Antiproliferative activity and apoptosis induction, of organo-antimony(III)–copper(I) conjugates, against human breast cancer cells

Abstract

Three known organo-antimony(III)–copper(I), mixed-metal small bioactive molecules (SBAMs) of formula [Cu(tpSb)3Cl] (1), [Cu2(tpSb)4Br2] (2) and [Cu2(tpSb)4I2] (3) (tpSb = triphenylstibine) were used for the clarification of their antiproliferative activity against human breast cancer cells: MCF-7 (hormone-dependent cells) and MDA-MB-231 (hormone-independent cells). The in vitro toxicity of 1–3 was studied against normal human foetal lung fibroblast cells (MRC-5). The genotoxicity of 1–3 was determined by the presence of micronucleus. The type of the cell death caused by 1–3 was determined using cell cycle arrest. The molecular mechanism of action of 1–3 was defined by their binding affinity towards CT-DNA (calf thymus DNA) using UV spectroscopy and viscosity measurements. Docking studies depict the interactions between 1–3 and DNA. Computations were also employed in order to rationalize the activity of these compounds. This is based on the contribution of metal aromaticity in the case of compounds 2 and 3 where the short Cu···Cu distance (2.7724(6) (2) and 2.7251(11) (3) Ǻ, respectively) suggests d10–d10 interaction between metal centres. Graphic abstract: The known small bioactive molecules of formula [Cu(tpSb)3Cl] (1), [Cu2(tpSb)4Br2] (2) and [Cu2(tpSb)4I2] (3) (tpSb = triphenylstibine) were used for the clarification of their antiproliferative activity against human breast cancer cells: MCF-7 (hormone-dependent (HD) cells) and MDA-MB-231 (hormone-independent (HI) cells).