According to MayoClinic.com, scientific evidence indicates that milk thistle seed extract is effective in reducing the number of deaths associated with cirrhosis of the liver.
MayoClinic.com and the University of Maryland Medical Center cite milk thistle seed extract as useful in the treatment of viral hepatitis. Both resources state that further research is necessary to strengthen the scientific evidence in favor of this benefit, however.
University of Minnesota researchers have indicated that the silymarin found in milk thistle seeds can prevent the growth of cancer cells in the cervix, breasts, prostate and skin. It is also effective in protecting the kidneys and liver from the harmful side effects of chemotherapy drugs.