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.

Chitosan-zinc chelate improves intestinal structure and mucosal function and decreases apoptosis in ileal mucosal epithelial cells in weaned pigs.

The present study was conducted to investigate the effects of chitosan (CS)-Zn on intestinal morphology, mucosal epithelial cell apoptosis and mucosal immune function in weanling pigs. A total of 150 weanling barrows with a body weight of 7.2 kg were randomly allocated into five groups. A basal diet without Zn supplementation was used as the control and other four groups were fed the control diet supplemented with 50 or 100 mg/kg of Zn as CS-Zn, 100 mg/kg of Zn as ZnSO4 and 3000 mg/kg of Zn as ZnO, respectively. The feeding trial lasted for 28 d. The results showed that serum diamine oxidase activities, d-lactate levels and endotoxin contents were lower in pigs fed dietary 100 mg/kg of Zn as CS-Zn or 3000 mg/kg of Zn as ZnO than in pigs fed the control or 100 mg Zn/kg as ZnSO4 diet. The ratios of the villus height:crypt depth of the duodenum, jejunum and ileum were higher in pigs that received 100 mg/kg of Zn as CS-Zn or a high level of Zn as ZnO than in pigs fed the control diet. Moreover, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL)-stained ileal epithelial cells were found in the control group, and apoptotic cells did not appear prominently in pigs that received the 100 mg/kg of CS-Zn or ZnO diet. Secretory IgA concentration in ileal mucus was increased in the dietary group that received 100 mg/kg of CS-Zn or ZnO. These results indicated that dietary 100 mg CS-Zn/kg had similar biological effects to dietary 3000 mg ZnO/kg on intestinal morphology, mucosal epithelial cell apoptosis and mucosal immune function.

Total Flavonoids of Astragalus Inhibit Activated CD4[Formula: see text] T Cells and Regulate Differentiation of Th17/Th1/Treg Cells in Experimental Autoimmune Encephalomyelitis Mice by JAK/STAT and NF[Formula: see text]B Signaling Pathways.

Multiple sclerosis (MS) is a neuroinflammatory disease characterized by CD4[Formula: see text] T cell-mediated immune cell infiltration and demyelination in the central nervous system (CNS). The subtypes of CD4[Formula: see text] T cells are T helper cells 1 (Th1), Th2, Th17, and regulatory T cells (Treg), while three other types of cells besides Th2 play a key role in MS and its classic animal model, experimental autoimmune encephalomyelitis (EAE). Tregs are responsible for immunosuppression, while pathogenic Th1 and Th17 cells cause autoimmune-associated demyelination. Therefore, suppressing Th1 and Th17 cell differentiation and increasing the percentage of Treg cells may contribute to the treatment of EAE/MS. Astragali Radix (AR) is a representative medicine with immunoregulatory, anti-inflammatory, antitumor, and neuroprotective effects.The active ingredients in AR include astragalus flavones, polysaccharides, and saponins. In this study, it was found that the total flavonoids of Astragus (TFA) could effectively treat EAE in mice by ameliorating EAE motor disorders, reducing inflammatory damage and demyelination, inhibiting the proportion of Th17 and Th1 cells, and promoting Tregs differentiation by regulating the JAK/STAT and NF[Formula: see text]B signaling pathways. This novel finding may increase the possibility of using AR or TFA as a drug with immunomodulatory effects for the treatment of autoimmune diseases.

Influence of Cu2+-loaded silicate on the growth performance and microflora of crucian carp Carassius auratus.

We investigated the effects of Cu2+-loaded silicate (CLS) on the growth performance, microflora of skin, gill and intestine, and intestinal morphology of crucian carp Carassius auratus. A total of 225 native wild crucian carp, with an average initial body weight of 20 g, were randomly divided into 5 treatment groups using 3 replicate tanks of 15 fish per group. The dietary treatments were (1) basal diet, (2) basal diet + CuSO4, (3) basal diet + silicate, (4) basal diet + 0.5% CLS and (5) basal diet + 50 mg kg(-1) chlortetracycline (CTC, purity 98.8%). The trial lasted for 60 d. We found that body weight increased slightly while feed conversion ratio decreased in the CLS-treated group compared with the control groups. The total number of aerobic bacteria counted in the intestine of carp fed the diet supplemented with the CLS (i.e. Vibrio sp. and E. coli), was significantly lower (p = 0.05) compared with the control groups and the CTC-treated fish, while lactobacillus counts were significantly higher (p = 0.05). Lactobacilli counts of the intestine increased significantly (p = 0.05). However, the microflora of the skin and gill was not affected by the addition of CuSO4, silicate, CLS or CTC. The height of the villi in the proximal, mid and distal intestine mucosa of the silicate- and CLS-treated groups was found to be longer (p = 0.05) compared with the villi of the control or the CTC-treated fish. Supplementation with CuSO4 had no effect on the microflora and the intestinal morphology (p = 0.05). These results indicate that CLS had an antibacterial activity in vivo, which may help protect the intestinal mucosa from invasion of pathogenic bacteria and their toxins.

Preparation, characterization and adsorption properties of chitosan nanoparticles for eosin Y as a model anionic dye.

The present study dealt with the adsorption of eosin Y, as a model anionic dye, from aqueous solution using chitosan nanoparticles prepared by the ionic gelation between chitosan and tripolyphosphate. The nanoparticles were characterized by atomic force microscopy (AFM), size and zeta potential analysis. A batch system was applied to study the adsorption of eosin Y from aqueous solution by chitosan nanoparticles. The results showed that the adsorption of eosin Y on chitosan nanoparticles was affected by contact time, eosin Y concentration, pH and temperature. Experimental data followed Langmuir isotherm model and the adsorption capacity was found to be 3.333 g/g. The adsorption process was endothermic in nature with an enthalpy change (DeltaH) of 16.7 kJ/mol at 20-50 degrees C. The optimum pH value for eosin Y removal was found to be 2-6. The dye was desorbed from the chitosan nanoparticles by increasing the pH of the solution.

Changes of porcine growth hormone and pituitary nitrogen monoxide production as a response to cadmium toxicity.

The present study was designed to investigate the effects of various cadmium concentrations on porcine growth hormone (GH) secretion in serum and cultured pituitary cells and to explore the possible mechanisms of cadmium toxicity. In feeding trial, 192 barrows (Duroc x Landrace x Yorkshire), with similar initial body weights, were randomly divided into four different treatment groups with three replicates for each treatment. The diets were supplemented for 83 days with 0, 0.5, 5.0, and 10.0 mg/kg cadmium (as CdCl2). For the cell culture trial, dispersed pituitary cells were incubated with graded doses of cadmium (0, 5, 10, 15, or 20 microM) for 24 h. Pigs treated with 10 mg/kg cadmium had significantly decreased serum GH content. 3-(4,5-dimethyl-2-yl)-2,5-diphenyl tetrazolium bromide assay showed that Cd toxicity was dose-dependent. Cell viability was reduced to 50% at 15 microM concentration. Administration of cadmium significantly reduced GH secretion, whereas cellular NO content and inducible nitric oxide synthase activity increased to a certain extent. These findings suggest that the decrease of GH might be related to NO production and to a change of NO signal pathway caused by cadmium.

Effects of dietary fresh fermented soybean meal on growth performance, ammonia and particulate matter emissions, and nitrogen excretion in nursery piglets.

This study was conducted to investigate the effects of fresh fermented soybean meal (FSM) on the growth performance of nursery piglets, nitrogen excretion in feces, and the concentrations of ammonia (NH3) and particulate matter (PM) in the piggery. A total of 472 nursery piglets (Landrace×Yorkshire, (16.3±0.36) kg body weight) were randomly allocated into two treatments with 236 pigs in each treatment. The pigs were fed the basal diet without fresh FSM (control) or diet containing 10% (100 g/kg) fresh FSM (FSM group), and the crude protein content of the two groups was consistent. The feeding trial lasted for 28 d. The results showed that the pigs fed fresh FSM had increased (P<0.05) average daily gain (ADG) compared with the control. There was no significant difference (P>0.05) in feed to gain ratio (F:G) between the two groups. During the whole experiment, the concentration of NH3 in the piggery decreased (P<0.05) by 19.0%, and the concentrations of PM (PM10 and PM2.5) in the piggery decreased (P<0.05) by 19.9% and 11.6%, respectively, in the FSM group, compared with the control. The ammonia nitrogen and nitrite content in feces increased (P<0.05) by 32.9% and 28.4%, respectively, in the FSM group. The fecal pH declined (P<0.05) significantly in the FSM group compared with the control. At the end of experiment, total protein (TP) concentration was increased (P<0.05) significantly and blood urea nitrogen (BUN) concentration was decreased (P<0.05) for pigs fed the diet with fresh FSM. The results indicated that dietary fresh FSM not only improved the growth performance of nursery piglets, but also reduced the NH3 concentration in the piggery due to nitrogen conversion, and decreased the concentrations of PM10 and PM2.5 in the piggery.

Effect of cadmium on lipid peroxidation and activities of antioxidant enzymes in growing pigs.

Malondialdehyde (MDA), glutathione (GSH) content, total antioxidant capacity (T-AOC) levels, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and glutathione transferase (GST) activities were studied in serum, liver, and kidney of growing pigs after graded doses of cadmium administration in diets. One hundred ninety-two barrows (Duroc x Landrace x Yorkshire), with similar initial body weight 27.67 +/- 1.33 kg, were randomly allotted into 4 different treatments with 3 replications (16 pigs per replication). The treatments received the same basal diet added with 0, 0.5, 5.0, and 10.0 mg/kg cadmium (as CdCl2), respectively. The results showed pigs treated with 10 mg/kg cadmium significantly decreased average daily gain (ADG) (p<0.05) and increased feed/gain ratio (F/G) (p<0.05) compared to the control. In this treatment, the contents of MDA increased significantly (p<0.05), GSH concentrations, T-AOC levels, and the activities of SOD, GSH-PX, and GST decreased significantly (p<0.05). The results indicate 10 mg/kg cadmium could decrease pig antioxidant capacity after extended exposure and cadmium-induced increase lipid peroxidation might not be only the result of the possibility of lower level of GSH but could also be as a result of direct action of cadmium on peroxidation reaction.

In vitro effects of chitosan nanoparticles on proliferation of human gastric carcinoma cell line MGC803 cells.

AIM: To investigate the effects of chitosan nanoparticles on proliferation of human gastric carcinoma cell line MGC803 in vitro and the possible mechanisms involved. METHODS: Chitosan nanoparticles were characterized by particle size, zeta potential, and morphology. After treatment with various concentrations of chitosan nanoparticles (25, 50, 75, 100 microg/mL) at various time intervals, cell proliferation, ultrastructural changes, DNA fragmentation, mitochondrial membrane potential (MMP), cell cycle phase distribution and apoptotic peaks of MGC803 cells were analyzed by MTT assay, electron microscopy, DNA agarose gel electrophoresis, and flow cytometry. RESULTS: Chitosan nanoparticles exhibited a small particle size as 65 nm and a high surface charge as 52 mV. Chitosan nanoparticles markedly inhibited cell proliferation of MGC803 cells with an IC50 value of 5.3 microg/mL 48 h after treatment. After treatment with chitosan nanoparticles, the typical necrotic cell morphology was observed by electron microscopy, a typical DNA degradation associated with necrosis was determined by DNA agarose electrophoresis. Flow cytometry showed the loss of MMP and occurrence of apoptosis in chitosan nanoparticles-treated cells. CONCLUSION: Chitosan nanoparticles effectively inhibit the proliferation of human gastric carcinoma cell line MGC803 in vitro through multiple mechanisms, and may be a beneficial agent against human carcinoma.

Changes in small intestinal morphology and digestive enzyme activity with oral administration of copper-loaded chitosan nanoparticles in rats.

The experiment was conducted to evaluate the effect of copper-loaded chitosan nanoparticles on the small intestinal morphology and activities of digestive enzyme and mucosal disaccharase in rats. Forty male Sprague-Dawley rats, with average body weight of 82 g, were randomly allotted to five groups (n = 8). All rats were received a basal diet (control) or the same basal diet added with 80 mg/kg BW CuSO(4), 80 mg/kg BW chitosan (CS-I), 80 mg/kg BW copper-loaded chitosan nanoparticles (CSN-I), 160 mg/kg BW copper-loaded chitosan nanoparticles (CSN-II), respectively. The experiment lasted 21 days. The results showed that the villus heights of the small intestinal mucosa in groups CSN-I and CSN-II were higher than those of the control, group CuSO(4) or CS-I. The crypt depth of duodenum and ileum mucosa in group CSN-I or CSN-II was depressed. Compared with the control, there were no significant effects of CuSO(4) or CS-I on the villus height and crypt depth of small intestinal mucosa. Supplementation with CSN improved the activities of trypsin, amylase and lipase in the small intestinal contents and maltase, sucrase and lactase of duodenum, jejunum, and ileum mucosa while there were no significant effects of CuSO(4) on the digestive enzyme activities of the small content compared with the control. The results indicated that intestinal morphology, activities of digestive enzyme in digesta and mucosal disaccharase were beneficially changed by treatment of copper-loaded chitosan nanoparticles.