Amoebicidal effect of Antimicrobial Peptides against Acanthamoeba castellanii: A study of cell death using Fluorescence imaging systems.

Acanthamoeba infections are hindered by limitations including prolonged treatment duration, cytotoxicity, limited efficacy against the resistant cystic stage, and a high rate of recurrence. Antimicrobial peptides (AMPs) demonstrate broad-spectrum antimicrobial activity, rapid mechanism of action, low potential for inducing resistance, and efficacy against both trophozoite and cyst forms, highlighting their potential as promising alternatives in the treatment of these infections. Herein, we report the amoebicidal activity of various peptides derived from cathelicidins and piscidins against Acanthamoeba castellanii Neff. Afterwards, the impact of the most effective peptide on the clinical features of a clinical strain of Acanthamoeba castellanii was evaluated using a fluorescence imaging system. Peptide OH_KR34 was the most active against A. castellanii Neff with an IC₅₀ values of 2.00 ± 0.58 µM. OH_KR34 was able to inhibit the clinical strain of A. castellanii (L10) with an IC50 of 5.75 ± 0.30 μM. We demonstrated that the peptide OH_KR34 (related to OH-CATH) induces cytoskeletal damage and trigger apoptosis-like process by disrupting cell membrane permeability, mitochondrial dysfunction and DNA fragmentation. This antimicrobial peptide could therefore offer a potential target to develop new anti-parasitic drugs.