Catha edulis

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Rosids
Cladus: Eurosids I
Ordo: Celastrales

Familia: Celastraceae
Genus: Catha
Species: Catha edulis
Name

Catha edulis (Vahl) Forssk. ex Endl., Fl. Aegypt.-Arab. 67: 63 (1775).
Synonyms

Catha forskalii A. Rich.
Catha glauca (Eckl. & Zeyh.) A. Chev.
Catha inermis G. F. Gmel.
Celastrus edulis (Forsk.) Vahl
Celastrus tsaad Ferr. & Gal. ex Walp.
Celastrus tsaad Ferret & Galinier
Dillonia abyssinica Sacleux
Hartogia thea E. Mey.
Methyscophyllum glaucum Eckl. & Zeyh.
Trigonotheca serrata Hochst.

Distribution
Native distribution areas:

Continental: Asia-Temperate
Regional: Arabian Peninsula
Saudi Arabia (Hejaz, C-Saudi Arabia), Yemen (N-Inner Yemen, W-Yemen)
Continental: Africa
Regional: Southern Africa
South Africa (Limpopo, Mpulamanga, KwaZulu-Natal, E-Cape Prov.), Swaziland, Zambia, Zimbabwe
Regional: Eastern Africa
Mozambique, Malawi, Tanzania, E-D.R. Congo (Zaire), Kenya, Uganda, Rwanda, Burundi, Ethiopia, Eritrea, Sudan, South Sudan,

References: Brummitt, R.K. 2001. TDWG – World Geographical Scheme for Recording Plant Distributions, 2nd Edition
References
Primary references

Forsskål, P. (†). 1775. Flora Aegyptiaco-Arabica. Sive descriptiones plantarum, quas per Aegyptum inferiorem et Arabiam felicem detexit, illustravit Petrus Forskål. Post mortem auctoris edidit Carsten Niebuhr. Ex officina Mölleri, Hauniae [Copenhagen]. DOI: 10.5962/bhl.title.41 BHL Reference page. : 67: 63.

Links

Hassler, M. 2019. Catha edulis. World Plants: Synonymic Checklists of the Vascular Plants of the World In: Roskovh, Y., Abucay, L., Orrell, T., Nicolson, D., Bailly, N., Kirk, P., Bourgoin, T., DeWalt, R.E., Decock, W., De Wever, A., Nieukerken, E. van, Zarucchi, J. & Penev, L., eds. 2019. Species 2000 & ITIS Catalogue of Life. Published online. Accessed: 2019 September 30. Reference page.
Govaerts, R. et al. 2019. Catha edulis in Kew Science Plants of the World online. The Board of Trustees of the Royal Botanic Gardens, Kew. Published online. Accessed: 2019 September 30. Reference page.
International Plant Names Index. 2019. Catha edulis. Published online. Accessed: September 30 2019.
Tropicos.org 2019. Catha edulis. Missouri Botanical Garden. Published online. Accessed: 30 September 2019.
USDA, ARS, Germplasm Resources Information Network. Catha edulis in the Germplasm Resources Information Network (GRIN), U.S. Department of Agriculture Agricultural Research Service. Accessed: 09-Oct-10.

Vernacular names
Afrikaans: Boesmanstee, Spelonketee
čeština: Kata jedlá
dansk: Khat
Deutsch: Kathstrauch
English: Abyssinian tea, African tea, Arabian tea, Arabic khat, Bushmen's tea, Wild tea
Esperanto: Ĥato
eesti: Katapõõsas
suomi: Khat
Nederlands: Qat
norsk nynorsk: Khat
norsk: Khat
polski: Czuwaliczka jadalna
português: Khat
русский: Кат
chiShona: mutsawhare, muzaramashawa
svenska: Kat
Türkçe: Gat
Tshivenda: luthadzi, iwani
isiXhosa: igqwaka
isiZulu: umhlwazi

'Khat, qat, gat or Sallaa (Catha edulis, family Celastraceae; pronounced /ˈkɑːt/, kaht; Arabic: قات qāt; Hebrew: קאת, qat; Somali: qaad) is a flowering plant native to tropical East Africa and the Arabian Peninsula. Its Amharic name in Ethiopia is ጫት.

Khat contains the alkaloid called cathinone, an amphetamine-like stimulant which is said to cause excitement, loss of appetite, and euphoria. In 1980, the World Health Organization classified khat as a drug of abuse that can produce mild to moderate psychological dependence (less than tobacco or alcohol) [1]. The plant has been targeted by anti-drug organizations like the DEA.[2] It is a controlled or illegal substance in many countries, but is legal for sale and production in many others.

Description

Khat is a slow-growing shrub or tree that grows to between 1.5 metres and 20 metres tall, depending on region and rainfall, with evergreen leaves 5–10 cm long and 1–4 cm broad. The flowers are produced on short axillary cymes 4–8 cm long, each flower small, with five white petals. The fruit is an oblong three-valved capsule containing 1–3 seeds.

History
Man chewing khat in Sana'a, Yemen, January 2009

Catha edulis appears to have originated in Ethiopia.[3] It now occurs in Arabia, Ethiopia, Kenya, Uganda, Tanzania, the Congo, Malawi, Zimbabwe, Zambia, and South Africa.[4] Sir Richard Burton suggested that khat was introduced to the Yemen from Ethiopia in the 15th century,[5] although this probably occurred much earlier. The ancient Egyptians considered the khat plant a "divine food" which was capable of releasing humanity's divinity. The Egyptians used the plant for more than its stimulating effects; they used it as a metamorphic process and transcended into "apotheosis", intending to make the user god-like.[6]

The earliest known documented description of khat dates is found in the Kitab al-Saidana fi al-Tibb, an 11th century work on pharmacy and materia medica written by Abū Rayhān al-Bīrūnī, a Persian scientist and biologist. Unaware of its origins, al-Bīrūnī wrote that khat is:[7]

"a commodity from Turkestan. It is sour to taste and slenderly made in the manner of batan-alu. But khat is reddish with a slight blackish tinge. It is believed that batan-alu is red, coolant, relieves biliousness, and is a refrigerant for the stomach and the liver."

In 1854, Malay writer Abdullah bin Abdul Kadir noted that the custom of chewing Khat was prevalent in Al Hudaydah in Yemen:

"You observed a new peculiarity in this city — everyone chewed leaves as goats chew the cud. There is a type of leaf, rather wide and about two fingers in length, which is widely sold, as people would consume these leaves just as they are; unlike betel leaves, which need certain condiments to go with them, these leaves were just stuffed fully into the mouth and munched. Thus when people gathered around, the remnants from these leaves would pile up in front of them. When they spat, their saliva was green. I then queried them on this matter: ‘What benefits are there to be gained from eating these leaves?’ To which they replied, ‘None whatsoever, it’s just another expense for us as we’ve grown accustomed to it’. Those who consume these leaves have to eat lots of ghee and honey, for they would fall ill otherwise. The leaves are known as Kad."[8]

Cultivation and uses

The khat plant is known by a variety of names, such as qat and gat in Yemen, qaat and jaad in Somalia, and chat in Ethiopia. It is also known as Jimma in the Oromo language and miraa in the Meru Language. Khat has been grown for use as a stimulant for centuries in the Horn of Africa and the Arabian Peninsula. There, chewing khat predates the use of coffee and is used in a similar social context.

Its fresh leaves and tops are chewed or, less frequently, dried and consumed as tea, in order to achieve a state of euphoria and stimulation; it also has anorectic side-effects. The leaves or the soft part of the stem can be chewed with either chewing gum or fried peanuts to make it easier to chew. Due to the availability of rapid, inexpensive air transportation, the plant has been reported in England, Wales, Rome, Amsterdam, Canada, Australia, New Zealand[9], and the United States. The international community has become more aware of this plant through media reports pertaining to the United Nations mission in Somalia (where khat use is widespread), as well as through its role in the Persian Gulf.

Khat use has traditionally been confined to the regions where it is grown, because only the fresh leaves have the desired stimulating effects. In recent years, however, improved roads, off-road motor vehicles, and air transportation have increased the global distribution of this perishable commodity. Traditionally, khat has been used as a socializing drug, and this is still very much the case in Yemen, where khat chewing is predominantly a male habit, although not exclusively so.[10] Yemenis use traditional costumes and chew the stimulating plant in the afternoons. Chewing khat is also part of the Yemeni business culture to promote decision-making, but foreigners are not expected to participate.

In other countries, khat is consumed largely by single individuals and at parties. It is mainly a recreational drug in the countries which grow khat, though it may also be used by farmers and laborers for reducing physical fatigue or hunger, and by drivers and students for improving attention. Within the counter-culture segments of the Kenyan elite population, khat (referred to as veve ) is used to counter the effects of a hangover or binge drinking, similar to the use of the coca leaf in South America. In Yemen, some women have their own saloons for the occasion, and participate in chewing khat with their husbands on weekends. In many places where it is grown, khat has become mainstream enough for many children to start chewing the plant before puberty.

Khat is so popular in Yemen that its cultivation consumes much of the country's agricultural resources. It is estimated that 40% of the country's water supply goes towards irrigating it,[11] with production increasing by about 10% to 15% every year. Water consumption is so high that groundwater levels in the Sanaa basin are diminishing; because of this, government officials have proposed relocating large portions of the population of Sana'a to the coast of the Red Sea.[10]

One reason for cultivating khat in Yemen so widely is the high income which it provides for farmers. Some studies done in 2001 estimated that the income from cultivating khat was about 2.5 million Yemeni rials per hectare, while fruits brought only 0.57 million rials per hectare. It is estimated that between 1970 and 2000, the area on which khat was cultivated grew from 8,000 hectares to 103,000 hectares.[12]

In Somalia, the Supreme Islamic Courts Council, which took control of much of the country in 2006, banned khat during Ramadan, sparking street protests in Kismayo. In November 2006, Kenya banned all flights to Somalia, citing security concerns, prompting protests by Kenyan khat growers. The Kenyan Member of Parliament from Ntonyiri, Meru North District stated that local land had been specialized in khat cultivation, that 20 tons worth $800,000 were shipped to Somalia daily, and that a flight ban could devastate the local economy.[13] With the victory of the Provisional Government backed by Ethiopian forces in the end of December 2006, khat has returned to the streets of Mogadishu, though Kenyan traders have noted that demand has not yet returned to pre-ban levels.[14]

Chemistry and pharmacology

The stimulant effect of the plant was originally attributed to "katin", cathine, a phenethylamine-type substance isolated from the plant. However, the attribution was disputed by reports showing the plant extracts from fresh leaves contained another substance more behaviorally active than cathine. In 1975, the related alkaloid cathinone was isolated, and its absolute configuration was established in 1978. Cathinone is not very stable and breaks down to produce cathine and norephedrine. These chemicals belong to the PPA (phenylpropanolamine) family, a subset of the phenethylamines related to amphetamines and the catecholamines epinephrine and norepinephrine.[15] In fact, cathinone and cathine have a very similar molecular structure to amphetamine.[16]

When khat leaves dry, the more potent chemical, cathinone, decomposes within 48 hours leaving behind the milder chemical, cathine. Thus, harvesters transport khat by packaging the leaves and stems in plastic bags or wrapping them in banana leaves to preserve their moisture and keep the cathinone potent. It is also common for them to sprinkle the plant with water frequently or use refrigeration during transportation.

When the khat leaves are chewed, cathine and cathinone are released and absorbed through the mucous membranes of the mouth and the lining of the stomach. The action of cathine and cathinone on the reuptake of epinephrine and norepinephrine has been demonstrated in lab animals, showing that one or both of these chemicals cause the body to recycle these neurotransmitters more slowly, resulting in the wakefulness and insomnia associated with khat use.[17]

Receptors for serotonin show a high affinity for cathinone suggesting that this chemical is responsible for feelings of euphoria associated with chewing khat. In mice, cathinone produces the same types of nervous pacing or repetitive scratching behaviors associated with amphetamines.[18] The effects of cathinone peak after 15 to 30 minutes with nearly 98% of the substance metabolized into norephedrine by the liver.[16]

Cathine is somewhat less understood, being believed to act upon the adrenergic receptors causing the release of epinephrine and norepinephrine.[19] It has a half-life of about 3 hours in humans. Because the receptor effect are similar to those of cocaine medication, treatment of the occasional addiction is similar to that of cocaine. The medication bromocriptine can reduce cravings and withdrawal symptoms within 24 hours.[20]
Growing

It takes nearly seven to eight years for the Khat plant to reach its full height. Other than access to sun and water, Khat requires little maintenance. Ground water is often pumped from deep wells by diesel engines to irrigate the crops, or brought in by water trucks. The plants are watered heavily starting around a month before they are harvested to make the leaves and stems soft and moist. A good Khat plant can be harvested four times a year, providing a year long source of income for the farmer.

Effects
Comparison of physical harm and dependence regarding various drugs (the British medical journal The Lancet[21])

Khat consumption induces mild euphoria and excitement. A meta-analysis in The Lancet has stated that khat creates a pleasuring effect to the same degree as ecstasy.[dubious – discuss] Individuals become very talkative under the influence of the drug and may appear to be unrealistic and emotionally unstable. The effects of oral administration of cathinone occur more rapidly than the effects of amphetamine, roughly 15 minutes as compared to 30 minutes in amphetamine. Khat can induce manic behaviors and hyperactivity.

The use of khat results in constipation. Dilated pupils (mydriasis) are prominent during khat consumption, reflecting the sympathomimetic effects of the drug, which are also reflected in increased heart rate and blood pressure. A state of drowsy hallucinations (hypnagogic hallucinations) may result when coming down from khat use, as well.

Withdrawal symptoms that may follow occasional use include mild depression and irritability. Withdrawal symptoms that may follow prolonged khat use include lethargy, mild depression, nightmares, and slight tremor. Khat is an effective anorectic (causes loss of appetite). Long-term use can precipitate the following effects: negative impact on liver function, permanent tooth darkening (of a greenish tinge), susceptibility to ulcers, and diminished sex drive.

Those who abuse the drug generally cannot stay without it for more than 4–5 days without feeling tired and having difficulty concentrating. Some researchers also say that khat is “an amphetamine-like substance”, and those who use it are more likely to develop mental illnesses. Others say that these mental illnesses are the result of the financial problems and the sleeplessness that the drug causes. But it is still unclear if the consumption of khat directly affects the mental health of the user or not.[15] Occasionally, a psychosis can result, resembling a hypomanic state in presentation.[22]

Cognitive Impairments

Regular khat use compromises the ability to inhibit undesirable behavior. Frequent use has been shown to decrease self-control.[23]

Demographics

It is estimated that several million people are frequent users of khat. Many of the users originate from countries between Ethiopia, [24]Sudan, Kenya, and Madagascar, and in the southwestern part of the Arabian Peninsula, especially Yemen. In Yemen, 80% of the males and 45% of the females were found to be khat users who had chewed daily for long periods of their life.

The traditional form of khat chewing in Yemen involves only male users; khat chewing by females is less formal and less frequent. In Saudi Arabia, the cultivation and consumption of khat are forbidden, and the ban is strictly enforced. The ban on khat is further supported by the clergy on the grounds that the Qur'an forbids anything that is harmful to the body. In Somalia, 61% of the population reported that they do use khat, 18% report habitual use, and 21% are occasional users.

Researchers estimate that about 70–80% of Yemenis between 16 and 50 years old chew khat, at least on occasion, and it has been estimated that Yemenis spend about 14.6 million person-hours per day chewing khat. Local researcher Ali Al-Zubaidi has estimated that the amount of money spent on khat has increased from 14.6 billion rials in 1990 to 41.2 billion rials in 1995. Researchers have also estimated that families spend about 17% of their income on khat.[12]

Research programs

The University of Minnesota recently launched an international program[25] focusing on health and brain effects of khat, led by professor Mustafa al'Absi. The Khat Research Program (KRP)[26] was funded by the National Institutes of Health of the United States. The inaugural event for the KRP was held in Sharm El-Sheik, Egypt, in December, 2009[27] in collaboration with the International Brain Research Organization (IBRO) and its local affiliates.

Health risks and benefits

Immediate effects:

* increased heart rate, breathing rate, body temperature, blood pressure
* increased alertness, excitement, and energy
* decreased appetite.

Long-term effects:

* increases in severity of psychological problems (such as depression, anxiety, irritation, and more severe psychological problems)
* difficulty sleeping
* impotence
* gastrointestinal tract problems, such as constipation
* inflammation of the mouth and other parts of the oral cavity
* oral cancer.[28][29]

Regulation

In 1965, the World Health Organization Expert Committee on Dependence-producing Drugs' Fourteenth Report noted, "The Committee was pleased to note the resolution of the Economic and Social Council with respect to khat, confirming the view that the abuse of this substance is a regional problem and may best be controlled at that level".[30] For this reason, khat was not Scheduled under the Single Convention on Narcotic Drugs. In 1980 the World Health Organization classified khat as a drug of abuse that can produce mild to moderate psychological dependence.

Africa

Somalia

On 17 November 2006 the usage and distribution of khat was made illegal in Somalia.[31] The Supreme Islamic Courts Council, which took control of much of the country in that year, banned khat during Ramadan, sparking street protests in Kismayo. With the surprise victory of the Provisional Government backed by Ethiopian forces in the end of December 2006, khat has returned to the streets of Mogadishu.[14]

Asia

Israel

Khat is consumed by older Israelis of Yemenite origin, and the raw plant is available for sale in several open markets. A cocktail of Arak and minced frozen khat, mixed with grapefruit juice, has become popular in the south of the country in recent years. In 2003, Hagigat, a pill based on extracted cathinone, began to be sold in kiosks in Israel.[32] Following several cases of hospitalization the Israeli Ministry of Health clasified cathinone as a dangerous drug and Hagigat has been outlawed.[33][34]. The plant itself is allowed to chew and sell as no harm was found in normal quantities.

Europe

France

Khat is prohibited in France as a stimulant.[15]

Iceland

In August 2010 the Icelandic police intercepted khat smuggling for the first time. 37 kg were confiscated. The drugs were most likely intended for sale in Canada.[35]

Netherlands

In the Netherlands the active ingredients of khat, cathine and cathinone, are qualified as hard drugs and forbidden. The use of the unprocessed plant is legal and unrestricted. Use is mostly limited to the Somali community.[36] In 2008 health minister Ab Klink decided against qualifying the unprocessed plant as drugs after consultation with experts.[37] Khat is usually imported by airplane due to its quick decay.[38]

Norway

In Norway khat is classified as a narcotic drug and is illegal to use, sell and possess. Most users are Somali immigrants and khat is smuggled from the Netherlands and England.[39]

Norwegian Customs seized 10 metric tons of khat in 2010, an increase from less than 4 in 2006.[40]

Poland

In Poland khat is classified as a narcotic drug and is illegal to use, sell and possess.[41]

United Kingdom

Although concerns have been expressed by commentators, health professionals and community members about the use of khat in the UK, particularly by immigrants from Somalia, Yemen and Ethiopia, it is not a currently a controlled substance.[42][43] As a result of these concerns, the Home Office commissioned successive research studies to look into the matter, and in 2005, presented the question of khat's legal status before the Advisory Council on the Misuse of Drugs. After a review of the evidence, the expert committee recommended in January 2006 that the status of khat as a legal substance should remain for the time being.[42]

In 2008, Conservative politician Sayeeda Warsi stated that a future Conservative government would ban khat.[44] The website of the Conservative Party, which is now the largest party in a coalition government in the UK, states that a Conservative government would "Tackle unacceptable cultural practices by", amongst other measures, "classifying Khat".[45] In 2009, the Home Office commissioned two new studies in the effects of khat use and in June 2010, a Home Office spokesperson stated: "The Government is committed to addressing any form of substance misuse and will keep the issue of khat use under close scrutiny".[46]

Because it is legal in the UK, and because of khat's short shelf life, Britain serves as a main gateway for khat being sent by air to North America.[47]

North America

Canada

In Canada, cathinone is a controlled substance under Schedule III of the Controlled Drugs and Substances Act (CDSA), meaning it is illegal to possess or obtain unless approved by a medical practitioner. Punishment for the possession of khat could lead to a maximum sentence of three years in prison. The maximum punishment for trafficking or possession with the intent of trafficking is ten years in prison.[48][48]

In 2008, Canadian authorities reported that khat is the most common illegal drug being smuggled at airports.[49]

United States

In the United States, cathine is a Schedule IV controlled substance and cathinone is a Schedule I drug, according to the U.S. Controlled Substance Act. The 1993 DEA rule placing cathinone in Schedule I noted that it was effectively also banning khat.

Cathinone is the major psychoactive component of the plant Catha edulis (khat). The young leaves of khat are chewed for a stimulant effect. Enactment of this rule results in the placement of any material which contains cathinone into Schedule I.[50]

Khat has been seized by local police and federal authorities on several occasions.[51]

The plant itself is specifically banned in Missouri.

Khat, to include all parts of the plant presently classified botanically as catha edulis, whether growing or not; the seeds thereof; any extract from any part of such plant; and every compound, manufacture, salt, derivative, mixture, or preparation of the plant, its seed or extracts.[52]

Oceania

Australia

In Australia, the importation of khat is controlled under the Customs (Prohibited Imports) Regulations 1956. Individual users must obtain permits from the Australian Quarantine and Inspection Service and the Therapeutic Goods Administration to import up to 5 kg per month for personal use[53] Permits must also be endorsed by the Australian Customs Service which regulates the actual import of the drug.[54] In 2003, the total number of khat annual permits was 294 and the total number of individual khat permits was 202.

There are two types of import permits. The single use Permit to Import can be used only once and you must request a new permit for each time you wish to import khat. Annual Permits are labelled as such and consist of two pages. Annual Permits allow you to import up to 5 kg once a month for up to twelve months.

–

Khat is listed as a Schedule 2 dangerous drug in Queensland, in the same category as cannabis.[55] Legality in NSW is not clear.[56]

References

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