Effect of Fish Oil Supplementation on IL-1β, TNF-α and Erythrocyte Membrane Stability in Experimental Acute Pancreatitis

Objective:To observe the relationship between stability of erythrocyte membrane and expression of cytokines such as interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in experimental acute pancreatitis after total parenteral nutrition with fish oil supplementation. To evaluate the protective effect of fish oil supplementation on the early stage of inflammatory reaction in acute pancreatitis. Methods: Male Sprague-Dawley rats were randomly divided into 4 groups: sham operated group (n=18), fish oil supplementation treatment group (n=18), soybean oil treatment group (n=18) and normal sodium treatment group (n=18). Acute pancrea-titis was induced in the last three groups by retro-injected of 5% sodium cholate (1 mL/kg) into pancreatic ducts for almost 30 seconds. Fish oil supplementation (2 mL/kg), soybean oil (2 mL/kg) or normal sodium (2 mL/kg) was given intravenous to rats in fish oil supplementation treatment group, soybean oil treatment group or normal sodium treatment group respectively after modeling. Severity of pancreatitis was confirmed by level of serum amylase and histopathology score. Erythrocyte fragility test was performed to decide stability of erythrocyte membrane. Expression of IL-1β and TNF-α was carried out by enzyme linked immunosorbent assay. Results:Successful modeling was determined by level of hyperamylasemia (3 times than that of normal rats) and high histopathology score (2). Compared with normal sodium, fish oil supplementation not soybean oil could significantly attenuate the expression of IL-1β and TNF-α (P0.05). This had a positive correlation with stability of erythrocyte membrane. Conclusion: By down-regulating the levels of IL-1β and TNF-α, fish oil supplementation reduces the damage induced by inflammatory reaction at the beginning of acute pancreatitis. Fish oil supplementation can enhance the stability of erythrocyte membrane ,and it outstrips soybean oil during the early stage of acute pancreatitis.