RESUMO
The concept of pre-emptive priming of skin pre-surgery offers a novel approach in optimizing cutaneous scarring outcome. We previously showed an anti-scarring topical (epigallocatechin-3-gallate (EGCG)) is effective in improving skin scarring when applied post-surgery. The objective was to deliver an active compound at the optimal time in order to maximize its impact and improve cutaneous scarring. Therefore, pre-emptive application of anti-scarring topical pre-surgery compared with post-surgery can potentially be superior on scarring outcome. This double-blinded randomized placebo-controlled trial compares the effects of pre-emptive priming of skin with an anti-scarring topical pre-surgery versus post-surgery. Healthy volunteers (n = 40) were split into 4-groups; each undergoing different modes of application versus placebo: Group-1 = priming (7Days) pre-injury, Group-2 = priming (3D) pre-injury, Group-3 = immediate (0D) day-of-injury, Group-4 = delayed application (14D) post-injury. Excisional skin-biopsies in upper-arms were evaluated weekly with multiple quantitative devices over 8-weeks. Histological, immunohistochemical, mRNA sequencing and QRT-PCR studies were performed on tissue-biopsies. EGCG reduced mast cells at weeks-4 and 8 by gene and protein analyses (p < 0.01). Group 1 was superior to other groups (p < 0.01) in both clinical (blood flow) and laboratory parameters (elastin and immune marker expression). Additionally, there was down-regulation of angiogenic-markers by mRNA-sequencing and of CD31 and VEGF-A at weeks-4 and 8 (p < 0.01) by immunohistochemistry and at week-4 (p < 0.05) by QRT-PCR. EGCG increased antioxidant levels (HO-1) at week-4 (p < 0.01) plus elastin at week-8 (p < 0.01). In conclusion, pre-emptive priming of skin pre-injury has significant beneficial effects on surgically induced skin scarring shown by reducing mast cells, blood flow and angiogenesis plus increasing elastin content. This clinical trial was registered with ISRCTN (ISRCTN70155584).
RESUMO
BACKGROUND: Epigallocatechin-3-gallate (EGCG), a polyphenol, influences cutaneous wound healing because of its antiangiogenic, anti-inflammatory, and antioxidant properties. We previously showed the role of EGCG in scarring in ex vivo human scar models. Here, we evaluate direct application of topical EGCG compared with zonal priming, a unique concept in the immediate treatment of the zone of injury at the time of wounding before scar formation. TRIAL DESIGN: Double-blind randomized controlled trial. METHODS: We assessed EGCG application compared with placebo over 1-6 weeks in scars created in 62 human volunteers using quantitative noninvasive devices, immunohistochemical analysis, mRNA sequencing, and quantitative real-time reverse transcriptase-PCR of tissue biopsy samples. RESULTS: EGCG reduced mast cells at weeks 1-3, as evidenced by gene and protein analyses (P ≤ 0.01). M2 macrophages were increased with EGCG compared with placebo. EGCG application by zonal priming significantly down-regulated VEGFA and CD31 at week 1 and at 1-2 weeks after direct application (P ≤ 0.01). Direct EGCG application also reduced scar thickness at weeks 1-3 (P = 0.001) and increased scar elasticity at week 4 (P = 0.01). Increased hydration was evident both noninvasively and by increased hyaluronic acid levels (P < 0.01) at week 3. CONCLUSIONS: We show the beneficial role of both zonal priming and direct EGCG application in scar therapy with positive effects on scar thickness, erythema, hydration, and elasticity. Trial register: International standard randomized controlled trial, registration number ISRCTN 18643079; July 16, 2018.