Thinned young apple polysaccharide improves hepatic metabolic disorder in high-fat diet-induced obese mice by activating mitochondrial respiratory functions

Apple polysaccharides have been previously demonstrated to have beneficial effects on hepatic metabolic functions. Approximately 1.9 million tons of young apples are thinned and abandoned annually in China, and whether the polysaccharide derived from these thinned young apples has metabolic benefits lacks evidence. Thinned young apple polysaccharide (TYAP) has been investigated in high fat diet (HFD)-induced obese mice for its effect on metabolic disorder. Water-soluble TYAP was isolated from thinned young apples and chemically characterized. TYAP administration at dosages of 400 mg/kg/day and 800 mg/kg/day significantly rescued HFD-induced hepatic metabolic impairment, reduced body weight gain, and ameliorated hepatic oxidative stress induced by HFD. In a palmitate-loaded HepG2 cell model, TYAP protected the cells from palmitate-induced insulin resistance and viability loss, suppressed mitochondrial ROS and improved the mitochondrial respiratory function impaired by palmitate. These findings suggest that TYAP could successfully attenuate obesity-associated hepatic metabolic disorder possibly by activating the hepatic mitochondrial respiratory function.