Dandelion: Difference between revisions

| images      =

| intro        = ''Taraxacum officinale'' G.H. Weber ex Wiggers -- dandelion -- is a perennial composite herb of Eurasian origin, now distributed across every inhabited continent and recognized by virtually every person alive, most of whom have at some point scattered its seeds from a spherical white clock. The French long ago named it pissenlit -- wet-the-bed -- which is an accurate clinical description of its principal medicinal action in the leaf, and it is this frankness of folk nomenclature that most concisely captures the herb's place in medicine: a plant dismissed as a weed by every suburban lawn, carrying a clinical evidence base in diuresis that most commercially marketed diuretic herbs cannot match, with the additional distinction of replenishing in the leaf the very potassium that synthetic diuretics strip away.

| traditional_uses = The earliest written records of dandelion in medicine come from 11th-century Arabic physicians -- Ibn Sina listed dandelion leaf in pharmacopoeial works -- and from the Welsh Physicians of Myddfai, a 13th-century medical guild whose manuscripts record it for liver and digestive complaints.{{citation needed}}<!-- Candidate: Pughe J, translator. The Physicians of Myddvai. London: Longman, 1861 (Meddygon Myddfai). Topic: Welsh Physicians of Myddfai on dandelion; liver and digestive indications. Also: Ibn Sina. Canon of Medicine, relevant section. No PMID; medieval primary and secondary sources. Verify at publish. --> By the 17th century ''T. officinale'' was established in every European herbal, universally respected as a hepatic bitter, a diuretic, and a spring tonic food -- the tender young leaves gathered from fields before the first flowering and eaten in salad as an annual seasonal cleanse.

Dandelion occupies an unusual dual role as food and medicine. Spring dandelion greens -- young leaves gathered before flowering, when bitter principles are concentrated and the leaves are most nutritionally dense -- are among the most nutritionally complete wild greens available in temperate climates, higher in vitamins A, C, and K, and in calcium, iron, and potassium, than most cultivated vegetables.{{citation needed}}<!-- Candidate: USDA National Nutrient Database; ''Taraxacum officinale'' nutritional composition. Topic: dandelion leaf nutrient profile vs cultivated vegetables. Verify from current USDA FoodData Central. --> Dandelion coffee -- roasted dried root decoction -- became a wartime staple in Britain and Europe during both World Wars when coffee was rationed, and remains a gentle, caffeine-free bitter digestive tonic in current herbal practice. In France, ''pissenlit au lard'' (dandelion greens with lardons and hot vinegar dressing) is a Burgundian spring classic with a history traceable to medieval monastic cooking.

| botany      = ''Taraxacum officinale'' G.H. Weber ex Wiggers is placed in tribe Cichorieae (formerly Lactuceae), subfamily Cichorioideae, family Asteraceae. The species epithet officinale (of the dispensary) signals long apothecary use; the genus name derives from the Arabic tarakhshagun or the medieval Latin corruption of it, meaning bitter herb. ''Taraxacum'' is an enormously complex genus: depending on the taxonomic authority, it contains anywhere from 60 to 2,000 or more microspecies, many of which are apomictic (reproducing without fertilization, generating clonal lineages). Most commercial medicinal supply and most clinical research uses ''T. officinale'' in the broad, aggregate sense rather than any single microspecies; pharmacopoeial monographs accept this broad usage.

Closely related: ''Taraxacum mongolicum'' (Pu Gong Ying; principal TCM medicinal species; used pharmacopoeially as equivalent to ''T. officinale'').

| constituents = '''Leaf constituents'''

The root holds a different pharmacological profile. Inulin -- a fructooligosaccharide prebiotic polysaccharide -- constitutes up to 40 percent of dry root weight in autumn-harvested material, falling to 1 to 2 percent in spring (when it has been consumed in new-growth production).{{citation needed}}<!-- Candidate: Chicco AG, D'Alessandro ME, Karabatas LM, et al. Journal of Nutritional Biochemistry or similar. Topic: dandelion root inulin content seasonal variation; autumn vs spring. Verify PMID via eutils "''Taraxacum'' inulin content seasonal." --> This seasonal variation is the pharmacological rationale for the traditional autumn-harvest preference. Taraxacoside, the principal bitter sesquiterpene glycoside of the root, contributes to the bitter-tonic and mild laxative actions. Phenolic acids (chicoric acid, caffeic acid derivatives), triterpenes (taraxasterol, taraxerol), and polyacetylenes complete the profile. Mineral content in the root, while lower per gram than the leaf, is still significant.

| pharmacodynamics = '''Diuretic mechanism (leaf)'''

Inulin is a well-characterized prebiotic: it selectively promotes the growth of beneficial gut microbiota (principally ''Bifidobacterium'' and ''Lactobacillus'' species) by serving as a fermentable substrate for these organisms while being resistant to digestion by human gut enzymes. The effect is dose-dependent and well-established for inulin regardless of botanical source; dandelion root is one of the most concentrated natural sources of inulin outside chicory root (''Cichorium intybus'') and Jerusalem artichoke (''Helianthus tuberosus'').{{citation needed}}<!-- Candidate: Niness KR. "Inulin and Oligofructose: What Are They?" J Nutr. 1999;129(7 Suppl):1402S-1406S. Topic: inulin prebiotic mechanism; selective gut microbiota promotion. Verify PMID via eutils "inulin prebiotic ''Bifidobacterium''." -->

| indications = '''Diuretic activity: human clinical evidence'''

Ovadje and colleagues have published a series of in vitro studies demonstrating that aqueous dandelion root extract selectively induces apoptosis in human leukemia cell lines through both intrinsic and extrinsic pathways, without significant toxicity to normal peripheral blood mononuclear cells.<ref name="ovadje2011">Ovadje P, Chatterjee S, Griffin C, Tran C, Hamm C, Pandey S. "Selective induction of apoptosis through activation of caspase-8 in human leukemia cells (Jurkat) by dandelion root extract." J Ethnopharmacol. 2011;133(1):86-91. PMID 20849941.</ref><ref name="ovadje2012">Ovadje P, Hamm C, Pandey S. "Efficient induction of extrinsic cell death by dandelion root extract in human chronic myelomonocytic leukemia (CMML)." PLoS One. 2012;7(2):e30604. PMID 22363452.</ref> These are laboratory findings in cell lines; they do not constitute clinical evidence of anticancer efficacy in humans. No clinical trials of dandelion root extract for cancer treatment have been completed or published. These findings are scientifically interesting and warrant further investigation but should not be represented as clinical evidence of therapeutic effect.

| preparations = Leaf infusion (tea): 4 to 8 g fresh or dried leaves per cup of hot water, steeped covered (volatile constituents are modest; the cover prevents steam loss rather than oil loss). Taken 2 to 3 times daily for diuretic and tonic use; or fresh leaves as salad greens (the traditional spring tonic form, maximally nutritious and minimally processed).

Root powder: 2 to 4 g per day in capsule or tablet form; convenient standardized option.

| dosing = '''Leaf (diuretic, tonic)'''

Dandelion has no recreational or psychoactive profile in any documented tradition. Neither the leaf nor the root produces altered consciousness, euphoria, sedation, or any psychoactive effect at any accessible dose. The bitter taste at higher leaf or root doses is limiting; above 10 to 15 g of dried root per day, mild nausea and diarrhea occur as the dose-limiting gastrointestinal effects. No dose ladder is warranted.

| pharmacokinetics = The pharmacokinetics of ''T. officinale'' constituents have not been well characterized. Taraxacoside and related sesquiterpene lactones are likely absorbed from the gastrointestinal tract and undergo hepatic metabolism; the kinetics are not documented to the same standard as pharmaceutical preparations. Inulin from the root is not absorbed -- it passes undigested to the large intestine where it is fermented by colonic microbiota; this is entirely the intended pharmacological mechanism for its prebiotic action rather than a bioavailability problem. Polyphenolic compounds (chicoric acid, caffeic acid derivatives) are absorbed in part from the small intestine and undergo conjugation and methylation by gut enzymes and hepatic CYP enzymes.{{citation needed}}<!-- Candidate: general polyphenol pharmacokinetics references; no ''Taraxacum''-specific PK data located. Topic: absorption and metabolism of taraxacoside and dandelion polyphenolics. Verify if ''Taraxacum''-specific PK study available via eutils "taraxacoside pharmacokinetics absorption." -->

| interactions    = Lithium: dandelion leaf's diuretic action reduces renal lithium clearance (as does any diuretic); this can elevate lithium plasma levels into the toxic range. Patients taking lithium should not use dandelion leaf preparations without medical supervision and lithium-level monitoring.{{citation needed}}<!-- Candidate: herbal-drug interaction references (Mills S, Bone K. Principles and Practice of Phytotherapy; or Brinker F. Herb Contraindications and Drug Interactions). Topic: dandelion diuresis and lithium toxicity interaction. No primary clinical trial; interaction is pharmacologically grounded from diuretic class effects. Verify from specialist interaction reference. -->

Anticoagulants (warfarin): dandelion leaves are very high in vitamin K. Patients on warfarin anticoagulation whose vitamin K intake changes significantly (including by adding large quantities of dandelion leaf to the diet) may experience INR instability. Consistency of intake is more important than avoidance.

| interactionsummary = Lithium: diuresis raises lithium levels (monitor). High vitamin K in leaf: INR variability with warfarin. Additive hypoglycemia possible with antidiabetic medicines.

| counseling      = The distinction between leaf and root preparations should be communicated clearly: the diuretic action resides principally in the leaf, and the hepatic-bitter and prebiotic actions in the root. A patient seeking fluid-retention relief should use the leaf infusion; a patient seeking liver support, digestive bitters, or prebiotic gut support should use the root decoction or roasted root.

MHRA traditional herbal registration: dandelion root preparations registered for traditional use for relief of minor digestive and urinary complaints.

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[[Category:Plants]]