Ecdysterone Enhances Muscle Insulin Signaling by Modulating Acylcarnitine Profile and Mitochondrial Oxidative Phosphorylation Complexes in Mice Fed a High-Fat Diet

RESULTS—At the end of the study, there were no differences in body weight, food intake, and energy expenditure between HFD groups with or without a diet supplemented with Ecdy L, except body weight was significantly lower in the Ecdy H group than in the HFD group (P , 0.05). Plasma glucose, insulin levels, and values of the homeostasis model assessment of insulin resistance in the Ecdy H group were significantly lower than in the HFD group (P , 0.01). Insulin-stimulated phosphorylation of insulin receptor substrate 1 and Akt1 in muscle was significantly increased in the Ecdy H group (P , 0.001) relative to the HFD group (P , 0.01). Moreover, muscle fatty acylcarnitine profile showed the HFD significantly increased muscle lipid contents compared with a low-fat diet (P , 0.01) but reduced OxPhos complex abundance. Ecdy reversed the effects of HFD-induced lipid accumulation by significantly increasing the abundance of mitochondrial OxPhos complex protein in muscle.