Purification and structural characterization of a polysaccharide from jujube for alleviating anemia of inflammation

• A new neutral polysaccharide (JP0-a) was extracted and purified from jujube • JP0-a was proved to be a glucan with a high molecular weight of 1.98☓10 6 Da • JP0-a was composed of 7 type of glycosidic bonds, of which →3)-glcp-(1→ dominates • JP0-a could alleviate anemia of inflammation via targeting IL-6/STAT3/Hepcidin axis in vitro and in vivo Jujube is a popular daily food, its abundant chemical composition endows it with good biological activities, positioning it as a promising future dietary supplement candidate. In China, jujube is often used for anemia prevention. However, the specific component in jujube and its mechanisms in preventing anemia of inflammation (AI) have not been clarified. In this study, a neutral polysaccharide (JP0-a) was isolated and purified from jujube . Structural characteristics, physicochemical properties and its potential effect on AI were explored. Structure characteristics results showed that JP0-a was a new neutral polysaccharide composed solely of glucose and mainly linked via →3)-Glcp-(1→, the molecular weight of JP0-a was 1.98×10 6 Da. Thermogravimetric analysis and X-ray diffraction demonstrated its amorphous structure with an eminent thermal stability. Scanning electron microscopy and atomic force microscope further disclosed its densely packed lamellar architecture which proving its good physical and chemical properties. In LPS-induced inflammatory HepG2 cells, JP0-a could down-regulate the expression of hepcidin, the master regulator of iron homeostasis in AI, mainly by reducing the level of IL-6 and inhibiting the phosphorylation of STAT3. In AI mice, JP0-a could alleviate the symptoms of mice, specifically manifested in increasing the hemoglobin concentration and the red blood cells number, decreasing the number of white blood cells, improving the iron deposition in spleen and liver, increasing the serum iron concentration, and decreasing the concentration of hepcidin and IL-6 in serum. These results showed that JP0-a could alleviate AI via targeting IL-6/STAT3/Hepcidin axis. Our study is the first to explore the polysaccharide of jujube in alleviating AI and elucidate its mechanism. In addition, this study established a foundation for the exploitation of functional foods of jujube polysaccharide in relieving AI.