Amino ozonides exhibit in vitro activity against Echinococcus multilocularis metacestodes

Area of Science:

• Medicinal Chemistry
• Parasitology
• Drug Discovery

Background:

• Artemisinin derivatives are used for malaria but have shown limited efficacy against Echinococcus multilocularis.
• Echinococcus multilocularis metacestodes are the parasitic stage targeted for treatment.

Purpose of the Study:

• To investigate the in vitro efficacy of synthetic ozonides (1,2,4-trioxolanes) against Echinococcus multilocularis metacestodes.
• To assess the cytotoxicity of potent ozonides in mammalian cell lines.

Main Methods:

• Screening of synthetic ozonides against E. multilocularis metacestodes at 20μM.
• Dose-response studies and cytotoxicity assays in mammalian cells (fibroblasts, hepatoma, Vero).
• Transmission electron microscopy (TEM) to observe structural damage in metacestodes.

Main Results:

• Four ozonides (OZ401, OZ455, OZ491, OZ494) demonstrated significant parasite death (60-100%) at 20μM.
• OZ401, OZ455, and OZ491 exhibited potent activity with IC50 values between 11μM and 14μM.
• Cytotoxicity was observed only at high concentrations in mammalian cells.
• TEM revealed metabolic impairment and progressive destruction of the parasite's germinal layer within 5 days.

Conclusions:

• Synthetic ozonides, particularly those with an aminopropylether substructure, are effective in vitro against Echinococcus multilocularis metacestodes.
• These compounds display a favorable safety profile with low cytotoxicity in mammalian cells.
• Synthetic ozonides represent promising lead compounds for further development against echinococcosis.