Substances & Homeopatic Remedies  Hyoscyamus niger
Constituents:  Apoatropine. Arsenic. Atropine. Calcium.
Chlorogenic acid. Choline. Copper. Coumarin. Esculetin. Fat.
Gaba. Hyoscyamine. Iron. Linoleic acid. Magnesium. Manganese.
Mucilage. Myristic acid. Oleic acid. Palmitic acid. Potassium.
Pyridine. Rutin. Scopolamine. Sodium. Stearic acid. Zinc.
(USDA).  Pharmacology - The alkaloids in Hyoscyamus are
parasympatholytic, competitively inhibiting the
neurotransmitter, acetylcholine. Its action is similar to 
Atropa belladonna, though the higher proportion of hyoscine in
Hyoscyamus makes cerebral excitement less likely. It has
peripheral effects on the autonomic nervous system and sedative
effects on the central nervous system.  Hyosciamine and hyoscine
cause a decrease in sweat, salivary, gastric and bronchial
secretions, decrease the tone of smooth muscle in the digestive
and urinary tracts, and increase the pulse rate.  Toxicology: 
All parts of this plant are poisonous; the seeds, however, are
the most a