Inducing inflammatory response in RAW264.7 and NK-92 cells by an arabinogalactan isolated from Ferula gummosa via NF-κB and MAPK signaling pathways.

The polysaccharide isolated from F. gummosa (FGP) was found homogenous with a weight average molecular weight (M) of 50.0 × 10 g/mol and radius of gyration (R) of 105.3 nm. The FGP was an arabinogalactan with a backbone formed of →6)-β-Galp-1→ residues having random branching points at C-3 extended with either β-Galp-(1→3)-β-Galp-(1→ or α-Araf-(1→ side chain residues. FGP exhibited proliferative effect on RAW264.7 cells and induced macrophages to exert proinflammatory response releasing NO and up-regulating the transcription of cytokines including TNF-α, IL-1β, IL-6 and IL-12. The FGP induced NK-92 cells to up-regulate the expressions of TNF-α, IFN-γ, granzyme-B, perforin, NKG2D and FasL. The presence of p-NF- κB, p-ERK, p-JNK and p-p38 in RAW264.7 and NK-92 cells indicated their activation through NF-κB and MAPKs signaling pathways. These findings suggested that polysaccharides from F. gummosa are potent in boosting immune system and thus may be considered for further studies of biomedical applications.