茶儿茶素防治放射性肺损伤的实验研究

目的探讨儿茶素对大鼠不同照射时期肺组织转化因子-β1(TGF-β1)、肿瘤坏死因子-α(TNF-α)蛋白的表达,阐述其对急性放射性肺损伤的防治作用及作用机制。方法成年雌性Wistar大鼠40只,随机表法分为4组:A组10只为对照组,腹腔注射生理盐水20 ml/kg/d;B组10只为单纯儿茶素组,腹腔注射儿茶素注射液100 mg/kg/d;C组10只为单纯照射组,全肺单次照射15 Gy+腹腔注射生理盐水20 ml/kg/d;D组10只为照射+儿茶素组,全肺单次照射15 Gy+腹腔注射儿茶素注射液100 mg/kg/d;每组各5只大鼠于照射后2周及6周处死,取肺组织作组织学与免疫组化检测,观察各组大鼠肺组织中TGF-β1、TNF-α蛋白表达的动态变化。结果 C组大鼠2周和6周时肺组织出现明显炎性损伤,D组急性肺炎性改变较C组明显减轻;A组和B组大鼠肺组织免疫组化TGF-β1、TNF-α阳性细胞数相对较低,C组的TGF-β1、TNF-α阳性细胞数较上述两组明显增高(p<0.05),D组阳性细胞数则介于两者之间,也显著低于C组(p<0.05)。结论儿茶素具有抑制TGF-β1、TNF-α蛋白表达,减轻早期放射性肺损伤炎症反应,对急性肺损伤有防治作用,其机制与抑制TGF-β1、TNF-α表达有关。     

Catechin content and the degree of its galloylation in oolong tea are inversely correlated with cultivation altitude

The taste quality of oolong tea generated from leaves of Camellia sinensis L. cultivated in the same mountain area is positively correlated to the cultivation altitude, partly due to the inverse correlation with the astringency of the tea infusion. The astringency of oolong tea mostly results from the presence of polyphenolic compounds, mainly catechins and their derivatives. Four catechins, (-)-epicatechin (EC) and (-)-epigallocatechin (EGC) together with their gallate derivatives (with relatively high astringency), (-)-EC gallate (ECG) and (-)-EGC gallate (EGCG), were detected as major compounds in oolong tea. The degrees of catechin galloylation, designated as ECG/(EC + ECG) and EGCG/(EGC + EGCG), in both oolong tea infusions and their fresh tea leaves, were found to be inversely correlated to the cultivation altitude at 200 m, 800 m, and 1300 m. A similar inverse correlation was observed when seven more oolong tea infusions and seven more fresh leaves harvested at altitude ranging from 170 m to 1600 m were recruited for the analyses. Moreover, catechin contents in oolong tea infusions were also found to be inversely correlated to the cultivation altitude. It is proposed that catechin content and the degree of its galloylation account for, at least partly, the inverse correlation between the astringency of oolong tea and the cultivation altitude.     

儿茶素对肾病综合征TGF-β1表达的影响研究

目的：研究儿茶素对肾病综合征大鼠TGF-β1表达的影响。方法：20只SD雌性大鼠随机分成正常组、肾病组、激素组、儿茶素治疗组共4组。实验末应用生化法测定血清中白蛋白(Alb)、总蛋白(TP)、三酰甘油(TG)、BUN、转化生长因子 β1(TGF-β1)及24 h尿蛋白排泄量,分别应用免疫组化与原位杂交法检测肾固有细胞中TGF-β1与TGF-β1mRNA的表达,并应用半定量评分法对各组大鼠病理改变进行计量分析。结果：儿茶素治疗组大鼠血清中总TGF-β1 ［(59.40±8.12) μg/L］、活性TGF-β1 ［(47.56±9.88) μg/L］,肾组织中TGF-β1 ［(45.1±2.0)%］、TGF-β1 mRNA 表达水平［(51.6±3.19)%］均明显低于肾病组［分别为(127.78±16.11) μg/L,(93.79±12.45) μg/L,(56.9±3.5)%,(60.4±4.8)%］(P<0.01);与肾病组相比,儿茶素治疗组血清Alb明显增高,TG含量明显下降［(11.28±4.18) g/L vs (1.46±0.71) g/L;(2.89±0.64) mmol/L vs (6.02±0.90) mmol/L;P<0.01］;与肾病组相比,儿茶素组大鼠肾脏病理损害明显减轻(P<0.05)。结论：儿茶素可通过抑制TGF-β1 mRNA的表达,降低肾脏局部及血清中活性TGF-β1蛋白表达水平,减轻肾脏损伤,改善肾功能,延缓肾脏病理慢性进展。     

生肌散质控方法的研究

目的 建立生肌散的质量标准。方法 采用TLC法对处方中血竭、冰片进行鉴别,用HPLC法测定方中君药儿茶中儿茶素的含量。结果 在TLC色谱中,能检出血竭、冰片。儿茶素在0．1762～3．524μg范围内,浓度与峰面积线性关系良好（r=0．9994）,样品的平均加样回收率为103．06％,RSD为0．39％（n=6）。结论 本文建立的方法对方中3味药材能准确、快速地进行定性、定量检测,可用于生肌散的质量控制。     

EGCG联合放疗治疗鼻咽癌裸鼠移植瘤模型

目的 研究表没食子儿茶素没食子酸酯(epigallocatechin-3-gallate,EGCG)对鼻咽癌裸鼠移植瘤放疗的增敏效应及survivin和VEGF的表达及意义.方法 体外培养低分化鼻咽癌CNE-2细胞,接种于20只雄性裸鼠皮下,待肿瘤结节约4～6 mm时,随机分为生理盐水组、EGCG组(30 mg/kg)...     

Pharmacological effects of green tea on the gastrointestinal system

Green tea is rich in polyphenolic compounds, with catechins as its major component. Studies have shown that catechins possess diverse pharmacological properties that include anti-oxidative, anti-inflammatory, anti-carcinogenic, anti-arteriosclerotic and anti-bacterial effects. In the gastrointestinal tract, green tea was found to activate intracellular antioxidants, inhibit procarcinogen formation, suppress angiogenesis and cancer cell proliferation. Studies on the preventive effect of green tea in esophageal cancer have produced inconsistent results; however, inverse relationships of tea consumption with cancers of the stomach and colon have been widely reported. Green tea is effective to prevent dental caries and reduce cholesterols and lipids absorption in the gastrointestinal tract, thus benefits subjects with cardiovascular disorders. As tea catechins are well absorbed in the gastrointestinal tract and they interact synergistically in their disease-modifying actions, thus drinking unfractionated green tea is the most simple and beneficial way to prevent gastrointestinal disorders.     

绿茶主要活性成分对叙利亚地鼠胚胎癌前细胞生长和凋亡的影响

目的建立叙利亚地鼠胚胎细胞（Syrian hamster embryo cell,SHE细胞）混合培养模型,研究表没食子儿茶素没食子酸酯（epigallocatechin-3-Gallate,EGCG）对SHE癌前细胞生长、增殖和凋亡的作用,探讨EGCG的抑癌机制。方法将SHE癌前细胞和正常细胞分别按1：10000、1：1000、1：100、1：10比例接种于6孔的培养皿中,培养7d,建立SHE细胞混合培养模型。以0μmol／L EGCG为对照组,分别选取浓度为0．5、1、5、10、50μmol／L的EGCG,通过SHE细胞生长实验,原位细胞凋亡实验、原位细胞增殖实验和基因芯片检测EGCG对SHE正常细胞、SHE癌前细胞和混合培养模型中SHE癌前细胞的生长、增殖、凋亡及相关调控基因表达的影响。结果SHE癌前细胞与正常细胞的比例为1：100是合适的混合培养模型。0．5、1、5、10μmol／L的EGCG促进了SHE正常细胞的生长,而浓度为50μmol／L的EGCG抑制了SHE正常细胞的生长。在1：200比例的SHE癌前细胞和正常细胞混合培养模型中,与对照组相比,浓度为5、10μmol／L的EGCG抑制了不同大小的SHE癌前细胞克隆的生长。对照组中SHE癌前细胞的DNA合成指数和凋亡指数分别是39．3％和6．5％,5、10p,mol／LEGCG作用后SHE癌前细胞的DNA合成指数分别降至25．6％和24．8％,细胞凋亡指数分别升至12．65％和14．5％。EGCG抑制了混合培养模型中SHE癌前细胞的生长和增殖,促进了其凋亡。EGCG对于细胞凋亡的调控可能通过p53、NF—KB、bcl-2通道的基因表达来实现;EGCG对于细胞增殖的调控可能通过阻滞细胞周期G1／S期实现。结论EGCG可能是通过抑制癌前细胞的增殖和促进其凋亡进而抑制癌症。     

桂木叶中儿茶素的提取分离与含量测定

【目的】提取分离桂木叶中活性成分儿茶素并建立其含量测定方法。【方法】采用硅胶柱层析及重结晶法分离桂木叶中儿茶素,通过光谱和波谱分析鉴定其化学结构。采用高效液相色谱(HPLC)法进行儿茶素的含量测定,色谱条件:Phenomenex prodigy C18色谱柱(250 mm×4.60 mm,5μm),流动相:乙腈—体积分数0.4%磷酸水梯度洗脱,流速:1.2 m L/min,检测波长:280 nm,柱温35℃,进样量10μL。【结果】经光谱和波谱分析鉴定,从桂木叶中分离得到的化合物为儿茶素,其纯度≥980 mg/g;儿茶素在20.04~120.24μg/m L范围内与峰面积线性关系良好(r=0.999 8);不同批次桂木叶样品中儿茶素含量为0.58~1.85 mg/g,平均回收率为98.07%(sR=1.84%)。【结论】首次确认了桂木叶含活性成分儿茶素,并建立其HPLC含量测定方法,所建方法简便、快速、定量准确,可为桂木叶的质量标准及资源开发提供参考依据。     

Protection of brain and pancreas from high-fat diet: effects of catechin and caffeine

To investigate the effect of a high-fat diet on brain and pancreas functions, we used SAMP10 mice that have characteristics of brain atrophy and cognitive dysfunction with aging. Simultaneously, we investigated the effect of green tea catechin consumption on high-fat diet feeding, because green tea catechin has been reported to improve brain atrophy, brain dysfunction and obesity. The body weight of mice fed a high-fat diet from 2 to 12 months was higher than that of the control, although the calorie intake was not. The high-fat diet also increased insulin secretion; however, the hypersecretion of insulin and obesity were suppressed when mice were fed a high-fat diet with green tea catechin and caffeine. Furthermore, brain atrophy was suppressed and the working memory, tested using Y-maze, improved in mice fed a high-fat diet containing green tea catechin and caffeine. The secretion of insulin might affect both obesity and brain function. A strong correlation was found between working memory and insulin release in mice fed a high-fat diet with green tea catechin and/or caffeine. The results indicate the protective effect of green tea catechin and caffeine on the functions of brain and pancreas in mice fed a high-fat diet.