Purification, Characterization and Biological Activity of Polysaccharides from Dendrobium officinale

Abstract

Polysaccharide (DOPA) from the stem of D. officinale, as well as two fractions (DOPA-1 and DOPA-2) of it, were isolated and purified by DEAE cellulose-52 and Sephacryl S-300 chromatography, and their structural characteristics and bioactivities were investigated. The average molecular weights of DOPA-1 and DOPA-2 were 394 kDa and 362 kDa, respectively. They were mainly composed of D-mannose, D-glucose, and had a backbone consisting of 1,4-linked β-D-Manp and 1,4-linked β-D-Glcp with O-acetyl groups. Bioactivity studies indicated that both DOPA and its purified fractions (DOPA-1 and DOPA-2) could activate splenocytes and macrophages. The D. officinale polysaccharides had stimulatory effects on splenocytes, T-lymphocytes and B-lymphocytes, promoting the cell viability and NO production of RAW 264.7 macrophages. Furthermore, DOPA, DOPA-1 and DOPA-2 were found to protect RAW 264.7 macrophages against hydrogen peroxide (H 2 O 2 )-induced oxidative injury by promoting cell viability, suppressing apoptosis and ameliorating oxidative lesions. These results suggested that D. officinale polysaccharides possessed antioxidant activity and mild immunostimulatory activity.

Optimization of the extraction process of polysaccharides from Dendrobium officinale and evaluation of the in vivo immunmodulatory activity

“…The antioxidant activities of thymus showed similar results, as listed in Table . Furthermore, at the cell level, the antioxidant activity of DOP was also found in RAW 264.7 cells treated by H 2 O 2 (Huang et al, ), which provided the support to our results that the DOP enhanced the antioxidant abilities.…”

“…Thus, it can be concluded that DOP can remarkably recover the balance of the splenic lymphocyte subtypes of the immunosuppressed mice. The similar phenomenon including the stimulatory effects of DOP on splenocytes were also found in other reports by MTT assays of RAW 264.7 cell line (Huang et al, 2016 (Yang et al, 2017). These results demonstrated that the two polysaccharides might affect the immune system through various mechanisms or pathways.…”

“…Specifically, the phagocytic ability of macrophages in high dose (P3) was 69% higher than that in the model group. Using RAW 264.7 cells for evaluation, it was reported that the DOP might promote the viability of macrophages rather than proliferation, and the polysaccharides showed inhibitions of the cell viability at 200 lg/ml (Huang et al, 2016). However, the antioxidant activity showed no correlation with the dose of DOP.…”

Comparison of structural, antioxidant and immuno‐stimulating activities of polysaccharides from Tremella fuciformis in two different regions of China

“…Viability of RAW264.7 cells was evaluated using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay (Huang et al, 2016). Cells were treated with TPS at different concentrations (25, 50, 75, 100 lg mL À1 ) for 48 h. Subsequently, 10 lL of 5 mg mL À1 MTT was added to each well and further incubated for 4 h. The formazan crystals were dissolved in 100 lL dimethyl sulfoxide (DMSO), and then the cells were analysed under a microplate reader (MK3, Thermo, Waltham, MA, USA) to measure the absorbance at 570 nm.…”

Artificial simulated gastrointestinal digestion of four carbohydrates containing beta‐d‐1 → 4 linkages and new GC‐TQ/MS‐MS method for characterising released monosaccharides

“…However, D. aphyllum is easy to plant and less costly, but is also less popular (Liu et al ., ). Polysaccharides extracted from D. officinale were reported to contain a backbone of (1 → 4)‐linked β‐ d ‐mannopyranosyl residues and β‐ d ‐glucopyranosyl residue (Xing et al ., ; Huang et al ., ).…”