Redox and apoptotic potential of novel ruthenium complexes in the rat blood and heart
Ruthenium(II) complexes offer the potential for lower toxicity compared to platinum(II) complexes. Our study aimed to compare cardiotoxicity of [Ru(Cl-tpy)(en)Cl][Cl], [Ru(Cl-tpy)(dach)Cl][Cl], [Ru(Cl-tpy)(bpy)Cl][Cl], cisplatin and saline through assessment of redox status and relative expression of apoptosis-related genes. A total of 40 Wistar albino rats were divided into five groups. Ruthenium groups received intraperitoneally single dose of complexes (4 mg/kg/week) for 4-weeks period; cisplatin group received cisplatin (4 mg/kg/week) and control group received saline (4 mL/kg/week) in the same manner as ruthenium groups. In collected blood and heart tissue samples, spectrophotometrically determination of oxidative stress biomarkers was performed. The relative expression of apoptosis-related genes (Bcl-2, Bax, and caspase-3) in hearts was examined by RT-PCR. Our results showed that systemic and cardiac pro-oxidative markers (TBARS and NO2-) were significantly lower in ruthenium groups compared to cisplatin group, while concentrations of antioxidative parameters (CAT, SOD, and GSSG) were significantly higher. Ruthenium administration led to significantly lower gene expression of Bax and caspase-3 compared to cisplatin-treated rats, while Bcl-2 remained unchanged. Applied ruthenium complexes have less pronounced potential for induction of oxidative stress-mediated cardiotoxicity compared to cisplatin. These findings may help for future studies that should clarify the mechanisms of cardiotoxicity of ruthenium-based metallodrugs.