Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| overview of antibacterial, antitoxin, antiviral, and antifungal activities of tea flavonoids and teas. | tea leaves produce organic compounds that may be involved in the defense of the plants against invading pathogens including insects, bacteria, fungi, and viruses. these metabolites include polyphenolic compounds, the six so-called catechins, and the methyl-xanthine alkaloids caffeine, theobromine, and theophylline. postharvest inactivation of phenol oxidases in green tea leaves prevents oxidation of the catechins, whereas postharvest enzyme-catalyzed oxidation (fermentation) of catechins in tea ... | 2007 | 17195249 |
| bioactive saponins and glycosides. xxv. acylated oleanane-type triterpene saponins from the seeds of tea plant (camellia sinensis). | seven new acylated oleanane-type triterpene oligoglycosides, theasaponins a(4) (1), a(5) (2), c(1) (3), e(8) (4), e(9) (5), g(1) (6), and h(1) (7), were isolated from the seeds of japanese tea plant (camellia sinensis). the structures of 1-7 were elucidated on the basis of chemical and physicochemical evidence. | 2007 | 17202702 |
| black tea ameliorates aflatoxin-induced lipid peroxidation in the kidney of mice. | oral administration of 25 and 50 mg of aflatoxin in 0.2 ml olive oil/animal/day for 30 days caused dose-dependent and significantly higher lipid peroxidation in the kidney of aflatoxin-treated mice than in the controls. the levels of non-enzymatic antioxidant such as glutathione as well as the enzymatic antioxidants such as superoxide dismutase, glutathione peroxidase and catalase were significantly lower in the kidney of aflatoxin-treated mice than in the controls. black tea extract (2%) treatm ... | 2006 | 17203869 |
| interactions between smoking and other exposures associated with lung cancer risk in women: diet and physical activity. | the objective of the study is to estimate the differences in the impact of diet and physical exercise on lung cancer risk in female nonsmokers vs. smokers, and reveal interactions, if any. in a hospital based case-control study, data collected by in-person interviews from 569 female lung cancer cases and 2120 controls were analyzed using unconditional logistic regression stratifying by appropriate factors. protective effects were observed for intake of milk/dairy products (or=0.57, 95%ci 0.35-0. ... | 2007 | 17203897 |
| effect of nitrogen form and root-zone ph on growth and nitrogen uptake of tea (camellia sinensis) plants. | tea (camellia sinensis) is considered to be acid tolerant and prefers ammonium nutrition, but the interaction between root zone acidity and n form is not properly understood. the present study was performed to characterize their interaction with respect to growth and mineral nutrition. | 2007 | 17204540 |
| green tea [camellia sinensis (l.) o. kuntze] extract reverses the despair behaviour in reserpinised and diabetic mice. | green tea (c. sinensis) extract (gte) dose dependently produced reversal of despair in normal, reserpinised and diabetic mice, thereby demonstrating an antidepressant effect. although the exact mechanism is yet to be explored, the possible inhibition of catechol-o-methyl transferase and monoamine oxidase enzymes may be responsible for antidepressant activity of gte. | 2006 | 17205714 |
| addition of milk prevents vascular protective effects of tea. | experimental and clinical studies indicate that tea exerts protection against cardiovascular diseases. however, a question of much debate is whether addition of milk modifies the biological activities of tea. we studied the vascular effects of tea, with or without milk, in humans and elucidated the impact of individual milk proteins in cell culture experiments, with isolated rat aortic rings and by hplc analysis. | 2007 | 17213230 |
| structure-activity relationships of tea compounds against human cancer cells. | the content of the biologically active amino acid theanine in 15 commercial black, green, specialty, and herbal tea leaves was determined as the 2,4-dinitrophenyltheanine derivative (dnp-theanine) by a validated hplc method. to define relative anticarcinogenic potencies of tea compounds and teas, nine green tea catechins, three black tea theaflavins, and theanine as well as aqueous and 80% ethanol/water extracts of the same tea leaves were evaluated for their ability to induce cell death in huma ... | 2007 | 17227049 |
| tea and cancer prevention: molecular mechanisms and human relevance. | tea made from the leaves of the plant camellia sinensis is a popular beverage. the possible cancer-preventive activity of tea and tea polyphenols has been studied extensively. this article briefly reviews studies in animal models, cell lines, and possible relevance of these studies to the prevention of human cancer. the cancer-preventive activity of tea constituents have been demonstrated in many animal models including cancer of the skin, lung, oral cavity, esophagus, stomach, liver, pancreas, ... | 2007 | 17234229 |
| black tea polyphenols restrict benzopyrene-induced mouse lung cancer progression through inhibition of cox-2 and induction of caspase-3 expression. | lung cancer is one of the leading causes of cancer related death in most developed and many developing countries of the world. due to lack of validated screening methods and poor prognosis, treatment of lung cancer has not improved significantly over the last two decades. therefore the risk of the disease needs to be minimized by preventive measures. one approach for lung cancer prevention envisages reversal or restriction of precancerous lesions by chemopreventive intervention. it demands a dee ... | 2006 | 17250449 |
| in vitro evaluation of the anticancer effect of lactoferrin and tea polyphenol combination on oral carcinoma cells. | we investigated the anticancer effects of green and black tea polyphenols alone and in combination with bovine milk lactoferrin (blf) on human tongue squamous carcinoma (cal-27) and normal human gingival fibroblast (hgf) cells. both green (polyphenon-e;p-e) and black tea polyphenols (polyphenon-b;p-b) preferentially inhibit the growth of cal-27 cells in a dose-dependent manner. based on the ic(50) values, p-e was found to be more effective than p-b and the combination of p-e and blf (1:2 ratio) ... | 2007 | 17258915 |
| fatty acids in tea shoots (camellia sinensis (l.) o. kuntze) and their effects on the growth of retinal rf/6a endothelial cell lines. | chemo-protective effects of tea on ocular diseases were recorded in chinese pharmacopoeia about 2000 years ago by eating tea. in the present study, contents of fatty acids (fas) in tea shoots were determined by capillary gc; and the growth of rf/6a cells was also investigated by exposure to various representative fas existing in tea shoots with pathologically relevant concentrations (40-500 microm) by ameliorated mtt assay and flow cytometry. electron spin resonance (esr) was used to measure oxy ... | 2007 | 17262883 |
| bioactive saponins and glycosides. xxviii. new triterpene saponins, foliatheasaponins i, ii, iii, iv, and v, from tencha (the leaves of camellia sinensis). | new triterpene saponins, foliatheasaponins i-v, were isolated from the methanolic extract of tencha [the leaves of camellia sinensis (l.) o. kuntze (theaceae)]. the chemical structures of these new saponins were elucidated on the basis of chemical and physicochemical evidence. among the new saponins, foliatheasaponins ii and iii, were found to inhibit release of beta-hexosaminidase, as a marker of antigen-induced degranulation, in rbl-2h3 cells. | 2007 | 17268104 |
| [studies on tea plants (camellia sinensis) germplasms using est-ssr marker]. | forty two tea varieties were analyzed by using 16 ssr primer sets derived from tea ests in this study, and 13 of the primer sets produced clear bands and 10 of them showed polymorphism, accounting for 76.9%. the pic (polymorphism information content) for each polymorphic primer set varied from 0.522 to 0.866, with a average about 0.73. totally 84 genotypes and 74 alleles were detected in all materials by 10 polymorphic markers, with the range from 4 to 12 and from 3 to 10 for each polymorphic pr ... | 2007 | 17284433 |
| evaluation of the astringency of black tea by a taste sensor system: scope and limitation. | grading the astringency of black tea by a taste sensor system was studied. the black tea samples manufactured in india and sri lanka were classified into ten steps on the basis of two standard solutions (0.65 mm and 0.26 mm egcg aqueous solutions). an organoleptic test demonstrated that the sensor output was correlative to the human gustatory sense. | 2007 | 17284831 |
| consumption of black tea or coffee and risk of ovarian cancer. | the goal of this study was to investigate the associations between ovarian cancer risk and usual consumption of black tea, regular coffee, or decaffeinated coffee. using a hospital-based case-control design, participants included 414 women with primary epithelial ovarian, fallopian, or peritoneal cancer and 868 age- and region-matched women with nonneoplastic conditions. all participants completed a comprehensive epidemiologic questionnaire. black tea consumption was associated with a linear dec ... | 2013 | 17291231 |
| black tea prevents cigarette smoke-induced apoptosis and lung damage. | cigarette smoking is a major cause of lung damage. one prominent deleterious effect of cigarette smoke is oxidative stress. oxidative stress may lead to apoptosis and lung injury. since black tea has antioxidant property, we examined the preventive effect of black tea on cigarette smoke-induced oxidative damage, apoptosis and lung injury in a guinea pig model. | 2007 | 17300721 |
| thea sinensis melanin prevents cisplatin-induced nephrotoxicity in mice. | the preventive effect of thea sinensis melanin (tsm) against cisplatin-induced nephrotoxicity was studied on icr mice. animals were given 20mg/kg i.p. of cisplatin, and tsm was injected i.p. in doses 10-40 mg/kg 2h before intoxication. the protective effects were evidenced by a complete inhibition of the cisplatin-induced elevation of serum blood urea nitrogen (bun), prevention of oxidative stress, and complete blockade of cisplatin-induced elevation of serum creatinine. tsm by itself, however, ... | 2007 | 17303299 |
| compositional analysis and preliminary toxicological evaluation of a tea polysaccharide conjugate. | tea polysaccharide conjugate is one of the main bioactive constituents of tea (camellia sinensis l.). the chemical composition and preliminary toxicological evaluation of a tea polysaccharide conjugate was investigated to determine the possibility of using it for human consumption. chemical analysis of tea polysaccharide conjugate showed that the tea polysaccharide conjugate was a nonstarch protein bounded acidic polysaccharide. the protein, neutral sugar, and uronic acid content of the tea poly ... | 2007 | 17305361 |
| dissipation kinetics of spiromesifen on tea (camellia sinensis) under tropical conditions. | spiromesifen (oberon) is a new insecticide and miticide of chemical class ketoenol active against white flies (bemisia spp., trialeuroides spp.) and spider mites (tetranychus and panonychus spp.). due to its potential significance in insect resistance management, it is important to establish its behaviour on crop and environment. in the present study, the degradation/dissipation of spiromesifen on tea crop under tropical environmental conditions was studied and its dt(50) (t(1/2)), and dt(90) (t ... | 2007 | 17307225 |
| antioxidant capacity of 55 medicinal herbs traditionally used to treat the urinary system: a comparison using a sequential three-solvent extraction process. | the prevalence of chronic renal disease exceeds 10% in industrialized societies. oxidative damage is thought to be one of the main mechanisms involved in nearly all chronic renal pathologies. | 2014 | 17309384 |
| oxidative coupling of the pyrogallol b-ring with a galloyl group during enzymatic oxidation of epigallocatechin 3-o-gallate. | in order to clarify the mechanism for formation of catechin oligomers during the fermentation stage of black tea manufacture, epigallocatechin-3-o-gallate, the most abundant tea flavanol in fresh tea leaves, was enzymatically oxidized and the resulting unstable quinone metabolites were converted to phenazine derivatives by treatment with o-phenylenediamine. in addition to formation of monomeric and dimeric derivatives, four trimeric derivatives were isolated whose structures were determined by a ... | 2007 | 17320123 |
| high-molecular-weight polyphenols from oolong tea and black tea: purification, some properties, and role in increasing mitochondrial membrane potential. | high-molecular-weight polyphenols from oolong and black teas increased mitochondrial membrane potential, as measured by a method using ciliated protozoan tetrahymena and rhodamine 123. these polyphenols, referred to as mitochondrial activation factors (mafs), were purified from oolong and black teas by solvent extraction and toyopearl column chromatography. the number-average molecular weights of the mafs were 9,000 to 18,000, and the weight-average molecular weights were 15,000 to 25,000. the m ... | 2007 | 17341825 |
| biosorption of copper(ii), lead(ii), iron(iii) and cobalt(ii) on bacillus sphaericus-loaded diaion sp-850 resin. | the biosorption of copper(ii), lead(ii), iron(iii) and cobalt(ii) on bacillus sphaericus-loaded diaion sp-850 resin for preconcentration-separation of them have been investigated. the sorbed analytes on biosorbent were eluted by using 1 mol l(-1) hcl and analytes were determined by flame atomic absorption spectrometry. the influences of analytical parameters including amounts of ph, b. sphaericus, sample volume etc. on the quantitative recoveries of analytes were investigated. the effects of alk ... | 2007 | 17386450 |
| evaluation of chemopreventive agents for genotoxic activity. | we conducted genetic toxicity evaluations of 11 candidate chemopreventive agents with the potential for inhibiting carcinogenesis in humans at increased risk of cancer. the compounds were evaluated for bacterial mutagenesis in the salmonella-e. coli assay, for mammalian mutagenesis in mouse lymphoma cells, for chromosome aberrations in chinese hamster ovary (cho) cells, and for micronucleus induction in mouse bone marrow. tested agents were indole 3-carbinol (i3c), bowman-birk inhibitor concentr ... | 2007 | 17387038 |
| use of tea extracts (camelia sinensis) in jelly candies as polyphenols sources in human diet. | diet rich in polyphenols may be important factor in preventing cardiovascular, neoplastic diseases and slowing down the aging processes. because tea (camelia sinensis) is most popular beverage containing relatively large amounts of polyphenols, it could be tremendously important source of polyphenolic constituents in human diet. however, there has been no data on the tea extracts use in particular everyday snacks. objective of the study was to investigate potential use of tea polyphenol extracts ... | 2007 | 17392075 |
| study on the antioxidant activity of tea flowers (camellia sinensis). | major chemical compounds in different extracts from tea flowers (camellia sinensis) were analyzed. distilled water or 70% ethanol extracts were then fractionated with chloroform, ethyl acetate and n-butanol, respectively. each extract fraction was tested its scavenging activities on 2,2-diphenyl-1-picrylhydrazyl (dpph) and hydroxyl free radicals. the results showed that ethyl acetate fraction of ethanol-extract of tea flower (eea) exhibited the highest quenching activity to hydroxyl radicals (sc ... | 2007 | 17392094 |
| theaflavin ameliorates cerebral ischemia-reperfusion injury in rats through its anti-inflammatory effect and modulation of stat-1. | theaflavin, a major constituent of black tea, possesses biological functions such as the antioxidative, antiviral, and anti-inflammatory ones. the purpose of this study was to verify whether theaflavin reduces focal cerebral ischemia injury in a rat model of middle cerebral artery occlusion (mcao). male sprague-dawley rats were anesthetized and subjected to 2 hours of mcao followed 24 hours reperfusion. theaflavin administration (5, 10, and 20 mg/kg, i.v.) ameliorated infarct and edema volume. t ... | 2006 | 17392572 |
| breast cancer prevention by green tea catechins and black tea theaflavins in the c3(1) sv40 t,t antigen transgenic mouse model is accompanied by increased apoptosis and a decrease in oxidative dna adducts. | tea consumption is associated with a reduced risk of mammary cancer as reflected by epidemiological studies and experiments in carcinogen-induced rodent models of mammary carcinogenesis. we tested the hypothesis that green tea catechins (gtc) or theaflavins from black tea (btt) interfere with mammary carcinogenesis in c3(1) sv40 t,t antigen transgenic multiple mammary adenocarcinoma (tag) mice and that gtc/btt affect tumor survival or oxidation status. tag mice received gtc/btt (0.05%) in drinki ... | 2007 | 17407311 |
| acute effects of tea on fasting and non-fasting plasma total homocysteine concentrations in human subjects. | plasma total homocysteine concentrations (thcy) are a putative risk factor for cvd. tea is a rich dietary source of polyphenols and caffeine, both of which may raise thcy. however, it is possible that much of any effect is transitory and may be influenced by the consumption of food. our objective was to investigate the acute effect of tea, at a dose representative of ordinary population intakes, on thcy and to determine whether consumption of a meal influences the magnitude of any effect. measur ... | 2007 | 17408524 |
| medicinal flowers. xiv. new acylated oleanane-type triterpene oligoglycosides with antiallergic activity from flower buds of chinese tea plant (camellia sinensis). | the methanolic extract from the flower buds of chinese tea plant (camellia sinensis (l.) o. kuntze) was found to inhibit release of beta-hexosaminidase from rbl-2h3 cells. from the methanolic extract, six new acylated oleanane-type triterpene oligoglycosides, floratheasaponins d-i, were isolated together with 21 known compounds including floratheasaponins a-c. the chemical structures of floratheasaponins d-i were elucidated on the basis of chemical and physicochemical evidence. the principal con ... | 2007 | 17409555 |
| potential exposure and risk of fluoride intakes from tea drinks produced in taiwan. | tea is the second most commonly consumed drink in the world. excess fluoride intakes from tea drinks may cause health effects. this work assesses infusible fluoride levels in popular tea sold in taiwan and evaluates potential exposure factors. lungjing, pouchong, tienguanyin, oolong, pureh, and black tea specimens were purchased from different counties in taiwan. fluoride levels were evaluated in one complete cycle of tea making as well as at different calcium carbonate contents in water, with g ... | 2008 | 17410113 |
| chemoprevention of rat mammary carcinogenesis by black tea polyphenols: modulation of xenobiotic-metabolizing enzymes, oxidative stress, cell proliferation, apoptosis, and angiogenesis. | chemoprevention of dietary constituents has emerged as a cost-effective approach to control the incidence of breast cancer. the present study was therefore designed to evaluate the chemopreventive efficacy of black tea polyphenols (polyphenon-b) during the preinitiation phase of 7,12-dimethylbenz[a]anthracene (dmba) induced mammary carcinogenesis using xenobiotic-metabolizing enzymes, cellular redox status, cell proliferation, apoptosis, and angiogenesis as biomarkers of chemoprevention. intraga ... | 2007 | 17415784 |
| [effect of plant biocomposites based on georgian tea "per se" and in combination with cisplatin on walker carcinosarcoma w-256 and guerin's carcinoma growth rate in rats]. | green tea biocomposite had effectivey hampered the growth of rat walker w-256 carcinoma and in less extent rat guerin's carcinoma. black tea biocomposite had not practically influenced on guerin's carcinoma growth. the biocomposite from green tea and extract from red vine rind and lemon suppressed at the level of tendency the growth of rat walker w-256 carcinoma. the biocomposite from green tea and extract from red vine rind had hampered only guerin's carcinoma growth and at the tendency had inc ... | 2006 | 17427433 |
| the structure of two n-methyltransferases from the caffeine biosynthetic pathway. | caffeine (1,3,7-trimethylxanthine) is a secondary metabolite produced by certain plant species and an important component of coffee (coffea arabica and coffea canephora) and tea (camellia sinensis). here we describe the structures of two s-adenosyl-l-methionine-dependent n-methyltransferases that mediate caffeine biosynthesis in c. canephora 'robusta', xanthosine (xr) methyltransferase (xmt), and 1,7-dimethylxanthine methyltransferase (dxmt). both were cocrystallized with the demethylated cofact ... | 2007 | 17434991 |
| antibacterial properties of traditionally used indian medicinal plants. | in search of broad-spectrum antibacterial activity from traditionally used indian medicinal plants, 66 ethanolic plant extracts were screened against nine different bacteria. of these, 39 extracts demonstrated activity against six or more test bacteria. twelve extracts showing broad-spectrum activity were tested against specific multidrug-resistant (mdr) bacteria, methicillin-resistant staphylococcus aureus (mrsa) and extended spectrum beta-lactamases (esbetal)-producing enteric bacteria. in vit ... | 2007 | 17440624 |
| ecological impact of solar ultraviolet-b (uv-b: 320-290 nm) radiation on corynebacterium aquaticum and xanthomonas sp. colonization on tea phyllosphere in relation to blister blight disease incidence in the field. | to assess the effects of solar uv-b radiation on phyllosphere bacteria of tea leaves in relation to blister blight disease in the field. | 2007 | 17451518 |
| effects of infusion time and addition of milk on content and absorption of polyphenols from black tea. | epidemiological studies assessing the health benefits of drinking black tea are equivocal. such disparity may reflect an inability of semiquantitative assessment to consider how infusion time and addition of milk affect the bioavailability of potentially beneficial antioxidant polyphenols. six brands of tea demonstrated similar increases in antioxidant capacity and total phenolic and catechin contents with increasing infusion time. these results were unaffected by the addition of milk. consumpti ... | 2007 | 17489604 |
| genetic base of tea (camellia sinensis l.) cultivars in sri lanka as revealed by pedigree analysis. | an understanding of genetic diversity and relationships among breeding materials is a prerequisite for crop improvement. coefficient of parentage (cop) can be used to measure the genetic diversity among genotypes on the basis of pedigree information. in the present study, cop was estimated for 56 cultivars, including commercial tea cultivars developed by the tea research institute of sri lanka and their parental lines. mean cop of the 56 accessions studied was 0.097 and the value was raised up t ... | 2007 | 17495345 |
| activation of endothelial nitric oxide synthase by dietary isoflavones: role of no in nrf2-mediated antioxidant gene expression. | the endothelium plays a key role in the maintenance of vascular homeostasis, and increased oxidative stress in vascular disease leads to reduced nitric oxide bioavailability and impaired endothelium-dependent relaxation of resistance vessels. although epidemiological evidence suggests that diets containing high amounts of natural antioxidants afford protection against coronary heart disease (chd), antioxidant supplementation trials have largely reported only marginal health benefits. there is co ... | 2007 | 17498676 |
| theaflavins induced apoptosis of lncap cells is mediated through induction of p53, down-regulation of nf-kappa b and mitogen-activated protein kinases pathways. | prostate cancer (pca), the most frequently diagnosed malignancy in men, represents an excellent candidate disease for chemoprevention studies because of its particularly long latency period, high rate of mortality and morbidity. infusion of black tea and its polyphenolic constituents have been shown to possess antineoplastic effects in androgen dependent pca in both in vivo and in vitro models including transgenic animals. in the present study, we report that black tea polyphenol, theaflavins (t ... | 2007 | 17499812 |
| black tea improves endothelial function in renal transplant recipients. | endothelial damage and dysfunction are commonplace in renal transplant recipients. impaired endothelial function is an important contributor to cardiovascular diseases. we hypothesized that short-term black tea consumption may improve endothelium-dependent arterial dilation in kidney recipients. | 2007 | 17524915 |
| modulatory effects of black tea polyphenols on oxidant-antioxidant profile and expression of proliferation, apoptosis, and angiogenesis-associated proteins in the rat forestomach carcinogenesis model. | chemoprevention by dietary constituents has emerged as a novel approach to control stomach cancer incidence. we therefore evaluated the chemopreventive effects of black tea polyphenols (polyphenon-b) on oxidant-antioxidant status, cell proliferation, apoptosis, and angiogenesis during n-methyl-n'-nitro-n-nitrosoguanidine (mnng)-induced gastric carcinogenesis. | 2007 | 17530359 |
| pseudomonas aeruginosa immobilized multiwalled carbon nanotubes as biosorbent for heavy metal ions. | pseudomonas aeruginosa immobilized multiwalled carbon nanotubes has been used as biosorbent for the solid phase extraction of some heavy metal ions in environmental samples. cobalt(ii), cadmium(ii), lead(ii), manganese(ii), chromium(iii) and nickel(ii) ions have been selected as analytes for the presented study, due to their important negative and positive roles in human life. in order to investigate quantitative biosorption conditions of the analytes, the influences of ph of the aqueous solutio ... | 2008 | 17532628 |
| tea (camellia sinensis) clones with shorter periods of winter dormancy exhibit lower accumulation of reactive oxygen species. | tea (camellia sinensis (l.) o. kuntze) is a perennial crop grown throughout the world. during winter, tea undergoes a dormancy period when growth of apical buds almost ceases, severely reducing the commercial yield of tea. low temperatures prevail during the period of winter dormancy, which alone or in combination with high solar irradiance have the potential to induce oxidative stress in plants. we studied six tea clones under field conditions to test whether a relationship exists between oxida ... | 2007 | 17545125 |
| redox potential of tea infusion as an index for the degree of fermentation. | redox potential of tea infusion is suggested as an index for the extent of tea fermentation. the potential was measured between platinum and ag/agcl electrode pair with a voltmeter with high input impedance (>1000 gohms). phosphate buffer (10 mm, ph 7.0) was used to extract the infusion and served as the supporting electrolytes for the electrochemical measurement. the reliability (the nernst's behavior) for redox potential measurement was verified with a standard redox couple, ferricyanide/ferro ... | 2007 | 17560382 |
| polyamines in tea processing. | the distribution of dietary polyamines, putrescine, spermidine and spermine, was determined during processing of camellia sinensis. black tea manufacture is carried by a series of processes on fresh tea leaves involving withering, rolling, fermentation, drying and sieving. the aim of this research was to determine the effect of tea processing on the polyamine content in relation with antioxidant enzymes, superoxide dismutase, lipid peroxidase and glutathione peroxidase. before processing, the sp ... | 2007 | 17566892 |
| effects of lifestyle on urinary 1-hydroxypyrene concentration. | this study aimed to clarify the variation of urinary excretion of 1-hydroxypyrene, which is a major metabolite of pyrene, in relation to lifestyle, including factors such as diet and smoking. the study subjects were 251 workers (male: 196, female: 55, mean age: 44.3) who were not occupationally exposed to pahs. urine specimens were collected from 8:00 a.m. to 11:00 a.m. and their 1-hydroxypyrene concentrations were determined by hplc. a questionnaire was distributed in order to learn gross aspec ... | 2007 | 17575398 |
| natural health products that inhibit angiogenesis: a potential source for investigational new agents to treat cancer-part 1. | an integrative approach for managing a patient with cancer should target the multiple biochemical and physiologic pathways that support tumour development and minimize normal-tissue toxicity. angiogenesis is a key process in the promotion of cancer. many natural health products that inhibit angiogenesis also manifest other anticancer activities. the present article focuses on products that have a high degree of anti-angiogenic activity, but it also describes some of the many other actions of the ... | 2006 | 17576437 |
| natural health products that inhibit angiogenesis: a potential source for investigational new agents to treat cancer-part 2. | the herbalist has access to hundreds of years of observational data on the anticancer activity of many herbs. laboratory studies are expanding the clinical knowledge that is already documented in traditional texts. the herbs that are traditionally used for anti-cancer treatment and that are anti-angiogenic through multiple interdependent processes (including effects on gene expression, signal processing, and enzyme activities) include artemisia annua (chinese wormwood), viscum album (european mi ... | 2006 | 17576449 |
| salivary hydrogen peroxide produced by holding or chewing green tea in the oral cavity. | tea (camellia sinensis) catechins have been studied for disease prevention. these compounds undergo oxidation and produce h(2)o(2). we have previously shown that holding tea solution or chewing tea leaves generates high salivary catechin levels. herein, we examined the generation of h(2)o(2) in the oral cavity by green tea solution or leaves. human volunteers holding green tea solution (0.1-0.6%) developed salivary h(2)o(2) with c(max) = 2.9-9.6 microm and auc(0 --> infinity) = 8.5-285.3 microm ... | 2007 | 17577746 |
| chemical profiling and gene expression profiling during the manufacturing process of taiwan oolong tea "oriental beauty". | oriental beauty, which is made from tea leaves infested by the tea green leafhopper (jacobiasca formosana) in taiwan, has a unique aroma like ripe fruits and honey. to determine what occurs in the tea leaves during the oolong tea manufacturing process, the gene expression profiles and the chemical profiles were investigated. tea samples were prepared from camellia sinensis var. sinensis cv. chin-shin dah-pang while the tea leaves were attacked by the insect. the main volatile compounds, such as ... | 2007 | 17587678 |
| artemisia herba-alba asso (asteraceae) has equivalent effects to green and black tea decoctions on antioxidant processes and some metabolic parameters in rats. | the objective was to compare the long-term effects of artemisia herba-alba asso decoction with a green or black tea decoction, prepared without sugar, on the antioxidant processes in rats. | 2007 | 17587792 |
| mixture-mixture design for the fingerprint optimization of chromatographic mobile phases and extraction solutions for camellia sinensis. | a composite simplex centroid-simplex centroid mixture design is proposed for simultaneously optimizing two mixture systems. the complementary model is formed by multiplying special cubic models for the two systems. the design was applied to the simultaneous optimization of both mobile phase chromatographic mixtures and extraction mixtures for the camellia sinensis chinese tea plant. the extraction mixtures investigated contained varying proportions of ethyl acetate, ethanol and dichloromethane w ... | 2007 | 17605980 |
| cadmium induced oxidative stress influence on glutathione metabolic genes of camellia sinensis (l.) o. kuntze. | glutathione, a tripeptide with sulfhydryl (-sh) group is a very crucial compound primarily involved in redox balance maintenance of the cellular environment. in this study, we monitored the influence of cd exposure on the transcript levels of glutathione metabolic genes in bud tissues, the youngest leaf, of camellia sinensis l. in addition, some physiochemical parameters were also studied. cd exposure decreased chlorophyll and protein contents, while increase was observed in lipid peroxidation u ... | 2007 | 17607728 |
| elevation protective role of camellia sinensis and urtica dioica infusion against trichloroacetic acid-exposed in rats. | this study was designed to investigate the protective effects of two traditionally used turkish medicinal plants, camellia sinensis (cs) and urtica dioica l. (ud), beverages used against chemical carcinogen trichloroacetic acid (tca)-exposure in rats. the preventive potential of the plant infusions was evaluated by measuring the level of serum marker enzymes, aspartate aminotransferase (ast), alanine aminotransferase (alt), creatine phosphokinase (cpk), acid phosphatase (acp), alkaline phosphata ... | 2007 | 17622976 |
| expression and purification of his-tagged flavonol synthase of camellia sinensis from escherichia coli. | flavonols, a class of bioactive polyphenols present in plants, are the products of flavonol desaturation catalyzed by flavonol synthase (fls). we cloned the cdna coding for the enzyme fls from camellia sinensis (csfls) by end-to-end pcr followed by 5'- and 3'-race. the putative csfls had 333 amino acid residues, displayed identities to the flss of arabidopsis and ginkgo of 53% and 52.5%, respectively, and contained several conserved elements found in the 2-oxoglutarate-fe(ii)-dioxygenase superfa ... | 2007 | 17629496 |
| black tea-induced decrease in il-10 and tgf-beta of tumor cells promotes th1/tc1 response in tumor bearer. | several lines of evidence support that impairment of host immune function by tumor may be related to several strategies of tumor escape from immunosurveillance. we found that in ehrlich's ascites carcinoma (eac)-bearing mice, the tumor cells secrete immunosuppressive cytokines, transforming growth factor beta (tgf-beta) and interleukin-10 (il-10) that induce a general t helper cells type 2 (th2) dominance dampening the t cytotoxic cells type 1 (tc1) population. interestingly, black tea at the an ... | 2007 | 17640168 |
| mechanism for the detoxification of aluminum in roots of tea plant (camellia sinensis (l.) kuntze). | to determine the mechanism of aluminum (al) detoxification in the roots of tea plants (camellia sinensis (l.) kuntze), the amounts of al and al-chelating compounds (fluoride (f), organic acids and catechins) were measured and the chemical forms of al in root cell extracts were identified by the application of 27al-nuclear magnetic resonance (nmr) spectroscopy. tea plants were cultivated in nutrient solutions containing 0, 4, 1.0 and 4.0 mm of al at ph 4.2 for approximately 10 weeks. the levels o ... | 2008 | 17643454 |
| studies of the antioxidative effects of green and black tea (camellia sinensis) extracts in rats. | this paper reports a comparative study of the antioxidative effects of black and green tea extracts in sodium oxalate-challenged rats. a dose of 10 mg/kg of body weight of sodium oxalate was used to induce lipid peroxidation in vivo. rats treated with sodium oxalate had 42.06 +/- 3.10 nm/hour, 45.39 +/- 9.75 mg/100 ml, 10.95 +/- 1.52%, 15.95 +/- 3.19 mg/dl, 112.25 +/- 5.15 mg/dl, 59.21 +/- 2.95 iu, 39.55 +/- 2.51 iu, and 150.62 +/- 9.62 ka/unit for serum levels of malondialdehyde, reduced ascorb ... | 2007 | 17651072 |
| tea polyphenols for health promotion. | people have been consuming brewed tea from the leaves of the camellia sinensis plant for almost 50 centuries. although health benefits have been attributed to tea, especially green tea consumption since the beginning of its history, scientific investigations of this beverage and its constituents have been underway for less than three decades. currently, tea, in the form of green or black tea, next to water, is the most widely consumed beverage in the world. in vitro and animal studies provide st ... | 2007 | 17655876 |
| the effect of green, black and white tea on the level of alpha and gamma tocopherols in free radical-induced oxidative damage of human red blood cells. | the present study was undertaken to investigate the effect of aqueous tea extracts on lipid peroxidation and alpha and gamma tocopherols concentration in the oxidative damage of human red blood cells (rbc). rbc was taken as the model for study of the oxidative damage was induced by cumene hydroperoxide (cumooh). the antioxidative property of leaf green tea, leaf and granulate of black tea and white tea at levels 1, 2, 4 g/150 ml of water were evaluated. the correlation was observed between reduc ... | 2007 | 17665865 |
| food interaction of oral uptake of iron / a clinical trial using 59fe. | a primary objective of the study was to evaluate how food as well as a specific enhancer or an inhibitor of iron uptake affect erythrocyte iron uptake after oral administration of iron(iii)-hydroxide polymaltose complex (ipc, maltofer) in subjects with or without iron deficiency. secondary objectives of the study were 1. to compare the uptake of 59fe in erythrocytes between subjects with or without iron deficiency, 2. to evaluate the 59fe activity in plasma after oral administration of ipc and 3 ... | 2007 | 17691590 |
| amelioration by black tea of sodium fluoride-induced changes in protein content of cerebral hemisphere, cerebellum and medulla oblongata in brain region of mice. | oral administration of sodium fluoride (naf, 6 and 12 mg/kg body weight/day) to swiss strain male albino mice for 30 days caused significant dose-dependant reduction in the content of acidic, basic, neutral, and total protein in cerebral hemisphere, cerebellum and medulla oblongata region of brain. after 30 days of naf treatment, followed by withdrawal of treatment for 30 days, partial but significant amelioration occurred. administration of 2% black tea extract alone for 30 days did not cause a ... | 2007 | 17695144 |
| dynamic ultrasound-assisted extraction of catechins and caffeine in some tea samples. | a novel dynamic ultrasound-assisted extraction (duae) device has been constructed for extraction of five catechins and caffeine in solid sample. the accurate, simple, reproducible and sensitive method for the determination of five catechins and caffeine has been developed and validated. a comparison has been made of the efficiencies by employing duae and conventionally static ultrasound-assisted extraction (uae). the proposed method can not only improve extraction efficiency but also decrease ti ... | 2016 | 17696011 |
| determination of theaflavins including methylated theaflavins in black tea leaves by solid-phase extraction and hplc analysis. | a quantitative method for four theaflavins and two methylated theaflavin derivatives in black tea leaves was developed by solid-phase extraction and a high-performance liquid chromatographic method with photodiode array detection. the theaflavins in black tea leaves were extracted three times with 40 vol 50% aqueous ethanol (mg dry tea powder/ml) containing 2% ascorbic acid. the ethanol extracts were diluted 4-fold with distilled water. all diluted extracts were directly applied to the solid-pha ... | 2007 | 17696441 |
| identification and comparison of phenolic compounds in the preparation of oolong tea manufactured by semifermentation and drying processes. | oolong tea manufactured via a semifermentation process possesses a taste and color somewhere between green and black teas. alteration of constituents, particularly phenolic compounds, in the infusion of oolong tea resulting from its manufacture, was analyzed by high-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry. the identified constituents contained 2 alkaloids, 11 flavan-3-ols, 8 organic acids and esters, 11 proanthocyanidin dimers, 3 theaflavins, ... | 2007 | 17696450 |
| tea and cancer chemoprevention: a comprehensive review. | dietary components that are capable of inhibiting the growth of cancer cells without affecting the growth of normal cells are receiving considerable attention in developing novel cancer-preventive approaches. tea, made from young leaves and leaf buds of the tea plant, 'camellia sinensis', and the world's second most consumed beverage, has received a great deal of attention both from the general public and the scientific community because tea polyphenols are strong antioxidants, and tea preparati ... | 2007 | 17696725 |
| influence of regular black tea consumption on tobacco associated dna damage and hpv prevalence in human oral mucosa. | black tea is more widely consumed than green tea worldwide, particularly in india. therefore, it is necessary to focus attention on black tea with respect to its health promoting and anti-cancer actions. in order to establish the concept that black tea is a potential candidate for cancer prevention, it is important to provide epidemiological evidence derived from investigations of human populations. in view of this, the objective of the present study was to determine the correlation between natu ... | 2007 | 17696743 |
| theanine prevents memory impairment induced by repeated cerebral ischemia in rats. | the present study investigated the neuroprotective effect of gamma-glutamylethylamide (theanine), a component japanese green tea (camellia sinensis), on memory impairment induced by twice-repeated cerebral ischemia in rats. theanine was injected i.p. immediately after the first occlusion. theanine (0.3 and 1 mg/kg) significantly prevented the impairment of spatial memory in rats subjected to repeated cerebral ischemia, 7 days after the second reperfusion. moreover, theanine (1 mg/kg) significant ... | 2008 | 17705146 |
| tea and coffee as the main sources of oxalate in diets of patients with kidney oxalate stones. | we analyzed nutritional habits of 22 stone formers with special regard to oxalate content as one of the main nutritional lithogenic factors associated with kidney stones. daily dietary oxalate intake was 354 +/- 261 mg and 406 +/- 265 mg in men and women respectively. these values were much higher than those found by other researches. the main sources of oxalate in diets were regular tea and coffee (80-85%). only 15-20% of oxalate was derived from other plant foods. patients did not adhere to hi ... | 2007 | 17711092 |
| theaflavins attenuate hepatic lipid accumulation through activating ampk in human hepg2 cells. | black tea is one of the world's most popular beverages, and its health-promoting effects have been intensively investigated. the antiobesity and hypolipidemic effects of black tea have attracted increasing interest, but the mechanisms underlying these phenomena remain unclear. in the present study, the black tea major component theaflavins were assessed for their hepatic lipid-lowering potential when administered in fatty acid overload conditions both in cell culture and in an animal experimenta ... | 2007 | 17720960 |
| flow injection potentiometric determination of total antioxidant activity of plant extracts. | a new flow injection potentiometric (fip) method, rapid, reproducible and simple to apply, has been developed for the in vitro evaluation of antioxidative capacity of aqueous plant extracts. this method is based on the transient negative signal measurements with a flow-type platinum electrode detector due to the composition change of a [fe(cn)6]3-/[fe(cn)6]4- redox-reagent solution. the variables affecting the signal height such as composition and concentration of redox-reagent, injected sample ... | 2006 | 17723555 |
| green tea and black tea consumption in relation to colorectal cancer risk: the singapore chinese health study. | the relationships between green tea and black tea consumption and colorectal cancer risk were examined within the singapore chinese health study, a prospective cohort study of diet and cancer involving >60,000 men and women. intake of green tea and black tea was assessed through in-person interviews. incident cancer cases and deaths among cohort members were identified through record linkage of the cohort database with respective databases from the nationwide singapore cancer registry and the si ... | 2007 | 17724377 |
| inhibition of 17alpha-hydroxylase/c17,20-lyase (cyp17) from rat testis by green tea catechins and black tea theaflavins. | in the course of screening for 17alpha-hydroxylase/c17,20-lyase inhibitors from food ingredients, the methanol soluble fraction of green tea and black tea, which were expected to be rich in catechin and theaflavin content, showed potent inhibitory activity. (-)-epigallocathechin gallate and theaflavin 3-o-gallate with a pirogallol moiety significantly inhibited c17,20-lyase activity on ic50 values of 24.5 microm and 11.5 microm respectively. they had potent cytotoxicity against human prostate ca ... | 2007 | 17827674 |
| polyphenols as potential indicators for drought tolerance in tea (camellia sinensis l.). | plant polyphenols have gained prominence in quality of plant products and in human health. an experiment was conducted to determine the association of tea polyphenols with water stress and their suitability as indicators for drought tolerance. the experiment was conducted in a 'rain-out' shelter, and consisted of six tea clones (bbk 35, trfk 6/8, trfk 76/1, trfk 395/2, trfk 31/30, and trfk 311/287) and four levels of soil water contents (38, 30, 22, and 14% v/v), which were maintained for a peri ... | 2007 | 17827703 |
| improved sample pre-treatment for determination of caffeine in tea using a cartridge filled with polyvinylpolypyrroridone (pvpp). | we have improved sample pre-treatment for the effective removal of polyphenols and simple analysis of caffeine in tea using a cartridge filled with polyvinylpolypyrroridone (pvpp). nearly 100% of catechins were removed from the green tea sample and caffeine was completely recovered in the range of 98.2-101.3% by sample pre-treatment with a pvpp cartridge. reproducibility of preparing pvpp pre-treatment cartridges was sufficient for quantitative analysis, because rsds of analytical values for caf ... | 2007 | 17827770 |
| phenolic antioxidants identified by esi-ms from yerba maté (ilex paraguariensis) and green tea (camelia sinensis) extracts. | aqueous extracts of green yerba maté (ilex paraguariensis) and green tea (camellia sinensis) are good sources of phenolic antioxidants, as already described in the literature. the subject of this study were organic extracts from yerba maté, both green and roasted, and from green tea. their phenolic profiles were characterized by direct infusion electrospray insertion mass spectrometry (esi-ms) and their free radical scavenging activity was determined by the dpph assay. organic extracts containin ... | 2007 | 17851401 |
| effect of extraction conditions on measured total polyphenol contents and antioxidant and antibacterial activities of black tea. | black tea was extracted for 2, 8 and 18 h with absolute acetone, n,n-dimethyl-formamide (dmf), ethanol and methanol and their 50% aqueous solutions. the extracts were screened for total polyphenol contents, antioxidant and antibacterial activities. the polyphenol content of the extracts was found to be in the range of 0.44-114.01 mg gallic acid equivalents (gae)/g dry weight tea, depending on the solvent used and the length of the extraction process. in general, aqueous acetone or dmf extracts d ... | 2007 | 17851405 |
| cellular responses and proteomic analysis of escherichia coli exposed to green tea polyphenols. | the purpose of this study was to characterize the cellular response and proteomic analysis of escherichia coli exposed to tea polyphenols (tpp) extracted from korean green tea (camellia sinensis l). tpp showed a dose-dependent bactericidal effect on e. coli. analysis of cell-membrane fatty acids of e. coli cultures treated with tpp identified unique changes in saturated and unsaturated fatty acids, whereas scanning electron microscopic analysis demonstrated the presence of perforations and irreg ... | 2007 | 17874165 |
| inhibitory effects of various beverages on human recombinant sulfotransferase isoforms sult1a1 and sult1a3. | sulfotransferase (sult) 1a1 and sult1a3 play important roles in the presystemic inactivation of beta(2) agonists in the liver and intestine, respectively. the study aimed to investigate the inhibitory effects of grapefruit juice, orange juice, green tea, black tea and oolong tea and their constituents on the activities of sult1a1 and sult1a3. the activities of both sult1a1 and sult1a3 were significantly inhibited by all the beverages investigated at a concentration of 10%. the beverage constitue ... | 2007 | 17876860 |
| the effect of an extract of green and black tea on glucose control in adults with type 2 diabetes mellitus: double-blind randomized study. | recent evidence suggests that tea from camellia sinensis (eg, green, oolong, and black tea) may have a hypoglycemic effect. we evaluated the ability of an extract of green and black tea to improve glucose control over a 3-month period. a double-blind, placebo-controlled, randomized multiple-dose (0, 375, or 750 mg per day for 3 months) study in adults with type 2 diabetes mellitus not taking insulin was performed. the primary end point was change in glycosylated hemoglobin at 3 months. the 49 su ... | 2007 | 17884442 |
| enzymatic oxidation of gallocatechin and epigallocatechin: effects of c-ring configuration on the reaction products. | tea leaf is rich in pyrogallol-type catechins, and their oxidation is important in the generation of black tea polyphenols. in the present study, the enzymatic oxidation of three pyrogallol-type catechins, (+)- and (-)-gallocatechins and (-)-epigallocatechin, was compared. the reactions yielded unstable quinone products, which were trapped as condensation products with o-phenylenediamine. the oxidation of (+)-gallocatechin proceeded very slowly compared to the reaction of (-)-epigallocatechin, a ... | 2008 | 17888464 |
| arsenic species and leaching characters in tea (camellia sinensis). | tea is one of the most popular non-alcoholic beverages consumed in the world. arsenic including species totalling to 47 chinese tea samples from 18 tea-producing provinces in china were analyzed. by simulating the infusion process, leaching characters, effects of extraction time and temperature on arsenic extraction were investigated. total amount of arsenic in tea leaf samples was in the range below the detection limit to 4.81 microg/g. leaching of arsenic was strongly affected by extraction ti ... | 2007 | 17892910 |
| a 6-month randomized pilot study of black tea and cardiovascular risk factors. | the effects of black tea consumption on cardiovascular risk factors have been inconsistent in previous randomized trials, all of which have been limited to a few weeks duration. | 2007 | 17892999 |
| chemical composition of green tea (camellia sinensis) infusions commercialized in portugal. | to evaluate the potential benefits and risks associated with tea consumption it is important to identify the constituents of this beverage. levels of some minerals, caffeine and catechins in green tea samples commercialized in portugal were evaluated. potassium is the metal present in larger amount (92-151 mg/l). the content of sodium, calcium, fluoride, aluminium, manganese and iron were 35-69, 1.9-3.5, 0.80-2.0, 1.0-2.2, 0.52-1.9, 0.020-0.128 mg/l, respectively. chromium and selenium were not ... | 2007 | 17899383 |
| specific formulation of camellia sinensis prevents cold and flu symptoms and enhances gamma,delta t cell function: a randomized, double-blind, placebo-controlled study. | determine if a specific formulation of camellia sinensis (csf) can prevent illness and symptoms due to cold and flu, and enhance gammadelta t cell function | 2007 | 17914132 |
| the effect of consuming instant black tea on postprandial plasma glucose and insulin concentrations in healthy humans. | to determine the effects of black tea on postprandial plasma glucose and insulin concentrations in healthy humans in response to an oral glucose load. | 2007 | 17914136 |
| the efficacy of black tea in ameliorating endothelial function is equivalent to that of green tea. | consumption of tea has been shown to improve endothelial function. it is assumed that catechins are the tea components responsible for these beneficial effects. in black tea, catechin concentrations are significantly lower than in green tea. the present study was designed to compare green and black tea with regard to amelioration of endothelial function. endothelial function in response to both teas was assessed in bovine aortic endothelial cells (baec) and rat aortic rings. to elucidate whether ... | 2008 | 17916273 |
| immobilised tyrosinase-based biosensor for the detection of tea polyphenols. | an amperometric principle-based biosensor containing immobilized enzyme tyrosinase has been used for detection of polyphenols in tea. the immobilized tyrosinase-based biosensor could detect tea polyphenols in the concentration range 10-80 mmol l(-1). immobilization of the enzyme by the crosslinking method gave good stable response to tea polyphenols. the biosensor response reached the steady state within 5 min. the voltage response was found to have a direct linear relationship with the concentr ... | 2007 | 17928999 |
| theaflavins induce g2/m arrest by modulating expression of p21waf1/cip1, cdc25c and cyclin b in human prostate carcinoma pc-3 cells. | cancer of the prostate gland (pca) is the most common invasive malignancy and is the second leading cause of cancer-related death in males. the polyphenolic constituents of black tea have gained considerable attention as chemopreventive agents. many studies have shown that black tea reduces the risk of several cancer types. in the present study, we studied the effect of a black tea polyphenol, theaflavin (tf), on cellular proliferation and cell death in the human prostate cancer cell line, pc-3. ... | 2007 | 17936851 |
| characterization of the constituents and antioxidant activity of brazilian green tea (camellia sinensis var. assamica iac-259 cultivar) extracts. | freeze-dried extracts from camellia sinensis var. assamica iac-259 cultivar named brazilian green tea were prepared by hot water and ultrasound-assisted extractions using leaves harvested in spring and summer. their caffeine and catechin contents were measured by high performance liquid chromatography-diode array detector. the antioxidant activity of the major green tea compounds and brazilian green tea extracts was evaluated using a 2,2-diphenyl-1-picrylhydrazyl (dpph) assay. the levels of caff ... | 2007 | 17937477 |
| serological detection and immunogold localization of cross-reactive antigens shared by camellia sinensis and exobasidium vexans. | pathogenicity of exobasidium vexans, causal agent of blister blight of tea, was studied in 30 commercially cultivated tea varieties by analysing the antigenic patterns of host and pathogen using immunological techniques. | 2007 | 17953578 |
| productivity and biochemical properties of green tea in response to full-length and functional fragments of hpag xooc, a harpin protein from the bacterial rice leaf streak pathogen xanthomonas oryzae pv. oryzicola. | harpin proteins from plant pathogenic bacteria can stimulate hypersensitive cell death (hcd), drought tolerance, defence responses against pathogens and insects in plants, as well as enhance plant growth. recently, we identified nine functional fragments of hpag;xooc, a harpin protein from xanthomonas oryzae pv.oryzicola, the pathogen that causes bacterial leaf streak in rice. fragments hpag;1-94'hpag;10-42, and hpag;62-138, which contain the hpag;xooc regions of the amino acid sequence as indic ... | 2007 | 17954972 |
| biotransformation of green tea polyphenols and the biological activities of those metabolites. | green tea ( camellia sinensis, theaceae) and its major polyphenol constituents, the catechins, have been reported to have many health benefits including the prevention of cancer and heart disease. many mechanisms of action have been proposed based on in vitro models; however, the importance of most of these mechanisms remains to be determined in vivo. the bioavailability and biotransformation of tea catechins play a key role in determining the importance of various mechanisms in vivo. likewise, ... | 2013 | 17963356 |
| modulation of the oxidative stress and nuclear factor kappab activation by theaflavin 3,3'-gallate in the rats exposed to cerebral ischemia-reperfusion. | the major pathobiological mechanisms of ir injury include excitotoxicity, oxidative stress, and inflammation. tf3, a major constituent of black tea, possesses biological functions such as anti-oxidative and anti-inflammatory activities. the purpose of this study was to verify the neuronal protective potential of tf3 and its mechanisms against cerebral ir injury in rats. tf3 administration (10 and 20 mg.kg-1) ameliorated the infarct volume. tf3 also decreased the content of mda and no. tf3 signif ... | 2007 | 17976306 |
| epigallocatechin-3-o-gallate inhibits the angiotensin ii-induced adhesion molecule expression in human umbilical vein endothelial cell via inhibition of mapk pathways. | epigallocatechin-3-o-gallate (egcg) is the main catechin, which is derived from camellia sinensis plant. vascular cell adhesion molecules (vcams) and intercellular adhesion molecules (icams) mediate the binding of inflammatory cells onto the vascular wall-promoting the early phase of atherosclerosis. in the present study, we investigated the mechanism(s) by which egcg inhibits angiotensin ii (ang ii)-induced elevation of the membrane associated vcam-1 and icam-1 in human umbilical vein endotheli ... | 2007 | 17982268 |
| molecular mechanism of black tea polyphenols induced apoptosis in human skin cancer cells: involvement of bax translocation and mitochondria mediated death cascade. | theaflavins (tf) and thearubigins (tr) are the most exclusive polyphenols of black tea. even though few previous reports showed the anticancer effects of tf through apoptosis, the potential effect of tr has not been appraised. this study investigated the induction of apoptosis in human skin cancer cells after treatment of tf and tr. we report that both tf and tr could exert inhibition of a431 (human epidermoid carcinoma) and a375 (human malignant melanoma) cell proliferation without adversely af ... | 2008 | 17984116 |
| a major ingredient of green tea rescues mice from lethal sepsis partly by inhibiting hmgb1. | the pathogenesis of sepsis is mediated in part by bacterial endotoxin, which stimulates macrophages/monocytes to sequentially release early (e.g., tnf, il-1, and ifn-gamma) and late (e.g., hmgb1) pro-inflammatory cytokines. our recent discovery of hmgb1 as a late mediator of lethal sepsis has prompted investigation for development of new experimental therapeutics. we previously reported that green tea brewed from the leaves of the plant camellia sinensis is effective in inhibiting endotoxin-indu ... | 2007 | 17987129 |
| black tea polyphenols mimic insulin/insulin-like growth factor-1 signalling to the longevity factor foxo1a. | in vertebrates and invertebrates, relationships between diet and health are controlled by a conserved signalling pathway responsive to insulin-like ligands. in invertebrate models for example, forkhead transcription factor family o (foxo) transcription factors in this pathway regulate the rate of aging in response to dietary cues, and in vertebrates, obesity and age-induced deficits in the same pathway are thought to contribute to dysregulation of hepatic gluconeogenesis through genes such as ph ... | 2008 | 18005251 |