''Lactuca virosa'' is a plant in the ''
Lactuca
''Lactuca'', commonly known as lettuce, is a genus of flowering plants in the family Asteraceae. The genus includes at least 50 species, distributed worldwide, but mainly in temperate Eurasia.
Its best-known representative is the garden lettuce ...
'' (lettuce) genus, often ingested for its mild
analgesic
An analgesic drug, also called simply an analgesic (American English), analgaesic (British English), pain reliever, or painkiller, is any member of the group of drugs used to achieve relief from pain (that is, analgesia or pain management). It ...
and
sedative
A sedative or tranquilliser is a substance that induces sedation by reducing irritability or excitement. They are CNS depressants and interact with brain activity causing its deceleration. Various kinds of sedatives can be distinguished, but t ...
effects.
It is related to common lettuce (''
L. sativa''), and is often called wild lettuce, bitter lettuce, laitue vireuse, opium lettuce, poisonous lettuce, tall lettuce, great lettuce
or rakutu-karyumu-so.
Description
''Lactuca virosa'' is
biennial
Biennial means (an event) lasting for two years or occurring every two years. The related term biennium is used in reference to a period of two years.
In particular, it can refer to:
* Biennial plant, a plant which blooms in its second year and th ...
, similar to prickly lettuce ''
Lactuca serriola
''Lactuca serriola'', also called prickly lettuce, milk thistle (not to be confused with ''Silybum marianum'', also called milk thistle), compass plant, and scarole, is an annual or biennial plant in the tribe Cichorieae within the family Asterac ...
'' but taller – it can grow to 200 cm (80 inches or almost 7 feet). It is also stouter, the stem and leaves are more purple flushed, and the leaves are less divided, but more spreading,
similarly to ''
Mycelis muralis'' but showing more than 5 florets.
The
achene
An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not ope ...
is purple black, without bristles at the tip. The
pappus is the same as ''Lactuca serriola''.
In the northern hemisphere, it flowers from July until September.
Distribution
Found coastally in
Great Britain
Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It is ...
, rarely in north-east of Ireland. ''Lactuca virosa'' is widespread across much of central and southern Europe. It can be found locally in the south east and east of
England
England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...
. In the rest of Great Britain it is very rare, and in Ireland it is absent. It is also found in the
Punjab
Punjab (; Punjabi: پنجاب ; ਪੰਜਾਬ ; ; also romanised as ''Panjāb'' or ''Panj-Āb'') is a geopolitical, cultural, and historical region in South Asia, specifically in the northern part of the Indian subcontinent, comprising ...
Region of
Pakistan
Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
and
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
where it grows in the wild.
In North America, it has been documented as introduced in
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
,
Alabama
(We dare defend our rights)
, anthem = "Alabama (state song), Alabama"
, image_map = Alabama in United States.svg
, seat = Montgomery, Alabama, Montgomery
, LargestCity = Huntsville, Alabama, Huntsville
, LargestCounty = Baldwin County, Al ...
,
Iowa
Iowa () is a state in the Midwestern region of the United States, bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west. It is bordered by six states: Wisconsin to the northeast, Illinois to the ...
, and
Washington, DC
)
, image_skyline =
, image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan ...
, and grows wild in other parts of the continent.
History
''Lactuca 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
The Royal Pharmaceutical Society of Great Britain (RPSGB) existed from its founding as the Pharmaceutical Society of Great Britain in 1841 until 2010. The word "Royal" was added to its name in 1988. It was the statutory regulatory and professional ...
in 1911. They discovered two chemicals responsible for the properties of ''L. virosa'';
lactucopicrin
Lactucopicrin (Intybin) 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'' (wild lettuce ...
and
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 sedativ ...
. In the United States, the plant experienced a resurgence in popularity in the 1970s. Today the plant is
un-scheduled by the
Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...
(FDA), meaning it is legal to grow, purchase, and own without prescription or license.
"Wild Salad" has long been known in the world of "natural remedies" or "alternative treatments". It is often referred to as the poor man's opium.
Pharmacology
A
latex
Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latexes are found in nature, but synthetic latexes are common as well.
In nature, latex is found as a milky fluid found in 10% of all flowering plants (angiosperms ...
which is called
lactucarium
Lactucarium is the milky fluid secreted by several species of lettuce, especially ''Lactuca virosa'', usually from the base of the stems. It is known as lettuce opium because of its sedative and analgesic properties. It has also been reported ...
can be derived from the extract of the stem secretions of ''Lactuca virosa''. Oils and extracts can also be produced from ''L. virosa''. These oils and extracts have sedative properties in rodents.
[ Although the standard definition of lactucarium requires its production from ''Lactuca virosa'', it was recognized that smaller quantities of lactucarium could be produced in a similar way from '']Lactuca sativa
Lettuce (''Lactuca sativa'') is an annual plant of the family Asteraceae. It is most often grown as a leaf vegetable, but sometimes for its stem and seeds. Lettuce is most often used for salads, although it is also seen in other kinds of food, ...
'' and ''Lactuca canadensis
''Lactuca canadensis'' is a species of wild lettuce known by the common names Canada lettuce, Canada wild lettuce, tall lettuce, and Florida blue lettuce.Weakley, Alan S''. Flora of the Southern and Mid-Atlantic States.'' UNC Herbarium, North Car ...
'' var. ''elongata'', and even that lettuce-opium obtained from ''Lactuca serriola
''Lactuca serriola'', also called prickly lettuce, milk thistle (not to be confused with ''Silybum marianum'', also called milk thistle), compass plant, and scarole, is an annual or biennial plant in the tribe Cichorieae within the family Asterac ...
'' or ''Lactuca quercina
''Lactuca quercina'' is a species of wild lettuce native to Europe and Asia. It is an annual or biennial herb in the tribe Cichorieae within the family Asteraceae growing from a taproot to maximum heights of or more.
''Lactuca quercina'' contai ...
'' was of superior quality.
''Lactuca virosa'' contains flavonoid
Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans.
Chemically, flavonoids ...
s, coumarin
Coumarin () or 2''H''-chromen-2-one is an aromatic organic chemical compound with formula . Its molecule can be described as a benzene molecule with two adjacent hydrogen atoms replaced by a lactone-like chain , forming a second six-membered h ...
s, and ''N''-methyl-β-phenethylamine. A variety of other chemical compounds have been isolated from ''L. virosa''. One of the compounds, 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 sedativ ...
, is an adenosine receptor
The adenosine receptors (or P1 receptors) are a class of purinergic G protein-coupled receptors with adenosine as the endogenous ligand. There are four known types of adenosine receptors in humans: A1, A2A, A2B and A3; each is encoded by a di ...
agonist ''in vitro
''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology an ...
'',[ while another, ]lactucopicrin
Lactucopicrin (Intybin) 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'' (wild lettuce ...
, has been shown to act as an acetylcholinesterase inhibitor
Acetylcholinesterase inhibitors (AChEIs) also often called cholinesterase inhibitors, inhibit the enzyme acetylcholinesterase from breaking down the neurotransmitter acetylcholine into choline and acetate, thereby increasing both the level and ...
''in vitro''.
References
General references
#
External links
Wild lettuce
Vaults of Erowid
Photo of herbarium specimen at Missouri Botanical Garden
{{Taxonbar, from=Q578927
virosa
Medicinal plants
Entheogens
Plants described in 1753
Taxa named by Carl Linnaeus
Flora of Europe