In vitro and in vivo evaluation of the diabetic wound healing properties of Saffron (Crocus Sativus L.) petals

Wound healing is a complex process orchestrated by interactions between a variety of cell types, including keratinocytes, fibroblasts, endothelial cells, inflammatory cells, and bioactive factors such as extracellular matrix (ECM) components, growth factors, and cytokines. Chronic wounds exhibit delayed proliferative phase initiation, reduced angiogenesis, impaired ECM synthesis, and persistent inflammatory response. Chronic wounds are one of the main challenges to the healthcare system worldwide, with a high cost for medical services. Hence, investigation of new approaches to accelerate wound healing is essential. Phytomedicines are considered as potential agents for improving the wound healing by accelerating epithelization, collagen synthesis, and angiogenesis. These natural compounds have various advantages including availability, ease of application, and high effectiveness in wound managment. This study aimed to investigate the biological effects of saffron or Crocus sativus L. (C. sativus) petal extract on cell survival, migration, and angiogenesis using MTT, scratch and in vitro tube formation assays. Moreover, the expression of collagen type I alpha 1 (COL1A1) and vascular endothelial growth factor (VEGF) were evaluated in human dermal fibroblasts (HDF)s and human umbilical vein endothelial cells (HUVEC)s, respectively. The effect of the C. sativus extract on the skin of diabetic mice was also monitored. The results showed that C. sativus petal extract promoted the viability and migration of HDFs and HUVECs. Moreover, C. sativus petal extract enhanced the formation of tube-like structures by HUVECs cultured on the Matrigel basement membrane matrix, indicating its potential to stimulate angiogenesis. Gene expression studies have shown the the C. sativus extract increases wound healing by upregulation of COL1A1 and VEGF, which are crucial factors involved in collagen deposition, epithelialization, and angiogenesis. Histological analysis revealed that C. sativus petal extract enhanced vascularity and increased the number of fibroblasts and collagen synthesis, ultimately accelerating wound closure compared to wounds treated with eucerin and commercial ointment in diabetic mice. Therefore, C. sativus petal extract has potential as a herbal treatment to improve the healing of diabetic wounds.