Vitamin E Reduces Adipose Tissue Fibrosis, Inflammation, and Oxidative Stress and Improves Metabolic Profile in Obesity

Abstract

Objective: To test whether enhancing the capability of adipose tissue to store lipids using antioxidant supplementation may prevent the lipotoxic effects and improve the metabolic profile of long-term obesity. Methods: C57BL/6J mice were randomized into three experimental groups for 28 weeks: control group (n510) fed chow diet (10% kcal from fat), obese group (O, n512) fed high-fat (HF) diet (45% kcal from fat), and obese group fed HF diet and supplemented twice a week with 150 mg of a-tocopherol (vitamin E) by oral gavage (OE, n512). Results: HF diet resulted in an obese phenotype with a marked insulin resistance, hypertriglyceridemia, and hepatic steatosis in O mice. Histological analysis of obese visceral adipose tissue (VAT) revealed smaller adipocytes surrounded by a fibrotic extracellular matrix and an increased macrophage infiltration, with the consequent release of proinflammatory cytokines. Vitamin E supplementation decreased oxidative stress and reduced collagen deposition in the VAT of OE mice, allowing a further expansion of the adipocytes and increasing the storage capability. As a result, circulating cytokines were reduced and hepatic steasosis, hypertriglyceridemia, and insulin sensitivity were improved. Conclusions: Our results suggest that oxidative stress is implicated in extracellular matrix remodeling and may play an important role in metabolic regulation.