Background and Objective: Adhesion formation is the commonest complication of abdominal surgery. Bearing an anti-oxidant activity, Silybum marianum may reduce adhesion formation. This study was an endeavor to shed light on the effect of Silybum marianum on intra-abdominal adhesions.

Materials and Methods: In this experimental study, 30 rats were randomly assigned to three groups: treated by 1% and 5% concentrations of the S. marianum extract (groups A and B) and distillated water (group C). After laparotomy, three longitudinal and transverse incisions (2 cm in length) were made on the right wall of the abdomen and a 2×2 piece was removed from peritoneal surface on the left side of the abdominal wall. In groups A, B and C, 3 mL of 1% and 5% of S. marianum extract or distillated water were administered into abdominal cavity of the rats, respectively. After 14 days, adhesion degrees were determined according to the number of adhesion bands (Canbaz scale). Data analysis was performed through SPSS 16 using Kruskal-Wallis and Mann-Whitney tests.

Results: There was a significant difference in adhesion formation among the groups (P=0.023). Adhesion degree in groups A and B were significantly lower than the control group (P<0.05).

Conclusion: S. marianum extract supported a preventive effect on intra-abdominal adhesion in rats, which gives rise to the evidence that it may be similarly effective for human cases. Throughout further clinical studies, this plant and its derived compounds might be applied in the treatment of such complications subsequent to abdominal surgeries.