Revision as of 22:04, 20 January 2013

Kava or Piper Methysticum is a pacific island plant in the same genus as the common pepper plant in the family Piperaceae. It is know as Awa, Ava Yaqona and sakau on other islands with many variations depending on whet island it originated from. The root of this plant has been and is still to this day consumed by many pacific islanders from New Guinea all the way to Hawaii and down into french Polynesia. Its primary use is as a sedative and a anxiolytic with many other tradional medicinal remedies. The primary active ingredients are in the root and are a series of kavalactones witch is concentrated in the roots but found also in lower amounts in the leaves and stems. The roots can be used fresh by maceration and cold water infusion or more popularly dried and stored for better shelf life and used in cold or warm water extractions. There is on going debate whether or not kava and its kavalactones have a hepatoxicity mainly to the liver due to unwanted chemicals from the leaves or extracted from the roots due to solvent based extracts.

Morphology

Piper Methysticum is a member of the pepper family, Piperaceae, which belongs to the order Piperales in the class Dicotyledonae. Ten of these in the Piperaceae species are products of human consumption used as spices or medicinal drugs. these include:

• P. nigrum (Pepper), one of the oldest known spices,
• P. betle
• P. cubeba (java pepper or tailed pepper), a plant native to indonesia wich was formerly used as a medicine and now as a spice.

It is a hardy, slow growing Perennial reaching heights of more then 3 meters. It is harvested for its rootstock or stump with Monopedial stems with sympodial branches growing from the stump. The stump is knotty, Think, and sometimes tuberous. From this rootstock extends laterally up to 3 meteres long. Rootstock color varies between white to dark yellowdepending upon the amount of kavalactones that are contained in the lemon yellow resin.

Cultivation

Although kava does produce flowers it is incapable of reproducing sexually; its propagation is vegetatively and is dependent solely on human effort. Farmers take cuttings from existing stems off harvested plants and planted i the ground somewhat sideways. New growth occurs at the stem bud at the axil of a lateral branch scar. An upright shoot develops, and then axillary buds and lateral axes appear. In the same way the root stock develops. Choose a site away from prevailing winds air currents can damage kava stems and rootstock, making them susceptible to disease. Shade must be provided during the first 30 months of growth. Along with adequate shade and protection from the wind, kava requires fairly high average temperatures (20-35c) and high humidity (70-100%). Kave grows best in deep, friable, well-draining soils that are rich in organic matter. The plant is very nutrient demanding. Highest yields are obtained on silica-clay soils with a pH OF 5.5-6.5 good drainage is essential.

Preparation and consumption

Traditional

In the Pacific kava is typically drunk at dusk, usually before the evening meal.Infused kava is never kept for long; Islanders prepare kava for immediate consumption. After drinking, people eat small amounts of food because kava tends to reduce appetite and over eating can cause nausea.

Several traditional methods of kava preparation all serve to extract the active chemical constitutes of fresh or dried rootstock. Processing basically involves chewing, grating, grinding or pounding kava stumps and roots and then infusing the processes mass into cold water. These methods break up and macerate the rootstock so that the kavalactones after more readily released in the cold water. Today mastication of fresh rootstock is only practiced in southern vanauatu and among some tribes in papua new guinea.

In Fiji men serving as village priests prepared kava every morning in men's houseshouses, or houses of ancestor worship, as an offering tho village ancestors. The priests and other men in the village would then drink kava together. The rootstock was prepared by grinding, not mastication, and the drink was infused in lead lines holes in the ground, in shallow wooden bowls that were sometimes human or animal in shape, of in plain clay vessels. Early fijians folders their kava by pouring it through bunches of backen fern leaves in a wooden canister like device, rather then using a stronger of hibiscus tiliaceus bark as is common in Polynesia. Fijians also did not drink our of coconut shells as they do today, but instead right out of the container.

In traditional samoan preperation, a young girl chased and served kava. The girl was preferably a virgin, who purified herself for kava preparation by washing her hands and wrists. After chewing kava, she mixed and infused the macerated root in a kava bowl and filtered out the residue with a hibiscus bark strainer. Samoan ceremony required the girl to sit cross legged and bare breasted on a mat behind the kava bowl, with flowers carefully arranged in her hair and wearing a grass skirt. This presented an image of beauty that added to the aesthetic dimension of kava preparation.

It the banks island of northern Vanuatu, Kava drinkers traditionally split into 2 groups, And a person from each group prepare kava for the other. As on most of the northern Vanuatu islands, preparation in the banks group involved the grinding of fresh kava over a large wooden dish using an elongated coral abrading stone. The inner surfaces of these wooden dishes eventually became covered with a grayish-green deposit that is also found at the bottom of coconut shells used as drinking bowls. This deposit is a resinous kavalactone residue that contains the plants active ingredients in concentrated form. Some drinkers periodically scrape the resin from there dishes and mix this with fresh water tho obtain a brew with very powerful effects.

Western Preparation

Kava preparation in the western world outside of the islands is a climbing trend with the emergence of natural products becoming more and more popular. Kava has moved from a ceremonial sense to more of a medicine with ease of use, from extracts of all solvents to pharmaceutical tablets with kavalactones as there main ingredient. Although there's is still a big consumer base for the traditional frozen or dried kava rootstock and is prepared in a semi traditional way.

In Western countries, kava is usually made from kava root powder or extracts. Generally, 2 tablespoons of powder is added per 8 oz. of water, but multiple tablespoons per 16 oz. of water to increase potency. The powder is then put into a muslin bag or nylon sock and soaked in water for about 30 minutes to allow the water to completely soak through the powdered fibers, after a thorough soaking the rootstock is then massaged for a few minutes under the water for a few minutes with breaks to squeeze the powder dry and repeating till the water is a creamy brown color.Lecithin is often added to aid in the process of emulsifying the kavalactones with water.

Another popular method is blending. Blended in a blender for several minutes then strained into a straining cloth; Nylon, cheesecloth, and silk screen are common materials for straining. The remaining liquid is squeezed from the pulp and then the process is repeated until one last strain and squeeze of the pulp and the rest is discarded. Often, coconut water, coconut milk, lemongrass, cocoa, sugar, or soy milk is added to improve flavor, and most of the time lecithin granules or some form of lecithin is added to aid in emulsifying of the water and better leaching of the kavalactones.

Pills and extracts

Pharmaceutical and herbal supplement companies extract kavalactones from the kava plant using solvents such as supercritical carbon dioxide, acetone and ethanol to 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.

Other then pills there is many places that sell extracts extracted from solvents such as supercritical carbon dioxide, acetone and ethanol. Carbon dioxide is showing to be the most preferred and most safe due to liver toxicity and more potent then the other solvent extracted products.

Chemistry and active principles

Kavalactones are the main principle chemicals that give the desired effects from kava.

Lactones

These chemicals are mostly, if not entirely, contained in its resin. These molecules are a series of lactones-that is, organic compounds containing oxygen, with similar structures. These are alpha- pyrones bearing a methoxyl group at carbon 4 and an aromatic styryl moiety at carbon 6.

The skeletons of the lactonic molecules isolated from kava rootstock are generally 4- methoxy-2- pyrones with phenyl or styryl substitutions at the 6- position. They consider of 13 carbon atoms, 6 of which from a benzene ring attached by a double bond to an unsaturated lactone. 15 lactones have been isolated from kava rootstock, 9 of which have been fully identified.

The following 6 compounds are present in the highest concentrations: yangonin, methysticin, dihydromethystic, kavain, dihydrokavain, and demethoxy-yangonin. 9 other compounds are of minor importance in the rootstock: dehydrokavain, cis-5-hydroxy-kavain, 7,8-dihydroyangonin, 5,6-dihydroyangonin, 5,6-dehydro-methysticin, 11-methoxy-yangonin, 11-hydroxy-yangonin, 11-methoxy-12-hydroxy-dehydro-kavain, and 10-methoxy-yangonin.

Some researchers have tried to classify kavalactones by reference to common characteristics. The simplest method of grouping is one suggested by hänsel, which supports the molecules according to the presence or absence of double bonds at the 5,6 and 7,8 positions and divided them into 2 major groups: the enolides, with 1 double bond, and the dienolides, with 2 double bonds. This system recognizes that primary chemical differences among the kavalactones involve the presence or absence of these double bonds as well as the presence or absence of substituent groups in the phenyl ring.

Flavokavains and other compounds

3 flavokavains labeled A, B , and C, have been identified in kava rootstock. Flavokavain C structure and synthesis were analyzed by a Indian team in 1976. Other substances isolated from the kava plant include an alcohol, ketones, a phytosterol, and organic acids.

Chemotypes

Effects