Woad

Isatis tinctoria Cruciferae woad, dyer's weed, radix isatidid

Location

Isatis tinctoria can be found alongside the south wall of the Research Building at Georgetown University. It is native to the Hebei, Shaanxi, Jiangxu and Anhui provinces in China (Bensky, et al 1993). I. tinctoria was historically cultivated in parts of America, England, France, Germany, and Italy and played a vital role in their economy (Oberthür, et al 2005).

Description

As a biannual plant, woad produces a basal rosette of leaves in its first year and in the second year puts out 5 – 6’ tall stems. Around May, woad blossoms with abundant small sprays of tiny neon yellow flowers, which are followed by the ripening of small black seeds, after which the plant dies (Roberts 2010).

Woad contains indoxyl-beta-glucoside, beta-sitosterol, isatin, arginine, glutamine, proline and tyrosine (Bensky, et al 1993). I. tinctoria leaves are high in isothiocyanates, which contribute to the flavor of broccoli, kale and other vegetables (Condurso, et al 2005).

Extracts of leaves, roots, and seeds will contain different phytochemicals (Mohn, Hamburger 2008). Post-harvest treatments will also affect the chemical composition of the plant (Maugard 2001).

History

Woad was traditionally used for treating wounds, ulcers, snakebites, hemorrhoids, and other inflammatory ailments (Oberthür, et al 2005). In addition woad has been a source for indigo dye since the time of antiquity, and it was economically vital to parts of England, France, Germany, and Italy (Oberthür, et al 2005).

Current Medicinal Uses

I. tinctoria is used for treating influenza and other infections. It exhibits antibacterial and antiviral effects, and it improves microcirculation (Huang 1999).

Extractions of I. Tinctoria leaves may augment the effects of antibiotics on staphylococcs infections, effects of penicillin, gentamicin, ciprofloxacin, and ceftriaxone (Yang 2005).

Isatis tinctoria has shown to have anti-fungal properties (Ahmad, et al 2008).

Woads contain alkaloids that inhibit COX-2/5-LOX and histamine releasing properties. These anti-inflammatory properties of I. tinctoria, specifically relating to the inhibition of 5-LOX, may be attributed to alpha-linoleic acid, a fatty acid that effects the inflammation pathway (Oberthür 2005). However, the topical application of these extracts has not been shown to decrease inflammation due to contact dermatitis (Heinemann 2004).

In animals, woad increases the circulating lymphcytes and the total white blood cell count in the peripheral blood. Human studies should be conducted to investigate the humoral and cellular functions of the polysaccharide components in Isatis tinctoria (Roxas, Jurenka 2007).

Adverse effects

No adverse effects have been reported. However, in Traditional Chinese Medicine, this herb is considered unsuitable for patients that are debilitated (Bensky 1993).

Comments

Woad is also called dyer’s weed (Bagust 2001) because it yields an indigo dye.

References

Ahmad I, Fatima I. Butyrylcholinesterase, Lipoxygenase Inhibiting and Antifungal Alkaloids from Isatis Tinctoria. J Enzyme Inhib Med Chem. 2008:3:313-6.

Bensky D, Gamble A & Kaptchuk T. Chinese Herbal Medicine: Materia Medica. Revised ed. Seattle: Eastland Press; 1993: 128.

Condurso C et al. The Leaf Volatile Constituents of Isatis Tinctoria by Solid-Phase Microextraction and Gas chromatography/Mass Spectrometry. Planta Med 2006; 72(10): 924-928. (Abstract)

Heinemann C, Schliemann-Willers S, Oberthür C, Hamburger M, Elsner P. Prevention of Experimentally Induced Irritant Contact Dermatitis by Extracts of Isatis Tinctoria Compared to Pure Tryptanthrin and its Impact on UVB-Induced Erythema. Planta Med. 2004 May;70(5):385-90.

Bagust, H. Hutchinson Dictionary of Plant Names: Common and Botanical. London. Hodder Arnold H&S. 2001

Huang KC. The Pharmacology of Chinese Herbs. 2nd ed. Washington, DC: CRC Press; 1999:401-402.

Maugard T. Identification of an Indigo Precursor from Leaves of Isatis Tinctoria (Woad). Phytochemistry 2001;897-904.

Mohn T. Hamburger M. Glucosinolate Pattern in Isatis Tinctoria and I. Indigotica Seeds. Planta Med 2008;74(8): 885-888 (Abstract)

Oberthür C, Jaggi R, Hamburger M. HPLC Based Activity Profiling for 5-Lipoxygenase Inhibitory Activity in Isatis Tinctoria Leaf Extracts. Filoterapia. 2005; 76: 324-32.

Roberts, M. Biology of Woad. (2010) All About Woad. http://www.woad.org.uk/html/growing_woad.html. Accessed May 28, 2010

Roxas M, Jurenka J. Colds and influenza: a review of diagnosis and conventional, botanical, and nutritional considerations. Altern Med Rev. 2007 Mar;12(1):25-48.

Wu JN. Illustrated Chinese Materia Medica, in Illustrated Chinese Materia Medica Anonymous 2005;369 available at http://site.ebrary.com/www/lib/uscisd/docDetail.action?docID=10142522.

Yang Z. The Synergistic Activity of Antibiotics Combined with Eight Traditional Chinese Medicines Against Two Different Strains of Staphylococcus Aureus. Colloids and Surfaces.B, Biointerfaces. 2005; 41:79-81.

Disclaimer

Information on this website is for educational purposes only. Many herbs historically used for medicine are considered too toxic to use today; some of these herbs have caused deaths. Do not ingest these herbs based on information on this website. We have not provided sufficient information for the safe medicinal use of any of these herbs, nor sufficient information for treatment of poisoning. All recreational use of these herbs is dangerous.