Silibinin (INN), also known as silybin, is the major active constituent of silymarin, a standardized extract of the milk thistle seeds containing mixture of flavonolignans consisting of among others of silibinin, isosilibinin,silicristin, and silidianin. Silibinin itself is mixture of two diastereomers, silybin A and silybin B, in approximately equimolar ratio. It can soluble in the organic solvent, such as Methanol, Ethanol, Acetone and so on. Both in vitro and animal research suggest that silibinin has hepatoprotective (antihepatotoxic) properties that protect liver cells against toxins.