Quercetin accelerated cutaneous wound healing in rats by increasing levels of VEGF and TGF-β1

Quercetin (3,3',4',5,7-penthydroxyflavone)-induced biological effects have been beneficial in various disease conditions. In this study, wound healing potential of quercetin was evaluated in a time-dependent manner in open excision wounds in adult Wistar rats. Experimentally-wounded rats were divided into two groups namely, control and quercetin-treated. Wounds were photographed and the area was measured on the day of wounding and on days 3, 7, 11 and 14 post-wounding. The granulation/healing tissue was collected on days 3, 7, 11 and 14 post-wounding for cytokine/growth factor measurements and histology/immunohistochemistry studies. There was significant time-dependent increase in wound closure in quercetin-treated rats. Vascular endothelial growth factor and transforming growth factor-β1 expressions were significantly upregulated in quercetin-treated rats, whereas tumor necrosis factor-α level was markedly reduced. Interleukin- 10 levels and CD31 stained vessels were markedly higher on day 3 and on day 7, respectively, in quercetin-treated rats. In H & E stained sections, quercetin-treated group showed less inflammatory cells, more fibroblast proliferation, increased microvessel density, better reepithelialization and more regular collagen deposition, as compared to control. The results suggest that topical application of quercetin promotes wound healing by effectively modulating the cytokines, growth factors and cells involved in inflammatory and proliferative phases of healing.