Teratogenic Research Articles

A novel hypothesis about mechanism of thalidomide action on pattern formation

Morphogenesis, the complex process governing the formation of functional living structures, is regulated by a multitude of molecular mechanisms at various levels. While research in recent decades has shed light on many pathways involved in morphogenesis, none singularly accounts for the precise geometric shapes of organisms and their components in space. To bridge this conceptual gap between specific molecular mechanisms and the creation of definitive morphological forms, we have proposed the "epigenetic code hypothesis" in our previous work. In this framework, "epigenetic" means any inheritable cellular information beyond the genetic code that regulates cell fate alongside genetic information. In this study, we conduct a comprehensive analysis of thalidomide's teratogenic effects through the lens of our proposed "epigenetic code" theory, revealing significant indirect support for our hypothesis. We also explore the structural and functional parallels between thalidomide and auxin.

A guidance for the enrichment of micropollutants from wastewater by solid-phase extraction before bioanalytical assessment

BackgroundWastewater can contain a complex mixture of organic micropollutants, with both chemical analysis and effect-based methods needed to identify relevant micropollutants and detect mixture effects. Solid-phase extraction (SPE) is commonly used to enrich micropollutants prior to analysis. While the recovery and stability of individual micropollutants by SPE has been well studied, few studies have optimized SPE for effect-based methods. The aim of the current study was to develop and evaluate two standard operating procedures (SOPs) for the enrichment of micropollutants in preparation for chemical analysis and bioanalysis, one covering a broad range of chemicals and the other selective for estrogenic chemicals.ResultsPristine surface water spiked with > 600 micropollutants was used to develop a generic extraction method for micropollutants with a wide range of physiochemical properties, while water spiked with estrogenic chemicals was used to identify a selective extraction method. Three different SPE sorbents were tested, with recoveries of individual chemicals and effect in assays indicative of mutagenicity, estrogenic activity, and fish embryo toxicity assessed. The sorbent HRX at pH 7 was selected for the generic extraction method as it showed the best recovery of both individual chemicals and effect in the bioassays. The sorbent HLB at pH 3 showed optimal recovery of estrogenic chemicals and estrogenic activity. The two optimal SPE methods were applied to spiked and unspiked wastewater effluents, with the concentrations of detected chemicals and observed effects similar to those of previous studies. The long-term storage of both extracts and SPE cartridges for estrogens and estrogenic activity after extraction with the HRX and HLB methods were evaluated, with estrogenic effectiveness close to 100% after 112 days when HLB was used.ConclusionsHRX is recommended for generic extraction, while HLB is optimal for the selective extraction of estrogenic micropollutants. However, if a laboratory only wants to use a single SPE sorbent, HLB can be used for both generic and selective extraction as it yielded similar chemical and effect recovery as HRX for a wide range of micropollutants. This paper is supplemented by the final SOP that includes a variant for generic extraction and one for the extraction of estrogenic chemicals.

Multiparameter analysis of Diuron and its metabolites (DCA and DCPMU) in different stages of zebrafish (Danio rerio) development

IntroductionDiuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) is a prominent herbicide in Brazilian agriculture, particularly in sugarcane farming. This herbicide persists in the environment and is transformed into potentially toxic metabolites, such as 3,4-dichloroaniline (DCA) and 3-(3,4-dichlorophenyl)-1-methylurea (DCPMU), raising concerns that encompass environmental contamination and One Health, which unites environmental and human health. Zebrafish are an appropriate experimental model to evaluate toxicity: they metabolically and genetically resemble humans and can be applied in ecotoxicology.MethodsIn this study, we have employed multiparameter evaluation to characterize the toxicity of environmentally relevant concentrations (0.5–100 μM) of Diuron, DCA, or DCPMU in Brazil, a developing country. In the early stages of zebrafish development, we performed the fish embryo toxicity test according to the guidelines established in OECD Protocol No. 236, extended to 144 h post fertilization (hpf). We also investigated the oxygen consumption rate in zebrafish embryos at 24 hpf, evaluated the acetylcholinesterase (AChE) enzymatic activity in zebrafish larvae at 96 hpf, and used the Comet Assay to assess DNA fragmentation in zebrafish larvae at 96 hpf. We subjected adult zebrafish to acute exposure for 96 h in accordance with OECD protocol no. 203 for the Acute Toxicity Test in Fish. Following this exposure, we analyzed mutagenicity by using the micronucleus test, which was complemented by quantification of nuclear anomalies (NA) in erythrocytes and further confirmed by histopathological investigations.Results and discussionExposure to any of the tested Diuron concentrations damaged DNA, and NA became significant beyond 10 μM Diuron. At 10 μM, DCA altered AChE activity, suggesting neuromuscular toxicity. Between 0.5 and 5 μM, DCA was potentially genotoxic, and 5–10 μM DCA induced nuclear pleomorphism. At all the tested concentrations, DCPMU damaged DNA, and NA emerged between 1 and 10 μM DCPMU. Adult zebrafish exposed to any of the tested Diuron, DCA, or DCPMU concentrations for 96 h did not exhibit significant histopathological alterations. Erythrocyte morphology analysis did not reveal mutagenicity. Although we observed non-mutagenic genotoxicity, chromosomal instability is of concern. The findings of this study contribute to our understanding of how Diuron and its metabolites affect zebrafish and highlights the need for multiparametric assessment to elucidate how herbicides and their metabolites impact the environment and human health. This endeavor informs regulatory measures for safely using Diuron and similar herbicides and reveals substantial implications for developing nations grappling with escalating water contamination due to pesticide use.

Hazardous effects of nickel ferrite nanoparticles and nickel chloride in early life stages of the freshwater snail Biomphalaria glabrata (Say, 1818).

Nickel ferrite nanoparticles (NiF NPs) have growing applications in biomedical and nanomedicine fields. However, knowledge concerning their ecotoxicity during the early developmental stages of invertebrates, such as gastropods, remains scarce. Thus, the current study aimed to evaluate whether NiF NPs and nickel chloride (NiCl2) induce toxic effects on embryos and newly hatched snails of freshwater species Biomphalaria glabrata (Say, 1818). NiF NPs were synthesized and characterized by multiple techniques, and their ecotoxicity was assessed by Biomphalaria embryotoxicity test (BET) during 144h of exposure and an acute toxicity test (96h) using newly hatched snails. NiF NPs induced mortality, developmental delay, reduced hatching rate, and promoted morphological changes in B. glabrata. Also, NiF NPs induced higher toxicity in embryos than in newly hatched B. glabrata. Overall, results showed that the early developmental stages of gastropods are a target group for nanoparticle toxicity in freshwater ecosystems.

Strengths and limitations of the worm development and activity test (wDAT) as a chemical screening tool for developmental hazards

The worm Development and Activity Test (wDAT) measures C. elegans developmental milestone acquisition timing and stage-specific spontaneous locomotor activity (SLA). Previously, the wDAT identified developmental delays and SLA level changes in C. elegans with mammalian developmental toxicants arsenic, lead, and mercury. 5-fluorouracil (5FU), cyclophosphamide (CP), hydroxyurea (HU), and ribavirin (RV) are teratogens that also induce growth retardation in developing mammals. In at least some studies on each of these chemicals, fetal weight reductions were seen at mammalian exposures below those that had teratogenic effects, suggesting that screening for developmental delay in a small alternative whole-animal model could act as a general toxicity endpoint to identify chemicals for further testing for more specific adverse developmental outcomes. Consistent with mammalian developmental effects, 5FU, HU, and RV were associated with developmental delays with the wDAT. Exposures associated with developmental delay induced hypoactivity with 5FU and HU, but slight hyperactivity with RV. CP is a prodrug that requires bioactivation by cytochrome P450s for both therapeutic and toxic effects. CP tests as a false negative in several in vitro assays, and it was also a false negative with the wDAT. These results suggest that the wDAT has the potential to identify some developmental toxicants, and that a positive wDAT result with an unknown may warrant further testing in mammals. Further assessment with larger panels of positive and negative controls will help qualify the applicability and utility of this C. elegans wDAT assay within toxicity test batteries or weight of evidence approaches for developmental toxicity assessment.

Vitamin A deficiency disturbs Ret expression and induces urinary tract developmental abnormalities in mice.

Moderate vitamin A levels during pregnancy are strongly related to normal embryonic development in both animal models and population studies. Abnormal development of urinary tract system is linked to either an excess or a shortage of vitamin A. The relationships among maternal vitamin A deficiency prior to conception, moderate vitamin A supplementation during pregnancy, and abnormal urinary system development in offspring are unclear. By creating preconception and preconception + pregnancy vitamin A insufficiency mouse models, we investigated whether moderate vitamin A treatment during pregnancy may reduce the prevalence of CAKUT and increase distant vitamin A levels in offspring, as well as any potential pathways involved. We effectively established a prepregnancy vitamin A-deficient mouse model by providing a particular diet with or without vitamin A for four weeks. The offspring of the hypovitaminosis A model group presented a greater proportion of neonatal urinary tract developmental malformations. Abnormalities in ureteral bud emergence and key molecules during renal development, such as p-Plcγ and Ret, may be the primary causes of offspring development of CAKUT as a result of mothers' hypovitaminosis A. Normal vitamin A diets, on the other hand, may help mitigate the teratogenic consequences of prepregnancy hypovitaminosis A, as well as defects produced by ureteral budding and major molecular changes. In contrast, the administration of normal vitamin A feeds during pregnancy may ameliorate the teratogenic effects of prepregnancy hypovitaminosis A to a certain extent and may also ameliorate the abnormalities associated with ureteral budding and key molecular changes.

Molecular mechanisms of thalidomide effectiveness on COVID-19 patients explained: ACE2 is a new ΔNp63α target gene.

COVID-19 pandemic is caused by the SARS-CoV-2 virus, whose internalization and infection are mediated by the angiotensin-converting enzyme 2 (ACE2). The identification of novel approaches to tackle this step is instrumental for the development of therapies for the management of COVID-19 and other diseases with a similar mechanism of infection. Thalidomide, a drug sadly known for its teratogenic effects, has potent immunomodulatory and anti-inflammatory properties. Treatment with this drug has been shown to improve the immune functions of COVID-19 patients and proposed for the management of COVID-19 in clinical practice through drug repositioning. Here, we investigated the molecular details linking thalidomide to ACE2 and COVID-19, showing that in conditions mimicking SARS-CoV-2-associated cytokine storm, the transcription factor ΔNp63α and ACE2 are stabilized, and IL-8 production is increased. In such conditions, we found p63 to bind to and regulate the expression of the ACE2 gene. We previously showed that ΔNp63α is degraded upon thalidomide treatment and now found that treatment with this drug-or with its analogue lenalidomide-downregulates ACE2 in a p63-dependent manner. Finally, we found that thalidomide treatment reduces in vitro infection by pseudo-SARS-CoV-2, a baculovirus pseudotyped with the SARS-CoV-2 spike protein. Overall, we propose the dual effect of thalidomide in reducing SARS-CoV-2 viral re-entry and inflammation through p63 degradation to weaken SARS-CoV-2 entry into host cells and mitigate lung inflammation, making it a valuable option in clinical management of COVID-19. KEY MESSAGES: Thalidomide treatment results in p63-dependent ACE2 downregulation. ACE2 is a p63 transcriptional target. Thalidomide reduces the "cytokine storm" associated to COVID-19. Thalidomide prevents viral re-entry of SARS-CoV-2 by p63-dependent ACE2 downregulation. Thalidomide is a modulator of SARS-CoV-2 or other ACE2-dependent infections. ACE2 is modulated by a pharmacological substance.

Sodium Fluoride Exposure Induces Developmental Toxicity and Cardiotoxicity in Zebrafish Embryos.

Fluorosis is a worldwide public health problem, in which the heart is an important target organ. However, studies on its toxicological mechanism in embryonic development are limited. This study assessed the toxicity of sodium fluoride (NaF) toward zebrafish embryos. We determined the mortality, hatching rate, phenotypic malformation, heart function, and morphology of zebrafish embryos after exposure to NaF. Subsequently, the molecular mechanism was revealed using high-throughput RNA sequencing analysis. The expression levels of key genes for heart development were detected using quantitative real-time reverse transcription PCR. The 50% lethal concentration (LC50) value of NaF toward zebrafish embryos at 96h post-fertilization was 335.75mg/L. When the concentration of NaF was higher than 200mg/L, severe deformities, such as pericardial edema, yolk sac edema, spine curvature, shortened body length, reduced head area, and eye area, were observed. The heart rate of the embryos exposed to NaF decreased in a dose-dependent fashion. The distance between the sinus venosus and bulbus arteriosus was significantly increased in the NaF-exposed group compared with that in the control group. The stroke volume and cardiac output decreased significantly in the NaF groups. Compared with the control group, the expression levels of Gata4, Tbx5a, Hand2, Tnnt2c, Nppa, and Myh6 were significantly increased in the NaF-treated group. Through transcriptome sequencing, 1354 differentially expressed genes (DEGs) were detected in the NaF (200mg/L) treated groups, including 1253 upregulated genes and 101 downregulated genes. Gene ontology functional analysis and Kyoto Encyclopedia of Genes and Genomes pathway analyses of the DEGs showed that cardiac-related pathways, such as actin cytoskeleton regulation, Jak-Stat, PI3k-Akt, and Ras, were activated in the NaF-exposed group. This study revealed the underlying mechanism of fluoride-induced cardiac morphological and functional abnormalities and provides clues for the clinical prevention and treatment of fluorosis.

The Perception of Contraceptive Practice Among Female Patients Treated With Isotretinoin in Saudi Arabia.

Background Practicing and following a Pregnancy Prevention Program (PPP) is crucial to prevent isotretinoin-induced teratogenicity. Our study aims to assess the current practice of dermatologists about PPP when prescribing oral isotretinoin and the compliance of the patients toward contraceptive methods. Methods The research used a cross-sectional design and utilized a probability sampling method in Saudi Arabia. An online self-administered questionnaire was used to collect data that included female participants who were previously treated/being treated with isotretinoin for acne. Data was analyzed using SPSS (IBM Inc., Armonk, New York). Results Our study examined 359 female patients receiving isotretinoin treatment. Isotretinoin was primarily used for severe nodular forms of acne resistant to regular treatment 229 (63.8%). Regarding awareness, 326 (90.8%) were familiar with isotretinoin's teratogenic effects, and 112 (31.2%) were familiar with the Saudi Food and Drug Authority's Pregnancy Prevention Program. Physicians were among the most prevalent information sources 254 (71%). In terms of isotretinoin usage, 227 (63.2%) had one course. Regarding contraceptive practice, 167 (46.5%) were informed about the necessity of a negative pregnancy test before starting treatment, and 29 (50.9%) of those who received more than two courses had good awareness. Conclusion The study identified a notable awareness gap among the participants, as over two-thirds demonstrated a poor awareness level regarding isotretinoin. A significant proportion of participants were informed about the importance of contraceptive practices, including the necessity of a negative pregnancy test before, during, and after treatment.

A Rare Mutation in MESP1 Increases the Risk of Congenital Heart Disease

Objective: In this study, we aim to screen MESP1 variants in congenital heart disease (CHD), and explore the biological functions of these variants. Methods: Targeted sequencing was used to screen MESP1 variants in a cohort of patients with CHD and healthy controls from Shandong Province, China, and confirm the variants with Sanger sequencing. Dual-luciferase reporter assay was used to assess the effects of MESP1 variants on the expression of downstream target genes in HEK293T and H9C2 cells. Binding affinity with NKX2-5 between variants and wild-type MESP1 was detected in HEK293T cells using an electrophoretic gel mobility shift assay (EMSA). The teratogenic effects of the MESP1 variants compared to the wild-type were explored with zebrafish embryo microinjection. Results: We identified two rare mutations, namely c.359T>C (p.L120P) and c.526A>T (p.T176S), in MESP1. The impact of these mutations was investigated using dual-luciferase reporter assay. Our findings demonstrate that compared to the wild-type, the mutation c.359T>C (p.L120P) significantly inhibits the expression of downstream target genes, whereas the mutation c.526A>T (p.T176S) does not exhibit altered activity. Further insights from EMSA revealed that the mutation c.359T>C (p.L120P) displays a reduced binding affinity with NKX2-5. Notably, our investigation involving zebrafish embryo microinjection unveiled a significant increase in the rate of malformation associated with the mutation c.359T>C (p.L120P). Conclusions: Two rare mutations in MESP1 were identified in the CHD cohort. Our in vitro and in vivo studies showed that MESP1 c.359T>C (p.L120P) is a loss-of-function mutation that may increase the risk of CHD.

Sensitivity assessment of Biomphalaria glabrata (SAY, 1818) using reference substance sodium dodecyl sulfate for ecotoxicological analyzes.

Sodium dodecyl sulfate (SDS) is a surfactant used and recommended by regulatory agencies as a reference substance in ecotoxicological analyzes. In this work, acute toxicity assays were performed with adults and embryos of the freshwater snail Biomphalaria glabrata, an endemic organism with environmental and public health importance, to evaluate the effects of the surfactant and establish a sensitivity control chart. The organisms were exposed to SDS for 24 h to a range of concentrations, as well as a control group. Six assays were performed to establish the control chart for adults (with a median LC50 of 36.87 mg L-1) and differential sensitivity was observed at each embryonic stage (EC50 = blastulae 33.03, gastrulae 35.03, trochophore 39.71 and veliger 72.55 mg L-1). The following behavioral responses were observed in exposed adult snails: release of hemolymph and mucus, body outside the shell, and penile overexposure. Embryos at the blastulae and gastrulae stages were more sensitive, and teratogenic effects were accentuated in the trochophore stage. The difference in results obtained between adults and embryos underscore the importance of carrying out analyzes at different developmental stages. The serial assays established with SDS for B. glabrata demonstrated efficiency and constancy conditions in the assays with good laboratory practice standards. The wide distribution of Biomphalaria species in several countries, their easy maintenance and cultivation in the laboratory, in addition to ecological importance, make them economical alternatives for ecotoxicological assays.

Investigation of the potential teratogenic effects of fructose on the embryo using the rat whole embryo culture model

Excessive consumption of fructose-sweetened foods and beverages is a growing concern worldwide. Studies have demonstrated that fructose consumption before and during pregnancy can result in adverse outcomes such as decreased decidualization, increased fetal losses, and low birth weight. The study investigated the teratogenic effects of fructose on rat embryos during organogenesis using whole embryo culture. Within the scope of the study, 4 groups were formed as control, low, medium, and high-dose fructose (HDF) with 10 embryos in each group. The 9.5-day-old rat embryos were cultured with different concentrations of fructose (1, 5 and 10 mM) for 48 h and the possible effects of fructose were examined using morphological scoring, histochemistry, immunofluorescence, and TUNEL methods. According to the analyses, protein synthesis and proliferation were decreased, vascular formation was suppressed, and apoptosis was increased in embryos exposed to fructose, especially at concentrations of 5 mM and above. According to the morphological scoring results, it was determined that heart, hind limb, and somite development were retarded in all experimental groups compared to the control group, developmental retardation increased in direct proportion to fructose concentration, and also significant malformations were observed in all parameters examined in the HDF group. In addition, analysis of yolk sac diameter, head length, crown rump length and somite numbers showed that these parameters were significantly decreased in all experimental groups. End of the study, it was concluded that fructose at concentrations of 1 mM and above may induce embryonic development retardation and other anomalies by decreasing protein synthesis and cell proliferation, suppressing vascular formation, and increasing apoptosis in embryonic tissues.

Determination of free formaldehyde in cosmetics products through derivatization with 2,4-DNPH using an optimized and validated HPLC-PDA method

AbstractFormaldehyde plays a significant role in the global economy due to its unique chemical properties and widespread use in both the medical field and various industrial sectors. However, formaldehyde (HCHO) is classified as a persistent organic pollutant and is known to be harmful. Exposure to formaldehyde, both direct and prolonged, can cause severe health issues and potentially lead to death. It is recognized as a human carcinogen by numerous organizations and can negatively impact the endocrine system, as well as having mutagenic or teratogenic effects. Formaldehyde has been detected in various matrices at levels exceeding those permitted by international health regulatory bodies. Chromatography, particularly high-performance liquid chromatography (HPLC) coupled with detection methods, is an analytical technique frequently used to determine volatile organic molecules, including formaldehyde. This investigation aimed to develop and validate an assay method to identify and quantify formaldehyde in cosmetic products using HPLC-PDA. The chosen isocratic system consisted of a ZORBAX RX-C8 column (250 mm × 4.6 mm; 5 μm) and a mobile phase mixture of acetonitrile and water in a 55:45 (v/v) ratio, with a flow rate of 1.5 mL min−1. Formaldehyde was detected at 353 nm after derivatization with a 0.1N 2,4-dinitrophenylhydrazine solution, with a retention time of approximately 5.0 min and a total run time of 7.0 min for formaldehyde. The method was validated according to ICH Q2 (R1) guidelines. The validation parameters demonstrated high selectivity, precision (RSD <2%), accuracy (mean recovery of 101.3%), linearity (r > 0.995 in the 1,000–2,400 ppm range), and a limit of quantification (LOQ) of 0.1 ppm. The validated analytical method was applied to 35 cosmetic products. None of these products were labeled as containing formaldehyde, although 6 imported products were labeled as containing formaldehyde-releasing preservatives. The results indicated that 88.6% of the samples tested positive for formaldehyde, with free formaldehyde levels ranging from 20 to 981 ppm. All samples contained formaldehyde levels below the 2000 ppm threshold.

Teratogenic Effect of Valproic Acids on Neural Tube Development: A Review

Teratogenic Effect of Valproic Acids on Neural Tube Development: A Review

Transcriptomic Point of Departure (tPOD) of androstenedione in zebrafish embryos as a potential surrogate for chronic endpoints

The transcriptomic Point of Departure (tPOD) is increasingly used in ecotoxicology to derive quantitative endpoints from RNA sequencing studies. Utilizing transcriptomic data in zebrafish embryos as a New Approach Methodology (NAM) is beneficial due to its acknowledgment as an alternative to animal testing under EU Directive 2010/63/EU. Transcriptomic profiles are available in zebrafish for various modes of action (MoA). The limited literature available suggest that tPOD values from Fish Embryo Toxicity (FET) tests align with, but are generally lower than, No Observed Effect Concentrations (NOEC) from long-term chronic fish toxicity tests.In studies with the androgenic hormone androstenedione in a Fish Sexual Development Test (FSDT), a significant shift in the sex ratio towards males was noted at all test concentrations, making it impossible to determine a NOEC (NOEC <4.34 μg/L). To avoid additional animal testing in a repetition of the FSDT and adhere to the 3Rs principle (replacement, reduction, and refinement), a modified zebrafish FET (zFET) was conducted aiming to determine a regulatory acceptable effect threshold. This involved lower concentration ranges (20 to 6105 ng/L), overlapping with the masculinization-observed concentrations in the FSDT. The tPOD analysis in zFET showed consistent results with previous FSDT findings, observing strong expression changes in androgen-dependent genes at higher concentrations but not at lower ones, demonstrating a concentration-response relationship.The tPOD values for androstenedione were determined as 24 ng/L (10th percentile), 60 ng/L (20th gene), and 69 ng/L (1st peak). The 10th percentile tPOD value in zFET was 200 times lower than the lowest concentration in the FSDT. Comparing the tPOD values to literature suggests their potential to inform on the NOEC range in FSDT tests.

THE EFFECT OF THE ANTIBIOTIC GENTAMICIN ON THE STAGES OF ONTOGENESIS IN CHICKEN EGGS

Introduction: Various studies have shown that the effects of the action of drugs, in addition to having positive effects, they can also provoke negative effects in different organs of the body, where by giving more doses in some cases it can exceed the therapeutic limit and become toxic and produce pathological effects in both experimental animals and humans. Uncontrolled use and drug overdose can lead to macroscopic histopathological changes and give teratogenic, mutagenic and carcinogenic effects. Purpose of the paper: This paper aims to study the effects of some drugs at different stages of embryonic development in chicken eggs. The research of this paper will consist of the toxic effect of drugs and macroscopic and microscopic histopathological changes in certain stages of embryonic development of chicken eggs. Material and method: In the study, fertilized chicken eggs were taken and incubated in the incubator for 21 days of incubation. The eggs were treated with the antibiotic gentamicin at certain stages of embryonic development. The eggs hatched on day thirteen, day fifteen, eighteen and day twentyone. Using the stereomicroscope with the macroscopic and microscopic method were analyzed ontogenetic changes in certain stages of embryonic development. Results: The given dose of the antibiotic gentamicin can have negative effects in certain stages of embryonic development in chicken eggs. The dose given in ampullary form in certain quantities to chicken eggs has inhibited and stagnated the processes of embryonic development at different stages compared to control eggs. Conclusion: The given dose of gentamicin can stagnate embryonic development in certain stages and can provoke changes in certain stages of embryonic development. This phenomenon encourages us to do even more detailed research in this direction to see the effect of the given dose and to analyze what consequences it can provoke overdoses at different stages of embryonic development and within the organism. The lethal dose applied at certain stages of ontogenesis may have lethal consequences for the chick embryo at certain stages of embryonic development.

Cellular uptake of multi-walled carbon nanotubes is associated to genotoxic and teratogenic effects towards the freshwater diatom Nitzschia linearis

The increase in industrial production of multi-walled carbon nanotubes (MWCNTs) raises concerns about their potential adverse effects associated to environmental releases, especially in aquatic environments where they are likely to accumulate. This study focuses on the environmental impact of MWCNTs, specifically on a benthic freshwater diatom (Nitzschia linearis), which plays a major role in the primary production of water bodies. The obtained results indicate that exposure to MWCNTs in the presence of natural organic matter (NOM) inhibits diatom's growth in a dose-dependent manner after 72 h of exposure. Interestingly, the photosystem II quantum yield (PSIIQY) in diatoms remains unaffected even after exposure to MWCNTs at 10 mg/L. After 48 h of exposure, MWCNTs are found to bind preferentially to extracellular polymeric substances (EPS) produced by diatoms, which could decrease their toxicity by limiting their interaction with this organism. However, measurement of genotoxicity and teratogenicity in diatoms exposed to MWCNTs revealed that the exposure to MWCNTs increased the occurrence of cells with micronuclei and abnormal frustules. Microscopy analyses including two-photon excitation microscopy (TPEM) revealed the internalization of MWCNTs. Investigations of the diatom's frustule structure using Scanning electron microscopy (SEM) indicated that the presence of pore structures constitutes a pathway allowing MWCNTs uptake. The presence in the diatom's cytoplasm of MWCNTs might possibly induce disturbances of the cellular components, leading to the observed genotoxic and teratogenic effects. In view of previous studies, this work underscores the need for further studies on the interaction between nanomaterials and different diatom species, given the species-specific nature of the interactions.

Evaluating the biomedical and environmental safety of selenium nanoparticles synthesized from black pepper seed extract

In recent times, sustainable synthesis of selenium nanoparticles (Se NPs) has seen a significant rise in research, focusing primarily on microbial and plant polysaccharide-based approaches for various bioapplications. However, there are limited studies on the use of extracts from herbal spice plants as capping agents for Se NPs. Therefore, this study investigates the pioneering synthesis of Se NPs using black pepper (Piper nigrum) seed extract (PSe NPs) and assesses their antioxidant properties, hemolytic potential, antibacterial and antibiofilm activities, cytotoxicity, phytotoxicity, in vivo toxicity in zebrafish embryos, and their effectiveness in prolonging the shelf life of food materials. The green-synthesized PSe NPs were thoroughly physicochemically characterized and found to be sphere-shaped with a medium diameter of 10–100 nm. The PSe NPs exhibited substantial antibacterial effects, being more effective against S. aureus (Gram-positive)than against S. typhi (Gram-negative). Furthermore, PSe NPs significantly inhibited MRSA biofilm growth at 500 μg/mL and showed notable antioxidant activity compared to standard gallic acid. Also at 500 μg/mL, PSe NPs induced significant hemolysis, whereas inferior concentrations did not. Cytotoxicity evaluations using the MTT assay revealed that PSe NPs significantly reduced the viability of human normal embryonic kidney (HEK 293) cells and human cervical cancer (HeLa) cells after 24 hours of treatment at concentrations of 0.1–500 μg/mL. This cytotoxic effect was associated with apoptosis, as shown by acridine orange/ethidium bromide staining. In phytotoxicity assays, PSe NPs revealed significant effects on seed germination and root and shoot growth of the mung bean (Vigna radiata). The zebrafish embryotoxicity assay indicated that PSe NPs at 500 µg/mL affected embryo morphology, mortality and survival rates 96 hours after fertilization. Furthermore, the application of PSe NPs gel coatings effectively reduced weight loss and extended the shelf life of fruits such as apples and pears, maintaining their natural appearance.

Sensitivity Variations in Developmental Toxicity of Imidacloprid to Zebrafish Embryos at Different Neurodevelopmental Stages.

Neonicotinoids are ubiquitous in global surface waters and pose a significant risk to aquatic organisms. However, information is lacking on the variations in sensitivity of organisms at different developmental stages to the neurotoxic neonicotinoids. We established a spectrum of toxicity to zebrafish embryos at four neurodevelopmental stages (1, 3, 6, and 8 h post fertilization [hpf]) and dechorionated embryos at 6 hpf based on external and internal exposure to imidacloprid as a representative neonicotinoid. Embryos at the gastrula stage (6 and 8 hpf) were more sensitive to imidacloprid than embryos at earlier developmental stages. Dechorionated embryos were more sensitive to imidacloprid than embryos with a chorion, suggesting that the chorion offers protection against pollutants. Nine sublethal effects were induced by imidacloprid exposure, among which uninflated swim bladder (USB) was the most sensitive. Water depth and air availability in the exposure chambers were critical factors influencing the occurrence of USB in zebrafish larvae. Internal residues of metabolites accounted for <10% of imidacloprid, indicating that imidacloprid was metabolized in a limited fashion in the embryos. In addition, acute toxicity of the main metabolite 5-hydroxy-imidacloprid was significantly lower than that of imidacloprid, indicating that the observed toxicity in embryos exposed to imidacloprid was mainly induced by the parent compound. Our research offers a fresh perspective on choosing the initial exposure time in zebrafish embryo toxicity tests, particularly for neurotoxicants. Environ Toxicol Chem 2024;43:2398-2408. © 2024 SETAC.

Identification, characterization, and in silico ADMET prediction of nirmatrelvir and its degradation products using HPLC-PDA and LC-QTOF-MS/MS.

Nirmatrelvir is a protease inhibitor that is essential for virus replication. Nirmatrelvir is indicated for the management of mild to severe cases of COVID-19 in individuals who are 12 years of age or older. Forced degradation studies of nirmatrelvir were carried out on the drug substance in solid and solution forms, subjecting it to various stress conditions according to International Conference on Harmonisation (ICH) Q1A(R2) and Q1B guidelines. The analytical method was validated as per the ICH Q2(R1) guidelines. The drug substance (nirmatrelvir) was subjected to hydrolysis (acidic, alkaline, and neutral), thermal, photolytic, and oxidative stress conditions. Five degradation products (DPs) of nirmatrelvir formed under hydrolytic (acidic and alkaline) and oxidative (2,2-azobisisobutyronitrile) stress conditions. These degradation products were identified and separated using reverse-phase HPLC on a phenomenex kinetex C8 column (250 mm ×4.6mm ×5μm) with gradient elution. The mobile phase consisted of 0.1% formic acid and acetonitrile, and detection was carried out at a wavelength of 210 nm. Nirmatrelvir and its five DPs were efficiently separated using reverse phase-HPLC. These five DPs were identified and characterized using LC-electrospray ionization (ESI)-Q-TOF-coupled mass spectrometry analysis in the ESI-positive ionization mode. The formation mechanisms of the DPs and the most probable mass fragmentation pathways for both nirmatrelvir and its DPs were elucidated. The developed method demonstrated selectivity, accuracy, linearity, and reproducibility, making it appropriate for quality control of nirmatrelvir and future research studies. Additionally, the physicochemical and Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) properties of nirmatrelvir and its DPs were predicted using ADMET predictor software. The toxicity profile revealed that DP2 and DP3 have teratogenic effects while DP1 and DP3 caused phospholipidosis.