Bidens (PROSEA)

Plant Resources of South-East Asia
Introduction

Protologue: Sp. pl. 2: 831 (1753); Gen. pl. ed. 5: 362 (1754).

Family: Compositae

Chromosome number: x= 12; B. bipinnata: 2n= 24, 36, 48, 72, B. biternata: 2n= 24, 48, 72, B. pilosa: 2n= 24, 36, 48, 72, B. tripartita: 2n= 48, 72

Major species

Bidens pilosa L.

Vernacular names

Beggar-tick, bur-marigold (En).
Bident (Fr)
Indonesia: hareuga (Sundanese), ketul (Javanese)
Thailand: noksai.

Origin and geographic distribution

Bidens is a large genus of about 200 species and has a worldwide distribution. Its centres of diversity are located in tropical and subtropical regions of North America and Africa. Only 4-5 species are found within the Malesian area.

Uses

Bidens is widely used in traditional medicine, against numerous complaints, often to soothe pain. Applications may be ascribed to its antiseptic and astringent properties. An infusion or a decoction of roots, leaves or flowers, or the juice of the leaves is used against coughs, headache, fever, constipation, diarrhoea, intestinal worms, stomach-ache, toothache, poisoning, muscular pains and as a bath to treat itching and rheumatic pains. Crushed leaves or flower-heads, sometimes heated over a fire, are applied on the skin to treat inflammations, burns, ulcers, boils or skin affections in general and as a haemostatic on wounds. A decoction of the leaves or the roots is applied on eyelids to treat eye infections. Roots are chewed against toothache, and tinctures of the flowers and leaves are applied as a mouthwash against toothache. Furthermore, the roots and seeds are used as an expectorant, emmenagogue, diuretic, and also against kidney-stones and gallstones. Seeds are sometimes used as an anaesthetic. An infusion of the leaves of B. pilosa is used in diabetes.

In Europe, B. tripartita was formerly valued for its diuretic and astringent properties, and used against fevers, gravel stone, bladder and kidney troubles and as a good styptic and remedy for ruptured blood vessels. In North America, the roots and seeds of B. tripartita are used as emmenagogue and in laryngeal and bronchial diseases. In Brazil, B. pilosa is used in the treatment of malaria.

The flowers of B. pilosa are used in the Philippines in the production of a kind of wine called "sinitsit". In Mexico, the leaves are used as a substitute for tea as a tonic and stimulant. In Indonesia and in Africa young, 2-5 cm long shoots and young leaves are eaten raw or cooked as a vegetable. They have a bitter astringent taste and are much relished in some regions. B. pilosa is readily browsed by domestic livestock, including poultry, and is sometimes used as a fodder. It is said to have a high nutritional value. The flowers are rich in nectar which yields a high-quality, reddish honey. In Thailand, B. bipinnata is considered an ornamental. Young shoots of B. biternata are eaten raw or steamed. Plants of B. tripartita yield a black dye which is used as a hair dye in China.

Production and international trade

In most regions B. pilosa is available as a weed to meet daily needs. In Indonesia, young shoots are for sale on local markets but no statistics are available.

Properties

Extracts of B. pilosa show antimalarial activity both in vitro and in vivo. The crude ethanol extract from B. pilosa (50 μg/ml) causes up to 90% inhibition of Plasmodium falciparum growth in vitro, compared with respectively 86-94% and 68-79% inhibition for the chloroform and butanol fraction (both at 50 μg/ml). In vivo, the crude ethanol extract and the chloroform fraction cause about 40% reduction of P. berghei parasitaemia in mice. Phenylacetylenes and flavonoids have been found in the ethanol extract from the leaves and the roots. The major component of the chloroform fractions from the roots was the phenylacetylene 1-phenylhepta-1,3-diyne-5-en-7-ol-acetate. Other Bidens species with aliphatic and phenylacetylenes and related compounds (thiophenes) were also found to be very active in vitro: 50 μg/ml of B. tripartita, which contains 13 acetylenes, reduced P. falciparum growth by 87%, and a similar dose of B. bipinnata, which has 9 acetylenes, gave a 70% reduction. However, extracts of B. biternata containing only 3 acetylenes showed only 38% inhibition at the same dose. The results indicate that the antimalarial activity of Bidens may be attributed to the presence of acetylene compounds. The therapeutic usefulness of these compounds seems limited, since they are easily oxidized by air and light.

Furthermore, acetylenes also have antimicrobial activity. A number of polyacetylenes, e.g. phenylhepta-1,3,5-triyne from petroleum ether and methanol/water extracts of B. pilosa are toxic to yeasts and some bacteria. This compound, which can also be isolated from the aqueous methanolic extract of leaves, flowers and achenes of B. bipinnata is an active anti-parasitic and exhibited marked insecticidal activity with LC₅₀ of 204 ng/cm² for the first instar larvae of the fall armyworm (Spodoptera frugiperda).

In literature, the polyacetylene 7-phenylhepta-2,4,6-triyne is reported phytotoxic to fibroblast cells. The polyacetylene β-D-glucopyranosyloxy-3-hydroxy-6(E)-tetradecen-8,10,12-triyne from B. pilosa shows overgrowing action against normal and transformed human cell lines in culture. Dried leaves of B. pilosa have a co-carcinogenic action for oesophageal tumours induced in rats. Consumption of the leaves, as in South Africa, has been found to promote the development of oesophageal cancer.

In addition to the acetylenes, other compounds such as phytosterols (β-sitosterol), triterpenes (friedelin and friedelan-3β-ol) and caffeic acid(s) are also reported from B. pilosa. The main flavonoids from leaf extracts of B. pilosa are aurones and chalcones. Since friedelin and friedelan-3β-ol, as well as several flavonoids have known anti-inflammatory properties, their detection in extracts from B. pilosa, together with the presence of the described acetylenes, may rationalize the use of B. pilosa in traditional medicine, especially for treating wounds, against inflammations and against bacterial infections of the gastro-intestinal tract.

The ethanolic extract of B. pilosa showed a very high inhibition of prostaglandin synthesis in an in vitro assay for cyclo-oxygenase inhibitors. The methanol extract of B. pilosa showed radio-protective activity for bone marrow. Besides the above-mentioned pharmacological activity, antihyperglycaemic, immunomodulator, anti-ulcer and hypotensive activity are reported.

Adulterations and substitutes

1-Phenylhepta-1,3-diyne-5-en-7-ol-acetate has also been isolated from Coreopsis species.

Description

Annual or perennial, usually erect herbs; stem branched, terete to 4-angled.
Leaves opposite or rarely whorled, upper leaves sometimes alternate, simple to deeply 2-3-pinnatisect, margins entire to dentate or serrate or variously incised, sessile or petiolate; stipules absent.
Inflorescence a terminal or axillary, capitulum, solitary or arranged in corymbose or panicle-like cymes; receptacle flat to conical, set with scales (paleae); involucre campanulate to hemispherical, 2-seriate, outer involucral bracts often much larger than the inner ones.
Ray flowers absent or present, sterile or female, ligulate, yellow, purple to lilac or white; disk flowers bisexual, with yellow to brownish-orange or purple, tubular, 4-5-toothed corolla; stamens 4-5, anthers fused brown to black, caudate to sagittate at base; style bifurcate with short to long arms.
Fruit a dorsiventrally compressed or 3-4(-6)-angled achene, linear-oblong to ellipsoidal or broadly obovate, not beaked, margins setulose, thickened or sometimes winged; pappus absent or composed of up to 4(-5) usually barbed bristles.
Seedling with epigeal germination; cotyledons free, strap-shaped to spathulate; hypocotyl elongated; leaves opposite.

Growth and development

B. pilosa produces seed (achenes) abundantly; one infructescence can produce 50-70 seeds, one plant up to 6000. The seed has no dormancy and germinates within 3-4 days. Seed viability is high and even 3-5-year-old seeds still have a viability of 80%. Phytochrome controls germination in B. pilosa and seeds germinate in darkness when the level of the pre-existing active form of phytochrome is above a certain threshold. The optimum range in day/night temperatures for germination is 25/20 °C - 35/30 °C at a photoperiod of 12 h. Temperatures below 15/10 °C and above 45/40 °C influence germination negatively. Flooding following seeding, even for a day, will reduce emergence to about 25%. Seedling emergence decreases further sharply with extended periods of flooding. In some areas 3-4 generations per year are possible, making B. pilosa often a noxious weed in cropped land. Flowering starts about 1.5-2 months after sowing; plants are self-fertile and seed is mature 1 month after flowering. Flowering and fruiting is throughout the year. The seed is easily distributed by animals and people because of the barbed bristles of the pappus which adhere to fur or to clothes. The effective way of dispersal has contributed to B. pilosa developing into a worldwide weed. Plants have the highest biomass of leaves at about flowering time.

Other botanical information

Bidens belongs to the tribe Heliantheae and is closely related to Coreopsis, with which some authors advocate uniting it. The taxonomy of Bidens is still unsatisfactory.

Due to its worldwide distribution, B. pilosa is a highly variable species: plants are erect or decumbent, leaves are simple to highly dissected with entire to dentate-serrate margins, heads may be discoid or radiate, ray flowers may be yellow, white or pinkish and short to long, the achenes may be awnless or have 2-5 bristles. In the past B. pilosa has been subdivided into 7 varieties, some with a number of formae. However, in America and South Africa it has been discovered that most of the taxa distinguished may occur in one population. Subdivision of the species is no longer considered useful, particularly because different ploidy levels seem to play a role in addition to the morphological variation. It is possible that what is now considered to represent B. pilosa in South-East Asia in fact consists of several species, as has appeared to be the case in North and Central America, but more biosystematic research is needed.

B. bipinnata closely resembles B. biternata and has been confused occasionally in literature because of erroneous identification of the material.

Ecology

All South-East Asian Bidens species are known as weeds of cropped land and appear also in roadsides, along watercourses, in brushwood and thickets, up to 2500 m altitude. They prefer sunny to slightly shaded places and moist soils. B. pilosa is a cosmopolitan weed of more than 30 crops and often becomes dominant after the eradication of perennial grasses. It displays allelopathic effects on a number of crops.

Propagation and planting

Optimal emergence occured when planting seeds less than 1 cm deep, with no emergence when planted as deep as 10 cm.

Harvesting

Leaves and flower-heads of Bidens are simply collected from the wild whenever the need arises. Plants are readily available in the surroundings of human habitation.

Genetic resources and breeding

In view of its widespread distribution and weedy nature, Bidens occurring in South-East Asia is unlikely to be at risk of genetic erosion.

Prospects

The traditional application of Bidens for its antiseptic and anti-inflammatory properties will remain of local importance, especially because plants are always readily available. The antimalarial properties deserve further attention.

Literature

Alvarez, L., Marquina, S., Villareal, M.L., Alonso, D., Arranda, E. & Delgado, G., 1996. Bioactive polyacetylenes from Bidens pilosa. Planta Medica 62(4): 355-357.
Ballard, R., 1986. Bidens pilosa complex (Asteraceae) in North and Central America. American Journal of Botany 73: 1452-1465.
Brandao, M.G.L., Krettli, A.U., Soares, L.S.R., Nery, C.G.C. & Marinuzzi, H.C., 1997. Antimalarial activity of extracts and fractions from Bidens pilosa and other Bidens species (Asteraceae) correlated with the presence of acetylene and flavonoid compounds. Journal of Ethnopharmacology 57: 131-138.
Geissberger, P. & Sequin, U., 1991. Constituents of Bidens pilosa L.: do the components found so far explain the use of this plant in traditional medicine? Acta Tropica 48(4): 251-261.
Holm, L.G., Plucknett, D.L., Pancho, J.V. & Herberger, J.P., 1977. The world's worst weeds. Distribution and biology. East-West Center, University Press of Hawaii, Honolulu, United States. pp. 185-189.
Jager, A.K., Hutchings, A. & Van Staden, J., 1996. Screening of Zulu medicinal plants for prostaglandin-synthesis inhibitors. Journal of Ethnopharmacology 52(2): 95-100.
Mesfin, T., 1993. An account of Bidens (Compositae: Heliantheae) for Africa. Kew Bulletin 48: 437-516.
Mirvish, S.S., Salmasi, S., Lawson, T.A., Pour, P. & Sutherland, D., 1985. Test of catechol, tannic acid, Bidens pilosa, croton oil, and phorbol for cocarcinogenesis of esophageal tumors induced in rats by methyl-n-amylnitrosamine. Journal of the National Cancer Institute 74(6): 1283-1290.
N'Dounga, M., Balansard, G., Babadjamian, A., David, P.T. & Gasqvet, M., 1983. Study on Bidens pilosa L. Identification and antiparasitic activity of 1-phenyl-1,3,5-heptatriyne. Plantes Médicinales et Phytothérapie 17: 64-75.
Wat, C.K., Biswas, R., Graham, E., Bohm, L. & Towers, G.H.N., 1978. UV-mediated antibiotic activity of phenylheptatryne in Bidens pilosa. Planta Medica 33(3): 309-310.

Selection of species

Authors

D.S. Alonzo & J.W. Hildebrand