Synthesis, Characterization of Low Molecular Weight Chitosan Selenium Nanoparticles and Its Effect on DSS-Induced Ulcerative Colitis in Mice.

Selenium nanoparticles have attracted extensive attention due to their good bioavailability and activity. In the present study, a new form of selenium nanoparticle (Low molecular weight chitosan selenium nanoparticles (LCS-SeNPs)) were synthesized in a system of sodium selenite and acetic acid. The size, element state, morphology and elementary composition of LCS-SeNPs were characterized by using various spectroscopic and microscopic measurements. The protection of LCS-SeNPs against dextran sulfate sodium (DSS)-induced intestinal barrier dysfunction and the inherent mechanisms of this process were investigated. The results showed that LCS-SeNPs, with an average diameter of 198 nm, zero-valent and orange-red relatively uniform spherical particles were prepared. LCS-SeNPs were mainly composed of C, N, O and Se elements, of which Se accounted for 39.03% of the four elements C, N, O and Se. LCS-SeNPs reduced colon injury and inflammation symptoms and improved intestinal barrier dysfunction. LCS-SeNPs significantly reduced serum and colonic inflammatory cytokines TNF-α and IL-6 levels. Moreover, LCS-SeNPs remarkably increased antioxidant enzyme GSH-Px levels in serum and colonic tissue. Further studies on inflammatory pathways showed that LCS-SeNPs alleviated DSS-induced colitis through the NF-κB signaling pathway, and relieved inflammatory associated oxidative stress through the Nrf2 signaling pathway. Our findings suggested that LCS-SeNPs are a promising selenium species with potential applications in the treatment of oxidative stress related inflammatory intestinal diseases.

Polysaccharides from Hemp Seed Protect against Cyclophosphamide-Induced Intestinal Oxidative Damage via Nrf2-Keap1 Signaling Pathway in Mice.

Hemp seed has been used as a traditional oriental medicine and health food in China for centuries. Polysaccharides from hemp seed (HSP) exhibit important properties of intestinal protection, but there are limited data on the specific underlying mechanism. The primary objective of this study was to investigate the protective effect of HSP on intestinal oxidative damage induced by cyclophosphamide (Cy) in mice. The results showed that pretreatment with HSP significantly increased the average daily gain, thymus index, spleen index, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activity in serum and ileal homogenate and significantly reduced malondialdehyde (MDA) content in ileal homogenate. In addition, the expression levels of SOD, GSH-Px, Nrf2, heme oxidase-1 (HO-1), and quinoneoxidoreductase-1 (NQO1) mRNA in ileal homogenate were significantly increased. Western blot results showed that HSP significantly upregulated the expression of Nrf2 protein and downregulated the expression of Keap1 protein in the ileum. Collectively, our findings indicated that HSP had protective effects on intestinal oxidative damage induced by Cy in mice, and its mechanism might be related to the activation of Nrf2-Keap1 signaling pathway.

Low Molecular Seleno-Aminopolysaccharides Protect the Intestinal Mucosal Barrier of Rats under Weaning Stress.

Low molecular seleno-aminopolysaccharide (LSA) was synthesized with sodium selenite and low molecular aminopolysaccharide (LA), which is an organic selenium compound. This study is aimed to investigate the protective effect of LSA on the intestinal mucosal barrier in weaning stress rats by detecting the intestinal tissue morphology and function, mucosal thickness and permeability, the structure of MUC2, antioxidant index, the expression level of intracellular transcription factor NF-E2-related factor 2 (Nrf2), and its related factors. The results showed that LSA significantly increased the height of intestinal villi (p < 0.05) and increased the thickness of intestinal mucosa and the number of goblet cells, which indicated that LSA has a protective effect on the intestinal mucosal barrier that is damaged by weaning. Moreover, LSA significantly reduced the level of DAO, D-LA, and LPS compared with the weaning group (p < 0.05), which indicated that LSA reduced the intestinal damage and permeability of weaning rats. In addition, LSA could increase the number and length of glycans chains and the abundance of acid glycans structures in the MUC2 structure, which indicated that LSA alleviated the changes of intestinal mucus protein structure. LSA significantly increased the levels of GSH-Px, SOD, LDH, and CAT, while it decreased the level of MDA in serum and intestinal tissue, which suggested that LSA significantly enhanced the antioxidant capacity and reduced oxidative stress of weaning rats. RT-PCR results showed that LSA significantly increased the expression level of antioxidant genes (GSH-Px, SOD, Nrf2, HO-1), glycosyltransferase genes (GalNT1, GalNT3, GalNT7) and mucin gene (MUC2) in intestinal mucosa (p < 0.05). The results of western blot showed that the LSA activated the Nrf2 signaling pathway by down-regulating the expression of Keap1and up-regulating the expression of Nrf2, and protected the intestinal mucosa from oxidative stress. Overall, LSA could play a protective role in intestinal mucosal barrier of weaning rats by activating the Nrf2 pathway and alleviating the alnormal change of mucin MUC2.

Protective Effect of Low Molecular Weight Seleno-Aminopolysaccharide on the Intestinal Mucosal Oxidative Damage.

Low molecular weight seleno-aminopolysaccharide (LSA) is an organic selenium compound comprising selenium and low molecular weight aminopolysaccharide (LA), a low molecular weight natural linear polysaccharide derived from chitosan. LSA has been found to exert strong pharmacological activity. In this study, we aimed to investigate the protective effect of LSA on intestinal mucosal oxidative stress in a weaning piglet model by detecting the growth performance, intestinal mucosal structure, antioxidant indices, and expression level of intracellular transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) and its related factors. Our results indicated that LSA significantly increased the average daily gain and feed/gain (p < 0.05), suggesting that LSA can effectively promote the growth of weaning piglets. The results of scanning electron microscope (SEM) microscopy showed that LSA effectively reduced intestinal damage, indicating that LSA improved the intestinal stress response and protected the intestinal structure integrity. In addition, diamine oxidase (DAO) and d-lactic acid (d-LA) levels remarkably decreased in LSA group compared with control group (p < 0.05), suggesting that LSA alleviated the damage and permeability of weaning piglets. LSA significantly increased superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) levels, but decreased malondialdehyde (MDA) level, indicating that LSA significantly enhanced the antioxidant capacity and reduced oxidative stress in weaning piglets. RT-PCR results showed that LSA significantly increased GSH-Px1, GSH-Px2, SOD-1, SOD-2, CAT, Nrf2, HO-1, and NQO1 gene expression (p < 0.05). Western blot analysis revealed that LSA activated the Nrf2 signaling pathway by downregulating the expression of Keap1 and upregulating the expression of Nrf2 to protect intestinal mucosa against oxidative stress. Collectively, LSA reduced intestinal mucosal damage induced by oxidative stress via Nrf2-Keap1 pathway in weaning stress of infants.

Immunomodulatory effect of low molecular-weight seleno-aminopolysaccharide on immunosuppressive mice.

Low molecular-weight seleno-aminopolysaccharides (LSA) have been shown to possess a variety of biological activities in vitro. In the present study, we further investigated the immunomodulatory effect of LSA on immunosuppressive mice induced by cyclophosphamide (CPA) and its molecular mechanism. The results demonstrated that LSA could significantly increase spleen and thymus indices, proliferation of splenic lymphocyte, the secretion of cytokines (IL-2, IL-4, IL-10 and INF-γ) of serum and ileum, and secretory immunoglobulin A (sIgA) content of small intestine. LSA dramatically improved the gene expression levels of IL-2, IL-4, IL-10 and INF-γ in small intestine by real-time fluorescent quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Furthermore, our data indicated that LSA could significantly increase the gene expression levels of IL-1ß and iNOS in RAW264.7 cells. LSA was further shown to remarkably promote inhibitor kappa Bα (IκBα) and nuclear factor-kappa B (NF-κB) p65 phosphorylation with western blot analysis. Taken together, these findings suggest that LSA has immunomodulatory activity on immunosuppressive mice and macrophage RAW264.7 cells, and its mechanism may be related to activation of NF-κB signaling pathway.

Protective effect of low molecular-weight seleno-aminopolysaccharides against H2O2-induecd oxidative stress in intestinal epithelial cells.

Organoselemium compounds possess strong antioxidant activity as well as protecting cells from DNA damage, mitochondrial injury, lipid peroxidation, protein denaturation and cell death. Herein, we used an in vitro oxidative model to further investigate the antioxidant effects of a novel organoselemium compound, low molecular-weight seleno-aminopolysaccharides (LSA) in intestinal porcine epithelial cells (IPEC-1), and the molecular mechanisms of these effects. Analysis by MTT assay showed that LSA could significantly increase the viability of IPEC-1 cells compared to cells exposed to H2O2. We found that the levels of different antioxidant enzymes could dramatically increase in LSA pretreatment group compared to H2O2 treatment group. Furthermore, LSA significantly increased the gene expression of antioxidant enzymes and phase 2 detoxifying enzymes in IPEC-1 cells, as measured by qRT-PCR. In addition, LSA up-regulated the expression level of intracellular transcription factor NF-E2-related factor 2 (Nrf2) and inhibited the level of kelch-like ECH-associated protein 1 (Keap1) with western blot analysis. Collectively, the present study suggested that LSA has the protective effect of IPEC-1 cells against H2O2-induecd oxidative stress, and its mechanism may be related to activation of Keap1/Nrf2 signaling pathway in intestinal epithelial cells.

Immunomodulatory effect of low molecular-weight seleno-aminopolysaccharides in intestinal epithelial cells.

Seleno-polysaccharides possess a variety of biological activities. In the present study, we further investigated the immunomodulatory effects of low molecular-weight seleno-aminopolysaccharides (LSA) in intestinal porcine epithelial cells (IPEC-1), and the molecular mechanisms of these effects. Analysis by ELISAs revealed that LSA could significantly increase the secretion of nitric oxide (NO), interleukin- 6 (IL-6), interleukin- 10 (IL-10), and tumor necrosis factor alpha (TNF-α). Moreover, LSA dramatically increased the gene expression levels of TNF-α, IL-6, IL-10, and iNOS in IPEC-1 cells, as determined by qRT-PCR. Western blot analysis further determined that LSA promotes inhibitor kappa B α (IĸBα), nuclear factor- kappa B (NF-κB) p65 phosphorylation. Taken together, these findings suggested that LSA has immunomodulatory activity on IPEC-1 cells, and its mechanism may be related to activation of the NF-ĸB signaling pathway.

[Diversity and in vitro antitumnor activity of endophytic fungi from mangrove plants Xylocarpus].

A total of 24 biologically pure entophytic fungal strains were isolated from stems, leaves, and seed coats of Xylocarpus plants by repeated purification, and identified with Internal Transcribed Spacer (ITS) rDNA molecular method, which belonging to 14 genera, 11 families, 9 orders and 3 classes. There were differences in genus and species levels among three plant materials from different habitats and species, and it was found that the strains of Phomopsis and Colletotrichum existed in all three plant materials. In vitro assay of antitumor activity by MTT method revealed that the EtOAc extracts of 15 strains exhibited potent antitumor activity. These results suggest that it is of value for further investigation on the above fungal strains.

Chemical composition and microstructure of uroliths associated with the feeding of high-level cottonseed meal diet to sheep.

The chemical composition and microstructure of five urolith samples (4 bladder stones and one kidney stone) associated with the feeding of high level of cottonseed meal (CSM) diet to Chinese merino fine wool sheep (Junken breed, Xinjiang) were examined by optical microscope, X-ray diffraction, X-ray energy dispersive spectrometry (EDS), scanning electron microscopy (SEM), and infrared spectroscopy analysis. The bladder stone samples appeared yellow or white, small powder and loose mass, and as finely granular under the optical microscope. However, the kidney stone samples from a experimental sheep were found as small brown mass, higher hardness, and as a cracklike structure. Oxygen, phosphorus, potassium and magnesium were found as four major elements in these uroliths by X-ray energy dispersive spectrometry (EDS). Potassium magnesium phosphate (MgKPO(4)) and potassium magnesium phosphate hexahydrate (MgKPO(4)·6H(2)O) were major components in the bladder stones, while less magnesium ammonium phosphate hexahydrate (MgNH(4)PO(4)·6H(2)O) examined by X-ray diffraction and infrared spectroscopy analysis. However, the newly found prismatic crystals, which were rich in magnesium and pyrophosphate, were identified as magnesium pyrophosphate (Mg(2)P(2)O(7)) in the kidney stone. The bladder stone samples appeared irregular mass and balls, cracked under SEM with low magnification, while appeared cracked, irregular layer-like, honeycomb-like or tiny balls under high magnification. The kidney stone samples were observed as cone, irregular block or layered crystal structures.