Tobacco genotoxicity depending on genetic types, agronomic practices, and aphicide treatments
In 2004 a three-year research program began both on tobacco alternative use and cigarette smoke condensate (CSC) mutagenesis. The aim of this last sub research project is to asses whether cigarette smoke condensate (CSC) mutagenesis depends on tobacco genotypes, or agronomic practices or both. This research will also allow to assess a true genotoxic hazard for human health from condensate instead of giving indications of doubtful tar content. CSC from two tobacco types (flue-cured, Virginia Bright, cultivated either as "topped" and "untopped" - grown as old Italian style - and air-cured Burley, cultivated either as "aromatic" and "neutral" - grown as Italian style -), each repeated in two different places in Italy, was used. Different nitrogen concentrations, different cure modalities and one or two aphicide treatments were also taken into consideration. Induction of chromosome aberrations (AC), sister chromatid exchanges (SCE) and micronuclei (MN), either in human lymphocytes and mammalian cell lines engineered with single cytochromes, were used as cytogenetic biomarker of genotoxicity. Preliminary data from 2004 growing showed differences in mutagenicity among CSC from different tobacco types and cultural techniques (topped vs. untopped, with the aromatic Burley being the most mutagenic). Furthermore, SCE induction seems dependent on metabolism, while AC are not. Experiments are in progress with 2005 tobacco cultivations to confirm and to extend these results.