Kava (Piper methysticum) is one of the most researched herbal anxiolytics showing the ability to significantly reduce anxiety symptoms in a variety of patients.
The most important constituents responsible for the pharmacological activity of kava rhizome are the fat- soluble kavalactones (kavapyrones). The kavalactones reach large numbers of targets that influence central nervous system activity. They interact with dopaminergic, serotonergic, GABAergic and glutamatergic neurotransmission, seem to inhibit monoamine oxidase (MAO) B and exert multiple effects on ion channels.
These combined effects are believed to explain kava’s significant anti-anxiety, relaxant and antispasmodic activity observed in vitro and in vivo for both kava extract and kavalactones.
Braun L, Munoz L. Kava kava, Piper methysticum. Compl Med 2007;36-39.