Influência da semente de linhaça nos fatores que contribuem para a síndrome metabólica em ratos Wistar

Abstract

Metabolic syndrome is a condition consisting of serious cardiovascular risk factors, including abdominal obesity, dyslipidemia, hypertension, glucose intolerance and decreased high density lipoprotein (HDL) levels. The diagnosis varies according to different protocols, which is controversial. Flaxseed is a source of omega 3, fiber and lignans, substances that influence the lipid profile, glucose homeostasis, the inflammatory process of obesity, and fat deposition. Our study aims to establish the influence of this seed on growth, biochemical parameters, and fat deposition of healthy female Wistar rats. Pregnant Wistar rats from the Laboratory of Experimental Nutrition/Universidade Federal Fluminense (LabNE/UFF), kept in cages with controlled temperature (21 to 23° C) and under dark/light cycle (12/12), receiving water and food ad libitum, were used. After delivery, the rats were divided into two groups: a Control Group (CG), fed on a diet based on casein, and a Linseed Group (GL), fed on a diet based on casein suplemented with 25% flaxseed. These diets were given to mothers during the lactation period. At weaning, 12 female pups from each group continued to receive these rations until they reached 200 days of life, when they were killed for blood collection through cardiac puncture and removal of visceral fat mass. Lipid profiles were analysed by means of BIOCLIN kits (Indústria Quibasa- Química Básica LTDA/Belo Horizonte-MG) Blood glucose was measured with an automatic meter (ACCU CHECK-Active, Roche®), through a glucose-oxidase reaction. Hormone levels determinations were done with commercial kits specific for each hormone. Statistical analysis was performed with the software S-Plus 6.0 for Windows. All p values under 0,05 were considered statistically significant. All data were submitted to the Kolmogorov-Smirnov test, to confirm if they had a normal distribution. The Student t-test was applied for those with a normal distribution, and the Wilcoxon rank sum test for all others. We observed lower values in food intake (p = 0.032) and final body weight (p = 0.001) in the GL. There was a reduction in total cholesterol (p<0.001), VLDL (p = 0.020), triglycerides (p = 0.01), and glucose (p = 0.001) levels in the group supplemented with flaxseed. There were no differences in HDL and in visceral fat mass between the experimental groups. Serum insulin, adiponectin and interleukin-6 did not undergo significant changes. According to these results, dietary supplementation with flaxseed reduces cardiovascular risk by improving lipid profile, and prevents the development of obesity.