Amanita muscaria (fly agaric): from a shamanistic hallucinogen to the search for acetylcholine.
The journal of the Royal College of Physicians of Edinburgh – March 01, 2018
Source: PubMed
Summary
The fly agaric mushroom, once a shamanistic hallucinogen, unexpectedly illuminated a fundamental biological process. Henry Dale initially hypothesized that muscarine, a compound from the mushroom, transmitted parasympathetic signals. However, he and Otto Loewi eventually isolated acetylcholine, proving it the body's true neurotransmitter. This pivotal insight into cholinergic receptors successfully led to valuable drugs like pilocarpine for glaucoma and ipratropium for lung conditions, showcasing its profound medical legacy.
Abstract
The mushroom Amanita muscaria (fly agaric) is widely distributed throughout continental Europe and the UK. Its common name suggests that it had been used to kill flies, until superseded by arsenic. The bioactive compounds occurring in the mushroom remained a mystery for long periods of time, but eventually four hallucinogens were isolated from the fungus: muscarine, muscimol, muscazone and ibotenic acid. The shamans of Eastern Siberia used the mushroom as an inebriant and a hallucinogen. In 1912, Henry Dale suggested that muscarine (or a closely related substance) was the transmitter at the parasympathetic nerve endings, where it would produce lacrimation, salivation, sweating, bronchoconstriction and increased intestinal motility. He and Otto Loewi eventually isolated the transmitter and showed that it was not muscarine but acetylcholine. The receptor is now known variously as cholinergic or muscarinic. From this basic knowledge, drugs such as pilocarpine (cholinergic) and ipratropium (anticholinergic) have been shown to be of value in glaucoma and diseases of the lungs, respectively.