Chitooligosaccharide-epigallocatechin gallate conjugate ameliorates lipid accumulation and promotes browning of white adipose tissue in high fat diet fed rats

Abstract

The prevalence of obesity has increased progressively worldwide. Obesity is characterized by excessive accumulation of fat in adipose tissues, leading to metabolic impairment. The anti-obese effects of chitooligosaccharide (COS) and epigallocatechin-3-gallate (EGCG) have been extensively clarified. This study aimed to investigate the effects and potential mechanisms of the COS-EGCG conjugate (CE) on anti-obesity, specifically by alleviating lipid accumulation and promoting the browning of white adipose tissue (WAT) in obese rats. Obesity as a consequence of a high-fat diet (HFD) was induced in male Wistar rats. The HFD was given for 16 weeks and the rats were then randomly subdivided into five groups namely: vehicle (control group), HFD plus CE at 150 mg/kg/day, HFD plus CE at 600 mg/kg/day, HFD plus COS at 600 mg/kg/day, and HFD plus atorvastatin at 10 mg/kg/day for 4 weeks. CE could reduce body weight, improve serum lipid profiles, and promote lipid metabolism via activation of AMP-activated protein kinase (AMPK) in WAT and enhance the processes of WAT browning by activating sirtuin 1 (Sirt 1), peroxisome proliferator-activated receptor-gamma coactivator (PGC1-α), and uncoupling the protein 1 (UCP1) signaling pathway. CE reduced obesity and promoted WAT browning in HFD-fed rats. Therefore, CE might be a new therapy for metabolic syndrome and obesity.