Carduus marianus, also known as milk thistle or St. Mary’s thistle, is an annual or biennial herb recognized by its purple flowers and spiny leaves and stems. It is used in homeopathy to treat a variety of medical conditions. The hard-shelled fruit is the only part of the plant that is used for medicinal purposes.
While native to the Mediterranean region, carduus marianus has been naturalized throughout Europe and parts of North America, where it grows in fields and on roadsides. Its spreading habits mean it is often looked upon as an undesirable weed. It thrives in dry, sunny weather and is an extremely hardy plant.
This herb is particularly valuable in homeopathic medicine, in which it is used to improve liver function. The plant's fruit provides silymarin, a liver-regenerating bioflavonoid used in the homeopathic treatment of cirrhosis and hepatitis. It also supplies an antidote to the deadly death cap mushroom.
Silymarin works in the liver by stabilizing cell membranes and regenerating liver cells. It also has antioxidant properties and helps to protect liver cells from free radical damage. It also filters toxins from the blood and may help to keep blood sugar at a steady level. Silymarin also may assist in regulating fats and reducing intestinal inflammation.
Carduus marianus is used in herbal remedies for several other medical conditions that are not liver-related. The herb stimulates the gall bladder and bowels, and promotes urination, which helps to keep kidneys healthy. It also may help to soften kidney stones and gallstones. Psoriasis and other skin conditions also may be improved by using the plant in an herbal remedy.
A home herbal remedy can be made by making a tincture of one part whole, ripe carduus marianus seeds to two parts diluted alcohol. The seeds are steeped in the alcohol in an airtight bottle and left in a cool, dark place for at least eight days. It is then strained, filtered and placed in a clean bottle. About 10 drops in water is taken to promote a healthy liver. The plant extract also is sold commercially for those who do not wish to make their own tincture.
Carduus marianus was used for many years in Europe as a way to increase lactation in nursing women. The belief was that eating a special diet including the herb would greatly increase milk production. The belief had no scientific basis, but legend had it that the white veins on the mottled leaves of the plant represented drops of the Virgin Mary’s milk that fell while she was nursing baby Jesus.