Embryonic exposure to butylparaben and propylparaben induced developmental toxicity and triggered anxiety-like neurobehavioral response associated with oxidative stress and apoptosis in the head of zebrafish larvae

Understanding the effects of perfluorobutane sulfonate in zebrafish larvae model (Danio rerio): Insights into potential ecotoxicological risks and human health

Perfluorobutane sulfonate (PFBS) is a synthetic organic molecule that belongs to the per and polyfluoroalkyl substances family. Due to its unique physicochemical characteristics, PFBS has been extensively used in consumer products and industries. However, its increasing usage and chemical stability cause environmental pollution and bioaccumulation. The toxicological effects of PFBS were not well studied. In this study, the impact of PFBS on zebrafish embryos was evaluated. PFBS (1000-1500 μM) exposure exhibited increased mortality and malformation in a concentration-dependent manner. After 96 hour post-fertilization of PFBS exposure, the LC50 was estimated to be 1378 μM. Furthermore, PFBS (1.4, 14, 140, 1400 μM) exposure significantly increases oxidative stress by suppressing antioxidant levels. Locomotor behavior analysis revealed that PFBS exposure caused locomotor changes in zebrafish larvae. Acetylcholine esterase activity was also reduced in the PFBS-exposed groups. Gene expression study showed that PFBS exposure downregulated the antioxidant gene expression in zebrafish larvae. Overall, the current study reveals that PFBS can trigger oxidative stress-induced apoptosis by reducing antioxidant activity in zebrafish larvae.

Bioaccumulation and ecotoxicity of parabens in aquatic organisms: Current status and trends

Parabens are preservatives widely used in personal care products, pharmaceuticals, and foodstuffs. However, they are still unregulated chemical compounds. Given their extensive use and presence in different environmental compartments, parabens can adversely affect animal health. Thus, the current study aimed to summarize and critically analyze the bioaccumulation and ecotoxicity of parabens in aquatic species. Studies have been mostly conducted in laboratory conditions (75%), using mainly fish and crustaceans. Field studies were carried out across 128 sampling sites in six countries. Paraben bioaccumulation was predominantly detected in fish muscle, liver, brain, gills, ovary, and testes. Among the parent parabens, methylparaben (MeP), ethylparaben (EtP), and propylparaben (PrP) have been detected frequently and more abundantly in tissues of marine and freshwater specimens, as well as the metabolite 4-hydroxybenzoic acid (4-HB). Parabens can induce lethal and sublethal effects on aquatic organisms, such as oxidative stress, endocrine disruption, neurotoxicity, behavioral changes, reproductive impairment, and developmental abnormalities. The toxicity of parabens varied according to species, taxonomic group, developmental stage, exposure time, and concentrations tested. This study highlights the potential bioaccumulation and ecotoxicological impacts of parabens and their metabolites on aquatic invertebrates and vertebrates. Additionally, future research recommendations are provided to evaluate the environmental risks posed by paraben contamination more effectively.

Toxicity of parental co-exposure of microplastic and bisphenol compounds on adult zebrafish: Multi-omics investigations on offspring

In recent years, the widespread use of bisphenol compounds and microplastics (MP) have attracted attention due to their harmful effects. Here, individual and combined effects of MP and bisphenol compounds, were assessed on adult zebrafish after co-exposure of bisphenol A (BPA) or bisphenol S (BPS) and 25 μm polyethylene MP. Impacts on their offspring (the F1 generation) were also investigated. The reproductive toxicity in adult zebrafish impacted exerted by bisphenol compounds were aggravated by the co-presence of MP. Transcriptomics and metabolomics further showed single or co-exposure of bisphenol compounds and MP could together regulate apoptosis, calcium signaling pathway and glycerophospholipid signaling pathways. Our results also showed the different toxicity mechanisms on transcriptional and metabolic profiles in the combination effects of bisphenol compounds and MP. The co-exposure of BPA and MP predominantly influenced neurotoxicity via the MAPK signaling pathway and voltage-dependent calcium channels, whereas the co-exposure of BPS and MP principally affected visual development through phototransduction and retinol metabolism. The co-exposure of BPA and MP, as well as BPS and MP, specifically regulate lipid metabolism and carbohydrate metabolism in zebrafish offspring, respectively. Overall, this study provided a deep understanding of the toxicity differences between co-exposure and single exposure of bisphenol compound and MP in zebrafish, as well as the transgenerational effects and potential molecular mechanisms of bisphenol compounds and MP in zebrafish offspring.

Genetic Evidence for Estrogenic Effects of Benzophenone-2 on Zebrafish Neurodevelopment and Its Signaling Mechanism

Estrogens play a crucial role in regulating various biological responses during the early stages of neurodevelopment. Benzophenone-2 (BP2), a widely used organic ultraviolet (UV) filter, has been proven as an estrogenic compound, whereas the estrogenic effects of BP2 on neurodevelopment remain largely unknown. Here, we investigated the neurodevelopmental toxicity of BP2 by exposing zebrafish embryos from 2 to 120 h postfertilization (hpf) at environmentally relevant concentrations. We demonstrated that early life exposure to BP2 induced multiple concentration-dependent impairments in the nervous system, including hypoactivity, abnormal brain morphology, impaired neurocyte proliferation, shortened axon, and increased neurocyte apoptosis. Moreover, metabolomic profiling revealed a decrease in dopamine (DA) and its metabolites in BP2-treated larvae. Using E2 treatment and morpholino knockdown assays, we provided strong genetic evidence that the BP2-induced behavioral disorders were associated with estrogen-dependent signaling, especially estrogen receptors 2a and 2b (esr2). Subsequently, transcriptomic profiling indicated that the activation of esr2 further inhibited the expression of LIM homeobox transcription factor 1 β a (lmx1ba), which is vital for normal neurodevelopment. Consistently, the overexpression of lmx1ba and inhibition of esr2 obviously alleviated BP2-caused neurotoxicity, uncovering a seminal role of esr2 and lmx1ba in BP2-induced neurodevelopmental toxicity. Our findings provide the first evidence in fish that BP2 can induce neurodevelopmental deficits and brain dysfunction and offer novel insights into the mechanisms of toxicity of BP2 as well as other emerging benzophenones.

Effects of long-term treatment with low concentration butylparaben on prostate organoids

Endocrine-disrupting compounds (EDCs), such as butylparaben (BP), which are used as preservatives in food and cosmetics, have been shown to negatively affect male reproductive health. Organs under the control of hormones such as androgens and estrogens, such as the prostate, are vulnerable to EDC stimulation. It is well known that BP can cause hormonal imbalances in the prostate and lead to various prostate diseases. However, studies on the long-term exposure of low-dose BP, which is common in daily life, are lacking, and existing studies rely heavily on in vitro tests to assess the risk of EDCs. Therefore, in this study, we investigated the long-term exposure effects of low-dose BP using a prostate organoid model that more closely resembles the target organ. When prostate organoids were treated with BP for a long period, hormonal imbalance was confirmed through differences in the expression of hormone receptors. In addition, reactive oxygen species (ROS) production was confirmed by DCFDA staining, and the protective effect of prostate organoids against stimulation was confirmed by increased protein levels of antioxidant factors. Through transcriptome analysis, we confirmed the occurrence of reproductive toxicity caused by BP. The long-term treatment of prostate organoids with BP causes hormonal imbalance and increased ROS exhibits reproductive toxicity and exerts a protective mechanism against BP through the expression of antioxidant factors. Our results highlight the potential of prostrate organoids as an alternative to animal experimental model and the need for further research on the effects of low EDC concentrations on male reproductive function.

Relationships between bisphenol A and paraben exposure, oxidative stress, and the activity of outer hair cells in the cochlea in children with hearing loss

This study aimed to determine the associations of childhood exposure to bisphenol A (BPA) and parabens (PBs) with oxidative stress and the activity of outer hair cells (OHCs) in the cochlea of children with hearing loss (HL). A total of 641 children were enrolled in this cross-sectional study. Urinary concentrations of BPA and four PBs including methyl paraben (MP), ethyl paraben (EP), propyl paraben (PP), and butyl paraben (BP) were quantified by using liquid chromatography-tandem mass spectrometry (LC/MSMS). Four urinary biomarkers of oxidative stress, 8-hydroxy-2'-deoxyguanosine (8-OHdG), 8-nitroguanine (8-NO2Gua), 4-hydroxynonenal mercapturic acid (HNE-MA), and 8-isoprostaglandin F2α (8-iso-PGF2α), were measured using high-performance liquid chromatography-electrospray ionization mass spectrometry. Hearing tests were conducted by an audiologist in the audiometric test room, and the results were confirmed by an otolaryngologist. The activity of OHCs in the cochlea was measured by distortion product otoacoustic emissions (DPOAEs). The associations of BPA/PB exposure and oxidative stress with the activity of OHCs at different frequencies were evaluated in the multivariable linear regression models. There were 91 children with HL, for an incidence of approximately 14.2 %. There was a significant negative association between the presence of EP (1.5 K Hz, 3 K Hz) or PP (2 K Hz) or 8-OHdG (1 K Hz, 1.5 K Hz, 2 K Hz) and the activity of OHCs in the left ear. Significant results were also observed for BPA (2 K Hz), MP (1 K Hz, 1.5 K Hz, 2 K Hz), EP (3 K Hz), and 8-OHdG (2 K Hz) in the right ear. This study revealed that exposure to BPA/PBs reduces the activity of OHCs, especially at middle frequencies, in children.

A systematic review of the toxic potential of parabens in fish

Parabens are the most prevalent ingredients in cosmetics and personal care products (PCPs). They are colorless and tasteless and exhibit good stability when combined with other components. Because of these unique physicochemical properties, they are extensively used as antimicrobial and antifungal agents. Their release into the aquatic ecosystem poses potential threats to aquatic organisms, including fish. We conducted an electronic search in PubMed (http://www.ncbi.nlm.nih.gov/pubmed) using the search term parabens and fish and sorted 93 articles consisting of methyl paraben (MTP), ethyl paraben (ETP), propyl paraben (PPP), butyl paraben (BTP), and benzyl paraben (BNP) in several fish species. Furthermore, we confined our search to six fish species (common carp, Cyprinus carpio; fathead minnows, Pimephales promelas; Japanese medaka, Oryzias latipes; rainbow trout, Oncorhynchus mykiss; Nile tilapia, Oreochromis niloticus; and zebrafish, Danio rerio) and four common parabens (MTP, ETP, PPP, and BTP) and sorted 48 articles for review. Our search indicates that among all six fish, zebrafish was the most studied fish and the MTP was the most tested paraben in fish. Moreover, depending on the alkyl chain length and linearity, long-chained parabens were more toxic than the parabens with short chains. Parabens can be considered endocrine disruptors (EDs), targeting estrogen-androgen-thyroid-steroidogenesis (EATS) pathways, blocking the development and growth of gametes, and causing intergenerational toxicity to impact the viability of offspring/larvae. Paraben exposure can also induce behavioral changes and nervous system disorders in fish. Although the USEPA and EU limit the use of parabens in cosmetics and pharmaceuticals, their prolonged persistence in the environment may pose an additional health risk to humans.

High-Throughput Transcriptomics Screen of ToxCast Chemicals in U-2 OS Cells

New approach methodologies (NAMs) aim to accelerate the pace of chemical risk assessment while simultaneously reducing cost and dependency on animal studies. High Throughput Transcriptomics (HTTr) is an emerging NAM in the field of chemical hazard evaluation for establishing in vitro points-of-departure and providing mechanistic insight. In the current study, 1201 test chemicals were screened for bioactivity at eight concentrations using a 24-h exposure duration in the human- derived U-2 OS osteosarcoma cell line with HTTr. Assay reproducibility was assessed using three reference chemicals that were screened on every assay plate. The resulting transcriptomics data were analyzed by aggregating signal from genes into signature scores using gene set enrichment analysis, followed by concentration-response modeling of signatures scores. Signature scores were used to predict putative mechanisms of action, and to identify biological pathway altering concentrations (BPACs). BPACs were consistent across replicates for each reference chemical, with replicate BPAC standard deviations as low as 5.6 × 10-3 μM, demonstrating the internal reproducibility of HTTr-derived potency estimates. BPACs of test chemicals showed modest agreement (R2 = 0.55) with existing phenotype altering concentrations from high throughput phenotypic profiling using Cell Painting of the same chemicals in the same cell line. Altogether, this HTTr based chemical screen contributes to an accumulating pool of publicly available transcriptomic data relevant for chemical hazard evaluation and reinforces the utility of cell based molecular profiling methods in estimating chemical potency and predicting mechanism of action across a diverse set of chemicals.

Propylparaben exposure impairs G2/M and metaphase-anaphase transition during mouse oocyte maturation

Propylparaben (PrPB) is a known endocrine disrupting chemicals that is widely applied as preservative in pharmaceuticals, food and cosmetics. PrPB has been detected in human urine samples and human serum and has been proven to cause functional decline in reproduction. However, the direct effects of PrPB on mammalian oocyte are still unknown. Here, we demonstrationed that exposure to PrPB disturbed mouse oocyte maturation in vitro, causing meiotic resumption arrest and first polar body extrusion failure. Our results indicated that 600 μM PrPB reduced the rate of oocyte germinal vesicle breakdown (GVBD). Further research revealed that PrPB caused mitochondrial dysfunction and oxidative stress, which led to oocyte DNA damage. This damage further disturbed the activity of the maturation promoting factor (MPF) complex Cyclin B1/ Cyclin-dependent kinase 1 (CDK1) and induced G2/M arrest. Subsequent experiments revealed that PrPB exposure can lead to spindle morphology disorder and chromosome misalignment due to unstable microtubules. In addition, PrPB adversely affected the attachment between microtubules and kinetochore, resulting in persistent activation of BUB3 amd BubR1, which are two spindle-assembly checkpoint (SAC) protein. Taken together, our studies indicated that PrPB damaged mouse oocyte maturation via disrupting MPF related G2/M transition and SAC depended metaphase-anaphase transition.

Impact of butylparaben on growth dynamics and microcystin-LR production in Microcystis aeruginosa

The presence of butylparaben (BP), a prevalent pharmaceutical and personal care product, in surface waters has raised concerns regarding its impact on aquatic ecosystems. Despite its frequent detection, the toxicity of BP to the cyanobacterium Microcystis aeruginosa remains poorly understood. This study investigates the influence of BP on the growth and physiological responses of M. aeruginosa. Results indicate that low concentrations of BP (below 2.5 mg/L) have negligible effects on M. aeruginosa growth, whereas higher concentrations (5 mg/L and 10 mg/L) lead to significant growth inhibition. This inhibition is attributed to the severe disruption of photosynthesis, evidenced by decreased Fv/Fm values and chlorophyll a content. BP exposure also triggers the production of reactive oxygen species (ROS), resulting in elevated activity of antioxidant enzymes. Excessive ROS generation stimulates the production of microcystin-LR (MC-LR). Furthermore, lipid peroxidation and cell membrane damage indicate that high BP concentrations cause cell membrane rupture, facilitating the release of MC-LR into the environment. Transcriptome analysis reveals that BP disrupts energy metabolic processes, particularly affecting genes associated with photosynthesis, carbon fixation, electron transport, glycolysis, and the tricarboxylic acid cycle. These findings underscore the profound physiological impact of BP on M. aeruginosa and highlight its role in stimulating the production and release of MC-LR, thereby amplifying environmental risks in aquatic systems.

Embryonic ethanol exposure induces oxidative stress and inflammation in zebrafish model: A dose-dependent study

Alcohol, or ethanol, is a major contributor to detrimental diseases and comorbidities worldwide. Alcohol use during pregnancy intervenes the developing embryos leading to morphological changes, neurocognitive defects, and behavioral changes known as fetal alcohol spectrum disorder (FASD). Zebrafish have been used as a model to study FASD; however, the mechanism and the impact of ethanol on oxidative stress and inflammation in the zebrafish FASD model remain unexplored. Hence, we exposed zebrafish embryos to different concentrations of ethanol (0 %, 0.5 %, 1.0 %, 1.25 %, and 1.5 % ethanol (v/v)) at 4-96 hours post-fertilization (hpf) to study and characterize the ethanol concentration for the FASD model to induce oxidative stress and inflammation. Here, we studied the survival rate and developmental toxicity parameters at different time points and measured oxidative stress, reactive oxygen species (ROS) generation, apoptosis, and pro-inflammatory gene expression in zebrafish larvae. Our findings indicate that ethanol causes various developmental abnormalities, including decreased survival rate, spontaneous tail coiling, hatching rate, heart rate, and body length, associated with increased malformation. Further, ethanol exposure induced oxidative stress by increasing lipid peroxidation and nitric oxide production and decreasing glutathione levels. Subsequently, ethanol increased ROS generation, apoptosis, and pro-inflammatory gene (TNF-α and IL-1β) expression in ethanol exposed larvae. 1.25 % and 1.5 % ethanol had significant impacts on zebrafish larvae in all studied parameters. However, 1.5 % ethanol showed decreased survival rate and increased malformations. Overall, 1.25 % ethanol is the ideal concentration to study the oxidative stress and inflammation in the zebrafish FASD model.

Butylparaben induced zebrafish (Danio rerio) kidney injury by down-regulating the PI3K-AKT pathway

Butylparaben, a common endocrine disruptor in the environment, is known to be toxic to the reproductive system, heart, and intestines, but its nephrotoxicity has rarely been reported. In order to study the nephrotoxicity and mechanism of butylparaben, we examined the acute and chronic effects on human embryonic kidney cells (HEK293T) and zebrafish. Additionally, we assessed the potential remedial effects of salidroside against butylparaben-induced nephrotoxicity. Our in vitro findings demonstrated oxidative stress and cytotoxicity to HEK293T cells caused by butylparaben. In the zebrafish model, the concentration of butylparaben exposure ranged from 0.5 to 15 μM. An assortment of experimental techniques was employed, including the assessment of kidney tissue morphology using Hematoxylin-Eosin staining, kidney function analysis via fluorescent dextran injection, and gene expression studies related to kidney injury, development, and function. Additionally, butylparaben caused lipid peroxidation in the kidney, thereby damaging glomeruli and renal tubules, which resulted from the downregulation of the PI3K-AKT signaling pathway. Furthermore, salidroside ameliorated butylparaben-induced nephrotoxicity through the PI3K-AKT signaling pathway. This study reveals the seldom-reported kidney toxicity of butylparaben and the protective effect of salidroside against toxicological reactions related to nephrotoxicity. It offers valuable insights into the risks to kidney health posed by environmental toxins.

Mechanistic interplay of dual environmental stressors: Bisphenol-A and cadmium-induced ovarian follicular damage and hepatocyte dysfunction in vivo

This study investigates the individual and combined toxic effects of Bisphenol A (BPA) and Cadmium (Cd) in zebrafish, recognizing the complex mixture of pollutants organisms encounter in their natural environment. Examining developmental, neurobehavioral, reproductive, and physiological aspects, the study reveals significant adverse effects, particularly in combined exposures. Zebrafish embryos exposed to BPA + Cd exhibit synergistically increased mortality, delayed hatching, and morphological abnormalities, emphasizing the heightened toxicity of the combination. Prolonged exposure until 10 days post-fertilization underscores enduring effects on embryonic development. BPA and Cd induce oxidative stress, as evidenced by increased production of reactive oxygen species and lipid peroxidation. This oxidative stress disrupts cellular functions, affecting lipid metabolism and immune response. Adult zebrafish exposed to BPA and Cd for 40 days display compromised neurobehavioral functions, altered antioxidant defenses, and increased oxidative stress, suggesting potential neurotoxicity. Additionally, disruptions in ovarian follicle maturation and skeletal abnormalities indicate reproductive and skeletal impacts. Histological analysis reveals significant liver damage, emphasizing the synergistic hepatotoxicity of BPA and Cd. Molecular assessments further demonstrate compromised cellular defense mechanisms, synaptic function, and elevated cellular stress and inflammation-related gene expression in response to combined exposures. Bioaccumulation analysis highlights differential tissue accumulation patterns. In conclusion, this study provides comprehensive insights into the multifaceted toxicological effects of BPA and Cd in zebrafish, raising concerns about potential adverse impacts on environmental ecosystems and human health.

Nanoplastic Exposure Mediates Neurodevelopmental Toxicity by Activating the Oxidative Stress Response in Zebrafish (Danio rerio)

The global accumulation and adverse effects of nanoplastics (NPs) are a growing concern for the environment and human health. In recent years, more and more studies have begun to focus on the toxicity of plastic particles for early animal development. Different particle sizes of plastic particles have different toxicities to biological development. Nevertheless, the potential toxicological effects of 20 nm NPs, especially on neurodevelopment, have not been well investigated. In this paper, we used fluorescence microscopy to determine neurotoxicity in zebrafish at different concentrations of NPs. Moreover, the behavioral analysis demonstrated that NPs induced abnormal behavior of zebrafish. The results revealed developmental defects in zebrafish embryos after exposure to different concentrations (0, 0.3, 3, and 9 mg/L) of NPs. The morphological deformities, including abnormal body length and the rates of heart, survival, and hatching, were induced after NP exposure in zebrafish embryos. In addition, the development of primary motor neurons was observed the inhibitory effects of NPs on the length, occurrence, and development of primary motor neurons in Tg(hb9:GFP). Quantitative polymerase chain reaction analysis suggested that exposure to NPs significantly affects the expression of the genes involved in the occurrence and differentiation of primary motor neurons in zebrafish. Furthermore, the indicators associated with oxidative stress and apoptosis were found to be modified in zebrafish embryos at 24 and 48 h following exposure to NPs. Our findings demonstrated that NPs could cause toxicity in primary motor neurons by activating the oxidative stress response and inducing apoptosis, consequently impairing motor performance.

Exploring Periostracum as an Alternative Root Canal Irrigant: Insights From Zebrafish Embryo Experiments

Objectives Root canal treatments aim to eliminate biofilms effectively. Considering the limitations of chemical irrigants, there is growing interest in natural alternatives like periostracum due to their antibacterial and fouling-resistant properties. This study aimed to assess periostracum's toxicity as a root canal irrigant by investigating its effects on zebrafish embryos' heart rate, survival rate, and hatching rate, as well as inflammation studies using neutral red assays comparing it to standard irrigants like ethylenediaminetetraacetic acid (EDTA), chlorhexidine (CHX), and sodium hypochlorite (NaOCl). Materials and methods Zebrafish embryos were exposed to varying concentrations of periostracum irrigant and standard irrigants. Heart rate, survival rate, and hatching rate were evaluated as indicators of developmental toxicity using microscopy. Statistical analysis, utilizing GraphPad Prism software (version 5.03, GraphPad Software, LLC, San Diego, California, United States), involved one-way ANOVA and Tukey's post-hoc test to determine significance levels (p < 0.05) across control and other groups based on triplicate means and standard deviation. Results The periostracum irrigant demonstrated superior survival rates, heart rates, and hatching rates at specific concentrations compared to standard irrigants (p < 0.01), maintaining favorable heart rates and hatching rates at those concentrations. However, higher concentrations resulted in diminished hatching rates (p < 0.05). Additionally, this study revealed increased inflammation when larvae were treated with NaOCl, EDTA, and CHX. Conversely, no inflammation was observed when subjected to periostracum irrigants. These findings suggest potential advantages of periostracum as a root canal irrigant due to its increased biocompatibility. Conclusion Periostracum displayed promising attributes in zebrafish embryo experiments, such as stable heart rate, hatching rate, and survival rate, along with reduced developmental toxicity and inflammation, indicating potential advantages as a root canal irrigant, including reduced toxicity compared to conventional agents. Further research involving diverse demographics and long-term effects is crucial to validate periostracum's clinical applicability and safety in endodontic therapies.

Biomonitoring of parabens in wild boars through hair samples analysis

Parabens are compounds widely utilized in the industry as preservative additives to personal care products, cosmetics and food. They pollute the environment and penetrate to the living organisms through the digestive tract, respiratory system and skin. Till now the knowledge about exposure of terrestrial wild mammals to parabens is extremely scarce. Therefore, this study for the first time assessed the concentration levels of five parabens commonly used in industry (methylparaben-MeP, ethylparaben-EtP propylparaben-PrP, benzylparaben -BeP and butylparaben-BuP). Substances have been analyzed in hair samples collected from wild boars using liquid chromatography-mass spectrometry (LC-MS) method. The hair is a matrix, which allows to study long-term exposure of organisms to parabens. During this study MeP was noted in 96.3% of samples with mean 88.3±72.9 pg/mg, PrP in 87.0% of samples with mean 8.5±3.3 pg/mg, BeP in 44.4% of samples with mean 17.2±12.3 pg/mg and EtP in 11.1% of samples with mean 17.2±4.8 pg/mg. In turn BuP was noted only in 3.7% of samples with concentration levels below limit of quantification (2.6 pg/mg). Statistically significant intragender differences in parabens levels have not been noted. Only BeP concentration levels depended on industrialization and density of human population of area, where the animals lived. This study indicates that wild boars are exposed to parabens, especially to MeP and PrP, and analysis of the hair seems to be a useful tool of biomonitoring of parabens in wild mammals.

Embryonic and larval exposure to propylparaben induces developmental and long-term neurotoxicity in zebrafish model

Parabens are preservatives found in cosmetics, processed foods, and medications. The harmful repercussions on the central nervous system by one of the most common parabens, propylparaben (PrP), are yet unknown, especially during development. In this study, the neurodevelopmental effects of PrP and long-term neurotoxicity were investigated in the zebrafish model, using an integrated approach. Zebrafish embryos were exposed to two different concentrations of PrP (10 and 1000 μg/L), then larvae were examined for their behavioral phenotypes (open-field behavior, startle response, and circadian rhythmicity) and relevant brain markers (cyp19a1b, pax6a, shank3a, and gad1b). Long-term behavioral and cognitive impacts on sociability, cerebral functional asymmetry and thigmotaxis were also examined on juveniles at 30 dpf and 60 dpf. Moreover, proteomics and gene expression analysis were assessed in brains of 60 dpf zebrafish. Interestingly, thigmotaxis was decreased by the high dose in larvae and increased by the low dose in juveniles. The expression of shank3a and gad1b genes was repressed by both PrP concentrations pointing to possible effects of PrP on neurodevelopment and synaptogenesis. Proteomics analysis evidenced alterations related to brain development and lipid metabolism. Overall, the results demonstrated that early-life exposure to PrP promotes developmental and persistent neurobehavioral alterations in the zebrafish model, affecting genes and protein levels possibly associated with brain diseases.

Co-encapsulation and release of apigenin and ascorbic acid in polyelectrolyte multilayer capsules for targeted polycystic ovary syndrome

Polycystic ovary syndrome (PCOS), a prevalent endocrine disorder in women of reproductive age, is linked to hormonal imbalances and oxidative stress. Our study investigates the regenerative potential of apigenin (AP, hydrophobic) and ascorbic acid (AC, hydrophilic) encapsulated within poly (allylamine hydrochloride) and dextran sulfate (PAH/DS) hollow microcapsules for PCOS. These microcapsules, constructed using a layer-by-layer (LbL) assembly, are found to be 4 ± 0.5 μm in size. Our research successfully demonstrates the co-encapsulation of AP and AC in a single PAH/DS system with high encapsulation efficiency followed by successful release at physiological conditions by CLSM investigations. In vitro tests with testosterone-treated CHO cells reveal that the dual-drug-loaded PAH/DS capsules effectively reduce intracellular ROS levels and apoptosis and offering protection. In an in-vivo zebrafish model, these capsules demonstrate active biodistribution to targeted ovaries and reduce testosterone levels through radical scavenging. Histopathological examinations show that the injected dual-drug-loaded PAH/DS microcapsules assist in the development of ovarian follicles in testosterone-treated zebrafish. Hence, this dual-drug-loaded system, capable of co-encapsulating two natural compounds, effectively interacts with ovarian cells, reducing cellular damage and normalizing PCOS conditions.

Histone acetyltransferases derived RW20 protects and promotes rapid clearance of Pseudomonas aeruginosa in zebrafish larvae

Pseudomonas is a group of bacteria that can cause a wide range of infections, particularly in people with weakened immune systems, such as those with cystic fibrosis or who are hospitalized. It can also cause infections in the skin and soft tissue, including cellulitis, abscesses and wound infections. Antimicrobial peptides (AMPS) are the alternative strategy due to their broad spectrum of activity and act as effective treatment against multi-drug resistance pathogens. In this study, we have used an AMP, RW20 (1RPVKRKKGWPKGVKRGPPKW20). RW20 peptide is derived from the histone acetyltransferases (HATs) of the freshwater teleost, Channa striatus. The antimicrobial prediction tool has been utilized to identify the RW20 sequence from the HATs sequence. We synthesized the peptide to explore its mechanism of action. In an in vitro assay, RW20 was challenged against P. aeruginosa and we showed that RW20 displayed antibacterial properties and damaged the cell membrane. The mechanism of action of RW20 against P. aeruginosa has been established via field emission scanning electron microscopy (FESEM) as well as fluorescence assisted cell sorter (FACS) analysis. Both these experiments established that RW20 caused bacterial membrane disruption and cell death. Moreover, the impact of RW20, in-vivo, was tested against P. aeruginosa-infected zebrafish larvae. In the infected larvae, RW20 showed protective effect against P. aeruginosa by increasing the larval antioxidant enzymes, reducing the excess oxidative stress and apoptosis. Thus, it is possible that HATs-derived RW20 can be an efficient antimicrobial molecule against P. aeruginosa.

Furan-based Chalcone Annihilates the Multi-Drug-Resistant Pseudomonas aeruginosa and Protects Zebra Fish Against its Infection

The emergence of carbapenem-resistant Pseudomonas aeruginosa, a multi-drug-resistant bacteria, is becoming a serious public health concern. This bacterium infects immunocompromised patients and has a high fatality rate. Both naturally and synthetically produced chalcones are known to have a wide array of biological activities. The antibacterial properties of synthetically produced chalcone were studied against P. aeruginosa. In vitro, study of the compound (chalcone derivative named DKO1), also known as (2E)-1-(5-methylfuran-2-yl)-3-(4-nitrophenyl) prop-2-en-1-one, had substantial antibacterial and biofilm disruptive action. DKO1 effectively shielded against P. aeruginosa-induced inflammation, oxidative stress, lipid peroxidation, and apoptosis in zebrafish larvae. In adult zebrafish, the treatment enhanced the chances of survivability and reduced the sickness-like behaviors. Gene expression, biochemical analysis, and histopathology studies found that proinflammatory cytokines (TNF-α, IL-1β, IL-6, iNOS) were down regulated; antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT) levels increased, and histoarchitecture was restored in zebrafish. The data indicate that DKO1 is an effective antibacterial agent against P. aeruginosa demonstrated both in vitro and in vivo.

Effect of pH on UV/H2O2-mediated removal of single, mixed and halogenated parabens from water

Adjusting pH values in aqueous environments can significantly improve the efficiency by which parabens and halo-parabens are removed. In this study, 20 neutral and deprotonated species were selected as models to investigate their pH-dependent removal mechanisms and kinetics by a UV/H2O2 process using density functional theory (DFT). Compared to neutral species, deprotonated species exhibit higher reactivity to HO• due to their high electron cloud density. H atom abstraction (HAA) reactions on the substitution groups are the most favorable pathways for neutral species, while radical adduct formation (RAF) reactions are the most favorable for deprotonated species. Single electron transfer (SET) reactions can be neglected for neutral species, while these reactions become a viable route for deprotonated molecules. The total reaction rate constants range from 1.63 × 109 to 3.74 × 1010 M- 1 s- 1 at pH 7.0, confirming the experimental results. Neutral and weakly alkaline conditions are favorable for the degradation of MeP and halo-parabens in the UV/H2O2 process. The order of removal efficiency at optimum pH is dihalo-parabens > mono-halo-parabens ≈ F, F-MeP > MeP. Furthermore, the transformation products must undergo oxidative degradation due to their high toxicity. Our findings provide new insights into the removal of parabens and their halogenated derivatives from wastewater.

Impact of butylparaben on β-cell damage and insulin/PEPCK expression in zebrafish larvae: Protective effects of morin

Butylparaben (BP), a common chemical preservative in cosmetic and pharmaceutical products, has been known to induce oxidative stress and disrupt endocrine function in humans. In contrast, morin, a flavonoid derived from the Moraceae family, exhibits diverse pharmacological properties, including anti-inflammatory and antioxidant. Despite this, the protective role of morin against oxidative stress-induced damage in pancreatic islets remains unclear. Therefore, in this study, we aimed to investigate the potential protective mechanism of morin against oxidative stress-induced damage caused by BP in zebrafish larvae. To achieve this, we exposed the zebrafish larvae to butylparaben (2.5 mg/L) for 5 days, leading to increased oxidative stress and apoptosis in β-cells. However, our compelling findings revealed that pretreatment with various concentrations of morin effectively reduced mortality and mitigated apoptosis and lipid peroxidation in β-cells induced by BP exposure. In addition, zebrafish larvae exposed to BP for 5 days exhibited evident β-cell damage. However, the pretreatment with morin showed promising effects by promoting β-cell proliferation and lowering glucose levels. Furthermore, gene expression studies indicated that morin pretreatment normalized PEPCK expression while increasing insulin expression in BP-exposed larvae. In conclusion, our findings highlight the potential of morin as a protective agent against BP-induced β-cell damage in zebrafish larvae. The observed improvements in oxidative stress, apoptosis, and gene expression patterns support the notion that morin could be further explored as a therapeutic candidate to counteract the detrimental effects of BP exposure on pancreatic β-cells.

Combined toxicity of aflatoxin B1 and tebuconazole to the embryo development of zebrafish (Danio rerio)

Mycotoxins and pesticides are pervasive elements within the natural ecosystem. Furthermore, many environmental samples frequently exhibit simultaneous contamination by multiple mycotoxins and pesticides. Nevertheless, a significant portion of previous investigations has solely reported the occurrence and toxicological effects of individual chemicals. Global regulations have yet to consider the collective impacts of mycotoxins and pesticides. In our present study, we undertook a comprehensive analysis of multi-level endpoints to elucidate the combined toxicity of aflatoxin B1 (AFB1) and tebuconazole (TCZ) on zebrafish (Danio rerio). Our findings indicated that AFB1 (with a 10-day LC50 value of 0.018 mg L-1) exhibits higher toxicity compared to TCZ (with a 10-day LC50 value of 2.1 mg L-1) toward D. rerio. The co-exposure of AFB1 and TCZ elicited synergistic acute responses in zebrafish. The levels of GST, CYP450, SOD, and Casp-9 exhibited significant variations upon exposure to AFB1, TCZ, and their combined mixture, in contrast to the control group. Additionally, eight genes, namely cat, cxcl-cic, il-1β, bax, apaf-1, trβ, ugtlab, and vtg1, displayed marked alterations when exposed to the chemical mixture as opposed to individual substances. Therefore, further exploration of the underlying mechanisms governing joint toxicity is imperative to establish a scientific basis for evaluating the risk associated with the combined effects of AFB1 and TCZ. Moreover, it is essential to thoroughly elucidate the organ system toxicity triggered by the co-occurrence of mycotoxins and pesticides.

Developmental toxicity and neurobehavioral effects of sodium selenite and selenium nanoparticles on zebrafish embryos

Selenium, a trace mineral, is essential for several physiological processes in humans and animals. It is an antioxidant vital for the immunological response, DNA synthesis, thyroid hormone metabolism, and antioxidant defense enzymes. Zebrafish embryos and larvae were exposed to different concentrations of sodium selenite (SodSe) and selenium nanoparticles (SeNs) at various developmental stages. The study evaluated the impact of SodSe and SeNs on larvae survival, hatching rate, and morphological abnormalities. Also, acridine orange staining was used to analyze the apoptotic cell death, and behavioral tests were conducted to assess anxiety-like behaviors. The results showed that both SodSe and SeNs influence the development and neurobehavior of zebrafish larvae in a concentration-dependent manner. SodSe at high concentration causes low survival rates, delayed hatching, and increased morphological defects in zebrafish larvae. In addition, exposure to SodSe resulted in elevated apoptosis in different larval tissues. Zebrafish larvae treated with SodSe and SeNs exhibited anxiety-like behaviour, increased thigmotaxis, less exploratory behaviour, and less swimming patterns. The nerve conductions and stimuli responses evaluated through acetylcholine esterase (AChE) and cortisol assays, revealed a decrease in the activity in a dose-dependent manner of SodSe and SeNs. Interestingly, the effects of SeNs were lower even at higher concentrations when compared with SodSe at lower concentrations on zebrafish embryos. This shows that SeNs synthesized through biological methods may be less toxic and may have lower effect on the development and neurobehavior of zebrafish larvae. Thus, our study confirms the cytotoxic and neurobehavioral effects of SodSe and suggests the use of SeNs at lower concentration to provide insights into better understanding of developmental stages and metabolic pathways in zebrafish larvae.

Physiological impact of personal care product constituents on non-target aquatic organisms

Personal care products (PCPs) are products used in cleaning, beautification, grooming, and personal hygiene. The rise in diversity, usage, and availability of PCPs has resulted in their higher accumulation in the environment. Thus, these constitute an emerging category of environmental contaminants due to the potential of its constituents (chemical and non-chemical) to induce various physiological effects even at lower concentrations (ng/L). For analyzing the impact of the PCPs constituents on the non-target organism about 300 article including research articles, review articles and guidelines were studied from 2000 to 2023. This review aims to firstly discuss the fate and accumulation of PCPs in the aquatic environment and organisms; secondly provides overview of environmental risks that are linked to PCPs; thirdly review the trends, current status of regulations and risks associated with PCPs and finally discuss the knowledge gaps and future perspectives for future research. The article discusses important constituents of PCPs such as antimicrobials, cleansing agents and disinfectants, fragrances, insect repellent, moisturizers, plasticizers, preservatives, surfactants, UV filters, and UV stabilizers. Each of them has been found to display certain toxic impact on the aquatic organisms especially the plasticizers and UV filters. These continuously and persistently release biologically active and inactive components which interferes with the physiological system of the non-target organism such as fish, corals, shrimps, bivalves, algae, etc. With a rise in the number of toxicity reports, concerns are being raised over the potential impacts of these contaminant on aquatic organism and humans. The rate of adoption of nanotechnology in PCPs is greater than the evaluation of the safety risk associated with the nano-additives. Hence, this review article presents the current state of knowledge on PCPs in aquatic ecosystems.

Transcriptome analysis reveals differences in developmental neurotoxicity mechanism of methyl-, ethyl-, and propyl- parabens in zebrafish embryos

Studies on the comparison of developmental (neuro) toxicity of parabens are currently limited, and unharmonized concentrations between phenotypic observations and transcriptome analysis hamper the understanding of their differential molecular mechanisms. Thus, developmental toxicity testing was conducted herein using the commonly used methyl- (MtP), ethyl- (EtP), and propyl-parabens (PrP) in zebrafish embryos. With a benchmark dose of 5%, embryonic-mortality-based point-of-departure (M-POD) values of the three parabens were determined, and changes in locomotor behavior were evaluated at concentrations of 0, M-POD/50, M-POD/10, and M-POD, where transcriptome analysis was conducted to explore the underlying neurotoxicity mechanism. Higher long-chained parabens were more toxic than short-chained parabens, as determined by the M-POD values of 154.1, 72.6, and 24.2 µM for MtP, EtP, and PrP, respectively. Meanwhile, exposure to EtP resulted in hyperactivity, whereas no behavioral effect was observed with MtP and PrP. Transcriptome analysis revealed that abnormal behaviors in the EtP-exposed group were associated with distinctly enriched pathways in signaling, transport, calcium ion binding, and metal binding. In contrast, exposure to MtP and PrP mainly disrupted membranes and transmembranes, which are closely linked to abnormal embryonic development rather than neurobehavioral changes. According to the changes in the expressions of signature mRNAs, tentative transcriptome-based POD values for each paraben were determined as MtP (2.68 µM), EtP (3.85 µM), and PrP (1.4 µM). This suggests that different molecular perturbations initiated at similar concentrations determined the extent and toxicity outcome differently. Our findings provide insight into better understanding the differential developmental neurotoxicity mechanisms of parabens.

Furan based synthetic chalcone derivative functions against gut inflammation and oxidative stress demonstrated in in-vivo zebrafish model

Inflammatory Bowel Disease (IBD) is a group of persistent intestinal illnesses resulting from bowel inflammation unrelated to infection. The prevalence of IBD is rising in industrialized countries, increasing healthcare costs. Whether naturally occurring or synthetic, chalcones possess a broad range of biological properties, including anti-inflammatory, anti-microbial, and antioxidant effects. This investigation focuses on DKO7 (E)-3-(4-(dimethylamino)phenyl)-1-(5-methylfuran-2-yl)prop-2-en-1-one, a synthesized chalcone with potential anti-inflammatory effects in a zebrafish model of intestinal inflammation induced by Dextran sodium sulfate (DSS). The in vitro study displayed dose-dependent anti-inflammatory as well as antioxidant properties of DKO7. Additionally, DKO7 protected zebrafish larvae against lipid peroxidation, reactive oxygen stress (ROS), and DSS-induced inflammation. Moreover, DKO7 reduced the expression of pro-inflammatory genes, including TNF-α, IL-1β, IL-6, and iNOS. Further, it reduced the levels of nitric oxide (NO) and lactate dehydrogenase (LDH) in the intestinal tissues of adult zebrafish and increased the levels of antioxidant enzymes such as Catalase (CAT) and superoxide dismutase (SOD). The protective effect of DKO7 against chemically (or DSS) induced intestinal inflammation was further verified using histopathological techniques in intestinal tissues. The furan-based chalcone derivative, DKO7, displayed antioxidant and anti-inflammatory properties. Also, DKO7 successfully reverses the DSS-induced intestinal damage in zebrafish. Overall, this study indicates the ability of DKO7 to alleviate DSS-induced gut inflammation in an in-vivo zebrafish.

Luteolin photo-protects zebrafish from environmental stressor ultraviolet radiation (UVB)

Ultraviolet B wavelength ray radiation (UVB) is an environmental stressor with detrimental effects to the aquatic and human systems but also enhances adverse effects when combined with several other environmental factors such as temperature and pollution. UV rays induce cellular oxidative damage and impair motility. This study aimed to examine the photo-protective activity of flavonoid luteolin against UV-B irradiation-induced oxidative stress and cellular damage using zebrafish. An in-vivo photoaging model was established using UV-B irradiation in zebrafish larvae exposed to 100 mJ/cm2. Data demonstrated that UV-B irradiation of swimming water enhanced production of ROS and superoxide anions as well as depleted total glutathione levels in zebrafish larvae. UV-B irradiation also triggered cellular damage and membrane rupture in zebra fish. Further, 100 mJ/cm2 of UV-B radiation exposure to adult-wild type zebrafish co-exposed with intraperitoneally (ip) injected luteolin upregulated the local neuroendocrine axes by activating vascular endothelial growth factor (VEGF) and elevating levels of pro-inflammatory cytokines IL-1β and TNF-α. Histologically, UV-B irradiation induced skin lesions and locomotory defects with clumping and degeneration of brain glial cells. However, luteolin effectively inhibited the excess production of reactive oxygen species (ROS) and decreased superoxide anion levels induced by UV-B irradiation. Luteolin restored the depleted glutathione levels. In addition, luteolin blocked apoptosis and lipidperoxidation. Luteolin protected adult zebrafish by downregulating the pro-inflammatory cytokine protein expression levels and diminishing VEGF activation. Luteolin also alleviated locomotory defects by inhibiting activation of microglia and inflammatory responses by preventing accumulation of glial cells and vacuolation. Data demonstrate that luteolin may protect zebrafish from UV-B-induced photodamage through DNA-protective, antioxidant and anti-inflammatory responses.

Aquatic Peptide: The Potential Anti-Cancer and Anti-Microbial Activity of GE18 Derived from Pathogenic Fungus Aphanomyces invadans

Small molecules as well as peptide-based therapeutic approaches have attracted global interest due to their lower or no toxicity in nature, and their potential in addressing several health complications including immune diseases, cardiovascular diseases, metabolic disorders, osteoporosis and cancer. This study proposed a peptide, GE18 of subtilisin-like peptidase from the virulence factor of aquatic pathogenic fungus Aphanomyces invadans, which elicits anti-cancer and anti-microbial activities. To understand the potential GE18 peptide-induced biological effects, an in silico analysis, in vitro (L6 cells) and in vivo toxicity assays (using zebrafish embryo), in vitro anti-cancer assays and anti-microbial assays were performed. The outcomes of the in silico analyses demonstrated that the GE18 peptide has potent anti-cancer and anti-microbial activities. GE18 is non-toxic to in vitro non-cancerous cells and in vivo zebrafish larvae. However, the peptide showed significant anti-cancer properties against MCF-7 cells with an IC50 value of 35.34 µM, at 24 h. Besides the anti-proliferative effect on cancer cells, the peptide exposure does promote the ROS concentration, mitochondrial membrane potential and the subsequent upregulation of anti-cancer genes. On the other hand, GE18 elicits significant anti-microbial activity against P. aeruginosa, wherein GE18 significantly inhibits bacterial biofilm formation. Since the peptide has positively charged amino acid residues, it targets the cell membrane, as is evident in the FESEM analysis. Based on these outcomes, it is possible that the GE18 peptide is a significant anti-cancer and anti-microbial molecule.

Synergetic effects of polyethylene microplastic and abamectin pesticides on the eyes of zebrafish larvae and adults through activation of apoptosis signaling pathways

Although the toxicity of microplastics (MPs) and pesticides has recently been described, the possible effects of combining these pollutants are poorly understood. Thus, we evaluated the potential impact of exposure to polyethylene MP (PE-MP) and abamectin (ABM) (alone and combined) in zebrafish. After five days, the combined exposure to MP and ABM decreased the survival rate compared to exposures to individual pollutants. A significant increase in reactive oxygen species (ROS), lipid peroxidation, apoptosis, and impairment in antioxidant response was observed in zebrafish larvae. Morphological changes in the eyes of zebrafish significantly increased in the combined exposure group than in the individual exposure. Furthermore, the bax and p53 expression (specific apoptotic genes) was significantly upregulated after the combined exposure to PE-MP and ABM. So, the synergetic effect of MP and ABM cannot be ignored, and further research on other higher models is required to confirm its consequences.

Serine Threonine-Protein Kinase-Derived IW13 Improves Lipid Metabolism via C/EBP-α/SREBP1/FAS Signaling Pathways in HFD-Induced Zebrafish In Vivo Larval Model

Obesity is linked to the development of major metabolic disorders such as type 2 diabetes, cardiovascular disease, and cancer. Recent research has focused on the molecular link between obesity and oxidative stress. Obesity impairs antioxidant function, resulting in dramatically increased reactive oxygen levels and apoptosis. In this study, we investigated the effect of IW13 peptide on inhibiting lipid accumulation and regulating the antioxidant mechanism to normalize the lipid metabolism in HFD induced zebrafish larvae. Our results showed that co-treatment with IW13 peptide showed a protective effect in HFD zebra fish larvae by increasing the survival and heart rate. However, IW13 peptide co-treatment reduced triglycerides and cholesterol levels while also restoring the SOD and CAT antioxidant enzymes. In addition, IW13 co-treatment inhibited the formation of lipid peroxidation and superoxide anion by regulating the glutathione level. Also, the results showed that IW13 specifically downregulated the expression of the lipogenic-specific genes (C/EBP-α, SREBP1, and FAS). The findings exhibited that the IW13 peptide with effective antioxidant and anti-obesity activity could act as a futuristic drug to treat obesity and oxidative stress-related diseases.

Interacted toxic mechanisms of ochratoxin A and tricyclazole on the zebrafish (Danio rerio)

Despite the current efforts to identify the mixtures of chemical pollutants, they are often "binned" into their corresponding pollutant groups. Limited studies have investigated complex mixtures of chemical pollutants co-occurring across different groups. The combined toxic impacts of several substances become a critical consideration in toxicology because chemical combinations can exert a greater deleterious effect than the single components in the mixture. In the current work, we assessed the joint impacts of ochratoxin A and tricyclazole on the zebrafish (Danio rerio) embryos and explored their underlying signaling pathways. Ochratoxin A displayed higher toxicity than tricyclazole, with a 10-day LC₅₀ of 0.16 mg L^-1, whereas that for tricyclazole was 1.94 mg L^-1. The combination of ochratoxin A and tricyclazole exhibited a synergistic impact on D. rerio. The activities of detoxification enzymes GST and CYP450, as well as apoptosis-associated enzyme caspase 3, were distinctly changed in most individual and mixture exposures comparing to the untreated group. Upon both individual and mixture exposures, more dramatic variations were detected in the expressions of nine genes, such as the apoptosis genes cas3 and bax, antioxidant gene mn-sod, immunosuppression gene il-1β, and the endocrine system genes trα, dio1, trβ, ugtlab, and crh, compared with the untreated group. These findings suggested that the simultaneous exposure to low doses of mycotoxins and pesticides in food commodities was more toxic than predicted from the individual chemicals. Considering the frequent co-occurrence of mycotoxins and pesticides in the diet, this synergy should be considered in future assessments.

PS9, Derived from an Aquatic Fungus Virulent Protein, Glycosyl Hydrolase, Arrests MCF-7 Proliferation by Regulating Intracellular Reactive Oxygen Species and Apoptotic Pathways

One of the most common diseases in women is breast cancer, which has the highest death globally. Surgery, chemotherapy, hormone treatments, and radiation are the current treatment options for breast cancer. However, these options have several adverse side effects. Recently, peptide-based drugs have gained attention as anticancer therapy. Studies report that peptides from biological toxins such as venom and virulent pathogenic molecules have potential therapeutic effects against multiple diseases, including cancers. This study reports on the in vitro anticancer effect of a short peptide, PS9, derived from a virulent protein, glycosyl hydrolase, of an aquatic fungus, Aphanomyces invadans. This peptide arrests MCF-7 proliferation by regulating intercellular reactive oxygen species (ROS) and apoptotic pathways. Based on the potential for the anticancer effect of PS9, from the in silico analysis, in vitro analyses using MCF-7 cells were executed. PS9 showed a dose-dependent activity; its IC50 value was 25.27-43.28 μM at 24 h. The acridine orange/ethidium bromide (AO/EtBr) staining, to establish the status of apoptosis in MCF-7 cells, showed morphologies for early and late apoptosis and necrotic cell death. The 2,7-dichlorodihydrofluorescein diacetate (DCFDA) staining and biochemical analyses showed a significant increase in reactive oxygen species (ROS). Besides, PS9 has been shown to regulate the caspase-mediated apoptotic pathway. PS9 is nontoxic, in vitro, and in vivo zebrafish larvae. Together, PS9 may have an anticancer effect in vitro.

Impacts of co-exposure to zearalenone and trifloxystrobin on the enzymatic activity and gene expression in zebrafish

Although humans and animals are usually exposed to combinations of toxic substances, little is known about the interactive toxicity of mycotoxins and farm chemicals. Therefore, we can not precisely evaluate the health risks of combined exposure. In the present work, using different approaches, we examined the toxic impacts of zearalenone and trifloxystrobin on zebrafish (Danio rerio). Our findings showed that the lethal toxicity of zearalenone to embryonic fish with a 10-day LC₅₀ of 0.59 mg L^-1 was lower than trifloxystrobin (0.037 mg L^-1). Besides, the mixture of zearalenone and trifloxystrobin triggered acute synergetic toxicity to embryonic fish. Moreover, the contents of CAT, CYP450, and VTG were distinctly altered in most single and combined exposures. Transcriptional levels of 23 genes involved in the oxidative response, apoptosis, immune, and endocrine systems were determined. Our results implied that eight genes (cas9, apaf-1, bcl-2, il-8, trb, vtg1, erβ1, and tg) displayed greater changes when exposed to the mixture of zearalenone and trifloxystrobin compared with the corresponding individual chemicals. Our findings indicated that performing the risk assessment based on the combined impact rather than the individual dosage response of these chemicals was more accurate. Nevertheless, further investigations are still necessary to reveal the modes of action of mycotoxin and pesticide combinations and alleviate their effects on human health.

Exposure to bisphenols, parabens and phthalates during pregnancy and postpartum anxiety and depression symptoms: Evidence from women with twin pregnancies

BACKGROUND

Women are vulnerable to suffer from the common mental disorders like anxiety and depression during the postpartum period. Exposure to bisphenols, parabens, and phthalates has been linked to anxiety and depression symptoms in the general population. However, little is known about their impacts on postpartum women.

OBJECTIVE

To evaluate the effects of individual and joint exposure to 11 nonpersistent chemicals during pregnancy on postpartum anxiety and depression.

METHODS

Among 278 mothers from the Wuhan Twin Birth Cohort (WTBC), bisphenols, parabens, and phthalate metabolites were measured in maternal urine samples from each trimester. Self-rating Anxiety Scale (SAS) and Edinburgh Postnatal Depression Scale (EPDS) were administrated at early pregnancy and 1 month and 6 months postpartum to determine anxiety and depression symptoms, respectively. Associations between urinary chemical biomarkers (individual or mixtures) and anxiety and depression symptoms were estimated using multiple informant model and quantile-based g-computation.

RESULTS

With adjustment for confounders, one quartile increase in the overall chemical mixture (bisphenols, parabens and phthalate metabolites) during the second trimester was associated with 1.03-point (95% CI: 0.07, 1.99, P = 0.036) higher EPDS score at 1 month postpartum, in which bisphenol A (BPA) and bisphenol F (BPF) contributed the most to the positive association. Consistent effects were also observed in the multiple informant models. We found that second-trimester BPA and BPF exposure individually showed the strongest and significant associations with anxiety and depression symptoms, and some of associations differed across trimesters (P_{trimester-int} < 0.05).

CONCLUSIONS

Second-trimester nonpersistent chemical exposure was associated with increased postpartum anxiety and depression symptoms.

Syringol, a wildfire residual methoxyphenol causes cytotoxicity and teratogenicity in zebrafish model

Natural toxicants, particularly methoxy phenols (MPs) generated by wildfire lignin, can accumulate in the environment, and cause serious health hazards in living organisms. Although the toxicity of MPs such as guaiacol and catechol has recently been described, there is minimal evidence of ecotoxicological effects of syringol. As a result, this study focuses on determining the toxicity by evaluating the cytotoxic and teratogenic effects of syringol in vitro and in vivo in human embryonic kidney (HEK-293) cells and zebrafish embryos, respectively. The ecotoxicity of syringol was predicted to be 63.8 mg/L using the ECOSAR (ECOlogical Structure Activity Relationship) prediction tool, and molecular docking analysis was used to determine the interaction and binding affinities of syringol with human apoptotic proteins in silico. In HEK-293 cells, exposure of syringol (0.5-2 mg/L) has induced cytotoxicity in a concentration-dependent manner. In zebrafish larvae, exposure of syringol (0.5-2 mg/L) has induced dose-dependent embryo toxic effects (or growth abnormalities such as yolk sac edema, pericardial edema, skeletal abnormality, and hyperemia), and changes in growth morphometrics (head height, eye, yolk sac, and pericardial area, heart rate) in particular, the heart rate of larvae was found to be significantly decreased (p<0.001). After a 4-day experimental trial, the accumulated concentration of syringol in zebrafish larvae was confirmed both qualitatively (HPLC-MS - High Performance Liquid Chromatography-Mass spectrometry) and quantitatively (LC-QTOF-HRMS - Liquid Chromatography-Quadrupolar Time of Flight-High Resolution Mass spectrometry). The craniofacial abnormalities induced by syringol exposure (0.5-2 mg/L) were detected as anomalies in cartilaginous development and locomotor deficits using alcian blue staining and locomotor analyses, respectively. Significant increase in oxidative stress parameters (including reactive oxygen species generation, lipid peroxidation, superoxide dismutase, catalase, lactate dehydrogenase and nitric oxide production) (p<0.001) and substantial decrease in glutathione levels were observed (p<0.05) in syringol exposed zebrafish larvae through enzymatic analysis. Additionally, through acridine orange staining and gene expression analyses, syringol (2 mg/L) was found to activate apoptosis in zebrafish larvae. Considering the cytotoxic, embryotoxic (teratogenicity), and oxidative stress-related apoptotic effects of syringol in the zebrafish model, syringol has the potential to emerge as a potent environmental toxicant posing serious health hazards in many living systems; however, further research on its toxicological effects on the actual ecosystem and in higher animal models is required to confirm its consequences.

Protective mechanism of ferulic acid against neomycin-induced ototoxicity in zebrafish

Ototoxicity refers to damage of sensory hair cells and functional hearing impairment following aminoglycosides exposure. Previously, we have determined that ferulic acid (FA) protected hair cells against serial concentrations of neomycin-induced ototoxic damage. The aim of the present study is to assess the mechanism and effects of FA on neomycin-induced hair cells loss and impact on mechanosensory-mediated behaviors alteration using transgenic zebrafish (pvalb3b: TagGFP). We first identified the optimal protective condition as pre/co-treatment method in early fish development. Pretreatment of the larvae with FA significantly protected against neomycin-induced hair cells loss through preventing neomycin passed through the cytoplasm of hair cells, and subsequently decreased reactive oxygen species production and TUNEL signals in 4 day post-fertilization (dpf) transgenic zebrafish larvae. Moreover, preservation of functional hair cells correlated directly with rescue of the altered swimming behavior, indicates FA pretreatment protects against neomycin ototoxic damage in 7-dpf transgenic zebrafish larvae. Together, our findings unravel the otoprotective role of FA as an effective agent against neomycin-induced ototoxic effects and offering the theoretical foundation for discovering novel candidates for hearing protection.

Endocrine Disruption of Propylparaben in the Male Mosquitofish (Gambusia affinis): Tissue Injuries and Abnormal Gene Expressions of Hypothalamic-Pituitary-Gonadal-Liver Axis

Propylparaben (PrP) is a widely used preservative that is constantly detected in aquatic environments and poses a potential threat to aquatic ecosystems. In the present work, adult male mosquitofish were acutely (4d) and chronically (32d) exposed to environmentally and humanly realistic concentrations of PrP (0, 0.15, 6.00 and 240 μg/L), aimed to investigate the toxic effects, endocrine disruption and possible mechanisms of PrP. Histological analysis showed time- and dose-dependent manners in the morphological injuries of brain, liver and testes. Histopathological alterations in the liver were found in 4d and severe damage was identified in 32d, including hepatic sinus dilatation, cytoplasmic vacuolation, cytolysis and nuclear aggregation. Tissue impairments in the brain and testes were detected in 32d; cell cavitation, cytomorphosis and blurred cell boundaries appeared in the brain, while the testes lesions contained spermatogenic cell lesion, decreased mature seminal vesicle, sperm cells gathering, seminiferous tubules disorder and dilated intercellular space. Furthermore, delayed spermatogenesis had occurred. The transcriptional changes of 19 genes along the hypothalamus-pituitary-gonadal-liver (HPGL) axis were investigated across the three organs. The disrupted expression of genes such as Ers, Ars, Vtgs, cyp19a, star, hsd3b, hsd17b3 and shh indicated the possible abnormal steroidogenesis, estrogenic or antiandrogen effects of PrP. Overall, the present results provided evidences for the toxigenicity and endocrine disruptive effects on the male mosquitofish of chronic PrP exposure, which highlights the need for more investigations of its potential health risks.

Copper sulfate induced toxicological impact on in-vivo zebrafish larval model protected due to acacetin via anti-inflammatory and glutathione redox mechanism

Copper sulfate (CuSO₄) as industrial effluent is intentionally or unintentionally released into water bodies and accumulates in the fish. Because of its numerous applications, CuSO₄ can be hazardous to non-target creatures, producing direct alterations in fish habitats. Acacetin is a flavonoid present in all vascular plants that are extensively dispersed in plant pigments and responsible for many natural hues. However, the impact of acacetin on mitigating the toxic effect of CuSO₄ in the in-vivo conditions is not known. The toxicity of acacetin was determined by measuring the survival, deformities and heart rate after treatment with various concentrations to larvae. The protective effect of acacetin was also observed in CuSO₄ exposed zebrafish larvae by reducing malformation, mortality rate and oxidative stress. Meanwhile, the acacetin-protected larvae from CuSO₄ effects through the molecular mechanism by suppressing pro-inflammatory genes (COX-2, TNF-α and IL-1) and upregulating antioxidant genes (GPx, GST and GR). Overall, our findings suggest that acacetin can act as a protective barrier against CuSO₄-induced inflammation in an in-vivo zebrafish larval model.

β-cells regeneration by WL15 of cysteine and glycine-rich protein 2 which reduces alloxan induced β-cell dysfunction and oxidative stress through phosphoenolpyruvate carboxykinase and insulin pathway in zebrafish in-vivo larval model

BACKGROUND

Pancreatic β-cells are susceptible to oxidative stress, leading to β-cell death and dysfunction due to enhanced ROS levels and type 2 diabetes. To inhibit the β-cells damages induced by the oxidative stress, the present study investigates the beneficial effect of various peptides (WL15, RF13, RW20, IW13 and MF18) of immune related proteins (cysteine and glycine-rich protein 2, histone acetyltransferase, vacuolar protein sorting associated protein 26B, serine threonine-protein kinase and CxxC zinc finger protein, respectively). Also, the molecular mechanism of WL15 from cysteine and glycine-rich protein 2 on β-cell regeneration was identified through PEPCK and insulin pathway.

MATERIALS AND METHODS

In this study, a total of five peptides including WL15, RF13, RW20, IW13, and MF18 were derived from immune-related proteins such as cysteine and glycine-rich protein 2, histone acetyltransferase, vacuolar protein sorting associated protein 26B, serine threonine-protein kinase and CxxC zinc finger protein, respectively. These protein sequences were obtained from an earlier constructed transcriptome database of a teleost Channa striatus. The identified peptides were evaluated for their antioxidant as well as antidiabetic activity. Based on the in silico analysis and in-vitro screening experiments, WL15 was predicted to have better antioxidant and antidiabetic activity among the five different peptides. Therefore, WL15 alone was further analyzed for apoptosis, antioxidant capacity, glucose metabolism, and gene expression performance, which was investigated on the alloxan (500 µM) induced zebrafish in vivo larval model.

RESULTS

The results showed alloxan exposure to zebrafish larvae for a day, the ROS was generated in the β-cells. Interestingly, WL15 treatment showed a protective effect by reducing the toxicity of alloxan exposed zebrafish larvae by increasing their survival and heart rate. Moreover, WL15 reduced the intracellular ROS level and apoptosis in alloxan-induced larvae. The superoxide anion and lipid peroxidation levels are also reduced by improving the glutathione content after the WL15 treatment. Besides, WL15 treatment increased the proliferation rate of β-cells and decreased the glucose level. Further, the gene expression studies revealed that WL15 treatment normalized the PEPCK expression while upregulating the insulin expression in alloxan exposed larvae.

CONCLUSION

Overall, the findings indicate that WL15 of cysteine and glycine-rich protein 2 can act as a potential antioxidant for type 2 diabetes patients in respect of improving β-cell regeneration.

Polystyrene Nanoplastic Exposure Induces Developmental Toxicity by Activating the Oxidative Stress Response and Base Excision Repair Pathway in Zebrafish (Danio rerio)

The widespread accumulation of nanoplastics is a growing concern for the environmental and human health. However, studies on the mechanisms of nanoplastic-induced developmental toxicity are still limited. Here, we systematically investigated the potential biological roles of nanoplastic exposure in zebrafish during the early developmental stage. The zebrafish embryos were subjected to exposure to 100 nm polystyrene nanoplastics with different concentrations (0, 100, 200, and 400 mg/L). The results indicated that nanoplastic exposure could decrease the hatching and survival rates of zebrafish embryos. In addition, the developmental toxicity test indicated that nanoplastic exposure exhibits developmental toxicity via the inhibition of the heart rate and body length in zebrafish embryos. Besides, behavioral activity was also significantly suppressed after 96 h of nanoplastic exposure in zebrafish larvae. Further biochemical assays revealed that nanoplastic-induced activation of the oxidative stress responses, including reactive oxygen species accumulation and enhanced superoxide dismutase and catalase activities, might affect developmental toxicity in zebrafish embryos. Furthermore, a quantitative polymerase chain reaction assay demonstrated that the mRNA levels of the base excision repair (BER) pathway-related genes, including lig1, lig3, polb, parp1, pold, fen1, nthl1, apex, xrcc1, and ogg1, were altered in zebrafish embryos for 24 h after nanoplastic exposure, indicating that the activation of the BER pathway would be stimulated after nanoplastic exposure in zebrafish embryos. Therefore, our findings illustrated that nanoplastics could induce developmental toxicity through activation of the oxidative stress response and BER pathways in zebrafish.

Screening of Serum Biomarkers of Coal Workers' Pneumoconiosis by Metabolomics Combined with Machine Learning Strategy

Pneumoconiosis remains one of the most serious global occupational diseases. However, effective treatments are lacking, and early detection is crucial for disease prevention. This study aimed to explore serum biomarkers of occupational coal workers’ pneumoconiosis (CWP) by high-throughput metabolomics, combining with machine learning strategy for precision screening. A case–control study was conducted in Beijing, China, involving 150 pneumoconiosis patients with different stages and 120 healthy controls. Metabolomics found a total of 68 differential metabolites between the CWP group and the control group. Then, potential biomarkers of CWP were screened from these differential metabolites by three machine learning methods. The four most important differential metabolites were identified as benzamide, terazosin, propylparaben and N-methyl-2-pyrrolidone. However, after adjusting for the influence of confounding factors, including age, smoking, drinking and chronic diseases, only one metabolite, propylparaben, was significantly correlated with CWP. The more severe CWP was, the higher the content of propylparaben in serum. Moreover, the receiver operating characteristic curve (ROC) of propylparaben showed good sensitivity and specificity as a biomarker of CWP. Therefore, it was demonstrated that the serum metabolite profiles in CWP patients changed significantly and that the serum metabolites represented by propylparaben were good biomarkers of CWP.