Effects and tolerance of silymarin (milk thistle) in chronic hepatitis C virus infection patients: a meta-analysis of randomized controlled trials.

Objective: This study aimed to evaluate the efficacy and safety of silymarin on chronic hepatitis C virus- (HCV-) infected patients.

Methods: Randomized controlled trials (RCTs) of silymarin in chronic HCV-infected patients up to April 1, 2014 were systematically identified in PubMed, Ovid, Web of Science, and Cochrane Library databases.

Results: A total of 222 and 167 patients in five RCTs were randomly treated with silymarin (or intravenous silibinin) and placebo, respectively. Serum HCV RNA relatively decreased in patients treated with silymarin compared with those administered with placebo, but no significance was found (P = 0.09). Meta-analysis of patients orally treated with silymarin indicated that the changes of HCV RNA are similar in the two groups (P = 0.19). The effect on alanine aminotransferase (ALT) of oral silymarin is not different from that of placebo (P = 0.45). Improvements in quality-of-life (Short Form-36) in both silymarin and placebo recipients were impressive but relatively identical (P = 0.09).

Conclusion: Silymarin is well tolerated in chronic HCV-infected patients. However, no evidence of salutary effects of oral silymarin has yet been reported based on intermediate endpoints (ALT and HCV RNA) in this population. Moreover, intravenous administration of silymarin should be further studied.