饮茶有助抗病毒

正近年来,国外研究人员对植物多酚进行的大量科学研究证实,植物多酚具有抗氧化、抗辐射等作用。在形形色色的植物多酚中,以茶叶所含的多酚物质即茶多酚最具抗氧化效果。近期,伊朗德黑兰大学药理系研究人员对茶多酚进行了深入研究,结果表明,儿茶素是茶多酚中最主要的有效成分之一。EGCG为儿茶素中抗氧化作用最强的物质,且绿茶中的EGCG含量更高。     

茶多酚的药理作用研究进展

茶多酚（tea polyphenol）又称茶鞣质,是茶叶中多酚类物质的总称,也是茶叶中有药理和保健功能的主要成分之一。研究发现茶多酚具有抗氧化、抗炎、抗肿瘤、抗辐射、抗高血脂、延缓衰老等药理和保健作用,有关茶多酚的研究目前已成为药学领域的研究热点。查阅近年来国内外关于茶多酚药理研究的文献,简要阐述其药理作用,为新药研发提供依据。     

茶多酚的抗氧化作用及机制

茶多酚是茶叶生物活性的主要有效成分，是一种天然抗氧化剂。本文从清除自由基、抑制酯质过氧化、螯合金属离子及增强其他抗氧化剂作用等方面对茶多酚的抗氧化作用研究作一综述。     

茶多酚的解毒作用研究进展

茶叶具有清头目、除烦渴、化痰、消食、利尿、解毒功能。茶多酚(Tea polyphenols,TP)是从茶叶中提取的一种多酚类化合物,其主要成分为儿茶素。已有研究发现,TP作为天然的自由基清除剂及抗氧化剂,具有抗氧化、抗肿瘤、抗衰老、抗菌消炎、抗病毒作用及防治心血管疾病等多种药理作     

茶叶中茶多酚提取分离技术的研究进展

简单介绍了茶叶中茶多酚和咖啡因的药理活性以及茶叶有效成分的组成和几种主要儿茶素类化合物的结构,分析探讨了提取分离废弃茶叶的原因和意义,并综述了近年来国内外有关茶叶中茶多酚提取分离技术的研究进展,包括溶剂提取法、离子沉淀法、超声波提取法、超临界流体萃取法、微波辅助萃取法、柱色谱法、大孔吸附树脂法和高速逆流色谱法,通过不同的实验过程对不同技术手段的应用及特点进行概述,并对这一研究领域的发展前景和发展方向做出展望。     

茶多酚的抗肿瘤研究概况简介

茶多酚的抗肿瘤研究概况简介姚林，王广增，赵伯阳绿茶多酚（ＧＴＰ）是茶叶的主要成分，约占茶干重的２５％，具有根强的抗氧化性和显著的清除自由基能力。茶多酚的抗肿瘤研究，主要有以下几方面：一、绿茶中抗氧化成份的研究其有效成份是茶多酚混合物，按其化学结构可分...     

天然抗氧剂茶多酚的化学和应用

我国人民具有饮茶的悠久历史，茶区分布广泛，品种繁多，因加工工艺而各具特色。茶叶中化学成份多达300多种，其中最主要的是茶多酚，此外尚有生物碱、蛋白质、矿物质、多种维生素等。各种茶叶具有很好的保健功能［1］，其中茶多酚具有很强的抗氧化能力。1988年卫生部在天津召开的全国食品添加剂卫生标准协作会会议上确认了茶叶天然氧化剂为我国食品添加剂之一，它是一种安全性高无副作用的天然抗氧化剂。本文仪就茶叶中含量最多的天然抗氧剂茶多酚的化学及其在防病治病和食品工业中的应用作一简单的介绍。1．茶多酚的化学结构及测定：茶多…     

茶多酚对心血管系统的药理作用

茶多酚是茶叶的主要成分，约占茶叶干重的２５％，它具有较强的抗氧化性能的清除氧自由基的能力。药理效应广泛，表现在降糖，降压，降脂，抗肿瘤等方面，文章着重介绍对心血管系统的药理作用。     

茶叶的防癌抗癌机理

茶是最受人喜欢的饮料之一,品茶更是一种享受。茶叶具有许多生物学活性和药理作用,如防癌抗癌、抗炎、抗病毒、清除自由基和抗氧化等。其中以防癌抗癌倍受关注。茶叶的防癌抗癌作用与其含的主要成分茶多酚有关。     

茶色素体外清除氧自由基及对老龄小鼠脂质过氧化作用的影响

研究表明,茶叶中的多酚类化合物具有较强的清除体内自由基作用及抗氧化作用。以往的观点认为儿茶素类化合物氧聚合会对其活性不利,近年来也有研究表明儿茶素类氧化产物在预防肿瘤和抑菌抗病毒等方面的生物学活性并不亚于茶多酚。本实验通过一定方法制得茶色素,并测定其在体外清除Ｏ和·ＯＨ的作用和对小鼠抗氧化能力的影响,目的是为氧化产物的抗氧化作用提供实验依据。１材料与方法１．１材料１．１．１茶色素自行制备。茶多酚（ＥＧＣＧ含量大于８５ ％）氧化后用用大孔树脂和＄吵ｄ盼ｔｈ－２０进行纯化。相对分子质量分布为４３３—…     

双水相体系协同超声法提取绿茶中的茶多酚

目的：优化双水相协同超声法提取绿茶中茶多酚的最佳工艺，并比较不同季节绿茶中茶多酚的含量。方法：以茶多酚含量为指标，选择乙醇浓度、硫酸铵浓度、料液比、超声时间进行单因素试验，在单因素试验基础上通过正交试验优选绿茶中茶多酚最佳提取工艺，采用最佳提取工艺提取并比较春、夏、秋季绿茶中茶多酚的含量。结果：最佳提取工艺为：采用45%乙醇、0.20 g·mL^-1硫酸铵的双水相溶液，以1∶90料液比，超声提取15 min；利用该提取条件测得不同季节绿茶中茶多酚含量为：夏季 > 秋季 > 春季。结论：双水相协同超声法可作为提取茶多酚的有效手段；夏茶可作为获取茶多酚的重要来源。     

Antioxidative and anti-carcinogenic activities of tea polyphenols

Tea (Camellia sinensis, Theaceace), a popular beverage consumed world-wide, has been studied for its preventive effects against cancer as well as cardiovascular, neurodegenerative, and other diseases. Most of the proposed beneficial effects have been attributed to the polyphenolic compounds in tea, but the nature of these activities and the molecular mechanisms of their actions remain unclear. Tea polyphenols are known to be strong antioxidants. Prevention of oxidative stress, modulation of carcinogen metabolism, and prevention of DNA damage have been suggested as possible cancer preventive mechanisms for tea and tea polyphenols. In this chapter, we discuss these topics in the light of biotransformation and bioavailability of tea polyphenols. We also review the preventive effects of tea polyphenols in animal models of carcinogenesis and some of the possible post-initiation mechanisms of action. Finally, we discuss the effects of tea consumption on cancer risk in humans. It is our aim to raise some of the unanswered questions regarding cancer prevention by tea and to stimulate further research in this area.     

Pharmacological profile of green tea and its polyphenols: a review

Tea (Camellia sinensis, Theaceae) is the second most consumed beverages in the world, next to water in terms of worldwide popularity. The chemical components of green tea chiefly include polyphenols, caffeine, and amino acids. Green tea is rich in catechins, of which (?)-epigallocatechin-3-gallate is the most abundant. As described in literature, green tea and its polyphenols are beneficial in curing a wide variety of diseases like cancer, diabetes, cardiovascular disease, obesity, etc. It also has antimicrobial activity, protects from solar radiations, and possesses neuroprotective properties. The current review article focuses on pharmacological profile associated with Green tea and its polyphenols. We hope that this review will expose areas for further study and encourage research on important public health issue.     

Chemical studies on plant polyphenols and formation of black tea polyphenols

Recent biological and pharmacological studies strongly suggested that plant polyphenols in foods, beverages and crude drugs have various health benefits. However, still there are chemically uncharacterized polyphenols, especially those with large molecular weights. The typical example is black tea polyphenols. Four tea catechins of fresh tea leaves are enzymatically oxidized in tea fermentation process of black tea manufacture to give a complex mixture of the oxidation products. Despite many efforts since 1950's, major part of the black tea polyphenols has not been clarified yet. We have investigated the oxidation mechanism of each catechin by employing a newly developed in vitro model fermentation system. The oxidation was initiated by enzymatic dehydrogenation of catechins, and subsequent intermolecular quinone-phenol coupling reactions followed by cascade-type degradation of the unstable products resulted in the formation of complex black tea polyphenols. Besides black tea polyphenols, this review introduces the chemistry of insolubilization of persimmon proanthocyanidins, wood polyphenols in connection with whisky polyphenols, and co-polymerization of cinnamaldehyde and proanthocyanidins in cinnamon bark.     

复方茶多酚膜剂的制备和质量控制

目的:制备复方茶多酚膜剂。方法:以茶多酚和木糖醇为主药制备复方茶多酚膜剂,采用高效液相色谱法测定主药的含量,对制备的膜剂进行质量控制。结果:该膜剂性质稳定,符合制剂要求,用HPLC法测定含量,茶多酚和木糖醇分别在0.024～0.144 mg.mL-1和0.012～0.072 mg.mL-1范围内线性关系良好,平均回收率分别为98.30%和99.75%,RSD分别为1.01%和0.76%。结论:该膜剂制备工艺简单,质量可靠,可供临床使用。     

市售茶饮料中茶多酚含量的测定与比较

目的：了解盐城市市售茶饮料中茶多酚的含量,并研究其影响因素。方法利用酒石酸亚铁比色法对茶饮料中的茶多酚进行测定。结果市售茶饮料茶多酚含量差别较大,其中绿茶茶饮料的平均含量为636.91mg/kg,乌龙茶和红茶茶饮料次之,花茶茶饮料中含量最低。茶多酚含量随放置时间的延长而减少,茶多酚的损失率增加,保健功能降低。结论盐城市市售茶饮料中茶多酚的含量有较大差异,并有部分样品不能达到国标要求。