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Hyoscyamus muticus L.

Protologue
Mant. pl. 1: 45 (1767).
Family
Solanaceae
Chromosome number
2n = 28, 56
Synonyms
Hyoscyamus falezlez Coss. (1864).
Vernacular names
Egyptian henbane, Egyptian hemp (En). Jusquiame d’Egypt (Fr). Meimendro negro (Po).
Origin and geographic distribution
In tropical Africa Hyoscyamus muticus is restricted to the fringes of the Sahara from Mauritania to Sudan. It also occurs in the Mediterranean countries.
Uses
Fresh leaves are applied as a poultice to relieve pain. Dried leaves are smoked in cigarettes to treat asthma but also for their intoxicating effect. The plant is reputed to be poisonous. Fatalities on record involve eating dates poisoned with the plant and eating locusts that had eaten the plant. The Tuareg people use the plant as a fish poison. In northern Nigeria it is sometimes cultivated for medicinal use.
Records of value for grazing vary and range from resulting in fat animals on the one hand to demented sheep on the other. The variation in alkaloid content by growth stage and among populations may be reasons for variations in its toxicity and its value as fodder.
Production and international trade
About 500–600 t of Hyoscyamus muticus stems and leaves, most of it collected in the wild, are exported annually from Egypt to Germany.
Properties
The leaves of Hyoscyamus muticus have a high alkaloid content, with up to 5.2% of dry matter in individual plants. In smaller amounts, alkaloids are also present in roots and stems and the marketed product is a mixture of stems and leaves. The major alkaloid is hyoscyamine, but scopolamine (= hyoscine), tigloidine and tropine are also present. Scopolamine content is of interest to the pharmaceutical industry. In general the level of scopolamine is low in leaves, as low as 0.02%, but in the ‘Cairo’ strain, the scopolamine content of the leaves can exceed 4%. Atropine (a racemic mixture of d- and l-hyoscyamine) and scopolamine are used in ophthalmology as an analgesic, and scopolamine is used to cure or prevent motion sickness. These tropane alkaloids are classified as anticholinergics as they bind to acetylcholine receptors. In-vitro production of hyoscyamine and scopolamine is feasible but is not economical.
The seed oil contains considerable quantities of sterols (about 11.6 g/kg) and tocopherols (about 2.9 g/kg) and is thought to be of medicinal interest.
Adulterations and substitutes
Species of other genera of Solanaceae such as Duboisia, Datura and Atropa are also used for their tropane alkaloids. Other species of Hyoscyamus also have medicinal uses and contain the same alkaloids but in lower concentrations.
Description
Perennial herb or shrub up to 1.5 m tall, glabrous or hairy; stems thick, succulent. Leaves arranged spirally, simple, with stellate and simple hairs; stipules absent; petiole 1.5–5.5(–13) cm long; blade elliptical to ovate, 4–12 cm × 1–9 cm, base cuneate, apex acute, margin coarsely toothed, upper leaves smaller and often entire. Inflorescence a dense terminal cyme, elongating up to 30 cm long or more. Flowers bisexual, 5-merous; calyx regular, funnel-shaped, 5-toothed, teeth c. 5 mm long, in fruit c. 2 cm long; corolla zygomorphic, broadly funnel-shaped, 5-lobed, lobes c. 2 cm long, white to pink with dark violet veins or spots; stamens exserted, anthers c. 4 mm long; ovary superior, 2-celled, style very long, thin. Fruit an obovoid capsule c. 6 mm in diameter, dehiscing by an equatorial circular slit, many-seeded. Seeds kidney- or wedge-shaped, c. 1 mm × 1.5 mm.
Other botanical information
Hyoscyamus comprises about 20 species and is found in Europe, northern Africa and south-western and central Asia. Hyoscyamus muticus has been introduced in India and Pakistan, tested as a crop and even subjected to breeding, but commercial cultivation apparently has not been successful. Most literature from Pakistan and India on Hyoscyamus muticus probably relates to other species. Hyoscyamus insanus Stocks occurs in Iran, Afghanistan, Pakistan and India and is used medicinally, sometimes even being cultivated for medicinal purposes. Hyoscyamus niger L. is commonly cultivated in India.
Ecology
Hyoscyamus muticus occurs in desert areas in rocky localities, wadis and plains.
Propagation and planting
Direct sowing is recommended. Germination has been reported as erratic and troublesome, but treatment of the seeds with concentrated sulphuric acid for 75 seconds, fluctuating temperatures between day and night and the use of kinetin (60 mg/l) all promote germination. Spacing for optimal leaf production and alkaloid yield is about 45 cm between rows and 15 cm in the rows.
Management
The critical period of competition with weeds is 30–75 days after sowing, when weeds can reduce yield by as much as 60%. In field trials in Egypt the response of Hyoscyamus muticus to compost and chicken manure, either alone or in combination with different rates of NPK, was investigated. All treatments increased plant height, number of branches, and fresh and dry weights of leaves, stems and roots per plant and per ha. Highest yield of alkaloids (about 88 kg/ha) was obtained with high levels of manure and NPK. The combined effect of organic manure and NPK resulted in the highest content of hyoscyamine (65% of total alkaloids). Irrigation can increase plant yield but reduces alkaloid content.
Diseases and pests
A large number of pests and diseases have been reported for Hyoscyamus muticus, but the extent of damage caused is unknown. Some of the more important problems are root-knot nematode (Meloidogyne incognita), Alternaria leaf spot, cucumber mosaic virus (CMV), bacterial blight (Pseudomonas cichorii) and aphids (Myzus persicae). In Sudan the plants were attacked by caterpillars (Heliothis sp.).
Harvesting
Hyoscyamus muticus should be harvested about 3 weeks after the beginning of flowering when the first fruits are ripe. After that time the alkaloid yield will drop, although the plant yield will still increase. In Sudan the summer crop is harvested after about 145 days, the winter crop after 190 days.
Yield
In Egypt and Sudan Hyoscyamus muticus yields about 2 t/ha of dry plant material and 20–30 kg/ha of alkaloids.
Handling after harvest
Fresh leafy stems are dried in the sun for 2–3 days and then dried in the shade till they are crisp and dry.
Genetic resources
Harvesting from the wild, as currently is the practice in most of the area where it is native, can deplete populations of Hyoscyamus muticus. This is an incentive for cultivation, but a serious danger of genetic erosion is not foreseen. There are a few accessions in germplasm collections in the United States, Germany, Switzerland and the Netherlands.
Breeding
In India breeding and selection work resulted in selection of a vigorously growing, autotetraploid, highly fertile mutant. It produced 4.5 t/ha of dry matter (about 23 kg alkaloids/ha), but this selection was never released. Scopolamine content was found to be inherited straightforwardly and with breeding the content could be increased by a factor 20 in 4 generations.
Prospects
Hyoscyamus muticus can become an important commercial crop in dry areas of tropical Africa. It could secure the supply of hyoscyamine and scopolamine for local pharmacological industries as well as for export markets. Selection, breeding and research into optimal management of the crop would offer prospects for increased productivity. Recent analysis of the seed oil makes it a potentially interesting source for essential fatty acids and lipid-soluble bioactives.
Major references
• Batanouny, K.H., 1999. Wild medicinal plants in Egypt: an inventory to support conservation and sustainable use. [Internet] Palm Press, Cairo, Egypt. 207 pp. http://www.iucn.org/ places/medoffice/nabp/web/documents/book/ chapter3.pdf. Accessed October 2006.
• Boulos, L., 2000. Flora of Egypt. Volume 3 (Verbenaceae-Compositae). Al Hadara Publishing, Caïro, Egypt. 373 pp.
• Bruneton, J., 1999. Pharmacognosy, phytochemistry, medicinal plants. Second Edition. Technique & Documentation Lavoisier, Paris, France. 1119 pp.
• El Sheikh, M.O.A., El Hassan, G.M., El Tayeb, A.H., Abdallah, A.A. & Antoun, M.D., 1982. Studies on Sudanese medicinal plants III: indigenous Hyoscyamus muticus as possible commercial source for hyoscyamine. Planta Medica 45: 116–119.
• Lavania, U.C., 1986. Genetic improvement of Egyptian henbane, Hyoscyamus muticus L. through induced tetraploidy. Theoretical and Applied Genetics 73: 292–298.
Other references
• Burkill, H.M., 2000. The useful plants of West Tropical Africa. 2nd Edition. Volume 5, Families S–Z, Addenda. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 686 pp.
• El-Bahr, M.K. & Ghanem, S.A., 1997. Production of tropane alkaloids in tissue cultures of Hyoscyamus muticus. Fitoterapia 68: 423–428.
• Misra, H.O., Sharma J.R. & Lal, R.K., 1992. Inheritance of biomass yield and tropane alkaloid content in Hyoscyamus muticus. Planta Medica 58: 81–83.
• Naguib, N.Y. & Aziz, E.E., 2003. Yield and quality of Hyoscyamus muticus L. in relation to some fertilizer treatments. Egyptian Journal of Horticulture 30(1/2): 1–17.
• Oksman-Caldentey, K.-M., Vuorela, H., Issenegger, M., Strauss, A. & Hiltunen, R., 1987. Selection for high tropane alkaloid content in Hyoscyamus muticus plants. Plant Breeding 99: 318–326.
• Oksman-Caldentey, K.-M., Parkkinen, O., Joki, E. & Hiltunen, R., 1989. Increased production of tropane alkaloids by conventional and transformed root cultures of Hyoscyamus muticus. Planta Medica 55: 682.
• Ramadan, M.F., Zayed, R. & El Shamy, H., 2007. Screening of bioactive lipids and radical scavenging potential of some Solanaceae plants. Food Chemistry 103(3): 885–890.
• Siddiqi, M.A., 1978. Solanaceae. In: Jaffri, S.M.H. & El-Gadi, A. (Editors). Flora of Libya. Vol. 62. Al Faateh University, Tripoli, Libya. 38 pp.
• SEPASAL, 2007. Hyoscyamus muticus. [Internet] Survey of Economic Plants for Arid and Semi-Arid Lands (SEPASAL) database. Royal Botanic Gardens, Kew, Richmond, United Kingdom. http://www.kew.org/ ceb/sepasal/. Accessed September 2007.
Sources of illustration
• Siddiqi, M.A., 1978. Solanaceae. In: Jaffri, S.M.H. & El-Gadi, A. (Editors). Flora of Libya. Vol. 62. Al Faateh University, Tripoli, Libya. 38 pp.
Author(s)
N.S. Alvarez Cruz
Unidad de Medio Ambiente, Delegación del CITMA, Cor. Legon 268 / Henry Reeve y Carlos Roloff, Sancti Spiritus 60100, Cuba


Editors
G.H. Schmelzer
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
A. Gurib-Fakim
Faculty of Science, University of Mauritius, Réduit, Mauritius
Associate editors
C.H. Bosch
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
M.S.J. Simmonds
Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AB, United Kingdom
R. Arroo
Leicester School of Pharmacy, Natural Products Research, De Montfort University, The Gateway, Leicester LE1 9BH, United Kingdom
A. de Ruijter
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
General editors
R.H.M.J. Lemmens
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
L.P.A. Oyen
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
Photo editor
A. de Ruijter
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article:
Alvarez Cruz, N.S., 2008. Hyoscyamus muticus L. In: Schmelzer, G.H. & Gurib-Fakim, A. (Editors). Prota 11(1): Medicinal plants/Plantes médicinales 1. [CD-Rom]. PROTA, Wageningen, Netherlands.
Distribution Map wild


1, flowering branch; 2, flower with calyx removed; 3, fruit.
Redrawn and adapted by Iskak Syamsudin



plant habit
obtained from
Sahara Nature


plant habit
obtained from
Sahara Nature


inflorescences
obtained from
Sahara Nature


flowers
obtained from
Sahara Nature