Estudo das propriedades antioxidantes de complexos nitrosilados de rutênio

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

This study shows the antioxidant and secondary the cytotoxic activity of five different ruthenium nitrosyl complexes: trans-[Ru(NH3)4(L)(NO)]Cl3 (A - D; being (A) L = Caffeine, (B) L = Theophylline, (C) L = Methyl-1-imidazole, (D) L = Benzoimidazole), and (E) cis-[Ru(NH3)4(NO)2]Cl3. Only the complex (A) (L = Caffeine) presented significant reactivity identified by the total antioxidant reactivity (TAR) assay and also potential scavenger activity of superoxide anion (O2"?) through the nitro blue tetrazolium (NBT) reduction test. The complexes (A), (B), (C), (D) and (E) showed capability to scavenge hydroxyl radicals ("OH). The respective potential decreased following the order D>A>B>C>E (most of the values of IC50 were smaller than 15 M). The system to generate the free radical used was Fe-acetonitrile acid (NTA) and deoxyribose oxidation protection. The inhibition of myoglobin oxidation potential induced by nitrogen monoxide ("NO) was observed for the complexes following the order C>B>D>E>A. The protection of lipid peroxidation in microsomes (MC) induced by H2O2 Fe3+ ascorbate system was effective for complexes (D) and (E), with values of IC50 below 100 M (concentration-dependent manner). In addition, lipoperoxidation promoted by ascorbyl radical in soybean phosphatidylcholine liposomes was inhibited in all samples presenting values of IC50 lower than 180 M, in which presented potential decrease following the order D>A>C>B>E. When evaluated in microsomes, some values of IC50 were similar. Furthermore, complex (A) protected also the lipoperoxidation induced by UV radiation in MC and only complex (D) protected lipoperoxidation induced by peroxynitrite. None of the complexes showed cytotoxicity tested in hepatocytes, but the complexes (A) and (C) caused significant death to a leukemic lymphoblastic cell line (L1210).

ASSUNTO(S)

celulas mortas antioxidantes rutenio farmacia farmacia

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