The enhanced healing effect of Anadenanthera colubrina ethanolic extract on excisional skin wounds in mice

Background: Anadenanthera colubrina has been widely used in traditional medicine as a healing agent. However, the body of evidence supporting the use of this extract as a wound healer is still limited. Therefore, the study aimed to investigate the effect of the ethanolic extract of Anadenanthera colubrina (EE Ac ) on the viability of L929 fibroblasts and its antioxidant potential in vitro, as well as its effect on the healing of excisional skin wounds in mice. Methods: The extract was analyzed for its major compound using HPLC, as well as for the total phenolic content. In vitro antioxidant activity was evaluated through radical scavenging assays, such as ABTS, DPPH, and FRAP. The cell viability of L929 fibroblasts treated with EE Ac was determined using the MTT assay. Skin excision was performed in female swiss mice and distributed groups: control (saline), vehicle (2% of DMSO in PG) or EE Ac (5%). Treatment was administered daily, and the progress of wound healing was monitored on days 0, 3, 7 and 14. The wounds was collected on days 1, 3, 7 and/or 14 for histological analysis. The concentration of cytokines TNF-α and IL-10, MPO and NAG activity enzymes were assessed in wounds, at various time points. Results: HPLC analysis showed that EE Ac has caffeic acid as its main compound. EE Ac exhibited a high total phenolic content and good antioxidant capacity against the evaluated free radicals. Furthermore, it was not cytotoxic to L929 fibroblasts. In mice, EE Ac reduced the wound area on the 3rd and 7th days and increased collagen deposition on the 14th day. Additionally, EE Ac reduced MPO activity on the 3rd day and NAG activity on the 7th day, in contrast to the increase in IL-10 cytokine concentration on the 7th day. Conclusion: EE Ac showed good antioxidant potential and does not present cytotoxicity in L929 cells. Taken together, our data demonstrate, for the first time, that EE Ac improved skin wound healing by modulating the inflammatory response during this phase of the repair process. This effect possibly led to efficient healing with increased collagen deposition, revealing its potential application as a healing agent.