Application of the buccal micronucleus cytome assay and analysis of PON1Gln192Arg and CYP2A69(−48T>G) polymorphisms in tobacco farmers

• Published in: Environmental and molecular mutagenesis 2012-08, Vol.53 (7), p.525-534
• Main Authors: Da Silva, Fernanda Rabaioli, Da Silva, Juliana, Nunes, Emilene, Benedetti, Danieli, Kahl, Vivian, Rohr, Paula, Abreu, Marina B., Thiesen, Flávia Valladão, Kvitko, Kátia
• Format: Article
• Language: English
• Subjects: Agriculture; Aryl Hydrocarbon Hydroxylases - genetics; Aryldialkylphosphatase - genetics; Biological and medical sciences; Brazil; buccal micronucleus cytome assay; Cell Death - drug effects; Cotinine; Cytochrome P-450 CYP2A6; DNA Damage - drug effects; Fundamental and applied biological sciences. Psychology; Genetic Markers - genetics; genetic polymorphism; Genetics of eukaryotes. Biological and molecular evolution; Humans; Medical sciences; Micronucleus Tests; Mouth Mucosa - cytology; Mutagenicity Tests; Nicotiana - chemistry; Nicotiana - toxicity; nicotine; Nicotine - analysis; Nicotine - toxicity; Occupational Exposure - adverse effects; pesticides; Pesticides - toxicity; Polymorphism, Genetic - genetics; tobacco farmers; Toxicology
• ISSN: 0893-6692; 1098-2280
• DOI: 10.1002/em.21713

Tobacco is a major Brazilian cash crop. Tobacco farmers apply large amounts of pesticides to control insect growth. Workers come into contact with green tobacco leaves during the tobacco harvest and absorb nicotine through the skin. In the present study, micronucleus frequency, cell death, and the frequency of basal cells were measured in tobacco farmers using the buccal micronucleus cytome assay (BMCyt), in parallel with measurement of blood butyrylcholinesterase (BChE) and nicotine levels. Polymorphisms in PONIGln192Arg and CYP2A6*9(−48T>G) were evaluated to verify the relationship between genetic susceptibility and the measured biomarkers. Peripheral blood and buccal cell samples were collected from 106 agricultural workers, at two different crop times (during pesticide application and leaf harvest), as well as 53 unexposed controls. BMCyt showed statistically significant increases in micronuclei, nuclear buds, and binucleated cells among exposed subjects in differentiated cells, and in micronuclei in basal cells. In addition, the exposed group showed higher values for condensed chromatin, karyorrhectic, pyknotic, and karyolitic cells, indicative of cell death, and an increase in the frequency of basal cells compared to the unexposed control group. A slight difference in mutagenicity using the BMCyt assay was found between the two different sampling times (pesticide application and leaf harvest), with higher micronucleus frequencies during pesticide application. Elevated cotinine levels were observed during the leaf harvest compared to the unexposed controls, while BChE level was similar among the farmers and controls. PONIGln192Arg and CYP2A6*9(−48T>G) polymorphisms were associated with DNA damage induced by pesticides and cell death. Environ. Mol. Mutagen., 2012. © 2012 Wiley Periodicals, Inc.