Methysticin is one of the six major kavalactones found in the kava plant.[1] Research suggests that methysticin and the related compound dihydromethysticin have CYP1A1 inducing effects which may be responsible for their toxicity.[2] Additionally, methysticin has been shown to potentiate GABAA receptor activity, contributing to the overall anxiolytic profile of the kava plant.[3]
Toxicity
Methysticin induces the function of the hepatic enzyme CYP1A1. This enzyme is involved in the toxification of benzo[a]pyrene into (+)-benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide, a highly carcinogenic substance. Another related compound is dihydromethysticin, which also induces the function of CYP1A1.[2][4][5] No report so far has described enhancement of CYP1A1 expression in animals or humans in vivo from any constituent of kava.[6]
^Uno, S; Dalton TP; Durkenne S; Curran CP (2004). "Oral exposure to benzo[a]pyrene in the mouse: detoxication by inducible cytochrome P450 is more important than metabolic activation". Molecular Pharmacology. 65 (5): 1225–37. doi:10.1124/mol.65.5.1225. PMID15102951. S2CID24627183.