Kavalactones are a class of

lactone Lactones are cyclic carboxylic esters, containing a 1-oxacycloalkan-2-one structure (), or analogues having unsaturation or heteroatoms replacing one or more carbon atoms of the ring. Lactones are formed by intramolecular esterification of the co ...

compounds found in kava roots and

Alpinia zerumbet ''Alpinia zerumbet'', commonly known as shell ginger, is a perennial species of ginger native to East Asia. They can grow up to tall and bear colorful funnel-shaped flowers. They are grown as ornamentals and their leaves are used in cuisine an ...

(Shell ginger). Kavalactones are under research for potential to have various

psychotropic A psychoactive drug, psychopharmaceutical, psychoactive agent or psychotropic drug is a chemical substance, that changes functions of the nervous system, and results in alterations in perception, mood, consciousness, cognition or behavior. Th ...

effects, including

anxiolytic An anxiolytic (; also antipanic or antianxiety agent) is a medication or other intervention that reduces anxiety. This effect is in contrast to anxiogenic agents which increase anxiety. Anxiolytic medications are used for the treatment of anxiet ...

and sedative/ hypnotic activities.

Enzyme inhibition

Kava extract has been shown in vitro to potentially inhibit a wide range of hepatic enzymes, suggesting a possible potential for interactions with many pharmaceuticals and herbal medications. In human volunteers in vivo inhibition is currently limited to CYP1A2, and CYP2E1 through use of probe drugs to measure inhibition.

Research

Several preliminary studies are assessing potential effects of kava, including its

actions and

hepatotoxicity Hepatotoxicity (from ''hepatic toxicity'') implies chemical-driven liver damage. Drug-induced liver injury is a cause of acute and chronic liver disease caused specifically by medications and the most common reason for a drug to be withdrawn fr ...

, but the role specifically of kavalactones among many other kava compounds for these effects remains under study. Kavalactone type compounds may help protect against high glucose induced cell damage.

Toxicity

Several kavalactones (e.g.

methysticin Methysticin is one of the six major kavalactones found in the kava plant. Research suggests that methysticin and the related compound dihydromethysticin have CYP1A1 inducing effects which may be responsible for their toxicity. Additionally, methys ...

and yangonin) affect a group of

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

s involved in

metabolism Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run c ...

, called

CYP1A1 Cytochrome P450, family 1, subfamily A, polypeptide 1 is a protein that in humans is encoded by the ''CYP1A1'' gene. The protein is a member of the cytochrome P450 superfamily of enzymes. Function Metabolism of xenobiotics and drugs CYP1A1 ...

Hepatotoxicity Hepatotoxicity (from ''hepatic toxicity'') implies chemical-driven liver damage. Drug-induced liver injury is a cause of acute and chronic liver disease caused specifically by medications and the most common reason for a drug to be withdrawn fr ...

occurred in a small portion of previously healthy kava users, particularly from extracts, as opposed to whole root powders.

Compounds

At least 18 different kavalactones have been identified to date, with methysticin being the first identified. Multiple analogues, such as ethysticin, have also been isolated. Some consist of a substituted α-pyrone as the lactone while others are partially saturated. The average

elimination half-life Biological half-life (also known as elimination half-life, pharmacologic half-life) is the time taken for concentration of a biological substance (such as a medication) to decrease from its maximum concentration ( Cmax) to half of Cmax in the bl ...

of kavalactones typically present in kava root is 9 hr.

Biosynthesis

The kavalactone biosynthetic pathway in Piper methysticum was described in 2019.

References

External links

*
The great kava boom: how Fiji's beloved psychoactive brew is going global
The Guardian, 2020 {{GABAAR PAMs Monoamine oxidase inhibitors GABAA receptor positive allosteric modulators Anxiolytics Analgesics Sedatives Anticonvulsants Nootropics