Signaling Pathway Involved in Macrophage Activation by Fructose‐Enriched Polysaccharides From Baizhu Shaoyao Powder

This study optimized ultrasound-assisted extraction (UAE) parameters for polysaccharides from Baizhu Shaoyao powder (BSP), characterized the structure of purified BSP polysaccharides (BSPP) and investigated their immunomodulatory effects on RAW264.7 macrophages. The optimal conditions yielded BSPP at 16.695 ± 0.23%. BSPP was characterized as fructose-enriched polysaccharides with a molecular weight (Mw) of 2.786 kDa, and exhibited amorphous morphology along with characteristic polysaccharide functional groups. BSPP enhanced macrophage pinocytosis and phagocytosis, upregulated antigen-presenting molecules/costimulatory markers, and stimulated inflammatory mediator production. RNA-seq revealed 1,832 DEGs, 66 GO terms, and 97 KEGG pathways with integrated network analysis identifying TNF and IL-1β as hub genes. Western blot analysis confirmed p38 MAPK/NF-κB pathway activation, and inhibitor experiments established TLR2/TLR4-mediated recognition and MyD88-dependent p38 MAPK/NF-κB signaling as essential for BSPP-induced macrophage activation. These findings provide a theoretical basis for enriching the pharmacodynamic material basis of BSP and expanding its clinical applications.