drug candidates for embryotoxicity and teratogenicity. To standardize the testing of drugs that might be used to treat pregnant women, the U.S. Food and Drug Administration (FDA) formulated special grade categories, labeled A, B, C, D and X, that define the level of risk associated with the use of a specific drug during pregnancy. Drugs in categories (Cat.) D and X are those with embryotoxic and/or teratogenic effects on humans and animals. However, which stages of pregnancy are affected by these agents and their molecular mechanisms are unknown. We describe here an embryonic stem cell test (EST) that classifies FDA pregnancy Cat.D and Cat.X drugs into 4 classes based on their differing effects on primitive streak formation. We show that ~84% of Cat.D and Cat.X drugs target this period of embryogenesis. Our results demonstrate that our modified EST can identify how a drug affects early embryogenesis, when it acts, and its molecular mechanism. Our test may thus be a useful addition to the drug safety testing armamentarium.

The aim of this study was to evaluate the toxicity of Stryphnodendron fissuratum pods in guinea pigs (Cavia porcellus) and test the hypothesis that this plant has teratogenic effects. Thus, sixteen guinea pigs were randomly divided into four groups of four animals each. Groups 10, 20 and 40 consisted of guinea pigs that received commercial food that contained crushed pods of S. fissuratum at concentrations of 10, 20 and 40 g/kg, respectively, during the period of organogenesis. Control group consisted of guinea pigs under the same management conditions that did not receive crushed pods of S. fissuratum in their food. In all experimental groups, the main clinical signs of poisoning consisted of anorexia, prostration, absence of vocalizations, alopecia, diarrhea, and abortions within the adult guinea pigs. Those that did not abort gave birth to weak, malnourished pups, some of which had fetal malformations. The main teratogenic changes consisted of eventration, arthrogryposis, amelia of the forelimbs, anophthalmia, microphthalmia, anotia and agnathia. The reductions in the number of offspring and the malformations observed in the experimental groups suggest that S. fissuratum affects fetal development and is teratogenic., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The brominated flame retardants (BFRs) 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH or DBE-DCBH) and allyl 2,4,6-tribromophenyl ether (ATE or TBP-AE) are alternative BFRs that have been introduced to replace banned BFRs. TBECH is a potential endocrine disrupter in human, chicken and zebrafish and in a recent study we showed that ATE, along with the structurally similar BFR 2,3-dibromopropyl 2,4,6-tribromophenyl ether (DPTE or TBP-DBPE) and its metabolite 2-bromoallyl 2,4,6-tribromophenyl ether (BATE or TBP-BAE) are potential endocrine and neuronal disrupters in human. In this study we analyzed ATE, BATE and DPTE for zebrafish androgen receptor (zAR) modulating properties. In silico analysis with two softwares, Molecular Operating Environment (MOE) and Internal Coordinate Mechanics (ICM), showed that ATE, BATE and DPTE bind to zAR. In vitro AR activation assay revealed that these three BFRs down-regulate 11-ketotestosterone (KT) mediated zAR activation. Exposure to 10 μM DPTE resulted in reduced hatching success and like TBECH, BATE and DPTE at 10 μM also had teratogenic properties with 20% and 50% back-bone curvature respectively. Gene transcription analysis in zebrafish embryos as well as in juveniles showed down-regulation of the androgen receptor and androgen response genes, which further support that these BFRs are androgen antagonists and potential endocrine disrupting compounds. Genes involved in steroidogenesis were also down-regulated by these BFRs. In view of this, the impact of these BFRs on humans and wildlife needs further analysis., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

With the rapid growth of nanotechnology and the applications of nanoparticles, environmental exposure to these particles is increasing. However, their impact in human and environmental health is not well studied. Anurans, with life stage comprising embryos, tadpoles and adults, have an extremely permeable skin which makes them excellent indicators of environmental health. This study evaluated the acute toxicity effects of polyaniline nanoparticles (PANI-Np) in different dispersant on embryos and larvae of Rhinella arenarum. The results showed that LC50 of PANI-Np dispersed in polyvinylpyrrolidone (PVP) were 1,500 mg/L, while LC50 by PANI-Np dispersed in PVP+PNIPAM (polyN-isopropylacrilamide) showed a highest toxicity (1,170 mg/L). The embryo teratogenicity increased with increasing exposure concentration in both kinds of PANI-Np although in PANI-Np1, there is an increased teratogenic effect associated with the polymer stabilizer PVP., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The toxicity of Nonylphenol, an emerging pollutant, on the common South American toad Rhinella arenarum was stage and time dependent, thus Median Lethal Concentrations (LC50) for acute (96h), short-term chronic (168h) and chronic exposure (336h) were 1.06; 0.96 and 0.17mgNP/L from embryonic period (S.4), whereas for exposure from larvae (S.25), LC50 remained constant at 0.37mgNP/L from 96h to 168h, decreasing to 0.11mgNP/L at 336h. NOEC-168h for exposure from embryos was 0.025mgNP/L. The Teratogenic Potential (NOEC-lethality/NOEC-sublethal effects) was 23 times higher than the threshold value, indicating a high risk for embryos to be malformed in absence of significant lethality and representing a threat for the species conservation. By comparing with other amphibians, the early development of R. arenarum was very sensitive to NP. The results highlight the relevance of extending the exposure time and look for the most sensitive stage in order to perform the bioassays for conservation purposes., (Copyright © 2014 Elsevier B.V. All rights reserved.)

We previously observed a higher incidence of congenital malformations in the fetuses of dams fed an oxidized frying oil (OFO)-containing diet during pregnancy. In this study, we hypothesized that, during pregnancy, maternal ingestion of OFO, specifically the oxidized components (i.e. the polar fraction), modulates peroxisome proliferator-activated receptor (PPARα) or aryl hydrocarbon receptor (AhR) transactivity, altering the metabolism of retinoic acid (RA), a well-characterized morphogen, resulting in teratogenesis. Pregnant C57BL/6J mice were divided into four groups which, from d1 (conception) to d18, were fed a diet containing 10 g/100 g of fresh soybean oil (SO), OFO or the non-polar (NP) or polar (PO) fraction of OFO. Reporter assays testing the transactivity of PPARα and AhR showed that free fatty acids from OFO, specifically the PO fraction, up-regulated PPARα transactivity and down-regulated AhR transactivity. In vivo study showed that the PO fraction group had a significantly higher number of dead fetuses and resorptions per litter than the SO and NP fraction groups. The incidence of abnormalities in terms of gross morphology and skeletal ossification of the fetus was greatest in the PO fraction group, followed by the OFO group, both values being significantly higher than in the other two groups. Hepatic expression of genes encoding enzymes associated with RA synthesis and catabolism in dams and fetuses was differentially affected by PO fraction assault. We conclude that OFO-mediated teratogenesis is associated with disturbed RA metabolism in the dams and fetuses caused, at least in part, by modulation of PPARα and AhR transactivity by the oxidized components in OFO., (Copyright © 2014 Elsevier Inc. All rights reserved.)

The acute and chronic toxicity of bisphenol A (BPA) was evaluated on the common South American toad Rhinella arenarum embryos and larvae by means of continuous and pulse exposure treatments. Embryos were treated continuously from early blastula (S.4) up to complete operculum (S.25), during early larval stages and by means of 24 h pulse exposures of BPA in concentrations ranging between 1.25 and 40 mg L(-1) , in order to evaluate the susceptibility to this compound in different developmental stages. For lethal effects, S.25 was the most sensitive and gastrula was the most resistant to BPA. The Teratogenic Index for neurula, the most sensitive embryonic stage for sublethal effects was 4.7. The main morphological alterations during early stages were: delayed or arrested development, reduced body size, persistent yolk plug, microcephaly, axial/tail flexures, edemas, blisters, waving fin, underdeveloped gills, mouth malformations, and cellular dissociation. BPA caused a remarkable narcotic effect from gill circulation stage (S.20) onwards in all the organisms exposed after 3 h of treatment with 10 mg L(-1) BPA. After recovering, the embryos exhibited scarce response to stimuli, erratic or circular swimming, and spasmodic contractions from 5 mg L(-1) onwards. Our results highlight the lethal and sublethal effectsof BPA on R. arenarum embryos and larvae, in the last case both at structural and functional levels., (Copyright © 2011 Wiley Periodicals, Inc., A Wiley Company.)

Birth defects may originate through multiple mechanisms and may be caused by a variety of possible exposures, including medications in early pregnancy. In this review, we describe six principal teratogenic mechanisms suspected to be associated with medication use: folate antagonism, neural crest cell disruption, endocrine disruption, oxidative stress, vascular disruption, and specific receptor- or enzyme-mediated teratogenesis. Knowledge about these mechanisms, for some of which evidence is mainly derived from animal models, may not only be relevant for etiologic and post-marketing research, but may also have implications for prescribing behavior for women of reproductive age. Since combinations of seemingly unrelated medications may have effects through similar teratogenic mechanisms, the risk of birth defects may be strongly increased in multi-therapy., (© 2014 Société Française de Pharmacologie et de Thérapeutique.)