Effect of acanthus ebracteatus vahl. extract in combination with collagen scaffold on angiogenesis and wound closure in mice skin model

Abstract

This research was to study the effects of Acanthus ebracteatus Vahl. (AE) extract on the efficacy of collagen scaffold for wound healing. Balb/c mice (22-25 g) were used for this study. Animals were anesthetized with sodium thiopental (20µg/ml, intraperitoneally). The dorsal skin was cut with 1.5×1.5 cm2 size, in order to develop a full-thickness wound. Wounded animals were divided into 8 groups: wound treated with normal saline (W+NSS), wound treated with AE, 0.03, 0.3 and 3 g/kg bw, (W+AE0.03, W+AE0.3, and W+AE3), wound implanted with bovine collagen scaffold (W+Coll), and W+Coll treated with AE at 3 doses (W+Coll+AE0.03, W+Coll+AE0.3, and W+ Coll+AE3). On day 3, 7 and 14 post-wound-operation, the wound area was measured using Digital Image analysis (Image Pro-Plus, Media Cybernetics, Inc). On day 3, the number of neutrophil infiltration was counted using H&E staining. On day 7 and 14, the angiogenesis in the wound area of each group was examined using intravital fluorescence microscopy and represented by percentage of capillary vascularity (%CV). The re-epithelialization and the level of VEGF were analyzed from wound tissue samples using H&E staining and ELISA, respectively. The results showed that: 1) number of neutrophil infiltration in W+Coll group increased significantly as compared to W+NSS (p=0.03), but in W+Coll+AE0.3, it decreased significantly as compared to W+Coll (p=0.02). 2) On day 14, the wound closure of all groups increased significantly as compared to W+NSS. 3) Re-epithelialization in W+AE0.03 and W+Coll+AE0.3 increased significantly as compared to W+NSS (p=0.05). 4) In W+AE0.03 and W+Coll+AE0.3, the % CV increased significantly as compared to W+NSS (p=0.001, p=0.03). 5) On day 7, VEGF level increased in W+Coll+AE0.3, significantly as compared to W+Coll (p=0.01). The combined treatment of Acanthus ebracteatus Vahl. extract (0.3 g/kg bw) with bovine collagen scaffold has shown the most benefit effects on wound management, which were attributed through the reduction of neutrophil infiltration, enhanced re-epithelialization and neocapillarization, and finally lead to rapid wound closure.