Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| effects on blood pressure of drinking green and black tea. | the flavonoid components of tea have been associated in epidemiological studies with a decreased risk of cardiovascular disease. flavonoids have been shown to have antioxidant and vasodilator effects in vitro; we therefore postulated that drinking green or black tea attenuates the well-characterized acute pressor response to caffeine and lowers blood pressure during regular consumption. | 1999 | 10404946 |
| antimicrobial activity of tea as affected by the degree of fermentation and manufacturing season. | bacillus subtilis, escherichia coli, proteus vulgaris, pseudomonas fluorescens, salmonella sp. and staphylococcus aureus were used to test the antimicrobial activity of tea flush extract and extracts of various tea products. among the six test organisms, p. fluorescens was the most sensitive to the extracts, while b. subtilis was the least sensitive. in general, antimicrobial activity decreased when the extents of tea fermentation increased. the antimicrobial activities of tea flush extract and ... | 1999 | 10426448 |
| disorganization of cell division of methicillin-resistant staphylococcus aureus by a component of tea (camellia sinensis): a study by electron microscopy. | a component of aqueous extracts of green tea (camellia sinensis), known to reverse methicillin-resistance in staphylococci, causes extensive morphological changes in methicillin-resistant but not in methicillin-sensitive staphylococcus aureus. clumps of partly divided cocci, consisting of up to 14 individuals, with thickened internal but normal external cell walls were seen by electron microscopy in cultures of methicillin-resistant s. aureus grown in the presence of the active principle. the mo ... | 1999 | 10427729 |
| antioxidant and eicosanoid enzyme inhibition properties of pomegranate seed oil and fermented juice flavonoids. | the antioxidant and eicosanoid enzyme inhibition properties of pomegranate (punica granatum) fermented juice and seed oil flavonoids were studied. the pomegranate fermented juice (pfj) and cold pressed seed oil (pcpso) showed strong antioxidant activity close to that of butylated hydroxyanisole (bha) and green tea (thea sinensis), and significantly greater than that of red wine (vitis vitifera). flavonoids extracted from pcpso showed 31-44% inhibition of sheep cyclooxygenase and 69-81% inhibitio ... | 1999 | 10432202 |
| proconvulsive effect of tea (camellia sinensis) in mice. | investigations were carried out to evaluate the effect of acute and chronic administration of both black and green tea on three models of experimentally induced convulsions in mice. tea extract (both black and green) significantly accelerated the onset of convulsion, increased the duration of convulsion and mortality in mice. since both the extracts failed to alter the gaba level in brain, based on the earlier report that both black and green tea might act on ca(2+) channels, it can be suggested ... | 1999 | 10441775 |
| statistical analysis of salivary ph changes after the intake of black tea and yerba maté supplemented with sweeteners. | many studies have demonstrated the effect of various beverages on hard tissues of the mouth. sugar consumption has also been avoided because it is associated with caries activity, and artificial sweetener research has been promoted. in this paper, data about the buffer capacity of black tea and yerba mate supplemented with sugar or one of two artificial sweeteners (barny diet and nutrasweet) were examined. salivary ph variations after the ingestion of both infusions were statistically analysed. ... | 1999 | 10453132 |
| black tea increases the resistance of human plasma to lipid peroxidation in vitro, but not ex vivo. | a number of in vitro studies have shown that polyphenols and flavonoids in tea exert significant antioxidant activity. however, epidemiologic and experimental studies have produced conflicting results. the purpose of the present study was to compare the antioxidant activity of black tea in vitro with that ex vivo. black tea polyphenols (btp), black tea extract (bte), or their major polyphenolic antioxidant constituent, epigallocatechin gallate (egcg), were added to human plasma and lipid peroxid ... | 1999 | 10468212 |
| mechanistic aspects of green tea as a cancer preventive: effect of components on human stomach cancer cell lines. | it is now well accepted that (-)-epigallocatechin gallate (egcg) inhibits carcinogenesis in the digestive tract in rodents. to understand the mechanisms of anticarcinogenesis, we first studied growth inhibition by egcg in human stomach cancer cell lines established at seoul national university (snu cell lines). inhibition by egcg of [3h]thymidine incorporation into eight snu cell lines was examined, in relation to transforming growth factor-beta (tgf-beta) responsiveness. various tea polyphenols ... | 1999 | 10470285 |
| inhibition of eleven mutagens by various tea extracts, (-)epigallocatechin-3-gallate, gallic acid and caffeine. | the antimutagenic properties of various tea extracts (green tea, pauchong tea, oolong tea and black tea) and their components including (-)-epigallocatechin-3-gallate (egcg), gallic acid and caffeine were examined by the ames test. the antimutagenic activity of the green tea extract against n-methyl-n'-nitro-n-nitrosoguanidine (mnng), folpet and monocrotophos was greater than those of pouchong, oolong and black tea extracts. the antimutagenic effects of tea extracts against 2-acetylaminofluorene ... | 1999 | 10478825 |
| inhibition of activator protein 1 activity and cell growth by purified green tea and black tea polyphenols in h-ras-transformed cells: structure-activity relationship and mechanisms involved. | ras gene mutation, which perpetually turns on the growth signal transduction pathway, occurs frequently in many cancer types. the mouse epidermal jb6 cell line has been transfected with a mutant h-ras gene to mimic carcinogenesis in vitro. these transformed cells (30.7b ras 12) are able to grow in soft agar, exhibiting anchorage independence and high endogenous activator protein 1 (ap-1) activity, which can be detected by a stable ap-1 luciferase reporter. the present study investigated the abil ... | 1999 | 10493515 |
| chemoprevention studies of heterocyclic amine-induced colon carcinogenesis. | the cooking of meat and fish produces heterocyclic amine mutagens, including 2-amino-1-methyl-6-phenylimidazo[4,5b]pyridine (phip) and 2-amino-3-methylimidazo[4,5-f]quinoline (iq). chronic administration of phip or iq to the f344 rat induces tumors at several sites, including adenocarcinomas of the colon, and short-term treatment leads to the formation of colonic aberrant crypt foci (acf). we have used these end-points to identify potential chemopreventive agents that might be effective against ... | 1999 | 10503900 |
| proliferation of hepatic peroxisomes in rats following the intake of green or black tea. | rats maintained on green, black or decaffeinated black tea (2.5%, w/v) as their sole drinking fluid displayed higher hepatic cn- insensitive palmitoyl coa oxidase activity than controls; the extent of increase was similar with the three types of tea. morphological examination of the liver using electron microscopy revealed an increase in the number of peroxisomes in the tea-treated animals. the same treatment of the animals with green and black tea resulted in a similar rise in hepatic microsoma ... | 1999 | 10514032 |
| fluoride in tea--its dental significance: a review. | it has long been accepted that fluoride accumulates in the leaves of the tea plant. camellia sinensis. in addition it is known that some of this fluoride is released into the infusion which is drunk as tea. the exact concentration of fluoride in a cup of tea and the effects of this fluoride have been the subject of many international studies. this review summarizes the main points of such studies which have been carried out in an attempt to establish the dental significance of fluoride in tea. t ... | 1998 | 10530119 |
| (z)-3-hexenyl and trans-linalool 3,7-oxide beta-primeverosides isolated as aroma precursors from leaves of a green tea cultivar. | 6-o-beta-d-xylopyranosyl-beta-d-glucopyranosides (beta-primeverosides) of (z)-3-hexenol and trans-linalool 3,7-oxide were newly isolated from fresh leaves of a tea cultivar (camellia sinensis var. sinensis cv. yabukita). in addition, the already identified beta-primeverosides of benzyl alcohol, methyl salicylate, and trans-linalool 3,6-oxide from an oolong tea cultivar were isolated from the yabukita cultivar. it was confirmed that all aglycones of the linalool oxide glycosides isolated here wer ... | 1999 | 10540751 |
| mechanisms of action of antioxidants as exemplified in vegetables, tomatoes and tea. | most chronic diseases, including coronary heart disease and many types of cancer depend on the in vivo conversion of cellular macromolecules or of carcinogens to specific reactive, oxidized forms. for that reason, health promoting nutrition involves the daily intake of five to 10 vegetables and fruits, fruit juices, red wine and tea that are rich sources of micronutrients with antioxidant properties, including the antioxidant vitamins c, e and beta-carotene. tomatoes contain lycopene, a stable, ... | 2007 | 10541449 |
| photoprotective effect of black tea extracts against uvb-induced phototoxicity in skin. | in previous studies, we showed that green tea and black tea extracts and their major polyphenolic constituents protect against uvb light-induced carcinogenesis in murine skin. all of these studies required chronic administration of tea extracts or specific constituents either topically or orally. however, it is not known whether acute or subchronic administration of black tea extracts or constituents can ameliorate uvb-induced early effects in skin. in the present study, cultured keratinocytes a ... | 1999 | 10546558 |
| growth-inhibiting effects of coptis japonica root-derived isoquinoline alkaloids on human intestinal bacteria. | the growth-inhibiting activity of coptis japonica (makino) root-derived materials toward eight human intestinal bacteria was examined using an impregnated paper disk method and compared to that of four commercially available isoquinoline alkaloids [berberine sulfate (bs), berberine iodide (bi), palmatine chloride (pc), and palmatine sulfate(ps)], as well as that of thea sinensis leaf-derived epigallocatechin gallate (egcg). the biologically active constituents of the coptis extract were characte ... | 1999 | 10552394 |
| novel antiallergic catechin derivatives isolated from oolong tea. | two catechin derivatives (c-1 and c-2) with potent antiallergic activity were isolated from taiwanese oolong tea by hplc techniques. from nmr and fab-ms analyses, the structures of c-1 and c-2 were elucidated as (-)-epigallocatechin 3-o-(3-o-methyl)gallate and (-)-epigallocatechin 3-o-(4-o-methyl)gallate, respectively. the oolong tea leaves contained 0.34% (dry weight) c-1 and 0.20% c-2. traces of c-2 were detected in only 1 of 15 varieties of green tea tested. c-1 was detected in 13 of 15 green ... | 1999 | 10552469 |
| role of polyphenol oxidase and peroxidase in the generation of black tea theaflavins. | it has been reported earlier that when macerated tea leaf is fermented at lower ph, the resultant black tea contains increased levels of theaflavin, an important quality marker in black tea. in an attempt to investigate the biochemistry and chemistry underlying this observation, in vitro oxidation experiments using polyphenol oxidase (ppo) from fresh tea leaves, horseradish peroxidase (pod), and tea catechins, precursors for theaflavins, were carried out. in vitro oxidation experiments using cru ... | 1999 | 10552528 |
| biosynthesis and catabolism of caffeine in low-caffeine-containing species of coffea. | leaves of coffea salvatrix, coffea eugenioides, and c. bengalensis contain approximately 3-7-fold lower levels of caffeine than those of coffea arabica. there was more extensive biosynthesis of caffeine from [8-(14)c]adenine in young leaves of c. arabica than in c. salvatrix, c. eugenioides, and c. bengalensis. degradation of [8-(14)c]caffeine, which is negligible in leaves of c. arabica, was also very slow in c.salvatrix and c. bengalensis. in contrast, [8-(14)c]caffeine was catabolized rapidly ... | 1999 | 10552667 |
| green tea (camellia sinensis) extract and its possible role in the prevention of cancer. | the american cancer society estimates that in the 1980s more than 4. 5 million americans died of cancer. in addition, there were nearly nine million new cases and about 12 million people were under medical care for cancer. with cancer being the second most common cause of death in the united states population, the possibility that readily-available natural substances may be beneficial in the prevention of cancer warrants closer examination. a growing body of research has demonstrated green tea p ... | 1999 | 10559550 |
| total antioxidant capacity of teas by the ferric reducing/antioxidant power assay. | this study aimed to compare in vitro antioxidant power of different types of tea (camellia sinensis). the ferric reducing/antioxidant power (frap) assay was used to measure the total antioxidant power of freshly prepared infusions of 25 types of teas. results showed that different teas had widely different in vitro antioxidant power and that the antioxidant capacity was strongly correlated (r = 0. 956) with the total phenolics content of the tea. expressed as micromol of antioxidant power/g of d ... | 1999 | 10563944 |
| inhibition of tpa-induced protein kinase c and transcription activator protein-1 binding activities by theaflavin-3,3'-digallate from black tea in nih3t3 cells. | tea is one of the most popular beverages in the world. several reports have shown that both green tea and black tea were able to inhibit tumor cell proliferation in animal models. in this study, we investigated the inhibitory effects of black tea polyphenols including theaflavin (tf-1), the mixture (tf-2) of theaflavin-3-gallate (tf-2a), and theaflavin-3'-gallate (tf-2b), theaflavin-3,3'-digallate (tf-3), thearubigin (tr), and a major green tea polyphenol (-)-epigallocatechin-3-gallate (egcg) on ... | 1999 | 10563991 |
| metabolism of theanine, gamma-glutamylethylamide, in rats. | the metabolism of theanine, one of the major amino acid components in tea (camellia sinensis), was studied in rats. high-performance liquid chromatography (hplc) with fluorometric detection was used to evaluate the nature of theanine's metabolites in plasma, urine, and tissues. in the urine samples collected after administration of 100, 200, and 400 mg each of theanine, intact theanine, l-glutamic acid, and ethylamine, these compounds were detected in a dose-dependent manner. when 200 mg of thea ... | 1999 | 10564022 |
| tea and health. | the possible beneficial effects of tea consumption in the prevention of cancer and cardiovascular diseases have been demonstrated in animal models and suggested by studies in vitro. similar beneficial effects, however, have not been convincingly demonstrated in humans: beneficial effects have been demonstrated in some studies but not in others. if such beneficial effects do exist in humans, they are likely to be mild, depending on many other lifestyle-related factors, and could be masked by conf ... | 2008 | 10575676 |
| fungi associated with black tea and tea quality in the sultanate of oman. | forty-eight samples of four popular commercial brands of black tea (camellia sinensis l.) were purchased from the local markets in muscat area, sultanate of oman. tea leaves were surveyed for mycoflora. five fungal species were isolated with a. niger as the most dominant in all the brands having percentage contamination ranging between 0.66% and 30.34%. other fungi isolated were aspergillusflavus, penicillium spp. and pacelomyces spp. but having average percentages of 0.6%, 0.84% and 0.21% respe ... | 1999 | 10598069 |
| application of near-infrared reflectance spectroscopy to the simultaneous prediction of alkaloids and phenolic substances in green tea leaves. | a near-infrared reflectance spectroscopic (nirs) method for the prediction of polyphenol and alkaloid compounds in the leaves of green tea [camellia sinensis (l.) o. kuntze] was developed. reference measurements of the individual catechins, gallic acid, caffeine, and theobromine were performed by reversed-phase hplc. the total polyphenols were determined according to the colorimetric folin-ciocalteu assay. using the partial least-squares algorithm, very good calibration statistics were obtained ... | 1999 | 10606573 |
| comparison of digestion methods for determination of trace and minor metals in plant samples. | in this paper, three dissolution methods using pressure digestion vessels (low-, medium-, and high-pressure vessels) for the determination of metals in plant samples are described. the plackett-burman saturated factorial design was used to identify the significant factors influencing wet ashing and to select optimized dissolution conditions. the three methods were statistically compared (on-way anova) on the same sample; no significant differences were obtained. in all cases the relative standar ... | 1999 | 10606575 |
| comparative chemopreventive mechanisms of green tea, black tea and selected polyphenol extracts measured by in vitro bioassays. | black tea extracts (hot aqueous, polyphenols and theaflavins) and green tea extracts (hot aqueous, polyphenols, epicatechin, epicatechin gallate, epigallocatechin and epigallocatechin gallate) were tested in nine standardized cell culture assays for comparative cancer chemopreventive properties. most black and green tea extracts strongly inhibited neoplastic transformation in mouse mammary organ cultures, rat tracheal epithelial cells and human lung tumor epithelial cells. nearly all tea fractio ... | 2000 | 10607735 |
| chemopreventive effects of tea extracts and various components on human pancreatic and prostate tumor cells in vitro. | pancreatic and prostate cancers pose serious problems to human health. to determine the potential for chemopreventive intervention against pancreatic and prostate cancers, black and green tea extracts and components of these extracts were examined in vitro for their effect on tumor cell growth. components included a mixture of polyphenols from green tea (gtp), mixtures of polyphenols (btp) and of theaflavins (mf) from black tea, and the purified components epicatechin-3-gallate (ecg) and epigall ... | 1999 | 10624710 |
| dietary fat, body weight, and cancer: contributions of studies in rodents to understanding these cancer risk factors in humans. | understanding diet and energy balance as risk factors for breast, colon, and other cancers requires information on the contribution of each factor and of interactions among factors to cancer risk. rodent models for breast cancer provide extensive data on effects of dietary fat and calories, energy balance, body weight gain, and physical activity on tumor development. analyses of the combined data from many studies have shown clearly that quality and quantity of dietary fat and energy balance con ... | 1999 | 10630593 |
| green tea in chemoprevention of cancer. | the concept of prevention of cancer using naturally occurring substances that could be included in the diet consumed by the human population is gaining increasing attention. tea, next to water, is the most popularly consumed beverage in the world and it is grown in about 30 countries. abundant data, amassed from several laboratories around the world in the last ten years, provided convincing evidence that polyphenolic antioxidants present in tea afford protection against cancer risk in many anim ... | 1999 | 10630599 |
| suppression of lipopolysaccharide-induced nuclear factor-kappab activity by theaflavin-3,3'-digallate from black tea and other polyphenols through down-regulation of ikappab kinase activity in macrophages. | we investigated the inhibition of ikappab kinase (ikk) activity in lipopolysaccharide (lps)-activated murine macrophages (raw 264.7 cell line) by various polyphenols including (-)-epigallocatechin-3-gallate, theaflavin, a mixture of theaflavin-3 gallate and theaflavin-3'-gallate, theaflavin-3,3'-digallate (tf-3), pyrocyanidin b-3, casuarinin, geraniin, and penta-o-galloyl-beta-d-glucose (5gg). tf-3 inhibited ikk activity in activated macrophages more strongly than did the other polyphenols. tf-3 ... | 2000 | 10644043 |
| progress in cancer chemoprevention. | more than 40 promising agents and agent combinations are being evaluated clinically as chemopreventive drugs for major cancer targets. a few have been in vanguard, large-scale intervention trials--for example, the studies of tamoxifen and fenretinide in breast, 13-cis-retinoic acid in head and neck, vitamin e and selenium in prostate, and calcium in colon. these and other agents are currently in phase ii chemoprevention trials to establish the scope of their chemopreventive efficacy and to devel ... | 1999 | 10668477 |
| inhibitory effects of tea extracts on the mutagenicity of 1-methyl-1, 2,3,4-tetrahydro-beta-carboline-3-carboxylic acid on treatment with nitrite in the presence of ethanol. | it has been shown that the mutagenicity of 1-methyl-1,2,3, 4-tetrahydro-beta-carboline-3-carboxylic acid (mtcca), a major mutagen precursor in soy sauce on treatment with nitrite and ethanol, was strongly decreased by the addition of hot water extracts of green, black and oolong teas in the reaction mixture when it was treated with 50mm nitrite at ph3.0, 37 degrees c for 60min in the presence of 7.5% ethanol. the mutagenicity-decreasing activity of the teas was scarcely decreased by washing the ... | 2000 | 10685009 |
| a single dose of tea with or without milk increases plasma antioxidant activity in humans. | to investigate the effect of black and green tea consumption, with and without milk, on the plasma antioxidant activity in humans. | 2000 | 10694777 |
| prokinetic effect of black tea on gastrointestinal motility. | the gastrokinetic effects of hot water extract of black tea [camellia sinensis, (l) o. kuntze (theaceae)] on gastrointestinal motility were studied both in vivo and in vitro. the extract significantly accelerated the gastrointestinal transit (git) in vivo in mice. these facilitatory effect was reduced after pretreatment with atropine, hemicholinium-3, morphine, indomethacin, mcn-a-343 and l-arginine. in guinea pig ileum, the extract facilitated the peristaltic reflex in response to pressures in ... | 2000 | 10698359 |
| inactivation of human type a and b influenza viruses by tea-seed saponins. | the effects of a mixture of tea-seed saponins obtained from the seeds of camellia sinensis var. sinesis on human influenza viruses types a and b were investigated. at the concentrations of 60, 80, and 100 micrograms/ml, respectively, the mixture inactivated viruses a/memphis/1/71 (h3n2), b/lee/40, and a/pr/8/34 (h1n1) almost completely. the mixture also inactivated type a virus a/pr/8/34 after inoculation at concentrations of 1-30 micrograms/ml dose-dependently. | 2000 | 10705466 |
| an improved method for the determination of green and black tea polyphenols in biomatrices by high-performance liquid chromatography with coulometric array detection. | tea polyphenols are strong antioxidants and are believed to have beneficial health effects. however, the blood and tissue levels of these compounds are not well characterized because of a lack of suitable analytical methods for the biological resolution of these compounds. previously, we developed methods for the analysis of three green tea catechins. now we report an improved method for the measurement of the levels of the different catechins and theaflavins in biological fluids and tissues. th ... | 2000 | 10706785 |
| progress in cancer chemoprevention: development of diet-derived chemopreventive agents. | because of their safety and the fact that they are not perceived as "medicine," food-derived products are highly interesting for development as chemopreventive agents that may find widespread, long-term use in populations at normal risk. numerous diet-derived agents are included among the >40 promising agents and agent combinations that are being evaluated clinically as chemopreventive agents for major cancer targets including breast, prostate, colon and lung. examples include green and black te ... | 2000 | 10721931 |
| tea and tea polyphenols in cancer prevention. | the inhibitory action of tea (camellia sinensis) and tea components against cancer formation has been demonstrated in different animal models involving different organ sites in many laboratories. the possible preventive activity of tea against cancer in humans, however, is not clear. a critical question is whether the information obtained from animal studies is applicable to humans because of possible species differences or the difference in the quantity of tea used in animal studies and that co ... | 2000 | 10721932 |
| insulin-like biological activity of culinary and medicinal plant aqueous extracts in vitro. | to evaluate the possible effects on insulin function, 49 herb, spice, and medicinal plant extracts were tested in the insulin-dependent utilization of glucose using a rat epididymal adipocyte assay. cinnamon was the most bioactive product followed by witch hazel, green and black teas, allspice, bay leaves, nutmeg, cloves, mushrooms, and brewer's yeast. the glucose oxidation enhancing bioactivity was lost from cinnamon, tea, witch hazel, cloves, bay leaf and allspice by poly(vinylpyrrolidone) (pv ... | 2000 | 10725162 |
| [chemical constituents of seeds of camellia sinensis var. assamica]. | five compounds were isolated from the acid-hydrolytic products of n-butanol extract and ethanol extract of the seeds of camellia sinensis var. assamica. their structures were elucidated by chemical and spectroscopic analyses as octacosane, three new acyl-sapogenins: 22-o-angeloyl theasapogenol b, 22-o-angeloyl theasapogenol e and 22-o-angeloyl theasapogenol a, and naringenin respectively. | 1997 | 10743215 |
| marked reduction in the minimum inhibitory concentration (mic) of beta-lactams in methicillin-resistant staphylococcus aureus produced by epicatechin gallate, an ingredient of green tea (camellia sinensis). | we found that epicatechin gallate, a constituent of an extract of tea leaves (green tea) markedly lowered the minimum inhibitory concentration (mic) of oxacillin and other beta-lactams, but not of other antibacterial agents tested, in strains of methicillin-resistant staphylococcus aureus. the antibacterial action of epicatechin gallate plus oxacillin was a bactericidal one. | 1999 | 10746177 |
| bioactive saponins and glycosides. xv. saponin constituents with gastroprotective effect from the seeds of tea plant, camellia sinensis l. var. assamica pierre, cultivated in sri lanka: structures of assamsaponins a, b, c, d, and e. | the saponin fraction from the seeds of the tea plant, camellia sinensis l. var. assamica pierre cultivated in sri lanka, was found to show a potent protective effect on gastric mucosal lesions induced by ethanol in rats. nine new acylated polyhydroxyoleanene-type triterpene oligoglycosides called assamsaponins a-i were isolated from the active saponin fraction together with three known saponins, theasaponin e1 and e2 and camelliasaponin b1. the structures of assamsaponins a-e were elucidated on ... | 1999 | 10748719 |
| hippuric acid as a major excretion product associated with black tea consumption. | 1. nine habitual tea-drinking volunteers were recruited and asked to follow a low-polyphenol and low-caffeine diet for 6 days and to provide daily 24-h urine samples. on day 4 of the experiment strong black tea brewed under standardized conditions was re-introduced to the volunteers' diet. 2. 1h-nmr and hplc profiling of the urine samples indicated that consumption of black tea (6-10 mugs per day) was associated with a significant (p = 0.00017) increase in hippuric acid excretion relative to con ... | 2000 | 10752646 |
| synergistic effects of thearubigin and genistein on human prostate tumor cell (pc-3) growth via cell cycle arrest. | there is evidence that habitual consumption of green tea by japanese men is correlated with a reduction in cancers, including prostate; soybean isoflavones are also associated with increased protection. the present study compared the anti-proliferative effect of black tea (camellia sinensis) polyphenol, thearubigin (tr), alone or combined with the isoflavone genistein, on human prostate (pc-3) carcinoma cells. tr administered alone did not result in any alteration of cell growth. when combined w ... | 2000 | 10766429 |
| correlation of chemopreventive efficacy data from the human epidermal cell assay with in vivo data. | continuous exposure to low doses of potentially mutagenic and carcinogenic chemicals over the human lifetime makes the identification of agents, which could reduce the ensuing risk of cancer, beneficial. the human epidermal cell (hec) assay includes multiple exposures to low, non-toxic doses of propane sultone, which increases cellular growth and inhibits differentiation, and co-exposure to potential chemopreventive agents to determine their ability to inhibit the increased growth or increase di ... | 2000 | 10769631 |
| cancer chemoprevention by tea polyphenols. | tea is one of the most widely consumed beverages, second only to water. many experimental researches in laboratory animals demonstrated that tea components had an inhibitory effect on carcinogenesis at a number of organ sites. the inhibitory effects of tea against carcinogenesis have been attributed to the biologic activities of the polyphenol fraction in tea. this review summarizes experimental data on chemopreventive effects of tea polyphenols in various tumor bioassay systems. many laboratory ... | 2000 | 10786933 |
| sickle cell anemia: a potential nutritional approach for a molecular disease. | a certain population of red blood cells in patients with sickle cell anemia has an elevated density and possesses an abnormal membrane. these "dense cells" have a tendency to adhere to neutrophils, platelets, and vascular endothelial cells, and, thus, they could trigger vasoocclusion and the subsequent painful crisis from which these patients suffer. we developed a laboratory method of preparing such dense cells and found that nutritional antioxidant supplements, hydroxyl radical scavengers, and ... | 2000 | 10793299 |
| tea as a potential chemopreventive agent in phip carcinogenesis: effects of green tea and black tea on phip-dna adduct formation in female f-344 rats. | the heterocyclic amine 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (phip) is formed during the cooking of proteinaceous animal foods (meat, chicken, and fish). phip is a carcinogen in the fischer 344 (f-344) rat; it induces mammary tumors in female rats and lymphomas and colon and prostate tumors in male rats. in f-344 rats, phip forms dna adducts in various organs, including the target organs. inhibition of phip-dna adduct formation is likely to lead to inhibition of phip tumorigenicity. we ... | 2000 | 10798216 |
| acute effects of ingestion of black and green tea on lipoprotein oxidation. | tea has been associated with a reduced risk of cardiovascular disease. one proposed mechanism of this risk reduction involves inhibition of lipoprotein oxidation in vivo by antioxidant polyphenolic compounds derived from tea. however, controlled interventions uniformly failed to show that ingestion of tea can inhibit ldl oxidation ex vivo. the absence of effects in previous studies may be due to the isolation of ldl particles from polyphenolic compounds that are present in the aqueous phase of s ... | 2000 | 10799371 |
| catechin contents of foods commonly consumed in the netherlands. 2. tea, wine, fruit juices, and chocolate milk. | catechins, compounds that belong to the flavonoid class, are potentially beneficial to human health. to enable an epidemiological evaluation of catechins, data on their contents in foods are required. hplc with uv and fluorescence detection was used to determine the levels of (+)-catechin, (-)-epicatechin, (+)-gallocatechin (gc), (-)-epigallocatechin (egc), (-)-epicatechin gallate (ecg), and (-)-epigallocatechin gallate (egcg) in 8 types of black tea, 18 types of red and white wines, apple juice ... | 2000 | 10820090 |
| triterpenoid saponins from the roots of tea plant (camellia sinensis var. assamica). | three olean-12-ene type triterpenoid saponins, named tr-saponins a, b and c, were isolated as methyl esters from tea roots (camellia sinesis var. assamica) after treatment with diazomethane. their structures were established as the methyl esters of 3-o-alpha-l-arabinopyranosyl (1-->3)-beta-d-glucuronopyranosyl-21, 22-di-o-angeloyl-r1-barrigenol-23-oic acid, 3-o-alpha-l-arabinopyranosyl (1-->3)-beta-d-glucuronopyranosyl-21-o-angeloyl-22-o-2-me thylbutanoyl-r1- barrigenol-23-oic acid and 3-o-alpha ... | 2000 | 10820808 |
| tea and other beverage consumption and prostate cancer risk: a canadian retrospective cohort study. | using participants in the 1970-1972 nutrition canada survey (ncs), a retrospective cohort study was conducted to assess the relationship between tea, as well as coffee, cola and alcohol, and the risk of developing prostate cancer. the mortality and cancer experience of male ncs participants aged 50-84 years was determined up to 31 december 1993. among the 3400 survey participants included in the study, 145 developed prostate cancer. no association was observed between tea (predominantly black te ... | 2000 | 10830580 |
| tea polyphenols: prevention of cancer and optimizing health. | the tea plant camellia sinesis is cultivated in >30 countries. epidemiologic observations and laboratory studies have indicated that polyphenolic compounds present in tea may reduce the risk of a variety of illnesses, including cancer and coronary heart disease. most studies involved green tea, however; only a few evaluated black tea. results from studies in rats, mice, and hamsters showed that tea consumption protects against lung, forestomach, esophagus, duodenum, pancreas, liver, breast, colo ... | 2000 | 10837321 |
| comparative study of antioxidant potential of tea with and without additives. | oxidative damage is one of the many mechanism leading to chronic diseases. therefore interest is growing in the protection afforded by antioxidant nutrients against free radical reactions. more recently, the attention has shifted to polyphenols. polyphenols are secondary plant metabolites occurring widely in plant food. they possess outstanding antioxidant properties, suggesting a possible protective role in man. tea (camellia sinensis) is a widely consumed beverage throughout the world containi ... | 2000 | 10846639 |
| reanalysis of blanc pd et al, "use of herbal products, coffee or black tea, and over-the-counter medications as self treatments among adults with asthma". | 2000 | 10887326 | |
| gallic acid metabolites are markers of black tea intake in humans. | gallic acid is one of the main phenolic components of black tea. the objective of this study was to identify urinary gallic acid metabolites with potential for use as markers of black tea intake. in an initial study, nine compounds, assessed by using gas chromatography-mass spectrometry, were found to increase in concentration in urine after 3 cups of black tea over 3 h. a subsequent study employed a controlled crossover design in which 10 subjects consumed 5 cups per day of black tea or water f ... | 2000 | 10888536 |
| electrospray characterization of selected medicinal plant extracts. | extracts of selected medicinal plants were examined by electrospray mass spectrometry (esi-ms). this technique allowed identification of the main components of each extract, thereby providing a typical finger-print of the examined plants. more specifically, anthocyanins (vaccinium myrtillus), isoflavones (glycine max, soybean), flavonol-glycosides and terpenes (ginkgo biloba), triterpenes (centella asiatica), caffeoyl-quinic acids (cynara scolymus, artichoke), ginsenosides (panax ginseng), catec ... | 2000 | 10898155 |
| trolox equivalent antioxidant capacity (teac) of ginkgo biloba flavonol and camellia sinensis catechin metabolites. | 2000 | 10898173 | |
| comparative analysis of tea catechins and theaflavins by high-performance liquid chromatography and capillary electrophoresis. | this paper describes the simultaneous determination of catechins and theaflavins in green and black teas, using reversed-phase high-performance liquid chromatography (hplc) and capillary electrophoresis (ce). the tea polyphenols analyzed included (+)-catechin, catechin gallate, (-)-epicatechin, epicatechin-3-gallate, epigallocatechin, epigallocatechin-3-gallate, theaflavin, theaflavin-3-monogallate, theaflavin-3'-monogallate and theaflavin-3,3'-gallate. these polyphenols together with six other ... | 2000 | 10905726 |
| kombucha, the fermented tea: microbiology, composition, and claimed health effects. | kombucha is a slightly sweet, slightly acidic tea beverage consumed worldwide, but historically in china, russia, and germany. kombucha is prepared by fermenting sweetened black tea preparations with a symbiotic culture of yeasts and bacteria. potential health effects have created an increased interest in kombucha. yet, only a few research studies have shown that kombucha has in vitro antimicrobial activity and enhances sleep and pain thresholds in rats. furthermore, kombucha consumption has pro ... | 2000 | 10914673 |
| tea intake and squamous cell carcinoma of the skin: influence of type of tea beverages. | differences in tea drinking habits are likely to vary by populations and could contribute to the inconsistencies found between studies comparing tea consumption and cancer risk. a population-based case-control study was used to evaluate how usual tea consumption patterns of an older population (n = 450) varied with history of squamous cell carcinoma (scc) of the skin. a detailed tea questionnaire was developed to assess specific tea preparation methods and patterns of drinking. in this southwest ... | 2000 | 10919744 |
| protease from sporosarcina sp. rrlj 1. | protease was isolated from sporosarcina rrlj1 which was collected from acid tea (camellia sinensis) plantations. it showed potential for production of the enzyme for commercial purposes. the study revealed that optimum ph for growth of the organism was 6.5-7 and supplement of casein (1%) in the medium was required for production of protease. enzyme production and enzyme activity was maximum in 72 hr old broth culture. maximum activity of the enzyme was found at ph 6.5. | 2000 | 10927879 |
| tandem mass spectrometry studies of green tea catechins. identification of three minor components in the polyphenolic extract of green tea. | liquid chromatography/electrospray ionization mass and tandem mass spectrometry (ms/ms) techniques were used to identify two minor components and one new compound in the polyphenolic extract of green tea (camellia sinensis). identification and structure assignments were based on previously reported sub-structural features in the ms/ms product, precursor and neutral loss scans of reference samples. the structures of two minor components, related to the known green tea components epicatechin galla ... | 2000 | 10934439 |
| inhibition of ultraviolet b-induced ap-1 activation by theaflavins from black tea. | theaflavins are believed to be key active components in black tea for chemoprevention of cancer. however, the molecular mechanisms underlying the inhibitory effects of theaflavins are not clear. with the jb6 mouse epidermal cell line, we investigated the effects of theaflavins on ultraviolet (uv) b radiation-induced activator protein-1 (ap-1)-dependent transcriptional activation and compared them with (-)-epigallocatechin-3-gallate (egcg), a major green tea polyphenol that has cancer chemopreven ... | 2000 | 10942531 |
| antioxidant potential of green and black tea determined using the ferric reducing power (frap) assay. | tea is one of the most commonly consumed beverages in the world and is rich in polyphenolic compounds collectively known as the tea flavonoids. tea flavonoids possess antioxidant properties in vitro and have been proposed as key protective dietary components, reducing risk of coronary heart disease and some cancers. the present study aimed to evaluate the possible effects of different preparation methods on the antioxidant properties of green and black tea. antioxidant potentials of tea infusate ... | 2000 | 10945114 |
| preparative separation of polyphenols from tea by high-speed countercurrent chromatography. | high-speed countercurrent chromatography (hsccc) was applied to the separation of polyphenols from tea leaves (camellia sinensis l.). the capability of hsccc to isolate pure tea polyphenols from complex mixtures on a preparative scale was demonstrated for catechins, flavonol glycosides, proanthocyanidins, and strictinin from green and black tea. the purity and identity of isolated compounds was confirmed by (1)h nmr and hplc-esi-ms/ms. gram quantities of polyphenols from tea can be isolated with ... | 2000 | 10956128 |
| green tea. | tea is one of the most widely consumed beverages in the world today, second only to water, and its medicinal properties have been widely explored. the tea plant, camellia sinensis, is a member of the theaceae family, and black, oolong, and green tea are produced from its leaves. it is an evergreen shrub or tree and can grow to heights of 30 feet, but is usually pruned to 2-5 feet for cultivation. the leaves are dark green, alternate and oval, with serrated edges, and the blossoms are white, frag ... | 2000 | 10956382 |
| [organochlorine pesticide residues in tea]. | organochlorine pesticides still exist as environmental pollutants in many countries. in this paper, the results of monitoring of organochlorine pesticides in teas taken from the polish market in 1998 year are presented. the monitoring included analysis of organochlorine insecticides and their metabolites (sigma ddt, sigma hch, hcb, heptachlor, epoxide heptachlor, and aldrin) in samples of black and green tea, and fruit tea. the mean concentration of the organochlorine compounds in the black tea ... | 2000 | 10959192 |
| effect of black tea on lipid peroxidation in carbon tetrachloride treated male rats. | this study examined the effects of black tea (camellia sinensis l.) on lipid peroxidation and glutathione levels in carbon tetrachloride (ccl4)-treated male wistar rats. three groups of rats formed two control groups and one treatment group. the control groups were fed with a standard diet, while the black tea group were fed the standard diet plus 6% by weight dried black tea leaves. after two months, the rats in the black tea group and in one control group were administered a single dose of ccl ... | 2000 | 10962644 |
| inhibition of non-haem iron absorption in man by polyphenolic-containing beverages. | the effects of different polyphenol-containing beverages on fe absorption from a bread meal were estimated in adult human subjects from the erythrocyte incorporation of radio-fe. the test beverages contained different polyphenol structures and were rich in either phenolic acids (chlorogenic acid in coffee), monomeric flavonoids (herb teas, camomile (matricaria recutita l.), vervain (verbena officinalis l.), lime flower (tilia cordata mill.), pennyroyal (mentha pulegium l.) and peppermint (mentha ... | 1999 | 10999016 |
| flavonoids protect against oxidative damage to ldl in vitro: use in selection of a flavonoid rich diet and relevance to ldl oxidation resistance ex vivo? | the ability of a range of dietary flavonoids to inhibit low-density lipoprotein (ldl) oxidation in vitro was tested using a number of different methods to assess oxidative damage to ldl. overall quercetin was the most effective inhibitor of oxidative damage to ldl in vitro. on this basis, a diet enriched with onions and black tea was selected for a dietary intervention study that compared the effect on the cu2+ ion-stimulated lag-time of ldl oxidation ex vivo in healthy human subjects of a high ... | 2000 | 11022850 |
| eat to live, not live to eat. | most of the prevailing chronic diseases in the world have an important nutritional component by directly causing a specific disease, enhancing the risk through phenomena of promotion, exerting a beneficial effect in decreasing risk, or preventing the disease. international studies in geographic pathology have shown that a given disease may have vastly different incidence and mortality as a function of residence. laboratory research in animal models can reproduce fairly accurately what is learned ... | 2000 | 11032452 |
| inhibition of 1,2-dimethylhydrazine-induced oxidative dna damage in rat colon mucosa by black tea complex polyphenols. | the effect of black tea polyphenols on 1,2-dimethylhydrazine (dmh)-induced oxidative dna damage in rat colon mucosa has been investigated. fischer 344 rats were treated orally with thearubigin (tr) or theafulvin (tfu) for 10 days (40 mg/kg), injected ip with dmh (20 mg/kg) or saline and sacrificed 24 hr after dmh administration. the levels of 8-hydroxy-2'-deoxyguanosine (8-ohdg) were measured in colonic mucosa dna and expressed as a ratio relative to 2'-deoxyguanosine (2dg). control rat mucosa h ... | 2000 | 11033196 |
| comparison of antioxidant and antimicrobial activities of tilia (tilia argentea desf ex dc), sage (salvia triloba l.), and black tea (camellia sinensis) extracts. | the antioxidant activity of the water extract of tilia argentea desf ex dc was determined by the thiocyanate method. the antioxidant activity of the water extract increased with the increasing amount of lyophilized extract (50-400 microg) added into the linoleic acid emulsion. statistically significant effect was determined in 100 microg and higher amounts. antioxidant activities of water extracts of tilia (tilia argentea desf ex dc), sage (salvia triloba l.), and two turkish black teas commerci ... | 2000 | 11052773 |
| separation and identification of twelve catechins in tea using liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry. | a method has been developed for the direct microscale determination of 12 catechins in green and black tea infusions. the method is based on liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (lc/apci-ms). standard catechin mixtures and tea infusions were analyzed by lc/apci-ms with detection of protonated molecular ions and characteristic fragment ions for each compound. the identities of eight major catechins and caffeine in tea were established based on lc retent ... | 2000 | 11055724 |
| effects of black tea, green tea and wine extracts on intestinal carcinogenesis induced by azoxymethane in f344 rats. | we investigated whether polyphenolic extracts from black tea, green tea or red wine affect azoxymethane (aom)-induced intestinal carcinogenesis. male f344 rats were treated 10 times (1 week apart) with aom (7.4 mg/kg, s.c.) and then allocated into groups receiving black tea, green tea or red wine extracts mixed in the diet at a dose of 50 mg/kg body weight for 16 weeks. in the rats treated with black tea or wine extracts, there were significantly fewer colorectal tumours than in controls (the me ... | 2000 | 11062155 |
| effect of black and green tea polyphenols on c-jun phosphorylation and h(2)o(2) production in transformed and non-transformed human bronchial cell lines: possible mechanisms of cell growth inhibition and apoptosis induction. | the biological activities of theaflavin (tf), theaflavin gallate (tfg) and theaflavin digallate (tfdig) from black tea and (-)-epigallocatechin 3-gallate (egcg) and (-)-epigallocatechin (egc) from green tea were investigated using sv40-immortalized (33bes) and ha-ras gene transformed (21bes) human bronchial epithelial cell lines. growth inhibition and cell viability were measured by trypan blue dye exclusion assay following 24 h treatment with the tea polyphenols. tfdig, egc and egcg displayed c ... | 2000 | 11062165 |
| consumption of black and green tea had no effect on inflammation, haemostasis and endothelial markers in smoking healthy individuals. | firstly, to study the effect of tea and tea polyphenols on cardiovascular risk indicators of the inflammatory system (il6, il1beta and tnf-alpha, crp), and on haemostasis and endothelial proteins with an acute phase behaviour (fibrinogen, vwf, pai-1, fviia and u-pa). secondly, to study the relationship between plasma levels of antioxidants (alpha-tocopherol, beta-carotene and vitamin c) and these acute-phase, cardiovascular risk indicators. | 2000 | 11083483 |
| bioactive saponins and glycosides. xvii. inhibitory effect on gastric emptying and accelerating effect on gastrointestinal transit of tea saponins: structures of assamsaponins f, g, h, i, and j from the seeds and leaves of the tea plant. | following the investigation of assamsaponins a, b, c, d, and e, four new saponins termed assamsaponins f, g, h, and i were isolated from the seeds of the tea plant (camellia sinensis l. var. assamica pierre), while assamsaponin j was isolated from its leaves. the structures of assamsaponins f-j were elucidated on the basis of chemical and physicochemical evidence and found to be 16,22-o-diacetyl-21-o-angeloyltheasapogenol e 3-o-[beta-d-galactopyranosyl (1-->2)][beta-d-glucopyranosyl(1 -->2)- alp ... | 2000 | 11086901 |
| isolation of black tea pigments using high-speed countercurrent chromatography and studies on properties of black tea polymers. | isolation of theaflavins and epitheaflavic acids from black tea using high-speed countercurrent chromatography (hsccc) on a preparative scale is demonstrated. hsccc also enabled the isolation of a polymeric fraction from black tea. according to roberts' classification, the polymeric fraction mainly consisted of sii thearubigins (tr). hplc analysis showed that the isolated material is free of any known chromatographically resolved tea constituents and eluted from reversed-phase packings as a conv ... | 2000 | 11087459 |
| analysis of glycosidically bound aroma precursors in tea leaves. 1. qualitative and quantitative analyses of glycosides with aglycons as aroma compounds. | twenty-six synthetic glycosides constituting aglycons of the main tea aroma compounds ((z)-3-hexenol, benzyl alcohol, 2-phenylethanol, methyl salicylate, geraniol, linalool, and four isomers of linalool oxides) were synthesized in our laboratory as authentic compounds. those compounds were used to carry out a direct qualitative and quantitative determination of the glycosides as aroma precursors in different tea cultivars by capillary gas chromatographic-mass spectrometric (gc-ms) analyses after ... | 2000 | 11087494 |
| inhibitory effects of tea catechins and o-methylated derivatives of (-)-epigallocatechin-3-o-gallate on mouse type iv allergy. | the inhibitory effects of tea catechins, the o-methylated derivatives of (-)-epigallocatechin-3-o-gallate (egcg), and the polyphenol extracts from tea leaves (camellia sinensis l.) on oxazolone-induced type iv allergy in male icr mice were investigated. four major tea catechins and two o-methylated derivatives, (-)-epigallocatechin-3-o-(3-o-methyl)gallate (egcg3' 'me) and (-)-epigallocatechin-3-o-(4-o-methyl)gallate (egcg4' 'me), showed significant inhibitory effects on mouse type iv allergy aft ... | 2000 | 11087533 |
| protection against nitric oxide toxicity by tea. | it is found that green tea and black tea are able to protect against nitric oxide (no(*)) toxicity in several ways. both green tea and black tea scavenge no(*) and peroxynitrite, inhibit the excessive production of no(*) by the inducible form of nitric oxide synthase (inos), and suppress the lps-mediated induction of inos. the no(*) scavenging activity of tea was less than that of red wine. the high activity found in the polyphenol fraction of black tea (btp) could not be explained by the mixed ... | 2000 | 11087552 |
| apolipoprotein e polymorphisms and concentration in chronic diseases and drug responses. | apolipoprotein (apo) e is an important circulating and tissue protein involved in cholesterol homeostasis and many other functions. the common polymorphism in the coding region of the gene, four polymorphisms in the promoter region, other additional single nucleotide polymorphisms, as well as several apo e variants have been identified. the common coding polymorphism strongly influences the lipid metabolism and the circulating concentration of apo e itself. this polymorphism is at the origin of ... | 2000 | 11097338 |
| consumption of black tea elicits an increase in plasma antioxidant potential in humans. | epidemiological studies suggest that the consumption of tea flavonoids may be associated with reduced risk of coronary heart disease, stroke and cancer-related deaths. the flavonoids are polyphenols which in vitro exhibit antioxidant properties. tea flavonoids are known to be rapidly absorbed into the circulation following oral ingestion. to date few studies have demonstrated that these bioavailable flavonoids retain antioxidant properties in vivo. nine healthy subjects aged between 26 and 59 (o ... | 2000 | 11103296 |
| differential effects of theaflavin monogallates on cell growth, apoptosis, and cox-2 gene expression in cancerous versus normal cells. | theaflavin (tf-1), theaflavin-3-monogallate and theaflavin-3'-monogallate mixture (tf-2), and theaflavin-3,3'-digallate (tf-3) are the major black tea polyphenols. here we compared the effects of these polyphenols on cell growth, apoptosis, and gene expression in normal and cancerous cells. we showed that tf-2 (10-50 microm) inhibited the growth of sv40 transformed wi38 human cells (wi38va) and caco-2 colon cancer cells but had little effect on the growth of their normal counterparts. the ic50s ... | 2000 | 11103814 |
| dermatomal pruritus precipitated by drinking excessive quantities of black tea. | 2000 | 11122071 | |
| construction of a genetic linkage map for camellia sinensis (tea). | genetic maps are a vital tool in cultivar improvement programmes for woody perennial tree crops such as tea (camellia sinensis). a population thought to be derived from two known, noninbred parents was scored for rapd and aflp markers, in order to develop a linkage map. however, a very high proportion of the markers exhibited unexpected segregation ratios in the light of their configurations in the parents, and an exploratory statistical analysis revealed patterns in the marker scores which can ... | 2000 | 11122412 |
| the bio-availability of fluoride from black tea. | to investigate the oral retention of fluoride from tea and its association with the tooth surface and acquired pellicle. | 2001 | 11137634 |
| chemical composition and antioxidant activity of strobilanthes crispus leaf extract. | this study investigated the components present in and the total antioxidant activity of leaves of strobilanthes crispus (l.) bremek or saricocalyx crispus (l.) bremek (acanthacea). proximate analyses and total antioxidant activity using ferric thiocyanate and thiobarbituric acid methods were employed. minerals content was determined using the atomic absorption spectrophotometer, whereas the water-soluble vitamins were determined by means of the uv-vis spectrophotometer (vitamin c) and fluorimete ... | 2000 | 11137889 |
| inhibition of human ldl lipid peroxidation by phenol-rich beverages and their impact on plasma total antioxidant capacity in humans. | mounting evidence shows that phenol-rich beverages exert strong antioxidant activity. however, in vivo evidence has produced conflicting results. in the present study, we studied the impact of the ingestion of 300 ml of black and green tea, alcohol-free red wine, alcohol-free white wine, or water on plasma total antioxidant capacity in five healthy volunteers. red wine has the highest content of phenolics (3.63 +/- 0.48 g qe/l), followed by green tea (2.82 +/- 0.07 g qe/l), black tea (1.37 +/- 0 ... | 2000 | 11137897 |
| [amounts of selected minerals in green and black teas]. | the paper contains the results of 19 minerals (ca, k, p, na, mg, zn, fe, mn, cu, f, ni, co, cr, li, sr, al, cd, hg, pb) determined in green and black species of market teas. the examined minerals (except phosphorus, fluoride and mercury) were determined by asa-method using air-acetylene flame (aluminium was determined in the nitrous oxide-acetylene flame). mercury was determined by cold vapour method. the phosphorus and fluoride was determined by spectrophotometry methods (phosphorus in the form ... | 2000 | 11138481 |
| novel approaches to chemoprevention of skin cancer. | protection against sun-induced damage leading to photocarcinogenesis in skin is a highly desirable goal. among various strategies, chemopreventive approaches utilizing non-toxic agents to prevent the occurrence of precancerous lesions or their surrogate markers are potentially attractive. epidemiological and experimental studies provide evidence that some naturally occurring chemical agents in the human diet can diminish cancer risk. aside from water, tea is the most common beverage consumed wor ... | 2000 | 11138532 |
| effect of dietary quercetin on oxidative dna damage in healthy human subjects. | the effect of dietary intake of flavonols (predominantly quercetin) on oxidative dna damage was studied in thirty-six healthy human subjects (sixteen men, twenty women). the study was a randomised crossover study, comprising two 14 d treatments of either a low-flavonol (lf) or high-flavonol (hf) diet with a 14 d wash-out period between treatments. subjects were asked to avoid foods containing flavonols, flavones and flavanols during the lf dietary treatment period and to consume one 150 g onion ... | 2000 | 11177210 |
| green, oolong and black tea extracts modulate lipid metabolism in hyperlipidemia rats fed high-sucrose diet. | the main goal of this study was to compare effects of ethanol-soluble fractions prepared from various types of teas on sucrose-induced hyperlipidemia in 5-week old male sprague-dawley rats. rats (n = 6-8 per group) weighed approximately 200 g were randomly divided into control diet, sucrose-rich diet, green tea, oolong tea and black tea groups. control-diet group was provided with modified ain-93 diet while the others consumed sucrose-rich diet. tea extracts (1% w/v) were supplied in the drink f ... | 2001 | 11179857 |
| black tea extract, thearubigin fraction, counteract the effects of botulinum neurotoxins in mice. | botulinum neurotoxin type a (bont/a, 1.5 nm) completely inhibited indirectly evoked twitches in in vitro mouse phrenic nerve-diaphragm preparations within 40 - 45 min. black tea extract, thearubigin fraction (trb), mixed with bont/a blocked the inhibitory effect of the toxin. the protective effect of trb extended to botulinum neurotoxins types b and e (bont/b and bont/e) and tetanus toxin, but not to tetrodotoxin. trb was also effective against oral toxicity of bont/a, b and e. thus, trb may be ... | 2001 | 11181419 |
| effects of black tea extract on transplantable and solid tumors in swiss albino mice. | the chemopreventive effects of green tea and its polyphenols are well documented in the literature. epidemiological studies have suggested that green tea consumption might be effective in the prevention of certain human cancers. about 80% of the tea is consumed as black tea. limited studies have been carried out to assess the usefulness of black tea as anti-carcinogen. the present set of investigations were initiated to study the anti-tumorigenic potential of aqueous black tea extract (ate) in s ... | 2000 | 11198223 |