Fig. 2: SP restores synovial homeostasis by alleviating oxidative stress and inflammatory modulation of macrophages.

A Fluorescence analysis of 2′,7′-dichlorofluorescein diacetate (DCFH-DA) in macrophages stimulated with lipopolysaccharides (LPS, 100 ng/mL) and different doses of SP (cells/mL, 1.2 × 10⁶, 2.5 × 10⁶, 5.0 × 10⁶, 1.0 × 10⁷) for 24 h. Scale bar = 75 μm. B Quantification of relative fluorescence intensity of DCFH-DA shown in panel A. C Real-time fluorescence quantitative PCR (RT-qPCR) analysis of TNF-α, iNOS, IL-1, IL-6, and IL-12 in macrophages stimulated with LPS (100 ng/mL) and different doses of SP (cells/mL, 1.2 × 10⁶, 2.5 × 10⁶, 5.0 × 10⁶, 1.0 × 10⁷) for 24 h. D Flow cytometry of CD86 marker in macrophages stimulated with LPS (100 ng/mL) and different doses of SP (cells/mL, 1.2 × 10⁶, 2.5 × 10⁶, 5.0 × 10⁶, 1.0 × 10⁷) for 24 h. E Flow cytometry of CD206 and CD11b markers in macrophages stimulated with interleukin-4 (IL-4, 20 ng/mL) and different doses of SP (cells/mL, 1.2 × 10⁶, 2.5 × 10⁶, 5.0 × 10⁶, 1.0 × 10⁷) for 24 h. F Quantification of CD86- or CD206-labeled positive cells shown in panels D and E. G RT-qPCR analysis of CD206, IL-10, and Arg-1 in macrophages stimulated with IL-4 (20 ng/mL) and different doses of SP (cells/mL, 1.2 × 10⁶, 2.5 × 10⁶, 5.0 × 10⁶, 1.0 × 10⁷) for 24 h. All data presented as mean (SD) are from three replicates. Statistical analysis was performed using one-way ANOVA followed by Tukey’s post-hoc test. The exact p-values were labeled.