Synthesis, characterization, cytotoxicity, and DNA binding of some new platinum(II) and platinum(IV) complexes with benzimidazole ligands

Abstract

In this study, two Pt(II) and three Pt(IV) complexes with the structures of [PtL₂Cl₂] (1), [PtL₂I₂] (2), [PtL₂Cl₂(OH)₂] (3), [PtL₂Cl₂(OCOCH₃)₂] (4), and [PtL₂Cl₄] (5) (L = benzimidazole as carrier ligand) were synthesized and evaluated for their in vitro antiproliferative activities against the human MCF-7, HeLa, and HEp-2 cancer cell lines. The influence of compounds 1–5 on the tertiary structure of DNA was determined by their ability to modify the electrophoretic mobility of the form I and II bands of pBR322 plasmid DNA. The inhibition of BamH1 restriction enzyme activity of compounds 1–5 was also determined. In general, it was found that compounds 1–5 were less active than cisplatin and carboplatin against MCF-7 and HeLa cell lines (except for 1, which was found to be more active than carboplatin against the MCF-7 cell line). Compounds 1 and 3 were found to be significantly more active than cisplatin and carboplatin against the HEp-2 cell line.

Keywords::

• Benzimidazole
• cytotoxic activity
• DNA binding
• gel electrophoresis
• platinum complexes

Acknowledgements

We would like to thank Prof. Dr. İbrahim Burgu (Faculty of Veterinary Medicine, Ankara University) for his valuable support.

Declaration of interest

Financial support of part of this work (ECZ-F-EMB(SU) 2006-1) by the Research Foundation of Mersin University is gratefully acknowledged.