Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 21, 2017; 23(27): 5004-5017
Published online Jul 21, 2017. doi: 10.3748/wjg.v23.i27.5004
Effect of silymarin on biochemical indicators in patients with liver disease: Systematic review with meta-analysis
Camila Ribeiro de Avelar, Emile Miranda Pereira, Priscila Ribas de Farias Costa, Rosângela Passos de Jesus, Lucivalda Pereira Magalhães de Oliveira
Camila Ribeiro de Avelar, Emile Miranda Pereira, Post-graduation Program, Federal University of Bahia, Salvador, Bahia 40.110-150, Brazil
Priscila Ribas de Farias Costa, Rosângela Passos de Jesus, Lucivalda Pereira Magalhães de Oliveira, Departament of Science Nutrition, Federal University of Bahia, Salvador, Bahia 40.110-150, Brazil
Author contributions: de Avelar CR and de Oliveira LPM contributed to conception and design of the study; de Avelar CR, Pereira EM and de Oliveira LPM contributed to acquisiton of data; de Avelar CR, de Farias Costa PR, de Jesus RP and de Oliveira LPM analyzed and interpreted the data; de Avelar CR and Pereira EM drafted the article; de Farias Costa PR, de Jesus RP and de Oliveira LPM critically revised the manuscript; all authors approved the final version to be published.
Conflict-of-interest statement: The authors deny any conflict of interest.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Camila Ribeiro de Avelar, MD, Post-graduation Program, Federal University of Bahia, 32 Araújo Pinho Street, Canela, Salvador, Bahia 40.110-150, Brazil.
Telephone: +55-71-32837719 Fax: +55-71-32837705
Received: January 28, 2017
Peer-review started: February 8, 2017
First decision: March 3, 2017
Revised: April 6, 2017
Accepted: June 18, 2017
Article in press: July 19, 2017
Published online: July 21, 2017

To evaluate the effect of silymarin on the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma glutamyl transpeptidase (γGT) in patients with liver diseases.


A systematic review with meta-analysis of ramdomized and controlled clinical trials was performed, evaluating the effects of sylimarin in patients with hepatic diseases, published by January 31, 2016. Clinical trials were sought on the basis of The Cochrane Central Register of Controlled Trials in the Cochrane Library, PubMed/Medline, Scopus, Web of Science, Lilacs and Clinical Trials. The trials with adult and elderly patients of both sexes, with Liver Diseases who took oral silymarin supplementation, as extract or isolated, as well as Silymarin combined with other nutrients, were included. The trials should provide information about the intervention, such as dosages and detailing of the product used, besides the mean and standard deviation of serum levels of ALT, AST and γGT of the baseline and at the end of the intervention.


An amount of 10904 publications were identified. From those, only 17 were included in the systematic review and 6 in the meta-analysis, according to the used selection criteria. In this meta-analysis, the results indicated a reduction of 0.26 IU/mL (95%CI: -0.46-0.07, P = 0.007) at the level of ALT and 0.53 IU/mL (95%CI: -0.74-0.32, P = 0.000) at the serum levels of AST after using the silymarin, both, statistically significant, but with no clinical relevance. There was no significant change in the γGT levels. Subgroup analyzes were also performed for the biochemical markers in relation to the type of intervention, whether silymarin isolated or associated with other nutrients and the time of intervention (whether ≥ 6 mo or < 6 mo). Significant differences were not found. The evaluated studies presented a high degree of heterogeneity and low methodological quality in the carried out analysis.


Silymarin minimally reduced, but without clinical relevance, the serum levels of ALT and AST. It is necessary to carry out studies with more appropriate methodological designs.

Keywords: Systematic review, Liver diseases, Milk thistle, Silymarin, Meta-analysis

Core tip: Silymarin is commonly prescribed in the practice of many professionals and ingested as self-medication for patients. Studies suggest benefits of its use in hepatic disorders, discussing its mechanisms of action and potential as a coadjutant in the treatment of those diseases. Favorable clinical outcomes as improvement of biochemical indicators and liver profile were observed in clinical trials. However, other studies are controversial or have not reported statistical significance in the improvement of these indicators. Facing the differences and methodological peculiarities of these studies, a systematic review with meta-analysis was performed to clarify the real benefits of silymarin in liver diseases.