Banca de DEFESA: JADSON FREITAS DA SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : JADSON FREITAS DA SILVA
DATE: 29/02/2024
TIME: 09:00
LOCAL: Online via Google Meet
TITLE:

Study of the toxic effects of deltamethrin and other pesticides as neuroprotective alternatives against deltamethrin intoxication in a zebrafish (Danio rerio) model

KEY WORDS:

Neuroprotection, Embryo, Toxicity, Essential oil

PAGES: 90
BIG AREA: Ciências Biológicas
AREA: Fisiologia
SUMMARY:

Deltamethrin (DM) is a widely used pyrethroid insecticide in agriculture, veterinary medicine, and public health. Exposure to this insecticide poses an imminent risk to pregnant women and fetuses, potentially resulting in congenital malformations. In this context, the study of less toxic insecticides such as botanical insecticides serve as alternatives to synthetic insecticides. Thus, this study aimed to evaluate the toxicity of synthetic insecticides like deltamethrin and botanicals as potential less toxic substitutes on the biological parameters of adult zebrafish (Danio rerio) and to identify substances with protective action against fetal deltamethrin intoxication using zebrafish embryos as an animal model. Adult animals were exposed for 70 days to synthetic and botanical insecticides where behavioral parameters were evaluated. Furthermore, embryos were exposed to concentrations of 100 - 1000 μg/L of deltamethrin where three experiments were conducted to develop a model of fetal DM intoxication using zebrafish. Finally, experiments were conducted with folic acid (FA) and vitamin A (nVA) as therapeutic agents against fetal DM intoxication. Exposure of adult zebrafish to deltamethrin resulted in 100% mortality of the animals, and mixtures containing deltamethrin altered behavior. Exposure to essential oils mainly altered foraging behavior. Epiboly was assessed at 8 h, and teratogenic effects and mortality were evaluated after 22 and 46 h of exposure. A dose-dependent reduction in epiboly was observed in the zebrafish embryo model for fetal deltamethrin intoxication. The percentage of epiboly in the experimental group of 500 μg/L was 55%. Animals exposed for 22 and 46 h to deltamethrin exhibited pericardial edema, yolk sac edema, spinal deformation, and tail deformation in embryos and larvae. Treatments with vitamin A (96.67%) and folic acid + vitamin A (91.11%) protected against fetal DM intoxication, showing a significant increase in animals without teratogenic effects. Besides protecting animals in terms of improved behavioral and morphometric parameters against fetal DM intoxication, we concluded that synthetic insecticides and essential oils can alter adult zebrafish behavior. Among the tested insecticides, deltamethrin was the most toxic. However, essential oil mixtures may be promising in insect control due to their low toxicity to fish. Regarding zebrafish as a model of fetal intoxication, a concentration of 500 μg/L and 22 h of exposure caused toxic effects during embryonic development, making it the best concentration and time for proposing a model for research in health and the discovery of substances with
protective action for the fetus. Based on the findings, it was possible to conclude that FA, vitamin A, and FA + nVA were effective in protecting zebrafish in epiboly, embryo-larval development such as reducing teratogenic effects and animal behavior against DM intoxication. nVA and FA + nVA were the most promising in the treatment against fetal DM intoxication.

COMMITTEE MEMBERS:
Presidente - PABYTON GONCALVES CADENA
Externo ao Programa - 1088089 - PIERRE CASTRO SOARES - UFRPEExterno à Instituição - FABRICIO OLIVEIRA SOUTO - UFPE
Externa à Instituição - MARIA DO CARMO DE BARROS PIMENTEL - UFPE
Externa à Instituição - MARIANE CAJUBÁ DE BRITTO LIRA NOGUEIRA - UFPE