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Home , Lactuca, Lactucarium, Lactuca canadensis, Lactuca virosa

Wild

Species (Family) Other constituents Mannitol, proteins, resins and sugars . virosa L. (/Compositae)

Synonym(s) Food Use Bitter Lettuce, Lettuce Wild lettuce is not used in foods, although the related Related Lactuca species include Lactuca sativa species L. sativa is commonly used as a salad ingre- (Garden Lettuce), Lactuca (Prickly Lettuce), dient. Lactuca altissima and (Wild Lettuce of America) Herbal Use Wild lettuce is stated to possess mild , ano- Part(s) Used dyne and properties . Traditionally, it has Leaf, latex been used for , restlessness and excitability in children, pertussis, irritable cough, priapism, dysme- Pharmacopoeial and Other norrhoea, nymphomania, muscular or articular pains, and specifically for irritable cough and insom- Monographs ,G7,G8,G4 ,G64) nia. (G BHC 1992 (G6) BHP 1996 (G9) Martindale 32nd edition (G43) Dosage (G36) PDR for Herbal Medicines 2nd edition Dried leaves 0.5-3.O g or by infusion three times (G6) daily . Legal Category (Licensed Products) (G37) Liquid extract 0.5-3.OmL (1 :1 in 25% alcohol) GSL three times daily . (G6)

(G6,G22,G48,G60,G64) Constituents Loctucorium (dried latex extract) (BPC 1934) 0.3- All parts of the contain a milky, white latex (sap) 1 .0 g three times daily . which, when collected and dried, forms the drug known as .(G33) Soft extract (BPC 1934) 0 .3-1 .0 g three times daily.

Acids Citric, malic and oxalic (up to 1%) acids ; Pharmacological Actions cichoric acid (phenolic) .( ' ) In vitro and animal studies (2,G33) , later disputed . N- Lactucarium has been noted to induce mydriasis .(G6) methyl-(3-phenethylamine, also disputed. (') This effect may be attributable to hyoscyamine, although the dried sap is reportedly devoid of this Coumarins Aesculin, cichoriin . (l) . An alcoholic extract of a related species, L . sativa, Flavones (e.g. apigenin, luteolin), flavo- has exhibited a sedative effect in toads, causing a nols (e.g. quercetin) and their glycosides .(') reduction in motor activity and behaviour .(3) Higher doses resulted in flaccid paralysis . In addition, an Terpenoids Bitter principles including the sesquiter- antispasmodic action on isolated smooth and striated pene lactones lactucin and lactupicrin () ; muscle, and in vitro negative chronotropic and (3-amyrin, germanicol, and lactucone (lactucerin) . inotropic effects on normal and stressed (tachycar- Lactucone is a mixture of a- and (3-lactucerol acet- dic) hearts were observed . The antispasmodic action ates, (3-lactucerol being identical to taraxasterol . was nored to be antagonised by calcium .

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Wild lettuce 483

Lactucin, lactupicrin and hyoscyamine have all Pharmaceutical Comment been proposed as the sedative components in wild The chemistry of wild lettuce is well documented lettuce. However in the above study, (3) the active although it is not clear which constituents represent component was uncharacterised and acted mainly the active components. Early reports of hyoscyamine peripherally, not readily crossing the blood-brain as a constituent have not been substantiated by barrier . The suggested mode of action was via subsequent study. No published information was interference with basic excitatory processes com- found to support the traditional herbal uses of mon to neural and muscular functions, and not via wild lettuce, although a sedative action in toads a neuromuscular block . has been reported for a related species L. sativa . In Low amounts (nanograms) of have view of the potential allergenicity of wild lettuce and been detected in Lactuca species, although the concentrations involved are considered too low to the lack of toxicity data, excessive use should be avoided. exert any obvious pharmacological effect . (G60)

Side-effects, Toxicity References None documented for L . virosa. Wild lettuce con- See also General References G6, G9, G10, G19, tains sesquiterpene lactones which are potentially (G19) G22, G31, G33, G36, G37, G42, G43, G48, G51, allergenic . Occupational dermatitis has been G60 and G64 . documented for L. sativa together with an urticarial eruption after ingestion of the leaves .(4--6,GS 1) The 1 Rees S, Harborne JB. Flavonoids and other milky sap of L. sativa is reported to be irritant. (G51) phenolics of Cichorium and related members of The toxicity of wild lettuce is stated to be low . the Lactuceae (Compositae). Bot J Linn Soc 1984; Consumption of large amounts of L. scariola has 89: 313-319 . caused poisoning in cattle, who developed pulmon- 2 Huang Z-J et al. Studies on herbal remedies I: Analysis of herbal smoking preparations alleged ary emphysema, severe dyspnoea, and weakness . (7) to contain lettuce (Lactuca sativa L.) and other Only the immature were reported to be toxic. natural products . J Pharm Sci 1982; 71: 270-271. L. sativa has been reported to produce only 3 GonzAlex-Lima F et al. Depressant pharmacolo- negative responses when tested for mutagenicity gical effects of a component isolated from lettuce, using the Ames test (Salmonella typhimurium Lactuca sativa. Int J Crude Drug Res 1986; 24: TA98, TA100) .(') 154-166. 4 Krook G. Occupational dermatitis from Lactuca Contra-indications, Warnings sativa (lettuce) and Cichorium (endive). Contact Overdosage may produce poisoning (G42) involving Dermatitis 1977; 3 : 27-36. stupor, depressed respiration, coma and even death . S Rinkel HJ, Balyeat RM . Occupational dermatitis due to lettuce . JAMA 1932; 98: 137-138. Wild lettuce may cause an allergic reaction in 6 Zeller W et al. sensitive individuals, in particular those with an The sensitizing capacity of compositae plants 6 . Guinea pig sensitization existing sensitivity to other members of the Aster- experiments with ornamental plants and weeds aceae/Compositae family. using different methods . Arch Dermatol Res 1985; 277: 28-35. Pregnancy and lactation The safety of wild lettuce 7 Anon Poisindex CD-ROM 1995; 85. Denver: has not been established. In view of the lack of Micromedex. toxicity data and the possibility of allergic reac- 8 White RD et al . An evaluation of acetone extracts tions, excessive use of wild lettuce during preg- from six plants in the Ames mutagenicity test . nancy and lactation should be avoided . Toxicol Lett 1983; 15 : 26-31 .