Kavalactone

Kavalactones are a class of lactone compounds found in the kava shrub. Kavalactones are under research for potential to have various psychotropic effects, including anxiolytic and sedative/hypnotic activities.
Enzyme inhibition.
Kava extract has been shown to potently inhibit a wide range of hepatic enzymes, suggesting a very high potential for interactions with many pharmaceuticals and herbal medications.
Research.
Several preliminary studies are assessing potential effects of kava, including its anxiolytic actions and hepatotoxicity, but the role specifically of kavalactones among many other kava compounds for these effects remains under study.
Toxicity.
Several kavalactones (e.g.methysticin and yangonin) have been reported to affect a group of enzymes involved in metabolism, called CYP1A1. Hepatotoxicity has been reported in a small portion of previously healthy kava users, particularly of extracts as opposed to whole root powders.
Numerous kavalactones have apoptotic effects on various human tissues, a mechanism under preliminary study for the toxic effects of kava use.
Toxic reactions appear to be idiosyncratic and immunoallergic in nature. Concurrent consumption of another hepatotoxic substance, such as alcohol or paracetamol, may significantly increase the risk.
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 of kavalactones typically present in kava root is 9 hr.
Biosynthesis.
The kavalactone biosynthetic pathway in Piper methysticum was described in 2019. 