in vitro antiamoebic activity of iranian allium sativum in comparison with metronidazole against entamoeba histolytica

background: amoebiasis is due to infection with the protozoan parasite entamoeba histolytica. the patients infected with e. histolytica must be treated right after definite diagnosis and no need to treat infected individuals with e. dispar isolates. metronidazole is used as a drug of choice against amoebiasis. however, like a lot of other chemical agents, this drug has its own side effects. this prompted us to carry out, an in vitro research into antiamoebic effect of iranian allium sativum (gar­lic), which has been used for centuries, as an herbal medicine, without harmful side effects. methods: hydro-alcoholic, hexanic extracts and essential oil of 100 gram of crushed a. sativum was isolated and the minimal inhibitory concentration (mic) of the extracts and essential oil in comparison with metronidazole were obtained on trophozoite of e. histolytica, hm-1: imss strain in tyi-s-33 medium. results: the mic for a. sativum hydroalcoholic, hexanic extracts and essential oil after 24 hours was 60mg ml -1 , 4mg ml -1 and 0.4mg ml -1 , respectively. after 48 hours the mic for a. sativum hexanic extract and essential oil was 3mg ml -1 and 0.3mg ml -1 , respectively. mic for metronidazole was obtained 2μg ml -1 and 1.5μg ml -1 after 24 hours and 48 hours, in that order.  conclusion: iranian a. sativum is effective on the trophozoites of e. histolytica species and the essential oil exhibited the greatest antiamoebic activity, at the lowest mic.