Alleviation effects of grape seed proanthocyanidin extract on inflammation and oxidative stress in a D-galactose-induced aging mouse model by modulating the gut microbiota.

Grape seed proanthocyanidin extract (GSPE) that prevents and alleviates the degenerative changes associated with aging has been receiving extensive attention. In our present work, the ageing model was induced by injection of 500 mg kg-1D-galactose daily for a period of eight weeks. The D-galactose-induced ageing mice model was used for evaluating the effect of GSPE on oxidative stress, inflammation levels and gut microbiota composition. D-Galactose induced oxidative damage and inflammation with a significant increase in malondialdehyde contents, myeloperoxidase activities and the levels of TNF-α and IL-1ß, as well as a reduction in the activities of glutathione peroxidase and reduced glutathione. Treatment with different doses of GSPE could significantly improve the antioxidant capacity and inflammation levels in the liver and brain, which is accompanied by increased Lachnospiraceae_NK4A136, Lactobacillus, Bifidobacterium, and Akkermansia, as well as decreased Helicobacter and Alistipes. In addition, the high-dose GSPE group exhibited greater potential to delay the ageing process than the low-dose group. Our results also showed that GSPE administration could downregulate the NLRP3 inflammasome signaling pathway for inhibiting inflammation levels in the brain tissue. This study provided a novel strategy to target the gut microbiota with regard to the effect of GSPE administration on alleviating aging-induced alterations via the gut microbiota-liver axis and gut microbiota-brain axis.

Grape seed proanthocyanidin extract ameliorates dextran sulfate sodium-induced colitis through intestinal barrier improvement, oxidative stress reduction, and inflammatory cytokines and gut microbiota modulation.

It is widely believed that grape seed proanthocyanidin extract (GSPE) exerts antioxidant and anti-inflammatory effects. Dietary supplementation with GSPE has been reported to alleviate colitis signs in mice, but the mechanisms involved require further exploration. The present study investigated how the oral administration of GSPE ameliorates colitis signs and reduces colitis-associated inflammation. C57BL/6 mice were treated with GSPE for 21 days. During the final 7 days of treatment, the mice were administered dextran sulfate sodium (DSS) dissolved in drinking water to induce experimental colitis. We found that GSPE treatment improved DSS-induced colitis, which was evidenced by decreases in disease activity index (DAI) scores, pathological scores, and oxidative stress and increases in zonula occludens-1 (ZO-1), occludin, and claudin-1 mRNA levels of colon tissue. Notably, the proinflammatory cytokines TNF-α and IL-1ß were significantly downregulated as a result of GSPE treatment in colon tissues. GSPE treatment also reduced NLR family pyrin domain-containing 3 (NLRP3) inflammasome mRNA levels of colon tissue. Furthermore, an analysis of 16S rRNA sequences showed that GSPE rebalanced the DSS-damaged gut microbiota, including reducing Bacteroidetes, Dubosiella, and Veillonella, increasing Verrucomicrobia and Akkermansia, and elevating the Firmicutes to Bacteroidetes ratio. In conclusion, GSPE supplementation alleviates DSS-induced colitis by modulating inflammatory cytokines and oxidation stress, maintaining the intestinal barrier, and improving the microbial community. These results indicate that GSPE might be a new dietary strategy for the treatment of ulcerative colitis.

Synbiotic supplementation containing Bifidobacterium infantis and xylooligosaccharides alleviates dextran sulfate sodium-induced ulcerative colitis.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease whose prevalence is increasing globally. A synbiotic has probiotic and prebiotic components and is regarded as a promising candidate for alleviating UC-associated inflammation. The purpose of this study is to determine whether there is an additive efficacy between the probiotic Bifidobacterium infantis (B. infantis) and the prebiotic xylooligosaccharide (XOS) against UC. C57BL/6 mice were treated with B. infantis, XOS, or synbiotic (combination of B. infantis and XOS) for 21 d. During the final 7 d of treatment, the mice were administered dextran sulfate sodium (DSS) dissolved in drinking water to induce colitis. All treatments decreased the disease activity index (DAI) and pathological scores, and synbiotic treatment was more efficacious than either the probiotic or prebiotic alone. Compared with the DSS-induced colitis group, all treatment groups significantly downregulated the proinflammatory cytokines TNF-α and IL-1ß, and synbiotic treatment significantly upregulated the anti-inflammatory cytokine IL-10 in the colon tissues. Furthermore, all treatments significantly reduced the NLR family pyrin domain containing 3 (NLRP3) inflammasome mRNA level in the colon tissues. All treatments significantly inhibited oxidative stress and increased zonula occludens-1 (ZO-1), occludin, and claudin-1 tight junction (TJ) molecule mRNA levels in the colon tissues. Therefore, the observed efficacy of synbiotics against colitis may be explained by the additive combination of the direct anti-inflammatory effects of the probiotic and prebiotic components and their ability to fortify colonic epithelial barrier integrity. Our findings suggest that a synbiotic is a promising dietary supplement or functional food for the effective management of UC.

A novel fungal beta-propeller phytase from nematophagous Arthrobotrys oligospora: characterization and potential application in phosphorus and mineral release for feed processing.

Phytases are widely utilized in feed industry to increase the utilization of phosphorus, minerals, and amino acids for improvement of animal and human nutrition. At present, all known ß-propeller phytases (BPP) have been generated from bacteria, particularly Bacillus. In this work we report for the first time a new fungal-derived BPP phytase. We identified a phytase highly differentially expressed only in the parasitic stage of a nematophagous fungus, Arhtrobotrys oliogospora, during the development of the 3D traps. We found that this phytase was homologous to the known bacterial BPP phytase, thus we referred the new phytase to Aophytase. The heterologous expression of codon-optimized Aophytase gene in Pichia pastoris was successfully investigated to yield recombinant Aophytase (r-Aophytase) with high specific enzyme activity of 74.71 U/mg, much higher than those of recombinant BPP phytases derived bacteria. The kinetic parameters of the r-Aophytase, the optimum pH and temperature, as well as the effects of surfactant, EDTA and different ions on its enzyme activity were further investigated. The potential utilization of r-Aophytase in feed processing was finally explored. We found that the optimal pH value was about 7.5, and the optimal temperature was 50 °C.; r-Aophytase significantly increased the release of inorganic phosphorus from soybean meal, and improved the release of soluble minerals from the durum wheat flour and finger millet flour. The findings indicate its potential utilization in the feed processing to ameliorate nutritional value of cereals and animal feed in the future.