Milk thistle seed (Silybum marianum) has a history dating back over two thousand years as a favorite among herbalists for its positive effects on the liver and gallbladder.  The ancient philosophers Pliny and Galen both praised the herb for liver cleansing. Now, milk thistle is one of the most well-researched plants for liver support applications.
What is the Active Component of Milk Thistle Seed?
The seeds contain the highest concentrations of the active compound, silymarin. Silymarin is an antioxidant that reduces free radical production and oxidative damage. It may also inhibit the binding of toxins to the liver. In animals, silymarin reduces liver injury caused by acetaminophen and has been shown to have positive effects on alcoholic liver disease, hepatitis and toxin-induced liver problems.    It’s also very encouraging that milk thistle has a good safety record; side effects are rare and serious toxicity has not been reported, neither have drug interactions.  
Liver Support Applications
With research that may open the door for more examples of traditional medicine to be successfully transposed into modern medical interventions, the Université of Montréal in Quebec assessed the protective potential of milk thistle extract in liver transplantation injury and concluded that silibinin shows promise in protecting the liver from certain damages. 
Milk thistle is native to the Mediterranean and the stems, also rich in antioxidants, are regularly eaten by those in the area to reduce oxidative damage in the liver and biliary tract.  Oxidative damage is thought to be one of the main mechanisms involved in nearly all chronic liver disorders. Overall, when investigating the value of herbal therapies for liver disorders, milk thistle is of high interest due to its high antioxidant capacity. 
Milk thistle seed has even been examined for a potential role in battling hepatitis C in Pakistan, where infection is a major problem. 
Other Actions of Milk Thistle
Interestingly, milk thistle seed has historically been given to people that ingested amanita, a toxic mushroom. It appears science agrees with this folk remedy, as researchers at the Institute of Complementary Medicine at University Hospital Zurich in Switzerland reviewed 65 papers on milk thistle trials and studies and, based on the available evidence, concluded it was reasonable to use silymarin for amanita toxicity. A review of all information also prompted them to encourage new research to explore new uses. 
Milk thistle has structural relation to compounds demonstrated active on liver metabolic processes, leading to speculation milk thistle reduces blood sugar. Further examination has in concluded the effects on liver glucose metabolism do have a blood sugar lowering effect. 
Milk thistle seed extract is known to have estrogenic effects and effects on memory by estrogen have been reported. Studies involving rats showed silybin administration during pregnancy resulted in positive brain changes and better memory. Could this lay the groundwork for further exploration of silybin and memory impairment diseases? 
– Dr. Edward F. Group III, DC, ND, DACBN, DCBCN, DABFM
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