Preparation, Structural Features and in vitro Immunostimulatory Activity of a Glucomannan From Fresh Dendrobium catenatum Stems

Abstract

Dendrobium catenatum polysaccharides (DCPs) have attracted attention due to their multiple physiological activities and health benefits. In this study, a novel water-soluble DCP was obtained from fresh D. catenatum stems through three-phase partitioning and ethanol precipitation at room temperature. Its structural characteristics, rheological property, and in vitro immunostimulatory activity were evaluated. Results demonstrated that DCP was a homogenous polysaccharide with a carbohydrate content of 92.75% and a weight-average molecular weight of 2.21 × 105 Da. This polysaccharide is an O-acetylated glucomannan comprised by glucose, mannose, and galacturonic acid in a molar ratio of 30.2:69.5:0.3 and mainly comprises (1→4)-β-D-mannopyranosyl (Manp), 2-O-acetyl-(1→4)-β-D-Manp, (1→6)-α-D-glucopyranosyl (Glcp), and (1→4)-α-D-Glcp residues. DCP exhibits an extended rigid chain in an aqueous solution and favorable steady shear fluid and dynamic viscoelastic behaviors. In vitro immunostimulating assays indicated that DCP activates RAW264.7 cells, thus markedly promoting macrophage proliferation and phagocytosis and increasing the levels of nitric oxide, interferon-γ, interleukin-6, and interleukin-1β. Moreover, the presence of O-acetyl group and high Mw in DCP might be responsible for its potent immunostimulatory activity in vitro. Therefore, our data suggested that DCP could be developed as a promising immunostimulant in functional food and pharmaceutical industries.

Research progress on extraction, purification, structure and biological activity of Dendrobium officinale polysaccharides

“…Thus, DLP-1 and DLP-2 could be used as functional food additives (51). Similarly, DCP also has immunostimulatory activity in vitro, the mechanism of which was similar to that of DLP-1 and DLP-2 (53). Meanwhile, two component polysaccharides (DOP-1 and DOP-2) were isolated from D. officinale by DEAE cellulose and Sephacryl S-400, which caused a significant stimulation of cytokine secretion of both splenocytes and macrophages.…”

Extraction and Purification, Structural Characterization and Biological Activity of a Polysaccharide, PRP‐1, from Plumeria rubra

“…Numerous studies have proved that polysaccharides from natural plants or other sources have a variety of properties, such as anti‐inflammatory, antioxidant, hypoglycemic, and immunostimulatory activities [9–13] . Among them, medicinal and edible substances are important sources of polysaccharides, which were proved to possess significant biological activities.…”

“…Numerous studies have proved that polysaccharides from natural plants or other sources have a variety of properties, such as anti-inflammatory, antioxidant, hypoglycemic, and immunostimulatory activities. [9][10][11][12][13] Among them, medicinal and edible substances are important sources of polysaccharides, which were proved to possess significant biological activities. It has been reported that the polysaccharide from Prunella vulgaris can promote the apoptosis of orbital fibroblasts and suppress the production of pro-inflammatory cytokines (NO, TNF-α, and IL-6) in RAW 264.7 cells.…”

Water-soluble non-starch polysaccharides of wild-simulated Dendrobium catenatum Lindley plantings on rocks and bark of pear trees

“…GMs have a main chain of β-(1,4)-linked d -glucopyranosyl and β-(1,4)-linked d -mannopyranosyl backbone sometimes with a α-(1,6)-linked d -galactose side chain ( Korolenko et al, 2019 ). These NSPs have excellent immuno-enhancing, anti-tumor, hepatoprotective, cardioprotective, and antioxidant activity ( Liu et al, 2022 , Wang et al, 2022 ). Particularly, mannose, one of the degradation products of GMs, is taken up by the same transporter(s) as glucose but slows growth in several tumor types in vitro and in vivo ( Gonzalez et al, 2018 ).…”