Modulation of cutaneous wound healing by silymarin in rats

Objective:To investigate the effect of topical application of silymarin on full-thickness cutaneous wounds in rats. Method:A full-thickness cutaneous defect (2x2cm) was induced on the back of 85 male and female Wister rats. The animals were randomly divided into four groups (n=20 in each group), treated with 1ml basal cream (placebo group), low-dose (6mg/ml/rat) and high-dose (12mg/ml/rat) silymarin, and untreated (control). Five rats remained uninjured to serve as comparisons for biomechanical analysis. Wounds were evaluated 10,20 and 30 days after injury, through histopathologic, biochemical and biomechanical analyses. Results: There was a significant (p < 0.05) increase observed in the amount of glycosaminoglycans and collagen present on days 10,20 and 30 for both low-dose and high-dose silymarin groups. Low-dose silymarin reduced the number of lymphocytes and enhanced the number of fibrocytes at the earlier stages of wound healing; however, high-dose silymarin reduced both lymphocytes and macrophages, and increased number of fibrocytes at the later stages of wound healing. Silymarin significantly improved alignment of the healing tissue, enhanced maturity of the collagen fibres and fibroblasts (p < 0,05), and increased the ultimate tensile strength and stress of the healing tissue. Conclusion: The results suggest that topical application of silymarin improved the morphological, biochemical and biomechanical properties of experimentally-induced wound defects in rats. Declaration of interest: There were no external sources of funding for this study. The authors have no conflicts of interest to declare.