title: Screening of some medicinal plants of Ethiopia for their anti-microbial properties and chemical profiles.
abstract: In the indigenous health care delivery system of Ethiopia, numerous plant species are used to treat diseases of infectious origin. Regardless of the number of species, if any of such claims could be verified scientifically, the potential significance for the improvement of the health care services would be substantial. The objective of this study was, therefore, to determine the presence of anti-microbial activity in the crude extracts of some of the commonly used medicinal plants as well as to identify the class of compounds in the plants that were subjected to such screening. Thus, the crude methanol, petroleum ether and aqueous extracts of 67 plant species were subjected to preliminary screening against 10 strains of bacterial species and 6 fungal strains using the agar dilution method. A sample concentration of 250-2000 microg/ml and 500-4000 microg/ml were used for the bacterial and fungal pathogens, respectively. The results indicated that 44 different plant species exhibited activity against one or more of the bacteria while one species, viz., Albizzia gummifera showed activity against all the 10 bacteria at different gradient of dilution. Twenty three species inhibited or retarded growth of one or more organisms at dilution as low as 250 microg/ml. Extracts of same plants species were also tested against six different fungal pathogenic agents of which eight species showed growth inhibition against one or more of the organisms. Trichila emetica and Dovyalis abyssinica, which inhibited growth of four and five fungal strains at 100 microg/ml concentration, respectively, were the most promising plants. Chemical screening conducted on the extracts of all the plants showed the presence of several secondary metabolites, mainly, polyphenols, alkaloids, tannins sterols/terpenes, saponins and glycosides. The plants containing more of these metabolites demonstrated stronger anti-microbial properties stressing the need for further investigations using fractionated extracts and purified chemical components.
authors.affiliation: Ethiopian Health and Nutrition Research Institute, P.O. Box 1242/5654, Addis Ababa, Ethiopia. aberraage@telecom.net.et
authors.forename: Aberra
authors.initials: A
authors.lastname: Geyid
authors.forename: Dawit
authors.initials: D
authors.lastname: Abebe
authors.forename: Asfaw
authors.initials: A
authors.lastname: Debella
authors.forename: Zewdneh
authors.initials: Z
authors.lastname: Makonnen
authors.forename: Frehiwot
authors.initials: F
authors.lastname: Aberra
authors.forename: Frehiwot
authors.initials: F
authors.lastname: Teka
authors.forename: Tesfaye
authors.initials: T
authors.lastname: Kebede
authors.forename: Kelbessa
authors.initials: K
authors.lastname: Urga
authors.forename: Kidist
authors.initials: K
authors.lastname: Yersaw
authors.forename: Teklele
authors.initials: T
authors.lastname: Biza
authors.forename: Bisrat Haile
authors.initials: BH
authors.lastname: Mariam
authors.forename: Mulugeta
authors.initials: M
authors.lastname: Guta
mesh_terms: D000890:Anti-Infective Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001231:Aspergillus flavus / Q000187:drug effects / Q000502:physiology; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D005002:Ethiopia; D008826:Microbial Sensitivity Tests / Q000379:methods; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D018514:Plant Structures; D010946:Plants, Medicinal; D013211:Staphylococcus aureus / Q000187:drug effects / Q000502:physiology
chemical_list: D000890:Anti-Infective Agents; D010936:Plant Extracts