**5. Conclusion**

Leptin is capable of promoting wound healing of skin by influencing epidermal keratinocytes proliferation, differentiation/function and migration, and angiogenesis in the connective tissue beneath the wounded area. Moreover, we showed that single dose and topically administration of leptin could promote wound healing in the skin without any side effects by using an adequate drug delivery system [33]. In addition to these findings, our previous study demonstrated that local administration of leptin could promote wound healing in the oral mucosa by enhancing epithelial cell migration and angiogenesis in the connective tissue beneath the wound [34]. Taken together, leptin is proven to play physiological roles in wounded area not only as a systemic hormone but also as a local growth factor. Importantly, these findings presented in this chapter declared the possible and promising usefulness of leptin as a new wound-healing promoting agent.
