Differential modulation of biomarkers of Metabolic Syndrome (MetS) in C57BL/6J mice by isomers of tocopherol

Abstract

Antioxidant activities of tocopherols are well documented. However, it has become evident they also exhibit other biologic activities. We investigated the effects of alpha (α) and gamma (γ) tocopherol on biomarkers of MetS in mice including, adipocyte peroxisome proliferator activated receptor (PPAR‐γ), uncoupling protein (UCP), fatty acid binding protein 4 (fabp4), CD36, hepatic PPAR α, and acyl CoA oxidase (ACO) expressions. C57BL/6J mice (n=75) were divided into 5 groups and placed on five different dietary regimens as follows. Groups 1 and 5 (control): low‐fat (LF) and high‐fat (HF) diets for 25 weeks, respectively; groups 2–4: HF diet for 15 weeks followed by 10 weeks on HF supplemented with αT, γT, αT + γT, respectively. Animals were sacrificed at the end of 25 weeks. α‐T and αT + γT significantly reduced weight gain and improved insulin sensitivity indices. Protein and mRNA expressions of adipocyte PPAR‐γ, UCP, fabp 4, CD36, hepatic PPAR α, and ACO were significantly increased with α‐T and αT + γT but not γT alone. ACO and fatty acid synthetase expressions in treatment groups were not different from HF controls. αT alone and in combination with γT led to modulation of biomarkers of MetS in mice. The study for the first time demonstrates the ability of αT to function as dual PPAR agonist in modulating biomarkers of MetS in vivo.Supported by grants from Texas Department of Agriculture, Human Nutrition Fund