Synthesis of platinum(II) complexes of 2-cycloalkyl-substituted benzimidazoles and their cytotoxic effects.

Five novel Pt(II) complexes with some 2-cycloalkyl-substituted benzimidazole carrier-ligands were synthesized and evaluated for their in vitro cytotoxic activities against HeLa and OVCAR-3 cell lines. A cell viability test revealed that [dichloro-bis(2-cycloheptylbenzimidazole) platinum(II)] is less cytotoxic than cisplatin, and its cytotoxic effect can be compared with that of carboplatin. Flow cytometric analysis revealed that this complex at 117 µM concentration causes apoptosis in approx. 72 % of the OVCAR-3 cell population. In addition, the complex was found to cause an increase in the SubG1 population of both OVCAR-3 and HeLa cells and to cause less apoptosis in HeLa cells than cisplatin.