山慈菇多糖对荷H22肝癌小鼠的抗肿瘤机制研究

研究山慈菇多糖对H22肝癌实体瘤小鼠的抗肿瘤作用及其机制。制作小鼠H22实体瘤肝癌模型,通过脾脏指数、胸腺指数分析其对小鼠免疫器官的影响,Elisa检测血清白介素-2(IL-2)含量、肿瘤坏死因子(TNFα)含量,免疫组化法观察(Bcl-2)表达水平。山慈菇多糖的低、中、高剂量组抑瘤率分别为43.74%、37.57%、30.76%,;能增强血清中IL2、TNFα活性;抗凋亡因子Bcl-2的表达量不同程度地减少。山慈菇多糖对H22肝癌小鼠具有一定的肿瘤抑制作用,本次实验不体现剂量依赖性,显示山慈菇多糖无毒副作用,能增强机体的抗肿瘤能力,降低肿瘤的持续增殖能力。     

猴头菌多糖对小鼠H22 肝癌移植瘤的抑制作用

目的：观察猴头菌多糖对小鼠移植性实体瘤H22的影响,并初步探讨其作用机制。方法：将H22瘤株接种于小鼠,制备移植性实体瘤模型。将70只小鼠随机分为正常组、模型组、阳性对照组、猴头菌多糖低、中、高剂量组(50、100、200mg/kg,以体质量计),正常组10只,其余各组12只,连续灌胃10d。阳性对照组以20mg/kg隔日腹腔注射环磷酰胺,末次给药后次日处死,计算肿瘤抑制率、胸腺及脾脏指数,检测荷瘤小鼠血清中肿瘤坏死因子-α(TNF-α)、白介素-2(IL-2)和血管内皮生长因子(VEGF)的水平;测定白细胞数和白蛋白含量。结果：不同剂量的猴头菌多糖抑瘤率均高于26%,显著提高胸腺指数,提高血中TNF-α和IL-2的水平,降低实体瘤组织VEGF的水平;不同程度的提高白蛋白水平;猴头菌多糖组白细胞数与模型组比较无明显差异,显著高于阳性对照组。结论：猴头菌多糖对H22荷瘤小鼠有明显的抑瘤作用,其机制可能是通过调节免疫功能和抑制肿瘤组织血管生成而发挥抗肿瘤作用。     

熊果酸对H22荷瘤小鼠抗肿瘤及肠道细菌群落结构多样性的影响

研究熊果酸对H22荷瘤小鼠抗肿瘤及肠道细菌的影响。皮下接种H22肝癌细胞构建移植瘤小鼠模型,设正常组、模型组、阳性对照组（环磷酰胺）和熊果酸组（低、中、高剂量）,连续给药3周后,计算抑瘤率和肝脾指数,检测血清T淋巴细胞亚群、白细胞介素-2（IL-2）和肿瘤坏死因子α（TNF-α）浓度,采用高通量测序技术分析熊果酸对H22荷瘤肠道细菌群落结构多样性的影响。结果显示,与模型组相比,熊果酸各剂量组均能显著减少移植瘤质量（P<0.05）,其中熊果酸中、高剂量组能显著提高荷瘤小鼠血清中T细胞亚群、IL-2和TNF-α的含量（P<0.05）。主成分分析（Principal Component Analysis,PCA）显示,与正常组比较,模型组和熊果酸低剂量组小鼠肠道细菌相似性差异显著（P<0.05）,而熊果酸中剂量组和高剂量组小鼠肠道细菌相似性差异不显著（P>0.05）。熊果酸各剂量组肠道细菌在门水平和科水平的比例和分布均比模型组更接近正常组。与模型组比较,熊果酸小鼠肠道Akkermansia和Lactobacillus丰度显著增加（P<0.05）,而Muribaculum显著减少（P<0.05）。表明熊果酸可抑制肿瘤生长,增强H22荷瘤小鼠免疫力,对肿瘤小鼠肠道细菌菌群紊乱具有一定恢复作用。     

山慈菇多糖对H22肝癌小鼠IL-2及p53蛋白表达的影响

研究山慈菇多糖对H22的体内抑制作用及其机制。建立小鼠H22腹水瘤和实体瘤模型观察山慈菇多糖的抑瘤作用,Elisa检测实体瘤小鼠外周血IL-2水平,HE染色法观察小鼠肿瘤组织的细胞形态,SABC免疫组化法检测p53蛋白表达情况。能改善腹水瘤小鼠的生存状态和延长生存天数,延长率为21.4%。实体瘤小鼠低、中、高剂量组抑瘤率分别为21.58%、32.76%、40.05%,IL-2的中高剂量组相对模型组都具有极显著性(P0.01),增强了p53蛋白的表达水平。山慈菇多糖延长了腹水瘤小鼠生存时间,解剖观察可能是减少小鼠体内炎症反应;实体瘤小鼠此次试验中呈现了一定的剂量依赖性,其机制可能与提高小鼠IL-2含量从而提高小鼠免疫力有关,p53随着肿瘤细胞分化程度下降而表达增加。     

鹰嘴豆肽抑制肿瘤作用和对免疫功能的影响

目的：探讨鹰嘴豆肽抑制肝癌H22细胞移植瘤的效果及对免疫功能的影响。方法：将小鼠随机分为正常对照组、阳性对照组、肿瘤对照组和鹰嘴豆肽低、中、高剂量组(50、100、200mg/(kg·d)),除正常组外,其余各组小鼠均在皮下接种肝癌H22细胞,建立肝癌小鼠模型。建模后第2天开始灌胃给药,连续给药10d。末次给药24h后拉托颈椎处死小鼠,测体质量、肿瘤大小、抑瘤率、胸腺指数、脾指数、巨噬细胞吞噬能力、脾细胞吞噬能力等。 结果：鹰嘴豆肽低、中、高3个剂量均可抑制H22肿瘤的生长,且没有阻碍小鼠体质量和免疫器官的增长。与肿瘤对照组相比,鹰嘴豆高剂量组可以显著提高小鼠迟发型超敏反应(DTH)的能力、淋巴细胞和巨噬细胞吞噬能力(P＜0.05),鹰嘴豆低、中剂量组对其也有一定的改善作用,但是没有表现出剂量依赖效应。 讨论：鹰嘴豆肽可能是通过增强H22肝癌小鼠的免疫功能来抑制肿瘤的生长,具体的作用机制还需要更深入的研究。     

绿蒜正己烷萃取物对H22荷瘤小鼠的影响

为了探讨绿蒜75%乙醇提取物的正己烷萃取物（简称绿蒜正己烷萃取物：GGHE）对H22荷瘤小鼠的抑瘤作用及对其免疫功能的影响,建立H22荷瘤小鼠模型。将60只小鼠平均分为6组：空白对照组、模型组、阳性对照组（环磷酰胺CTX,20 mg/kg）、GGHE低中高剂量组（L-GGHE：75 mg/kg;M-GGHE：150 mg/kg;H-GGHE：300 mg/kg),连续给药14 d。测定小鼠体重、水食量、肝脏中SOD、GSH-Px、CAT、ALT、AST的活性和MDA的含量;测定小鼠血清中细胞因子TNF-α、IL-2和VEGF的含量;计算水食效率、瘤体积、抑瘤率、脏器指数;分析肿瘤组织的病理特征。实验结果表明：M-GGHE的抑瘤率达71.48%。与模型组相比,GGHE能显著提高小鼠水食效率、胸腺及脾脏指数以及IL-2,TNF-α的水平,降低VEGF的表达。不同程度的提高肝脏组织中抗氧化酶SOD、GSH-Px和CAT的活力、降低MDA的含量以及转氨酶ALT和AST的活力。结论：GGHE对H22荷瘤小鼠的肿瘤生长有一定的抑制作用,改善了荷瘤小鼠的生存质量,提高了荷瘤小鼠的抗氧化水平和免疫功能。本实验提示可将绿蒜75%乙醇提取物的正己烷萃取物开发成治疗肝癌的候选药物。     

绿蒜正己烷萃取物对H22荷瘤小鼠的抑瘤作用

为了探讨绿蒜75%乙醇提取物的正己烷萃取物(简称绿蒜正己烷萃取物:GGHE)对H22荷瘤小鼠的抑瘤作用及对其免疫功能的影响,建立H22荷瘤小鼠模型。将60只小鼠平均分为6组:空白对照组、模型组、阳性对照组(环磷酰胺CTX,20 mg/kg)、GGHE低中高剂量组(L-GGHE:75 mg/kg;M-GGHE:150 mg/kg;H-GGHE:300 mg/kg),连续给药14 d。测定小鼠体重、水食量、肝脏中SOD、GSH-Px、CAT、ALT、AST的活性和MDA的含量;测定小鼠血清中细胞因子TNF-α、IL-2和VEGF的含量;计算水食效率、瘤体积、抑瘤率、脏器指数;分析肿瘤组织的病理特征。实验结果表明:M-GGHE的抑瘤率达71.48%。与模型组相比,GGHE能显著提高小鼠水食效率、胸腺及脾脏指数以及IL-2,TNF-α的水平,降低VEGF的表达。不同程度的提高肝脏组织中抗氧化酶SOD、GSH-Px和CAT的活力、降低MDA的含量以及转氨酶ALT和AST的活力。结论:GGHE对H22荷瘤小鼠的肿瘤生长有一定的抑制作用,改善了荷瘤小鼠的生存质量,提高了荷瘤小鼠的抗氧化水平和免疫功能。本实验提示可将绿蒜75%乙醇提取物的正己烷萃取物开发成治疗肝癌的候选药物。     

核桃蛋白多肽对脂多糖诱导的小鼠急性肝损伤的保护作用

构建脂多糖（LPS）诱导小鼠急性肝损伤模型,研究核桃蛋白多肽（WPP）对肝损伤的保护作用。实验小鼠随机分为5组（空白对照组,LPS模型组,LPS+WPP低、中、高剂量组）,连续灌胃WPP 5周后,采用尾静脉注射LPS诱导肝损伤,检测各处理组小鼠肝脏指数、血清中谷丙转氨酶（ALT）和谷草转氨酶（AST）活性、肝组织中超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-Px）活性、组织病理学变化以及血清中炎症因子白细胞介素IL-1β和IL-6水平。结果表明：与LPS模型组相比,WPP高剂量组肝脏指数显著降低（P<0.05）,WPP中、高剂量组小鼠血清中ALT和AST活性极显著下降（P＜0.01）,WPP低、中、高剂量组小鼠血清中IL-1β和IL-6含量极显著下降（P＜0.01）,WPP中、高剂量组小鼠肝组织中SOD活性显著升高（P<0.05）,WPP低、中、高剂量组小鼠肝组织中GSH-Px活性极显著升高（P＜0.01）;组织病理学观察发现,WPP低、中、高剂量组小鼠肝组织病理损伤明显减轻。WPP对LPS造成的小鼠急性肝损伤具有明显的保护作用。     

灵芝复合剂乙酸乙酯提取物的化学组成及其抗肿瘤活性

该文研究了灵芝复合剂乙酸乙酯提取物（Ganoderma lucidum Complex Ethyl Acetate Extract,GCE）的化学组成及抗肿瘤活性。GCE由灵芝、菟丝子、五味子、党参（质量比50.3:25.2:15.7:8.8）组成复合剂后再经乙酸乙酯萃取所得。试验采用超高压液相色谱飞行时间质谱联用仪（UPLC-Q-TOF-MS）分析其物质组成;设空白组、模型组、阳性对照组、GCE低、中、高剂量组。检测其抑瘤率,脏器指数,脾淋巴细胞增殖能力,血清细胞因子。结果表明：GCE主要由11种化合物组成：L-焦谷氨酸、DL-亮氨酸腺苷、D-赤酮酸内酯、L-正亮氨酸、邻苯三酚、2-羟基-3-甲基吡喃-4-酮、绿原酸、3-（3,4,5-三甲氧基苯基）丙酸、槲皮素、五味子素;GCE低、中、高剂量组（50、100、200 mg/kg）H22荷瘤小鼠的抑瘤率分别为35.14%、38.25%、50.87%;与模型组相比,GCE低、中、高剂量均能显著促进小鼠脾淋巴细胞的增殖（P<0.01）;GCE高剂量能显著促进小鼠的IL-6、TNF-α和IL-12分泌（P<0.05）。结论,GCE对H22荷瘤小鼠肿瘤有一定抑制作用,该研究结果可为抗肿瘤功能的产品研发提供新思路。     

玛咖生物碱对人肝癌细胞Bel-7402和H22荷瘤小鼠的抑制作用

探究玛咖生物碱对Bel-7402细胞体外抗肝癌活性及体内抗H22肝癌活性的影响。通过0.5%的盐酸95%乙醇溶液提取获得玛咖生物碱粗提物,并通过进一步的酸溶碱沉方法纯化获得玛咖生物碱,通过MTT法测定不同剂量玛咖生物碱对Bel-7402细胞抑制率的影响,并进一步通过体内抗肝癌H22荷瘤小鼠试验,考察不同剂量玛咖生物碱体内抗肝癌活性影响。细胞实验表明,不同剂量组玛咖生物碱对Bel-7402细胞有一定的抗肝癌活性,其抗癌活性高低顺序为:玛咖生物碱高剂量组玛咖生物碱中剂量组玛咖生物碱低剂量组。体内抗肝癌试验表明,玛咖生物碱高、中剂量组具有显著的抗肝癌活性。可见,玛咖生物碱具有一定的抗肝癌活性,这为玛咖生物碱活性的研究提供新的方向。     

Co-precipitation of whey and pea protein – indication of interactions

The aim was to optimise the yield of co-precipitation of whey protein isolate (WPI) and pea protein isolate (PPI) and compare co-precipitates and protein blends with respect to solubility. The yield of co-precipitates was tested with different protein ratios of WPI and PPI in combination with different temperatures and acid precipitation (pH 4.6). The highest precipitation yield was obtained at protein ratios WPI < PPI, high temperature and alkaline protein solvation. The solubility was measured by an instability index and absorption spectroscopy of re-suspended precipitated proteins at pH 3, 7 and 11.5. Co-precipitates had significantly lower solubility than protein blends. Protein ratios WPI > PPI, low precipitation temperature and high pH showed the highest solubility. Differences in protein composition between co-precipitates and protein blends were observed with SDS-PAGE and matrix-assisted laser desorption ionisation time-of-flight, and indicated different protein–protein interaction in samples, which needs further investigations.     

大豆蛋白溶解性研究

该文概述大豆蛋白溶解特性及其与一般物质溶解差异,介绍提高大豆蛋白溶解性改性方法及研究现状,对比不同改性增溶方法优、缺点,并提出今后大豆蛋白改性研究方向。     

细菌中蛋白质样品制备方法研究进展

细菌在生长繁殖时,细菌蛋白的表达受到环境影响而存在较大差异,使得细菌蛋白表达具有复杂性.在食品生产加工过程中可能会受到致病菌污染,细菌产生的内毒素和外毒素均会对人体健康构成威胁,因此需要高灵敏度和高特异性的检测方法来定量分析和鉴定食品中的细菌毒素.蛋白组学方法可以揭示细菌蛋白组成及其潜在的生物学功能,感染过程中菌体蛋白...     

Physicochemical and Functional Properties of Soy Protein Substrates Modified by Low Levels of Protease Hydrolysis

ABSTRACT: Endo-protease treatments achieving low degrees of hydrolysis (DH 2% and 4%) were used to improve functional properties of hexane-extracted soy flour (HESF), extruded-expelled partially defatted soy flour (EESF), ethanol-washed soy protein concentrate (SPC), and soy protein isolate (SPI). These substrates had protein dispersibility indices ranging from 11% to 89%. Functional properties, including solubility profile (pH 3 to 7), emul-sification capacity and stability, foaming capacity and stability, and apparent viscosity were determined and related to surface hydrophobicity and peptide profiles of the hydrolysates. Protein solubilities of all substrates increased as DH increased. Emulsification capacity and hydrophobicity values of the enzyme-modified HESF and EESF decreased after hydrolysis, whereas these values increased for SPC and SPI. Emulsion stability was improved for all 4% DH hydrolysates. Hydrolyzed SPC had lower foaming capacity and stability. For substrates other than SPC, foaming properties were different depending on DH. Hydrolysis significantly decreased the apparent viscosities regardless of substrate. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) indicated differences in the molecular weight profiles of the hydrolysates. HESF and EESF, which had high proportions of native-state proteins, showed minor changes in the peptide profile due to hydrolysis compared with SPC and SPI.     

大豆蛋白生产与应用现状

该文综述大豆蛋白制品—大豆蛋白粉、大豆分离蛋白、大豆浓缩蛋白、大豆组织蛋白生产现状、存在问题及大豆蛋白在面制品、肉制品、乳制品、饮料制品等中应用现状。     

Effects of silage protein degradability and fermentation acids on metabolizable protein concentration: A meta-analysis of dairy cow production experiments

A meta-analysis was conducted using data from dairy cow production studies to evaluate silage metabolizable protein (MP) concentrations. The data consisted of 397 treatment means in 130 comparisons, in which the effects of silage factors (e.g., date of harvest, wilting, silage additives) were investigated. Within a comparison, a fixed amount of the same concentrate was fed. A prerequisite of data to be included in the analysis was that silage dry matter (DM), crude protein (CP), ammonia N, lactic acid (LA), and total acid (TA) concentrations and digestibility were determined. A smaller data set (n = 248) comprised studies in which silage water-soluble N concentration was also analyzed. The supply of MP was estimated as amino acids absorbed from the small intestine using a model with constant values for ruminal effective protein degradability (EPD) and intestinal digestibility of rumen undegraded protein. Microbial protein was calculated on the basis of digestible carbohydrates and rumen degradable protein (RDP). Alternative models were used to estimate microbial protein formation, assuming the energy values of RDP and TA to be equivalent to 1.00, 0.75, 0.50, 0.25, and 0 times that of digestible carbohydrates. Because EPD values are seldom determined in production trials, they were derived using empirical models that estimate them from other feed components. The goodness of fit of models was compared on the basis of root mean squared error (RMSE) of milk protein yield (MPY) predicted from MP supply (adjusted for random study effect) and Akaike's information criterion. Metabolizable protein supply calculated from basal assumptions predicted MPY precisely within a study (RMSE = 16.2 g/d). Variable contribution of RDP to the energy supply for microbial synthesis influenced the precision of MPY prediction very little, but RMSE for MPY increased markedly when the energy supply of rumen microbes was corrected for TA concentration. Using predicted rather than constant EPD values also increased RMSE of MPY prediction. These observations do not mean that the supply of MP from undegraded feed protein is constant. However, it suggests that our current methods overestimate the range in EPD values and that the techniques have so many inherent technical problems that they can mask the true differences between the feeds. Including new elements in feed protein evaluation models may not improve the precision of production response predictions unless the consequent effects on the supply of other nutrients are taken into account.     

大豆分离蛋白改性对其功能性质影响

大豆分离蛋白是大豆蛋白最为精制形式,广泛应用于食品工业,并在不同产品中表现出不同功能。该文综述近年来大豆分离蛋白物理、化学、酶法及基因工程改性对其功能性质影响,经不同方式改性可产生合适功能性质,从而拓宽大豆分离蛋白在食品工业中应用。     

The structures and functions of ice crystal-controlling proteins from bacteria

Many organisms have evolved into unique mechanisms which minimize freezing injury due to extracellular ice formation. Specifically, certain bacteria have produced a few proteins each with different functions. For example, the ice nucleation protein acts as a template for ice formation, which is responsible for imparting ice nucleating activity. The anti-nucleating protein inhibits the fluctuation of ice nucleus formation by a foreign particle in the water drop. Also, the antifreeze proteins depress the freezing temperature, modify or suppress ice crystal growth, inhibit ice recrystallization, and protect the cell membrane from cold-induced damage. In this article, a review on the current knowledge of the structure and the function of these three types of proteins, which are capable of interacting with ice itself or its nuclei from bacteria.     

Effect of amidation on the foaming and physico-chemical properties of bovine serum albumin

Amidation of bovine serum albumin (BSA) was achieved by a water-soluble carbo-diimide, ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC)-mediated reaction using ammonium chloride as the nucleophile. Partial and substantial amidation of 0.5% (w/v) BSA in 5.5 m ammonium chloride solution with 1 times 10-²mmol EDC over 120 min and 1 times 10^-1mmol EDC over 10 min respectively was achieved on a large scale using diafiltration for rapid termination of the reaction and purification. Residual ammonium chloride otherwise enhanced foaming properties. The amidated proteins were characterized by isoelectric focusing, electrophoresis and hydrophobicity and disulphide- and sulphydryl-group measurements. Compared with native BSA, partially amidated BSA (PA-BSA) produced enhanced foam expansion and foam stability values. This was attributed to minimal denaturation and to the presence of both acidic and basic components (pI range 5.25–7.50) within the single protein. In contrast, substantially amidated BSA (SA-BSA) (pI range 7–9.1) had similar foaming properties to those of the ultrafiltered BSA control which were slightly lower than those of native BSA. However SA-BSA interacted synergistically with native BSA producing enhanced foaming properties particularly at the 1:1 ratio through electrostatic interactions, conformational changes and increased hydrophobicity.     

几种新型花生蛋白产品的生产

本文从花生蛋白质利用的角度介绍了几种新型花生蛋白产品的加工工艺，针对我国人民膳食结构中蛋白质的摄入水平较低的实际情况，论述了花生蛋白开发利用的必要性，展望了花生蛋白开发利用的广阔前景。