Astragaloside IV enhances diabetic wound healing involving upregulation of alternatively activated macrophages

Astragaloside IV (AS-IV), one of the major active compounds extracted from Astragali Radix , has been used experimentally for its potent antiinflammatory and immunoregulatory activities. In this study, we further investigate the potential efficacy of AS-IV on impaired wound healing in streptozotocin-induced diabetic mice. A full-thickness skin wound was produced on the back of diabetic mice and treated with AS-IV or vehicle topically. Our results showed that AS-IV application promoted diabetic wound repair with wounds gaping narrower and exhibiting augmented reepithelialization . AS-IV enhanced the collagen deposition and the expression of extracellular matrix (ECM)-related genes such as fibronectin and collagen IIIa, which implies a direct effect of AS-IV on matrix synthesis. AS-IV also improved the new blood vessel formation in wound tissue with increased numbers of endothelial cells and enhanced expression of VEGF and vWF. Moreover, the beneficial effect of AS-IV was related to the development of polarized alternatively activated macrophages, which involved in resolution of inflammation and facilitation of wound repair. All together, these findings suggest that AS-IV may play a potential effect on maintenance of cutaneous homeostasis and acceleration of diabetic wound healing.