Plants containing
thujone have widespread use and hence have significant human exposure. α-
Thujone caused
seizures in rodents following gavage administration. We investigated the toxicokinetics of α-
thujone in male and female F344/N rats and B6C3F1 mice following intravenous and gavage administration of α-
thujone or a mixture of α- and β-
thujone (which will be referred to as α,β-
thujone). Absorption of α-
thujone following gavage administration was rapid without any dose-, species-, sex- or test article-related effect. Absolute bioavailability of α-
thujone following administration of α-
thujone or α,β-
thujone was generally higher in rats than in mice. In rats, females had higher bioavailability than males following administration of either test article although a sex difference was not observed in mice. Cmax and AUC∞ increased greater than proportional to the dose in female rats following administration of α-
thujone and in male and female mice following administration of α,β-
thujone suggesting possible saturation of elimination kinetics with increasing dose. Dose-adjusted AUC∞ for male and female rats was 5- to 15-fold and 3- to 24-fold higher than mice counterparts following administration of α-
thujone and α,β-
thujone, respectively (p-value<0.0001 for all comparisons). Following both intravenous and gavage administration, α-
thujone was distributed to the brains of rats and mice with females, in general, having higher brain:plasma ratios than males. These data are in support of the observed toxicity of α-
thujone and α,β-
thujone where females were more sensitive than males of both species to α-
thujone-induced neurotoxicity. In general there was no difference in toxicokinetics between test articles when normalized to α-
thujone concentration.