KAVA 化学特性,用途語,生産方法
天然物の起源
Kava is a shrub found on the South Sea Islands.
使用
Kava is used as an anxiolytic, antiepileptic, antidepressant, antipsychotic, and for anxiety, attention defi cit-hyperactivity disorder, insomnia, restlessness, and headaches. It is also used as a muscle relaxant and to promote wound healing
適応症
Kava-kava (Piper methysticum) is a South Pacific island
shrub the rhizome or root of which was used in the past
as a ceremonial beverage and that today is popular as
an anxiolytic. Historically, women prepared the kava by
pounding and then chewing it. After being allowed to
ferment in bowls, the kava was drunk by male islanders
to mark a special event.The herb would induce a pleasant
euphoric tranquility and contribute to the group’s
social cohesion.The active ingredients are thought to be
kavapyrones (also known as kavalactones), a family of
related synergistically active compounds that include
kawain and methysticin.
作用機序
The exact mechanism of action is unclear, but it is
thought that kavapyrones may act in the amygdala, producing
a tranquilizing and muscle relaxant effect.
Despite inducing mild sedation and euphoria, there is
usually no cognitive or memory impairment at typical
doses. Chewing the root results in a local anesthetic effect
with temporary numbness. High doses may cause
gait impairment, dilated pupils, and eventually impaired
motor performance.
臨床応用
Kava may be effective for the short-term treatment of
anxiety. A number of small trials have shown extracts,
standardized to 70% kavapyrones, to be significantly
and consistently more effective than placebo. Additional
studies suggest that kava acts centrally as a muscle
relaxant and likely has neuroprotective and nonopioid
analgesic properties.
副作用
Although kava was considered relatively safe until recently,
GI upset, headache, allergic skin reactions, elevated
liver function tests, and rare extrapyramidal reactions
may occur. It should be avoided in patients with
known liver disease. Slowed reflexes and diminished
judgment may occur at high doses. Heavy chronic use
may produce a psychological (rather than physiological)
habituation and a pellagralike skin condition
known as kava dermatitis characterized by reddened
eyes and dry flaking skin with a yellow discoloration;
flavokawains A and B are yellow pigments isolated
from kava and are likely causative. Despite the resemblance
to pellagra, niacin does not reverse this condition.
Heavy kava users have also been observed to lose
weight and have low plasma protein levels and low
platelet and lymphocyte counts. Pulmonary hypertension
and shortness of breath have rarely occurred. Kava
should be avoided in pregnant women and children,
since the consequences of use are unknown. A recent
cause for concern is an uncommon idiosyncratic liver
toxicity associated with kava use; in some cases, this has
been severe enough to warrant liver transplantation. It
is unclear whether kava alone is to blame, but the safety
of this herb is under review. Several European countries,
where this problem was first reported, have either
suspended sales or are acting to make kava a prescription
drug.
Kava should not be used with alcohol, benzodiazepines,
barbiturates or other sedatives because of their
additive effects. In one case, coma resulted from mixing
alprazolam and kava. Patients have complained that
kava, while relaxing the body, may be less effective for
mental anxiety with obsessive or racing thoughts than
are the benzodiazepines.
KAVA 上流と下流の製品情報
原材料
準備製品