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Amphotericin B-induced damage of Trypanosoma cruzi epimastigotes
1Departamento de Microbiologia Geral, Universidade Federal do Rio de Janeiro, Brazil.
Abstract:
Amphotericin B (AmB) autoxidation resulted in oxygen consumption, superoxide anion formation and production of thiobarbituric acid (TBA)-reactive material (malondialdehyde). Malondialdehyde formation increased after incubation of the drug with ascorbate-ADP-FeCl3. Growth of Trypanosoma cruzi epimastigotes in the presence of AmB induced a decrease in the free fatty acid content of the cells (57% in control cells vs. 7% in AmB-treated cells), and in the proportion of unsaturated fatty acids as well as cell killing. No changes were detected on sterol content. No evidence was found for lipid peroxidation as a mechanism of cell injury by this antibiotic.
Insights
Amphotericin B causes cell damage in Trypanosoma cruzi by altering fatty acid content, not through lipid peroxidation. This antifungal drug affects cell membranes, leading to parasite death.
Area of Science:
- Antimicrobial drug research
- Parasitology
- Biochemistry
Background:
- Amphotericin B (AmB) is a vital antifungal agent.
- Its mechanism of action, particularly concerning cell membrane interactions, requires further elucidation.
- Understanding AmB's effects on parasites like Trypanosoma cruzi is crucial for developing targeted therapies.
Purpose of the Study:
- To investigate the biochemical changes in Trypanosoma cruzi epimastigotes upon exposure to Amphotericin B.
- To determine if lipid peroxidation is a key mechanism in AmB-induced cell injury.
- To analyze the impact of AmB on the fatty acid composition of parasite cell membranes.
Main Methods:
- Amphotericin B autoxidation was analyzed for oxygen consumption and reactive oxygen species.
- Lipid peroxidation markers, such as malondialdehyde, were measured.
- Trypanosoma cruzi epimastigotes were incubated with AmB, and their fatty acid and sterol content was analyzed.
- Cell viability was assessed.
Main Results:
- Amphotericin B autoxidation produced superoxide anions and malondialdehyde.
- Incubation with ascorbate-ADP-FeCl3 enhanced malondialdehyde formation.
- AmB treatment significantly reduced free fatty acids and unsaturated fatty acids in Trypanosoma cruzi cells.
- Cell killing was observed, but sterol content remained unchanged.
- No direct evidence for lipid peroxidation as the primary injury mechanism was found.
Conclusions:
- Amphotericin B induces cell death in Trypanosoma cruzi by significantly altering the cell membrane's fatty acid profile.
- The primary mechanism of injury does not appear to be lipid peroxidation.
- Further research into AmB's membrane-disrupting effects is warranted for antiparasitic drug development.