Ginger polysaccharides enhance intestinal immunity by modulating gut microbiota in cyclophosphamide-induced immunosuppressed mice.

In this study, the immunity-enhancing effect of ginger polysaccharides UGP1 and UGP2 on CTX-induced immunosuppressed mice was evaluated. The results showed that ginger polysaccharide could effectively alleviate the symptoms of weight loss and dietary intake reduction induced by CTX, increase fecal water content, reduce fecal pH, and protect immune organs of immunosuppressed mice. In addition, ginger polysaccharides also stimulated the secretion of cytokines IL-2, IL-4, TNF-α and immunoglobulin Ig-G in the serum of mice, increased the expression of Occludin and Claudin-1, and restored the level of short-chain fatty acids in the intestine to improve immune deficiency. Furthermore, ginger polysaccharides significantly reduced the relative abundance ratio of the Firmicutes and Bacteroidetes in mice and increased the relative abundance of Verrucomicrobia and Bacteroidetes at the phylum level. At the family level, ginger polysaccharides increased the relative abundance of beneficial bacteria such as Muribaculaceae, Bacteroidaceae and Lactobacillaceae, and decreased the relative abundance of harmful bacteria such as Rikenellaceae and Lachnospiraceae. Spearman correlation analysis indicated that ginger polysaccharides could enhance intestinal immunity by modulating gut microbiota associated with immune function. These results indicated that ginger polysaccharides have the potential to be a functional food ingredients or a natural medicine for the treatment of intestinal barrier injury.

Characterization and antioxidant activity of polysaccharides obtained from ginger pomace using two different extraction processes.

In this study, two different processes of hot water (HW) and ultrasonic-assisted (UA) for the extraction of polysaccharide from ginger pomace (GPPs) were employed under their respective best parameters, and the characterization and antioxidant activity of the purified polysaccharide (HW-GPP1, HW-GPP2, HW-GPP3, and UA-GPP1, UA-GPP2, UA-GPP3, respectively) were analyzed. The data implied that the yield of the polysaccharide obtained by UA was higher than that of HW. Meanwhile, two kinds of GPPs possessed the different preliminary structural characteristics including molecular weight distributions, total sugar and protein content, uronic acid content, while similar monosaccharide compositions and sulfuric radical contents. In vitro antioxidant activity assays indicated that UA-GPP3 showed the strongest scavenging abilities on DPPH radicals, while UA-GPP2 possessed the strongest scavenging abilities on hydroxyl and superoxide radicals. Moreover, the antioxidant activity of each fractions of GPPs extracted by UA was better than that of the corresponding fractions of GPPs extracted by HW. These results showed that UA was more beneficial to enhance the extraction yields of the polysaccharides, and also resulted in GPPs with higher bioactivity. Therefore, it indicated that UA-GPPs could be used as a potential natural antioxidant. Accordingly, the ginger pomace could be used as a potential source for natural antioxidant.

Antimicrobial and antioxidant activities of Flammulina velutipes polysaccharides and polysaccharide-iron(III) complex [corrected].

FVP is polysacchrides obtained from Flammulina velutipes. A polysacchride named FVP2 was isolated from FVP by DEAE cellulose-52 chromatography and Sephadex G-100 size-exclusion chromatography. FVP-Fe and FVP2-Fe were synthesized by neutralization of FeCl3 carbohydrate solution. The antibacterial and antifungal activities of FVP, FVP2, FVP-Fe, FVP2-Fe were investigated and their antioxidant effects on hydroxyl, 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide anion, 2,2'-azobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, reducing power, inhibition of malondialdehyde (MDA) were assessed in vitro. The results suggested that FVP-Fe and FVP2-Fe significantly suppressed the growth of bacteria Staphylococcus aureus, Escherichia coli, and Bacillus subtilis, and have relatively strong antioxidant activity to scavenge superoxide anion radical. In addition, FVP exhibited strong antioxidant activity to eliminate hydroxyl, DPPH, ABTS radicals, had high reducing power and inhibited the MDA production of health mice liver homogenate induced by auto-oxidation and Fe2+-H2O2 system.