Genotoxic effect induced by dried nicotiana tabacum leaves from tobacco barns (kiln-houses) in chinese hamster lung fibroblast cells (V79)

ABSTRACT

Nicotiana tabacum is the most cultivated tobacco species in the state of Rio Grande do Sul, Brazil. Workers who handle the plant are exposed to the leaf components during the harvesting process and when separating and classifying the dried leaves. In addition to nicotine, after the drying process, other components may be found including tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons, as well as pesticides residues. The objective of this study was to examine the genotoxicity attributed to the aqueous extract of dried tobacco leaves obtained from tobacco barns using Chinese hamster lung fibroblast cells (V79) as a model system by employing alkaline comet assay, micronucleus (MN) and Ames test. MTT assay was used to assess cytotoxicity and establish concentrations for this study. Data demonstrated cell viability > 85% for concentrations of 0.625–5 mg/ml while the comet assay indicated a significant increase in DNA damage at all concentrations tested. A significant elevation of MN and nuclear buds (NBUD) was found for 5 mg/ml compared to control and other dry tobacco leaves concentrations (0.625–2.5 mg/ml). Mutagenicity was not found using the Salmonella/Microsome test (TA98, TA100, and TA102 strains) with and without metabolic activation. The concentration of inorganic elements was determined employing the PIXE technique, and 13 inorganic elements were detected. Using CG/MS nicotine amounts present were 1.56 mg/g dry tobacco leaf powder. Due to the observed genotoxicity in V79 cells, more investigations are needed to protect the health of tobacco workers exposed daily to this complex mixture of toxic substances present in dry tobacco leaves.

KEYWORDS:

• Dry tobacco leaves
• nicotine
• genotoxicity
• mutagenicity
• V79 cells

Acknowledgments

The authors are thankful to Rafael de Souza Godoi for System Biology. This work was supported by Lutheran University of Brazil (ULBRA), and Brazilian agencies: National Council for Scientific and Technological Development (CNPq), Foundation for Research Support of Rio Grande do Sul (FAPERGS), and Commission of the Improvement of Higher Educational Personnel (CAPES - Finance Code 001).

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

This work was supported by the Foundation for Research Support of Rio Grande do Sul (FAPERGS Lutheran University of Brazil; Brazilian agencies: National Council for Scientific and Technological Development (CNPq); Commission of the Improvement of Higher Educational Personnel (CAPES)