Milk Thistle (Silybum marianum)

Milk Thistle: Medical Uses

Milk thistle improves liver function tests and helps to counteract mushroom (Amanita phalloides) poisoning if taken within 24 hours after ingestion of the mushroom. It can also be used for chemical-induced liver damage, cirrhosis, and viral hepatitis.

Historical Uses

Milk thistle has been used traditionally for liver complaints.

Growth

A member of the aster family, milk thistle is native to southern and western Europe and some parts of the U.S.

Part Used

• Fruits, known as achenes ()

Major Chemical Compounds

• Silymarin

• Silibinin

Milk Thistle: Clinical Uses

Milk thistle improves liver function tests and reverses mushroom (Amanita phalloides) poisoning if given within 24 hours after ingestion of the mushroom. It can also be used for chemical-induced liver damage, cirrhosis, and viral hepatitis. Silibinin may be useful in prostate cancer. It is approved by the German Commission E for dyspepsia, liver damage, and liver disease.

Mechanism of Action

This herb has antioxidant, hepatoprotective, and hepatorestorative properties. It also increases the gluthione content of liver, inhibits leukotrienes, and stimulates protein synthesis. Silibinin, an antioxidant in milk thistle, has been shown to inhibit prostate cancer cells, although the mechanism of action is still unknown.

Milk Thistle: Dosage

Standardized capsules or tablets: 420 mg divided into two to three doses a day. Results are usually seen after 6 to 8 weeks and should be verified by liver function tests. After 6 to 8 weeks, dosage may be reduced to 280 mg daily.

Tea: Silymarin is poorly soluble in water and therefore should not be taken in tea form.

Side Effects

The patient may develop loose stools at high doses.

Contraindications

• Monitor blood glucose levels in diabetic patients. Standard anti-hyperglycemic medications may need to be reduced..

Herb-Drug Interactions

Monitor blood glucose levels in patients taking diabetic medications.

Pregnancy and Breast-Feeding

There are no restrictions. However, use cautiously in pregnant patients because the herb has a laxative effect.

Summary of Studies

Palasciano et al. (1995). Fifteen subjects receiving butyrophenones and phenothiazines were also given 400 mg b.i.d. of concentrated extracts from the fruits of milk thistle. Results: milk thistle protected the liver from the adverse effects of these drugs.

Fintelmann (1986). Results: Milk thistle reduced the hepatotoxic effects of phenytoin.

Milk Thistle: Warnings

Milk thistle is poorly soluble in water and therefore should not be taken in tea form.

Milk thistle may cause loose stools at high doses.

• Monitor your blood sugar levels closely if you have diabetes or take an antidiabetic medication.

• Avoid use of this herb if you are pregnant or breast-feeding.