Milk Thistle


Milk Thistle (Silybum marianum Gaertn), is a member of the family Asteraceae. Also known as the Marian, St. Mary’s, and Our Lady’s thistle, Milk Thistle should not be confused with the blessed or holy thistle (Cnicus benedictus), an entirely different species.

Milk Thistle is a tall herb with prickly leaves and a milky sap that is native to the Mediterranean region of Europe. Milk thistle is among the most ancient of all known herbal medicines, having been used as a folk remedy for centuries for liver complaints. Recent research has demonstrated that extracts of milk thistle do indeed protect against some very nasty liver toxins.

Research has uncovered a host of antihepatotoxic (liver protectant) compounds commonly referred to as silymarin. Silymarin has been shown to consist of a large number of flavonolignans, including silybin, isosilybin, dehydrosilybin, silydianin and silychristin. Animal studies have shown that silymarin exerts a liver protective effect against a variety of toxins, including the phallo toxins of the deadly Amanita phalloides mushroom.

Amanita phalloides is one of the most poisonous mushrooms in the world, containing toxins that are particularly destructive to the liver. Ingestion of this mushroom can lead to severe liver damage and death if untreated. The active ingredient of the herb is a bioflavonoid mixture called silymarin, the principal component of which is silybin. In animal experiments, when silymarin was given before poisoning by the Amanita phalloides mushroom, it was found to be 100 percent effective in preventing liver damage. Silymarin was also found to be completely effective if given to animals within ten minutes of exposure to the poison. When given within twenty-four hours it still prevented death and greatly reduced the amount of liver damage.

Silymarin also confers protection against the liver damage from dangerous solvents such as carbon tetrachloride and ethanol (alcohol). Silymarin has been used in the treatment of hepatic disorders in humans, and a German medical study found that liver function in patients with chronic hepatitis improved after three months of therapy with silymarin. A later study reported on the use of 420 milligrams of silymarin daily in patients with cirrhosis of the liver. Of twenty followed up for six to thirty-six months, ten were definitely improved and four had deteriorated.

The results of numerous studies suggest that silymarin not only protects liver cells by preventing the actions of toxic substances but that it also stimulate protein synthesis to accelerate the regeneration and production of liver cells.

Silymarin and component silybin function as antioxidants, protecting cell membranes from free-radical-mediated oxidative damage. This type of damage is known as lipid peroxidation. Most liver toxins produce their damaging effects by free radical mechanisms. Both silymarin and silybin protect red blood cell membranes against lipid peroxidation and hemolysis (breaking down of the red blood cells) caused by certain red blood cell poisons.

Milk thistle is presently available in the United States in concentrations that contain up to 80% silymarin. Silymarin is not soluble in water, and is therefore ineffective when taken in the form of a tea. Oral use requires a concentrated product. Milk thistle is marketed in the United States as a food supplement in the form of capsules containing 200 to 250 mg. of a concentrated extract representing 160 to 200 mg. of silymarin. Though relatively free from adverse affects, those with liver problems who wish to use milk thistle should be monitored by a health care professional to determine the products effectiveness.

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