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Factors causing differences in immune activities between pectin and pectin-derived oligosaccharides have not been fully studied. In this article, four samples with different molecular weights and monosaccharide compositions, including polygalacturonic acid (poly-GA) and its oligosaccharide (oligo-GA), navel orange peel pectin (NP) and its oligosaccharide (oligo-NP), were used to compare their immunomodulatory properties on RAW264.7 cells. All samples had nontoxic effect on cells, oligo-GA and oligo-NP could increase the production of nitric oxide and cytokines to a much higher level than poly-GA and NP. The findings revealed that reducing the molecular weight and preserving the branched regions of pectin-derived samples could improve their immune-enhancing effects on macrophages. Interestingly, the addition of TAK-242 (TLR4 inhibitor) also demonstrated that the tested pectin oligosaccharides could stimulate the activation of macrophages through TLR4 signaling pathway. These results confirmed the potential value of pectin oligosaccharides, and provided theoretical support for their application in the pharmaceutical industry. • Molecular weight and glycosyl composition could influence the immunity of pectin. • Pectin oligosaccharides showed better immune-enhancing activity than pectin. • Oligo-NP could significantly increase the secretion of NO, TNF-α, and IL-6. • Pectin oligosaccharides could activate macrophages through TLR4 signaling pathway. [ABSTRACT FROM AUTHOR]

Ginseng, a commonly used medicinal herb, contains polysaccharide as one of the bioactive compounds. This study aimed at evaluating the immune enhancement effects of Korean ginseng berry polysaccharides (GBPs) on macrophage RAW264.7 cells and their chemical characteristics. The crude polysaccharide (GBP-C) was extracted and fractionated to different polysaccharides (GBP-F1, GBP-F2, and GBP-F3). GBPs were mainly composed of rhamnose, arabinose, mannose, glucose and galactose, with molecular weights (Mw) ranging from 16 × 103 to 328 × 103 g/mol. While all the GBPs significantly increased the NO production in a dose-dependent manner, GBP-F2 showed the highest immune-enhancing effects. GBP-F2 up-regulated the mRNA expression of iNOS, IL-1β, IL-6, IL-10, and TNF-α through activating phosphorylation of NF-κB-p65, ERK1/2, JNK, and p38 to a greater extent than the other GBPs samples. These results indicate that GBPs, and especially GBP-F2, have strong immune enhancement effects desirable for application in the food and pharmaceutical industries.

Ginseng, a commonly used medicinal herb, contains polysaccharide as one of the bioactive compounds. This study aimed at evaluating the immune enhancement effects of Korean ginseng berry polysaccharides (GBPs) on macrophage RAW264.7 cells and their chemical characteristics. The crude polysaccharide (GBP-C) was extracted and fractionated to different polysaccharides (GBP-F1, GBP-F2, and GBP-F3). GBPs were mainly composed of rhamnose, arabinose, mannose, glucose and galactose, with molecular weights (Mw) ranging from 16 × 103 to 328 × 103 g/mol. While all the GBPs significantly increased the NO production in a dose-dependent manner, GBP-F2 showed the highest immune-enhancing effects. GBP-F2 up-regulated the mRNA expression of iNOS, IL-1β, IL-6, IL-10, and TNF-α through activating phosphorylation of NF-κB-p65, ERK1/2, JNK, and p38 to a greater extent than the other GBPs samples. These results indicate that GBPs, and especially GBP-F2, have strong immune enhancement effects desirable for application in the food and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

A novel polysaccharide DG2 was obtained from the Dendrobium officinale endophytic fungus Fusarium solani DO7. The structural characterization and immunological activity of DG2 were investigated. Results showed that DG2 with the molecular weight of 152.8 kDa was composed of Galp, Manp, Glcp and Araf at a molar ratio of 4.3:1.9:2.8: 1.0. The main linkage types of DG2 were (1 → )-β-D-Glc, (1 → 4)-β-D-Glc, (1 → 3,6)-β-D-Gal and (1 → 6)-β-D-Gal, which demonstrated DG2 was a novel galactoglucan and different from other fungal and botanic polysaccharide. Furthermore, DG2 did not contain deoxynivalenol, and showed no direct toxicity to human embryonic kidney cells and RAW 264.7 cells. Meanwhile, DG2 could increase the TNF-α, IL-6 and iNOs mRNA expression levels of RAW264.7 cells, and further promote the production of TNF-α, IL-6 and NO. These results suggested DG2 could enhance macrophage-mediated immune responses and have the potential to be an attractive functional food supplement candidate for the hypoimmunity therapies.

Graphical abstract Highlights: • Fusarium solani DO7 was isolated from the stem of Dendrobium officinale. • A novel polysaccharide DG2 was isolated from F. solani DO7. • DG2 showed no toxicity to human embryonic kidney cells and RAW 264.7 cells. • DG2 possesses higher immune enhancement activity. • DG2 had good potential as functional food candidate. Abstract A novel polysaccharide DG2 was obtained from the Dendrobium officinale endophytic fungus Fusarium solani DO7. The structural characterization and immunological activity of DG2 were investigated. Results showed that DG2 with the molecular weight of 152.8 kDa was composed of Gal p , Man p , Glc p and Ara f at a molar ratio of 4.3:1.9:2.8: 1.0. The main linkage types of DG2 were (1 →)-β-D-Glc, (1 → 4)-β-D-Glc, (1 → 3,6)-β-D-Gal and (1 → 6)-β-D-Gal, which demonstrated DG2 was a novel galactoglucan and different from other fungal and botanic polysaccharide. Furthermore, DG2 did not contain deoxynivalenol, and showed no direct toxicity to human embryonic kidney cells and RAW 264.7 cells. Meanwhile, DG2 could increase the TNF-α, IL-6 and iNOs mRNA expression levels of RAW264.7 cells, and further promote the production of TNF-α, IL-6 and NO. These results suggested DG2 could enhance macrophage-mediated immune responses and have the potential to be an attractive functional food supplement candidate for the hypoimmunity therapies. [ABSTRACT FROM AUTHOR]

In the present study, the physiochemical and biological properties of crude mycelium polysaccharide (CMCP) and purified mycelium polysaccharide (MCP) extracted from the Tremella aurantialba mycelium were investigated. A series of physiochemical properties were determined, including the total sugar, uronic acid and protein content, monosaccharide composition and structure, and molecular weight. The reducing power and scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals were determined to investigate the antioxidant activity of CMCP and MCP. Furthermore, the immunostimulatory activity of the polysaccharides was evaluated by detecting the effects of CMCP and MCP on proliferation, nitric oxide (NO) production and cytokine secretion by RAW264.7 cells. The chemical analysis revealed that MCP had a molecular weight of 4.3x104 g/mol and was composed primarily of D-glucose, D-galactose and D-mannose. The total carbohydrate contents of MCP and CMCP were 86.59 and 11.92%, respectively. Compared with CMCP, MCP demonstrated improved antioxidant properties. In addition, MCP induced RAW264.7 macrophage proliferation, NO production and secretion of tumor necrosis factor-α, interleukin (IL)-1 and IL-6. These findings suggest that the total carbohydrate content may contribute to the improvement of antioxidant and immunostimulatory activities of MCP. [ABSTRACT FROM AUTHOR]