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Prota 11(1): Medicinal plants/Plantes mιdicinales 1 Record display |
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Protologue Engl., Pflanzenr. IV, 147, 7: 245 (1914). Family Euphorbiaceae Chromosome number 2n = 18 Origin and geographic distribution Alchornea laxiflora occurs from Nigeria east to Ethiopia and south to DR Congo and through East Africa to Zimbabwe, Mozambique, north-eastern South Africa and Swaziland. Uses In Nigeria a decoction of the leaves is taken to treat inflammatory and infectious diseases. It is also a common ingredient in herbal antimalarial preparations. In Tanzania the ground leaves are taken in water to treat hernia. The leaf sap and root decoction are drunk to treat pain in neck and shoulders. The ash of the stem pith is applied to a stiff neck. In Nigeria the leaves are used as packing and preservation material for kola nuts. Small branches are used as chew sticks. Straight stems are used as fence poles. Properties Preliminary phytochemical screening revealed the presence of alkaloids, cardiac glycosides, saponins and phenolic compounds in the roots, and in lower amounts, in the leaves. From the ethyl acetate soluble fraction of the crude methanolic leaf extract the flavonoids quercetin and the quercetin-related compounds rutin and quercitrin were isolated. These compounds showed significant antimicrobial activity against several gram-positive and gram-negative bacteria and fungi. The anti-oxidant activity of the root and leaf extracts have been compared with that of the standard anti-oxidant butylated hydroxyanisole. The crude hexane and methanol extracts of Alchornea laxiflora showed 6575% activity for root extracts, and ca. 40% activity for leaf extracts in comparison to the standard anti-oxidant compound. Botany Deciduous, erect to straggling shrub or small tree up to 7(10) m tall, monoecious with male and female inflorescences on separate branches; bark smooth, pale grey, flaking; young shoots shortly hairy to almost glabrous. Leaves alternate, simple; stipules linear, 28 mm long; petiole 17(9) cm long, thickened at both ends with 2 filiform, 13 mm long stipels at top; blade elliptical-lanceolate to oblong-oblanceolate, 518 cm Χ 38 cm, base rounded or cuneate, apex acuminate, margins shallowly toothed, glandular at base, sparingly shortly hairy on the veins, base 3-veined, reddish when young. Male inflorescence an axillary spike or raceme up to 12 cm long, developing on older twigs just before new leaf flush, bracts ovate, 1.55 mm long; female inflorescence a terminal, lax spike up to 10 cm long, few-flowered, bracts ovate-lanceolate, 23 mm long, glandular at base. Flowers unisexual, sessile; male flowers with 24(5), almost round to ovate, reflexed, yellowish green or white sepals, petals absent, stamens 89, filaments united into a basal plate; female flowers with 56, almost round to ovate, acute, unequal, slightly toothed sepals, petals absent, ovary superior, almost globose, c. 1 mm Χ 1.5 mm, scarcely 3-lobed, smooth, shortly hairy, styles (2)3, up to 1.5 cm long, united at base, red. Fruit a 3-lobed capsule 57 mm Χ 78 mm, smooth, dark green, brown or black, slightly shortly hairy, 3-seeded. Seeds ovoid to almost globose, c. 4 mm Χ 3 mm, smooth or slightly rough, slightly shiny, pale brown or greyish. Alchornea is pantropical and comprises about 50 species, of which 6 occur in tropical Africa. Ecology Alchornea laxiflora occurs in evergreen forest and associated bushland, in riverine thickets, from sea-level up to 1600 m altitude. Genetic resources and breeding Alchornea laxiflora is locally common throughout its wide distribution area, and is probably not threatened by genetic erosion. Prospects Alchornea laxiflora has interesting antibacterial and pain-suppressing activities, which merit further research. The antioxidant activities of the leaves are interesting as well, and more research is needed to elucidate the effectiveness under different conditions. Major references Farombi, E.O., Ogundipe, O.O., Uhunwangho, E.S., Adeyanju, M.A. & Moody, J.O., 2003. Antioxidant properties of extracts from Alchornea laxiflora (Benth) Pax and Hoffman. Phytotherapy Research 17(7): 713716. Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp. Ogundipe, O.O., Moody, J.O., Houghton, P.J. & Odelola, H.A., 2001. Bioactive chemical constituents from Alchornea laxiflora (Benth.) Pax and Hoffman. Journal of Ethnopharmacology 74(3): 275280. Radcliffe-Smith, A., 1996. Euphorbiaceae, subfamilies Phyllantoideae, Oldfieldioideae, Acalyphoideae, Crotonoideae and Euphorbioideae, tribe Hippomaneae. In: Pope, G.V. (Editor). Flora Zambesiaca. Volume 9, part 4. Royal Botanic Gardens, Kew, Richmond, United Kingdom. pp. 1337. Other references Burkill, H.M., 1994. The useful plants of West Tropical Africa. 2nd Edition. Volume 2, Families EI. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 636 pp. Kokwaro, J.O., 1993. Medicinal plants of East Africa. 2nd Edition. Kenya Literature Bureau, Nairobi, Kenya. 401 pp. Ogundipe, O.O., Moody, J.O., Houghton, P.J. & Odelola, H.A., 2001. Bioactive chemical constituents from Alchornea laxiflora (Benth.) Pax and Hoffman. Journal of Ethnopharmacology 74(3): 275280. Radcliffe-Smith, A., 1987. Euphorbiaceae (part 1). In: Polhill, R.M. (Editor). Flora of Tropical East Africa. A.A. Balkema, Rotterdam, Netherlands. 407 pp. Author(s)
Editors
Correct citation of this article: Schmelzer, G.H., 2007. Alchornea laxiflora (Benth.) Pax & K.Hoffm. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(1): Medicinal plants/Plantes mιdicinales 1. [CD-Rom]. PROTA, Wageningen, Netherlands. |