Effects of Omega-3 Polyunsaturated Fatty Acids on Cognitive Function after Splenectomy in Rats

BACKGROUND: Postoperative cognitive dysfunction (POCD) is a common complication after abdominal surgery. Several studies have reported that POCD is related to neuroinflammation caused by surgery. Omega-3 polyunsaturated fatty acids (PUFAs) can effectively inhibit the systematic inflammatory response. So, we use fish oil to study the effect of fish oil on inflammation, immunity, and cognitive behavior after splenectomy in rats. METHODS: 60 SD (Sprague-Dawley) rats were randomly divided into control group (group C, n = 20), surgery group (group S, n = 20), and omega-3 (fish oil) intervention group (group F, n = 20). Omega-3 PUFA was injected intraperitoneally from 3 days before operation to 7 days after operation in group F, and normal saline was injected simultaneously in group S. Rats in group S and group F received splenectomy under general anesthesia. Morris water maze behavioral evaluation was performed on the first, third, fifth, and seventh day after operation. The levels of IL-1β (interleukin-1β), IL-6 (interleukin-6), TNF-α (tumor necrosis factor-α), SOD (superoxide dismutase), and GSH-PX (glutathione peroxidase) were detected. RESULTS: Serums IL-1β, IL-6, and TNF-α concentrations in group S and group F were higher than those in group C (P < 0.01), while those inflammatory cytokines in group F were significantly lower than those in group S (P < 0.01); serum GSH-PX levels in group F were higher than group S (P < 0.01). The Morris water maze behavior test performance of group F was better than that of group S (P < 0.05). CONCLUSION: Omega-3 PUFA can effectively improve postoperative inflammatory response, reduce the damage of antioxidant defense system, and improve postoperative cognitive function.