Caracterização e estabilidade dos óleos de coco, linhaça, baru e soja, e seu efeito metabólico em camundongos swiss

Abstract

The Western dietary pattern is characterized by a predominance of polyunsaturated fatty acids (PUFA) omega-6 and saturated fats, and deficient in omega-3 and other unsaturated fats. Pattern that has been associated with increased visceral fat and inflammatory process; in addition, the stability and nutritional quality of lipid sources must be considered. Thus, the aim of this study was to characterize coconut, linseed and baru oils, and a control, soybean oil, as to its impact on metabolic parameters of Swiss mice, and also its quality and stability. All oils were evaluated for identity, optical behavior, thermal and oxidative stability, as well as lipid quality, while the in vivo experiment took place with Swiss mice (Mus musculus), randomly assigned to three experimental groups (coconut oil group - CG; linseed oil - LG; baru oil - BG) and the control group with soybean oil - SG, varying only the lipid source in experimental diets, with 7% of lipids according to the standardized diet; animals were followed and weighed weekly. At the end of 60 days, the animals were anesthetized and euthanized by exsanguination. The body fat sites were removed and weighed. In the collected serum, the total lipid profile (total cholesterol and fractions) and fasting glucose were performed; a model of peritonitis was performed to quantify the leukocyte infiltrate of each group, body weight, fat sites (epididymal, mesenteric, peritoneal, perirenal and omental) with respective adiposity index (AI), and liver weight, as well as analysis histological liver of animals. Regarding the thermal and oxidative behavior, oils rich in PUFA (Soybean, Linseed and Baru oils) showed lower oxidative stability (induction periods of 1.7h, 1.0h and 0.9h, respectively, compared to 39.8h for Coconut oil), even in Soybean and Linseed oils presenting tocopherols (emission bands between 300 and 400nm) and carotenoids (bands between 500 and 600nm, and quantified at 15.13 and 24.37mcg/g, respectively). In animals, GB and GC had lower AI (p<0.0001), however, lower HDL values (p<0.05). While GL significantly (p<0.05) increased HDL levels and reduced LDL and tryglicerides values. For histological analysis, GS (p<0.05) had more microvesicular lesions. In addition, the GL showed lower leukocyte recruitment (p<0.01), as well as in the CG (p<0.0001), indicating a possible anti-inflammatory effect. A diet rich in PUFA n-6 (GS) showed worsed histological lesions and visceral fat parameters, while GL, a source of alpha-linolenic acid, was shown to have a cardioprotective action, and GC, a source of lauric acid, reduced adiposity and lower leukocyte recruitment. Therefore, new future studies are suggested with the combination of alpha-linolenic acid and lauric acid sources, which could play an anti-inflammatory and cardiovascular protection role.