Estudo da genotoxicidade e do perfil metabólico de trabalhadores expostos aos agrotóxicos para identificação de potenciais biomarcadores no biomonitoramento da exposição ocupacional.

• Ano de defesa: 2022
• Autor(a) principal: Daniela Magalhães Nolasco
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; Brasil; FARMACIA - FACULDADE DE FARMACIA; Programa de Pós-Graduação em Análises Clínicas e Toxicológicas; UFMG
• Palavras-chave em Português: Agrotóxicos; Metabolômica untargeted; LC-MS; GC-MS; Genotoxicidade
• Link de acesso: http://hdl.handle.net/1843/50460

Pesticides constitute a heterogeneous category of chemical products intended specifically for the control and mitigation of pests. With the constant increase in use in the country, the risk to human health and the environment has increased proportionally, occurring due to occupational and environmental exposure to these compounds. The use of these chemicals is associated with several toxic effects related to acute and chronic toxicity, such as infertility, hormonal disorders, psychiatric disorders and cancer. The present work aimed to evaluate genotoxicity using the Comet and Cytoma assays, associated with the study of the metabolic profile of individuals occupationally exposed to pesticides, applying the metabolomics tool to identify potential new biomarkers. For this, genotoxicity tests were carried out on male individuals occupationally exposed and female individuals environmentally exposed to pesticides. The comet assay results were carried out in males exposed occupationally and females, exposed environmentally to pesticides. The comet assay results showed a DNA damage level of 15.93 ± 3.50 for the male group and 13.02 ± 1.79 for the female group. Comparison was performed using the Mann-Whitney test, which showed greater genotoxic damage in male volunteers compared to female volunteers (p=0.0068). With regard to cell alterations, the results were statistically evaluated and there was no significant difference in relation to binucleated cells (p=0.057) and cells with karyorrhexis (p=0.159), but it was possible to perceive a significant increase in relation to the number of cells karyolytic (p=0.004), micronuclei (p=0.004) and pyknotic cells (p=0.0003) in individuals occupationally exposed to pesticides. Metabolomics was carried out in plasma and urine of the same occupationally exposed individuals and individuals in the control group, using liquid chromatography and gas chromatography techniques coupled with mass spectrometry (UPLC-MS and GC-MS). Multivariate analysis of the metabolome was performed using Principal Components Analysis (PCA), Partial Least Squares Discriminant Analysis (PLS-DA) or Partial Least Squares Discriminant Orthogonal Analysis (OPLS-DA), which demonstrated good separation of samples from studied groups. From the results obtained by UPLC-MS, it was possible to identify 21 discriminating metabolites in plasma and 17 in urine. With the analysis of the ROC curve, the compounds with the greatest potential for biomarkers were revealed. Comprehensive analysis of the metabolic pathways influenced by exposure to pesticides revealed changes, mainly, in the metabolism of amino acids and several classes of lipids. It was possible to infer that exposure to these chemicals produces toxicity through multiple mechanisms, such as oxidative stress, inflammatory reactions, membrane changes and mitochondrial dysfunction. The results found by the GC-MS analysis were not able to discriminate metabolites with potential for possible biomarkers. This study indicated that the integrated approach, with the use of metabolomics and evaluation of genotoxicity biomarkers, provided important information on complex biological responses.