However, the precise mechanisms underlying the psychotropic, sedative, and anxiolytic actions of kavain and related kavalactones are still debated. Direct binding to the benzodiazepine/flumazenilbinding site of the GABA-A receptor does not occur with kavain enantiomers.[3] Many studies involved kava extracts from different plant parts and are, therefore, not applicable to kavain itself. In 2016, kavain was shown to bind at the extrasynaptic α4β2δ GABAA receptor and potentiateGABA efficacy, similarly to barbiturates.[4]
A comparative review of in-vivo studies with kavain (and related kavapyrones) to commonly used antiepileptic drugs and mood stabilizers affecting ion fluxes indicates that the kavapyrones are weakly Na+ antagonistic and therefore antiepileptic. They also have pronounced L- type Ca2+ channel antagonistic properties and act as a positive modulator of the early K+ outward current, which contribute to mood stabilizing properties similar to lamotrigine.[5]
^Grunze, Heinz; Langosch, Jens; Schirrmacher, Karin; Bingmann, Dieter; Von Wegerer, Jörg; Walden, Jörg (2001). "Kava pyrones exert effects on neuronal transmission and transmembraneous cation currents similar to established mood stabilizers - a review". Progress in Neuro-Psychopharmacology and Biological Psychiatry. 25 (8): 1555–70. doi:10.1016/S0278-5846(01)00208-1. PMID11642654. S2CID41325450.
^Rowe, A.; Narlawar, R.; w. Groundwater, P.; Ramzan, I. (2011). "Kavalactone Pharmacophores for Major Cellular Drug Targets". Mini Reviews in Medicinal Chemistry. 11 (1): 79–83. doi:10.2174/138955711793564088. PMID21034404.