(HealthDay News) – Use of the milk thistle extract silymarin does not provide additional benefit compared with placebo for patients with treatment-resistant chronic hepatitis C virus (HCV), according to a study published in the July 18 issue of the Journal of the American Medical Association.
Michael W Fried, MD, from the University of North Carolina at Chapel Hill, and colleagues conducted a multicenter trial involving 154 patients with chronic HCV infection and serum alanine aminotransferase (ALT) levels of ≥65U/L who were previously unsuccessfully treated with interferon-based therapy. After enrollment, from May 2008–May 2010, participants were randomized to receive 420mg silymarin, 700mg silymarin, or matching placebo, administered three times daily for 24 weeks, with follow-up through March 2011.
The researchers found that only two participants in each treatment group met the primary outcome measure of normal ALT level (≤45U/L or a 50% decline from baseline values; 3.8%, 4%, and 3.8%, respectively, for placebo, 420mg and 700mg silymarin). At the end of treatment there were no significant differences in the mean decline in serum ALT activity across the three treatment groups, nor were there significant differences in HCV RNA levels or quality of life measures. The adverse event profile was comparable for silymarin and placebo.
“Oral silymarin, used at higher than customary doses, did not significantly alter biochemical or virological markers of disease activity in patients with chronic HCV infection who had prior treatment with interferon-based regimens,” the authors write.
Several authors disclosed financial ties to pharmaceutical companies, including Rottapharm Madaus, which manufactures silymarin, and Abbott Molecular; both companies provided supplies for the trial.