title: Effects of a novel β-lapachone derivative on Trypanosoma cruzi: Parasite death involving apoptosis, autophagy and necrosis.
abstract: Natural products comprise valuable sources for new antiparasitic drugs. Here we tested the effects of a novel β-lapachone derivative on Trypanosoma cruzi parasite survival and proliferation and used microscopy and cytometry techniques to approach the mechanism(s) underlying parasite death. The selectivity index determination indicate that the compound trypanocidal activity was over ten-fold more cytotoxic to epimastigotes than to macrophages or splenocytes. Scanning electron microscopy analysis revealed that the R72 β-lapachone derivative affected the T. cruzi morphology and surface topography. General plasma membrane waving and blebbing particularly on the cytostome region were observed in the R72-treated parasites. Transmission electron microscopy observations confirmed the surface damage at the cytostome opening vicinity. We also observed ultrastructural evidence of the autophagic mechanism termed macroautophagy. Some of the autophagosomes involved large portions of the parasite cytoplasm and their fusion/confluence may lead to necrotic parasite death. The remarkably enhanced frequency of autophagy triggering was confirmed by quantitating monodansylcadaverine labeling. Some cells displayed evidence of chromatin pycnosis and nuclear fragmentation were detected. This latter phenomenon was also indicated by DAPI staining of R72-treated cells. The apoptotis induction was suggested to take place in circa one-third of the parasites assessed by annexin V labeling measured by flow cytometry. TUNEL staining corroborated the apoptosis induction. Propidium iodide labeling indicate that at least 10% of the R72-treated parasites suffered necrosis within 24 h. The present data indicate that the β-lapachone derivative R72 selectively triggers T. cruzi cell death, involving both apoptosis and autophagy-induced necrosis.
authors: Lab. Biologia Parasitária, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz - FIOCRUZ, Brazil; Departamento de Ciências Biológicas, Universidade Estadual de Santa Cruz UESC, Brazil.
authors: Danielle Oliveira
authors: DO
authors: Dos Anjos
authors: Lab. Biologia Parasitária, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz - FIOCRUZ, Brazil.
authors: Eliomara Sousa
authors: ES
authors: Sobral Alves
authors: Instituto de Química, Universidade Federal Rural do Rio de Janeiro-UFRRJ, Brazil.
authors: Vinicius Tomaz
authors: VT
authors: Gonçalves
authors: Lab. Biologia Parasitária, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz - FIOCRUZ, Brazil.
authors: Sheila Suarez
authors: SS
authors: Fontes
authors: Lab. Biologia Parasitária, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz - FIOCRUZ, Brazil.
authors: Mateus Lima
authors: ML
authors: Nogueira
authors: Lab. Biologia Parasitária, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz - FIOCRUZ, Brazil.
authors: Ana Márcia
authors: AM
authors: Suarez-Fontes
authors: Instituto de Química, Universidade Federal Rural do Rio de Janeiro-UFRRJ, Brazil.
authors: João Batista
authors: JB
authors: Neves da Costa
authors: Faculdade de Medicina da Universidade Federal de Mato-Grosso (UFMT), Brazil.
authors: Fabricio
authors: F
authors: Rios-Santos
authors: Lab. Biologia Parasitária, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz - FIOCRUZ, Brazil. Electronic address: vannier@bahia.fiocruz.br.
authors: Marcos André
authors: MA
authors: Vannier-Santos
mesh_terms: D017209:Apoptosis; D001343:Autophagy; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D009285:Naphthoquinones / Q000494:pharmacology*; D009336:Necrosis; D014344:Trypanocidal Agents / Q000494:pharmacology*; D014349:Trypanosoma cruzi / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology
chemical_list: D009285:Naphthoquinones; D014344:Trypanocidal Agents; C014638:beta-lapachone
keywords: Chagas disease; Chemotherapy; Natural products; Trypanosoma cruzi; β–lapachone derivative