Applying the Drosophila wing spot test to assess the genotoxic impact of 10 essential oil constituents used as flavouring agents or cosmetic ingredients

The genotoxicity of 10 essential oil constituents was evaluated using the Drosophila melanogaster (Meigen) somatic mutation and recombination test, also known as the wing spot test, in the frame of a screening project aiming at evaluating the mutagenic activity of widely used substances, natural or not. Of the compounds that we tested here, L-carveol, dihydrocarveol, (+)-dihydrocarvone, (-)-fenchone and (-)-carvyl acetate did not exhibit any mutagenic or recombinogenic activity, whereas (+/-)-linalool, S-(+)-carvone and S-(-)-limonene gave inconclusive results. In contrast, alpha-phellandrene and R-(-)-carvone significantly increased the frequency of mutant spots when compared with the negative control, suggesting mutagenic activity even at the lowest concentration used (1.5 mu l/ml). Moreover, these data clearly demonstrate differences in activity between stereoisomers such as S-(+)- and R-(-)-carvone. Given that alpha-phellandrene and R-(-)-carvone are widely used compounds, further research is needed in order to have a better understanding of their activity and a clearer picture of their genotoxicity in order to decide whether they should remain or not in the lists of compounds that are safe to use. Copyright (C) 2011 John Wiley & Sons, Ltd.