Coix seed is recognized as a functional medicinal food due to its valuable biological activities, with polysaccharides being the primary active compounds. In this study, an ultrasonic-assisted enzymatic extraction technique was employed, and response surface methodology was used to optimize the yield of polysaccharides to 9.55 ± 0.26%. A novel neutral polysaccharide, CSPsN-1, was purified with a molecular weight of 7.75 kDa. CSPsN-1 was composed of arabinose, galactose, glucose, xylose, and mannose in molar ratios of 0.48: 7.92: 86.39: 2.42: 2.79. Its backbone composed of →4)-α-D-Glcp-(1→ and →3,4)-α-D-Glcp-(1→ units, with terminal residues of α-D-Glcp. In vitro experiments, CSPsN-1 enhanced glucose consumption in insulin-resistant HepG2 cells and upregulated GLUT4 expression by activating the PI3K/AKT signaling pathway. These findings suggest that CSPsN-1 holds significant promise as a functional ingredient for treating insulin resistance and related metabolic disorders.
Keywords: PI3K/AKT signaling pathway; anti‐insulin resistance effect; coix seed; polysaccharides; structural characteristics.
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