Prota 11(1): Medicinal plants/Plantes mιdicinales 1
Feddes Repert. 53: 37 (1944).
Origin and geographic distribution
Bulbine capitata is native to Namibia, Botswana, Zimbabwe, Swaziland, Lesotho and South Africa.
In Botswana a root decoction of Bulbine capitata is applied to the skin to cure rashes and sexually transmitted diseases. In Lesotho it is taken orally as a mild purgative and to cure gonorrhoea.
Production and international trade
In local markets in Botswana both roots and leaves of Bulbine capitata are sold for medicinal use.
Anthraquinones, phenylanthraquinones and isofuranonaphthoquinones have been isolated from the roots and leaves of Bulbine capitata. Several isofuranonaphthoquinones from the roots showed antioxidant activity in a human lipoprotein oxidation assay, some of them with activity comparable to that of quercetin, a flavonoid with established antioxidant activity. These compounds also demonstrated weak antiplasmodial activities in vitro. Bulbine capitata is said to have antibiotic and antipyretic properties, but these remain unsubstantiated.
Tufted, perennial herb up to 45 cm tall, with rhizome up to 5 cm Χ 1 cm. Leaves in a basal rosette, simple, erect to arching, without stipules and petiole, up to 25 cm Χ 2 mm, fleshy, at base extending into a tubular sheath, old leaf bases persistent. Inflorescence a terminal, densely flowered raceme 215 cm long; peduncle up to 25 cm long; bracts ovate, 210 mm long, auricled, persistent. Flowers bisexual, regular, 3-merous; pedicel up to 20 mm long at flowering, 35 mm in fruit; tepals 6, oblong-ovate, c. 7 mm Χ 3 mm, 1-veined, yellow; stamens 6, c. 6 mm long, densely bearded in upper third; ovary superior, 3-celled, style terete, stigma head-shaped. Fruit an ovoid capsule c. 7 mm long, dehiscing loculicidally, brown to black, many-seeded. Seeds pyramidal, 23 mm long, brownish black.
Bulbine comprises about 60 species, most of them restricted to southern Africa. Bulbine narcissifolia Salm-Dyck, a native of Botswana, South Africa and Lesotho, has several medicinal uses in South Africa. The fresh leaf sap is applied to wounds to promote healing, as a wart and corn remedy, and to cure ringworm and rash. A cold infusion of the leaves is used as a purgative. A decoction of the roots is taken to relieve rheumatic pain and to induce pregnancy. In southern Africa Bulbine capitata flowers in spring.
Bulbine capitata grows in scattered clumps in open grassland and thorn scrub on sandy soil and on rocky hillsides at about 1000 m altitude.
Bulbine capitata is only harvested from the wild.
Genetic resources and breeding
There are no reports on threats to Bulbine capitata and harvesting of rhizomes is probably sustainable. Once demand for rhizomes increases the wild populations may need protection.
The chemistry of Bulbine capitata has been the subject of in-depth studies. The potential of the isolated isofuranonaphthoquinones in the development of antimalarial drugs, as well as in the development of coronary artery disease, in which the oxidation of lipoproteins is thought to play a critical role, deserves more research attention.
Abegaz, B.M., Ngadjui, B.T., Bezabih, M. & Mdee, L.K., 1999. Novel natural products from marketed plants of eastern and southern Africa. Pure and Applied Chemistry 71(6): 919926.
Bezabih, M., Abegaz, B.M., Dufall, K., Croft, K., Skinner-Adams, T. & Davis, T.M.E., 2001. Antiplasmodial and anti-oxidant isofuranonaphthoquinones from the roots of Bulbine capitata. Planta Medica 67: 340344.
Bezabih, M., Motlhagodi, S. & Abegaz, B.M., 1997. Isofuranonaphthoquinones and phenolic and knipholone derivatives from the roots of Bulbine capitata. Phytochemistry 46(6): 10631067.
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Bezabih, M. & Abegaz, B.M., 1998. 4-Demethylknipholone from aerial parts of Bulbine capitata. Phytochemistry 48(6): 10711073.
Bringmann, G., Menche, D., Bezabih, M.-T., Abegaz, B.M. & Kaminsky, R., 1999. Antiplasmodial activity of knipholone and related natural phenylanthraquinones. Planta Medica 65(8): 757758.
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Correct citation of this article:
Bosch, C.H., 2006. Bulbine capitata Poelln. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(1): Medicinal plants/Plantes mιdicinales 1. [CD-Rom]. PROTA, Wageningen, Netherlands.