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 polysaccharides of sea cucumber Acaudina leucoprocta on hydrogen peroxide-induced oxidative injury in RAW264.7 cells.

The aim of this experiment was to investigate the protective effects of polysaccharides of sea cucumber Acaudina leucoprocta (ALP) against hydrogen peroxide (H2O2) induced oxidative injury in RAW264.7 cells. Analysis of monosaccharide composition and structure of one fraction from ALP (ALPN) were analyzed by High Performance Liquid Chromatography (HPLC) and Fourier Transform Infrared Spectoscopy (FT-IR). The results showed that ALPN contain sulfate groups, which is sulfated polysaccharides. The results from MTT assay indicated that ALPN could markedly increase viability of cells compared with RAW264.7 cells exposed to H2O2. Moreover, ALPN significantly increased the levels of catalase (CAT), glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD), decreased the production of malondialdehyde (MDA) and lactate dehydrogenase (LDH) in RAW264.7 cells. The data from RT-PCR showed that ALPN (300 µg/mL) could increase the gene expression levels of SOD1 and GPX1. ALPN could also observably increase the protein expression level of Nrf2 and decrease the protein expression level of Keap1 with western blot. Collectively, this study suggested that polysaccharides of sea cucumber Acaudina leucoprocta (ALP) could effectively protect RAW264.7 cells against H2O2-induced oxidative injury. This protection mechanism may be related to activation of the Nrf2/Keap1 signaling pathway.

Hemp seed polysaccharides protect intestinal epithelial cells from hydrogen peroxide-induced oxidative stress.

The purpose of this study was to investigate structure of Hemp seed polysaccharide (HSP) and the protective effect of HSP from H2O2-induced oxidative damage in IPEC-1 cells and the possible mechanism of this protection. Analysis of monosaccharide composition and structure of two fractions HSP0 and HSP0.2 from polysaccharide of Hemp seed (HSPc) were analyzed by high performance liquid chromatography (HPLC) and Fourier transform infrared spectroscopy (FT-IR). The results showed that both HSP0 and HSP0.2 contain sulfate groups, which are sulfated polysaccharides. In IPEC-1 cells model, the release of LDH and MDA was significantly decreased, and the activities of SOD, GSH-Px and CAT were significantly increased in HSP0 and HSP0.2-treated group. HSP0.2 dramatically increased the gene expression of antioxidant enzymes and phase II detoxification enzymes measured by real-time fluorescent quantitative reverse transcription-polymerase chain reaction (qRT-PCR). In addition, HSP0.2 up-regulated the expression level of intracellular transcription factor Nuclear factor erythroid-2-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 HSP0.2 has the protective effect of IPEC-1 cells against H2O2-induecd oxidative stress. This protection mechanism may be related to activation of the Keap1/Nrf2 signaling pathway.

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.

Liver transcriptome analysis of the Sparus macrocephlus in response to Vibrio parahaemolyticus infection.

The black seabream (Sparus macrocephlus) is an economically pivotal aquaculture species cultured in China and Southeast Asian countries. To understand the molecular immune mechanisms underlying the response to Vibrio parahaemolyticus, a comparative gene transcription analysis were performed with utilized fresh livers of V. parahaemolyticus-immunized Sparus macrocephlus with a control group through RNA-Seq technology. A total of 256663 contigs were obtained after excluded the low-quality sequences and assembly. The average length of contigs collected from this research is 1066.93 bp. Furthermore, blast analysis indicates 30747 contigs were annotated based on homology with matches in the NT, NR, gene, and string databases. A gene ontology analysis was employed to classify 21598 genes according to three major functional categories: molecular function, cellular component, and biological process. A total of 14470 genes were discovered in 303 KEGG pathways. RSEM and EdgeR were introduced to estimate 3841 genes significantly different expressed (False Discovery Rate<0.001) which includes 4072 up-regulated genes and 3771 down-regulated genes. A significant enrichment analysis of these differentially expressed genes and isogenes were conducted to reveal the major immune-related pathways which refer to the toll-like receptor, complement, coagulation cascades, and chemokine signaling pathways. In addition, 92175 potential simple sequence repeats (SSRs) and 121912 candidate single nucleotide polymorphisms (SNPs) were detected and identified sequencely in the Sparus macrocephlus liver transcriptome. This research characterized a gene expression pattern for normal and the V. parahaemolyticus -immunized Sparus macrocephlus for the first time and not only sheds new light on the molecular mechanisms underlying the host-V. parahaemolyticus interaction but contribute to facilitate future studies on Sparus macrocephlus gene expression and functional genomics.

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.

Molecular Weight-Dependent Immunostimulative Activity of Low Molecular Weight Chitosan via Regulating NF-κB and AP-1 Signaling Pathways in RAW264.7 Macrophages.

Chitosan and its derivatives such as low molecular weight chitosans (LMWCs) have been found to possess many important biological properties, such as antioxidant and antitumor effects. In our previous study, LMWCs were found to elicit a strong immunomodulatory response in macrophages dependent on molecular weight. Herein we further investigated the molecular weight-dependent immunostimulative activity of LMWCs and elucidated its mechanism of action on RAW264.7 macrophages. LMWCs (3 kDa and 50 kDa of molecular weight) could significantly enhance the mRNA expression levels of COX-2, IL-10 and MCP-1 in a molecular weight and concentration-dependent manner. The results suggested that LMWCs elicited a significant immunomodulatory response, which was dependent on the dose and the molecular weight. Regarding the possible molecular mechanism of action, LMWCs promoted the expression of the genes of key molecules in NF-κB and AP-1 pathways, including IKKß, TRAF6 and JNK1, and induced the phosphorylation of protein IKBα in RAW264.7 macrophage. Moreover, LMWCs increased nuclear translocation of p65 and activation of activator protein-1 (AP-1, C-Jun and C-Fos) in a molecular weight-dependent manner. Taken together, our findings suggested that LMWCs exert immunostimulative activity via activation of NF-κB and AP-1 pathways in RAW264.7 macrophages in a molecular weight-dependent manner and that 3 kDa LMWC shows great potential as a novel agent for the treatment of immune suppression diseases and in future vaccines.

Composition and anti-inflammatory effect of polysaccharides from Sargassum horneri in RAW264.7 macrophages.

Sulfated polysaccharides extracted from brown marine algae have been shown to possess a variety of biological activities. We assessed the potential activity of the sulfated polysaccharide from Sargassum horneri (SP) and its isolated two major components (fraction-1 (F1) and fraction-2 (F2)), on anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. In the present study, analysis of polysaccharide chemical composition found that the constituent ratios of sulfate ester and fucose in SP and F1 were 4.95% vs 7.6%, and 4.48% vs 55.9%, respectively, suggesting that F1 may be a major sulfated polysaccharide containing fucose. Meanwhile, our findings demonstrated that TNF-α secretion levels were significantly (P<0.05) decreased by SP and F1 treatments in LPS-stimulated RAW264.7 cells in a dose-dependent manner under the preventive and repair experimental models. Pro-/anti-inflammatory (TNF-α/IL-10) cytokines secretion ratios by LPS-stimulated RAW264.7 macrophages were significantly (P<0.05) inhibited by SP and F1 treatments, particularly by F1 (at high dose, 200µg/ml). Moreover, NO release and iNOS activity were significantly (P<0.05) inhibited by F1. Collectively, the present study suggested that purified component, F1 from SP, had strong anti-inflammatory effects on LPS-stimulated RAW264.7 macrophages in the preventive and repair manner through inhibiting TNF-α secretion levels and NO release.

Fucosterol, a sterol extracted from Sargassum fusiforme, shows antidepressant and anticonvulsant effects.

We previously showed that extracts of Sargassum fusiforme significantly reduce immobility time in the forced swim test and tail suspension test, suggesting that these extracts possess antidepressant-like effects. Here, fucosterol extracted from S. fusiforme was evaluated for antidepressant and anticonvulsant activities in mice. Fucosterol (10, 20, 30 and 40mg/kg) significantly shortened immobility time in the forced swim test and tail suspension test for30min after treatment but had no effect on locomotor activity in the open field test. Fucosterol significantly increased serotonin, norepinephrine and the metabolite 5-hydroxyindoleacetic acid in mouse brain, suggesting that the effects of fucosterol may be mediated through these neurotransmitters. As assessed using maximal electroshock, fucosterol (20, 40, 100mg/kg) possessed anticonvulsant activity, whereas rotarod toxicity test results indicated that fucosterol did not induce neurotoxicity at the same dose levels in mice. Thus, fucosterol may be a useful antidepressant adjunct candidate for treating depression in patients with epilepsy. A significant increase in hippocampal brain-derived neurotrophic factor (BDNF) levels was found in the fucosterol 20mg/kg group (P<0.05). Our findings suggested that fucosterol may possess an antidepressant-like effect, which may be mediated by increasing central BDNF levels.

Immunostimulative Activity of Low Molecular Weight Chitosans in RAW264.7 Macrophages.

Chitosan and its derivatives such as low molecular weight chitosans (LMWCs) have been reported to exert many biological activities, such as antioxidant and antitumor effects. However, complex and molecular weight dependent effects of chitosan remain controversial and the mechanisms that mediate these complex effects are still poorly defined. This study was carried out to investigate the immunostimulative effect of different molecular weight chitosan in RAW264.7 macrophages. Our data suggested that two LMWCs (molecular weight of 3 kDa and 50 kDa) both possessed immunostimulative activity, which was dependent on dose and, at the higher doses, also on the molecular weight. LMWCs could significantly enhance the the pinocytic activity, and induce the production of tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), interferon-γ (IFN-γ), nitric oxide (NO) and inducible nitric oxide synthase (iNOS) in a molecular weight and concentration-dependent manner. LMWCs were further showed to promote the expression of the genes including iNOS, TNF-α. Taken together, our findings suggested that LMWCs elicited significantly immunomodulatory response through up-regulating mRNA expression of proinflammatory cytokines and activated RAW264.7 macrophage in a molecular weight- and concentration-dependent manner.

Partially hydrolyzed bamboo (Phyllostachys heterocycla) as a porous Bioadsorbent for the removal of Pb(II) from aqueous mixtures.

A novel porous succinylated bioadsorbent was prepared by the partial enzymatic hydrolysis of bamboo (Phyllostachys heterocycla) and its subsequent modification with succinic anhydride. Pb(II) removal from solutions that also contained sodium chloride and an amino acid was investigated using the bioadsorbent. Enzymatic hydrolysis increased the number of accessible hydroxyl groups and surface area of the raw bamboo, and created many pores within the material. The porous succinylated bioadsorbent exhibited high efficiency for Pb(II) binding. The sodium chloride content significantly decreased the Pb(II) adsorption capacity, whereas a minor effect was observed in the presence of arginine. The experimental data could be accurately described by a pseudo-second-order kinetics model, and the adsorption proceeded via an ion exchange mechanism. Even in a solution containing sodium chloride and arginine, the maximum adsorption capacity of Pb(II) by the porous succinylated bioadsorbent was 99.5 mg/g at 303 K.

Protective effect of polysaccharides from Sargassum horneri against oxidative stress in RAW264.7 cells.

This study was designed to investigate chemical composition and the protective effects of polysaccharides isolated from Sargassum horneri against hydrogen peroxide (H2O2)-induced oxidative injury in RAW264.7 cells. Results showed that isolated polysaccharides (SHSc) and the major fractions (SHS1, SHS0.5) contained sulfate ester, and SHS1 was high fucose-containing sulfated polysaccharide. After preincubation with three isolated polysaccharides, RAW264.7 cells viability were significantly restored and decreased in cellular LDH release (P<0.05). SHS1 and SHS0.5 decreased intracellular ROS level, intracellular NO and malonic dialdehyde (MDA) level (P<0.05), restoring activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) (P<0.05), decreasing inducible nitric oxide synthase (iNOS) (P<0.05). Moreover, preincubation of SHS1 with RAW264.7 cells resulted in the increase of the gene expression level of endogenous antioxidant enzymes such as MnSOD and GSH-Px (P<0.05). These results clearly showed that SHSc and its fractions could attenuate H2O2-induced stress injury in RAW264.7 cells, and a similar efficiency in protecting RAW264.7 cells against H2O2-induced oxidative injury between SHS1 and Vitamin C. Taken together, our findings suggested that SHS1 can effectively protect RAW264.7 cells against oxidative stress by H2O2, which might be used as a potential natural antioxidant in the functional food and pharmaceutical industries.

[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.

Chitosan nanoparticles attenuate hydrogen peroxide-induced stress injury in mouse macrophage RAW264.7 cells.

This study was carried out to investigate the protective effects of chitosan nanoparticles (CNP) against hydrogen peroxide (H2O2)-induced oxidative damage in murine macrophages RAW264.7 cells. After 24 h pre-incubation with CNP (25-200 µg/mL) and chitosan (CS) (50-200 µg/mL, as controls), the viability loss in RAW264.7 cells induced by H2O2 (500 µM) for 12 h was markedly restored in a concentration-dependent manner as measured by MTT assay (P < 0.05) and decreased in cellular LDH release (P < 0.05). Moreover, CNP also exerted preventive effects on suppressing the production of lipid peroxidation such as malondialdehyde (MDA) (P < 0.05), restoring activities of endogenous antioxidant including superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) (P < 0.05), along with increasing total antioxidant capacity (T-AOC) (P < 0.05). In addition, pre-incubation of CNP with RAW264.7 cells for 24 h resulted in the increase of the gene expression level of endogenous antioxidant enzymes, such as MnSOD and GSH-Px (P < 0.05). At the same concentration, CNP significantly decreased LDH release and MDA (P < 0.05) as well as increased MnSOD, GSH-Px, and T-AOC activities (P < 0.05) as compared to CS. Taken together, our findings suggest that CNP can more effectively protect RAW264.7 cells against oxidative stress by H2O2 as compared to CS, which might be used as a potential natural compound-based antioxidant in the functional food and pharmaceutical industries.

Chitosan nanoparticles act as an adjuvant to promote both Th1 and Th2 immune responses induced by ovalbumin in mice.

The study was conducted to investigate the promoted immune response to ovalbumin in mice by chitosan nanoparticles (CNP) and its toxicity. CNP did not cause any mortality or side effects when mice were administered subcutaneously twice with a dose of 1.5 mg at 7-day intervals. Institute of Cancer Research (ICR) mice were immunized subcutaneously with 25 µg ovalbumin (OVA) alone or with 25 µg OVA dissolved in saline containing Quil A (10 µg), chitosan (CS) (50 µg) or CNP (12.5, 50 or 200 µg) on days 1 and 15. Two weeks after the secondary immunization, serum OVA-specific antibody titers, splenocyte proliferation, natural killer (NK) cell activity, and production and mRNA expression of cytokines from splenocytes were measured. The serum OVA-specific IgG, IgG1, IgG2a, and IgG2b antibody titers and Con A-, LPS-, and OVA-induced splenocyte proliferation were significantly enhanced by CNP (P < 0.05) as compared with OVA and CS groups. CNP also significantly promoted the production of Th1 (IL-2 and IFN-γ) and Th2 (IL-10) cytokines and up-regulated the mRNA expression of IL-2, IFN-γ and IL-10 cytokines in splenocytes from the immunized mice compared with OVA and CS groups. Besides, CNP remarkably increased the killing activities of NK cells activity (P < 0.05). The results suggested that CNP had a strong potential to increase both cellular and humoral immune responses and elicited a balanced Th1/Th2 response, and that CNP may be a safe and efficacious adjuvant candidate suitable for a wide spectrum of prophylactic and therapeutic vaccines.

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.