[Effect of asiaticoside on the expression of transforming growth factor-beta mRNA and matrix metalloproteinases in hypertrophic scars].

OBJECTIVE: To investigate the effect of asiaticoside on the expressions of transforming growth factor (TGF)-beta mRNA, matrix metalloproteinases (MMPS) and tissue inhibitors of metalloproteinases (TIMPs) in postburn hypertrophic scars. METHODS: Nine specimens of postburn (5-8 months) hypertrophic scars with asiaticoside treatment and 9 without asiaticoside treatment were collected for testing the expressions of MMPS, TIMPs, type I and III collagen and TGF-beta mRNA by immunohistochemistry and in situ hybridization methods, followed by image analysis of the results. RESULTS: The expressions of TGF-beta mRNA and MMPS/TIMPS were all detected in the fibroblast cytoplasm. The expression of TGF-beta(1) mRNA in asiaticoside-treated scars was significantly lower than that in scars without asiaticoside treatment (P<0.01). In contrast, the expression of TGF-beta(3) mRNA was significantly higher in asiaticoside group (P<0.05). The expression of TIMP1 in asiaticoside group was significantly lower than that in non-asiaticoside group (P<0.01), and the expression of type I collagen in asiaticoside-treated scars was lower than that in non-asiaticoside-treated specimens (P<0.05), but the expression of MMP(1), MMP(2) and TIMP(2) and type III collagen exhibited no significant differences between the two groups (P>0.05). CONCLUSION: Asiaticoside can down-regulate TGF-beta(1) mRNA and TIMP(1) expressions and up-regulate TGF-beta(3) mRNA expression in postburn hypertrophic scars, and is also capable of decomposing the products of type I collagen, contributing to the reduction of hypertrophic scar formation.