ABSTRACT
Sporotrichosis is the most frequent subcutaneous mycosis in the world and its increasing incidence has led to the search for new therapeutic options for its treatment. In this study, we demonstrated that three structural analogues of miltefosine (TCAN26, TC19, and TC70) showed inhibitory activity against Sporothrix schenckii sensu stricto and that TCAN26 was more active in vitro than miltefosine against several isolates. Scanning electron microscopy showed that S. schenckii exposure to TCAN26 resulted in cells that were slightly more elongated than untreated cells. Transmission electron microscopy showed that TCAN26 treatment induced loss of the regular cytoplasmic electron-density and altered the cell envelope (disruption of the cell membrane and cell wall, and increased cell wall thickness). Additionally, TCAN26 concentrations required to kill S. schenckii cells were lower than concentrations that were cytotoxic in mammalian cells, and TCAN26 was more selective than miltefosine. Thus, the adamantylidene-substituted alkylphosphocholine TCAN26 is a promising molecule for the development of novel antifungal compounds, although further investigations are required to elucidate the mode of action of TCAN26 in S. schenckii cells.
Subject(s)
Humans , Adamantane/pharmacokinetics , Antifungal Agents/pharmacology , Phosphorylcholine/analogs & derivatives , Sporothrix/drug effects , Adamantane/chemistry , Antifungal Agents/chemistry , Cell Membrane/drug effects , Drug Substitution , Microbial Sensitivity Tests , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Phosphorylcholine/chemistry , Phosphorylcholine/pharmacology , Sporothrix/classification , Sporothrix/ultrastructureABSTRACT
OBJECTIVES: Apoptosis is the process of programmed cell death (PCD) that occurs in both animal and plant cells. Protozoan parasites possess metacaspase and these caspase-related proteases could be involved in the PCD pathways in these organisms. Therefore we analyzed the activities of metacaspase and PARP genes in Leishmania infantum (MCAN/IR/96/LON49) treated with miltefosine. MATERIALS AND METHODS: Anti-leishmania activity of miltefosine was studied by treatment of cultured promastigotes with various concentration of miltefosine. MTT assay and Annexin-V FLUOS staining by using FACS flow cytometry methods were used. Cytotoxic potential of HePC on the amastigots of L.infantum was evaluated in J774 cell line. In addition, metacaspase and PARP genes expression of treated L. infantum were studied. RESULTS: Miltefosine led to dose-dependent death of L. infantumwith features compatible with apoptosis. Over expression of metacaspase and PARP was seen 6 hr after treatment. CONCLUSIONS: Our study showed that miltefosine exerts cytotoxic effect on L. infantum via an apoptotic-related mechanism.