RESUMEN
Lysozyme is an anti-bacterial protein that is widely distributed in nature. Our previous studies revealed that lysozyme shows anti-inflammatory effect on hyperinflammatory macrophages in vitro. The effect of lysozyme on lipopolysaccharide-induced inflammation model mice was examined in this study. Oral administration of lysozyme at 2250 mg/kg body weight/day (high-dose group) significantly suppressed interleukin (IL)-6 and tumor necrosis factor-α levels in the serum. IL-6 level in the spleen was significantly suppressed by lysozyme at 450 mg/kg body weight/day (middle-dose group) and high-dose group due to the suppression of gene expression level. The gene expression levels of IL-1ß and IL-12 were also decreased by lysozyme in the high-dose group. In addition, lysozyme significantly suppressed IL-6 level in the liver in the high-dose group. Our findings suggest that lysozyme mitigates inflammatory condition in vivo by suppressing inflammatory cytokine levels in serum and organs from LPS-induced inflammation model mice.
RESUMEN
Lysozyme from hen egg has been reported to possess an anti-inflammatory effect. However, little is known about its detailed mechanism. The mechanism of anti-inflammatory effect of lysozyme was examined in this study. When mouse macrophage-like cell line RAW264.7 cells and mouse peritoneal macrophages were activated with lipopolysaccharide (LPS) and then treated with lysozyme, the production of tumor necrosis factor-α and interleukin-6 was significantly suppressed. The effect was induced by suppressing the gene expression levels of both cytokines. Phagocytosis activity of peritoneal macrophages was not altered by the treatment with lysozyme, suggesting that lysozyme shows the anti-inflammatory effect without inhibiting the phagocytotic response of macrophages. In addition, lysozyme inhibited phosphorylation of c-jun N-terminal kinase (JNK) and was taken up by macrophages within 1 h after treatment of the cells with lysozyme. Overall results suggest that lysozyme is taken up intracellularly and suppresses LPS-induced inflammatory responses by inhibiting JNK phosphorylation.
