Iron is an important
element that modulates the production of
reactive oxygen species, which are thought to play a causative role in biological processes such as mutagenesis and
carcinogenesis. The potential genotoxicity of
dietary iron has been seldom studied in human leukocyte and only few reports have investigated in human colon
tumor cells. Therefore, DNA damage and repair capacity of human leukocytes were examined using comet assay for screening the potential toxicity of various
iron-overloads such as
ferric-nitrilotriacetate (
Fe-NTA), FeSO(4),
hemoglobin and
myoglobin, and compared with 200μM of H(2)O(2) and HNE. The
iron-overloads tested were not cytotoxic in the range of 10-1000 microM by
trypan blue exclusion assay. The exposure of leukocytes to
Fe-NTA (500 and 1000 microM), FeSO(4) (250-1000 microM),
hemoglobin (10 microM) and
myoglobin (250 microM) for 30 min induced significantly higher DNA damage than NC. Treatment with 500 and 1000 microM of
Fe-NTA showed a similar genotoxic effect to H(2)O(2), and a significant higher genotoxic effect than HNE. The genotoxicity of FeSO(4) (250-1000 microM),
hemoglobin (10 microM) and
myoglobin (250 microM) was not significantly different from that of H(2)O(2) and HNE.
Iron-overloads generated
DNA strand break were rejoined from the first 1h. Their genotoxic effect was not observed at 24h. These data from this study provide additional information on the genotoxicity of
iron-overloads and self-repair capacity in human leukocytes.