Isolation of potassium salt of oxadiazole-2-thione and in vitro anticancer activities of its Cu(ii) and Zn(ii) complexes against MDA-MB-231 human breast carcinoma cells

Abstract

A potassium 4-(pyridyl)-1,3,4-oxadiazole-2-thione was isolated in a basic medium, and its complexes [Cu(en)₂(pot)₂] (1) and [Zn(en)₂(pot)₂]HBr·CH₃OH (2) containing ethylenediamine (en) as secondary ligand were synthesized and fully characterized. Upon changing the reaction conditions, the Cu(II) complex (1) adopts an octahedral geometry around the metal center. The cytotoxic activity of ligand (Kpot·H₂O) along with complexes 1 and 2 was tested, and their anticancer activity against MDA-MB-231 human breast cancer cells was demonstrated, with complex 1 exhibiting superior cytotoxicity against these cells as compared to Kpot·H₂O and complex 2. According to the DNA nicking assay, the ligand (Kpot·H₂O) was found to be more potent to scavenge hydroxyl radicals even at a lower concentration (50 μg mL⁻¹) than that of both complexes. The wound healing assay revealed that ligand Kpot·H₂O and its complexes 1 and 2 attenuated the migration of the above-mentioned cell line. The loss of cellular and nuclear integrity and induction in the activity of Caspase-3 suggest the anticancer potential of ligand Kpot·H₂O and its complexes 1 and 2 against MDA-MB-231 cells.