Monday, 29 November 2010

(3) Therapeutic Profile: Milk Thistle - Silybum marianum

Milk Thistle - Silybum marianum

The Milk Thistle is a flowering plant of the daisy family, Asteraceae. They are native to the Mediterranean regions of Europe, North Africa and the Middle East. The name "Milk Thistle" derives from two features of the leaves: they are mottled with splashes of white and they contain a milky sap.

There are two species currently classified: Silybum ebumeum Coss. & Dur. var. hispanicum and Silybum marianum (L.) Gaertner, otherwise known as the Variegated Thistle. The latter is the species that I will be discussing today, and is by far more widely known.

Medicinal Properties

Increasing research is being undertaken on the physiological effects, therapeutic properties and possible medical uses of Milk Thistle. It is believed to give some remedy for liver diseases (e.g. viral hepatitis) and the extract, silymarin, is used in pharmaceutical medicine.

Traditional Milk Thistle extract is made from the seeds, which contain approximately 4-6% silymarin. The extract consists of about 65-80% silymarin (a flavonolignan complex) and 20-35% fatty acids, including linoleic acid. Silymarin is a complex mixture of polyphenolic molecules, including seven closely related flavonoligans (silybin A, silybin B, isosilybin A, isosilybin B, silychristin, isosilychristin, silydianin) and one flavonoid (taxifolin).
In clinical trials silymarin has typically been administered in amounts ranging from 420-480mg per day in two to three divided doses. However high doses have been studied, such as 600mg daily in the treatment of type II diabetes and 600 or 1200mg daily in patients chronically infected with hepatitis C virus. An optimal dosage for Milk Thistle preparations has not been established.

Research into the biological activity of silymarin and its possible medical uses has been conducted in many countries since the 1970s, but the quality of the research has been uneven. Milk Thistle has been reported to have protective effects on the liver and to greatly improve its function. It has been typically used to treat liver cirrhosis, chronic hepatitis (liver inflammation), toxin-induced liver damage (including the prevention of severe liver damage from Amanita phalloides ('death cap' mushroom poisoning)), and gallbladder disorders.

In a 2009 study published in the journal Cancer, Milk Thistle showed promise in reducing the liver damaging effects of chemotherapy in a study of 50 children.

In a recent 2007 event, a family of six were treated with Milk Thistle and a combination of other treatments including penicillin - which when administered with Milk Thistle seems to amplify the overall effects - to save them from ingested poisonous mushrooms. While five of the six made a full recovery, the grandmother showed liver recovery but was overcome by kidney failure related to the poisonous mushrooms. Showing that Milk Thistle did indeed have a medicinally beneficial effect.

Milk Thistle protects and regenerates the liver in most liver diseases such as cirrhosis (hardening of the liver), jaundice and hepatitis (inflammation of the liver), and cholangitis (inflammation of bile ducts resulting in decreased bile flow). It is one of the best examples of preventative medicine that we have today as it not only protects each cell of the liver from incoming toxins, but simultaneously encourages the liver to cleanse itself of damaging substances, such as alcohol, drugs, medications, mercury and heavy metals, pesticides, anesthesia, and poisons.

One of the special qualities of Milk Thistle is that it cleanses and detoxifies an overburdened and stagnant liver while also being able to strengthen and tonify a weak liver; thus, delivering potent medicine to clogged, excess conditions as well as to weakened, deficient conditions. One of the tasks of the liver is to cleanse the blood. If the liver energy is stagnant it will be unable to effectively cleanse the blood; this can result in skin problems ranging from acne to psoriasis, eczema, and dermatitis. It is also effective for treating congestion of the kidneys, spleen, and pelvic region.

The suggested dosage for Milk Thistle is 12 to 15g of dried herb (200 to 400mg silymarin) per day or silymarin-phosphatidylcholine complex 100 to 200mg two times per day. For liver protection, 120mg silymarin (about 2 capsules) two times per day. For liver damage from alcohol, drugs, or chemicals, the recommended dosage of silymarin-phosphatidylcholine should be increased from two times per day to three times per day. However, these have not been scientifically confirmed.

Seed Handling

The seeds of the Milk Thistle have been used for 2000 years to treat chronic liver disease and protect the liver against toxins. Modern use of Milk Thistle in medicine is limited to the seeds.

Milk Thistle thrives in open areas. Also cultivated as an ornamental plant, Milk Thistle prefers a sunny position and self-seeds readily. The flower heads are picked in full bloom in early summer, the seeds are collected in late summer.

The seeds of the Milk Thistle are picked from the dried flower head in the Autumn. The seeds are black or dark brown with a shiny coating, crowned with feathery tufts like those of dandelion seeds. Freshly collected seed will germinate only at cool temperatures, but seed stored dry for five monhts will germinate at warm temperatures.
Milk Thistle isn't particularly demanding as to soil type, it has been reported to do well on compacted clay soils; very light soils are not recommended. A full sun location is also recommended.

Before planting, each seed must have the feathery tuft removed, this is the only cleaning the seed really needs. Once a tray has been filled with the compost of choice, the seeds must be placed into the tray, as they are large enough to be placed in a regimented order. Once the tray has been filled with seeds, about 1 cm seperating each seed - in rows, they can be covered with compost. The seeds are large enough that a layer of gravel may be put on top of the compost layer, as the seedlings will be strong enough for slightly more resistance.

Optimum germination has been reported under conditions of 2-15 degrees C at night (air temperature), alternated with daytime temperatures of 10-30 degrees C. Recommended sowing depth is one cm, and germination should take place within one to three weeks. The plant needs four to five months to grow and mature.


Milk Thistle seed preparations have been used for the treatment of liver disease since antiquity.

Pliny the Elder (A.D. 23-79), the first century Roman physician/naturalist wrote about the use of the plant as a vegetable, but warned it was not worth the effort to boil it, as it was troublesome to cook. He mentioned that the juice of the plant, mixed with honey, is excellent for "carrying off bile" - perhaps the first reference to the use of Milk Thistle for liver-related conditions.

The Physica of Hildegarde of Bingen, an important medieval German manuscript, the first herbal written by a woman, composed about 1150 then first published in 1533, wrote about the uses of the roots, whole plant, and leaves of the Milk Thistle, which was called "vehedistel"  or Venus Thistle.

In the eighteenth century, Culpepper notes that Milk Thistle is effectual "to open the obstructions of the liver and spleen, and thereby is good against the jaundice", he also wrote that "The seed and distilled water are held powerful to all the purposes aforesaid, and besides, it is often applied both inwardly to drink, and outwardly with cloths or spunges [sic.], to the region of teh liver, to cool the distemper thereof..."

Potential Uses in Green Pharmacy Preparations

Milk Thistle capsules can be purchased at most health food stores or herb shops.

Very young leaves of this herb can be used in salads, although they contain only traces of silymarin. In addition to their medicinal value, the seeds can be roasted, ground and used as a substitute for coffee.

It would seem that the most appropriate and applicable Green Pharmacy prepartions regarding Milk Thistle are those that can be consumed. The most potent part of the Milk Thistle is the seed, so it would seem that a preparation such as an infusion would be the most ideal. An alcohol tincture using the seeds would be a suitable infusion, allowing for a quick release and absorption of the silymarin.


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