Evaluation of the antioxidant activity and the healing action of the ethanol extract of Calotropis procera bark against surgical wounds

The objective of the present study was to evaluate the antioxidant potential and the wound healing effect of the ethanolic extract of the bark of Calotropis procera. The antioxidant study was evaluated in vitro, using 2,2-diphenylpicrylhydrazyl (DPPH) and deoxyribose degradation assays. Wound healing was studied using excision and incision wound on normal and dexamethasone-suppressed wound healing rodent models. Alkaloids, flavonoids, proteins and phenols were screened in the extract used whereas saponins and true tannins were absent. The extract contains only 12.5 gallic acid equivalent and 399.54 rutin equivalent. It was found to inhibit DPPH and deoxyribose oxidation (IC(50) = 24.24 and 5.40 respectively). In vivo study demonstrated a significant reduction in the epithelialization time (P < 0.001) to 17-18 days in normal and dexamethasone treated rats following the ethanolic extract of the bark of C. procera application. The same extract also significantly increased the breaking strength in dexamethasone treated rats. Histological examination of incision wounds of treated group showed matured extracellular matrix, numerous fibroblasts. This study illustrated an excellent potential of the bark of C. procera therapy on dermal wound healing, with a tentative mechanism of action related to improved collagen deposition and reduced inflammatory reaction.