铁观音茶提取物对脂多糖诱导RAW264.7细胞炎症反应的抑制作用及机制

研究铁观音茶提取物对脂多糖(LPS)诱导的RAW264.7细胞炎症反应的抑制作用及机制。用脂多糖作用于RAW264.7细胞,建立炎症模型,并用吲哚美辛和不同浓度铁观音提取物处理,检测NO和IL-6的分泌情况,qPCR检测一氧化氮合酶(iNOS)、环氧合酶2(COX-2)、肿瘤坏死因子α(TNF-α)、单核细胞趋化蛋白1(MCP-1)、白细胞介素6(IL-6)mRNA相对表达,Western Blot检测炎症相关蛋白激酶(IKKβ),核转录因子κB抑制因子(IκB)、核转录因子κB p65(NF κB p65)及其磷酸化产物的相对表达。结果显示,铁观音茶提取物能显著抑制炎症介质NO分泌和IL-6蛋白表达量(p<0.05),抑制炎症相关基因iNOS、COX-2、TNF-α和MCP-1等表达,并极显著抑制NF-κB信号通路相关蛋白IKKβ、IkB和p65的磷酸化(p<0.01)。以上结果表明,铁观音茶提取物可明显抑制LPS诱导的RAW264.7细胞炎症反应,其机制可能与抑制NF-κB信号通路激活有关。     

高核苷酸酵母水解物对脂多糖诱导RAW264.7细胞免疫调节的影响

为探讨高核苷酸酵母水解物对RAW264.7小鼠巨噬细胞免疫活性调节及其相关作用机制,采用脂多糖(1μg/mL)刺激RAW264.7细胞来建立体外细胞炎症模型,以不同质量浓度的高核苷酸酵母水解物干预来明确其抗炎效果。ELISA法检测细胞培养上清中白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)的含量,RT-PCR法检测相关mRNA表达水平,Western blot法检测细胞iNOS及胞核内核转录因子NF-κBp65蛋白水平。结果表明:高核苷酸酵母水解物作用RAW264.7细胞的安全范围≤150μg/mL。与LPS模型组相比,质量浓度60～150μg/mL的高核苷酸酵母水解物能显著增强RAW264.7吞噬能力,高核苷酸酵母水解物(60～150μg/mL)能有效抑制脂多糖(lipopolysaccharide,LPS)诱导RAW264.7细胞释放NO、TNF-α、IL-1β和IL-6炎症因子及相关mRNA表达,降低iNOS及NF-κB蛋白水平。研究结果证实了高核苷酸酵母水解物对LPS刺激RAW264.7细胞炎症的保护作用,作用机制与NF-κB通路有关,为食疗干预慢性病提供一定的理论依据。     

DPA体外抗炎活性及机制研究

以脂多糖(LPS)诱导的RAW264.7巨噬细胞为炎症的体外模型,以炎症介质【NO和前列腺素E2(PGE2)】和炎症因子(TNF-α,IL-1β,IL-6和IL-10)为指标,研究二十二碳五烯酸(DPA)的体外抗炎活性,并从NF-κB代谢通路的角度探究DPA体外抗炎活性的作用机制。结果表明,DPA可以显著抑制iNOS和COX-2的表达,抑制炎症介质NO和PGE2的分泌,并且,DPA通过调控促炎因子(TNF-α,IL-1β,IL-6)和抑炎因子(IL-10)的平衡发挥抗炎作用。Western blot结果表明,DPA显著抑制NF-κB代谢通路中p50和p65的磷酸化,限制p50/p65核内转移,抑制炎症级联反应,发挥抗炎作用。     

姬松茸多糖诱导巨噬细胞释放NO的机制

以小鼠巨噬细胞RAW264.7为研究对象,研究姬松茸多糖对其NO释放和iNOS表达的作用,并通过检测IκBα蛋白磷酸化水平的变化来探究姬松茸多糖诱导巨噬细胞释放NO的分子机制。结果表明,姬松茸多糖可剂量依赖性增强RAW264.7细胞NO的释放与iNOS蛋白的表达,且两者趋势一致。此外,25μg/mL姬松茸多糖能够增强RAW264.7细胞中p-IκBα蛋白的表达量,且在45min时达到最高,证明其能够激活NF-κB信号转导通路。综上,姬松茸多糖通过NF-κB途径上调巨噬细胞iNOS的表达,进而促进NO释放。     

大蒜素对脂多糖诱导腹腔巨噬细胞炎症反应的抑制作用及机制

目的:探讨大蒜素对脂多糖(LPS)诱导小鼠腹腔巨噬细胞炎症反应的抑制作用及机制。方法:建立LPS诱导小鼠腹腔巨噬细胞炎症反应细胞模型,并用地塞米松和不同浓度大蒜素处理,MTT法检测细胞活力,中性红吞噬实验检测吞噬能力,Griess法检测一氧化氮(NO)及ELISA法检测COX-2酶活性和IL-6的分泌,qPCR检测环氧合酶2(COX-2)、一氧化氮合酶(iNOS)和IL-6的mRNA表达水平,Western Blot检测COX-2、iNOS和IL-6的蛋白表达以及核转录因子NF-κB p65及其磷酸化产物的相对表达。结果:大蒜素浓度在40~160 μg/mL范围内对腹腔巨噬细胞均无细胞毒性;与LPS组比较,大蒜素处理组能促进腹腔巨噬细胞的吞噬能力,能显著(P<0.05)抑制炎症因子COX-2酶活性、NO和IL-6的分泌,能显著(P<0.05)抑制基因COX-2、iNOS和IL-6 mRNA和蛋白的相对表达,并极显著(P<0.01)抑制NF-κB p65信号通路的磷酸化。结论:大蒜素能显著抑制LPS诱导的小鼠腹腔巨噬细胞的炎症反应,其机制可能与抑制NF-κB信号通路激活有关。     

蒲公英糖蛋白体外抗炎作用及对NF-κB信号通路的调控

探讨蒲公英糖蛋白(glycoprotein from Taraxacum,TG)对由脂多糖引起的RAW264.7细胞炎症的抗炎效果,并阐明其活性的基本分子机制。利用脂多糖刺激RAW264.7细胞,建立体外炎症模型,采用噻唑蓝比色法检测TG对RAW264.7细胞的增殖毒性,Griess试剂法检测了一氧化氮(nitric oxide,NO)的分泌情况,反转录聚合酶链式反应检测炎症细胞因子——白细胞介素-6(interleukin 6,IL-6)和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)m RNA以及诱导型一氧化氮合酶(inducible nitric oxide synthase,i NOS)m RNA的表达水平,酶联免疫吸附测定法测定IL-6和TNF-α的分泌量,Western blot检测P-IκB-α蛋白的表达水平,用以研究TG对核转录因子-κB(nuclear factor-kappa B,NF-κB)信号转导通路的抑制作用。结果表明:TG能够显著甚至极显著地抑制NO的分泌,IL-6、TNF-α、i NOS的m RNA的表达,IL-6和TNF-α的分泌(P0.05、P0.01)。TG高度显著上调了IκB-α的蛋白表达(P0.001),并显著下调了P-IκB-α的蛋白表达(P0.05),且与TG质量浓度成正比。其中在TG质量浓度为250、500、1 000μg/m L时对TNF-α分泌量的抑制率分别为28.6%、65.4%、89.3%,对IL-6分泌量的抑制率分别为32.3%、54.1%、85.7%。TG间接抑制了NF-κB信号转导途径,有显著的体外抗炎效果且抗炎效果与TG的质量浓度呈剂量依赖性。     

羊栖菜多酚通过核转录因子-κB/丝裂原活化蛋白激酶通路缓解脂多糖诱导的RAW264.7细胞炎症反应

目的：研究羊栖菜多酚对脂多糖（lipopolysaccharide,LPS）诱导小鼠单核巨噬细胞白血病细胞RAW264.7细胞炎症反应的影响。方法：噻唑蓝法测定细胞活力;Griess法测定一氧化氮（NO）水平;实时荧光定量聚合酶链式反应测定白细胞介素（interleukin,IL）-6、IL-1β、肿瘤坏死因子（tumor necrosis factor,TNF）-α、环氧合酶2（cyclooxygenase-2,COX-2）和诱导型一氧化氮合酶（inducible nitric oxide synthase,iNOS）的基因相对表达量;流式细胞术测定细胞吞噬能力;蛋白免疫印迹法测定信号通路丝裂原活化蛋白激酶（mitogen-activated protein kinases,MAPKs）和核转录因子（nuclear factor,NF）-κB信号通路关键蛋白表达水平。结果：羊栖菜多酚对RAW264.7细胞的安全质量浓度范围为0～160 μg/mL。与LPS组相比,羊栖菜多酚剂量依赖性降低巨噬细胞吞噬能力并抑制NO的生成。同时,羊栖菜多酚下调促炎细胞因子（IL-1β、IL-6、TNF-α）和炎症诱导酶（iNOS、COX-2）的mRNA水平,且作用效果与给药剂量及LPS刺激时间相关。这些炎性介质的表达与羊栖菜多酚抑制p38 MAPK和NF-κB p65的激活有关。结论：羊栖菜多酚可通过减弱p38 MAPK和NF-κB p65信号通路的激活水平,抑制下游炎症介质的转录表达,从而缓解LPS诱导的巨噬细胞炎症反应。     

澳洲坚果油脂对脂多糖诱导小鼠肠道损伤的改善作用研究

澳洲坚果油（MO）富含单不多饱和脂肪酸，尤其是棕榈油酸，具有多种生物活性。本研究采用脂多糖（LPS）构建小鼠肠道损伤模型，研究澳洲坚果油脂对肠道损伤的改善作用及其机理。将小鼠随机分为4组：对照组（CON）、MO组（2.5 mL/（kg·d））、LPS组（5 mg/kg）、LPS+MO组，检测小鼠空肠组织病理变化、抗氧化指标、Toll样受体4/细胞核转录因子（TLR4/NF-κB）基因炎性因子、空肠组织病理学变化、细胞凋亡及炎症通路关键因子表达水平。结果表明：澳洲坚果油改善了LPS诱导的小鼠肠道病理形态；与LPS组相比，LPS+MO组显著增强了总抗氧化能力（T-AOC）、超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-Px）水平（P<0.01），降低了丙二醛（MDA）水平（P<0.01）；LPS+MO组TLR4和NF-κB mRNA转录水平以及NF-κB蛋白表达水平显著低于LPS组；MO显著抑制了LPS诱导的肠道促炎因子肿瘤坏死因子-α（TNF-a）和白细胞介素-6（IL-6）表达水平（P<0.01）。因此，澳洲坚果油具有改善LPS诱导的小鼠急性肠道损伤作用，与提高肠道抗氧化水平和抑制TLR4/NF-κB通路有关。     

野生蒙古口蘑多糖通过STAT3和HIF-1α通路对LPS诱导的巨噬细胞发挥抗炎调节作用

研究蒙古口蘑多糖提取物对脂多糖(LPS)诱导小鼠单核巨噬细胞(RAW264.7细胞)炎症保护作用的机理。用不同预量质量浓度的蒙古口蘑多糖处理RAW264.7细胞,通过CCK-8法检测细胞活性;Griess法测定NO的产生量;酶联免疫吸附测定肿瘤坏死因子-α(TNF-α),白介素1β(IL-1β);实时定量检测缺氧诱导因子1α(HIF-1α)、诱导型一氧化氮和酶(iNOS)、核因子κB(NF-κB)、信号转导和转录激活因子3(STAT3)和环氧化酶2(COX-2)的mRNA表达量;免疫印迹检测HIF-1α、NF-κB、STAT3和COX-2蛋白质的表达量。结果表明,蒙古口蘑多糖提取物作用RAW264.7细胞的最大剂量为100μg/mL;与LPS模型组相比,蒙古口蘑多糖提取物质量浓度0.01、0.1、1、10μg/mL均能有效抑制NO(抑制率分别是38.21%、64.17%、58.16%和79.42%)、TNF-α(抑制率分别为27.91%、36.31%、36.14%、45.09%)和IL-1β(抑制率分别为47.75%、58.47%、60.21%、64.55%)的产生;在质量浓度为10μg/mL的蒙古口蘑多糖提取物作用下,除NF-κB外,HIF-1α、STAT3、COX-2和iNOS的mRNA的表达量均降低;免疫印迹的结果也显示,除NF-κB外,HIF-1α、NF-κB、STAT3及COX-2的蛋白质的表达量均有不同程度的降低。蒙古口蘑多糖提取物对脂多糖(LPS)诱导的RAW264.7细胞具有保护作用,其抗炎的机制主要通过JAK-STAT3及HIF-1α信号通路,而不主要通过NF-κB信号通路发挥作用。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.