An updated systematic review with meta-analysis for the clinical evidence of silymarin

Background: The potential benefit of silymarin ( special extract from the fruits of Silybum marianum) in the treatment of liver diseases remains a controversial issue. Methods: For this systematic review electronic databases identified 65 papers for the search terms silymarin, silibinin, silicristin or milk thistle and clinical trial. Only 19 complied with the criteria 'double-' or 'single-blind'. These publications were analysed from a clinical point of view and meta-analytic calculations were performed. Results: The clinical evidence of a therapeutic effect of silymarin in toxic liver diseases is scarce. There is no evidence of a favourable influence on the evolution of viral hepatitis, particularly hepatitis C. In alcoholic liver disease, comparing with placebo, aspartate aminotransferase was reduced in the silymarin-treated groups (p = 0.01) while alkaline phosphatase was not. In liver cirrhosis, mostly alcoholic, total mortality was 16.1% with silymarin vs. 20.5% with placebo (n.s.); liver-related mortality was 10.0% with silymarin vs. 17.3% with placebo (p = 0.01). Conclusions: Based on the available clinical evidence it can be concluded - concerning possible risks / probable benefits - that it is reasonable to employ silymarin as a supportive element in the therapy of Amanita phalloides poisoning but also (alcoholic and grade Child 'A') liver cirrhosis. A consistent research programme, consolidating existing evidence and exploring new potential uses, would be very welcome.