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A new polysaccharide fraction (ATP) was obtained from Armillariella tabescens mycelium. Structural analysis suggested that the backbone of ATP was →4)- α -D-Glc p (1 → 2)- α -D-Gal p (1 → 2)- α -D-Glc p (1 → 4)- α -D-Glc p (1→, which branched at O-3 of →2)- α -D-Glc p (1 → and terminated with T- α -D-Glc p or T- α -D-Man p. Besides, ATP significantly alleviated ulcerative colitis (UC) symptoms and inhibited the production of pro-inflammation cytokines (IL-1 β , IL-6). Meanwhile, ATP could improve colon tissue damage by elevating the expression of MUC2 and tight junction proteins (ZO-1, occludin and claudin-1) levels and enhance intestinal barrier function through inhibiting the activation of MMP12/MLCK/ p -MLC2 signaling pathway. Further studies exhibited that ATP could increase the relative abundance of beneficial bacteria such as f. Muribaculacese , g. Muribaculaceae , and g. Alistips , and decrease the relative abundance of g. Desulfovibrio , g. Colidextribacter , g. Ruminococcaceae and g.Oscillibacter , and regulate the level of short-chain fatty acids. Importantly, FMT intervention with ATP-derived microbiome certified that gut microbiota was involved in the protective effects of ATP on UC. The results indicated that ATP was potential to be further developed into promising therapeutic agent for UC. [Display omitted] • A new polysaccharide of Armillariella tabescens (ATP) was purified and characterized. • ATP significantly alleviated UC symptoms and regulated inflammatory response. • ATP improved the integrity of intestinal epithelial barrier in UC mice. • ATP could modulate gut microbiota and SCFAs levels. [ABSTRACT FROM AUTHOR]

Mucus penetration is one of the physiologic barriers of inhalation and nanocarriers can effectively facilitate the permeation of drugs. The interactions between the nanocarriers and mucin are crucial for penetration across the mucus layer on the respiratory tract. In this study, we proposed a molecular dynamics (MD) simulation method for the screening of polysaccharides that acted as the surface modification materials for inhalable nano-preparations to facilitate mucus penetration. MD revealed all-atom interactions between the monomers of polysaccharides, including dextran (DEX)/hyaluronic acid (HA)/carboxymethyl chitosan (CMCS) and the human mucin protein MUC5AC (hMUC5AC). The obtained data showed that DEX formed stronger non-covalent bonds with hMUC5AC compared to HA and CMCS, which suggested that HA and CMCS had better mucus permeability than DEX. For the in vitro verification, HA/CMCS-coated liposomes and DEX/PEG-inserted liposomes were prepared. The results of mucin interactions and mucus penetration studies confirmed that HA and CMCS possessed the weakest interactions with mucin and facilitated the mucus penetration, which was in consistent with the data from MD simulation. This work may shed light on the MD simulation-based screening of surface modification materials for inhalable nano-preparations to facilitate mucus penetration. [ABSTRACT FROM AUTHOR]

Chemotherapy, the most common class of anticancer drugs, is considerably limited owing to its adverse side effects. In this study, we aimed to evaluate the protective effect and mechanism of action of large-leaf yellow tea polysaccharides (ULYTP-1, 1.29 × 104 Da) against chemotherapeutic 5-fluorouracil (5-Fu). Structural characterisation revealed that ULYTP-1 was a β-galactopyranouronic acid. Furthermore, ULYTP-1 promoted autolysosome formation, activating autophagy and reducing the oxidative stress and inflammation caused by 5-Fu. Our in vivo study of 4 T1 tumour-bearing mice revealed that ULYTP-1 also attenuated 5-Fu toxicity through modulation of the gut microbiota. Moreover, ULYTP-1 effectively protected immune organs and the liver from 5-Fu toxicity, while promoting its tumour-inhibitory properties. The current findings provide a new strategy for optimising chemotherapy regimens in the clinic. [Display omitted] • Polysaccharide ULYTP-1 was extracted from large-leaf yellow tea. • ULYTP-1 is a β-galactopyranouronic acid with a spongy steric configuration. • ULYTP-1 activates autophagy to alleviate 5-fluorouracil-induced liver injury. • ULYTP-1 alleviated gut dysbiosis in 4 T1 tumour-bearing mice. [ABSTRACT FROM AUTHOR]