Atropa belladonna

Deadly nightshade
Illustration from Köhler's Medicinal Plants 1887
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Solanales
Family:	Solanaceae
Genus:	Atropa
Species:	A. belladonna
Binomial name
Atropa belladonna L.

Atropa belladonna or Atropa bella-donna, commonly known as belladonna or deadly nightshade, is a perennial herbaceous plant in the family Solanaceae, native to Europe, North Africa, and Western Asia. The foliage and berries are extremely toxic, containing tropane alkaloids. These toxins include scopolamine and hyoscyamine which cause a bizarre delirium and hallucinations,^[1] and are also used as pharmaceutical anticholinergics. The drug atropine is derived from the plant.

It has a long history of use as a medicine, cosmetic, and poison. Before the Middle Ages, it was used as an anesthetic for surgery, the ancient Romans used it as a poison (the wife of Emperor Augustus and the wife of Claudius both used it to murder contemporaries) and predating this it was used to make poison tipped arrows. The genus name "atropa" comes from Atropos, one of the three Fates in Greek mythology, and the name "bella donna" is derived from Italian and means "beautiful woman".

Description

Atropa belladonna

Atropa belladonna is a branching herbaceous perennial, often growing as a subshrub, from a fleshy rootstock. Plants grow to 1.5 metres (4.9 ft) tall with 18 centimetres (7.1 in) long ovate leaves. The bell-shaped flowers are tyrian purple with green tinges and faintly scented. The fruits are berries, which are green ripening to a shiny black, and approximately 1 centimetre (0.39 in) in diameter. The berries are sweet and are consumed by animals that disperse the seeds in their droppings, even though the seeds contain toxic alkaloids.^[2] There is a pale yellow flowering form called Atropa belladonna var. lutea with pale yellow fruit.

Atropa belladona is rarely used in gardens, but when grown it is usually for its large upright habit and showy berries.^[3] It is naturalized in parts of North America, where it is often found in shady, moist locations with limestone-rich soils. It is considered a weed species in parts of the world,^[4] where it colonizes areas with disturbed soils.^[5] Germination of the small seeds is often difficult, due to hard seed coats that cause seed dormancy. Germination takes several weeks under alternating temperature conditions but can be sped up with the use of gibberellic acid.^[6] The seedlings need sterile soil to prevent damping off and resent root disturbance during transplanting.

Naming and taxonomy

The first botanical description was by Linnaeus in Species Plantarum in 1753.^[7] It is in the nightshade family (Solanaceae), which it shares with potatoes, tomatoes, eggplants, jimsonweed, tobacco, wolfberry, and chili peppers. The common names for this species include belladonna, deadly nightshade, divale, dwale,^[8] banewort, devil's cherries, naughty man's cherries, black cherry, devil's herb, great morel, and dwayberry.^[9]

The name Atropa is thought to be derived from that of the Greek goddess Atropos, one of the three Greek fates or destinies who would determine the course of a man's life by the weaving of threads that symbolized their birth, the events in their life and finally their death; with Atropos cutting these threads to mark the latter.^[10][11] The name "belladonna" comes from the Italian language, meaning "beautiful lady";^[8] originating either from its usage as cosmetic for the face, or, more probably, from its usage to increase the pupil size in ladies.^[10][11]

Toxicity

Flowers of belladonna

Belladonna is one of the most toxic plants found in the Western hemisphere. All parts of the plant contain tropane alkaloids.^[12] The berries pose the greatest danger to children because they look attractive and have a somewhat sweet taste.^[9] The consumption of two to five berries by children and ten to twenty berries by adults can be lethal. The root of the plant is generally the most toxic part, though this can vary from one specimen to another. Ingestion of a single leaf of the plant can be fatal to an adult.^[12]

The active agents in Belladonna, atropine, hyoscine (scopolamine), and hyoscyamine, have anticholinergic properties.^[13][14] The symptoms of belladonna poisoning include dilated pupils, sensitivity to light, blurred vision, tachycardia, loss of balance, staggering, headache, rash, flushing, dry mouth and throat, slurred speech, urinary retention, constipation, confusion, hallucinations, delirium, and convulsions.^[15][13][16] In 2009, atropa belladonna that was mistaken for blueberries with six berries ingested by an adult woman was documented to result in severe anticholinergic syndrome.^[17] The plant's deadly symptoms are caused by atropine's disruption of the parasympathetic nervous system's ability to regulate non-volitional/subconscious activities such as sweating, breathing, and heart rate. The antidote for belladonna poisoning is physostigmine or pilocarpine, the same as for atropine.^[18]

Atropa belladonna is also toxic to many domestic animals, causing narcosis and paralysis.^[19] However, cattle and rabbits eat the plant seemingly without suffering harmful effects.^[16] In humans its anticholinergic properties will cause the disruption of cognitive capacities like memory and learning.^[14]

Uses

Cosmetics

The common name belladonna originates from its historic use by women - Bella Donna is Italian for beautiful lady. Drops prepared from the belladonna plant were used to dilate women's pupils, an effect considered attractive.^[20][21] Belladonna drops act as an antimuscarinic, blocking receptors in the muscles of the eye that constrict pupil size.^[22] Belladonna is currently rarely used cosmetically, as it carries the adverse effects of causing minor visual distortions, inability to focus on near objects, and increased heart rate. Prolonged usage was reputed to cause blindness.^[23]

Medicine

Belladonna tinctures, decoctions, and powders as well as alkaloid salt mixtures are produced for pharmaceutical use and these are often standardised at 1037 parts hyoscyamine to 194 parts atropine and 65 parts scopolamine. The alkaloids are compounded with phenobarbital and/or kaolin and pectin for use in various functional gastrointestinal disorders. The tincture, used for identical purposes, remains in most pharmacopoeias, with a similar tincture of Datura stramonium having been in the US Pharmacopoeia at least until the late 1930s. The combination of belladonna and opium, in powder, tincture, or alkaloid form, is particularly useful by mouth or as a suppository for diarrhoea and some forms of visceral pain and can be made by a compounding pharmacist and may be available as a a manufactured fixed combination product in some countries (see, e.g., B&O Supprettes). A banana-flavoured liquid (most common trade name: Donnagel PG) was available until 31. December 1992 in the United States.

Scopolamine is used as the hydrobromide salt for GI complaints, motion sickness, and to potentiate the analgesic and anxiolytic effects of opioid analgesics.

Atropine is used as the sulphate as a mydriatic and cycloplegic for eye examinations. It is also used as an antidote to organophosphate and carbamate poisoning and is loaded in an autoinjector for use in case of a nerve gas attack. Atropinisation (administration of a sufficient dose to block nerve gas effects) results in 100 per cent blockade of the muscarinic acetylcholine receptors and atropine sulphate is the benchmark for measuring the power of anticholinergic drugs.

Hyoscyamine is used as the sulphate or hydrobromide for GI problems and Parkinson's Disease. Its side effect profile is intermediate betwixt that of atropine and scopolamine, and can also be used to combat the toxic effects of organophosphates.

There is currently insufficient scientific evidence to recommend the use of A. belladonna in its natural form for any condition,^[13] although some of its components, in particular l-atropine which was purified from belladona in the 1830s, have accepted medical uses.^[16] Donnatal is a prescription pharmaceutical, approved in the United States by the FDA, that combines natural belladonna alkaloids in a specific, fixed ratio with phenobarbital to provide peripheral anticholinergic/antispasmodic action and mild sedation. According to its labeling, it is possibly effective for use as adjunctive therapy in the treatment of irritable bowel syndrome (irritable colon, spastic colon, mucous colitis) and acute enterocolitis.^[24]

Traditional and alternative medicine

Berries of belladonna

A. belladonna has been used in traditional treatments for centuries for an assortment of conditions including headache, menstrual symptoms, peptic ulcer disease, histaminic reaction, inflammation, and motion sickness,^[13] with at least one 19th century eclectic medicine journal explaining how to prepare a Belladona tincture for direct administration to patients.^[25]

Homeopathic belladonna preparations have been sold as treatments for various conditions, although there is no scientific evidence to support their efficacy.^[26][27] Clinically and in research trials, the most common preparation is diluted to the 30C level in homeopathic notation. This level of dilution does not contain any of the original plant,^[27] although preparations with lesser dilutions which statistically contain trace amounts of the plant are advertised for sale.^[28]

Recreational drug

Atropa belladonna, along with related plants such as jimson weed (Datura stramonium), have occasionally been used as a recreational drug because of the vivid hallucinations and delirium that it produces. These hallucinations are most commonly described as very unpleasant, however, and recreational use is considered extremely dangerous because of the high risk of unintentional fatal overdose.^[29][30][31] In addition, the central nervous system effects of atropine include memory disruption, which may lead to severe confusion.^[32]

Poison

The tropane alkaloids of A. belladonna were used as poisons and early humans made poisonous arrows from the plant.^[33] in Ancient Rome it was used as a poison by Agrippina the Younger, wife of Emperor Claudius, and Livia, who is rumored to have used it to kill her husband Emperor Augustus.^[34][33]

Macbeth of Scotland, when he was still one of the lieutenants of King Duncan I of Scotland, used it during a truce to poison the troops of the invading Harold Harefoot, King of England, to the point that the English troops were unable to stand their ground and had to retreat to their ships.^[11]

Folklore

Leaves of belladonna

In the past, it was believed that witches used a mixture of belladonna, opium poppy, and other plants, typically poisonous (such as monkshood and poison hemlock) in flying ointment they applied to help them fly to gatherings with other witches. Carlo Ginzburg and others have argued that flying ointments were preparations meant to encourage hallucinatory dreaming; a possible explanation for the inclusion of belladonna and opium poppy in flying ointments concerns the known antagonism between tropane alkaloids of belladonna (specifically scopolamine) and opiate alkaloids in the opium poppy, Papaver somniferum (specifically morphine), which produces a dream-like waking state. This antagonism was known in folk medicine, discussed in eclectic (botanical) medicine formularies^[35], and posited as the explanation of how flying ointments might have actually worked in contemporary writing on witchcraft.^[36] The antagonism between opiates and tropanes is the original basis of the Twilight Sleep that was provided to Queen Victoria to deaden pain as well as consciousness during childbirth, and which was later modified so that isolated alkaloids were used instead of plant materials. The belladonna herb was also notable for its unpredictable effects from toxicity.^[37][38]

See also

• List of plants poisonous to equines
• List of poisonous plants

Notes

References

Further reading

• "Compounds in deadly nightshade". USDA, ARS, National Genetic Resources Program. Phytochemical and Ethnobotanical Databases. Beltsville, Maryland: National Germplasm Resources Laboratory. http://sun.ars-grin.gov:8080/npgspub/xsql/duke/plantdisp.xsql?taxon=143. Retrieved 2005-07-28.