ABSTRACT
The main objective of this work was to investigate the mechanism of Astragalus aqueous extract ulcer healing in diabetic foot model rats through the hypoxia-inducible factor 1-alpha (HIF-1É)/vascular endothelial growth factor (VEGF) signalling pathway. Fifty specific-pathogen-free male Sprague Dawley rats were divided into blank (A), model control (B), Astragalus extract (C) and mupirocin (D) treatment groups. Group A received a regular diet, whereas the other groups received a high-fat/high-sugar diet and intraperitoneal streptozotocin injections to induce diabetes. Diabetic foot ulcers were created via skin excision. Subsequently, ulcers were debrided daily. Groups B, C and D received wet saline gauze, wet gauze with Astragalus extract and gauze with mupirocin, respectively, on the affected area. Group A received no treatment. After 14 days, the rats were assessed for ulcer healing and general condition. Immunohistochemistry was used to detect HIF-1É and VEGF levels in the dorsalis pedis artery, and ELISA was used to determine serum IL-6 and CRP levels. The results revealed that Groups C and D had significantly faster ulcer healing compared with Group B (p < 0.01), and ulcer healing was faster in Group C than in Group D (p < 0.01). Group C exhibited notably higher HIF-1É and VEGF protein expression levels compared with Groups B and D (p < 0.01). IL-6 and CRP expression levels in Groups C and D were significantly lower than those in Group B (p < 0.01). In summary, Astragalus aqueous extract effectively treats diabetic foot ulcers by up-regulating HIF-1É and VEGF expression, activating the HIF-1É/VEGF pathway, improving local tissue ischaemia and hypoxia, promoting collateral circulation and enhancing dorsalis pedis artery formation, thereby accelerating ulcer repair in diabetic rats.
Subject(s)
Astragalus Plant , Diabetic Foot , Hypoxia-Inducible Factor 1, alpha Subunit , Plant Extracts , Rats, Sprague-Dawley , Signal Transduction , Vascular Endothelial Growth Factor A , Wound Healing , Animals , Diabetic Foot/drug therapy , Diabetic Foot/metabolism , Male , Vascular Endothelial Growth Factor A/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Signal Transduction/drug effects , Plant Extracts/pharmacology , Plant Extracts/therapeutic use , Astragalus Plant/chemistry , Wound Healing/drug effects , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/complications , Rats , Interleukin-6/metabolism , Interleukin-6/blood , C-Reactive Protein/metabolismABSTRACT
Passive radiant cooling is a potentially sustainable thermal management strategy amid escalating global climate change. However, petrochemical-derived cooling materials often face efficiency challenges owing to the absorption of sunlight. We present an intrinsic photoluminescent biomass aerogel, which has a visible light reflectance exceeding 100%, that yields a large cooling effect. We discovered that DNA and gelatin aggregation into an ordered layered aerogel achieves a solar-weighted reflectance of 104.0% in visible light regions through fluorescence and phosphorescence. The cooling effect can reduce ambient temperatures by 16.0°C under high solar irradiance. In addition, the aerogel, efficiently produced at scale through water-welding, displays high reparability, recyclability, and biodegradability, completing an environmentally conscious life cycle. This biomass photoluminescence material is another tool for designing next-generation sustainable cooling materials.