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Lettuce Opium

Scientific Name(s): Lactuca sativa var capitata L. (garden lettuce)., Lactuca virosa L. (wild lettuce).
Common Name(s): Acrid lettuce, Garden lettuce, German lactucarium, Greater prickly lettuce, Green endive, Lettuce opium, Strong-scented lettuce, Wild lettuce

Clinical Overview

Use

Lettuce opium has been used as a topical antiseptic, as folk medicine to ameliorate a variety of conditions, and as a narcotic substitute or enhancer. It is also a mild sedative and hypnotic. There is little evidence to support its use for any indication.

Dosing

There is no recent clinical evidence to support specific dose recommendations.

Contraindications

Contraindications have not yet been identified.

Pregnancy/Lactation

Information regarding safety and efficacy in pregnancy and lactation is lacking.

Interactions

None well documented.

Adverse Reactions

Lettuce opium contains sesquiterpene lactones; therefore, oral ingestion may be associated with allergic reactions.

Toxicology

Injection of wild lettuce opium and valerian root has been associated with transient fevers, chills, abdominal pain, flank and back pain, neck stiffness, headache, leucocytosis, and mild liver function abnormalities in 3 young adults.

Botany

Widely cultivated, lettuce flowers from July to September. This biennial herb grows to 1.8 m. The large leaves can attain lengths of 0.46 m. The stalks are rich in a milky-white sap that flows freely when the stems are broken.1

History

Lettuce opium has been used in folk medicine for indications ranging from aiding circulation to treating swollen genitals. In Europe, it is used as a substitute for opium in cough mixtures.2 In homeopathy, a tincture has been used for laryngitis, bronchitis, asthma, cough, and urinary tract infections.3 The juice of the stem covering yields a medicinal extract known as thridace, the use and efficacy of which is widely disputed.4

In Chinese medicine, lettuce preparations have been widely used. The dried juice has been recommended as a topical wound antiseptic, and the seeds have been used as a galactogogue (to increase the flow of milk in nursing mothers). It has been claimed that the flowers and seeds are effective in reducing fevers.5 Lettuce opium products have been marketed as legal highs or narcotic substitutes intended to be smoked alone or in combination with marijuana to enhance potency and flavor.6 Its analgesic and sedative attributes seem more based on fiction than fact.

Chemistry

Some confusion exists regarding the nomenclature of the products derived from L. virosa and related plants. Flowering lettuce plants contain large amounts of a milky-white sap, which has a bitter taste and strong opiate-like odor. When the juice is collected and is exposed to air, it turns a brownish color. This substance is called lactucarium, a mixture of compounds to which the touted narcotic properties of the product have been ascribed. Lactucarium has been reported to contain approximately 0.2% lactucin, a sesquiterpinoid lactone. Additionally, the mixture contains a volatile oil, caoutchouc, mannitol, and lactucerol (taraxasterol) (approximately 50%). Lactucerin, also found in the latex, is the acetyl derivative of taraxasterol, a widely distributed triterpene.5, 7

Reports that lactucarium contains hyoscyamine have been refuted.8 A report that L. virosa contains N-methyl-beta-phenylethylamine9 also has been refuted.6

Uses and Pharmacology

Hallucinogenic Effects

A variety of legal, alternate "hallucinogenic" products containing lettuce opium have been available on the market. Brand names of such products include Lettucine, Black Gold, Lettucene, Lettuce Hash, and Lopium. These products contain a lettuce derivative or lactucarium and are smoked in pipes or heated in small bowls, and the vapors are inhaled. These extracts are sometimes combined with damiana distillates, African yohimbe bark, or catnip distillates.

Animal data

Research reveals no animal data regarding the use of lettuce opium for hallucinogenic effects.

Clinical data

The hallucinogenic effect is usually mild and appears to be related to the degree of user expectation. There is no pharmacologic basis for the purported hallucinogenic effects of lettuce opium.

Other uses

Lettuce leaf cigarettes have been marketed as nicotine-free tobacco substitutes. Support for such alternatives has been variable because of slow acceptance of the unique flavor and the lack of a nicotine-induced kick.

Phytochemical and biological screening of several Lactuca species indicates that the genus has no antimicrobial activity, slight antitumor activity, and can produce gross CNS effects in mice.10, 11 However, the Lactuca species has resistance to viruses, bacteria, and fungi (Bremia lactucae).12

While lactucin and lactucopicrin have been reported to have depressant and sedative activity on the CNS, these compounds are chemically unstable; commercial lactucarium contains little, if any, of these.13 Latex of L. sativa has been shown to inhibit the growth of Candida albicans in vitro.14 Extracts of L. sativa resulted in hypotension when administered to dogs.6

Dosing

There is no recent clinical evidence to support specific dose recommendations.

Pregnancy / Lactation

Information regarding safety and efficacy in pregnancy and lactation is lacking.

Interactions

None well documented.

Adverse Reactions

Case reports are lacking; however, a possible association exists between lettuce ingestion and a localized oral allergic reaction.15

Toxicology

Reports of mydriasis, dizziness, anxiety, urinary retention, decreased bowel sounds, and sympathetic over-activity have been published. An anticholinergic mechanism is suggested.16 Mortality in dogs has been reported following intravenous administration.16, 17

References

1. Lactuca virosa. USDA, NRCS. 2016. The PLANTS Database (http://plants.usda.gov, September 2016). National Plant Data Team, Greensboro, NC 27401-4901 USA. Accessed September 2016.
2. Lewis WH. Medical Botany. New York, NY: J. Wiley and Sons; 1977.
3. Schauenberg P, Paris F. Guide to Medicinal Plants. New Canaan, CT: Keats Publishing; 1977.
4. Grieve MA. Modern Herbal. New York, NY: Dover Publications; 1971.
5. Brown JK, Malone MH. Legal highs-constituents, activity, toxicology and herbal folklore. Pacific Information Service on Street Drugs. 1977;5:36.
6. Huang ZJ, Kinghorn AD, Farnsworth NR. Studies on herbal remedies I: analysis of herbal smoking preparations alleged to contain lettuce (Lactuca sativa L.) and other natural products. J Pharm Sci. 1982;71:270-271.7062258
7. Bachelor FW, Ito S. A revision of the sterochemistry of lactucin. Can J Chem. 1973;51:3626.
8. Willaman JJ, Li HL. Lloydia. 1970;33:1.5520302
9. Marquardt P, Classen HG, Schumacher KA. N-Methylphenethylamine, an indirect sympathicomimetic agent in vegetables. Arzneimittelforschung. 1976;26:2001-2003.1037233
10. Bhakuni DS, Dhar ML, Dhar MM, Dhawan BN, Gupta B, Srimal RC. Screening of Indian plants for biological activity. Indian J Exp Biol. 1971;9:91-102.5089325
11. Fong HH, Farnsworth NR, Henry LK, Svoboda GH, Yates MJ. Biological and phytochemical evaluation of plants. X. Test results from a third two-hundred accessions. Lloydia. 1972;35:35-48.5037480
12. Chupeau MC, Maisonneuve B, Bellec Y, Chupeau Y. A Lactuca universal hybridizer, and its use in creation of fertile interspecific somatic hybrids. Mol Gen Genet. 1994;245:139-145.7816020
13. Tyler VE. The New Honest Herbal. Philadelphia, PA: G.F. Stickley Co.; 1987.
14. Moulin-Traffort J, Giordani R, Regli P. Antifungal action of latex saps from Lactuca sativa L. and Asclepias curassavica L. Mycoses. 1990;33:383-392.2090937
15. Bernton HS. Oral allergy after lettuce ingestion. JAMA. 1974;230:613.
16. Mullins ME, Horowitz BZ. The case of salad shooters: intravenous injection of wild lettuce extract. Vet Hum Toxicol. 1998;40:290-291.9778767
17. Besharat S, Besharat M, Jabbari A. Wild lettuce (Lactuca virosa) toxicity. BMJ Case Rep. 2009;2009.2168692010.1136/bcr.06.2008.0134

Disclaimer

This information relates to an herbal, vitamin, mineral or other dietary supplement. This product has not been reviewed by the FDA to determine whether it is safe or effective and is not subject to the quality standards and safety information collection standards that are applicable to most prescription drugs. This information should not be used to decide whether or not to take this product. This information does not endorse this product as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this product. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this product. This information is not specific medical advice and does not replace information you receive from your health care provider. You should talk with your health care provider for complete information about the risks and benefits of using this product.

This product may adversely interact with certain health and medical conditions, other prescription and over-the-counter drugs, foods, or other dietary supplements. This product may be unsafe when used before surgery or other medical procedures. It is important to fully inform your doctor about the herbal, vitamins, mineral or any other supplements you are taking before any kind of surgery or medical procedure. With the exception of certain products that are generally recognized as safe in normal quantities, including use of folic acid and prenatal vitamins during pregnancy, this product has not been sufficiently studied to determine whether it is safe to use during pregnancy or nursing or by persons younger than 2 years of age.

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