Marijuana, Absinthe and Thujone
“if you drink too much absinthe, you suddenly realize why van Gogh cut his ear off.”
Johnny Depp: Expressen (Sweden)
Johnny Depp drinking absinthe in “From Hell”
Marijuana, absinthe and the central nervous system.
by J. Del Castillo, M. Anderson, G. M. Rubottom
THERE are striking similarities between the psychological actions of the liqueur absinthe and the experiences frequently reported by users of marijuana. We have therefore compared the properties of thujone and tetrahydrocannabinol (THC), which are believed to be the active principles of Artemisia absinthium and Cannabis sativa, respectively. Both substances are terpenoid, derived from the essential oils absinthol and cannabinol, and are formed by similar biosynthetic mechanisms.
Absinthe: The Price of Creativity : Solano (2002)
Thujone has a molecular structure similar to that of another terpenoid essential oil, tetrahydrocannabinol (THC). THC is the chemical in marijuana that induces its notorious ‘high’. Its functional side groups, which resemble those of THC, are thought to act at the same specific receptor sites in the central nervous system as those occupied by THC.
Thujone appears to effect chloride ion channels in the central nervous system. In neurobiology, ion channels are protein channels in cell membranes that allow ions to pass from extracellular solution to intracellular solution and vice versa. Most ion channels are selective and only allow certain ions to pass through. Each neuron has ion channels with various ion selectivities. Each nerve cell’s parallel conductivity of “information” down its axon is contingent upon the opening and closing of ion channels along its cell membrane. At the end of a neuron, at its synapse, neurotransmitters are released based upon the “information” passed down by the changing concentration gradient and charge.
Neurotransmitters are chemical substances that cross the synapse between a presynaptic nerve ending and a post synaptic nerve ending. At the membrane of the post synaptic neuron the transmitter substances interacts with a receptor. Depending on the type of receptor, the result may be an excitatory or an inhibitory effect on the postsynaptic nerve cell.
GABA is the neurotransmitter substance gamma-aminobutyric acid. A GABA receptor is any of several membrane proteins that bind GABA and mediate its channels. GABA type A receptors produce an inhibitory effect on postsynaptic nerve cell membranes. Studies show that alpha-thujone in absinthe is a rapidly-acting and readily detoxified modulator of the gamma-amino butyric acid-gated chloride ion channel. Thujone also acts as a GABA-type A receptor antagonist. Thujone competitively inhibits the binding of the radioactive convulsant [(sub3)H] ethynylbicycloorthobenzoate to the known convulsant site linked to GABA-type A receptors in mammalian brain membranes. Without access to GABA, a natural inhibitor of nerve impulses, neurons fire too easily and their signaling goes out of control. Perhaps this explains the state of psychosis and high sensitization described by the creative individuals who were addicted to the effects of absinthe.
Scientists had documented thujone’s effects by 1916, but “nobody had ever figured out exactly where the toxin was working,” says Hold. The original concentration of Old absinthe was about 260 parts per million of alpha-thujone. Though today the drink, which is still made in the Czech Republic, Spain, and most recently Great Briton, typically contains less than 10 parts per million. This is below the maximum concentration permitted by European beverage guidelines.