Kavalactone

Kavalactones are the main psychoactive components of the roots of "Piper methysticum" (kava), a shrub common on some Pacific Ocean islands. Another class of compounds found in "P. methysticum" are the Flavokawains, which are substituted chalcones in nature and not lactones, and thus they are not kavalactones.

Extraction

The rhizome and roots of the shrub are ground, grated and steeped in water to produce a non-alcoholic drink which is said to promote sociability, mental clarity, and reduction of anxiety "(see main kava entry)". The quantity and ratio of kavalactones present vary dramatically and are highest when roots are extracted with solvents rather than by conventional tea preparation "(but note safety issues; see kava)". [cite journal | author=Hu, A "et al" | title=Determination of six kavalactones in dietary supplements and selected functional foods containing Piper methysticum by isocratic liquid chromatography with internal standard | journal=J AOAC Int. | volume=88 | issue=1 | year=2005 | pages=16–25 | pmid=15759721]

Some use lipids to aid in kavalactone extraction. (ie; whole milk, oils, etc.)

Compounds

At least 18 different kavalactones have been identified to date, with Methysticin being the first identified. The Flavokawains are not kavalactones and as such are not included in the table below, which only lists natural kavalactones that have been identified in "P. methysticum" (and thus does not include pharmacologically interesting synthetic analogues, such as ethysticin). [cite journal | author=Shulgin, A | title=The narcotic pepper - the chemistry and pharmacology of Piper methysticum and related species | journal=Bull. Narc. | volume=25 | issue=59 | year=1973 | pages=59–74]

Kavalactones: General structures

Kavalactones

Name	Structure	R1	R2	R3	R4
Yangonin	1	-OCH3	-H	-H	-H
10-methoxyyangonin	1	-OCH3	-H	-OCH3	-H
11-methoxyyangonin	1	-OCH3	-OCH3	-H	-H
11-hydroxyyangonin	1	-OCH3	-OH	-H	-H
5,6-dehydrokavain	1	-H	-H	-H	-H
11-methoxy-12-hydroxydehydrokavain	1	-OH	-OCH3	-H	-H
7,8-dihydroyangonin	2	-OCH3	-H	-H	-H
Kavain	3	-H	-H	-H	-H
5-hydroxykavain	3	-H	-H	-H	-OH
5,6-dihydroyangonin	3	-OCH3	-H	-H	-H
7,8-dihydrokavain	4	-H	-H	-H	-H
5,6,7,8-tetrahydroyangonin	4	-OCH3	-H	-H	-H
5,6-dehydromethysticin	5	-	-	-H	-H
Methysticin	7	-	-	-H	-H
7,8-dihydromethysticin	8	-	-	-H	-H

Effects

Effects of kavalactones include mild sedation, a slight numbing of the gums and mouth, and vivid dreams. Kava has been reported to improve cognitive performance and promote a cheerful mood. [cite journal | author=Thompson, R "et al" | title=Enhanced cognitive performance and cheerful mood by standardized extracts of Piper methysticum (Kava-kava) | journal=Hum Psychopharmacol. | volume=19 | issue=4 | year=2004 | pages=243–250 | pmid=15181652 | doi=10.1002/hup.581] Muscle relaxant, anaesthetic, anticonvulsive and anxiolytic effects are thought to result from direct interactions of kavalactones with voltage-gated ion channels. [cite journal | author=Cairney, S "et al" | title=The neurobehavioural effects of kava | journal=Aust N Z J Psychiatry | volume=36 | issue=5 | year=2002 | pages=657–652 | pmid=12225450 | doi=10.1046/j.1440-1614.2002.01027.x] Research currently suggests that kavalactones potentiate GABA_A activity but do not alter levels of dopamine and serotonin in the CNS. [cite journal | author=Hunter, A | title=Kava (Piper methysticum) back in circulation | journal=Australian Centre for Complementary Medicine | volume=25 | issue=7 | year=2006 | pages=529] Heavy, long-term kava use does not cause any reduction of ability in saccade and cognitive tests but is associated with elevated liver enzymes. [cite journal | author=Cairney, S "et al" | title=Saccade and cognitive function in chronic kava users | journal=Neuropsychopharmacology | volume=28 | issue=2 | year=2003 | pages=389–396 | pmid=12589393 | doi=10.1038/sj.npp.1300052]

Desmethoxyyangonin, one of the six major kavalactones, is a reversible MAO-B inhibitor (Ki 280 nM) [Uebelhack R, Franke L, Schewe HJ (1998): “Inhibition of platelet MAO-B by kava pyrone-enriched extract from kava-kava.” Pharmacopsychiatry 31(5):187-92. PMID 9832350] and is able to increase dopamine levels in the nucleus accumbens. This finding might correspond to the slightly euphoric action of kava. [Baum SS, Hill R, Rommelspacher H (1998): “Effect of kava extract and individual kavapyrones on neurotransmitter levels in the nucleus accumbens of rats.” Prog Neuropsychopharmacol Biol Psychiatry 22(7):1105-20. PMID 9829291]

Kavain in both enantiomeric forms inhibit the reuptake of noradrenalin at the transporter (NAT), but not of serotonin (SERT). [Seitz U, Schule A, Gleitz J (1997): " [3H] -monoamine uptake inhibition properties of kava pyrones." Planta Med. 63(6):548-9. PMID 9434608] An elevated extracellular NA level in the brain may account for the reported enhancement of attention and focus with kava.

Adverse effects

The United States Food and Drug Administration (FDA) has warned that very rare cases of liver damage or fulminant liver failure may be caused by kava-containing supplements. However, these injuries might result from pipermethystine [cite journal | author=Nerurkar, PV "et al" | title=In vitro toxicity of kava alkaloid, pipermethystine, in HepG2 cells compared to kavalactones | journal=Toxicological Sciences | volume=79 | issue=1 | year=2004 | pages=106–111 | pmid=14737001 | doi=10.1093/toxsci/kfh067] , an alkaloid present in portions of the plant used industrially but normally discarded in traditional preparations "(see kava)".

ee also

* List of Entheogens

References

External links

* [http://www.erowid.org/plants/kava/kava_chemistry2.shtml NIH Kava Chemistry & Toxicology Executive Summary]