Silymarin: an old remedy with a challenging future?

Silymarin, a flavanolignan-containing standardized extract obtained from the fruits of Silybum marianum, is a traditional phytotherapic product widely used for the treatment of liver diseases including hepatitis , cirrhosis and bile secretion dysfunction. Recent preclinical data and some clinical investigations also support its use in the management of non-alcoholic fatty liver disease (NAFLD). Despite this evidence, silymarin efficacy has not yet been supported by clear-cut dose-related pharmacokinetic data, although several attempts have been made to enhance the oral absorption of flavanolignans, its putative active principles. However, positive results have been obtained with lecithin-based formulations (Phytosome®) of silybin, the main flavanolignans in silymarin, which showed improved oral absorption in preclinical and clinical trials. The Phytosome® delivery system has also been applied to silymarin with promising preclinical results consistent with the oral bioavailability of most of the flavanolignans present in the extract. These data may help optimize the dose for clinical efficacy in liver protection and also pave the way for the use of silymarin in new therapeutic areas where recent findings indicate a major role for the entire phytocomplex.