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1,8-Dihydroxyanthraquinones, present in
laxatives, fungi imperfecti, Chinese herbs and
possibly vegetables, are in debate as human
carcinogens. We screened a variety of vegetables
(cabbage lettuce, beans, peas), some herbs and
herbal-flavoured liquors for their content of
the 'free' anthraquinones emodin, chrysophanol
and physcion. For qualitative and quantitative
analysis, reversed-phase HPLC (RP-LC), gas
chromatography-mass spectrometry (GC-MS) and
RP-LC-MS were used. The vegetables showed a
large batch-to-batch variability, from 0.04 to
3.6, 5.9 and 36 mg total anthraquinone per kg
fresh weight in peas, cabbage lettuce, and
beans, respectively. Physcion predominated in
all vegetables. In the herbs grape vine leaves,
couch grass root and plantain herb,
anthraquinones were above the limit of
detection. Contents ranged below 1 mg/kg (dry
weight). All three anthraquinones were also
found in seven of 11 herbal-flavoured liquors,
in a range of 0.05 mg/kg to 7.6 mg/kg. The
genotoxicity of the analysed anthraquinones was
investigated in the comet assay, the
micronucleus test and the mutation assay in
mouse lymphoma L5178Y tk+/- cells. Emodin was
genotoxic, whereas chrysophanol and physcion
showed no effects. Complete vegetable extract on
its own did not show any effect in the
micronucleus test. A lettuce extract completely
abolished the induction of micronuclei by the
genotoxic anthraquinone danthron. Taking into
consideration the measured concentrations of
anthraquinones, estimated daily intakes, the
genotoxic potency, as well as protective effects
of the food matrix, the analysed constituents do
not represent a high priority genotoxic risk in
a balanced human diet. |