Prota 11(1): Medicinal plants/Plantes médicinales 1
Sp. pl. 2: 1005 (1753).
n = 9
Lobed croton (En). Velame pó de galinha (Po).
Origin and geographic distribution
Croton lobatus occurs in the Caribbean and South America, tropical Africa and the Arabian Peninsula. In Africa it is found from Senegal east to Eritrea and Ethiopia.
Throughout West Africa a leaf decoction is drunk as a strong purgative. A leaf paste mixed with palm oil is applied to treat guinea worm sores, ulcers, skin diseases and headache. In Côte d’Ivoire and Togo leaf decoctions are used as an enema to treat gynaecological affections. Heated leaves are rubbed on to the skin to treat rheumatic and costal pain. An enema made from a root bark decoction is used as a purgative. A strong arrow poison is made by crushing the plant into a paste with a little water. In Togo leaf sap is used as eye drops to treat eye problems and unconsciousness. In Benin a decoction of the flowers or roots is taken as an antispasmodic in case of risk of abortion and of hiccup. The penis is washed with a maceration of the leafy twigs as an aphrodisiac. A leaf decoction with honey and palm oil is taken to treat stiff limbs. A leaf decoction is also taken to treat fever. In Nigeria the leaf sap is applied to lessen the pain of scorpion stings.
From the stems and leaves of Croton lobatus the monocyclic terpene alcohol vomifoliol, the diterpene geranylgeraniol, the triglyceride lobaceride (characterized by unusual poly-unsaturated fatty acids), steroids (e.g. ergosterol), the triterpene betulinic acid and several other compounds were isolated. Betulinic acid is a potent HIV-1 antiviral compound, and inhibits the growth of Plasmodium falciparum, whereas geranylgeraniol induces apoptosis in leukaemia cell lines.
A methanolic root extract showed significant antiplasmodial activity, against strains that are sensitive to chloroquine as well as resistant ones.
Monoecious branched, annual herb up to 1 m tall; taproot long; branches densely stellate hairy. Leaves alternate, lobed; stipules small, filiform; petiole up to 10 cm long; blade deeply 3–5-lobed, in outline 2.5–10 cm in diameter, lobes oblanceolate to obovate, basal glands absent, apex acuminate, margins toothed, stellate hairy to almost glabrous on both sides. Inflorescence a slender, axillary or terminal raceme up to 12.5 cm long, with small male flowers in upper half and female flowers in lower half. Flowers unisexual, 5-merous, regular, yellowish green; pedicel short; male flowers with elliptical sepals c. 2 mm long, petals oblanceolate, c. 2 mm long, stamens 10–13, free; female flowers with linear-lanceolate sepals c. 5 mm long, petals represented by a hair c. 1.5 mm long, ovary superior, rounded, densely hairy, 3-celled, styles 3, deeply 2-fid, lobes linear. Fruit an almost globular capsule c. 7 mm in diameter, stellate hairy, green, 3-seeded. Seeds ellipsoid, c. 6 mm × 3 mm, covered with wart-like protuberances. Seedling with epigeal germination.
Croton comprises about 1200 species and occurs throughout the warmer regions of the world. It is best represented in the Americas; about 65 species occur in continental Africa and about 125 in Madagascar. Croton lobatus is a host of nematodes (Meloidogyne spp.), of fungi causing powdery mildew, and of cucumber mosaic virus (CMV).
Croton lobatus occurs in open sandy localities, often on river banks, along road sides and on waste land. It is a weed of cultivation.
As a weed, Croton lobatus is often invasive and difficult to eradicate from arable land because of its strong taproot and lateral roots. However, effective control with herbicides is possible.
Genetic resources and breeding
As Croton lobatus is common and often even weedy throughout its distribution area, there is no risk of genetic erosion.
Croton lobatus has several interesting local medicinal applications. It is very poisonous, so due care should be taken when using it. Several potentially active compounds have been identified, but information concerning the pharmacology is lacking, except for an encouraging result concerning its antimalarial activity. More research is therefore needed.
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Sources of illustration
• Akoègninou, A., van der Burg, W.J. & van der Maesen, L.J.G. (Editors), 2006. Flore analytique du Bénin. Backhuys Publishers, Leiden, Netherlands. 1034 pp.
Correct citation of this article:
Schmelzer, G.H., 2007. Croton lobatus L. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(1): Medicinal plants/Plantes médicinales 1. [CD-Rom]. PROTA, Wageningen, Netherlands.
Source: Flore analytique du Bénin