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Endogenous Formation of Nitrosamines and Oxidative DNA-Damaging Agents in Tobacco Users
Published in Roger O. McClellan, Critical Reviews in Toxicology, 2017
J. Nair, H. Ohshima, U. J. Nair, H. Bartsch
The above studies demonstrate that tobacco smoking at least doubles the exposure to nitroso compounds in smokers (Figure 1). The major factors influencing endogenous nitrosation reactions probably are the levels of nitrogen oxides (NOx, nitrosating agents) in the smoke, salivary nitrate, and the thiocyanate metabolically formed from hydrogen cyanide. All are present in high concentrations (NOx, up to a few hundred micrograms per smoked cigarette5), and smokers have higher thiocyanate levels in their saliva.20 In addition, the formaldehyde and acetaldehyde present in tobacco smoke may further enhance the nitrosation reaction.5 Nitrosatable secondary amines such as dimethylamine, pyrrolidine, and the alkaloids nornicotine, anabasine, and anatabine are present in tobacco smoke.2
Genotoxic effect induced by dried nicotiana tabacum leaves from tobacco barns (kiln-houses) in chinese hamster lung fibroblast cells (V79)
Published in Journal of Toxicology and Environmental Health, Part A, 2021
Daiana Dalberto, Caroline Cardoso Nicolau, Melissa Rosa De Sousa, Ana Letícia Hilário Garcia, Fernanda Boaretto, Jaqueline Nascimento Picada, Guilherme Maurício Soares De Souza, Paola Chytry, Johnny Ferraz Dias, Cleverson Costa Feistel, Alexandre Barros Falcão Ferraz, Ivana Grivicich, Juliana Da Silva
When dried leaves are processed, a lot of dust is generated releasing many compounds. Tobacco dust affects the respiratory tract in exposed individuals resulting in different forms of allergies, dizziness, and vomiting (Fiori et al. 2015; Riquinho and Hennington 2012; Saleeon et al. 2016; Umadevi 2003; Zaga et al. 2021). During the classification of the tobacco leaves, the producer has contact not only with nicotine but also with tobacco-specific nitrosamines (TSNAs) (Hoffmann et al. 1994; Hoffmann; Hoffmann and Hoffmann 1997) and polycyclic aromatic hydrocarbons (PAHs) (Alves et al. 2016; Hoffmann; Hoffmann and Hoffmann 1997). These compounds and some pesticides used in the cultivation of tobacco are classified as mutagenic, which lead to a significant contribution to human cancer (Hoffmann and Hoffmann and Hoffmann 1997; IARC (International Agency for Research on câncer) 2007). Tobacco-specific nitrosamines (TSNAs) are generated from alkaloids including nicotine, nornicotine, anatabine, and anabasine during the healing, fermentation, and aging processes of tobacco leaves. Polycyclic aromatic hydrocarbons (PAHs) are released during tobacco curing associated with the combustion process with the use of wood to produce heat (Alves et al. 2016; IARC (International Agency for Research on câncer) 2007; Umadevi 2003). Several studies demonstrated cytotoxicity, genotoxicity, and mutagenicity attributed to exposure to tobacco products, green tobacco, and occupational dust exposure (Da Silva et al. 2014; Gao, Prasad, and Zacharias 2014; Kahl et al. 2018; Moghbel et al. 2016); however, little is known regarding the cytotoxicity and genotoxicity induced by dry leaves of N. tabacum.