Mucuna pruriens

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Mucuna pruriens
Mucuna pruriens flower.jpg
Mucuna pruriens inflorescence
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Fabales
Family: Fabaceae
Subfamily: Faboideae
Genus: Mucuna
Species:
M. pruriens
Binomial name
Mucuna pruriens
(L.) DC.
Synonyms [1]
  • Carpogon capitatusRoxb.
  • Carpogon niveusRoxb.
  • Carpopogon capitatusRoxb.
  • Carpopogon niveumRoxb.
  • Carpopogon pruriens(L.) Roxb.
  • Dolichos pruriensL.
  • Macranthus cochinchinensisLour.
  • Marcanthus cochinchinenseLour.
  • Mucuna aterrima(Piper & Tracy) Holland
  • Mucuna atrocarpaF.P.Metcalf
  • Mucuna axillarisBaker
  • Mucuna bernierianaBaill.
  • Mucuna capitataWight & Arn.
  • Mucuna cochinchinense(Lour.) A.Chev.
  • Mucuna cochinchinensis(Lour.) A.Chev.
  • Mucuna deeringiana(Bort) Merr.
  • Mucuna esquiroliiH. Lév.
  • Mucuna esquiroliiH.Lev.
  • Mucuna hassjoo(Piper & Tracy) Mansf.
  • Mucuna hirsutaWight & Arn.
  • Mucuna luzoniensisMerr.
  • Mucuna lyoniiMerr.
  • Mucuna martiniiH.Lev. & Vaniot
  • Mucuna minimaHaines
  • Mucuna nivea(Roxb.) DC.
  • Mucuna nivea(Roxb.) Wight & Arn.
  • Mucuna prurita(L.) Hook.
  • Mucuna pruritaWight
  • Mucuna sericophyllaPerkins
  • Mucuna utilisWight
  • Mucuna velutinaHassk.
  • Negretia mitisBlanco
  • Stizolobium aterrimumPiper & Tracy
  • Stizolobium capitatum(Roxb.) Kuntze
  • Stizolobium cochinchinense(Lour.) Burk
  • Stizolobium deeringianumBort
  • Stizolobium hassjooPiper & Tracy
  • Stizolobium hirsutum(Wight & Arn.) Kuntze
  • Stizolobium niveum(Roxb.) Kuntze
  • Stizolobium pruriens(L.) Medik.
  • Stizolobium pruritum(Wight) Piper
  • Stizolobium utile(Wall. ex Wight) Ditmer
  • Stizolobium velutinum(Hassk.) Piper & Tracy

Mucuna pruriens is a tropical legume native to Africa and tropical Asia and widely naturalized and cultivated. [2] Its English common names include monkey tamarind, velvet bean, Bengal velvet bean, Florida velvet bean, Mauritius velvet bean, Yokohama velvet bean, cowage, cowitch, lacuna bean, and Lyon bean. [2]

Contents

The plant is notorious for the extreme itchiness it produces on contact, [3] particularly with the young foliage and the seed pods. It also produces many medium-sized red swollen bumps on the skin with the itching. It has agricultural and horticultural value, and is used in herbalism.

Description

Mucuna pruriens is an annual climbing shrub with long vines that can reach over 15 metres (50 feet) in length. When the plant is young, it is almost completely covered with fuzzy hairs, but when older, it is almost completely free of hairs. The leaves are tripinnate, ovate, reverse ovate, rhombus-shaped or widely ovate. The sides of the leaves are often heavily grooved and the tips are pointy. In young specimens, both sides of the leaves have hairs. The stems of the leaflets are 2–3 millimetres (11618 inch) long. Additional adjacent leaves are present and are about 5 mm (14 in) long.

The flower heads take the form of axially arrayed panicles. They are 15–32 centimetres (6–13 in) long and have two or three, or many flowers, which can be white, lavender, or purple. The accompanying leaves are about 12.5 mm (12 in) long; the flower stand axes are from 2.5–5 mm (18316 in). The bell is 7.5–9 mm (51638 in) long and silky. The sepals are longer or of the same length as the shuttles. The crown is purplish or white. The flag is 1.5 mm (116 in) long. The wings are 2.5–3.8 cm (1–1+12 in) long.

In the fruit-ripening stage, a 4–13 cm (2–5 in) long, 1–2 cm (3834 in) wide, unwinged, leguminous fruit develops. There is a ridge along its length and the husk is covered in loose, orange hairs that cause a severe itch if they contact skin. [4] [5] The pods carry up to seven seeds, which are shiny black or brown drift seeds. They are flattened uniform ellipsoids, 1–1.9 cm (3834 in) long, .8–1.3 cm (3812 in) wide and 4–6.5 cm (2–3 in) thick. The hilum , the base of the funiculus (connection between placenta and plant seeds) is a surrounded by a significant arillus (fleshy seed shell). The dry weight of the seeds is 55–85 grams (2–3 ounces)/100 seeds. [6]

Velvet bean Mucuna pruriens (Khajkuiri) in Kawal, AP W2 IMG 1506.jpg
Velvet bean
Seed pod, the hairs of which cause a dire itch Mucuna-pruriens-fruit.jpg
Seed pod, the hairs of which cause a dire itch
Seeds Black mucuna Seed.jpg
Seeds

Chemistry

The seeds of the plant contain about 3.1–6.1% L-DOPA. [7] M. pruriens var. pruriens has the highest content of L-DOPA. An average of 52.11% degradation of L-DOPA into damaging quinones and reactive oxygen species was found in seeds of M. pruriens varieties. [8]

Taxonomy

Subspecies

Varieties

Itch-inducing properties

The hairs lining the seed pods contain serotonin and the protein mucunain, which cause severe itching when the pods are touched. [3] [7] The calyx below the flowers is also a source of itchy spicules and the stinging hairs on the outside of the seed pods are used in some brands of itching powder. [3] [10] Scratching the exposed area can spread the itching to other areas touched, which can cause blindness if in the area of the eyes. [11] Once this happens, the subject tends to scratch vigorously and uncontrollably and for this reason the local populace in northern Mozambique refer to the beans as "mad beans" (feijões malucos). The seed pods are known as "Devil Beans" in Nigeria.

Uses

In many parts of the world, M. pruriens is used as an important forage, fallow and green manure crop. [12] Since the plant is a legume, it fixes nitrogen and fertilizes soil. In Indonesia, particularly Java, the beans are eaten and widely known as 'Benguk'. The beans can also be fermented to form a food similar to tempeh and known as Benguk tempe or 'tempe Benguk'.

M. pruriens is a widespread fodder plant in the tropics. To that end, the whole plant is fed to animals as silage, dried hay or dried seeds. M. pruriens silage contains 11–23% crude protein, 35–40% crude fiber, and the dried beans 20–35% crude protein. It also has use in the countries of Benin and Vietnam as a biological control for problematic Imperata cylindrica grass. [12] M. pruriens is said to not be invasive outside its cultivated area. [12] However, the plant is invasive within conservation areas of South Florida, where it frequently invades disturbed land and rockland hammock edge habitats. Cooked fresh shoots or beans can also be eaten. The plant contains relatively high (3–7% dry weight) levels of l-DOPA, [13] which some people are sensitive to; it can cause nausea, vomiting, cramping, arrhythmias, and hypotension.

Traditional medicine

The plant and its extracts have long been used in tribal communities as an antidote for snakebite. More recently, its effects against bites by Naja (cobra), [14] Echis (saw-scaled viper), [15] Calloselasma (Malayan pit viper), and Bungarus (krait) species have been studied.[ citation needed ]

The dried leaves of M. pruriens are sometimes smoked.[ why? ] [5]

References

  1. "The Plant List: A Working List of All Plant Species". 2013. Retrieved 8 March 2015.
  2. 1 2 3 4 "Mucuna pruriens". Germplasm Resources Information Network . Agricultural Research Service, United States Department of Agriculture . Retrieved 8 March 2015.
  3. 1 2 3 Andersen HH, Elberling J, Arendt-Nielsen L (September 2015). "Human surrogate models of histaminergic and non-histaminergic itch" (PDF). Acta Dermato-Venereologica. 95 (7): 771–77. doi: 10.2340/00015555-2146 . PMID   26015312.
  4. Reddy VB, Iuga AO, Shimada SG, LaMotte RH, Lerner EA (April 2008). "Cowhage-evoked itch is mediated by a novel cysteine protease: a ligand of protease-activated receptors". The Journal of Neuroscience. 28 (17): 4331–35. doi:10.1523/JNEUROSCI.0716-08.2008. PMC   2659338 . PMID   18434511.
  5. 1 2 3 Rätsch, Christian (1998). Enzyklopädie der psychoaktiven Pflanzen. Botanik, Ethnopharmakologie und Anwendungen. Aarau: AT-Verl. p. 15. ISBN   978-3-85502-570-1.
  6. "Factsheet - Mucuna pruriens". www.tropicalforages.info. Archived from the original on 2008-05-15. Retrieved 2008-02-23.
  7. 1 2 Dart, Richard C. (2004). Medical Toxicology – Google Book Search. Lippincott Williams & Wilkins. ISBN   978-0-7817-2845-4 . Retrieved 2008-03-15.
  8. Pulikkalpura H, Kurup R, Mathew PJ, Baby S (June 2015). "Levodopa in Mucuna pruriens and its degradation". Scientific Reports. 5 (1): 11078. Bibcode:2015NatSR...511078P. doi:10.1038/srep11078. PMC   4460905 . PMID   26058043.
  9. "Dictionary Update: Corrected and/or Modified Entries [listing]". October 27, 2009. Archived from the original on 27 October 2009.[ failed verification ]
  10. G. V. Joglekar, M. B. Bhide J. H. Balwani. An experimental method for screening antipruritic agents. British Journal of Dermatology. Vol. 75 Iss. 3 p. 117 – March 1963
  11. The Complete Guide to Edible Wild Plants. New York: Skyhorse Publishing and United States Department of the Army. 2009. p. 129. ISBN   978-1-60239-692-0. OCLC   277203364.
  12. 1 2 3 "Factsheet – Mucuna pruriens". www.tropicalforages.info. Archived from the original on 2008-05-15. Retrieved 2008-05-21.
  13. Cohen, Pieter A.; Avula, Bharathi; Katragunta, Kumar; Khan, Ikhlas (1 October 2022). "Levodopa Content of Mucuna pruriens Supplements in the NIH Dietary Supplement Label Database". JAMA Neurology. 79 (10): 1085–86. doi:10.1001/jamaneurol.2022.2184. PMC   9361182 . PMID   35939305.
  14. Tan NH, Fung SY, Sim SM, Marinello E, Guerranti R, Aguiyi JC (June 2009). "The protective effect of Mucuna pruriens seeds against snake venom poisoning". Journal of Ethnopharmacology. 123 (2): 356–58. doi:10.1016/j.jep.2009.03.025. PMID   19429384.
  15. "Characterization of the factor responsible for the antisnake activity of Mucuna Pruriens' seeds" (PDF). Journal of Preventive Medicine and Hygiene. 40: 25–28. 1999. Archived from the original (PDF) on 2010-09-23. Retrieved 2011-03-23.

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