Tissue repair and wound healing are complex processes that involve
inflammation, granulation and tissue remodeling. Interactions of different cells,
extracellular matrix proteins and their receptors are involved in wound healing, and are mediated by
cytokines and
growth factors. Previous studies from our laboratory have shown that
curcumin (
diferuloylmethane), a
natural product obtained from the rhizomes of Curcuma longa, enhanced cutaneous wound healing in rats and guinea pigs. In this study, we have evaluated the efficacy of
curcumin treatment by oral and topical applications on impaired wound healing in diabetic rats and genetically diabetic mice using a full thickness 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, and macrophages into the
wound bed, and a higher
collagen content. Immunohistochemical localization showed an increase in
transforming growth factor-beta1 in
curcumin-treated
wounds compared to controls. Enhanced
transforming growth factor-beta1 mRNA expression in treated
wounds was confirmed by in situ hybridization, and
laser scan cytometry. A delay in the apoptosis patterns was seen in diabetic
wounds compared to
curcumin treated
wounds as shown by
terminal deoxynucleotidyl transferase-mediated deoxyuridyl
triphosphate nick end labeling analysis.
Curcumin was effective both orally and topically. These results show that
curcumin enhanced
wound repair in diabetic impaired healing, and could be developed as a pharmacological agent in such clinical settings.