Evolvulus alsinoides (PROSEA)

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Plant Resources of South-East Asia
Introduction
List of species


Evolvulus alsinoides (L.) L.


Protologue: Sp. pl. ed. 2: 392 (1762).
Family: Convolvulaceae
Chromosome number: 2n= 26

Synonyms

Convolvulus alsinoides L. (1753).

Vernacular names

  • Thailand: bai to kaan (north-eastern)
  • Vietnam: bất giao.


Origin and geographic distribution

E. alsinoides occurs in most dry tropical and subtropical regions of the world.

Uses

In South-East Asia, India and Africa, the whole bitter plant is used extensively as a febrifuge, tonic, alterative, antidiarrhoeal and anthelminthic. In the Philippines, the entire plant is taken in an infusion to cure bowel complaints, and also as a vermifuge and a febrifuge. In India, it is also applied for syphilis, scrofula, snake bites and an infusion prepared with oil is applied to promote hair growth. In Kenya, sores are treated by application of the powdered leaves, and in Tanzania, the pounded leaves are put on enlarged glands in the neck. In India and Nigeria, the leaves are made into cigarettes, which are smoked to relieve bronchitis and asthma, while the fragrant smoke is also used to perfume houses. In northern Ghana the plant is used in love-potions and in religious practices. In Mexico, the bitter plant decoction is taken as a remedy for gonorrhoea.

E. alsinoides is grazed by cattle, although the leaves are bitter.

Properties

E. alsinoides is reported to contain flavonols and saponins. Cultured tissues of E. alsinoides accumulate ergot alkaloids: amides of the indole derivative D-lysergic acid, which is biosynthetically derived from the amino acid tryptophan. Although the best known source of the ergot alkaloids is the sclerotium of the fungus Claviceps purpurea or related fungi, several lysergic acid alkaloids have also been isolated from members of the family Convolvulaceae .

The ethanol extract of the whole plant shows anti-ulcer and anticatatonic activity in rats. In vivo, the extract significantly reduced the incidence of ulcers in aspirin-treated rats and reduced the incidence of catatonia in chlorpromazine-treated rats. In mice, the extract showed central nervous system depressant activity with ED50at 450 mg/kg. A water extract of the corolla inhibited spore germination and mycelial growth of the fungi Alternaria brassicae , A. brassicicola and Fusarium oxysporum . Other types of extracts also showed some (weak) antifungal and antibacterial activity.

Adulterations and substitutes

Several members of the family Convolvulaceae contain lysergic acid alkaloids, e.g. Ipomoea violaceae L. and Rivea corymbosa (L.) Hallier f.


Description

A very variable, perennial herb or subshrub; stems slender, reclining and spreading, or erect, 12-70 cm long, not twining, more or less branched, deep-rooted. Leaves alternate, entire, widely spaced, oblong to elliptical or lanceolate, 1-4 cm × 0.2-1 cm, base cuneate, apex acute or mucronate, densely or sparsely white hairy; petiole absent; stipules absent. Inflorescence an axillary 1-3 flowered cyme, peduncle filiform, 2.5-3.5 cm long, pedicel up to 1 cm long, often 2-4 subulate bracts at the base. Flower 5-merous, actinomorphic, calyx 5-partite, sepals small, 3 mm long, villose, not enlarged in fruit, corolla campanulate to rotate, 4-8(-12) mm wide, pale blue, sometimes white; stamens 5, included or exserted, filaments adnate to the corolla tube; ovary 2-celled, styles 2, each with 2-lobed stigma. Fruit a rounded capsule, 3-4 mm long, mostly 4-valved, glabrous, partly enclosed in the calyx. Seeds (1-)4, smooth, black. Seedling with epigeal germination, cotyledons deeply emarginate.

Growth and development

E. alsinoides germinates at the beginning of the rainy season, and starts flowering after 8 weeks.

Other botanical information

About 98 species are described in Evolvulus , mainly in the New World, from the South of the United States to Argentina. Two of these are also present in the Old World, of which the polymorphic E. alsinoides occurs with about 15 varieties. Six of these are recognized in Malesia, but they tend to intergrade. Some Evolvulus species are cultivated for their striking blue flowers.

Ecology

E. alsinoides is a weed of sandy, open, dry grassland and rock localities, in most of the tropics and subtropics, often on limestone, at low and medium altitudes. It is locally abundant.

Propagation and planting

E. alsinoides is propagated by seed.

In vitro production of active compounds

Ergot alkaloids occur in small amounts in callus tissue cultures of the leaves of E. alsinoides . The cultures are established on Murashige and Skoog medium supplemented with 2 mg/l 2,4-D, 0.4 mg/l kinetin and 2% sucrose. The production of these alkaloids can be increased by a factor of 10-40, depending on the treatment, by supplementing known precursors such as L-tryptophan, 5-methyltryptophan and mevalonic acid.

Diseases and pests

In India, E. alsinoides is attacked by the root fungus Sclerotium rolfsii , and gall formation on the aerial parts is caused by Albugo evolvuli . It is also an alternative host for the larvae and pupae of the potato cutworm ( Agrotis ypsilon ) in India.

Harvesting

Whole plants of E. alsinoides are uprooted for use.

Handling after harvest

E. alsinoides is normally used fresh.

Genetic resources and breeding

E. alsinoides is a relatively widespread herb, and is not likely to be threatened by genetic erosion. Some cultivation trials for medicinal purposes of the species have been carried out in India.

Prospects

Little information is available about the pharmacology and phytochemistry of E. alsinoides , therefore it is not yet possible to fully evaluate its potential. Since ergot alkaloids are of interest in medicine (e.g. in the treatment of migraine, and in reducing post-partum haemorrhage) it might have some potential for the local market, depending on the quantity and type of compounds that can be isolated.


Literature

  • Burkill, H.M., 1985. The useful plants of West tropical Africa. 2nd Edition. Vol. 1. Royal Botanic Gardens, Kew, United Kingdom. p. 530.
  • Nambiar, G.R. & Mehta, A.R., 1981. Influence of sugars on ergot alkaloid production by cell suspensions of Evolvulus alsinoides L. Indian Journal of Experimental Biology 19(6): 535-537.
  • Purohit, M.G., Shanthaveerappa, B.K., Badami, S. & Swamy, H.K.S., 1995. Antimicrobial activity of various extracts of Evolvulus alsinoides (Convolvulaceae). Indian Journal of Microbiology 35(1): 77-78.
  • Purohit, M.G., Shanthaveerappa, B.K., Badami, S. & Swamy, H.K.S., 1996. Antiulcer and anticatatonic activity of alcoholic extract of Evolvulus alsinoides (Convolvulaceae). Indian Journal of Pharmaceutical Sciences 58(3): 110-112.
  • Quisumbing, E., 1978. Medicinal plants of the Philippines. Katha Publishing Co., Quezon City, the Philippines. pp. 756-757.
  • van Oostroom, S.J., 1953. Evolvulus. In: van Steenis, C.G.G.J. (Editor): Flora Malesiana. Series 1, Vol. 4. Noordhoff-Kolff, Djakarta, Indonesia. pp. 395-398.

Other selected sources

18,

  • Council of Scientific and Industrial Research, 1948-1976. The wealth of India: a dictionary of Indian raw materials & industrial products. 11 volumes. Publications and Information Directorate, New Delhi, India.508, 696, 719, 922.

Authors

G.H. Schmelzer & N. Bunyapraphatsara