Pyridaben impaired cell cycle progression through perturbation of calcium homeostasis and PI3K/Akt pathway in zebrafish hepatocytes

Developmental and organ toxicity of fenpropimorph in zebrafish: Involvement of apoptosis and inflammation

Pesticides are increasingly the focus as a prominent factor in environmental pollution. Fenpropimorph, a widely utilized morpholine fungicide, is a significant water pollutant. Because of its extensive usage, fenpropimorph is readily detected in diverse aquatic ecosystems. Despite its well-known toxicity to aquatic organisms, its toxicity to zebrafish development and accompanying mechanics remain unexplored. To assess fenpropimorph's toxicity and potential mechanism, we employed the zebrafish model, a representative tool in toxicological studies. Our results showed that exposure to fenpropimorph reduced embryonic viability during the early stages of development and reduced head and body size. Moreover, fenpropimorph triggered apoptosis, DNA fragmentation, and inflammation. Aberrations in the vascular network were observed in the fli1:eGFP transgenic zebrafish model. Additionally, neurotoxic impacts were further assessed using transgenic olig2:dsRed zebrafish, accompanied by a reduction of liver size and fluorescence intensity of fabp10a:dsRed zebrafish. mRNA expression analysis related to corresponding organ development further supported our data. Overall, our research suggests that fenpropimorph may cause aberrations in aquatic organisms.

Fenoxycarb induces cardiovascular, hepatic, and pancreatic toxicity in zebrafish larvae via ROS production, excessive inflammation, and apoptosis

Fenoxycarb, a carbamate insecticide, functions as a juvenile hormone agonist to inhibit pests, and its detection in aquatic environments is concerning because of its widespread application. These concerns have led to ecotoxicological studies on aquatic crustaceans; however, research on the effects of fenoxycarb on the developmental processes of organisms is limited. In the present study, the deleterious effects of fenoxycarb on zebrafish development and the related cellular mechanisms mediating this toxicity were addressed. Exposure to sublethal concentrations of fenoxycarb (0, 0.5, 1, and 2 mg/L) resulted in morphological defects in zebrafish larvae, particularly in the heart region, eyes, and body length. These defects were accompanied by an increase in the number of apoptotic cells and the upregulation of related gene expression. Moreover, fenoxycarb increased ROS production and the number of macrophages, and altered the expression of immune-related genes, thereby inducing inflammation. These results revealed various abnormalities in the heart, vasculature, liver, and pancreas, as confirmed by transgenic models, such as cmlc2:DsRed, fli1a:EGFP, and fabp10a:DsRed;elastase:GFP. These developmental impairments were associated with the altered expression levels of genes involved in the development and function of each organ. These results suggest that fenoxycarb can affect multiple organs through excessive inflammation during development and highlight its potent toxic effects on other non-target organisms.

Exposure to acifluorfen induces developmental toxicity in the early life stage of zebrafish

Acifluorfen, a selective herbicide from the diphenyl ether family, targets broad leaf weeds. Diphenyl ether inhibits chlorophyll production in green plants by inhibiting protoporphyrinogen oxidase (PPO), causing cellular damage. Despite its known impacts on plants, the influence of acifluorfen on zebrafish embryo development remains unclear. In this study, we explored the LC50 of acifluorfen in early-stage wild-type zebrafish, determining it to be 54.99 mg/L. Subsequent examinations revealed morphological changes in zebrafish, including reduced body length. Using the cmlc2:dsRED transgenic model, we observed heart dysfunction in acifluorfen-exposed zebrafish, marked by an enlarged heart area, edema, and decreased heart rate. In response to dose-dependent acifluorfen exposure, the inhibition of angiogenesis in the brain was observed in transgenic zebrafish models (fli1a:eGFP). Organ malformations, specifically in the liver and pancreas, were noted, in lfabp:dsRED;elastase:eGFP transgenic models, indicating reduced organ size in acifluorfen-exposed zebrafish. Furthermore, acifluorfen heightened the expression of apoptosis-related genes (casp8, casp9, and tp53) in zebrafish embryos. We then determined whether acifluorfen affected the viability of zebrafish liver (ZFL) cells based on its effects on liver development in vivo. The results indicated that the proliferation of ZFL cells decreased significantly in a dose-dependent manner. Additionally, acifluorfen-treated ZFL cells exhibited a slight increase in apoptotic cells stained with annexin V and propidium iodide. In summary, these findings establish a baseline concentration for acifluorfen's effects on aquatic ecosystems and non-target organisms.