The Comparative Survey on the Cytotoxic Effects of Amphipathic Peptide mCM11 (Modified CM11) and Metronidazole on ST1 and ST3 of Blastocystis sp.

Background: Blastocystis sp. is an opportunistic worldwide protozoan that is life-threatening in immunocompromised individuals; several efforts were performed against Blastocystis sp. in in vivo and in vitro conditions to find an alternative for metronidazole (MTZ). Objectives: The aim of the present study was to survey the cytotoxic effects of peptide mCM11 (modified CM11) and MTZ on ST1 and ST3 of Blastocystis sp. in vitro. Materials and Methods: In the present study, after the culture of the parasite (in Dulbecco’s modified Eagle medium [DMEM] and Caco-2 cell lines), the anti-parasitic effect of different concentrations of either MTZ (1.25-80 μg/mL) or mCM11 (1-128 μg/mL) for 24, 48, and 72 hours was evaluated via a 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide assay and flow cytometry. Results: A dose-time-dependent decrease in cell viability was detected after cell line and parasite exposure. The cytotoxic effect of the peptide on cell lines increased during 24, 48, and 72 hours, and the greatest anti-parasitic effect was observed at the highest concentration (128) after 72 hours. In addition, the ST3 showed more sensitivity to the mCM11. Conclusion: The findings of the current research about the mCM11 peptide were promising compared to MTZ, and by further optimizing the peptide, better effects can be imagined for it, so that it can be a potential alternative to MTZ. However, more studies with a case-control design seem to be necessary in in vivo conditions.