Development of a joint derivatization protocol for the unequivocal identification of the monosaccharide composition in four dendrobium polysaccharides and free monosaccharide by GC-MS.

The determination of monosaccharides is crucial for studying the structure of polysaccharides and the composition of free monosaccharides in living organisms. Based on previous derivatization gas chromatography-mass spectrometry (GC-MS) methods, we aimed to develop a novel analytical protocol for better quantifying monosaccharides. In this study, sugar alcohol acetylation, saccharonitrile acetylation, silylation and a combination of sugar alcohols acetylation and saccharonitrile acetylation were compared. The optimal method was verified with the monosaccharide determination of four polysaccharides and four free monosaccharides from Dendrobium. The results showed that the novel combined derivatization method was superior to the other three methods in terms of content analysis of monosaccharides. Furthermore, it possessed good linearity (all calibration curves showed relative coefficients ≥ 0.999), sensitivity, precision (relative standard deviation < 2%), and accuracy (recovery, 95.7-105%). Finally, the novel method established in this study was successfully employed in determining the monosaccharide composition of four polysaccharides and four free monosaccharide samples from Dendrobium.

Dendrobium Polysaccharides Mitigate CSE-induced Inflammatory Damage of Human Bronchial Epithelial Cells via TLR4/NF-κB Pathway / 中国实验方剂学杂志

ObjectiveTo observe the effects of Dendrobium polysaccharides on the secretion of inflammatory cytokines and Toll-like receptor 4 （TLR4）/nuclear factor （NF）-κB pathway in 16HBE cells exposed to cigarette smoke extract （CSE）. MethodThe 16HBE cells were classified into the control， CSE， and CSE+ Dendrobium polysaccharides （100， 200， 400 mg·L-1） groups. The cell-counting kit-8 （CCK-8） assay was employed to measure the cell viability， and a microscope was used to observe the cell morphology. The enzyme-linked immunosorbent assay was employed to measure the levels of interleukin （IL）-8， IL-1β， IL-4， IL-13， and transforming growth factor （TGF）-β in cell culture supernatants. Real-time PCR was carried out to determine the mRNA levels of Toll-like receptor 4 （TLR4）， nuclear factor-κB （NF-κB）， and IL-4. Western blot was employed to determine the protein levels of interleukin-4 receptor （IL-4R）， TLR4， myeloid differentiation primary response protein 88 （MyD88）， NF-κB， phosphorylated nuclear factor-κB （p-NF-κB）， and nucleoproteins nuclear factor-κB （NEs-NF-κB）. The immunofluorescence assay was employed to measure the nuclear translocation of NF-κB. ResultCompared with the control group， the CSE group showed elevated levels of IL-8， IL-1β， IL-4， IL-13， and TGF-β in the cell culture supernatants （P<0.05， P<0.01）， up-regulated expression levels of TLR4， MyD88， NF-κB， p-NF-κB， NEs-NF-κB， and IL-4 （P<0.01）， and significant nuclear translocation of NF-κB. Compared with the CSE group， Dendrobium polysaccharides increased the cell survival rate， recovered the cell activity， lowered the levels of IL-8， IL-1β， IL-4， IL-13， and TGF-β， down-regulated the expression of TLR4， MyD88， NF-κB， p-NF-κB， NEs-NF-κB， and IL-4 （P<0.05， P<0.01）， and reduced the nuclear translocation of NF-κB. ConclusionDendrobium polysaccharides showed significant protective effects on the 16HBE cells exposed to CSE by inhibiting the TLR4/NF-κB signaling pathway.

A Systematic Review on Polysaccharides from Dendrobium Genus: Recent Advances in the Preparation, Structural Characterization, Bioactive Molecular Mechanisms, and Applications.

Dendrobium polysaccharides (DPSs) have aroused people's increasing attention in recent years as a result of their outstanding edible and medicinal values and non-toxic property. This review systematically summarized recent progress in the different preparation techniques, structural characteristics, modification, various pharmacological activities and molecular mechanisms, structure-activity relationships, and current industrial applications in the medicinal, food, and cosmetics fields of DPSs. Additionally, some recommendations for future investigations were provided. A variety of methods were applied for the extraction and purification of DPSs. They possessed primary structures (e.g., glucomannan, rhamnogalacturonan I type pectin, heteroxylan, and galactoglucan) and conformational structures (e.g., random coil, rod, globular, and a slight triple-helical). And different molecular weights, monosaccharide compositions, linkage types, and modifications could largely affect DPSs' bioactivities (e.g., immunomodulatory, anti-diabetic, hepatoprotective, gastrointestinal protective, antitumor, anti-inflammatory, and anti-oxidant activities). It was worth mentioning that DPSs were significant pharmaceutical remedies and therapeutic supplements especially due to their strong immunity enhancement abilities. We hope that this review will lay a solid foundation for further development and applications of Dendrobium polysaccharides.

Protective effects of NDP on LPS induced neuron injuries in rat mixed cultures / 中国药理学通报

Aim To investigate the protective effect of noble dendrobium polysaccharides ( NDP ) on lipopo-lysaccharide ( LPS)-induced neuron injuries in newborn rat cerebral cortex glial cells and neuron mixed cul-tures.Methods The primary cultures of newborn rat cortical neurons and glial cells were established and the existence of the neurons , astrocytes and microglia was verified respectively .NDP was given to LPS-induced mixed cultures , the mRNA levels of IL-1β, TNF-αand COX-2 were assayed by real time PCR .Results NDP reduced the glial cell activation and neuron dam-age after it was given to LPS-induced mixed cultures . The mRNA levels of IL-1β, TNF-α, COX-2 were re-duced .Conclusion NDP protects against LPS-in-duced neuron-inflammation in neurons and glial cells cultures.

Comparison of hypoglycemic and antioxidative effects of polysaccharides from four different Dendrobium species.

Four polysaccharides from Dendrobium huoshanense (DHP), D. officinale (DOP), D. nobile (DNP) and D. chrysotoxum (DCP), which had obvious differences in intrinsic viscosities and monosaccharide compositions, were extracted to compare their hypoglycemic and antioxidative activities in alloxan-induced diabetic mice by oral administration. The analysis of fasting blood glucose, glycosylated serum protein and serum insulin levels showed that DHP, DOP and DNP, but not DCP, possessed significant hypoglycemic effect with the decreasing order of DHP>DNP>DOP. Histopathological observation confirmed the capability of DHP, DOP and DNP to intervene the damage in pancreas tissues. The determination of superoxide dismutase, catalase, malonaldehyde and L-glutathione levels in the liver and kidney displayed that DHP, DOP and DNP had protective effects against alloxan-induced oxidative damage and the effect of DHP ranked first. These results suggested that there were significant differences in hypoglycemic and antioxidative activities between four Dendrobium polysaccharides, which may be contributed to their physicochemical properties.