共查询到19条相似文献,搜索用时 46 毫秒
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目的:本研究旨在探究金松酸(sciadonic acid,SA)对高脂饮食诱导小鼠肥胖的改善作用。方法:将48只C57BL/6雄鼠适应性喂养一周后随机分为正常组(C)、阳性对照组(S)、模型组(M)、金松酸低剂量组(LSA)、金松酸中剂量组(MSA)和金松酸高剂量组(HSA)。造模和给药同时进行,持续16周,低、高剂量组每日固定时间灌胃不同剂量的金松酸溶液。实验结束后从血脂代谢、肝脏脂肪代谢、肝脏氧化应激、肝脏脂质合成和代谢相关基因的表达等几个方面探讨金松酸调节肥胖小鼠脂质代谢的潜在机制。结果表明,高剂量金松酸干预肥胖小鼠能显著降低血清中总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)含量,增加高密度脂蛋白胆固醇(HDL-C)(P<0.05),抑制体重增长,减少附睾脂肪积累,对肝组织损伤具有改善作用。此外,金松酸能明显提高小鼠体内超氧化物歧化酶(SOD)、谷胱甘肽过氧化酶(GSH-Px)等抗氧化酶的活性(P<0.05),并显著降低氧化终产物MDA的生成(P<0.05),缓解体内氧化应激反应,并通过调节脂质代谢相关基因的表达,抑制脂质合成,改善脂质代... 相似文献
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目的 研究燕麦β-葡聚糖对高脂饮食小鼠肥胖及肠道菌群影响.方法 30只雄性C57BL/6J小鼠随机分为3组(正常组、模型组和燕麦组),监控饲喂期小鼠饮食量和体重.饲喂25周后,测定血脂指标、内脏脂肪重量、空腹血糖、糖耐受量及肠道菌群情况.结果 与模型组相比,燕麦 β-葡聚糖能使小鼠体重增加7.37%,血液中甘油三酯含量... 相似文献
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为研究茶多酚中的表没食子儿茶素(EGC)和表没食子儿茶素没食子酸酯(EGCG)的抗αs1-酪蛋白致敏机理,首先用αs1-酪蛋白致敏BALB/C小鼠,在激发阶段用EGC和EGCG给予营养干预,以降低αs1-酪蛋白致敏小鼠的过敏反应。以小鼠体内肥大细胞蛋白酶含量、组胺含量、特异性抗体IgE水平、细胞因子分泌水平以及组织病理学观察为主要指标,评价EGC和EGCG降低αs1-酪蛋白致敏小鼠过敏反应的能力。结果表明:EGC和EGCG均可显著降低过敏小鼠的肥大细胞蛋白酶、组胺、特异性IgE抗体和Th2型细胞因子水平。同时,组织病理学结果显示:EGC和EGCG显著降低肠、胸腺、脾脏和肺的病变程度。本研究结果可为茶多酚调控牛乳过敏原致敏反应发生的路径提供理论参考,未来可从信号转导和基因表达水平方面进一步探讨抗过敏机制。 相似文献
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探讨高脂饮食对健康小鼠肠道菌群的影响。正常对照组饲喂普通饲料,高脂组饲喂高脂饲料。实验期间每周利用传统培养法和荧光原位杂交(fluorescent in situ hybridization,FISH)技术对小鼠进行肠道微生物菌群结构信息的分析。结果表明:高脂组的小鼠体质量与正常对照组相比显著增加(P<0.01),呈明显肥胖态;传统培养法与FISH技术得到的肠道菌群数量变化趋势一致,但FISH技术检测得到的菌落数要明显地高于传统培养法。高脂组小鼠肠道中乳酸杆菌、双歧杆菌及肠球菌的数量显著降低,与正常对照组相比差异极显著(P<0.01);而肠道中肠杆菌的数量呈上升趋势,与正常对照组相比差异显著(P <0.05)。提示高脂饮食能显著改变健康小鼠肠道菌群的结构从而引发慢性低度炎症,并可能进一步诱导肥胖的产生。 相似文献
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目的:探究复合蛋白肽对高脂饮食诱导肥胖大鼠糖脂代谢的改善作用。方法:将雄性SD大鼠随机分为肥胖模型组、空白对照组,肥胖模型组给予高脂饲料持续喂养4w,筛选肥胖敏感大鼠分为低(LPP)、中(MPP)、高(HPP)剂量组,饲料中复合蛋白肽的含量分别为25%、50%、100%,另设与低、中剂量组等热量饲喂的模型对照组1(MC1)和高剂量组等热量的模型对照组2(MC2)。给予复合蛋白肽干预4w后,检测各组大鼠体重与脂肪含量、肝脏脂肪蓄积以及棕色脂肪能量代谢相关蛋白情况。结果:复合蛋白肽能够显著降低肥胖大鼠的体重、脂肪含量及血脂水平,同时能够降低肝脏脂滴密度,增加线粒体氧化磷酸化复合物(OXPHOS)、解偶联蛋白1(UCP1)表达水平。结论:复合蛋白肽能降低肥胖大鼠体内脂肪含量和血脂水平,可能与增强棕色脂肪组织中OXPHOS和UCP1表达相关。 相似文献
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绿茶是亚洲及中东地区最流行的饮品之一,具有抗癌、抗炎、抗菌、抗氧化、治疗心脑血管疾病、改善肥胖和糖尿病等活性。表没食子儿茶素没食子酸酯(Epigallo catechin-3-gallate,EGCG)是绿茶中含量最高的多酚类物质,具有抗肿瘤的功效。已知细胞凋亡是各种抗癌药物引发细胞死亡的主要方式,因此诱导癌细胞凋亡是治疗癌症的一个明确目标。大量研究报道了EGCG的抗肿瘤活性,并揭示了EGCG诱导肿瘤细胞凋亡的作用及机制,因此本文综述了近几年EGCG诱导肿瘤细胞凋亡的作用及机制,包括p53、STAT3、Akt、p38MAPK、Wnt/β-catenin和TRAIL等与凋亡相关的途径,还综述了EGCG与天然产物、抗肿瘤药物及其它化合物协同诱导肿瘤细胞凋亡的作用机制,并对EGCG的生物利用率、体内实验及临床实验的开展进行了展望,为EGCG的临床应用提供理论依据。 相似文献
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本研究旨在探讨表没食子儿茶素没食子酸酯(Epigallocatechin-3-gallate,EGCG)对葡聚糖硫酸钠(Dextran sulfate sodium,DSS)诱导的小鼠结肠炎和肠道菌群的影响。将C57BL/6雄性小鼠分为正常对照组、肠炎模型组和EGCG处理组(50 mg/kg),每组10只,连续灌胃给药9 d。通过称取小鼠体质量,观察并记录小鼠大便黏稠度、大便出血情况,测量小鼠结肠长度和检测血清中炎症因子来评估EGCG对DSS诱导的小鼠结肠炎症的改善作用;通过分析结肠病理形态、紧密连接蛋白的表达量、肠道菌群多样性和肠道菌群结构来评估EGCG对DSS诱导的结肠炎小鼠肠道菌群的影响。结果表明,EGCG能够有效改善DSS诱导的结肠炎小鼠体质量的下降、腹泻、便血、结肠缩短等不良反应;缓解DSS诱导的小鼠结肠炎导致的全身性慢性炎症和肠道屏障损伤;改善DSS诱导的结肠炎小鼠肠道菌群紊乱,恢复肠道菌群多样性,降低厚壁菌门的相对丰度,提高拟杆菌门的相对丰度,促进有益菌Akkermansia、Alistipes和Bacteroides的增殖并抑制有害菌Desulfovibrio、Escherichia-Shigella和Helicobacter的生长。因此,EGCG通过保护肠道屏障和调节肠道菌群紊乱,从而有效改善DSS诱导的小鼠结肠炎症。 相似文献
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热加工既可以消除食品中的有害微生物,又可以改变肉类食品风味、质地及营养特性和消化特性,而过度热加工会导致蛋白质氧化,对水产品的感官品质和营养价值产生负面影响。为降低蛋白质在热加工中的氧化水平,常加入天然多酚类物质以改善蛋白质的功能特性或营养价值。研究不同浓度表没食子儿茶素没食子酸酯(EGCG)和表没食子儿茶素(EGC)对微波加热的海鲈鱼鱼片感官特性和蛋白氧化的影响。结果表明:EGCG和EGC使微波加热的海鲈鱼鱼片蒸煮损失率显著下降,相比对照组,蒸煮损失率分别降低了47.98%~62.72%,38.54%~58.63%。硬度和咀嚼度下降,羰基含量也下降;水分含量和巯基含量上升。EGCG和EGC显著改善了海鲈鱼鱼片肌肉纤维组织的断裂和聚集情况;降低了鱼片中的酸味感且没有增加其涩味感;EGCG和EGC减少了氮氧化合物类的挥发性气味,促使含硫化合物类气味的生成。 相似文献
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探讨槲皮素干预对高脂饮食诱导肥胖小鼠结肠组织炎症的改善作用及机制。将30只雄性C57BL/6J小鼠随机分为3组:低脂对照组(low-fat diet, LF)、高脂喂养组(high-fat diet,HF)、高脂喂养+槲皮素干预组(50 mg/kg·BW,HF+Q)。槲皮素干预的给药方式为灌胃给予,每天灌胃1次,持续20周。采用苏木精-伊红染色观察结肠组织形态结构,ELISA试剂盒检测肠内容物中脂多糖(LPS)含量,Real-time PCR和Western Blotting测定结肠中细胞因子[白介素-1β(IL-1β)、白介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)]水平,以及检测槲皮素干预对TLR4/NF-κβ信号通路的影响。槲皮素干预显著减少肥胖小鼠的体重增加(p0.05),修复结肠组织形态学上的损伤,能够显著降低LPS含量至5.04 ng/mL(vs HF组:7.01 ng/mL,p0.05),分别抑制结肠组织中炎性因子TNF-α(39.04%)、IL-1β(17.73%)和IL-6(25.47%)的蛋白表达,以及抑制TLR4/NF-κβ信号通路的激活。结论提示,槲皮素对肥胖小鼠结肠组织炎症具有改善作用,减少炎性因子的表达,其作用机制可能和抑制TLR4/NF-κβ信号通路的激活相关。 相似文献
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Differences in the amount and structure of extractable skin and seed tannins amongst red grape varieties 总被引:2,自引:0,他引:2
F. MATTIVI U. VRHOVSEK D. MASUERO D. TRAINOTTI 《Australian Journal of Grape and Wine Research》2009,15(1):27-35
Background and Aims: Red wine is a very rich source of flavanols, consisting of catechins and oligomeric and polymeric proanthocyanidins (PAs). The aim of this study was to investigate the composition of the fraction of flavanols, which is extractable from the grape into the wine.
Methods and Results: Using HPLC-DAD-MS analysis carried out before and after thioacidolysis of wine-like extracts obtained from skins and seeds, the flavanol composition of 20 samples derived from Cabernet Sauvignon, Carmenere, Marzemino, Merlot, Pinot Noir, Syrah and Teroldego was determined.
Conclusions: It was confirmed that grape extracts are mainly rich in monomers and small oligomers (mean degree of polymerization <8). Grape seed extracts contained three monomers (catechin, epicatechin and epicatechin gallate) and procyanidin oligomers. Grape skin extracts contained four monomers (catechin, epicatechin, gallocatechin and epigallocatechin), procyanidins and prodelphinidins oligomers. Upper and extension units of PAs were constituted mainly of epicatechin units, with the co-presence of catechin and epicatechin gallate in the seed PAs, and of gallocatechin in the case of skin PAs. The terminal units of the grape PAs were a mixture of five compounds, the same found also as monomers. Catechin gallate, gallocatechin gallate and epigallocatechin gallate, which are found in other flavanol-rich, plant-derived foods and beverages, were not present in grape extracts.
Significance of the Study: The grape variety determines both the amount and the structure of wine flavanols, leading to differences in the composition, which are likely to play an important role in the nutritional and sensorial properties of the wines. 相似文献
Methods and Results: Using HPLC-DAD-MS analysis carried out before and after thioacidolysis of wine-like extracts obtained from skins and seeds, the flavanol composition of 20 samples derived from Cabernet Sauvignon, Carmenere, Marzemino, Merlot, Pinot Noir, Syrah and Teroldego was determined.
Conclusions: It was confirmed that grape extracts are mainly rich in monomers and small oligomers (mean degree of polymerization <8). Grape seed extracts contained three monomers (catechin, epicatechin and epicatechin gallate) and procyanidin oligomers. Grape skin extracts contained four monomers (catechin, epicatechin, gallocatechin and epigallocatechin), procyanidins and prodelphinidins oligomers. Upper and extension units of PAs were constituted mainly of epicatechin units, with the co-presence of catechin and epicatechin gallate in the seed PAs, and of gallocatechin in the case of skin PAs. The terminal units of the grape PAs were a mixture of five compounds, the same found also as monomers. Catechin gallate, gallocatechin gallate and epigallocatechin gallate, which are found in other flavanol-rich, plant-derived foods and beverages, were not present in grape extracts.
Significance of the Study: The grape variety determines both the amount and the structure of wine flavanols, leading to differences in the composition, which are likely to play an important role in the nutritional and sensorial properties of the wines. 相似文献
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目的:研究自胎儿期开始长期膳食摄入染料木素对ICR雌、雄子代小鼠血脂及肝脏的影响。方法:自ICR母鼠妊娠第1天开始分别以0、5、25、50 mg/(kg·d)(以体质量计,下同)的染料木素灌胃母鼠并在子代小鼠出生后继续对子代小鼠进行相同的处理,分别于子代小鼠出生后第21、42、80天对其分离血清和肝脏,测定血清中甘油三酯(triglyceride,TG)、总胆固醇(total cholesterol,TC)、低密度脂蛋白胆固醇(low densitylipoprotein cholesterol,LDL-C)含量;采用苏木精-伊红染色对子代小鼠肝脏进行组织形态观察。结果:自胎儿期开始长期膳食摄入染料木素可降低第21、42、80天ICR雌、雄子代小鼠的血清TC水平,且这种作用在第42、80天时更显著;自胎儿期开始长期膳食摄入染料木素还可以降低子代小鼠血清中TG和LDL-C水平,且对雄性子代小鼠LDL-C的降低效果更显著。染色结果显示自胎儿期开始长期膳食摄入染料木素可能会增加子代小鼠肝脏脂肪变性的风险。结论:自胎儿期开始长期膳食摄入染料木素可降低子代小鼠血清中TC、TG、LDL-C水平,同时可能会增加子代小鼠肝脏脂肪变性的风险。 相似文献
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PR Jeyaramraja PK Pius R Raj Kumar D Jayakumar 《Journal of the science of food and agriculture》2003,83(12):1187-1191
The impact of water stress on the biochemical constituents that determine black tea quality was investigated. Phenylalanine ammonia lyase (PAL) activity was highest in the drought tolerant ‘Assam’ cultivar UPASI‐2, followed by UPASI‐8 and UPASI‐9, under non‐stress conditions. Under soil moisture stress a reduction in PAL activity was found in all three clones investigated. A strong positive correlation was observed between an increase in soil moisture deficit and a decrease in PAL activity. Lower PAL activity correlated well with lower synthesis of flavanols such as epigallocatechin gallate (EGCG) and epicatechin gallate (ECG), which are important precursors of theaflavin‐3,3′‐digallate that determines final tea quality. Altered synthesis of EGCG and ECG could be due to their molecular rearrangement at elevated leaf temperature during drought. Synthesis of quality constituents such as gallic acid and caffeine declined significantly owing to both drought and waterlogging stress. The reduction in gallic acid due to water stress could lead to lower synthesis of theaflavin fractions such as epitheaflavic acid, epitheaflavic acid‐3′‐gallate and theaflavic acid and, thereby, quality deterioration. Similarly to drought, flooding stress was also found to alter the biochemical constituents necessary for tea quality. Copyright © 2003 Society of Chemical Industry 相似文献
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本文研究了表没食子儿茶素没食子酸酯磷脂复合物的体外抗氧化活性。将EGCG和大豆卵磷脂溶于无水乙醇,制备得到EGCG磷脂复合物。通过高效液相色谱(HPLC)测定,发现制备得到的EGCG磷脂复合物中EGCG的复合率大于99%,并利用紫外扫描、红外光谱、X射线衍射等方法对其结构进行表征,说明通过本实验方法制备得到了目标复合物。通过DPPH、FRAP、TEAC等方法测定EGCG磷脂复合物的体外抗氧化活性,结果表明EGCG磷脂复合物的体外抗氧化能力显著高于VE(P0.05)。同时测定添加EGCG磷脂复合物后,不同贮藏时间(3、6、9、12和15 d)反映大豆油氧化的指标。结果表明EGCG磷脂复合物对于大豆油的氧化具有抑制作用且呈现剂量依赖关系,并且在贮藏15 d时,抗氧化效果显著好于BHT(P0.05)。研究表明,制备得到的EGCG磷脂复合物具有显著的抗氧化活性,并且可以有效抑制大豆油的氧化。 相似文献
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Jin Ze Xu Lai Kwok Leung Yu Huang Zhen‐Yu Chen 《Journal of the science of food and agriculture》2003,83(15):1617-1621
The present study was carried out to quantify green tea epicatechin (GTE) derivatives and to investigate the origin of epicatechin epimers present in 18 selected canned or bottled tea drinks. The major GTEs present in tea are (?)‐epigallocatechin gallate (EGCG), (?)‐epigallocatechin (EGC), (?)‐epicatechin gallate (ECG) and (?)‐epicatechin (EC). HPLC analysis showed that the content of total GTEs was lower (16.4–268.3 mg l?1) in the canned and bottled tea drinks than in tea traditionally prepared as a beverage in a cup or teapot (3–5 g l?1). The major finding was that they contained higher levels of epicatechin epimers, namely (?)‐gallocatechin gallate (GCG), (?)‐gallocatechin (GC), catechin gallate (CG) and (?)‐catechin (C), than of GTEs, ranging from 7.6 to 331.8 mg l?1. To investigate the origin of these epimers, GTEs were extracted from longjing green tea and autoclaved at various temperatures for 10–60 min. It was found that at least 50% of GTEs were epimerised to their corresponding epimers when autoclaved at 120 °C for 20 min. It is concluded that epicatechin epimers in tea drinks are not originally present in green tea leaf but are instead derived from thermal conversion of GTEs. Copyright © 2003 Society of Chemical Industry 相似文献
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该研究以KM小鼠作为实验动物,研究2.5、5.0、7.5、10、15 μmol/L五个浓度梯度下棒曲霉素对小鼠体重、肾脏系数等的影响,并通过各项肾脏切片染色试验验证PAT对肾脏的毒性损伤。其中PAT浓度对体重增长率基本无影响,两者之间几乎无相关关系;而随着PAT浓度增大,肾脏系数有逐渐增大的趋势,其中7.5 μmol/L和10 μmol/L PAT处理的差异显著(p<0.05);随着PAT浓度增加,苏木素-伊红(hematoxylin-eosin,HE)染色后可观察到大片细胞基质和胞外基质,蓝紫色细胞核逐渐减少且细胞核密度逐渐降低,此外PAT浓度较高时出现了长条状空白;Masson染色后肾小球发生明显的纤维硬化情况,且胞间充血;过碘酸雪夫(Periodic Acid-Schiff,PAS)染色后出现了少量糖原,可知糖原没有被正常降解。因此,PAT浓度的增加会导致核密度降低、肾脏细胞皱缩、胶原纤维增加、糖原分解被抑制等问题,从而对KM小鼠肾脏造成严重损伤。研究结果将为进一步研究棒曲霉素对肾脏的损伤提供理论支持。 相似文献
19.
Zhen‐Yu Chen Shu Wang Kwong Man Simon Lee Yu Huang Walter K
K Ho 《Journal of the science of food and agriculture》2001,81(10):1034-1038
The aim of this study was to use AlCl3 in the extraction of green tea flavanols (GTFs) from longjing green tea and examine the factors that influence the yield of GTF extract. Dry tea leaves were soaked in hot distilled water and the infusion was obtained by filtration. To the tea infusion, varying amounts of AlCl3 were added, causing precipitation of GTFs. After adjusting the pH to 4.0–6.5 and centrifugation, the yellow precipitate was collected. Sulphuric acid solution (40%) was then used to dissolve the GTFs from the yellow precipitate. The GTF solution was extracted using an equal volume of ethyl acetate. After the removal of ethyl acetate using a rotary evaporator, the GTF extract was redissolved in distilled water and the whole process was repeated. The resulting GTF extract was freeze‐dried. It was found that the amount of AlCl3 used and the pH and temperature of the precipitation mixture significantly affected the yield and purity of GTF extract. A yield of 9.6 g extract per 100 g dry tea leaves with GTFs > 94% could be obtained if AlCl3 was used in the ratio of 15 g per 100 g equivalent dry tea leaves and the pH of the precipitation mixture was adjusted to 5.5 at 30 °C. © 2001 Society of Chemical Industry 相似文献