Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| oxidative coupling of the pyrogallol b-ring with a galloyl group during enzymatic oxidation of epigallocatechin 3-o-gallate. | in order to clarify the mechanism for formation of catechin oligomers during the fermentation stage of black tea manufacture, epigallocatechin-3-o-gallate, the most abundant tea flavanol in fresh tea leaves, was enzymatically oxidized and the resulting unstable quinone metabolites were converted to phenazine derivatives by treatment with o-phenylenediamine. in addition to formation of monomeric and dimeric derivatives, four trimeric derivatives were isolated whose structures were determined by a ... | 2007 | 17320123 |
| antioxidant capacity of 55 medicinal herbs traditionally used to treat the urinary system: a comparison using a sequential three-solvent extraction process. | the prevalence of chronic renal disease exceeds 10% in industrialized societies. oxidative damage is thought to be one of the main mechanisms involved in nearly all chronic renal pathologies. | 2014 | 17309384 |
| dissipation kinetics of spiromesifen on tea (camellia sinensis) under tropical conditions. | spiromesifen (oberon) is a new insecticide and miticide of chemical class ketoenol active against white flies (bemisia spp., trialeuroides spp.) and spider mites (tetranychus and panonychus spp.). due to its potential significance in insect resistance management, it is important to establish its behaviour on crop and environment. in the present study, the degradation/dissipation of spiromesifen on tea crop under tropical environmental conditions was studied and its dt(50) (t(1/2)), and dt(90) (t ... | 2007 | 17307225 |
| compositional analysis and preliminary toxicological evaluation of a tea polysaccharide conjugate. | tea polysaccharide conjugate is one of the main bioactive constituents of tea (camellia sinensis l.). the chemical composition and preliminary toxicological evaluation of a tea polysaccharide conjugate was investigated to determine the possibility of using it for human consumption. chemical analysis of tea polysaccharide conjugate showed that the tea polysaccharide conjugate was a nonstarch protein bounded acidic polysaccharide. the protein, neutral sugar, and uronic acid content of the tea poly ... | 2007 | 17305361 |
| thea sinensis melanin prevents cisplatin-induced nephrotoxicity in mice. | the preventive effect of thea sinensis melanin (tsm) against cisplatin-induced nephrotoxicity was studied on icr mice. animals were given 20mg/kg i.p. of cisplatin, and tsm was injected i.p. in doses 10-40 mg/kg 2h before intoxication. the protective effects were evidenced by a complete inhibition of the cisplatin-induced elevation of serum blood urea nitrogen (bun), prevention of oxidative stress, and complete blockade of cisplatin-induced elevation of serum creatinine. tsm by itself, however, ... | 2007 | 17303299 |
| black tea prevents cigarette smoke-induced apoptosis and lung damage. | cigarette smoking is a major cause of lung damage. one prominent deleterious effect of cigarette smoke is oxidative stress. oxidative stress may lead to apoptosis and lung injury. since black tea has antioxidant property, we examined the preventive effect of black tea on cigarette smoke-induced oxidative damage, apoptosis and lung injury in a guinea pig model. | 2007 | 17300721 |
| consumption of black tea or coffee and risk of ovarian cancer. | the goal of this study was to investigate the associations between ovarian cancer risk and usual consumption of black tea, regular coffee, or decaffeinated coffee. using a hospital-based case-control design, participants included 414 women with primary epithelial ovarian, fallopian, or peritoneal cancer and 868 age- and region-matched women with nonneoplastic conditions. all participants completed a comprehensive epidemiologic questionnaire. black tea consumption was associated with a linear dec ... | 2013 | 17291231 |
| evaluation of the astringency of black tea by a taste sensor system: scope and limitation. | grading the astringency of black tea by a taste sensor system was studied. the black tea samples manufactured in india and sri lanka were classified into ten steps on the basis of two standard solutions (0.65 mm and 0.26 mm egcg aqueous solutions). an organoleptic test demonstrated that the sensor output was correlative to the human gustatory sense. | 2007 | 17284831 |
| [studies on tea plants (camellia sinensis) germplasms using est-ssr marker]. | forty two tea varieties were analyzed by using 16 ssr primer sets derived from tea ests in this study, and 13 of the primer sets produced clear bands and 10 of them showed polymorphism, accounting for 76.9%. the pic (polymorphism information content) for each polymorphic primer set varied from 0.522 to 0.866, with a average about 0.73. totally 84 genotypes and 74 alleles were detected in all materials by 10 polymorphic markers, with the range from 4 to 12 and from 3 to 10 for each polymorphic pr ... | 2007 | 17284433 |
| bioactive saponins and glycosides. xxviii. new triterpene saponins, foliatheasaponins i, ii, iii, iv, and v, from tencha (the leaves of camellia sinensis). | new triterpene saponins, foliatheasaponins i-v, were isolated from the methanolic extract of tencha [the leaves of camellia sinensis (l.) o. kuntze (theaceae)]. the chemical structures of these new saponins were elucidated on the basis of chemical and physicochemical evidence. among the new saponins, foliatheasaponins ii and iii, were found to inhibit release of beta-hexosaminidase, as a marker of antigen-induced degranulation, in rbl-2h3 cells. | 2007 | 17268104 |
| fatty acids in tea shoots (camellia sinensis (l.) o. kuntze) and their effects on the growth of retinal rf/6a endothelial cell lines. | chemo-protective effects of tea on ocular diseases were recorded in chinese pharmacopoeia about 2000 years ago by eating tea. in the present study, contents of fatty acids (fas) in tea shoots were determined by capillary gc; and the growth of rf/6a cells was also investigated by exposure to various representative fas existing in tea shoots with pathologically relevant concentrations (40-500 microm) by ameliorated mtt assay and flow cytometry. electron spin resonance (esr) was used to measure oxy ... | 2007 | 17262883 |
| in vitro evaluation of the anticancer effect of lactoferrin and tea polyphenol combination on oral carcinoma cells. | we investigated the anticancer effects of green and black tea polyphenols alone and in combination with bovine milk lactoferrin (blf) on human tongue squamous carcinoma (cal-27) and normal human gingival fibroblast (hgf) cells. both green (polyphenon-e;p-e) and black tea polyphenols (polyphenon-b;p-b) preferentially inhibit the growth of cal-27 cells in a dose-dependent manner. based on the ic(50) values, p-e was found to be more effective than p-b and the combination of p-e and blf (1:2 ratio) ... | 2007 | 17258915 |
| black tea polyphenols restrict benzopyrene-induced mouse lung cancer progression through inhibition of cox-2 and induction of caspase-3 expression. | lung cancer is one of the leading causes of cancer related death in most developed and many developing countries of the world. due to lack of validated screening methods and poor prognosis, treatment of lung cancer has not improved significantly over the last two decades. therefore the risk of the disease needs to be minimized by preventive measures. one approach for lung cancer prevention envisages reversal or restriction of precancerous lesions by chemopreventive intervention. it demands a dee ... | 2006 | 17250449 |
| tea and cancer prevention: molecular mechanisms and human relevance. | tea made from the leaves of the plant camellia sinensis is a popular beverage. the possible cancer-preventive activity of tea and tea polyphenols has been studied extensively. this article briefly reviews studies in animal models, cell lines, and possible relevance of these studies to the prevention of human cancer. the cancer-preventive activity of tea constituents have been demonstrated in many animal models including cancer of the skin, lung, oral cavity, esophagus, stomach, liver, pancreas, ... | 2007 | 17234229 |
| structure-activity relationships of tea compounds against human cancer cells. | the content of the biologically active amino acid theanine in 15 commercial black, green, specialty, and herbal tea leaves was determined as the 2,4-dinitrophenyltheanine derivative (dnp-theanine) by a validated hplc method. to define relative anticarcinogenic potencies of tea compounds and teas, nine green tea catechins, three black tea theaflavins, and theanine as well as aqueous and 80% ethanol/water extracts of the same tea leaves were evaluated for their ability to induce cell death in huma ... | 2007 | 17227049 |
| addition of milk prevents vascular protective effects of tea. | experimental and clinical studies indicate that tea exerts protection against cardiovascular diseases. however, a question of much debate is whether addition of milk modifies the biological activities of tea. we studied the vascular effects of tea, with or without milk, in humans and elucidated the impact of individual milk proteins in cell culture experiments, with isolated rat aortic rings and by hplc analysis. | 2007 | 17213230 |
| green tea [camellia sinensis (l.) o. kuntze] extract reverses the despair behaviour in reserpinised and diabetic mice. | green tea (c. sinensis) extract (gte) dose dependently produced reversal of despair in normal, reserpinised and diabetic mice, thereby demonstrating an antidepressant effect. although the exact mechanism is yet to be explored, the possible inhibition of catechol-o-methyl transferase and monoamine oxidase enzymes may be responsible for antidepressant activity of gte. | 2006 | 17205714 |
| effect of nitrogen form and root-zone ph on growth and nitrogen uptake of tea (camellia sinensis) plants. | tea (camellia sinensis) is considered to be acid tolerant and prefers ammonium nutrition, but the interaction between root zone acidity and n form is not properly understood. the present study was performed to characterize their interaction with respect to growth and mineral nutrition. | 2007 | 17204540 |
| interactions between smoking and other exposures associated with lung cancer risk in women: diet and physical activity. | the objective of the study is to estimate the differences in the impact of diet and physical exercise on lung cancer risk in female nonsmokers vs. smokers, and reveal interactions, if any. in a hospital based case-control study, data collected by in-person interviews from 569 female lung cancer cases and 2120 controls were analyzed using unconditional logistic regression stratifying by appropriate factors. protective effects were observed for intake of milk/dairy products (or=0.57, 95%ci 0.35-0. ... | 2007 | 17203897 |
| black tea ameliorates aflatoxin-induced lipid peroxidation in the kidney of mice. | oral administration of 25 and 50 mg of aflatoxin in 0.2 ml olive oil/animal/day for 30 days caused dose-dependent and significantly higher lipid peroxidation in the kidney of aflatoxin-treated mice than in the controls. the levels of non-enzymatic antioxidant such as glutathione as well as the enzymatic antioxidants such as superoxide dismutase, glutathione peroxidase and catalase were significantly lower in the kidney of aflatoxin-treated mice than in the controls. black tea extract (2%) treatm ... | 2006 | 17203869 |
| bioactive saponins and glycosides. xxv. acylated oleanane-type triterpene saponins from the seeds of tea plant (camellia sinensis). | seven new acylated oleanane-type triterpene oligoglycosides, theasaponins a(4) (1), a(5) (2), c(1) (3), e(8) (4), e(9) (5), g(1) (6), and h(1) (7), were isolated from the seeds of japanese tea plant (camellia sinensis). the structures of 1-7 were elucidated on the basis of chemical and physicochemical evidence. | 2007 | 17202702 |
| overview of antibacterial, antitoxin, antiviral, and antifungal activities of tea flavonoids and teas. | tea leaves produce organic compounds that may be involved in the defense of the plants against invading pathogens including insects, bacteria, fungi, and viruses. these metabolites include polyphenolic compounds, the six so-called catechins, and the methyl-xanthine alkaloids caffeine, theobromine, and theophylline. postharvest inactivation of phenol oxidases in green tea leaves prevents oxidation of the catechins, whereas postharvest enzyme-catalyzed oxidation (fermentation) of catechins in tea ... | 2007 | 17195249 |
| [the roots of cha and gambir]. | this article attempts to trace the origin of tea. the author believes the ancient chinese tea, "chia", is either jicha (water extract from the pith of acacia catechu that grows naturally in the mountainous border between the yunnan province of china and southern asian countries) or jicha-kagikazura (water extract from the young branches and leaves of uncaris gambir, originally found in india/sri lanka). both were pulverized after being kiln-dried and then mixed with water to produce a thick susp ... | 2005 | 17152831 |
| protective effect of black and green tea against carbon tetrachloride-induced oxidative stress in rats. | to assess the effects of green and black tea on carbon tetrachloride (ccl4)-induced oxidative stress in rats. | 2006 | 17143353 |
| the effects of tea extracts on proinflammatory signaling. | skin toxicity is a common side effect of radiotherapy for solid tumors. its management can cause treatment gaps and thus can impair cancer treatment. at present, in many countries no standard recommendation for treatment of skin during radiotherapy exists. in this study, we explored the effect of topically-applied tea extracts on the duration of radiation-induced skin toxicity. we investigated the underlying molecular mechanisms and compared effects of tea extracts with the effects of epigalloca ... | 2006 | 17140430 |
| 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 |
| reduction of ciclosporin and tacrolimus nephrotoxicity by plant polyphenols. | the immunosuppressants ciclosporin (cyclosporin a, csa) and tacrolimus can cause severe nephrotoxicity. since csa increases free radical formation, this study investigated whether an extract from camellia sinensis, which contains several polyphenolic free radical scavengers, could prevent nephrotoxicity caused by csa and tacrolimus. rats were fed powdered diet containing polyphenolic extract (0-0.1%) starting 3 days before csa or tacrolimus. free radicals were trapped with alpha-(4-pyridyl-1-oxi ... | 2006 | 17132217 |
| 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 |
| age-related variations in flavonoid intake and sources in the australian population. | to estimate flavonoid intake in the australian population. | 2006 | 17125569 |
| black tea polyphenols protect against 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis. | dietary chemoprevention has emerged as a cost-effective approach for cancer control. we evaluated the chemopreventive effects of black tea polyphenols (polyphenon-b) administration during the preinitiation phase of 7,12-dimethylbenz[a]anthracene (dmba)-induced hamster buccal pouch (hbp) carcinogenesis. the expression of proliferating cell nuclear antigen (pcna) in the buccal pouch and the concentration of lipid peroxides, protein carbonyl, and the antioxidant status in the buccal pouch, liver an ... | 2006 | 17120615 |
| inhibition of folic acid uptake by catechins and tea extracts in caco-2 cells. | in this present study it was aimed to determine whether the catechins contained in green tea and the whole extracts of camellia sinensis (theaceae) inhibit the uptake of folic acid by caco-2 cell monolayers. our results indicate that (-)-epigallocatechin 3-gallate (egcg) and (-)-epicatechin 3-gallate (ecg) inhibit cellular folic acid uptake with ic50 values of 34.8 micromol/l and 30.8 micromol/l, respectively. furthermore, green and black tea extracts were also found to inhibit folic acid uptake ... | 2007 | 17117344 |
| the screening analysis of antiradical activity of some plant extracts. | there is a need for screening studies in order to select plant extracts or plant raw materials with strong antiradical activity which could be used as medicines or substances to protect food from oxidation. in this paper the antiradical activities of some plant raw materials were investigated. | 2006 | 17115006 |
| potential health benefits of green tea (camellia sinensis): a narrative review. | 2013 | 17113495 | |
| trapping reactions of reactive carbonyl species with tea polyphenols in simulated physiological conditions. | the carbonyl stress that leads to the formation of advanced glycation end products (ages) in diabetes mellitus has drawn much attention recently. reactive alpha-dicarbonyl compounds, such as glyoxal (go) and methylglyoxal (mgo), have been shown to be a high potential glycation agent in vitro and in vivo. in this study, epicatechins in green tea and theaflavins in black tea were found to be able to reduce the concentration of mgo in physiological phosphate buffer conditions. modified mgo derivati ... | 2006 | 17103374 |
| inhibition of pathogenic bacterial adhesion by acidic polysaccharide from green tea (camellia sinensis). | an acidic polysaccharide cs-f2 from camellia sinensis was examined to characterize its anti-adhesive effects against pathogenic bacteria, most notably helicobacter pylori, propionibacterium acnes, and staphylococcus aureus. cs-f2 showed marked inhibitory activity against the pathogen-mediated hemagglutination with a minimum inhibitory concentration (mic) between 0.01 and 0.1 mg/ml, which is lower than the previously reported mic values for panax ginseng and artemisia capillaris. the inhibitory e ... | 2006 | 17090112 |
| manufacture of a beverage from cheese whey using a "tea fungus" fermentation. | kombucha is a sour beverage reported to have potential health effects prepared from the fermentation of black tea and sugar with a "tea fungus", a symbiotic culture of acetic acid bacteria and yeasts. although black tea is the preferred substrate for kombucha fermentation, other beverages have also been tested as substrates with fair results. cheese whey is a by-product with a good amount of fermentable lactose that has been used before in the production of beverages, so the objective of this st ... | 2003 | 17061515 |
| membrane filtration - atomic absorption spectrometry combination for copper, cobalt, cadmium, lead and chromium in environmental samples. | cellulose nitrate membrane filter was used for the preconcentration-separation of cu, co, cd, pb and cr ions. the analyte ions were collected on the membrane filter by the aid of carmine. then membrane filter was dissolved by using nitric acid. the levels of the analytes in the final solutions were determined by flame atomic absorption spectrometry (faas). the analytical parameters including ph, amounts of carmine, sample volumes etc. have been optimized. no influences have been observed from th ... | 2007 | 17058008 |
| efficacy of 12 weeks supplementation of a botanical extract-based weight loss formula on body weight, body composition and blood chemistry in healthy, overweight subjects--a randomised double-blind placebo-controlled clinical trial. | the aim of this study was to evaluate the efficacy and safety of composite extracts in reducing weight, as the main outcome measure. secondary measures of the study were body composition change. | 2006 | 17052970 |
| green tea and skin cancer: photoimmunology, angiogenesis and dna repair. | human skin is constantly exposed to numerous noxious physical, chemical and environmental agents. some of these agents directly or indirectly adversely affect the skin. cutaneous overexposure to environmental solar ultraviolet (uv) radiation (290-400 nm) has a variety of adverse effects on human health, including the development of melanoma and nonmelanoma skin cancers. therefore, there is a need to develop measures or strategies, and nutritional components are increasingly being explored for th ... | 2007 | 17049833 |
| in vivo and in vitro effects of tea extracts on enterotoxigenic escherichia coli-induced intestinal fluid loss in animal models. | enterotoxigenic escherichia coli (etec) infection is a major cause of dehydrating diarrhoea in infants and early-weaned piglets living under subhygienic conditions. we studied the effect of different tea types and subfractions on the intestinal fluid and electrolyte losses involved in etec diarrhoea. | 2006 | 17033520 |
| [impact of green tea on oxidative stress induced by ammonium metavanadate exposure in male rats]. | transitional metals, as vanadium, are known to exert noxious effects by generating oxidative stress. addition of antioxidants in the diet could decrease the cytotoxic effect related to the oxidative stress. the present study, carried out in wistar rats, is a contribution to the evaluation of protective effects of green tea camellia sinensis, which is known to be rich in antioxidant compounds (polyphenols...). rats were divided into four groups: (c) was control, (v) was given ammonium metavanadat ... | 2006 | 17027638 |
| glucose-lowering effect of powder formulation of african black tea extract in kk-a(y)/tajcl diabetic mouse. | we observed the suppressive effect of a powder formulation of african black tea extract prepared from the leaves of camellia sinensis on type 2 non-insulin dependent diabetic mice, kk-a(y)/tajcl. black tea extract significantly showed suppressive effect of the elevation of blood glucose on oral glucose tolerance test of 8 week-old kk-a(y)/tajcl mice (p < 0.05). long-term treatment with black tea extract showed significant suppression of post-prandial blood glucose and obesity (p < 0.05). the wei ... | 2006 | 17024853 |
| molecular targets of tea polyphenols in the cardiovascular system. | tea-derived polyphenols have attracted considerable attention in the prevention of cancer and cardiovascular diseases. in comparison to tumour cells, the elucidation of their molecular targets in cardiovascular relevant cells is still at the beginning. although promising experimental and clinical data demonstrate protective effects for the cardiovascular system, little information is actually available on how these beneficial effects of tea polyphenols are mediated at the cellular level. by affe ... | 2007 | 17020753 |
| mechanisms of cancer prevention by green and black tea polyphenols. | drinking green tea is associated with decreased frequency of cancer development. this review outlines the wide range of mechanisms by which epigallocatechin gallate (ecgc) and other green and black tea polyphenols inhibit cancer cell survival. egcg suppressed androgen receptor expression and signalling via several growth factor receptors. cell cycle arrest or apoptosis involved caspase activation and altered bcl-2 family member expression. egcg inhibited telomerase activity and led to telomere f ... | 2006 | 17017850 |
| pro-oxidative effects of tea and polyphenols, epigallocatechin-3-gallate and epigallocatechin, on g6pd-deficient erythrocytes in vitro. | glucose-6-phosphate dehydrogenase (g6pd)-deficient subjects are vulnerable to chemical-induced hemolysis if exposed to oxidative agents. recent studies reported that green tea and its constituents might act as pro-oxidants. our objective was to investigate effects of tea and its polyphenolic components on the oxidative status of human g6pd-deficient erythrocytes. erythrocytes of g6pd-deficient (n = 8) and normal (n = 8) subjects were incubated with water extracts of 3 types of tea samples (black ... | 2006 | 17016632 |
| the effects of tea on psychophysiological stress responsivity and post-stress recovery: a randomised double-blind trial. | tea has anecdotally been associated with stress relief, but this has seldom been tested scientifically. | 2007 | 17013636 |
| assessment of the polyphenolic composition of the organic extracts of mauritian black teas: a potential contributor to their antioxidant functions. | there is increasing interest in the emerging view that tea improves the antioxidant status in vivo and thereby helps to lower risk of certain types of cancer, coronary heart disease and stroke and its component biofactors could provide prophylactic potential for these diseases. the polyphenolic composition and the antioxidant properties of organic extracts (acetone/methanol) of mauritian commercial black teas were evaluated. hplc data of the individual compounds revealed remarkably high levels ( ... | 2006 | 17012766 |
| the effects of chronic tea intake on platelet activation and inflammation: a double-blind placebo controlled trial. | tea drinking appears to protect against the development of coronary heart disease (chd), but the mediating pathways are uncertain. we studied the effects of 6 weeks of black tea or placebo on platelet activation, c-reactive protein (crp), total antioxidant status, and soluble (s) p-selectin in a randomized double-blind trial. | 2007 | 17010979 |
| enhancement of erythrocyte antioxidants by green and black tea polyphenols during 7,12-dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis. | we evaluated the comparative chemopreventive efficacy of green tea polyphenols (polyphenon-e) and black tea polyphenols (polyphenon-b) on 7,12-dimethylbenz[a]anthracene (dmba)-induced hamster buccal pouch (hbp) carcinogenesis. lipid peroxidation, reduced and oxidized glutathione (gsh and gssg, respectively), and the gsh-dependent enzymes glutathione peroxidase and glutathione s-transferase in the erythrocytes were used as biomarkers of chemoprevention. enhanced lipid peroxidation in erythrocytes ... | 2006 | 17004901 |
| peracetylation as a means of enhancing in vitro bioactivity and bioavailability of epigallocatechin-3-gallate. | (-)-epigallocatechin-3-gallate (egcg) is the widely studied catechin in green tea (camellia sinensis). previously, we have reported the low bioavailability of egcg in rats and mice. as a means of improving the bioavailability of egcg, we have prepared a peracetylated egcg derivative (acegcg) and herein report its growth inhibitory activity and cellular uptake in vitro, as well as bioavailability in mice. acegcg exhibited enhanced growth inhibitory activity relative to egcg in both kyse150 human ... | 2006 | 16997910 |
| phenolic acids in berries, fruits, and beverages. | the contents of soluble and total phenolic acids were analyzed in samples of 29 berries and berry products, 24 fruits and fruit peels, and 12 beverages. variation of phenolic acids in berries was also studied. soluble phenolic acids were extracted with methanolic acetic acid, and a tentative quantification was performed by high-performance liquid chromatography (hplc). the total phenolic acid content was determined by hplc after alkaline and acid hydrolyses. the content of total phenolic acids a ... | 2006 | 16968082 |
| differentially expression of tua1, a tubulin-encoding gene, during flowering of tea plant camellia sinensis (l.) o. kuntze using cdna amplified fragment length polymorphism technique. | the complementary dna (cdna) amplified fragment length polymorphism technique was used to isolate transcript-derived fragments corresponding to genes involved in the flowering of tea plant. comparative sequence analysis of an approximately 300 bp differential fragment amplified by primer combination e11m11 revealed 80%-84% similarity to the corresponding part of an a-tubulin gene of other species. the complete cdna sequence of this a-tubulin was cloned by the rapid amplification of cdna ends tec ... | 2006 | 16953305 |
| a comparative study on the antimutagenic properties of aqueous extracts of aspalathus linearis (rooibos), different cyclopia spp. (honeybush) and camellia sinensis teas. | antimutagenic activity of aqueous extracts of the south african herbal teas, aspalathus linearis (rooibos) and cyclopia spp. (honeybush) was compared with that of camellia sinensis (black, oolong and green) teas in the salmonella mutagenicity assay using aflatoxin b(1) (afb(1)) and 2-acetylaminofluorene (2-aaf) as mutagens. the present study presents the first investigation on antimutagenic properties of c. subternata, c. genistoides and c. sessiliflora. the herbal teas demonstrated protection a ... | 2006 | 16949333 |
| determination of trace elements in herbal tea products and their infusions consumed in thailand. | nineteen elements, mg, al, ca, v, cr, mn, fe, co, ni, cu, zn, se, sr, sb, ba, as, cd, hg, and pb, were determined in three types of popular herbal tea products, gynostemma pentaphyllum, camellia sinensis, and morus alba. these herbal tea products, both imported and locally made products, are widely consumed in thailand and worldwide. microwave-assisted acid digestion was used for all of the samples, and the element contents were determined by icp-ms. the concentrations of all elements varied amo ... | 2006 | 16939361 |
| metabonomics approach to determine metabolic differences between green tea and black tea consumption. | the purpose of this study was to compare the effects of black and green tea consumption on human metabolism. seventeen healthy male volunteers consumed black tea, green tea, or caffeine in a randomized crossover study. twenty-four-hour urine and blood plasma samples were analyzed by nmr-based metabonomics, that is, high-resolution 1h nmr metabolic profiling combined with multivariate statistics. green and black tea consumption resulted in similar increases in urinary excretion of hippuric acid a ... | 2006 | 16939360 |
| high-throughput analysis of catechins and theaflavins by high performance liquid chromatography with diode array detection. | increased interest in potential health-protective activities of flavonoid-rich tea has created the need to take advantage of hplc column and system advances in order to optimize methodologies for flavonoid analysis. two new rp-c18 methods for hplc-dad analysis of tea flavonoids were developed to facilitate separation of catechins within 5 min and separation of catechins and theaflavins within 10 min total analysis time. calibration results indicate that these methods have on-column limits of det ... | 2006 | 16919286 |
| adsorption of chlorhexidine and black tea onto in vitro salivary pellicles, as studied by ellipsometry. | the adsorption from 0.2% (w/w) chlorhexidine and black tea solutions onto an in vitro pellicle from whole unstimulated saliva on hydroxyapatite discs was studied by ellipsometry. it was found that chlorhexidine adsorbed to the pellicle and caused a modification of the pellicle properties, leading to a subsequent increase in adsorption of salivary and black tea components. there was a distinct order-of-addition effect, whereby chlorhexidine followed by black tea gave an overall greater adsorption ... | 2006 | 16911105 |
| correlation between the in vitro antioxidant activity and polyphenol content of aqueous extracts from bulgarian herbs. | the water phase antioxidant activity of extracts from 23 bulgarian medicinal plants was studied in relation to their polyphenol content in comparison with mate, black tea, honeybush and rooibos foreign species. antioxidant activity was measured by the abts (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)) cation radical decolorization assay, and the total polyphenol content was assayed according to the folin-ciocalteu method. five bulgarian plant extracts exhibited higher antioxidant activ ... | 2006 | 16906640 |
| antiproliferative and apoptosis inducing effect of lactoferrin and black tea polyphenol combination on hamster buccal pouch carcinogenesis. | combination chemoprevention using tea polyphenols as one of the components has received growing consideration in recent years. the present study was designed to evaluate the antiproliferative and apoptosis inducing effects of bovine lactoferrin (blf) and black tea polyphenol (polyphenon-b: p-b) combination on 7,12-dimethylbenz[a]anthracene (dmba)-induced hamster buccal pouch (hbp) carcinogenesis. topical application of dmba for 14 weeks induced buccal pouch tumours that showed aberrant expressio ... | 2006 | 16905260 |
| pre-exposure to a novel nutritional mixture containing a series of phytochemicals prevents acetaminophen-induced programmed and unprogrammed cell deaths by enhancing bcl-xl expression and minimizing oxidative stress in the liver. | from a disease-prevention perspective, recent progress in phytochemical and nutraceutical research clearly suggests (benefits outweigh the risk pattern). although powerful antioxidant properties have been the most acclaimed mechanism of action for these entities, the individual antioxidants studied in clinical trials do not appear to have consistent preventative effects. the actions of the antioxidant nutrients alone do not explain the observed health benefits of diets rich in fruits and vegetab ... | 2006 | 16902808 |
| [damage to and protection of sperm dna]. | the damage to sperm dna is one of the most important causes of male infertility. some sperm with damaged dna may escape from the sperm surveillance mechanism and transmit the damage to the offspring. so research on the damage to sperm dna has become one of the hot spots in reproductive medicine. the factors that would damage sperm dna include oxidative stress, microelements, reproductive toxic substances, radioactive rays, and so on, while the body depends on the compressed sperm dna and anti-ox ... | 2006 | 16894946 |
| protection from experimental colitis by theaflavin-3,3'-digallate correlates with inhibition of ikk and nf-kappab activation. | inflammatory bowel disease (ibd) is associated with activation of nuclear factor kappa b (nf-kappab) involved in regulating the expression of inducible nitric oxide synthase (inos) and proinflammatory cytokine genes. as theaflavin-3,3'-digallate (tfdg), the most potent anti-oxidant polyphenol of black tea, down-regulates nf-kappab activation, we investigated if tfdg is beneficial in colonic inflammation by suppressing inos and proinflammatory cytokines. | 2006 | 16880762 |
| epigallocatechin-3-gallate (egcg): chemical and biomedical perspectives. | the compound (-)-epigallocatechin-3-gallate (egcg) is the major catechin found in green tea [camellia sinensis l. ktze. (theaceae)]. this polyphenolic compound and several related catechins are believed to be responsible for the health benefits associated with the consumption of green tea. the potential health benefits ascribed to green tea and egcg include antioxidant effects, cancer chemoprevention, improving cardiovascular health, enhancing weight loss, protecting the skin from the damage cau ... | 2006 | 16876833 |
| coq9 potentiates green tea antioxidant activities in wistar rats. | green tea (camellia sinensis), and coq(9 )when given to wistar rats produced a partial reversal on reserpine induced oxidative stress and liver damage. green tea, with its abundant polyphenol (-)epigallocatechin 3-gallate (ecgc) and other catechins, is known for its antioxidative characteristics influencing lipid metabolism. ubiquinone, abundant in heart muscle, is also a potent antioxidant with known effects in numerous pathologies. however the combined effect of ecgc and ubiquninone has not be ... | 2005 | 16873954 |
| tea flavanols inhibit angiotensin-converting enzyme activity and increase nitric oxide production in human endothelial cells. | a diversity of pharmacological effects on the cardiovascular system have been reported for camellia sinensis: antioxidative, antiproliferative and anti-angiogenic activity, and nitric oxide synthase activation. the purpose of this study was to investigate if the connection between tea and angiotensin-converting enzyme (ace) and nitric oxide (no) might be an explanation of the pharmacological effects of tea on the cardiovascular system. cultured endothelial cells from human umbilical veins (huvec ... | 2006 | 16872562 |
| urinary flavonoids and phenolic acids as biomarkers of intake for polyphenol-rich foods. | estimation of dietary intake of polyphenols is difficult, due to limited availability of food composition data and bias inherent to dietary assessment methods. the aim of the present study was to evaluate the associations between the intake of polyphenol-rich foods and the urinary excretion of several phenolic compounds and therefore explore whether these phenolic compounds could be used as a biomarker of intake. fifty-three participants of the su.vi.max study (a randomised primary-prevention tr ... | 2006 | 16870009 |
| black tea--helpful or harmful? a review of the evidence. | to consider whether consumption of black tea has a positive or negative impact on health. | 2007 | 16855537 |
| effect of liming and seasonal variation on lead concentration of tea plant (camellia sinensis (l.) o. kuntze). | tea is a widely consumed beverage. however, recent studies revealed that there were an increasing number of cases of tea products exceeding the former maximum permissible concentration (mpc) in china for pb (2 mg kg(-1)). tea pb contamination is an issue affecting trade and consumer confidence. root uptake of pb could contribute significantly to pb accumulation in tea leaves due to the strong acidity of many tea garden soils. we conducted pot and field experiments to evaluate the effect of limin ... | 2007 | 16844190 |
| chemopreventive potential of diallylsulfide, lycopene and theaflavin during chemically induced colon carcinogenesis in rat colon through modulation of cyclooxygenase-2 and inducible nitric oxide synthase pathways. | chemoprevention of colorectal cancer has become essential in the modern industrialized world as cancer of the large bowel has become one of the major causes of cancer mortality, second only to lung cancer. colon cancer integrates lifestyle factors and multistep genetic alterations, and without preventive intervention, a substantial part of the population is likely to develop colorectal cancer at some point during their lives. diet and nutrition clearly play a role in the etiology of colon cancer ... | 2006 | 16835502 |
| evaluation of the hypolipemic property of camellia sinensisvar. ptilophylla on postprandial hypertriglyceridemia. | a naturally decaffeinated tea, camellia sinensis var. ptilophylla (cocoa tea), has long been popular in southern china as a healthy beverage. our experiments indicate that a single oral administration of 500 mg/kg of cocoa tea extract suppresses increases in plasma triacylgycerol (tg) levels when fed with 5 ml/kg of olive or lard oil in mice and that the inhibition rates are 22.9% and 31.5%, respectively, compared with controls. under the same condition, cocoa tea extract did not affect the leve ... | 2006 | 16819905 |
| isotheasaponins b1-b3 from camellia sinensis var. sinensis tea leaves. | three saponins, isotheasaponins b1-b3, were isolated from the leaves of the tea plant camellia sinensis var. sinensis, and their structures were determined to be theasapogenol b [beta-d-galactopyranosyl(1-->2)][beta-d-xylopyranosyl(1-->2)-alpha-l-arabinopyranosyl(1-->3)]-beta-d-gulcopyranosiduronic acid with two acyl groups by spectroscopic analysis. | 2006 | 16808937 |
| hepatotoxicity due to extracts of chinese green tea (camellia sinensis): a growing concern. | 2006 | 16793166 | |
| characterization of epoxydecenal isomers as potent odorants in black tea (dimbula) infusion. | in a black tea (dimbula) infusion, the potent "sweet and/or juicy" odorants were identified as the cis- and trans-4,5-epoxy-(e)-2-decenals by comparison of their gas chromatography retention indices, mass spectra, and odor quality to those of the actual synthetic compounds. of the two odorants, cis-4,5-epoxy-(e)-2-decenal has been identified for the first time in the black tea. on the basis of the aroma extract dilution analysis on the flavor distillate obtained using the solvent-assisted flavor ... | 2006 | 16787030 |
| epicatechins purified from green tea (camellia sinensis) differentially suppress growth of gender-dependent human cancer cell lines. | the anticancer potential of catechins derived from green tea is not well understood, in part because catechin-related growth suppression and/or apoptosis appears to vary with the type and stage of malignancy as well as with the type of catechin. this in vitro study examined the biological effects of epicatechin (ec), epigallocatechin (egc), ec 3-gallate (ecg) and egc 3-gallate (egcg) in cell lines from human gender-specific cancers. cell lines developed from organ-confined (hh870) and metastatic ... | 2006 | 16786054 |
| nutritional risk factors for the development of chronic obstructive pulmonary disease (copd) in male smokers. | the aim of this study was to investigate whether nutritional risk factors, especially black tea consumptions, are inversely associated with the development of chronic obstructive pulmonary disease (copd) in male smokers. | 2006 | 16782241 |
| tea polyphenols and theaflavins are present in prostate tissue of humans and mice after green and black tea consumption. | green and black tea have shown promise in the chemoprevention of prostate cancer. the objective of this study was to determine the bioavailability and bioactivity of tea polyphenols (pp) and theaflavins in human serum and human and mouse tissues. a decaffeinated black tea diet was administered to c57bl/6 mice. pps and theaflavins were found in the small and large intestine, liver, and prostate in conjugated and free forms. the relative prostate bioavailability of theaflavin was 70% higher than t ... | 2006 | 16772446 |
| acute effect of black and green tea on aortic stiffness and wave reflections. | while most studies have shown an inverse relation between tea consumption and cardiovascular risk, other studies have shown opposite results. aortic stiffness and wave reflections are markers of cardiovascular disease and prognosticators of cardiovascular risk. | 2006 | 16766780 |
| methods for the volumetric estimation of tea tannin in green-leaf and black tea. a new alkaline permanganate method. | 1940 | 16747284 | |
| effects of light and darkness on polyphenol distribution in the tea plant (camellia sinensis l.). | 1. flavonoid synthesis was able to proceed in darkness in young shoots and seedlings of the tea plant, but was increased by light. 2. the initial effect of darkness was to inhibit synthesis of the a ring or its linkage to the phenylpropane moiety of the flavonoid, but later the hydroxylation state of the flavanols was affected, leading to smaller proportions of gallocatechins and of complex leucoanthocyanins. 3. the esterification of catechins with gallic acid was less affected, so that the rati ... | 1969 | 16742673 |
| the purification and some properties of the polyphenol oxidase from tea (camellia sinensis l.). | 1. polyphenol oxidase (ec 1. 10. 3.-) from the shoots of the tea plant was purified about 5000-fold on a dry-weight basis. 2. at an intermediate stage of purification four soluble yellow fractions were obtained. they are believed to represent complexes of a basic enzyme protein with acidic phenolic oxidation products and nucleic acids. after removal of the complex-forming materials the fractions were blue and similar to each other. about 40% of the activity could not be extracted from the aceton ... | 1966 | 16742427 |
| protective effect of black tea against ethanol-induced oxidative modifications of liver proteins and lipids. | black tea has been recently ascertained as a source of water-soluble antioxidants that may enhance cellular antioxidant abilities. the present study was designed to investigate the efficacy of the preventive effect of black tea on oxidative modifications of liver lipids and proteins of 2-month-old rats intoxicated chronically (28 days) with ethanol. | 2006 | 16736070 |
| copper (ii) ion selective liquid membrane electrode based on new schiff base carrier. | cu2+ selective pvc membrane electrode based on new schiff base 2, 2'-[1,9 nonanediyl bis (nitriloethylidyne)]-bis-(1-naphthol) as a selective carrier was constructed. the electrode exhibited a linear potential response within the activity range of 1.0 x 10(-6) - 5.0 x 10(-3) moll(-1) with a nernstian slope of 29 +/- 1 mv decade(-1) of cu2+ activity and a limit of detection 8.0 x 10(-7) mol l(-1). the response time of the electrode was fast, 10 s, and stable potentials were obtained within the ph ... | 2016 | 16734023 |
| plant growth promotion and induction of resistance in camellia sinensis by bacillus megaterium. | bacillus megaterium de bary trs-4 was isolated from tea rhizosphere and tested for its ability to promote growth and cause disease reduction in tea plants. in vivo studies revealed the ability of this bacterium to promote growth of tea plants very significantly. brown root rot disease, caused by fomes lamaoensis was markedly reduced by application of the bacterium to the soil. population of f. lamaoensis in soil before and after application of b. megaterium, as determined by elisa and dot-blot u ... | 2006 | 16721878 |
| metabolite profiling and characterization of somaclonal variants in tea (camellia spp.) for identifying productive and quality accession. | a study has been undertaken to characterize 15 field grown somaclonal variants derived from cotyledonary tissues of upasi-10 using morphological, physiological and biochemical characters. although variants were derived from upasi-10, a very few variants possessed unique "chinery" characters while others exhibited "assam" characters. however, no variant showed identical morphological characters aligning with the parent. somaclonal variants showed distinct variation in terms of photosynthetic carb ... | 2006 | 16714038 |
| selected diet and lifestyle factors are associated with estrogen metabolites in a multiracial/ethnic population of women. | diet and lifestyle factors, body size, and smoking behavior may influence estrogen metabolism, but the nature of these relations may vary according to race/ethnic groups. we evaluated the association of lifestyle factors with estrogen metabolites 2-hydroxyestrone (2-ohe1) and 16alpha-hydroxyestrone (16alpha-ohe1) in a racially diverse population. with a cross-sectional study design, urine samples from 1881 african-american, caucasian, chinese, japanese, and hispanic women, aged 42-52 y, from the ... | 2006 | 16702326 |
| the effect of green tea in oxidative stress. | green tea, an infusion prepared with the leaves of camellia sinensis is particularly rich in flavonoids, which are strong antioxidants. tea drinking, by providing antioxidants, may become valuable in several oxidative stress conditions. our aim was to evaluate the effect of green tea drinking on some factors reflecting the development of oxidative stress in plasma and in erythrocytes. | 2006 | 16698148 |
| black tea extract and its major polyphenolic pigment may ameliorate the gastrointestinal disorder in irritable bowel syndrome. | 2006 | 16678978 | |
| transdermal delivery of (-)-epigallocatechin-3-gallate, a green tea polyphenol, in mice. | epigallocatechin-3-gallate (egcg) is the most studied catechin in green tea (camellia sinensis). egcg and green tea are cancer preventive in many animal models, and numerous mechanisms have been proposed in cell lines. egcg is poorly bioavailable in man and rodents. we hypothesized that transdermal delivery of egcg could result in improved bioavailability. following application of egcg transdermal gel (50 mg kg(-1), t.d.) to skh-1 mice, egcg was observed in the epidermis (1365.7-121.0 ng g(-1)) ... | 2006 | 16640828 |
| green tea, black tea and colorectal cancer risk: a meta-analysis of epidemiologic studies. | experimental studies have supported tea as a chemopreventive agent for colorectal cancer. no quantitative summary of the epidemiologic evidence on tea and colorectal cancer risk has ever been performed. the current meta-analysis included 25 papers conducted in 11 countries across three continents (north america, asia and europe). summary odds ratios (ors) for highest versus non/lowest tea consumption levels were calculated based on fixed and random effects models. the meta-regression and stratif ... | 2006 | 16638787 |
| comparison of the antioxidant activity of roasted tea with green, oolong, and black teas. | although the antioxidant properties of green, oolong, and black teas have been well studied, antioxidant activity has not been examined in roasted tea. therefore, in the current studies, we investigated the antioxidant activity of roasted tea in comparison with those of green, oolong, and black teas. using water extracts of the various teas, we examined the total phenolic content as well as the antioxidant activities, including the reducing power, the 1,1-diphenyl-2-picrylhydrazyl (dpph) radical ... | 2005 | 16638659 |
| ethyl acetate extract from black tea prevents neuromuscular blockade by botulinum neurotoxin type a in vitro. | botulinum neurotoxin produced by clostridium botulinum is the strongest neurotoxin and causes botulism in mammals. the current study aimed to find an inactivator for botulinum neurotoxin in black, oolong, roasted, and green teas. the ability of the four teas to inactivate the neuromuscular blocking action of botulinum neurotoxin was determined. water extracts from black, oolong, and roasted teas protected against the toxicity of botulinum neurotoxin type a in mouse phrenic nerve-diaphragm prepar ... | 2005 | 16638658 |
| high tea consumption diminishes salivary 17beta-estradiol concentration in polish women. | we hypothesized that among reproductive-age women consuming large quantities of tea, the production of estradiol would be suppressed. it has been shown that catechins and theaflavines, the major constituents of tea, inhibit aromatase, an enzyme which catalyses the conversion of androgens to oestrogens. our study included polish women living in urban (n 61) and rural (n 48) areas. women collected daily saliva samples for one complete menstrual cycle and filled out dietary questionnaires. saliva s ... | 2006 | 16611391 |
| potent inhibitory effects of black tea theaflavins on off-odor formation from citral. | the present study was conducted to investigate the ability of black tea theaflavins to inhibit the off-odor formation from citral under acidic aqueous conditions. acidic buffer solutions (ph 3.0) containing citral (10 mg/l) and an inhibitor (0-5 mg/l) were stored at 40 degrees c for 2 weeks. the formation of possible off-odorants p-cresol and p-methylacetophenone in the citral solutions was monitored by high-performance liquid chromatography. a mixture of the theaflavins showed inhibitory effect ... | 2006 | 16608230 |
| induction of neutral endopeptidase (nep) activity of sk-n-sh cells by natural compounds from green tea. | deposition of amyloid beta-peptide as senile plaques in the brain is one of the neuropathological hallmarks of alzheimer's disease, which is the most prevalent progressive neurodegenerative disease leading to dementia. neutral endopeptidase is one of the major beta-amyloid-degrading enzymes in the brain. to examine the influence of different polyphenols and other natural products from green tea extract (from camellia sinensis, theaceae), we used the neuroblastoma cell line sk-n-sh and studied th ... | 2006 | 16597367 |
| beneficial effects of green tea--a review. | tea is the most consumed drink in the world after water. green tea is a 'non-fermented' tea, and contains more catechins, than black tea or oolong tea. catechins are in vitro and in vivo strong antioxidants. in addition, its content of certain minerals and vitamins increases the antioxidant potential of this type of tea. since ancient times, green tea has been considered by the traditional chinese medicine as a healthful beverage. recent human studies suggest that green tea may contribute to a r ... | 2006 | 16582024 |
| metabolic effects of spices, teas, and caffeine. | consumption of spiced foods or herbal drinks leads to greater thermogenesis and in some cases to greater satiety. in this regard, capsaicin, black pepper, ginger, mixed spices, green tea, black tea and caffeine are relevant examples. these functional ingredients have the potential to produce significant effects on metabolic targets such as satiety, thermogenesis, and fat oxidation. a significant clinical outcome sometimes may appear straightforwardly but also depends too strongly on full complia ... | 2006 | 16580033 |
| determination of minerals extracted from several commercial teas (camellia sinensis) to hot water (infusion). | mineral contents of some tea and their infusions drunk in turkey were established by inductively coupled plasma atomic emission spectrometry. the al, ca, k, mg, mn, p, and s contents were very high in both infusions and tea (i.e., pieces of the tea plant). the as, cd, cr, li, pb, and se contents of infusion and tea were found to be very low. the level of k of all samples is higher than those of other minerals. generally, mineral contents of tea were found to be higher than those of tea infusions ... | 2006 | 16579740 |
| preconcentration system for cadmium and lead determination in environmental samples using polyurethane foam/me-btanc. | in this work, polyurethane foam (puf) loaded with 2-(6'-methyl-2'-benzothiazolylazo)chromotropic acid (me-btanc) was packed in a minicolumn and it was used in an on-line preconcentration system for cadmium and lead determination. optimum hydrodynamic and chemical conditions for metal sorption were investigated. the effects of several foreign substances on the adsorption of cadmium and lead were also reported. the enrichment factor obtained was 37 (cd and pb) for 180 s preconcentration time. the ... | 2006 | 16530947 |
| green tea polyphenols and its constituent epigallocatechin gallate inhibits proliferation of human breast cancer cells in vitro and in vivo. | tea [camellia sinensis (theaceae)] intake is second only to water in terms of worldwide popularity as a beverage. the green tea polyphenols have been shown to have a protective effect in prostate cancer in various pre-clinical animal models and has been reported to be effective in several other cancer types as well. an inverse association between the risk of breast cancer and the intake of green tea has also been reported in asian americans. several epidemiological studies have shown that breast ... | 2007 | 16519995 |
| fluoride levels in various black tea commodities: measurement and safety evaluation. | in order to determine the fluoride content of various products of black tea and to make safety evaluations, 37 commodities in the different manufactured forms of tea were assessed by means of ion-selective electrode and spectrophotometric methods. the results showed wide differences in fluoride levels. the fluoride content was found 0.95-1.41 mg/l in black tea sticks, 0.70-2.44 mg/l in black tea granules and 1.15-6.01 mg/l in black tea bags. of the products tested, the fluoride content was great ... | 2006 | 16510229 |