Herb Favored by Hep C Patients Has No Medical Benefit: Study
By Rob Goodier
NEW YORK (Reuters Health) Nov 10 - Milk thistle extract, an herbal supplement popular among patients with chronic liver disease, had no benefit for hepatitis C patients, a new study found.
In a randomized multicenter trial, milk thistle-the botanical compound silymarin-did not beat the placebo at improving liver function test results.
"The study was not able to document specific efficacy in hepatitis C virus," said Dr. Henry Bodenheimer, Jr., a hepatologist at the Beth Israel Medical Center in New York City who chaired the study's data safety monitoring committee.
"Milk thistle is also used in many other forms of liver disease, but has not often been systematically studied," Dr. Bodenheimer added in an email to Reuters Health.
Dr. Michael Fried, at the University of North Carolina at Chapel Hill, who led the study, presented the results November 8 at the American Association for the Study of Liver Diseases annual meeting in San Francisco.
Patients take silymarin as an alternative to, or to supplement, conventional HCV therapy, which can be toxic and have a limited effect, Dr. Bodenheimer said.
Accordingly, Dr. Fried's team restricted the study to 154 hepatitis C patients who had not responded to interferon therapies. The patients also had serum alanine aminotransferase (ALT) enzyme levels greater than 65 IU/L, with a median of 106 IU/L. A normal level is 45 IU/L, Dr. Fried's team writes.
The researchers randomly assigned the patients to one of three groups, two of which took high doses of a standardized form of silymarin at 420mg or 700mg three times daily. The third group took a placebo.
The silymarin doses in the study were 4.5-7.5 times higher than customary, the researchers said in their abstract for the meeting. The doses were chosen based on results of an earlier phase I study.
Of the 138 patients who completed the 24-week study, 90% were able to adhere to at least 80% of the pill regimen. In spite of the compliance, however, the mean drop in serum ALT was not significantly different between the three groups. And only two patients in each group met the primary endpoint, either normalization of ALT or a drop of at least 50% from baseline.
Silymarin is a polyphenolic flavenoid that, in vitro, is an antioxidant and anti-inflammatory. Its pharmacokinetics in this study, and its effect on hepatitis C virus RNA, have not yet been reported.
"In my experience, the use of this agent is patient driven rather than being prescribed by physicians," Dr. Bodenheimer said.