58º Congresso Brasileiro de Genética
Resumos do 58o Congresso Brasileiro de Genética • 11 a 14 de setembro de 2012
Rafain Palace Hotel e Convention Center • Foz do Iguaçu • PR • Brasil
www.sbg.org.br - ISBN 978-85-89109-06-2
32
Assessment of genotoxicity in oral mucosa
epithelial cells of farm workers from Canoas
city (RS) exposed to pesticides
Boeira, JM1,2; Hernandes, KC1; Canalli, BJ1; Schenkel, R3;. Saffi, J4
1
Universidade Estadual do Rio Grande do Sul, UERGS, Novo Hamburgo, RS; 3Emater-Ascar, Regional Canoas, RS;
4
Universidade Federal de Ciências da Saúde de Porto Alegre, UFCSPA, Porto Alegre, RS.
[email protected]
Keywords: Genotoxicity, Micronuclei, Nuclear changes, Pesticides, Oral mucosa cells.
Pesticides are responsible for several adverse effects on human health other than acute intoxications. Many studies
have reported associations between exposure to agricultural chemicals and various health outcomes, including
different kinds of cancer. The Micronucleus test is used as an indicator of genotoxic exposition, since it is associated
with chromosome aberrations. Micronuclei (MN) are chromatin fragments which, after aberrant mitoses, do not
become included in the main nucleus. In this study we evaluated MN frequencies and other nuclear changes (NCs),
karyorrhexis (KR), karyolysis (KL), broken egg (BE), and binucleus (BC) in buccal mucosa cells of 30 subjects
exposed to pesticides (from Canoas city, RS) and 30 healthy subjects non exposed to pesticides (control group). This
study was approved by the Committee on Research Ethics – CEP/PUCRS, Protocol 11/05575), and all individuals
gave informed consent. All the subjects also completed a detailed questionnaire with habits (sports, food, drugs,
tobacco, alcohol, coffee, etc.), as well as occupational, medical and family history, duration of application of the
pesticides, kind of pesticides and personal protective equipment (PPE) used. Buccal mucosa cells were collected
with cytobrush. These cells were washed (0.9% saline), centrifuged and fixed with ethanol: acetic acid (3:1). The
samples were then applied to clean microscope slides and stained by the Feulgen reaction and counterstained with
Fast Green. Three slides were prepared for each subject and 1,000 cells were evaluated per slide to determine the MN
frequencies and NCs. Nuclear abnormalities (NCs) were classified according to Tolbert et al. (1992). If they were
connected with chromatin bridge they were identified as broken egg (BE). Cells with two nuclei were considered as
binucleates (BC). Nuclei fragmented into irregular pieces were scored as karyorrhexis (KR). Nuclear dissolution, in
which a Feulgen-negative, ghost-like image of the nucleus remains, was evaluated as karyolysis (KL).The analysis of
MN and NCs was performed with a light microscope (objective with magnification of 100×). The results showed
a significant increase in the frequency of MN and in the nuclear changes (NCs) in buccal cells in the group of
subjects exposed to pesticides, when compared to the control group (P < 0,05; Mann–Whitney U-test, two-tail).
According to the answers to the questionnaire, the great majority of subjects in the exposed group were in contact
with many pesticides, including Organophosphorus, Phosphanoglycine, Oxadiazin, Pyretroyds, Urea, among others
chemical classes. These results indicate that these pesticides may induce effective alterations on oral mucosa cells.
Financial Support: CNPq and FAPERGS.