绿茶及绿茶多酚对阿尔茨海默病的神经保护作用

氧化应激反应在阿尔茨海默病（AD）的发生中具有重要作用。绿茶及绿茶多酚作为公认的抗氧化剂，可减轻脂质过氧化反应，抑制氧化性DNA损伤，进而调节细胞凋亡过程，并可能抑制胆碱酯酶活性，干预淀粉样前体蛋白的生物合成，减轻淀粉样蛋白的沉积，从而干预AD的病理过程，发挥神经保护作用。     

茶皂甙对原发性高血压大鼠肾素-血管紧张素-醛固酮系统的影响

目的：探讨茶皂甙（TSP）对原发性高血压大鼠（SHR）肾素-血管紧张素-醛固酮系统（RAAS）的影响。方法：24只雄性SHR被随机分为4组,高血压对照组、卡托普利组（150 mg.kg^-1.d^-1）、TSP高剂量组（1600 mg.kg^-1.d^-1）、TSP低剂量组（400 mg.kg^-1.d^-1）,每组6只;另选6只雄性WKY（Wistar-Nyoto）大鼠作为正常血压对照组。每日给予各组大鼠相应药物灌胃,高血压对照组给予等量蒸馏水。8周末,自大鼠腹主动脉取血,用于测定血浆肾素活性（PRA）、血管紧张素（Ang）、Ang、醛固酮含量;同时测定主动脉组织中Ang含量。结果：高血压对照组血浆Ang、Ang及组织中Ang含量均显著高于正常血压对照组（P均〈0.01）,而血浆PRA及醛固酮水平有所升高,但差异无显著性。与高血压对照组相比,TSP高剂量组Ang含量明显升高（P〈0.01）、Ang和醛固酮含量显著降低（P均〈0.01）;组织中的Ang含量显著下降（P〈0.01）。结论：TSP可显著升高Ang水平,减少Ang生成,推测降压机制主要是通过影响RAAS,发挥类似血管紧张素转换酶抑制剂或Ang拮抗剂的作用。     

In vitro anti‐adhesive activity of green tea extract against pathogen adhesion

Camellia sinensis polysaccharide has been reported to possess anti‐adhesive activity against pathogens. The present study was designed to investigate whether hot water extracts obtained from green tea leaves might inhibit pathogen adhesion to human or mouse cell lines. Green tea extract‐4 (CSI‐4) with the maximum yield of 4% (w/v) is composed of a major proportion of carbohydrates containing 40% uronic acids, but lack of catechins. It showed strong inhibitory activities against hemagglutination mediated by pathogens Helicobacter pylori, Propionibacterium acnes and Staphylococcus aureus with the minimum inhibitory concentrations of 0.01‐0.5 mg/mL. CSI‐4 further demonstrated an inhibitory effect on the adhesion of these pathogens to host cell lines with the IC₅₀ values (50% inhibition of adhesion) of 0.14–2.3 mg/mL. It exhibited the highest activity against P. acnes, but no inhibitory effects were observed against Lactobacillus acidophilus, Bifidobacterium bifidum, Escherichia coli, or Staphylococcus epidermidis. Our results suggest that CSI‐4 may exert a selective anti‐adhesive effect against certain pathogenic bacteria with no adverse effects against beneficial or commensal bacteria. Copyright © 2008 John Wiley & Sons, Ltd.     

茶多酚对5500m低压条件下吸纯氧引起的小鼠心肌自由基代谢异常的保护作用

目的 观察天然抗氧化剂茶多酚（Tea Polyphenols,TP)对模拟飞行低压吸纯氧引起的小鼠心肌自由基代谢异常的保护作用。方法 42只雄性昆明种小鼠随机分为3组（n=14):对照组（A）、5500m低压吸氧组（B）和TP保护组（C）。B、C两组置于动物低压舱在5500m低压下吸氧（＞96％）,2h/d,3d/wk,共8wk。上舱暴露前,C组灌胃给予TP100mg/kg,另2组给予蒸馏水。末次实验后次日将小鼠断头处死,迅速取出心肌组织。测定心肌超氧化物歧化酶（SOD）活性和丙二醛（MDA）、一氧化氮（NO）含量。另外,用免疫组化法对心肌组织Cu,Zn-SOD和诱生型NO合酶（iNOS)的含量进行定性观察。结果 与对照比较,B组MDA水平、SOD添性和Cu,Zn-SOD酶含量明显升高（P＜0．05）;TP有明显保护作用：降低MDA生成（P＜0．01）,SOD活性和含量恢复正常。与之相反,重复5500m低压吸氧暴露后,心肌NO含量和iNOS表达明显降低。重复给予TP使NO代谢恢复正常。结论 天然抗氧化剂茶多酚对模拟飞行低压吸纯氧引起的心肌自由基代谢异常具有保护作用。     

茶多酚对胃缺血再灌注致黏膜毛细血管内皮超微结构损伤的保护作用

目的观察茶多酚（polyphenols of tea，PPT）对胃缺血再灌注致胃黏膜毛细血管内皮超微结构损伤的保护作用。方法将30只雄性sD大鼠随机分成6组（n=5）：空白对照组、手术组、20mg／kg PPT组、40mg／kg PPT组、80mg／kg PPT组、160mg／kg PPT组。在成功制作胃缺血动物模型的基础上，观察大鼠胃缺血30min后再灌注12h胃黏膜组织毛细血管内皮细胞超微结构的变化。结果茶多酚可显著减轻胃黏膜组织毛细血管内皮细胞超微结构的损伤。结论茶多酚对胃缺血再灌注致胃黏膜毛细血管内皮损伤具有保护作用，且存在剂量关系。     

Dietary Natural Compounds and Vitamins as Potential Cofactors in Uterine Fibroids Growth and Development

An analysis of the literature generated within the past 20 year-span concerning risks of uterine fibroids (UFs) occurrence and dietary factors was carried out. A link between Vitamin D deficiency and UFs formation is strongly indicated, making it a potent compound in leiomyoma therapy. Analogs of the 25-hydroxyvitamin D3, not susceptible to degradation by tissue 24-hydroxylase, appear to be especially promising and tend to show better therapeutic results. Although research on the role of Vitamin A in the formation of fibroids is contradictory, Vitamin A-enriched diet, as well as synthetic retinoid analogues, may be preventative or limit the growth of fibroids. Unambiguous conclusions cannot be drawn regarding Vitamin E and C supplementation, except for alpha-tocopherol. Alpha-tocopherol as a phytoestrogen taking part in the modulation of estrogen receptors (ERs) involved in UF etiology, should be particularly avoided in therapy. A diet enriched in fruits and vegetables, as sources of carotenoids, polyphenols, quercetin, and indole-3-carbinol, constitutes an easily modifiable lifestyle element with beneficial results in patients with UFs. Other natural substances, such as curcumin, can reduce the oxidative stress and protect against inflammation in leiomyoma. Although the exact effect of probiotics on uterine fibroids has not yet been thoroughly evaluated at this point, the protective role of dairy products, i.e., yogurt consumption, has been indicated. Trace elements such as selenium can also contribute to antioxidative and anti-inflammatory properties of a recommended diet. In contrast, heavy metals, endocrine disrupting chemicals, cigarette smoking, and a diet low in antioxidants and fiber were, alongside genetic predispositions, associated with UFs formation.     

Development of a Novel UPLC-MS/MS Method for the Simultaneous Determination of 16 Mycotoxins in Different Tea Categories

The contamination of potential mycotoxins in tea production and consumption has always been a concern. However, the risk monitoring on multiple mycotoxins remains a challenge by existing methods due to the high cost and complex operation in tea matrices. This research has developed a simple ultra-performance liquid chromatography-tandem mass spectrometry strategy based on our homemade purification column, which can be applied in the detections of mycotoxins in complex tea matrices with high-effectively purifying and removing pigment capacity for 16 mycotoxins. The limits of detection and the limits of quantification were in the ranges of 0.015~15.00 and 0.03~30.00 µg·kg⁻¹ for 16 mycotoxins, respectively. Recoveries from mycotoxin-fortified tea samples (0.13~1200 µg·kg⁻¹) in different tea matrices ranged from 61.27 to 118.46%, with their relative standard deviations below 20%. Moreover, this method has been successfully applied to the analysis and investigation of the levels of 16 mycotoxins in major categories of tea and the monitoring of multiple mycotoxins in processed samples of ripened Pu-erh. In conclusion, the proposed strategy is simple, effective, time-saving, and low-cost for the determination of a large number of tea samples.     

余苣降酸茶的HPLC指纹图谱研究

目的:建立余苣降酸茶HPLC指纹图谱,以控制该中药复方茶剂的质量。方法:采用HPLC梯度洗脱法测定余苣降酸茶的指纹图谱,色谱柱为Waters Sun Fire C18色谱柱(250 mm×4.6 mm,5μm);流动相为0.2%磷酸水溶液-乙腈,柱温:30℃,检测波长:308 nm,进样量:10μl,流速:1.0 ml·min^-1。结果:测得10批余苣降酸茶供试品HPLC色谱图,并标示出20个共有峰,确定其中2个已知峰分别为没食子酸和葛根素;并明确了20个共有峰的原药材归属。结论:该方法建立的余苣降酸茶HPLC指纹图谱重复性好,色谱峰信息量大,为全面控制该制剂的质量提供了可靠的方法。     

红茶菌发酵液抑菌作用研究

目的 研究不同pH值下红茶菌发酵液及其蛋白提取液的抗菌作用,为探寻新的抗菌物质奠定基础. 方法 采用K-B纸片扩散法检测不同pH值下红茶菌发酵液及不同量的蛋白提取液分别对大肠埃希菌、金黄色葡萄球菌和白色念珠菌的抑菌作用. 结果 红茶菌发酵液在酸性条件下对金黄色葡萄球菌和大肠埃希菌的生长具有明显的抑制作用,而在碱性条件下均未表现出抑制作用;红茶菌蛋白提取液对金黄色葡萄球菌和大肠埃希菌有抑菌活性,红茶菌发酵液及蛋白提取液对白色念珠菌无明显抑菌作用. 结论 红茶菌发酵液具有明显的抑制金黄色葡萄球菌和大肠埃希菌生长的作用.红茶菌发酵产生的蛋白质类物质是红茶菌液中的抑菌活性成分之一,具有用作食品抑菌剂的潜在价值.     

都匀毛尖对小鼠肝脏CYP3A酶活性及其mRNA水平的影响

目的:研究绿茶对细胞色素P450 3A(CYP3A)酶活性及其mRNA水平的影响,推测绿茶对药物代谢的作用.方法:绿茶选用都匀毛尖,120只昆明种雄性小鼠随机分为4组,对照组正常饮食饮水,低、中、高剂量绿茶组分别予0.25 g/(kg·d)、0.5 g/(kg·d)、1.0g/(kg·d)都匀毛尖茶汤灌胃,分别在1周、2周、3周时处死小鼠,测定小鼠肝脏微粒体CYP3A的活性,并用RT-PCR技术检测小鼠肝脏中CYP3A11 mRNA水平.结果:都匀毛尖能抑制CYP3A酶活性,呈时间-剂量依赖性;都匀毛尖可抑制CYP3A11 mRNA表达,且呈时间-剂量依赖性.结论:都匀毛尖对CYP3A的酶活性及mRNA水平均呈时间-剂量依赖性抑制作用,提示都匀毛尖可能通过影响CYP3A酶活性对药物的代谢发挥作用.