Isolation, structural elucidation and immuno-stimulatory properties of polysaccharides from Cuminum cyminum.

The aim of the present study was to evaluate the effect of water-soluble polysaccharides from Cuminum cyminum to induce inflammatory response in immune cells and understand their underlying mechanisms. Weight average molecular weight (Mw) of polysaccharides varied between 191.4-512.2 × 103 g/mol. Polysaccharides induced RAW264.7 cells to release nitric oxide and express TNF-α, IL-1β, IL-6 and IL-12 inflammatory cytokines. Polysaccharides activated NK-92 cells to produce TNF-α, IFN-γ, perforin, granzyme B, NKG2D and FasL. Activations of RAW264.7 and NK-92 cells were through NF-κB and MAPKs signal pathways indicated by the presence of phosphorylated NF-κB, ERK, JNK and p38 proteins. The polysaccharide structure was mainly constituted of →4)-Galp-(1→, →3)-Galp-(1→, →2)-Arap-(1→ and →2)-Arap-(1→ glycosidic linkages. Overall results suggested that polysaccharides from C. cyminum possessing lower MW and greater expanded conformation more effectively stimulate RAW264.7 and NK-92 cells and thus could be considered for further studies on their biomedical applications.