Effect of botulinum toxin type A on the expression of substance P, calcitonin gene-related peptide, transforming growth factor beta-1 and alpha smooth muscle actin A in wound healing in rats / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the effect of botulinum toxin type A on the expression of substance P (SP), calcitonin gene-related peptide (CGRP), transforming growth factor beta-1 (TGF-beta1) and alpha smooth muscle actin A (alpha-SMA) in wound healing.</p><p><b>METHODS</b>60 rats were randomly divided into group C (control) group L (low-dose) and group H (high-dose), with 20 rats in each group. The wound-healing model was established by excision of four full-thickness skin (1 cm x 1 cm, around the injection site) on the back of all SD rats on the 7th day after BTA injection. The wound size was measured and the expression of SP, CGRP, TGF-beta1 and alpha-SMA in wound granulation tissue was assayed by immunohistochemical staining and computerized image analysis before operation, and 3 days, 7 days and 14 days after operation.</p><p><b>RESULTS</b>All the wounds healed 14 days after operation. The wound size in L and H group was not significantly different with that in C group on the 3rd day and 7th day after operation. The positive immuno-staining of SP, CGRP, TGF-beta1 and alpha-SMA in group L and H was significantly weaker than those in C group. Meanwhile, the positive immuno-staining of all above substances in H group was weaker than those in L group significantly.</p><p><b>CONCLUSIONS</b>Botulinum toxin type A can decrease the expression of SP, CGRP, TGF-beta1, and alpha-SMA in wound healing in a dose-dependent manner with no effect on the healing time.</p>

Effect of botulinum toxin type A injection on hypertrophic scar in rabbit ear model / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the effect of botulinum toxin type A (Botox A) injection on hypertrophic scar in rabbit ear model.</p><p><b>METHODS</b>The hypertrophic scar model was established in 16 Japanese rabbits' ears. These wounds were divided into two groups as group T (treated with Botox A, n = 48) and group S (not treated, n = 48). The wounds healing times and scar hypertrophy were observed with 8 specimen of normal skin at the rabbit ears as sham group B. HE stain was used to assess the hypertrophic index (HI). The expression of collagen I and III was tested by western-blot. The cell cycle of fibroblasts was studied by flow cytometry.</p><p><b>RESULTS</b>The HI was significantly lower in group T than in group S (P < 0.01). The expression of collagen I and III, as well as the ratio of I to III, was markedly stronger in group S than in group T (P < 0.01). Compared with group T, more fibroblasts were in G2-M in group S and fewer in G0-G1 (P < 0.05).</p><p><b>CONCLUSIONS</b>Local injection of Botox A can inhibit the formation of hypertrophic scar and the activity of fibroblasts in rabbit ear model. It can significantly decrease the expression of collagen I and III in hypertrophic scar, as well as the ratio of collagen I to III. It serves as the basis for the treatment of hypertrophic scar with Botox A.</p>