The Effect of Elaeagnus angustifolia L. Leaf Extract on Encephalitozoon intestinalis, Acanthamoeba castellanii, and Leishmania major

PURPOSE: Parasitic diseases are a major global health concern. Treating these diseases presents many challenges. Elaeagnus angustifolia L. (EA) is renowned for its anti-oxidant, anti-inflammatory, and anti-microbial properties, and various parts of the plant are used to treat a variety of ailments. This study aims to evaluate the in vitro activity of the EA leaves against Encephalitozoon intestinalis (E. intestinalis), Acanthamoeba castellanii (A. castellanii), and Leishmania major (L. major) at different concentrations and incubation times. METHODS: Spore load was measured by real-time PCR using an infection model in human kidney epithelial (HEK) 293 cells for E. intestinalis. The viability of A. castellanii trophozoites and cysts, and L. major promastigotes was determined by trypan blue staining and hemocytometry. RESULTS: Elaeagnus angustifolia L. leaf extract significantly reduced the spore DNA load in E. intestinalis infections at a concentration of 5 µg/mL, but was ineffective at lower concentrations. The extract decreased the viability of A. castellanii trophozoites and cysts, as well as L. major promastigotes, at varying rates depending on the time and dose. It was particularly effective against A. castellanii cysts at low doses. CONCLUSION: The biological activity of the plant extract obtained from the leaves of Elaeagnus angustifolia L. against three different parasites suggests that it could be used as a promising alternative in the treatment of parasitic infections.