Differential Effects of High-Fish Oil and High-Lard Diets on Cells and Cytokines Involved in the Inflammatory Process in Rat Insulin-Sensitive Tissues

Abstract

Dietary fat sources may differentially affect the development of inflammation in insulin-sensitive tissues during chronic overfeeding. Considering the anti-inflammatory properties of ω-3 fatty acids, this study aimed to compare the effects of chronic high-fish oil and high-lard diets on obesity-related inflammation by evaluating serum and tissue adipokine levels and histological features in insulin-sensitive tissues (white adipose tissue, skeletal muscle and liver). As expected, a high-lard diet induced systemic and peripheral inflammation and insulin resistance. Conversely, compared with a high-lard diet, a high-fish oil diet resulted in a lower degree of systemic inflammation and insulin resistance that were associated with a lower adipocyte diameter as well as lower immunoreactivity for transforming growth factor β 1 (TGFβ1) in white adipose tissue. A high-fish oil diet also resulted in a lower ectopic lipid depot, inflammation degree and insulin resistance in the skeletal muscle and liver. Moreover, a high-fish oil diet attenuated hepatic stellate cell activation and fibrogenesis in the liver, as indicated by the smooth muscle α-actin (α-SMA) and TGFβ1 levels. The replacement of lard (saturated fatty acids) with fish oil (ω-3 fatty acids) in chronic high-fat feeding attenuated the development of systemic and tissue inflammation.

A high-fish-oil diet prevents adiposity and modulates white adipose tissue inflammation pathways in mice

“…On the opposite way, rats fed with a high-fish-oil diet present smaller adipocyte diameters compared with high-fat (lard)-fed animals [41]. Feeding rats with a 1:1 EPA/DHA ratio ameliorates adipocyte hypertrophy, and this benefit is associated with diminished macrophage infiltration and, consequently, diminished inflammation [42], as observed in the current study.…”

Sunflower Oil but Not Fish Oil Resembles Positive Effects of Virgin Olive Oil on Aged Pancreas after Life-Long Coenzyme Q Addition

“…The higher degree of inflammation and fibrosis in pancreas found in animals fed on FO seems contradictory with those from animal studies where n-3 fatty acid-rich diets shows anti-inflammatory effects, although pancreas was not directly studied [ 66 , 67 , 68 , 69 ]. However, other studies have also indicated an absence of such effects [ 70 ] or even pro-oxidant and pro-inflammatory effects for these types of fatty acids [ 71 , 72 ]; in addition, it has also been observed that some treatment based on them can decrease lifespan [ 73 , 74 , 75 , 76 ]. So, the amount, the animal model, age or treatment time seem to be important factors affecting n-3 fatty acid effects that need to be explored in more detail.…”

Skeletal Muscle Mitochondrial Bioenergetics and Morphology in High Fat Diet Induced Obesity and Insulin Resistance: Focus on Dietary Fat Source

“…On the other hand, unsaturated FA prevent c-Src membrane partitioning and activation and block JNK activation with consequent beneficial effects on insulin sensitivity (Holzer et al, 2011 ). Considering the anti-inflammatory properties of ω-3 PUFAs, in a recent study, we compared the effects of chronic high-fish oil and high-lard diets on obesity-related inflammation by evaluating serum and tissue adipokine levels and histological features in insulin-sensitive tissues (white adipose tissue, liver and skeletal muscle) (Lionetti et al, 2014b ). We showed that the replacement of lard (saturated FA) with fish oil (ω-3 PUFAs) in chronic high-fat feeding attenuated the development of systemic and tissue inflammation.…”

“…We showed that the replacement of lard (saturated FA) with fish oil (ω-3 PUFAs) in chronic high-fat feeding attenuated the development of systemic and tissue inflammation. Indeed, compared with a high-lard diet, a high-fish oil diet resulted in a lower degree of systemic inflammation and IR that were associated with a lower ectopic lipid depot, inflammation degree and IR in the skeletal muscle (Lionetti et al, 2014b ). In a further study on the same experimental design, we confirmed that the replacement of lard with fish oil in HF diet had preventive effects on obesity and systemic inflammation and IR development as well as we showed a fusion mitochondrial phenotype in association with the improvement of IR in skeletal muscle (Lionetti et al, 2013 ).…”