Ruthenium(II) complexes: synthesis, cytotoxicity in vitro, apoptosis, DNA-binding, photocleavage, and antioxidant activity studies

Abstract

Two new ruthenium(II) complexes, [Ru(dmp)₂(APIP)](ClO₄)₂ (1) (APIP = 2-(2-aminophenylimidazo[4,5-f][1,10]phenanthroline), dmp = 2,9-dimethyl-1,10-phenanthroline) and [Ru(dmp)₂(HAPIP)](ClO₄)₂ (2) (HAPIP = 2-(2-hydroxyl-5-aminophenyl)imidazo[4,5-f][1,10]phenanthroline), were synthesized and characterized. The DNA-binding properties of these complexes were investigated by absorption titration, viscosity measurements, and photoactivated cleavage. The DNA-binding constants for 1 and 2 have been determined to be 2.3 (± 0.3) × 10⁴ (mol L⁻¹)⁻¹ and 3.3 (± 0.4) × 10⁴ (mol L⁻¹)⁻¹. The results indicate that 1 and 2 interact with DNA through intercalative mode. The cytotoxicities of 1 and 2 were assessed against BEL-7402, HepG-2 and MCF-7 cell lines using standard MTT assay. The apoptosis induced by these complexes was studied with the acridine orange/ethidium bromide staining method. The antioxidant activity on hydroxyl radical was also investigated.

Keywords:

• Ruthenium(II) complexes
• Cytotoxicity
• Apoptosis
• Antioxidant activity
• DNA binding

Acknowledgments

This work was supported by the National Nature Science Foundation of China (Nos. 31070858 and 30800227) and Guangdong Pharmaceutical University for financial supports.