study on the effect of Myrtus communis and Olibanum on Giardia lamblia infection in Egypt

Giardia lamblia is one of the most common protozoal infections in humans. Although metronidazole [MTZ] is the drug of choice for treatment of giardiasis, yet its chemical composition poses major threats. The search for new alternative therapeutic approaches for this parasitic disease in replacement of MTZ. The effect of Myrtus Communis [MC; called Aas plant in Arabic] and Olibanum [OL; called Leban in Arabic] on G. lamblia were studied. Extracts of MC [methyl alcohol, petroleum ether, chloroform, ethyl acetate and aqueous extracts] amid ethanol extract of OL were used. In vitro culture of G. lamblia trophozoites on TYI-S-33 medium was done, followed by inoculation of the plants' extracts in three different concentrations. This was evaluated by trophiozoite multiplication, adherence assay and electron microscopic study. The in viva effect was evaluated by histopathological study of the duodenum of experimentally infected mice after treatment by each herb. All plant extracts affected G. lamblia trophozoites in a manner dependent on concentration and time of exposure. In low concentration, both herbs significantly decreased the in vitro adherence of tropliozoites when compared to infection control group, while there was no statistical difference when compared to MTZ control group. Extensive ultrastructural changes of Giardia trophozoites were evident after 48 hours exposure to each medical herb. Histopathological examination of duodenum of G. lamblia infected mice showed epithelial microvillus abnormalities, which improved after administration of MC and OL extracts. Results confirm the antiparasitic effect of MC and OL on G. lamblia as an alternative to MTZ, to overcome its resistance and hazards