Copper, but not iron, enhances apoptosis-inducing activity of antioxidants
Satoh, K.; Kadofuku, T.; Sakagami, H.
Anticancer Research 17(4a): 2487-2490
1997
ISSN/ISBN: 0250-7005 PMID: 9252668 Document Number: 477235
Addition of either CuCl or CuCl-2 significantly enhanced sodium ascorbate or sodium 5,6-benzylidene-L-ascorbate (SBA)-induced cytotoxicity and internucleosomal DNA cleavage in human promyelocytic leukemic HL-60 cells. On the other hand, the addition of either FeCl-2 or FeCl-3 inhibited the cytotoxic activity of ascorbate. These effects were observed even if the cells were exposed for only 20 minutes to metals and ascorbates. Copper also stimulated the gallate or caffeate-induced apoptotic cell death, whereas iron was inhibitory. Both copper and iron enhanced the radical intensity of ascorbates, but slightly reduced the radical intensity of gallate and caffeate, suggesting that radical intensity is not the sole determinant of apoptosis induction. Metals did not significantly change the methionine oxidation stimulated by ascorbate, gallate or caffeate. Methionine oxidation may not be indispensable for antioxidant-induced apoptosis.