⿢An active polysaccharide (DHPD1) was isolated from Dendrobium huoshanense.⿢DHPD1 was shown to inhibit the apoptosis of human lens epithelial cells.⿢The active core domain of DHPD1 was prepared using pectinase hydrolyzation.⿢The basic structure features of the core domain of DHPD1 were characterized.⿢DHPD1 and its core domain prevent cell apoptosis via alleviating cell inflammation.The aim of this work was to investigate the core structure of a Dendrobium huoshanense polysaccharide DHPD1 required for the inhibition of lens epithelial cell apoptosis. In order to obtain the fragments containing the core domain, pectinase was employed to hydrolyze DHPD1. After 24 h reaction, it is interesting that the hydrolyzation seemed to be stopped, leading to a final enzymatic fragment DHPD1-24 with molecular weight about 1552 Da. Compared to DHPD1, although the bioactivity is decreased, DHPD1-24 remained the ability to inhibit the H2O2-induced apoptosis of human lens epithelial (HLE) cells via suppressing the MAPK signaling pathways. These results suggested that DHPD1-24 might be the core domain required for DHPD1 to inhibit HLE cell apoptosis. Methylation analysis showed DHPD1-24 was composed of (1 ⿿ 5)-linked-Araf, (1 ⿿ 3,6)-linked-Manp, 1-linked-Glcp, (1 ⿿ 4)-linked-Glcp, (1 ⿿ 6)-linked-Glcp, (1 ⿿ 4,6)-linked-Glcp, (1 ⿿ 6)-linked-Galp and 1-linked-Xylp in a molar ratio of 1.06:1.53:2.11:2.04:0.93:0.91:0.36:1.01. Moreover, the primary structural features of DHPD1-24 were characterized by NMR spectrum.

•The amylopectin was extracted from lotus root (LRA).•The addition of LRA enhanced the texteral and thermal properties of WPI gels.•The addition of LRA resulted in a stable three-dimensional gel network of WPI.•LRA might be a good candidate for the gel production in food industry.The effects of lotus root amylopectin (LRA) on the formation of whey protein isolate (WPI) gels were investigated at the concentration range from 0 to 1.0% (w/v) by determining the texteral, thermal and rheological properties. Results exhibited these properties of WPI gels could be significantly enhanced by the addition of LRA in a concentration-dependent manner. Compared the gel with free of starch, the gel strength, water holding capacity and thermal transition temperature of WPI gel containing 1% (w/v) amylopectin were enhanced by 12.7-fold, 24.9% and 3.6 °C, respectively. According to the analysis of scanning electron microscopy, colorimetric reaction and Fourier transform infrared spectroscopy measurements, it was concluded that the LRA-induced enhancement of WPI gel properties was possibly attributed to the formation of stable three-dimensional gel network, increased contents of reactive sulfhydryl group, CN bond and/or NH bond. Results suggested that LRA might be a good gel modifier.

•Dendrobium huoshanense polysaccharide (DHP) possesses immunostimulatory activity.•TLR4 was observed to be the pattern recognition receptor (PRR) of DHP.•DHP activates macrophages via TLR4-mediated signaling pathways.The present work aimed at investigating the pattern recognition receptor (PRR) and immunostimulatory mechanism of a purified Dendrobium huoshanense polysaccharide (DHP). We found that DHP could bind to the surface of macrophages and stimulate macrophages to secrete NO, TNF-α and IL-1β. To unravel the mechanism for the binding of DHP to macrophages, flow cytometry, confocal laser-scanning microscopy, affinity electrophoresis, SDS-PAGE and western blotting were employed to verify the type of PRR responsible for the recognition of DHP by RAW264.7 macrophages and peritoneal macrophages of C3H/HeN and C3H/HeJ macrophages. Results showed that toll-like receptor 4 (TLR4) was an essential receptor for macrophages to directly bind DHP. Further, the phosphorylation of ERK, JNK, Akt and p38 were observed to be time-dependently promoted by DHP, as well as the nuclear translocation of NF-κB p65. These results suggest that DHP activates macrophages via its direct binding to TLR4 to trigger TLR4 signaling pathways.

•Polysaccharide (CCP) is one of the main active compounds in Chinese chive.•Ultrasound-assisted extraction method was employed to extract CCP in this work.•A kinetic model was established to describe the extraction process of CCP.•Based on the model, the extraction condition was optimized for CCP extraction.•The ultrasound-acted target of CCP was determined in the process of extraction.Chinese chive, a famous green vegetable, is widely cultivated in the Asia. In the present study, we found that ultrasound caused the degradation of Chinese chive polysaccharides (CCP) in the process of extraction. Since lacking the consideration of polysaccharide degradation, the traditional kinetic models can not reflect the real extraction process of CCP. Therefore, a modified kinetic model was thus established by introducing a parameter of degradation coefficient based on the Fick’s second law, suggesting the diffusion and degradation of CCP is highly dependent on the ultrasonic power, extraction temperature and solid-liquid ratio. According to this modified model, the maximum CCP yield was obtained under an optimal extraction condition including extraction temperature 37 °C, ultrasonic power 458 w, extraction time 30 min and solid-liquid ratio 1:32. The objective polysaccharides responding to ultrasound were shown to be four different fractions, contributing to the increased diffusion and degradation of CCP by ultrasound treatment.

A homogeneous polysaccharide fraction (DOP-W3-b) with a high intestinal immunomodulating activity was obtained from the stems of Dendrobium officinale through a bioactivity-guided sequential isolation procedure based on the screening of Peyer's patch-mediated immunomodulating activity. Oral administration experiments of mice showed that DOP-W3-b could effectively regulate intestinal mucosal immune activity by changing intestinal mucosal structures, promoting the secretions of cytokines from Peyer's patches (PPs) and mesenteric lymph nodes (MLNs), and increasing the production of secretory immunoglobulin A (sIgA) in the lamina propria. Structure analysis indicated that DOP-W3-b was composed of mannose and glucose in a molar ratio of 4.5 with a relatively low molecular weight of 1.543 × 104 Da, and its repeat unit contained a backbone consisting of β-(1→4)-D-Manp, β-(1→4)-D-Glcp and β-(1→3,6)-D-Manp residues, a branch consisting of β-(1→4)-D-Manp, β-(1→4)-D-Glcp and terminal β-D-Glcp, and O-acetyl groups attached to O-2 of β-(1→4)-D-Manp. These results suggested that DOP-W3-b was a new polysaccharide with an essential potential for modulating body's immune functions.

•A homogenous polysaccharide (LJP-31) was isolated from Laminaria japonica.•The basic structure features of LJP-31 were characterized.•The activation of macrophages by LJP-31 and the related mechanism were studied.In this work, a novel water-soluble homogeneous polysaccharide (LJP-31) with a molecular mass of 2.24 × 106 Da was isolated and purified from Laminaria japonica using DEAE-cellulose and Sephacryl S500 chromatography. Results showed that LJP-31 mainly consists of arabinose, mannose, glucose and galactose in a molar ratio of 1.0:7.8:6.6:0.8. LJP-31 exhibited significant stimulation on macrophages and enhanced the production of NO, TNF-α, IL-1β, IL-6 and IL-10 as well as the up-regulation of their gene expressions. Western blot analysis suggested that LJP-31 has the positive effects on the translocation of NF-κB p65 from cytoplasm to nucleus and the phosphorylation of IκBα, ERK1/2, JNK1/2 and P38 in macrophages. Flow cytometric and confocal laser-scanning microscopy analysis indicated that toll-like receptor 4 (TLR4) was at least one of the recognition receptors of LJP-31 on the plasma membrane of macrophages. Taken together, LJP-31 may exert its immunostimulating potency via TLR4 activation of MAPK and NF-κB signaling pathways.

•An active polysaccharide DHPD2 was extracted from the PLBs of Dendrobium huoshanense.•The structural features of DHPD2 were characterized.•The anti-glycation activity of DHPD2 was strengthened after sulfated modification.•The sulfation position on sugar residues of DHPD2 were determined by NMR technology.Dendrobium huoshanense, an important food material, has been used to make teas and soups in the folk of China for centuries. In the present study, an antiglycation polysaccharide DHPD2 with molecular weight of 8.09 × 106 Da was extracted from the protocorm-like bodies of D. huoshanense. The backbone of DHPD2 contained (1→5)-linked α-l-Araf, (1→6)-linked α-d-Glcp, (1→6)-linked β-d-Glcp, (1→4)-linked β-d-Glcp, (1→3,6)-linked β-d-Galp and (1→6)-linked β-d-Galp, with the branches of terminal α-d-Xlyp and β-d-Manp. DHPD2 was further modified using chlorosulfonic acid–pyridine method, giving two sulfated derivatives with the substitution degree of 0.475 and 0.940. The appearance of two new characteristic absorption bands at near 1250 and 822 cm−1 in FT-IR spectra revealed the success of sulfation occurred to DHPD2. Moreover, the sulfated derivatives exhibited stronger inhibitory abilities on protein glycation than those of DHPD2. NMR analysis disclosed that the sulfation on C2 and C6 of sugar residues was beneficial to enhance this activity.

•Extraction conditions of polysaccharide from jellyfish (JSP) were optimized.•The methods to remove proteins from crude JSP were studied.•The ethanol precipitation conditions for JSP purification were investigated.•The physicochemical properties of different JSP fractions were compared.•JSP showed strong inhibitory effects on macrophage-derived foam cell formation.In this work, response surface methodology was used to determine optimum conditions for extraction of polysaccharides from jellyfish skin (JSP). The optimum parameters were found to be raw material to water ratio 1:7.5 (w/v), extraction temperature 100 °C and extraction time 4 h. Under these conditions, the JSP yield reached 1.007 mg/g. Papain (15 U/mL) in combination with Sevag reagent was beneficial in removing proteins from JSP. After precipitation with ethanol at final concentration of 40%, 60% and 80% in turn, three polysaccharide fractions of JSP1, JSP2 and JSP3 were obtained from JSP, respectively. The three fractions exhibited different physicochemical properties with respect to molecular weight distribution, monosaccharide composition, infrared absorption spectra, and glycosyl bond composition. In addition, JSP3 showed strong inhibitory effects on oxidized low-density lipoprotein (oxLDL) induced conversion of macrophages into foam cells, which possibly attributed to the down-regulation of some atherogenesis-related gene expressions.