Dandelion

Scientific Name(s): Taraxacum officinale Weber, also referred to as Leontodon taraxacum L. Family: Asteraceae (daisies)

Common Name(s): Dandelion , lion's tooth

Uses

Dandelion has been used for its nutritional value in addition to other uses including diuresis, regulation of blood glucose, liver and gall bladder disorders, appetite stimulation, and for dyspeptic complaints.

Dosing

Dandelion root has been used as a tonic for digestive complaints in doses of 9 to 12 g/day, prepared as a tea. 1

Contraindications

Contraindications have not yet been identified.

Pregnancy/Lactation

Generally recognized as safe or used as food. Safety and efficacy for dosages above those in foods unproven and should be avoided.

Interactions

None well documented.

Adverse Reactions

Contact dermatitis and gastric discomfort have been reported.

Toxicology

Dandelion may be potentially toxic because of the high concentration of potassium, magnesium, and other minerals.

Botany

The dandelion is a weedy composite plant with a rosette of leaves radiating from its base. The stem is smooth and hollow and bears a solitary yellow head consisting solely of ray flowers, which produces a cluster of numerous tiny, tufted, single-seed fruits. The plant has a deep taproot. The leaves may be nearly smooth-edged, toothed or deeply cut; the toothed appearance gives rise to the plant's name (dent-de-lion means “lion's tooth” in French). 2 This perennial plant can reach 20 inches in height. It grows wild in most parts of the world and is cultivated in France and Germany. 3

History

The dandelion is mentioned as early as the 10th century by Arab physicians, who used it for medicinal purposes. 4 The plant was also recommended in an herbal written in the 13th century by the physicians of Myddfai in Wales. 3 It is native to Europe and Asia, but was naturalized in North America and now grows widely as a weed in nearly all temperate climates. It is cultivated by some European growers, and more than 100 specialized varieties have been developed. The bitter greens are used raw in salads, in wine making or cooked like spinach. The root is roasted and used to brew a coffee-like beverage said to lack the stimulant properties of coffee. Dandelions have long been used in herbal remedies for diabetes and disorders of the liver (the sugars in the plant are said not to aggravate this disease) and as a laxative and tonic. The juice of the leaves has been used to treat skin diseases, loss of appetite and to stimulate the flow of bile. 4

Chemistry

Dandelions are one of nature's richest green vegetable sources of beta-carotene, from which vitamin A is created (14,000 IU/100 g leaf vs. 11,000 IU/100 g in carrots). They are also a very good source of fiber, potassium (297 mg or 7.6 mEq/100 mg leaf), iron, calcium, magnesium, phosphorus, thiamine and riboflavin. Sodium and vitamins C and D are also present. 5

Dandelions contain acids including caffeic, p-hydroxyphenyl-acetic, chlorogenic, oleic, palmitic acids, and the fatty acids linoleic and linolenic. Other acids found are gallic and ascorbic acids.

The plant also contains terpenoids, sesquiterpenes (responsible for the bitter taste), triterpenes (beta-amyrin, taraxol and taraxerol), luteolin and the glycoside apigenin. Other reported constituents in dandelion include choline, inulin, pectin, glutin, gum, resin, sterols (β-sitosterol, stigmasterol, taraxasterol, homotaraxasterol) coumestrol and sugars (fructose, sucrose, glucose). 3 , 6 , 7

Reports are available evaluating fructofuranosidases from dandelion roots, 8 taraxinic acid 1′-O-beta-D-glucopyranoside 9 and furan fatty acid content. 10

Uses and Pharmacology

Dandelion has been classified as a hepatic, mild laxative, cholegogue, diaphoretic, analgesic, stimulant, tonic and a regulator of blood glucose. 6 , 7 , 11 , 12 , 13 , 14 , 15 The roots have been used as a laxative, diuretic, tonic, hepatic and for spleen ailments. 7 , 12 , 14 Root and leaves have been used for heartburn, bruises, chronic rheumatism, gout, diabetes, eczema and other skin problems as well as for cancers. 12 , 13

Diuretic
Animal data

Diuretic effects of dandelion extracts have been documented in mice. 6 One animal study indicated a greater diuretic effect achieved from herbal extracts than root extracts and compared the effects of a 50 mL/kg body weight dose (2 g dried herb/kg) to the effects achieved with 80 mg/kg of furosemide. 6 This study also reported the effects of dandelion to be greater than other plant diuretics, including Equisetum and Juniper berry. 6 , 11 This diuretic effect, likely a result of sesquiterpene lactone activity and high potassium content, 11 has been used to treat high blood pressure. 3 , 11 A later report observed no significant diuretic activity from the plant. 16 These same sesquiterpene lactones may contribute to dandelion's demonstrated mild anti-inflammatory activity. 6 , 12

Clinical data

Research reveals no clinical data regarding the use of dandelion for diuresis.

Liver and gall bladder disorders

Dandelion is effective as a detoxifying herb, working primarily on the liver and gallbladder to remove waste. It may aid gallbladder ailments and help “dissolve” gallstones. 3 However, dandelion should only be used for gallstones under a physician's direction; it is generally contraindicated in bile duct obstruction, empyema or ileus. 6 , 11 , 12 , 13

Animal data

Increases of bile secretion in rats (40% or more) have been attributed to activity of bitter sesquiterpene lactones in the root. 12 These lactones also increase gastric secretions that can cause gastric discomfort. 11 , 12

Clinical data

Research reveals no clinical data regarding the use of dandelion for liver and gall bladder disorders.

Regulation of blood glucose
Animal data

Hypoglycemic effects have been demonstrated in healthy, non-diabetic rabbits with a maximum decrease in blood glucose achieved at a dose of 2 g/kg. 6 The maximum effect of dandelion was reported to be 65% of the effect produced by tolbutamide 500 mg/kg. 6 Another report found no effect on glucose homeostasis in mice. 17 Inulin, reported to have antidiabetic activity, may contribute to dandelion's glucose regulating properties. 14 , 18

Clinical data

Research reveals no clinical data regarding the use of dandelion for regulation of blood glucose.

Other uses

Use for dyspeptic disorders may be attributed to the anti-ulcer and gastric antisecretory activity of taraxerol, one of the terpenoid alcohols also found in the root. 4 Dandelion is also considered an appetite-stimulating bitter. 5 , 11 The bitter principles, previously known as taraxacin which have recently been identified as eudesmanolides, are contained in the leaves and appear to be unique to dandelion. 11 In vitro antitumor activity with a mechanism similar to that of lentinan (a tumor polysaccharide) has been reported. 6 , Taraxacum species have been used in China for over 1100 years in treating breast cancer and other breast ailments. 12 Clinical studies using Chinese Taraxacum species also support the use of dandelion to treat hepatitis as well as various respiratory infections. 12

Dosage

Dandelion root has been used as a tonic for digestive complaints in doses of 9 to 12 g/day, prepared as a tea. 1

Pregnancy/Lactation

Generally recognized as safe or used as food. Safety and efficacy for dosages above those in foods unproven and should be avoided.

Interactions

None well documented.

Adverse Reactions

Like many plants in this family, dandelions are known to cause contact dermatitis in sensitive individuals. 19 , 20 A case report of a 9-year-old boy describes positive patch test reactions to dandelion and other compositae-plant oleo resins. 21 Two out of seven patients, each with histories of dandelion dermatitis, reacted not only to dandelion extracts, but to a sesquiterpene mix. 22 These sesquiterpene lactones are believed to be the allergenic principles in dandelion. 3 Taraxinic acid 1′-O-beta-D-glucopyranoside has also been identified as an allergenic component. 23

Toxicology

Acute toxicity of dandelion is low. LD 50 values in mice for the root are 36.8 g/kg and for herb are 28.8 g/kg. 3 A case report describes toxicity in a patient taking an herbal combination tablet that included dandelion. It was unclear as to which constituents were responsible. 24 Dandelion may be potentially toxic because of the high content of potassium, magnesium and other minerals. 25

Bibliography

1. Gruenwald J, ed. PDR for Herbal Medicines . 2nd ed. Montvale, NJ: Thomson Medical Economics; 2000:245–246.
2. Seymour ELD. The Garden Encyclopedia. 1936.
3. Chevallier A. Encyclopedia of Medicinal Plants . New York, NY: DK Publishing, 1996;140.
4. Loewenfeld C, Back P. The Complete Book of Herbs and Spices . David E. Charles. London: Seymour, 1974.
5. Brooks S. Prot J Bot Med 1996;1(4):231.
6. Newall CA, Anderson LA, Phillipson JD, eds. Herbal Medicines: A Guide for Health-Care Professionals . London: Pharmaceutical Press; 1996.
7. Duke J. CRC Handbook of Medicinal Herbs . Boca Raton, FL: CRC Press Inc., 1989;476-477.
8. Rutherford P, et al. Biochem J . 1972;126(3):569-573.
9. Hausen B. Derm Beruf Umwelt . 1982;30(2):51-53.
10. Hannemann K, et al. Lipids . 1989;24(4):296-298.
11. Bisset NG, ed. Max Wichtl. Herbal Drugs and Phytopharmaceuticals . Boca Raton, FL: CRC Prss Inc., 1994;486-489.
12. Leung AY; Fosters. Encyclopedia of Common Natural Ingredients . New York: John Wiley and Sons, Inc., 1996;205-207.
13. Brooks S. Prot J Bot Med . 1998;2(3):268.
14. Brooks S. Prot J Bot Med . 1996;1(3):163.
15. Brooks S. Prot J Bot Med . 1995:1(1):70.
16. Hook I, et al. Int J Pharmacognosy . 1993;31(1):29-34.
17. Swanston-Flatt S, et al. Diabetes Res . 1989;10(2):69-73.
18. Duke JA. Handbook of Biologically Active Phytochemicals and Their Activities . Boca Raton, FL: CRC Press, Inc., 1992;86.
19. Larregue M, et al. Ann Dermatol Venerol . 1978;105:547.
20. Hausen BM, Schulz KH. Derm Beruf Umwelt . 1978;26:198.
21. Guin J, et al. Arch Dermatol . 1987;123(4):500-502.
22. Lovell C, et al. Contact Dermatitis . 1991;25(3):135-188.
23. Hausen BM. Derm Beruf Umwelt . 1982;30:51.
24. DeSmet P, et al. BMJ . 1996 Jul 13;313:92.
25. Hamlin T. Can J Hosp Pharm . 1991;44(1):39-40.

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