Isolation, purification, structural characterization, and hypoglycemic activity assessment of polysaccharides from Hovenia dulcis (Guai Zao).

Hovenia dulcis polysaccharides (HDPs) have a variety of important biological activities associated with potential applications in food engineering, pharmacy science, and health care. Herein, we isolated and purified polysaccharides from H. dulcis. Chemical composition analysis revealed that the purified polysaccharides (HDPs-2A) were composed of different molar ratios of mannose, Rha, GalA, GlcA, Glc, Gal, and Ara and had a molecular weight of 372.91 kDa. The structure of HDPs-2A was assessed by FT-IR, periodate oxidation, Smith degradation, methylation analysis, and NMR, allowing us to determine that the backbone of HDPs-2A is composed primarily of →5)-α-L-Araf-(1→, →5)-α-L-Araf-(1→, →3,5)-α-L-Araf-(1→, →6)-β-D-Galp-(1→, →3,6)-β-D-Galp-(1→, T-β-D-Galp, →3)-β-D-Galp-(1→, and T-α-D-Glcp. The results of atomic force microscopy (AFM) showed that HDPs-2A present an irregular polymer particle morphology in water. X-ray diffraction (XRD) results showed that HDPs-2A have a single crystal structure. Finally, we demonstrated that HDPs-2A have a good therapeutic effect on a rat model of type 2 diabetes.

Yang B ，Luo Y ，Sang Y ，Kan J ... -  《-》

High-pressure ultrasonic-assisted extraction of polysaccharides from Hovenia dulcis: Extraction, structure, antioxidant activity and hypoglycemic.

In this study, high-pressure ultrasonic-assisted extraction (HUE) technology was used for polysaccharide extraction from Hovenia dulcis (HDPS). A maximal extraction yield (11.81 ± 0.26%) was obtained using the response surface method (RSM) with optimized HUE conditions (Ultrasound power 330 W, 68 °C, and 22 min). Results showed that HDPS mainly contained neutral sugar (47.81 ± 1.56%), uronic acid (12.52 ± 0.15%), and protein (3.64 ± 0.24%), specifically. HDPS was comprised of mannose, rhamnose, galacturonic acid, glucose, galactose and arabinose in a molar ratio of 3.20%, 20.40%, 4.81%, 11.14%, 27.37% and 33.08%, respectively. And with an average molecular weight of 185.22 kDa for its major component (accounting for 90.13% for HDPS). The result obtained from the X-ray diffraction pattern confirmed a semi-crystalline nature of the sample. HUE-HDPS suggested typical shear thinning behavior and non-Newtonian properties. Additionally, HUE-HDPS exhibited better chemical antioxidant activities in DPPH, ABTS, hydroxyl radical scavenging and Fe2+ chelation activity. The in-vitro and in-vivo experiments indicated that HUE-HDPS had obviously hypoglycemic effects. Accordingly, the polysaccharides from Hovenia dulcis might serve as a natural antioxidant and hypoglycemic agent.

Yang B ，Wu Q ，Luo Y ，Yang Q ，Wei X ，Kan J ... -  《-》

Polysaccharide from Hovenia dulcis (Guaizao) improves pancreatic injury and regulates liver glycometabolism to alleviate STZ-induced type 1 diabetes mellitus in rats.

Hovenia dulcis is a traditional medicinal and edible plant and has a major geographical presence in China. In this study, a polysaccharide purified from H. dulcis (HDPs-2A) was found to ameliorate type 1 diabetes mellitus (T1DM) in streptozotocin-induced diabetic rat. HDPs-2A treatment resulted in significantly lower fasting blood glucose levels, but higher body weight, plasma insulin, and liver glycogen levels. Moreover, HDPs-2A improved dyslipidemia, pancreatic oxidative stress, and reduced serum pro-inflammatory factors. In addition, HDPs-2A up-regulated PDX-1, activated and up-regulated IRS2 expression, and regulated apoptosis and regeneration of islet β cells to recover islet β-cell function injury in TIDM rats. HDPs-2A also up-regulated the expression of pancreatic GK and GLUT2 to improve insulin secretion ability of islet β-cells, ultimately improving the glucose metabolism disorder of T1DM rats. Moreover, HDPs-2A significantly up-regulated the expression of GK and down-regulated the expression of G6Pase in liver to improve liver glycogen synthesis, inhibit liver gluconiogenesis, and improve liver glucose metabolism disorder of T1DM rats. In summary, the hypoglycemic mechanisms of HDPs-2A may include regulating the regeneration and apoptosis of islet β-cells and activating liver glycometabolism-related signaling pathways in T1DM rats.

Yang B ，Luo Y ，Wei X ，Kan J ... -  《-》

Structural Characterization and Immunostimulatory Activity of Heteropolysaccharides from Fuzhuan Brick Tea.

Chen G ，Bai Y ，Zeng Z ，Peng Y ，Zhou W ，Shen W ，Zeng X ，Liu Z ... -  《-》

Characterization of a new heteropolysaccharide from green guava and its application as an α-glucosidase inhibitor for the treatment of type II diabetes.

Jiao Y ，Hua D ，Huang D ，Zhang Q ，Yan C ... -  《-》