d-Xylose suppresses adipogenesis and regulates lipid metabolism genes in high-fat diet–induced obese mice

d-Xylose, a natural pentose, has been reported to reduce postprandial glucose levels, although its effect on lipid metabolism has not been investigated. Therefore, this study hypothesized that d-xylose, as an alternative sweetener, suppresses adipogenesis and lipid metabolism by regulating blood lipid profiles, blood glucose levels, and related gene expression in high-fat diet (HFD)–induced obese mice. Mice were fed a normal diet, a 60% HFD diet, or an HFD with 5% or 10% of the total sucrose content supplemented with d-xylose (Xylo 5 and Xylo 10 diets, respectively). Weight gain, food intake, and serum lipid levels for each group were measured. After 12 weeks, histopathology of liver sections and assays of gene expression related to adipogenesis and lipid metabolism in visceral fat and liver tissues were analyzed. Body weight gain; fasting blood glucose levels; weights of subcutaneous and visceral adipose tissues; and serum biochemical markers, including total cholesterol and low-density lipoprotein cholesterol, low-/high-density lipoprotein, and total cholesterol/high-density lipoprotein, were significantly lowered in the Xylo 5 and Xylo 10 groups. In addition, d-xylose supplementation resulted in the down-regulation of adipogenesis-related genes, including sterol regulatory element-binding protein 1C, fatty acid synthase, adipocyte protein 2, and CCAAT/enhancer-binding protein α in visceral adipose tissues. Histopathologically, Xylo 5 and Xylo 10 supplementation reduced HFD-induced fat accumulation in the liver and decreased expressions of fatty acid synthase and peroxisome proliferator-activated receptor γ. d-Xylose supplementation also enhanced lipid oxidation by increasing expressions of carnitine palmitoyltransferase 1A; cytochrome P450, family 4, subfamily a, polypeptide 10; and acyl-CoA oxidase. In conclusion, our finding suggests that d-xylose may help prevent or attenuate the progression of obesity-related metabolic disorders by alleviating adipogenesis and dyslipidemia and improving lipid oxidation.