Mailuo Shutong Pill ameliorates diabetic foot ulcers in rats by suppressing ferroptosis induced by lipid peroxidation

Diabetic foot ulcer (DFU) is associated with inflammation, imbalance of the oxidation-antioxidation, lipid peroxidation, and ferroptosis. Mailuo Shutong Pill (MLSTP) has significant anti-inflammatory and ferroptosis effects. Clinical research has confirmed that MLSTP promotes the healing of DFU wounds. The precise mechanism of action remains incompletely understood.

This study investigated the therapeutic efficacy of MLSTP in treating DFU rats and explored underlying mechanisms.

The establishment of the DFU model involved creating two 2-cm-diameter skin wounds on the back of diabetic rats. After model establishment, rats received MLSTP or metformin (MET) treatment. The wound healing promotion effect of MLSTP was evaluated through wound healing rate assessment and hematoxylin-eosin (H&E) analysis. The study measured the concentrations of interleukin-4 (IL-4), interleukin-10 (IL-10), transforming growth factor-β1 (TGF-β1), interleukin-1 beta (IL-1β), interleukin-6(IL-6), and tumor necrosis factor-alpha (TNF-α) in skin tissue. The regulatory effect of MLSTP on the redox balance of skin tissue was evaluated by measuring oxidative stress indicators, including malondialdehyde (MDA), glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD). Combining network pharmacology, serum non-targeted metabolomics, and proteomics analysis, we systematically elucidated the multidimensional mechanisms of MLSTP in treating DFU. Finally, the key proteins were verified using Western Blot.

Histopathology and wound healing rate indicated that MLSTP promotes the healing of DFU wounds. MLSTP can reduce the concentrations of pro-inflammatory factors such as IL-1β, IL-6, and TNF-α, and increase the concentrations of anti-inflammatory factors such as TGF-β, IL-4, and IL-10. Western Blot study revealed that MLSTP inhibits TLR4/MyD88/NF-κB and the NLRP3/Cleaved caspase-1/GSDMD signaling pathway. Results indicate that MLSTP can alleviate the inflammation around the DFU tissue. According to the studies of network pharmacology and non-targeted metabolomics, MLSTP regulates the biosynthesis of unsaturated fatty acids by modulating the AGE-RAGE-SREBP signaling axis. MLSTP improves lipid metabolism disorders by inhibiting the PPARα/γ pathway, reducing lipid deposition in tissues. The proteomics results confirmed that MLSTP can regulate the ferroptosis process in skin tissues. The multi-omics evidence demonstrates that MLSTP regulates fatty acid synthesis metabolism to inhibit both lipid peroxidation and associated ferroptosis, ultimately promoting the healing of DFU-impaired wounds.

MLSTP promotes wound healing by regulating the inflammatory microenvironment, improving fatty acid synthesis disorders, and inhibiting ferroptosis mediated by lipid peroxidation and oxidative stress disorders. Research elucidated the mechanism by which MLSTP promotes wound healing in DFU. It also laid an important theoretical basis for future treatment of DFU.