Effect of dietary fat saturation on lipid metabolism, arachidonic acid turnover and peritoneal macrophage oxidative stress in mice

Abstract

We investigated the effects of a saturated fat diet on lipid metabolism and arachidonic acid (AA) turnover in mouse resident peritoneal macrophages. The pro-oxidative effect of this diet was also studied. Female C57BL/6 mice were weaned at 21 days of age and assigned to either the experimental diet containing coconut oil (COCO diet), or the control diet containing soybean oil as fat source (10 mice per group). The fat content of each diet was 15% (w/w). Mice were fed for 6 weeks and then sacrificed. The concentration of total lipids, triglycerides, (LDL + VLDL)-cholesterol, thiobarbituric acid-reactive substances (TBARS) and reduced glutathione were increased in the plasma of mice fed the COCO diet, without changes in phospholipid or total cholesterol concentrations compared to control. The concentrations of total cholesterol, free and esterified cholesterol, triglycerides, and TBARS were increased in the macrophages of COCO-fed mice, while the content of total phospholipids did not change. The phospholipid composition showed an increase of phosphatidylcholine and a decrease of phosphatidylethanolamine. The [ 3 H]-AA distribution in the phospholipid classes showed an increase in phosphatidylcholine and phosphatidylethanolamine. Incorporation of [ 3 H]-cholesterol into the macrophages of COCO-fed mice and into the cholesterol ester fraction was increased. The COCO diet did not affect [ 3 H]-AA uptake but induced an increase in [ 3 H]-AA release. The COCO diet also enhanced AA mobilization induced by lipopolysaccharide. These results indicate that the COCO diet, high in saturated fatty acids, alters the lipid metabolism and AA turnover of peritoneal macrophages in female mice and also produces a significant degree of oxidative stress.

Dietary Fats and the Risk of Oxidative Stress in a Group of Apparently Healthy Women – a Short Report

“…In animal studies, saturated fat feeding caused symptoms of oxidative stress [Oliveros et al, 2004;Diniz et al, 2004], while in humans, reduction of the saturated fat intake was associated with a diminished LDL susceptibility to oxidation [Yu-Poth et al, 2000], and a saturated fat replacement for the monounsaturated or polyunsaturated fat lowered plasma cholesterol, LDL-cholesterol and HDL--cholesterol [Hodson et al, 2001].…”

Membrane Fatty Acids, Oxidative Burst and Phagocytosis after Enrichment of P388D1 Monocyte/Macrophages with Essential 18-Carbon Fatty Acids

“…If so, this action must occur through an antioxidant mechanism that is independent of ␣ -tocopherol. Another explanation is that a low cellular PUFA content, such as occurs when the medium is not supplemented with high concentrations of PUFA, results in increased oxidative stress as reported following the feeding of a low PUFA diet to mice [44] . A third explanation is that PUFA may prevent the efficient assembly of NADPH oxidase because of changes in membrane composition, fluidity or organization.…”

Antioxidant potential of barley extract in rats subjected to a high-fat diet

“…Sources of saturated and unsaturated fats induce oxidative stress in rat liver (MARCZUK-KRYNICKA et al, 2009), as found by Oliveros et al (2004), when increasing the levels of TBARS tissues of rats fed a diet rich in saturated fat. In the present study, it was observed an increase in the levels of MDA (also determined by TBARS) in the liver of rats fed a diet rich in fat pork.…”