Influence of glycosyl composition on the immunological activity of pectin and pectin-derived oligosaccharide.

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 Mechanisms for Anti-aging of Low-Vacuum Cold Plasma Pretreatment in Caenorhabditis elegans.

Cold plasma pretreatment has the potential of anti-aging. However, its molecular mechanism is still not clear. Here, cold plasma pretreatment was firstly used to investigate the anti-aging effects of Caenorhabditis elegans using transcriptomic technique. It showed that the optimal parameters of discharge power, processing time, and working pressure for cold plasma pretreatment were separately 100 W, 15 s, and 135 Pa. The released 0.32 mJ/cm2 of the moderate apparent energy density was possibly beneficial to the strong positive interaction between plasma and C. elegans. The longest lifespan (13.67 ± 0.50 for 30 days) was obviously longer than the control (10.37 ± 0.46 for 23 days). Furthermore, compared with the control, frequencies of head thrashes with an increase of 26.01% and 37.31% and those of body bends with an increase of 33.37% and 34.51% on the fourth and eighth day, respectively, indicated movement behavior was improved. In addition, the variation of the enzyme activity of superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) hinted that the cold plasma pretreatment contributed to the enhanced anti-aging effects in nematodes. Transcriptomics analysis revealed that cold plasma pretreatment resulted in specific gene expression. Anatomical structure morphogenesis, response to stress, regulation of biological quality, phosphate-containing compound metabolic process, and phosphorus metabolic process were the most enriched biological process for GO analysis. Cellular response to heat stress and HSF1-dependent transactivation were the two most enriched KEGG pathways. This work would provide the methodological basis using cold plasma pretreatment and the potential gene modification targets for anti-aging study.

A method for quantitative characterization of incomplete degradation products of polygalacturonic acid.

Biological activity of incomplete degradation products of polygalacturonic acid (IDPP) is closely related to its molecular weight and molecular weight distribution. Therefore, it is necessary to provide a reliable quantitative characterization method for evaluating these types of bioproducts. A novel method was established in this work for the quantitative characterization of IDPP based upon ethanol fractional precipitation. IDPP was fractionated into several fractions with high recovery (>95%), and the average molecular weights of each fraction was in descending order with the increase of ethanol concentration. Oligosaccharides (polymerization degree: 2-20) could be effectively harvested from the polygalacturonic acid enzymatic hydrolysate by ethanol precipitation. Moreover, the developed method had good repeatability and could also be applied to quantify enzymatic hydrolysis products of citrus-derived pectin polysaccharides. In conclusion, this paper provides a simple, accurate method for the quantitative characterization of IDPP and a strategy for the extraction of oligosaccharides.

Production performance, egg quality, plasma biochemical constituents and lipid metabolites of aged laying hens supplemented with incomplete degradation products of galactomannan.

This study was conducted to investigate the efficacy of incomplete degradation products of galactomannan (IDPG) on the production performance, egg quality, plasma parameters, and lipid metabolites of laying hens. A total of 288 laying hens were allocated into 4 treatments and fed diets supplemented with 0%, 0.01%, 0.025%, and 0.05% IDPG. Results showed that IDPG supplementation significantly increases egg production and decreases feed conversion ratio (P < 0.05). Eggs laid by hens receiving IDPG exhibited higher eggshell strength (P < 0.05). Moreover, IDPG supplementation significantly increased the serum albumin content, and decreased the blood ammonia content as well as triglyceride levels in serum and liver (P < 0.05). Overall, IDPG can be considered as an effective feed additive due to its capacity of improving egg production, increasing plasma protein, and changing lipid metabolism of laying hens.

Effects of seleno-Sesbania canabina galactomannan on anti-oxidative and immune function of macrophage.

Seleno-polysaccharides have become a major topic for research owing to their high anti-oxidative capacity and immune-enhancing activities. In this study, galactomannan (GM) was isolated from Sesbania cannabina, and next modified using HNO3-Na2SeO3 method to obtain six varieties of seleno-galactomannans (SeGMs). FT-IR and GPC results showed the changes in chemical structure of SeGMs, indicating successful combination of selenium and GM. By measuring superoxide dismutase and malondialdehyde, the SeGMs showed a stronger protective effect against H2O2-induced oxidative damage in vitro than unmodified GM using macrophage RAW264.7 cell as a model, and the effect of SeGMs-14 was prominent. However, the selenylation modification did not show any obvious effect on the immunomodulatory activity of GM, as determined by the index of tumor necrosis factor-α, interleukin-6, and interleukin-1ß. Overall, the prepared SeGMs from galactomannan could potentially serve as a dietary supplement of Se or an organic antioxidant.

Biomimetic galactomannan/bentonite/graphene oxide film with superior mechanical and fire retardant properties by borate cross-linking.

With the great demand for high-strength integrated materials in various industries, products from renewable resources were expected to replace petroleum-based materials. Inspired by the hierarchical structure of nacre, in this work, bentonite and graphene oxide (GO) were incorporated into the galactomannan (GM) matrix to prepare a ternary nanocomposite, which was further cross-linked and strengthened with borate. The chemical structure of the composite was analyzed with SEM, FTIR, XPS and XRD, revealing a co-assembly reaction between GO, bentonite and GM, accompanied by the borate crosslinking. This synergistic strengthen effect resulted in a composite possessing a maximum tensile stress and toughness of 231.16 MPa and 4.53 MJ/m3, respectively, harder than most of the previously reported hemicellulose composites. Moreover, the nanocomposites showed excellent fire retardant property with a limiting oxygen index of 46.8 % due to the introduction of bentonite and GO, which shows potential application in fire-protective insulation, packaging and coating.

Synthesis and Characterization of an Antioxidative Galactomannan⁻Iron(III) Complex from Sesbania Seed.

Galactomannan, a water-soluble polymer in the cell wall of leguminous plants, has been proven to possess anticancer and antioxidative activity. In this work, galactomannan with different molecular weights (GM-40 and GM-65) was obtained from Sesbania seeds and synthesized into galactomannan⁻iron(III) complexes, which are termed as GM-40-Fe and GM-65-Fe, respectively. These galactomannan⁻iron(III) complexes are intended to function as organic iron supplements to treat iron deficiency with the added benefit of antioxidative activity. The prepared galactomannan⁻iron(III) complexes were characterized for chemical composition, morphology, antioxidant capacity, and bioavailability in vitro. The results showed that galactomannan⁻iron(III) complexes could be produced with iron contents as high as 65.4 mg/g. Antioxidant assays indicated that both GM-40-Fe and GM-65-Fe exhibited antioxidant activities for scavenging radicals in vitro. The iron release/bioavailability assays showed that the iron was easily released into artificial gastric and intestinal juices, resulting in iron release rates of 88⁻94% over 300 min. These results suggest that galactomannan⁻iron(III) complexes synthesized from Sesbania seed polysaccharides are capable of being administered as organic iron supplements to patients with iron deficiency.