''Mucuna pruriens'' is a tropical

legume A legume () is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock f ...

native to

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

and

tropical Asia Tropical Asia refers to the entirety of the areas in Asia with a tropical climate. These areas are of geographic and economic importance due to their natural resources and biodiversity, which include many species of agricultural value. There are ...

and widely naturalized and cultivated. Its English

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...

s include monkey tamarind, velvet bean, Bengal velvet bean, Florida velvet bean, Mauritius velvet bean, Yokohama velvet bean, cowage, cowitch, lacuna bean, and Lyon bean. The plant is notorious for the extreme itchiness it produces on contact, particularly with the young foliage and the seed pods. It also produces many medium-sized red swollen bumps along with the itching. It has agricultural and horticultural value and is used in

herbalism Herbal medicine (also herbalism) is the study of pharmacognosy and the use of medicinal plants, which are a basis of traditional medicine. With worldwide research into pharmacology, some herbal medicines have been translated into modern reme ...

Description

''Mucuna pruriens'' is an annual climbing

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

with long vines that can reach over 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 A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are tripinnate, ovate, reverse ovate,

rhombus In plane Euclidean geometry, a rhombus (plural rhombi or rhombuses) is a quadrilateral whose four sides all have the same length. Another name is equilateral quadrilateral, since equilateral means that all of its sides are equal in length. The ...

-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 long. Additional adjacent leaves are present and are about long. The flower heads take the form of axially arrayed

panicle A panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a panicle are of ...

s. They are long and have two or three, or many flowers, which can be white, lavender, or purple. The accompanying leaves are about long; the flower stand axes are from . The bell is long and silky. The

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

s are longer or of the same length as the shuttles. The crown is purplish or white. The flag is long. The wings are long. In the fruit-ripening stage, a long, wide, unwinged,

leguminous A legume () is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock for ...

fruit develops. There is a ridge along its length and the

husk Husk (or hull) in botany is the outer shell or coating of a seed. In the United States, the term husk often refers to the leafy outer covering of an ear of maize (corn) as it grows on the plant. Literally, a husk or hull includes the protective ...

is covered in loose, orange hairs that cause a severe

itch Itch (also known as pruritus) is a sensation that causes the desire or reflex to scratch. Itch has resisted many attempts to be classified as any one type of sensory experience. Itch has many similarities to pain, and while both are unpleasant ...

if they contact skin. The pods carry up to seven seeds, which are shiny black or brown

drift seed __NOTOC__ Drift seeds (also sea beans) and drift fruits are seeds and fruits adapted for long-distance dispersal by water. Most are produced by tropical trees, and they can be found on distant beaches after drifting thousands of miles through oce ...

s. They are flattened uniform ellipsoids, long, wide and thick. The '' hilum'', the base of the '' funiculus'' (connection between placenta and plant seeds) is a surrounded by a significant ''

arillus An aril (pronounced ), also called an arillus, is a specialized outgrowth from a seed that partly or completely covers the seed. An arillode or false aril is sometimes distinguished: whereas an aril grows from the attachment point of the see ...

'' (fleshy seed shell). The dry weight of the seeds is /100 seeds.

Chemistry

The seeds of the plant contain about 3.1–6.1% , with trace amounts of

serotonin Serotonin () or 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter. Its biological function is complex and multifaceted, modulating mood, cognition, reward, learning, memory, and numerous physiological processes such as vomiting and vas ...

nicotine Nicotine is a natural product, naturally produced alkaloid in the nightshade family of plants (most predominantly in tobacco and ''Duboisia hopwoodii'') and is widely used recreational drug use, recreationally as a stimulant and anxiolytic. As ...

, and

bufotenine Bufotenin (5-HO-DMT, bufotenine) is a tryptamine derivative - more specifically, a DMT derivative - related to the neurotransmitter serotonin. It is an alkaloid found in some species of toads (especially the skin), mushrooms and plants. The nam ...

. ''M. pruriens'' var. ''pruriens'' has the highest content of . An average of 52.11% degradation of into damaging

quinones The quinones are a class of organic compounds that are formally "derived from aromatic compounds uch as benzene or naphthalene">benzene.html" ;"title="uch as benzene">uch as benzene or naphthalene] by conversion of an even number of –CH= group ...

and reactive oxygen species was found in seeds of ''M. pruriens'' varieties.

Taxonomy

Subspecies

*''Mucuna pruriens'' ssp. ''deeringiana'' (Bort) Hanelt *''Mucuna pruriens'' ssp. ''pruriens''

Varieties

* ''Mucuna pruriens'' var. ''hirsuta'' (Wight & Arn.) Christine Melanie Wilmot-Dear, Wilmot-Dear * ''Mucuna pruriens'' var. ''pruriens'' (L.) DC.Picapica
/ref> * ''Mucuna pruriens'' var. ''sericophylla'' * ''Mucuna pruriens'' var. ''utilis'' (Wall. ex Wight) L.H.Bailey is the non-stinging variety grown in

Honduras Honduras, officially the Republic of Honduras, is a country in Central America. The republic of Honduras is bordered to the west by Guatemala, to the southwest by El Salvador, to the southeast by Nicaragua, to the south by the Pacific Oce ...

Itch-inducing properties

The hairs lining the seed pods contain serotonin and the protein

mucunain The proteolytic enzyme mucunain is a protein in the tissues of certain legumes of the genus ''Mucuna'', especially velvet bean (''Mucuna pruriens''). In these species the mucunain is found in stiff hairs, or trichomes, covering the seed A se ...

, which cause severe itching when the pods are touched. 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 Itching powder is a powder or powder-like substance that induces itching when applied onto human skin. This is usually done as a practical joke or prank to an unsuspecting victim. Description and uses The cause of the irritation can be mechanical ...

.G. V. Joglekar, M. B. Bhide J. H. Balwani. An experimental method for screening antipruritic agents. ''British Journal of Dermatology''. Volume 75 Issue 3 Page 117 - March 1963 Scratching the exposed area can spread the itching to other areas touched, which can cause blindness if in the area of the eyes. Once this happens, the subject tends to scratch vigorously and uncontrollably and for this reason the local populace in northern

Mozambique Mozambique (), officially the Republic of Mozambique ( pt, Moçambique or , ; ny, Mozambiki; sw, Msumbiji; ts, Muzambhiki), is a country located in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi ...

refer to the beans as "mad beans" (''feijões malucos''). The seed pods are known as "Devil Beans" in

Nigeria Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...

Uses

In many parts of the world, ''M. pruriens'' is used as an important

forage Forage is a plant material (mainly plant leaves and stems) eaten by grazing livestock. Historically, the term ''forage'' has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used m ...

fallow Fallow is a farming technique in which arable land is left without sowing for one or more vegetative cycles. The goal of fallowing is to allow the land to recover and store organic matter while retaining moisture and disrupting pest life cycles ...

and

green manure In agriculture, a green manure is a crop specifically produced to be incorporated into the soil while still green. Typically, the green manure's biomass is incorporated with a plow or disk, as is often done with (brown) manure. The primary goal ...

crop. Since the plant is a legume, it fixes nitrogen and fertilizes soil. In

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

, particularly

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...

, the beans are eaten and widely known as 'Benguk'. The beans can also be fermented to form a food similar to

tempeh Tempeh or tempe (; jv, ꦠꦺꦩ꧀ꦥꦺ, témpé, ) is a traditional Indonesian food made from fermented soybeans. It is made by a natural culturing and controlled fermentation process that binds soybeans into a cake form. A fungus, ''Rhizopus ...

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 Silage () is a type of fodder made from green foliage crops which have been preserved by fermentation to the point of acidification. It can be fed to cattle, sheep and other such ruminants (cud-chewing animals). The fermentation and storage p ...

, 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 Benin ( , ; french: Bénin , ff, Benen), officially the Republic of Benin (french: République du Bénin), and formerly Dahomey, is a country in West Africa. It is bordered by Togo to the west, Nigeria to the east, Burkina Faso to the north ...

and

Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...

as a biological control for problematic ''

Imperata cylindrica ''Imperata cylindrica'' (commonly known as cogongrass or kunai grass ) is a species of Perennial plant, perennial rhizomatous grass native to tropical and subtropical Asia, Micronesia, Melanesia, Australia, Africa, and southern Europe. It has al ...

'' grass. ''M. pruriens'' is said to not be invasive outside its cultivated area. 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 , which some people are sensitive to; it can cause nausea, vomiting, cramping, arrhythmias, and hypotension. Up to 88% of the can be extracted from ''M. pruriens'' by boiling and soaking for approximately 48 hours. The efficiency of the process can be slightly improved by using approximately 0.25–0.50%

sodium bicarbonate Sodium bicarbonate (IUPAC name: sodium hydrogencarbonate), commonly known as baking soda or bicarbonate of soda, is a chemical compound with the formula NaHCO3. It is a salt composed of a sodium cation ( Na+) and a bicarbonate anion ( HCO3−) ...

Traditional medicine

The plant and its extracts have long been used in tribal communities as an antidote for

snakebite A snakebite is an injury caused by the bite of a snake, especially a venomous snake. A common sign of a bite from a venomous snake is the presence of two puncture wounds from the animal's fangs. Sometimes venom injection from the bite may occu ...

. More recently, its effects against bites by ''

Naja ''Naja'' is a genus of venomous elapid snakes commonly known as cobras (or "true cobras"). Members of the genus ''Naja'' are the most widespread and the most widely recognized as "true" cobras. Various species occur in regions throughout Afric ...

'' ( cobra), ''

Echis ''Echis'' (common names: saw-scaled vipers, carpet vipersSpawls S, Branch B. 1995. ''The Dangerous Snakes of Africa''. Dubai: Ralph Curtis Books. Oriental Press. 192 pp. .) is a genus of vipers found in the dry regions of Africa, the Middle East ...

'' (

saw-scaled viper ''Echis'' (common names: saw-scaled vipers, carpet vipersSpawls S, Branch B. 1995. ''The Dangerous Snakes of Africa''. Dubai: Ralph Curtis Books. Oriental Press. 192 pp. .) is a genus of vipers found in the dry regions of Africa, the Middle Eas ...

), ''

Calloselasma :''Common names: Malayan ground pit viper, Malayan pit viper, Malayan ground snake, Malayan moccasin. ''Calloselasma'' is a monotypic genus created for a venomous pit viper species, ''C. rhodostoma'', which is endemic to Southeast Asia from Thai ...

'' ( Malayan pit viper), and ''

Bungarus ''Bungarus'' is a genus of venomous elapid snakes, the kraits ("krait" is pronounced , rhyming with "kite"), found in South and Southeast Asia. The genus ''Bungarus'' has 16 species. Distribution Kraits are found in tropical Asia, from near Ira ...

'' (

krait ''Bungarus'' is a genus of venomous elapid snakes, the kraits ("krait" is pronounced , rhyming with "kite"), found in South and Southeast Asia. The genus ''Bungarus'' has 16 species. Distribution Kraits are found in tropical Asia, from near Ira ...

) species have been studied. It has been investigated as a treatment for

Parkinson's disease Parkinson's disease (PD), or simply Parkinson's, is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. The symptoms usually emerge slowly, and as the disease worsens, non-motor symptoms becom ...

due to its high content, while the seeds have been recognized for their ability to significantly alleviate neurotoxicity associated with the condition. The seeds have also been used for treating mood disorders, as well as for

sexual dysfunction Sexual dysfunction is difficulty experienced by an individual or partners during any stage of normal sexual activity, including physical pleasure, desire, preference, arousal, or orgasm. The World Health Organization defines sexual dysfunction as ...

in Tibb-e-Unani and

Ayurvedic medicine Ayurveda () is an alternative medicine system with historical roots in the Indian subcontinent. The theory and practice of Ayurveda is pseudoscientific. Ayurveda is heavily practiced in India and Nepal, where around 80% of the population repor ...

. The dried leaves of ''M. pruriens'' are sometimes smoked.

References

External links

''Mucuna pruriens'' (U.S. Forest Service)

''Mucuna pruriens'' protects against snakebite venom

''Mucuna pruriens'' var. ''utilis''
(Photos)
Chemicals in: Mucuna pruriens (L.) DC. (Dr. Duke's Phytochemical and Ethnobotanical Databases)

''Mucuna pruriens'' a Comprehensive Review

* ttps://web.archive.org/web/20110609131117/http://www.uady.mx/~veterina/publicaciones/journal/2002-2-3/Szabo-b.pdf Research Paper Showing Quantitative Phytochemical Analysis
''Mucuna pruriens'' (Kapikacchu, Atmagupta) entry in Caldecott
{{Taxonbar, from=Q953611 pruriens Medicinal plants of Asia Edible legumes Forages Nitrogen-fixing crops Plants described in 1759 Flora of Nepal