Abstract
Herein, we have synthesized and characterized a new benzimidazole-derived "BnI" ligand and its copper(II) complex, [Cu(BnI)₂],
, and zinc(II) complex, [Zn(BnI)₂],
, using elemental analysis and various spectroscopic techniques. Interaction of complexes
and
with the biomolecules viz. HSA (human serum albumin) and DNA were studied using absorption titration, fluorescence techniques, and in silico molecular docking studies. The results exhibited the significant binding propensity of both complexes
and
, but complex
showed more avid binding to HSA and DNA. Also, the nuclease activity of
and
was analyzed for pBR322 DNA, and the results obtained confirmed the potential of the complexes to cleave DNA. Moreover, the mechanistic pathway was studied in the presence of various radical scavengers, which revealed that ROS (reactive oxygen species) are responsible for the nuclease activity in complex
, whereas in complex
, the possibility of hydrolytic cleavage also exists. Furthermore, the cytotoxicity of the ligand and complexes
and
were studied on a panel of five different human cancer cells, namely: HepG2, SK-MEL-1, HT018, HeLa, and MDA-MB 231, and compared with the standard drug, cisplatin. The results are quite promising against MDA-MB 231 (breast cancer cell line of
), with an IC
value that is nearly the same as the standard drug. Apoptosis was induced by complex
on MDA-MB 231 cells predominantly as studied by flow cytometry (FACS). The adhesion and migration of cancer cells were also examined upon treatment of complexes
and
. Furthermore, the in vivo chronic toxicity profile of complexes
and
was also studied on all of the major organs of the mice, and found them to be less toxic. Thus, the results warrant further investigations of complex
.