Abstract:
Exposure of tobacco workers handling dried tobacco leaves has been linked to an increased risk of toxicity and respiratory illness due to the presence of nicotine and other chemicals. This study aimed to evaluate the DNA damage caused by the exposure of tobacco growers during the dry
leaf classification process and the relation to cellular mechanisms. A total of 86 individuals participated in the study, divided into a group exposed
to dry tobacco (n = 44) and a control group (n = 42). Genotoxicity was evaluated using the alkaline comet assay and lymphocyte micronucleus
(MN) assay (CBMN-Cyt), and measurement of telomere length. The levels of oxidative and nitrosative stress were evaluated through the formation
of thiobarbituric acid reactive species, and nitric oxide levels, respectively. The inorganic elements were measured in the samples using particleinduced X-ray emission method. The combination of variables was demonstrated through principal component analysis and the interactions were
expanded through systems biology. Comet assay, MN, death cells, thiobarbituric acid reactive species, and nitrosative stress showed a significant
increase for all exposed groups in relation to the control. Telomere length showed a significant decrease for exposed women and total exposed
group in relation to men and control groups, respectively. Bromine (Br) and rubidium (Rb) in the exposed group presented higher levels than control
groups. Correlations between nitrate and apoptosis; Br and MN and necrosis; and Rb and telomeres; besides age and DNA damage and death cells
were observed. The systems biology analysis demonstrated that tobacco elements can increase the nuclear translocation of NFKB dimers inducing
HDAC2 expression, which, associated with BRCA1 protein, can potentially repress transcription of genes that promote DNA repair. Dry tobacco
workers exposed to dry leaves and their different agents showed DNA damage by different mechanisms, including redox imbalance.
