Description
Medicinal Parts
The medicinal parts of the plant are the ripe seed and the fresh or dried roots.
Flower and Fruit
The crimson flowers grow in long-peduncled, loose cymes. The heads are fairly large, globose, and almost glabrous. All flowers are funnel-shaped and androgynous. The bracts are green and coriaceous with a barb-shaped, inward-curving tip. The fruit is compressed and has a bristly tuft, which falls off easily. The fruits separate from their stems on ripening.
Leaves, Stem, and Root
The plant grows to a height of 80 to 150 cm. The stem is erect, rigid, grooved, branched, and downy to wooly. The leaves are alternate, petiolate, broad to ovate-cordate. They are blunt and slightly wooly to hairy on the underside. The lowest leaves are very large and have a latex-filled stem.
Habitat
Burdock grows in Europe, northern Asia, and North America.
Production
Burdock root consists of the fresh or dried underground parts of Arctium lappa, Arctium minus, and/or Arctium tomentosum. Roots are gathered in the autumn of the plant's first year or the early part of the second year.
Other Names
Bardana, Beggar's Buttons, Burr Seed, Clot-Bur, Cockle Buttons, Cocklebur, Fox's Clote, Great Burr, Happy Major, Hardock, Hareburr, Lappa, Love Leaves, Personata, Philanthropium, Thorny Burr
Actions & Pharmacology
Compounds
Volatile oil (small amounts) of very complex make-up: including, among others, phenylacetaldehyde, benzaldehyde, 2-alkyl-3-methoxy-pyrazines
Lignans: neoarchtiin A
Sesquiterpene lactones
Polyynes: chief components are trideca-1, 11-dien-3, 5,7,9-tetrain, as well as sulfur derivatives
Caffeic acid derivatives: including chlorogenic acid, isochlorogenic acid
Polysaccharides: insulin (fructose), mucilage's (xyloglucans, acidic xylans)
Triterpenes: including alpha-amyrin, omega-taraxasterol, present to some extent as acetic acid ester
Phytosterols: beta-sitosterol, stigmasterol, campesterol and their esters
Tannins
Effects
There are no human clinical trials validating the use of burdock root for any indication. Animal and in vitro data report that burdock may have antibacterial, antineoplastic, antioxidant, antiretroviral, and anti-inflammatory and hepatoprotective properties. The most extensive in vitro and animal research has been on the antineoplastic activity of burdock (Ryu et al, 1995; Umehara et al, 1993; Morita et al, 1984; Dombradi, 1970). Burdock exhibited antibacterial activity in vitro (Izzo et al, 1995) and inhibits human immunodeficiency virus (HIV-1) in vitro (Collins et al, 1997).
Antibacterial Effects
Eighty-percent ethanol extracts of aerial portions of burdock showed activity against Bacillus subtilis and Salmonella typhi H but not Staphylococcus, Streptococcus, Escherichia coli, Klebsiella, Pseudomonas, or Proteus (Izzo et al, 1995). The antimicrobial activity documented for burdock has been attributed to the polyacetylene constituents, (Schulte et al, 1967) although only traces of these compounds are found in the dried commercial herb (Wagner et al, 1983). No antibacterial activity was noted for the butyrolactone lignan glycoside arctiin and its aglycone, arctigenin, isolated from burdock achenes, against a variety of gram-positive and -negative organisms in vitro (Ryu et al, 1995).
Anti-Inflammatory Effects
A hot aqueous extract of achenes of burdock exhibited significant activity at inhibiting platelet-activating factor (PAF) binding to platelets in vitro (Iwakami et al, 1992). Methanol extracts from burdock achenes showed anticomplementary activity at a concentration of 0.05 g crude material/mL (6.3 mg/mL of the extract) in vitro. The active constituents were shown to be lignans such as lappaols B and H, arctigenin, matairesinol, and arctiin found in the ethyl acetate eluate of the methanol extract (Oshima et al, 1988).
Antineoplastic Effects
The burdock achene-derived butyrolactone lignan glycoside arctiin and its aglycone, arctigenin, exhibited antiproliferative activity against five human cancer cell lines in vitro. The activity of these constituents was significantly less than that of podophyllotoxin but similar to that of cisplatin and doxorubicin. These lignans bear structural similarity to podophyllotoxin (Ryu et al, 1995).
Lignans, such as arctigenin from the achenes of burdock, induced normalizing differentiation of a murine myeloid leukemia cell line into non-neoplastic phagocytic cells in vitro at concentrations of 5 micromolar. Sesquilignans and dilignans from burdock showed much weaker activity. Similar activity was not seen in a human leukemia cell line (Umehara et al, 1993).
An unidentified constituent of a fresh juice extract of burdock root showed antimutagenic activity against a wide range of mutagens in vitro. The compound was active against mutagens requiring metabolic activation as well as those that did not. Heating and exposure to proteolytic enzymes did not eliminate the antimutagenic activity. Manganese chloride eliminated the antimutagenicity of the extract. The active constituent was a polyanionic substance of high molecular weight (Morita et al, 1984).
Antioxidant Effects
Hot aqueous burdock root extracts showed superoxide dismutase-like activity and quenched hydroxyl radicals in vitro (Lin et al, 1996). Five caffeoylquinic acid compounds from the root of burdock showed more potent antioxidant activity than alpha-tocopherol, caffeic acid, or chlorogenic acid in vitro (Maruta et al, 1995).
Antiretroviral Effects
Aqueous extracts of achenes of burdock showed 90% inhibition of human immunodeficiency virus (HIV)-1 gp120 protein binding to the CD4 receptor in vitro (Collins et al, 1997).
Hepatoprotective Effects
Compared to untreated carbon tetrachloride-exposed controls, serum glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) levels were significantly lower in animals treated with any level of burdock extract (p<0.01 to 0.05). There was a clear dose-response effect. Liver histology was also markedly less abnormal in the animals given burdock extract. The burdock extracts, at a concentration of 300 and 1000 mg/kg, showed a superior ability to maintain normal serum GOT and GPT levels compared to 25 mg/kg silymarin (no statistical analysis provided). The authors suggest the activity was due to burdock's antioxidant properties (Lin et al, 1996).
Clinical Trials
There are no controlled and/or open-label clinical trials validating the use of burdock root for any indication.
Indications & Usage
Unproven Uses
Preparations of Burdock Root are used for ailments and complaints of the gastrointestinal tract, as a diaphoretic and diuretic, and for blood purifying. Externally, it is used for ichthyosis, psoriasis, and seborrhea of the scalp. The claimed efficacies have not been documented.
Chinese Medicine
Burdock is used to treat carbuncles, ulcers and erythema of the skin as well as sore throats. Efficacy has not been proved.
Contraindications
Pregnancy
The achene or fruit of Burdock should not be used during the first trimester of pregnancy.
Precautions & Adverse Reactions
No health hazards or side effects are known in conjunction with the proper administration of designated therapeutic dosages. There is a slight potential for sensitization via skin contact with the drug. Anti-cholinergic symptoms have been reported in multiple cases related to consumption of burdock products (Bryson et al, 1978; Rhoads et al, 1984-1985). These were due to adulteration of the products with atropine-containing herbs and not due to any constituents or properties inherent to burdock (De Smet, 1993a).
Burdock can be safely combined with pharmaceutical drugs other than the combination of any Burdock tincture or alcohol extract with disulfiram or metronidazole due to the alcohol content.
Drug Interactions
No interaction data is available.
Dosage
Mode of Administration
Administered as a drug and, for external use, in the form of burdock oil (extract with fat oil).
Preparation
Tea: steep 2.5 g (1 teaspoon) of the drug with 150 mL boiling water.
How Supplied
- Capsules – 460 mg and 475 mg
- Fluid Extract – 1:1
Daily Dose
Tea. 1 cup 1 to 2 times a day.
