SOLANACEAE include more than 2500 species from tropical and temperate regions; many are native to South America (potato, tomato, pepper, tobacco) and the majority belongs to the genus Solanum.
Important botanical genus in western medicine are Datura, Atropa (belladonna), Hyoscyamus (henbane).
Datura are herbs, more rarely shrubs , very poisonous.
Some are decorative with their flowers and foliage, many grow spontaneously in rubble, uncultivated land, bordering crops, roads and homes.
DATURA TOXIC ATROPINE SCOPOLAMINE HYOSCYAMINE HALLUCINOGENIC ANTALGIC SEDATIVE SPASMOLYTIC
Datura stramonium is cosmopolitan and often invasive, other species are more localized;
D. metel
in India, in Africa and naturalized in the Mediterranean basin,
D. inoxia
in tropical America
(Mexico and West Indies),
D. suavolens,
D. arborea
in South America,
D. sanguinea
in the Andean region.
Datura stramonium (officinal) is an annual plant with dark green cut leaves, solitary flowers, white sometimes purple, large (5 to 10 cm). The fruit is a spiny capsule, as often in the genus Datura, containing many small seeds.
CHEMICAL COMPOSITION AND PROPERTIES
Datura and its cousins belladonna and henbane have a similar chemical composition;
- 15 to 20% of mineral substances,
- and especially 0.2 to 0.5% of tropane alkaloids : hyoscyamine and scopolamine.
All parts of the datura contain them, but it is in the leaves and seeds that the concentration is the highest.
HYOSCYAMINE AND ATROPINE have the same chemical formula and the same pharmacological activity.
The first is optically active, the second is not (racemic) and it is the latter that is used in medicine, although probably not present in the living plant.
They are PARASYMPATHICOLYTIC which competitively and reversibly inhibit the binding of acetylcholine to the receptors and thus give a sympathicomimetic appearance effect:
- quite quickly a tachycardia with slight increase in blood pressure,
- decreased bowel movement, uterine tone and bile duct but increased pressure in the bladder, suppression of bronchospasm due to acetylcholine,
- significant reduction of secretions: salivary, sweat, bronchial, lacrimal, digestive,
- mydriasis (dilation of the pupil) progressive by paralysis of the constrictor muscles of the iris.
At TOXIC DOSE, there is excitement of the central nervous system (CNS) with agitation, hallucinations, delirium, mental confusion;
At a LOW DOSE, on the contrary, a sedative tendency.
SCOPOLAMINE has also a parasympathicolytic effect but less marked, against effects more clear on the CNS: sedative, hypnotic with amnesia and depressive tendency.
At high doses it is an incapacitant until coma.
USES
Datura is a hallucinogenic plant that has been used by « wizards », « shamans » and « medium healers ».
Its use is particularly dangerous because the quantity of leaves to be smoked or to be ingested to obtain the hallucinogenic effect is difficult to dose.
At a high dose (which corresponds to a few g of leaf), the delirium is furious with convulsions then coma and sometimes death.
At low dose the effects are just parasympathicolytic.
Fantastic hallucinations that begin 2 to 4 hours after absorption and last for several hours are powerful, it is « the devil’s herb », the drink of Sabbaths or an initiatory drink (see « The teachings of Don Juan, A Yaqui Way of Knowledge, »by Carlos Castaneda).
In East Africa the datura was used as a test poison in « judgments of god », ordalies.
In India, many criminal suicides or poisonings are due to datura.
The datura used to be an important medicinal plant, but now is almost only prescribed in homeopathy : 3DH sedative, 4DH antiasthmatic antispasmodic, 3CH regulator of arterial circulation, 6CH bronchial disorders.
We will not detail the indications of tropane alkaloids extracted from datura, they are only used under control of medical doctors or nurses : atropine and scopolamine.
ATROPINE : pre-anesthesia, ophthalmology, painful and spasmodic manifestations of the digestive tract and the urinary system, antidote (neurotoxic gaz, pesticides).
SCOPOLAMINE : pre-anesthesia and parkinsonian disorders, motion sickness patch(with the risk of urinary retention in case of prostatic disorders).
More anecdotally, in the tropics the dried fumigated datura leaf are sometimes used to calm asthma attack and the slightly warm green leaf is put as a poultice on painful joints.
ABSTRACT
THE « DEVIL’S HERB »
Datura are poisonous but their leaves and seeds contain several alkaloids important in medicine : atropine, hyosciamine, scopolamine.
The datura leaves and their total extracts are hardly used any more; they are anti-asthmatic, soothing, anti-spasmodic, but difficult to use because they are too toxic. Datura extracts are still used (very diluted), in homeopathy.
Copyright 2019 : Dr Jean-Michel Hurtel
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