Menna-Barreto 2009 Free Radic Biol Med
|Menna-Barreto RF, Goncalves RL, Costa EM, Silva RS, Pinto AV, Oliveira MF, de Castro SL (2009) The effects on Trypanosoma cruzi of novel synthetic naphthoquinones are mediated by mitochondrial dysfunction. Free Radic Biol Med 47:644-53.
Abstract: Despite ongoing efforts, the current treatment for Chagas disease is still unsatisfactory, mainly because of the severe side effects and variable efficacy of the available nitroheterocycles. Our group has been assaying natural quinones isolated from Brazilian flora, and their derivatives, as alternative chemotherapeutic agents against Trypanosoma cruzi. From C-allyl lawsone three naphthofuranquinones were synthesized, which were active against trypomastigotes and epimastigotes. Here, we further investigated the activity and the mechanisms of action of these quinones. They exhibited powerful effects on intracellular amastigotes, presenting low toxicity to the host cells. Ultrastructural analyses of treated epimastigotes and trypomastigotes indicated a potent effect of the three naphthofuranquinones on the parasite mitochondrion, which appeared drastically swollen and with a washed-out matrix profile. Fluorescence-activated cell sorting analysis of rhodamine 123-stained T. cruzi showed that the three naphthofuranquinones caused a potent dose-dependent collapse of the mitochondrial membrane potential, especially in the epimastigote form. Naphthofuranquinones also decreased specifically mitochondrial Complex I-III activity in both epimastigotes and trypomastigotes, parallel to a reduction in succinate-induced oxygen consumption. Mitochondrial hydrogen peroxide formation was also increased in epimastigotes after treatment with the naphthofuranquinones. Our results indicate that the trypanocidal action of the naphthofuranquinones is associated with mitochondrial dysfunction, leading to increased reactive oxygen species generation and parasite death. • Keywords: Trypanosoma cruzi; Chagas disease; Chemotherapy; Naphthoquinones; Reactive oxygen species; Superoxide; Metabolism; Free radicals
• O2k-Network Lab: BR Rio de Janeiro Oliveira MF
Labels: MiParea: Respiration, Pharmacology;toxicology
Stress:Oxidative stress;RONS Organism: Protists
Regulation: mt-Membrane potential Coupling state: OXPHOS, ET