Silybum marianum (milk thistle) is a flavonoid having an affinity for the liver. Its
hepatoprotective and hepatorestorative
effects make silymarin one of the best nutraceutical for many liver
disorders. It is primarily used to regenerate hepatocytes, where it
improves the flow of bile and fat to and from the liver as well as heal
liver cells. Less known, but of equal value, is that it is also an excellent
antioxidant. Its antioxidant properties make it valuable in a wide variety
of degenerative diseases.
The major active ingredient is considered to be the flavonolignan , silybin , a lipid
soluble, poorly absorbed compound. Betaine, which has been shown to
be a liver protectant, is also found in the plant. There are other
flavonolignans in milk thistle, but they appear
less significant. Perhaps of more importance are the essential oils
and trace minerals found in the herb.
Modes of Action:
As an antioxidant silymarin, inhibits benzoyl peroxide-induced tumor promotion, oxidative
stress and inhibits the inflammatory responses with certain types of
tumors. Silymarin increases the biliary excretion and the
endogenous pool of bile salts by stimulating the synthesis of hepatoprotective
bile salts, such as beta- muricholate and ursodeoxycholate.
It enhances Phase II and inhibits Phase I liver detoxification, which can effectively
balance detoxification since the by-products of Phase I detoxification
are often more toxic than the original products from which they are
Phase I detoxification, the Cytrochrome P450 enzymes, often produce free radicals which must be removed by Phase II detoxification. Silymarin, allowing for greater conjugation of these
free radicals, enhances Glucuronic acid, a part of Phase II detoxification.
Once conjugated the can be removed from the body through the bile ducts.
Silymarin has been shown to lower elevated levels of bilirubin, aspartate aminotransferase (AST), and alanine amino-transferase (ALT). In part this is due to its
ability to stimulate the production of heplatocellular
Adding to the long list of beneficial effects of this nutraceutical is its anti-lipid peroxidation effect. Silymarin will inhibit the formation of leukotrienes from polyunsaturated
fatty acids in the liver, via its inhibition of the enzyme lipoxygenase,
stabilized mast cells, modulated immune functions, and is
The anti- iflammatory effect of silymarin is significant, and has been proven in studies. This allows the practitioner to elect not to use Western antiinflammatories such as prednisone.
Amanita Mushroom Poisoning
Some species of Amanita mushrooms have powerful hepatotoxins, including amanitin and
phalloidin. Milk thistle has gained much recognition in its ability
to reducing death rates from exposure to Amanita mushrooms up to 100%.
Liver enzyme studies and liver biopsies in studies involving
dogs shows a significant hepatoprotective effect for silymarin when given toxic doses
of Amanita mushrooms.
Other Clinical Uses
Silymarin has been shown to be of some benefit is treatment of liver disease in alcoholics,
although it is not as effective as one might expect.
Silymarin is very helpful in the treatment of liver cirrhosis. One study is indicative
of this beneficial aspect of the herb. This study, involving 170 patients
with liver cirrhosis, were given 420 mg/day of silymarin for an average
of 41 months. These patients showed a significant improvement in survival
(58% in silymarin-treated patients and 39% in the placebo group).
In Western medicine, colchicine is often used to inhibit liver fibrosis. This is, however,
of questionable value, especially when considering the potential toxicity
In one study the use of silymarin was as effective
as colchicine in the treatment of liver disease, and had none of the
untoward effects exhibited with colchicine.
Silymarin also inhibits fibrosis in lung tissue, kidney tissue, pancreas and other organs throughout the body.
Being a powerful Antioxidant, it can help improve many degenerative conditions throughout
the body, including kidney disease, heart disease, and diabetes.
Silymarin is found throughout the entire plant, but is concentrated in the fruit and seeds. Since the seeds have a high content of silymarin, it is an excellent seed to feed birds that have liver disease.
If used in too high a dose, it can cause a loose stool due to the increase in bile it produces.