The high-polarity fraction of tail fat derived from Lanzhou Fat-Tailed sheep enhances skin wound healing through the regulation of inflammatory factors and the TGF-β1/Smad3 signaling pathway

Lanzhou Fat-Tailed sheep (LFTS), a local characteristic sheep breed in Gansu province, China, possess tail fat with low cholesterol content and a unique aroma. This fat exhibit moisturizing, anti-inflammatory, and immunity-enhancing properties. In this study, the tail fat of LFTS was used as raw material, and three components with varying polarities were obtained via silica gel column chromatography. It was observed that HPF, the high polarity fraction of LFTS tail fat, had significant scavenging effect on DPPH, ABTS⁺, ·OH, and O₂^- radicals. Application of different polarity fractions of sheep tail fat to a whole skin defect model in mice. The results indicated that HPF, MPF, and LPF were outperformed the NT group in terms of wound healing rate, scab removal time, anti-inflammatory effects, and the promotion of collagen fibers production and remodeling. Notably, the HPF fraction reduced serum IL-1β in the mouse wound model, a pro-inflammatory cytokine associated with wound inflammation. Additionally, HPF decreased the levels of pro-inflammatory factors IL-1β and TNF-α while increasing the levels of the growth factor TGF-β1 in the skin of trauma model mice. Pathological analysis revealed that HPF accelerated the generation of hair follicles, sebaceous glands, and promoted collagen deposition and remodeling, thereby preventing scar formation. qRT-PCR and Western blot analyses of wounds and surrounding skin demonstrated that HPF upregulated the transcription and protein expression of TGF-β1 while downregulating Smad3 transcription and expression, thus enhancing wound healing.