Effects of amiodarone and posaconazole on the growth and ultrastructure of Trypanosoma cruzi

• Published in: International journal of antimicrobial agents 2012-07, Vol.40 (1), p.61-71
• Main Authors: Veiga-Santos, Phercyles, Barrias, Emile S, Santos, Júlio F.C, de Barros Moreira, Thiago Luiz, de Carvalho, Tecia Maria Ulisses, Urbina, Julio A, de Souza, Wanderley
• Format: Article
• Language: English
• Subjects: adverse effects; Amiodarone; Amiodarone - pharmacology; animal disease models; Animals; anti-infective agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antimalarials - pharmacology; Autophagy; Autophagy - drug effects; Biological and medical sciences; cell death; Cell Survival - drug effects; Chagas disease; Drug Interactions; drugs; electron microscopy; fluorescence microscopy; Golgi apparatus; humans; Infectious Disease; Inhibitory Concentration 50; Medical sciences; Mice; Microscopy, Electron; Organelles - drug effects; Organelles - ultrastructure; parasites; patients; Pharmacology. Drug treatments; plasma membrane; Posaconazole; Synergism; therapeutics; Triazoles - pharmacology; Trypanosoma cruzi; Trypanosoma cruzi - drug effects; Trypanosoma cruzi - growth & development; Trypanosoma cruzi - physiology; Trypanosoma cruzi - ultrastructure; ultrastructure; vacuoles
• ISSN: 0924-8579; 1872-7913
• DOI: 10.1016/j.ijantimicag.2012.03.009

Abstract The antifungal posaconazole (PCZ) is the most advanced candidate for the treatment of Chagas disease, having potent anti- Trypanosoma cruzi activity in vitro and in animal models of the disease as well as an excellent safety profile in humans. Amiodarone (AMD) is the antiarrhythmic drug most frequently used for the symptomatic treatment of chronic Chagas disease patients, but it also has specific anti- T. cruzi activity. When used in combination, these drugs exhibit potent synergistic activity against the parasite. In the present work, electron microscopy was used to analyse the effects of both compounds, acting individually or in combination, against T. cruzi . The 50% inhibitory concentration (IC50 ) against epimastigote and amastigote forms was 25 nM and 1.0 nM for PCZ and 8 μM and 5.6 μM for AMD, respectively. The antiproliferative synergism of the drugs (fractional inhibitory concentration < 0.5) was confirmed and the ultrastructural alterations in the parasite induced by them, leading to cell death, were characterised using electron microscopy. These alterations include intense wrinkling of the protozoan surface, swelling of the mitochondrion, shedding of plasma membrane vesicles, the appearance of vesicles in the flagellar pocket, alterations in the kinetoplast, disorganisation of the Golgi complex, accumulation of lipid inclusions in the cytoplasm, and the formation of autophagic vacuoles, the latter confirmed by immunofluorescence microscopy. These findings indicate that the association of PCZ and AMD may constitute an effective anti- T. cruzi therapy with low side effects.