title: Antioxidant and 15-lipoxygenase inhibitory activities of the Malian medicinal plants Diospyros abyssinica (Hiern) F. White (Ebenaceae), Lannea velutina A. Rich (Anacardiaceae) and Crossopteryx febrifuga (Afzel) Benth. (Rubiaceae).
abstract: The African flora contains numerous medicinal plants whose biological and chemical properties are incompletely known. Antioxidant and radical scavenging properties of plants are subject to intensive research. In the work described here, we have investigated the antioxidant activity of the plants Diospyros abyssinica (root bark), Lannea velutina (root bark and stem bark) and Crossopteryx febrifuga (seeds). Extracts of different polarity were assayed for radical scavenging activity, using the stable free radical diphenylpicrylhydrazyl, and for inhibition of enzymatic lipid peroxidation mediated by soybean 15-lipoxygenase. All plants investigated showed activity, but there were large differences between plants and between extracts. In general, Diospyros abyssinica and Lannea velutina were richer in antioxidants than Crossopteryx febrifuga. Lipophilic extracts were not active as radical scavengers, but did inhibit 15-lipoxygenase. Semipolar extracts (80% aqueous ethanol and methanol) of Diospyros abyssinica and Lannea velutina showed the highest activity both as radical scavengers and lipoxygenase inhibitors, and also gave the highest extract yields. These plants therefore appear to be excellent sources of antioxidants.
authors.affiliation: Department of Traditional Medicine, Bamako, Mali; Department of Pharmacognosy, Institute of Pharmacy, University of Oslo, P.O. Box 1068 Blindern, N-0316 Oslo, Norway.
authors.forename: Ababacar
authors.initials: A
authors.lastname: Maiga
authors.forename: Karl Egil
authors.initials: KE
authors.lastname: Malterud
authors.forename: Drissa
authors.initials: D
authors.lastname: Diallo
authors.forename: Berit Smestad
authors.initials: BS
authors.lastname: Paulsen
mesh_terms: D027926:Anacardiaceae; D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D001093:Arachidonate 15-Lipoxygenase / Q000378:metabolism; D029788:Diospyros; D004305:Dose-Response Relationship, Drug; D031262:Ebenaceae; D004791:Enzyme Inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000302:isolation & purification / Q000494:pharmacology; D016859:Lipoxygenase Inhibitors; D008302:Mali; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology; D018517:Plant Roots; D018547:Plant Stems; D010946:Plants, Medicinal; D019666:Rubiaceae
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D016859:Lipoxygenase Inhibitors; D010936:Plant Extracts; D001093:Arachidonate 15-Lipoxygenase