Zanthoxylum rubescens (PROTA)

Plant Resources of Tropical Africa
Introduction


General importance
Geographic coverage Africa
Geographic coverage World
Medicinal
Timber
Fuel
Fibre

File:Map Zanthoxylum rubescens.gif

distribution in Africa (wild)

File:Linedrawing Zanthoxylum rubescens.gif

1, part of leaf; 2, male inflorescence; 3, fruit. Redrawn and adapted by Iskak Syamsudin

Zanthoxylum rubescens Planch. ex Hook.f.

Protologue: Hook., Niger Fl.: 270 (1849).

Family: Rutaceae

Synonyms

Fagara rubescens (Planch. ex Hook.f.) Engl. (1896).

Origin and geographic distribution

Zanthoxylum rubescens occurs throughout most of West, Central and East tropical Africa, from Senegal east to Kenya and south to Tanzania and northern Angola.

Uses

In Liberia the aromatic leaves are chewed as an emetic in cases of food poisoning. In Côte d’Ivoire a stem bark decoction is taken to treat fevers associated with malaria and to treat urinary tract infections. The stem bark is crushed into a paste as an embrocation for contusions. Bark powder is applied to sores. In Nigeria the stem bark and slightly peppery roots are chewed to relieve toothache and infections of the mouth. In Gabon leaves are macerated in lime juice and taken to treat insanity; the maceration is also applied to snakebites. A stem bark decoction is taken to treat gonorrhoea.

In West Africa Zanthoxylum rubescens is widely used in the construction of houses because of its durability and termite resistant wood properties. It is also used for furniture, joinery and carving. In Kenya, however, it is considered tough but perishable. The wood is burnt for firewood and charcoal. In Nigeria the stem bark and roots are used as chew sticks for dental hygiene.

Properties

A large number of amides and alkaloids have been isolated from different parts of the plant. The stem bark and roots are rich in aromatic amides of the cinnamoylamide type. They include arnottianamide, cyclopropane-carboxamide, dioxamin, dioxamide, herclavine, lemairamin, lemairamide, rubescenamin, zanthomamin, zanthosinamide and zanthosin. The stem bark furthermore contains rubemamin, rubemamide and zanthomamide.

From the pericarps of ripe fruits dioxamin, dioxamide, herclavine, zanthomamide and zanthosin were isolated. The triterpene lupeol has been isolated from the roots.

From the stem bark and roots several aliphatic amides have been isolated, including N-isobutyltetradeca-2, 4-dienamide.

From the stem bark and roots several alkaloids were isolated, including the benzophenanthridine alkaloids dihydroavicine, chelerythrine and dihydrochelerythrine. The roots furthermore contain the benzophenanthridine alkaloids nitidine, fagaronine and methoxychelerythrine, the furoquinoline alkaloid skimmiamine, the acridone alkaloids arborinine and 1-hydroxy-3-methoxyacridone and the aporphine alkaloids tembetarine, magnoflorine and N-methyl-corydine. The stem bark furthermore contains the benzophenanthridine alkaloid nornitidine. The leaves contain an essential oil dominated by sesquiterpenoid compounds (E)-nerolidol (44.4–70.2%) and β-caryophyllene (22.1%). The wood contains calcium oxalate.

The alkaloid fraction as well as lemairamide and zanthomamide showed weak antimalarial activity in vitro against a chloroquine-sensitive strain and chloroquine-resistant strain of Plasmodium falciparum.

The sapwood is yellow-white, the heartwood is pale yellow, rather light, but tough.

Description

Shrub or small tree up to 8 m tall; branches and branchlets with straight or recurved blackish thorns 5–10 mm long; branchlets reddish.
Leaves alternate, imparipinnately compound with (3–)4–7 pairs of leaflets, 30–70 cm long, very aromatic; stipules absent; rachis glabrous or minutely short-hairy, flat on top or winged; leaflets with petiolule 2–5 mm long, up to 4 cm long on terminal leaflet; leaflets (almost) opposite, broadly elliptical to oblong-elliptical, (5–)10–20(–30) cm × (2.5–)8–15 cm, apex abruptly acuminate, base cuneate and slightly unequal, margin toothed towards apex, thickly papery, glabrous or sometimes short-hairy along the midrib, with many glandular dots, more conspicuous along the margin, pinnately veined with 8–12 pairs of lateral veins.
Inflorescence a terminal pyramidal panicle 20–40 cm long, short-hairy to woolly hairy.
Flowers unisexual, 4(–5)-merous, regular; pedicel 0.5–2.5 mm long; sepals 4, c. 0.5 mm long, short-hairy; petals oblong to elliptical-oblong, 1.2–2 mm long, apex obtuse, glabrous, creamy white; male flowers with 5 petals and 5 stamens, ovary rudimentary; female flowers with 4 tiny staminodes, ovary superior, carpel 1.
Fruit a broadly ellipsoid or globose follicle 5–8 mm in diameter, orange-red, pitted with pale red glands, sepals and petals persistent, 1-seeded.
Seed globose, 5–5.5 mm in diameter, black and shiny.

Other botanical information

Zanthoxylum is pantropical and comprises about 200 species, with tropical America being richest in species. Mainland Africa harbours about 35 species, whereas about 5 species are endemic to Madagascar.

Ecology

Zanthoxylum rubescens occurs in dry forest and thickets, and in semi-deciduous or evergreen forest, as well as riverine forest, at 600–1800 m altitude. In Côte d’Ivoire it flowers in March and June and fruits from February to March.

Propagation and planting

Zanthoxylum rubescens is propagated from seedlings and wildlings.

Genetic resources

Zanthoxylum rubescens is widely distributed in Africa and is relatively common. It is therefore not threatened by genetic erosion.

Prospects

Zanthoxylum rubescens contains many interesting biochemical compounds, including amides and alkaloids, but pharmacological tests are limited. As several of the isolated compounds have proven interesting biological activities in other plant species, it is certainly worth to continue pharmacological research of the amides and alkaloids, to evaluate their potential. It would also be necessary to establish the safety profiles, as several Zanthoxylum species are known to be toxic.

Major references

Adesina, S.K., 2005. The Nigerian Zanthoxylum; chemical and biological values. African Journal of Traditional, Complementary and Alternative Medicines 2(3): 282–301.

Burkill, H.M., 1997. The useful plants of West Tropical Africa. 2nd Edition. Volume 4, Families M–R. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 969 pp.

Hawthorne, W. & Jongkind, C., 2006. Woody plants of western African forests: a guide to the forest trees, shrubs and lianes from Senegal to Ghana. Kew Publishing, Royal Botanic Gardens, Kew, United Kingdom. 1023 pp.

Kokwaro, J.O., 1982. Rutaceae. In: Polhill, R.M. (Editor). Flora of Tropical East Africa. A.A. Balkema, Rotterdam, Netherlands. 52 pp.

Oyedeji, A.O., Lawal, O.A., Adeniyi, B.A., Alaka, S.A. & Tetede, E., 2008. Essential oil composition of three Zanthoxylum species. Journal of Essential Oil Research 20(1): 69–71.

Neuwinger, H.D., 2000. African traditional medicine: a dictionary of plant use and applications. Medpharm Scientific, Stuttgart, Germany. 589 pp.

Penali, L., Mulholland, D.A., Tano, K.D., Cheplogoi, P.K. & Randrianarivelojosia, M., 2007. Low antiplasmodial activity of alkaloids and amides from the stem bark of Zanthoxylum rubescens (Rutaceae). Parasite 14(2): 161–164.

Other references

Adesina, S.K., 1989. Three new amides from Zanthoxylum rubescens. Planta Medica 55(3): 324–326.

Adesina, S.K.,Olatunji, O.A., Bergenthal D. & Reisch, J., 1988. Trans-cinnamoylamides from Zanthoxylum rubescens pericarps. Pharmazie 43(7): 517–518.

Adesina, S.K. & Reisch, J., 1989. Amides from Zanthoxylum rubescens. Phytochemistry 28(3): 839–842.

Aubréville, A., 1959. La flore forestière de la Côte d’Ivoire. Deuxième édition révisée. Tome deuxième. Publication No 15. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 341 pp.

Fish, F., Gray, A.I. & Waterman, P.G., 1974. Further constituents of the rootbark of Zanthoxylum rubescens. Planta Medica 25(3): 281–284.

Fish, F. & Waterman, P.G., 1972. Methanol soluble quaternary alkaloids from African Fagara spp. Phytochemistry 11(10): 3007–3014.

Gilbert, G., 1958. Rutaceae. In: Robyns, W., Staner, P., Demaret, F., Germain, R., Gilbert, G., Hauman, L., Homès, M., Jurion, F., Lebrun, J., Vanden Abeele, M. & Boutique, R. (Editors). Flore du Congo belge et du Ruanda-Urundi. Spermatophytes. Volume 7. Institut National pour l’Étude Agronomique du Congo belge, Brussels, Belgium. pp. 69–108.

Kakudidi, E.K., 2004. Cultural and social uses of plants from and around Kibale National Park, Western Uganda. African Journal of Ecology 42: 114–118.

Kakudidi, E.K., 2007. A study of plant materials used for house construction around Kibale National Park, western Uganda. African Journal of Ecology 45: 22–27.

Moody, J.O. & Sofowora, A., 1984. Leaf alkaloids of Zanthoxylum rubescens. Planta Medica 50(1): 101–103.

Olabanji, S.O., Makanju, O.V., Haque, A.M.I., Bouso, M.C., Ceccato, D., Cherubini, R. & Moschini, G., 1996. PIGE-PIXE analysis of chewing sticks of pharmacological importance. Nuclear Instruments and Methods in Physics Research B 113: 368–372.

Olatunji, O., 1992. Comparative wood anatomy of some species of Zanthoxylum (Rutaceae) in Nigeria. Nigerian Journal of Botany 5: 1–14.

Tra Bi, F.H., 1997. Utilisations des plantes, par l’homme, dans les forêts classées du Haut-Sassandra et de Scio, en Côte d’Ivoire. Thèse pour obtenir le Doctorat de troisième cycle, Faculté des Sciences et Techniques, Université de Cocody, Abidjan, Côte d’Ivoire. 215 pp.

Waterman, P.G., Gray, A.I. & Crichton, E.G., 1976. A comparative study on the alkaloids of Zanthoxylum leprieurii, Zanthoxylum lemairei and Zanthoxylum rubescens from Ghana. Biochemical Systematics and Ecology 4(4): 259–262.

Sources of illustration

Aubréville, A., 1959. La flore forestière de la Côte d’Ivoire. Deuxième édition révisée. Tome deuxième. Publication No 15. Centre Technique Forestier Tropical, Nogent-sur-Marne, France. 341 pp.

Author(s)

J.R.S. Tabuti, Institute of Environment and Natural Resources (MUIENR), Makerere University, P.O. Box 7062, Kampala, Uganda

Correct citation of this article

Tabuti, J.R.S., 2011. Zanthoxylum rubescens Planch. ex Hook.f. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. Accessed 23 April 2026.

See the Prota4U database.