Effects of direct electric current on Herpetomonas samuelpessoai: An ultrastructural study.
The literature shows that the effects of direct electric currents on biological material are numerous, including bactericidal, fungicidal, parasiticidal, and anti-tumoral, among others. Non-pathogenic trypanosomatids, such as Herpetomonas samuelpessoai, have emerged as important models for the study of basic biological processes performed by a eukaryotic cell. The present study reports a dose-dependent anti-protozoan effect of direct electric treatment with both cathodic and anodic current flows on H. samuelpessoai cells. The damaging effects can be attributable to the electrolysis products generated during electric stimulation. The pH of the cell suspension was progressively augmented from 7.4 to 10.5 after the cathodic treatment. In contrast, the anodic treatment caused a pH decrease varying from 7.4 to 6.5. Transmission electron microscopy analyses revealed profound alterations in vital cellular structures (e.g., mitochondrion, kinetoplast, flagellum, flagellar pocket, nucleus, and plasma membrane) after exposure to both cathodic and anodic current flows. Specifically, cathodic current flow treatment induced the appearance of autophagic-like structures on parasite cells, while those submitted to an anodic current flow presented marked disorganization of plasma membrane and necrotic appearance. However, parasites treated in the intermediary chamber (without contact with the electrodes) did not present significant changes in viability or morphology, and no pH variation was detected in this system. The use of H. samuelpessoai as a biological model and the direct electric current experimental approach used in our study provide important information for understanding the mechanisms involved in the cytotoxic effects of this physical agent.
Laboratory of Multidisciplinary Pharmaceutical Sciences, Department of Drugs, Faculty of Pharmacy, Centre of Health Sciences (CCS), Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil.
Marina das Neves
Md
Gomes
Cesar Augusto Antunes
CA
Teixeira
Gleyce Moreno
GM
Barbosa
Marcela Teso
MT
Froes
Maria Bernadete
MB
Silva
Venicio Feo
VF
da Veiga
Rosangela Maria de Araújo
RM
Soares
André Luis Souza
AL
dos Santos
Carla
C
Holandino
D002470:Cell Survival; D004553:Electric Conductivity / Q000009:adverse effects*; D014351:Trypanosomatina / Q000166:cytology / Q000648:ultrastructure*