表没食子儿茶素没食子酸酯预防正畸固定矫治者的牙釉质白斑

文题释义： 龋白斑：很多接受正畸固定矫治的患者其牙面上会呈现白垩色的点或斑块，临床上表现为龋白斑(white spot lesions，WSL)，即釉质脱矿，如病变进一步发展甚至会形成龋洞。 表没食子儿茶素没食子酸酯(Epigallocatechin gallate，EGCG)：是茶多酚中最有效的活性成分，属于儿茶素。EGCG具有抗菌、抗病毒、抗氧化、抗动脉硬化、抗血栓形成、抗血管增生、抗炎以及抗肿瘤作用。绿茶里有EGCG，但红茶里没有，因为红茶里的EGCG被转化成了茶玉红精。EGCG在医药保健上具有防治癌症等多种疾病和增强免疫力等功能。 背景：目前已有大量研究证实表没食子儿茶素没食子酸酯(Epigallocatechin gallate，EGCG)可应用于牙科治疗中，但目前尚未有临床研究讨论EGCG用于托槽的釉质粘接是否可以减少临床上正畸术后白斑的发生率。目的：探讨EGCG应用于预防正畸固定矫治患者牙釉质白斑发生的价值。方法：选择接受正畸固定矫治治疗的50例符合纳入排除标准的患者，采用自身对照法，右侧使用添加有1 g/L EGCG的粘接剂(EGCG组)，左侧使用不含EGCG的粘接剂(对照组)，其余治疗步骤和材料均相同。于治疗开始后3，6和12个月检测目标牙位(16，11，46，26，31，36)牙釉质脱矿指数(EDI)和釉质白斑的发生率，并统计托槽脱落情况。研究方案的实施符合柳州市人民医院对研究的相关伦理要求，患者及监护人对试验过程完全知情同意。结果与结论：①EGCG组和对照组在试验期间托槽脱落率差异无显著性意义(P > 0.05)；②在治疗开始后3个月，2组白斑发生率和牙釉质脱矿指数值差异无显著性意义(P > 0.05)，治疗6，12个月，EGCG组白斑发生率和牙釉质脱矿指数值均较对照组显著降低(P < 0.05)；③结果说明，添加有1 g/L EGCG的粘接剂可以在不影响托槽粘接强度的情况下，起到预防正畸固定矫治患者牙釉质脱矿和白斑发生作用，且能长期维持。 ORCID: 0000-0002-5325-5037(杨柳青) 中国组织工程研究杂志出版内容重点：组织构建；骨细胞；软骨细胞；细胞培养；成纤维细胞；血管内皮细胞；骨质疏松；组织工程     

Epigallocatechin Gallate: A Review of Its Beneficial Properties to Prevent Metabolic Syndrome

Obesity and being overweight are linked with a cluster of metabolic and vascular disorders that have been termed the metabolic syndrome. This syndrome promotes the incidence of cardiovascular diseases that are an important public health problem because they represent a major cause of death worldwide. Whereas there is not a universally-accepted set of diagnostic criteria, most expert groups agree that this syndrome is defined by an endothelial dysfunction, an impaired insulin sensitivity and hyperglycemia, dyslipidemia, abdominal obesity and hypertension. Epidemiological studies suggest that the beneficial cardiovascular health effects of diets rich in green tea are, in part, mediated by their flavonoid content, with particular benefits provided by members of this family such as epigallocatechin gallate (EGCG). Although their bioavailability is discussed, various studies suggest that EGCG modulates cellular and molecular mechanisms of various symptoms leading to metabolic syndrome. Therefore, according to in vitro and in vivo model data, this review attempts to increase our understanding about the beneficial properties of EGCG to prevent metabolic syndrome.     

表没食子儿茶素没食子酸酯抗肿瘤作用机制的研究进展

绿茶中的活性成分已经被证明具有预防和控制癌症的作用,其中表没食子儿茶素没食子酸酯（EGCG）抗癌活性最高。EGCG能够通过调控氧化应激、阻滞肿瘤细胞周期、抑制肿瘤血管形成、诱导肿瘤细胞凋亡等途径实现抗肿瘤效果。因此对EGCG抗肿瘤作用机制的进行了综述,以期为EGCG的临床应用提供参考。     

氯沙坦联合表没食子儿茶素没食子酸酯对大鼠糖尿病肾病治疗的研究

目的观察氯沙坦联合表没食子儿茶素没食子酸脂（EGCG）对糖尿病肾病大鼠的肾脏保护作用。方法采用链脲佐菌素（60mg·kg^-1）腹腔注射建立糖尿病大鼠模型,模型成功后分为正常组、糖尿病组、氯沙坦组、EGCG组、氯沙坦＋EGCG组。EGCG组和氯沙坦＋EGCG组每周给予ECd2G10mg·kg^-1腹腔注射,氯沙坦组和氯沙坦＋EGCG组每天给予氯沙坦40rag·kg^-1灌胃。分别测定各组4、8、12周时血肌酐（Cr）、尿素氮（BUN）、葡萄糖（GLU）、甘油三酯（TG）、总胆固醇（CHOL）、高低密度脂蛋白（HDL）、低密度脂蛋白（LDL）、白蛋白（Alb）、24h尿蛋白定量（24hPro）。应用RealtimePCR法检测肾皮质活性氧（ReactiveOxygenSpecies,ROS）产生的主要通路NADPH氧化酶Nox4mRNA表达、Westernblot法检测肾皮质蛋白NADPH氧化酶Nox4的表达。结果糖尿病组相对于正常对照组Cr,BUN,TG,CHOL,HDL,LDL,24hPro水平均显著升高（P〈0．05）。与糖尿病组比较,氯沙坦组、EGCG组、氯沙坦＋ECa2G组大鼠Cr、24hPro有显著减少（P〈0．05）,但GLU,BUN,TG,CHOL,HDL,LDL均无明显减少（P〉0．05）。与氯沙坦组和EGCG组比较,氯沙坦＋ECA2G组Cr,GLU,BUN,TG,CHOL,HDL,LDL,ALB,24hPro均有差异但差异不明显（P〉0．05）。在第4和12周与正常组比较,糖尿病组大鼠肾小球硬化明显;与糖尿病组比较,氯沙坦组、EGCG组、氯沙坦＋EGCG组大鼠肾小球硬化均显著改善;与氯沙坦组比较,EGCG组、氯沙坦＋EGCG组大鼠。肾小球硬化缓解更加明显;在电子显微镜观察下与正常组比较,糖尿病组大鼠肾小球足细胞明显融合,氯沙坦组少量融合,而EGCG组和氯沙坦＋EGCG组足细胞基本完好。糖尿病组Nox4蛋白表达最高;与EGCG组和氯沙坦组比较,氯沙坦＋EGCG组Nox4蛋白表达均降低,并且随着时间的推移降低更加显著（P〈0．05）。第4、8、12周NADPH氧化酶Nox4mRNA表达均降低,但不同时间点同组之间差异不是很明显（P〉0．05）。结论EGCG协同氯沙坦通过下调NAD—PH氧化酶Nox4的表达,抑制氧化应激对糖尿病大鼠肾脏的损伤,对糖尿病肾病具有良好的保护作用。     

EGCG-mediated autophagy flux has a neuroprotection effect via a class III histone deacetylase in primary neuron cells

Prion diseases caused by aggregated misfolded prion protein (PrP) are transmissible neurodegenerative disorders that occur in both humans and animals. Epigallocatechin-3-gallate (EGCG) has preventive effects on prion disease; however, the mechanisms related to preventing prion diseases are unclear. We investigated whether EGCG, the main polyphenol in green tea, prevents neuron cell damage induced by the human prion protein. We also studied the neuroprotective mechanisms and proper signals mediated by EGCG. The results showed that EGCG protects the neuronal cells against human prion protein-induced damage through inhibiting Bax and cytochrome c translocation and autophagic pathways by increasing LC3-II and reducing and blocking p62 by using ATG5 small interfering (si) RNA and autophagy inhibitors. We further demonstrated that the neuroprotective effects of EGCG were exhibited by a class III histone deacetylase; sirt1 activation and the neuroprotective effects attenuated by sirt1 inactivation using sirt1 siRNA and sirtinol. We demonstrated that EGCG activated the autophagic pathways by inducing sirt1, and had protective effects against human prion protein-induced neuronal cell toxicity. These results suggest that EGCG may be a therapeutic agent for treatment of neurodegenerative disorders including prion diseases.     

EGCG对去势雌性大鼠骨量丢失的预防作用

目的:研究表没食子儿茶素没食子酸酯[(-)-epigallocatechin-3-gallate,EGCG]早期预防雌性去势大鼠骨量丢失的作用?方法:12周龄雌性Sprague-Dawley大鼠分为3组:A组,双侧卵巢切除去势术后第3天开始连续12周以10 mg/(kg?d) EGCG腹腔内注射;B组,仅接受双侧卵巢切除去势术,不接受EGCG干预;C组,假手术组,不接受EGCG干预?在实验终点时刻(24周龄)制作大鼠胫骨和股骨的离体标本用于micro-CT扫描,测量骨密度(BMD)和相关骨形态学参数:松质骨骨组织总量(total bone volume,TV)?骨量(bone volume,BV)?骨体积分数?平均骨小梁厚度?平均骨小梁数量和骨小梁分离度?皮质骨厚度和皮质骨骨体积分数;并对大鼠股骨远端骨组织进行HE染色?结果:根据micro-CT分析,A组大鼠的BMD和骨体积分数显著高于B组(P < 0.05)?A组松质骨分离度显著低于B组(P < 0.05)?其余骨形态学参数3组之间无统计学差异(P > 0.05)?骨组织学研究显示C组松质骨密度较A组和B组更加致密,A组松质骨密度则介于B组和C组之间?结论:EGCG在延缓雌性大鼠骨量丢失方面有积极作用,但是在年轻的雌性大鼠卵巢切除去势后以10 mg/(kg?d)的剂量预防性腹腔注射EGCG并不能完全恢复丢失的骨量?     

Bioactive nutrients - Time for tolerable upper intake levels to address safety

There is increasing interest by consumers, researchers, and regulators into the roles that certain bioactive compounds, derived from plants and other natural sources, can play in health maintenance and promotion, and even prolonging a productive quality of life. Research has rapidly emerged suggesting that a wide range of compounds and mixtures in and from plants (such as fruits and vegetables, tea and cocoa) and animals (such as fish and probiotics) may exert substantial health benefits. There is interest in exploring the possibility of establishing recommended intakes or dietary guidance for certain bioactive substances to help educate consumers. A key aspect of establishing dietary guidance is the assessment of safety/toxicity of these substances. Toxicologists need to be involved in both the development of the safety framework and in the evaluation of the science to establish maximum intake/upper limits.     

EGCG在抗鼻咽癌中对MMP-2表达的抑制作用

目的 探讨表没食子酸儿茶素没食子酸酯(EGCG)对鼻咽癌细胞MMP-2基因表达的影响,揭示EGCG抗鼻咽癌的作用机制。方法 应用低分化鼻咽癌细胞株CNE2细胞,5%CO2、37℃培养48 h,按照不同浓度EGCG(0、40、80、160 mg/L)进行分组处理。①应用MTT法检测各组培养细胞的增殖抑制率;②Transwell侵袭实验检测EGCG作用后CNE2细胞侵袭力;③半定量逆转录PCR(RT-PCR)细胞中MMP-2 mRNA表达;④应用蛋白印迹检测培养细胞的蛋白表达。结果 MTT及Transwell侵袭实验结果显示,随着EGCG的浓度和作用时间的增加,CNE2细胞的增殖能力及侵袭能力明显减弱,不同浓度EGCG作用后在三个不同的时间点与相应的对照组比较,差异有统计学意义(P0.05),且逐步抑制程度呈现出剂量-效应和时间-效应的依赖关系;半定量逆转录PCR(RT-PCR)和Western-Blot检测结果分别显示,随着EGCG作用浓度和时间的增加,MMP-2 mRNA表达和MMP-2的蛋白表达呈现出下降的趋势(P0.05)。结论 EGCG能够通过抑制CNE2细胞MMP-2的表达,从而降低了CNE2细胞的侵袭和转移,从而起到抗鼻咽癌作用。     

Chemoprevention of liver cancer by plant polyphenols

Primary liver cancer or hepatocellular carcinoma (HCC) is one of the most frequent tumors representing the fifth commonest malignancy worldwide and the third cause of mortality from cancer. Currently, the treatments for HCC are not so effective and new strategies are needed for its fight. Chemoprevention, the use of natural or synthetic chemical agents to reverse, suppress or prevent carcinogenesis is considered an important way for confronting HCC. Many of the chemopreventive agents are phytochemicals, namely non-nutritive plant chemicals with protective or disease preventive properties. In this review, we focus on plant polyphenols, one of the most important classes of phytochemicals, their chemopreventive properties against HCC and discuss the molecular mechanisms accounting for this activity.