Anti-Blastocystis in vitro activity and in vivo efficacy of the ethanol extracts of Origanum syriacum L. and Ceratonia siliqua

Background: Blastocystosis is significantly implicated in irritable bowel disease, and its current available drugs do not provide a complete cure and have several side effects.Objective: In order to search for a safe natural alternative treatment for blastocystosis, the study investigated both in vitro activity and in vivo effect of two natural medicinal plants extracts, Origanum syriacum L. (Marjoram) and Ceratonia siliqua (Carob) on Blastocystis spp. isolated from symptomatic patients.Material and Methods: The ethanolic extracts of the two plants, O. syriacum L. and C. siliqua were prepared in 3 concentrations (0.5, 2.5, 5.0 mg/ml), and screened phytochemically. Blastocystis-positive stool samples from symptomatic patients were cultured in Jones medium. Cultured Blastocystis cysts were used to screen the in vitro anti-Blastocystis activity of both plant extracts. Lab-bred mice were experimentally infected with cultured Blastocystis and treated with different concentrations of the extract of both plants to assess their in vivo effect. Metronidazole (MTZ) was used as a control drug in both in vitro and in vivo studies.Results: Ethanolic extract of both plants showed dose and time dependent anti-Blastocystis effects both in vitro and in vivo. C. siliqua at 5.0 mg/ml showed the highest anti-Blastocystis efficacy and had a maximum significant growth inhibition rate compared to MTZ.Conclusion: The ethanolic extract of C. siliqua is a promising, effective, safe, natural, environmentally -friendly, anti-Blastocystis alternative therapy. O. syriacum L. had a fair anti-Blastocystis effect and could be used as a supportive additive.