Abstract: Objective: To determine the effect of Shuxuetong injection on the expression s of matrix metalloproteinase 2 (MMP-2) and ɑ-smooth muscle actin (ɑ-SMA) in hypertrophic scar of rabbit ear. Methods: Nine New Zealand white rabbits were selected randomly. Firstly we established a hyperplastic scar model of rabbit ears. When the wounds were reepithelialized after 30 days, the nine rabbits were randomly divided into three groups: blank control group, triamcinolone acetonide injection group and Shuxuetong injection group (3 rabbits in each group). After 20 days，the thickness of scar was measured and the scar hyperplasia index was calculated. The histological structure and the collagen fiber expression were observed by hematoxylin-eosin (HE) and VG staining. The levels of MMP-2 or α-SMA mRNA and protein levels were detected by qRT-PCR and Western Blot. Results: The scar thickness, scar hyperplasia index, the mRNA and protein level of MMP-2 and ɑ-SMA were 36.67±1.74, 1.19±0.07, 0.28±0.04, 0.53±0.06,1.40±0.34 and 0.56±0.06, respectively, in the Shuxuetong group, were 35.33±3.51, 1.25±0.15, 0.18±0.01, 0.39±0.03, 1.03±0.1 and 0.50±0.03, in the triamcinolone acetonide group, and were 85.00±7.38, 2.77±0.37, 1.01±0.07, 0.83±0.06, 4.43±0.47 and 0.81±0.05 in the blank control group. HE staining and VG staining showed that the fibroblasts and collagen fibers in the triamcinolone acetonide group and Shuxuetong group were less than that in the blank control.group. Conclusion: Shuxuetong injection can inhibit the proliferation of scar tissue by decreasing the expression of MMP-2 and α-SMA.

Key words: hypertrophic scar, Shuxuetong, triamcinolone acetonide, MMP-2, ɑ-SMA