Wound healing activity of Delonix elata stem bark extract and its isolated constituent quercetin-3-rhamnopyranosyl-(1-6) glucopyranoside in rats☆

Delonix elata L. is a Ceasalpinaceae species and is traditionally used in India for treatment of skin diseases, liver diseases and rheumatic problems. However, systematic evaluation of its wound healing activity is lacking. Thus, in the present study, we aimed to assess the wound healing activity of D. elata stem bark extract (DSE) and its isolated constituent quercetin-3-rhamnopyranosyl-(1-6) glucopyranoside (QRPG) in rats. The formulations effects on wound healing were assessed by the wound contraction rate, epithelialization period, tensile strength, content of the hydroxyproline, hexosamine and uronic acid in granulation tissue, histopathological studies and Col 1 α (I) expression level in wound tissue by reverse transcription polymerase chain reaction (RT-PCR) study. The topical application of DSE ointment caused faster epithelialization, significant wound contraction (100%), and better tensile strength (710.5±10.5 g/cm2), while QRPG showed wound epithelialization with 98.2% contraction, better than that of the control group (78.18%). The biochemical analysis of granulation tissue revealed that DSE and QRPG significantly increased hydroxyproline, hexosamine and uronic acid content. A significant increase in the expression of Col 1 α (I) was observed in the wound tissue of DSE and QRPG treated rats. DSE and QRPG were shown to enhance wound healing by increasing collagen synthesis through up-regulation of Col 1 α (I), thus validating ethnomedicinal uses.