Enhanced concentration-dependent cytotoxic effect of the dinuclear copper(II) complex of L-carnitine [Cu2(L-carnitine)2Cl2(H2O)2]Cl2, compared to L-carnitine or copper chloride dihydrate, in human leukemic cell lines.

We studied the antitumor properties of the dinuclear copper(II) complex of l-carnitine [Cu 2( l-carnitine) 2Cl 2(H 2O) 2]Cl 2, as well as those of l-carnitine and copper chloride dihydrate, in human leukemic cells. The complex was synthesized and characterized using EPR, (1)H NMR, (13)C NMR, IR, and UV-vis analyses. Its cytotoxic effect on the human leukemia cell lines HL-60 and K562 was studied by assessing the metabolic activity of cells (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT method), the structural integrity of cell membrane using Trypan blue assay, and the proliferation capacity of cells studying growth curves. Both leukemia cell lines showed a concentration-specific increased cytotoxicity of the complex, compared to l-carnitine or copper chloride dihydrate, with distinct underlying mechanisms, which were decreased proliferation efficiency for HL-60 cells and increased necrotic phenomena for K562 cells. Our results are indicative of a concentration-specific enhanced antileukemic effect of the complex, implying its value as a tool in the implementation of leukemia.