Lactuca virosa
Encyclopedia
Lactuca virosa is a plant in the Lactuca
Lactuca
Lactuca, commonly known as lettuce, is a genus of flowering plants in the daisy family Asteraceae. The genus includes about 100 species, distributed worldwide, but mainly in temperate Eurasia....

(lettuce) genus, ingested often for its mild psychotropic (specifically hypnotic
Hypnotic
Hypnotic drugs are a class of psychoactives whose primary function is to induce sleep and to be used in the treatment of insomnia and in surgical anesthesia...

 or sedative
Sedative
A sedative or tranquilizer is a substance that induces sedation by reducing irritability or excitement....

) effects which are often described as being similar to that of opium
Opium
Opium is the dried latex obtained from the opium poppy . Opium contains up to 12% morphine, an alkaloid, which is frequently processed chemically to produce heroin for the illegal drug trade. The latex also includes codeine and non-narcotic alkaloids such as papaverine, thebaine and noscapine...

. It is related to common lettuce (L. sativa), and is often called Wild Lettuce, Bitter lettuce, Laitue vireuse, Opium Lettuce, Poisonous Lettuce, or Rakutu-Karyumu-So.

It can be found locally in the south east and east of England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

. In the rest of Great Britain it is very rare, and in Ireland it is absent.

In North America, it has been documented as introduced in California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

, Alabama
Alabama
Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...

, Iowa
Iowa
Iowa is a state located in the Midwestern United States, an area often referred to as the "American Heartland". It derives its name from the Ioway people, one of the many American Indian tribes that occupied the state at the time of European exploration. Iowa was a part of the French colony of New...

, and Washington, DC, and grows wild in other parts of the continent.

Description

It is biennial
Biennial plant
A biennial plant is a flowering plant that takes two years to complete its biological lifecycle. In the first year the plant grows leaves, stems, and roots , then it enters a period of dormancy over the colder months. Usually the stem remains very short and the leaves are low to the ground, forming...

, similar to Prickly lettuce Lactuca serriola
Lactuca serriola
Prickly Lettuce is an annual or biennial plant, slightly foetid, that is commonly considered a weed of orchards, roadsides and field crops. The closest wild relative of cultivated lettuce , it grows throughout the temperate regions of all major continents. The leaves grow along a spiny stem and...

 but taller - it can grow to 200 cm. It is also stouter, the stem and leaves are more purple flushed, the leaves are less divided, but more spreading.

The achene is purple black, without bristles at the tip. The pappus
Pappus (flower structure)
The pappus is the modified calyx, the part of an individual disk, ray or ligule floret surrounding the base of the corolla, in flower heads of the plant family Asteraceae. The pappus may be composed of bristles , awns, scales, or may be absent. In some species, the pappus is too small to see...

 is the same as Lactuca serriola.

It flowers from July until September.

History

L. virosa was used in the 19th century by physicians when opium could not be obtained. It was studied extensively by the Council of the Pharmaceutical Society of Great Britain in 1911. They discovered two chemicals responsible for the properties of L. virosa; lactucopicrin
Lactucopicrin
Lactucopicrin is a bitter substance that has a sedative and analgesic effect, acting on the central nervous system. It is a sesquiterpene lactone, and is a component of lactucarium, derived from the plant Lactuca virosa , as well as being found in some related plants such as Cichorium intybus...

 and lactucin
Lactucin
Lactucin is a bitter substance that forms a white crystalline solid and belongs to the group of sesquiterpene lactones. It is found in some varieties of lettuce and is an ingredient of lactucarium. It has been shown to have analgesic and sedative properties....

. In the United States, the plant experienced a resurgence in popularity in the 1970s. Today the plant is un-scheduled
Controlled Substances Act
The Controlled Substances Act was enacted into law by the Congress of the United States as Title II of the Comprehensive Drug Abuse Prevention and Control Act of 1970. The CSA is the federal U.S. drug policy under which the manufacture, importation, possession, use and distribution of certain...

 by the Food and Drug Administration
Food and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...

 (FDA), meaning it is legal to grow, purchase and own without prescription or license.

Pharmacology

The effects of ingesting L. virosa are similar to opium
Opium
Opium is the dried latex obtained from the opium poppy . Opium contains up to 12% morphine, an alkaloid, which is frequently processed chemically to produce heroin for the illegal drug trade. The latex also includes codeine and non-narcotic alkaloids such as papaverine, thebaine and noscapine...

, although no opiates are present in the plant. A latex derived from the extract of the stem secretions of Lactuca virosa, a simple preparation in a manner resembling opium, which is called lactucarium
Lactucarium
Lactucarium is the milky fluid secreted by several species of lettuce, especially Lactuca virosa, usually from the base of the stems. Lactucarium is known as lettuce opium because of its sedative and analgesic properties...

. One of the active compounds, lactucin
Lactucin
Lactucin is a bitter substance that forms a white crystalline solid and belongs to the group of sesquiterpene lactones. It is found in some varieties of lettuce and is an ingredient of lactucarium. It has been shown to have analgesic and sedative properties....

, is an adenosine receptor
Adenosine receptor
The adenosine receptors are a class of purinergic receptors, G protein-coupled receptors with adenosine as endogenous ligand.-Pharmacology:...

 agonist, while another, lactucopicrin
Lactucopicrin
Lactucopicrin is a bitter substance that has a sedative and analgesic effect, acting on the central nervous system. It is a sesquiterpene lactone, and is a component of lactucarium, derived from the plant Lactuca virosa , as well as being found in some related plants such as Cichorium intybus...

, has been shown to act as an acetylcholinesterase inhibitor
Acetylcholinesterase inhibitor
An acetylcholinesterase inhibitor or anti-cholinesterase is a chemical that inhibits the cholinesterase enzyme from breaking down acetylcholine, increasing both the level and duration of action of the neurotransmitter acetylcholine.- Uses :Acetylcholinesterase inhibitors:* Occur naturally as...

. Effects are felt quickly but do not last long, between half an hour to a couple of hours, and they dwindle slowly. The plant has been used as an anesthetic and a sleep aid, as well as recreationally. Oils and extracts can also be produced from L. virosa. These oils and extracts are often added to tea to help induce sleep. While its use as a galactagogue
Galactagogue
A galactagogue is a substance that promotes lactation in humans and other animals. It may be synthetic, plant-derived, or endogenous.-Herbal:The most commonly cited galactagogues are herbal...

 (a substance that increases breast milk) has been reported, the sedative effects on the baby would strongly argue against its use for this purpose. Many add the greens to salads, though the leaves of L. virosa are more bitter than other salad greens. Smoking involves either dried leaves or a sticky precipitate extracted from the leaves. Beverages can be prepared by soaking the leaves in alcohol.

The plant contains flavonoid
Flavonoid
Flavonoids , are a class of plant secondary metabolites....

s, which have strong anti-oxidant properties. L. virosa has also been found to contain coumarin
Coumarin
Coumarin is a fragrant chemical compound in the benzopyrone chemical class, found in many plants, notably in high concentration in the tonka bean , vanilla grass , sweet woodruff , mullein , sweet grass , cassia cinnamon and sweet clover...

s, and N-methyl-β-phenethylamine
Methylphenethylamine
Methylphenethylamine is a chemical compound derived from phenethylamine. Its N-substitution results in less metabolism by monoamine oxidase than phenylethylamine itself....

.

General references


External links

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