Improvement of wound healing by capsaicin through suppression of the inflammatory response and amelioration of the repair process.

Wound healing is a complex biological process involving cytokines with four phases: Hemostasis, inflammation, proliferation and remodeling. Understanding the molecular mechanism of the inflammation phase could improve wound healing in the clinic as excess inflammation is a critical point for dysregulation of normal wound healing. Capsaicin (CAP), a major component of chili peppers, is known to exhibit anti­inflammatory properties through a range of different pathways, such as the neurogenic inflammation and nociception pathways. To improve the understanding of the relationship between CAP and wound healing, it is crucial to elucidate the CAP­related molecular panel involved in regulating inflammation. Therefore, the present study aimed to analyze the effects of CAP on wound healing using an in vitro cell model and an in vivo animal model. Cell migration, viability and inflammation were examined using fibroblasts, and wounds were evaluated in mice under CAP treatment. In the present study, it was found that 10 µM CAP increased cell migration and decreased interleukin 6 (IL­6) expression in in vitro cell assays. In the in vivo animal experiments, the CAP­treated wounds exhibited lower densities of polymorphonuclear neutrophils and monocytes/macrophages, as well as lower IL­6 and C­X­C motif chemokine ligand 10 protein levels. Furthermore, in CAP­treated wounds, CD31­positive capillaries and collagen deposition at the late phase of wound healing were present at higher densities. In summary, an improvement in wound healing by CAP was shown through suppression of the inflammatory response and amelioration of the repair process. These findings suggest that CAP has potential as a natural therapeutic agent for the treatment of wound healing.