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.
In this study, novel composite titanium-based metal-organic framework (MOF) beads were synthesized from titanium based metal organic framework MIL-125 and chitosan (CS) and used to remove Pb(II) from ...wastewater. The MIL-125-CS beads were prepared by combining the titanium-based MIL-125 MOF and chitosan using a template-free solvothermal approach under ambient conditions. The surface and elemental properties of these beads were analyzed using scanning electron microscopy, Fourier transform infrared and X-ray photoelectron spectroscopies, as well as thermal gravimetric analysis. Moreover, a series of experiments designed to determine the influences of factors such as initial Pb(II) concentration, pH, reaction time and adsorption temperature was conducted. Notably, it was found that the adsorption of Pb(II) onto the MIL-125-CS beads reached equilibrium in 180 min to a level of 407.50 mg/g at ambient temperature. In addition, kinetic and equilibrium experiments provided data that were fit to the Langmuir isotherm model and pseudo-second-order kinetics. Furthermore, reusability tests showed that MIL-125-CS retained 85% of its Pb(II)-removal capacity after five reuse cycles. All in all, we believe that the developed MIL-125-CS beads are a promising adsorbent material for the remediation of environmental water polluted by heavy metal ions.
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.
Controlling surface composition of bimetallic catalysts is of significance in energy conversion and storage. Here, we controlled thermal treatment to synthesize different surface composition of ...bimetallic catalysts with average diameter <4nm. We report the synthesis of Pt3Ni catalyst with Pt-skin surface directly supported on porous graphitic carbon (PC), which showed over 300% increase in mass activity compared with Pt/C for the oxygen reduction reaction (ORR). The high activity and stability are attributed to the Pt-skin structure and the morphology of PC. When we tuned the surface composition to Ni-rich, it showed 300% increase in mass activity when compared with Pt/C towards oxidizing of HCOOH. Our approach to control surface composition can be used to design nanocatalysts for different reaction and are simple, effective and promotional to be industrialized.
Display omitted
Background
Whether adherence to the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) cancer prevention recommendations is associated with a reduced risk of pancreatic ...cancer remains controversial. Additionally, no study has investigated this association in the US population. Hence, we investigated the association of adherence to the 2018 WCRF/AICR cancer prevention recommendations with pancreatic cancer incidence and mortality in a US population.
Methods
A population‐based cohort of 95 962 participants was identified. A score incorporating eight WCRF/AICR components was constructed to reflect adherence to the WCRF/AICR guidelines, with higher scores representing greater adherence to the guidelines. Cox and competing risk regression were used to calculate risk estimates for pancreatic cancer incidence and mortality, respectively. Restricted cubic spline functions were used to test nonlinearity.
Results
In the fully adjusted model, higher overall WCRF/AICR scores were shown to be associated with lower risks of developing pancreatic cancer (hazard ratiotertile 3 vs 1:0.67; 95% confidence interval: 0.49, 0.90; Ptrend = .0099) and mortality due to this cancer (subdistribution hazard ratiotertile 3 vs 1 0.65; 95% confidence interval: 0.47, 0.89; Ptrend = .0108) in a linear dose–response manner (all Pnonlinearity > .05). The component “be physically active” was shown to be a key contributor to the observed associations. No association of the diet‐specific WCRF/AICR score with pancreatic incidence and mortality was found.
Conclusions
Adherence to the 2018 WCRF/AICR guidelines, especially “be physically active,” confers reduced risks of pancreatic cancer incidence and mortality in the US population; however, adherence to dietary components alone does not confer such beneficial effects.
In this prospective study of 95962 American adults, we found that greater adherence to the 2018 WCRF/AICR recommendations was associated with lower risks of pancreatic cancer incidence and mortality. However, such beneficial effects were not found for adherence to diet‐specific recommendations alone.Importantly, the component “be physically active” was found to be a key driver of the observed associations.
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.
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-1β 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.
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.
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.
Display omitted
Fucosterol, extracted from S. fusiforme significantly shortened immobility time in the forced swim test and tail suspension test 30min 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, and fucosterol may possess an antidepressant-like effect, which may be mediated by increasing central BDNF levels. Fucosterol possessed anticonvulsant activity in maximal electroshock test. Thus, fucosterol may be a useful antidepressant adjunct candidate for treating depression in patients with epilepsy.
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.
PDF
