Introduction: Milk Thistle is a traditional herbal medicine that contains some active ingredients including Silymarin. The aim of this study was to investigate the effect of short term silymarin supplementation on aspartate aminotransferase (AST), alanine aminotransaminase (ALT) and alkaline phosphatase (ALP) serum levels induced by one-bout aerobic exercise in active male.

Methods: In a experimental, Twenty-two active male, after completing consent forms were randomly divided into two equal groups including supplement and placebo groups. After 7 days of supplementation period (6 mg/kg/day silymarin or placebo) all subjects performed an aerobic exercise including running on the treadmill with 65-70% heart rate reserve for 30 minutes. Blood samples were taken at four phases (baseline, after supplementation period, immediately and 24 hours after the exercise). Data was analyzed by repeated measure ANOVA, Bonferroni and independent t-tests.

Results: Results showed that after 30 min aerobic exercise, levels of serum liver enzymes significantly increased immediately and 24 hours after exercise in Silymarin and placebo groups (p=0.01). However, after 24 hours of aerobic exercise, all liver enzymes was decreased significantly in Silymarin group comparing to placebo group (p=0.038).

Conclusion: Based on the present findings, it seems that Silymarin supplementation can inhibit aerobic exercise induced hepatocellular damage in active male.