Thujone in Absinthe

(Alpha-thujone)

Alcoholic beverages have seen their fair share of bans around the globe. From the absolute ban of alcohol is countries such as Libya, Saudi Arabia, Bangladesh, Sudan and a few other countries, to the prohibition of alcohol era of the United States in the 1920’s. In countries where alcohol has been permitted to be purchased, manufactured and consumed there is one type of liquor that has been banned from a handful of countries and only in recent times has become legal in a dilute form, the liquor absinthe. The reason behind the ban on this liquor is from the presence of thujone. Thujone is a chemical toxin isolated from Artemisia absinthium, commonly known as wormwood. Historically thujone content in absinthe was around 350 ppm. Current available content of legal absinthe is 9 ppm.






Wormwood isolates have been used in medical remedies for years. Alpha-thujone has also been used as an antinociceptive (reducing sensitivity to painful stimuli), insecticidal, and anthelmintic (an agent that causes expulsion of parasitic intestinal worms) activity (Hold, 2000). It is has also been used to treat loss of appetite, dyspeptic disorders and liver and gallbladder conditions (Blumenthal, 1998). Alpha-thujone is considered the active stereoisomer between the two compounds (Hold, 2000).






Alpha-thujone acts as a receptor antagonist (competes and blocks agonist binding sites). Alpha-thujone activates the GABA receptor, which upon activation Cl- ions pass through the pores resulting in hyperpolarization of the neuron. This action in turn prevents the opportunity for successful action potential. The neurotoxic effects that alpha-thujone causes in mice has been recorded to induce convulsion action that occurs when GABA-gated chloride channel are activated. In mice the LD50 is 45mg/kg.(Hold, 2000).