Genotoxic effects of the alpha, beta-unsaturated aldehydes 2-trans-butenal, 2-trans-hexenal and 2-trans, 6-cis-nonadienal.

The genotoxic effects of the 2-alkenals crotonaldehyde, 2-trans-hexenal and 2-trans-6-cis-nonadienal were studied by cytogenetic methods, analyzing frequencies of sister-chromatid-exchanges, numerical and structural chromosome aberrations and micronucleus induction in human blood lymphocytes and cells of the permanent Namalva line. Crotonaldehyde and hexenal were tested in concentrations of 5 microM to 250 microM and nonadienal from 5 microM to 70 microM. Significant dose-related increases of sister-chromatid-exchanges and micronuclei were found for all three compounds. Structural chromosomal aberrations were significantly increased only by crotonaldehyde, but not by hexenal and nonadienal. In contrast numerical chromosome aberrations were not induced by crotonaldehyde whereas hexenal and nonadienal were potent inducers of aneuploidy. The micronuclei were classified by using a centromere-specific DNA probe in a fluorescence in situ hybridization assay. Hexenal and nonadienal increased the percentage of centromere-positive micronuclei, nonadienal being considerably more potent than hexenal. From these results it was concluded that crotonaldehyde acts more as a clastogen whereas hexenal and nonadienal preferentially show aneugenic effects.