Fennel essential oil and its nanoemulsion modulate macrophage-mediated inflammatory responses and promote pressure ulcer healing.

A chronic inflammatory microenvironment represents a major barrier to the healing of pressure ulcers (PUs). Fennel essential oil (FEO), an active extract from the traditional medicinal plant Foeniculum vulgare, exhibits potent anti-inflammatory effects. However, its therapeutic potential in the context of PUs remains largely unexplored. In this study, an FEO nanoemulsion was prepared, and both an in vivo PUs model and an in vitro macrophage hypoxia/reoxygenation (H/R) injury model were established to evaluate the effect of FEO and its nanoformulation on wound healing and inflammation responses. In vitro, FEO promoted fibroblast and endothelial cell proliferation and migration, while attenuating H/R-induced macrophage inflammation via inhibition of NF-κB and HIF-1α pathway crosstalk. In vivo, FEO effectively suppressed wound inflammation and enhanced collagen deposition, neovascularization, and regeneration of skin appendages. These findings highlight the therapeutic promise of FEO for PU treatment and suggest a novel strategy for improving wound healing outcomes.