1H-NMR METABOLOMIC APPROACH REVEALS THAT CONJUGATED LINOLEIC ACID SUPPLEMENTATION IMPROVES THE LIVER METABOLOME PROFILE IN RATS WITH METABOLIC SYNDROME

Introduction:  Metabolic syndrome (MS) is a combination of metabolic and medical disorders such as obesity, elevated fasting glucose, hypertension and dyslipidemia. Conjugated linoleic acid (CLA) has been reported to have beneficial effects on atherosclerosis and insulin resistance, as well as in obesity, all of them related to MS. The metabolome is directly related to the phenotype and NMR-based metabolomics is a potent approach to study the metabolic profile in the liver. Aim:  The aim of this study was to determine the effect of a chronic administration of CLA in the liver metabolome of rats with MS. Materials and Methods:  Five-week-old male Wistar rats (n=16) were divided into three groups. The first one was fed a normal standard diet (STD), the second one - a cafeteria diet (CAF) for 10 weeks and the third was fed a CAF for 10 weeks and treated with CLA (100mg/Kg) the last 3 weeks. Animals were sacrificed by decapitation and livers were stored at -80 o C. Aqueous and lipid extracts from each liver were analysed by 1H-NMR spectrometry. Results:  The results showed different metabolic profiles in the three groups. CLA reverted the increase of lactate, alanine and glucose levels induced by the CAF diet. However, betaine and methionine levels remained low in CAF and CAF+CLA groups. CLA decreased diglyceride levels, while triglyceride levels remained as those of CAF group. Besides, esterified cholesterol levels were increased in the liver of CAF+CLA rats. Conclusion:  CLA supplementation is able to modify significantly the liver metabolic profile of rats with MS. CLA could improve the insulin resistance associated with MS by decreasing diglyceride levels in the liver because diglycerides repress insulin receptor activity through protein kinase C e (PKC e ). Acknowledgements :  This research was supported by the grant AGL2013-40707-R (AEI/FEDER, UE) from the Spanish Government