Identification of Polysaccharides From Dipsacus asperoides and Their Effects on Osteoblast Proliferation and Differentiation in a High-Glucose Environment

Polysaccharides (DAI-1 and DAI-2) from Dipsacus asperoides (D. asperoides) were obtained using mixed-bed ion exchange resin and Sephadex G-50 column chromatography following which their properties, structures, and activities were investigated. The results showed that DAI-1 and DAI-2 were homogeneous in nature, with glucose the only constituent, and had molecular masses of 17 and 4 kDa, respectively. Methylation analysis indicated that the backbones of DAI-1 and DAI-2 were mainly composed of (1→6)-linked glucose residues. DAI-1 possessed a small number of side chains and a branch point of (1→3, 6)-glucose, while DAI-2 lacked branching. Activity assays demonstrated that exposing osteoblasts to different DAI-1 concentrations (25, 50, or 100 μg/mL) in a high-glucose environment induced cell proliferation and led to a significant increase in bone morphogenetic protein 2 (BMP-2) and runt-related transcription factor 2 (Runx2) expressions at both the mRNA and protein levels. Moreover, DAI-1 treatment significantly increased alkaline phosphatase (ALP) and osteocalcin (OCN) activities in osteoblasts. Combined, our results suggested that DAI-1 may promote osteoblast proliferation and differentiation in a high-glucose environment.

Pulverization Using Liquid Nitrogen Significantly Improves Physical Properties of Powder and Extraction Yield of Polysaccharides of Astragalus mongholicus

Astragalus mongholicus is a famous traditional Chinese medicinal herb because of its human health benefits and bioactive compounds. Pulverization process directly affects quality and dissolution of bioactive compounds of A. mongholicus. In the present study, liquid nitrogen was introduced to pulverization process of A. mongholicus. The pulverization with addition of liquid nitrogen (LNP) effectively retained powder color, crushed tissue fiber, and reduced hardness of A. mongholicus. Furthermore, LNP significantly improved elasticity and solubility of the powder, as well as soluble solid contents. In addition, extraction yield of polysaccharides, characteristic bioactive compounds in A. mongholicus, was increased by 10.5 % by combination of LNP and Tween-80 enzyme extraction. These results suggest that LNP can be a promising technology for preparation of A. mongholicus powder. The information will also contribute to improvement of manufacturing technology of Chinese medicinal herb.