Effects of Dermal Exposure to Nicotiana tabacum (Jean Nicot, 1560) Leaves in Mouse Evaluated by Multiple Methods and Tissues

Abstract

Tobacco farmers are routinely exposed to complex mixtures of the compounds present in tobacco leaves, including organic and inorganic pesticides. Penetration through skin is the most significant route of uptake in occupational exposure to chemicals, including dust and liquids containing toxic and carcinogenic substances. This study evaluates the genotoxic effect of tobacco leaves with and without dermal exposure to flumetralin in Mus musculus, determining cell damage by the micronucleus test and the Comet assay as well as antioxidant enzyme activities and hematologic parameters. Nicotine was used as positive control. Blood samples were collected for 0, 3, 24 and 48 h exposure periods, and DNA damage by Comet assay and micronucleus test was evaluated for all these periods. Bone marrow and liver cells were also evaluated for the 48 h exposure period. Significant differences between Comet assay results in blood cells from animals exposed to tobacco leaves with and without pesticide were found in 24 and 48 h exposure periods in relation to negative control. Bone marrow cells from the group exposed to leaves with pesticide (48 h) also demonstrated significant increase in DNA damage. Concerning the micronucleus test, only animals exposed to tobacco leaves without pesticide (24 h) showed increase in frequency of micronuclei when compared to the negative control. Oxidative stress activities also were demonstrated for different groups. The results demonstrate the injury effect caused by tobacco leaves in different Mus musculus tissues, suggesting that the effects of dermal exposure to tobacco leaves are caused by complex mixtures present in the plant, but mainly by nicotine.

Genotoxic biomonitoring of tobacco farmers: Biomarkers of exposure, of early biological effects and of susceptibility

“…Several studies have described the acute health effects of nicotine toxicity in tobacco workers [45,46]. Genotoxic effects induced by tobacco leaves were investigated only in Mus musculus, where positive results were found [47]. In another study from our group, using the same farm workers from RS an increase in cotinine level during leaf harvest was observed, which confirms exposure to nicotine for this group [48].…”

Genotoxicity of Nicotiana tabacum leaves on Helix aspersa

“…Nicotine caused a concentration-dependent increase in DNA fragmentation, as assessed by the Comet assay, in mini-organ cultures of human nasal epithelium, indicating a direct genotoxic effect (Sassen et al , 2005); similar findings have been reported for lymphatic tissue of palatine tonsils and peripheral lymphocytes (Kleinsasser et al , 2005). Nicotine has also been implicated in free radical generation in various types of rodent and human cells, with a direct relationship between reactive oxygen species (ROS) induction and DNA damage (Yildiz et al , 1999; Argentin and Cichetti, 2004; Da Silva et al , 2010). …”

Effects of Nigella sativa (Habbatus sauda) Oil and Nicotine Chronic Treatments on Sperm Parameters and Testis Histological Features of Rats

“…It is an alkaloid found mainly in plants and is present in high concentrations in tobacco ( Nicotiana tabacum ). Besides being a natural insecticide [5], nicotine is pharmacologically active and has a negative impact on the reproductive system and fertility of males [6, 7]. …”