Evaluation of Anti-amoebic Activity of Peganum harmala Ethanolic Extract on Acanthamoeba In vitro

Acanthamoeba is an opportunistic protozoan pathogen that is known to infect the cornea to produce eye keratitis and the central nervous system to produce lethal granulomatous encephalitis. The overall aim of the present study was to determine the anti-amoebic potential of natural compound Peganum harmala against the trophozoites and cysts of Acanthamoeba in vitro.
In this experimental study, a clinical isolate of Acanthamoeba was cultured and genotyped. The ethanolic extract of Peganum harmala was prepared. The trophozoites and cysts were collected by washing in page's saline. Various concentrations (1.25, 2.5, 5, and 10 mg/ml) of the ethanolic extract and polyhexanide 0.02% drop as positive control were tested at three different times (24, 48 and 72 h) on trophozoites and cysts of Acanthamoeba in vitro. The viability of trophozoites or cysts was tested by eozin method, MTT, and flowcytometry analysis.
The results revealed that alcoholic extract had remarkable inhibitory effect on the proliferation of Acanthamoeba cysts as compared to non-treated control, and the inhibition was time and dose dependent. In the presence of 10 mg/ml ethanolic extract in medium culture after 72 h, no viable trophozoites were determined and 21.10% cysts of Acanthamoeba were viable. Percentage of trophozoites and cysts viability after adding polyhexanide 0.02% drop in medium culture after 72 hours was 0% and 23.71%, respectively.
Ethanolic extracts of Peganum harmala could be considered a new natural compound against the Acanthamoeba trophozoites and cysts. Further works are required to evaluate the exact effect of this extract on Acanthamoeba agents in animal models.