Milk Thistle (Silybum marianum) is one of my favourite herbs for liver health. Milk Thistle is the most well-researched plant in the treatment of liver disease.
The active complex of Milk Thistle is a lipophilic extract from the seeds of the plant and is composed of three isomer flavonolignans (silybin, silydianin, and silychristin) collectively known as silymarin. Silybin is a component with the greatest degree of biological activity and makes up 50% to 70% of silymarin. Silymarin is found in the entire plant but it is concentrated in the fruit and seeds. I always look for products that note the Silybin content.
Silymarin acts as an antioxidant by reducing free radical production and lipid peroxidation. It has antifibrotic activity and may act as a toxin blockade agent by inhibiting binding of toxins to the hepatocyte cell membrane receptors. In animals, silymarin reduces liver injury caused by alcohol, Paracetamol (acetaminophen), carbon tetrachloride (CCl4), radiation, iron overload, phenylhydrazine, and cold ischaemia. Silymarin has been used to treat alcoholic liver disease, acute and chronic viral hepatitis, and toxin-induced liver diseases.
When formulating liquid herbs or prescribing tablets/capsules/powders for liver and digestive health, I always include Milk Thistle. It is essential.
Reference: Abenavoli L et al. Milk thistle in liver diseases: past, present, future. Phytother Res. 2010 Oct; 24(10): 1423-32.