A novel polysaccharide from Polygonatum cyrtonema fibrous root mediates anti-diarrheal effects by reprogramming macrophage M1/M2 polarization

Huangjing (Polygonati Rhizoma) is an important medicinal and edible herb, which can be taken orally, brewed in tea, steeped in wine, or used in food processing.The fibrous roots of Polygonum cyrtonema, usually discarded as a waste, need to be removed from the tubers before processing. A homogeneous polysaccharide was purified from the Fibrous Root of Polygonatum cyrtonema (PCFP) in this study. PCFP was a branched polysaccharide composed of Fruf-(2 → ， → 6)-Fruf-(2 → ， → 1)-Fruf-(2 → ， → 6)-Glcp-(1 → ，and →1,6)-Fruf-(2→. PCFP has demonstrated efficacy in mitigating diarrhea in mice, repairing disrupted intestinal mucosal architecture, and enhancing the production of MUC2 protein. It also fosters the expression of ZO-1 protein in the intestines of mice suffering from bacterial diarrhea. Besides, PCFP notably enhances the transcription of genes associated with both M1 (IL-1β, IL-6, iNOS) and M2 (IL-10, TGF-β1, Arg-1) macrophage markers in RAW264.7 cells. Additionally, flow cytometry analysis corroborates that PCFP effectively induces M1/M2 macrophage polarization. In conclusion, PCFP may exert its anti-diarrhea effect by inducing balanced M1/M2 polarization of macrophages in intestinal tissue to maintain intestinal homeostasis. These findings establishes a crucial base for the application of PCFP in crafting functional foods designed for the prevention and healing of intestinal injuries.