Cuscuta australis (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Cuscuta australis R.Br.

Protologue: Prodr.: 491 (1810).

Family: Convolvulaceae

Chromosome number: 2n= unknown

Cuscuta hygrophilae Pearson (1901).

• Indonesia: majamuju, jamuju, cacingan (Java)
• Vietnam: tơ hồng nam.

C. australis occurs in large parts of tropical and subtropical Asia and Australia, and also in Africa and southern Europe. In Malesia, it has been recorded for Peninsular Malaysia, Singapore, Sumatra, Java and New Guinea. Its seeds and those of C. chinensis Lamk are often imported from China for medicinal purposes, and it is likely that the species have spread through wasted seeds, e.g. into Malesia. In fact, they have been one of the most commonly used drugs of Chinese traditional medicine since ancient times.

In Indonesia, C. australis is used in traditional medicine as an emollient, sedative, sudorific and tonic, and to treat urinary complaints. In Chinese traditional medicine, the seeds are applied as a sedative, against diabetes, urinary complaints, impotency and opacity of the cornea; they are often used in combination with other plant products. The seed is also used in Vietnam for similar purposes. Seed extracts of C. chinensis are applied to treat acne and dandruff.

An ether-insoluble resin glycoside fraction from C. australis seeds is considered to be a complex mixture of glycosidic ester-type oligomers with a core consisting of a number of cuscutic acids each acylated with one or two carboxylic acid moieties. An alcoholic extract increased the percentage and index of phagocytosis of macrophages as well as hemolysin and proliferation of lymphocytes up to normal level in mice with burn injury. C. australis may serve as a kind of immunopotentiator for mammals. Tests on mice have also shown that a C3-binding glycoprotein obtained from the European C. europaea L. has strong immunostimulatory properties both in vivo and in vitro.

The alkaloid cuscutamine, 5 lignans (e.g. cuscutosides A and B), some flavonoids and cinnamic acid derivatives have been isolated from C. chinensis seeds. C. chinensis is reputed to have antitumour activity in the Unani system of medicine in India. In tests with mice, a hot water extract markedly delayed the appearance and retarded the growth of skin papillomas and the incidence of carcinoma induced by 7,12-dimethylbenz[a]anthracene; its prophylactic effect was found to be statistically significant. An aqueous extract of whole C. chinensis plants exhibits anticonvulsant, analgesic and hypotensive activities when administered by gastric intubation.

An antiviral protein, showing a highly significant virus-inhibiting property, has been isolated from an aqueous extract of C. reflexa Roxb. plants. This species has also been found in Java.

A parasitic herb; stem slender, filiform, twining, up to 1 m long, greenish-yellow, golden or orange, with haustoria. Leaves reduced to minute scales. Inflorescence a lateral, compact cymose glomerule, subsessile, few to many-flowered. Flowers bisexual, regular, usually 5-merous; pedicel 1-2.5 mm long; calyx cupular, about as long as corolla tube; corolla cupular, c. 2 mm long, the tube inside with bifid and fimbriate scales, lobes about as long as tube, persistent, white or creamy white; stamens inserted on corolla above the scales; ovary superior, depressed globose, 2-celled, styles 2. Fruit a depressed globose capsule 3-4 mm in diameter, enclosed by corolla, irregularly opening, (3-)4-seeded. Seeds ovoid, c. 1.5 mm long, brownish.

Cuscuta is sometimes considered to represent a separate family Cuscutaceae , differing from Convolvulaceae in its completely parasitic habit, lacking green leaves. It is sometimes confused with Cassytha ( Lauraceae ), which is similar in habit but has 3-merous flowers and berries. Cuscuta comprises approximately 170 species and is cosmopolitan. Its main centre of speciation is North and South America. In the Malesian region, 4 species have been found, of which only C. australis is more widely distributed. C. australis is often confused with C. chinensis , which differs in its circumscissile fruit and keeled corolla lobes. In a major part of the areas of distribution of the species both occur, and they are probably used indiscriminately in traditional medicine. C. chinensis has not yet been recorded in the Malesian region.

C. australis occurs as a parasite on numerous dicotyledonous herbaceous or shrubby plants, in Malesia up to 500 m altitude, but in China up to 2000 m. It has a preference for wetter places, e.g. along watercourses.

Management C. australis is liable to become a pest of crops in the Malesian region, like C. chinensis , which is sometimes a problematic parasite of soya bean in China.

C. australis is extremely widely distributed and not in danger of genetic erosion.

Cuscuta has several interesting medicinal properties, including immunostimulatory, antitumour and antiviral properties, which deserve more attention. A taxonomical study of Cuscuta in South-East Asia is desirable because some species (e.g. C. australis and C. chinensis ) are commonly confused and the literature is consequently often difficult to interpret.

210, 221, 247, 1016.

60, 121, 334, 671, 682, 889, 1013, 1026.

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Djadja Siti Hazar Hoesen