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Prota 11(1): Medicinal plants/Plantes médicinales 1 Record display |
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Protologue Linnaea 27: 344 (1843). Family Euphorbiaceae Chromosome number 2n = 20 Origin and geographic distribution Euphorbia schimperiana occurs in Cameroon and from Eritrea south through East Africa, Rwanda, Burundi and eastern DR Congo to Zimbabwe and Mozambique. It also occurs in Madagascar and Rodrigues (Mauritius), and on the Arabian Peninsula. Uses In Rwanda the latex is used as ear drops to treat otitis. Leaf powder is applied to impetigo and stubborn skin infections. In Ethiopia an infusion of the aerial parts is taken as a purgative, to treat venereal diseases and as an anthelmintic. The fruits, crushed together with roots of Cyathula polycephala Baker, and mixed with water are taken to treat anthrax in cattle. In Kenya and Tanzania leaf paste in water is taken to treat coughs and colds. In Tanzania a leaf and root decoction is taken as a purgative. The latex is applied externally to treat snakebites. In Kenya the plants are grazed by all domestic animals. Properties The methanol extract of dry stems showed strong molluscicidal activity (LD50 = 5.7 ppm) against Biomphalaria pfeifferi, a vector of schistosomiasis. This activity was associated with terpenoids and phenolics. The effects of the extract on various snail tissues (gut, digestive gland and epidermal layer) were time and concentration dependent, and the results show that the epithelium layer is probably the primary site affected. The toxic and mutagenic activities of the methanol extract of the stems were investigated in mice, and showed slight toxicity to the skin and moderately irritant activity to the ocular tissue. The extract significantly increased the frequency of micronuclei division, especially at high concentrations, indicating that it has mutagenic activity. Botany Monoecious, much-branched, annual or short-lived perennial herb up to 2 m tall, glabrous or with long, crisped hairs on the stem below the leaves or on the fruit; stems with conspicuous leaf scars, with latex. Leaves alternate, simple and entire, sessile, crowded; stipules absent; blade ovate-lanceolate to lanceolate, up to 15 cm × 2 cm, base cuneate, apex with short point, midvein winged on lower surface. Inflorescence an axillary or terminal cyme consisting of clusters of flowers, each cluster called a ‘cyathium’, in 3–15-branched umbels; branches up to 15 cm long; bracts sessile, deltoid, 1–4 cm long, long-acuminate; cyathia with peduncle up to 3 mm long, c. 2 mm × 2 mm, with a cup-shaped involucre, lobes quadrangular, c. 0.5 mm long, shallowly 2-lobed, hairy at margin; glands 4, transversely elliptical, c. 1 mm × 1.5–2 mm, 2-horned, horns up to 1.5 mm long, green turning brownish red, each involucre containing 1 female flower surrounded by many male flowers. Flowers unisexual; male flowers sessile, bracteoles linear, fringed, perianth absent, stamen c. 4.5 mm long; female flowers with pedicel up to 5.5 mm long, ovary superior, glabrous or hairy, 3-celled, styles 3, up to 2.5 mm long, fused at base, apex 2-fid, spreading. Fruit a deeply 3-lobed capsule c. 4 mm × 4.5 mm, base truncate, 3-seeded. Seeds oblong, slightly compressed, 2–2.5 mm × 1.5–2 mm, smooth, shiny black becoming grey; caruncle 0.5 mm in diameter, wrinkled, yellowish. Euphorbia comprises about 2000 species and has a worldwide distribution, with at least 750 species occurring in continental Africa and about 150 in Madagascar and the Indian Ocean islands. Euphorbia schimperiana belongs to section Esula, a group of annual or perennial herbs characterized by the absence of stipules, cyathia in terminal umbel-like cymes, leafy or deltoid bracts, 4 involucral glands, entire or with 2 horns, fruits exserted on reflexed pedicel and seeds with a caruncle. In Euphorbia schimperiana 3 varieties have been recognized: var. schimperiana, which is completely glabrous, var. pubescens (N.E.Br.) S.Carter, with short-hairy stem below the leaves and var. velutina N.E.Br. with hairy fruits. Euphorbia depauperata Hochst. ex A.Rich. is a variable perennial herb which also belongs to section Esula and which occurs in West, East and southern Africa. In Ethiopia a leaf or root infusion is taken as an anthelmintic and purgative. In Kenya the plant is grazed by all domestic animals. Ecology Euphorbia schimperiana occurs in grassland, evergreen bushland and montane forest, at 1350–3000 m altitude. It is also a weed in cultivation. Genetic resources and breeding Euphorbia schimperiana is a widespread and variable species with a tendency to form distinctive local variants. Prospects Euphorbia schimperiana is promising as a molluscicide, but more research is needed to identify the chemical compounds responsible for this activity. Major references • Burkill, H.M., 1994. The useful plants of West Tropical Africa. 2nd Edition. Volume 2, Families E–I. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 636 pp. • Carter, S. & Radcliffe-Smith, A., 1988. Euphorbiaceae (part 2). In: Polhill, R.M. (Editor). Flora of Tropical East Africa. A.A. Balkema, Rotterdam, Netherlands. pp. 409–597. • Ekram, S.A. & Najia, A.A., 2006. Mammal toxicity and mutagenicity assessment of the methanol extract of the molluscicidal plant Euphorbia schimperiana. Pakistan Journal of Biological Sciences 9(10): 1911–1916. • Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp. Other references • Al Zanbagi, N.A., Banaja, A.E.A. & Barrett, J., 2000. Molluscicidal activity of some Saudi Arabian Euphorbiales against the snail Biomphalaria pfeifferi. Journal of Ethnopharmacology 70(2): 119–125. • Al Zanbagi, N.A., Banaja, A.E.A. & Barrett, J., 2002. The histopathology of Euphorbia schimperiana methanol extract on the gut, digestive gland and epidermal layer of Biomphalaria pfeifferi. Journal of the Medical Research Institute - Alexandria University 23(2): 25–35. • Al Zanbagi, N.A, Barrett, J. & Banaja, A.E.A., 2000. On the use of plant-derived compounds (terpenoids and phenolics) from Euphorbia schimperiana as a molluscicidal agent for the control of schistosomiasis. Journal of the Medical Research Institute - Alexandria University 21(4): 73–78. • Jansen, P.C.M., 1981. Spices, condiments and medicinal plants in Ethiopia, their taxonomy and agricultural significance. Agricultural Research Reports 906. Centre for Agricultural Publishing and Documentation, Wageningen, Netherlands. 327 pp. • Yineger, H., Kelbessa, E., Bekele, T. & Lulekal, E., 2007. Ethnoveterinary medicinal plants at Bale Mountains national park, Ethiopia. Journal of Ethnopharmacology 112: 55–70. Author(s)
Editors
Correct citation of this article: Schmelzer, G.H., 2008. Euphorbia schimperiana Scheele. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(1): Medicinal plants/Plantes médicinales 1. [CD-Rom]. PROTA, Wageningen, Netherlands. |