Evaluation of the anti-Acanthamoeba potential of Myriophyllum spicatum on Acanthamoeba castellanii trophozoites

Myriophyllum spicatum is a submerged aquatic macrophyte known for its allelopathic and antimicrobial properties. This study investigated the amoebicidal activity of ethanolic M. spicatum leaf extract against Acanthamoeba castellanii trophozoites. Plant samples were collected from the Terme River (Samsun), extracted with ethanol, and tested at concentrations ranging from 1.5 to 48 µg/mL over 24, 48, and 72 hours. Trophozoite viability was assessed using trypan blue staining, and statistical analysis was performed with SPSS and Jamovi software. Results showed significant dose- and time-dependent reductions in trophozoite viability, with an IC50 value of 26.5 µg/mL at 72 hours. The highest inhibition was observed at 48 µg/mL, resulting in a 33% reduction in viability. Principal Component Analysis revealed distinct clustering of higher concentrations from lower doses and control. The study highlights M. spicatum’s potential as a natural anti-amoebic agent. Given the parasite's resistance to conventional drugs and the increasing threat of Acanthamoeba infections, particularly in developing regions, plant-based compounds offer promising alternatives. Further research is recommended to evaluate the extract’s effects on the cyst stage and explore its therapeutic applications. This study is the first to report the anti-Acanthamoeba effect of M. spicatum, contributing novel insight into aquatic plant-based antiparasitic agents.