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.