Eicosapentaenoic acid suppresses ocular inflammation in endotoxin-induced uveitis

Purpose: To investigate the effect of eicosapentaenoic acid (EPA) on acute ocular inflammation in an animal model of endotoxin-induced uveitis (EIU). Methods: C57Bl/6 mice (6-week-old males) were orally treated with EPA at a dose of 50 mg/kg/day for 5 days. EIU was then induced in the animals by intraperitoneal injection of 160 mu g lipopolysaccharide (LPS). Twenty-four hours after LPS injection, leukocyte adhesion to the retinal vasculature was evaluated by the concanavalin A lectin perfusion-labeling technique, and leukocyte infiltration into the vitreous cavity was quantified. Furthermore, the protein levels of monocyte chemotactic protein (MCP)-1, interleukin (IL)-6, intercellular adhesion molecule-1 and phospholyrated nuclear factor (NF)-kappa B p65 in the retina and retinal pigment epithelium (RPE)-choroid complex were examined by enzyme-linked immunosorbent assay (ELISA). Results: At 24 h after LPS injection, the EIU animals treated with oral EPA administration showed a significant decrease in leukocyte adhesion to the retinal vessels by 43.4% (p< 0.01) and leukocyte infiltration into the vitreous cavity by 49.2% (p<0.05). In addition, EPA significantly reduced the protein levels of MCP-1 and IL-6 in the retina and the RPE-choroid complex. Furthermore, phosphorylation of NF-kappa B was suppressed by EPA treatment. Conclusions: Our data suggest that EPA inhibits multiple inflammatory molecules in vivo. EPA may become a novel strategy in the prevention and/or treatment of ocular inflammatory diseases.