Antigiardial activity of some plant extracts and fractions from Ghana

Giardiasis, an intestinal parasitic infection is caused by the flagellate unicellular eukaryotic protozoan Giardia lamblia [1]. It affects mainly infants and young people [2, 3]. It was responsible for nearly 90% of intestinal protozoan infections in children and adolescents in Ghana [4]. Metronidazole is used for its treatment [5]) and it has major side effects such as metallic taste, headache and dry mouth. There is increased resistance of G. lamblia to metronidazole [6]. There is need for search new anti-giardial drug. Almost 80% of the world population depends on herbal medicine for their primary healthcare needs and about 25% of the active medicinal compounds used as medications were derived from plants [7]. The crude extracts include ethyl acetate extract of stem bark of Erythrophleum ivorense A. Chev., ethanol leaf and stem extracts of Sargassum vulgare C. Agardh, Ulva fasciata Delile, Albizia glaberrima (Schumach. & Thonn.) Benth, ethyl acetate and petroleum ether fractions of Margaritaria nobilis L. f. and xylopic acid (XA) isolated from aqueous fruits extract of Xylopia ethiopica (Dunal) A. Rich were tested against WB strain of G. lamblia using the method described by Debnath et al. [8]. Extracts of S. vulgare, M. nobilis, U. fasciata, A. glaberrima and E. ivorense, and XA showed activity with IC₅₀ of 65.63, 20.53, 50.30, 14.38, 44.25 and 11.45ug/mL, respectively and the reference compound, metronidazole, had IC₅₀ of 5µM. These indicate that the selected plant extracts and fractions may contain bioactive compounds that have activity against G. lamblia.

Acknowledgements: The authors are grateful to WIPO and Australian government for the fellowship offered to GKD and graduate students and their supervisors of Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana for their kind donation of plant extracts, fractions and compounds.

Keywords: Giardia lamblia, giardiasis, metronidazole, medicinal plants, extracts, fractions.

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