Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| inhibition of carcinogenesis by tea: the evidence from experimental studies. | in its various forms, tea is one of the most widely consumed beverages in the world. elucidation of the chemical components of tea has revealed that the beverage is a rich repository of antioxidants. among these are the polyphenolics, common to green tea, but also found in black teas together with oxidized polymers that in part account, for the darkened color. consumption of tea on a regular basis has been associated with reduced risk of several forms of cancer in human populations, with the str ... | 1997 | 9447274 |
| cancer rates among drinkers of black tea. | studies in experimental animals have shown that compounds in tea can inhibit the process of carcinogenesis, with the beneficial effects accruing to both green and black teas. herein epidemiologic studies around the world are reviewed to assess the rates and risks of cancer among black tea drinkers. ecologic data suggest at most a modest benefit on total cancer, as there is considerable international variation in black tea consumption but generally small differences in overall cancer rates. cohor ... | 1997 | 9447273 |
| use of herbal products, coffee or black tea, and over-the-counter medications as self-treatments among adults with asthma. | there are few data on the use of alternative therapies in adult asthma and their impact on health outcomes. | 1997 | 9438488 |
| effects of tea and chlorophyllin on the mutagenicity of n-hydroxy-iq: studies of enzyme inhibition, molecular complex formation, and degradation/scavenging of the active metabolites. | green tea and black tea inhibit the formation of carcinogen-dna adducts and colonic aberrant crypts in rats given 2-amino-3-methylimidazo[4, 5-f]quinoline (iq), a mutagen from cooked meat. the salmonella mutagenicity assay was used in the present study to test individual constituents of tea as inhibitors of 2-hydroxyamino-3-methylimidazo[4, 5-f]quinoline (n-hydroxy-iq), a direct-acting metabolite of iq. testing of pure compounds at doses relevant to their levels in tea identified epigallocatechi ... | 1997 | 9435888 |
| carbonic anhydrase from camelia sinensis (tea) leaves. | carbonic anhydrase (ca) (carbonate hydrolyase; e,c,4.2.1.1) from leaves of mature camelia sinensis was purified and characterized. the purification level was 53 fold. the optimum temperature for maximal enzyme activity is 50 degrees c. the optimum ph was 6.8 and this ph varied between 6.5 and 7.5. each enzyme molecule is a hexamer with an m(r) of 169,000 with subunits of m(r) = 28,000. | 1997 | 9413559 |
| microbiological screening of indian medicinal plants with special reference to enteropathogens. | the world health organisation (who) has recommended that all member states actively promote native medicines in their country. ten indian medicinal plants were screened for antibacterial activity specific to enteropathogens. diffusion and dilution methods were used to measure the antibacterial activity. allium sativum, camellia sinensis, and chamaesyce hirta showed higher activity when compared to the rest. they had a minimum bactericidal concentration (mbc) of < 100 micrograms/ml and gave inhib ... | 1997 | 9395690 |
| effects of green tea, black tea and dietary lipophilic antioxidants on ldl oxidizability and atherosclerosis in hypercholesterolaemic rabbits. | the hypothesis that tea or dietary lipid-soluble antioxidants reduce atherogenesis by lowering the oxidizability of low-density lipoprotein (ldl) was investigated. five groups of 20 female new zealand white rabbits were fed a restricted amount of a high-fat (30 en%) semipurified diet supplemented with cholesterol (0.15%, w/w) for 21 weeks. the vitamin e content of the control diet was 40 mg/kg diet. the animals received either green tea or black tea in their drinking water or vitamin e (200 mg/k ... | 1997 | 9395271 |
| inhibitory effect of black tea on the growth of established skin tumors in mice: effects on tumor size, apoptosis, mitosis and bromodeoxyuridine incorporation into dna. | female cd-1 mice were initiated with a single topical application of 7,12-dimethylbenz[a]anthracene and promoted with 12-o-tetradecanoylphorbol-13-acetate. mice with established papillomas were then treated with black tea or decaffeinated black tea (approximately 4 mg tea solids/ml) as the sole source of drinking fluid for 11-15 weeks. in four separate experiments, oral administration of black tea inhibited the growth of papillomas (increase in tumor volume/mouse) by an average of 35%, 37%, 41% ... | 1997 | 9395217 |
| effects of theaflavins on n-nitrosomethylbenzylamine-induced esophageal tumorigenesis. | the purpose of this experiment was to compare the inhibitory effects of the polyphenol fraction of black tea, theaflavins (tf), the polyphenol fraction of green tea, and (-)-epigallocatechin-3-gallate (egcg) in the rat esophageal tumor model. the tea fractions were administered in the drinking water at concentrations of 360 and 1,200 ppm for two weeks before administration of the esophageal carcinogen n-nitrosomethylbenzylamine (nmba). nmba was administered subcutaneously in 10% dimethyl sulfoxi ... | 1997 | 9383778 |
| protective effects of tea polyphenols against oxidative damage to red blood cells. | tea polyphenols (tpp) from black and green teas were evaluated for their antioxidant effects on normal red blood cells (rbc) and beta-thalassemic rbc membranes challenged with exogenous oxidants in vitro. the tpp of both types protected rbc against primaquine-induced lysis; they also protected the whole cells and the membranes against h2o2-induced lipid peroxidation so that about 80% protection was reached at [tpp] = 10 microg/ml. tpp from black tea at the same concentration protected normal rbc ... | 1997 | 9374417 |
| inhibition of phorbol ester tumor promoter 12-o-tetradecanoylphorbol-13-acetate-caused inflammatory responses in sencar mouse skin by black tea polyphenols. | over the past 10 years many studies from several laboratories defined anticarcinogenic and anti-inflammatory effects of tea, a widely consumed beverage by the human population. much of such work has been conducted with green tea or its polyphenolic constituents. regarding black tea, studies have shown that its water extract affords protection against tumor promotion caused by chemical carcinogens or ultraviolet b radiation in murine skin carcinogenesis models. several studies have shown that top ... | 1997 | 9363999 |
| urine levels of aluminum after drinking tea. | a microwave-assisted acid digestion procedure coupled with a graphite furnace atomic absorption method has been applied in the determination of aluminum (al) in urine to verify the correlation of free forms of al in tea infusions and urinary excretion of al. significant urinary al excretion has been found in 24-h urine of four volunteers after tea drinking. however, the difference in amount of al excretion in urine between the consumption of oolong (black tea) and long-jin (green tea), each of t ... | 1997 | 9359993 |
| possible mechanisms of antimutagens by various teas as judged by their effects on mutagenesis by 2-amino-3-methylimidazo[4,5-f]quinoline and benzo[a]pyrene. | possible mechanisms of antimutagenicity of various tea extracts (green, pouchong, oolong and black tea) toward 2-amino-3-methylimidazo[4,5-f]quinoline (iq) and benzo[a]pyrene (b[a]p) were investigated using a salmonella/microsome assay. tea extracts exhibited no inhibitory effects toward iq and b[a]p in bio-antimutagenic assays, indicating that their antimutagenic activity is desmutagenic in nature. the mutagenicities of iq and b[a]p decreased as the reaction periods of tea extracts with promuta ... | 1997 | 9357568 |
| consumption of green or black tea does not increase resistance of low-density lipoprotein to oxidation in humans. | epidemiologic studies indicated that tea consumption reduces the risk of cardiovascular disease. we assessed the effect of green or black tea consumption on resistance of low-density lipoprotein (ldl) to oxidation ex vivo and on serum lipid concentrations in healthy volunteers. in a 4-wk parallel comparison trial, 45 volunteers consumed 900 ml (6 cups) mineral water, green tea, or black tea/d. blood samples drawn while subjects were fasting were obtained before and after the study. the effect on ... | 1997 | 9356529 |
| some perspectives on dietary inhibition of carcinogenesis: studies with curcumin and tea. | topical application of curcumin inhibits chemically induced carcinogenesis on mouse skin, and oral administration of curcumin inhibits chemically induced oral, forestomach, duodenal, and colon carcinogenesis. curcumin and other inhibitors of cyclooxygenase and lipoxygenase are thought to inhibit carcinogenesis by preventing the formation of arachidonic acid metabolites. in contrast to our expectation of a tumorigenic effect of arachidonic acid, we found that treatment of 7,12-dimethylbenz[a]anth ... | 1997 | 9349692 |
| inhibition of collagenases from mouse lung carcinoma cells by green tea catechins and black tea theaflavins. | theaflavin and theaflavin digallate, which are components of black tea were examined by in vitro invasion assay with mouse lewis lung carcinoma ll2-lu3 cells, which are highly metastatic. the compounds inhibited invasion by the tumor cells. gelatin zymography showed that the cells secreted matrix metalloproteinases (mmps), probably including mmp-2 and mmp-9, which may be involved in tumor cell invasion and metastasis. theaflavin and theaflavin digallate also inhibited mmps from the culture mediu ... | 1997 | 9339552 |
| theophylline metabolism in higher plants. | metabolism of [8-(14)c]theophylline was investigated in leaf segments from camellia sinensis (tea), camellia irrawadiensis, ilex paraguariensis (maté) and avena sativa, root segments of vigna mungo seedlings and cell suspension cultures of catharanthus roseus. there was extensive uptake and metabolism of [8-(14)c]theophylline by leaves of tea and camellia irrawadiensis and, to a lesser extent, maté. these purine alkaloid-containing species converted [8-(14)c]theophylline into 3-methylxanthine, x ... | 1997 | 9305805 |
| effects of dietary consumption of black tea infusion alone and in combination with known clastogens on mouse bone marrow chromosomes in vivo. | black tea infusion in water, in concentrations simulating human consumption, was administered by gavage daily to male swiss mice for 7 days. one set was given tea once daily and the other twice daily. the mice were then exposed to two known clastogens: chromium (vi) as potassium dichromate and mitomycin c on day 7, and killed after 24 hr. chromosome damage was studied in preparations made from bone marrow following colchine injection of all mice, and examination of the cells after pretreatment i ... | 1997 | 9301648 |
| effect of black tea drinking on blood lipids, blood pressure and aspects of bowel habit. | thirty-one men (47 (sd 14) years) and thirty-four women (35 (sd 13) years) took part in a 4-week randomized cross-over trial to compare the effect of six mugs of black tea daily v. placebo (water, caffeine, milk and sugar) on blood lipids, bowel habit and blood pressure, measured during a run-in period and at the end of weeks 2, 3 and 4 of the test periods. compliance was established by adding a known amount of p-aminobenzoic acid (paba) to selected tea bags, and then measuring its excretion in ... | 1997 | 9292758 |
| effect of green tea (camellia sinensis) extract on the rat diaphragm. | the effect of hot water extract of green tea on skeletal muscle and its neurotransmission was studied employing innervated and denervated rat diaphragm. green tea extract (gte) has a facilitatory effect at lower concentrations and a paralytic effect at higher concentrations on skeletomotor function. gte did not have any effect on direct twitch responses or on acetylcholine (ach) and kcl induced contractures of denervated rat diaphragm and it antagonised the submaximal paralytic effect of d-tuboc ... | 1997 | 9292413 |
| purification and characterization of a novel class iii peroxidase isoenzyme from tea leaves. | a novel, basic (isoelectric point > 10), heme peroxidase isoenzyme (tp; relative molecular weight = 34,660 +/- 10, mean +/- se) that can account for a significant part of the ascorbate peroxidase activity in tea (camellia sinensis) leaves has been purified to homogeneity. the ultraviolet/visible absorption spectrum is typical of heme-containing plant peroxidases, with a soret peak at 406 nm (epsilon = 115 mm-1 cm-1) and an a406/a280 value of 3.4. the enzyme has a high specific activity for ascor ... | 1997 | 9276947 |
| inhibitory activity of green and black tea in a free radical-generating system using 2-amino-3-methylimidazo[4,5-f]quinoline as substrate. | green tea and black tea inhibit colon carcinogenesis in rats exposed to the cooked meat mutagen 2-amino-3-methylimidazo[4,5-f]quinoline (iq). in the present investigation, green tea, black tea and (-)-epigallocatechin gallate (egcg) were shown to block the production of oxygen free radicals derived from iq in the presence of nadph-cytochrome p450 reductase. in kinetic studies using iq as the substrate and dmpo as a free radical spin trap, egcg increased the k(m) of the reaction without altering ... | 1997 | 9263532 |
| [effect of tea extracts, catechin and caffeine against type-i allergic reaction]. | the antiallergic effects of green tea, oolong tea, and black tea extracts by hot water were examined. these extracts inhibited the passive cutaneous anaphylaxis (pca) reaction of rat after oral administration. three tea catechins, (--)-epigallocatechin (egc), (--)-epicatechin gallate (ecg), and (--)-epigallocatechin gallate (egcg) isolated from green tea showed stronger inhibitory effects than that of a green tea extract on the pca reaction. the inhibitory effects of egc and egcg on the pca reac ... | 1997 | 9261215 |
| polyphenols as inhibitors of carcinogenesis. | many polyphenolic compounds have demonstrated anticarcinogenic activities in animal models. these compounds include flavanone, flavonols, isoflavone, and catechins. in this article, tea catechins will be used as an example to illustrate current research in this area. many laboratory studies have demonstrated the inhibition of tumorigenesis in animal models by different tea preparations. the animal models include tumorigenesis in the mouse lung, rat and mouse esophagi, mouse forestomach, mouse sk ... | 1997 | 9255589 |
| reproducibility of self-administered questionnaire in epidemiological surveys. | we evaluated the reproducibility of data on intake frequency of 33 food items, beverage intake frequency of 3 items, drinking and smoking habits, and past history of 10 diseases obtained from a self-administered questionnaire. the survey subjects consisted of 263 aged 39 to 79 years individuals in the general population. after about one year interval these subjects consecutively participated in two surveys and were unintentionally requested to answer to the same questionnaire. the means of perce ... | 1997 | 9255026 |
| effect of tea flavonoid supplementation on the susceptibility of low-density lipoprotein to oxidative modification. | dietary flavonoid intake has been reported to be inversely associated with the incidence of coronary artery disease. to clarify the possible role of tea flavonoids in the prevention of atherosclerosis, we investigated the effects of tea flavonoids on the susceptibility of low-density lipoprotein (ldl) to oxidative modification. in an in vitro study, catechins or theaflavins (25-400 mumol/l) were added to plasma and incubated for 3 h at 37 degrees c. then, the ldl fraction was separated by ultrac ... | 1997 | 9250103 |
| [prophylactic effect of black tea extract as gargle against influenza]. | we examined whether gargling with black tea prevents influenza infection. tests were carried out during a five month period (october 1992 to march 1993). the control group that followed their normal daily routine, whereas the test group that gargled with 0.5 w/v% black tea extract twice daily (at 8 a.m. and 5 p.m.). influenza viruses were isolated from influenza patients and an antigen analysis was carried out. as a result, two strains of influenza a viruses (h3n2) and ten strains of b virus wer ... | 1997 | 9248263 |
| microbiological activity of whole and fractionated crude extracts of tea (camellia sinensis), and of tea components. | aqueous extracts of teas (camellia sinensis) of different types and from various sources inhibited a wide range of pathogenic bacteria, including methicillin-resistant staphylococcus aureus. tea extracts were bactericidal to staphylococci and yersinia enterocolitica at well below 'cup of tea' concentrations. activity was confined to one of four fractions obtained from a green tea extract by partition chromatography. testing of pure tea compounds and closely related chemicals suggested that the a ... | 1997 | 9228784 |
| chemoprotection: a review of the potential therapeutic antioxidant properties of green tea (camellia sinensis) and certain of its constituents. | 1997 | 9211396 | |
| the influence of coffee with milk and tea with milk on the bioavailability of tetracycline. | the effect of milk added to coffee or black tea on the bioavailability of tetracycline was evaluated in 12 healthy volunteers according to a crossover design. results showed that even a small volume of milk containing extremely small amounts of calcium severely impair the absorption of the drug, so that the presence of this metal ion should be carefully controlled in order to avoid decreasing the available tetracycline. | 1997 | 9210983 |
| anti-human immunodeficiency virus activity of oligosaccharides from rooibos tea (aspalathus linearis) extracts in vitro. | the active substances, acid polysaccharides, were extracted with 1% sodium hydroxide from the leaves of rooibos tea (aspalathus linearis), du zhong cha (eucommia ulmoides oliv.) and japanese tea leaves (camellia sinensis var. sinensis). the alkaline extracts of rooibos tea and du-zhong tea leaves, but not japanese tea leaves suppressed the hiv-induced cytopathicity using hiv (htlv-iii) infected mt-4 cells, having extremely low cytotoxicity: its 50% effective concentration (ec50) was 12-67 microg ... | 1997 | 9209319 |
| effects of tea, decaffeinated tea, and caffeine on uvb light-induced complete carcinogenesis in skh-1 mice: demonstration of caffeine as a biologically important constituent of tea. | oral administration of green or black tea inhibited uvb light-induced complete carcinogenesis in the skin of skh-1 mice. green tea was a more effective inhibitor than black tea. oral administration of decaffeinated green or black tea resulted in substantially less inhibitory activity than did administration of the regular teas, and in one experiment, administration of a high-dose level of the decaffeinated teas enhanced the tumorigenic effect of uvb. oral administration of caffeine alone had a s ... | 1997 | 9205068 |
| chemoprotection against the formation of colon dna adducts from the food-borne carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (phip) in the rat. | the mutagenic heterocyclic aromatic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (phip), is a pyrolysis product in cooked foods that has been shown to be a rat colon carcinogen and has been implicated in the etiology of human colon cancer. in order to identify chemoprotection strategies that could be carried out in humans, a pilot study was conducted in which phip-dna-adduct levels were quantified in the colons of male f344 rats that had been subjected to 16 different putative chemopro ... | 1997 | 9202746 |
| anti-allergic effect of tea-leaf saponin (tls) from tea leaves (camellia sinensis var. sinensis). | we investigated the anti-allergic effect of tea-leaf saponin (tls), which was a mixture of saponins separated from the leaves of camellia sinensis var. sinensis, in guinea pigs and rats. tls (20-100 mg/kg) dose-dependently inhibited experimentally-induced asthma, and id50 was 61.7 mg/kg. tls (20-100 mg/kg) dose-dependently inhibited a 48 h homologous pca (passive cutaneous anaphylaxis) reaction, and the inhibitory effect was similar to that of tranilast. tls (1-100 microg/ml) also inhibited the ... | 1997 | 9178940 |
| herbal teas and populace health care in tropical china. | commercial chinese herbal tea is the development of the populace in tropical and subtropical china consequential to their fight against infectious diseases and their struggle to explore local plants to relieve fever, to alleviate pain, to restore strength and to modulate immunity against viral epidemics. from these ethnomedical experiences, two types of herbal teas were commercialized, namely, liangcha and medicated teas. liangcha refers to a ready-made decoction infused from wild plants served ... | 1997 | 9167003 |
| an investigation of the antioxidant activity of black tea using enhanced chemiluminescence. | antioxidants are important species which possess the ability to protect the body from damage caused by free radical-induced oxidative stress. a variety of free radical-scavenging antioxidants exist within the body many of which are derived from dietary sources. there is currently much interest in the antioxidant role of flavonoids and other polyphenols found in tea, wine, fruit and vegetables. enhanced chemiluminescence is a simple technique which can be used as a rapid and sensitive assay for m ... | 1997 | 9161850 |
| characterization of early pulmonary hyperproliferation and tumor progression and their inhibition by black tea in a 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced lung tumorigenesis model with a/j mice. | the pathogenesis of pulmonary tumors induced by a tobacco carcinogen, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (nnk), and its inhibition by black tea have been characterized. female a/j mice (6 weeks old) were treated with a single dose of nnk (103 mg/kg of body weight, i.p.) on day 0, and the cell proliferation index was measured by the incorporation of bromodeoxyuridine (brdurd) immunohistochemically. the number of brdurd-labeled cells increased in the bronchiolar epithelium from day 2 t ... | 1997 | 9157981 |
| antioxidant flavonols and ischemic heart disease in a welsh population of men: the caerphilly study. | antioxidant flavonols and their major food source, black tea, have been associated with a lower risk of ischemic heart disease (ihd) and stroke in dutch men. we investigated whether flavonol intake predicted a lower rate of ihd in 1900 welsh men aged 45-59 y, who were followed up for 14 y. flavonol intake, mainly from tea to which milk is customarily added, was not related to ihd incidence [relative risk (rr), highest compared with lowest quartile: 1.0; 95% ci: 0.6, 1.6; p for trend = 0.996; n = ... | 1997 | 9129481 |
| tea, or tea and milk, inhibit mammary gland and colon carcinogenesis in rats. | research was performed on the effect of tea, or tea and milk, instead of drinking water, in rat models of cancer in the mammary gland or colon. solutions of 1.25% (w/v) black tea, or 1.85% (v/v) milk in tea were prepared three times per week. sd rats were given tea beginning at 42 days of age; one group was gavaged 5 mg 7,12-dimethylbenz[a]anthracene (dmba) at 49 days of age; another group received 8.4 mg 2-amino-3-methylimidazo[4,5-f]quinoline (iq) twice per week beginning at age 49, then 14 mg ... | 1997 | 9103322 |
| tea and health: a historical perspective. | in many parts of the world, green tea and black tea are produced from the plant camellia sinensis. tea is one of the most widely consumed beverages, second only to water. it is one of the safest beverages since it is made with boiling, sterile water and has been popular for over 4000 years. dogma has it that people knew it might have health promoting properties since it was frequently used as fluid supply for patients suffering from infectious diseases. however, detailed, focused research on the ... | 1997 | 9103320 |
| comparison of metabolic effects of vegetables and teas with colorectal proliferation and with tumour development in dmh-treated f344 rats. | the aim of this study was to screen potentially chemopreventive vegetables and teas for their effects as human dietary components for the colorectal epithelium and also to seek biomarkers of preventive efficacy. groups of f344 rats were adapted to a human basal diet supplemented with vegetables or teas, having known contents of glucosinolates, polyphenols and anti-oxidants. both inductions and suppressions were found for overall glutathione s-transferase (gst) and quinone reductase activities. t ... | 1997 | 9103311 |
| a rp-hplc method for the determination of tea catechins. | an hplc method with gradient elution for the quantification of catechins ((-)-epigallocatechin (egc), (+)-catechin (c), (-)-epicatechin (ec), (-)-epigallocatechingallate (egcg) and (-)-epicatechingallate (ecg)) in tea was developed. the method was used to determine catechins in black tea, green tea and oolong tea. sample preparation was simple because only filtration and adjustment of ph was required. the levels of catechins in different teas varied between <5 and 287 (egc), 17 and 94 (ec), 18 a ... | 1997 | 9103282 |
| [effect of tea-leaf saponin on blood pressure of spontaneously hypertensive rats]. | the antihypertensive effect of tea-leaf saponin (the saponin mixture isolated from leaves of camellia sinensis var. sinensis) was examined in spontaneously hypertensive rats (shr). tea-leaf saponin reduced a time-dependent increase in blood pressure dose-dependently when it was administered orally to young shr (7 weeks old) for 5 d. oral administration of tea-leaf saponin to elder shr (15 weeks old) for 5 d decreased the mean blood pressure by 29.2 mmhg at the dose of 100mg/kg compared to the co ... | 1996 | 9019528 |
| cis- and trans-linalool 3,7-oxides and methyl salicylate glycosides and (z)-3-hexenyl beta-d-glucopyranoside as aroma precursors from tea leaves for oolong tea. | two new alcoholic aroma precursors, cis- and trans-linalool, 3,7-oxides 6-o-beta-d-apiofuranosyl-beta-d-glucopyranosides (1 and 2), as well as two already known compounds, (z)-3-hexenyl beta-d-glucopyranoside (3) and methyl salicylate 6-o-beta-d-xylopyranosyl-beta-d-glucopyranoside (beta-primeveroside: 4), and another new monoterpendiol glycoside, 8-hydroxygeranyl beta-primeveroside (5) have recently been isolated as aroma precursors in tea leaves (camellia sinensis var. sinensis cv. maoxie) rea ... | 1996 | 8987857 |
| effects of tea (camellia sinensis) chemical compounds on ethanol metabolism in icr mice. | the effects of a green tea (camellia sinensis) extract on ethanol metabolism in icr male mice were studied. a crude green tea extract (gte) and the tea components as (-)-epigallocatechin gallate (egcg), (-)-epigallocatechin (egc), and caffeine were administered before the tests. one hour later, the mice were orally given 2g/kg body weight (b.w.) of ethanol (20% ethanol w/v). the results show that the levels in the blood and liver of ethanol and acetaldehyde were lower, and that the levels of ace ... | 1996 | 8987593 |
| fungicidal and insect controlling properties of proteus strain rrlj 16, isolated from tea, camellia sinensis (l) o kuntze, plantations. | a strain of proteus rrlj 16, isolated from acid (ph 4.5-5.5) iron rich tea (camellia sinensis) plantation soil, produced siderophores with single absorption peak at 370 nm when cultured in iron free medium. extracted crude fraction of siderophores and live cultures showed in vitro antibiosis against five species of pathogenic fungi. when the strain was cultured in a normal bacteriological medium without iron stress, it produced an insect repellent compound. the culture filtrate sprayed (dilution ... | 1996 | 8979512 |
| tea and cancer prevention: an evaluation of the epidemiologic literature. | animal and in vitro studies provide evidence of an anticarcinogenic potential of active ingredients in teas. this review encompasses epidemiologic studies of stomach, colon, and lung cancer as well as the evidence of a relationship between tea drinking and cancer at large in humans. cohort studies do not suggest a protective role for tea drinking in the total risk of cancer. site-specific studies reveal a more complex picture. the epidemiologic studies on tea drinking and stomach cancer do not j ... | 1997 | 8970175 |
| a comparison of the antimutagenic potential of green, black and decaffeinated teas: contribution of flavanols to the antimutagenic effect. | the present study was undertaken to compare the antimutagenic activity of aqueous extracts, at the concentrations used for human consumption, from green, black and decaffeinated black tea. antimutagenic potential was evaluated against three indirect-acting dietary carcinogens, glu-p-1, benzo(a)pyrene and nitrosopyrrolidine. all three types of tea gave rise to strong and concentration-dependent suppression of the mutagenicity of the three premutagens in the presence of an activation system. no ma ... | 1996 | 8962430 |
| inhibitory effects of tea catechins, black tea extract and oolong tea extract on hepatocarcinogenesis in rat. | inhibitory effects of individual tea catechins ((--)-epicatechin, (--)-epigallocatechin, (--)-epicatechin gallate, (--)-epigallocatechin gallate), black tea extract and oolong tea extract on hepatocarcinogenesis were investigated. male f344 rats received a single dose of diethylnitrosamine (200 mg/kg, i.p.), and thereafter phenobarbital (0.05%) was administered in the drinking water for a period of 6 weeks. tea catechins, black tea extract or oolong tea extract were given during the entire exper ... | 1996 | 8957060 |
| tea polyphenols as inhibitors of mutagenicity of major classes of carcinogens. | previous research suggested that the mutagenicity of some genotoxic carcinogens, mainly heterocyclic amines, was decreased by green or black tea extracts, or tea polyphenol fractions. thus, it seemed important to test a variety of genotoxic carcinogens with distinct chemical structures and means of biochemical activation as regards modification of mutagenicity in appropriate strains of salmonella typhimurium by 3 concentrations of polyphenols 60, 100, or b, standard commercial polyphenol prepara ... | 1996 | 8950350 |
| ascorbyl radical scavenging activity of polyphenols. | a variety of tannin and lignin-related compounds were compared for their ability to modify the ascorbyl radical intensity of sodium ascorbate. hot-water extracts prepared from green tea, black tea and pine cone (pinus parviflora sieb. et zucc.), and various wines potently scavenged ascorbyl radical intensity. low molecular weight tannins and phenylpropenoid monomers showed the greatest scavenging activity, whereas the dehydrogenation polymers of phenylpropenoids were much less active. on the oth ... | 1996 | 8917403 |
| aflatoxin and cyclopiazonic acid production by a sclerotium-producing aspergillus tamarii strain. | the production of aflatoxins b1 and b2 by aspergillus tamarii (subgenus circumdati section flavi) is reported for the first time. the fungus was isolated from soil collected from a tea (camellia sinensis) field in miyazaki prefecture, japan. three single-spore cultures, nrrl 25517, nrrl 25518, and nrrl 25519, were derived from subcultures of the original isolate 19 (mz2). each of these single-spore cultures of a. tamarii produced aflatoxins b1 and b2 and cyclopiazonic acid, as well as black, pea ... | 1996 | 8899995 |
| antioxidant properties of ethanolic and aqueous extracts of green tea compared to black tea. | 1996 | 8878934 | |
| black tea, green tea, and tea polyphenols. effects on trace element status in weanling rats. | previous studies have shown that tea consumption can impair trace element metabolism, particularly iron status, and increase the risk of anemia in humans and animals. more recently, however, evidence has been accumulating to show that, in animals, consumption of green tea or its polyphenols is associated with a reduction of the incidence and severity of a variety of experimentally induced cancers. in this study we have monitored the growth, trace element status, including hematological parameter ... | 1996 | 8862735 |
| antibacterial effect of theaflavin, polyphenon 60 (camellia sinensis) and euphorbia hirta on shigella spp.--a cell culture study. | antibacterial effect of compounds extracted from camellia sinensis l. and the methanol extract of euphorbia hirta l. were studied against dysentery causing shigella spp. using the vero cell line. cytotoxicity studies of the extracts were performed using the cell line and the non-cytotoxic concentration of the extract was tested for antibacterial activity against the cytopathic dose of the pathogen. these extracts were found to be non-cytotoxic and effective antibacterial agents. | 1995 | 8847884 |
| dietary modulation of the carcinogenicity of the heterocyclic amines. | heterocyclic amines (hcas) are potent mutagens and carcinogens formed during cooking of meats or fish. they are, therefore, widely consumed by humans. | 1995 | 8844815 |
| inhibitory effect of six green tea catechins and caffeine on the growth of four selected human tumor cell lines. | green tea is an aqueous infusion of dried unfermented leaves of camellia sinensis (family theaceae) from which numerous biological activities have been reported including antimutagenic, antibacterial, hypocholesterolemic, antioxidant, antitumor and cancer preventive activities. from the aqueous-alcoholic extract of green tea leaves, six compounds (+)-gallocatechin (gc), (-)-epicatechin (ec), (-)-epigallocatechin (egc), (-)-epicatechin gallate (ecg), (-)-epigallocatechin gallate (egcg) and caffei ... | 1996 | 8826614 |
| chemopreventive effects of green and black tea on pulmonary and hepatic carcinogenesis. | the chemopreventive effects of decaffeinated green and black tea treatment on liver and lung tumorigenesis were examined in carcinogen-treated mice. male c3h mice were given decaffeinated green or decaffeinated black tea in their drinking water prior to, during, and after treatment with diethylnitrosamine (50 micrograms/kg bw, i.p., once per week for 8 weeks). after 40 weeks of tea treatment, mice were sampled and examined for pulmonary and hepatic tumors. mice treated with both dena and tea dis ... | 1996 | 8742322 |
| caffeine induces cytochrome p4501a2: induction of cyp1a2 by tea in rats. | previous reports indicated that treatment of rats with green tea or black tea extracts increased cyp1a2 activity, but such an induction was not observed with decaffeinated green tea in our preliminary study. herein we report a comparative study on the induction of cyp1a2 with different tea preparations and caffeine as an inducer. when green tea (2%) or black tea (2%) was given to male fischer 344 rats as the sole source of drinking fluid for 21 days, a 2.4- or 2.7-fold induction, respectively, o ... | 1996 | 8723732 |
| [antimicrobial and anti-inflammatory actions of tea-leaf saponin]. | antimicrobial and anti-inflammatory actions of tea-leaf saponin, which was a mixture of saponin separated from leaves of camellia sinensis var. sinensis, were investigated. tea-leaf saponin showed relatively high antimicrobial activity against pathogenic dermal fungi and its mic value for microsporum audouinii was 10 microgam/ml. on the other hand, tea-leaf saponin inhibited rat paw edema induced by carrageenin in a dose dependent manner. activation of hyaluronidase, one of the enzymes involved ... | 1996 | 8721352 |
| protection by green tea, black tea, and indole-3-carbinol against 2-amino-3-methylimidazo[4,5-f]quinoline-induced dna adducts and colonic aberrant crypts in the f344 rat. | male f344 rats were exposed for 8 weeks to extracts of green tea (2% w/v) or black tea (1% w/v), or to 0.1% dietary indole-3-carbinol (i3c). in weeks 3 and 4 of the study, rats were given 2-amino-3-methylimidazo[4,5-f]quinoline (iq) every other day by oral gavage (50 mg/kg body wt) in order to induce aberrant crypt foci (acf) in the colon. compared with controls given iq alone, all three inhibitors reduced the number of total aberrant crypts per colon, and green tea and i3c inhibited significant ... | 1996 | 8706244 |
| geranyl 6-o-alpha-l-arabinopyranosyl-beta-d-glucopyranoside isolated as an aroma precursor from leaves of a green tea cultivar. | a new glycosidic aroma precursor was isolated from green tea leaves (camellia sinensis var. sinensis cv. yabukita) along with the known primeverosides of cis-linalool 3,6-oxide, linalool and geraniol. these glycosides were separated by chromatographic isolation on amberlite xad-2, ods flash chromatography, and finally hplc. the chemical structure of the new unknown glycoside was confirmed as geranyl 6-o-alpha-l-arabinopyranosyl-beta-d-glucopyranoside (geranyl beta-vicianoside) by spectrometric a ... | 1996 | 8704326 |
| inhibitory effects of green tea polyphenols on growth and cellular adherence of an oral bacterium, porphyromonas gingivalis. | effects of polyphenolic compounds isolated from green tea (camellia sinensis) on the growth and adherence of porphyromonas gingivalis onto human buccal epithelial cells were investigated. green tea polyphenols, especially (-)-epigallocatechin gallate (egcg) which is a dominant component of tea polyphenols, completely inhibited the growth and adherence of p. gingivalis onto the buccal epithelial cells at concentrations of 250-500 micrograms/ml. among the polyphenolic compounds, (-)-epicatechin ga ... | 1996 | 8704303 |
| tea drinking and haemostasis: a randomized, placebo-controlled, crossover study in free-living subjects. | the hypothesis that tea drinking may protect against coronary heart disease (chd) through effects on clotting as measured by plasma fibrinogen, tissue-type plasminogen activator (tpa) and plasminogen activator inhibitor-1 (pai-1) was tested in 65 healthy volunteers (31 men and 34 women; aged 20-74 years) in a randomized, blind, placebo-controlled, crossover study lasting 10 weeks (run-in phase 2 weeks, tea and placebo phases 4 weeks). during the placebo phase, intakes of milk, sugar, water and c ... | 2007 | 8698279 |
| the effect of teas on the in vitro mutagenic potential of heterocyclic aromatic amines. | water extracts of eight brands (five types: 'green', 'black', 'oolong', decaffeinated and instant) of common teas (derived from camellia sinensis) and infusions of six randomly selected herbal teas were examined for inhibitory or potentiating effects on the mutagenicity of eight heterocyclic aromatic amines (haa) using the ames salmonella typhimurium ta98 and s-9 assay. haa, produced in foods during regular heat processing of meat, exhibit mutagenic/carcinogenic activities. tea extracts from c. ... | 1996 | 8690310 |
| relationship between antimutagenic activity and major components of various teas. | the objectives of this study were to determine the major components in tea leaves and tea extracts and to study the relationship between chemical content and antimutagenic activity of various tea extracts. the amount of catechins in various tea extracts was in the order: green tea (26.7%) > oolong tea (23.2%) > pouchong tea (15.8%) > black tea (4.3%). the amounts of caffeine and phenolic compounds in oolong tea extracts were 8.3 and 32.4%, respectively; these amounts were greater than those in t ... | 1996 | 8671713 |
| [ dietary intake of fluorine through of tea prepared by the traditional method in senegal]. | the consumption of tea in senegal is known and called "trois normaux". the use of thea sinensis as drink many times per day with a lot of sugar, may cause some public health problems. in the aim to face that situation, we have analysed the fluor level in the available tea samples in the senegalese market in respect of the ways of the preparation. the fluor level has been analysed by ionometric specific electrode. the concentrations were from 3.8 to 6.1 mg/l in the infusion and from 11.1 mg/l in ... | 1994 | 8654184 |
| reduction of oxalate content of foods by the oxalate degrading bacterium, eubacterium lentum wyh-1. | urinary oxalate may contribute far more than urinary calcium to the pathogenesis of urinary calculi. urinary oxalate may be reduced by restricting the intake of foods high in oxalate. the oxalate content foods might be reduced by oxalate-degrading bacteria. the purpose of this experiment was to reduce the oxalate content of foods with an oxalate-degrading bacterium which was isolated from the feces of japanese male. | 1996 | 8646596 |
| thermospray-lc-ms analysis of various groups of polyphenols in tea. ii: chlorogenic acids, theaflavins and thearubigins. | an account is given of the application of thermospray lc-ms in the analysis of caffeoyl- and p-coumaroylquinic acids, theaflavins and thearubigins in black tea. all compounds, except for the thearubigens, could be detected as the pseudo-molecular ion [m + h]+. in addition to [m + h]+, other species such as adducts with sodium, ammonium and potassium, as well as solvent clusters were observed. the formation of those adducts depended upon on the structure of the compound. a fragmentation of chloro ... | 1996 | 8638432 |
| re: consumption of black tea and cancer risk: a prospective cohort study. | 1996 | 8637037 | |
| dietary flavonoids, antioxidant vitamins, and incidence of stroke: the zutphen study. | epidemiological studies suggested that consumption of fruit and vegetables may protect against stroke. the hypothesis that dietary antioxidant vitamins and flavonoids account for this observation is investigated in a prospective study. | 1996 | 8629875 |
| inhibition of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (phip) mutagenicity by black and green tea extracts and polyphenols. | solutions of lyophilized preparations of standard black and green tea extracts were made and tested over a range of six concentrations as inhibitors of the mutagenicity caused by the fool mutagen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (phip) in the salmonella typhimurium ta98 assay containing s9 fraction from rats induced with alpha-naphthoflavone and phenobarbital. extracts of both black and green tea were equally good inhibitors of mutagenicity. purified polyphenols were prepared from ... | 1996 | 8618547 |
| in vivo antioxidant effect of green and black tea in man. | evaluation of the vitro antioxidant activity of green and black tea, their in vivo effect on plasma antioxidant potential in man and the effect of milk addition. | 1996 | 8617188 |
| the comparative tea staining potential of phenolic, chlorhexidine and anti-adhesive mouthrinses. | staining of teeth and mucous membranes is a well-known side-effect with chlorhexidine mouthrinses in which dietary chromogens play an important rôle. the purpose of this study was to determine whether a co-polymer anti-adhesive agent would prevent staining by a low concentration chlorhexidine solution. additionally, the possibility that an essential oil/phenolic rinse product may cause staining was investigated. the rinses studied were the anti-adhesive alone and combined with 0.02% chlorhexidin ... | 1995 | 8613560 |
| antimicrobial properties of tea (camellia sinensis l.). | 1995 | 8585711 | |
| endotoxin induced production of interleukin-6 is enhanced by vitamin e deficiency and reduced by black tea extract. | studies were performed to investigate the effect of a polyphenol rich extract from black tea and vitamin e on bacterial lipopolysaccharide (endotoxin) induced il-6 production, alterations in liver glutathione and antioxidant acute phase protein (caeruloplasmin) concentration, in rats fed on a synthetic diet for 21 days. in the vitamin e sufficient group a significantly lower il-6 concentration than in vitamin e deficient animals was observed. addition of tea extract to the diet produced a simila ... | 1995 | 8564528 |
| the yeast spectrum of the 'tea fungus kombucha'. | the tea fungus 'kombucha' is a symbiosis of acetobacter, including acetobacter xylinum as a characteristic species, and various yeasts. a characteristic yeast species or genus has not yet been identified. kombucha is mainly cultivated in sugared black tea to produce a slightly acidulous effervescent beverage that is said to have several curative effects. in addition to sugar, the beverage contains small amounts of alcohol and various acids, including acetic acid, gluconic acid and lactic acid, a ... | 1995 | 8559192 |
| polyphenols as cancer chemopreventive agents. | this article summarizes available data on the chemopreventive efficacies of tea polyphenols, curcumin and ellagic acid in various model systems. emphasis is placed upon the anticarcinogenic activity of these polyphenols and their proposed mechanism(s) of action. tea is grown in about 30 countries and, next to water, is the most widely consumed beverage in the world. tea is manufactured as either green, black, or oolong; black tea represents approximately 80% of tea products. epidemiological stud ... | 1995 | 8538195 |
| consumption of black tea and cancer risk: a prospective cohort study. | tea is one of the most frequently consumed beverages in the world. antioxidant polyphenol compounds (such as catechins and flavonols) are abundantly present in both green and black teas and have been observed to have anticarcinogenic properties in cell and animal model studies. in black tea, however, most of the catechins have been oxidized to forms that may have reduced anticarcinogenic properties. despite indications from experimental studies that tea may protect against cancer, epidemiologic ... | 1996 | 8537983 |
| aluminium and fluoride in hospital daily diets and in teas. | the levels of aluminium and fluoride have been determined in hospital daily diets including breakfast, dinner and supper, as well as in black teas and herbal teas purchased from the local market. in tea, aluminium was determined directly in a sample solution by atomic absorption spectroscopy using nitrous oxide and an acetylene flame. for analysis of the hospital diet, samples containing lower levels of aluminium were analysed using a spectrophotometric method which measured aluminium in the for ... | 1995 | 8525696 |
| tea and cancer. | tea is one of the most popular beverages consumed worldwide. the relationship between tea consumption and human cancer incidence is an important concern. this topic has been studied in different populations by many investigators, but no clear-cut conclusion can be drawn. whereas some studies have shown a protective effect of tea consumption against certain types of cancers, other studies have indicated an opposite effect. our purpose is to provide a critical review of this topic, covering basic ... | 1993 | 8515490 |
| gastro-intestinal availability of aluminium from tea. | the in vitro speciation of aluminium (al) in black tea infusion (ph 4.8) was assessed using 3000, 10,000 and 30,000 da cut-off ultrafilters, and the effect of adding human gastric juice (ph 2.3) and then raising the ph to 6.5 were also studied. 78% al in the tea infusion passed through the 3000-da ultrafilter; this percentage increased to more than 90% with the addition of gastric juice at ph 2.3, but then reduced to approximately 5% when the incubate was adjusted to ph 6.5. the breakdown of tea ... | 1993 | 8514217 |
| enhancement of gap junctional intercellular communication in tumor promoter-treated cells by components of green tea. | green tea (camellia sinensis) has been reported to inhibit tumor promotion in vivo and in vitro. many tumor promoters inhibit gap junctional intercellular communication (gjic) which may be an important mechanism of promotion. in the present study, we hypothesized that green tea would enhance gjic in promoter-treated cells. an aqueous extract of green tea (gte) and several of its constituents were tested for their effects on gjic in p,p'-dichlorodiphenyltrichloroethane (ddt)-, 12-o-tetradecanoylp ... | 1993 | 8481889 |
| organochlorine pesticide residues in black tea, camomile, and linden. | 1993 | 8467130 | |
| bactericidal catechins damage the lipid bilayer. | the mode of antibacterial action of, the green tea (camellia sinensis) extracts, (-)-epigallocatechin gallate (egcg) and (-)-epicatechin (ec) was investigated. strong bactericidal egcg caused leakage of 5,6-carboxyfluorescein from phosphatidylcholine liposomes (pc), but ec with very weak bactericidal activity caused little damage to the membrane. phosphatidylserine and dicetyl phosphate partially protected the membrane from egcg-mediated damage when reconstituted into the liposome membrane with ... | 1993 | 8466924 |
| inhibitory effects of tea extracts and (-)-epigallocatechin gallate on dna synthesis and proliferation of hepatoma and erythroleukemia cells. | polyphenols extracted from green or black tea with ethyl acetate were strongly inhibitory for dna synthesis in htc rat hepatoma cells and ds19 mouse erythroleukemia cells at concentrations of 0.1-0.2 mg/ml. there was less inhibition with a subsequent black tea fraction extracted with butanol and with the residual water-soluble fraction. although cell proliferation was inhibited by (-)-epigallocatechin gallate and the tea extracts, there were only marginal effects on differentiation of ds19 cells ... | 1993 | 8443796 |
| k and ca content of fresh green tea, black tea, and tea residue determined by x-ray fluorescence analysis. | x-ray fluorescence (xrf) can be successfully used for the qualitative and quantitative elemental analysis of various agricultural products. its simplicity, high throughput and the possibility of automation make it useful for screening large numbers of samples. the k and ca content of 138 samples of fresh green tea, black tea and black tea residues were determined by applying the xrf system. such a method of mineral analysis of food products is not very common. tea from different tea-growing area ... | 1993 | 8438623 |
| inhibitory effect of tea catechins on collagenase activity. | a major purpose of this study was to examine inhibitory effect of the catechin derivatives from japanese green tea camellia sinensis on collagenase activity. the crude tea catechins, which contain (+)-catechin (c), (-)-epicatechin (ec), (+)-gallocatechin (gc), (-)-epigallocatechin (egc), (-)-epicatechin gallate (ecg), and (-)-epigallocatechin gallate (egcg), were tested for their ability to inhibit the prokaryotic and eukaryotic cell derived collagenase activities. among the tea catechins tested ... | 1993 | 8396176 |
| isolation of camelliaside c from "tea seed cake" and inhibitory effects of its derivatives on arachidonate 5-lipoxygenase. | a new flavonol glycoside, camelliaside c, was isolated from "tea seed cake" prepared from the defatted seeds of camellia sinensis o. kuntze. the structure was determined as kaempferol 3-o-beta-d-galactopyranosyl-(1-->2)-beta-d-glucopyranoside by spectroscopic methods (fab-ms, uv, ir, 1h- and 13c-nmr) and the enzymatic transformation of camelliaside c to astragalin. camelliaside c showed an inhibitory effect on the arachidonate 5-lipoxygenase of rbl-1 cells (ic50:1.4 x 10(-4)m) as did camelliasid ... | 1993 | 8370116 |
| inhibition of iron absorption prolongs the life span of drosophila. | the life span of drosophila melanogaster (oregon r) males was found to be proportional to the logarithm of the iron content of the diet. life span was also shown to be proportional to the rate of iron accumulation for drosophila, mice and man. the total body iron content was found to correlate with the total calcium content of adult drosophila. iron content during the developmental stages, however, remained relatively constant and did not change with changes in the calcium concentrations. dietar ... | 1993 | 8326745 |
| oolong tea polyphenols inhibit experimental dental caries in spf rats infected with mutans streptococci. | an extract of oolong tea (semifermented tea leaves of camellia sinensis) and its chromatographically isolated polyphenolic compound was examined for in vitro inhibitory effects on glucosyltransferases (gtases) of mutans streptococci and on caries development in sprague-dawley rats infected with mutans streptococci. the samples showed no detectable effect on the growth of mutans streptococci. however, insoluble glucan synthesis from sucrose by the gtases of streptococcus mutans mt8148r and strept ... | 1993 | 8319255 |
| dietary tannins from cowpeas and tea transiently alter apparent calcium absorption but not absorption and utilization of protein in rats. | tannins reportedly alter absorption and utilization of protein and minerals. the present study investigated the effect of tannins extracted from 'mississippi silver' cowpeas and black tea when incorporated into nutritionally balanced diets. condensed tannins were incorporated into the diet of weanling male sprague-dawley rats at 0.0, 0.0057, 0.0171 and 0.057 g/100 g diet for 28 d. ingestion of tannin from cowpeas or tea did not change significantly growth rate, protein efficiency ratio, apparent ... | 1994 | 8308578 |
| prognostic significance of selected lifestyle factors in urinary bladder cancer. | to examine the prognostic significance of lifestyle factors in urinary bladder cancer, we conducted a follow-up study of 258 incident bladder cancer patients, who were originally recruited in a case-control study in metropolitan nagoya. information on individual survivals was obtained from the computer data-file of the tumor registry of the nagoya bladder cancer research group. univariate analyses revealed significant associations of 5-year survivorship with educational attainment, marital statu ... | 1993 | 8294212 |
| the inhibitory effect of chinese tea and its polyphenols on in vitro and in vivo n-nitrosation. | the objective of this study is to evaluate the possible role of chinese tea as a natural inhibitor of n-nitrosation, and to compare the relative inhibitory potency of various kinds of chinese tea in vitro and in vivo. studies on the inhibitory effect of 145 samples of chinese tea on the formation of n-nitrosomorpholine (nmor) showed that the inhibitory potency of the 7 types of chinese tea differed greatly, the average blocking rate of green tea (89.04%, n = 60), crush, tear, and curl (ctc) blac ... | 1993 | 8292269 |
| [determination of minerals and trace elements in selenium tea from the enschi district, people's republic of china, and in its infusions using inductively coupled plasma-atomic emission spectrometry, graphite furnace atomic absorption spectrometry and instrumental neutron activation analysis]. | the enschi district in hubei province, peoples republic of china is geochemically one of the two seleniferous regions, producing both selenium (se) black tea and the se green tea. three samples of green tea with different se contents and one non-se tea were analysed. the following mineral and trace elements were determined by inductively coupled plasma-atomic emission spectrometry (icp-aes): k, ca, mg, na, p, s, al, mn, fe, ba, sr, co, ni, cu, zn, mo, and cr. except for mo, co, and cr, all other ... | 1993 | 8273425 |
| experimental studies on the treatment of frostbite in rats. | the effect of treatment by high dose of vitamin c, rapid rewarming by 37 degrees c water alone and with vitamin c, rapid rewarming by 37 degrees c decoction of indian black tea alone and with vitamin c for experimentally produced frostbite was evaluated in 6 groups (25 each) of rats. frostbite was produced experimentally in the hind limbs by exposing the animals at -15 degrees c for 1h using the harness technique. the degree of injury was assessed and classified on the basis of tissue necrosis a ... | 1993 | 8262579 |
| [contents of aluminum and manganese in tea leaves and tea infusions]. | we measured the contents of aluminum and manganese in tea leaves and tea infusions by means of various standardized infusion conditions, and by using flameless atomic absorption spectrophotometry, and investigated the influence of infusion conditions on the elution of aluminum and manganese into the tea infusions. furthermore, we tried to estimate the daily intake of aluminum and manganese due to drinking tea infusions. the content of aluminum in tea leaves was 1420 micrograms/g in case of wulon ... | 1993 | 8254994 |
| effects of shooting period, times within shooting periods and processing systems on the extract, caffeine and crude fiber contents of black tea. | the extract, caffeine and crude fibre contents of black tea, from different shooting periods, different times within each shooting period and processed by five different commercial rolling methods, were examined. the extract and crude fibre contents of black tea were significantly (p < 0.01) affected by all these factors and their interactions. the caffeine content of black tea was affected by the shooting period and times within the shooting period. it was determined that processing methods did ... | 1993 | 8249478 |
| determination of flavone c-glycosides in tea. | an hplc method for the determination of flavone c-glycosides (fcg) from black tea has been developed. sample clean-up was accomplished by means of polyamide column chromatography, followed by enzyme hydrolysis of interfering compounds such was flavonol glycosides and a second polyamide column chromatographic step. using hplc with gradient elution and photodiode array detection eight fcg were separated. seven fcg were isolated by means of preparative hplc. identification was carried out using co- ... | 1993 | 8237118 |
| three-month oral repeated administration toxicity study of seed saponins of thea sinensis l. (ryokucha saponin) in rats. | ryokucha saponin (rsp), which is one of the ingredients of green tea, was administered orally to rats for 3 months at dose levels of 50, 150 and 500 mg/kg/day to assess any toxic effects. as positive control, 1200 mg/kg/day of quillaia saponin (qsp), which contains saponins equivalent in amount to those in 500 mg rsp/kg/day, was administered. the no-effect level of rsp was 50 mg/kg/day and the lowest-observed-effect level of rsp was 150 mg/kg/day for both sexes, so that the true no-effect level ... | 1994 | 8206442 |