Lysozyme from hen egg white ameliorates lipopolysaccharide-induced systemic inflammation in mice.

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.