Lethal action of the nitrothiazolyl-salicylamide derivative nitazoxanide via induction of oxidative stress in Leishmania (L.) infantum.
Studying the cellular death pathways in Leishmania is an important aspect of discovering new antileishmanials. While using a drug repositioning approach, the lethal action of the nitrothiazolyl-salicylamide derivative nitazoxanide (NTZ) was investigated against Leishmania (L.) infantum. The in vitro antileishmanial activity and cytotoxicity were assessed using both parasite stages and mammalian NCTC cells, respectively. The lethal action of NTZ was investigated by detecting the phosphatidylserine (PS) exposure, reactive oxygen species (ROS) regulation, plasma membrane permeability, mitochondrial membrane potential and ultrastructural modifications by transmission electron microscopy. NTZ's activity against L. infantum was confirmed, producing IC50 values of 42.71μg/mL against promastigotes and 6.78μg/mL against intracellular amastigotes. NTZ rapidly altered the cellular metabolism of promastigotes by depolarising the mitochondrial membrane and up-regulating the reactive oxygen species (ROS). In addition, the flow cytometry data revealed an intense and time-dependent exposure of PS in promastigotes. When using SYTOX(®) Green as a fluorescent probe, NTZ demonstrated no interference in plasma membrane permeability. The ultrastructural alterations in promastigotes were time-dependent and caused chromatin condensation, plasma membrane blebbing and mitochondrial swelling. These data suggest that NTZ induced oxidative stress in L. (L.) infantum and might be a useful compound for investigating new therapeutic targets.
Department of Parasitology, Instituto Adolfo Lutz, Av. Dr. Arnaldo, 351, 01246-900 São Paulo, SP, Brazil.
Juliana Tonini
JT
Mesquita
Erika Gracielle
EG
Pinto
Noemi Nosomi
NN
Taniwaki
Andres Jimenez
AJ
Galisteo
Andre Gustavo
AG
Tempone
D000981:Antiprotozoal Agents / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D002463:Cell Membrane Permeability / Q000187:drug effects; D020128:Inhibitory Concentration 50; D018314:Leishmania infantum / Q000187:drug effects* / Q000502:physiology* / Q000648:ultrastructure; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D046529:Microscopy, Electron, Transmission; D051336:Mitochondrial Membranes / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D009574:Nitro Compounds; D018384:Oxidative Stress; D021261:Parasitic Sensitivity Tests; D017382:Reactive Oxygen Species / Q000032:analysis; D013844:Thiazoles / Q000494:pharmacology*
D000981:Antiprotozoal Agents; D009574:Nitro Compounds; D017382:Reactive Oxygen Species; D013844:Thiazoles; C041747:nitazoxanide
Leishmania; Mitochondria; Nitazoxanide; Oxidative stress; Phosphatidylserine; Therapy