유청단백질 Glycomacropeptide에서 분리한 NANA의 안전성 및 염증저하 메카니즘 구명 연구

Anti-inflammatory Effects and Its Mechanisms of NANA (N-Acylneuraminic Acid) Isolated from Glycomacropeptide

The focus of this study was to clarify the relation between the nitric oxide (NO) production and cytokine expression including tumor necrosis factor-${\alpha}$ (TNF) and interleukin-6 (IL-6), and also investigated the effect of G-NANA (N-acylneuraminic acid isolates from glycomacropeptide) or S-NANA (Synthetic N-acylneuraminic acid) on LPS stimuli from RAW264.7 cell. The NANA is the predominant sialic acid found in mammalian cells and G-NANA is isolation of GMP (GMP is a valuable bioactive peptide with a varying degree of glycosylation including sialic acid). The lipopolysaccharide (LPS) of Gram-negative bacteria induces the expression of cytokines and potent inducers of inflammatory cytokines such as TNF-${\alpha}$ and IL-6. In this experiment, upon stimulation with increasing concentrations of chitosan, the LPS-stimulated TNF-${\alpha}$ and IL-6 secretion was significantly recovered with in the incubation media of RAW264.7 cells. Consistently, RT-PCR with mRNA and immunoblot analysis with anti-cytokine antiserum including TNF-${\alpha}$ and IL-6 showed that the amount of TNF-${\alpha}$ and IL-6 secretion in the incubation media recovered with the concentration of chitosan. The LPS-stimulated NO secretion was significantly recovered with in the 6 and 12 h incubation media of RAW264.7 cells, too. The recovery effect of G-NANA on IL-6 and NO secretion may be induced via the stimulus of TNF-${\alpha}$ in RAW264.7 cell. These results once again suggest that G-NANA may have the anti-inflammatory effect via the stimulus of TNF-${\alpha}$ in the LPS-stimulated inflammation in RAW264.7 cells.