El-badri E. Osman2023-12-212023-12-212017https://ds.eaeu.edu.sd/handle/10.58971/889Abstract: Entamoeba histolytica is ranked third on the list of parasitic protozoan infections leading to death behind malaria and schistosomiasis. It is estimated also up to 200 millions of people are chronically infected with Giardia lamblia globally. Metronidazole is the drug currently widely used and recommended in the treatment of amoebiasis and giardiasis. However; sometimes it causes adverse effects such as myoplasia, neuralgia, allergic dermatitis, and others. The in vitro antiprotozoal activities of some selected Sudanese medicinal plants (Acacia nilotica subsp. nilotica, Adansonia digitata, Cyperus rotundus and Nigella sativa) were determined against Entamoeba histolytica and Giardia lamblia by employing the sub-culture method. The mammalian cytotoxicity of the investigated plants against normal Vero cell line was determined by applying MTT [(4, 5- dimethyl thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] method. All plants examined 100% inhibition at a concentration 500 µg/ml after 96 h; this was compared with Metronidazole which gave 95% inhibition at concentration 312.5 µg/ml at the same time against Entamoeba histolytica and Giardia lamblia. In addition, cytotoxicity (MTT-assay) of these plants against normal Vero cell line which verified the safety of the examined extracts with an IC50 less 100 µg/ml. These studies prove the potent activity of extracts against E. histolyica and G. lamblia trophozoites in vitro with verified safety evidence for use.other