Kava
Overview
Kava or kava-kava (Piper
Piper (genus)
Piper, the pepper plants or pepper vines , are an economically and ecologically important genus in the family Piperaceae...

: Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 for 'pepper', methysticum: (Latinized) Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...

 for 'intoxicating') is a crop of the western Pacific.

The name kava(-kava) is from Tongan
Tongan language
Tongan is an Austronesian language spoken in Tonga. It has around 200,000 speakers and is a national language of Tonga. It is a VSO language.-Related languages:...

 and Marquesan
Marquesan language
Marquesan is a collection of East-Central Polynesian dialects, of the Marquesic group, spoken in the Marquesas Islands of French Polynesia. They are usually classified into two groups, North Marquesan and South Marquesan, roughly along geographic lines....

; other names for kava include awa (Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

), 'ava
Samoa 'ava ceremony
The Ava Ceremony is one of the most important customs of the Samoa Islands involving a solemn ritual where a ceremonial beverage is shared to mark most important occasions in Samoan society. The Samoan word ava is a cognate of the Polynesian word kava associated with the kava cultures in Oceania...

 (Samoa
Samoa
Samoa , officially the Independent State of Samoa, formerly known as Western Samoa is a country encompassing the western part of the Samoan Islands in the South Pacific Ocean. It became independent from New Zealand in 1962. The two main islands of Samoa are Upolu and one of the biggest islands in...

), yaqona (Fiji
Fiji
Fiji , officially the Republic of Fiji , is an island nation in Melanesia in the South Pacific Ocean about northeast of New Zealand's North Island...

), and sakau (Pohnpei
Pohnpei
Not to be confused with Pompeii, the ancient city destroyed by Vesuvius in AD 79.Pohnpei "upon a stone altar " is the name of one of the four states in the Federated States of Micronesia , situated among the Senyavin Islands which are part of the larger Caroline Islands group...

).

The roots of the plant are used to produce a drink with sedative
Sedative
A sedative or tranquilizer is a substance that induces sedation by reducing irritability or excitement....

 and anesthetic properties.
Encyclopedia
Kava or kava-kava (Piper
Piper (genus)
Piper, the pepper plants or pepper vines , are an economically and ecologically important genus in the family Piperaceae...

: Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 for 'pepper', methysticum: (Latinized) Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...

 for 'intoxicating') is a crop of the western Pacific.

The name kava(-kava) is from Tongan
Tongan language
Tongan is an Austronesian language spoken in Tonga. It has around 200,000 speakers and is a national language of Tonga. It is a VSO language.-Related languages:...

 and Marquesan
Marquesan language
Marquesan is a collection of East-Central Polynesian dialects, of the Marquesic group, spoken in the Marquesas Islands of French Polynesia. They are usually classified into two groups, North Marquesan and South Marquesan, roughly along geographic lines....

; other names for kava include awa (Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

), 'ava
Samoa 'ava ceremony
The Ava Ceremony is one of the most important customs of the Samoa Islands involving a solemn ritual where a ceremonial beverage is shared to mark most important occasions in Samoan society. The Samoan word ava is a cognate of the Polynesian word kava associated with the kava cultures in Oceania...

 (Samoa
Samoa
Samoa , officially the Independent State of Samoa, formerly known as Western Samoa is a country encompassing the western part of the Samoan Islands in the South Pacific Ocean. It became independent from New Zealand in 1962. The two main islands of Samoa are Upolu and one of the biggest islands in...

), yaqona (Fiji
Fiji
Fiji , officially the Republic of Fiji , is an island nation in Melanesia in the South Pacific Ocean about northeast of New Zealand's North Island...

), and sakau (Pohnpei
Pohnpei
Not to be confused with Pompeii, the ancient city destroyed by Vesuvius in AD 79.Pohnpei "upon a stone altar " is the name of one of the four states in the Federated States of Micronesia , situated among the Senyavin Islands which are part of the larger Caroline Islands group...

).

The roots of the plant are used to produce a drink with sedative
Sedative
A sedative or tranquilizer is a substance that induces sedation by reducing irritability or excitement....

 and anesthetic properties. Kava is consumed throughout the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

 cultures of Polynesia
Polynesia
Polynesia is a subregion of Oceania, made up of over 1,000 islands scattered over the central and southern Pacific Ocean. The indigenous people who inhabit the islands of Polynesia are termed Polynesians and they share many similar traits including language, culture and beliefs...

 including Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

, Vanuatu
Vanuatu
Vanuatu , officially the Republic of Vanuatu , is an island nation located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is some east of northern Australia, northeast of New Caledonia, west of Fiji, and southeast of the Solomon Islands, near New Guinea.Vanuatu was...

, Melanesia
Melanesia
Melanesia is a subregion of Oceania extending from the western end of the Pacific Ocean to the Arafura Sea, and eastward to Fiji. The region comprises most of the islands immediately north and northeast of Australia...

 and some parts of Micronesia
Micronesia
Micronesia is a subregion of Oceania, comprising thousands of small islands in the western Pacific Ocean. It is distinct from Melanesia to the south, and Polynesia to the east. The Philippines lie to the west, and Indonesia to the southwest....

. Kava is sedating and is primarily consumed to relax without disrupting mental clarity. Its active ingredients are called kavalactones. A Cochrane Collaboration
Cochrane Collaboration
The Cochrane Collaboration is a group of over 28,000 volunteers in more than 100 countries who review the effects of health care interventions tested in biomedical randomized controlled trials. A few more recent reviews have also studied the results of non-randomized, observational studies...

 systematic review
Systematic review
A systematic review is a literature review focused on a research question that tries to identify, appraise, select and synthesize all high quality research evidence relevant to that question. Systematic reviews of high-quality randomized controlled trials are crucial to evidence-based medicine...

 of its evidence concluded that it was likely to be more effective than placebo
Placebo
A placebo is a simulated or otherwise medically ineffectual treatment for a disease or other medical condition intended to deceive the recipient...

 at treating short-term social anxiety
Social anxiety
Social anxiety is anxiety about social situations, interactions with others, and being evaluated or scrutinized by other people...

. Safety concerns have been raised over liver toxicity largely due to the use of stems and leaves by supplement makers, as opposed to solely the root of the plant as dictated by traditional uses. However, based on a retrospective study of retained P. methysticum drug materials in Germany, the alkaloid
Alkaloid
Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...

 pipermethystine
Pipermethystine
Pipermethystine is an alkaloid present in the aerial portions of the kava plant.-Toxicity:Pipermethystine is known to induce hepatoxicity in humans, and is believed to be the cause of liver failure in individuals consuming kava supplements....

, occurring to about 0.2% in the leaves, is an unlikely cause for the observed hepatotoxicity
Hepatotoxicity
Hepatotoxicity implies chemical-driven liver damage.The liver plays a central role in transforming and clearing chemicals and is susceptible to the toxicity from these agents. Certain medicinal agents, when taken in overdoses and sometimes even when introduced within therapeutic ranges, may injure...

. Whether kava hepatotoxicity may be due to contamination with aflatoxins or other mould hepatotoxins, requires further studies. Heavy use of kava with comorbid alcohol consumption or an existing liver condition appears to lead to malnutrition, weight loss, liver damage (causing elevated serum γ -glutamyl transferase
Transferase
In biochemistry, a transferase is an enzyme that catalyzes the transfer of a functional group from one molecule to another . For example, an enzyme that catalyzed this reaction would be a transferase:In this example, A would be the donor, and B would be the acceptor...

 and high-density lipoprotein
Lipoprotein
A lipoprotein is a biochemical assembly that contains both proteins and lipids water-bound to the proteins. Many enzymes, transporters, structural proteins, antigens, adhesins, and toxins are lipoproteins...

 cholesterol
Cholesterol
Cholesterol is a complex isoprenoid. Specifically, it is a waxy steroid of fat that is produced in the liver or intestines. It is used to produce hormones and cell membranes and is transported in the blood plasma of all mammals. It is an essential structural component of mammalian cell membranes...

 levels), renal dysfunction
Renal failure
Renal failure or kidney failure describes a medical condition in which the kidneys fail to adequately filter toxins and waste products from the blood...

, rashes, pulmonary hypertension
Pulmonary hypertension
In medicine, pulmonary hypertension is an increase in blood pressure in the pulmonary artery, pulmonary vein, or pulmonary capillaries, together known as the lung vasculature, leading to shortness of breath, dizziness, fainting, and other symptoms, all of which are exacerbated by exertion...

, macrocytosis
Macrocytosis
Macrocytosis is the enlargement of red blood cells with near-constant hemoglobin concentration, and is defined by a mean corpuscular volume of greater than 100 femtolitres .- Causes :...

 of red cells, lymphocytopenia
Lymphocytopenia
Lymphocytopenia, or lymphopenia, is the condition of having an abnormally low level of lymphocytes in the blood. Lymphocytes are a white blood cell with important functions in the immune system...

, and decreasing platelet
Platelet
Platelets, or thrombocytes , are small,irregularly shaped clear cell fragments , 2–3 µm in diameter, which are derived from fragmentation of precursor megakaryocytes.  The average lifespan of a platelet is normally just 5 to 9 days...

 volumes.

Preparation and consumption

Traditional preparation

Kava is consumed in various ways throughout the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

 cultures of Polynesia
Polynesia
Polynesia is a subregion of Oceania, made up of over 1,000 islands scattered over the central and southern Pacific Ocean. The indigenous people who inhabit the islands of Polynesia are termed Polynesians and they share many similar traits including language, culture and beliefs...

, Vanuatu
Vanuatu
Vanuatu , officially the Republic of Vanuatu , is an island nation located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is some east of northern Australia, northeast of New Caledonia, west of Fiji, and southeast of the Solomon Islands, near New Guinea.Vanuatu was...

, Melanesia
Melanesia
Melanesia is a subregion of Oceania extending from the western end of the Pacific Ocean to the Arafura Sea, and eastward to Fiji. The region comprises most of the islands immediately north and northeast of Australia...

 and some parts of Micronesia
Micronesia
Micronesia is a subregion of Oceania, comprising thousands of small islands in the western Pacific Ocean. It is distinct from Melanesia to the south, and Polynesia to the east. The Philippines lie to the west, and Indonesia to the southwest....

 and Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. Traditionally it is prepared by either chewing, grinding or pounding the roots of the kava plant. Grinding is done by hand against a cone-shaped block of dead coral
Coral
Corals are marine animals in class Anthozoa of phylum Cnidaria typically living in compact colonies of many identical individual "polyps". The group includes the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton.A coral "head" is a colony of...

; the hand forms a mortar
Mortar and pestle
A mortar and pestle is a tool used to crush, grind, and mix solid substances . The pestle is a heavy bat-shaped object, the end of which is used for crushing and grinding. The mortar is a bowl, typically made of hard wood, ceramic or stone...

 and the coral a pestle. The ground root/bark is combined with only a little water, as the fresh root releases moisture during grinding. Pounding is done in a large stone with a small log. The product is then added to cold water and consumed as quickly as possible.

The extract is an emulsion
Emulsion
An emulsion is a mixture of two or more liquids that are normally immiscible . Emulsions are part of a more general class of two-phase systems of matter called colloids. Although the terms colloid and emulsion are sometimes used interchangeably, emulsion is used when both the dispersed and the...

 of kavalactone droplets in starch. The taste is slightly pungent, while the distinctive aroma depends on whether it was prepared from dry or fresh plant, and on the variety. The colour is grey to tan to opaque greenish.

Kava prepared as described above is much more potent than processed kava. Chewing produces the strongest effect because it produces the finest particles. Fresh, undried kava produces a stronger beverage than dry kava. The strength also depends on the species and techniques of cultivation. Many find mixing powdered kava with hot water makes the drink stronger. However the active ingredients of kava, such as Kavalactone, are ruined at 140 °F (60 °C). Most tea steeps at 180 °F (82.2 °C) for at least a couple of minutes which will reduce the potency of the kava.

In Vanuatu, a strong kava drink is normally followed by a hot meal or tea. The meal traditionally follows some time after the drink so that the psychoactives are absorbed into the bloodstream quicker. Traditionally no flavoring is added.

In Papua New Guinea, the locals in Madang province refer to their kava as "waild koniak" ("wild cognac" in English).

Fijians commonly share a drink called grog made by pounding sun-dried kava root into a fine powder, straining and mixing it with cold water. Traditionally, grog is drunk from the shorn half-shell of a coconut, called a bilo. Grog is very popular in Fiji
Fiji
Fiji , officially the Republic of Fiji , is an island nation in Melanesia in the South Pacific Ocean about northeast of New Zealand's North Island...

, especially among young men, and often brings people together for storytelling and socializing. Drinking grog for a few hours brings a numbing and relaxing effect to the drinker, grog also numbs the tongue and it is typical that grog drinking be followed by a "chaser" or sweet or spicy snack to follow a bilo.

Modern preparation

In Western
Western world
The Western world, also known as the West and the Occident , is a term referring to the countries of Western Europe , the countries of the Americas, as well all countries of Northern and Central Europe, Australia and New Zealand...

 countries, Kava beverage is usually made from Kava root powder. The root is dried and then finely ground into powder before being exported. Generally one tablespoon of powder is added per cup of water, but sometimes as much as a half a cup of powder (eight tablespoons) is added per cup of water to increase potency. The powder is then soaked in water for approximately 30 minutes to allow the water to completely soak through the powdered fibers. Lecithin
Lecithin
Lecithin is a generic term to designate any group of yellow-brownish fatty substances occurring in animal and plant tissues, and in egg yolk, composed of phosphoric acid, choline, fatty acids, glycerol, glycolipids, triglycerides, and phospholipids .The word lecithin was originally coined in 1847 by...

 is often added to aid in the process of emulsifying the kavalactones with water. The Kava powder, water, and lecithin are blended in a blender for several minutes then strained into a straining cloth. Nylon
Nylon
Nylon is a generic designation for a family of synthetic polymers known generically as polyamides, first produced on February 28, 1935, by Wallace Carothers at DuPont's research facility at the DuPont Experimental Station...

, cheesecloth
Cheesecloth
Cheesecloth is a loosewoven gauze-like cotton cloth used primarily in cheese making and cooking.Cheesecloth is available in at least seven different grades, from open to extra-fine weave. Grades are distinguished by the number of threads per inch in each direction.- Uses :The primary use of...

, and silk screen are common materials for straining. The remaining liquid is squeezed from the pulp and the rest is discarded. As an alternative to the blender method, with the powdered pulp enclosed within the straining material, the pulp is massaged for five to thirty minutes in water, then the liquid is wrung out. The more pressure that is applied to the wet powdered pulp while wringing it out, the more kavalactones will be released from it. Finally the pulp resin is discarded and the beverage is enjoyed. Often coconut
Coconut
The coconut palm, Cocos nucifera, is a member of the family Arecaceae . It is the only accepted species in the genus Cocos. The term coconut can refer to the entire coconut palm, the seed, or the fruit, which is not a botanical nut. The spelling cocoanut is an old-fashioned form of the word...

 water, coconut milk, lemongrass, cocoa
Cocoa solids
Cocoa solids are the low-fat component of chocolate. When sold as an end product, it may also be called cocoa powder, cocoa, and cacao....

, sugar
Sugar
Sugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...

, or soy milk is added to improve flavor.

Pills

Pharmaceutical companies and herbal supplement companies extract kavalactones from the kava plant using solvents such as acetone
Acetone
Acetone is the organic compound with the formula 2CO, a colorless, mobile, flammable liquid, the simplest example of the ketones.Acetone is miscible with water and serves as an important solvent in its own right, typically as the solvent of choice for cleaning purposes in the laboratory...

 and ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...

 and produce pills standardized with between 30% and 90% kavalactones. Some kava herbal supplements have been accused of contributing to very rare but severe hepatotoxic reactions (see section on safety) such may have been due to the use of plant parts other than the root, such as stems or peelings that are known to have been exported to European manufacturers. A kava pill usually has anywhere from 60 mg to 150 mg of kavalactones. By comparison the typical bowl of traditionally prepared kava beverage has around 250 mg of kavalactones.

Herbal medicine

Kava is chewed by some to relieve symptoms of throat pain, as Kava produces a "numbing" effect on the tongue and throat. The Kava is first chewed in the back of the mouth for 5 to 10 minutes while swallowing the saliva and kavalactones released from the process. The Kava produces an effect similar to that of a chloraseptic
Chloraseptic
Chloraseptic is an American brand of oral analgesic produced by Prestige Brands Inc, used for the relief of minor sore throat and mouth pain. Its active ingredient is phenol, a compound whose antiseptic properties were discovered by Sir Joseph Lister....

 spray (An over-the-counter medicine to alleviate sore throat by numbing it, via pump-sprayed into the mouth).

Pharmacology

Kava's active principal ingredients are the kavalactone
Kavalactone
Kavalactones are a class of lactone compounds found in the kava shrub.-Compounds:At least 18 different kavalactones have been identified to date, with methysticin being the first identified.Analogues, such as ethysticin, have also been isolated....

s, of which at least 15 have been identified and are all considered psychoactive. Only six of them produce noticeable effects, and their concentrations in kava plants vary. Different ratios can produce different effects.

Pharmacodynamics

Effects of kavalactones include mild sedation
Sedation
Sedation is the reduction of irritability or agitation by administration of sedative drugs, generally to facilitate a medical procedure or diagnostic procedure...

, a slight numbing
Paresthesia
Paresthesia , spelled "paraesthesia" in British English, is a sensation of tingling, burning, pricking, or numbness of a person's skin with no apparent long-term physical effect. It is more generally known as the feeling of "pins and needles" or of a limb "falling asleep"...

 of the gums and mouth, and vivid dreams. Kava has been reported to improve cognitive performance and promote a cheerful mood. Kava has similar effects to benzodiazepine
Benzodiazepine
A benzodiazepine is a psychoactive drug whose core chemical structure is the fusion of a benzene ring and a diazepine ring...

 medications, including muscle relaxant
Muscle relaxant
A muscle relaxant is a drug which affects skeletal muscle function and decreases the muscle tone. It may be used to alleviate symptoms such as muscle spasms, pain, and hyperreflexia. The term "muscle relaxant" is used to refer to two major therapeutic groups: neuromuscular blockers and spasmolytics...

, anaesthetic, anticonvulsive
Anticonvulsant
The anticonvulsants are a diverse group of pharmaceuticals used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of bipolar disorder, since many seem to act as mood stabilizers, and in the treatment of neuropathic pain. The goal of an...

 and anxiolytic
Anxiolytic
An anxiolytic is a drug used for the treatment of anxiety, and its related psychological and physical symptoms...

 effects. They are thought to result from direct interactions of kavalactones with voltage-gated ion channel
Voltage-gated ion channel
Voltage-gated ion channels are a class of transmembrane ion channels that are activated by changes in electrical potential difference near the channel; these types of ion channels are especially critical in neurons, but are common in many types of cells....

s. Research currently suggests that kavalactones potentiate GABAA activity but do not alter levels of dopamine
Dopamine
Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...

 and serotonin
Serotonin
Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...

 in the CNS
Central nervous system
The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...

. Heavy, long-term kava use does not cause any reduction of ability in saccade
Saccade
A saccade is a fast movement of an eye, head or other part of an animal's body or device. It can also be a fast shift in frequency of an emitted signal or other quick change. Saccades are quick, simultaneous movements of both eyes in the same direction...

 and cognitive tests but is associated with elevated liver enzymes.

Desmethoxyyangonin
Desmethoxyyangonin
Desmethoxyyangonin or 5,6-dehydrokawain is one of the six major kavalactones found in the Piper methysticum plant.-Pharmacology:...

, one of the six major kavalactones, is a reversible MAO-B inhibitor (Ki 280 nM
Mole (unit)
The mole is a unit of measurement used in chemistry to express amounts of a chemical substance, defined as an amount of a substance that contains as many elementary entities as there are atoms in 12 grams of pure carbon-12 , the isotope of carbon with atomic weight 12. This corresponds to a value...

) and is able to increase dopamine
Dopamine
Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...

 levels in the nucleus accumbens
Nucleus accumbens
The nucleus accumbens , also known as the accumbens nucleus or as the nucleus accumbens septi , is a collection of neurons and forms the main part of the ventral striatum...

. This finding might correspond to the slightly euphoric action of kava.

Kavain
Kavain
Kavain is the main kavalactone found mostly in the roots of the Kava plant.-Pharmacology:Kavain has anticonvulsive properties, attenuating vascular smooth muscle contraction through interactions with voltage-dependent Na+ and Ca2+ channels...

, in both enantiomer
Enantiomer
In chemistry, an enantiomer is one of two stereoisomers that are mirror images of each other that are non-superposable , much as one's left and right hands are the same except for opposite orientation. It can be clearly understood if you try to place your hands one over the other without...

ic forms, inhibits the reuptake
Reuptake
Reuptake, or re-uptake, is the reabsorption of a neurotransmitter by a neurotransmitter transporter of a pre-synaptic neuron after it has performed its function of transmitting a neural impulse....

 of noradrenalin at the transporter (NAT
Norepinephrine transporter
The norepinephrine transporter , also known as solute carrier family 6 member 2 , is a protein that in humans is encoded by the SLC6A2 gene....

), but not of serotonin
Serotonin
Serotonin or 5-hydroxytryptamine is a monoamine neurotransmitter. Biochemically derived from tryptophan, serotonin is primarily found in the gastrointestinal tract, platelets, and in the central nervous system of animals including humans...

 (SERT
Serotonin transporter
The serotonin transporter is a monoamine transporter protein.This protein is an integral membrane protein that transports the neurotransmitter serotonin from synaptic spaces into presynaptic neurons. This transport of serotonin by the SERT protein terminates the action of serotonin and recycles it...

). An elevated extracellular
Extracellular
In cell biology, molecular biology and related fields, the word extracellular means "outside the cell". This space is usually taken to be outside the plasma membranes, and occupied by fluid...

 noradrenalin level in the brain may account for the reported enhancement of attention
Attention
Attention is the cognitive process of paying attention to one aspect of the environment while ignoring others. Attention is one of the most intensely studied topics within psychology and cognitive neuroscience....

 and focus.

Effects

Medical literature sometimes claims Kava has a "potential for addiction" because "it produces mild euphoria and relaxation"
In a traditional setting, a moderately potent kava drink causes effects within 20–30 minutes that last for about two and a half hours, but can be felt for up to eight hours. Some report longer term effects up to two days after ingestion, including a feeling of mental clarity, patience, and an ease of acceptance. The effects of kava are most often compared to alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....

, or diazepam
Diazepam
Diazepam , first marketed as Valium by Hoffmann-La Roche is a benzodiazepine drug. Diazepam is also marketed in Australia as Antenex. It is commonly used for treating anxiety, insomnia, seizures including status epilepticus, muscle spasms , restless legs syndrome, alcohol withdrawal,...

.

The sensations, in order of appearance, are slight tongue and lip numbing (the lips and skin surrounding may appear unusually pale); mildly talkative and sociable behavior; clear thinking; calmness; relaxed muscles; and a sense of well-being. As with other drugs that affect the GABA receptors, there can also be paradoxical dysphoria
Dysphoria
Dysphoria is medically recognized as a mental and emotional condition in which a person experiences intense feelings of depression, discontent and indifference to the world around them.Mood disorders can induce dysphoria, often with a heightened risk of suicide, especially in...

. The numbing of the mouth is caused by the two kavalactones kavain and dihydrokavain which cause the contraction of the blood vessels in these areas acting as a local topical anesthetic. These anesthetics can also make one's stomach feel numb. Sometimes this feeling has been mistaken for nausea. Some report that caffeine, consumed moderately in conjunction with kava can significantly increase mental alertness.

The effects of a kava drink vary widely with the particular selection of kava plant(s) and amount. A potent drink results in a faster onset with a lack of stimulation; the user's eyes become sensitive to light, the person soon becomes somnolent
Somnolence
Somnolence is a state of near-sleep, a strong desire for sleep, or sleeping for unusually long periods . It has two distinct meanings, referring both to the usual state preceding falling asleep, and the chronic condition referring to being in that state independent of a circadian rhythm...

 and then has deep, dreamless sleep within 30 minutes. Sleep is often restful and there are pronounced periods of sleepiness correlating to the amount and potency of kava consumed. After wakening the drinker usually does not experience any mental or physical after effects
Hangover
A hangover describes the sum of unpleasant physiological effects following heavy consumption of alcoholic beverages. The most commonly reported characteristics of a hangover include headache, nausea, sensitivity to light and noise, lethargy, dysphoria, diarrhea and thirst, typically after the...

. However, this sleep has been reported as extremely restful and the user often wakes up more stimulated than he or she normally would (though excessive consumption of exceptionally potent brew has been known to cause pronounced sleepiness into the next day). Although heavy doses can cause deep dreamless sleep, it is reported that many people experience lighter sleep and rather vivid dreams after drinking moderate amounts of kava.

Adverse effects

Australian studies focused on populations with heavy concomitant consumption of alcohol and overall poor health. In one study, heavy kava use in an Aboriginal
Australian Aborigines
Australian Aborigines , also called Aboriginal Australians, from the latin ab originem , are people who are indigenous to most of the Australian continentthat is, to mainland Australia and the island of Tasmania...

 community in Arnhem Land
Arnhem Land
The Arnhem Land Region is one of the five regions of the Northern Territory of Australia. It is located in the north-eastern corner of the territory and is around 500 km from the territory capital Darwin. The region has an area of 97,000 km² which also covers the area of Kakadu National...

 was associated with overall poor health, a puffy face, scaly rash, and a slight increase in patellar reflexes. There are also several documented adverse interactions with drugs, both prescription and non-prescription – including, but not limited to, Anticonvulsants, Alcohol, Anti-Anxiety Medications, Antipsychotic Medications, and Levodopa.

Detection in biological fluids

Recent usage of kava has been documented in forensic investigations by quantitation of kavain in blood specimens. The principal urinary metabolite, conjugated 4'-OH-kavain, is generally detectable for up to 48 hours.

Kava culture


Kava is used for medicinal, religious, political, cultural and social purposes throughout the Pacific. These cultures have a great respect for the plant and place a high importance on it. In Fiji, for example, a formal yaqona (kava) ceremony will often accompany important social, political, religious, etc. functions, usually involving a ritual presentation of the bundled roots as a sevusevu (gift), and drinking of the yaqona itself.

Correspondingly, the paraphernalia surrounding the traditional kava ceremony are expertly crafted. Traditionally designed Kava bowls are bowls made from a single piece of wood, with multiple legs. More modern examples are also highly decorated, often carved and inlayed with mother of pearl and shell.

Kava is used primarily at social gatherings to increase amiability and to relax after work. It has great religious significance, being used to obtain inspiration. Among some Christian denominations and sects in the Western Pacific, such as the Church of Jesus Christ of Latter-day Saints, the drink has been seen as a vice to some, and some young members of these religions often reject its traditional and non-traditional uses. However, among many mainline Christian denominations, i.e. the Roman Catholic, Methodist, and Anglican churches, kava drinking is encouraged where it replaces alcohol.

Botany and agronomy

There are several cultivar
Cultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...

s of kava, with varying concentrations of primary and secondary psychoactive substances. The largest number are grown in the Republic of Vanuatu, and so it is recognised as the "home" of kava. Kava was historically grown only in the Pacific islands of Hawaii, Federated States of Micronesia
Micronesia
Micronesia is a subregion of Oceania, comprising thousands of small islands in the western Pacific Ocean. It is distinct from Melanesia to the south, and Polynesia to the east. The Philippines lie to the west, and Indonesia to the southwest....

, Vanuatu
Vanuatu
Vanuatu , officially the Republic of Vanuatu , is an island nation located in the South Pacific Ocean. The archipelago, which is of volcanic origin, is some east of northern Australia, northeast of New Caledonia, west of Fiji, and southeast of the Solomon Islands, near New Guinea.Vanuatu was...

, Fiji
Fiji
Fiji , officially the Republic of Fiji , is an island nation in Melanesia in the South Pacific Ocean about northeast of New Zealand's North Island...

, the Samoa
Samoa
Samoa , officially the Independent State of Samoa, formerly known as Western Samoa is a country encompassing the western part of the Samoan Islands in the South Pacific Ocean. It became independent from New Zealand in 1962. The two main islands of Samoa are Upolu and one of the biggest islands in...

s and Tonga
Tonga
Tonga, officially the Kingdom of Tonga , is a state and an archipelago in the South Pacific Ocean, comprising 176 islands scattered over of ocean in the South Pacific...

. Some is grown in the Solomon Islands
Solomon Islands
Solomon Islands is a sovereign state in Oceania, east of Papua New Guinea, consisting of nearly one thousand islands. It covers a land mass of . The capital, Honiara, is located on the island of Guadalcanal...

 since World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, but most is imported. Kava is a cash crop in Vanuatu and Fiji.

The kava shrub thrives in loose, well-drained soils where plenty of air reaches the roots. It grows naturally where rainfall is plentiful (over 2,000 mm/yr). Ideal growing conditions are 70–95 °F (21.1–35 °C) and 70–100% relative humidity. Too much sunlight is harmful, especially in early growth, so kava is an understory
Understory
Understory is the term for the area of a forest which grows at the lowest height level below the forest canopy. Plants in the understory consist of a mixture of seedlings and saplings of canopy trees together with understory shrubs and herbs...

 crop.

Kava cannot reproduce sexually. Female flowers are especially rare and do not produce fruit even when hand-pollinated. Its cultivation is entirely by propagation from stem cuttings.

Traditionally, plants are harvested around 4 years of age, as older plants have higher concentrations of kavalactones. But in the past two decades farmers have been harvesting younger and younger plants, as young as 18 months. After reaching about 2 m height, plants grow a wider stalk and additional stalks, but not much taller. The roots can reach a depth of 60 cm.

Strains and origins

One of the most potent strains is called "Isa" in Papua New Guinea, and also called "Tuday" in Hawaii. In Vanuatu it is considered a type of "Tudei" kava, pronounced as "two-day" because it is said to have effects lasting two days due to its chemical profile being high in the kavalactone dihydromethysticin. The plant itself is a strong, very hardy, fast-growing variety with multiple light to dark green stems covered with raised dark spots.

In Vanuatu, there are strict laws over the exportation of Kava. Only strains they deem as "noble" varieties that are not too weak or too potent are allowed to be exported. Only the most desirable strains for every day drinking are selected to be noble varieties in order to maintain quality control. In addition their laws mandate that exported kava must be at least five years old and farmed organically. Their most popular noble strains are "Boroguu" or "Boronggoru" from Pentecost Island
Pentecost Island
Pentecost Island is one of the 83 islands that make up the South Pacific nation of Vanuatu. It lies due north of capital Port Vila. Pentecost Island is known as Pentecôte in French and Pentikos in Bislama. The island was known in its native languages by names such as Vanu Aroaroa, although these...

. "Melomelo" from Ambae island, (called 'sese' in North Pentecost) and "Palarasul" kava from Espiritu Santo
Espiritu Santo
Espiritu Santo is the largest island in the nation of Vanuatu, with an area of . It belongs to the archipelago of the New Hebrides in the Pacific region of Melanesia. It is in the Sanma Province of Vanuatu....

 Island. In Vanuatu, Tudei (two-days) kava is reserved for special ceremonial occasions and exporting it is not allowed. "Palisi" is a popular Tudei variety.

In Hawaii, there are many other strains of kava. Some of the most popular strains are the "Mahakea," "Mo'i," "Hiwa" and "Nene" varieties. The Ali'i (kings) of old Hawaii coveted the special kava they called "Mo'i" that had a strong cerebral effect due to a predominant amount of the kavalactone kavain. This sacred variety was so important to them that no one but royalty could ever experience it, "lest they suffer an untimely death." The reverence for Hiwa in old Hawai‘i is evident in this portion of a chant recorded by N.B. Emerson and quoted by Handy and Handy. "This refers to the cup of sacramental‘awa brewed from the strong, black ‘awa root (‘awa hiwa) which was drunk sacramentally by the kumu hula":
 
The day of revealing shall see what it sees:
A seeing of facts, a sifting of rumors,
An insight won by the black sacred ‘awa,
A vision like that of a sacred god!
 
Winter describes a hula prayer for inspiration which contains the line, "He ‘ike pū ‘awa hiwa." Pukui and Elbert translated this as "a knowledge from kava offerings." Winter explains that ‘awa, especially of the Hiwa variety, was offered to hula deities in return for knowledge and inspiration. [pg. 34, Hawaiian 'Awa, Views of an Ethnobotanical Treasure, 2006].
Other strains are found in Fiji, Tonga, and Samoa.

Composition

Fresh kava root contains on average 80% water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

. Dried root contains approximately 43% starch
Starch
Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...

, 20% fibers, 15% kavalactone
Kavalactone
Kavalactones are a class of lactone compounds found in the kava shrub.-Compounds:At least 18 different kavalactones have been identified to date, with methysticin being the first identified.Analogues, such as ethysticin, have also been isolated....

s, 12% water, 3.2% sugar
Sugar
Sugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...

s, 3.6% protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

s, and 3.2% minerals
Micronutrient
Micronutrients are nutrients required by humans and other living things throughout life in small quantities to orchestrate a whole range of physiological functions, but which the organism itself cannot produce. For people, they include dietary trace minerals in amounts generally less than 100...

. Kavalactone content is greatest in the roots and decreases higher up the plant. Relative concentrations of 15%, 10% and 5% have been observed in the root, stump, and basal stems, respectively.

The mature roots of the kava plant are harvested after a minimum of 4 years (at least five years ideally) for peak kavalactone content. Most kava plants produce around 50 kg (110 lb) of root when they are harvested. Kava root is classified into two categories: crown root (or chips) and lateral root. Crown roots are the large diameter pieces that look like big (1.5 to 5 in (38.1 to 127 mm) diameter) wooden poker chips. Most kava plants consist of approximately 80% crown root upon harvesting. Lateral roots are smaller diameter roots that look more like a typical root. A mature kava plant is approximately 20% lateral roots. Kava lateral roots have the highest content of kavalactones in the kava plant. "Waka" grade kava is kava that is made of lateral roots only.

Basic research on anti-cancer potential

On 15 February 2006, the Fiji Times
Fiji Times
The Fiji Times is a daily English-language newspaper published in Suva, Fiji. Established in Levuka on 4 September 1869, it is Fiji's oldest newspaper still operating....

and Fiji Live
Fiji Live
Fijilive is an online newspaper and business and cultural directory in Fiji. The site is owned by the Future Group of Companies owned by Fiji entrepreneur Yashwant Gaunder....

 reported that researchers at the University of Aberdeen
University of Aberdeen
The University of Aberdeen, an ancient university founded in 1495, in Aberdeen, Scotland, is a British university. It is the third oldest university in Scotland, and the fifth oldest in the United Kingdom and wider English-speaking world...

 in Scotland
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

 and the Laboratoire de Biologie Moleculaire du Cancer in Luxembourg
Luxembourg
Luxembourg , officially the Grand Duchy of Luxembourg , is a landlocked country in western Europe, bordered by Belgium, France, and Germany. It has two principal regions: the Oesling in the North as part of the Ardennes massif, and the Gutland in the south...

 had discovered that kava may treat ovarian cancer
Ovarian cancer
Ovarian cancer is a cancerous growth arising from the ovary. Symptoms are frequently very subtle early on and may include: bloating, pelvic pain, difficulty eating and frequent urination, and are easily confused with other illnesses....

 and leukemia
Leukemia
Leukemia or leukaemia is a type of cancer of the blood or bone marrow characterized by an abnormal increase of immature white blood cells called "blasts". Leukemia is a broad term covering a spectrum of diseases...

. Kava compounds inhibited the activation of a nuclear factor that led to the growth of cancer cells. The Aberdeen University researchers published in the journal The South Pacific Journal of Natural Science that kava methanol
Methanol
Methanol, also known as methyl alcohol, wood alcohol, wood naphtha or wood spirits, is a chemical with the formula CH3OH . It is the simplest alcohol, and is a light, volatile, colorless, flammable liquid with a distinctive odor very similar to, but slightly sweeter than, ethanol...

 extracts had been shown to kill leukemia and ovarian cancer cells in test tube
Test tube
A test tube, also known as a culture tube or sample tube, is a common piece of laboratory glassware consisting of a finger-like length of glass or clear plastic tubing, open at the top, usually with a rounded U-shaped bottom....

s. The kava compounds were shown to target only cancerous cells; no healthy cells were harmed. This may help explain why kava consumption is correlated with decreased incidence of cancer.

Fiji Kava Council Chairman Ratu
Ratu
Ratu is a title used by Fijians of chiefly rank. An equivalent title, Adi is used by females of chiefly rank.-Etymology:Ra is a prefix in many titles and Tu is simply "chief"...

 Josateki Nawalowalo
Josateki Nawalowalo
Ratu Josateki Tuivanuavou Nacagilevu Nawalowalo, commonly known as Ratu Jo Nawalowalo, was a Fijian chief, businessman, and the Chairman of the Kadavu Provincial Council...

 welcomed the findings, saying that they would boost the kava industry. For his part, Agriculture Minister Ilaitia Tuisese
Ilaitia Tuisese
Ilaitia Bulidiri Tuisese is a Fijian politician, who currently serves in the Cabinet as Minister for Fisheries and Forests.Tuisese was appointed Minister for Regional Development and Minister for Multi-Ethnic Questions in the interim government that was formed in July 2000 the wake of the failed...

 called on the researchers to help persuade members of European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...

 to lift their ban on kava imports.

In November 2008, the EU announced its lifting of the kava trade ban, which had been imposed due to accusations made in 2001 and since debunked through scientific review of the facts.

Skin rashes

Chronic and heavy use of kava for a period of three months or more has occasionally been reported to cause a scaly, yellow skin rash and an eye irritation that disappears after discontinuation of the herb. The rash resembles one brought on by a niacin
Niacin
"Niacin" redirects here. For the neo-fusion band, see Niacin .Niacin is an organic compound with the formula and, depending on the definition used, one of the forty to eighty essential human nutrients.Niacin is one of five vitamins associated with a pandemic deficiency disease: niacin deficiency...

 (vitamin B3) deficiency; however, a double-blind, placebo-controlled study showed no change in the rash after niacin supplementation. The 29 Tonga
Tonga
Tonga, officially the Kingdom of Tonga , is a state and an archipelago in the South Pacific Ocean, comprising 176 islands scattered over of ocean in the South Pacific...

 islanders who presented with the rash after heavy kava consumption—more than 900 g/week—were given either 100 mg of oral niacinamide or placebo. No statistically significant improvement was seen in the supplementing group, suggesting niacin deficiency may not cause the rash, which is more characteristic of an acquired ichthyosis
Ichthyosis
Ichthyosis is a heterogeneous family of at least 28, generalized, mostly genetic skin disorders. All types of ichthyosis have dry, thickened, scaly or flaky skin...

.

Reports of liver damage and regulation

In 2001, concerns were raised about the safety of commercial kava products. There were allegations of liver toxicity in some people who had used dietary supplements containing kava extract (but not in anyone who had drunk kava the traditional way).
The allegations of liver damage consequently prompted action of many regulatory agencies in European countries where the legal precautionary principle so mandated. In the UK
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, the Medicines for Human Use (Kava-kava) (Prohibition) Order 2002 prohibits the sale, supply or import of most derivative medicinal products. Kava is banned in Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

, France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

, and the Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

. The health agency of Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 issued a stop-sale order for kava in 2002. But legislation in 2004 made the legal status of kava murky to many, especially since not everyone is aware that a stop-sale order does not constitute a ban such as that applies in several European countries. Kava is not illegal in Canada and doesn't fall under any of the Food and Drugs Act & Regulations. Many retailers have been ignoring the no-sale order without further consequence than having Health Canada issue warnings about the product's safety. At least one US manufacturer of kava products who had suspended export to Canada in 2002 has since lifted the restriction and resumed shipping kava to Canada after obtaining confirmation that it wasn't illegal for Canadians to import kava. The United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 CDC
Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...

 has released a report
expressing reservations about the use of kava and its possibly adverse side effects (specifically severe liver toxicity), as has the Food and Drug Administration
Food and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...

 (FDA). The aviation medicine branch of the FAA has strongly recommended against any use of Kava by pilots (http://aviationmedicine.com/articles/index.cfm?fuseaction=displayArticle&articleID=48) In Australia, the supply of kava is regulated through the National Code of Kava Management. The sale and supply of kava is prohibited in western Australia and the Northern territory. The Australian Therapeutic Goods Administration
Therapeutic Goods Administration
The Therapeutic Goods Administration is the regulatory body for therapeutic goods in Australia . It is a Division of the Australian Department of Health and Ageing established under the Therapeutic Goods Act 1989 ...

 has recommended that no more than 250 mg of kavalactones be taken in a 24 hour period. According to the Medicines Control Agency in the U.K., there is no safe dose of kava, as there is no way to predict which individuals would have adverse reactions, if any.

In a 2009 study by the University of Queensland
University of Queensland
The University of Queensland, also known as UQ, is a public university located in state of Queensland, Australia. Founded in 1909, it is the oldest and largest university in Queensland and the fifth oldest in the nation...

, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, researchers found that the study's participants did not show any signs of potential liver damage, contrary to concerns that prompted European, British and Canadian authorities to ban kava sales in 2002. Kava products sold in those countries were based on ethanol or acetone extracts of the kava plant, not the water-soluble extracts used traditionally by Pacific islanders and approved for sale in Australia.

It has been suggested that Flavokawain B is the hepatotoxic chemical in Kava. It is not known if this chemical survives traditional preparation of the herb.

Toxicology of pill from kava extracts with stems and leaves

The legal intervention of several countries stimulated research, and hepatotoxic substances were found in the stems and leaves of the plant. Researchers from the University of Hawaii at Manoa
University of Hawaii at Manoa
The University of Hawaii at Mānoa is a public, co-educational university and is the flagship campus of the greater University of Hawaii system...

 found that an alkaloid
Alkaloid
Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...

 called pipermethystine (formula 1), contained in stem peelings and leaves but not in the roots, had toxic effects on liver cells in vitro
In vitro
In vitro refers to studies in experimental biology that are conducted using components of an organism that have been isolated from their usual biological context in order to permit a more detailed or more convenient analysis than can be done with whole organisms. Colloquially, these experiments...

and in vivo
In vivo
In vivo is experimentation using a whole, living organism as opposed to a partial or dead organism, or an in vitro controlled environment. Animal testing and clinical trials are two forms of in vivo research...

. In rats fed with 10 mg/kg pipermethystine for two weeks, indications of hepatic toxicity were found. Comparable signs of toxicity were not detected with kava rhizome
Rhizome
In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...

 extracts (100 mg/kg, 2 weeks), (73 mg/kg, 3 months).

Flavokavain B
Flavokavain B
Flavokavain B is a flavokavain found in the kava plant.-External links:* at the United States National Library of Medicine...

, found in the plant's rhizome
Rhizome
In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...

 (large horizontal underground stem), may also contribute to toxic effects.
It is also known that some of the kavapyrones
Kavalactone
Kavalactones are a class of lactone compounds found in the kava shrub.-Compounds:At least 18 different kavalactones have been identified to date, with methysticin being the first identified.Analogues, such as ethysticin, have also been isolated....

 block several subtypes of the enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

 cytochrome P450,
which can result in adverse interactions with other drugs used concomitantly.

Hawaiian researchers learned from a trader in Fijian kava that European pharmaceutical companies eagerly bought up the stem and leaves peelings when demand for kava extract soared in Europe in 2000 and 2001. Before 2002, substantial amounts of aerial parts of the kava plant were being exported to North America and Europe and obviously used for the production of commercial pill extracts. For traditional use in the South Pacific, stem peelings and leaves are discarded, and only the rhizomes are used and extracted with water. This may explain why native populations that make heavy use of kava experience side effects that are mild, temporary, and confined to the skin, whereas industrialized countries that have newly adopted kava occasionally show severe, acute responses.

Toxicity of traditional kava beverage preparations

In April 2003, University of Hawaii scientists reported to have discovered that traditionally discarded stem peelings and leaves of kava contain a toxic alkaloid—not present in the plant's roots. European pharmaceutical companies are known to have purchased such peelings when demand for kava extract soared in 2000-2001.

Two studies still allege changes in liver function, with the first describing the effects as temporary and reversible when discontinuing kava use. There is evidence of health concerns among heavy alcohol drinkers, including poor nutrition and a rise in liver enzymes typically associated with liver damage.

Another study published in the journal Pytochemistry in 2003 indicates that traditional aqueous preparations of Kava also extract glutathione, which alcoholic extracts lack when they are made with high concentrations of alcohol. The authors discover that the glutathione in traditional preparations interacts with the kava-lactones and prevents cell death. They claim that in all standardized extracts that contributed to liver damage, there were only the kava-lactones without any glutathione.

Allergy

Allergic reactions are usually mild and include itchy skin or itchy throat, and hives on the skin usually prevalent on the user's belly region.

See also

  • Kava culture
    Kava culture
    Kava cultures are the religious and cultural traditions of western Oceania which consume kava. There are similarities in the use of kava between the different cultures, but each one also has its own traditions.-Hawaii:...

  • Samoa 'ava ceremony
    Samoa 'ava ceremony
    The Ava Ceremony is one of the most important customs of the Samoa Islands involving a solemn ritual where a ceremonial beverage is shared to mark most important occasions in Samoan society. The Samoan word ava is a cognate of the Polynesian word kava associated with the kava cultures in Oceania...

  • List of herbs with known adverse effects
  • Alcohol and Drugs History Society
    Alcohol and Drugs History Society
    The Alcohol and Drugs History Society is a scholarly organization whose members study the history of a variety of illegal, regulated, and unregulated drugs such as opium, alcohol, and coffee. Organized in 2004, the ADHS is the successor to a society with a more limited scope, the Alcohol and...

  • Samoan plant names
    Samoan plant names
    These are some Samoan plant names in alphabetical order in the Samoan language and their corresponding descriptions in English. Many are used in traditional medicines in the Samoa Islands comprising Samoa and American Samoa.-See also:...


Literature

  • The Mars Trilogy
    Mars trilogy
    The Mars trilogy is a series of award-winning science fiction novels by Kim Stanley Robinson that chronicles the settlement and terraforming of the planet Mars through the intensely personal and detailed viewpoints of a wide variety of characters spanning almost two centuries...

     by Kim Stanley Robinson
    Kim Stanley Robinson
    Kim Stanley Robinson is an American science fiction writer known for his award-winning Mars trilogy. His work delves into ecological and sociological themes regularly, and many of his novels appear to be the direct result of his own scientific fascinations, such as the fifteen years of research...

    , Spectra, 1993. ISBN 0-553-09204-9. Contains many references to Kava, and "Kavajava" – kava mixed with coffee. The book uses kava as the social drink of choice for the "Martians" (human colonizers of Mars).

  • The Sex Lives of Cannibals
    The Sex Lives of Cannibals
    The Sex Lives of Cannibals: Adrift in the Equatorial Pacific is a 2004 travelogue by author J. Maarten Troost describing the two years he and his girlfriend spent living on the Tarawa atoll in the Pacific island nation of Kiribati...

    : Adrift in the Equatorial Pacific by J. Maarten Troost
    J. Maarten Troost
    J. Maarten Troost is the author of three books about his experiences in the Pacific Islands and 3-month trip to China. Troost writes about the part of his life spent in the South Pacific in Getting Stoned with Savages and The Sex Lives of Cannibals -- and one on a trip to China: Lost on Planet...

    , Broadway Books, New York, 2004. ISBN 0-7679-1530-5.

  • Getting Stoned with Savages
    Getting Stoned with Savages
    Getting Stoned with Savages: A Trip Through the Islands of Fiji and Vanuatu is a 2007 travelog by J. Maarten Troost. The book is a humorous account of the author and his wife's time on the Pacific island nations of Vanuatu and Fiji. It is a follow-up to Troost's first work The Sex Lives of...

    : A Trip Through the Islands of Fiji and Vanuatu by J. Maarten Troost
    J. Maarten Troost
    J. Maarten Troost is the author of three books about his experiences in the Pacific Islands and 3-month trip to China. Troost writes about the part of his life spent in the South Pacific in Getting Stoned with Savages and The Sex Lives of Cannibals -- and one on a trip to China: Lost on Planet...

    , Broadway Books, New York, 2006. ISBN 978-0-7679-2199-2. ISBN 0-7679-2199-2.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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