High-fat fish oil diet prevents hypothalamic inflammatory profile in rats

Abstract

Whether PUFA diets affect inflammatory mediators in central and peripheral sites is not clear. We investigated the effect of high-fat PUFA diets on the expression of proteins involved in inflammatory pathways in hypothalamus, muscle, and liver. Male rats were fed for 2 months with either chow or high-fat diets enriched with either soy (n-6 PUFAs) or fish oil (n-3 PUFAs). The fish group had normal body weight, low serum NEFA, reduced hypothalamic levels of TNF- α , IL-6, and TRAF6, and increased levels of IL-10 receptor. In contrast, the soy group had increased body weight and hypothalamic levels of TRAF6 and NF κ Bp65. In muscle, the fish diet reduced TNF- α and IL-6 levels. Both PUFA diets increased muscle IL-10 levels and reduced liver TNF- α and IL-6 levels. The data showed that the high-fat soy diet induced activation of the hypothalamic NF κ B inflammatory pathway, a feature predisposing to feeding and energy expenditure disturbances associated with the development of obesity. On the other hand, the high-fat fish diet improved the central and the peripheral inflammatory profile via reduction of intracellular inflammatory mediators, suggesting a protection against obesity.

Figure 1

Body mass gain (a) and serum levels of nonesterified fatty acids (b) and endotoxin (c) of rats fed with control (n = 6), soy (n = 5), or fish diet (n = 8). *P < 0.05 versus control; ^# P < 0.05 soy versus fish.

Figure 2

Hypothalamic protein levels of TNF-α (a), IL-6 (b), IL-10 (c), IL-1β (d), TNF-α receptor (e), IL-6 receptor (f), and IL-10 receptor (g) of rats fed with control (n = 6–9), soy (n = 7–8), or fish diet (n = 6–10). *P < 0.05 versus control; ^# P < 0.05 soy versus fish.

Figure 3

Hypothalamic protein levels of TLR2, TLR4, MyD88, TRAF-6, NFκBp50, and NFκBp65 of rats fed with control (n = 5–8), soy (n = 5–8), or fish diet (n = 5–8). *P < 0.05 versus control; ^# P < 0.05 soy versus fish.

Figure 4

Liver and muscle protein levels of TNF-α, IL-6, and IL-10 of rats fed with control (n = 5), soy (n = 4), or fish diet (n = 4). *P < 0.05 versus control; ^# P < 0.05 soy versus fish.