The In Vivo Effects of Cytokines Modulation for BALB/C Mice Fed with a Traditional Combined Chinese Herb‐Soaked Solution,Yi‐Fey Ruenn‐Hou Tea

An experiment was conducted to investigate the effects of Yi‐Fey Ruenn‐Hou (YR) Tea, a combination of Chinese herbs, 10% licorice root, 10% American ginseng, 10% Radix Paeoniae alba and 70% green tea‐soaked solution, on the cytokine modulation in Balb/C mice. Four groups of mice were administered either 1ml of drinking water (group A) or 2 mg/ml (group B), 8 mg/ml (group C), 40 mg/ml (group D) of a saturated solution of combined Chinese herbs daily for six months. The physiological and pathological characteristics of the mice were observed during the time, and the mice were weighed and at least two mice were sacrificed each month for pathological detection of the brain, heart, liver, spleen and kidney and cytokine analysis. The results revealed neither weight difference nor pathological change among the four groups, however, serum‐cytokine assay indicated that the cytokine modulation effects are consistent, and the most obvious cytokine modulation effect was observed in group D, which was the highest dosage employed for treating the mice. TH2‐pattern cytokines responded earlier and higher in group D than in groups B and C. Furthermore, the effect of YR Tea on cytokine modulation in vivo is predominantly TH2‐pattern and is dependent on its dosage (P < 0.05).     

Development of a monoclonal antibody-based ELISA to detect Escherichia coli O157:H7

A pair of monoclonal antibodies (mAb) from 10 murine hybridomas secreting Escherichia coli O157:H7 (E. coli O157:H7)-specific mAbs were selected for the development of the sandwich ELISA to detect E. coli O157:H7. On the basis of pairwise interaction analysis, mAb-1 was selected as a capture antibody while mAb-6 was used as a detection antibody. The buffer system which provided the greatest difference between the specific E. coli O157:H7-positive antigen and the negative control was chosen. This sandwich ELISA showed good linearity when the concentration of E. coli O157:H7 was in the range of 10⁵–10⁸ cfu/mL, and the sensitivity was 1×10⁴ cfu/mL. With 8-h enrichment of bacteria, this ELISA was found to detect 0.4 cfu/g E. coli O157:H7 in artificially contaminated green tea samples.     

绿茶中维生素C氧化动力学模型研究

运用定温法和加速试验相结合的方法,对绿茶中维生素C氧化进行动力学分析研究,探讨通过维生素C的保留量预测绿茶保质期方法的可行性。研究中比较了动力学中常用的4种反应机理函数模式,通过试验与理论分析,得出线性最佳的三维扩散函数作为绿茶中维生素C的反应机理函数,获得了其前因子、活化能等动力学参数以及反应速率常数与温度的关系。研究结果为深入研究茶叶包装及其保质期预测提供了技术基础。     

Fluoride levels in various black tea,herbal and fruit infusions consumed in Turkey

The fluoride contents were determined by ion-selective electrode in 26 black tea samples originally produced in Turkey, Sri Lanka, India and Kenya, and in 14 herbal and seven fruit infusions originated from Turkey. Fluoride content in black tea infusions ranged from 0.57 to 3.72 mg/L after 5 min of brewing. Higher fluoride levels were found in black teas originated from Turkey when compared with teas originated from Sri Lanka. Moreover higher fluoride levels were determined in black tea bags compared with granular and stick-shaped black teas. However, herbal and fruit infusions were characterized by low values of fluoride (0.02–0.04 mg/L) after 5 min of brewing and increasing brewing time to 10 min caused only slight increases in some infusions. As a result, consuming tea infusions prepared from some black tea available in Turkish market, especially black tea bags, in large quantities may lead to exposion to a high amount of fluoride which may cause dental fluorosis. Although fruit and herbal infusions are safer to consume their fluoride contents are too low for caries prevention. In countries such as Turkey where tea is traditionally consumed, the fluoride concentration and daily safety precautions should be indicated on tea products.     

Topical application of green and white tea extracts provides protection from solar-simulated ultraviolet light in human skin

Background:  Tea polyphenols have been found to exert beneficial effects on the skin via their antioxidant properties.
Aims:  We sought to determine whether topical application of green tea or white tea extracts would prevent simulated solar radiation-induced oxidative damages to DNA and Langerhans cells that may lead to immune suppression and carcinogenesis.
Methods:  Skin samples were analysed from volunteers or skin explants treated with white tea or green tea after UV irradiation. In another group of patients, the in vivo immune protective effects of green and white tea were evaluated using contact hypersensitivity to dinitrochlorobenzene.
Results:  Topical application of green and white tea offered protection against detrimental effects of UV on cutaneous immunity. Such protection is not because of direct UV absorption or sunscreen effects as both products showed a sun protection factor of 1. There was no significant difference in the levels of protection afforded by the two agents. Hence, both green tea and white tea are potential photoprotective agents that may be used in conjunction with established methods of sun protection.     

绿茶饮液对大鼠膀胱肿瘤生长和间隙连接蛋白43表达的影响

目的观察绿茶对大鼠膀胱肿瘤生长和间隙连接蛋白43（Cx43）表达的影响。方法以N-丁基-N-（4-羟丁基）亚硝胺诱导形成大鼠膀胱癌动物模型。将39只成年雄性Wistar大白鼠随机分成正常对照组、膀胱癌模型组和绿茶组。24周后在麻醉下切除大鼠膀胱肿瘤组织并观察病理学改变，称量瘤体湿重并计算抑瘤率，免疫组织化学和DNA原位缺口末端标记法分别检测肿瘤微血管密度（MVD）和细胞凋亡指数（AI），半定量逆转录聚合酶链反应和Western印迹检测膀胱肿瘤组织Cx43mRNA及其蛋白的表达水平。结果绿茶组的膀胱肿瘤癌变发生率、瘤体湿重、MVD分别为38．46％（5／13）、（4．47±1．01）g、（2977±776），均显著低于模型组83．33％（10／12）、（5．63±1．27）g、（3708±570）（Χ^2=0．041、t=0．018、t=0．014，P均〈0．05），瘤重抑制率为20．82％；AI（22．46±2．90）％明显高于模型组（4．92±1．00）％（t=0．000，P〈0．01）。绿茶组的Cx43mRNA和蛋白的表达均极显著高于模型组（t=0．002、t=0．000，P均〈0．01）。结论绿茶能上调Cx43在大鼠膀胱肿瘤组织中的表达和增强Cx43介导的间隙连接通讯功能，从而有效抑制大鼠膀胱肿瘤的生长。     

米心红茶原料氟固定初步研究

目的:研究羊骨提取的骨盐乳剂对米心红茶原料的固定理氟作用。方法:将乳剂掺入米心红茶原料,晾干,分析水溶性氟、茶色及茶多酚。结果:当红茶原料中加入0%~2.5%再生骨盐乳剂(干骨盐计),可使茶原料中0%~63.31%水溶性氟被固定,固定剂用量为1.5%时水溶性氟被控制到300 mg/kg以下,茶水色和茶多酚含量无明显改变。结论:红茶原料的水溶性氟可被骨盐乳剂所固定。     

荞麦茶中总黄酮微波萃取的研究

目的荞麦茶为原料研究总黄酮的微波萃取法。方法以总黄酮提取率为指标，以固液比、溶剂浓度、萃取温度和萃取时间为影响因素进行单因素实验，然后进行四因素四水平的正交实验。结果确定了微波萃取的最佳提取条件为：萃取温度85℃，萃取时间25min，固液比1：12，溶剂浓度60％。结论微波法提取荞麦茶中的总黄酮快速、有效，有一定的应用前景。     

茶色素治疗急性椎—基底动脉脑梗塞279例临床分析

为了研究茶色素治疗急性椎－基底动脉脑梗塞病的临床疗效，选择确诊的急性椎－基底动脉脑梗塞病人，随机分为治疗组１４０例，对照组１３９例，治疗组又分成小剂量组，大剂量组，比较两组疗效，在治疗８周末这个时点上茶色素组优于对照组，大剂量茶色素治疗组又优于小剂量组，差异有显著性，茶色素是一种较理想的治疗急性椎－基底动脉脑梗塞的药物。     

茶色素对人血管内皮细胞一氧化氮合酶表达的影响

目的：研究茶色素对人血管内皮细胞一氧化氮合酶（ｅＮＯＳ）基因表达的影响。方法：应用ｗｅｓｔｅｒｎ ｂｌｏｔ和ＲＴ－ＰＣＲ等分子生物学方法分别从ｅＮＯＳ蛋白水平和ＲＮＡ水平研究茶色素对ｅＮＯＳ表达的影响。结果：８０、４０、ｍｇ／Ｌ的茶色素明显诱导人血管内皮细胞ｅＮＯＳ表达，并有剂量反应关系。结论：茶色素诱导人血管内皮细胞ｅＮＯＳ表达是其抗动脉粥样硬化的机制之一。