Silibinin, also known as silybin (CAS No.: 22888-70-6), is the active ingredient of the flavanonol complex silymarin, which is obtained from the fruit of the milk thistle (Silybum marianum) used for medicinal purposes. The extract is standardized to silibinin in terms of its active ingredient content.
Chemically speaking, silibinin is a mixture of silybin A and silybin B. Isolated silibinin is used in the treatment of liver poisoning caused by toxins of the tuber leaf fungus (amatoxins) such as amanitin and phalloidin. The therapy is administered intravenously. The liver-protective effect is due to the cell membrane-stabilizing properties of silibinin. The absorption of the amatoxins of the tuber leaf fungus into the liver cells is impeded and their enterohepatic circulation is prevented. A second mechanism of action is the inhibition of the release of TNF-α.
Since its introduction into the treatment of amanitin-related fungal poisoning, the mortality rate has fallen to 5 to 12 % with timely treatment, compared to 20 to 30 % previously.
Silibinin also inhibits xanthine oxidase and is therefore effective in hyperuricemia.