Prota 11(1): Medicinal plants/Plantes médicinales 1
Journ. Bot. 2: 337 (1864).
Origin and geographic distribution
Macaranga monandra occurs from southern Nigeria east to Uganda and south to Tanzania and Angola.
In Gabon a decoction of the stem bark is taken as a galactagogue. In Congo the decoction, together with the bark of Pentaclethra eetveldeana De Wild. & T.Durand, is taken by women to treat sterility. A bark decoction is drunk to treat dyspnoea. A large amount of bark decoction is drunk in case of threatened abortion. A twig bark decoction is taken to treat intercostal neuralgia.
In DR Congo Macaranga monandra is considered a good food plant for different species of edible caterpillars. The wood is considered a good firewood.
Hexane and ethyl acetate fractions of the methanol extract of the stem bark showed growth inhibition of different plant fungi: Colletotrichum acutatum, Colletotrichum fragariae, Colletotrichum gloeosporioides, Fusarium oxysporum, Botrytis cinerea, Phomopsis obscurans and Phomopsis viticola. Two active clerodane-type diterpenes were isolated: kolavenic acid and 2-oxo-kolavenic acid. These 2 compounds showed moderate growth inhibition of Phomopsis viticola and Botrytis cinerea. Isolated from other plants, these compounds also showed cytotoxic and antibacterial activities.
Dioecious, much-branched medium-sized tree up to 25 m tall, with bushy crown, usually with a spiny bole; spines sparse, up to 7.5 cm long, blunt; young shoots, petioles and inflorescences densely hairy. Leaves alternate, simple; stipules linear-lanceolate, 5–7 mm long, soon falling; petiole 4–10 cm long; blade ovate, oblong-ovate to elliptical-oblong, (5–)11–16(–20) cm × (3–)6–10(–12) cm, base rounded, cuneate or truncate to shallowly cordate with 2 basal glands, apex acuminate, margins coarsely toothed, softly hairy above, later glabrescent, densely and minutely yellowish glandular-punctate and shortly hairy on the main veins beneath. Male inflorescence an axillary, many-flowered panicle 3–9 cm long, bracts up to 1 cm long; female inflorescence an axillary, few-flowered raceme (2–)3–5.5 cm long, bracts up to 1 cm long. Flowers unisexual, petals absent, disk absent; male flowers almost sessile, calyx lobes 3, broadly ovate, c. 0.5 mm long, pale greenish brown to brownish white, stamens usually 2, fused at base, minute; female flowers with pedicel up to 1 mm long, extending to 1–2 cm in fruit, calyx cup-shaped, c. 1 mm long, splitting into 3 lobes, ovary superior, 1.5–2 mm long, densely yellowish glandular, 2-celled, stigma sessile, recurved, c. 1 mm long. Fruit a transversely ovoid drupe 6–7 mm × 8–9 mm, densely yellowish glandular, becoming blackish when ripe, sometimes late dehiscent, stigma persistent, 1-seeded. Seed almost globose, 5–6 mm long, rough, dull, brownish to blackish.
Macaranga comprises about 280 species, of which about 30 are native to tropical continental Africa and about 15 to Madagascar and the Indian Ocean islands. Several other Macaranga species occurring in Central Africa are medicinally used. In Congo, leaf sap of Macaranga angolensis (Müll.Arg.) Müll.Arg. is rubbed on painful spots, sores and wounds, or a vapour bath with the leaf decoction is taken to treat bronchitis. In Gabon a bark infusion is drunk to treat hypermenorrhoea and dysmenorrhoea. In DR Congo a stem bark decoction of Macaranga saccifera Pax together with salt is taken to treat headache. The large leaves are used to wrap seeds and tobacco for storage purposes.
Macaranga monandra occurs in secondary forest and is common in riverine, lakeside and swamp-edge forest, from sea-level up to 1500 m altitude. It is a fast-growing, light-demanding pioneer species of forest gaps.
Macaranga monandra can be grown from seeds and cuttings. It is the main competitor of Aucoumea klaineana Pierre in forest gaps as it grows slightly faster.
Genetic resources and breeding
Macaranga monandra is relatively widespread and a fast-growing pioneer species of forest gaps. It is therefore not threatened by genetic erosion.
The stem bark of Macaranga monandra has several gynaecological applications. Kolavenic acid and 2-oxo-kolavenic acid, isolated from the stem bark, show antifungal activity against plant fungi. However, nothing is known about the pharmacological activity of Macaranga monandra against human pathogens.
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Correct citation of this article:
Schmelzer, G.H., 2007. Macaranga monandra Müll.Arg. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(1): Medicinal plants/Plantes médicinales 1. [CD-Rom]. PROTA, Wageningen, Netherlands.