Curcumin enhances the expression of growth associated protein-43 (GAP-43) in healing tissue of diabetic rats

In our earlier studies, we have reported that that topical application of curcumin caused faster healing of cutaneous wounds in diabetic rats which was might be due to their antioxidant, anti-inflammatory and angiogenic potentials. The aim of this study was to examine the effect of topical application of curcumin on neuronal growth in healing tissue in streptozotocin-induced diabetic rats. Excision cutaneous wound was created in diabetic rats and wounded rats were divided into three groups viz. i) control, ii) pluronic F-127 gel-treated and iii) curcumintreated. The pluronic F-127 gel (25%) and curcumin (0.3%) in pluronic gel were topically applied once daily for 19 days. Five rats were killed on days 3, 7, 14 and 19 from each group and granulation/healing tissue was collected and processed for immunohistochemical analysis of Growth Associated Protein-43 (GAP-43) positive nerve fibers. The curcumin treatment increased GAP-43 positive nerve fibers, as compared to other groups. The results of our study suggested that topical curcumin application has neuroprotective effect in the healing tissue of diabetic wounded rats.