Preventive effects of jujube polysaccharides on fructose-induced insulin resistance and dyslipidemia in mice
High fructose intake is associated with adverse metabolic syndromes. This study was designed to investigate whether the polysaccharides derived from Zizyphus jujube cv. Shaanbeitanzao (ZSP) could alleviate high fructose-induced insulin resistance and dyslipidemia in mice. ZSP was identified by capillary zone electrophoresis as an acidic heteropolysaccharide with L-arabinose, D-galactose and D-galacturonic acid being the main component monosaccharides. Mice were provided with 20% high-fructose water and ZSP was administered intragastrically at doses of 0, 200 or 400 mg kg−1 BW for 4 weeks. Fructose-treated mice showed hyperglycemia, hyperinsulinemia and dyslipidemia with impaired insulin sensitivity (p < 0.05). Administration of ZSP at a dose of 400 mg kg−1 BW significantly reduced the serum levels of glucose, insulin, TC, TG, LDL-C, and VLDL-C (p < 0.01). ZSP also markedly improved the HDL-C level, homeostasis model assessment for insulin resistance (HOMA-IR) and β-cell function (HOMA-β), and decreased the atherogenic index (AI) of the mice exposed to high-fructose water. Histopathological test with H&E and oil red O staining confirmed liver steatosis induced by a high-fructose diet and the hepatoprotective effect of ZSP. These findings indicate that the jujube polysaccharides may ameliorate insulin resistance and dyslipidemia in fructose-treated mice.