Polysaccharide from Asparagus officinalis activated macrophages through NLRP3 inflammasome based on RNA-seq analysis

Some polysaccharides with established medical and nutritional values have been identified to possess immunomodulatory properties devoid of any toxic or adverse effects. Previous studies have demonstrated that water-soaked polysaccharides from the skin of white asparagus can enhance cytokine release in RAW 264.7 macrophages, however, the underlying mechanism governing immune regulation remains elusive. In this study, we obtained a lower molecular weight polysaccharide (AP) through acid extraction, with an average MW of approximately 9.5 kDa. SEM and AFM spectroscopy analysis revealed well-dispersed spherical particle with triple helix conformation for AP, characterized by intertwined branching structures. Treatment with AP resulted in a time-dependent increase in nitric oxide levels and cytokine production in both RAW 264.7 cells and primary peritoneal macrophages. RNA-seq analysis indicated that AP activated macrophages via NLRP3 inflammasome signaling pathway. Furthermore, AP activated MAPKs and JAK/STAT signaling pathways to amplify the inflammatory response. Additionally, administration of AP improved visceral index and reduced inflammatory cell counts in CYP-induced immunosuppressed mice models. These findings suggest that AP holds potential as an immuno-enhancement mediator, wherein MAPK and JAK/STAT3 signaling pathways play a role in NLRP3 inflammasome activation of macrophages.