Potential effect of functional milk fat, naturally enriched in conjugated linoleic acid, on the prevention of liver lipid accumulation and some biochemical mechanisms involved in the liver triacylglycerol regulation in high-fat fed rats.

Conjugated linoleic acid (CLA) might regulate the lipid depots in liver and adipose tissue. As there is an association between maternal nutrition, fat depots and risk of offspring chronic disease, the aim was to investigate the effect of maternal CLA consumption on TAG regulation and some inflammatory parameters in adult male rat offspring receiving or not receiving CLA. Female Wistar rats were fed control (C) or CLA-supplemented (1 %, w/w) diets during 4 weeks before and throughout pregnancy and lactation. After weaning, male offspring of CLA rats were fed C or CLA diets (CLA/C and CLA/CLA groups, respectively), whereas C male rat offspring were fed a C diet (C/C group) for 9 weeks. Serum TAG levels were increased in the CLA/CLA and CLA/C groups, associated with a reduction of lipoprotein lipase activity and weights of adipose tissue. The liver TAG levels were decreased in the CLA/CLA group, related to a significant reduction of fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC) and glucose-6-phosphate dehydrogenase enzyme activities, as well as to the mRNA levels of FAS, ACC, stearoyl-CoA desaturase-1 and sterol regulatory element-binding protein-1c. Even though normal TAG levels were found in the liver of CLA/C rats, a reduction of lipogenesis was also observed. Thus, these results demonstrated a programming effect of CLA on the lipid metabolic pathways leading to a preventive effect on the TAG accretion in adipose tissue and the liver of male rat offspring. This knowledge could be important to develop some dietary strategies leading to a reduced incidence of obesity and fatty acid liver disease in humans.

Resumen Introducción: Las enfermedades cardiovasculares (ECV) causan el 25% de las muertes en el mundo. En América, Argentina ocupa el cuarto lugar. Factores como sedentarismo, tabaquismo, hábitos alimentarios y predisposición genética, serían responsables. El objetivo fue estimar la prevalencia de factores de riesgo (FR) de ECV en estudiantes de Nutrición.Material y métodos: Se realizó un estudio descriptivo-transversal, en 185 estudiantes, entre 19-30 años. Se midieron peso, talla y circunferencia de cintura (CC). Se interrogó sobre antecedentes familiares de enfermedades crónicas no transmisibles (ECNT), tabaquismo, alcohol y actividad física (AF). Se cuantificó colesterol total (CT), HDL-colesterol (HDL-c), LDL-colesterol (LDL-c), triglicéridos (TG), glucosa, índice de Castelli (IC) y la relación TG/HDL-col. Los datos se analizaron estadísticamente con el programa Minitab 16.Resultados: En la población estudiada (21,9 ± 2,9 años) se halló un 75,7% de antecedentes de ECNT. El 8,1% fumaba, el 56,2% tomaba bebidas alcohólicas y la mitad no realizaba AF. El índice de masa corporal mostró 10,3% de sobrepeso y 2,2% de obesidad, y el riesgo cardiovascular según CC fue 9,7%. El parámetro más alterado fue LDL-c (48,1%). El 21,1% presentó hipercolesterolemia y el 22,2%, HDL-col disminuido. El IC fue 3,43 ± 0,96, cuando se evaluó la cifra de riesgo, el 33,3% de los varones y el 18,8% de las mujeres, la superaba. El 11,4% tuvo TG/HDL-col elevado. Hubo asociación entre CC-TG y CC-TG/HDL-col.Conclusiones: Como la mayoría de los FR cardiovascular son modificables, se sugiere establecer programas de educación alimentaria nutricional y promoción de estilos de vida saludable.

Maternal nutritional programming by a high-fat (HF) diet is related to hepatic lipid accumulation and steatosis in offspring. Conjugated linoleic acid (CLA) might ameliorate impaired hepatic lipid homoeostasis; therefore, the aim was to investigate the potential preventive effect of maternal CLA consumption on TAG metabolism alterations induced by HF diets in adult male rat offspring receiving or not receiving CLA. Female Wistar rats were fed a control (C) diet, HF diet or HF diet supplemented with CLA (HF+CLA) for 4 weeks before mating and throughout pregnancy and lactation. After weaning, for 9 weeks, male offspring of C or HF rats continued with the same diets as their mothers (C/C or HF/HF groups, respectively) and male offspring of HF+CLA rats were fed HF or HF+CLA diets (HF+CLA/HF or HF+CLA/HF+CLA groups, respectively). Nutritional parameters, serum and liver TAG levels, the TAG secretion rate (TAG-SR) and the activities as well as gene expression of key hepatic enzymes involved in TAG regulation were assessed. The most interesting results were that maternal CLA decreased epididymal white adipose tissue weight and prevented serum and liver TAG accumulation induced by a HF diet in adult male offspring receiving or not receiving CLA. The prevention of liver steatosis in HF+CLA/HF+CLA and HF+CLA/HF offspring was associated with an increased hepatic TAG-SR. Overall, this study provides evidence that maternal CLA consumption programmes TAG regulation and in this way contributes to lowering lipid levels in tissues and preventing liver steatosis in particular.