Design, synthesis, and structural evaluation of metal complexes of azepane-1-carbodithioate for targeting human breast cancer: investigating cytotoxic activity against the MDA-MB-231 cell line

Abstract

In this article, we have reported the synthesis and structural characterization of complexes containing Co(III), Cu(II), Zn(II), and Hg(II) metal cations. The ligand potassium azepane-1-carbodithioate (acdt) behaves as a monodentate and bidentate and forms complexes with the metals mentioned above. We investigated the electronic and emission spectra of the ligand potassium azepane-1-carbodithioate (acdt) and its metal complexes [Co(acdt)₃]·CHCl₃ (1), [Cu(acdt)₂] (2), [Zn₂(μ₂-acdt)₂(acdt)₂] (3), and [PhHg(acdt)] (4). A photoluminescence study was also carried out and the results revealed that all compounds are fluorescent. Furthermore, this synthesized ligand and its complexes are passed through to examine their cytotoxic activity against human breast cancer cell line MDA-MB-231 and results suggested that complex [Co(acdt)₃]·CHCl₃ has sufficiently better activity than others. Furthermore, we have explored the impact of the synthesized ligand and its transition metal complexes on glucose metabolism within the human breast cancer cell line MDA-MB-231. Inhibiting glucose uptake can induce starvation in cancer cells, potentially resulting in cell death due to energy deprivation. Our results indicate that the Co(III) complex-treated group exhibited a greater inhibition of glucose uptake compared to groups treated with ligands and other metal complexes such as Cu, Zn, and Hg. Furthermore, we also measured the extracellular NO level in the ligand and its metal complexes of Co(III), Cu(II), Zn(II), and Hg(II) treated MDA-MB-231 cells and results indicated that the free ligand and its metal complexes induced the production of nitric oxide in MDA-MB-231 cells. Among the four metal complexes, Co-complex 1 elevated the nitric oxide level in MDA-MB-231 cells to 75.91 μM. In contrast, the groups treated with the complexes of Cu(II) (2), Zn(III) (3), and Hg(II) (4) induced NO levels of 62.91, 49.24, and 33.10 μM, respectively. This suggests that complex 1 induces nitric oxide production and enhances oxidative stress in MDA-MB-231 cells more significantly compared to the groups treated with the free ligand as well as with metal complexes 2–4. Overall, the data strongly suggest that complex 1 exhibits significant anticancer activity against the human breast cancer cell line MDA-MB-231, making it a promising candidate for combating breast cancer progression.