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Milk thistle |
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| Milk thistle (Silybum marianum) is a member of the Compositae family. Milk thistle is an annual or biennial native to the Mediterranean, but now widespread throughout the world. The plant has a long stem which branches upward and can reach a height of 5 feet. The leaves are broad and wavy with lance-shaped pointed tips. They are shiny green with numerous vein-like white markings. The large, alternate leaves are waxy-lobed, toothed and thorny, as in other genera of thistle. The lower leaves are cauline. The upper leaves have a clasping base. They have large, disc-shaped pink-to-purple, rarely white, solitary flower heads at the end of the stem. The flowers consist of tubular florets. The phyllaries under the flowers occur in many rows, with the outer row with spine-tipped lobes and apical spines. The fruit is a black achene with a white pappus. The small hard fruits in the flowers resemble seeds and are the part of the plant used medicinally. Milk thistle is also known as holy thistle, lady's thistle, Mary thistle, Marian thistle, St. Mary thistle, silybum, and Silybum marianum. |
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Active constituents of milk thistle |
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| The active ingredients in milk thistle consist of silymarin and a variety of other flavonolignans (flavonoids). Silymarin is a mixture of at least for flavonolignans, including silibinin (also known as silybinin), isosilybinin (isosilibinin), silychristin (silichristin), and silydianin (silidianin). It is the primary active ingredient in milk thistle and believed to be the biologically active constituents responsible for milk thistle's antioxidant and hepatoprotective effects. Silymarin alters liver cell membranes which prevent toxins from passing through the cell. It inhibits the release or the synthesis of certain enzymes which are toxic to liver tissue. Silymarin also keeps new liver cells from being destroyed by these same substances, reduces inflammation, and has potent antioxidant effects. Silymarin has also exhibited significant antioxidant capabilities and can help reduce inflammation by inhibiting certain enzymes. Other flavonolignans found in milk thistle seeds include dehydrosilybin, desoxysilycristin, desoxysilydianin, silandrin, silybinome, silyhermin, and neosilyhermin. In addition, milk thistle contains apigenin, silybonol, myristic, oliec acid, palmitic acid, stearic acid, and betaine hydrochloride. Betaine hydrochloride is a hepatoprotector which contributes to the hepato-protective properties of the milk thistle. |
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Medicinal uses and health benefits of milk thistle |
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| Milk thistle has been used for stomach and appetite complaints, liver problems, gallbladder problems, and as an antidote to death cap (Amanita) mushroom poisoning. Silymarin in milk thistle functions as a potent antioxidant, stabilizes cellular membranes,
stimulates detoxification pathways, stimulates regeneration of liver tissue, inhibits the growth of certain cancer cell lines, exerts direct cytotoxic activity toward certain cancer cell lines, and may increase the efficacy of certain chemotherapy agents. Silymarin binds hepatocyte (liver cell) membranes which protects them from the potential damage of environmental toxins, foreign chemicals, endogenous poisons and free radicals. Milk thistle can also detoxify liver cells of deadly mushroom poisoning.
Milk thistle is hepatoprotective of liver damage by enhancing DNA polymerase, stabilizing cell membranes and scavenging free radicals. Milk thistle extract has been recommended for the prevention and treatment of various liver disorders including viral hepatitis, fatty liver associated with long term alcohol use, and liver damage from drugs and industrial toxins such as carbon tetrachloride. Silymarin enters the liver cells and promotes their ability to produce certain enzymes which are vital to liver health. This action can speed the healing of liver cells from injury or disease. Milk thistle is a powerful antioxidant. Silymarin's antioxidant activity is up to ten times more potent than vitamin E. Antioxidants are thought to prevent or lessen damage to body cells that is caused by a chemical process called oxidation. By changing the outside layer of liver cells, silymarin may also keep certain harmful chemicals from getting into liver cells. Milk thistle is prescribed for HIV-positive patients to protect the liver from diseases such as hepatitis and from the hepatotoxic effects of other medications prescribed for HIV treatment.
Milk thistle extracts have also been used to treat adults with alcoholic liver damage. Excessive alcohol intake depletes the amount of toxin-neutralizing glutathione in the liver and can cause severe scarring and dysfunction, a condition called cirrhosis. Milk thistle may improve cirrhosis and lengthen the lives of cirrhosis patients. Milk Thistle can be used to increase the secretion and flow of bile from the liver and gall bladder. Milk thistle also acts to protect the kidneys, brain and other vital organs from toxin damage, treats allergic reactions, reduces inflammation and promotes healing. It also helps to emulsify fats and enhance bile flow, making it a good remedy for indigestion.
The active chemical components of the milk thistle have been shown to slow cell growth in some types of cancer. Antioxidants protect against tumor promotion by inhibiting oxidative stress induced by tumor promoters. An ingredient called silibinin reduces levels of prostate-specific antigen (PSA), a compound linked to prostate cancer, while inhibiting the growth of certain prostate tumor cells. |
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Dosage and administration of milk thistle |
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| Milk thistle may be taken as tablets, capsules, liquid extracts, tinctures, or by eating the seed. Standardized extracts contain 70-80% of the flavonoligan mixture, silymarin. Silymarin does not dissolve easily in water and is extracted from the seeds with an alcohol solution. For this reason, milk thistle teas are likely not effective and should be avoided. Germany's Commission E recommends daily dosages of 200 mg to 400 mg or about three capsules. Doses ranging from 160 to 800 milligrams daily by mouth have been used for cirrhosis, hepatitis and toxic liver damage. |
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Side effects, precautions, interactions |
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Negative side effects have been rarely reported from milk thistle. Possible side effects may include stomach pain, nausea, vomiting, diarrhea, headache, rash or other skin reactions, joint pain, impotence, and anaphylaxis. Due to the estrogen-like effect that may be associated with taking milk thistle plant extract, pregnant women and women with hormone-dependent conditions should not take it. Men who have prostate cancer should not take it without consulting a doctor. Milk thistle may interfere with the effects of estrogen replacement therapy and oral contraceptives due to its possible estrogenic effects. Milk thistle could decrease the insulin requirements of diabetic patients with alcoholic liver cirrhosis. |
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Milk Thistle, or Sylbum marianum, saw medicinal applications as early as the first century with the Romans who used it primarily to treat liver problems. Modern scientific studies suggest that the active substances in Milk Thistle, particularly silymarin, protect the liver from damage which may be caused by toxins, alcohol, viruses and certain drugs. The extracts in this formula are the finest quality available. Turmeric and Artichoke extracts are combined with Milk Thistle extract to provide additional synergistic benefits. Click here for more information.