High ratio of ω-3/ω-6 polyunsaturated fatty acids targets mTORC1 to prevent high-fat diet-induced metabolic syndrome and mitochondrial dysfunction in mice

Adjusting omega-3/omega-6 polyunsaturated fatty acids (PUFAs) ratio in high-fat diet is one potential mean to improve metabolic syndrome; however, underlying mechanisms remain unclear. Four groups of mice were fed 60% kcal diets with saturated fatty acids, three different omega-3/omega-6 PUFAs ratios (low, middle and high) for 12 weeks, respectively. Body weight, atherosclerosis marker, insulin signal index and level of lipid accumulation in liver were significantly lowered in High group compared with saturated fatty acids group and Low group at week 12. Expressions of p-mTOR and raptor were inhibited by high omega-3 PUFAs. Importantly, omega-3 PUFAs intake up-regulated mitochondrial electron transport chain and tricarboxylic acid cycle pathway through metabolomics analysis in liver. Mitochondrial complexes activities were raised, fumaric acid was reduced and oxidative stress was alleviated in High group. We conclude that consuming long-term high-fat diet with same calories but high omega-3/omega-6 PUFAs ratio relieves metabolic syndrome by regulating mTORC1 pathway to enhance mitochondrial function. (C) 2020 Elsevier Inc. All rights reserved.