Polyhydroxy steroids isolated from starfish (Asterina pectinifera) and their embryotoxicity

Many marine organisms possess an essential capacity to produce secondary metabolites that exhibit toxic characteristics. A new polyhydroxy steroid, 24-methyl-5α-cholestane-24(28)-ene-3β, 4β, 6α, 7α, 8, 15β, 16β, 26-octol-6-O-sodium sulphate (1) was isolated from starfish (Asterina pectinifera), along with five polar steroid compounds (2-6) that were previously identified. NMR (1H and 13C NMR, 1H-1H COSY, HSQC, HMBC, and NOESY) and HR-ESI-MS were employed for structure elucidations. The embryotoxicity and teratogenicity of the isolated compounds were assessed using embryos of marine medaka (Oryzias melastigma). Compound 5 exhibited moderate embryotoxicity (96h-LC50: 65 μM).

Embryotoxicity Induced by Triclopyr in Zebrafish (Danio rerio) Early Life Stage

Triclopyr, an auxin-like herbicide that is widely employed for managing weeds in food crops and pastures, has been identified in various environmental settings, particularly aquatic ecosystems. Limited understanding of the environmental fate of this herbicide, its potential repercussions for both the environment and human health, and its insufficient monitoring in diverse environmental compartments has caused it to be recognized as an emerging contaminant of concern. In this study, we have investigated how triclopyr affects zebrafish, considering a new alternative methodology. We focused on the endpoints of developmental toxicity, neurotoxicity, and behavior of zebrafish embryos and larvae. We determined that triclopyr has a 96 h median lethal concentration of 87.46 mg/L (341.01 µM). When we exposed zebrafish embryos to sublethal triclopyr concentrations (0.5, 1, 5, 10, and 50 μM) for up to 144 h, we found that 50 µM triclopyr delayed zebrafish egg hatchability. Yolk sac malabsorption was significant at 0.5, 1, 5, and 10 µM triclopyr. In zebrafish larvae, uninflated swim bladder was significant only at 50 µM triclopyr. Furthermore, zebrafish larvae had altered swimming activity after exposure to 10 µM triclopyr for 144 h. In summary, these comprehensive results indicate that even low triclopyr concentrations can elicit adverse effects during early zebrafish development.

Developmental toxicity of pyriproxyfen induces changes in the ultrastructure of neural cells and in the process of skull ossification

Some studies relate the use of pyriproxyfen (PPF) in drinking water with damage to embryonic neurodevelopment, including a supposed association with cases of microcephaly. However, the effects on neural cells and skull ossification in embryos remain unclear. This study aims to investigate the effects of PPF on the structure and ultrastructure of brain cells and its influence on the skull ossification process during embryonic development. Chicken embryos, used as an experimental model, were exposed to concentrations of 0.01 and 10 mg/l PPF at E1. The findings demonstrated that PPF led to notable ultrastructural alterations such as reduced cilia and microvilli of ependymal cells and damage to mitochondria, endoplasmic reticulum, Golgi bodies, and cell membranes in neural cells. The frequency of changes and the degree of these cell damage between the forebrain and midbrain were similar. PPF induced a reduction in fox3 transcript levels, specific for differentiation of neurons, and a reduction in the NeuN protein content related to mature neurons and dendritic branches. PPF impacted the ossification process of the skull, as evidenced by the increase in the ossified area and the decrease in inter-bone spacing. In conclusion, this study highlights the ability of PPF to affect neurodevelopmental processes by inducing ultrastructural damage to neural cells, concomitant with a reduction in NeuN and fox3 expression. This detrimental impact coupled with deficiencies in skull ossification can prevent the proper growth and development of the brain.

Assessing the Toxicity of Benzotriazole Ultraviolet Stabilizers to Fishes: Insights into Aryl Hydrocarbon Receptor-Mediated Effects

Benzotriazole ultraviolet stabilizers (BUVSs) are chemicals used to mitigate UV-induced damage to manufactured goods. Their presence in aquatic environments and biota raises concerns, as certain BUVSs activate the aryl hydrocarbon receptor (AhR), which is linked to adverse effects in fish. However, potencies of BUVSs as AhR agonists and species sensitivities to AhR activation are poorly understood. This study evaluated the toxicity of three BUVSs using embryotoxicity assays. Zebrafish (Danio rerio) embryos exposed to BUVSs by microinjection suffered dose-dependent increases in mortality, with LD50 values of 4772, 11 608, and 56 292 ng/g-egg for UV-P, UV-9, and UV-090, respectively. The potencies and species sensitivities to AhR2 activation by BUVSs were assessed using a luciferase reporter gene assay with COS-7 cells transfected with the AhR2 of zebrafish and eight other fishes. The rank order of potency for activation of the AhR2 from all nine species was UV-P > UV-9 > UV-090. However, AhR2s among species differed in sensitivities to activation by up to 100-fold. An approximate reversed rank order of species sensitivity was observed compared to the rank order of sensitivity to 2,3,7,8-tetrachlorodibenzo[p]dioxin, the prototypical AhR agonist. Despite this, a pre-existing quantitative adverse outcome pathway linking AhR activation to embryo lethality could predict embryotoxicities of BUVSs in zebrafish.

Sublethal Effects of Polystyrene Nanoplastics on the Embryonic Development of Artemia salina (Linnaeus, 1758)

Currents, wave motion, solar radiation, and abrasion are mechanisms responsible for the degradation of large plastic artifacts and contribute to the dispersion of micro and nanoplastics into aquatic ecosystems, which are, currently, the most dangerous threats due to their invisibility and persistence. The present work evaluated the possible lethal and sublethal effects of amino-modified polystyrene nanoplastics (nPS-NH2) with diameters of 50 nm and 100 nm on Artemia salina (A. salina), an organism at the base of the trophic chain of the aquatic system, using a widely used model for the analysis of embryotoxicity from environmental pollutants. For this purpose, after evaluating the biodistribution of nanoplastics in the body of the tested animals, several endpoints such as anomalies, apoptosis, and ROS production were assessed. In addition, particular attention was dedicated to evaluating the correlation between toxicity and the particle size tested. The results reported that, despite the absence of a lethal impact, several sublethal effects involving gut and body size malformations, as well as the enhancement of apoptosis and oxidative stress in relation to an increase in tested concentration and a decrease in nanoparticle size.

Effects of Tributyltin-Contaminated Aquatic Environments and Remediated Water on Early Development of Sea Urchin (Hemisentrotus pulcherrimus)

In this study, gametotoxicity and embryotoxicity experiments were performed using Hemicentrotus pulcherrimus to investigate the toxic effects of tributyltin (TBT). The effects of TBT on fertilization and embryogenesis were assessed at various concentrations (0, 0.02, 0.05, 0.09, 0.16, 0.43, 0.73, 4.68, and 9.22 ppb). The fertilization rates decreased in a concentration-dependent manner, with significant reduction following treatment with TBT at 0.05 ppb. Embryos exhibited developmental impairment after TBT exposure at each tested concentration. The frequency of developmental inhibition delay that treatment with TBT delayed embryonic development in a dose-dependent manner, with 100% of embryos exhibiting developmental impairment at 4.68 ppb. During developmental recovery tests, embryos cultured in fresh media without TBT showed advanced embryonic development. Although the observed normal development after transferring the developmentally delayed embryos to fresh media without TBT offers prospects for the restoration of contaminated environments, embryonic development remained incomplete. These results suggest that TBT adversely affects the early embryonic development of H. pulcherrimus.

Chemical Composition, In Vitro Antitumor Effect, and Toxicity in Zebrafish of the Essential Oil from Conyza bonariensis (L.) Cronquist (Asteraceae)

The essential oil from Conyza bonariensis (Asteraceae) aerial parts (CBEO) was extracted by hydrodistillation in a Clevenger-type apparatus and was characterized by gas chromatography-mass spectrometry. The antitumor potential was evaluated against human tumor cell lines (melanoma, cervical, colorectal, and leukemias), as well as non-tumor keratinocyte lines using the MTT assay. The effect of CBEO on the production of Reactive Oxygen Species (ROS) was evaluated by DCFH-DA assay, and a protection assay using the antioxidant N-acetyl-L-cysteine (NAC) was also performed. Moreover, the CBEO toxicity in the zebrafish model was assessed. The majority of the CBEO compound was (Z)-2-lachnophyllum ester (57.24%). The CBEO exhibited selectivity towards SK-MEL-28 melanoma cells (half maximal inhibitory concentration, IC50 = 18.65 ± 1.16 µg/mL), and induced a significant increase in ROS production. In addition, the CBEO's cytotoxicity against SK-MEL-28 cells was reduced after pretreatment with NAC. Furthermore, after 96 h of exposure, 1.5 µg/mL CBEO induced death of all zebrafish embryos. Non-lethal effects were observed after exposure to 0.50-1.25 µg/mL CBEO. Additionally, significant alterations in the activity of enzymes associated with oxidative stress in zebrafish larvae were observed. These results provide evidence that CBEO has a significant in vitro antimelanoma effect by increasing ROS production and moderate embryotoxicity in zebrafish.

Green Chromatographic Methods and in Vitro Pharmacological Analysis of Varronia curassavica Leaf Derivatives

Varronia curassavica displays anti-inflammatory, antiulcerogenic, and antioxidant activities. Herein, we employed new UHPLC -UV green chromatographic methods for the analysis of in vitro antioxidant and anti-inflammatory activities of V. curassavica and its embryotoxicity in Zebrafish. Cordialin A, brickellin, and artemetin were purified from the ethanol (EtOH) extract of V. Curassavica leaves and identified using spectrometric techniques. In line with Green Analytical Chemistry principles, the proposed UHPLC methods involve the use of ethanol as organic modifier with low mobile phase consumption, and without sample pretreatment (OLE-UHPLC-UV). The application of the Agree and HPLC-EAT tools for greenness assessment yielded this pattern: HPLC-UV (reference) Collapse

Key Words

• Varronia curassavica
• anti-inflammatory
• antioxidant
• embryotoxicity
• green chemistry

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MESH Headings

• Animals
• Plant Extracts/chemistry
• Antioxidants/chemistry
• Zebrafish
• Anti-Inflammatory Agents/pharmacology
• Plant Leaves/chemistry
• Ethanol

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Grants

• Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES)
• #465637/2014-0 National Institute of Science and Technology on Biodiversity and Natural Products - INCT-BioNat

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Affiliation(s)

Isabela Jacob Moro Department of Drugs and Medicines, São Paulo State University (Unesp), School of Pharmaceutical Sciences, Araraquara-Jaú Road, Km 01, s/n, 14.801-903, Araraquara, SP, Brazil
Flávio Alexandre Carvalho Department of Drugs and Medicines, São Paulo State University (Unesp), School of Pharmaceutical Sciences, Araraquara-Jaú Road, Km 01, s/n, 14.801-903, Araraquara, SP, Brazil
Juhan Augusto Scardelato Pereira Department of Drugs and Medicines, São Paulo State University (Unesp), School of Pharmaceutical Sciences, Araraquara-Jaú Road, Km 01, s/n, 14.801-903, Araraquara, SP, Brazil
Gabriela Brasil Romão Department of Drugs and Medicines, São Paulo State University (Unesp), School of Pharmaceutical Sciences, Araraquara-Jaú Road, Km 01, s/n, 14.801-903, Araraquara, SP, Brazil
André Faibicher Department of Drugs and Medicines, São Paulo State University (Unesp), School of Pharmaceutical Sciences, Araraquara-Jaú Road, Km 01, s/n, 14.801-903, Araraquara, SP, Brazil
Winner Duque Rodrigues Department of Drugs and Medicines, São Paulo State University (Unesp), School of Pharmaceutical Sciences, Araraquara-Jaú Road, Km 01, s/n, 14.801-903, Araraquara, SP, Brazil
Renata Pires Assis Department of Clinical Analysis, São Paulo State University (Unesp), School of Pharmaceutical Sciences, Araraquara-Jaú Road, Km 01, s/n, 14.801-903, Araraquara, SP, Brazil
Iguatemy Lourenço Brunetti Department of Clinical Analysis, São Paulo State University (Unesp), School of Pharmaceutical Sciences, Araraquara-Jaú Road, Km 01, s/n, 14.801-903, Araraquara, SP, Brazil
Junya de Lacorte Singulani Department of Clinical Analysis, São Paulo State University (Unesp), School of Pharmaceutical Sciences, Araraquara-Jaú Road, Km 01, s/n, 14.801-903, Araraquara, SP, Brazil
Ana Marisa Fusco-Almeida Department of Clinical Analysis, São Paulo State University (Unesp), School of Pharmaceutical Sciences, Araraquara-Jaú Road, Km 01, s/n, 14.801-903, Araraquara, SP, Brazil
André Gonzaga Dos Santos Department of Drugs and Medicines, São Paulo State University (Unesp), School of Pharmaceutical Sciences, Araraquara-Jaú Road, Km 01, s/n, 14.801-903, Araraquara, SP, Brazil

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Cyclophilin A as a Pro-Inflammatory Factor Exhibits Embryotoxic and Teratogenic Effects during Fetal Organogenesis

The precise balance of Th1, Th2, and Th17 cytokines is a key factor in successful pregnancy and normal embryonic development. However, to date, not all humoral factors that regulate and influence physiological pregnancy have been completely studied. Our data here pointed out cyclophilin A (CypA) as the adverse pro-inflammatory factor negatively affecting fetal development and associated with pregnancy complications. In different mouse models in vivo, we demonstrated dramatic embryotoxicity and teratogenicity of increased CypA levels during pregnancy. Using generated transgenic models, we showed that CypA overexpression in fetal tissues induced the death of all transgenic fetuses and complete miscarriage. Administration of recombinant human CypA in a high dose to pregnant females during fetal organogenesis (6.5-11.5 dpc) exhibited teratogenic effects, causing severe defects in the brain and bone development that could lead to malformations and postnatal behavioral and cognitive disorders in the offspring. Embryotoxic and teratogenic effects could be mediated by CypA-induced up-regulation of M1 macrophage polarization via activation of the STAT1/3 signaling pathways. Here, we propose secreted CypA as a novel marker of complicated pregnancy and a therapeutic target for the correction of pregnancy complications.

Toxic effects of bisphenol AF on the embryonic development of marine medaka (Oryzias melastigma)

Bisphenol AF (BPAF), an emerging environmental endocrine disruptor, has been detected in surface waters worldwide and has adverse effects on aquatic organisms. The accumulation of BPAF in oceans and its potential toxic effect on marine organisms are important concerns. In this study, the effects of BPAF (10, 100, 1, and 5 mg/L) on marine medaka (Oryzias melastigma) were evaluated, including effects on the survival rate, heart rate, hatchability, morphology, and gene expression in embryos. The survival rate of marine medaka embryos was significantly lower after treatment with 5 mg/L BPAF than in the solvent control group. Exposure to 1 mg/L and 5 mg/L BPAF significantly reduced hatchability. Low-dose BPAF (10 μg/L) significantly accelerated the heart rate of embryos, while high-dose BPAF (5 mg/L) significantly decreased the heart rate. BPAF exposure also resulted in notochord curvature, pericardial edema, yolk sac cysts, cardiovascular bleeding, and caudal curvature in marine medaka. At the molecular level, BPAF exposure affected the transcript levels of genes involved in the thyroid system (dio1, dio3a, trhr2, tg, and thra), cardiovascular system (gata4, atp2a1, and cacna1da), nervous system (elavl3 and gap43), and antioxidant and inflammatory systems (sod, pparβ, and il-8) in embryos. These results indicate that BPAF exposure can alter the expression of functional genes, induce abnormal development, and reduce the hatching and survival rates in marine medaka embryos. Overall, BPAF can adversely affect the survival and development of marine medaka embryos, and BPAF may not be an ideal substitute for BPA.

Pre-imaginal exposure to mancozeb induces morphological and behavioral deficits and oxidative damage in Drosophila melanogaster

Mancozeb (MZ), a manganese/zinc containing ethylene-bis-dithiocarbamate, is a broad-spectrum fungicide. Chronic exposure to MZ has been related to several organisms' neurological, hormonal, and developmental disorders. However, little is known about the post-natal effects of developmental exposure to MZ. In this study, Drosophila melanogaster was subjected to a pre-imaginal (eggs-larvae-pupae stage) model of exposure to MZ at 0.1 and 0.5 mg/mL. The emergence rate, body size, locomotor performance, sleep patterns, and molecular and biochemical parameters were evaluated in post-emerged flies. Results demonstrate that pre-imaginal exposure to MZ significantly impacted early emerged flies. Additionally, reduced progeny viability, smaller body size and delaying in emergence period, locomotor impairment, and prolonged sleep time were observed. Content of glucose, proteins, and triglycerides were altered, and the bioenergetics efficiency and oxidative phosphorylation at complex I were inhibited. mRNA stade state levels of genes responsive to stress, metabolism, and regulation of circadian cycle (Nrf2, p38, Hsp83, Akt1, GPDH, tor, per, tim, dILP2, and dILP6) were augmented, pointing out to stimulation of antioxidant defenses, insulin-dependent signaling pathway activation, and disruption of sleep regulation. These data were followed by increased lipid peroxidation and lower glutathione levels. In addition, the activity of catalase and glutathione-S-transferase were induced, whereas superoxide dismutase was inhibited. Together, these results demonstrate that developmental exposure to MZ formulation led to phenotype and behavioral alterations in young flies, possibly related to disruption of energetic metabolism, oxidative stress, and deregulation of genes implied in growth, sleep, and metabolism.

Acute Toxicity of the Dinoflagellate Amphidinium carterae on Early Life Stages of Zebrafish (Danio rerio)

Dinoflagellates of the genus Amphidinium can produce a variety of polyketides, such as amphidinols (AMs), amphidinoketides, and amphidinin, that have hemolytic, cytotoxic, and fish mortality properties. AMs pose a significant threat to ecological function due to their membrane-disrupting and permeabilizing properties, as well as their hydrophobicity. Our research aims to investigate the disparate distribution of AMs between intracellular and extracellular environments, as well as the threat that AMs pose to aquatic organisms. As a result, AMs containing sulphate groups such as AM19 with lower bioactivity comprised the majority of A. carterae strain GY-H35, while AMs without sulphate groups such as AM18 with higher bioactivity displayed a higher proportion and hemolytic activity in the extracellular environment, suggesting that AMs may serve as allelochemicals. When the concentration of extracellular crude extracts of AMs reached 0.81 µg/mL in the solution, significant differences in zebrafish embryonic mortality and malformation were observed. Over 96 hpf, 0.25 μL/mL of AMs could cause significant pericardial edema, heart rate decrease, pectoral fin deformation, and spinal deformation in zebrafish larvae. Our findings emphasized the necessity of conducting systematic research on the differences between the intracellular and extracellular distribution of toxins to gain a more accurate understanding of their effects on humans and the environment.

Polymer Chemical Identity as a Key Factor in Microplastic-Insecticide Antagonistic Effects during Embryogenesis of Sea Urchin Arbacia lixula

As a proxy for pollutants that may be simultaneously present in urban wastewater streams, the effects of two microplastics-polystyrene (PS; 10, 80 and 230 μm diameter) and polymethylmethacrylate (PMMA; 10 and 50 μm diameter)-on fertilisation and embryogenesis in the sea urchin Arbacia lixula with co-exposure to the pyrethroid insecticide cypermethrin were investigated. Synergistic or additive effects were not seen for plastic microparticles (50 mg L^-1) in combination with cypermethrin (10 and 1000 μg L^-1) based on evaluation of skeletal abnormalities or arrested development and death of significant numbers of larvae during the embryotoxicity assay. This behaviour was also apparent for male gametes pretreated with PS and PMMA microplastics and cypermethrin, where a reduction in sperm fertilisation ability was not evidenced. However, a modest reduction in the quality of the offspring was noted, suggesting that there may be some transmissible damage to the zygotes. PMMA microparticles were more readily taken up than PS microparticles, which could suggest surface chemical identity as potentially modulating the affinity of larvae for specific plastics. In contrast, significantly reduced toxicity was noted for the combination of PMMA microparticles and cypermethrin (100 μg L^-1), and may be related to less ready desorption of the pyrethroid than PS, as well as cypermethrin activating mechanisms that result in reduced feeding and hence decreased ingestion of microparticles.

Effects of Sodium Arsenite on the Myocardial Differentiation in Mouse Embryonic Bodies

Arsenic in inorganic form is a known human carcinogen; even low levels of arsenic can interfere with the endocrine system. In mammalian development, arsenic exposure can cause a malformation of fetuses and be lethal. This study examined the effects of sodium arsenite (SA) as the inorganic form of arsenic in embryonic bodies (EBs) with three germ layers in the developmental stage. This condition is closer to the physiological condition than a 2D cell culture. The SA treatment inhibited EBs from differentiating into cardiomyocytes. A treatment with 1 μM SA delayed the initiation of beating, presenting successful cardiomyocyte differentiation. In particular, mitochondria function analysis showed that SA downregulated the transcription level of the Complex IV gene. SA increased the fission form of mitochondrion identified by the mitochondria number and length. In addition, a treatment with D-penicillamine, an arsenic chelator, restored the beat of EBs against SA, but not mitochondrial dysfunction. These findings suggest that SA is a toxicant that induces mitochondrial damage and interferes with myocardial differentiation and embryogenesis. This study suggests that more awareness of SA exposure during pregnancy is required because even minuscule amounts have irreversible adverse effects on embryogenesis through mitochondria dysfunction.

Study of the Embryonic Toxicity of TiO2 and ZrO2 Nanoparticles

Currently, the widespread use of TiO₂ and ZrO₂ nanoparticles (NPs) in various industries poses a risk in terms of their potential toxicity. A number of experimental studies provide evidence of the toxic effect of TiO₂ and ZrO₂ NPs on biological objects. In order to supplement the level of knowledge and assess the risks of toxicity and danger of TiO₂ and ZrO₂ NPs, we decided to conduct a comprehensive experiment to study the embryonic toxicity of TiO₂ and ZrO₂ NPs in pregnant rats. For the experiment, mongrel white rats during pregnancy received aqueous dispersions of powders of TiO₂ and ZrO₂ NPs at a dose of 100 mg/kg/day. To characterize the effect of TiO₂ and ZrO₂ NPs on females and the postnatal ontogenesis of offspring, a complex of physiological and biochemical research methods was used. The results of the experiment showed that TiO₂ NPs as ZrO₂ NPs (100 mg/kg per os) cause few shifts of similar orientation in the maternal body. Neither TiO₂ NPs nor ZrO₂ NPs have an embryonic and teratogenic effect on the offspring in utero, but both modify its postnatal development.

Embryotoxicity and Teratogenicity of Steroidal Saponin Isolated from Ophiopholis mirabilis

Benthic invertebrates produce secondary metabolites that serve as defenses against consumers and promote their fitness. To explore the chemical defense in marine benthic echinoderms, the chemical constituents of Ophiopholis mirabilis were investigated. A steroidal monoglycoside, asterosaponin P1, was isolated from O. mirabilis for the first-time using column chromatography. The chemical structure was characterized by spectroscopic and spectrometric methods. The embryotoxicity and teratogenicity of the isolated compound were assessed using the zebrafish embryo assay, a powerful vertebrate animal model system to study mechanisms of toxicity. When applied at high concentrations, asterosaponin P1 causes a significant increase in embryo mortality. A moderate LC₅₀ of asterosaponin P1 appeared to be time- and concentration-dependent in its toxicity to zebrafish embryos. Teratogenicity in zebrafish embryos also included morphological defects, decreased hatchability, and a reduced heart rate. These findings revealed that steroidal saponin extracted from O. mirabilis exhibited acute toxic effects on zebrafish embryos, suggesting a potential chemical defense function in marine habitats.

PCNB exposure during early embryogenic development induces developmental delay and teratogenicity by altering the gene expression in Xenopus laevis

Pentachloronitrobenzene (PCNB) is an organochlorine fungicide commonly used to treat seeds against seedling infections and controlling snow mold on golf courses. PCNB has been demonstrated to be toxic to living organisms, including fish and several terrestrial organisms. However, only phenotypical deformities have been studied, and the effects of PCNB on early embryogenesis, where primary organogenesis occurs, have not been completely studied. In the current study, the developmental toxicity and teratogenicity of PCNB is evaluated by using frog embryo teratogenesis assay Xenopus (FETAX). Our results confirmed the teratogenic potential of PCNB revealing the teratogenic index of 1.29 during early embryogenesis. Morphological studies revealed tiny head, bent axis, reduced inter ocular distance, hyperpigmentation, and reduced total body lengths. Whole mount in situ hybridization and reverse transcriptase polymerase chain reaction were used to identify PCNB teratogenic effects at the gene level. The gene expression analyses revealed that PCNB was embryotoxic to the liver and heart of developing embryos. Additionally, to determine the most sensitive developmental stages to PCNB, embryos were exposed to the compound at various developmental stages, demonstrating that the most sensitive developmental stage to PCNB is primary organogenesis. Taken together, we infer that PCNB's teratogenic potential affects not just the phenotype of developing embryos but also the associated genes and involving the oxidative stress as a possible mechanism of toxicity, posing a hazard to normal embryonic growth. However, the mechanisms of teratogenesis require additional extensive investigation to be defined completely.

Toxico-pathological effects of ochratoxin A and its diastereoisomer under in ovo conditions and in vitro evaluation of the toxicity of these toxins against the embryo Gallus gallus fibroblast cell line

Herein, we conducted a comparative study on the embryotoxicity of ochratoxin A (OTA) and its diastereomer 2'R-ochratoxin A (2'R-OTA) under in ovo conditions, as well as assess the in vitro embryotoxicity of these substances together with ochratoxin B and α-ochratoxin, using chicken (Gallus gallus domesticus) embryo cell lines. In ovo tests involved egg incubation of 8 different groups (i.e., control "0"-no puncture or injection (standard incubation); "00"-punctured eggs without injection; "OTA 0.25," "OTA 0.50," "OTA 0.75," "2'R-OTA 0.25," "2'R-OTA 0.50," "2'R-OTA 0.75"-eggs containing OTA or 2'R-OTA at 0.25, 0.50, and 0.75 µg/egg concentration, respectively). The results confirmed OTA's impact on early and late embryo mortality, where chick hatchability decreased with increasing toxin dosage. Both OTA and 2'R-OTA demonstrated embryotoxicity, however, in the case of the highest OTA diastereomer dose, nearly 11% higher chick hatchability was observed compared with the group that received OTA. 2'R-OTA dosage did not reduce parameters chick quality compared to chicks hatched from control group eggs. OTA concentrations were higher than 2'R-OTA detected in chicken organs such as liver and kidney, whereas 2'R-OTA concentrations were higher in blood serum and heart. The presented studies highlighted the differences in the ability to accumulate toxins in certain organs, which, to a certain extent, may affect the potential toxicity on individual organs. Additionally, during in vitro tests, when assessing the cytotoxic effects of OTA and its analogues toward the chicken embryonic cell line in an MTT assay, the cell metabolic activity was inhibited to a comparable extent at 27-times higher concentration of 2'R-OTA than OTA (0.24 µM). Also, comparably lower toxicity was attributed to the remaining OTA derivatives.

Toxic, cytotoxic and genotoxic effect of plumbagin in the developmental stages of Biomphalaria glabrata (Say, 1818-intermediate host) and cercaricidal activity against the infectious agent of schistosomiasis mansoni

BACKGROUND

Snails of the genus Biomphalaria are intermediate hosts of Schistosoma mansoni, the main etiological agent of schistosomiasis mansoni, which affects about 236.6 million people in tropical and subtropical regions of the world. The World Health Organization recommends the population control of vector snails as one of the strategies to reduce the prevalence and incidence of schistosomiasis. In this study, molluscicidal and antiparasitic activities of plumbagin, a naturally sourced naphthoquinone with a range of biological effects, were evaluated against B. glabrata and cercariae of S. mansoni.

RESULTS

After 24 h of exposure, plumbagin demonstrated molluscicidal activity at low concentrations against embryos (LC₅₀ of 0.56, 0.93, 0.68, 0.51 and 0.74 μg mL^-1 for the blastula, gastrula, trochophore, veliger and hippo stage, respectively) and adult snails (LC₅₀ of 3.56 μg mL^-1 ). There were no changes in exposed snails' fecundity or fertility; however, plumbagin was able to increase the frequency of DNA damage and the number of hemocytes, with apoptosis and binucleation being the main hemocyte alterations. In addition, plumbagin showed death of S. mansoni cercariae in the concentration of 1.5 μg mL^-1 in 60 min, while showing moderate toxicity to Artemia salina.

CONCLUSION

Plumbagin proved to be a promising substance for the control of B. glabrata population, intermediate host of S. mansoni, as well as the cercariae, infective stage for humans (definitive host), while being moderately toxic to A. salina, a crustacean widely used in ecotoxicity tests. © 2022 Society of Chemical Industry.

Cyclophosphamide Induces Lipid and Metabolite Perturbation in Amniotic Fluid during Rat Embryonic Development

Cyclophosphamide (CP) has been proven to be an embryo-fetal toxic. However, the mechanism responsible for the toxicity of the teratogenic agent has not been fully explored. This study aimed to examine the teratogenicity of CP when administered in the sensitive period of pregnant rats. The effect of CP on the lipid and metabolic profiles of amniotic fluid was evaluated using a UHPLC-Q-Exactive Orbitrap MS-based method. Metabolome analysis was performed using the MS-DIAL software with LipidBlast and NIST. Initially, we identified 636 and 154 lipid compounds in the positive and negative ion modes and 118 metabolites for differential analysis. Mainly 4 types of oxidized lipids in the amniotic fluid were found to accumulate most significantly after CP treatment, including very-long-chain unsaturated fatty acids (VLCUFAs), polyunsaturated fatty acid (PUFA)-containing triglycerides (TGs), oxidized phosphatidylcholine (PC), and sphingomyelin (SM). Tryptophan and some long-chain saturated fatty acids were lowered pronouncedly after CP treatment. These findings suggest that CP may exert teratogenic toxicity on pregnant rats through maternal and fetal oxidative stress. The UHPLC-Q-Exactive Orbitrap MS-based lipidomics approach is worthy of wider application for evaluating the potential toxicity of other agents (toxicants) during embryonic development.

[Effects of nanopolystyrene nanoplastic exposure on the development and neurotoxicity of fetal rats during gestation]

Objective: To investigate the effects of polystyrene nanoplastics (PS-NPs) exposure during gestation on the growth and neurotoxicity of fetal rats. Methods: Twenty-seven SD pregnant rats were randomly divided into 9 groups with three rats in each group. The experimental group of PS-NPs was given 0.5, 2.5, 10 and 50 mg/kg of PS-NPs suspension with different particle sizes (25 and 50 nm) by gavage, wihe the control group was given ultrapure water by gavage. The time of gavage is from the 1st to the 18th day of pregnancy. The morphological changes of the placenta were observed; compare the number of male and female fetuses, live/dead/absorbed fetuses, body weight, body length, placental weight, and organ coefficients of kidney, liver, brain and intestine of fetal rats; the prefrontal cortex, hippocampus and striatum of the fetal rats were taken to measure related biochemical indicators. Results: Compared with the control group, the placenta of the PS-NPs exposed group was found to have structural damage, which increased in a dose-dependent manner. The area ratio of trophoblast was significantly increased (P＜0.05), and the area ratio of labyrinth was significantly decreased (P＜0.05); In the prefrontal cortex, hippocampus and striatum of fetal rats, the levels of IL-1β, IL -6 and TNF-α were significantly increased in the 10 and 50 mg/kg PS-NPs exposed group (P＜0.05), and more significantly elevated in the 25 nm group than those in the 50 nm group at 10 mg/kg exposure (P＜0.05) the CAT activity was significantly decreased in 2.5, 10 and 50 mg/kg PS-NPs exposure groups (P＜0.05), while the SOD and GSH-Px activities were significantly decreased in 25 nm exposure groups and 2.5, 10 and 50 mg/kg 50 nm PS-NPs exposure groups (P＜0.05), the MDA content was significantly increased in 10, 50 mg/kg 25 nm PS-NPs exposure groups and 50 mg/kg 50 nm PS-NPs exposure groups (P＜0.05). Conclusion: Maternal PS-NPs exposure during gestation may affect the growth and development of fetal rats by damaging the placental barrier and produce neurotoxicity in fetal rats, causing oxidative stress and inflammatory responses in various brain regions, and smaller particle sizes and higher doses of polystyrene nanoplastic exposure have more significant neurotoxic effects on the offspring.

Toward better assessments of developmental toxicity using stem cell-based in vitro embryogenesis models

In the past few decades, pluripotent stem cells have been explored as nonanimal alternatives to assess the developmental toxicity of chemicals. To date, numerous versions of stem cell-based assays have been reported that are allegedly effective. Nonetheless, none of the assays has become the gold standard in developmental toxicity assessment. Why? This article discusses several issues in the hope of facilitating the refinement of stem cell assays and their acceptance as the cornerstone in predictive developmental toxicology. Each stem cell assay is built on a limited representation of embryogenesis, so that multiple assays are needed to detect the diverse effects of various chemicals. To validate and compare the strengths and weaknesses of individual assays, standardized lists of reference chemicals should be established. Reference lists should consist of exposures defined by toxicokinetic data, namely maternal plasma concentrations that cause embryonic death or malformations, and also by the effects on the molecular machineries that control embryogenesis. Although not entirely replacing human or animal tests, carefully selected stem cell assays should serve as practical and ethical alternatives to proactively identify chemical exposures that disturb embryogenesis. To achieve this goal, unprecedented levels of coordination and conviction are required among research and regulatory communities.

Modulatory Effects of Arctostaphylos uva-urs Extract In Ovo Injected into Broiler Embryos Contaminated by Aflatoxin B1

In ovo injection of nutrients can modulate the embryo’s physiological responses against aflatoxin B1 (AFB1) embryotoxicity. This hypothesis was tested using in ovo injection of Arctostaphylos uva-ursi (Ar. uu.) methanolic extract. The total polyphenols, total flavonoids, total antioxidant capacity, and GC-MS analysis were all assessed in the Ar. uu. methanolic extract. A total of 180 ten-day-old embryonated eggs were distributed into six groups of 30 replicates each. The first group was used as a control (non-injected), and the second, third, fourth, fifth, and sixth groups were injected with 10 µ double-distilled water (DDW), 500 µL methanol, 0.01 g Ar. uu./500 µL methanol, 50 ng AFB1/10 µL DDW, and 50 ng AFB1 in 10 µ DDW + 0.01 g Ar. uu./500 µL methanol, respectively. The relative embryo weight, residual yolk sac weight, tibia length and weight, and survival were recorded. Total and differential leukocytes, oxidative stress, and humoral immune responses were observed. The residual yolk sac was lower (p < 0.05) in the Ar. uu. group than other groups. The embryonic growth (tibia weight and length) was enhanced in AFB1 + Ar. uu.-injected embryos compared with those injected with AFB1 alone. In conclusion, in ovo injection of Arctostaphylos uva-ursi could modulate AFB1-induced toxicity in chicken embryos.

Decabromodiphenyl ethane affects embryonic development by interfering with nuclear F-actin in zygotes and leads to cognitive and social disorders in offspring mice

Decabromodiphenyl ethane (DBDPE) is a novel retardant. DBDPE is used in various flammable consumer products such as electronics, building materials, textiles, and children's toys. The presence of DBDPE in humans makes it extremely urgent to assess the health effects of DBDPE exposure. Here, we used female mice as an animal model to investigate the effects of DBDPE on embryonic development and offspring health. The results showed that 50 μg/kg bw/day of DBDPE exposure did not affect spindle rotation in oocytes after fertilization, but led to a decrease of pronuclei (PN) in zygotes. Further investigation found that DBDPE interferes with the self-assembly of F-actin in PN, resulting in PN reduction, DNA damage, and reduced expression of zygotic genome activating genes, and finally leading to abnormal embryonic development. More importantly, we found that maternal DBDPE exposure did not affect the growth and development of the first generation of offspring (F1) mice, but resulted in behavioral defects in F1 mice. Female F1 mice from DBDPE-exposed mothers exhibited increased motor activity and deficits in social behavior. Both female and male F1 mice from DBDPE-exposed mothers exhibited cognitive memory impairment. These results suggest that DBDPE has developmental toxicity on embryos and has a cross-generational interference effect. It is suggested that people should pay attention to the reproductive toxicity of DBDPE. In addition, it also provides a reference for studying the origin of neurological diseases and indicates that adult diseases caused by environmental pollutants may have begun in the embryonic stage.

Synthesis, Anticancer Potential and Comprehensive Toxicity Studies of Novel Brominated Derivatives of Bacterial Biopigment Prodigiosin from Serratia marcescens ATCC 27117

Prodigiosins (prodiginines) are a class of bacterial secondary metabolites with remarkable biological activities and color. In this study, optimized production, purification, and characterization of prodigiosin (PG) from easily accessible Serratia marcescens ATCC 27117 strain has been achieved to levels of 14 mg/L of culture within 24 h. Furthermore, environmentally friendly bromination of produced PG was used to afford both novel mono- and dibrominated derivatives of PG. PG and its Br derivatives showed anticancer potential with IC₅₀ values range 0.62–17.00 µg/mL for all tested cancer cell lines and induction of apoptosis but low selectivity against healthy cell lines. All compounds did not affect Caenorhabditiselegans at concentrations up to 50 µg/mL. However, an improved toxicity profile of Br derivatives in comparison to parent PG was observed in vivo using zebrafish (Danio rerio) model system, when 10 µg/mL applied at 6 h post fertilization caused death rate of 100%, 30% and 0% by PG, PG-Br, and PG-Br_2, respectively, which is a significant finding for further structural optimizations of bacterial prodigiosins. The drug-likeness of PG and its Br derivatives was examined, and the novel Br derivatives obey the Lipinski’s “rule of five”, with an exemption of being more lipophilic than PG, which still makes them good targets for further structural optimization.

Determination of the embryotoxic effect of maropitant using an in ovo model

The aim of this research was to determine the embryotoxic and teratogenic effects and lethal dose (LD50) of maropitant in ovo, using fertile chicken eggs. The study was designed in two stages, CHEST-I and CHEST-II. For CHEST-I, 210 fertile eggs were divided into seven equal groups; control, saline solution and 5 different doses of maropitant (10, 5, 2.5, 1.25, 0.625 mg/kg) injected groups. For CHEST-II, 150 fertile eggs were divided into five equal groups; control, saline solution and 3 different doses of maropitant (8, 6, 4 mg/kg)-injected groups. Eggs were opened on day 21 of incubation. Maropitant did not cause teratogenicity at any dose, while higher embryonic death rates were observed at doses above 4 mg/kg. The LD50 dose of maropitant was determined as 7.24 mg/kg. In conclusion, maropitant should only be used after full consideration of risks and benefits in pregnancy.

Evaluation of the maternal and developmental toxicity of 6-methylmercaptopurine riboside in rats

Thiopurine prodrugs (azathioprine, AZA, and 6-mercaptopurine, 6MP) are embryotoxic to rodents and rabbits. Little is known about the developmental toxicity of 6-methylmercaptopurine riboside (6MMPr), a thiopurine drug metabolite that is thought to mediate its liver toxicity. A limb bud assay found that 6MMPr impairs the in vitro morphogenetic differentiation of mouse limb extremities, being more potent than 6MP in the assay. This study evaluated the embryotoxicity of 6MMPr (0, 7.5, 15, 30mg/kg bw sc) in rats after single-dose exposure in mid organogenesis (GD10). One group of pregnant rats was similarly treated with 6MP (15mg/kg bw sc). After C-section (GD21), fetuses were weighed, and examined for external abnormalities. One third of each litter was examined for soft-tissue abnormalities while the remaining fetuses were cleared and stained for skeleton evaluation. 6MMPr caused a dose-dependent maternal weight loss followed by recovery before term pregnancy. Except for a nonsignificant increase in embryolethality and slight reduction in fetal weight at 30mg/kg bw, no indication of embryotoxicity was noted at this dose or at lower doses of 6MMPr. In contrast, 6MP led to nearly 98% of post-implantation losses in the presence of slight-to-mild maternal toxicity. These results are consistent with the notion that maternal treatment with 6MMPr affects embryo development, causing a nonsignificant increase in embryolethality and a slight reduction in fetal weight at 30mg/kg bw. However, there was no increase in abnormalities at this dose, which was severely toxic to the dams, as reflected in the maternal weight gain data.

The Human Induced Pluripotent Stem Cell Test as an Alternative Method for Embryotoxicity Testing

The evaluation of substances for their potency to induce embryotoxicity is controlled by safety regulations. Test guidelines for reproductive and developmental toxicity rely mainly on animal studies, which make up the majority of animal usage in regulatory toxicology. Therefore, there is an urgent need for alternative in vitro methods to follow the 3R principles. To improve human safety, cell models based on human cells are of great interest to overcome species differences. Here, human induced pluripotent stem cells (hiPSCs) are an ideal cell source as they largely recapitulate embryonic stem cells without bearing ethical concerns and they are able to differentiate into most cell types of the human body. Here, we set up and characterized a fetal bovine serum (FBS)-free hiPSC-based in vitro test method, called the human induced pluripotent stem cell test (hiPS Test), to evaluate the embryotoxic potential of substances. After 10 days in culture, hiPSCs develop into beating cardiomyocytes. As terminal endpoint evaluations, cell viability, qPCR analyses as well as beating frequency and area of beating cardiomyocytes by video analyses are measured. The embryotoxic positive and non-embryotoxic negative controls, 5-Fluorouracil (5-FU) and Penicillin G (PenG), respectively, were correctly assessed in the hiPS Test. More compounds need to be screened in the future for defining the assay’s applicability domain, which will inform us of the suitability of the hiPS Test for detecting adverse effects of substances on embryonic development.

A novel human stem cell-based biomarker assay for in vitro assessment of developmental toxicity

BACKGROUND

Testing for developmental toxicity according to the current regulatory guidelines requires large numbers of animals, making these tests very resource intensive, time-consuming, and ethically debatable. Over the past decades, several alternative in vitro assays have been developed, but these often suffered from low predictability and the inability to provide a mechanistic understanding of developmental toxicity.

METHODS

To identify embryotoxic compounds, we developed a human induced pluripotent stem cells (hiPSCs)-based biomarker assay. The assay is based on the differentiation of hiPSCs into functional cardiomyocytes and hepatocytes. Proper stem cell differentiation is investigated by morphological profiling and assessment of time-dependent expression patterns of cell-specific biomarkers. In this system, a decrease in the expression of the biomarker genes and morphology disruption of the differentiated cells following compound treatment indicated teratogenicity.

RESULTS

The hiPSCs-based biomarker assay was validated with 21 well-established in vivo animal teratogenic and non-teratogenic compounds during cardiomyocyte and hepatocyte differentiation. The in vivo teratogenic compounds (e.g., thalidomide and valproic acid) markedly disrupted morphology, functionality, and the expression pattern of the biomarker genes in either one or both cell types. Non-teratogenic chemicals generally had no effect on the morphology of differentiated cells, nor on the expression of the biomarker genes. Compared to the in vivo classification, the assay achieved high accuracy (91%), sensitivity (91%), and specificity (90%).

CONCLUSION

The assay, which we named ReproTracker®, is a state-of-the-art in vitro method that can identify the teratogenicity potential of new pharmaceuticals and chemicals and signify the outcome of in vivo test systems.

Evaluation of the Toxicity of Bisphenol A in Reproduction and Its Effect on Fertility and Embryonic Development in the Zebrafish (Danio rerio)

Bisphenol A (BPA) is a chemical substance commonly used in the manufacture of plastic products. Its inhalation or ingestion from particles in suspension, water, and/or polluted foods can trigger toxic effects related to endocrine disruption, resulting in hormonal, reproduction, and immunological alterations in humans and animals. The zebrafish (Danio rerio) is an ideal experimental model frequently used in toxicity studies. In order to assess the toxic effects of BPA on reproduction and embryonic development in one generation after parental exposure to it, a total of 80 zebrafish, males and females, divided into four groups in duplicate (n = 20) were exposed to BPA concentrations of 500, 50, and 5 µg L^-1, along with a control group. The fish were kept in reproduction aquariums for 21 days. The embryos obtained in the crosses were incubated in a BPA-free medium and observed for signs of embryotoxicity. A histopathological study (under optical and electron microscopes) was performed of adult fish gonads. The embryos of reproducers exposed to BPA were those most frequently presenting signs of embryotoxicity, such as mortality and cardiac and musculoskeletal malformations. In the histopathological studies of adult individuals, alterations were found in ovocyte maturation and in spermatazoid formation in the groups exposed to the chemical. Those alterations were directly related to BPA action, affecting fertility in both sexes, as well as the viability of their offspring, proportionally to the BPA levels to which they were exposed, so that our results provide more information by associating toxic effects on the offspring and on the next generation.

Neuromotor activity inhibition in zebrafish early-life stages after exposure to environmental relevant concentrations of caffeine

Caffeine (CAF), a neuroactive compound, has been found in surface waters at concentrations ranging from few nanograms up to micrograms and may induce adverse effects in aquatic vertebrates. Thus, the aim of this study was to evaluate the potential of CAF in affecting fish early-life stages in a wide concentration range, including occurring levels in surface waters. Specimens of zebrafish in early-life stages were exposed to CAF for 168 h and survival, developmental alterations, locomotor activity and acetylcholinesterase activity were evaluated. CAF induced mortality in embryos unable to hatch or in larvae after hatching (LC₅₀ - 168 h = 283.2 mg/L). Tail deformities were observed in organisms exposed to concentrations ≥ 40 mg/L, while edemas were found at concentrations of 100 mg/L. CAF also decreased the total swimming time and distance moved of exposed organisms (LOEC = 0.0006 mg/L). Locomotor inhibition may be associated with an acetylcholinesterase inhibition observed at concentration ≥ 0.0088 mg/L. Therefore, the hazard of CAF for fish populations deserves further attention since unexpected effects on neuro-behavioral parameters occurs at concentrations often detected in natural aquatic ecosystems.

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.

Comparative Toxicity Assessment of Kratom Decoction, Mitragynine and Speciociliatine Versus Morphine on Zebrafish (Danio rerio) Embryos

Background: Kratom (Mitragyna speciosa Korth), a popular opioid-like plant holds its therapeutic potential in pain management and opioid dependence. However, there are growing concerns about the safety or potential toxicity risk of kratom after prolonged use.

Aim of the study: The study aimed to assess the possible toxic effects of kratom decoction and its major alkaloids, mitragynine, and speciociliatine in comparison to morphine in an embryonic zebrafish model.

Methods: The zebrafish embryos were exposed to kratom decoction (1,000–62.5 μg/ml), mitragynine, speciociliatine, and morphine (100–3.125 μg/ml) for 96 h post-fertilization (hpf). The toxicity parameters, namely mortality, hatching rate, heart rate, and morphological malformations were examined at 24, 48, 72, and 96 hpf, respectively.

Results: Kratom decoction at a concentration range of ≥500 μg/ml caused 100% mortality of zebrafish embryos and decreased the hatching rate in a concentration-dependent manner. Meanwhile, mitragynine and speciociliatine exposure resulted in 100% mortality of zebrafish embryos at 100 μg/ml. Both alkaloids caused significant alterations in the morphological development of zebrafish embryos including hatching inhibition and spinal curvature (scoliosis) at the highest concentration. While exposure to morphine induced significant morphological malformations such as pericardial oedema, spinal curvature (lordosis), and yolk edema in zebrafish embryos.

Conclusion: Our findings provide evidence for embryonic developmental toxicity of kratom decoction and its alkaloids both mitragynine and speciociliatine at the highest concentration, hence suggesting that kratom consumption may have potential teratogenicity risk during pregnancy and thereby warrants further investigations.

Fragment-type 4-azolylcoumarin derivatives with anticancer properties

Several coumarin derivatives with a directly attached azole substituent at C-4 were synthesized and biologically studied for their anticancer properties. The cell lines used for this investigation (HeLa, K-562, MDA-MB-53, and MCF-7) demonstrated different sensitivities. The best response in the MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) assay was shown by K-562 cells, with compounds displaying activity (3c, IC₅₀ 3.06 μM; 4a, IC₅₀ 5.24 μM; 4c, IC₅₀ 4.7 μM) similar to that of cisplatin (IC₅₀ ~6 μM), which was used as the standard. The studied azole-substituted coumarins demonstrated weaker activity toward other cell lines, except for compound 4c, which was equally potent in the case of MCF-7 cells. Additional biological evaluations supported interference with the cell cycle as a potential mechanism of action and confirmed the absence of toxicity in zebrafish embryos. On the basis of these initial results, 4-azole coumarins should be explored further. Although their activity would need additional optimization, the fact that these compounds are fragment-like structures with MW <300 and clog P <3 offers enough flexibility to fine-tune their drug-like properties.

Reproductive issues in women on direct oral anticoagulants

Direct oral anticoagulants (DOACs) are replacing warfarin and other vitamin K antagonists for a wide range of indications. Advantages of DOAC therapy are fewer food and drug interactions and fixed dosing without routine laboratory monitoring, making DOACs the perfect choice especially for younger patients, in whom the main indication for anticoagulation is prevention and treatment of venous thromboembolism (VTE). Although DOACs are safer and much more convenient than other anticoagulant alternatives, their profile may have drawbacks, especially for younger female patients in whom reproductive issues need special considerations. These may include the issue of heavy menstrual bleeding (HMB) during anticoagulant therapy, the embryotoxicity risk from inadvertent DOAC exposure during pregnancy, and the prevention or planning of pregnancies during DOAC therapy. This review summarizes the most relevant evidence in this increasingly important field of women's health.

Phytochemical and Safety Evaluations of Zingiber ottensii Valeton Essential Oil in Zebrafish Embryos and Rats

Zingiber ottensii Valeton (ZO) exhibits pharmacological activity and has long been used in traditional medicine. However, reports about its safety profiles are limited. The present study aimed to evaluate the phytochemical profile and the toxic effects of ZO essential oil on the development of zebrafish and acute oral toxicity in rats. The essential oil was isolated from ZO rhizomes, and phytochemicals were analyzed using a gas chromatography-mass spectrometer (GC-MS). The embryotoxic and teratogenic effects of ZO essential oil were evaluated in zebrafish embryos and larvae and the acute oral toxicity was determined in rats. GC-MS results showed the essential oil contained zerumbone as a major phytoconstituent (24.73%). The zebrafish embryotoxicity of ZO essential oil appeared to be concentration- and time-dependent manner, with a moderate LC₅₀ (1.003 µg/mL). Teratogenicity in zebrafish embryos also included morphological defects, decreased hatchability, and reduced heart rate. In rats, ZO essential oil (2000 mg/kg, p.o.) resulted in no mortality or significant toxicities. These findings suggest that ZO has embryotoxic and teratogenic effects in zebrafish embryos but does not result in death or acute oral toxicity in rats. Further long-term toxicity studies are needed to confirm the safety of products developed from ZO essential oil.

Bioprospecting of Less-Polar Constituents from Endemic Brown Macroalga Fucus virsoides J. Agardh from the Adriatic Sea and Targeted Antioxidant Effects In Vitro and In Vivo (Zebrafish Model)

The endemic brown macroalga Fucus virsoides J. Agardh from the Adriatic Sea was in the focus of the present research. The volatiles of fresh (FrFv) and air-dried (DrFv) samples of F. virsoides obtained by headspace solid-phase microextraction (HS-SPME) and hydrodistillation (HD) were analyzed by gas chromatography equipped with flame ionization detector and mass spectrometry (GC-FID/MS). The major HS-FrFv compound was pentadecane (61.90-71.55%) followed by pentadec-1-ene (11.00-7.98%). In HS-DrFv, pentadec-1-ene was not present, and few lower aliphatic compounds appeared, as well as benzaldehyde and benzyl alcohol. In HD-FrFv, particularly abundant were alkenes (such as pentadec-1-ene (19.32%), or (E)-pentadec-7-ene (8.35%)). In HD-DrFv, more oxidation products were present (e.g., carbonyl compounds such as tridecanal (18.51%)). The fatty acids profile of freeze-dried sample (FdFv) after conversion to methyl esters was determined by GC-FID, and oleic acid was dominant (42.28%), followed by arachidonic acid (15.00%). High-performance liquid chromatography-high-resolution mass spectrometry with electrospray ionization (HPLC-ESI-HRMS) was used for the screening of less polar fractions (F3 and F4) of F. virsoides. Mono- and diglycerides of stearic, palmitic, oleic, and arachidonic acids were found. Terpenoids and steroids comprised the compounds C20H30(32)O2 and C29H48O(2). Among carotenoids, fucoxanthin was identified. Chlorophyll derivatives were also found (C55H74(72)N4O(5-7)), dominated by pheophytin a. The antioxidant activity of the fractions was investigated by in vitro assays (oxygen radical absorbance capacity (ORAC), reduction of radical cation (ABTS•+), 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) assay, and ferric reducing antioxidant power (FRAP)) and by in vivo zebrafish model (along with fish embryotoxicity). In vitro experiments proved good radical scavenging abilities of F3 and F4 fractions, which were additionally supported by the protective effect against hydrogen peroxide-induced oxidative stress in zebrafish embryos.

Engineering spatial-organized cardiac organoids for developmental toxicity testing

Emerging technologies in stem cell engineering have produced sophisticated organoid platforms by controlling stem cell fate via biomaterial instructive cues. By micropatterning and differentiating human induced pluripotent stem cells (hiPSCs), we have engineered spatially organized cardiac organoids with contracting cardiomyocytes in the center surrounded by stromal cells distributed along the pattern perimeter. We investigated how geometric confinement directed the structural morphology and contractile functions of the cardiac organoids and tailored the pattern geometry to optimize organoid production. Using modern data-mining techniques, we found that pattern sizes significantly affected contraction functions, particularly in the parameters related to contraction duration and diastolic functions. We applied cardiac organoids generated from 600 μm diameter circles as a developmental toxicity screening assay and quantified the embryotoxic potential of nine pharmaceutical compounds. These cardiac organoids have potential use as an in vitro platform for studying organoid structure-function relationships, developmental processes, and drug-induced cardiac developmental toxicity.

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Micropattern-based geometric confinement directs cardiac organoid development

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Cardiac organoid structure-function relationships are guided by organoid size

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Cardiac organoids can be used as an in vitro embryotoxicity assessment tool

Behavioural effects of early-life exposure to parabens in zebrafish larvae

Parabens are classified as endocrine disrupting chemicals due to their ability to activate several nuclear receptors causing changes in hormones-dependent signalling pathways. Central nervous system of developing organisms is particularly vulnerable to changes in hormonal pathways, which could lead to altered brain function, abnormal behaviour and even diseases later in life. The aim of the present study was to investigate the effects of exposure to butylparaben (BuP), ethylparaben (EtP) and methylparaben (MeP) during early development on nervous system using zebrafish larvae's behavioural models. Zebrafish were exposed until 4 days post fertilization (dpf) to three concentrations of each paraben chosen considering the environmentally realistic concentrations of human exposure and the benchmark-dose lower bound calculated for zebrafish larvae (BuP: 5, 50 and 500 μg/L; EtP: 50, 500 and 5000 μg/L; MeP: 100, 1000 and 10,000 μg/L). Activity in novel and in familiar environment, thigmotaxis, visual startle response and photic synchronization of the behavioural circadian rhythms were analysed at 4, 5 and 6 dpf. Zebrafish larvae exposed to BuP 500 μg/L and EtP 5000 μg/L revealed increased anxiety-like behaviour in novel environment. Larvae treated with 500 μg/L of BuP showed reduced activity in familiar and marginally in unfamiliar environment, and larvae exposed to 5000 μg/L of EtP exhibited hyperactivity in familiar environment. Parabens exposure did not influence the visual startle response and the photic synchronization of circadian rhythms in zebrafish larvae. This research highlighted as the exposure to parabens has the potential to interfere with behavioural development of zebrafish.

Six catalytic activities and cytotoxicity of immunoglobulin G and secretory immunoglobulin A from human milk

In the milk of healthy women, antibodies were found with different catalytic activities (abzymes), which are absent in the sera of other healthy people. Moreover, it was previously shown that DNase antibodies-abzymes of patients with autoimmune diseases are cytotoxic to cancer cells. In this work, it was first shown that IgG and secretory IgA (sIgA) do not possess embryotoxicity; they practically do not affect the development of fertilized eggs of sea urchins but demonstrate sperm toxicity. After addition to the eggs of sperm preincubated with IgG and sIgA, the number of unfertilized eggs was increased, in the case of sIgA 1.6-fold higher than that for IgG. The suppression of the growth of MCF-7 breast cancer cells by sIgA was 2.2 times more effective than with IgG antibodies. The relative enzymatic activity of milk sIgA was higher than IgG (-fold): 1.9 (DNase), 4.6 (amylase), 1.7 (peroxidase), 1.3 (protease), 3.7 [hydrolysis of poly(C)], 3.3 [hydrolysis of poly(U)], and 1.7 (oxidation of 3,3'-diaminobenzidine). One of the possible reasons for the observed difference between sIgA and IgG could be that all 6 catalytic activities of sIgA were, on average, 2.6 times higher than that for IgG. Correlation coefficients between all the relative 6 enzymatic activities of IgG and sIgA and their toxicity to sea urchin sperm and to cancer cells were calculated. Maximum correlation coefficients were observed for DNase (+0.71), protease (+0.64) activities for sIgA, as well as protease (+0.59) and RNase (+0.77) of IgG with their toxicity toward sperm. The correlation coefficients were also high between peroxidase activity (+0.85) of sIgA and poly(U) hydrolysis by IgG (+0.58) with their suppression of tumor cell growth. It has been suggested that the catalytic activities of abzymes may be important in the manifestation of their sperm toxicity and inhibition of cancer cell growth.

Methionine alleviates aflatoxinb1-induced broiler chicks embryotoxicity through inhibition of caspase-dependent apoptosis and enhancement of cellular antioxidant status

Practical methods for preventing embryotoxicity in chickens that are caused by aflatoxin-B1 (AFB1) are currently rare. Binding absorbers are commonly used in feeding stuff to reduce laying hens' exposure to off-contaminated diets, thus reducing residue exposure to fertilized eggs. Nonetheless, several adsorbents have been shown to affect the use of nutrients and the absorption of minerals in poultry. Thus, seeking an effective strategy to counter or control embryotoxicity in broiler chicks caused by AFB1 is a problem. A total of 180 embryonated eggs were injected with 36 ng AFB1 with or without 5.90 mg L-methionine (Met) 30 embryonated eggs each, followed by incubation in an incubator until hatching time. The in ovo injection of Met significantly reduced toxicity caused by AFB1 in broiler embryos by enhancing the liver and kidney functions, lipid profiles, and alleviated oxidative stress during the incubation period. Furthermore, the relative gene expressions (SSTR5, TSH-β, Bcl-2, GSH-Px, GST-a, and SOD in the liver) were up-regulated with in ovo injection of AFB1+Met compared to AFB1 alone. Moreover, there was a dowin-regulated trend in Bax, Caspases-3, Caspases-7, Caspases-9, CYP1A1, CYP2H1, and P53 gene expression with in ovo injection of AFB1+Met compared to AFB1 alone. The in ovo injection of Met led to less apoptotic cells in liver tissues. Such results might be necessary for the poultry industry as it is focused on managing the embryotoxicity of AFB1, which affecting poultry production and welfare. Results from this study demonstrated that in ovo Met injection could alleviate AF-induced toxicity in chicken embryos.

Toxicological assessment of a bioactive extract from Triplaris gardneriana Wedd. seeds using alternative models

The Triplaris gardneriana Wedd. seeds extract has great therapeutic potential due to numerous biological activities such as antioxidant, antibacterial and anti-inflammatory, which are associated with phenolic content. Although this herbal preparation has shown many benefits, recently their toxicity profile has begun to be explored. In this present study, the toxic effects of T. gardneriana seeds ethanolic extract (EETg) on biological systems of different taxonomical groups and levels of complexity (from cell culture to lower vertebrates) were assessed, through a variety of viability and toxicological assays. It was found that EETg did not impair the Saccharomyces cerevisiae growth at the highest tested concentration (200 µg/mL), and no toxicant evidence was observed in Aedes aegypti larvae or in Drosophila melanogaster adult stage. Contrarily, the extract reduced the viability of undifferentiated Caco-2 cells (250 µg/mL, 40% of viable cells), but did not affect differentiated ones. The embryotoxicity in Danio rerio model showed a LC₅₀ of 7.41 mg/L (95% confidence interval, 4.78 - 11.49 mg/L). EETg did not show signs of toxicity in the majority of the models used, but lethality and malformations in zebrafish embryos occurred. Further analyses are needed to better understand the selective toxicity mechanism of EETg on zebrafish, as well as whether the toxic effects happen in higher vertebrates.

Developmental toxicity induced by Cu(OH)2 nanopesticide in zebrafish embryos

The current study evaluates the adverse effects of Cu(OH)₂ nanopesticide (CNPE) on the early life stages of zebrafish (Danio rerio). The developmental toxicity was determined using different parameters such as mortality (including LC₅₀ ), hatching, heart rates, malformations, and alteration of the gene expressions. Zebrafish embryos (4 hpf-hours postfertilization) were exposed to 1.0, 2.0, 4.0, 8.0, and 16.0 mg/l CNPE doses until 96 hpf. The 96 hours LC₅₀ was recorded at 6.258 mg/l. Seventy-two hpf total malformation index values for 2.0, 4.0, and 8.0 mg/l CNPE doses were 4.3, 7.2 and 7.9, respectively. 1.0 mg/l CNPE is not toxic for the zebrafish embryos/larvae. 2.0 to 8.0 CNPE doses caused some abnormalities in embryos/larvae morphology, including lack of body parts, tail deformities, chorda deformity, bubbled head, scoliosis, lordosis, weak or non-pigmentation, decreased heart rate and larva length. 16.0 mg/l CNPE caused mortality in 72 hpf. The expression levels of seven immune system-related genes (il-1β, il-8, cebp, tlr4, hsp70, NF-kB, and mtf-1) were examined. The transcription level of il-1β, il-8, tlr4, hsp70, and NF-kB genes significantly increased in the CNPE exposure groups. While the expression of the mtf-1 gene considerably decreased, the cebp gene expression level did not change in the 4.0 and 8.0 mg/l CNPE doses. In conclusion, CNPE could induce developmental toxicity with malformations in embryos/larvae and alter the gene expression.

The overview of current evidence on the reproductive toxicity of dibutyl phthalate

Over the past years, many legitimate concerns have been raised about the effects of dibutyl phthalate (DBP) as an endocrine disruptor, especially on reproduction. The aim of this publication is to critically review the literature related to the developmental and reproductive toxicity of DBP in animals. Several electronic databases were systematically searched until 2019. Studies were qualified for the review if they: linked exposure to DPB with reproduction, were published in English after 1990, and were conducted on animals. In the studies of the testicular effects of DBP on experimental animals, the most common effects of exposure included reduced fertility, atrophic changes in male gonads, degenerative changes in the epididymis, as well as a reduction in sperm count and motility, cryptorchidism, hypospadias, poor sperm quality and other genital defects (decreased testicular weight, delayed spermatogenesis, Leydig cell aggregation, impaired Sertoli cell maturation, and significant inhibitions of testicular enzymes). The embryotoxic effects of DBP on laboratory animals included mainly an increase in fetal resorption and a decrease in live births. The teratogenic effects of DBP also manifest as skeletal malformations in fetuses, malformations of male gonads and other genital effects. On the basis of the literature data, it is clearly demonstrated that DBP shows anti-androgenic effects; however, there are also reports confirming its weak estrogenic effect. Additionally, lower doses cause more adverse effects than the highest dose, which is an important fact because of the widespread environmental exposure to DBP. The studies clearly confirm that DBP is an endocrine disruptor. Int J Occup Med Environ Health. 2021;34(1):15-37.

Toxicity of nanoplastics during the embryogenesis of the ascidian Ciona robusta (Phylum Chordata)

Nanoplastics are considered contaminants of emerging concern at the global scale. The recent evidence of their occurrence in seawater from the Mediterranean Sea calls for a thorough evaluation of their impact on marine life and in particular on vulnerable life stages such as planktonic embryos. Here, we investigated the impact of increasing nominal concentrations of 50 nm amino-modified (PS-NH₂) and 60 nm carboxy-modified (PS-COOH) polystyrene nanoparticles (PS NPs) on the embryonic development of the ascidian Ciona robusta (phylum Chordata), a common benthic invertebrate living in Mediterranean coastal areas with the peculiarity of being an early chordate developmental model. A strong agglomeration of PS-COOH (approx. 1 µm) was observed in natural sea water (NSW) already at time 0, while PS-NH₂ resulted still monodispersed (approx. 130 nm) but largely aggregated after 22 h with a microscale dimension similar to those negatively charged. However, their effect on C. robusta embryos development largely differed at 22 h: PS-COOH did not affect larvae phenotypes nor their development, while PS-NH₂ caused a dose-dependent effect (EC₅₀ (22 h) of 7.52 μg mL^-1) with various degrees of phenotype malformations (from mild to severe) and impairment of larval swimming. Embryos (up to 30%) exposed to 15 µg mL^-1PS-NH₂ resulted not developed and the majority was unable to hatch. Calculated PS-NH₂ EC₅₀ resulted higher than those available for other marine invertebrate species, suggesting a protective role of the egg envelopes surrounding C. robusta embryos toward nanoplastics exposure.

Effects of embryonic exposure to chromium (VI) on blood parameters and liver microstructure of 1-day-old chickens

Hexavalent chromium (Cr(VI)) has carcinogenic, nephrotoxic, hepatotoxic, and neurotoxic effects. Exposure to Cr(VI) can also lead to hematological alterations and blood biochemical changes. The literature on Cr(VI) toxicity concerns mostly adult forms of vertebrates. In this study, an attempt was made to determine the effect on the developing chicken embryo of Cr(VI) in ovo administration. It was observed that chromium affected the hatchability of chicks in a dose-dependent manner. At a dose from 25 to 250 μg per egg, Cr(VI) resulted in a statistically significant reduction of hatchability. Chromium administrated at lower doses (1.56 and 2.5 μg per egg) caused a statistically insignificant increase of hatchability. However, chromium at a level of LD₅₀ (15.6 μg per egg) or 1/10 LD₅₀ (1.56 per egg) did not cause major changes in hematological parameters or plasma biochemical indices in newly hatched chicks. The same doses did not lead to any histopathological changes in the liver.

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.

Effects of sublethal application of Deepwater Horizon oil to bird eggs on embryonic heart and metabolic rate

Following large crude oil spills, oil from feathers of brooding birds and oiled nesting material can transfer to eggs, resulting in reduced embryonic viability for heavily oiled eggs. Eggs may also be subjected to trace or light oiling, but functional teratogenic effects from sublethal crude oil exposure have not been examined. We assessed whether sublethal application of weathered Deepwater Horizon crude oil to the eggshell surface alters heart rate and metabolic rate in Zebra Finch (Taeniopygia guttata) embryos. We first determined sublethal applications with a dosing experiment. Embryo viability for eggs exposed to 5 μL or more of crude oil decreased significantly. We conducted a second experiment to measure heart rate and metabolic rate (CO₂ production) 5 and 9 d after 1 sublethal application of crude oil to eggshells on day 3 of incubation. One application of 1.0 or 2.5 µL of crude oil reduced embryonic heart rate and metabolic rate on day 12 of incubation. Using unfertilized eggs, we measured the transfer of polycyclic aromatic hydrocarbons (PAHs) from the eggshell surface to egg contents 9 d after a single application of sublethal crude oil. Our results suggest avian eggs externally exposed to small amounts of crude oil may exhibit protracted embryonic development and impaired postnatal cardiac performance.

Safety of Artemisinin Derivatives in the First Trimester of Pregnancy: A Controversial Story

Artemisinin combination therapy (ACT) is recommended by the World Health Organization (WHO) as first line treatment for uncomplicated malaria both in adults and children. During pregnancy, ACT is considered safe only in the second and third trimester, since animal studies have demonstrated that artemisinin derivatives can cause foetal death and congenital malformation within a narrow time window in early embryogenesis. During this period, artemisinin derivatives induce defective embryonic erythropoiesis and vasculogenesis/angiogenesis in experimental models. However, clinical data on the safety profile of ACT in pregnant women have not shown an increased risk of miscarriage, stillbirth, or congenital malformation, nor low birth weight, associated with exposure to artemisinins in the first trimester. Although further studies are needed, the evidence collected up to now is prompting the WHO towards a change in the guidelines for the treatment of uncomplicated malaria, allowing the use of ACT also in the first trimester of pregnancy.

A Phenotypic and Genotypic Evaluation of Developmental Toxicity of Polyhexamethylene Guanidine Phosphate Using Zebrafish Embryo/Larvae

Polyhexamethylene guanidine-phosphate (PHMG-P), a guanidine-based cationic antimicrobial polymer, is an effective antimicrobial biocide, potent even at low concentrations. Due to its resilient bactericidal properties, it has been used extensively in consumer products. It was safely used until its use in humidifiers led to a catastrophic event in South Korea. Epidemiological studies have linked the use of PHMG-P as a humidifier disinfectant to pulmonary fibrosis. However, little is known about its harmful impacts other than pulmonary fibrosis. Thus, we applied a zebrafish embryo/larvae model to evaluate developmental and cardiotoxic effects and transcriptome changes using RNA-sequencing. Zebrafish embryos were exposed to 0.1, 0.2, 0.3, 0.4, 0.5, 1, and 2 mg/L of PHMG-P from 3 h to 96 h post fertilization. 2 mg/L of PHMG-P resulted in total mortality and an LC₅₀ value at 96 h was determined at 1.18 mg/L. Significant developmental changes were not observed but the heart rate of zebrafish larvae was significantly altered. In transcriptome analysis, immune and inflammatory responses were significantly affected similarly to those in epidemiological studies. Our qPCR analysis (Itgb1b, TNC, Arg1, Arg2, IL-1β, Serpine-1, and Ptgs2b) also confirmed this following a 96 h exposure to 0.4 mg/L of PHMG-P. Based on our results, PHMG-P might induce lethal and cardiotoxic effects in zebrafish, and crucial transcriptome changes were linked to immune and inflammatory response.