BIOLOGICALS Induction of nuclear anomalies in exfoliated buccal cells of coca chewers: results of a field study Armen Nersesyan • Michael Kundi • Georg Krupitza • Gustavo Barcelos • Miroslav Mis ˇı ´k • Georg Wultsch • Juan Carrion • Gladys Carrion-Carrera • Siegfried Knasmueller Received: 17 July 2012 / Accepted: 25 October 2012 / Published online: 6 November 2012 Ó Springer-Verlag Berlin Heidelberg 2012 Abstract The leaves of coca (Erythroxylum coca var. coca), a South American shrub which contains cocaine, other alkaloids and phenolics are widely used by indige- nous populations of the Andes. It is currently not known if coca consumption causes genotoxic effects in humans. This information is important to predict potential long-term toxic effects such as cancer induction. Therefore, the buccal cytome assay was used to analyze oral cells from 45 uni- and bilateral chewers and 23 controls living in the Altiplano of the Peruvian Andes. In total, 123,471 cells were evaluated from chewers and 57,916 from controls. Information concerning the consumption levels and habits and also use of lime were collected with questionnaires. Chewing of the leaves did not induce nuclear anomalies reflecting genetic damage such as micronuclei (MNi) and nuclear buds; in the highest exposure group (but not in the overall group) even a significant decrease in the frequen- cies of cells with MNi (by 64 %) was observed. However, we found significantly elevated levels of other nuclear anomalies (karyorrhexis and karyolysis) which reflect cytotoxic effects in the coca users. The frequencies of these anomalies increased with the daily consumption and when lime was used to improve the release of the alkaloids. In contrast to other chewing habits (betel, tobacco and khat), consumption of coca leaves does not induce genetic instability in cells from the oral cavity and our findings indicate that no adverse health effects take place in chewers which are associated with DNA damage. How- ever, the significant increase in certain anomalies shows that acute toxic effects are caused by coca consumption. Keywords Coca leaves Á Chewing Á Buccal cells Á Cytome assay Á Genotoxicity Á Cytotoxicity Introduction A number of studies show that chewing of plant-derived materials such as tobacco, betel and khat causes formation of micronuclei (MNi) in buccal cells (Kassie et al. 2001; Joshi et al. 2011; Kausar et al. 2009). MNi in exfoliated cells that are formed as a consequence of structural and numerical chromosomal aberrations are considered as a reliable biomarker for cancer risks in humans (Bonassi et al. 2011). Therefore, the mentioned findings indicate adverse health effects as a consequence of chewing. In the case of betel, khat and tobacco, this assumption is also supported by results of epidemiological studies (Petti 2009; El-Wajeh and Thornhill 2009). A. Nersesyan Á G. Barcelos Á M. Mis ˇı ´k Á G. Wultsch Á S. Knasmueller (&) Department of Internal Medicine 1, Institute of Cancer Research, Medical University of Vienna, Borschkegasse 8A, 1090 Vienna, Austria e-mail: siegfried.knasmueller@meduniwien.ac.at M. Kundi Institute of Environmental Health, Medical University of Vienna, Kinderspitalgasse 15, 1095 Vienna, Austria G. Krupitza Institute of Clinical Pathology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria G. Barcelos School of Pharmaceutical Sciences of Ribeira ˜o Preto, University of Sa ˜o Paulo, Ribeira ˜o Preto, SP, Brazil J. Carrion Á G. Carrion-Carrera Faculdad de Zootecnia, Universidad Nacional Agraria La Molina, Av. La Molina s/n, La Molina aptdo, 12-056 Lima, Peru 123 Arch Toxicol (2013) 87:529–534 DOI 10.1007/s00204-012-0969-1