|
Though kava's primary use
throughout Oceania is as a social, mood-enhancing
beverage, the plant is also part of the native
pharmacopoeia of that region, and is used medicinally
for a wide range of conditions. The primary
folk-medicinal use of kava is for urogenital
inflammation and cystitis. But kava is also drunk to
relieve headaches, to restore vigor in the face of
general weakness, to promote urination, to soothe an
unruly stomach, to cure whooping cough in children, and
to ease the symptoms of asthma and tuberculosis.
Applied topically, kava is useful for treating fungal
infections and for soothing stings and skin
inflammations. Interestingly, kava appears to inhibit
gonorrhea. In those areas where kava is consumed
regularly, the rate of gonorrhea is very low. Anecdotal
tales of kava being drunk to successfully treat
gonorrhea are many. Though no mechanism for this action
is known, the statistically low incidence of gonorrhea
in kava-drinking populations, and the recovery of kava
drinkers from active gonorrhea, is well documented.
The first researcher to engage in a serious
investigation of the medicinal applications of kava was
Cuzent, who in 1860 made extracts of kava rootstock and
roots, and isolated a crystalline substance he dubbed
kavahine. Cuzent developed kava-based pills, an
oleoresin, an alcohol extract, and a syrup. By the end
of the 1800s, kava preparations were available in German
herbal shops.
In the early 1900s kava-based remedies made their way
into the British pharmaceutical codex. In 1914 kava was
listed in the British Pharmacopoeia under the name "kava
rhizome."
In 1920 kava appeared in European dispensaries as a
sedative and hypotensive. Kava also appeared in the U.S.
Dispensatory as a treatment for chronic irritations of
the urogenital tract. In 1950 the U.S. Dispensatory
listed kava for the treatment of both gonorrhea and
nervous disorders, under the drug names "Gonosan" and "Neurocardin"
respectively.
Prior to World War II kava from Pohnpei was used by
the Japanese for the preparation of a medicine used to
treat gonorrhea. According to export records from that
time, large shipments of kava were sent to Japan for the
manufacture of pills. In 1985, popular Japanese
newspapers touted kava as an effective remedy for the
common cold. Today Kaviase, a French pharmaceutical
product manufactured by drug giant Merrell Dow, is
recognized by health officials of that country for the
treatment of urinary tract infections.
Currently, approximately 100 tons of kava are shipped
annually to European laboratories for the manufacture of
medicinal kava preparations. U.S. companies are now
becoming aware of kava as well, and are beginning to
release kava products in liquid extract, pill, and
capsule forms. The following kava products are currently
available in the European market.
Kava's chemistry has been investigated intensively.
The medicinally active constituents of kava are a group
of resinous compounds known as kavalactones, or
kavapyrones. The kavalactones have been the objects of
chemical research since the mid-1800s, and much is known
about their mode of activity. While as many as fifteen
kavalactones are known, only six appear in kava to any
significant extent. These six kavalactones are
demethoxy-yangonin, dihydrokavain, yangonin, kavain,
dihydromethysticin and methysticin. Their detection,
analysis, and study over the past 130 years is a
peripatetic detective tale worthy of Sir Arthur Conan
Doyle's telling.
While today the analysis of the kavalactones is made
easy by advanced analytical laboratory machinery, in the
1800s such research was slow and arduous. Almost
simultaneously, Gobley in 1860 and Cuzent in 1861
isolated the first of the kavalactones, known today as
methysticin. Prior to agreement on its proper name,
methysticin was known variously as kavatin, kanakin,
kavakin, and kawakin. The giant scientific step of
isolating methysticin opened the door to subsequent
chemical progress with the resinous extract of kava. In
1874, Scientists Nolting and Kopp isolated another
kavalactone which went nameless until it was dubbed
yangon in by Lewin in 1886.
Following the publication of Lewin's seminal 1886
treatise on kava, Uber Piper Methysticum, numerous
researchers leapt test-tube first into the kava fray. In
1908, Winzheimer isolated dihydromethysticin, the most
active tranquilizer of all the kavalactones. Between
1914 and 1933, Borsche and his various colleagues
isolated two additional kavalactones, kawain and
dihydrokawain. They also determined the chemical
structures of those two kavalactones and the three
others that had been previously discovered.
Borsche and his colleagues published a series of
fourteen papers on the subject, adding greatly to the
body of kava science. A chemical error made by Borsche
regarding the actual structure of yangonin was corrected
in 1950 by Macierewicz, and yangonin was subsequently
synthesized in 1960 by Bu'Lock and Smith. In 1959 Klohs,
Keller, and Williams isolated demethoxyyangonin, and in
1962, Mors, Magalhaes, and Gottlieb reported the
isolation of 5,6-dihydromethysticin, 11- methoxyyangonin
and 11methoxynoryangonin. Further detailed analysis of
the structure of kavalactones and their activity has
been conducted by Keller and Klohs, Shulgin, and Duve
and Duffield.
Parallel to the chemical investigation of the
kavalactones, the study of their pharmacology, or drug
activity, has also been of keen interest to researchers,
and continues unabated to this day. Pioneering plant
researcher Lewin was the first to evaluate the activity
of the kavalactones.
Using kava resin administered by intraperitoneal
injection, Lewin found that the compound produced
paralysis in frogs, and sedated pigeons and sparrows to
such an extent that they were temporarily rendered
unable to fly. When resin was injected subcutaneously
into cats, the animals fell into a deep sleep. While
these experiments may seem crude by today's standards,
at the time they were groundbreaking, and they set the
pace for further pharmacological investigation.
In Schubel's investigations as reported in 1924, he
found that kava resin administered in large enough doses
could produce temporary paralysis of sensory nerves and
smooth muscle. Interestingly, Schubel also made a
discovery that supported the mastication of kava as the
most effective means of preparation.
In experiments conducted with frog hearts, he discovered
that kava extract was more potent if made from root that
had been incubated with saliva. He speculated that the
starch-digesting enzyme (ptyalin) in saliva more
effectively liberated the resinous compounds from the
root, thus yielding a stronger extract.
In Van Veen's 1938 work with pigeons, administration of
kava resin put the birds to sleep within fifteen
minutes. Upon awakening the birds appeared fully revived
and recovered. The same results were achieved with
monkeys. In an important discovery, Van Veen found that
the effect of kava extract was enhanced when put into a
lecithin/ water emulsion. This has been subsequently
confirmed. The presence of lipids such as lecithin or
vegetable oils appears to enhance the absorption and
uptake of the kavalactones, rendering them more potent.
After Van Veen, the soporific effects of large doses of
kava's active agents was subsequently demonstrated by
Hansel and Beiersdorff in their 1959 work on the
kavalactones dihydrokawain and dihydromethysticin. In
1967 Meyer was able to show that the primary activity of
the kavalactones was as muscle relaxants. This work
opened the door for further research on the
kavalactones as potent skeletal muscle relaxants that
work on the central spinal nerves and compare favorably
with synthetic drugs used for the same purpose.
While work using the various isolated, synthesized
kavalactones has yielded interesting results, the
potency of each as a separate molecule is less
significant than the potency of all the kavalactones
taken together in their natural form. For example, in
humans isolated dihydromethysticin must be taken in
doses of 800-1200 milligrams to produce a tranquilizing
effect. Yet a single coconut shell of kava, yielding
approximately 250 milligrams of resinous kavalactones,
can produce a tranquilizing effect. In 1959 Klohs was
able to demonstrate that there is a synergistic activity
among the kavalactones that enhances their potency when
taken together. This is not an uncommon finding in the
investigation of natural substances.
The various antioxidant carotenoids, including alpha and
beta carotene, lutein, zeaxanthin, and cryptoxanthin,
appear to enhance immunity better and offer greater
protection against certain forms of cancer when consumed
together from natural sources as compared with their
isolated, synthesized forms. The kavalactones do the
same. Time and again researchers discover that the
extraction and isolation of specific molecules produces
an inferior medicine as compared with the same compound
in its natural complex of ancillary and related
compounds. In lay terms, you're often much better off
eating the natural plant than taking the synthetic drug.
Let me recap in brief what is known regarding kava's
pharmacological activity. The nature of the effects that
kava produces depends on the variety of kava plant being
used, the age of the plant, and the ratio of
kavalactones found in that type. The potency of the kava
preparation, whether it is consumed on a full or empty
stomach, and the set and setting of the user will all
influence the actual effects each user will experience.
First and foremost, kava is a local anesthetic, with
potency similar to that of cocaine and procaine. It
numbs the tongue and throat when drunk in its
traditional form or when taken orally as a liquid
extract. Kava is a first-rate sedative, producing a
state of calm, and promoting sleep if taken in
sufficient quantity.
Kava is an excellent analgesic, but its mode of activity
as a pain reliever has yet to be determined. It is
superior to aspirin in its analgesic effects, and less
potent than morphine. Kava is an excellent muscle
relaxant and can make the pain of an aching back, a sore
neck, or any other cramped, sore, or injured muscle
disappear. As an aid in the relief of both cystitis and
gonorrhea, kava appears to be beneficial, though the
exact mechanism for this action is not yet fully
understood. Some researchers believe that this action is
due to kava's antifungal activity.
The kavalactones have demonstrated significant
antifungal activity against some human pathogens.
Unfortunately, kava appears to have no effect on Candida
albicans yeast. Kava also possesses anticonvulsant
properties. Promising studies with epileptics show that
kava enhances control over grand mal seizures.
While kava produces no side effects when taken in
moderate doses, its abuse can admittedly lead to health
problems. A 1988 study of heavy kava use among
Aboriginals in Arnhem Land in Australia showed that
excessive kava consumption in the range of 310 to 440
grams of kava per week contributed to deteriorating
health. Like Native Americans, Australian Aboriginals
were overwhelmed by European colonists, who over the
course of a couple of centuries succeeded in pushing the
natives off their land, disenfranchising them, and
irreparably damaging their traditional culture.
Today some tribal Aboriginals are making a concerted
effort to restore traditional customs and culture, but
for many Aboriginals the future is bleak. Relegated to
history, they no longer fit into the new Australian
culture, a construct devised by foreign interlopers.
Left floating in a social limbo, Australian Aboriginals
have followed in the footsteps of virtually all
displaced native people before them; they have a
ferociously high rate of alcoholism and drug abuse. One
of the primary causes of death among young Aboriginal
men is petrol sniffing, a practice in which gas tanks
are punctured and the fumes inhaled.
Into this downward spiral of cultural entropy came kava,
a cheap, regionally-produced plant which, unlike many
other psychoactive products, is readily available and
legal. Kava, a sedative which can stupefy if consumed in
very high doses on a regular basis, is a perfect partner
in the pursuit of oblivion. Some malnourished
Aboriginals reputedly combine strong kava and hard
alcohol, for a mind- and body-whacking experience. The
ravages of advanced malnutrition, coupled with the
extreme over-use of a potent plant sedative, result in a
pitiable condition of deteriorated health and
stupefaction.
Because those studied also smoked tobacco heavily and
consumed large quantities of alcohol, separating out the
risk factors of over consumption of kava is difficult.
To put the Aboriginals daily kava dose into perspective,
such amounts require drinking well over a gallon of kava
per day, a significant feat.
Heavy abusers studied suffered from shortness of breath,
dry, scaly skin, liver damage, and alterations in red
and white blood cells and platelets. The malnutrition
was due to the fact that kava consumption literally
replaced much of the subjects' food intake. Just as one
hundred cups of coffee per day can kill you, gallons of
kava per day can ruin your health. This is no surprise.
Even beneficial plants must be used in appropriate
doses.
Excerpted from "Kava: Medicine Hunting in Paradise" by
Chris Kilham. |
