Soybean and fish oil mixture increases IL-10, protects against DNA damage and decreases colonic inflammation in rats with dextran sulfate sodium (DSS) colitis

Abstract

It was investigated whether dietary polyunsaturated fatty acids (PUFA) could influence colonic injury, tissue DNA damage, cytokines and myeloperoxidase activity (MPO) and plasma corticosterone in DSS-induced colitis rats. Male weaning Wistar rats were fed for 47 days with an AIN-93 diet with control (C), fish (F) or a mixture of fish and soybean oil (SF). The colitis was induced from day 36 until day 42 by 3% DSS in drinking water. On day 48, blood samples were collected for corticosterone determination. The distal colon was excised for histological analysis and to quantify the cytokine (IL-4, IL-10 and INF-γ), MPO and DNA damage. The disease activity index (DAI) was recorded daily during colitis induction. The DAI, MPO, histological analyses showed decreases only in the SF group compared with the C group. IL-10 was increased and DNA damage was reduced in the groups F and SF, and an inverse correlation between these variables was found. There were no differences in corticosterone, IFN-γ and IL-4 levels. Soybean and fish oil mixture may be effective in improving colonic injury and DNA damage, and it could be an important complementary therapy in UC to reduce the use of anti-inflammatory drugs and prevent colorectal cancer.

Dietary oils modify the host immune response and colonic tissue damage followingCitrobacter rodentiuminfection in mice

“…We used custom-prepared diets to show that, in the postweaning animal, colonic membrane phospholipids are remarkably plastic to substantial alteration in their n-6 and n-3 fatty acids within a relatively short 4-wk period of altering the fatty acid but not fat content of the diet. High intake of 20:5n-3 and 22:6n-3 consumed before and during the course of C. rodentium infection attenuated colonic injury, consistent with the beneficial effect of dietary n-3 fatty acids observed in other experimental models of colitis (1,4,11,42). In contrast, high n-6 fatty acid intake exacerbated the inflammatory response.…”

Higher Fecal Bile Acid Hydrophobicity Is Associated with Exacerbation of Dextran Sodium Sulfate Colitis in Mice

“…Although tissue and dietary ratios are difficult to compare, it is possible that a very high dose of fish oil is detrimental in colitis, whereas a moderate dose is protective. In the present study, we used a much higher dose of fish oil (27.2% kcal) compared with all previous studies on fish oil and colitis (17.2% kcal) (33,(36)(37)(38). However, because we did not see any significant effect from fish oil, this difference does not explain discrepancies among previous studies.…”

“…Whereas some studies have shown that fish oil supplementation (5% wt:wt) reduces DSS-induced weight loss and DNA damage (33) or that other n-3 (v) oils ameliorate inflammation in the same model (34,35), several studies report the opposite. Fish oil, varying between 0.75 and 8% wt:wt, has severely exacerbated colitis scores in several colitis models: DSS colitis (36), the IL-10 knockout mouse (37), and the H. hepaticus-induced colitis model (38), in which fish oil resulted in a dose-dependently higher intestinal histopathological score.…”

Partial replacement of dietary linoleic acid with long chain n-3 polyunsaturated fatty acids protects against dextran sulfate sodium-induced colitis in rats

“…Diet with 6% fish oil and 1% corn oil (n-6:n-3 ratio of 0.17) aggravated the colitis [36]. Another study demonstrated that compared to fish oil alone, fish oil and soybean oil blend (n-6:n-3 ratio of 2) attenuate DSS induced colitis [37]. These studies suggest that high dosage of fish oil is detrimental to the colitis whereas moderate dose is protective.…”