| l-theanine, a natural constituent in tea, and its effect on mental state. | tea is the most widely consumed beverage in the world after water. tea is known to be a rich source of flavonoid antioxidants. however tea also contains a unique amino acid, l-theanine that may modulate aspects of brain function in humans. evidence from human electroencephalograph (eeg) studies show that it has a direct effect on the brain (juneja et al. trends in food science & tech 1999;10;199-204). l-theanine significantly increases activity in the alpha frequency band which indicates that it ... | 2008 | 18296328 |
| an exposure and risk assessment for fluoride and trace metals in black tea. | exposure and associated health risks for fluoride and trace metals in black tea were estimated. fifty participants were randomly recruited to supply samples from the tea that they drink, and self-administer a questionnaire that inquired about personal characteristics and daily tea intake. analyzed trace metals included aluminum, arsenic, barium, cadmium, cobalt, chromium, copper, manganese, nickel, strontium, and zinc. fluoride and four metals (al, cr, mn, ni) were detected in all samples while ... | 2008 | 18329795 |
| theaflavin-3-gallate and theaflavin-3'-gallate, polyphenols in black tea with prooxidant properties. | this study compared the in vitro responses of human gingival fibroblasts and of carcinoma cells derived from the tongue to theaflavin-3-gallate (tf-2a) and theaflavin-3'-gallate (tf-2b), polyphenols in black tea. the antiproliferative and cytotoxic effects of the theaflavin monomers were more pronounced to the carcinoma, than to the normal, cells. in phosphate buffer at ph 7.4, the theaflavins generated hydrogen peroxide and the superoxide anion, suggesting that their mode of toxicity may be due ... | 2008 | 18346048 |
| polymeric black tea polyphenols induce phase ii enzymes via nrf2 in mouse liver and lungs. | among tea polyphenols, the anti-initiating properties of polymeric black tea polyphenols (pbps), the most abundant polyphenols in black tea, are poorly elucidated. hence, this study was undertaken to investigate the effects of pbp extract on the induction of phase ii enzymes. pbp extract induced transcriptional up-regulation of phase ii enzymes in liver and lungs by increasing nrf2-mediated antioxidant-responsive element (are) binding. pbp extract did not alter nrf2 or keap1 at the transcription ... | 2008 | 18358244 |
| characteristics of catechin- and theaflavin-mediated cardioprotection. | catechins and theaflavins-the main polyphenolic substances of green and black tea, respectively-exert a plethora of beneficial effects on the cardiovascular system. in a model of h(2)o(2)-mediated oxidative stress, we investigated the effects of epigallocatechin-3-gallate (egcg) and theaflavin-3,3'-digallate (tf3) on neonatal rat cardiomyocytes. pretreatment with egcg or tf3 1 hr prior to induction of oxidative stress by h(2)o(2) effectively protected cardiac myocytes as determined by measuring ... | 2008 | 18367631 |
| levels of selected heavy metals in black tea varieties consumed in saudi arabia. | the metal contents (fe, cu, zn, mn, cr, pb, ni, cd, co) of 17 black tea samples were analyzed by using inductively coupled plasma atomic emission spectroscopy (icp-aes). among the investigated metals mn was the highest (1,071.7 microg/g), whereas pb showed minimum levels (0.30 microg/g). iron was the second highest element found in black tea samples. lowest pb concentration (0.30 microg/g) was found in abu jabal tea; whereas maximum (2.2 microg/g) was found in manasul tea. lowest cd concentratio ... | 2008 | 18373271 |
| a mixture of extracts of black and green teas and mulberry leaf did not reduce weight gain in rats fed a high-fat diet. | tea extracts are used in many over-the-counter preparations claiming to promote weight loss. the rationale for this usage includes reports that green tea extract increases thermogenesis, and extracts of green and black tea and mulberry leaf inhibit the digestion/absorption of carbohydrate and fat. the investigators in this study tested the potential of increasing doses of a mixture of three extracts (50-percent black tea, 20-percent green tea, and 30-percent mulberry) to induce weight loss, stea ... | 2008 | 18377102 |
| nutritional risk factors for the development of hypertension in diabetic patients. | the aim of this cross-sectional study was to determine the significant limitations, sensitivity, specificity, partial correlations, and odds ratios of nutrient intake in patients with and without hypertension with type 2 diabetes mellitus. diabetic patients (n=220) with clinical diagnosis of hypertension and diabetic patients (n=230) without hypertension were included in this study. the questionnaire form included a list of 65 food items formed from five main food groups (grain, meat and alterna ... | 2009 | 18394930 |
| polymeric black tea polyphenols inhibit mouse skin chemical carcinogenesis by decreasing cell proliferation. | the aim of this study was to investigate the antitumour promoting effects and possible mechanisms of action of the most abundant polymeric black tea polyphenols (pbps 1-5) or thearubigins, in vivo. | 2008 | 18400024 |
| evaluation of toxicity of green tea catechins with 90-day dietary administration to f344 rats. | green tea catechins (gtc), polyphenols extracted from the stalks and leaves of camellia sinensis, are found in the different types of tea beverages and as antioxidant additives to many foods, snacks, fats and fatty oils. as a part of their safety assessment, subchronic toxicity was investigated in male and female f344 rats with dietary administration at concentrations of 0 (control), 0.3%, 1.25% and 5.0% for 90 days. the average daily intakes of gtc in each group were 180, 764 and 3525mg/kg body ... | 2008 | 18400353 |
| availability of weight-loss supplements: results of an audit of retail outlets in a southeastern city. | the sale of nonprescription weight-loss products accounts for millions of dollars spent by americans trying to lose weight, yet there is little evidence for effectiveness and there are multiple safety concerns. the purpose of this study was to determine what products, and ingredients within products, were available at retail outlets in a metropolitan area. a purposive sampling strategy identified 73 retail outlets. an audit form was used to collect information from product labels. the audit iden ... | 2006 | 17126636 |
| pharmacological studies on indian black tea (leaf variety) in acute and chronic inflammatory conditions. | infusions of indian black tea (bti), when administered orally, produced significant inhibition of rat paw oedema, induced with carrageenin (pre and post treatment) and arachidonic acid. bti was also found to inhibit peritoneal capillary permeability and caused a marked reduction of lipopolysaccharide induced pge(2) generation. in these models, the observed antioedema effect was similar to that of bw755c (a dual inhibitor of cyclooxygenase and 5-lipoxygenase enzymes). bti was found to scavenge su ... | 2008 | 18446842 |
| the cupric ion reducing antioxidant capacity and polyphenolic content of some herbal teas. | the total antioxidant capacity of the aqueous extracts of some endemic herbs-prepared as infusions by steeping these herbs in hot water--was assayed with bis(neocuproine)copper(ii) chloride, also known as the cupric ion reducing antioxidant capacity (cuprac) reagent, which was easily accessible, rapid, stable and responsive to both hydrophilic and lipophilic antioxidants. the highest antioxidant capacities of some herbal teas available in the turkish market were observed for scarlet pimpernel (a ... | 2006 | 17135020 |
| 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 |
| monitoring the binding processes of black tea thearubigin to the bovine serum albumin surface using quartz crystal microbalance with dissipation monitoring. | the binding processes of thearubigin, which is one of the two major polyphenols (the other one is theaflavin) that gives black tea its characteristic color and taste, to the bovine serum albumin (bsa) surface have been investigated by quartz crystal microbalance with dissipation monitoring (qcm-d). the mass and thickness of the thearubigin adlayer on bsa surfaces at various thearubigin concentrations, salt concentrations, and ph values have been determined by qcm-d using the voigt model. our res ... | 2007 | 18031008 |
| 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 |
| cloning and characterization of a cytosolic glutamine synthetase from camellia sinensis (l.) o. kuntze that is upregulated by aba, sa, and h2o2. | a cdna encoding glutamine synthetase, one of the enzymes of the gs/gogat pathway, was cloned from camellia sinensis (csgs). the isolated cdna consists of 1,071 nucleotides encoding a polypeptide of 356 amino acids with an estimated isoelectric point of 6.13. the recombinant protein purified from escherichia coli using ni-nta affinity chromatography showed molecular mass of 39.2 kda. the purified protein was confirmed by blotting with anti-his antibodies. catalytic parameters of the protein were ... | 2008 | 18074244 |
| effect of black tea brew of camellia sinensis on sexual competence of male rats. | in sri lankan traditional medicine black tea brew (btb) of camellia sinensis (l.) o. kuntze (theaceae) is claimed to have male sexual stimulant activity. as this claim is not scientifically tested and proven, this study was undertaken to evaluate the effects of btb on male sexual competence. | 2008 | 18565706 |
| extract of black tea (pu-ehr) inhibits postprandial rise in serum cholesterol in mice, and with long term use reduces serum cholesterol and low density lipoprotein levels and renal fat weight in rats. | a water-soluble extract of a traditional chinese fermented black tea, pu-ehr, decomposes bile acid cholesterol micelles. this black tea extract (bte) was studied to see if it could decrease the postprandial elevation of blood cholesterol levels after a single administration in ddy mice. it was found that bte (0.3 g/kg) significantly decreased the postprandial rise in blood cholesterol levels after oral administration of cholesterol (130 mg/kg). a non-fermented tea (i.e. green tea) extract did no ... | 2008 | 18570239 |
| assessment of fluoride concentration and daily intake by human from tea and herbal infusions. | the fluoride content in infusions of commercially available black, green, oolong, pu-erh and white teas was determined by ion-selective electrode. herbal infusions as well as instant tea and ready-to-drink tea beverages were also examined. it is found that brewing time (5, 10 and 30 min) does increase the fluoride content, which in infusions of black tea (5 min brewing) was higher than that in the other types of tea, with contents ranging between 0.32 and 4.54 mg/l for black tea to 0.37-0.54 mg/ ... | 2008 | 18078704 |
| epigallocatechin-3-gallate inhibits interleukin-1beta-induced muc5ac gene expression and muc5ac secretion in normal human nasal epithelial cells. | it has been reported that the proinflammatory cytokine interleukin-1beta (il-1beta) induces mucus hypersecretion in normal human nasal epithelial (nhne) cells and that the map kinase pathway may be an important signal pathway in il-1beta-induced muc5ac gene expression. green tea (camellia sinensis) polyphenols are potent anti-inflammatory agents and have been shown to inhibit inflammation in tumor cell lines and cultured respiratory epithelial cells. in this study, we examined the effect of (-)- ... | 2008 | 18155512 |
| differential effects of black versus green tea on risk of parkinson's disease in the singapore chinese health study. | data from asian populations on dietary and lifestyle factors associated with parkinson's disease are sparse. in 1993-2005, the authors examined these factors in relation to parkinson's disease in the singapore chinese health study, a prospective cohort of 63,257 chinese men and women. baseline data were collected through in-person interviews using structured questionnaires. all 157 incident parkinson's disease cases were identified either through follow-up interviews or via linkage with hospital ... | 2008 | 18156141 |
| in vitro mitigation of arsenic toxicity by tea polyphenols in human lymphocytes. | the groundwater arsenicals have brought dreadful misery for the people residing in the endemic regions of west bengal, india. arsenic-related anomalies include arsenicosis, hyperkera-tosis, gastric complications, liver fibrosis, peripheral neuropathy, and cancer. some of these diseases have been frequently associated with overproduction of reactive oxygen species that cause dna damage and improper functioning of body's antioxidant defense mechanism. natural polyphenols present in tea serve as ex ... | 2007 | 18197836 |
| green tea consumption is associated with decreased dna damage among gstm1-positive smokers regardless of their hogg1 genotype. | the levels of tobacco-related dna adducts in human tissues reflect a dynamic process that is dependent on the intensity and time of exposure to tobacco smoke, the metabolic balance between activation of detoxification mechanisms, and the removal of adducts by dna repair and/or cell turnover. urinary 8-hydroxydeoxyguanosine (8-ohdg) is probably 1 of the most abundant dna lesions formed during oxidative stress and is proposed as a sensitive biomarker of the overall oxidative dna damage and repair. ... | 2008 | 18641208 |
| the association between personal habits and bladder cancer in turkey. | in this study, we analyzed the effect of turkish coffee and black tea consumption, alcohol intake and smoking on bladder cancer. | 2008 | 18247151 |
| theaflavin-3,3'-digallate, a component of black tea: an inducer of oxidative stress and apoptosis. | treatment of human oral squamous carcinoma hsc-2 cells and normal gn46 fibroblasts with theaflavin-3,3'-digallate (tf-3), a polyphenol in black tea, showed a concentration and time dependent inhibition of growth, with the tumor cells more sensitive than the fibroblasts. in buffer and in cell culture medium, tf-3 generated reactive oxygen species, with lower levels detected in buffer amended with catalase and superoxide dismutase, indicating the generation of hydrogen peroxide and superoxide, res ... | 2008 | 18248951 |
| salivary hydrogen peroxide produced by holding or chewing green tea in the oral cavity. | tea (camellia sinensis) catechins have been studied for disease prevention. these compounds undergo oxidation and produce h(2)o(2). we have previously shown that holding tea solution or chewing tea leaves generates high salivary catechin levels. herein, we examined the generation of h(2)o(2) in the oral cavity by green tea solution or leaves. human volunteers holding green tea solution (0.1-0.6%) developed salivary h(2)o(2) with c(max) = 2.9-9.6 microm and auc(0 --> infinity) = 8.5-285.3 microm ... | 2007 | 17577746 |
| expression and purification of his-tagged flavonol synthase of camellia sinensis from escherichia coli. | flavonols, a class of bioactive polyphenols present in plants, are the products of flavonol desaturation catalyzed by flavonol synthase (fls). we cloned the cdna coding for the enzyme fls from camellia sinensis (csfls) by end-to-end pcr followed by 5'- and 3'-race. the putative csfls had 333 amino acid residues, displayed identities to the flss of arabidopsis and ginkgo of 53% and 52.5%, respectively, and contained several conserved elements found in the 2-oxoglutarate-fe(ii)-dioxygenase superfa ... | 2007 | 17629496 |
| proteome analysis of tea pollen (camellia sinensis) under different storage conditions. | the protein complement of tea pollen collecting from tea tree (camellia sinensis) was compared under different storage conditions. protein was partially identified using a combination of the 2d-page, maldi-tof/ms, mascot, and xproteo search engine. two hundred and sixty-nine and 396 proteins were detected in pollen stored at room temperature (rt) and -20 degrees c, respectively. forty-three of the identified proteins were assigned to defense-related functions, energy metabolism, cytoskeleton, nu ... | 2008 | 18680303 |
| topographic and radiographic profile assessment of dental erosion. part iii: effect of green and black tea on human dentition. | this study compared green and black tea to soda and orange juice in terms of their erosive effect on the human dentition. vinegar and water were used as active and passive control fluids. an accelerated in vitro test was used to monitor how short- and long-term exposure to these fluids affected the topography and morphology of the coronal segments of the human dentition. this 20-week test was conducted under controlled conditions, independent of the influencing factors of the oral environment. t ... | 2008 | 18683403 |
| effect of genistein on the bioavailability and intestinal cancer chemopreventive activity of (-)-epigallocatechin-3-gallate. | the green tea (camellia sinensis) catechin, (-)-epigallocatechin-3-gallate (egcg), has shown cancer-preventive activity in animal models. previously, we have reported the bioavailability of egcg in rats and mice. here, we report that cotreatment of ht-29 human colon cancer cells with genistein (from soy) increased cytosolic egcg by 2- to 5-fold compared with treatment with egcg only. inclusion of genistein, at non-cytotoxic concentrations, increased the growth inhibitory effects of egcg against ... | 2008 | 18684728 |
| black tea-induced decrease in il-10 and tgf-beta of tumor cells promotes th1/tc1 response in tumor bearer. | several lines of evidence support that impairment of host immune function by tumor may be related to several strategies of tumor escape from immunosurveillance. we found that in ehrlich's ascites carcinoma (eac)-bearing mice, the tumor cells secrete immunosuppressive cytokines, transforming growth factor beta (tgf-beta) and interleukin-10 (il-10) that induce a general t helper cells type 2 (th2) dominance dampening the t cytotoxic cells type 1 (tc1) population. interestingly, black tea at the an ... | 2007 | 17640168 |
| 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 |
| characterisation of lysozyme activity in the in situ pellicle using a fluorimetric assay. | lysozyme is among the most protective enzymes in the pellicle layer. the aim of the present study was to establish a precise fluorimetric assay for determination and characterisation of lysozyme activity immobilised in the initial in situ formed pellicle. for in situ pellicle formation, bovine enamel slabs were fixed on maxillary splints and carried by six subjects for different times (3, 30 min) on buccal and palatal sites. the enzymatic assay was based on hydrolysis of cell walls from micrococ ... | 2009 | 18810509 |
| the effect of green, black and white tea on the level of alpha and gamma tocopherols in free radical-induced oxidative damage of human red blood cells. | the present study was undertaken to investigate the effect of aqueous tea extracts on lipid peroxidation and alpha and gamma tocopherols concentration in the oxidative damage of human red blood cells (rbc). rbc was taken as the model for study of the oxidative damage was induced by cumene hydroperoxide (cumooh). the antioxidative property of leaf green tea, leaf and granulate of black tea and white tea at levels 1, 2, 4 g/150 ml of water were evaluated. the correlation was observed between reduc ... | 2007 | 17665865 |
| amelioration by black tea of sodium fluoride-induced changes in protein content of cerebral hemisphere, cerebellum and medulla oblongata in brain region of mice. | oral administration of sodium fluoride (naf, 6 and 12 mg/kg body weight/day) to swiss strain male albino mice for 30 days caused significant dose-dependant reduction in the content of acidic, basic, neutral, and total protein in cerebral hemisphere, cerebellum and medulla oblongata region of brain. after 30 days of naf treatment, followed by withdrawal of treatment for 30 days, partial but significant amelioration occurred. administration of 2% black tea extract alone for 30 days did not cause a ... | 2007 | 17695144 |
| tea and cancer chemoprevention: a comprehensive review. | dietary components that are capable of inhibiting the growth of cancer cells without affecting the growth of normal cells are receiving considerable attention in developing novel cancer-preventive approaches. tea, made from young leaves and leaf buds of the tea plant, 'camellia sinensis', and the world's second most consumed beverage, has received a great deal of attention both from the general public and the scientific community because tea polyphenols are strong antioxidants, and tea preparati ... | 2007 | 17696725 |
| 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 |
| green and black tea extracts inhibit hmg-coa reductase and activate amp kinase to decrease cholesterol synthesis in hepatoma cells. | recent studies have demonstrated that green and black tea consumption can lower serum cholesterol in animals and in man, and suppression of hepatic cholesterol synthesis is suggested to contribute to this effect. to evaluate this hypothesis, we measured cholesterol synthesis in cultured rat hepatoma cells in the presence of green and black tea extracts and selected components. green and black tea decreased cholesterol synthesis by up to 55% and 78%, respectively, as measured by a 3-h incorporati ... | 2009 | 18926682 |
| 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 regular black tea consumption on tobacco associated dna damage and hpv prevalence in human oral mucosa. | black tea is more widely consumed than green tea worldwide, particularly in india. therefore, it is necessary to focus attention on black tea with respect to its health promoting and anti-cancer actions. in order to establish the concept that black tea is a potential candidate for cancer prevention, it is important to provide epidemiological evidence derived from investigations of human populations. in view of this, the objective of the present study was to determine the correlation between natu ... | 2007 | 17696743 |
| polyphenols as potential indicators for drought tolerance in tea (camellia sinensis l.). | plant polyphenols have gained prominence in quality of plant products and in human health. an experiment was conducted to determine the association of tea polyphenols with water stress and their suitability as indicators for drought tolerance. the experiment was conducted in a 'rain-out' shelter, and consisted of six tea clones (bbk 35, trfk 6/8, trfk 76/1, trfk 395/2, trfk 31/30, and trfk 311/287) and four levels of soil water contents (38, 30, 22, and 14% v/v), which were maintained for a peri ... | 2007 | 17827703 |
| 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 |
| phenolic antioxidants identified by esi-ms from yerba maté (ilex paraguariensis) and green tea (camelia sinensis) extracts. | aqueous extracts of green yerba maté (ilex paraguariensis) and green tea (camellia sinensis) are good sources of phenolic antioxidants, as already described in the literature. the subject of this study were organic extracts from yerba maté, both green and roasted, and from green tea. their phenolic profiles were characterized by direct infusion electrospray insertion mass spectrometry (esi-ms) and their free radical scavenging activity was determined by the dpph assay. organic extracts containin ... | 2007 | 17851401 |
| effect of extraction conditions on measured total polyphenol contents and antioxidant and antibacterial activities of black tea. | black tea was extracted for 2, 8 and 18 h with absolute acetone, n,n-dimethyl-formamide (dmf), ethanol and methanol and their 50% aqueous solutions. the extracts were screened for total polyphenol contents, antioxidant and antibacterial activities. the polyphenol content of the extracts was found to be in the range of 0.44-114.01 mg gallic acid equivalents (gae)/g dry weight tea, depending on the solvent used and the length of the extraction process. in general, aqueous acetone or dmf extracts d ... | 2007 | 17851405 |
| cellular responses and proteomic analysis of escherichia coli exposed to green tea polyphenols. | the purpose of this study was to characterize the cellular response and proteomic analysis of escherichia coli exposed to tea polyphenols (tpp) extracted from korean green tea (camellia sinensis l). tpp showed a dose-dependent bactericidal effect on e. coli. analysis of cell-membrane fatty acids of e. coli cultures treated with tpp identified unique changes in saturated and unsaturated fatty acids, whereas scanning electron microscopic analysis demonstrated the presence of perforations and irreg ... | 2007 | 17874165 |
| inhibitory effects of various beverages on human recombinant sulfotransferase isoforms sult1a1 and sult1a3. | sulfotransferase (sult) 1a1 and sult1a3 play important roles in the presystemic inactivation of beta(2) agonists in the liver and intestine, respectively. the study aimed to investigate the inhibitory effects of grapefruit juice, orange juice, green tea, black tea and oolong tea and their constituents on the activities of sult1a1 and sult1a3. the activities of both sult1a1 and sult1a3 were significantly inhibited by all the beverages investigated at a concentration of 10%. the beverage constitue ... | 2007 | 17876860 |
| 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 |
| molecular mechanism of black tea polyphenols induced apoptosis in human skin cancer cells: involvement of bax translocation and mitochondria mediated death cascade. | theaflavins (tf) and thearubigins (tr) are the most exclusive polyphenols of black tea. even though few previous reports showed the anticancer effects of tf through apoptosis, the potential effect of tr has not been appraised. this study investigated the induction of apoptosis in human skin cancer cells after treatment of tf and tr. we report that both tf and tr could exert inhibition of a431 (human epidermoid carcinoma) and a375 (human malignant melanoma) cell proliferation without adversely af ... | 2008 | 17984116 |
| a major ingredient of green tea rescues mice from lethal sepsis partly by inhibiting hmgb1. | the pathogenesis of sepsis is mediated in part by bacterial endotoxin, which stimulates macrophages/monocytes to sequentially release early (e.g., tnf, il-1, and ifn-gamma) and late (e.g., hmgb1) pro-inflammatory cytokines. our recent discovery of hmgb1 as a late mediator of lethal sepsis has prompted investigation for development of new experimental therapeutics. we previously reported that green tea brewed from the leaves of the plant camellia sinensis is effective in inhibiting endotoxin-indu ... | 2007 | 17987129 |
| effects of green, oolong and black teas and related components on the proliferation and invasion of hepatoma cells in culture. | the effects of teas and related components on the proliferation and invasion of cancer cells were examined by employing both in vitro proliferation and invasion assay systems. powdered green, oolong and black tea extracts dose-dependently inhibited proliferation and invasion of a rat ascites hepatoma cell line of ah109a but did not affect the proliferation of the normal mesentery-derived mesothelial cells (m-cells) isolated from rats; higher concentrations of powdered oolong and black teas could ... | 1999 | 19003122 |
| inhibition of hepatoma cell invasion beneath mesothelial-cell monolayer by sera from tea- and related component-treated rats and their modes of action. | the bioavailability and action of teas on the invasion of a rat ascites hepatoma cell line, ah109a, were determined and their modes of action were by co-culturing the cancer cells with a rat mesentery-derived mesothelial-cell (m-cell) monolayer in the presence of sera from rats orally given teas and their component, (-)-epigallocatechin gallate (egcg). the rat sera obtained 2 and 5 hr after oral intubation of a low concentration of green, oolong, or black tea, or egcg significantly inhibited ah1 ... | 2001 | 19003330 |
| 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 |
| an early gene of the flavonoid pathway, flavanone 3-hydroxylase, exhibits a positive relationship with the concentration of catechins in tea (camellia sinensis). | tea (camellia sinensis (l.) o. kuntze) leaves are a major source of flavonoids that mainly belong to the flavan 3-ols or catechins. apart from being responsible for tea quality, these compounds have medicinal properties. flavanone 3-hydroxylase (f3h) is an abundant enzyme in tea leaves that catalyzes the stereospecific hydroxylation of (2s)-naringenin to form (2r,3r)-dihydrokaempferol. we report a full-length cdna sequence of f3h from tea (csf3h accession no. ay641730). csf3h comprised 1365 bp w ... | 2008 | 18595847 |
| chemoprotective properties of rooibos (aspalathus linearis), honeybush (cyclopia intermedia) herbal and green and black (camellia sinensis) teas against cancer promotion induced by fumonisin b1 in rat liver. | the chemoprotective properties of unfermented and fermented rooibos (aspalathus linearis) and honeybush (cyclopia intermedia) herbal teas, and green and black teas (camellia sinensis) were investigated against fumonisin b1 (fb1) promotion in rat liver utilizing diethylnitrosamine (den) as cancer initiator. the various teas differently affected the clinical chemical parameters associated with liver and kidney damage associated with fb1 suggesting specific fb1/iron/polyphenolic interactions. green ... | 2009 | 19041360 |
| a preconcentration system for determination of copper and nickel in water and food samples employing flame atomic absorption spectrometry. | a separation/preconcentration procedure using solid phase extraction has been proposed for the flame atomic absorption spectrometric determination of copper and nickel at trace level in food samples. the solid phase is dowex optipore sd-2 resin contained on a minicolumn, where analyte ions are sorbed as 5-methyl-4-(2-thiazolylazo) resorcinol chelates. after elution using 1 mol l(-1) nitric acid solution, the analytes are determinate employing flame atomic absorption spectrometry. the optimizatio ... | 2009 | 18620809 |
| green tea (camellia sinensis) attenuates nephropathy by downregulating nox4 nadph oxidase in diabetic spontaneously hypertensive rats. | green tea (gt), through its antioxidant properties, may be useful to treat or prevent human diseases. because several lines of evidence suggest that oxidative stress contributes to the pathogenesis of diabetic nephropathy, we tested the hypothesis that gt prevents diabetes and hypertension-related renal oxidative stress, attenuating renal injury. spontaneously hypertensive rats (shr) with streptozotocin-induced diabetes and nondiabetic shr were treated daily with tap water or freshly prepared gt ... | 2009 | 19056645 |
| 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 |
| the study of antioxidant and anticarcinogenic green tea and black tea. | tea is one of the most popular beverages consumed worldwide. the relationship between tea consumption and human cancer incidence is an important concern. the effect of tea extract and ingredients, polyphenol and caffeine on the mutagenicity of sodium azide was examined in vitro by using salmonella typhimurium ta100, ta98 and ta1535 in the presence of induced rat liver s9 fractions. experimental studies have demonstrated the significant antimutagenic and anticarcinogenic effects of both green and ... | 2007 | 19069905 |
| in vitro assessment of the effectiveness of whitening dentifrices for the removal of extrinsic tooth stains. | this in vitro study evaluated the effectiveness of whitening dentifrices for the removal of extrinsic tooth stains. twenty dental blocks (4 x 4 mm), including enamel and dentine, removed from freshly extracted bovine incisors, were randomly divided into 4 groups: g1--distilled water, g2--colgate, g3--crest extra whitening and g4--rapid white. in all specimens, the dentin was covered with colorless nail polish, and the enamel was left exposed. next, the specimens were immersed in a solution of bl ... | 2008 | 18622478 |
| a review of the epidemiological evidence on tea, flavonoids, and lung cancer. | tea and its main bioactive ingredients, the flavonoids, have been associated with human cancer for several decades. in this article, an overview is provided of observational epidemiological studies of lung cancer incidence in relation to intake of green tea, black tea, flavonols/flavones, and catechins. a pubmed search was conducted in september 2007. articles were selected if they provided risk ratios (relative risk or odds ratio) for lung cancer and were of observational design (cohort, case-c ... | 2008 | 18641207 |
| 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 |
| quality assessment and quantitative analysis of flavonoids from tea samples of different origins by hplc-dad-esi-ms. | components of green tea ( camellia sinensis) have been of considerable interest in recent years because of their potential utility as pharmaceutical agents, particularly for their antioxidant and anticarcinogenic activity. responding to the increasing scientific validation of numerous health benefits of tea, a comprehensive approach was adopted to carry out analysis for the quality assessment of flavonoids in tea samples of different origins. for this purpose, extraction, separation, and mass sp ... | 2008 | 18442252 |
| cloning and differential expression of qm like protein homologue from tea [camellia sinensis (l.) o. kuntze]. | the qm like protein gene encodes for ribosomal protein l10, which is implicated in tumor suppression, transcription factor regulation, and ribosome stability in yeast and mammals. present study describes cloning of a full-length qm cdna (csqm) from tea leaves using differential display of mrna followed by rapid amplification of cdna ends. expression of csqm was studied in leaves of different stages of development and under various external cues. csqm contained an open reading frame of 651 bases, ... | 2009 | 18454353 |
| 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 |
| effect of black tea in diethylnitrosamine-induced esophageal carcinogenesis in mice. | to evaluate the effect of black tea on esophageal carcinogenesis induced by the oral administration of diethylnitrosamine (den). | 2008 | 18641802 |
| [mechanism study of tea pigment on the selective against the colony growth of preneoplastic and normal syrian hamster embryo cells]. | to use co-cultures of she normal and preneoplastic cells in order to study the chemopreventive effects of doses of tea pigment (tp) from black tea on growth, proliferation, apoptosis and related regulation gene expression of normal and preneoplastic she cells. | 2008 | 18646525 |
| cloning of two cdnas encoding a family of atp sulfurylase from camellia sinensis related to selenium or sulfur metabolism and functional expression in escherichia coli. | atp sulfurylase, the first enzyme in the sulfate assimilation pathway of plants, catalyzes the formation of adenosine phosphosulfate from atp and sulfate. here we report the cloning of two cdnas encoding atp sulfurylase (aps1 and aps2) from camellia sinensis. they were isolated by rt-pcr and race-pcr reactions. the expression of aps1 and aps2 are correlated with the presence of atp sulfurylase enzyme activity in cell extracts. aps1 is a 1415-bp cdna with an open reading frame predicted to encode ... | 2008 | 18657428 |
| [chemical studies on plant polyphenols and formation of black tea polyphenols]. | recent biological and pharmacological studies strongly suggested that plant polyphenols in foods, beverages and crude drugs have various health benefits. however, still there are chemically uncharacterized polyphenols, especially those with large molecular weights. the typical example is black tea polyphenols. four tea catechins of fresh tea leaves are enzymatically oxidized in tea fermentation process of black tea manufacture to give a complex mixture of the oxidation products. despite many eff ... | 2008 | 18670177 |
| selective effects of tea extract and its phenolic compounds on human peripheral blood mononuclear cell cytokine secretions. | the effects of black tea extract (bte) and some of its pure phenolics on human peripheral blood mononuclear cell (pbmc) cytokine secretion were examined in vitro. | 2009 | 18686109 |
| 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 |
| differential growth suppression of human melanoma cells by tea (camellia sinensis) epicatechins (ecg, egc and egcg). | we previously reported that catechins of green tea have different antiproliferative effects on cell lines derived from gender-dependent cancers; epicatechin 3-gallate (ecg) had the strongest inhibitory effect. in the present study, we examined the effects of epigallocatechin (egc), epicatechin-gallate (ecg) and egc 3-gallate (egcg) on the viability, density, doubling time and cycle number of cell lines derived from melanoma metastasized to lymph nodes (mb-1133 and se-0154) or distant organs (ch- ... | 2009 | 18955299 |
| biosorption of heavy metals on aspergillus fumigatus immobilized diaion hp-2mg resin for their atomic absorption spectrometric determinations. | a solid phase extraction procedure based on biosorption of copper(ii), lead(ii), zinc(ii), iron(iii), nickel(ii) and cobalt(ii) ions on aspergillus fumigatus immobilized diaion hp-2mg has been investigated. the analytical conditions including amounts of a. fumigatus, eluent type, flow rates of sample and eluent solutions were examined. good recoveries were obtained to the spiked natural waters. the influences of the concomitant ions on the retentions of the analytes were also examined. the detec ... | 2006 | 18970890 |
| 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 |
| column solid-phase extraction of nickel and silver in environmental samples prior to their flame atomic absorption spectrometric determinations. | a biosorption procedure for preconcentration-separation of nickel(ii) and silver(i) at trace levels on bacillus sphaericus-loaded chromosorb 106 (bslc106) has been presented in this work. the conditions like ph, amounts of microorganism, eluent type, etc. for the quantitative adsorption of the analyte ions on bscl106 column were investigated. the analyte ions were quantitatively recovered and desorbed at ph range of 6.0-7.0 and 10 ml of 1m hcl, respectively. the effects of various cationic and a ... | 2009 | 18977595 |
| 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 |
| 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 |
| in vitro and in vivo anti-allergic effects of 'benifuuki' green tea containing o-methylated catechin and ginger extract enhancement. | 'benifuuki', a tea (camellia sinensis l.) cultivar in japan, is rich in anti-allergic epigallocatechin-3-o-(3-o-methyl) gallate (egcg3''me). 'benifuuki' green tea and simultaneous addition of ginger extract remarkably suppressed cytokine (tnf-alpha and mip-1alpha) secretion from mouse bone marrow-derived mast cells after antigen stimulation and, as expected, suppressed delay-type allergy. after drinking 'benifuuki' green tea containing 43.5 mg of egcg and 8.5 mg of egcg3''me, the auc (area under ... | 2007 | 19003003 |
| 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 |
| 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 |
| determination of 8-oxo-2'-deoxyguanosine and creatinine in murine and human urine by liquid chromatography/tandem mass spectrometry: application to chemoprevention studies. | urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodg) represents a non-invasive biomarker for oxidative stress and may be useful for monitoring chemotherapeutic and chemopreventive interventions associated with cancer-related alterations in oxidative stress. we describe the development and validation of two separate liquid chromatography/tandem mass spectrometry (lc/ms/ms) selected reaction monitoring (srm) methods for the determination of 8-oxodg and creatinine in both murine and human urine us ... | 2009 | 19072863 |
| 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 |
| green and black tea are equally potent stimuli of no production and vasodilation: new insights into tea ingredients involved. | epidemiological studies suggest that consumption of tea is associated with beneficial cardiovascular effects. since different types of tea are consumed throughout the world, a question of much interest is whether green tea is superior to black tea in terms of cardiovascular protection. we therefore compared the effects of green and black tea on nitric oxide (no) production and vasodilation and elucidated the tea compounds involved. we chose a highly fermented black tea and determined concentrati ... | 2009 | 19101751 |
| in vitro anti-adhesive activity of green tea extract against pathogen adhesion. | camellia sinensis polysaccharide has been reported to possess anti-adhesive activity against pathogens. the present study was designed to investigate whether hot water extracts obtained from green tea leaves might inhibit pathogen adhesion to human or mouse cell lines. green tea extract-4 (csi-4) with the maximum yield of 4% (w/v) is composed of a major proportion of carbohydrates containing 40% uronic acids, but lack of catechins. it showed strong inhibitory activities against hemagglutination ... | 2009 | 19107860 |
| 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 |
| green tea, black tea consumption and risk of lung cancer: a meta-analysis. | studies investigating the association of green tea and black tea consumption with lung cancer risk have reported inconsistent findings. to provide a quantitative assessment of this association, we conducted a meta-analysis on the topic. studies were identified by a literature search in pubmed from 1966 to november 2008 and by searching the reference lists of relevant studies. summary relative risk (rr) estimates and their corresponding 95% confidence intervals (cis) were calculated based on rand ... | 2009 | 19128856 |
| separation of proanthocyanidins isolated from tea leaves using high-speed counter-current chromatography. | the proanthocyanidin extract from tea (camellia sinensis) leaves was purified for the further study of the biological role of proanthocyanidins in blister blight leaf disease of tea, which is caused by the fungus exobasidium vexans. an aqueous acetone extract of proanthocyanidins prepared from healthy tea leaves was partially purified using sephadex lh-20 chromatography. the crude proanthocyanidin extract obtained was fractionated with high-speed counter-current chromatography (hsccc) using the ... | 2009 | 19136115 |
| in vitro comparison of visual and computer-aided pre- and post-tooth shade determination using various home bleaching procedures. | due to inter- and intraexaminer differences, subjective evaluation of tooth color is deemed problematic. | 2009 | 19167533 |
| in vitro inhibition of helicobacter pylori urease with non and semi fermented camellia sinensis. | helicobacter pylori is the etiological agent in duodenal and peptic ulcers. the growing problem of antibiotic resistance by the organism demands the search for novel compounds, especially from natural sources. this study was conducted to evaluate the effect of camellia sinensis extracts on the urease enzyme that is a major colonization factor for h. pylori. | 2009 | 19172056 |
| the ameliorative effect of black tea extract and quercetin on bisphenol a-induced cytotoxicity. | the purpose of our study was, to explore the possible ameliorating effects of black tea extract and quercetin, against bisphenol a-induced cytotoxicity. for this, human red blood corpuscles (rbc) were taken as the model. blood samples collected in edta vials from healthy adults were used for preparation of rbc suspension. this suspension was treated with bisphenol a (0-150 microg/ml) with and without black tea extract or quercetin (0-200 microg/ml). the results showed that addition of bisphenol ... | 2009 | 19226967 |
| [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 |
| green and black tea consumption and risk of stroke: a meta-analysis. | experimental models of stroke provide consistent evidence of smaller stroke volumes in animals ingesting tea components or tea extracts. to assess whether a similar association of black or green tea consumption with reduced risk is evident in human populations, we sought to identify and summarize all human clinical and observational data on tea and stroke. | 2009 | 19228856 |