EC, epicatechin

EC,表儿茶素
  • 文章类型: Journal Article
    由白化茶品种加工而成的绿茶通常具有鲜味和新鲜香气。这项研究确定了由两种白化病茶品种制成的绿茶,一个有白芽的人(叫奈白,NB)和另一个有黄芽(称为黄金芽,HJY).味觉化合物分析表明,在HJY绿茶中,没食子酸儿茶素高度集中,而NB绿茶中的非没食子酸和氨基酸含量更高。CsTA(参与没食子酸儿茶素的分解代谢)在HJY茶芽中显示出高表达,导致没食子酸作为β-葡糖gallin生物合成的前体在HJY中含量丰富。CsPDX2.1(负责茶氨酸水解)在NB中的表达水平低于HJY芽。脂肪酸衍生的挥发物(FADV),糖结合挥发物(GBVs)和类胡萝卜素衍生挥发物(CDVs)在HJY绿茶中高度集中,而氨基酸衍生的挥发物在NB绿茶中高度集中。
    Green tea processed from albino tea varieties often has umami taste and fresh aroma. This study identified green teas made from two types of albino tea cultivar, one having the white shoots (called Naibai, NB) and the other having the yellow shoots (called Huangjinya, HJY). Taste compounds analyses showed that galloylated catechins were highly concentrated in HJY green teas, whereas non-galloylated catechins and amino acids were more abundant in NB green teas. CsTA (involved in the catabolism of galloylated catechins) showed high expression in HJY tea shoots, resulting in gallic acid as a precursor for β-glucogallin biosynthesis being abundant in HJY. CsPDX2.1 (responsible for theanine hydrolyzation) had a lower expression level in NB than HJY shoots. Fatty acid-derived volatiles (FADVs), glycosidically bound volatiles (GBVs) and carotenoid-derived volatiles (CDVs) were highly concentrated in HJY green teas, whereas amino acids-derived volatiles were highly concentrated in NB green teas.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    尽管几种人工纳米疗法已被批准用于转移性乳腺癌的实际治疗,他们低效的治疗结果,严重的不良影响,大规模生产的高成本仍然是关键的挑战。在这里,我们开发了一种替代策略,通过使用来自茶花的天然纳米载体(TFEN)特异性触发乳腺肿瘤细胞凋亡并抑制其肺转移.这些纳米载体具有理想的粒径(131nm),外泌体样形态,和负zeta电位。此外,TFEN被发现含有大量的多酚,黄酮类化合物,功能蛋白,和脂质。细胞实验表明,由于刺激活性氧(ROS)扩增,TFEN对癌细胞显示出强细胞毒性。细胞内ROS数量的增加不仅可以触发线粒体损伤,但也阻止细胞周期,导致体外抗增殖,反移民,和抗乳腺癌细胞侵袭活性。进一步的小鼠研究表明,静脉内(i.v.)注射或口服给药后的TFEN可以在乳腺肿瘤和肺转移部位积聚,抑制乳腺癌的生长和转移,并调节肠道微生物群。这项研究为通过静脉内和口服途径抑制乳腺癌及其肺转移的天然外泌体样纳米平台的绿色生产带来了新的见解。
    Although several artificial nanotherapeutics have been approved for practical treatment of metastatic breast cancer, their inefficient therapeutic outcomes, serious adverse effects, and high cost of mass production remain crucial challenges. Herein, we developed an alternative strategy to specifically trigger apoptosis of breast tumors and inhibit their lung metastasis by using natural nanovehicles from tea flowers (TFENs). These nanovehicles had desirable particle sizes (131 nm), exosome-like morphology, and negative zeta potentials. Furthermore, TFENs were found to contain large amounts of polyphenols, flavonoids, functional proteins, and lipids. Cell experiments revealed that TFENs showed strong cytotoxicities against cancer cells due to the stimulation of reactive oxygen species (ROS) amplification. The increased intracellular ROS amounts could not only trigger mitochondrial damage, but also arrest cell cycle, resulting in the in vitro anti-proliferation, anti-migration, and anti-invasion activities against breast cancer cells. Further mice investigations demonstrated that TFENs after intravenous (i.v.) injection or oral administration could accumulate in breast tumors and lung metastatic sites, inhibit the growth and metastasis of breast cancer, and modulate gut microbiota. This study brings new insights to the green production of natural exosome-like nanoplatform for the inhibition of breast cancer and its lung metastasis via i.v. and oral routes.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

       PDF(Pubmed)

  • 文章类型: Journal Article
    Inhibition of excessive fructose intake in the small intestine could alleviate fructose-induced diseases such as hypertension and non-alcoholic fatty liver disease. We examined the effect of phytochemicals on fructose uptake using human intestinal epithelial-like Caco-2 cells which express the fructose transporter, GLUT5. Among 35 phytochemicals tested, five, including nobiletin and epicatechin gallate (ECg), markedly inhibited fructose uptake. Nobiletin and ECg also inhibited the uptake of glucose but not of L-leucine or Gly-Sar, suggesting an inhibitory effect specific to monosaccharide transporters. Kinetic analysis further suggested that this reduction in fructose uptake was associated with a decrease in the apparent number of cell-surface GLUT5 molecules, and not with a change in the affinity of GLUT5 for fructose. Lastly, nobiletin and ECg suppressed the permeation of fructose across Caco-2 cell monolayers. These findings suggest that nobiletin and ECg are good candidates for preventing diseases caused by excessive fructose intake.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

  • 文章类型: Journal Article
    目的:体外崩解和溶出是评估口服剂型性能和质量的常规方法。当前工作的目的是确定胶囊壳材料与绿茶提取物之间相互作用的潜力,以及它对释放的影响。
    方法:将绿茶提取物配制成简单的胶囊粉末制剂,其胶囊壳材料为明胶或HPMC来源。崩解时间与药典和生物相关介质中的溶出曲线一起确定。
    结果:所有配方在30分钟内崩解,符合植物制剂的USP标准。明胶胶囊在所有介质中都实现了速释溶出曲线,而不是指定的HPMC制剂。对于pH1.2的HPMCgell和FeSSIF介质中的两种HPMC制剂,溶出度释放尤其受损,这表明食物相互作用的潜力。
    结论:所研究的HPMC胶囊材料的延迟释放可能归因于儿茶素之间的相互作用,绿茶提取物的主要成分,和胶囊壳材料。建议在释放膳食补充剂或临床试验研究产品之前评估体外溶出,以确保疗效。
    OBJECTIVE: In vitro disintegration and dissolution are routine methods used to assess the performance and quality of oral dosage forms. The purpose of the current work was to determine the potential for interaction between capsule shell material and a green tea extract and the impact it can have on the release.
    METHODS: A green tea extract was formulated into simple powder-in-capsule formulations of which the capsule shell material was either of gelatin or HPMC origin. The disintegration times were determined together with the dissolution profiles in compendial and biorelevant media.
    RESULTS: All formulations disintegrated within 30 min, meeting the USP criteria for botanical formulations. An immediate release dissolution profile was achieved for gelatin capsules in all media but not for the specified HPMC formulations. Dissolution release was especially impaired for HPMCgell at pH 1.2 and for both HPMC formulations in FeSSIF media suggesting the potential for food interactions.
    CONCLUSIONS: The delayed release from studied HPMC capsule materials is likely attributed to an interaction between the catechins, the major constituents of the green tea extract, and the capsule shell material. An assessment of in vitro dissolution is recommended prior to the release of a dietary supplement or clinical trial investigational product to ensure efficacy.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

  • 文章类型: Journal Article
    Green tea is rich in polyphenol flavonoids including catechins. Epigallocatechin 3-gallate (EGCG) is the most abundant and potent green tea catechin. EGCG has been extensively studied for its beneficial health effects as a nutriceutical agent. Based upon its chemical structure, EGCG is often classified as an antioxidant. However, treatment of cells with EGCG results in production of hydrogen peroxide and hydroxyl radicals in the presence of Fe (III). Thus, EGCG functions as a pro-oxidant in some cellular contexts. Recent investigations have revealed many other direct actions of EGCG that are independent from anti-oxidative mechanisms. In this review, we discuss these novel molecular mechanisms of action for EGCG. In particular, EGCG directly interacts with proteins and phospholipids in the plasma membrane and regulates signal transduction pathways, transcription factors, DNA methylation, mitochondrial function, and autophagy to exert many of its beneficial biological actions.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

公众号