885

12(2): Medicinal and poisonous plants 2

Achyranthes L.

Sp. pl. 1: 20 (1753).

AMARANTHACEAE

x = 21; Achyranthes aspera: 2n = 42; Achyranthes bidentata: 2n = 42, 84

Major species Achyranthes aspera L.

Achyranthes is a small genus of 8—10 species, distributed throughout the Old World, from Africa and Asia to Polynesia, also introduced into America.

In South-East Asia, China, India and Africa, the leaves and fruits of Achyranthes aspera are considered healing and are applied to wounds, abscesses, boils and eczema. The plant, especially the bitter root, has anodynal properties, and a decoction of the roots is drunk for rheumatism, stomach-ache, menstruation pains and stitch. In India, a maceration of the roots or flower stalk is applied to scorpion stings and snake bites, while in Peninsular Malaysia, the seeds are applied to snake bites. In Malaysia and Indonesia, Achyranthes aspera is rubbed on the body of young children against convulsions. In Indonesia, Fiji, the Philippines, China and India, the root or the whole plant is considered diuretic and purgative, and are used for dysentery, malaria and other fevers, tonsilitis, pneumonia, dysmenorrhoea, induction of labour and haematuria. In the Philippines, Java, India and Tanzania the sap is used in the form of eye drops to clear corneal opacity. In India, the plant is considered a remedy for inflammations of the internal organs, piles, itch, abdominal enlargements and enlarged cervical glands. Hindus use the ashes for preparing caustic alkaline preparations (vegetable salt). A decoction of the root is drunk with honey within one month of conception as an abortifacient, and a 10 cm-long root is inserted into the vagina for abortion of a three-month-old foetus. In China, the root is also used for urinary tract infections, syphilis, nose bleeding, toothache and bleeding gums. In Nigeria and Senegal, an infusion of the leaves is taken as a tonic, an astringent, a diuretic and an expectorant. In Samoa, Achyranthes aspera is used as a tonic for children. In India and Ivory Coast, suppositories are made from the leaves for the treatment of haemorrhoids. In India, the flowers, ground and mixed with sugar are given for menorrhagia and rabies. Powdered seeds are soaked in milk and given for biliousness. In China, the plant is contra-indicated in pregnancy, excessive menstruation and spleen deficiencies.
In Korea, Vietnam and China, the roots of Achyranthes bidentata are widely used as an expectorant, anti-inflammatory, antipyretic, antirheumatic, anti-arthritic and diuretic. In China, the root is prescribed as an emmenagogue, to facilitate delivery, and for vaginal discharges. The stem and leaves are taken for malaria. The whole plant is considered a tonic. In Malaysia, it is used internally as an anthelmintic. In Vietnam, the roots are widely applied for rheumatism, lumbago, dysmenorrhagia, hypertension, hypercholesterol, arteriosclerosis, dysuria, haematuria, contusion, congestion and angina. They are also used in decoction in the case of placenta retention. In Java, Achyranthes bidentata is used as a vermifuge for horses, and chewed with betel leaf (Piper betle L.) for infections or malignant ulcers in the mouth.
The young leaves of Achyranthes aspera are eaten in Indonesia (Java, the Moluccas), China and in Tanzania. In India, the seeds of Achyranthes bidentata have been used as a substitute for grain in times of famine. The stem is used as a toothbrush.

Achyranthes bidentata is cultivated in China and Vietnam, and exported to Indonesia, but no statistics on trade are known.

The water soluble alkaloid achyranthine was isolated from the roots of Achyranthes aspera. They also contain 0.05% of the triterpene oleanolic acid and its glycosides. The shoots are rich in alkanes, e.g. 17-pentatriacontanol, tritriacontanol, and 36,47-dihydroxyhenpentacontan-4-one. From the seeds a series of triterpene saponins (saponins A—D) was isolated, which gave oleanolic acid, glucose, galactose, xylose and rhamnose upon hydrolysis.
Several extracts and purified fractions and/or compounds showed pharmacological activities. For example, achyranthine produces hypotension, cardiac depression, dilatation of blood vessels in dogs, spasmogenic effect in frog rectus muscle and diuretic and purgative effect in albino rats. In addition, an alkaloidal extract of the stems of Achyranthes aspera also exhibited activity against Bacillus subtilis, Pseudomonas aeruginosa, Shigella dysenteriae and Staphylococcus aureus in vitro.
The isolated triterpene saponins from the seeds increased the tone and force of contraction of isolated heart preparations of frog, guinea-pig and rabbit. This effect was quicker in onset and shorter in duration than that exerted by digoxin. On a molecular level it was also found that the saponins increased the phosphorylase activity of rat heart.
Powdered Achyranthes aspera plants, methanol or water extracts of the whole plant, administered orally to normal and alloxan diabetic rabbits, produced a dose-dependent hypoglycaemic effect in both normal and diabetic animals. In addition, a 7-day acute toxicity study did not reveal any adverse effects at doses of up to 8 g/kg/day given orally. Furthermore, an ethanol extract of the plant showed 30% anti-implantation activity in early pregnancy of albino rats, at a dose of 250 mg/kg, but had no effect in late pregnancy. A benzene extract of Achyranthes aspera is found to be abortifacient in rabbits.
The diuretic activity of Achyranthes aspera is probably due to the presence of a large quantity of potassium salts.
In leprosy patients, a decoction of the whole plant of Achyranthes aspera, together with diamino-diphenyl-sulphone showed definite improvement in general health and the bacterial index. It is useful for subacute and medium types of leprosy. Furthermore, the seeds show large inhibition zones for the growth of the bacteria Bacillus subtilis, Escherichia coli, Pseudomonas cichorii and Salmonella typhimurium in vitro. The crude extract of the whole plant showed 70—85% activity against the larvae of the cattle tick Boophilus microplus. The roots also contain the insect-moulting hormones ecdysterone and inokosterone.
The roots of Achyranthes bidentata contain about 1% betaine, and 0.9—1.4% oleanolic acid. Besides several common sterols, flavonoids and phenolic acids, they also contain the anthracene derivative chrysophanol.
An extract of the roots had a hypotensive effect on normal and renal-type hypertensive rats as well as spasmodic effects in mice. A root extract also showed significant hypotensive action and blood cholesterol concentration in humans, in Vietnam. The anti-inflammatory effects of the roots, tested in 4 acute and/or sub-acute inflammatory models in vivo, are marked. An extract of the roots containing polysaccharides (ABP) inhibited tumour growth in S180-bearing mice by 31—40%, and when co-administered with cyclophosphamide by up to 58%. ABP at 50 and 100 mg/kg intraperitoneally potentiated LAK cell activity and increased Con-A-induced production of tumour necrosis factor from murine splenocytes. ABP at 1—2 µg/ml also strongly inhibited S180 and K562 cell proliferation in vitro. Sulphated ABP showed high activity against HSsAG and HBeAg and herpes simplex virus type 1. In addition, the benzene extract of the whole plant of Achyranthes bidentataadministered orally showed significant anti-fertility, anti-implantation and anti-early-pregnancy effects in mice; the chloroform extract was devoid of these activities, however.

In China, roots of Cyathula prostrata (L.) Blume are used as a substitute for Achyranthes roots.

Erect or ascending, branched herbs. Leaves opposite, simple; petiole present; stipules absent. Inflorescence an erect, terminal or axillary spike, elongated after flowering, many-flowered, few flowers open at the same time. Flowers bisexual, solitary, deflexed after anthesis, bract membranaceous, acute, persistent, subtended by 2 bracteoles, base concave, with a short wing, apex long spinescent; tepals 5, membranaceous to herbaceous-coriaceous, 1—more-veined, very acute, spreading during anthesis, erect in fruit, pungent in fruit or not; stamens 5, much shorter than perianth, filaments connate at base in a short cup, alternating with short, broad pseudo-staminodes, fimbriate or not, anthers oblong, 2-celled; ovary superior, ovule 1, style filiform, short, persistent, stigma capitate. Fruit an ellipsoid utricle, thin-walled, indehiscent, falling off with perianth and spines. Seed solitary, ovoid. Seedling with epigeal germination.

Achyranthes can be found flowering throughout the year when sufficient water is available. It has no photoperiodic requirements for flowering. On arable land and in areas with a distinct monsoon, Achyranthes aspera grows like an annual, while in shaded and protected areas it is a perennial.

Achyranthes aspera and Achyranthes bidentata are very closely related. In southern India, Sri Lanka to Japan and Malaysia, morphological transitions between Achyranthes aspera and Achyranthes bidentata have not been observed. However, in north-western India, Pakistan and Africa, intermediate types occur for important morphological characteristics such as the adnate wings on the bracteoles and the hairiness of the pseudo-staminodes. Their ecological preferences are also not strictly differentiated either throughout the distribution area. Reducing Achyranthes bidentata to the rank of subspecies under Achyranthes aspera would not solve this problem, and more field and genetic studies are needed in order to elucidate their status.

Achyranthes comprises weedy herbs usually found near human settlements or along roads and footpaths, in humid and drier climates.

Achyranthes is propagated by seed. Because the bracts are reflexed, they adhere easily to animal fur and clothes. Individual Achyranthes aspera plants may produce up to about 3000—9500 seeds, whereas the 1000-seed weight fluctuates between 1.3 g and 2.6 g. The seeds germinate equally under light, shade and dark conditions. Planting distance of Achyranthes bidentata is 60—90 cm, in full sunlight 30—60 cm. In Vietnam, the best time for sowing is November. The seeds are soaked for 24 hours in water before sowing or are sown directly, and are sown at 30—40 kg/ha. Sesbania sp. (Leguminosae) is sown beforehand to provide shade.

Achyranthes bidentata is cultivated in China on rich, slightly acid, sandy soils.

In India, several diseases including leaf spot caused by Cercospora achyranthes, leaf blight caused by Alternaria alternata and cucumber mosaic virus are found on Achyranthes aspera. Meloidogyne javanica nematodes attack its roots. Achyranthes aspera is often infected with the thrips Caliothrips indicus.

In China and Vietnam, the roots from 1 and 2 year-old plants of Achyranthes bidentata are dug up in autumn or early winter, when the foliage dies back. Leaves and stems are harvested in summer for use in tinctures or crushed for the juice.

In China, the root of Achyranthes bidentata is traditionally sun-dried and used in decoctions, extracts and powder. The roots can also be stir-fried in rice wine or used fresh. In Vietnam, the roots are washed, small roots removed, and then dried in the shade for several days. Afterwards they are stacked for a week in the shade, till ridges appear on the roots. They are then fumigated with sulphur for 24 hours, and completely dried.

. Both Achyranthes species are widespread, weedy, readily found near settlements, and therefore not endangered. No germplasm collections of Achyranthes are known to exist.

Several fractions and/or purified constituents of Achyranthes showed various interesting pharmacological effects, both in vitro and in vivo. Therefore, further research is needed to fully evaluate these preliminary results for future applications.

Akhtar, M.S. & Iqbal, J., 1991. Evaluation of the hypoglycemic effects of Achyranthes aspera in normal and alloxan-diabetic rabbits. Journal of Ethnopharmacology 31(1): 49—58.
Quisumbing, E., 1978. Medicinal plants of the Philippines. Katha Publishing Co., Quezon City, the Philippines. pp. 263—265.
Raman, M.H., Faroque, A.B.M & Islam, S.N., 1996. Studies on the antibacterial properties of Achyranthes aspera stems. Fitoterapia 67(1): 92—93.
Townsend, C.C., 1973. Notes on Amaranthaceae - 1. Kew Bulletin 28(1): 141—146.
Varshney, M.D., Sharma, B.B. & Gupta, D.N., 1986. Antifertility screening of plants. Part II. Effect of ten indigenous plants on early and late pregnancy in albino rats. Comparative Physiology and Ecology 11(4): 183—189.
Yu, S. & Zang, Y., 1995. Effect of Achyranthes bidentata polysaccharides (ABP) on antitumor activity and immune function of S180-bearing mice. Chinese Journal of Oncology 17(4): 275—278. (in Chinese)

J. Raymakers & G.H. Schmelzer

Achyranthes aspera
Achyranthes bidentata

Raymakers, J. & Schmelzer, G.H., 2001. Achyranthes L.. In: van Valkenburg, J.L.C.H. and Bunyapraphatsara, N. (Editors): Plant Resources of South-East Asia No 12(2): Medicinal and poisonous plants 2. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea

The following species in this genus are important in this commodity group and are treated separatedly in this database:
Achyranthes aspera
Achyranthes bidentata