Commission E Monograph: Milk Thistle Fruit

Name of drug: Cardui mariae fructus, milk thistle fruit

Composition of drug: Milk thistle fruit consists of ripe seed of Silybum marianum (L.) Gaertner [Fam. Asteraceae], freed from the pappus, and its preparations in effective dosage. The drug contains silibinin, silydianin and silychristin.

Uses: Crude drug—dyspeptic [digestive] complaints. Formulations*—toxic liver damage; for supportive treatment in chronic inflammatory liver disease and hepatic cirrhosis.

Contraindications: none known

Side effects: Crude drug—none known; Formulations—a mild laxative effect has been observed in occasional instances.

Interactions with other drugs: none known

Dosage: Unless otherwise prescribed, average daily dose of drug is 12 to 15 g; formulations equivalent to 200 to 400 mg of silymarin, calculated as silibinin.

Mode of administration: Powdered drug for making infusions and other galenical formulations to be taken by mouth.

Actions: Silymarin acts as an antagonist in many experimental liver-damage models: phalloidin and -amanitin (death-cap toxins), lanthanides, carbon tetrachloride, galactosamine, thioacetamide, and the hepatotoxic virus FV3 of cold-blooded vertebrates.

The therapeutic activity of silymarin is based on two sites or mechanisms of action: a) it alters the structure of the outer cell membrane of the hepatocytes in such a way as to prevent penetration of the liver toxin into the interior of the cell; b) it stimulates the action of nucleolar polymerase A, resulting in an increase in ribosomal protein synthesis, and thus stimulates the regenerative ability of the liver and the formation of new hepatocytes.

*Note: "Formulation" refers to an extract standardized to at least 70 percent silymarin, the collective name for the three compounds listed in the "Composition of drug" section above.

Reprinted with permission from The Complete German Commission E Monographs—Therapeutic Guide to Herbal Medicines, a 700-page guide featuring 380 monographs. The guide is published by the American Botanical Council, Austin, Texas, 1998.