Cinnamaldehyde causes developmental neurotoxicity in zebrafish via the oxidative stress pathway that is rescued by astaxanthin

Buprofezin causes early developmental toxicity of zebrafish (Danio rerio) embryos: morphological, physiological and biochemical responses

Buprofezin (BPFN), a pesticide used to control crop pests and diseases, causes potential harm to aquatic animals and the environment by leaching into aquatic ecosystems. However, there are limited studies on the toxicity of BPFN to aquatic organisms. Using zebrafish embryos, we integrated flow cytometry, qRT-PCR, RNA-seq and other techniques to assess BPFN's developmental toxicity. Additionally, IBRv2 index and Mantel test correlation were applied to comprehensively evaluate the developmental toxicity of BPFN. The results showed that BPFN induced cytotoxicity, including increased reactive oxygen species levels, mitochondrial membrane potential depolarization, and apoptosis, which further resulted in developmental toxicity of zebrafish embryos such as delayed hatching, reduced survival rate, and severe morphological deformities. BPFN also affected the number and distribution of immune cells, resulting in immunotoxicity, and disrupted the endogenous antioxidant system by altering the activities of catalase, superoxide dismutase, and glutathione S-transferase and contents of malondialdehyde and glutathione. Gene expression analysis revealed that BPFN induced changes in the expression of genes associated with oxidative stress, apoptosis, inflammation, swim bladder development, and eye development. In the comprehensive evaluation, BPFN showed the strongest developmental toxic effect in the 20 μM BPFN-treated group at 48 hpf, and there was the significant correlation between embryonic development, oxidative stress, apoptosis, and inflammatory response. The rescue experiment confirmed that astaxanthin can alleviate the embryonic developmental toxicity caused by BPFN to a certain extent. In summary, BPFN induced early developmental toxicity in zebrafish embryos, which might be associated with mitochondria-mediated apoptosis pathway induced by oxidative stress.

Risk assessment of developmental and neurotoxicity by the flavoring agent perillaldehyde: NAC (N-acetylcysteine) mitigation of oxidative stress-mediated inhibition of the Nrf2 pathway

Perillaldehyde (PAE), a prevalent flavoring agent, has raised safety concerns due to conflicting evidence regarding its toxicity. This study provides a comprehensive assessment of the developmental and neurotoxic effects of PAE in zebrafish, elucidating the underlying mechanisms of its toxicity. Results showed that PAE affected the viability and hatching rate of zebrafish at 96 h postfertilization with the 50 % lethal concentration (LC50) of 7.975 mg/L. Furthermore, exposed‌ to a non-lethal concentration of 4 mg/L PAE induced a spectrum of morphological abnormalities, such as pericardial edema, delayed yolk sac absorption, reduced body length, and microphthalmia. Behavioral observations revealed that PAE reduced motor ability, and was accompanied by an increase in spontaneous turning angle and angular velocity. Using the TG(elav13:EGFP) transgenic model, we observed the number of newborn neurons was reduced, indicating that PAE induced obvious neurotoxic effects. Additionally, this concentration facilitated the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA), concomitantly decreasing the activity of antioxidant enzymes. QRT-PCR analysis revealed that PAE down-regulated Nestin and Neurogenin1 gene expression, up-regulated Glipr1a and Nox1 gene expression, and inhibited the Nrf2/HO-1 pathway. Notably, co-administration of N-acetylcysteine (NAC), an inhibitor of oxidative stress, mitigated oxidative stress levels and partially ameliorated the neurotoxicity. These findings suggest that oxidative stress is the primary mediator of PAE-induced neurotoxicity. This study provides crucial insights for the safe application of PAE.

Transgenerational toxicity assessment of [C8mim]Br: Focus on early development, antioxidant defense, and transcriptome profiles in zebrafish

1-Methyl-3-octylimidazolium bromide ([C8mim]Br), one of the most widely used and studied ionic liquids, is a contaminant of emerging concern. Acute exposure to high doses of [C8mim]Br has been shown to induce a variety of toxicity effects in exposed animals. However, the detrimental effects of chronic parental exposure to low doses of [C8mim]Br on unexposed offspring and the underlying mechanisms remain largely unknown. To this end, spawning-capable female and male zebrafish (F0 generation) were separately exposed to 25, 250, and 2500 μg/L of [C8mim]Br for eight weeks and were then mated to spawn. The resulting eggs (F1 generation) were collected and cultured in [C8mim]Br-free media for 96 h. We found that the early growth and development of F1 embryo-larvae, which were not directly exposed to [C8mim]Br, were significantly inhibited. This was evidenced by delayed hatching, increased mortality, reduced body weight, slowed heartbeat, poor motility (decreased spontaneous tail-coiling movements and diminished escape responses to touch stimuli and water swirling), and uninflated swim bladders. Furthermore, fluorescent probe labeling and biochemical analyses revealed an accumulation of reactive oxygen species and impairment of the antioxidant defense system in F1 larvae from [C8mim]Br-exposed F0 parents, indicating the induction of oxidative stress. Finally, transcriptomic sequencing demonstrated that the differentially expressed genes in F1 larvae were primarily involved in muscle development and contraction performance, offering mechanistic insights into the poor motility and associated developmental defects observed in F1 embryo-larvae. Overall, this transgenerational toxicity assessment underscores the adverse outcomes of parental [C8mim]Br exposure on unexposed offspring, providing a crucial aspect of the ecological risks of [C8mim]Br.

E-cigarette flavoring chemicals and vehicles adversely impact the functions of pigmented human retinal ARPE-19 cells

Electronic cigarettes (ECs) have been shown to adversely impact the human eye's retinal pigment epithelium (RPE). Flavored e-liquids induced cytotoxicity in unpigmented human ARPE-19 cells independent of nicotine's presence in my previous study. In the current study, human ARPE-19 cells pigmented by sepia melanin were employed to examine the effects of four flavoring chemicals, vanillin, menthol, furanone, and cinnamaldehyde, and EC vehicles propylene glycol (PG)/vegetable glycerin (VG) ratios (0:100, 80:20, 100:0 % v/v), on metabolic activity, membrane integrity, oxidative stress, and wound healing capacity of these cells. Results demonstrate that cinnamaldehyde was the most cytotoxic flavoring, and all vehicles showed marked cytotoxicity at the highest concentration of 10 %. All four flavorings elicited a significant production of reactive oxygen species (ROS), while the three vehicles did not impact ROS levels. Vanillin significantly (p < 0.05) suppressed wound healing, while furanone and cinnamaldehyde had no effects, although menthol promoted wound healing at the lowest concentration. Moreover, the vehicles with two ratios of 0:100 PG/VG and 80:20 PG/VG suppressed wound healing. Together, these results suggest that vanillin and VG-containing vehicles exert the greatest adverse effects on ARPE-19 cells. These findings underscore the potential harm that exposure to ECs can cause to the human retina.

Isavuconazole Induces Neurodevelopment Defects and Motor Behaviour Impairment in Zebrafish Larvae

Isavuconazole is a broad-spectrum antifungal drug used for the treatment of serious infections caused by invasive aspergillosis and mucormycosis in adults. With the continuous use of this drug, its safety and environmental impact have received increasing attention. However, information on the adverse effects of the drug is very limited. Fish is a particularly important model for assessing environmental risks. In this study, the aquatic vertebrate zebrafish was used as a model to study the toxic effects and mechanisms of isavuconazole. We exposed zebrafish embryos to 0.25, 0.5, and 1 mg/L of isavuconazole 6 h after fertilization. The results showed that at 72 hpf, isavuconazole exposure reduced heart rate, body length, and survival of zebrafish embryos compared to controls. Secondly, when isavuconazole reached a certain dose level (0.25 mg/L), it caused morphological changes in the Tg(elavl3:eGFP) transgenic fish line, with the head shrunk, the body bent, the fluorescence intensity becoming weaker, the abnormal motor behaviour, etc. At the same time, exposure of zebrafish embryos to isavuconazole downregulated acetylcholinesterase (AchE) and adenosine triphosphate (ATPase) activities but upregulated oxidative stress, thereby disrupting neural development and gene expression of neurotransmitter pathways. In addition, astaxanthin partially rescued the neurodevelopmental defects of zebrafish embryos by downregulating oxidative stress. Thus, our study suggests that isavuconazole exposure may induce neurodevelopment defects and behavioural disturbances in larval zebrafish.

Cinnamaldehyde alleviates aspirin-induced gastric mucosal injury by regulating pi3k/akt pathway-mediated apoptosis, autophagy and ferroptosis

BACKGROUND

Gastric mucosal injury is a chronic and progressive stomach disease that can be caused by nonsteroidal anti-inflammatory drugs (NSAIDs). Therefore, there is an urgent need to find safe and effective drugs to prevent gastric mucosal injury due to NSAIDs. Cinnamaldehyde (CA) is a bioactive compound extracted from the rhizome of cinnamon and has various pharmacological functions, including anti-inflammatory, analgesic, antiapoptotic, and antioxidant activities. However, the potential pharmacological effect of CA on gastric mucosal injury remains unknown.

PURPOSE

The aim of this study was to investigate the protective effects of CA on aspirin-induced gastric mucosal injury and to explore its mechanism of action METHODS: The effect of CA on gastric mucosal injury was investigated in vitro and in vivo, in vitro mouse model of gastric mucosal injury induced by aspirin, in vitro model of GES-1 cell injury by aspirin and Erastin. The mechanism of action of CA was determined using Transcriptomics and bioinformatics.

RESULTS

CA exerted its protective effects against gastric mucosal injury by modulating the downstream targets, including mTOR, GSK3β, and NRF2, via the PI3K/AKT signaling pathway to inhibit autophagy, apoptosis, and ferroptosis in the gastric epithelial cells. Further cellular experiments confirmed that the PI3K/AKT pathway was a key target for CA against gastric mucosal injury.

CONCLUSION

This study provides the first evidence of CA, an active compound in cinnamon, possessing therapeutic potential in preventing and treating gastric mucosal injury, with its mechanism involving the regulation of apoptosis, autophagy, and ferroptosis in gastric epithelial cells mediated by the PI3K/AKT signaling pathway.

Lapatinib combined with doxorubicin causes dose-dependent cardiotoxicity partially through activating the p38MAPK signaling pathway in zebrafish embryos

Because of its enhanced antitumor efficacy, lapatinib (LAP) is commonly used clinically in combination with the anthracycline drug doxorubicin (DOX) to treat metastatic breast cancer. While it is well recognized that this combination chemotherapy can lead to an increased risk of cardiotoxicity in adult women, its potential cardiotoxicity in the fetus during pregnancy remains understudied. Here, we aimed to examine the combination of LAP chemotherapy and DOX-induced cardiotoxicity in the fetus using a zebrafish embryonic system and investigate the underlying pathologic mechanisms. First, we examined the dose-dependent cardiotoxicity of combined LAP and DOX exposure in zebrafish embryos, which mostly manifested as pericardial edema, bradycardia, cardiac function decline and reduced survival. Second, we revealed that a significant increase in oxidative stress concurrent with activated MAPK signaling, as indicated by increased protein expression of phosphorylated p38 and Jnk, was a notable pathophysiological event after combined LAP and DOX exposure. Third, we showed that inhibiting MAPK signaling by pharmacological treatment with the p38MAPK inhibitor SB203580 or genetic ablation of the map2k6 gene could significantly alleviate combined LAP and DOX exposure-induced cardiotoxicity. Thus, we provided both pharmacologic and genetic evidence to suggest that inhibiting MAPK signaling could exert cardioprotective effects. These findings have implications for understanding the potential cardiotoxicity induced by LAP and DOX combinational chemotherapy in the fetus during pregnancy, which could be leveraged for the development of new therapeutic strategies.

Acer truncatum Bunge seed oil ameliorated oxaliplatin-induced demyelination by improving mitochondrial dysfunction via the Pink1/Parkin mitophagy pathway

Dietary nutritional support for special populations is an effective and feasible method to improve the quality of life of patients and reduce medical pressure. Acer truncatum Bunge seed oil (ATSO) is widely recognized for its ability to promote nerve myelin regeneration. To evaluate the ameliorative effects of ATSO on chemotherapy-induced demyelination, a zebrafish model of chemotherapy-induced demyelination was established. The results showed that 100 μg mL-1 of ATSO reversed tail morphology damage, axon degeneration, touch response delay, ROS level upregulation and the expression of myelin basic protein decrease in chemotherapy-induced zebrafish. In addition, the expression of myelin markers (including sox10, krox20, and pmp22) in oxaliplatin-induced cells was markedly reversed by ATSO and its active components (gondoic acid, erucic acid, and nervonic acid). ATSO and its active components could reverse demyelination by ameliorating mitochondrial dysfunction. Conversely, linoleic acid and linolenic acid promoted demyelination by exacerbating mitochondrial dysfunction. Moreover, the Pink1/Parkin pathway was recognized as the main reason for ATSO and its active components improving mitochondrial function by activating mitophagy and restoring autophagic flow. Taken together, this study demonstrated that ATSO and its active components could be further developed as novel functional food ingredients to antagonize demyelination.

Temperature- and chemical-induced neurotoxicity in zebrafish

Throughout their lives, humans encounter a plethora of substances capable of inducing neurotoxic effects, including drugs, heavy metals and pesticides. Neurotoxicity manifests when exposure to these chemicals disrupts the normal functioning of the nervous system, and some neurotoxic agents have been linked to neurodegenerative pathologies such as Parkinson's and Alzheimer's disease. The growing concern surrounding the neurotoxic impacts of both naturally occurring and man-made toxic substances necessitates the identification of animal models for rapid testing across a wide spectrum of substances and concentrations, and the utilization of tools capable of detecting nervous system alterations spanning from the molecular level up to the behavioural one. Zebrafish (Danio rerio) is gaining prominence in the field of neuroscience due to its versatility. The possibility of analysing all developmental stages (embryo, larva and adult), applying the most common "omics" approaches (transcriptomics, proteomics, lipidomics, etc.) and conducting a wide range of behavioural tests makes zebrafish an excellent model for neurotoxicity studies. This review delves into the main experimental approaches adopted and the main markers analysed in neurotoxicity studies in zebrafish, showing that neurotoxic phenomena can be triggered not only by exposure to chemical substances but also by fluctuations in temperature. The findings presented here serve as a valuable resource for the study of neurotoxicity in zebrafish and define new scenarios in ecotoxicology suggesting that alterations in temperature can synergistically compound the neurotoxic effects of chemical substances, intensifying their detrimental impact on fish populations.

A Short Review of the Toxicity of Dentifrices-Zebrafish Model as a Useful Tool in Ecotoxicological Studies

This review aims to summarize the literature data regarding the effects of different toothpaste compounds in the zebrafish model. Danio rerio provides an insight into the mechanisms of the ecotoxicity of chemicals as well as an assessment of their fate in the environment to determine long-term environmental impact. The regular use of adequate toothpaste with safe active ingredients possessing anti-bacterial, anti-inflammatory, anti-oxidant, and regenerative properties is one of the most effective strategies for oral healthcare. In addition to water, a typical toothpaste consists of a variety of components, among which three are of predominant importance, i.e., abrasive substances, fluoride, and detergents. These ingredients provide healthy teeth, but their environmental impact on living organisms are often not well-known. Each of them can influence a higher level of organization: subcellular, cellular, tissue, organ, individual, and population. Therefore, it is very important that the properties of a chemical are detected before it is released into the environment to minimize damage. An important part of a chemical risk assessment is the estimation of the ecotoxicity of a compound. The zebrafish model has unique advantages in environmental ecotoxicity research and has been used to study vertebrate developmental biology. Among others, the advantages of this model include its external, visually accessible development, which allows for providing many experimental manipulations. The zebrafish has a significant genetic similarity with other vertebrates. Nevertheless, translating findings from zebrafish studies to human risk assessment requires careful consideration of these differences.

Chemical Profiling and Antioxidant and Anti-Amyloid Capacities of Salvia fruticosa Extracts from Greece

An increasingly common ailment in elderly persons is Alzheimer's disease (AD), a neurodegenerative illness. Present treatment is restricted to alleviating symptoms; hence, there is a requirement to develop an effective approach to AD treatment. Salvia fruticosa (SF) is a medicinal plant with a documented neuroprotective potential. To identify extracts of increased neuroprotectivity, we partitioned the methanolic extract of SF aerial parts from Greece into several fractions, by employing solvents of different polarities. The fractions were chemically identified and evaluated for their antioxidancy and anti-neurotoxic potential against amyloid beta peptides 25-35 (Aβ25-35). Carnosol and carnosic acid were among the prominent compounds, while all partitions showed significant antioxidant capacity, with the diethyl ether and ethyl acetate partitions being the most potent. These, along with the aqueous and the butanolic fractions, demonstrated statistically significant anti-neurotoxic potential. Thus, our findings further validate the neuroprotective potential of SF and support its ethnopharmacological usage as an antioxidant. The particular properties found define SF as a promising source for obtaining extracts or bioactive compounds, possibly beneficial for generating AD-related functional foods or medications. Finally, our results encourage plant extract partitioning for acquiring fractions of enhanced biological properties.

Molecular, morphological and behavioral alterations of zebrafish (Danio rerio) embryos/larvae after clorprenaline hydrochloride exposure

Chlorprenaline hydrochloride (CLOR) is a typical representative of β-adrenergic agonists that may be used illegally as a livestock feed additive and may have adverse impacts on the environment. In the present study, zebrafish embryos were exposed to CLOR to investigate its developmental toxicity and neurotoxicity. The results demonstrated that CLOR exposure led to adverse effects on developing zebrafish, such as morphological changes, a high heart rate, and increased body length, resulting in developmental toxicity. Moreover, the up-regulation of activities of superoxide dismutase (SOD) and catalase (CAT) and the enhancement of malondialdehyde (MDA) content illustrated that CLOR exposure activated oxidative stress in exposed zebrafish embryos. Meanwhile, CLOR exposure also caused alterations in locomotive behavior in zebrafish embryos, including an increase in acetylcholinesterase (AChE) activity. Quantitative polymerase chain reaction (QPCR) results showed that the transcription of genes related to the central nervous system (CNS) development, namely, mbp, syn2a, α1-tubulin, gap43, shha, and elavl3, indicated that CLOR exposure could lead to neurotoxicity in zebrafish embryos. These results showed that CLOR exposure could cause developmental neurotoxicity in the early stages of zebrafish development and that CLOR might induce neurotoxicity by altering the expression of neuro-developmental genes, elevating AChE activity, and activating oxidative stress.