Cytotoxicity and DNA/BSA binding ability of copper(II) complexes with dimethylbithiazole

摘要

The interaction of two copper(II) complexes [Cu(dmbt)(2)NO3](NO3) and [CuCl(dmbt)(mu-Cl)](2) with calf-thymus DNA has been explored by using absorption, emission, and thermal denaturation. Both complexes illustrate high interaction ability with calf-thymus DNA, with intrinsic binding constants K (b) of 1.7 x 10(5) and 1.4 x 10(5) M-1 at 298 K, respectively, which is in the range of those found for typical classical intercalators. The intermolecular interaction between Cu complexes and bovine serum albumin (BSA) under imitated physiological conditions was investigated using UV-Vis and fluorescence. Tryptophan quenching experiment showed that both complexes bind BSA strongly, with dynamic quenching constants of 1.16 x 10(5) M-1 s(-1) and 1.64 x 10(5) M-1 s(-1), respectively, at 298 K, and a single class of binding site for the complexes on BSA. Both Cu complexes were also used for in vitro cytotoxicity evaluation against four cultures, NIH-3T3, Caco-2, HT-29, and T47D by MTT assay. Interestingly, nitrate contained complex illustrated no toxicity on normal cell line (NIH-3T3), with twice antitumor activity against colon carcinoma (HT-29), comparing with cisplatin.