Publications

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
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
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
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
comparative evaluation of antiproliferative, antiangiogenic and apoptosis inducing potential of black tea polyphenols in the hamster buccal pouch carcinogenesis model.	to evaluate the relative chemopreventive efficacy of two black tea polyphenols, polyphenon-b [p-b] and btf-35 on 7,12-dimethylbenz [a]anthracene (dmba)-induced hamster buccal pouch (hbp) carcinogenesis.	2007	18053169
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
quasi-flow injection analysis for rapid determination of caffeine in tea using the sample pre-treatment method with a cartridge column filled with polyvinylpolypyrrolidone.	the sample pre-treatment method using a polyvinylpolypyrrolidone (pvpp) cartridge column combined with a quasi-flow injection analysis (quasi-fia) system realized the rapid determination of caffeine in three types of tea, green, oolong and black tea. the measurement time for each tea sample pre-treated using a pvpp cartridge column was shortened to 20s. in the present system, the limits of detection and quantification were 0.3 microm (1.5 pmol injected) and 0.7 microm (3.5 pmol injected), respec ...	2008	18054948
comparison of antioxidant potency of commonly consumed polyphenol-rich beverages in the united states.	a number of different beverage products claim to have antioxidant potency due to their perceived high content of polyphenols. basic and applied research indicates that pomegranate juice (pj), produced from the wonderful variety of punica granatum fruits, has strong antioxidant activity and related health benefits. although consumers are familiar with the concept of free radicals and antioxidants, they are often misled by claims of superior antioxidant activity of different beverages, which are u ...	2008	18220345
role of quercetin (a natural herbal compound) in allergy and inflammation.	an investigated flavonoid, quercetin, is reviewed in this article. quercetin is a bioflavonoid found in red wine, grapefruit, onions, apples, black tea, and, in lesser amounts, in leafy green vegetables and beans. quercetin has an antioxidant and anti-inflammatory activity and prevents cancer. quercitin inhibits the growth of certain malignant cells in vitro, and histamine and most cyclin-dependent kinases and also displays unique anticancer properties. quercetin is a natural compound that block ...	2008	18187018
combination of hsccc and sephadex lh-20 methods an approach to isolation and purification of the main individual theaflavins from black tea.	in order to separate the main individual theaflavin monomers from black tea, high-speed countercurrent chromatography (hsccc) and sephadex lh-20 column chromatography were applied. the results showed that theaflavin (tf1), theaflavin-3-gallate (tf2a), theaflavin-3'-gallate (tf2b) and theaflavin-3,3'-digallate (tf3) can be obtained by hsccc using a solvent system composed of n-hexane-ethyl acetate-methanol-water (1:3:1:6, v/v/v/v), but the tf1 was containing epicatechin-3-gallate (ecg). similarly ...	2008	18063426
the acute effect of green tea consumption on endothelial function in healthy individuals.	tea consumption is associated with decreased cardiovascular risk. flow-mediated dilatation (fmd) of the brachial artery is related to coronary endothelial function and it is an independent predictor of cardiovascular risk. black tea has a beneficial effect on endothelial function; the effect, however, of green tea on brachial artery reactivity has not been defined yet.	2008	18525384
structural determination and dpph radical-scavenging activity of two acylated flavonoid tetraglycosides in oolong tea (camellia sinensis).	two major acylated flavonoid tetraglycosides were isolated from the methanol extract of oolong tea. their structures were elucidated by spectroscopic methods as quercetin 3-o-[2(g)-(e)-coumaroyl-3(g)-o-beta-d-glucosyl-3(r)-o-beta-d-glucosylrutinoside] (1) and kaempferol 3-o-[2(g)-(e)-coumaroyl-3(g)-o-beta-d-glucosyl-3(r)-o-beta-d-glucosylrutinoside] (2). compounds 1 and 2 exhibited scavenging activity against dpph radical with ec(50) values of 30.5 and 487.2 microm, respectively.	2008	18520094
effect of sucrose concentration on the products of kombucha fermentation on molasses.	fermentation of 1.5g/l of indian black tea, sweetened with adequate quantities of molasses (containing approx. 70g/l, 50g/l and 35g/l of sucrose), was conducted using domestic kombucha. inoculation was performed with 10% of fermentation broth from a previous process. the fermentation in cylindrical vessels containing 2l of liquid phase, was carried out at 22±1°c for 14 days, with periodical sampling, to measure ph, content of acids (total, acetic and l-lactic), content of remaining sucrose, and ...	2008	26065754
methylglyoxal: its presence and potential scavengers.	hyperglycemia is the most important factor for the onset and progress of diabetic complications. a growing body of evidence indicates that the increase in reactive carbonyl intermediates such as methylglyoxal (mg) is a consequence of hyperglycemia in diabetes. several studies have shown that higher levels of mg are present in diabetic patients' plasma compared to non-diabetics. glyoxal (go) and mg, the two major alpha-dicarbonyl compounds found in humans, are very reactive and lead to nonenzymat ...	2008	18296351
determination of theanine, gaba, and other amino acids in green, oolong, black, and pu-erh teas with dabsylation and high-performance liquid chromatography.	dabsyl chloride (dimethylaminoazobenzene sulfonyl chloride), a useful chromophoric labeling reagent for amino acids and amines, was developed in this laboratory in 1975. although several methods have been developed to determine various types of amino acids, a quick and easy method of determining theanine, gaba, and other amino acids has not been developed in one hplc system. in this paper are analyzed the free amino acid contents of theanine and gaba in different teas (green tea, black tea, oolo ...	2008	18652476
beverage consumption and the prevalence of tooth loss in pregnant japanese women: the osaka maternal and child health study.	recently, there has been growing interest in the impact of beverage consumption on dental health because changes have occurred in the types and quantities of beverage consumed. this cross-sectional study investigated the relationship between consumption frequencies of various beverages and the prevalence of tooth loss among young adult women. study subjects were 1002 pregnant japanese women. tooth loss was defined as previous extraction of one or more teeth. dietary habits were evaluated by a va ...	2008	18646593
nongallated compared with gallated flavan-3-ols in green and black tea are more bioavailable.	green tea and black tea (bt) contain gallated [(-)-epigallocatechin-3-gallate (egcg), (-)-epicatechin-3-gallate] and nongallated [(-)-epicatechin, (-)-epigallocatechin (egc)] tea polyphenols (pp). during bt production, pp undergo oxidation and form larger polymers such as theaflavins (the) and thearubigins, which contribute to the health benefit of bt. this article gives an overview of the role of chemical characteristics and endogenous metabolism of tea pp and their bioavailability in humans an ...	2008	18641202
flavonoids, flavonoid-rich foods, and cardiovascular risk: a meta-analysis of randomized controlled trials.	the beneficial effects of flavonoid consumption on cardiovascular risk are supported by mechanistic and epidemiologic evidence.	2008	18614722
a physiological model of tea-induced astringency.	the mechanism by which solutions containing polyphenols are perceived as astringent is not clearly understood. salivary proline-rich proteins and histatins are products of salivary glands and rapidly bind polyphenols - thought to be the main astringent compound in such as tea and wine. however it is unclear how this interaction leads to the altered oral mouthfeel known as astringency which is characterised by a dry, puckered feeling all around the mouth. to determine the role of saliva in the pe ...	2008	18590751
new phenolic components and chromatographic profiles of green and fermented teas.	a standardized profiling method based on liquid chromatography with diode array and electrospray ionization mass spectrometric detection (lc-dad-esi/ms) was applied to establish the phenolic profiles of 41 green teas and 25 fermented teas. more than 96 phenolic compounds were identified that allowed the teas to be organized into five groups. epigallocatechin gallate (egcg) was the major phenolic component of green tea made from mature leaves (group 2), while green tea made from the younger buds ...	2008	18686968
influence of green and black tea on folic acid pharmacokinetics in healthy volunteers: potential risk of diminished folic acid bioavailability.	previous in vitro studies using caco-2 cell monolayers suggested a possible interaction between green and black tea and folic acid at the level of intestinal absorption. the main purpose of the present study was to investigate a possible pharmacokinetic interaction between tea and folic acid in healthy volunteers. in an open-labeled randomized cross-over study, the pharmacokinetic interaction between tea and folic acid (0.4 mg and 5 mg) was investigated in healthy volunteers. water was used as t ...	2008	18551467
shoot epicatechin and epigallocatechin contents respond to water stress in tea [camellia sinensis (l.) o. kuntze].	an experiment was conducted to determine the association of tea catechins to water stress in tea, with the objective of determining their suitability as indicators for predicting drought tolerance in tea (camellia sinensis). the study 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 content (38, 30, 22, and 14% v/v), which were arranged in a complete randomized design and replicated 3 times. the treatments were main ...	2008	18460799
association between soy and green tea (camellia sinensis) diminishes hypercholesterolemia and increases total plasma antioxidant potential in dyslipidemic subjects.	to evaluate the hypolipemic and antioxidant effects of soy and green tea alone and/or in association in dyslipidemic subjects.	2008	18455656
contribution of p53-mediated bax transactivation in theaflavin-induced mammary epithelial carcinoma cell apoptosis.	theaflavins, the bioactive flavonoids of black tea, have been demonstrated to inhibit proliferation and induce apoptosis in a variety of cancer cells. however, the contribution of p53 in mammary epithelial carcinoma cell apoptosis by theaflavins remains unclear. it has been reported that p53 triggers apoptosis by inducing mitochondrial outer membrane permeabilization through transcription-dependent and -independent mechanisms. using wild-type and mutant p53-expressing as well as p53-null cells w ...	2008	18454316
preparative isolation and purification of theaflavins and catechins by high-speed countercurrent chromatography.	high-speed countercurrent chromatography (hsccc) has been applied for the separation of theaflavins and catechins. the hsccc run was carried out with a two-phase solvent system composed of hexane-ethyl acetate-methanol-water-acetic acid (1:5:1:5:0.25, v/v) by eluting the lower aqueous phase at 2 ml/min at 700 rpm. the results indicated that pure theaflavin, theaflavins-3-gallate, theaflavins-3'-gallate and theaflavin-3,3'-digallate could be obtained from crude theaflavins sample and black tea. t ...	2008	18436487
potential anthelmintics: polyphenols from the tea plant camellia sinensis l. are lethally toxic to caenorhabditis elegans.	a novel gallate of tannin, (-)-epigallocatechin-(2 beta-->o-->7',4 beta-->8')-epicatechin-3'-o-gallate (8), together with (-)-epicatechin-3-o-gallate (4), (-)-epigallocatechin (5), (-)-epigallocatechin-3-o-gallate (6), and (+)-gallocatechin-(4 alpha-->8')-epigallocatechin (7), were isolated from the tea plant camellia sinensis (l.) o. kuntze var. sinensis (cv., yabukita). the structure of 8, including stereochemistry, was elucidated by spectroscopic methods and hydrolysis. the compounds, along w ...	2008	18404315
iron absorption in young indian women: the interaction of iron status with the influence of tea and ascorbic acid.	ascorbic acid (aa) enhances and tea inhibits iron absorption. it is unclear whether iron status influences the magnitude of this effect.	2008	18400710
a case-control study of lifestyle and lung cancer associations by histological types.	the objective of the study was to investigate the contribution of dietary factors and physical exercise to the variation in the risk of lung cancer and its major histological types among men and women in the czech republic, and reveal interactions between smoking and diet/physical exercise, if any. in a hospital based case-control study, data collected by in-person interviews from 1096 microscopically confirmed lung cancer cases (587 women, 509 men) and 2966 controls were analyzed using uncondit ...	2008	18348651
polymer-like polyphenols of black tea and their lipase and amylase inhibitory activities.	lipase and amylase inhibitory activities of black tea were examined. after solvent partitioning of a black tea extract with the ethyl acetate and n-butanol, the two soluble fractions showed comparable inhibitory activities. activity in the ethyl acetate fraction was mainly attributable to polyphenols with low-molecular weights, such as theaflavin gallates. on the other hand, the active substance in the n-butanol layer was ascertained to be a polymer-like substance. 1h- and 13c-nmr spectra showed ...	2008	18310934
element composition of tea leaves and tea infusions and its impact on health.	tea infusion is the most frequently consumed beverage worldwide next to water, with about 20 billion cups consumed daily. in taiwan, daily consumption averages 2.5 cups of tea infusion per person. many studies have concluded that tea has numerous beneficial effects on health. however, some undesirable trace elements, such as arsenic, chromium, cadmium, lead, etc., are a concern. this study has three aims: (1) to measure the concentrations of arsenic and heavy metal elements, such as chromium, ca ...	2008	18309449
the influence of different food and drink on tics in tourette syndrome.	tourette syndrome (ts) is characterized by waxing and waning motor and vocal tics. because standard medication often remains unsatisfactory, many patients seek alternative medicine. the aim of this study was to increase experience about the influence of food and drinks in ts.	2008	18307557
association between consumption of black tea and iron status in adult africans in the north west province: the thusa study.	the association between black tea consumption and iron status was investigated in a sample of african adults participating in the cross-sectional thusa (transition and health during urbanization of south africans) study in the north west province, south africa. data were analysed from 1605 apparently healthy adults aged 15-65 years by demographic and ffq, anthropometric measurements and biochemical analyses. the main outcome measures were hb and serum ferritin concentrations. no associations wer ...	2008	18275622
immobilized proanthocyanidins for the capture of bacterial lipopolysaccharides.	proanthocyanidins (pacs) are an abundant class of compounds found in a variety of plant materials. here we demonstrate the application of these materials as capture molecules for the removal of bacterial lipopolysaccharide (lps) from solution. pacs from whole cranberries, grape juice, black tea, and cranberry juice were purified and immobilized onto thiol-activated sepharose beads. this material was used in pull-down type assays for the capture of lps. the binding of lps by pacs has been shown t ...	2008	18257561
gas chromatographic method for the determination of hexaconazole residues in black tea.	a highly reliable, quantitative and sensitive analytical method for determining the residues of the fungicide, hexaconazole in black tea is described. the proposed method is based on liquid-liquid extraction followed by gas chromatographic determination, using nitrogen phosphorus detector (gc-npd) for the identification and quantitation of hexaconazole. the most appropriate solvent mixture for extracting hexaconazole residues from black tea was n-hexane:acetone at 1:1 (v/v). the extract was clea ...	2008	18257139
expression and biochemical characterization of beta-primeverosidase and application of beta-primeverosylamidine to affinity purification.	beta-primeverosidase (pd) is a family 1 glycosidase catalyzing the hydrolysis of beta-primeverosides (6-o-beta-d-xylopyranosyl-beta-d-glucopyranosides) to release a disaccharide primeverose. to investigate how pd recognizes the disaccharide moiety of beta-primeverosides, the recombinant pd was expressed by a baculovirus-insect cell system. the recombinant pd was secreted from high five cells and was properly modified with n-glycosylation and correct cleavage at the n-terminal signal peptide. the ...	2008	18256510
simple and rapid uv spectrophotometry of caffeine in tea coupled with sample pre-treatment using a cartridge column filled with polyvinylpolypyrrolidone (pvpp).	we have applied a sample pre-treatment method with a cartridge column filled with polyvinylpolypyrrolidone (pvpp) to the effective removal of polyphenols and simple uv spectrophotometry of caffeine in tea. the absorption maximum length (lambda(max)) for caffeine was close to those for tea catechins in aqueous 1% acetic acid; therefore, the uv spectrum of a non-treated green tea sample had a large absorption wave. in contrast, the absorbance of the green tea sample was gradually reduced by pvpp c ...	2008	18239305
immunostimulating activity of a crude polysaccharide derived from green tea (camellia sinensis) extract.	green tea extract is well-known to reduce the risk of a variety of diseases. here, we investigated the immunostimulating activity of tea polysaccharide (tps), one of the main components in green tea extract. the water extracts from mature or immature tea leaves were precipitated by using ethanol at room temperature. the sediment was washed with ethanol and acetone alternately and then dried. we used the phagocytic activity of macrophage-like cells as an indicator of immune function activation. c ...	2008	18232634
tea polyphenols, their biological effects and potential molecular targets.	tea is the most popular beverage in the world, second only to water. tea contains an infusion of the leaves from the camellia sinensis plant rich in polyphenolic compounds known as catechins, the most abundant of which is (-)-egcg. although tea has been consumed for centuries, it has only recently been studied extensively as a health-promoting beverage that may act to prevent a number of chronic diseases and cancers. the results of several investigations indicate that green tea consumption may b ...	2008	18228206
identification of green tea's (camellia sinensis (l.)) quality level according to measurement of main catechins and caffeine contents by hplc and support vector classification pattern recognition.	high performance liquid chromatography (hplc) was identified green tea's quality level by measurement of catechins and caffeine content. four grades of roast green teas were attempted in this work. five main catechins ((-)-epigallocatechin gallate (egcg), (-)-epigallocatechin (egc), (-)-epicatechin gallate (ecg), (-)-epicatechin (ec), and (+)-catechin (c)) and caffeine contents were measured simultaneously by hplc. as a new chemical pattern recognition, support vector classification (svc) was ap ...	2008	18952392
green tea (camellia sinensis) and cancer prevention: a systematic review of randomized trials and epidemiological studies.	green tea is one of the most popular beverages worldwide. this review summarizes the beneficial effects of green tea on cancer prevention.	2008	18940008
green tea, soy, and mammographic density in singapore chinese women.	there is increasing evidence from observational studies that breast cancer risk is inversely associated with soy and green tea consumption. we investigated the effects of these two dietary agents on mammographic density, a well-established biomarker for breast cancer risk, in a cross-sectional analysis of mammograms and validated food frequency questionnaires from 3,315 chinese women in singapore. percent mammographic density (pmd) was assessed using a reproducible computer-assisted method. we u ...	2008	19064551
theaflavins from black tea, especially theaflavin-3-gallate, reduce the incorporation of cholesterol into mixed micelles.	tea is one of the most widely consumed beverages in the world and may be associated with reduced heart disease rates. theaflavins, which are formed in the production of black tea, have been suggested being responsible for the blood-cholesterol-lowering (bcl) effects of tea. we hypothesized that the effect of theaflavins on bcl could be through interference in the formation of dietary mixed micelles, which could result in reduced intestinal cholesterol absorption. micelles were produced by mixing ...	2008	19049290
soft drink intake is associated with diet quality even among young japanese women with low soft drink intake.	unsweetened traditional japanese tea has long been the main beverage consumed in japan, with soft drinks only recently forming a part of people's diets. evidence suggests an association between soft drink intake and poor diet quality among youth in the united states. the association is not yet fully examined in the population with relatively low intake level of soft drinks such as the current japanese population.	2008	19027402
microwave heating of tea residue yields polysaccharides, polyphenols, and plant biopolyester.	microwave heating was used to produce aqueous-soluble components from green, oolong, and black tea residues. heating at 200-230 degrees c for 2 min extracted 40-50% of polysaccharides and 60-70% of the polyphenols. solubilization of arabinose and galactose by autohydrolysis occurred with heating above 170 degrees c, whereas heating above 200 degrees c was necessary to solubilize xylose. catechins were soluble in water by heating at low temperature (110 degrees c); however, new polyphenols having ...	2008	18998700
an epidemiologic study of tongue lesions in 1901 iranian dental outpatients.	the aim of this study was to assess the frequency of nine tongue conditions and evaluate their relationship to oral hygiene status and personal habits in a northern iranian population.	2008	18997919
phenolic content and antioxidative capacity of green and white tea extracts depending on extraction conditions and the solvent used.	the efficiencies of different solvents in the extraction of phenolics from bagged and loose leaves of white and green tea, after different extraction times, as well as the antioxidative capacity of the obtained extracts, were investigated. the developed hplc method has the potential to separate and determinate 17 phenolics widely distributed in plants, but in investigated tea extracts only four catechins and traces of three flavonols and one flavone were separated and detected based on compariso ...	2008	26047270
coffee, tea, and incident type 2 diabetes: the singapore chinese health study.	increasing coffee intake was inversely associated with risk of type 2 diabetes in populations of european descent; however, data from high-risk asian populations are lacking as are data on tea intake in general.	2008	18842784
screening of dhfr-binding drugs by maldi-tofms.	the class of antimetabolite chemotherapeutical agents has been used to treat cancers in humans for almost 50 years and gives significant results by binding dihydrofolate reductase (dhfr), a key enzyme in dna synthesis. therefore, finding new active compounds inhibiting dna synthesis through their binding to dhfr is of prime interest. the aim of this work is to describe a protocol designed to study the binding of compounds to dhfr. this screening protocol involves matrix-assisted laser desorption ...	2008	18841351
total polyphenol content and antioxidant capacity of commercially available tea (camellia sinensis) in argentina.	tea, camellia sinensis (l.) o. kuntze (theaceae) is cultivated in argentina in the northeastern region (provinces of misiones and corrientes), between 26 degrees and 28 degrees south latitude, the southernmost area of the world where tea is cultivated. the objective of this work was to determine the total polyphenol content and the in vitro antioxidant capacity of green and black tea cultivated and industrialized in argentina. twelve samples of eight brands were analyzed. the total polyphenol co ...	2008	18778031
medicinal flowers. xxii. structures of chakasaponins v and vi, chakanoside i, and chakaflavonoside a from flower buds of chinese tea plant (camellia sinensis).	two acylated oleanane-type triterpene oligoglycosides, chakasaponins v and vi, an aromatic glycoside, chakanoside i, and an acylated flavonol oligoglycoside, chakaflavonoside a, were isolated from the flower buds of chinese tea plant [camellia sinensis (l.) o. kuntze]. the chemical structures of those new glycosides were elucidated on the basis of chemical and physicochemical evidence.	2008	18758105
[consumption of tea among population on the far north of russia].	aim of present study was the getting data on tea and coffee consumption among population on the far north by 24-hour recall of dietary intake. about 84% of population have consumed the black tea. mean daily black and green tea intake among all population were 335 ml and 49 ml, correspondingly.	2008	19227859
[liver injury induced by "natural remedies": an analysis of cases submitted to the spanish liver toxicity registry].	toxic liver damage associated with the use of natural remedies is a growing health problem.	2008	19159172
delayed effects of coffee, tea and sucrose on postprandial glycemia in lean, young, healthy adults.	in observational studies, habitual coffee consumption has been linked to a lower risk of type 2 diabetes. we hy-pothesized that the mechanism may be related to delayed effects on postprandial glycemia. the aim of this study is to investigate the glycemic and insulinemic effects of consumption of caffeinated and decaffeinated coffee, sweetened and unsweetened, tea and sucrose, 1 h prior to a high carbohydrate meal. on separate occasions in random order, lean young healthy subjects (n = 8) consume ...	2008	19114405
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
effects of green and black tea biocomposites on endogenous synthesis, metabolism and genotoxic effect of carcinogenic n-nitrosodimethylamine.	to study the modifying effect of green and black tea biocomposites on endogenous synthesis and genotoxic action of the carcinogenic n-nitrosodimethylamine.	2008	19112429
[historical consideration of tea trees and tea flowers, especially regarding the use of tea flowers as food].	not only tea leaves, but also many kinds of plants have been used as tea, even those plants not belonging to camellia sinensis, and they should be called "tea out of tea" in the lucidophyllous forest zone. generally, the tea leaf is drank after being decocted (almost boiled). the growth distribution of tea ranges in a belt-like zone of 30-40 degrees north latitude. therefore, tea might have grown wild as "yamacha (mountain tea)" from ancient times in japan as well as china. the first recored of ...	2008	19227653
health potential for functional green teas?	obesity is a major health problem in the developed and developing world. many "functional" foods and ingredients are advocated for their effects on body composition but few have consistent scientific support for their efficacy. however, an increasing amount of mechanistic and clinical evidence is building for green tea. the tea plant is naturally rich in a group of antioxidants known as catechins. unlike black tea, green tea production involves little processing and fermentation and therefore, g ...	2008	19685436
chromatographic examinations of tea's protection against lipid oxidative modifications.	ethanol metabolism is accompanied by generation of free radicals that damage cell components, especially lipids. the present study was designed to investigate the efficacy of the preventive effect of black tea on the lipid oxidative modifications in different tissues (plasma, liver, brain, kidney, stomach, lung, intestine, and spleen) of 12-month-old rats chronically intoxicated with ethanol. ethanol intoxication caused changes in the level/activity of antioxidants that led to the significant in ...	2008	19696910
changes in phospholipid composition studied by hplc and electric properties of liver cell membrane of ethanol-poisoned rats.	ethanol introduced into the organism undergoes rapid metabolism to acetaldehyde and then to acetic acid. the process is accompanied by formation of reactive oxygen species (ros), which damage mainly lipids of membrane cells. the effects of ros can be neutralized by administering preparations with antioxidant properties. the natural preparations of this kind are teas.this paper reports data on the effect of green and black tea on the surface charge density, content of phospholipids, and level of ...	2008	19696939
inhibitory effect of tea polyphenols on hepatic preneoplastic foci in wistar rats.	tea (camellia sinensis) is one of the most widely used beverages worldwide and tea consumption has been shown to have an inverse correlation to the incidence of human cancers in epidemiological and experimental studies. in the present study, the protective effects of green tea polyphenols (gtp) and black tea polyphenols (btp) in wistar rats were assessed by medium-term bioassay, using altered hepatic foci (ahf) as end point. animals were exposed to a single dose of diethylnitrosamine (den; 200 m ...	2008	19057850
a study on toxicity of gasoline and gm-10 on liver of mice and it's amelioration by black tea extract.	the aim of present study is to investigate the ameliorative effect of black tea extract on gasoline and gm-10 induced toxicity in liver of mice. eighty healthy male mice weighing 38-40 g approximately were divided into eight groups which included untreated control and various treated groups. mice were treated with gasoline 462 mg/kg/day and gm-10 low dose (206 mg/kg/day) and high dose (412 mg/kg/day) subcutaneously for 30 days. black tea extract was given as 2 g/100 ml drinking water (2% w/v) in ...	2008	19051608
caging a beast in the inflammation arena: use of chinese medicinal herbs to inhibit a late mediator of lethal sepsis, hmgb1.	sepsis refers to a systemic inflammatory response syndrome resulting from a microbial infection, which kills > 225,000 people annually in the u.s. alone. the high mortality of sepsis is partly mediated by bacterial endotoxin, which stimulates macrophages/monocytes to sequentially release early (e.g., tnf) and late (e.g., hmgb1) pro-inflammatory cytokines. although early proinflammatory cytokines may be protective against infection, excessive accumulation of late-acting proinflammatory mediators ...	2008	19079688
antihypercholesterolemic effect of chinese black tea extract in human subjects with borderline hypercholesterolemia.	a water-soluble extract of a traditional chinese black tea (pu-ehr) has been shown to precipitate mixed bile salt micelles in foods. in addition, long-term ingestion of this black tea extract (bte) significantly reduces blood cholesterol levels in rats. we investigated the effects of bte tablets (a formula designed to enhance compliance) as a dietary supplement in a 3-month double-blind randomized group comparison study in borderline hypercholesterolemic human subjects (n = 47). all subjects ing ...	2008	19083445
long-term caffeine consumption reverses tumor-induced suppression of the innate immune response in adult mice.	caffeine (1,3,7-trimethylxanthine), the active principle alkaloid of coffee ( coffea arabica) and tea ( camellia sinensis) possesses a restraining effect on tumor-induced suppression of the specific immune response in adult mice. the present study deals with the effect of long-term consumption of caffeine in the development of ehrlich ascites carcinoma (eac) cells in adult swiss female mice, in relation to the innate immune response and tumor growth. although the consumption of caffeine alone fo ...	2008	19016405
an aqueous extract of green tea camellia sinensis increases expression of th1 cell-specific anti-asthmatic markers.	the present study provides evidence of the anti-asthmatic signaling activity of an aqueous fraction of green tea using specific in vitro and in vivo assays in an ovalbumin-induced asthmatic model. mice sensitized to ovalbumin were orally administered an aqueous extract of camellia sinensis. the lungs of these mice were then examined by hematoxylin and eosin staining and elisa analysis to measure cytokine expression. the aqueous extract of camellia sinensis exhibited potent anti-asthmatic activit ...	2008	19020774
antiproliferative and antimicrobial activity of traditional kombucha and satureja montana l. kombucha.	to carry out a preliminary investigation of the biological activity of kombucha beverages from camellia sinensis l. (black tea) and satureja montana l. (winter savory tea), that have consuming acidity.	2008	18979556
in vitro antioxidative potential of lactoferrin and black tea polyphenols and protective effects in vivo on carcinogen activation, dna damage, proliferation, invasion, and angiogenesis during experimental oral carcinogenesis.	the present study was designed to evaluate the in vitro antioxidant potential of bovine lactoferrin (blf) and black tea polyphenols [polyphenon-b (p-b)] as well as in vivo inhibitory effects on the development of 7,12-dimethylbenz[a]anthracene (dmba)-induced hamster buccal pouch (hbp) carcinomas. antioxidant activity was screened using a panel of assays including 1,1-diphenyl-2-picrylhydrazyl (dpph), 2,2'-azinobis-(3-ethyl-benzothiazoline-6-sulfonic acid) (abts), hydroxyl radical anion (oh*), su ...	2008	18980016
black tea polyphenols modulate xenobiotic-metabolizing enzymes, oxidative stress and adduct formation in a rat hepatocarcinogenesis model.	the present study was designed to investigate the modulatory effects of black tea polyphenols (polyphenon-b) on phase i and phase ii xenobiotic-metabolizing enzymes and oxidative stress in a rat model of hepatocellular carcinoma (hcc). liver tumours induced in male sprague-dawley rats by dietary administration of rho-dimethylaminoazobenzene (dab) increased cytochrome p450 (total and cyp1a1, 1a2 and 2b isoforms), cytochrome b(5), cytochrome b(5) reductase, glutathione s-transferase (gst total and ...	2008	18985486
pcr differential display-based identification of regulator of g protein signaling 10 as the target gene in human colon cancer cells induced by black tea polyphenol theaflavin monogallate.	we have previously reported that black tea polyphenol theaflavin monogallate (tf-2) suppressed cox-2 and induced apoptosis in human colon cancer cells [lu, j.b., ho, c.-t., ghai, g., chen, k.y., 2000. differential effects of theaflavin monogallates on cell growth, apoptosis and cox-2 gene expression in cancerous versus normal cells. cancer res. 60, 6465-6471.]. we now extended the study by using pcr-based differential display to search for genes that were selectively induced by tf-2. here we rep ...	2008	18992738
polymeric black tea polyphenols inhibit 1,2-dimethylhydrazine induced colorectal carcinogenesis by inhibiting cell proliferation via wnt/beta-catenin pathway.	tea polyphenols like epigallocatechin gallate and theaflavins are established chemopreventive agents for colorectal carcinogenesis. however, studies on evaluating similar chemopreventive properties of thearubigins or polymeric black tea polyphenols (pbps), the most abundant polyphenols in black tea, are limited. hence, in the present study we aim to investigate chemopreventive effects along with probable mechanisms of action of pbp extract employing 1,2-dimethylhydrazine (dmh)-induced colorectal ...	2008	18037152
green tea protects rats against autoimmune arthritis by modulating disease-related immune events.	green tea, a product of the dried leaves of camellia sinensis, is the most widely consumed beverage in the world. the polyphenolic compounds from green tea (pgt) possess antiinflammatory properties. we investigated whether pgt can afford protection against autoimmune arthritis and also examined the immunological basis of this effect using the rat adjuvant arthritis (aa) model of human rheumatoid arthritis (ra). aa can be induced in lewis rats (rt.1(l)) by immunization with heat-killed mycobacter ...	2008	18936206
influence of culture media and environmental factors on mycelial growth and sporulation of lasiodiplodia theobromae (pat.) griffon and maubl.	lasiodiplodia theobromae, a common tea (camellia sinensis) pathogen, usually does not sporulate or sporulates poorly in common media, which makes spore production difficult. in this study the effects of culture media, carbon source, nitrogen source, temperature, ph and light on mycelial growth and sporulation were evaluated. among several carbon sources tested, glucose and sucrose were found superior for growth. potassium nitrate supplemented media showed maximum growth amongst the tested inorga ...	2008	18972700
paenibacillus camelliae sp. nov., isolated from fermented leaves of camellia sinensis.	a novel bacterium, strain blls-2(t) was isolated from pu'er tea. the isolate was gram-positive, endospore-forming motile rod that grew at 15 approximately 42 degrees c and ph 6.0 approximately 10.2. the dna g+c content was 48.3 mol%, the predominant isoprenoid quinone was mk-7, and the predominant cellular fatty acid was anteiso-c15:0 (54.2%) followed by c16:0 (15.5%) and iso-c16:0 (8.2%). the polar lipid pattern of blls-2(t) was characterized by the presence of diphosphatidylglycerol, phosphati ...	2008	18974954
characterization of cellulose production by a gluconacetobacter xylinus strain from kombucha.	the aims of this work were to characterize and improve cellulose production by a gluconoacetobacter xylinus strain isolated from kombucha and determine the purity and some structural features of the cellulose from this strain. cellulose yield in tea medium with both black tea and green tea and in hestrin and schramm (hs) medium under both static and agitated cultures was compared. in the tea medium, the highest cellulose yield was obtained with green tea (approximately 0.20 g/l) rather than blac ...	2008	18704575
efficacy and safety of chinese black tea (pu-ehr) extract in healthy and hypercholesterolemic subjects.	water-extracted chinese black tea (pu-ehr) exerts a precipitating effect on mixed bile salt micelles in foods. the amount of black tea extract (bte) effective for hypercholesterolemia (hc) was examined in humans.	2008	18769024
antibacterial effects of green tea polyphenols on clinical isolates of methicillin-resistant staphylococcus aureus.	the antibacterial effects of tea polyphenols (tpp) extracted from korean green tea (camellia sinensis) against clinical isolates of methicillin-resistant staphylococcus aureus (mrsa) were evaluated. characterization of the minimal inhibitory concentration (mic) of oxacillin for 30 s. aureus strains isolated from patients treated with oxacillin identified 13 strains with an oxacillin mic >or= 4 microg/ml as methicillin-resistant staphylococcus aureus (mrsa) (range: 8 to 512 microg/ml), while 17 s ...	2008	18781360
preservation of kombucha tea-effect of temperature on tea components and free radical scavenging properties.	kombucha tea is sugared black tea fermented with a consortium of acetic acid bacteria and yeasts (tea fungus) for 14 days. the tea tastes slightly sweet and acidic. the formation of tea fungal biofilms during storage is a big problem when kombucha tea is being stored and commercialized. various thermal treatments have been tried for long-term storage of kombucha tea. the present study revealed the influence of heat on the biochemical constituents and the free radical scavenging properties of kom ...	2008	18781766
high level of genetic diversity among the selected accessions of tea (camellia sinensis) from abandoned tea gardens in western himalaya.	to revive cultivation of the tea unique to the western himalayan region, it is important to evaluate the seed-derived bushes available in the area's abandoned gardens. this study used quantitative leaf characters, catechin content, and aflp markers to assess these china cultivar type bushes. compared with other china cultivar germplasm, these accessions showed a higher level of diversity among themselves. among the quantitative morphological characters, leaf length is important in distinguishing ...	2008	18784998
tea polyphenols benefit vascular function.	tea, the most popular beverage worldwide, is consumed in three basic forms; green tea, black tea and oolong tea. tea contains over 4,000 chemicals some of which are bioactive. in recent years there has been a mounting interest in understanding the cardiovascular and metabolic benefits of polyphenolic flavonoids in tea, which can be used as a supplement among patients. diverse cardioprotective effects of consuming tea or tea polyphenols have been described on pathological conditions, e. g. hypert ...	2008	18815738
quantitative assessment of metals in local brands of tea in pakistan.	in present study, mn, fe, zn, cu, co, pb, cr, ni and cd were analyzed by faas in green and black tea samples of locally available in the pakistani market. na and k were also determined by flame photometer. tea leaves can be the source of mineral components and trace elements, as well as some undesirable substances due to exposure to the environment. among the metals tested, k was the most abundant one followed by na, mn and fe. fortunately, toxic heavy metals, pb and cd, had the lowest contents ...	2008	18817205
volatile components of camellia sinensis inhibit growth and biofilm formation of oral streptococci in vitro.	this study aimed to evaluate the efficacy of semi fermented and non fermented camellia sinensis extracts (black and green tea) and comparison between them against streptococcus mutans atcc 25175, s. mitis atcc 9811 and s. sanguis atcc 10556 that are responsible for dental caries and bacteremias following dental manipulations. minimum inhibitory concentrations of both tea extracts were assessed by well diffusion and broth dilution methods and examination of cell adherence (biofilm inhibitory conc ...	2008	18817265
in vitro effects of tea polyphenols on redox metabolism, oxidative stress, and apoptosis in pc12 cells.	tea polyphenols, especially catechins, have been reported to be potent antioxidants and beneficial in oxidative stress-related diseases including cancer. numerous animal and cell culture models demonstrate anticancer effects of tea catechins. experimental and epidemiological evidence suggests the use of black tea polyphenols (btp), green tea catechins (especially epigallocatechin gallate [egcg]), and other polyphenols in preventing the progression of cancer both in animal and human populations. ...	2008	18837911
different types of tea products attenuate inflammation induced in trypanosoma brucei infected mice.	an in vivo study was carried out to determine the effect of different types of kenyan tea extracts on male swiss albino mice infected with trypanosoma brucei brucei isolate ketri 2710. the isolate produced a similar clinical picture after a pre-patent period of 5 days post-infection (dpi). parasitemia levels in the untreated mice and those given different teas developed exponentially at similar rates reaching similar densities at the peak of parasitemia 8 dpi. between 9 and 13 dpi parasitemia de ...	2008	18456544
safety of green tea extracts : a systematic review by the us pharmacopeia.	green tea [camellia sinensis (l.) kuntze] is the fourth most commonly used dietary supplement in the us. recently, regulatory agencies in france and spain suspended market authorization of a weight-loss product containing green tea extract because of hepatotoxicity concerns. this was followed by publication of adverse event case reports involving green tea products. in response, the us pharmacopeia (usp) dietary supplement information expert committee (dsi ec) systematically reviewed the safety ...	2008	18484782
epigallocatechin gallate improves serum lipid profile and erythrocyte and cardiac tissue antioxidant parameters in wistar rats fed an atherogenic diet.	oxidative stress is believed to contribute to the pathogenesis of hypercholesterolaemic atherosclerosis; hence, various antioxidant compounds are being evaluated for potential anti-atherogenic effects. the present study assessed the efficacy of epigallocatechin gallate (egcg), an antioxidant component of the plant camellia sinensis, in improving serum lipid profile and antioxidant parameters in erythrocytes and cardiac tissue in rats fed an atherogenic diet. in male albino wistar rats fed an ath ...	2008	18485145
pretreatment with black tea polyphenols modulates xenobiotic-metabolizing enzymes in an experimental oral carcinogenesis model.	the objective of this study was to evaluate the chemopreventive potential of the black tea polyphenols polyphenon-b and btf-35 during the preinitiation phase of 7,12-dimethylbenz[a]anthracene (dmba)-induced hamster buccal pouch (hbp) carcinogenesis. hamsters were divided into six groups. animals in groups 2 and 3 received diet containing polyphenon-b and btf-35, respectively, 4 weeks before carcinogen administration when they were 6 weeks of age and continued until the final exposure to carcinog ...	2008	18543609