Curcumin enhances wound healing in streptozotocin induced diabetic rats and genetically diabetic mice

Tissue repair and wound healing are complex processes that involve inflamma tion, granulation and tissue remodeling. interactions of different cells, e xtracellular matrix proteins and their receptors are involved in wound heal ing, and are mediated by cytokines and growth factors. Previous studies fro m our laboratory have shown that curcumin (diferuloylmethane), a natural pr oduct obtained from the rhizomes of Curcuma longa, enhanced cutaneous wound healing in rats and guinea pigs. In this study, we have evaluated the effi cacy of curcumin treatment by oral and topical applications on impaired wou nd healing in diabetic rats and genetically diabetic mice using a full thic kness cutaneous punch wound model. Wounds of animals treated with curcumin showed earlier re-epithelialization, improved neovascularization, increased migration of various cells including dermal myofibroblasts, fibroblasts, a nd macrophages into the wound bed, and a higher collagen content. Immunohis tochemical localization showed an increase in transforming growth factor-be ta 1 in curcumin-treated wounds compared to controls. Enhanced transforming growth factor-beta 1 mRNA expression in treated wounds was confirmed by in situ hybridization, and laser scan cytometry. A delay in the apoptosis pat terns was seen in diabetic wounds compared to curcumin treated wounds as sh own by terminal deoxynucleotidyl transferase-mediated deoxyuridyl triphosph ate nick end labeling analysis. Curcumin was effective both orally and topi cally. These results show that curcumin enhanced wound repair in diabetic i mpaired healing, and could be developed as a pharmacological agent in such clinical settings.