One of the challenges of chemotherapy is the side effect of liver inflammation, which can necessitate a reduction in dose or even discontinuance of the drug. However, a new study described in an article published online on December 14, 2009 in the American Cancer Society journal Cancer reveals that the herb milk thistle, which contains the liver protective compound silibinin, reduces inflammation of the liver in children receiving treatment for acute lymphoblastic leukemia (ALL).
Extracts of milk thistle have been evaluated for the treatment of liver damage from alcohol and other toxins, yet data concerning the herb's value in chemotherapy-associated liver problems is limited. In a double-blinded trial, Kara Kelly, MD, of the New York-Presbyterian Hospital/Columbia University Medical Center’s Herbert Irving Comprehensive Cancer Center and her colleagues randomized 50 children with inflammation of the liver due to chemotherapy for ALL to receive a placebo or an extract containing one part silibinin to two parts phosphatidylcholine (a nutrient that improves silibinin's bioavailability) for 28 days. Each capsule contained 80 milligrams silibinin, and the number of capsules administered was determined by the patient's weight. The liver enzymes aspartate amino transferase (AST) and amino alanine transferase (ALT) were measured at the beginning of the study, at the end of the treatment period and one month following the end of treatment.
While no significant changes in liver enzymes were observed immediately following treatment, total bilirubin levels were lower by 50 percent in 5 patients who received milk thistle and none of the placebo group. One month after treatment, the enzyme AST was significantly lower in children who received milk thistle and a trend toward lower ALT levels than those measured at baseline was observed compared to the placebo group. The authors attribute the late response to delayed effects, inadequate dosing or short duration of supplementation.
The need to reduce chemotherapy due to liver toxicity was less in patients who received milk thistle compared to those who received a placebo, although the difference was not considered significant according to the authors. In laboratory tests, milk thistle was demonstrated not to interfere with chemotherapy's anticancer effect.
The study is the first randomized, controlled clinical trial to investigate the feasibility and safety of milk thistle in combination with chemotherapy for children being treated for cancer. "Milk thistle needs to be studied further, to see how effective it is for a longer course of treatment, and whether it works well in reducing liver inflammation in other types of cancers and with other types of chemotherapy," Dr Kelly stated. "However, our results are promising as there are no substitute medications for treating liver toxicity."