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Rauvolfia vomitoria Afzel.

Protologue
Stirp. Guinea med.: 1 (1817).
Family
Apocynaceae
Chromosome number
2n = 22, 66
Vernacular names
Poison devil’s pepper, African snakeroot, African serpent wood, swizzle stick (En). Berenquete (Po).
Origin and geographic distribution
Rauvolfia vomitoria occurs from Senegal east to Uganda and Tanzania and south to DR Congo and Angola. It is cultivated in many parts of the tropics and subtropics.
Uses
In the entire distribution area of Rauvolfia vomitoria a root decoction, root macerate or powdered root in water is taken to treat diarrhoea, rheumatism, jaundice, venereal diseases and snakebites. Root products are also widely taken to treat hypertension, and as a sedative to calm people with epilepsy, and people who are psychotic or mentally ill; they are also used to wash children with colic or fever. Externally, macerated or powdered root or sometimes pulped fruit are applied to a range of skin problems, such as rash, pimples, chicken pox, wounds, scabies, psoriasis, leprosy, haemorrhoids, head lice and parasitic skin diseases. A root decoction is used as a mouth wash against gingivitis or thrush. The stem bark or leaves are also used for these purposes, but to a lesser extent. The stem bark, leaf decoction and latex of young twigs are widely used as purgative or emetic.
In Guinea the root maceration is applied to tumours. In Liberia a bark infusion is taken to cure fever. A leaf infusion is rubbed in against yaws. Dried or fresh pulverized roots in palm wine or oil are taken to treat female sterility. A root decoction is used in massages and baths to treat rheumatism, tiredness and rachitis. In Togo pulverized root bark in brandy is taken to treat tuberculosis. In Cameroon a decoction of powdered roots is taken to treat diabetes and malaria. In the Central African Republic a root decoction is taken to treat hernia. In Côte d’Ivoire leaf sap is rubbed between the toes to treat infections caused by humidity. A leaf maceration is used for bathing children with fever. In Gabon chopped and boiled leaves mixed with fat are applied to the skin to cure rheumatism and sprains. A mixture of pulverized root or leaf sap with plant oil or lemon juice is applied to the hair to stop hair loss. In Nigeria the root and leaves in decoction are taken to treat indigestion, as a tonic, and as abortifacient. In Equatorial Guinea the latex is used for cicatrization of wounds.
In the Central African Republic the roots of Rauvolfia vomitoria, alone or together with seeds of Strophanthus gratus (Wall. & Hook.) Franch., are pounded to a paste, which serves as arrow poison. In DR Congo the roots are a common additive to Periploca nigrescens Afzel. hunting poison. In Equatorial Guinea the root scrapings are mixed with cassava meal and put in bait as a rat poison. In West Africa the root is considered aphrodisiac when taken in palm wine.
Rauvolfia vomitoria is widely planted as an ornamental in West Africa, as a shade tree for cacao and coffee and as a support for vanilla. It is also grown as a live fence. The young twigs with a whorl of branches at the end are used as mixers for drinks. Larger branches are similarly used to stir the indigo mixture in dyeing pits. The wood is of little economic importance, although the heartwood is fairly hard; small kitchen utensils are made from it, and it is used as a substitute for boxwood. It is also used as firewood. A yellow dye is produced from the bark.
Production and international trade
In the 1970s the stem bark and root bark of Rauvolfia vomitoria were collected from West and Central Africa, and nearly 200 t of reserpine were sold in total, mainly in tablet form for use in human medicines. Reserpine was also widely added as a sedative to animal feed. Nowadays, reserpine is still widely sold through the internet, mainly in India and the United States.
Properties
Rauvolfia vomitoria contains a large number of indole alkaloids, between 40 and 80. Most occur in very small amounts and several are disputed. Most alkaloids occur in an unstable complex, and seasonal variation is present as well. Leaves contain 0.03–0.8% total alkaloids, stem bark about 0.6%, roots 0.15–0.2% and root bark 1.5–2%.
The alkaloids of Rauvolfia vomitoria can be grouped into 5 main types: (1) yohimbine and derivatives, including reserpine and deserpidine (11-demethoxyreserpine); (2) the heteroyohimbine type, including ajmalicine (raubasine), reserpinine (rescinnamine) and reserpiline; (3) sarpagane derivatives, including sarpagine (raupine); (4) the dihydro-indole type, including ajmaline; (5) the anhydronium bases, including alstonine, serpentine and serpenticine. Other groups include the oxindoles and pseudoindoxyls. Serpentinine is the only dimeric yohimbin-related alkaloid isolated so far.
In the root bark reserpiline is the major component, followed by reserpine, reserpinine and ajmaline. In the stem bark reserpiline is also the major component, with small amounts of isoreserpiline and yohimbine. The leaves were found to contain mainly geissoschizol, but no reserpine, reserpinine or ajmaline. The alkaloids in the leaves comprised about 41% heteroyohimbines and 52% oxindoles. The unripe fruit contains several alkaloids, but they are absent in the ripe fruits.
Of the Rauvolfia alkaloids, 5 are used in medicine: reserpine, reserpinine, deserpidine, ajmalicine and ajmaline. There are several patented methods for the extraction of the main component reserpine. Furthermore, several simple and accurate methods have been developed to identify Rauvolfia alkaloids, e.g. reserpine, serpentine and ajmaline.
Reserpine is a well-known antihypertensive, antipsychotic and sedative. It is a sympatholytic agent acting indirectly on the peripheral and central nerve terminals. It impairs the storage of biogenic amines resulting in depletion of norepinephrine, dopamine, and serotonin. Depletion of norepinephrine induces a lasting drop in blood pressure. Contra-indications for using reserpine are depression, peptic ulcer, and hypersensitivity to the alkaloid. Side effects of the medication include drowsiness, nasal congestion, salivary and gastric hypersecretion, paradoxical anxiety, depression and retention of water and Na+. Overdose may cause respiratory depression, slowed heartbeat, hypotension, confusion, tremors, convulsions and gastro-intestinal distress. Reserpine has been shown to enhance the hypoglycaemic effect of insulin and the hyperglycaemic effect of adrenalin, and has inhibited the physiological hyperglycaemic response in diabetic patients. Because of the necessary high doses and the resulting dangerous side effects, reserpine lost its importance as a medicine. It is only used in low doses for mild to moderately severe high blood pressure, often together with ajmalicine. Reserpinine and deserpidine are reserpine analogues. Both alkaloids have the same effects as reserpine, and can be used to treat the same conditions, while their side effects are reported to be less pronounced. Reserpiline is marked sympatholytic and hypotensive with no noticeable depressant effects on the central nervous system and no sedative properties. It also lacks most of the side effects of reserpine and its analogues. Ajmalicine is an α-adrenergic blocking spasmolytic which, at high doses, moderates the activity of the vasomotor centres, especially in the brain stem causing an increase of the blood flow to the brain. It is mainly used in products that treat the psychological and behavioural problems associated with senility, stroke and head injuries. Ajmaline is an anti-arrhythmic, which substantially decreases the rate of depolarization of atrial and ventricular cells. Its toxicity has limited its uses and it is mainly prescribed against rapid irregular cardiac beat. Because of its toxicity it is no longer marketed in several countries. Several other Rauvolfia alkaloids have hypotensive or sedative activities, but most are less effective.
An ethanolic leaf extract of Rauvolfia vomitoria showed a reduction in blood sugar levels of normal and alloxan-induced diabetic rabbits, comparable to that of tolbutamide. A root decoction did not have any adverse effect on the oestrous cycle, fertilization or implantation, and did not show foetotoxicity or hormone-induced infertility in a laboratory test with rats. A root bark extract showed antibacterial activity in vitro against several human pathogens.
The wood is white, reddening with age; the heartwood is fairly hard.
Adulterations and substitutes
The Indian Rauvolfia serpentina (L.) Benth. ex Kurz was formerly the main source of reserpine, but has been replaced to a large extent by Rauvolfia vomitoria. The roots of Catharanthus roseus (L.) G.Don are the main source of ajmalicine for the pharmaceutical industry.
Description
Shrub or medium-sized tree up to 20(–40) m tall; bole up to 80 cm in diameter; bark pale to dark grey-brown or dark brown, smooth or fissured. Leaves in whorls of 3–5, crowded at the top of branches, simple and entire; stipules absent; petiole 0.5–3.5 cm long; blade elliptical to narrowly elliptical, 2.5–27 cm × 2–9 cm, base cuneate, apex acuminate, glabrous. Inflorescence a lax to congested cyme in terminal whorls of 1–4, 15–450-flowered; peduncle 1.5–8.5 cm long, shortly hairy. Flowers bisexual, regular, 5-merous, fragrant; pedicel 1–4.5 mm long; sepals fused at base, unequal, ovate, 1–2 mm long; corolla tube cylindrical, 6–10(–12) mm long, constricted below the insertion of the stamens, slightly narrowed at the mouth, glabrous outside with 3 hairy belts inside, greenish, lobes axe-shaped, 1–2 mm long, white, yellow or creamy; stamens inserted at 4.5–7 mm above the corolla base, included; ovary superior, globose to oblong or ovoid, composed of 2 partly fused carpels, usually only 1 developing into fruit, style 2.5–5 mm long, pistil head cylindrical with a basal collar and a stigmoid apex. Fruit a globose to ovoid or ellipsoid drupe 8–14 mm long, orange or red, 1-seeded. Seed ellipsoid, 6–8 mm long, laterally compressed.
Other botanical information
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 vomitoria has flowers of 2 different shapes: slender, small flowers and robust flowers. The slender flowers occur, as far as verified, on diploid plants, while the robust flowers occur on hexaploid plants. Both flower types occur throughout the area of distribution, although the large-flowered type is not known from East Africa. The root bark of diploid plants contains less reserpine than that of hexaploids.
Rauvolfia serpentina was introduced from India into West Africa. In Nigeria a root infusion is taken to treat snakebites. The root has been used in Ayurvedic medicine in India since ancient times to treat snakebites, mental diseases and epilepsy, and is still important in local medicine and in alkaloid production.
Growth and development
Rauvolfia vomitoria can be found flowering and fruiting almost throughout the year, but sometimes not and usually less abundantly during the rainy season.
Ramification in Rauvolfia is determined by the leaves in whorls; branches terminate in 2–5 branchlets or inflorescences developing in the axils of the leaves. This results in an umbellate ramification and a candelabra-shaped habit. The flowers are pollinated by insects such as small bees and flies, and the fruits are dispersed by birds.
Ecology
Rauvolfia vomitoria occurs in bush vegetation, gallery forest, secondary vegetation where fallow periods are long, and along roadsides, from sea-level up to 1600 m altitude.
Propagation and planting
Rauvolfia vomitoria is usually propagated by seed, although stem and root cuttings can also be used. Wild seedlings can be successfully transplanted and cultivated. For sowing, fruits are collected when ripe and dried. The seeds lose their viability quickly, and need to be sown within 6 months after ripening. In Ghana tests with vegetative propagation of root and shoot cuttings in vitro have been moderately successful.
Management
Rauvolfia vomitoria can be coppiced or pollarded.
Diseases and pests
Rauvolfia vomitoria is a host of the pathogen causing collar crack of cacao.
Harvesting
Roots may be harvested annually in a non-destructive way by cutting them 10 cm from the taproot. All plant parts are harvested whenever the need arises. In Ghana dry season samples were found to contain a higher content of alkaloids than wet season samples.
Handling after harvest
The stem bark or roots of Rauvolfia vomitoria can be used fresh or dried and powdered for later use.
Genetic resources
Rauvolfia vomitoria is widely distributed throughout its distribution area, but it is possibly endangered in several countries, e.g. in Ghana, due to overharvesting.
Prospects
The use of reserpine has declined significantly in recent decades in Western countries because of its strong side effects and the availability of more effective alternatives. In developing countries, products based on Rauvolfia are still in demand owing to their easy availability and comparatively low prices, but it is expected that they will gradually be replaced by safer alternatives. Continued research might reveal new possibilities for reserpine and related compounds.
Major references
• 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.
• Iwu, M.M., 1993. Handbook of African medicinal plants. CRC Press, Boca Raton, Florida, United States. 464 pp.
• 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.
• Oduro, A.C., 2000. Survey of tree species associated with cocoa cultivation in Osino District of Ghana and vegetative propagation of three of them. M.Phil. Crop Science degree thesis, Department of Crop Science, School of Agriculture, University of Cape Coast, Cape Coast, Ghana. 121 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.
Other references
• 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.
• Aké Assi, L., Abeye, J., Guinko, S., Riguet, R. & Bangavou, X., 1985. Médecine traditionnelle et pharmacopée - Contribution aux études ethnobotaniques et floristiques en République Centrafricaine. Agence de Coopération Culturelle et Technique, Paris, France. 140 pp.
• Bedu-Addo, K., 1993. Effect of the crude extract of the root of Rauwolfia vomitoria on the reproduction of female albino rats (Rattus norvegicus). M.Phil. degree thesis, Department of Biological Sciences, Faculty of Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana. 100 pp.
• Bruneton, J., 1999. Pharmacognosy, phytochemistry, medicinal plants. Second Edition. Technique & Documentation Lavoisier, Paris, France. 1119 pp.
• Burkill, H.M., 2000. The useful plants of West Tropical Africa. 2nd Edition. Volume 5, Families S–Z, Addenda. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 686 pp.
• Dasi, K.A., 2004. Chromatographic (TLC) analysis of alkaloids of Rauvolfia vomitoria. B.Pharm. degree thesis, Department of Pharmaceutical Chemistry, Faculty of Pharmacy, K.N.U.S.T., Kumasi, Ghana. 57 pp.
• Duez, P., Chamart, S., Lejoly, J., Hanocq, M., Zeba, B., Sawadogo, M., Guissou, P. & Molle, L., 1986. A study of the natural sites and cultural conditions of Rauwolfia vomitoria Afz. in Burkina Faso in relation to alkaloid content. Tropicultura 4(3): 100–108.
• Duez, P., Chamart, S., Lejoly, J., Hanocq, M., Zeba, B., Sawadogo, M. & Guissou, P., 1987. Potentialitées d’utilisation rationnelle du Rauvolfia vomitoria en médecine traditionnelle. Médecine Traditionnelle et Pharmacopée 1(1): 29–46.
• Kalanda, K., Ataholo, M. & Ilumbe, B., 1995. Contribution à la connaissance des plantes médicinales du Haut-Zaïre: plantes antihémorroïdaires de Kisangani. Revue de Médecines et Pharmacopées Africaines 9(1): 51–58.
• Latham, P., 2004. Useful plants of Bas-Congo province, Democratic Republic of the Congo. DFID, London, United Kingdom. 320 pp.
• Muanza, D.N., Dangala, N.L. & Mpay, O., 1993. Zairean medicinal plants as diarrhea remedies and their antibacterial activities. African Study Monographs 14(1): 53–63.
• Nkongmeneck, B.A., Tsabang, N., Zapfack, L., Nzooh Dongmo, Z., Nguenang, G.M., Lando, G., Carlson, T.J. & Keita, A., 2000. Voies de recours thérapeutiques du diabète et plantes utilisées par les diabétiques au Cameroun: cas de Yaoundé et ses environs. Revue de Médecines et Pharmacopées Africaines 14: 89–98.
• Nwodo, N.J, Okide, G.B, Okonta, J.M. & Ebebe, I.M., 2003. Antidiabetic effect of Rauwolfia vomitoria ethanolic leaf extract in rabbits. Journal of Tropical Medicinal Plants 4(1): 71–74.
• Terashima, H. & Ichikawa, M., 2003. A comparative ethnobotany of the Mbuti and Efe hunter-gatherers in the Ituri forest, Democratic Republic of Congo. African Study Monographs 24(1–2): 1–168.
• World Agroforestry Centre, undated. Agroforestree Database. [Internet] World Agroforestry Centre (ICRAF), Nairobi, Kenya. http://www.worldagroforestry.org/ Sites/TreeDBS/ aft.asp. Accessed June 2006.
Sources of illustration
• 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.
Author(s)
G.H. Schmelzer
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands


Editors
G.H. Schmelzer
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
A. Gurib-Fakim
Faculty of Science, University of Mauritius, Réduit, Mauritius
Associate editors
C.H. Bosch
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
M.S.J. Simmonds
Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, United Kingdom
R. Arroo
Leicester School of Pharmacy, Natural Products Research, De Montfort University, The Gateway, Leicester LE1 9BH, United Kingdom
A. de Ruijter
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
General editors
R.H.M.J. Lemmens
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
L.P.A. Oyen
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
Photo editor
A. de Ruijter
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article:
Schmelzer, G.H., 2007. Rauvolfia vomitoria Afzel. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(1): Medicinal plants/Plantes médicinales 1. [CD-Rom]. PROTA, Wageningen, Netherlands.
Distribution Map wild


1, flowering branch; 2, part of stem bark; 3, flower; 4, fruits.
Redrawn and adapted by Achmad Satiri Nurhaman



flowering plant


leafy branch


leafy branch with infructescence