In conclusion, our results demonstrate that tobacco
leaves are genotoxic in H. aspersa. The genotoxicity,
mutagenicity and enzymatic inhibition caused by exposure
to tobacco leaves was probably mediated by the complex
mixture of substances (nicotine, coumarins, traces of saponins,
flavonoids and different inorganic elements) present
in these leaves. Our findings confirm the sensitivity of the
Comet assay and MN test in detecting damage caused by
Genotoxicity of Nicotiana tabacum 273
Table 3 - Protein content and cytochrome activities of digestive glands from Helix aspersa individuals exposed to lettuce leaves (control) or tobacco
leaves.
Parameters Control (n = 6) Tobacco leaves (n = 6)
Protein (mg/mL) 8.33 0.49 6.59 2.23
Cytochrome b5 (nmol/mg) 35.47 4.26 26.92 2.86**
Cytochrome P450 (nmol/mg) 126.09 6.99 84.6 15.48***
Cytochrome P420 (nmol/mg) 231.72 12.41 149.55 31.98***
The values are the mean SD. *p < 0.01 and *p < 0.001 compared to the control group (Students t-test).
complex mixtures such as that present in tobacco leaves.
Several biological markers have been proposed for assessing
exposure to tobacco or tobacco smoke in order to elucidate
the mechanisms of DNA damage. In this work, we
attempted to interpret the biological action of complex mixtures
of components present in tobacco leaves. This approach
may be useful for studying complex mixtures in
other plant species.