Rubus (PROSEA Medicinal plants)
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Introduction |
Rubus L.
- Protologue: Sp. pl. 1: 492 (1753); Gen. pl. ed. 5: 864 (1754).
- Family: Rosaceae
- Chromosome number: x= 7; R. moluccanus: 2n = 28
Major species
- Rubus moluccanus L.,
- R. rosifolius J.E. Smith.
Vernacular names
- Blackberry, raspberry (En)
- Mûre, framboise (Fr).
Origin and geographic distribution
Rubus comprises some hundreds of species, apart from the microspecies in the apogamous R. fruticosus L./ R. caesius L. complex, and has an almost cosmopolitan distribution. In Malesia about 50 native species are found, New Guinea and the Philippines being richest in species, followed by Java and Sumatra. Within Malesia, New Guinea is the only centre of endemism with 12 endemic species; the other islands have very few endemic species or none at all.
Uses
The traditional medicinal use of South-East Asian Rubus is very similar to the traditional use of Rubus in Europe. Leaves and roots are used for their astringent and tonic properties in mild diarrhoea. In Malaysia, a decoction of the roots of R. moluccanus is drunk for dysentery and urinary disorders. The leaves are externally applied in fever. The leaves are included in a traditional steam bath for the first week after childbirth. In Indonesia, the roots are chewed with other ingredients for intestinal disorders. Fresh leaves chewed with roasted coconut are said to cure thrush. Chewed with betel nut (Areca catechu L.) they are considered antitussive and a remedy to avoid a miscarriage. The fruits of R. moluccanus and R. rosifolius are occasionally mentioned as a remedy for nightly micturition. In Papua New Guinea, the leaves of both species are chewed and spat onto sores, to promote healing. In the Philippines, a decoction of the roots of R. rosifolius is given as an expectorant, and a syrup of the fruit as a demulcent. R. alceifolius Poir. is used indiscriminately as R. moluccanus in traditional Thai and Malay medicine. In Sabah, the pounded inner stem of R. alceifolius or R. moluccanus (misidentified as R. glomeratus Blume) is applied as a paste to mouth ulcers. In Vietnam, the fruit of R. alceifolius is used in folk medicine as a stomachic. In Papua New Guinea, the fruits of R. glomeratus (synonym R. ledermannii Focke) cooked and eaten with fish, are considered a tonic. In Simbu Province (Papua New Guinea), the leaves with bark sap of Pipturus argenteus (J.G. Forster) Wedd. added are heated and eaten daily to relieve a bad cough. In Morobe Province, the extracted stem sap of R. neo-ebudicus Guillaumin (synonym R. brassii Merr. & Perry) is drunk as a tonic by elderly people. In Java (Indonesia), the ground leaves of R. fraxinifolius Poir. mixed with water are occasionally used in dysentery. In Papua (Indonesia), it is used to treat wounds and for internal sickness. In Papua New Guinea, the juice of heated leaves of possibly the former species (identified as R. muelleri F.M. Bailey, nom. illeg.) is used on cuts and scratches. Roots and leaves of R. parvifolius L. are used in folk medicine in East Asia and eastern Australia. The plant is credited with astringent, anti-inflammatory, diuretic, antipyretic, antilithic, antithrombotic and resolvent properties. In Sumatra (Indonesia), the shoots of R. alceifolius are eaten as a vegetable. The fruits of several species are locally collected as luxury food. Outside their natural range Rubus are often considered noxious weeds.
Production and international trade
Rubus is only used on a local scale.
Properties
Rubus plants contain tannins, which, due to their astringent properties are responsible for their traditional use in cases of diarrhoea and throat troubles. As an example, dried leaves of Rubus fruticosus L. (blackberry) contain about 8% tannin of the hydrolysable type (gallotannins).
Aqueous extracts of R. parvifolius, from China, proved useful in shortening bleeding time and coagulation time in mice, shortening euglobulinlysis time in rabbits, and inhibited platelet thrombosis in rabbits in vivo. R. parvifolius extracts increased coronary flow in isolated rat heart, preventing rats from pituitrin-induced changes of electrocardiogram (ECG). Furthermore, R. parvifolius extracts increased the tolerance of mice to hypoxia. The toxicity of R. parvifolius is reported to be insignificant.
Description
- Shrubs, usually climbing, straggling or creeping, rarely erect; twigs and other parts nearly always with prickles. Leaves alternate, compound or simple; petiole present; stipules free.
- Inflorescence terminal, mostly paniculate, at the end of axillary leafy branches of determinate growth.
- Flowers 5-merous, mostly bisexual; sepals free, persistent; petals free, usually white; stamens many, ovaries many on a mostly elevated torus.
- Fruits cohering and falling as a collective fruit, either together with the dried torus (blackberry-like) or without and hollow (raspberry-like).
- Seed with a thin testa.
Growth and development
Pollination is by insects and dispersal is obviously endozoochorous.
Other botanical information
R. alceifolius, R. glomeratus and R. moluccanus are closely resembling species that are often confused. Plants are often designated as the more common, and very variable, R. moluccanus. Uses mentioned for any of these species may well be mutually exchangeable. R. alceifolius differs in the shape of the closed flower buds and in the stipules which have very thin, filiform lobes. R. glomeratus differs in the leaf indumentum, which is never entirely closed and the leaf surface remains visible.
Ecology
The majority of Malesian Rubus belongs to the mountain flora and occurs only above 1000-1500 m altitude. A dozen Rubus species are found at lower elevations, and only 3 species occur down to sea-level (R. fraxinifolius, R. moluccanus and R. rosifolius). Most species are light-loving and are restricted to more or less open places, either natural or anthropogenic.
Propagation and planting
Vegetative propagation of Rubus is by root suckers (stolons).
Diseases and pests
R. rosifolius is susceptible to strawberry mild yellow edge potexvirus (SMYEPV), which causes yellow leaf margins in e.g. strawberry.
Harvesting
Leaves and roots of Rubus are collected whenever the need arises. Fruits are collected when ripe.
Handling after harvest
Roots and leaves of Rubus are either used fresh or dried for future use.
Genetic resources and breeding
All Rubus species treated here have a large area of distribution, either naturally or as a result of cultivation, and do not seem to be at risk of genetic erosion. Their preference for disturbed habitats tends to make them less vulnerable. However, molecular studies have revealed that in its natural range intra-island gene flow in R. moluccanus is high, but significant differentiation may occur over even short distances on individual islands. Preservation of only a limited number of populations would therefore be inadequate. Likewise the genetic basis of Rubus is very limited, given that it behaves as a weed outside its natural range.
Prospects
Little is known about the phytochemistry and phyto-pharmacology of Rubus. The presence of (gallo-)tannins is well documented, as well as the application in cases of diarrhoea and throat-troubles of these compounds. More research is needed to fully evaluate other possibilities.
Literature
- Bean, A.R., 1997. A revision of Rubus subg. Idaeobatus (Focke) Focke (Rosaceae) in Australia. Austrobaileya 4(4): 677-689.
- Busemeyer, D.T., Pelikan, S., Kennedy, R.S. & Rogstad, S.H., 1997. Genetic diversity of Philippine Rubus moluccanus L. (Rosaceae) populations examined with VNTR DNA probes. Journal of Tropical Ecology 13(6): 867-884.
- Holdsworth, D.K., 1993. Medicinal plants of the Gazelle Peninsula, New Britain Island, Papua New Guinea. Part II. International Journal of Pharmacognosy 31: 19-22.
- Kalkman C., 1991. Rubus L. In: Verheij, E.W.M. & Coronel, R.E. (Editors): Plant Resources of South-East Asia No 2. Edible fruits and nuts. Pudoc, Wageningen, the Netherlands. pp. 277-278.
- Perry, L.M., 1980. Medicinal plants of East and Southeast Asia. Attributed properties and uses. MIT Press, Cambridge, Massachusetts, United States & London, United Kingdom. p. 346.
- Zhu, Z., Zhang, H. & Yuan, M., 1990. Pharmacological study of Rubus parvifolius L. Chung Kuo Chung Yao Tsa Chih 15(7): 427-429, 447. (in Chinese)
Selection of species
Authors
- J.L.C.H. van Valkenburg
