Banca de QUALIFICAÇÃO: NIELY PRISCILA CORREIA DA SILVA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : NIELY PRISCILA CORREIA DA SILVA
DATE: 16/03/2026
TIME: 09:30
LOCAL: Online via Google Meet
TITLE:

Study of the toxic effects of pesticides used in corn cultivation on the physiology and behavior of zebrafish (Danio rerio) and identification of protective alternatives against fetal intoxication

KEY WORDS:

Zebrafish; Embryofetal toxicity; Herbicides; Corn; Post-emergence; Technological prospecting.

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

Brazil is among the largest consumers of pesticides worldwide, particularly in corn cultivation, which extensively employs herbicides such as nicosulfuron (NIC), diuron (DIU), and imazapir (IMA). Although essential for weed control and the maintenance of agricultural productivity, these compounds pose potential risks to human health. Gestational exposure is of particular concern, as pesticides can cross the placental barrier and interfere with embryofetal development, being associated with congenital malformations, prematurity, and neurobehavioral alterations. Simultaneously, the analysis of technological innovation enables a comprehensive understanding of the development landscape and the main advancement trends related to these products. In this context, the present study aimed to conduct a technological prospection to map the patent filing landscape related to post-emergence herbicides used in corn cultivation, as well as to evaluate the embryofetal effects of NIC, DIU, and IMA in zebrafish (Danio rerio), proposing an experimental model of fetal intoxication. The technological prospection was performed using a qualitative and quantitative descriptive approach through consultation of national and international patent databases. Inclusion criteria considered the presence of the keywords “Corn,” “Pesticide” or “Herbicide,” “Weeds,” and “Post emergent” in the title or abstract of the documents. In the experimental assays, zebrafish embryos were exposed to concentrations of 10, 100, 500, and 1000 µg/L of the herbicides during two critical developmental windows (2–24 hpf and 24–48 hpf). Mortality and teratogenic effects were evaluated in both exposure periods up to 144 hpf. Patent database searches identified 466 documents related to the topic. The United States ranked first in number of filings, accounting for approximately 64.8% of the identified documents, while the corporate sector was responsible for the majority of registrations (96.6%). Experimentally, the three herbicides induced concentration-dependent lethal and sublethal effects in zebrafish embryos, with 1000 µg/L being the most toxic concentration. Nicosulfuron exhibited the highest relative toxicity in both exposure periods. The early embryonic stage (2–24 hpf) demonstrated greater sensitivity compared to the later stage (24–48 hpf). The main teratogenic effects observed included developmental delay, pericardial edema, yolk sac edema, and axial deformities affecting the tail and spine. It is concluded that the technological prospection data reveal diversity in chemical classes and modes of action among post-emergence herbicides used in corn cultivation, reflecting ongoing innovation and technological advancement in the sector. Moreover, the experimental findings demonstrated increased susceptibility during the early embryonic period, indicating heightened vulnerability during critical stages of embryogenesis, such as gastrulation and organogenesis, which are biologically comparable to the first trimester of human pregnancy. These findings reinforce the potential of zebrafish as an experimental model for embryofetal toxicity assessment in vertebrates, contributing to preventive strategies and bioethically sound approaches in the health field.

COMMITTEE MEMBERS:
Presidente - PABYTON GONCALVES CADENA
Interno - PAULO ROBERTO ELEUTERIO DE SOUZA
Externo ao Programa - 2140782 - ALEX SOUZA MORAES - UFRPE