| ABSTRACT: |
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Antioxidants were found to protect against the genotoxic effects of
chemical and physical mutagenic and clastogenic agents. This study focused
on the capacity of antioxidants to reduce an intrinsic and persistent
chromosome instability. As a model system, strains of C127 cells, which
were transformed by bovine papillomavirus (BPV) DNA and which carry BPV
DNA varying from 20 to 160 copies, were used. Transformed cells of 10
different strains showed a persistently high incidence of mitotic
irregularities detectable at anaphase and telophase (27.3-58.9%), an
elevated frequency of cells with micronuclei (6.6-34.7%), and a broad
spectrum of nuclear sizes, as measured by image analysis. A 3-day exposure
to retinoic acid, retinol, beta-carotene, canthaxanthin, ascorbic acid and
ellagic acid greatly reduced the degree of chromosome instability, whereas
catechin, eugenol and pyrogallol showed a smaller inhibitory effect, and
curcumin had no detectable effect on the frequency of mitotic
irregularities. After withdrawal of retinoic acid treatment, the high
levels of chromosome instability reappeared. The possibility that the
protective effect of the retinoids and carotenoids examined in the model
system points to their beneficial administration to human cells with an
intrinsic or acquired chromosome instability is discussed. |