Milk thistle was formerly known as Carduus marianus; "carduus" is the Latin word for "thistle." Its other Latin names are Silybum marianum, which it is most commonly known by today, and Mariana mariana.
The genus name of milk thistle, Silybum, is credited to Dioscorides, a Greek physician of the first century who attributed this name to edible plants among the thistles, according to Brigitte Mars in "The Desktop Guide to Herbal Medicine: The Ultimate Multidisciplinary Reference to the Amazing Realm of Healing Plants." Dioscorides gave the plant "marianum" as a species name in honor of the Virgin Mary.
Milk thistle is also called silymarin (which denotes the mixture of its active components), wild artichoke, Mary thistle, holy thistle, silibinin, Marian thistle and lady thistle.
MilkThistle.com notes that milk thistle recognizes when to promote the growth of new cells in the body's healing process, and it knows when to stop the growth of harmful, dysfunctional cells, as in cancer. Its list of uses -- including for liver diseases, gallstones, toxicity, cancer and high cholesterol -- demonstrates that milk thistle takes on different functions in the face of adverse health conditions. Milk thistle works in harmony with the normal functions of the liver; it supports and improves liver functions and protects liver cells, according to the National Center for Complementary and Alternative Medicine. Silymarin, an antioxidant found in the milky substance in the plant's leaves, is composed of the flavonoids silibinin, silidianin and silicristin, which protect new liver cells and have a detoxifying effect on the liver. The antioxidant promotes the liver's ability to clean out accumulated toxins in the liver and blood, and when milk thistle is taken regularly, it prevents the buildup of toxins in the liver.