Study on the characterization of polysaccharide from Tuber sinense and its desensitization effect to β-lactoglobulin in vivo

Conjugation of chitopentaose with β-lactoglobulin using Maillard reaction, and its effect on the allergic desensitization in vivo

The conjugation of chitopentaose (CHP) on β-lactoglobulin (βLg) via Maillard reaction was used to desensitize βLg. The stable βLg-CHP conjugate (βC-4) was formed at 4 h incubation, which contains 5 CHP attached molecules and a conjugated degree of 42 %. The conjugation promoted the thermal stability and emulsifying properties of βLg, and inhibited the immunoglobulin E (IgE) combining capacity by decreasing the content of β-sheet in βLg. Moreover, βLg-CHP conjugates were imparted with anti-oxidant properties and anti-inflammatory activities. Further, the combined action of inhibited IgE combining capacity and anti-inflammatory activities improved the allergy desensitization in βLg sensitized mice. The results showed that overexpressed IgE and inflammatory factors, unbalanced Th1-/Th2- immune cytokines were significantly attenuated after βLg was conjugated with CHP, avoiding the inflammatory lesions in spleen and colon. Additionally, the adverse changes in gut microbiota were alleviated in βC-4 group with a decrease of Bacteroidetes and increase of Firmicutes at phylum level and the probiotic bacteria of Lactobacillaceae was significantly improved at the family level. Thus, the conjugation of CHP can desensitize allergic reaction caused by βLg.

Extraction, Isolation, Screening, and Preliminary Characterization of Polysaccharides with Anti-Oxidant Activities from Oudemansiella raphanipies

Response surface methodology (RSM) was used to find the optimal extraction process of Oudemansiella raphanipies polysaccharides (ORPs). The results showed that the optimal extraction parameters were an alkali concentration of 0.02 mol/L, a ratio of material to liquid of 1:112.7 g/mL, an extraction temperature of 66.0 °C, and an extraction time of 4.0 h. Under the optimal conditions, the yield of ORPs was raised to 16.2 ± 0.1%. The antioxidant activities of ORPs-I~V were determined and compared, and ORPs-V was further purified by chromatography, with an average molecular weight (Mw) of 18.86 kDa. The structure of ORPs-V was determined by Fourier transform-infrared spectroscopy (FT-IR), monosaccharide analysis, and nuclear magnetic resonance (NMR) spectroscopy. The ORPs-V comprised fucose, rhamnose, arabinose, glucose, galactose, mannose, xylose, fructose, galacturonic acid, and glucuronic acid at a ratio of 1.73:1.20:1.13:2.87:8.71:2.89:1.42:0.81. Compared to other ORPs, ORPs-V showed the strongest antioxidant activities (ABTS radical cation, hydroxyl radical and DPPH scavenging activities, and reducing power), and were able to significantly increase the activities of superoxide dismutase, catalase, lactate dehydrogenase, and glutathione peroxidase. However, they reduced the malondialdehyde content in mice fed a high-fat diet. These results indicate that ORPs-V may be good anti-oxidant agents to be applied in functional foods.

Structural characteristics of polysaccharide from Zingiber striolatum and its effects on gut microbiota composition in obese mice

To investigate a polysaccharide from Zingiber striolatum favorably modulates gut microbiota in mice fed a high-fat diet. Z. striolatum was utilized to extract the crude polysaccharide CZSP, which was subsequently refined using DEAE-52 cellulose and Sephadex G-150 to yield the novel polysaccharide Zingiber strioatum pure polysaccharide-1 (ZSPP-1). ZSPP-1 was an acidic heteroglycan made up of galactose, mannose, glucose, xylose, arabinose, glucuronic acid, and galacturonic acid with an average molecular weight of 1.57 × 106 Da. The structure of ZSPP-1 was investigated by FT-IR, methylation and NMR analysis, and the results denoted that the linkage structure types include T-Manp-linked, β-Xylp-(1,2)-linked, β-Galp-(1,4)-linked, α-GlcpA-(1,6)-linked, β-Arap-(1,4)-linked, α-Glcp-(1,3,4,6)-linked, α-Glcp-(1,2)-linked, and β-T-Xylp-linked, in which β-Galp-(1,4)-linked and α-GalpA-(1,4)-linked might be the main linkage. The results of the intervention experiments showed that ZSPP-1 changed the intestinal flora structure of the Firmicutes and Bacteroidetes in obese mice, and promoted the growth of beneficial bacteria such as Akkermansia, Lactobacillus, and Bacteroides in the intestine. It also restored the imbalanced flora structure due to high-fat diet to normal. It also restored the imbalanced flora structure due to high-fat diet to normal. Z. striolatum polysaccharides presented a considerable advantage in alleviating high-fat diet induced obesity, which indicates that it can be further exploited as a natural functional food resource.