Immunomodulatory\nAcidic Polysaccharide from Jujube\nFruit (Zizyphus jujuba Mill.): Insight\ninto Their Chemical Characteristics and Modes of Action

Jujube (Zizyphus jujuba Mill.) has\nbeen consumed globally as a fruit and a nutraceutical food for millennia.\nThis study presents the isolation and purification of a novel water-soluble\npolysaccharide fraction, ZJMP-2, from Z. jujuba Mill. ZJMP-2 underwent characterization through Fourier transform\ninfrared (FT-IR), high-performance gel permeation chromatography-laser\nlight scattering (HPGPC-LLS), gas chromatography-mass spectrometry\n(GC-MS), scanning electron microscopy (SEM), atomic force microscopy\n(AFM), and nuclear magnetic resonance (NMR) analyses. It consists\nof glucose, galactose, arabinose, rhamnose, and galacturonic acid\nin molar ratios of 0.41:0.08:0.11:0.05:0.33 and boasts an average\nmolecular weight of approximately 57.8 kDa. Its backbone features\nthe structure →2)-α-l-Rha<i>p</i>-(1\n→ 4)-α-d-Gal<i>p</i>A-(1 →\n4)-α-d-Gal<i>p</i>A-6OMe-(1 → 4)-α-d-Gal<i>p</i>A-(1 → 3, 4)-α-d-Glc<i>p</i>-(1 →, with branching at →5)-α-l-Ara<i>f</i>-(1 →, →4)-β-d-Gal<i>p</i>-(1 →, and →4)-α-d-Glc<i>p</i>-(1→ at position O-3 of →3,\n4)-α-d-Glc<i>p</i>-(1 →. These structural\nvariations contribute to the pronounced immunoregulatory effects of\nZJMP-2. Specifically, ZJMP-2 significantly elevated the expression\nlevels of TLR4, NF-κB, and TRAF6 proteins, enhancing RAW264.7\ncell activity, index of splenic lymphocytes, and the production of\ncytokines and NO, thereby activating macrophages and promoting lymphocyte\nproliferation. <i>In vivo</i> studies demonstrated that\nZJMP-2 promoted the heart, spleen, and bone marrow indices, peripheral\nblood and spleen cell counts, and the number of heart and bone marrow\ncells in mice. These findings demonstrated that ZJMP-2 has potential\nas an immunomodulator and provides valuable insights for developing\nnatural immunomodulators in the pharmaceutical industry.