Banca de DEFESA: RENATA MEIRELES OLIVEIRA PADILHA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : RENATA MEIRELES OLIVEIRA PADILHA
DATE: 31/03/2023
TIME: 08:00
LOCAL: Online via Google Meet
TITLE:

Toxic effects of insecticides used in mosquito control on biological parameters of zebrafish (Danio rerio) related to microcephaly and other malformations

KEY WORDS:

Keywords: toxicity; pesticides; teratogenicity; microcephaly; epiboly

PAGES: 100
BIG AREA: Ciências Biológicas
AREA: Fisiologia
SUBÁREA: Fisiologia Geral
SUMMARY:

The pesticides pyriproxyfen (PPF), malathion (MAL) and Bacillus thurigiensis israelensis (BTI) were used in Brazil and Pernambuco during the microcephaly epidemic and no study has evaluated combined toxic effects in non-target organisms and whether there was a relationship with microcephaly. In view of this, the objective of this thesis was to evaluate the toxicity of single PPF, MAL, and BTI and their mixtures in the zebrafish (Danio rerio) animal model. First, to study reports of microcephaly and the toxicity of PPF in animal models (murine and zebrafish), a systematic review was performed. Second, the evaluation of the single and binary mixtures of PPF, MAL, and BTI using the embryo-larval zebrafish model. Analysis of epiboly at 8 hpf (hour post-fertilization), mortality (until 144 hpf), affected animals (48 and 96 hpf), heart rate (24, 72, and 120 hpf), morphometry and larval behavior at 144 hpf (thigmotaxis, touch sensitivity, and optomotor response) were evaluated. After the inclusion and exclusion criteria, 13 papers were selected. No reports of microcephaly have been observed at recommended doses of PPF. However, doses above the recommendation caused toxic effects in animal models. Single PPF and MAL exposure reduced the percent epiboly and PPF+MAL had the lowest percent epiboly. All groups showed significant mortality, and MAL caused 100% mortality at 96 hpf. BTI induced low mortality. PPF showed significant toxicity in affected animals. However, MAL and their binary mixtures were more toxic at 48 and 96 hpf. The heart rate reduction was observed in MLT and MLT+PPF groups. A reduction of head measurements in the PPF+MAL mixture was observed. Behavioral changes were observed in MLT+BTI and PPF+MAL with decreased sensitivity to touch and thigmotaxis. Additionally, all groups had affected optomotor response. MAL and PPF+MAL were the most toxic pesticides affecting zebrafish embryo-larval development and behavior. Due to its simultaneous use in mosquito control, it is necessary to reevaluate this strategy in the control due to the severe toxic effects observed in this thesis.

COMMITTEE MEMBERS:
Presidente - PABYTON GONCALVES CADENA
Interno - ANISIO FRANCISCO SOARES
Interno - PAULO ROBERTO ELEUTERIO DE SOUZA
Externo ao Programa - 1088089 - PIERRE CASTRO SOARES - UFRPEExterno à Instituição - CRISTIANO APARECIDO CHAGAS - UFPE