Biological approaches to characterize the mode of action of two 5-nitroindazolinone prototypes on Trypanosoma cruzi bloodstream trypomastigotes.
The phenotypic activity of two 5-nitroindazolinones, i.e. 2-benzyl-1-propyl (22) and 2-benzyl-1-butyl (24) derivatives, previously proposed as anti-Trypanosoma cruzi prototypes, was presently assayed on bloodstream trypomastigotes (BT) of the moderately drug-resistant Y strain. Further exploration of putative targets and cellular mechanisms involved in their activity was also carried out. Therefore, transmission electron microscopy, high-resolution respirometry and flow cytometry procedures were performed on BT treated for up to 24 h with the respective EC50 value of each derivative. Results demonstrated that although 22 and 24 were not as active as benznidazole in this in vitro assay on BT, both compounds triggered important damages in T. cruzi that lead to the parasite death. Ultrastructural alterations included shedding events, detachment of plasma membrane and nuclear envelope, loss of mitochondrial integrity, besides the occurrence of a large number of intracellular vesicles and profiles of endoplasmic reticulum surrounding cytoplasmic organelles such as mitochondrion. Moreover, both derivatives affected mitochondrion leading to this organelle dysfunction, as reflected by the inhibition in oxygen consumption and the loss of mitochondrial membrane potential. Altogether, the findings exposed in the present study propose autophagic processes and mitochondrial machinery as part of the mode of action of both 5-nitroindazolinones 22 and 24 on T. cruzi trypomastigotes.
CEI Campus Moncloa, UCM-UPM & CSIC,Madrid,Spain.
Cristina
C
Fonseca-Berzal
Laboratório de Biologia Celular,Instituto Oswaldo Cruz,Fiocruz, Av. Brasil 4365,21040-900 Rio de Janeiro,Brazil.
Cristiane França
CF
DA Silva
Laboratório de Biologia Celular,Instituto Oswaldo Cruz,Fiocruz, Av. Brasil 4365,21040-900 Rio de Janeiro,Brazil.
Rubem F S
RF
Menna-Barreto
Laboratório de Biologia Celular,Instituto Oswaldo Cruz,Fiocruz, Av. Brasil 4365,21040-900 Rio de Janeiro,Brazil.
Marcos Meuser
MM
Batista
CEI Campus Moncloa, UCM-UPM & CSIC,Madrid,Spain.
José A
JA
Escario
CEI Campus Moncloa, UCM-UPM & CSIC,Madrid,Spain.
Vicente J
VJ
Arán
CEI Campus Moncloa, UCM-UPM & CSIC,Madrid,Spain.
Alicia
A
Gómez-Barrio
Laboratório de Biologia Celular,Instituto Oswaldo Cruz,Fiocruz, Av. Brasil 4365,21040-900 Rio de Janeiro,Brazil.
Maria DE Nazaré C
Mde N
Soeiro
D000818:Animals; D001343:Autophagy / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects; D014355:Chagas Disease / Q000469:parasitology; D004721:Endoplasmic Reticulum / Q000187:drug effects; D005434:Flow Cytometry; D007191:Indazoles / Q000494:pharmacology*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D046529:Microscopy, Electron, Transmission; D008928:Mitochondria / Q000187:drug effects; D009593:Nitroimidazoles / Q000494:pharmacology; D009685:Nuclear Envelope / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects; D014344:Trypanocidal Agents / Q000494:pharmacology*; D014349:Trypanosoma cruzi / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure
C000622672:2-benzyl-1-butyl-5-nitroindazolin-3-one; C000622671:2-benzyl-5-nitro-1-propylindazolin-3-one; D007191:Indazoles; D009593:Nitroimidazoles; D014344:Trypanocidal Agents; C009999:benzonidazole
Chagas disease; autophagy; flow cytometry; high-resolution respirometry; mitochondrion; transmission electron microscopy