植物多酚的防癌抗癌作用

植物多酚是植物中广泛存在的一大类多酚化合物的总称,包括多酚（如单宁）、黄酮、酚酸等。体外实验研究表明植物多酚对多种人癌细胞具有增殖抑制作用,抑制动物体内肿瘤生长。其作用机理与抗氧化、调控细胞周期、诱导肿瘤细胞凋亡和分化、影响血管生成和肿瘤细胞信号传导等有关。对植物多酚的防癌抗癌作用,值得进一步深入研究。     

二甲胺四环素联合茶多酚对早期种植体周围软组织炎患者牙周指标、炎性因子以及龈沟液RANKL、Shh水平的影响

摘要 目的：探讨二甲胺四环素联合茶多酚对早期种植体周围软组织炎患者牙周指标、炎性因子以及龈沟液核因子-?资?茁受体活化因子配体（RANKL）、音猬因子（Shh）水平的影响。方法：将106例于我院就诊的早期种植体周围软组织炎患者纳入研究,以信封抽签法分为对照组（n=53,二甲胺四环素治疗）和研究组（n=53,二甲胺四环素联合茶多酚治疗）。对比两组患者治疗前、治疗4周后的牙周指标、炎性因子、疗效以及龈沟液RANKL、Shh水平,记录两组治疗期间不良反应情况。结果：治疗4周后研究组临床总有效率90.57%（48/53）高于对照组73.58%（39/53）（P<0.05）。两组不良反应发生率对比无差异（P>0.05）。两组治疗4周后改良菌斑指数（mPLI）、改良龈沟出血指数（mSBI）、种植体周袋探诊深度（PPD）和血清白介素-1β（IL-1β）、单核细胞趋化蛋白-1(MCP-1)水平以及龈沟液RANKL、Shh水平均下降,且研究组低于对照组（P<0.05）。结论：二甲胺四环素联合茶多酚治疗早期种植体周围软组织炎患者,疗效显著,可有效改善患者牙周情况,降低患者血清IL-1β、MCP-1水平以及龈沟液RANKL、Shh水平,安全可靠。     

Modulation of phosphatidylinositol-3-kinase/protein kinase B- and mitogen-activated protein kinase-pathways by tea polyphenols in human prostate cancer cells

We have earlier shown that oral infusion of a polyphenolic fraction isolated from green tea, at a human achievable dose (equivalent to six cups of green tea per day), significantly inhibits prostate cancer (PCA) development and metastasis in transgenic adenocarcinoma of mouse prostate (TRAMP) model that closely mimics progressive form of human prostatic disease (Gupta et al. [2001]: Proc. Natl. Acad. Sci. U.S.A. 98:10350-10355.). A complete understanding of the mechanism(s) and molecular targets of PCA chemopreventive effects of tea polyphenols may be useful in developing novel approaches for its prevention. In this study, we employed two distinct human PCA cell lines viz. DU145 (androgen-unresponsive prostate carcinoma cells) and LNCaP (androgen-responsive prostate carcinoma cells) and, employing immunoblot analysis, we evaluated the effect of epigallocatechin-3-gallate (EGCG), the major polyphenol present in green tea and theaflavins (TF), the major polyphenol present in black tea on phosphatidylinositol-3-kinase (PI3K)/protein kinase B (PKB) and mitogen-activated protein kinase (MAPK) pathways. Both EGCG and TF treatment were found to (i) decrease the levels of PI3K and phospho-Akt and (ii) increase Erk1/2 in both DU145 and LNCaP cells. Our data showing the inhibition of the constitutive levels of PI3K and the phosphorylation of Akt could be important because the treatment approaches should be aimed at the inhibition of the constitutive levels of PI3K and Akt. Our data also suggest that Erk1/2 could be involved in the anti-cancer effects of EGCG and TF. Taken together, our study, for the first time demonstrated the modulation of the constitutive activation of PI3K/Akt and Erk1/2 pathways by EGCG as well as TF. We suggest that detailed studies in appropriate tumor model system are needed to establish the relevance of the cell culture work to in vivo models.     

Positive effects of temperature and growth conditions on enzymatic and antioxidant status in lettuce plants

The contents of two bioactive compounds (polyphenols and flavonoids) and their antioxidant and enzyme activities were determined in the leaves of six lettuce (Latuca sativa L.) cultivars subjected to 4 different day/night temperatures for 6 weeks.The total polyphenol and anthocyanin contents and the corresponding antioxidant activities were the highest at 13/10 °C and 20/13 °C, followed by 25/20 °C and 30/25 °C. The enzymatic activities of polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL) were also the highest at low day/night temperatures, but the peroxidase (POD) activity was decreased at low day/night temperatures and increased at high day/night temperatures.The most significant positive correlation existed between anthocyanin content and PPO activity, total polyphenols and their antioxidant activities. The results showed that at relatively low temperatures, lettuce plants have a high antioxidant and enzymatic status. These results provide additional information for the lettuce growers.     

应用量子化学方法研究茶多酚类抗氧化剂的构效关系

采用分子力学和量子化学从头计算方法,研究了不同结构茶多酚（Green tea polyphenol,GTP)抗氧化活性的构效关系。计算结果表明,茶多酚类的抗氧化活性与其释放活泼氢生成苯氧自由基的能力有关,添生大小与O－H间的Mulliken集居数、前线轨道能量、反应终态能量下降量及苯氧自由基稳定性有关。     

Effect of bioaugmentation of activated sludge with white-rot fungi on olive mill wastewater detoxification

AIMS: To test the potential use of Phanerochaete chrysosporium and other white-rot fungi to detoxify olive mill wastewaters (OMW) in the presence of a complex activated sludge. To combine the aerobic with anaerobic treatment to optimize the conversion of OMW in biogas. METHODS AND RESULTS: A 25-l air lift reactor was used to pretreat OMW by white-rot fungi. Detoxification of the OMW was monitored by size exclusion HPLC analysis, chemical oxygen demand (COD)/biological oxygen demand (BOD(5)) ratio evolution, and bioluminescence toxicity test. Anaerobic treatment of OMW was performed in a 12-l anaerobic filter reactor. Efficiency of the treatment was evaluated by organic matter removal, and biogas production. By comparison with the pretreatment by activated sludge only, the bioaugmentation with Phanerochaete chrysosporium or Trametes versicolor led to high removal of organic matter, decreased the COD/BOD(5) ratio and the toxicity. The subsequent anaerobic digestion of the OMW pretreated with activated sludge-white-rot fungi showed higher biomethanization yields than that pretreated with activated sludge only. Higher loading rates (7 g COD l(-1) day(-1)) were reached without any acidification or inhibition of biomethanization. CONCLUSIONS: The use of white-rot fungi, even in the presence of complex biological consortia to detoxify OMW, proved to be possible and made the anaerobic digestion of OMW for methane production feasible. SIGNIFICANCE AND IMPACT OF THE STUDY: The use of fungi for OMW reuse and energy production could be adapted to industrial applications.     

Effects of polyphenol-rich plant products from grape or hop as feed supplements on iron,zinc and copper status in piglets

Polyphenol-rich plant products as feed supplements have been shown to exert beneficial effects on feed efficiency in piglets. However, tannins as components of polyphenol-rich plant products are able to reduce the absorption of various trace elements. The present study investigated the effect of two polyphenol-rich dietary supplements, grape seed and grape marc meal extract (GME) and spent hops (SH), on iron (Fe), zinc (Zn) and copper (Cu) status in piglets supplied adequately with those trace elements. A trial with three groups of piglets which received a Control diet or the same diet supplemented with either 1% GME or 1% SH over a period of 4 weeks was performed. Concentrations of Fe, Zn and Cu in plasma, total iron binding capacity and saturation of transferrin in plasma did not differ between the three groups. Piglets fed the diet supplemented with SH showed no differences in the concentrations of Fe, Zn and Cu in the liver in comparison to the Control group. Piglets fed the diets supplemented with GME showed slightly lower concentrations of Zn and Cu in the liver than Control piglets (p < 0.05); however, concentrations of both elements remained in the physiological range. Overall, this study shows that the polyphenol-rich plant products GME and SH had marginal effect on the status of Fe, Zn and Cu in piglets.     

基于代谢组学的植物多酚及其肠道健康效应研究进展

综述了植物多酚的分类和来源、在代谢组学技术的驱动下,新型多酚物质的鉴定、控制植物多酚合成途径的关键因子以及多酚的功能特性的研究进展,阐述了植物多酚在肠道中的代谢以及其作为“益生元”调节肠道微生态并影响机体健康的重要功能。目前的研究表明不同植物多酚在调节肠道微生态方面存在差异,多数有促进肠道有益菌作用,并通过与肠道微生物“互作”发挥促进健康效应。总之,植物多酚作为“益生元”影响人体健康可能离不开肠道微生物的介导。各个植物多酚的益生功能也需要进一步阐析,在此过程中需要考虑宿主,膳食等混杂因素的综合影响,且需要拓展临床应用方面的研究。     

植物多酚通过microRNA调控脂质代谢研究进展

microRNA（简称miRNA）是长度18~25个核苷酸的非编码RNA分子,具有调控mRNA的翻译和/或稳定性的功能,从而在转录后水平调节不同基因的表达。人体内约60%编码蛋白的基因的表达受到miRNA调节,其中包括脂质代谢调控相关基因。植物多酚具有良好的生物活性,可以通过调节脂质代谢相关miRNAs,如miR-122和miR-33的表达进而发挥降血脂等活性。该文综述了miRNA调控脂质代谢相关mRNA的作用机制以及植物多酚在这一过程中的可能作用。     

茶叶中咖啡因和茶多酚提取技术研究

本文研究茶叶品种和质量、提取剂种类和萃取溶剂量对咖啡因和茶多酚提取得率、提取率和纯度的影响,结果表明:茶叶质量高,咖啡因和茶多酚的含量、得率和纯度就高。95％乙醇提取咖啡因和茶多酚的得率、提取率和纯度最高。1％氧化钙水溶液单纯提取咖啡因的得率、提取率和纯度较高。增加萃取次数和萃取溶剂量可提高咖啡因和茶多酚的得率,对产品纯度没有影响。