Silymarin, a flavonolignan from 'milk thistle' (Silybum marianum) plant is used almost exclusively for hepatoprotection and amounts to 180 million US dollars business in Germany alone. In this review we discuss about its safety, efficacy and future uses in
liver diseases. The use of
silymarin may replace the polyherbal formulations and will avoid the major problems of standardization, quality control and contamination with
heavy metals or
bacterial toxins.
Silymarin consists of four flavonolignan isomers namely--
silybin,
isosilybin,
silydianin and
silychristin. Among them,
silybin being the most active and commonly used.
Silymarin is orally absorbed and is excreted mainly through bile as sulphates and conjugates.
Silymarin offers good protection in various toxic models of experimental
liver diseases in laboratory animals. It acts by antioxidative, anti-
lipid peroxidative, antifibrotic, anti-inflammatory, membrane stabilizing, immunomodulatory and liver regenerating mechanisms.
Silymarin has clinical applications in
alcoholic liver diseases,
liver cirrhosis, Amanita
mushroom poisoning, viral
hepatitis, toxic and
drug induced liver diseases and in diabetic patients. Though
silymarin does not have
antiviral properties against hepatitis virus, it promotes
protein synthesis, helps in regenerating liver tissue, controls
inflammation, enhances glucuronidation and protects against
glutathione depletion.
Silymarin may prove to be a useful
drug for hepatoprotection in
hepatobiliary diseases and in hepatotoxicity due to drugs. The non traditional use of
silymarin may make a breakthrough as a new approach to protect other organs in addition to liver. As it is having a good safety profile, better patient tolerability and an effective
drug at an affordable price, in near future new derivatives or new combinations of this
drug may prove to be useful.