Journ. Bot. appl. 1: 122 (1813).|
x = 10, 11; Desmodium adscendens, Desmodium gangeticum, Desmodium microphyllum, Desmodium triflorum: 2n = 22
Vernacular names Tick clovers (En). Vietnam: h[af]n the.
Origin and geographic distribution Desmodium consists of about 300 species found in the tropical and subtropical regions of Africa, Central and South America, East Asia and Oceania; some species occur in temperate regions. The centre of origin of the genus is South-East Asia. The highest species diversity is found in an area stretching from India eastward to western and south-western China and Malesia (25 species reported). Mexico is a second centre of diversity.
Uses Desmodium shows a wide range of medicinal uses. In South-East Asia, they are considered diuretic (Desmodium gangeticum, Desmodium repandum, Desmodium styracifolium); other prominent uses are the treatment of diarrhoea, dysentery and stomach-ache (Desmodium diffusum, Desmodium gangeticum, Desmodium heterophyllum (Willd.) DC., Desmodium triflorum, Desmodium velutinum), wounds, ulcers and other skin problems (Desmodium gangeticum, Desmodium triflorum, Desmodium sequax), stones in the gall bladder, kidneys or bladder (Desmodium gangeticum, Desmodium styracifolium) and headache, toothache or other pains (Desmodium gangeticum, Desmodium microphyllum, Desmodium ormocarpoides, Desmodium sequax).|In the Philippines, a decoction of Desmodium triflorum is used as a mouthwash and as an expectorant. In India, fresh leaves of Desmodium triflorum are used internally as a galactagogue; and in Taiwan, the whole plant is used against fever, rheumatism, jaundice and gonorrhoea.|Desmodium auricomum Grah. ex Benth. and Desmodium caudatum (Thunb. ex Murray) DC. are reportedly used in local medicine in Indo-China, but no specific uses are mentioned. Desmodium adscendens, Desmodium incanum DC. (synonym: Desmodium canum Schinz & Thell.) and Desmodium renifolium Schindler do occur in South-East Asia, but reports of medicinal use are only available from outside the region. Desmodium incanum is used as a diuretic, stomachic, febrifuge and hemostatic in Central America. Desmodium renifolium is used as a febrifuge in Taiwan.|Desmodium heterocarpon (L.) DC. and Desmodium heterophyllum are primarily forages, but are also used medicinally in Malesia. The boiled roots of Desmodium heterocarpon are used in Malaysia to poultice sore breasts, and a decoction of the plant is regarded as a tonic and a bechic. In Cambodia, the stems of Desmodium heterocarpon subsp. angustifolium H. Ohashi are applied to fractures and snake bites. In Taiwan, a decoction of the roots is used against rickets in children. Desmodium heterophyllum is applied in Malaysia to treat sores, earache, stomach-ache and abdominal complaints. In India, the roots are considered carminative, tonic and diuretic, the leaves are used as a galactagogue, and a decoction of the whole plant is used to treat stomach-ache and abdominal problems.|Desmodium contains a considerable number of species used as pasture and fodder crops, species used for ground cover and green manure; some of these have medicinal applications as well.
Properties Desmodium is very rich in alkaloids and related amino compounds, biosynthetically derived from different precursors.|From Desmodium gangeticum, the following alkaloids and nitrogen-containing compounds have been isolated: hypaphorine, N,N-dimethyltryptamine, N,N-dimethyltryptamine-Nb-oxide, 5-methoxy-N,N-dimethyltryptamine, 5-methoxy-N,N-dimethyltryptamine-Nb-oxide (alkaloids, all derived from the amino acid tryptophan), Nb-methyl-tetrahydroharman, 2-methyl-6-methoxy-'BETA'-carbolinium cation (harman-type alkaloids, derived from the amino acid tryptophan), hordenine (= N,N-dimethyltyramine), N-methyltyramine, candicine (alkaloids derived from the amino acid tyrosine), 'BETA'-phenylethylamine (amine, structurally related to tyramine) and choline (quaternary nitrogen compound). Of these alkaloids, hordenine is known to increase the urinary flow, and to be a remedy for diarrhoea and dysentery.|Other reported constituents are the pterocarpanoids (isoflavonoids) gangetin, gangetinin and desmodin. Gangetin isolated from the roots of Desmodium gangeticum has been found to adversely affect the fertility and reproductive system of male rats. Gangetin caused a dose-dependent impairment of fertility, reduced the vaginal sperm count and enhanced pre-implantation losses. Aqueous root extracts have shown mild diuretic action, relaxant effects on intestine muscles of rats and dogs, and antibacterial, antifungal and anti-inflammatory activity. The alkaloid fraction of stems and leaves has shown relaxant (curariform) effects on frog rectal muscles. Methanolic extracts of Nigerian Desmodium gangeticum plants have shown in vitro anti-leishmanial activity.|Desmodium styracifolium contains triterpenoid saponins, of which soyasaponin I has been found to be effective against kidney stones. In a study with rats the extract inhibited the formation of calcium oxalate stones in kidneys by increasing the output of urine, decreasing the excretion of calcium and increasing the urinary excretion of citrate. Aqueous extracts have shown in vivo hypotensive action in rats through cholinergic receptor stimulation and autonomic ganglion and 'ALFA'-adrenoreceptor blockade. Furthermore, the extract relaxed isolated methoxamine preconstricted helical tail artery strips and was positive chronotropic without apparent effect on the contractile force. The flavonoid fraction exhibited hypotensive activity. From the leaves of Desmodium adscendens, alkaloids (tetrahydroisoquinolones, derived from tyrosine), amines ('BETA'-phenylethylamines, indole-3-alkylamines) and triterpenoid saponins (dehydrosoyasaponin I, soyasaponin I and soyasaponin III) have been isolated. The three saponins, especially dehydrosoyasaponin I, are potent potassium channel openers. This may be related to the reported use of Desmodium adscendens against asthma and dysmenorrhoea, because opening of K-channels is expected to cause smooth muscle of the lung and uterus to relax. Desmodium adscendens extracts have also been reported to inhibit the synthesis and release of histamines, prostaglandins and arachidonic acid. A hot water extract causes a dose-dependent reduction in the amount of spasmogens released anaphylactically and in anaphylactic-induced contractions of ileal muscle in guinea-pigs. Ethanolic leaf extracts have shown analgesic and hypothermic activity in mice. In addition, they delayed the onset of pentylenetetrazole forelimb clonus, and general seizures induced by kainic acid.|Alcoholic extracts of Desmodium triflorum showed good in vitro anthelmintic activity against human Ascaris lumbricoides. Alkaloids and related nitrogen-containing compounds reported from Desmodium triflorum (roots and/or leaves) include: hypaphorine, hypaphorine-methylester, N,N-dimethyltryptamine-Nb-oxide, S-(+)-N,N-dimethyltryptophan-methylester (alkaloids derived from tryptophan), hordenine (= N,N-dimethyltyramine), 3,4-dihydroxyphenylethyl-trimethyl-ammoniumhydroxide (alkaloids derived from tyrosine), trigonelline, S-(-)-stachydrine, tyramine, 'BETA'-phenylethylamine, choline and betaine. The total alkaloid fraction has shown anti-spasmodic, sympathomimetic, central nervous system stimulant and curare-mimetic activity. Other reported constituents of Desmodium triflorum include: indole-3-acetic acid, the flavonoid-C-glycosides vitexin, isovitexcin and 2''-O-glucosylvitexin, the flavone apigenin, and the polyhydric alcohol (+)-pinitol.|From Desmodium caudatum N,N-dimethyltryptamine, bufotenine, bufotenine-N-oxide (alkaloids derived from tryptophan), swertisin (flavonoid-C-glycoside) and the flavone desmodol have been isolated. From ethanolic root extracts of Desmodium incanum, three anti-microbial isoflavones (desmodianones A, B and C) have been isolated, which have shown in vitro activity against Bacillus subtilis, Mycobacterium smegmatis, Staphylococcus aureus and Streptococcus faecalis.
Description Herbs, shrubs or subshrubs, rarely trees, mostly erect or ascendent, but frequently decumbent or subclimbing. Leaves alternate, 3-foliolate in most species, but frequently 1- and 3-foliolate, occasionally exclusively 1-foliolate and rarely 5-7-foliolate, petiole pulvinate, stipulate; leaflets variously shaped, lateral leaflets usually smaller than terminal one, chartaceous to coriaceous, reticulately veined, with 1 stipel at the base of lateral and 2 at the base of terminal leaflets. Inflorescence mostly racemose or paniculate, rarely fasciculate, terminal or terminal and axillary; bracts dimerous or rarely monomerous, early deciduous, primary bracts larger than secondary ones, usually narrowly ovate, secondary bracts mostly subulate or narrowly ovate; bracteoles present or absent. Flowers pedicellate, calyx usually broadly campanulate, 4-5-lobed; corolla variously coloured, often pink to pale purple, papilionaceous, standard usually broadly obovate to almost orbicular, rounded or emarginate at the apex, not auriculate, sometimes short-clawed, wings short-clawed, with oblong lamina, rounded to obtuse at the apex, keel acute or obtuse at the apex; androecium monadelphous or diadelphous, stamens 10, anthers basifixed; ovary superior, narrowly oblong, sessile or stipitate, often many-ovuled, style inflexed or incurved, stigma terminal or lateral, capitate or minute. Fruit a jointed pod, often narrowly oblong or linear, flat or rarely turgid, mostly indehiscent, usually with straight or hooked hairs; articles usually elliptical to quadrangular. Seeds transversely broadly elliptical or broadly ovate to elliptical or depressed ovate, flat or turgid, hilum lateral. Seedling usually with epigeal germination; cotyledons thin leaf-like; first two leaves opposite and simple, subsequent ones alternate and similar to leaves of adult plants.
Growth and development Desmodium appears to be predominantly self-pollinating. However, when flowers are touched, they spring open and release pollen, which makes outcrossing possible. Desmodium diffusum, Desmodium gangeticum, Desmodium microphyllum, Desmodium repandum, Desmodium sequax, Desmodium styracifolium, Desmodium triflorum and Desmodium velutinum are reported to have nodulating ability.
Other botanical information Desmodium belongs to the subtribe Desmodiinae of the tribe Coronilleae within the subfamily Papilionoideae. The genus Desmodium in the broad sense has been divided into seven genera: Codariocalyx, Dendrolobium, Desmodium s.s., Dicerma, Hegnera, Phyllodium and Tadehagi. It is difficult to classify Desmodium s.s., because of the morphological variation and the continuity of morphological features across species borders; further taxonomic studies are needed. Here, the narrow sense of Desmodium is assumed.
Ecology Desmodium is mainly found in humid to sub-humid regions of the tropics and subtropics, on acid soils (pH < 6.5). The usual habitats are open woodland and forest clearings. In equatorial regions, Desmodium species are found from sea-level up to 3000 m altitude. The photoperiod sensitivity varies with the species.
Propagation and planting In general, propagation of Desmodium is by seed. The degree of scarification necessary for successful germination varies between species. The information available concerns species used as a forage or cover crop, and no detailed information is available on species used for medicinal purposes.
Diseases and pests Desmodium is affected by a range of diseases. On a worldwide base, important pathogens are the fungi Synchytrium desmodii and Phanerochaeta salmonicolor, causing wart and pink disease respectively, the root-knot nematodes Meloidogyne arenaria, Meloidogyne hapla, Meloidogyne incognita and Meloidogyne javanica, and the stem gall nematode Pterotylenchus cecidogenus. South-East Asian reports include the sooty moulds Meliola bantamensis, Meliola bicornis and Meliola scabriseta var. integra on Desmodium gangeticum. A very wide range of diseases has been reported for Desmodium gangeticum in India. Desmodium adscendens has been reported to be resistant to attacks of Meloidogyne species.
Prospects Desmodium shows a broad range of traditional medicinal uses, some of which have already been related to the presence and activity of specific compounds. Further research on possible uses of the various Desmodium species seems worthwhile. Further taxonomic studies and germplasm collection are needed to exploit the potential of this genus.
Author: N. Setyowati-Indarto & M. Brink
Source of This Article:
Setyowati-Indarto, N. & Brink, M., 1999. Desmodium Desv.In: de Padua, L.S., Bunyapraphatsara, N. and Lemmens, R.H.M.J. (Editors). Plant Resources of South-East Asia No. 12(1): Medicinal and poisonous plants 1. Backhuys Publisher, Leiden, The Netherlands, pp. 242-250
Setyowati-Indarto, N. & Brink, M., 1999. Desmodium Desv.[Internet] Record from Proseabase. de Padua, L.S., Bunyapraphatsara, N. and Lemmens, R.H.M.J. (Editors).
PROSEA (Plant Resources of South-East Asia) Foundation, Bogor, Indonesia. http://www.proseanet.org.
Accessed from Internet: 10-Jul-2020