Elemicin is a constituent of natural
aromatic phenylpropanoids
present in many herbs and spices. However, its potential to cause
toxicity remains unclear. To examine the potential toxicity and associated
mechanism, elemicin was administered to mice for 3 weeks and serum
metabolites were examined. Enlarged livers were observed in elemicin-treated
mice, which were accompanied by lower ratios of unsaturated- and saturated-lysophosphatidylcholines
in plasma, and inhibition of stearoyl-CoA desaturase 1 (Scd1) mRNA expression in liver. Administration of the unsaturated fatty
acid oleic acid reduced the toxicity of 1′-hydroxylelemicin,
the primary oxidative metabolite of elemicin, while treatment with
the SCD1 inhibitor A939572 potentiated its toxicity. Furthermore,
the in vitro use of recombinant human CYPs and chemical inhibition
of CYPs in human liver microsomes revealed that CYP1A1 and CYP1A2
were the primary CYPs responsible for elemicin bioactivation. Notably,
the CYP1A2 inhibitor α-naphthoflavone could attenuate the susceptibility
of mice to elemicin-induced hepatomegaly. This study revealed that
metabolic activation of elemicin leads to SCD1 inhibition in liver,
suggesting that upregulation of SCD1 may serve as potential intervention
strategy for elemicin-induced toxicity.