Immune-Enhancing Effects of Polygonatum cyrtonema Polysaccharides in Immunodeficient Zebrafish

To evaluate the immune-enhancing effects of Polygonatum cyrtonema polysaccharides in vivo, an immunodeficiency zebrafish model was established by microinjecting vinorelbine tartrate into the caudal vein. Effects of the polysaccharides (500, 1000 and 2000 μg/mL) on neutrophil counts were assessed in Tg (mpx:GFP) zebrafish. Transcriptome sequencing was employed to investigate the immunomodulatory effects of the polysaccharides. The results revealed a dose-dependent increase in neutrophil counts following treatment with the polysaccharides. Transcriptomic profiling identified 1286 DEGs across the three comparison groups. GO and KEGG enrichment analyses indicated that the polysaccharides could modulate immune-related pathways in the zebrafish model. Two enriched KEGG pathways, including the MAPK signaling and the mTOR signaling pathway, were utilized to analyze immune-related gene expression. To validate RNA-seq data, qRT-PCR was performed on selected DEGs, including il1b, crk, fgf10b, atp6v1aa, and eif4e1c. The results confirmed that the expression patterns of these genes were consistent with the RNA-seq data. Within the tested concentrations (500, 1000 and 2000 μg/mL), the polysaccharides exhibited a dose-dependent immunostimulatory effect, with the highest immunostimulatory response observed at 2000 μg/mL. The molecular level primarily involves the enhancement of neutrophil function through the modulation of multiple immune-related pathways. These findings provide a theoretical basis for the potential application of Polygonatum cyrtonema polysaccharides as a natural immunomodulatory agent.