Prota 11(1): Medicinal plants/Plantes médicinales 1
Bull. Misc. Inform. Kew 1894: 21 (1894).
2n = 22, 44
Rauvolfia obscura K.Schum. (1895), Rauvolfia rosea K.Schum. (1895), Rauvolfia cumminsii Stapf (1902).
Origin and geographic distribution
Rauvolfia mannii occurs from Liberia east to Kenya and south to northern Angola and Malawi.
In Côte d’Ivoire and DR Congo dried or fresh pulverized roots in palm wine or water are taken to treat gastro-intestinal disorders, poisoning, jaundice, gonorrhoea or female sterility. The root powder is applied to wounds to improve healing. Root powder, fruit pulp or pulped seeds are rubbed on the head to kill lice and to other parts of the body to kill skin parasites. Bark sap is applied to the eyes to treat epilepsy. In Nigeria the bark in gin is taken as a general tonic. In DR Congo a root decoction is taken to treat fever and diabetes. As a gargle, it is used to treat dental caries. In Kenya the boiled root mixed with fat is rubbed on the body of a person suffering from itch and pimples. In Kenya and DR Congo the roots are used as an arrow poison supplement.
The roots of Rauvolfia mannii contain the indole alkaloids reserpine and ajmaline, whereas ajmalicine (δ-yohimbine), reserpiline, serpentine and alstonine occur as minor components. Vincamajine has been isolated as major component of the leaves. Extracts from the roots are highly toxic. Reserpine is hypotensive, reducing heart beat; it is sedative and tranquilizing. Reserpiline is hypotensive. Ajmalicine is a coronary and peripheral vasodilator.
An extract from the root caused skeletal muscle relaxation in rats following intraperitoneal administration. In another experiment a root extract showed in-vitro antibacterial and anti-amoebic activities against a range of human pathogens, and also antispasmodic activity.
Shrub or small tree up to 8 m tall; bark greenish- to grey-brown, scaly. Leaves in whorls of 3–6, crowded at the top of branches, simple and entire; stipules absent; petiole up to 2.5 cm long; blade ovate to obovate or elliptical, 2.5–28 cm × 0.5–10.5 cm, base cuneate, apex acuminate. Inflorescence a terminal or pseudo-axillary, lax to congested cyme, 3–50-flowered; peduncle up to 6 cm long, glabrous. Flowers bisexual, regular, 5-merous, fragrant; pedicel 1–8 mm long; sepals fused at base, unequal, ovate to narrowly elliptical, 0.5–3 mm long; corolla tube cylindrical, 2.5–10.5 mm long, widening at the insertion of the stamens, green to white or yellowish-white, often with pink or red stripes, glabrous outside, short hairy at base inside, lobes axe-shaped to elliptical or ovate, 1–3.5 mm long, white to pink or red-brown, or yellow; stamens inserted at 2–8 mm above the corolla base, included or exserted; ovary superior, globose to oblong or ovoid, composed of 2 partly fused or free carpels, style 1–6 mm long, pistil head cylindrical with a basal collar and a stigmoid apex. Fruit an obcordate drupe 5–12 mm long, laterally compressed, when only 1 carpel developed ellipsoid or ovoid, red, 1–2-seeded. Seeds ellipsoid, 4–11 mm long, laterally compressed.
Rauvolfia is a pantropical genus of about 60 species, of which 7 occur in continental Africa, 2 in Madagascar, and 1 in Madagascar and Comoros. Rauvolfia mannii can be found flowering and fruiting throughout the year.
Rauvolfia mannii occurs in rainforest, riverine forest and old secondary forest, from sea-level up to 2500 m altitude.
Genetic resources and breeding
Rauvolfia mannii is relatively common in its area of distribution and therefore not likely to be endangered by genetic erosion.
Rauvolfia mannii contains similar pharmacological compounds to those found in other Rauvolfia species, but the quantities are not known. More research is needed to evaluate the possible future of Rauvolfia mannii as a source of pharmacologically important alkaloids. If the alkaloid quantities are low, the species will remain of local importance only.
• Harris, M.J., Stewart, A.F. & Court, W.E., 1968. The assay of Rauwolfia cumminsii by quantitative thin-layer chromatography. (African Rauwolfia species-7). Planta Medica 16(2): 217–223.
• Iwu, M.M. & Court, W.E., 1977. Root alkaloids of Rauwolfia cumminsii Stapf. Planta Medica 32(2): 158–161.
• Neuwinger, H.D., 1996. African ethnobotany: poisons and drugs. Chapman & Hall, London, United Kingdom. 941 pp.
• Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.
• van Dilst, F.J.H. & Leeuwenberg, A.J.M., 1991. Rauvolfia L. in Africa and Madagascar. Series of revisions of Apocynaceae 33. Bulletin du Jardin Botanique Nationale de Belgique 61(1–2): 21–69.
• Adjanohoun, E.J., Ahyi, A.M.R., Aké Assi, L., Baniakina, J., Chibon, P., Cusset, G., Doulou, V., Enzanza, A., Eymé, J., Goudoté, E., Keita, A., Mbemba, C., Mollet, J., Moutsamboté, J.-M., Mpati, J. & Sita, P. (Editors), 1988. Médecine traditionnelle et pharmacopée - Contribution aux études ethnobotaniques et floristiques en République Populaire du Congo. Agence de Coopération Culturelle et Technique, Paris, France. 606 pp.
• Burkill, H.M., 1985. The useful plants of West Tropical Africa. 2nd Edition. Volume 1, Families A–D. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 960 pp.
• Eno, A.E. & Itam, E.H., 2001. Skeletal muscle relaxants in the root extract of Rauvolfia cumminsii. Pharmaceutical Biology 39(4): 268–272.
• Omino, E.A. & Kokwaro, J.O., 1993. Ethnobotany of Apocynaceae species in Kenya. Journal of Ethnopharmacology 40: 167–180.
• Patel, M.B., Poisson, J., Pousset, J.L. & Rowson, J.M., 1965. Vincamajine, the major alkaloid of leaves of Rauwolfia mannii Stapf. Journal of Pharmacy and Pharmacology 17(5): 323–324.
• Ruppert, M., Ma, X.-Y. & Stockigt, J., 2005. Alkaloid biosynthesis in Rauvolfia- cDNA: cloning of major enzymes of the ajmaline pathway. Current Organic Chemistry 9(15): 1431–1444.
• Sandberg, F. & Cronlund, A., 1982. An ethnopharmacological inventory of medicinal and toxic plants from equatorial Africa. Journal of Ethnopharmacology 5: 187–204.
• Timmins, P. & Court, W.E., 1975. Leaf alkaloids of Rauwolfia obscura. Planta Medica 27(2): 105–111.
• Tona, L., Kambu, K., Mesia, K., Cimanga, K., Apers, S., De Bruyne, T., Pieters, L., Totte, J. & Vlietinck, A.J., 1999. Biological screening of traditional preparations from some medicinal plants used as antidiarrhoeal in Kinshasa, Congo. Phytomedicine 6(1): 59–66.
Correct citation of this article:
Schmelzer, G.H., 2007. Rauvolfia mannii Stapf. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(1): Medicinal plants/Plantes médicinales 1. [CD-Rom]. PROTA, Wageningen, Netherlands.
leafy branch with infructescences