1. Background
2. Objectives
3. Methods
3.1. Animals
3.2. Establishment and Grouping of Staphylococcus Aureus-Infected Wounds in Mice
3.2.1. Culture and Preparation of Staphylococcus Aureus Suspension
3.2.2. Animal Grouping and Treatment
3.3. Histopathological Analysis of Wound Tissues With H&E Staining
3.4. Enzyme-Linked Immunosorbent Assay
3.5. Western Blot
3.6. Immunofluorescence Staining
3.7. RNA Extraction and Quantitative Real-Time PCR
3.8. Statistical Analysis
4. Results
4.1. DOP Promotes Body Weight Recovery and Wound Healing in Mice With Infected Wounds
DOP ameliorates body weight recovery and promotes wound healing in infected mice. Body weight changes in mice from the Sham, Infection, DOP, and DOP + EX527 groups were recorded at baseline and on days 0, 3, 7, and 14 to evaluate the effect of DOP on weight recovery in infected mice. A, Quantitative analysis of wound healing in each group from day 0 to day 14 (unit: mm2); B, Representative wound images of mice from the Sham, Infection, DOP, and DOP + EX527 groups were captured at the same intervals to visualize wound closure dynamics. Values are expressed as mean ± SD (n = 3/group). Descriptive statistics only; no inferential testing was performed.
4.2. DOP Alleviates Histopathological Damage in Infected Wounds
DOP modulates histopathological damage and inflammatory cytokine expression in infected wounds. (A) H&E-stained sections of wound tissues obtained from the Sham, Infection, DOP, and DOP + EX527 groups showing inflammatory cell infiltration, tissue necrosis, and granulation tissue formation. Images were captured at 200 × (50 μm scale bar) and 400 × (20 μm scale bar). (B-D) Levels of TNF-α (B), IL-1β (C), and IL-6 (D) in wound tissue homogenates were quantified by ELISA. Values are expressed as mean ± SD (n = 3/group). Group comparisons were made using 1-way ANOVA. ***P < 0.001, ****P < 0.0001 vs Infection group; #P < 0.05, ##P < 0.01 vs DOP group.
4.3. DOP Reduces Pro-Inflammatory Cytokine Levels in Infected Wounds
4.4. DOP Suppresses the NF-κB Pathway by Activating SIRT1-Mediated HMGB1 Deacetylation and Nuclear Retention
DOP activates SIRT1 to mediate HMGB1 deacetylation/nuclear retention and suppresses the NF-κB pathway. (A-B) SIRT1 protein levels detected by immunoblotting (A) and quantified (B), demonstrating that DOP upregulates SIRT1 expression, an effect reversed by the SIRT1 inhibitor EX527. (C-D) Immunoblot assessment of total HMGB1, cytosolic HMGB1, and nuclear HMGB1 (C), with densitometry (D), indicating that DOP promotes HMGB1 deacetylation and nuclear retention via SIRT1, thereby inhibiting its cytosolic translocation. (E-F) Immunoblot detection of IκBα and phosphorylated NF-κB p65 (E) and corresponding quantification (F). Data are presented as mean ± SD (n = 3/group). Analysis used 1-way ANOVA with Tukey post hoc test. **P < 0.01, ***P < 0.001, ****P < 0.0001 vs indicated groups; #P < 0.05, ##P < 0.01 vs DOP group; ns indicates not significant.
4.5. DOP Potentially Exerts Its Anti-Inflammatory Effects Through SIRT1-Mediated Deacetylation of HMGB1 at K29
DOP exerts anti-inflammatory effects via SIRT1-mediated HMGB1-K29 deacetylation. (A) Immunofluorescence staining of acetylated HMGB1-K29 (Ace-HMGB1-K29) in wound tissues from the Sham, Infection, DOP, and DOP + EX527 groups. (B) Quantitative analysis of Ace-HMGB1-K29 levels. (C) mRNA levels of TNF-α, IL-1β, and IL-6 quantified by real-time PCR. Data are presented as mean ± SD (n = 3/group). Statistical analysis was performed using 1-way ANOVA. ***P < 0.001, ****P < 0.0001 vs indicated groups; #P < 0.05, ##P < 0.01 vs DOP group.



