Intoxication with huperzine A, a potent anticholinesterase found in the fir club moss.
BACKGROUND
Herbs from Lycopodium are generally reputed to be nontoxic and are occasionally used for preparing a salubrious tea. In Europe, the common Lycopodium clavatum can be easily confused with Lycopodium selago, the fir club moss.


METHODS
We report 2 patients who drank a tea, erroneously prepared from dried herbs of Lycopodium selago, which resulted in sweating, vomiting, diarrhea, dizziness, cramps, and slurred speech. These symptoms were suggestive of a cholinergic mechanism. To elucidate the active principle, aqueous extracts of Lycopodium selago were checked for their suspected anticholinesterase activity using human erythrocytes as an enzyme source in a modified Ellman assay. The extracts did exhibit significant anticholinesterase activity. The anticholinesterase(s) were most effectively extracted with dichloromethane and isolated by high-performance liquid chromatography. The major compound with anticholinesterase activity co-chromatographed with authentic huperzine A, but had a 2-3-fold higher inhibitory potency than the racemic standard. The amount of huperzine A found in the Lycopodium selago sample used for the tea preparation was calculated to be sufficient for a relevant acetylcholinesterase inhibition.


CONCLUSIONS
The signs and symptoms of Lycopodium selago poisoning are consistent with the anticholinesterase activity of huperzine A and should favorably respond to atropine therapy. This report demonstrates once more that laymen should not be encouraged to gather their remedies from "Mother Nature" without advanced botanical knowledge.
Felgenhauer
N
N
Toxikologische Abteilung der II. Med. Klinik, Klinikum r.d. Isar, TU München, Germany. N.Felgenhauer@lrz.tu-muenchen.de
Zilker
T
T
Worek
F
F
Eyer
P
P
D000470:Alkaloids; D001628:Beverages / Q000506:poisoning*; D002800:Cholinesterase Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000506:poisoning*; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry* / Q000506:poisoning*; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000506:poisoning*
D000470:Alkaloids; D002800:Cholinesterase Inhibitors; D010936:Plant Extracts; D012717:Sesquiterpenes; C050426:huperzine A