Antioxidant activity of new ruthenium compounds.

Many biological properties have been attributed to ruthenium complexes including anti-tumor activity and the attenuation of reperfusion damage and infarct size. In this work, we characterize the antioxidant activity of trans-[RuCl2(nic)4] where nic is 3-pyridinecarboxylic acid and trans-[RuCl2(i-nic)4] where i-nic is 4-pyridinecarboxylic acid by (i) evaluation of total antioxidant potential (TRAP); (ii) prevention of DNA damage induced by hydrogen peroxide using the alkaline comet assay; and (iii) the prevention of lipid peroxidation and cell death induced by iron in liver slices. Our results suggest that nic has stronger antioxidant potential when compared to the i-nic. Higher doses (above 200 microM) of these compounds gave genotoxic effects, but the antioxidant potential could be obtained with the use lower doses (0.1-10 microM).