Natural Polyphenols from Euterpe oleracea Seed (açaí) Extract Prevent Brown Adipose Tissue Dysfunction and Metabolic Alterations Induced by High-Fat Diet in C57Bl/6 Mice

Abstract

Brown adipose tissue (BAT) plays a key role in energy expenditure and is increasingly recognized as a potential target in obesity treatment. BAT dysfunction is characterized by compromised mitochondrial biogenesis and thermogenesis, as well as oxidative stress and inflammation. This study evaluated whether polyphenol-rich açaí seed extract (ASE) could prevent BAT dysfunction in C57BL/6 mice fed a high-fat (HF) diet. Male C57BL/6 mice were divided into three groups: control (10% lipid diet), HF (60% lipid diet), and HF+ASE (60% lipid diet + 300 mg/kg/day) for 12 weeks. ASE showed promising effects in preventing body mass gain, visceral adiposity, hyperglycemia, and dyslipidemia without affecting energy intake. In BAT, ASE preserved the typical multilocular morphology and prevented whitening. ASE restored the expression of thermogenic markers (UCP-1, β 3 -AR) and lipolytic enzymes (ATGL, HSL, PLIN-1), as well as PPAR α and mitochondrial biogenesis markers (PGC-1 α , NRF1, and TFAM). Furthermore, ASE treatment reduced oxidative damage by decreasing malondialdehyde (MDA) levels and 8-isoprostane immunostaining and increased antioxidant defense through increased superoxide dismutase (SOD) activity. It also attenuated BAT inflammation by lowering MCP-1 and TNF- α expression. These results suggest that ASE mitigates obesity-induced BAT structural changes and dysfunction through its antioxidant, anti-inflammatory, and beneficial metabolic actions. These beneficial effects of ASE in BAT may represent a new target in preventing obesity.