The Effectiveness of Silymarin in the Prevention of Anti-tuberculosis Drug-induced Hepatotoxicity: A Randomized Controlled Clinical Trial

Background: Several animal studies have shown the protective effect of silymarin (the extract of Silybum marianum seeds) against anti-tuberculosis drug-induced hepatotoxicity (ATDH). However, the knowledge of ATDH of silymarin in humans is scarce. In this study, we aimed to clinically evaluate it. Methods: During this randomized controlled clinical trial, 36 new cases of tuberculosis (TB) were enrolled to receive either silymarin 150 mg twice daily for two weeks along with a standard anti-TB therapeutic regimen (experimental group; n = 16) or standard anti-TB therapeutic regimen alone (control group; n = 21). Liver function tests (serum AST, ALT, ALP, and total bilirubin) at the end of weeks 1 and 2 as well as the rate of ATDH during the study were determined and compared between the groups. Results: No significant differences between the experimental and control groups were observed at the end of the first week regarding liver function tests; However, at the end of the second week, the mean serum levels of AST (P = 0.03) and ALP (P = 0.04) were significantly lower in the experimental group. ALT (P = 0.016) and ALP (P = 0.027) levels in the experimental group significantly decreased during the study, while the changes in the control group were not significant. Two patients in the control group (9.5%) developed ATDH, while no one in the experimental group manifested this adverse effect. Conclusions: Our study suggests that silymarin use has the potential for the reduction of anti-TB drug-induced hepatotoxicity.