In vitro activity of Trigonella foenum graecum seeds against a clinical strain of Acanthamoeba genotype T4

Acanthamoeba keratitis (AK) is a sight-threatening infection of the cornea disease that often presents with a lengthy and not fully effective treatment. Current therapeutic options against Acanthamoeba are not very effective against the cyst. Calibrated trophozoite/cyst suspension was incubated with the same volume of serial dilutions of the Trigonella foenum graecum aqueous extract (200, 250, 350, 450, 600, and 750 mg/mL) in microcentrifuge tubes and mixed by pipetting up and down. After that, the tubes were incubated at 26 ºC for 24, 48 and 72 h. The obtained result revealed that incubation of the extract (at concentrations ranging from 200 to 750 mg/mL) with Acanthamoeba was able to decrease the number of viable trophozoites and cysts. In the presence of up to 450 mg/ml non-viable trophozoites were observed whereas cysts were only eliminated when incubated with 750 mg/ml of the extract. Furthermore, no cytotoxicity of the extract even at the highest concentration tested in the study showed to be toxic for corneal cells. Further researches are needed to determine the exact active compounds involved in the anti-Acanthamoeba activities of Trigonella foenum graecum. To this end, T. foenum graecum could be a promising agent in the development of novel therapeutic substances against Acanthamoeba.