Sphaeranthus (PROSEA)
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Introduction |
Sphaeranthus L.
- Protologue: Sp. pl. 2: 927 (1753); Gen. pl. ed. 5: 399 (1754).
- Family: Compositae
- Chromosome number: x= 10; S. africanus, S. indicus: 2n= 20
Major species
- Sphaeranthus africanus L.,
- S. indicus L.
Vernacular names
- Globe thistle, hardheads (En)
- Philippines: sambong-gala (Tagalog)
- Thailand: matom seua, yaa khon klong.
Origin and geographic distribution
Sphaeranthus consists of 38 species, distributed throughout the tropics of the Old World from Africa to Australia, with a small outlying area in Iraq and Iran. Most species are confined to Africa; 4 species do not occur in Africa. The wide range of the genus is due to 3 species, of which 1 does not occur in Africa, whereas 3 other species have a narrow, non-African distribution.
Uses
Sphaeranthus species occurring in South-East Asia and India are widely used in decoction or as a powder for their tonic, diuretic and stimulant effects in stomach, liver and intestinal problems. The young parts, roots, flower heads or seeds are also used, often in combination with sugar to counteract the bitterness, against worms or as a gargle to cure a sore throat and against cough. The odour is transmitted to urine and sweat.
In India and Indo-China, S. africanus is further used as an emollient and resolvent, applied as a poultice, and in India a decoction of the leaves and tops is employed against venereal diseases.
In India, the paste of S. indicus, prepared with cooking oil, is applied against itch and skin diseases. The red oil, obtained through steam-distillation, may possess antibacterial properties, and is administered against Vibrio cholerae, Micrococcus pyogenes var. aureus, and against tuberculosis. In Pakistan, the plant is used in the treatment of glandular swellings, bronchitis, jaundice and nervous depressions.
In Indonesia, the leaves of S. indicus are eaten as a pot herb. In India the seeds fried in sesame oil or the cooked roots are considered a strong aphrodisiac. The young plant is also mashed with butter and flour and applied against decolouration and loss of hair. In Indonesia, the herb is also used as fodder for cattle.
An aqueous extract of the stem and leaves of Sphaeranthus is used as an insecticide, especially against American cockroaches. The leaves are mixed with rice to prevent damage by insect pests during storage.
S. indicus is also employed as a fish poison, or stuffed in the holes of crabs to kill them.
Production and international trade
Sphaeranthus is only used in local medicine and is not traded on the international market.
Properties
Upon steam distillation, S. indicus yields a red, viscous essential oil (0.01-0.02%) with a bitter taste. Its major constituents are the terpenes cadinene, α-ionone and β-carophyllene and the phenylpropanoid p-methoxycinnanaldehyde. Further compounds include ocimene, α-terpinene, citral, geraniol, geranyl acetate, β-ionone. The essential oil of S. indicus shows in vitro antibacterial activity against Salmonella spp., Shigella spp. and Vibrio cholerae.
Other compounds isolated from the areal parts or flower heads are sesquiterpene lactones, mainly 7-hydroxylated eudesmanolides (e.g. 7α-hydroxyfrullanolide) and the sesquiterpenoids cryptomeridiol and 4-epicryptomeridiol. 7α-Hydroxyfrullanolide shows cytotoxicity and anti-tumour activity against a number of human cancer cell lines. The compound can also be transformed by Aspergillus into 7α-hydroxy-11,13-dihydrofrullanolide and 13-acetyl-7α-hydroxyfrullanolide.
The sesquiterpene glycoside sphaeranthanolide, isolated from S. indicus flower heads, exhibits immune-stimulating activity in the Jerne plaque assay (examination of antibody production ability of mice plasma cells).
A bicyclic sesquiterpene lactone, isolated from a petroleum ether extract of S. indicus, caused longer larval and pupal developmental periods and larval mortality of Culex quinquefasciatus (causing filariasis) at increasing concentration. A S. indicus extract of moderate concentration is mentioned as causing an increase of seedling growth of wheat, although it has no effect on the germination rate.
Very little is known about the phytochemistry of S. africanus. Its leaves and flowers demonstrate a moderate toxic effect on the oriental fruit fly.
Adulterations and substitutes
Lavender oil (Lavandula angustifolia Miller) resembles the essential oil of S. indicus and could be used as a substitute. Spilanthes acmella Murray (Compositae) seems to possess the same properties as Sphaeranthus africanus.
Description
- Erect annual, fragrant herbs with spreading branches, more or less hairy, often glandular; taproot well developed.
- Leaves alternate, simple, obovate to oblong, margins dentate to almost entire, mostly forming broad wings along the stem; petiole with decurrent wings; stipules absent.
- Inflorescence composed of tiny heads, forming globose, terminal clusters, surrounded by a few involucral bracts, heads subsessile on a common receptacle, bracts of heads, when present, more or less membranous, narrow, acute, dry, hairy or not.
- Flowers all tubular; marginal flowers female, few to many, fertile, slender, minutely 2-3-toothed; disk flowers bisexual, solitary or few, fertile or sterile, lower half of tube thickened, upper part soft, 4-5-toothed; stamens 5, anther-bases sagittate, auricles acute or tailed, style shortly bifid in female flowers, subentire in the others.
- Fruit an oblong achene, angular, tipped by the persistent, hardened part of the corolla; pappus absent.
- Seedling with epigeal germination; hypocotyl glabrous; cotyledons subsessile, glabrous; first pair of leaves opposite, subsequent leaves alternate.
Growth and development
Sphaeranthus often grows gregariously, forming large patches.
Other botanical information
Sphaeranthus belongs to the tribe Inuloideae and is characterized by having a large number of heads crowded together and forming a glomerule. There are no ligulate flowers but 2 kinds of tubular flowers are present.
Ecology
Sphaeranthus prefers humid and sunny localities on light to heavy soils. They are often weedy, and can be controlled through manual weeding and herbicides.
Propagation and planting
Seeds of Sphaeranthus are hydrochorous, and germinate at the beginning of the rainy season, or when the water level in rice fields is low.
Husbandry
Sphaeranthus is harvested for local use from rice fields and along ditches whenever the need arises.
Diseases and pests
In India, the caterpillars of Diacrisia obliqua survive on S. indicus, after the harvest of soya bean, and before they enter pupal diapause. S. indicus is also a host for the cicadellid Orosius albicinctus, the vector of sesame phyllody disease.
Harvesting
Sphaeranthus is harvested in any of its developmental stages.
Genetic resources and breeding
Sphaeranthus occurs widely in anthropogenic habitats as a weed and the species described here are not at risk of genetic erosion. No germplasm collections are known to exist and no breeding work has been executed.
Prospects
Sesquiterpene lactones in general display interesting pharmacological activities, e.g. in the field of anti-tumour or immuno-modulating action. Genera like Sphaeranthus which contain these compounds, might thus be potentially of interest in the development of new lead compounds.
Literature
- Burkill, I.H., 1966. A dictionary of the economic products of the Malay Peninsula. Revised reprint. Vol. 2. Ministry of Agriculture and Co-operatives, Kuala Lumpur, Malaysia. pp. 2098-2099.
- Grierson, A.J.C., 1980. Compositae. In: Dassanayake, M.D. & Fosberg, F.R. (Editors): A revised handbook to the flora of Ceylon. Vol. 1. Amerind Publishing Co., New Delhi, India. pp. 181-183.
- Quisumbing, E., 1978. Medicinal plants of the Philippines. Katha Publishing Co., Quezon City, the Philippines. pp. 998-999.
- Ross-Craig, S., 1962. A revision of the genus Sphaeranthus. In: Tailor, G. (Editor): Hooker’s Icones Plantarum, Series 5, Vol. 6. Bentham-Moxon Trustees, Royal Botanic Gardens, Kew, Richmond, Surrey, United Kingdom. pp. 1-90, figs. 3501-3525.
- Sharma, M.C., 1996. Ovicidal and growth disrupting activity of Sphaeranthus indicus extract against filaria vector. International Pest Control 38(5): 160-161.
- Shekhani, M.S., Shah, P.M., Yasmin, A., Siddiqui, R., Perveen, S., Khan, K.M., Kazmi, S.U. & Atta-ur-Rahman, 1990. An immunostimulant sesquiterpene glycoside from Sphaeranthus indicus. Phytochemistry 29(8): 2573-2576.
Selection of species
Authors
- Wongsatit Chuakul, Noppamas Soonthornchareonnon, Orawan Ruangsomboon
