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Sample records for 5-epi-aristolochene synthase teas

  1. Structural basis for cyclic terpene biosynthesis by tobacco 5-epi-aristolochene synthase

    SciTech Connect

    Starks, C.M.; Noel, J.P. |; Back, K.; Chappell, J.

    1997-09-19

    Terpene cyclases catalyze the synthesis of cyclic terpenes with 10-, 15-, and 20-carbon acyclic isoprenoid diphosphates as substrates. Plants have been a source of there natural products by providing a homologous set of terpene synthases. The crystal structures of 5-epi-aristolochene synthase, a sesquiterpene cyclase from tobacco, alone and complexed separately with two farnesyl diposphate analogs were analyzed. These structures reveal an unexpected enzymatic mechanism for the synthesis of the bicyclic product, 5-epi-aristolochene, and provide a basis for understanding the stereochemical selectivity displayed by other cyclases in the biosynthesis of pharmacologically important cyclic terpenes. As such, these structures provide templates for the engineering of novel terpene cyclases.

  2. Formation of a Novel Macrocyclic Alkaloid from the Unnatural Farnesyl Diphosphate Analogue Anilinogeranyl Diphosphate by 5-Epi-Aristolochene Synthase

    PubMed Central

    Rising, Kathleen A.; Crenshaw, Charisse M.; Koo, Hyun Jo; Subramanian, Thangaiah; Chehade, Kareem A. H.; Starks, Courtney; Allen, Keith D.; Andres, Douglas A.; Spielmann, H. Peter; Noel, Joseph P.; Chappell, Joe

    2015-01-01

    As part of an effort to identify substrate analogs suitable for helping to resolve structural features important for terpene synthases, the inhibition of 5-epi-aristolochene biosynthesis from farnesyl diphosphate (FPP) by the tobacco 5-epi-aristolochene synthase incubated with anilinogeranyl diphosphate (AGPP) was examined. The apparent noncompetitive nature of the inhibition supported further assessment of how AGPP might be bound to crystallographic forms of the enzyme. Surprisingly, the bound form of the inhibitor appeared to have undergone a cyclization event consistent with the native mechanism associated with FPP catalysis. Biocatalytic formation of a novel 13-membered macrocyclic paracyclophane alkaloid was confirmed by high-resolution GC-MS and NMR analysis. This work provides insights into new biosynthetic means for generating novel, functionally diversified, medium-sized terpene alkaloids. PMID:25897591

  3. Computational design and selections for an engineered, thermostable terpene synthase

    PubMed Central

    Diaz, Juan E; Lin, Chun-Shi; Kunishiro, Kazuyoshi; Feld, Birte K; Avrantinis, Sara K; Bronson, Jonathan; Greaves, John; Saven, Jeffery G; Weiss, Gregory A

    2011-01-01

    Terpenoids include structurally diverse antibiotics, flavorings, and fragrances. Engineering terpene synthases for control over the synthesis of such compounds represents a long sought goal. We report computational design, selections, and assays of a thermostable mutant of tobacco 5-epi-aristolochene synthase (TEAS) for the catalysis of carbocation cyclization reactions at elevated temperatures. Selection for thermostability included proteolytic digestion followed by capture of intact proteins. Unlike the wild-type enzyme, the mutant TEAS retains enzymatic activity at 65°C. The thermostable terpene synthase variant denatures above 80°C, approximately twice the temperature of the wild-type enzyme. PMID:21739507

  4. A single-vial analytical and quantitative gas chromatography-mass spectrometry assay for terpene synthases.

    PubMed

    O'Maille, Paul E; Chappell, Joe; Noel, Joseph P

    2004-12-15

    A quantitative assay for the analysis of sesquiterpene synthases, wherein each reaction mixture is formulated in glass gas chromatography vials, overlaid with organic solvent such as ethyl acetate, and subsequently vortexed to extract hydrocarbon reaction products into the organic phase after a suitable incubation period, was developed. The product-enriched organic phase is then sampled in an automated fashion and injected directly into a gas chromatograph-mass spectrometer without further workup for analysis and quantification of hydrocarbon products. Application of the vial assay to the analysis of amorpha-4,11-diene synthase (ADS), a sesquiterpene synthase, demonstrated the sensitivity of the assay for detection of major and minor reaction products and most notably for the identification of several sesquiterpene products that had escaped previous detection. A steady-state kinetic analysis of tobacco 5-epi-aristolochene synthase (TEAS), another sesquiterpene synthase, validated the quantitative nature of the assay, providing an alternative means to the established method of using radiolabeled substrate, extraction, and scintillation counting. This simplified assay provides a standardized method to facilitate analysis of terpene synthases and diverse mutant enzyme libraries by supplanting the common practice of using larger scale reactions, multiple extractions, and evaporative concentration of the organic phase prior to gas chromatography-mass spectrometry (GC-MS) analysis. PMID:15556559

  5. Surrogate splicing for functional analysis of sesquiterpene synthase genes.

    PubMed

    Wu, Shuiqin; Schoenbeck, Mark A; Greenhagen, Bryan T; Takahashi, Shunji; Lee, Sungbeom; Coates, Robert M; Chappell, Joseph

    2005-07-01

    A method for the recovery of full-length cDNAs from predicted terpene synthase genes containing introns is described. The approach utilizes Agrobacterium-mediated transient expression coupled with a reverse transcription-polydeoxyribonucleotide chain reaction assay to facilitate expression cloning of processed transcripts. Subsequent expression of intronless cDNAs in a suitable prokaryotic host provides for direct functional testing of the encoded gene product. The method was optimized by examining the expression of an intron-containing beta-glucuronidase gene agroinfiltrated into petunia (Petunia hybrida) leaves, and its utility was demonstrated by defining the function of two previously uncharacterized terpene synthases. A tobacco (Nicotiana tabacum) terpene synthase-like gene containing six predicted introns was characterized as having 5-epi-aristolochene synthase activity, while an Arabidopsis (Arabidopsis thaliana) gene previously annotated as a terpene synthase was shown to possess a novel sesquiterpene synthase activity for alpha-barbatene, thujopsene, and beta-chamigrene biosynthesis. PMID:15965019

  6. Surrogate Splicing for Functional Analysis of Sesquiterpene Synthase Genes1[w

    PubMed Central

    Wu, Shuiqin; Schoenbeck, Mark A.; Greenhagen, Bryan T.; Takahashi, Shunji; Lee, Sungbeom; Coates, Robert M.; Chappell, Joseph

    2005-01-01

    A method for the recovery of full-length cDNAs from predicted terpene synthase genes containing introns is described. The approach utilizes Agrobacterium-mediated transient expression coupled with a reverse transcription-polydeoxyribonucleotide chain reaction assay to facilitate expression cloning of processed transcripts. Subsequent expression of intronless cDNAs in a suitable prokaryotic host provides for direct functional testing of the encoded gene product. The method was optimized by examining the expression of an intron-containing β-glucuronidase gene agroinfiltrated into petunia (Petunia hybrida) leaves, and its utility was demonstrated by defining the function of two previously uncharacterized terpene synthases. A tobacco (Nicotiana tabacum) terpene synthase-like gene containing six predicted introns was characterized as having 5-epi-aristolochene synthase activity, while an Arabidopsis (Arabidopsis thaliana) gene previously annotated as a terpene synthase was shown to possess a novel sesquiterpene synthase activity for α-barbatene, thujopsene, and β-chamigrene biosynthesis. PMID:15965019

  7. Characterization of Novel Sesquiterpenoid Biosynthesis in Tobacco Expressing a Fungal Sesquiterpene Synthase.

    PubMed

    Zook, M.; Hohn, T.; Bonnen, A.; Tsuji, J.; Hammerschmidt, R.

    1996-09-01

    The gene encoding trichodiene synthase (Tri5), a sesquiterpene synthase from the fungus Fusarium sporotrichioides, was used to transform tobacco (Nicotiana tabacum). Trichodiene was the sole sesquiterpene synthase product in enzyme reaction mixtures derived from unelicited transformant cell-suspension cultures, and both trichodiene and 5-epi-aristolochene were observed as reaction products following elicitor treatment. Immunoblot analysis of protein extracts revealed the presence of trichodiene synthase only in transformant cell lines producing trichodiene. In vivo labeling with [3H]mevalonate revealed the presence of a novel trichodiene metabolite, 15-hydroxytrichodiene, that accumulated in the transformant cell-suspension cultures. In a trichodiene-producing transformant, the level of 15-hydroxytrichodiene accumulation increased after elicitor treatment. In vivo labeling with [14C]acetate showed that the biosynthetic rate of trichodiene and 15-hydroxytrichodiene also increased after elicitor treatment. Incorporation of radioactivity from [14C]acetate into capsidiol was reduced following elicitor treatment of a trichodiene-producing transformant as compared with wild type. These results demonstrate that sesquiterpenoid accumulation resulting from the constitutive expression of a foreign sesquiterpene synthase is responsive to elicitation and that the farnesyl pyrophosphate present in elicited cells can be utilized by a foreign sesquiterpene synthase to produce high levels of novel sesquiterpenoids. PMID:12226394

  8. Pu-erh tea, green tea, and black tea suppresses hyperlipidemia, hyperleptinemia and fatty acid synthase through activating AMPK in rats fed a high-fructose diet.

    PubMed

    Huang, Hsiu-Chen; Lin, Jen-Kun

    2012-02-01

    Although green tea extract has been reported to suppress hyperlipidemia, it is unclear how tea extracts prepared from green, oolong, black and pu-erh teas modulate fatty acid synthase expression in rats fed on a high-fructose diet. In this animal study, we evaluated the hypolipidemic and hypoleptinemia effect of these four different tea leaves fed to male Wistar rats for 12 weeks. The results showed that a fructose-rich diet significantly elevated serum triacylglycerols, cholesterol, insulin, and leptin concentrations, as compared with those in the control group. Interestingly, consuming tea leaves for 12 weeks almost normalized the serum triacylglycerols concentrations. Again, rats fed with fructose/green tea and fructose/pu-erh tea showed the greatest reduction in serum TG, cholesterol, insulin and leptin levels. In contrast, serum cholesterol and insulin concentrations of the fructose/oolong tea-fed rats did not normalize. The relative epididymal adipose tissue weight was lower in all rats supplemented with tea leaves than those fed with fructose alone. There was molecular evidence of improved lipid homeostasis according to fatty acid synthase (FAS) protein expression. Furthermore, supplementation of green, black, and pu-erh tea leaves significantly decreased hepatic FAS mRNA and protein levels, and increased AMPK phosphorylation, compared with those of rats fed with fructose only. These findings suggest that the intake of green, black, and pu-erh tea leaves ameliorated the fructose-induced hyperlipidemia and hyperleptinemia state in part through the suppression of FAS protein levels and increased AMPK phosphorylation.

  9. Molecular recognition of the substrate diphosphate group governs product diversity in trichodiene synthase mutants.

    PubMed

    Vedula, L Sangeetha; Rynkiewicz, Michael J; Pyun, Hyung-Jung; Coates, Robert M; Cane, David E; Christianson, David W

    2005-04-26

    The X-ray crystal structures of Y305F trichodiene synthase and its complex with coproduct inorganic pyrophosphate (PP(i)) and of Y305F and D100E trichodiene synthases in ternary complexes with PP(i) and aza analogues of the bisabolyl carbocation intermediate are reported. The Y305F substitution in the basic D(302)RRYR motif does not cause large changes in the overall structure in comparison with the wild-type enzyme in either the uncomplexed enzyme or its complex with PP(i). However, the loss of the Y305F-PP(i) hydrogen bond appears to be compensated by a very slight shift in the position of the side chain of R304. The putative bisabolyl carbocation mimic, R-azabisabolene, binds in a conformation and orientation that does not appear to mimic that of the actual carbocation intermediate, suggesting that the avid inhibition by R- and S-azabisabolenes arises more from favorable electrostatic interactions with PP(i) rather than any special resemblance to a reaction intermediate. Greater enclosed active-site volumes result from the Y305F and D100E mutations that appear to confer greater variability in ligand-binding conformations and orientations, which results in the formation of aberrant cyclization products. Because the binding conformations and orientations of R-azabisabolene to Y305F and D100E trichodiene synthases do not correspond to binding conformations required for product formation and because the binding conformations and orientations of diverse substrate and carbocation analogues to other cyclases such as 5-epi-aristolochene synthase and bornyl diphosphate synthase generally do not correspond to catalytically productive complexes, we conclude that the formation of transient carbocation intermediates in terpene cyclization reactions is generally under kinetic rather than thermodynamic control. PMID:15835903

  10. X-ray Crystal Structure of Aristolochene Synthase from Aspergillus terreus and Evolution of Templates for the Cyclization of Farnesyl Diphosphate

    SciTech Connect

    Shishova,E.; Di Costanzo, L.; Cane, D.; Christianson, D.

    2007-01-01

    Aristolochene synthase from Aspergillus terreus catalyzes the cyclization of the universal sesquiterpene precursor, farnesyl diphosphate, to form the bicyclic hydrocarbon aristolochene. The 2.2 {angstrom} resolution X-ray crystal structure of aristolochene synthase reveals a tetrameric quaternary structure in which each subunit adopts the {alpha}-helical class I terpene synthase fold with the active site in the 'open', solvent-exposed conformation. Intriguingly, the 2.15 {angstrom} resolution crystal structure of the complex with Mg{sup 2+}{sub 3}-pyrophosphate reveals ligand binding only to tetramer subunit D, which is stabilized in the 'closed' conformation required for catalysis. Tetramer assembly may hinder conformational changes required for the transition from the inactive open conformation to the active closed conformation, thereby accounting for the attenuation of catalytic activity with an increase in enzyme concentration. In both conformations, but especially in the closed conformation, the active site contour is highly complementary in shape to that of aristolochene, and a catalytic function is proposed for the pyrophosphate anion based on its orientation with regard to the presumed binding mode of aristolochene. A similar active site contour is conserved in aristolochene synthase from Penicillium roqueforti despite the substantial divergent evolution of these two enzymes, while strikingly different active site contours are found in the sesquiterpene cyclases 5-epi-aristolochene synthase and trichodiene synthase. Thus, the terpenoid cyclase active site plays a critical role as a template in binding the flexible polyisoprenoid substrate in the proper conformation for catalysis. Across the greater family of terpenoid cyclases, this template is highly evolvable within a conserved {alpha}-helical fold for the synthesis of terpene natural products of diverse structure and stereochemistry.

  11. X-ray crystal structure of aristolochene synthase from Aspergillus terreus and evolution of templates for the cyclization of farnesyl diphosphate.

    PubMed

    Shishova, Ekaterina Y; Di Costanzo, Luigi; Cane, David E; Christianson, David W

    2007-02-20

    Aristolochene synthase from Aspergillus terreus catalyzes the cyclization of the universal sesquiterpene precursor, farnesyl diphosphate, to form the bicyclic hydrocarbon aristolochene. The 2.2 A resolution X-ray crystal structure of aristolochene synthase reveals a tetrameric quaternary structure in which each subunit adopts the alpha-helical class I terpene synthase fold with the active site in the "open", solvent-exposed conformation. Intriguingly, the 2.15 A resolution crystal structure of the complex with Mg2+3-pyrophosphate reveals ligand binding only to tetramer subunit D, which is stabilized in the "closed" conformation required for catalysis. Tetramer assembly may hinder conformational changes required for the transition from the inactive open conformation to the active closed conformation, thereby accounting for the attenuation of catalytic activity with an increase in enzyme concentration. In both conformations, but especially in the closed conformation, the active site contour is highly complementary in shape to that of aristolochene, and a catalytic function is proposed for the pyrophosphate anion based on its orientation with regard to the presumed binding mode of aristolochene. A similar active site contour is conserved in aristolochene synthase from Penicillium roqueforti despite the substantial divergent evolution of these two enzymes, while strikingly different active site contours are found in the sesquiterpene cyclases 5-epi-aristolochene synthase and trichodiene synthase. Thus, the terpenoid cyclase active site plays a critical role as a template in binding the flexible polyisoprenoid substrate in the proper conformation for catalysis. Across the greater family of terpenoid cyclases, this template is highly evolvable within a conserved alpha-helical fold for the synthesis of terpene natural products of diverse structure and stereochemistry. PMID:17261032

  12. Cloning and bacterial expression of sesquiterpene cyclase, a key branch point enzyme for the synthesis of sesquiterpenoid phytoalexin capsidiol in UV-challenged leaves of Capsicum annuum.

    PubMed

    Back, K; He, S; Kim, K U; Shin, D H

    1998-09-01

    Sesquiterpene cyclase, a branch point enzyme in the general isoprenoid pathway for the synthesis of phytoalexin capsidiol, was induced in detached leaves of Capsicum annuum (pepper) by UV treatment. The inducibility of cyclase enzyme activities paralleled the absolute amount of cyclase protein(s) of pepper immunodetected by monoclonal antibodies raised against tobacco sesquiterpene cyclase. A cDNA library was constructed with poly(A)+ RNA isolated from 24 h UV-challenged leaves of pepper. A cDNA clone for sesquiterpene cyclase in pepper was isolated by using a tobacco 5-epi aristolochene synthase gene as a heterologous probe. The predicted protein encoded by this cDNA was comprised of 559 amino acids and had a relative molecular mass of 65,095. The primary structural information from the cDNA clone revealed that it shared 77%, 72% and 49% identity with 5-epi aristolochene, vetispiradiene, and cadinene synthase, respectively. The enzymatic product catalyzed by the cDNA clone in bacteria was identified as 5-epi aristolochene, as judged by argentation TLC. RNA blot hybridization demonstrated the induction of an mRNA consistent with the induction of cyclase enzyme activity in UV-treated pepper. PMID:9816674

  13. Formation of Volatile Tea Constituent Indole During the Oolong Tea Manufacturing Process.

    PubMed

    Zeng, Lanting; Zhou, Ying; Gui, Jiadong; Fu, Xiumin; Mei, Xin; Zhen, Yunpeng; Ye, Tingxiang; Du, Bing; Dong, Fang; Watanabe, Naoharu; Yang, Ziyin

    2016-06-22

    Indole is a characteristic volatile constituent in oolong tea. Our previous study indicated that indole was mostly accumulated at the turn over stage of oolong tea manufacturing process. However, formation of indole in tea leaves remains unknown. In this study, one tryptophan synthase α-subunit (TSA) and three tryptophan synthase β-subunits (TSBs) from tea leaves were isolated, cloned, sequenced, and functionally characterized. Combination of CsTSA and CsTSB2 recombinant protein produced in Escherichia coli exhibited the ability of transformation from indole-3-glycerol phosphate to indole. CsTSB2 was highly expressed during the turn over process of oolong tea. Continuous mechanical damage, simulating the turn over process, significantly enhanced the expression level of CsTSB2 and amount of indole. These suggested that accumulation of indole in oolong tea was due to the activation of CsTSB2 by continuous wounding stress from the turn over process. Black teas contain much less indole, although wounding stress is also involved in the manufacturing process. Stable isotope labeling indicated that tea leaf cell disruption from the rolling process of black tea did not lead to the conversion of indole, but terminated the synthesis of indole. Our study provided evidence concerning formation of indole in tea leaves for the first time. PMID:27263428

  14. Backyard Teas.

    ERIC Educational Resources Information Center

    Young, Darrell D.

    1996-01-01

    Describes plants commonly found in residential areas that can be used for making tea: chicory, chickweed, red clover, goldenrod, gill-over-the-ground, pineapple weed, plantain, self-heal, sheep sorrel, and wild strawberry. Includes proper plant name, areas where the plant grows, identifying plant features, what part is used in making tea, and tea…

  15. Hypotriacylglycerolemic and antiobesity properties of a new fermented tea product obtained by tea-rolling processing of third-crop green tea (Camellia sinensis) leaves and loquat (Eriobotrya japonica) leaves.

    PubMed

    Tanaka, Kazunari; Tamaru, Shizuka; Nishizono, Shoko; Miyata, Yuji; Tamaya, Kei; Matsui, Toshiro; Tanaka, Takashi; Echizen, Yoshie; Ikeda, Ikuo

    2010-01-01

    We manufactured a new fermented tea by tea-rolling processing of third-crop green tea (Camellia sinensis) leaves and loquat (Eriobotrya japonica) leaves. The mixed fermented tea extract inhibited pancreatic lipase activity in vitro, and effectively suppressed postprandial hypertriacylglycerolemia in rats. Rats fed a diet containing 1% freeze-dried fermented tea extract for 4 weeks had a significantly lower liver triacylglycerol concentration and white adipose tissue weight than those fed the control diet lacking fermented tea extract. The activity of fatty acid synthase in hepatic cytosol markedly decreased in the fermented tea extract group as compared to the control group. The serum and liver triacylglycerol- and body fat-lowering effects of the mixed fermented tea extract were strong relative to the level of dietary supplementation. These results suggest that the new fermented tea product exhibited hypotriacylglycerolemic and antiobesity properties through suppression of both liver fatty acid synthesis and postprandial hypertriacylglycerolemia by inhibition of pancreatic lipase.

  16. Black tea

    MedlinePlus

    ... flow. Some people use black tea for preventing tooth decay and kidney stones. In combination with various other ... that men who get more phytoestrogens in their diet have a lower risk of developing lung cancer ...

  17. Pseudouridine synthases.

    PubMed

    Hamma, Tomoko; Ferré-D'Amaré, Adrian R

    2006-11-01

    Pseudouridine synthases are the enzymes responsible for the most abundant posttranscriptional modification of cellular RNAs. These enzymes catalyze the site-specific isomerization of uridine residues that are already part of an RNA chain, and appear to employ both sequence and structural information to achieve site specificity. Crystallographic analyses have demonstrated that all pseudouridine synthases share a common core fold and active site structure and that this core is modified by peripheral domains, accessory proteins, and guide RNAs to give rise to remarkable substrate versatility.

  18. Tea Tree Oil

    MedlinePlus

    96262 ... https://nccih.nih.gov/health/tea/treeoil.htm ... us ... 96262 ... https://nccih.nih.gov/health/tea/treeoil.htm ... Herbal Medicine ... Herbal Medicine/Specifics ... us ... 96262 ... https:// ...

  19. Tea enhances insulin activity.

    PubMed

    Anderson, Richard A; Polansky, Marilyn M

    2002-11-20

    The most widely known health benefits of tea relate to the polyphenols as the principal active ingredients in protection against oxidative damage and in antibacterial, antiviral, anticarcinogenic, and antimutagenic activities, but polyphenols in tea may also increase insulin activity. The objective of this study was to determine the insulin-enhancing properties of tea and its components. Tea, as normally consumed, was shown to increase insulin activity >15-fold in vitro in an epididymal fat cell assay. Black, green, and oolong teas but not herbal teas, which are not teas in the traditional sense because they do not contain leaves of Camellia senensis, were all shown to increase insulin activity. High-performance liquid chromatography fractionation of tea extracts utilizing a Waters SymmetryPrep C18 column showed that the majority of the insulin-potentiating activity for green and oolong teas was due to epigallocatechin gallate. For black tea, the activity was present in several regions of the chromatogram corresponding to, in addition to epigallocatechin gallate, tannins, theaflavins, and other undefined compounds. Several known compounds found in tea were shown to enhance insulin with the greatest activity due to epigallocatechin gallate followed by epicatechin gallate, tannins, and theaflavins. Caffeine, catechin, and epicatechin displayed insignificant insulin-enhancing activities. Addition of lemon to the tea did not affect the insulin-potentiating activity. Addition of 5 g of 2% milk per cup decreased the insulin-potentiating activity one-third, and addition of 50 g of milk per cup decreased the insulin-potentiating activity approximately 90%. Nondairy creamers and soy milk also decreased the insulin-enhancing activity. These data demonstrate that tea contains in vitro insulin-enhancing activity and the predominant active ingredient is epigallocatechin gallate. PMID:12428980

  20. Low caffeine content in novel grafted tea with Camellia sinensis as scions and Camellia oleifera as stocks.

    PubMed

    Deng, Wei-Wei; Li, Min; Gu, Chen-Chen; Li, Da-Xiang; Ma, Lin-Long; Jin, Yang; Wan, Xiao-Chun

    2015-05-01

    Caffeine, a purine alkaloid, is a major secondary metabolite in tea leaves. The demand for low caffeine tea is increasing in recent years, especially for health reasons. We report a novel grafted tea material with low caffeine content. The grafted tea plant had Camellia sinensis as scions and C. oleifera as stocks. The content of purine alkaloids was determined in the leaves of one-year-old grafted tea plants by HPLC. We also characterized caffeine synthase (CS), a key enzyme involved in caffeine biosynthesis in tea plants, at the expression level. The expression patterns of CS were examined in grafted and control leaves by Western blot, using a self-prepared polyclonal antibody with high specificity and sensitivity. The expression of related genes (TCS1, tea caffeine synthase gene, GenBank accession No. AB031280; sAMS, SAM synthetase gene, AJ277206; TIDH, IMP dehydrogenase gene, EU106658) in the caffeine biosynthetic pathway was investigated by qRT-PCR. HPLC showed that the caffeine content was only 38% as compared with the non-grafted tea leaves. Immunoblotting analysis showed that CS protein decreased by half in the leaves of grafted tea plants. qRT-PCR revealed no significant changes in the expression of two genes in the upstream pathway (sAMS and TIDH), while the expression of TCS1 was greatly decreased (50%). Taken together, these data revealed that the low caffeine content in the grafted tea leaves is due to low TCS1 expression and CS protein accumulation.

  1. Black tea polyphenols: a mechanistic treatise.

    PubMed

    Butt, M S; Imran, A; Sharif, M K; Ahmad, Rabia Shabir; Xiao, Hang; Imran, M; Rsool, H A

    2014-01-01

    Dietary interventions are among the emerging trends to curtail physiological malfunctioning like cancer, diabetes, cardiac complications, etc. The essence of phytonutrients has developed the concept of nutraceuticals at the junction of diet health linkages. In this context, theaflavin & thearubigins are the oxidized derivatives of black tea catechins during fermentation having nutraceutical potential owing to esterification of hydroxyl ring with digallate esters. Theaflavin may influence activation of transcription factors such as NFnB or AP-1 that ultimately hinder the formation of nitric oxide expression gene. Likewise, black tea contains a unique amino acid theanine acts as neurotransmitter owing to its ability to cross the blood-brain barrier. Moreover, it boasts immunity by enhancing the disease-fighting ability of gamma delta T cells. Theaflavin & thearubigins act as safeguard against oxidative stress thereby effective in the cardiac functioning. The mechanistic approach of these antioxidants is likely to be associated with inhibition of redox sensitive transcription factors & pro-oxidant enzymes such as xanthine oxidase or nitric oxide synthase. However, their involvement in antioxidative enzyme induction as in glutathione-S-transferases is also well documented. They act as curative agent against numerous pathological disorders by disrupting the electron chain thus inhibiting the progression of certain ailments. Black tea polyphenols established themselves as strong antioxidants due to their standard one-electron potential, and their vitality is dependent on the concentration of polyphenols and pH for their inclusive execution. Present review is an attempt to enrich the readers regarding the health promoting aspects of black tea polyphenols. Concomitantly, it needs core attention of researchers for the exploitations of black tea flavanols as an important dietary constituent for the vulnerable segment.

  2. [Comparison of green tea and four other kind of teas].

    PubMed

    Li, Li; Xu, Lijia; Peng, Yong; Shi, Renbing; Xiao, Peigen

    2011-01-01

    Nowadays, tea and the substitution (other kinds of tea) take an important status in the drinking, food, health product and the related industry. The most popular Green tea, Maté originated from South America, Large-leaved Kudingcha, Small-leaved Kudingcha, and the Eagle tea used civilian have many similarities on history, chemical constituents and biological activities. In this article, we summarized the similarities and the characteristics of the Green tea and the other four teas in order to provide scientific evidences for better development of the tea and substitutions. PMID:21473143

  3. Green tea in dermatology.

    PubMed

    Pazyar, Nader; Feily, Amir; Kazerouni, Afshin

    2012-01-01

    The purpose of this brief review is to summarize all in vitro, in vivo, and controlled clinical trials on green tea preparations and their uses in dermatology. An extensive literature search was carried out to identify in vivo and in vitro studies as well as clinical trials. Twenty studies were assessed and the results suggest that oral administration of green tea can be effective in the scavenging of free radicals, cancer prevention, hair loss, and skin aging plus protection against the adverse effects associated with psoralen-UV-A therapy. Topical application of green tea extract should be potentially effective for atopic dermatitis, acne vulgaris, rosacea, androgenetic alopecia, hirsutism, keloids, genital warts, cutaneous leishmaniasis, and candidiosis. There are promising results with the use of green tea for several dermatologic conditions; however, the efficacy of oral and topical green tea has not always been confirmed. PMID:23346663

  4. Green tea in dermatology.

    PubMed

    Pazyar, Nader; Feily, Amir; Kazerouni, Afshin

    2012-01-01

    The purpose of this brief review is to summarize all in vitro, in vivo, and controlled clinical trials on green tea preparations and their uses in dermatology. An extensive literature search was carried out to identify in vivo and in vitro studies as well as clinical trials. Twenty studies were assessed and the results suggest that oral administration of green tea can be effective in the scavenging of free radicals, cancer prevention, hair loss, and skin aging plus protection against the adverse effects associated with psoralen-UV-A therapy. Topical application of green tea extract should be potentially effective for atopic dermatitis, acne vulgaris, rosacea, androgenetic alopecia, hirsutism, keloids, genital warts, cutaneous leishmaniasis, and candidiosis. There are promising results with the use of green tea for several dermatologic conditions; however, the efficacy of oral and topical green tea has not always been confirmed.

  5. Antioxidant activity of tea polyphenols in vivo: evidence from animal studies.

    PubMed

    Frei, Balz; Higdon, Jane V

    2003-10-01

    Tea is particularly rich in polyphenols, including catechins, theaflavins and thearubigins, which are thought to contribute to the health benefits of tea. Tea polyphenols act as antioxidants in vitro by scavenging reactive oxygen and nitrogen species and chelating redox-active transition metal ions. They may also function indirectly as antioxidants through 1) inhibition of the redox-sensitive transcription factors, nuclear factor-kappaB and activator protein-1; 2) inhibition of "pro-oxidant" enzymes, such as inducible nitric oxide synthase, lipoxygenases, cyclooxygenases and xanthine oxidase; and 3) induction of phase II and antioxidant enzymes, such as glutathione S-transferases and superoxide dismutases. The fact that catechins are rapidly and extensively metabolized emphasizes the importance of demonstrating their antioxidant activity in vivo. Animal studies offer a unique opportunity to assess the contribution of the antioxidant properties of tea and tea polyphenols to the physiological effects of tea administration in different models of oxidative stress. Most promising are the consistent findings in animal models of skin, lung, colon, liver and pancreatic cancer that tea and tea polyphenol administration inhibit carcinogen-induced increases in the oxidized DNA base, 8-hydroxy-2'-deoxyguanosine. In animal models of atherosclerosis, green and black tea administration has resulted in modest improvements in the resistance of lipoproteins to ex vivo oxidation, although limited data suggest that green tea or green tea catechins inhibit atherogenesis. To determine whether tea polyphenols act as effective antioxidants in vivo, future studies in animals and humans should employ sensitive and specific biomarkers of oxidative damage to lipids, proteins and DNA.

  6. Tea and Cardiovascular Disease

    PubMed Central

    Deka, Apranta; Vita, Joseph A.

    2011-01-01

    There is increasing evidence for a protective effect of tea consumption against cardiovascular disease. This review summarizes the available epidemiological data providing evidence for and against such an effect. We also review observational and intervention studies that investigated an effect of tea and tea extracts on cardiovascular risk factors, including blood pressure, serum lipids, diabetes mellitus, and obesity. Finally, we review potential mechanisms of benefit, including anti-inflammatory, anti-oxidant, and anti-proliferative effects, as well as favorable effects on endothelial function. Overall, the observational data suggest a benefit, but results are mixed and likely confounded by lifestyle and background dietary factors. The weight of evidence indicates favorable effects on risk factors and a number of plausible mechanisms have been elucidated in experimental and translational human studies. Despite the growing body evidence, it remains uncertain whether tea consumption should be recommended to the general population or to patients as a strategy to reduce cardiovascular risk. PMID:21477653

  7. Tea Tells All

    ERIC Educational Resources Information Center

    Roever, Carol

    2007-01-01

    A beverage, as well as the way it is served, can be a window into the soul of a culture. For the author and her husband, Turkish tea helped them understand and enjoy the culture of Turkey. They learned that the broad nuances of culture can be as instructive as a classroom experience. The tea story begins in Chicago in the spring of 2005 when the…

  8. Cocoa tea (Camellia ptilophylla) water extract inhibits adipocyte differentiation in mouse 3T3-L1 preadipocytes

    PubMed Central

    Li, Kai Kai; Liu, Chuek Lun; Shiu, Hoi Ting; Wong, Hing Lok; Siu, Wing Sum; Zhang, Cheng; Han, Xiao Qiang; Ye, Chuang Xing; Leung, Ping Chung; Ko, Chun Hay

    2016-01-01

    Cocoa tea (Camellia ptilophylla) is a naturally decaffeinated tea plant. Previously we found that cocoa tea demonstrated a beneficial effect against high-fat diet induced obesity, hepatic steatosis, and hyperlipidemia in mice. The present study aimed to investigate the anti-adipogenic effect of cocoa tea in vitro using preadipocytes 3T3-L1. Adipogenic differentiation was confirmed by Oil Red O stain, qPCR and Western blot. Our results demonstrated that cocoa tea significantly inhibited triglyceride accumulation in mature adipocytes in a dose-dependent manner. Cocoa tea was shown to suppress the expressions of key adipogenic transcription factors, including peroxisome proliferator-activated receptor gamma (PPAR γ) and CCAAT/enhancer binding protein (C/EBP α). The tea extract was subsequently found to reduce the expressions of adipocyte-specific genes such as sterol regulatory element binding transcription factor 1c (SREBP-1c), fatty acid synthase (FAS), Acetyl-CoA carboxylase (ACC), fatty acid translocase (FAT) and stearoylcoenzyme A desaturase-1 (SCD-1). In addition, JNK, ERK and p38 phosphorylation were inhibited during cocoa tea inhibition of 3T3-L1 adipogenic differentiation. Taken together, this is the first study that demonstrates cocoa tea has the capacity to suppress adipogenesis in pre-adipocyte 3T3-L1 similar to traditional green tea PMID:26833256

  9. Cocoa tea (Camellia ptilophylla) water extract inhibits adipocyte differentiation in mouse 3T3-L1 preadipocytes.

    PubMed

    Li, Kai Kai; Liu, Chuek Lun; Shiu, Hoi Ting; Wong, Hing Lok; Siu, Wing Sum; Zhang, Cheng; Han, Xiao Qiang; Ye, Chuang Xing; Leung, Ping Chung; Ko, Chun Hay

    2016-02-01

    Cocoa tea (Camellia ptilophylla) is a naturally decaffeinated tea plant. Previously we found that cocoa tea demonstrated a beneficial effect against high-fat diet induced obesity, hepatic steatosis, and hyperlipidemia in mice. The present study aimed to investigate the anti-adipogenic effect of cocoa tea in vitro using preadipocytes 3T3-L1. Adipogenic differentiation was confirmed by Oil Red O stain, qPCR and Western blot. Our results demonstrated that cocoa tea significantly inhibited triglyceride accumulation in mature adipocytes in a dose-dependent manner. Cocoa tea was shown to suppress the expressions of key adipogenic transcription factors, including peroxisome proliferator-activated receptor gamma (PPAR γ) and CCAAT/enhancer binding protein (C/EBP α). The tea extract was subsequently found to reduce the expressions of adipocyte-specific genes such as sterol regulatory element binding transcription factor 1c (SREBP-1c), fatty acid synthase (FAS), Acetyl-CoA carboxylase (ACC), fatty acid translocase (FAT) and stearoylcoenzyme A desaturase-1 (SCD-1). In addition, JNK, ERK and p38 phosphorylation were inhibited during cocoa tea inhibition of 3T3-L1 adipogenic differentiation. Taken together, this is the first study that demonstrates cocoa tea has the capacity to suppress adipogenesis in pre-adipocyte 3T3-L1 similar to traditional green tea.

  10. Cocoa tea (Camellia ptilophylla) water extract inhibits adipocyte differentiation in mouse 3T3-L1 preadipocytes.

    PubMed

    Li, Kai Kai; Liu, Chuek Lun; Shiu, Hoi Ting; Wong, Hing Lok; Siu, Wing Sum; Zhang, Cheng; Han, Xiao Qiang; Ye, Chuang Xing; Leung, Ping Chung; Ko, Chun Hay

    2016-01-01

    Cocoa tea (Camellia ptilophylla) is a naturally decaffeinated tea plant. Previously we found that cocoa tea demonstrated a beneficial effect against high-fat diet induced obesity, hepatic steatosis, and hyperlipidemia in mice. The present study aimed to investigate the anti-adipogenic effect of cocoa tea in vitro using preadipocytes 3T3-L1. Adipogenic differentiation was confirmed by Oil Red O stain, qPCR and Western blot. Our results demonstrated that cocoa tea significantly inhibited triglyceride accumulation in mature adipocytes in a dose-dependent manner. Cocoa tea was shown to suppress the expressions of key adipogenic transcription factors, including peroxisome proliferator-activated receptor gamma (PPAR γ) and CCAAT/enhancer binding protein (C/EBP α). The tea extract was subsequently found to reduce the expressions of adipocyte-specific genes such as sterol regulatory element binding transcription factor 1c (SREBP-1c), fatty acid synthase (FAS), Acetyl-CoA carboxylase (ACC), fatty acid translocase (FAT) and stearoylcoenzyme A desaturase-1 (SCD-1). In addition, JNK, ERK and p38 phosphorylation were inhibited during cocoa tea inhibition of 3T3-L1 adipogenic differentiation. Taken together, this is the first study that demonstrates cocoa tea has the capacity to suppress adipogenesis in pre-adipocyte 3T3-L1 similar to traditional green tea. PMID:26833256

  11. Structure, mechanism and function of prenyltransferases.

    PubMed

    Liang, Po-Huang; Ko, Tzu-Ping; Wang, Andrew H-J

    2002-07-01

    In this review, we summarize recent progress in studying three main classes of prenyltransferases: (a) isoprenyl pyrophosphate synthases (IPPSs), which catalyze chain elongation of allylic pyrophosphate substrates via consecutive condensation reactions with isopentenyl pyrophosphate (IPP) to generate linear polymers with defined chain lengths; (b) protein prenyltransferases, which catalyze the transfer of an isoprenyl pyrophosphate (e.g. farnesyl pyrophosphate) to a protein or a peptide; (c) prenyltransferases, which catalyze the cyclization of isoprenyl pyrophosphates. The prenyltransferase products are widely distributed in nature and serve a variety of important biological functions. The catalytic mechanism deduced from the 3D structure and other biochemical studies of these prenyltransferases as well as how the protein functions are related to their reaction mechanism and structure are discussed. In the IPPS reaction, we focus on the mechanism that controls product chain length and the reaction kinetics of IPP condensation in the cis-type and trans-type enzymes. For protein prenyltransferases, the structures of Ras farnesyltransferase and Rab geranylgeranyltransferase are used to elucidate the reaction mechanism of this group of enzymes. For the enzymes involved in cyclic terpene biosynthesis, the structures and mechanisms of squalene cyclase, 5-epi-aristolochene synthase, pentalenene synthase, and trichodiene synthase are summarized. PMID:12135472

  12. Structure, mechanism and function of prenyltransferases.

    PubMed

    Liang, Po-Huang; Ko, Tzu-Ping; Wang, Andrew H-J

    2002-07-01

    In this review, we summarize recent progress in studying three main classes of prenyltransferases: (a) isoprenyl pyrophosphate synthases (IPPSs), which catalyze chain elongation of allylic pyrophosphate substrates via consecutive condensation reactions with isopentenyl pyrophosphate (IPP) to generate linear polymers with defined chain lengths; (b) protein prenyltransferases, which catalyze the transfer of an isoprenyl pyrophosphate (e.g. farnesyl pyrophosphate) to a protein or a peptide; (c) prenyltransferases, which catalyze the cyclization of isoprenyl pyrophosphates. The prenyltransferase products are widely distributed in nature and serve a variety of important biological functions. The catalytic mechanism deduced from the 3D structure and other biochemical studies of these prenyltransferases as well as how the protein functions are related to their reaction mechanism and structure are discussed. In the IPPS reaction, we focus on the mechanism that controls product chain length and the reaction kinetics of IPP condensation in the cis-type and trans-type enzymes. For protein prenyltransferases, the structures of Ras farnesyltransferase and Rab geranylgeranyltransferase are used to elucidate the reaction mechanism of this group of enzymes. For the enzymes involved in cyclic terpene biosynthesis, the structures and mechanisms of squalene cyclase, 5-epi-aristolochene synthase, pentalenene synthase, and trichodiene synthase are summarized.

  13. Green tea: potential health benefits.

    PubMed

    Schneider, Craig; Segre, Tiffany

    2009-04-01

    Green tea has been used widely and in high doses for centuries as a health tonic in many societies. Evidence suggests that green tea is effective for treating genital warts. There is some supportive evidence for the use of green tea in cancer prevention. Drinking green tea is associated with a decrease in all-cause mortality, but not in cancer-related mortality. Small clinical studies have found that green tea may also be helpful in losing and managing weight, and lowering cholesterol. Epidemiologic evidence suggests that green tea may prevent stroke and cardiovascular disease. Green tea appears to be safe, although there have been case reports of hepatotoxicity possibly related to a specific extract in pill or beverage form. Green tea seems to be a low-risk complementary therapy for a number of conditions, but more studies are needed.

  14. Factors affecting the levels of tea polyphenols and caffeine in tea leaves.

    PubMed

    Lin, Yung-Sheng; Tsai, Yao-Jen; Tsay, Jyh-Shyan; Lin, Jen-Kun

    2003-03-26

    An isocratic HPLC procedure was developed for the simultaneous determination of caffeine and six catechins in tea samples. When 31 commercial teas extracted by boiling water or 75% ethanol were analyzed by HPLC, the levels of (-)-epigallocatechin 3-gallate (EGCG), and total catechins in teas were in the order green tea (old leaves) > green tea (young leaves) and oolong tea > black tea and pu-erh tea. Tea samples extracted by 75% ethanol could yield higher levels of EGCG and total catechins. The contents of caffeine and catechins also have been measured in fresh tea leaves from the Tea Experiment Station in Wen-Shan or Taitung; the old tea leaves contain less caffeine but more EGCG and total catechins than young ones. To compare caffeine and catechins in the same tea but manufactured by different fermentation processes, the level of caffeine in different manufactured teas was in the order black tea > oolong tea > green tea > fresh tea leaf, but the levels of EGCG and total catechins were in the order green tea > oolong tea > fresh tea leaf > black tea. In addition, six commercial tea extracts were used to test the biological functions including hydroxyl radical scavenging, nitric oxide suppressing, and apoptotic effects. The pu-erh tea extracts protected the plasmid DNA from damage by the Fenton reaction as well as the control at a concentration of 100 microg/mL. The nitric oxide suppressing effect of tea extracts was in the order pu-erh tea >/= black tea > green tea > oolong tea. The induction of apoptosis by tea extract has been demonstrated by DNA fragmentation ladder and flow cytometry. It appeared that the ability of tea extracts to induce HL-60 cells apoptosis was in the order green tea > oolong > black tea > pu-erh tea. All tea extracts extracted by 75% ethanol have stronger biological functions than those extracted by boiling water.

  15. Tea polyphenols for health promotion.

    PubMed

    Khan, Naghma; Mukhtar, Hasan

    2007-07-26

    People have been consuming brewed tea from the leaves of the Camellia sinensis plant for almost 50 centuries. Although health benefits have been attributed to tea, especially green tea consumption since the beginning of its history, scientific investigations of this beverage and its constituents have been underway for less than three decades. Currently, tea, in the form of green or black tea, next to water, is the most widely consumed beverage in the world. In vitro and animal studies provide strong evidence that polyphenols derived from tea may possess the bioactivity to affect the pathogenesis of several chronic diseases. Among all tea polyphenols, epigallocatechin-3-gallate has been shown to be responsible for much of the health promoting ability of green tea. Tea and tea preparations have been shown to inhibit tumorigenesis in a variety of animal models of carcinogenesis. However, with increasing interest in the health promoting properties of tea and a significant rise in scientific investigation, this review covers recent findings on the medicinal properties and health benefits of tea with special reference to cancer and cardiovascular diseases. PMID:17655876

  16. Stilbene Synthase and Chalcone Synthase 1

    PubMed Central

    Rolfs, Claus-Henning; Kindl, Helmut

    1984-01-01

    Cultured cells of Picea excelsa capable of forming stilbenes and flavanoids have been established. Unlike needles of intact plants containing piceatannol (3,3′,4′,5-tetrahydroxystilbene) and stilbene glycosides the cultured cells converted phenylalanine and p-coumaric acid primarily into resveratrol monomethyl ether (3,4′-dihydroxy-5-methoxystilbene) and naringenin. Partially purified enzyme preparations were assayed for chalcone synthase as well as for stilbene synthase activity converting malonyl-CoA plus p-coumaroyl-CoA into 3,4′,5-trihydroxystilbene (resveratrol). Although stilbene synthase and chalcone synthase use the same substrates and exhibit similar molecular properties, i.e. molecular weight and subunit molecular weight, they are two different proteins. This difference was demonstrated by gel electrophoresis and by means of monospecific antibodies. PMID:16663649

  17. Relationship between gene expression and the accumulation of catechin during spring and autumn in tea plants (Camellia sinensis L.)

    PubMed Central

    Liu, Min; Tian, Heng-lu; Wu, Jian-Hua; Cang, Ren-Rong; Wang, Run-Xian; Qi, Xiao-Hua; Xu, Qiang; Chen, Xue-Hao

    2015-01-01

    The tea plant (Camellia sinensis L.) is an important commercial crop with remarkably high catechin concentrations. Tea is popular worldwide given the plant's health benefits. Catechins are the main astringent substance in tea and are synthesized mainly via the phenylpropanoid pathway. In this study, eight cultivars of tea plants harvested both in spring and autumn were used to investigate differences in catechin concentrations by using high-performance liquid chromatography. The expression levels of genes associated with catechin biosynthesis were investigated using reverse transcription-quantitative polymerase chain reaction. The results indicated that the total catechin (TC) concentrations were significantly higher in tea plants harvested in autumn than in those harvested in spring, based on higher concentrations of epigallocatechin (EGC) in autumn tea (P<0.01). The expression of the genes phenylalanine ammonia-lyase (PAL), flavanone 3-hydroxylase (F3H), flavonoid 3′,5′-hydroxylase (F3′5′H), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS) is closely related to the TC content of tea plants in both spring and autumn. Positive correlations between PAL, cinnamate 4-hydroxylase (C4H), F3H, and DFR expression and EGC accumulation in autumn tea were identified, with correlation coefficients of 0.710, 0.763, 0.884, and 0.707, respectively. A negative correlation between ANS expression level and EGC concentrations in tea plants harvested in spring was noted (r=−0.732). Additionally, negative correlations between F3H and ANS expression levels and the catechin content were identified in spring tea, whereas the correlations were positive in autumn tea. Significant differences in the F3H and ANS expression levels between spring and autumn tea indicate that F3H and ANS are potentially key genes affecting catechin accumulation in tea plants. PMID:26504566

  18. Relationship between gene expression and the accumulation of catechin during spring and autumn in tea plants (Camellia sinensis L.).

    PubMed

    Liu, Min; Tian, Heng-Lu; Wu, Jian-Hua; Cang, Ren-Rong; Wang, Run-Xian; Qi, Xiao-Hua; Xu, Qiang; Chen, Xue-Hao

    2015-01-01

    The tea plant (Camellia sinensis L.) is an important commercial crop with remarkably high catechin concentrations. Tea is popular worldwide given the plant's health benefits. Catechins are the main astringent substance in tea and are synthesized mainly via the phenylpropanoid pathway. In this study, eight cultivars of tea plants harvested both in spring and autumn were used to investigate differences in catechin concentrations by using high-performance liquid chromatography. The expression levels of genes associated with catechin biosynthesis were investigated using reverse transcription-quantitative polymerase chain reaction. The results indicated that the total catechin (TC) concentrations were significantly higher in tea plants harvested in autumn than in those harvested in spring, based on higher concentrations of epigallocatechin (EGC) in autumn tea (P<0.01). The expression of the genes phenylalanine ammonia-lyase (PAL), flavanone 3-hydroxylase (F3H), flavonoid 3',5'-hydroxylase (F3'5'H), dihydroflavonol 4-reductase (DFR), and anthocyanidin synthase (ANS) is closely related to the TC content of tea plants in both spring and autumn. Positive correlations between PAL, cinnamate 4-hydroxylase (C4H), F3H, and DFR expression and EGC accumulation in autumn tea were identified, with correlation coefficients of 0.710, 0.763, 0.884, and 0.707, respectively. A negative correlation between ANS expression level and EGC concentrations in tea plants harvested in spring was noted (r=-0.732). Additionally, negative correlations between F3H and ANS expression levels and the catechin content were identified in spring tea, whereas the correlations were positive in autumn tea. Significant differences in the F3H and ANS expression levels between spring and autumn tea indicate that F3H and ANS are potentially key genes affecting catechin accumulation in tea plants. PMID:26504566

  19. Expression of caffeine biosynthesis genes in tea (Camellia sinensis).

    PubMed

    Li, Yeyun; Ogita, Shinjiro; Keya, Chaman Ara; Ashihara, Hiroshi

    2008-01-01

    Using semi-quantitative reverse transcription-PCR, we studied the expression of genes encoding caffeine synthase (TCS1), inosine-5'-monophosphate dehydrogenase (TIDH), S-adenosyl-L-methionine synthase (sAMS), phenylalanine ammonia-lyase (PAL) and alpha-tubulin (Tua1) in young and mature leaves, stems and roots of 4-month-old tea seedlings and young and old tea tissue cultures. The amounts of transcripts of TCS1 were much higher in young leaves than in other parts of the plant. Expression of TIDH was greater in leaves than in other parts. Little difference in the amounts of transcripts of PAL, sAMS and Tua1 was found between various organs of tea seedlings. Larger amounts of transcripts of TCS1 and PAL were found in young callus tissues than in old tissues. These results support our conclusion deriving from previous enzymatic and metabolic studies that caffeine is synthesized mainly in young leaf tissues. We propose that marked caffeine biosynthesis in young leaves is dependent on a greater expression of the TCS1 gene in the organ.

  20. Aqueous extract of Yerba Mate tea lowers atherosclerotic risk factors in a rat hyperlipidemia model.

    PubMed

    Gao, Hongli; Liu, Zhaochun; Wan, Wenju; Qu, Xiaolan; Chen, Meihua

    2013-08-01

    Yerba Mate tea (Mate) is believed to be a natural source of cardioprotective lipid-lowering and antioxidant compounds. In this study, the antihyperlipidemic and antioxidant effects of Mate tea in a rat hyperlipidemia model were investigated. Male Sprague-Dawley rats were divided randomly into five groups and fed varying diets: standard diet, hyperlipidemic diet, and hyperlipidemic diet supplemented with low, moderate, or high concentrations of Mate tea aqueous extract (1%, 2%, and 4% w/v, respectively). Compared to the hyperlipidemic control group, Mate tea reduced significantly the total body weight and lowered serum levels of total cholesterol, triglyceride, and low-density lipoprotein-cholesterol, and caused the elevation of serum levels of high-density lipoprotein-cholesterol. Moreover, activities of superoxide dismutase and glutathione peroxidase in serum were elevated significantly, whereas the levels of malondialdehyde decreased. In addition, Mate tea treatment ameliorated significantly the severe fatty degeneration of liver cells that occurred in the hyperlipidemic groups. The relative levels of sterol regulatory element binding protein 1 and its target fatty acid synthase, as well as acetyl-CoA carboxylase mRNA transcripts were reduced, whereas peroxisome proliferator-activated receptor alpha mRNA transcripts were elevated in the Mate tea groups. Our results suggest that Mate tea exerts strong antioxidant and lipid-lowering effects, prevents hepatic fatty deposition, and regulates the expression of lipid metabolic regulators. It can therefore be used to reduce the risk of atherosclerosis.

  1. Sassafras tea and diaphoresis.

    PubMed

    Haines, J D

    1991-09-15

    A patient whose main symptom is sweating can present a diagnostic challenge. Dr Haines describes a case in which diaphoresis was caused not by a conventional medication or illness but rather by a life-style change in which the patient began consuming sassafras tea.

  2. Tea and Telling Stories.

    ERIC Educational Resources Information Center

    Michael, Pamela

    2001-01-01

    The annual Women's and Girls' Tea Party and Storytelling Ceremony is held in a Berkeley redwood grove by a creek. Seeking to generate community support for creek restoration, the ceremony/celebration/site-specific performance piece uses childhood rituals and story telling to help participants connect emotionally to each other, the place, its past,…

  3. Caffeine content of brewed teas.

    PubMed

    Chin, Jenna M; Merves, Michele L; Goldberger, Bruce A; Sampson-Cone, Angela; Cone, Edward J

    2008-10-01

    Caffeine is the world's most popular drug and can be found in many beverages including tea. It is a psychostimulant that is widely used to enhance alertness and improve performance. This study was conducted to determine the concentration of caffeine in 20 assorted commercial tea products. The teas were brewed under a variety of conditions including different serving sizes and steep-times. Caffeine was isolated from the teas with liquid-liquid extraction and quantitated by gas chromatography with nitrogen-phosphorus detection. Caffeine concentrations in white, green, and black teas ranged from 14 to 61 mg per serving (6 or 8 oz) with no observable trend in caffeine concentration due to the variety of tea. The decaffeinated teas contained less than 12 mg of caffeine per serving, and caffeine was not detected in the herbal tea varieties. In most instances, the 6- and 8-oz serving sizes contained similar caffeine concentrations per ounce, but the steep-time affected the caffeine concentration of the tea. These findings indicate that most brewed teas contain less caffeine per serving than brewed coffee. PMID:19007524

  4. Green tea and bone metabolism.

    PubMed

    Shen, Chwan-Li; Yeh, James K; Cao, Jay J; Wang, Jia-Sheng

    2009-07-01

    Osteoporosis is a major health problem in both elderly women and men. Epidemiological evidence has shown an association between tea consumption and the prevention of age-related bone loss in elderly women and men. Ingestion of green tea and green tea bioactive compounds may be beneficial in mitigating bone loss of this population and decreasing their risk of osteoporotic fractures. This review describes the effect of green tea or its bioactive components on bone health, with an emphasis on (i) the prevalence and etiology of osteoporosis; (ii) the role of oxidative stress and antioxidants in osteoporosis; (iii) green tea composition and bioavailability; (iv) the effects of green tea and its active components on osteogenesis, osteoblastogenesis, and osteoclastogenesis from human epidemiological, animal, as well as cell culture studies; (v) possible mechanisms explaining the osteoprotective effects of green tea bioactive compounds; (vi) other bioactive components in tea that benefit bone health; and (vii) a summary and future direction of green tea and bone health research and the translational aspects. In general, tea and its bioactive components might decrease the risk of fracture by improving bone mineral density and supporting osteoblastic activities while suppressing osteoclastic activities.

  5. The Full-Size ABCG Transporters Nb-ABCG1 and Nb-ABCG2 Function in Pre- and Postinvasion Defense against Phytophthora infestans in Nicotiana benthamiana.

    PubMed

    Shibata, Yusuke; Ojika, Makoto; Sugiyama, Akifumi; Yazaki, Kazufumi; Jones, David A; Kawakita, Kazuhito; Takemoto, Daigo

    2016-05-01

    The sesquiterpenoid capsidiol is the major phytoalexin produced by Nicotiana and Capsicum species. Capsidiol is produced in plant tissues attacked by pathogens and plays a major role in postinvasion defense by inhibiting pathogen growth. Using virus-induced gene silencing-based screening, we identified two Nicotiana benthamiana (wild tobacco) genes encoding functionally redundant full-size ABCG (PDR-type) transporters, Nb-ABCG1/PDR1 and Nb-ABCG2/PDR2, which are essential for resistance to the potato late blight pathogen Phytophthora infestans Silencing of Nb-ABCG1/2 compromised secretion of capsidiol, revealing Nb-ABCG1/2 as probable exporters of capsidiol. Accumulation of plasma membrane-localized Nb-ABCG1 and Nb-ABCG2 was observed at the site of pathogen penetration. Silencing of EAS (encoding 5-epi-aristolochene synthase), a gene for capsidiol biosynthesis, reduced resistance to P. infestans, but penetration by P. infestans was not affected. By contrast, Nb-ABCG1/2-silenced plants showed reduced penetration defense, indicating that Nb-ABCG1/2 are involved in preinvasion defense against P. infestans Plastidic GGPPS1 (geranylgeranyl diphosphate synthase) was also found to be required for preinvasion defense, thereby suggesting that plastid-produced diterpene(s) are the antimicrobial compounds active in preinvasion defense. These findings suggest that N. benthamiana ABCG1/2 are involved in the export of both antimicrobial diterpene(s) for preinvasion defense and capsidiol for postinvasion defense against P. infestans.

  6. Developmentally Regulated Sesquiterpene Production Confers Resistance to Colletotrichum gloeosporioides in Ripe Pepper Fruits

    PubMed Central

    Im, Soonduk; Han, Yun-Jeong; Lee, Sungbeom; Back, Kyoungwhan; Kim, Jeong-Il; Kim, Young Soon

    2014-01-01

    Sesquiterpenoid capsidiol, exhibiting antifungal activity against pathogenic fungus, is accumulated in infected ripe pepper fruits. In this study, we found a negative relation between the capsidiol level and lesion size in fruits infected with Colletotrichum gloeosporioides, depending on the stage of ripening. To understand the developmental regulation of capsidiol biosynthesis, fungal-induced gene expressions in the isoprenoid biosynthetic pathways were examined in unripe and ripe pepper fruits. The sterol biosynthetic pathway was almost shut down in healthy ripe fruits, showing very low expression of hydroxymethyl glutaryl CoA reductase (HMGR) and squalene synthase (SS) genes. In contrast, genes in the carotenoid pathway were highly expressed in ripe fruits. In the sesquiterpene pathway, 5-epi-aristolochene synthase (EAS), belonging to a sesquiterpene cyclase (STC) family, was significantly induced in the ripe fruits upon fungal infection. Immunoblot and enzyme activity analyses showed that the STCs were induced both in the infected unripe and ripe fruits, while capsidiol was synthesized discriminatively in the ripe fruits, implying diverse enzymatic specificity of multiple STCs. Thereby, to divert sterol biosynthesis into sesquiterpene production, infected fruits were pretreated with an SS inhibitor, zaragozic acid (ZA), resulting in increased levels of capsidiol by more than 2-fold in the ripe fruits, with concurrent reduction of phytosterols. Taken together, the present results suggest that the enhanced expression and activity of EAS in the ripe fruits play an important role in capsidiol production, contributing to the incompatibility between the anthracnose fungus and the ripe pepper fruits. PMID:25286411

  7. Residues and contaminants in tea and tea infusions: a review.

    PubMed

    Abd El-Aty, A M; Choi, Jeong-Heui; Rahman, Md Musfiqur; Kim, Sung-Woo; Tosun, Alev; Shim, Jae-Han

    2014-01-01

    Consumers are very aware of contaminants that could pose potential health hazards. Most people drink tea as an infusion (adding hot water); however, in some countries, including India, China and Egypt, tea is drunk as a decoction (tea and water are boiled together). An infusion usually brings the soluble ingredients into solution, whereas a decoction brings all soluble and non-soluble constituents together. Therefore, a cup of tea may contain various kinds of contaminants. This review focuses on green and black tea because they are most commonly consumed. The target was to examine the transfer rate of contaminants - pesticides, environmental pollutants, mycotoxins, microorganisms, toxic heavy metals, radioactive isotopes (radionuclides) and plant growth regulators - from tea to infusion/brewing, factors contributing to the transfer potential and contaminants degradation, and residues in or on the spent leaves. It is concluded that most contaminants leaching into tea infusion are not detected or are detected at a level lower than the regulatory limits. However, the traditional practice of over-boiling tea leaves should be discouraged as there may be a chance for more transfer of contaminants from the tea to the brew.

  8. Recent advances on tea polyphenols

    PubMed Central

    Kanwar, Jyoti; Taskeen, Mujtaba; Mohammad, Imthiyaz; Huo, Congde; Chan, Tak Hang; Dou, Qing Ping

    2012-01-01

    Over the past decade many scientific and medical studies have focused on green tea for its long-purported health benefits. There is convincing evidence that tea is a cup of life. It has multiple preventive and therapeutic effects. This review thus focuses on the recent advances of tea polyphenols and their applications in the prevention and treatment of human cancers. Of the various polyphenols in tea, (−)-Epigallocatechin-3-gallate (EGCG) is the most abundant, and active compound studied in tea research. EGCG inhibits several molecular targets to inhibit cancer initiation and modulates several essential survival pathways to block cancer progression. Herein, we describe the various mechanisms of action of EGCG and also discuss previous and current ongoing clinical trials of EGCG and green tea polyphenols in different cancer types. PMID:22201858

  9. Black tea: chemical analysis and stability.

    PubMed

    Li, Shiming; Lo, Chih-Yu; Pan, Min-Hsiung; Lai, Ching-Shu; Ho, Chi-Tang

    2013-01-01

    Tea is the most popular flavored and functional drink worldwide. The nutritional value of tea is mostly from the tea polyphenols that are reported to possess a broad spectrum of biological activities, including anti-oxidant properties, reduction of various cancers, inhibition of inflammation, and protective effects against diabetes, hyperlipidemia and obesity. Tea polyphenols include catechins and gallic acid in green and white teas, and theaflavins and thearubigins as well as other catechin polymers in black and oolong teas. Accurate analysis of black tea polyphenols plays a significant role in the identification of black tea contents, quality control of commercial tea beverages and extracts, differentiation of various contents of theaflavins and catechins and correlations of black tea identity and quality with biological activity, and most importantly, the establishment of the relationship between quantitative tea polyphenol content and its efficacy in animal or human studies. Global research in tea polyphenols has generated much in vitro and in vivo data rationally correlating tea polyphenols with their preventive and therapeutic properties in human diseases such as cancer, and metabolic and cardiovascular diseases etc. Based on these scientific findings, numerous tea products have been developed including flavored tea drinks, tea-based functional drinks, tea extracts and concentrates, and dietary supplements and food ingredients, demonstrating the broad applications of tea and its extracts, particularly in the field of functional food.

  10. Tea creaming in nonfermented teas from Camellia sinensis and Ilex vomitoria.

    PubMed

    Kim, Youngmok; Talcott, Stephen T

    2012-11-28

    Tea creaming is the development of a cloudy or hazy appearance in tea and ready-to-drink tea products on cooling and is highly undesirable in the tea beverage industry. Commonly associated with fermented black or oolong teas, the objective of this study was to investigate the physicochemical mechanism of the formation of tea cream in nonfermented green tea (Camellia sinensis) and a caffeine-containing botanical tea from yaupon holly (Ilex vomitoria) that is free of catechin-based polyphenolics. Four tea-creaming activators (phenolics, soluble protein, caffeine, and metal ions) were added to tea infusions as well as decaffeinated teas created by chloroform extraction. Tea-creaming activators increased the weight and turbidity of both teas with the exception of soluble protein addition (as bovine serum albumin) to green tea, whereas the greatest increase in turbidity occurred with the addition of metal ions in green tea. Tea creaming was equally developed at three incubation temperatures (4, 25, and 40 °C) in both teas, but tea-creaming compositions in each tea were different at the incubating temperatures. The antioxidant capacity of each tea was lowered after creaming due to the loss of antioxidants that participated in tea cream formation. PMID:23148671

  11. Prevention of heterocyclic amine formation by tea and tea polyphenols.

    PubMed

    Weisburger, J H; Nagao, M; Wakabayashi, K; Oguri, A

    1994-08-15

    Heterocyclic amines (HCAs), formed during the cooking of meats and fish, are thought to be the genotoxic carcinogens associated with important types of human cancer in meat-eating populations, such as cancer of the breast, colon or pancreas. We studied the effect of black or green tea, and of the tea polyphenols theaflavine gallate (TFG, black tea) and epigallocatechin gallate (EGCG, green tea) on the formation of typical HCAs, 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), using the model in vitro systems of Jägerstad. Green tea and black tea and solutions of TFG and EGCG lower the formation of PhIP by 62-85% during 1 h heating at 160 degrees C of 1 mmol creatinine, 1 mmol phenylalanine and 0.5 mmol glucose in 3.3 ml diethylene glycol-water (10:1), where the inhibitors replaced 0.3 ml of the water. The production of MeIQx and related HCAs, in the same system but with 1 mmol glycine instead of phenylalanine was likewise reduced, determined by amounts of mutagens formed. In the latter systems, the teas were not, or less effective, but the polyphenols were inhibitory. Thus, the tea products represent another approach to lower the formation of HCAs.

  12. Delivery of tea polyphenols to the oral cavity by green tea leaves and black tea extract.

    PubMed

    Lee, Mao-Jung; Lambert, Joshua D; Prabhu, Saileta; Meng, Xiaofeng; Lu, Hong; Maliakal, Pius; Ho, Chi-Tang; Yang, Chung S

    2004-01-01

    Catechins and theaflavins, polyphenolic compounds derived from tea (Camellia sinensis, fam. Theaceae), have been reported to have a wide range of biological activities including prevention of tooth decay and oral cancer. The present study was undertaken to determine the usefulness of green tea leaves and black tea extract for the delivery of catechins and theaflavins to the oral cavity. After holding either green tea leaves (2 g) or brewed black tea (2 g of black tea leaves in 100 ml) in the mouth for 2-5 min and thoroughly rinsing the mouth, high concentrations of catechins (C(max) = 131.0-2.2 micro M) and theaflavins (C(max) = 1.8-0.6 micro M) were observed in saliva in the 1st hour. Whereas there was significant interindividual variation in the peak levels of catechins and theaflavins, the overall kinetic profile was similar, with t(1/2) = 25-44 min and 49-76 min for catechins and theaflavins, respectively (average coefficient of variation in t(1/2) was 23.4%). In addition to the parent catechin and theaflavin peaks, five unidentified peaks were also observed in saliva after black tea treatment. Hydrolysis of theaflavin gallates, apparently by salivary esterases, was observed in vitro and in vivo. These results indicate that tea leaves can be used as a convenient, slow-release source of catechins and theaflavins and provide information for the possible use of tea in the prevention of oral cancer and dental caries. PMID:14744744

  13. Association mapping of caffeine content with TCS1 in tea plant and its related species.

    PubMed

    Jin, Ji-Qiang; Yao, Ming-Zhe; Ma, Chun-Lei; Ma, Jian-Qiang; Chen, Liang

    2016-08-01

    Caffeine is the most abundant purine alkaloid in majority of tea plant and its related species. This purine alkaloid contributes to the important flavor and health attributes of tea. Tea caffeine synthase 1 (TCS1, EC 2.1.1.159/2.1.1.160) gene plays a crucial role in caffeine biosynthesis. The objective of this study was to investigate the genetic relationship between the TCS1 and caffeine content of tea plant and its related species using association mapping. We identified 87 single-nucleotide polymorphisms (SNPs, π = 0.00447) by resequencing the TCS1 locus of 44 tea accessions. Linkage disequilibrium (LD) analysis showed that LD did not extend over the entire gene (r(2) < 0.1, within 1000 bp). Two cleaved amplified polymorphism sequence (CAPS) markers were developed from sequence variations (SNP4318 and SNP6252). By association mapping, we identified SNP4318 associated with caffeine content in four environments, explaining 4.0%-7.7% of the phenotypic variance. We also validated the significant marker-trait associations in site-directed mutagenesis experiments. Examination of allelic variation and linkage disequilibrium by a candidate-gene-based approach can help to decipher the genetic basis of caffeine biosynthesis. Moreover, the SNP marker identified in this study can potentially be applied for future marker-assisted selection to improve tea quality.

  14. [Historical consideration of tea trees and tea flowers, especially regarding the use of tea flowers as food].

    PubMed

    Harima, Shoichi; Yoshikawa, Masayuki; Tokuoka, Kiyoshi

    2008-01-01

    Not only tea leaves, but also many kinds of plants have been used as tea, even those plants not belonging to Camellia sinensis, and they should be called "tea out of tea" in the Lucidophyllous forest zone. Generally, the tea leaf is drank after being decocted (almost boiled). The growth distribution of tea ranges in a belt-like zone of 30-40 degrees north latitude. Therefore, tea might have grown wild as "YAMACHA (mountain tea)" from ancient times in Japan as well as China. The first recored of tea drinking in Japan is the ceremony of "GYOUCHA" at the Imperial Court of the Emperor SHOUMU in 729. On the other hand, the oldest book about tea in China (CHAKYOU) was written in 770. Therefore, it seems that tea drinking started at nearly the same time in both countries. Tea was dispensed as medical supplies by Chinese medicinal prescription (SENKYUCHACHOUSAN) in Japan, but in China, tea was used as powdered medicine for drinking (SEICHA). However, the leaf of a certain plant used as "tea out of tea," was applied as a galenical preparation for traditional Chinese medicinal constitution. However, it is not possible to judge whether or not there was adaptability in Chinese medicine theory. In Japan, when tea was first consumed as a food, other than a few exceptions tea leaves were used as a coarse tea (BANCHA) until the latter half of the Meiji period. Mixing in air by stirring a tea solution, and at the same time, letting tea match with hot water. It was wisdom to improve the taste. As a result, in order to make bubble well, both of the condition and technique were devised. One of the approaches was to add the dried plant of Leguminosae (saponin) or tea flower (saponin), when "BANCHA" was decorted. And also tools such as a bamboo tea whisk (CHASEN) as well as bowl (GOROHACHI-CHAWAN), were conceived. "FURICHA" was served as a medicine by KUUYASHOUNIN in Japan in 951. Afterwards, the prayer ceremonies at shrines and temples used CHARAZU," showing the custom to serve tea in

  15. [Historical consideration of tea trees and tea flowers, especially regarding the use of tea flowers as food].

    PubMed

    Harima, Shoichi; Yoshikawa, Masayuki; Tokuoka, Kiyoshi

    2008-01-01

    Not only tea leaves, but also many kinds of plants have been used as tea, even those plants not belonging to Camellia sinensis, and they should be called "tea out of tea" in the Lucidophyllous forest zone. Generally, the tea leaf is drank after being decocted (almost boiled). The growth distribution of tea ranges in a belt-like zone of 30-40 degrees north latitude. Therefore, tea might have grown wild as "YAMACHA (mountain tea)" from ancient times in Japan as well as China. The first recored of tea drinking in Japan is the ceremony of "GYOUCHA" at the Imperial Court of the Emperor SHOUMU in 729. On the other hand, the oldest book about tea in China (CHAKYOU) was written in 770. Therefore, it seems that tea drinking started at nearly the same time in both countries. Tea was dispensed as medical supplies by Chinese medicinal prescription (SENKYUCHACHOUSAN) in Japan, but in China, tea was used as powdered medicine for drinking (SEICHA). However, the leaf of a certain plant used as "tea out of tea," was applied as a galenical preparation for traditional Chinese medicinal constitution. However, it is not possible to judge whether or not there was adaptability in Chinese medicine theory. In Japan, when tea was first consumed as a food, other than a few exceptions tea leaves were used as a coarse tea (BANCHA) until the latter half of the Meiji period. Mixing in air by stirring a tea solution, and at the same time, letting tea match with hot water. It was wisdom to improve the taste. As a result, in order to make bubble well, both of the condition and technique were devised. One of the approaches was to add the dried plant of Leguminosae (saponin) or tea flower (saponin), when "BANCHA" was decorted. And also tools such as a bamboo tea whisk (CHASEN) as well as bowl (GOROHACHI-CHAWAN), were conceived. "FURICHA" was served as a medicine by KUUYASHOUNIN in Japan in 951. Afterwards, the prayer ceremonies at shrines and temples used CHARAZU," showing the custom to serve tea in

  16. Tea drinking and cancer risk: epidemiologic evidence

    PubMed

    Chow; Blot; McLaughlin

    1999-04-01

    Tea and tea compounds have been shown to inhibit carcinogenic processes in experimental animals, raising the possibility that tea drinking may lower cancer risk in humans. However, epidemiologic studies have produced inconsistent evidence on the relation between tea drinking and cancer risk. Ecological data show considerable international variation in tea consumption but relatively small differences in cancer rates. Results from case-control and cohort studies also are inconclusive. Nevertheless, high consumption of tea has been linked to a reduced risk of digestive tract cancers in a number of epidemiologic studies. A lack of detailed information on duration and amount of tea drinking, a narrow range of tea intake in some study populations, inadequate control for confounding, and potential biases in recall and reporting of tea drinking patterns in case-control studies may have contributed to the diverse findings. Further research is needed before definitive conclusions on tea's impact upon cancer risk in humans can be reached. PMID:10202387

  17. Green tea and theanine: health benefits.

    PubMed

    Cooper, Raymond

    2012-03-01

    Historically, the medicinal use of green tea dates back to China 4700 years ago and drinking tea continues to be regarded traditionally in Asia as a general healthful practice. Numerous scientific publications now attest to the health benefits of both black and green teas, including clinical and epidemiological studies. Although all tea contains beneficial antioxidants, high-quality green and white teas have them in greater concentrations than black tea. Today, scientists believe that the main active ingredients of green tea include the polyphenols, in particular the catechins and the amino acid, theanine. Studies on the health benefits of drinking tea, particularly green tea, are finding exciting results, particularly in cancer research. Modern studies in both Asia and the West have provided encouraging results indicating that drinking green tea contributes to fighting many different kinds of cancers including stomach, oesophageal, ovarian and colon. Recent studies describing the health benefits of these compounds will be reviewed.

  18. The chemistry and biotransformation of tea constituents.

    PubMed

    Sang, Shengmin; Lambert, Joshua D; Ho, Chi-Tang; Yang, Chung S

    2011-08-01

    Tea (Camellia sinensis, Theaceae) is one of the most widely consumed beverages in the world. The three major types of tea, green tea, oolong tea, and black tea, differ in terms of the manufacture and chemical composition. There are numerous studies in humans, animal models, and cell lines to suggest potential health benefits from the consumption of tea, including prevention of cancer and heart diseases. Many of the health benefits have been attributed to the polyphenolic constituents in tea. Catechins and their dimers (theaflavins) and polymers (thearubigins) have been identified as the major components in tea. Methylation, glucuronidation, sulfation, and ring-fission metabolism represent the major metabolic pathways for tea catechins. The present review summarizes the data concerning the chemistry and biotransformation of tea constituents. PMID:21371557

  19. [Studies on tea and health].

    PubMed

    Han, Chi

    2011-11-01

    Many studies, both national and international, have shown that tea has protective effects on many chronic diseases and their risk factors. In cancer prevention, our studies indicated that tea drinking could inhibit the carcinogenicity of various chemical carcinogens, including oral tumors induced by 7,12-dimethylbenz[a]anthracene (DMBA) in Golden hamsters, esophageal tumors in rats by blocking in vivo synthesis of N-Nitroso-methylbenzylamine (NMBzA), esophageal cancer induced by NMBzA in rats, precancerous liver lesions (r-GT and GST-P) induced by diethylnitrosamine (DENA) in rats, intestinal preneoplastic lesion (ACF) and intestinal tumors induced by 1,2-dimethyl-hydrazine (DMH) in rats, lung carcinoma induced by nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone(NNK) in A/J mice. Our studies have also shown that the protective effects of tea against cancer is a combined effects of various tea ingredients, among which the major ones are polyphenols and tea pigments. Based on animal studies, antioxidant properties, protection against DNA damage and modulation of immune functions were found to be the main mechanisms of anticancer effects of tea. In human trials, tea drinking showed protective effects against oxidative damage and DNA damage caused by cigarette smoking. Mixed tea drinking significantly blocked lesion progress in patients with oral mucosa leukoplakia, therefore, demonstrated its protective effects on oral cancer. Our studies have also shown effects of tea on prevention of cardiovascular diseases (CVD). For example, tea pigments was found to significantly inhibit LDL oxidation induced by Cu2+, Fe2+ in in vitro studies. In vivo studies showed that tea could prevent blood coagulation, facilitate fibrinogen dissolution, inhibit platelet aggregation, lower endothelin levels, enhance GSH-Px activities, protect against oxidated LDL-induced damage in endothelium cells, and prevent atherosclerosis of coronary arteries. The mechanisms of these protective

  20. Antioxidant effects of green tea

    PubMed Central

    FORESTER, SARAH C.; LAMBERT, JOSHUA D.

    2013-01-01

    Consumption of green tea (Camellia sinensis) may provide protection against chronic diseases, including cancer. Green tea polyphenols are believed to be responsible for this cancer preventive effect, and the antioxidant activity of the green tea polyphenols has been implicated as a potential mechanism. This hypothesis has been difficult to study in vivo due to metabolism of these compounds and poor understanding of the redox environment in vivo. Green tea polyphenols can be direct antioxidants by scavenging reactive oxygen species or chelating transition metals as has been demonstrated in vitro. Alternatively, they may act indirectly by up-regulating phase II antioxidant enzymes. Evidence of this latter effect has been observed in vivo, yet more work is required to determine under which conditions these mechanisms occur. Green tea polyphenols can also be potent pro-oxidants, both in vitro and in vivo, leading to the formation of hydrogen peroxide, the hydroxyl radical, and superoxide anion. The potential role of these pro-oxidant effects in the cancer preventive activity of green tea is not well understood. The evidence for not only the antioxidant, but also pro-oxidant, properties of green tea are discussed in the present review. PMID:21538850

  1. Effect of cocoa tea (Camellia ptilophylla) co-administrated with green tea on ambulatory behaviors.

    PubMed

    He, Rong-rong; Xie, Guo; Yao, Xin-Sheng; Kurihara, Hiroshi

    2009-04-23

    We investigated the effects of cocoa tea and its main active compound theobromine on ambulatory activity, compared with green tea and caffeine. Although cocoa tea and theobromine themselves didn't change the ambulatory behaviors as green tea and caffeine did, combined administration with green tea or caffeine showed a synergistic action. The obtained data are perhaps contribution to the consumption of cocoa tea in the world. PMID:19352019

  2. Chemopreventive efficacy of green tea drinking against 1,2-dimethyl hydrazine-induced rat colon carcinogenesis.

    PubMed

    Sadik, Nermin A H

    2013-04-01

    Colorectal cancer is one of the leading causes of tumour-related deaths. In the present study, the chemopreventive effect of green tea on 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis was studied in male Wistar rats. The DMH group received subcutaneous injections of DMH (30 mg kg(-1) body weight) once a week for 30 weeks, the normal group received the vehicle of DMH, and the DMH + green tea group received DMH simultaneously with 1% green tea as their sole source of drinking fluid throughout the experimental period. In the DMH group treated with green tea, significant reductions in gene overexpressions of colonic nuclear factor κB (NF-κB), tumour necrosis factor α, inducible nitric oxide synthase and cyclooxygenase 2, and NF-κB immunostaining indicates the anti-inflammatory effect of green tea in attenuating colon cancer. Moreover, the anti-angiogenic and anti-invasiveness effects of green tea were revealed as reductions of both vascular endothelial growth factor and matrix metalloproteinase-7 mRNA expression levels. These effects were confirmed by the significant reduction of serum tumour necrosis factor α, C-reactive protein levels, inhibition of tumour incidence, and nearly normal survival rate and colonic architecture. It can be concluded that green tea exerts a potent chemopreventive effect on colon carcinogenesis possibly due to the inhibition of NF-κB.

  3. Tea and human health: biomedical functions of tea active components and current issues*

    PubMed Central

    Chen, Zong-mao; Lin, Zhi

    2015-01-01

    Originating in China, tea and tea planting have spread throughout the world since the middle of the Tang dynasty. Now people from 160 countries in the world are accustomed to tea drinking. A brief history of tea’s medicinal role in China and its spread to the world are introduced. The effectiveness of tea active components and tea drinking on major human diseases, including cancer, metabolic syndrome, cardiovascular disease, and neurodegenerative diseases, is discussed. Also presented are some related issues, such as the bioavailability of tea active components, the new formulations of tea polyphenols, and the safety for consumers of dietary supplements containing tea polyphenols. PMID:25644464

  4. K and Ca content of fresh green tea, black tea, and tea residue determined by X-ray fluorescence analysis.

    PubMed

    Nas, S; Gokalp, H Y; Sahin, Y

    1993-01-01

    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 areas of Turkey, green tea of different shooting periods, black tea processed at different tea plants and tea residues from these black tea were analysed. The K content of green tea, processed black tea and tea residues after brewing were found to have ranges of 19,049-26,254 mg/kg, 21,904-26,883 mg/kg and 9,468-13,778 mg/kg, respectively. In the same samples the Ca content was determined as 3,580-4,799 mg/kg, 3,370-4,823 mg/kg, and 3,743-5,733 mg/kg, respectively. These findings were compared with the results of atomic emission techniques and it was concluded that the XRF system could be effectively used for quantitative analysis of the K and Ca content of tea samples.

  5. Geranyl diphosphate synthase from mint

    DOEpatents

    Croteau, Rodney Bruce; Wildung, Mark Raymond; Burke, Charles Cullen; Gershenzon, Jonathan

    1999-01-01

    A cDNA encoding geranyl diphosphate synthase from peppermint has been isolated and sequenced, and the corresponding amino acid sequence has been determined. Accordingly, an isolated DNA sequence (SEQ ID No:1) is provided which codes for the expression of geranyl diphosphate synthase (SEQ ID No:2) from peppermint (Mentha piperita). In other aspects, replicable recombinant cloning vehicles are provided which code for geranyl diphosphate synthase or for a base sequence sufficiently complementary to at least a portion of the geranyl diphosphate synthase DNA or RNA to enable hybridization therewith (e.g., antisense geranyl diphosphate synthase RNA or fragments of complementary geranyl diphosphate synthase DNA which are useful as polymerase chain reaction primers or as probes for geranyl diphosphate synthase or related genes). In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding geranyl diphosphate synthase. Thus, systems and methods are provided for the recombinant expression of geranyl diphosphate synthase that may be used to facilitate the production, isolation and purification of significant quantities of recombinant geranyl diphosphate synthase for subsequent use, to obtain expression or enhanced expression of geranyl diphosphate synthase in plants in order to enhance the production of monoterpenoids, to produce geranyl diphosphate in cancerous cells as a precursor to monoterpenoids having anti-cancer properties or may be otherwise employed for the regulation or expression of geranyl diphosphate synthase or the production of geranyl diphosphate.

  6. Geranyl diphosphate synthase from mint

    DOEpatents

    Croteau, R.B.; Wildung, M.R.; Burke, C.C.; Gershenzon, J.

    1999-03-02

    A cDNA encoding geranyl diphosphate synthase from peppermint has been isolated and sequenced, and the corresponding amino acid sequence has been determined. Accordingly, an isolated DNA sequence (SEQ ID No:1) is provided which codes for the expression of geranyl diphosphate synthase (SEQ ID No:2) from peppermint (Mentha piperita). In other aspects, replicable recombinant cloning vehicles are provided which code for geranyl diphosphate synthase or for a base sequence sufficiently complementary to at least a portion of the geranyl diphosphate synthase DNA or RNA to enable hybridization therewith (e.g., antisense geranyl diphosphate synthase RNA or fragments of complementary geranyl diphosphate synthase DNA which are useful as polymerase chain reaction primers or as probes for geranyl diphosphate synthase or related genes). In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding geranyl diphosphate synthase. Thus, systems and methods are provided for the recombinant expression of geranyl diphosphate synthase that may be used to facilitate the production, isolation and purification of significant quantities of recombinant geranyl diphosphate synthase for subsequent use, to obtain expression or enhanced expression of geranyl diphosphate synthase in plants in order to enhance the production of monoterpenoids, to produce geranyl diphosphate in cancerous cells as a precursor to monoterpenoids having anti-cancer properties or may be otherwise employed for the regulation or expression of geranyl diphosphate synthase or the production of geranyl diphosphate. 5 figs.

  7. Comparative characterisation of green tea and black tea cream: physicochemical and phytochemical nature.

    PubMed

    Lin, Xiaorong; Chen, Zhongzheng; Zhang, Yuanyuan; Luo, Wei; Tang, Hao; Deng, Baibiao; Deng, Jian; Li, Bin

    2015-04-15

    Tea cream is prevalent in various types of tea, yet a comparison of the mechanism of creaming in different teas remains uncertain. Here, we compared physicochemical characteristics, phytochemical composition, and simulated digestive profiles of green tea and black tea cream, looking to exploit their concentration and structure based mechanisms and in vitro bioaccessibility. Green tea cream particles were roughly one order of magnitude larger than those of black tea in size. Moreover, creaming concentrations of catechins, proteins and methylxanthines of green tea were dramatically higher than black tea. As major creaming components, gallated catechins, theaflavins, thearubigins, theabrownines, proteins and methylxanthines also exhibited high creaming affinities. Green tea cream particles, which were completely destroyed by simulated digestion, had few impacts on digestive recoveries of catechins and methylxanthines. In comparison, black tea cream particles were more stable under mimicking digestion, and clarification remarkably decreased the in vitro bioaccessibility of catechins and methylxanthines.

  8. Green tea gets molecular.

    PubMed

    Rouzer, Carol A; Marnett, Lawrence J

    2011-09-01

    Green tea and its major polyphenolic flavonoid, epigallocatechin gallate (EGCG), have been credited with cancer chemopreventive activity for many years; the mechanism for this activity, however, has remained obscure. Now, as reported in this issue of the journal (beginning on page 1366), Urusova and colleagues showed direct binding of EGCG to the peptidyl prolyl cis/trans isomerase Pin1, which inhibited Pin1 enzymatic activity. They showed that Pin1 expression is required for EGCG effects on cell growth, c-Jun activation, and transcription regulation mediated by NF-κB and activator protein-1. The data provide a glimpse of the mechanism of action of EGCG and set a new bar for the future study of natural products with chemopreventive activity. PMID:21893494

  9. Antimutagenic properties of green tea.

    PubMed

    Bunkova, R; Marova, I; Nemec, M

    2005-03-01

    In this work biological effects of two common kinds of green tea (Chinese Gunpowder and Japanese Sencha) were analyzed using three independent tests of antimutagenicity: 1) the Ames test with Salmonella typhimurium TA98, 2) cytogenetic analysis of peripheral blood lymphocytes (CAPL), and 3) test with Saccharomyces cerevisiae D7. Tea extracts were allowed to be antimutagenic based on their ability to inhibit the mutagenic effect of standard mutagens. Amounts of (-)catechin and (-)catechin gallate in tea extracts were determined by high performance liquid chromatography on reversed phase (RP-HPLC). Antioxidant capacity was found using total radical-trapping antioxidant parameter (TRAP) method. Extracts from Gunpowder and Sencha exhibited high antimutagenic activity in the Ames test (24.7+/-3.7% and 34.1+/-2, 1% of inhibition without metabolic activation; 74.9+/-1.7% and 62.7+/-4.3% of inhibition with metabolic activation, respectively) as well as in S. cerevisiae D7 test (Gunpowder: 62.7+/-5.7% of Trp convertants inhibition and 52.6+/-5.3% of Ilv revertants inhibition; Sencha: 45.6+/-4.2% of Trp convertants inhibition, 50.0+/-4.8% of Ilv revertants inhibition). In the CAPL method reduced number of abberant cells as well as decreased number of chromosome breaks was observed using both green tea extracts. Antioxidant capacity and antimutagenicity of green tea extracts was higher than activity of tea catechins and flavonoids.

  10. [Contents of aluminum and manganese in tea leaves and tea infusions].

    PubMed

    Matsushima, F; Meshitsuka, S; Nose, T

    1993-10-01

    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 wulong tea, 576 micrograms/g in black tea, and 520 micrograms/g in green tea. The content of manganese was 1440 micrograms/g in the case of wulong tea, 670 micrograms/g in green tea, and 535 micrograms/g in black tea. The concentration of aluminum in tea infusions was 1.49-5.58 micrograms/ml in wulong tea, 0.90-4.92 micrograms/ml in green tea, and 0.64-4.35 micrograms/ml in black tea. The concentration of manganese was 1.75-6.67 micrograms/ml in green tea, 0.94-4.04 micrograms/ml in wulong tea, and 0.78-3.24 micrograms/ml in black tea. The ratio of the molar concentration of aluminum to that of manganese was 1-2:1 in tea leaves, and 1-5:1 in tea infusions. In the case of elevated-temperature infusion, increases of the concentrations of aluminum and manganese in tea infusions were recognized. By repeating infusion three times according to the standard method for ingredient analysis of food, 18-29% of the total content of aluminum in tea leaves was eluted, and 12-29% of the total content of manganese was eluted.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8254994

  11. Preparation of partially decaffeinated instant green tea.

    PubMed

    Ye, Jian-Hui; Liang, Yue-Rong; Jin, Jing; Liang, Hue-Ling; Du, Ying-Ying; Lu, Jian-Liang; Ye, Qian; Lin, Chen

    2007-05-01

    The caffeine level of instant tea extracted from decaffeinated leaf tea with 4.0 mg g-1 caffeine is commonly above 10.0 mg g-1, the maximum limit of caffeine for decaffeinated instant tea. Further removal of caffeine by active carbon (AC) from the green tea extract was investigated. It showed that the removal of caffeine from the tea extract solutions depended on the treatment time and tea extract concentration while the ethanol concentration and pH had little effect on the removal of caffeine. According to the removal of caffeine and the ratio of total catechins to caffeine in the tested samples, the optimum decaffeination conditions were determined to be as follows: tea extract concentration 15-30 g L-1 for common tea extract but higher for partially decaffeinated tea leaf extract; ratio of tea solution to AC, 100 mL:4 g; treatment time, 4 h; and natural tea extract pH. Instant tea powder extracted from partially decaffeinated leaf tea with a caffeine level of 4.03 mg g-1 and further decaffeinated by AC had a caffeine level of 7.81 mg g-1, which was 31% lower than that without AC treatment.

  12. Preparation of partially decaffeinated instant green tea.

    PubMed

    Ye, Jian-Hui; Liang, Yue-Rong; Jin, Jing; Liang, Hue-Ling; Du, Ying-Ying; Lu, Jian-Liang; Ye, Qian; Lin, Chen

    2007-05-01

    The caffeine level of instant tea extracted from decaffeinated leaf tea with 4.0 mg g-1 caffeine is commonly above 10.0 mg g-1, the maximum limit of caffeine for decaffeinated instant tea. Further removal of caffeine by active carbon (AC) from the green tea extract was investigated. It showed that the removal of caffeine from the tea extract solutions depended on the treatment time and tea extract concentration while the ethanol concentration and pH had little effect on the removal of caffeine. According to the removal of caffeine and the ratio of total catechins to caffeine in the tested samples, the optimum decaffeination conditions were determined to be as follows: tea extract concentration 15-30 g L-1 for common tea extract but higher for partially decaffeinated tea leaf extract; ratio of tea solution to AC, 100 mL:4 g; treatment time, 4 h; and natural tea extract pH. Instant tea powder extracted from partially decaffeinated leaf tea with a caffeine level of 4.03 mg g-1 and further decaffeinated by AC had a caffeine level of 7.81 mg g-1, which was 31% lower than that without AC treatment. PMID:17407319

  13. Green tea composition, consumption, and polyphenol chemistry.

    PubMed

    Graham, H N

    1992-05-01

    Tea is grown in about 30 countries but is consumed worldwide, although at greatly varying levels. It is the most widely consumed beverage aside from water with a per capita worldwide consumption of approximately 0.12 liter per year. Tea is manufactured in three basic forms. Green tea is prepared in such a way as to preclude the oxidation of green leaf polyphenols. During black tea production oxidation is promoted so that most of these substances are oxidized. Oolong tea is a partially oxidized product. Of the approximately 2.5 million metric tons of dried tea manufactured, only 20% is green tea and less than 2% is oolong tea. Green tea is consumed primarily in China, Japan, and a few countries in North Africa and the Middle East. Fresh tea leaf is unusually rich in the flavanol group of polyphenols known as catechins which may constitute up to 30% of the dry leaf weight. Other polyphenols include flavanols and their glycosides, and depsides such as chlorogenic acid, coumarylquinic acid, and one unique to tea, theogallin (3-galloylquinic acid). Caffeine is present at an average level of 3% along with very small amounts of the other common methylxanthines, theobromine and theophylline. The amino acid theanine (5-N-ethylglutamine) is also unique to tea. Tea accumulates aluminum and manganese. In addition to the normal complement of plant cell enzymes, tea leaf contains an active polyphenol oxidase which catalyzes the aerobic oxidation of the catechins when the leaf cell structure is disrupted during black tea manufacture. The various quinones produced by the enzymatic oxidations undergo condensation reactions which result in a series of compounds, including bisflavanols, theaflavins, epitheaflavic acids, and thearubigens, which impart the characteristic taste and color properties of black tea. Most of these compounds readily form complexes with caffeine. There is no tannic acid in tea. Thearubigens constitute the largest mass of the extractable matter in black tea but

  14. Molecular and biochemical characterization of caffeine synthase and purine alkaloid concentration in guarana fruit.

    PubMed

    Schimpl, Flávia Camila; Kiyota, Eduardo; Mayer, Juliana Lischka Sampaio; Gonçalves, José Francisco de Carvalho; da Silva, José Ferreira; Mazzafera, Paulo

    2014-09-01

    Guarana seeds have the highest caffeine concentration among plants accumulating purine alkaloids, but in contrast with coffee and tea, practically nothing is known about caffeine metabolism in this Amazonian plant. In this study, the levels of purine alkaloids in tissues of five guarana cultivars were determined. Theobromine was the main alkaloid that accumulated in leaves, stems, inflorescences and pericarps of fruit, while caffeine accumulated in the seeds and reached levels from 3.3% to 5.8%. In all tissues analysed, the alkaloid concentration, whether theobromine or caffeine, was higher in young/immature tissues, then decreasing with plant development/maturation. Caffeine synthase activity was highest in seeds of immature fruit. A nucleotide sequence (PcCS) was assembled with sequences retrieved from the EST database REALGENE using sequences of caffeine synthase from coffee and tea, whose expression was also highest in seeds from immature fruit. The PcCS has 1083bp and the protein sequence has greater similarity and identity with the caffeine synthase from cocoa (BTS1) and tea (TCS1). A recombinant PcCS allowed functional characterization of the enzyme as a bifunctional CS, able to catalyse the methylation of 7-methylxanthine to theobromine (3,7-dimethylxanthine), and theobromine to caffeine (1,3,7-trimethylxanthine), respectively. Among several substrates tested, PcCS showed higher affinity for theobromine, differing from all other caffeine synthases described so far, which have higher affinity for paraxanthine. When compared to previous knowledge on the protein structure of coffee caffeine synthase, the unique substrate affinity of PcCS is probably explained by the amino acid residues found in the active site of the predicted protein. PMID:24856135

  15. Molecular and biochemical characterization of caffeine synthase and purine alkaloid concentration in guarana fruit.

    PubMed

    Schimpl, Flávia Camila; Kiyota, Eduardo; Mayer, Juliana Lischka Sampaio; Gonçalves, José Francisco de Carvalho; da Silva, José Ferreira; Mazzafera, Paulo

    2014-09-01

    Guarana seeds have the highest caffeine concentration among plants accumulating purine alkaloids, but in contrast with coffee and tea, practically nothing is known about caffeine metabolism in this Amazonian plant. In this study, the levels of purine alkaloids in tissues of five guarana cultivars were determined. Theobromine was the main alkaloid that accumulated in leaves, stems, inflorescences and pericarps of fruit, while caffeine accumulated in the seeds and reached levels from 3.3% to 5.8%. In all tissues analysed, the alkaloid concentration, whether theobromine or caffeine, was higher in young/immature tissues, then decreasing with plant development/maturation. Caffeine synthase activity was highest in seeds of immature fruit. A nucleotide sequence (PcCS) was assembled with sequences retrieved from the EST database REALGENE using sequences of caffeine synthase from coffee and tea, whose expression was also highest in seeds from immature fruit. The PcCS has 1083bp and the protein sequence has greater similarity and identity with the caffeine synthase from cocoa (BTS1) and tea (TCS1). A recombinant PcCS allowed functional characterization of the enzyme as a bifunctional CS, able to catalyse the methylation of 7-methylxanthine to theobromine (3,7-dimethylxanthine), and theobromine to caffeine (1,3,7-trimethylxanthine), respectively. Among several substrates tested, PcCS showed higher affinity for theobromine, differing from all other caffeine synthases described so far, which have higher affinity for paraxanthine. When compared to previous knowledge on the protein structure of coffee caffeine synthase, the unique substrate affinity of PcCS is probably explained by the amino acid residues found in the active site of the predicted protein.

  16. Aluminium and fluoride contents of tea, with emphasis on brick tea and their health implications.

    PubMed

    Wong, M H; Fung, K F; Carr, H P

    2003-01-31

    Tea plant takes up a large quantity of aluminium (Al) and fluoride (F) from acidic soils. It has been known that fluorosis can be developed for people who consume a large quantity of tea made from brick tea, a low quality tea consisting mainly of old tea leaves in China. In addition, it has been claimed that Alzheimer's disease (AD) is linked with the Al content in the human brain. Therefore, the high Al content in tea, especially brick tea is also a concern. This article reviews the basis background on tea including classification, growth conditions, types of tea leaves and their production, and processing of tea. Special emphasis is made on the transfer of Al and F from soil to tea plant and then to tea liquor. Health implications of drinking a large quantity of tea liquor especially those made from brick tea are discussed. Recommendations are suggested to reduce the uptake of these two elements by tea plant, and lower their contents in tea products.

  17. Microbiological activity of whole and fractionated crude extracts of tea (Camellia sinensis), and of tea components.

    PubMed

    Yam, T S; Shah, S; Hamilton-Miller, J M

    1997-07-01

    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 antibacterial activity of extracts of green tea can be explained by its content of epigallocatechin, epigallocatechin gallate and epicatechin gallate. In black tea extracts, theaflavin and its gallates are additional antibacterially active components. PMID:9228784

  18. Hybrid polyketide synthases

    DOEpatents

    Fortman, Jeffrey L.; Hagen, Andrew; Katz, Leonard; Keasling, Jay D.; Poust, Sean; Zhang, Jingwei; Zotchev, Sergey

    2016-05-10

    The present invention provides for a polyketide synthase (PKS) capable of synthesizing an even-chain or odd-chain diacid or lactam or diamine. The present invention also provides for a host cell comprising the PKS and when cultured produces the even-chain diacid, odd-chain diacid, or KAPA. The present invention also provides for a host cell comprising the PKS capable of synthesizing a pimelic acid or KAPA, and when cultured produces biotin.

  19. Metabolic Changes of Caffeine in Tea Plant (Camellia sinensis (L.) O. Kuntze) as Defense Response to Colletotrichum fructicola.

    PubMed

    Wang, Yu-Chun; Qian, Wen-Jun; Li, Na-Na; Hao, Xin-Yuan; Wang, Lu; Xiao, Bin; Wang, Xin-Chao; Yang, Ya-Jun

    2016-09-01

    Tea plant (Camellia sinensis) is one of the most economically valuable crops in the world. Anthracnose can affect the growth of leaves and cause serious yield losses of tea. Tea plants are rich in secondary metabolites; however, their roles in resistance to anthracnose are unclear. Herein we compared the contents of total phenolics, catechins, and caffeine in two cultivars with different resistances to anthracnose during Colletotrichum fructicola infection. (-)-Epigallocatechin-3-gallate (EGCG), (+)-catechin (C), caffeine, and critical regulatory genes were induced in C. fructicola-resistant tissues. In vitro antifungal tests showed that caffeine more strongly inhibited mycelial growth than tea polyphenols and catechins. Both electron microscopy and bioactivity analysis results showed that caffeine can affect mycelial cell walls and plasma membranes. Through promoter sequences analysis, a number of stress response-related cis-acting elements were identified in S-adenosylmethionine synthetase and tea caffeine synthase. These results demonstrated that (-)-EGCG, (+)-C, and caffeine may be involved in the resistance of tea plants to anthracnose.

  20. Metabolic Changes of Caffeine in Tea Plant (Camellia sinensis (L.) O. Kuntze) as Defense Response to Colletotrichum fructicola.

    PubMed

    Wang, Yu-Chun; Qian, Wen-Jun; Li, Na-Na; Hao, Xin-Yuan; Wang, Lu; Xiao, Bin; Wang, Xin-Chao; Yang, Ya-Jun

    2016-09-01

    Tea plant (Camellia sinensis) is one of the most economically valuable crops in the world. Anthracnose can affect the growth of leaves and cause serious yield losses of tea. Tea plants are rich in secondary metabolites; however, their roles in resistance to anthracnose are unclear. Herein we compared the contents of total phenolics, catechins, and caffeine in two cultivars with different resistances to anthracnose during Colletotrichum fructicola infection. (-)-Epigallocatechin-3-gallate (EGCG), (+)-catechin (C), caffeine, and critical regulatory genes were induced in C. fructicola-resistant tissues. In vitro antifungal tests showed that caffeine more strongly inhibited mycelial growth than tea polyphenols and catechins. Both electron microscopy and bioactivity analysis results showed that caffeine can affect mycelial cell walls and plasma membranes. Through promoter sequences analysis, a number of stress response-related cis-acting elements were identified in S-adenosylmethionine synthetase and tea caffeine synthase. These results demonstrated that (-)-EGCG, (+)-C, and caffeine may be involved in the resistance of tea plants to anthracnose. PMID:27541180

  1. THOR Turbulence Electron Analyser: TEA

    NASA Astrophysics Data System (ADS)

    Fazakerley, Andrew; Moore, Tom; Owen, Chris; Pollock, Craig; Wicks, Rob; Samara, Marilia; Rae, Jonny; Hancock, Barry; Kataria, Dhiren; Rust, Duncan

    2016-04-01

    Turbulence Heating ObserveR (THOR) is the first mission ever flown in space dedicated to plasma turbulence. The Turbulence Electron Analyser (TEA) will measure the plasma electron populations in the mission's Regions of Interest. It will collect a 3D electron velocity distribution with cadences as short as 5 ms. The instrument will be capable of measuring energies up to 30 keV. TEA consists of multiple electrostatic analyser heads arranged so as to measure electrons arriving from look directions covering the full sky, i.e. 4 pi solid angle. The baseline concept is similar to the successful FPI-DES instrument currently operating on the MMS mission. TEA is intended to have a similar angular resolution, but a larger geometric factor. In comparison to earlier missions, TEA improves on the measurement cadence. For example, MMS FPI-DES routinely operates at 30 ms cadence. The objective of measuring distributions at rates as fast as 5 ms is driven by the mission's scientific requirements to resolve electron gyroscale size structures, where plasma heating and fluctuation dissipation is predicted to occur. TEA will therefore be capable of making measurements of the evolution of distribution functions across thin (a few km) current sheets travelling past the spacecraft at up to 600 km/s, of the Power Spectral Density of fluctuations of electron moments and of distributions fast enough to match frequencies with waves expected to be dissipating turbulence (e.g. with 100 Hz whistler waves).

  2. Green tea and the skin.

    PubMed

    Hsu, Stephen

    2005-06-01

    Plant extracts have been widely used as topical applications for wound-healing, anti-aging, and disease treatments. Examples of these include ginkgo biloba, echinacea, ginseng, grape seed, green tea, lemon, lavender, rosemary, thuja, sarsaparilla, soy, prickly pear, sagebrush, jojoba, aloe vera, allantoin, feverwort, bloodroot, apache plume, and papaya. These plants share a common character: they all produce flavonoid compounds with phenolic structures. These phytochemicals are highly reactive with other compounds, such as reactive oxygen species and biologic macromolecules, to neutralize free radicals or initiate biological effects. A short list of phenolic phytochemicals with promising properties to benefit human health includes a group of polyphenol compounds, called catechins, found in green tea. This article summarizes the findings of studies using green tea polyphenols as chemopreventive, natural healing, and anti-aging agents for human skin, and discusses possible mechanisms of action.

  3. Polyphenol composition of a functional fermented tea obtained by tea-rolling processing of green tea and loquat leaves.

    PubMed

    Shii, Takuya; Tanaka, Takashi; Watarumi, Sayaka; Matsuo, Yosuke; Miyata, Yuji; Tamaya, Kei; Tamaru, Shizuka; Tanaka, Kazunari; Matsui, Toshiro; Kouno, Isao

    2011-07-13

    Phenolic constituents of a new functional fermented tea produced by tea-rolling processing of a mixture (9:1) of tea leaves and loquat leaves were examined in detail. The similarity of the phenolic composition to that of black tea was indicated by high-performance liquid chromatography comparison with other tea products. Twenty-five compounds, including three new catechin oxidation products, were isolated, and the structures of the new compounds were determined to be (2R)-2-hydroxy-3-(2,4,6-trihydroxyphenyl)-1-(3,4,5-trihydroxyphenyl)-1-propanone 2-O-gallate, dehydrotheasinensin H, and acetonyl theacitrin A by spectroscopic methods. In addition, theacitrinin A and theasinensin H were obtained for the first time from commercial tea products. Isolation of these new and known compounds confirms that reactions previously demonstrated by in vitro model experiments actually occur when fresh tea leaves are mechanically distorted and bruised during the production process.

  4. Sharing a bowl of tea.

    PubMed

    Sen, S

    1993-06-01

    Soshitsu Sen's keynote speech before a symposium on population and the environment is summarized unofficially by the editorial staff. The instability of human thinking is given as the cause for the present destruction of the environment. In a visit to the His Majesty King of Sweden, Sen remarked that stabilizing human minds can be achieved within the tea ceremony through "serving tea heartily, receiving it with gratitude, and offering it to another." In this way, the spirit of concern for others can be practiced in everyday life and tranquility of mind reached. News broadcasts of starving parents and children as victims of civil war are disheartening. The Japanese people are not suffering such hunger, even though the economy has not been as robust as desired. The analogy is provided in the story by Chuang Chou about King Hun Dun and King Xiu and man's good intentions, which nonetheless destroy the earth. Japan has experienced forest and environmental destruction on the road to economic prosperity and satisfaction of self-interests. The advice on living in accord with nature is to appreciate each season for its own changes. For example, when it is the winter season, the complaint is about the cold and the desire is for spring; but when spring comes, the desire is for the cooler weather of fall. the ordinary way is to appreciate all seasons and is the best way of sustaining a healthy environment. In the garden of the tea hut, humans enter without their worldly title, position, and means; at the water basin, hands and mouth are cleansed, and entrance is made through a small hole into the hut much the same as emerging from the womb. Worldly matters are dispensed with and purity of thought is shared in the sharing of the bowl of green tea, saying "after you" to one another. Christianity and the Way of Tea share the same symbols of purification. The black tea bowl is in harmony with the green tea. Fatigue is relieved when gazing upon the color green; examples are given

  5. Sharing a bowl of tea.

    PubMed

    Sen, S

    1993-06-01

    Soshitsu Sen's keynote speech before a symposium on population and the environment is summarized unofficially by the editorial staff. The instability of human thinking is given as the cause for the present destruction of the environment. In a visit to the His Majesty King of Sweden, Sen remarked that stabilizing human minds can be achieved within the tea ceremony through "serving tea heartily, receiving it with gratitude, and offering it to another." In this way, the spirit of concern for others can be practiced in everyday life and tranquility of mind reached. News broadcasts of starving parents and children as victims of civil war are disheartening. The Japanese people are not suffering such hunger, even though the economy has not been as robust as desired. The analogy is provided in the story by Chuang Chou about King Hun Dun and King Xiu and man's good intentions, which nonetheless destroy the earth. Japan has experienced forest and environmental destruction on the road to economic prosperity and satisfaction of self-interests. The advice on living in accord with nature is to appreciate each season for its own changes. For example, when it is the winter season, the complaint is about the cold and the desire is for spring; but when spring comes, the desire is for the cooler weather of fall. the ordinary way is to appreciate all seasons and is the best way of sustaining a healthy environment. In the garden of the tea hut, humans enter without their worldly title, position, and means; at the water basin, hands and mouth are cleansed, and entrance is made through a small hole into the hut much the same as emerging from the womb. Worldly matters are dispensed with and purity of thought is shared in the sharing of the bowl of green tea, saying "after you" to one another. Christianity and the Way of Tea share the same symbols of purification. The black tea bowl is in harmony with the green tea. Fatigue is relieved when gazing upon the color green; examples are given

  6. Health-promoting effects of green tea

    PubMed Central

    SUZUKI, Yasuo; MIYOSHI, Noriyuki; ISEMURA, Mamoru

    2012-01-01

    Green tea is manufactured from the leaves of the plant Camellia sinensis Theaceae and has been regarded to possess anti-cancer, anti-obesity, anti-atherosclerotic, anti-diabetic, anti-bacterial, and anti-viral effects. Many of the beneficial effects of green tea are related to the activities of (−)-epigallocatechin gallate (EGCG), a major component of green tea catechins. For about 20 years, we have engaged in studies to reveal the biological activities and action mechanisms of green tea and EGCG. This review summarizes several lines of evidence to indicate the health-promoting properties of green tea mainly based on our own experimental findings. PMID:22450537

  7. Interaction of chlorpromazine with tea and coffee.

    PubMed Central

    Cheeseman, H J; Neal, M J

    1981-01-01

    1 The interaction between phenothiazine neuroleptics with tea and coffee was studied in vitro. 2 Filtered infusions of tea and coffee caused precipitation of all the neuroleptics studied. Tea always caused a heavier precipitate than coffee. 3 The constituent or constituents of tea and coffee responsible for precipitating the neuroleptics was not identified. Solutions of caffeine, caffeine citrate and sodium chloride did not form a precipitate with chlorpromazine but precipitates were formed by sodium salicylate, sodium benzoate and trisodium citrate. 4 The interaction between chlorpromazine (CPZ) and tea was studied quantitatively using radiolabelled drug and it was found that the precipitation of [3H]-CPZ with a given quantity of tea was 'saturable'. The proportion of CPZ precipitated by a 'standard cup of tea' was 80% at low doses of the drug (10-40 mg) whilst at high doses (800 mg), the proportion of the drug precipitated was approximately 20%. 5 The interaction was further studied in vivo by the oral administration of tea and CPZ to rats. The cataleptic effect of CPZ was significantly reduced by the simultaneous administration of tea and this was apparently not due to the caffeine present in tea. 6 The results suggest that a substantial proportion of orally administered neuroleptic may be precipitated as a highly insoluble compound if coffee, or more especially tea, is taken close to drug administration. This interaction might affect the absorption of phenothiazines given orally to patients. PMID:7197984

  8. Monoterpene synthases from common sage (Salvia officinalis)

    DOEpatents

    Croteau, Rodney Bruce; Wise, Mitchell Lynn; Katahira, Eva Joy; Savage, Thomas Jonathan

    1999-01-01

    cDNAs encoding (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase from common sage (Salvia officinalis) have been isolated and sequenced, and the corresponding amino acid sequences has been determined. Accordingly, isolated DNA sequences (SEQ ID No:1; SEQ ID No:3 and SEQ ID No:5) are provided which code for the expression of (+)-bornyl diphosphate synthase (SEQ ID No:2), 1,8-cineole synthase (SEQ ID No:4) and (+)-sabinene synthase SEQ ID No:6), respectively, from sage (Salvia officinalis). In other aspects, replicable recombinant cloning vehicles are provided which code for (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase, or for a base sequence sufficiently complementary to at least a portion of (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase DNA or RNA to enable hybridization therewith. In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase. Thus, systems and methods are provided for the recombinant expression of the aforementioned recombinant monoterpene synthases that may be used to facilitate their production, isolation and purification in significant amounts. Recombinant (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase may be used to obtain expression or enhanced expression of (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase in plants in order to enhance the production of monoterpenoids, or may be otherwise employed for the regulation or expression of (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase, or the production of their products.

  9. Analysis of Naturally Occurring Fluoride in Commercial Teas and Estimation of Its Daily Intake through Tea Consumption.

    PubMed

    Peng, Chuan-yi; Cai, Hui-mei; Zhu, Xiao-hui; Li, Da-xiang; Yang, Yun-qiu; Hou, Ru-yan; Wan, Xiao-chun

    2016-01-01

    The aim of this study was to determine the levels of fluoride in commercial teas and to estimate the contribution of tea consumption to the fluoride recommended daily allowance. A total of 558 tea products in 6 categories, green tea, black tea, oolong tea, pu'er tea, white tea, and reprocessed tea, were collected in the period from 2010 to 2013. The levels of fluoride in infusions of these teas were determined by a fluoride-ion selective electrode. The mean fluoride level in all of the tea samples was 85.16 mg/kg. For each category of tea, the mean fluoride levels were 63.04, 99.74, 52.19, 101.67, 159.78, and 110.54 mg/kg for green tea, black tea, white tea, pu'er tea, oolong tea, and reprocessed tea, respectively. The fluoride content of tea from 4 tea zones in descending order were Southern tea zone (111.39 mg/kg) > Southwest tea zone (78.78 mg/kg) > Jiangnan tea zone (71.73 mg/kg) > Jiangbei tea zone (64.63 mg/kg). These areas produced teas with lower fluoride levels than available foreign-produced tea (161.11 mg/kg). The mean chronic daily intake (CDI) was 0.02 mg/(kg•day) or 1.27 mg/kg. Generally, consuming tea from these 6 categories does not result in the intake of excessive amounts of fluoride for the general population.

  10. Dietary gallate esters of tea catechins reduce deposition of visceral fat, hepatic triacylglycerol, and activities of hepatic enzymes related to fatty acid synthesis in rats.

    PubMed

    Ikeda, Ikuo; Hamamoto, Reina; Uzu, Kazunori; Imaizumi, Katsumi; Nagao, Koji; Yanagita, Teruyoshi; Suzuki, Yuko; Kobayashi, Makoto; Kakuda, Takami

    2005-05-01

    Tea catechins, rich in (-)-epigallocatechin gallate and (-)-epicatechin gallate, or heat-treated tea catechins in which about 50% of the (-)-epigallocatechin gallate and (-)-epicatechin gallate in tea catechins was epimerized to (-)-gallocatechin gallate and (-)-catechin gallate, were fed to rats at 1% level for 23 d. Visceral fat deposition and the concentration of hepatic triacylglycerol were significantly lower in the tea catechin and heat-treated tea catechin groups than in the control group. The activities of fatty acid synthase and the malic enzyme in the liver cytosol were significantly lower in the two catechin groups than in the control group. In contrast, the activities of carnitine palmitoyltransferase and acyl-CoA oxidase in the liver homogenate were not significantly different among the three groups. These results suggest that the reduction in activities of enzymes related to hepatic fatty acid synthesis by the feeding of tea catechins or heat-treated tea catechins can cause reductions of hepatic triacylglycerol and possibly of visceral fat deposition.

  11. Cadmium in Jamaican Bush Teas

    PubMed Central

    Hoo Fung, LA; Rattray, VR; Lalor, GC

    2014-01-01

    Samples of Jamaican plants used as bush teas were collected from households in high soil-cadmium (Cd) areas of central Jamaica and analysed by graphite furnace atomic absorption spectrophotometry for total cadmium and for cadmium extractable with a hot water brew as prepared for human consumption to determine their contribution to dietary cadmium exposure. The concentrations ranged from < 0.03 to 6.85 μg/g for total Cd, between 1 and 15% of which was extracted with a hot water brew. One cup (200 ml) of the teas examined was found to contain < 0.04–1.18 μg of Cd and would contribute 0.1 – 0.3 μg of Cd to a person's dietary intake. This is significantly below the provisional tolerable weekly intake (PTWI) of 7 μg Cd/kg body weight established by the World Health Organization (WHO). While this suggests that bush tea consumption does not contribute significantly to the PTWI, some of the teas examined exceed the WHO recommendation of less than 0.3 mg/kg Cd for medicinal plants. PMID:25303189

  12. TEA -- Temperature and energy accumulated

    SciTech Connect

    Borresen, B.A.; Marken, A.V.

    1999-07-01

    Energy quality relates to energy supply temperatures. Instead of the exergy term, a TEA curve was introduced for evaluating the planned 100 GWh district heating system of Fornebu, outside Oslo. The questions that were raised when analyzing the energy system were: (1) how could one make a design that improves the use of low temperature energy? (2) is a design with low flow rate, i.e., low pipeline costs, compatible with the use of low temperature energy? (3) can one visualize the quality of the energy used through the distributed temperatures and the corresponding quantity of energy? A spreadsheet analysis tool for the TEA curve was implemented, and used for the heating plant design and optimization at Fornebu. The paper presents the TEA curve and shows how evaluations may be done. Different design temperatures ranging from 60 C/50 C to 110 C/40 C are included in the discussion. The main findings are: The TEA curve demonstrates clearly the use of energy quality; Avoid shunting, utilize the available high temperatures when possible; and A 75 C/40 C design improves the level of energy use compared to a 60 C/50 C design.

  13. Green tea and skin--anticarcinogenic effects.

    PubMed

    Mukhtar, H; Katiyar, S K; Agarwal, R

    1994-01-01

    Because of its special aroma, green tea is a popular beverage consumed by some human populations worldwide. In recent years, many laboratory studies have shown that in a variety of animal tumor bioassay systems the administration of green tea, specifically the polyphenolic fraction isolated from green tea leaves (green tea polyphenols), affords protection against cancer induction. In mouse skin tumor bioassay systems, topical application of green tea polyphenols to skin has been shown to result in protection against a) 3-methylcholanthrene-induced skin tumorigenicity, b) 7,12-dimethylbenz(a)anthracene (DMBA)-induced skin tumor initiation, c) 12-O-tetradecanoylphorbol-13-acetate and other tumor promoters caused tumor promotion in DMBA-initiated skin, and d) benzoyl peroxide- and 4-nitroquinoline N-oxide caused enhanced malignant progression of nonmalignant lesions. Green tea extract has also been shown to cause partial regression of established skin papillomas in mouse. Similarly, chronic oral feeding of green tea polyphenols or water extract of green tea has also been shown to result in the protection against both chemical carcinogen- and ultraviolet B radiation-induced skin tumorigenicity. Collectively these data suggest that green tea possesses significant chemopreventive effect against each stage of carcinogenesis, and that it may be useful against inflammatory responses associated with the exposure of skin to chemical tumor promoters as well as to solar radiation. Available data regarding the mechanism by which green tea affords these diversified effects is discussed.

  14. Antimutagenic and anticarcinogenic activity of tea polyphenols.

    PubMed

    Kuroda, Y; Hara, Y

    1999-01-01

    Tea is the most popular beverage, consumed by over two thirds of the world's population. Tea is processed differently in different parts of the world to give green (20%), black (78%) or oolong tea (2%). Green tea is consumed mostly in Japan and China. The antimutagenic and anticarcinogenic activities of green tea are extensively examined. The chemical components of green and black tea are polyphenols, which include EC, ECG, EGC, EGCG and TFs. This article reviews the epidemiological and experimental studies on the antimutagenicity and anticarcinogenicity of tea extracts and tea polyphenols. In Japan, an epidemiological study showed an inverse relationship between habitual green tea drinking and the standardized mortality rates for cancer. Some cohort studies on Chanoyu (Japanese tea ceremony) women teachers also showed that their mortality ratio including deaths caused by malignant neoplasms were surprisingly low. The antimutagenic activity against various mutagens of tea extracts and polyphenols including ECG and EGCG has been demonstrated in microbial systems (Salmonella typhimurium and Escherichia coli), mammalian cell systems and in vivo animal tests. The anticarcinogenic activity of tea phenols has been shown in experimental animals such as rats and mice, in transplantable tumors, carcinogen-induced tumors in digestive organs, mammary glands, hepatocarcinomas, lung cancers, skin tumors, leukemia, tumor promotion and metastasis. The mechanisms of antimutagenesis and anticarcinogenesis of tea polyphenols suggest that the inhibition of tumors may be due to both extracellular and intracellular mechanisms including the modulation of metabolism, blocking or suppression, modulation of DNA replication and repair effects, promotion, inhibition of invasion and metastasis, and induction of novel mechanisms. PMID:9878691

  15. Antimutagenic and anticarcinogenic activity of tea polyphenols.

    PubMed

    Kuroda, Y; Hara, Y

    1999-01-01

    Tea is the most popular beverage, consumed by over two thirds of the world's population. Tea is processed differently in different parts of the world to give green (20%), black (78%) or oolong tea (2%). Green tea is consumed mostly in Japan and China. The antimutagenic and anticarcinogenic activities of green tea are extensively examined. The chemical components of green and black tea are polyphenols, which include EC, ECG, EGC, EGCG and TFs. This article reviews the epidemiological and experimental studies on the antimutagenicity and anticarcinogenicity of tea extracts and tea polyphenols. In Japan, an epidemiological study showed an inverse relationship between habitual green tea drinking and the standardized mortality rates for cancer. Some cohort studies on Chanoyu (Japanese tea ceremony) women teachers also showed that their mortality ratio including deaths caused by malignant neoplasms were surprisingly low. The antimutagenic activity against various mutagens of tea extracts and polyphenols including ECG and EGCG has been demonstrated in microbial systems (Salmonella typhimurium and Escherichia coli), mammalian cell systems and in vivo animal tests. The anticarcinogenic activity of tea phenols has been shown in experimental animals such as rats and mice, in transplantable tumors, carcinogen-induced tumors in digestive organs, mammary glands, hepatocarcinomas, lung cancers, skin tumors, leukemia, tumor promotion and metastasis. The mechanisms of antimutagenesis and anticarcinogenesis of tea polyphenols suggest that the inhibition of tumors may be due to both extracellular and intracellular mechanisms including the modulation of metabolism, blocking or suppression, modulation of DNA replication and repair effects, promotion, inhibition of invasion and metastasis, and induction of novel mechanisms.

  16. Determination of flavonol glycosides in green tea, oolong tea and black tea by UHPLC compared to HPLC.

    PubMed

    Jiang, Heyuan; Engelhardt, Ulrich H; Thräne, Claudia; Maiwald, Beate; Stark, Janina

    2015-09-15

    An UHPLC method for the determination of flavonol glycosides (FOG) from green and oolong tea vs. black tea has been developed for the first time. Sample clean-up method by means of polyamide column chromatography was optimized with multiple-step elution. Using UHPLC and HPLC with gradient elution and photodiode array detection, eighteen FOG compounds were determined with the aid of electrospray tandem mass spectrometry. These FOG compounds were qualified on both UHPLC and HPLC, and this UHPLC method successfully separated rutin (quercetin-3-O-rutinoside) and K-grg (kaempferol-3-O-glucorhamnoglucoside) while conventional HPLC method did not. The total amounts of FOG compounds in the tea samples were 2.32-5.67g/kg dry weight (calculated as aglycones), and there is no significant difference for the total FOG content among green tea, oolong tea and black tea. However, kaempferol glycosides are more abundant in green teas, while oolong tea has more quercetin and myricetin glycosides. In black tea quercetin glycosides were most abundant.

  17. Studies on quality of orthodox teas made from anthocyanin-rich tea clones growing in Kangra valley, India.

    PubMed

    Joshi, Robin; Rana, Ajay; Gulati, Ashu

    2015-06-01

    Recently anthocyanin-rich purple tea varieties have been developed. The quality of these new purple tea varieties developed in Kangra valley was assessed, and compared with the quality of tea from standard Kangra clone. Purple tea shoots (PL) recorded higher amount of polyphenols compared to standard green tea shoot (GL) while epigallocatechin gallate (EGCG) recorded higher levels in GL. Higher levels of theaflavins were recorded in orthodox black tea from purple shoots (BTP) compared to black tea (BT) made from green shoots. Both theanine and caffeine recorded higher levels in GL. Volatile flavour profiles of these teas showed qualitative and quantitative differences. Aroma extract dilution assay showed higher dilution factors in BTP than BT. Orthodox teas from purple shoots exhibited higher antioxidant activity compared to standard black tea. Strong correlation of total quality scores with aroma and infusion colour was observed. Tea from anthocyanin-rich cultivars can become specialty teas with high antioxidant activity.

  18. Electronic nose based tea quality standardization.

    PubMed

    Dutta, Ritaban; Kashwan, K R; Bhuyan, M; Hines, E L; Gardner, J W

    2003-01-01

    In this paper we have used a metal oxide sensor (MOS) based electronic nose (EN) to analyze five tea samples with different qualities, namely, drier month, drier month again over-fired, well fermented normal fired in oven, well fermented overfired in oven, and under fermented normal fired in oven. The flavour of tea is determined mainly by its taste and smell, which is generated by hundreds of Volatile Organic Compounds (VOCs) and Non-Volatile Organic Compounds present in tea. These VOCs are present in different ratios and determine the quality of the tea. For example Assamica (Sri Lanka and Assam Tea) and Assamica Sinesis (Darjeeling and Japanese Tea) are two different species of tea giving different flavour notes. Tea flavour is traditionally measured through the use of a combination of conventional analytical instrumentation and human or ganoleptic profiling panels. These methods are expensive in terms of time and labour and also inaccurate because of a lack of either sensitivity or quantitative information. In this paper an investigation has been made to determine the flavours of different tea samples using an EN and to explore the possibility of replacing existing analytical and profiling panel methods. The technique uses an array of 4 MOSs, each of, which has an electrical resistance that has partial sensitivity to the headspace of tea. The signals from the sensor array are then conditioned by suitable interface circuitry. The data were processed using Principal Components Analysis (PCA), Fuzzy C Means algorithm (FCM). We also explored the use of a Self-Organizing Map (SOM) method along with a Radial Basis Function network (RBF) and a Probabilistic Neural Network classifier. Using FCM and SOM feature extraction techniques along with RBF neural network we achieved 100% correct classification for the five different tea samples with different qualities. These results prove that our EN is capable of discriminating between the flavours of teas manufactured under

  19. Tea and its consumption: benefits and risks.

    PubMed

    Hayat, Khizar; Iqbal, Hira; Malik, Uzma; Bilal, Uzma; Mushtaq, Sobia

    2015-01-01

    The recent convention of introducing phytochemicals to support the immune system or combat diseases is a centuries' old tradition. Nutritional support is an emerging advancement in the domain of diet-based therapies; tea and its constituents are one of the significant components of these strategies to maintain the health and reduce the risk of various malignancies. Tea is the most frequently consumed beverage worldwide, besides water. All the three most popular types of tea, green (unfermented), black (fully fermented), and oolong (semifermented), are manufactured from the leaves of the plant Camellia sinensis. Tea possesses significant antioxidative, anti-inflammatory, antimicrobial, anticarcinogenic, antihypertensive, neuroprotective, cholesterol-lowering, and thermogenic properties. Several research investigations, epidemiological studies, and meta-analyses suggest that tea and its bioactive polyphenolic constituents have numerous beneficial effects on health, including the prevention of many diseases, such as cancer, diabetes, arthritis, cardiovascular disease (CVD), stroke, genital warts, and obesity. Controversies regarding beneficialts and risks of tea consumption still exist but the limitless health-promoting benefits of tea outclass its few reported toxic effects. However, with significant rise in the scientific investigation of role of tea in human life, this review is intended to highlight the beneficial effects and risks associated with tea consumption.

  20. The Japanese Tea Ceremony and stress management.

    PubMed

    Keenan, J

    1996-01-01

    When people attend a Japanese Tea Ceremony, they often remark that it had a calming effect on them. The Tea Ceremony can be much more than that, however. Serious practitioners of tea develop a mind set and body control that enables them to transform tension-producing details of everyday life into moments of beauty, meaningfulness and tranquility. This effect comes from ritualizing ordinary chores and giving them an esthetic dimension and a noble motivation. Such discipline of mind and body also enables tea people to concentrate solely on the present moment, thereby shutting out worries about the past and anxieties about the future. PMID:8550688

  1. [Toxic hepatitis triggered by green tea].

    PubMed

    Rohde, Johan; Jacobsen, Claire; Kromann-Andersen, Hans

    2011-01-17

    Green tea is associated with various beneficial health effects, but several cases of hepatotoxic side effects have been reported. We present the first Danish case of toxic hepatitis following the consumption of 4-6 cups of green tea per day for six months. Green tea's main chemical component is epigallocatechin gallate (EGCG). Animal studies have shown that EGCG accumulated in the liver is most toxic when consumed fasting and that it causes greater hepatotoxicity upon repeated administration. Green tea hepatotoxicity should be kept in mind and cases are notifiable to the food authorities. PMID:21241631

  2. The Japanese Tea Ceremony and stress management.

    PubMed

    Keenan, J

    1996-01-01

    When people attend a Japanese Tea Ceremony, they often remark that it had a calming effect on them. The Tea Ceremony can be much more than that, however. Serious practitioners of tea develop a mind set and body control that enables them to transform tension-producing details of everyday life into moments of beauty, meaningfulness and tranquility. This effect comes from ritualizing ordinary chores and giving them an esthetic dimension and a noble motivation. Such discipline of mind and body also enables tea people to concentrate solely on the present moment, thereby shutting out worries about the past and anxieties about the future.

  3. Caffeine biosynthesis and degradation in tea [Camellia sinensis (L.) O. Kuntze] is under developmental and seasonal regulation.

    PubMed

    Mohanpuria, Prashant; Kumar, Vinay; Joshi, Robin; Gulati, Ashu; Ahuja, Paramvir Singh; Yadav, Sudesh Kumar

    2009-10-01

    To study caffeine biosynthesis and degradation, here we monitored caffeine synthase gene expression and caffeine and allantoin content in various tissues of four Camellia sinensis (L.) O. Kuntze cultivars during non-dormant (ND) and dormant (D) growth phases. Caffeine synthase expression as well as caffeine content was found to be higher in commercially utilized tissues like apical bud, 1st leaf, 2nd leaf, young stem, and was lower in old leaf during ND compared to D growth phase. Among fruit parts, fruit coats have higher caffeine synthase expression, caffeine content, and allantoin content. On contrary, allantoin content was found lower in the commercially utilized tissues and higher in old leaf. Results suggested that caffeine synthesis and degradation in tea appears to be under developmental and seasonal regulation.

  4. TEA laser gas mixture optimization

    NASA Astrophysics Data System (ADS)

    Lipchak, W. Michael; Luck, Clarence F.

    1982-11-01

    The topographical plot of an optimized parameter, such as pulse energy or peak power, on the gas mixture plane is presented as a useful aid in realizing optimum mixtures of helium, carbon dioxide, and nitrogen, for operation of CO2 TEA lasers. A method for generating such a plot is discussed and an example is shown. The potential benefits of this graphical technique are also discussed.

  5. TEA laser gas mixture optimization

    SciTech Connect

    Lipchak, W.M.; Luck, C.F.

    1982-11-01

    The topographical plot of an optimized parameter, such as pulse energy or peak power, on the gas mixture plane is presented as a useful aid in realizing optimum mixtures of helium, carbon dioxide, and nitrogen, for operation of CO/sub 2/ TEA lasers. A method for generating such a plot is discussed and an example is shown. The potential benefits of this graphical technique are also discussed.

  6. 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.

    PubMed

    Huang, M T; Xie, J G; Wang, Z Y; Ho, C T; Lou, Y R; Wang, C X; Hard, G C; Conney, A H

    1997-07-01

    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 substantial inhibitory effect on UVB-induced carcinogenesis, and adding caffeine to the decaffeinated teas restored the inhibitory effects of these teas on UVB-induced carcinogenesis. In additional studies, topical application of a green tea polyphenol fraction after each UVB application inhibited UVB-induced tumorigenesis. The results indicate that caffeine contributes in an important way to the inhibitory effects of green and black tea on UVB-induced complete carcinogenesis.

  7. Natural allelic variations of TCS1 play a crucial role in caffeine biosynthesis of tea plant and its related species.

    PubMed

    Jin, Ji-Qiang; Yao, Ming-Zhe; Ma, Chun-Lei; Ma, Jian-Qiang; Chen, Liang

    2016-03-01

    Tea caffeine synthase 1 (TCS1) is an enzyme that catalyzes the methylation of N-3 and N-1 and considered to be the most critical enzyme in the caffeine biosynthetic pathway of tea plant. This study shows that TCS1 has six types of allelic variations, namely, TCS1a, TCS1b, TCS1c, TCS1d, TCS1e, and TCS1f, with a 252 bp insertion/deletion mutation in the 5'-untranslated region. Among tea plant and its related species, TCS1a is the predominant allele, and TCS1b-f are the rare alleles that mainly appear in few wild germplasms. The full-length cDNA sequences of three new alleles, namely, TCS1d, TCS1e, and TCS1f, were isolated from specific germplasms, and all of recombinant proteins have higher caffeine synthase (CS, EC 2.1.1.160) activity than theobromine synthase (TS, EC 2.1.1.159). Amino acid residue 269 is responsible for the difference in TCS activity and substrate recognition, which was demonstrated by using site-directed mutagenesis experiments. Furthermore, natural variations in TCS1 change the transcription levels. There are two molecular mechanisms controlling the caffeine biosynthesis in low-caffeine-accumulating tea germplasms, i.e., TCS1 allele with low transcription level or its encoded protein with only TS activity. Allelic variations of TCS1 play a crucial role in caffeine biosynthesis. Taken together, our work provides valuable foundation for a comprehensive understanding of the mechanism of caffeine biosynthesis in section Thea plants and useful guidance for effective breeding.

  8. Modulatory effect of green tea extract on hepatic key enzymes of glucose metabolism in streptozotocin and high fat diet induced diabetic rats.

    PubMed

    Sundaram, Ramalingam; Naresh, Rajendran; Shanthi, Palanivelu; Sachdanandam, Panchanatham

    2013-05-15

    The study was undertaken to evaluate the antidiabetic effect of green tea extract on carbohydrate metabolic key enzymes in control and streptozotocin high fat diet -induced diabetic rats. The daily oral treatment of green tea extract (300 mg/kg body weight) to diabetic rats for 30 days resulted in a significant reduction in the levels of plasma glucose, glycosylated hemoglobin (HbA1c) and increase in the levels of insulin and hemoglobin. The altered activities of the key enzymes of carbohydrate metabolism such as hexokinase, pyruvate kinase, lactate dehydrogenase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, glucose-6-phosphate dehydrogenase, glycogen synthase and glycogen phosphorylase in liver of diabetic rats were significantly reverted to near normal levels by the administration of green tea extract. Further, green tea extract administration to diabetic rats improved muscle and hepatic glycogen content suggesting the antihyperglycemic potential of green tea extract in diabetic rats. The obtained results were compared with metformin, a standard oral hypoglycemic drug. Thus, this study indicates that the administration of green tea extract to diabetic rats resulted in alterations in the metabolism of glucose with subsequent reduction in plasma glucose levels.

  9. Separation of catechin compounds from different teas.

    PubMed

    Jin, Yinzhe; Jin, Chun Hua; Row, Kyung Ho

    2006-02-01

    Catechin compounds from Korean and Chinese green tea, and pu-erh, Indian black, Longjing, Tieguanyin, Bamboo, Jasmine, Oolong, Flower, Red teas, as potential anticancer and antioxidant components, were target material in this work. After extracting the green tea with water at 50 degrees C for 4 h, the extract was partitioned with water/chloroform, which was best suited to remove caffeine impurity from the extract. Further, the resulting extract was partitioned with water/ethyl acetate to deeply purify the five catechin compounds epigallocatechin, (+) catechin, epicatechin, epigallocatechin gallate and epicatechin gallate. The extracted samples were analyzed by reversed-phase high performance liquid chromatography. The mobile phase applied was the binary system of A (water/acetic acid, 100/0.1 vol%) and B (acetonitrile/acetic acid 100/0.1 vol%) from 90:10 to 70:30 (A:B vol%) in a linear gradient over 30 min time. The amount of catechin compounds extracted from Chinese green tea was 114.65% higher than from the Korean green tea. Comparing various tea sorts, the green teas contained more than 1.7 times of the five catechin compounds contained in other teas.

  10. Wire ageing with the TEA photocathode

    SciTech Connect

    Va`vra, J.

    1996-06-01

    Recently several RICH protypes successfully tested a gaseous TEA photocathode. However, its wire ageing behavior is unknown. In principle, TEA is a more strongly bonded molecule than TMAE, and, as a result, one would expect better wire ageing behavior. This paper explores this question.

  11. Travelling with tea: a Tuckerella’s tale

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tuckerella japonica appears strongly associated with tea (Camellia sinensis (L.) Kuntze., Theaceae) and, due to certain cultural practices in tea production, has in fact become a world traveller, accompanying the greatly coveted tea plant as it spread across the planet. The history of tea productio...

  12. Determination of phthalate esters in teas and tea infusions by gas chromatography-mass spectrometry.

    PubMed

    Du, Liping; Ma, Lijuan; Qiao, Yang; Lu, Yan; Xiao, Dongguang

    2016-04-15

    Phthalate esters (PAEs), a group of environmental pollutants which are carcinogenic to human body, have been detected in teas. In this work, five PAEs in teas and tea infusions were quantitatively determined by a modified simultaneous distillation extraction (SDE) coupled with gas chromatography-mass spectrometry. After the optimization of SDE, the proposed method afforded a wide range of linearity and high linear regression coefficients with the limits of detection range of 0.24-3.72 μg/kg. The average recoveries were 79.83-116.67% for tea samples and 78.22-101.64% for tea infusions with all the relative standard deviations below 20%. The total content of five PAEs in teas was 1.135-3.734 mg/kg and the total dissolving ratio of five PAEs from tea to infusion was 19.05-28.07% for the selected tea samples. The risk assessment result of all the selected tea samples demonstrated that the population with the habit of drinking tea won't cause risk to human health.

  13. Volatile compounds and sensory characteristics of various instant teas produced from black tea.

    PubMed

    Kraujalytė, Vilma; Pelvan, Ebru; Alasalvar, Cesarettin

    2016-03-01

    Various instant teas produced differently from black tea [freeze-dried instant tea (FDIT), spray-dried instant tea (SDIT), and decaffeinated instant tea (DCIT)], were compared for their differences in volatile compounds as well as descriptive sensory analysis (DSA). A total of 63 volatile compounds in all tea samples (eight aldehydes, ten alcohols, nine ketones, five esters, eight acids, ten terpenes/terpenoids, ten furans/furanones, two pyrroles, and one miscellaneous compound) were tentatively identified. Black tea, FDIT, SDIT, and DCIT contained 60, 55, 47, and 40 volatile compounds, respectively. Ten flavour attributes such as after taste, astringency, bitter, caramel-like, floral/sweet, green/grassy, hay-like, malty, roasty, and seaweed were identified. Intensities for a number of flavour attributes (except for caramel-like in SDIT and bitter and after taste in DCIT) were not significantly different (p>0.05) among tea samples. The present study suggests that instant teas can also be used as good alternative to black tea.

  14. Green tea, black tea consumption and risk of lung cancer: a meta-analysis.

    PubMed

    Tang, Naping; Wu, Yuemin; Zhou, Bo; Wang, Bin; Yu, Rongbin

    2009-09-01

    Studies investigating the association of green tea and black tea consumption with lung cancer risk have reported inconsistent findings. To provide a quantitative assessment of this association, we conducted a meta-analysis on the topic. Studies were identified by a literature search in PubMed from 1966 to November 2008 and by searching the reference lists of relevant studies. Summary relative risk (RR) estimates and their corresponding 95% confidence intervals (CIs) were calculated based on random-effects model. Our meta-analysis included 22 studies provided data on consumption of green tea or black tea, or both related to lung cancer risk. For green tea, the summary RR indicated a borderline significant association between highest green tea consumption and reduced risk of lung cancer (RR=0.78, 95% CI=0.61-1.00). Furthermore, an increase in green tea consumption of two cups/day was associated with an 18% decreased risk of developing lung cancer (RR=0.82, 95% CI=0.71-0.96). For black tea, no statistically significant association was observe through the meta-analysis (highest versus non/lowest, RR=0.86, 95% CI=0.70-1.05; an increment of two cups/day, RR=0.82, 95% CI=0.65-1.03). In conclusion, our data suggest that high or an increase in consumption of green tea but not black tea may be related to the reduction of lung cancer risk.

  15. Polysaccharides from Chinese tea: recent advance on bioactivity and function.

    PubMed

    Cao, Hui

    2013-11-01

    Tea (Camellia sinensis) has a long history of medicinal use in Asian countries such as China, Japan, India and Thailand as ancient as 500,000 years ago. Tea is globally one of the most popular and lowest cost beverages, next only to water. Tea leaves are popularly consumed with unfermented (green tea), semi-fermented (oolong tea), and fermented (black and puerh) forms. The chemical composition of tea mainly includes polyphenols (TPP), proteins, polysaccharides (TPS), chlorophyll, and alkaloids. Great advances have been made in chemical and bioactive studies of catechins and polyphenols from tea in recent decades. However, polysaccharides from tea materials have received much less consideration than TPP. Recently, TPS from tea leaves and flowers have attracted great interest. The number of relevant publications has increased rapidly in recent years. Herein, the bioactivities and function aspects of TPS from Chinese tea were reviewed. PMID:23994784

  16. Green and black tea are equally potent stimuli of NO production and vasodilation: new insights into tea ingredients involved.

    PubMed

    Lorenz, Mario; Urban, Janka; Engelhardt, Ulrich; Baumann, Gert; Stangl, Karl; Stangl, Verena

    2009-01-01

    Epidemiological studies suggest that consumption of tea is associated with beneficial cardiovascular effects. Since different types of tea are consumed throughout the world, a question of much interest is whether green tea is superior to black tea in terms of cardiovascular protection. We therefore compared the effects of green and black tea on nitric oxide (NO) production and vasodilation and elucidated the tea compounds involved. We chose a highly fermented black tea and determined concentrations of individual tea compounds in both green and black tea of the same type (Assam). The fermented black tea was almost devoid of catechins. However, both teas stimulated eNOS activity and phosphorylation in bovine aortic endothelial cells (BAEC) as well as vasorelaxation in rat aortic rings to a similar extent. In green tea, only epigallocatechin-3-gallate (EGCG) resulted in pronounced NO production and NO-dependent vasorelaxation in aortic rings. During tea processing to produce black tea, the catechins are converted to theaflavins and thearubigins. Individual black tea theaflavins showed a higher potency than EGCG in NO production and vasorelaxation. The thearubigins in black tea are highly efficient stimulators of vasodilation and NO production. Green and black tea compounds induced comparable phosphorylation of eNOS and upstream signalling kinases. Whereas stimulation of eNOS activity by EGCG was only slightly affected by pretreatment of cells with various ROS scavengers, TF3(theaflavin-3',3-digallate)-induced eNOS activity was partially inhibited by PEG-catalase. These results implicate that highly fermented black tea is equally potent as green tea in promoting beneficial endothelial effects. Theaflavins and thearubigins predominantly counterbalance the lack of catechins in black tea. The findings may underline the contribution of black tea consumption in prevention of cardiovascular diseases. PMID:19101751

  17. Attraction of the tea aphid, toxoptera aurantii, attraction to combinations of volatiles and colors related to tea plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The tea aphid, Toxoptera aurantii Boyer (Homoptera: Aphididae), is a major pest of the tea plant, Camellia sinensis. Fourteen volatile compounds were identified by GC-MS from air passed over intact tea shoots (ITSV). Electrophysiological and behavioral responses of the winged tea aphids to ITSV as w...

  18. Brewing and volatiles analysis of three tea beers indicate a potential interaction between tea components and lager yeast.

    PubMed

    Rong, Lei; Peng, Li-Juan; Ho, Chi-Tang; Yan, Shou-He; Meurens, Marc; Zhang, Zheng-Zhu; Li, Da-Xiang; Wan, Xiao-Chun; Bao, Guan-Hu; Gao, Xue-Ling; Ling, Tie-Jun

    2016-04-15

    Green tea, oolong tea and black tea were separately introduced to brew three kinds of tea beers. A model was designed to investigate the tea beer flavour character. Comparison of the volatiles between the sample of tea beer plus water mixture (TBW) and the sample of combination of tea infusion and normal beer (CTB) was accomplished by triangular sensory test and HS-SPME GC-MS analysis. The PCA of GC-MS data not only showed a significant difference between volatile features of each TBW and CTB group, but also suggested some key compounds to distinguish TBW from CTB. The results of GC-MS showed that the relative concentrations of many typical tea volatiles were significantly changed after the brewing process. More interestingly, the behaviour of yeast fermentation was influenced by tea components. A potential interaction between tea components and lager yeast could be suggested. PMID:26616936

  19. Brewing and volatiles analysis of three tea beers indicate a potential interaction between tea components and lager yeast.

    PubMed

    Rong, Lei; Peng, Li-Juan; Ho, Chi-Tang; Yan, Shou-He; Meurens, Marc; Zhang, Zheng-Zhu; Li, Da-Xiang; Wan, Xiao-Chun; Bao, Guan-Hu; Gao, Xue-Ling; Ling, Tie-Jun

    2016-04-15

    Green tea, oolong tea and black tea were separately introduced to brew three kinds of tea beers. A model was designed to investigate the tea beer flavour character. Comparison of the volatiles between the sample of tea beer plus water mixture (TBW) and the sample of combination of tea infusion and normal beer (CTB) was accomplished by triangular sensory test and HS-SPME GC-MS analysis. The PCA of GC-MS data not only showed a significant difference between volatile features of each TBW and CTB group, but also suggested some key compounds to distinguish TBW from CTB. The results of GC-MS showed that the relative concentrations of many typical tea volatiles were significantly changed after the brewing process. More interestingly, the behaviour of yeast fermentation was influenced by tea components. A potential interaction between tea components and lager yeast could be suggested.

  20. Regulation of formation of volatile compounds of tea (Camellia sinensis) leaves by single light wavelength.

    PubMed

    Fu, Xiumin; Chen, Yiyong; Mei, Xin; Katsuno, Tsuyoshi; Kobayashi, Eiji; Dong, Fang; Watanabe, Naoharu; Yang, Ziyin

    2015-11-16

    Regulation of plant growth and development by light wavelength has been extensively studied. Less attention has been paid to effect of light wavelength on formation of plant metabolites. The objective of this study was to investigate whether formation of volatiles in preharvest and postharvest tea (Camellia sinensis) leaves can be regulated by light wavelength. In the present study, in contrast to the natural light or dark treatment, blue light (470 nm) and red light (660 nm) significantly increased most endogenous volatiles including volatile fatty acid derivatives (VFADs), volatile phenylpropanoids/benzenoids (VPBs), and volatile terpenes (VTs) in the preharvest tea leaves. Furthermore, blue and red lights significantly up-regulated the expression levels of 9/13-lipoxygenases involved in VFADs formation, phenylalanine ammonialyase involved in VPBs formation, and terpene synthases involved in VTs formation. Single light wavelength had less remarkable influences on formation of volatiles in the postharvest leaves compared with the preharvest leaves. These results suggest that blue and red lights can be promising technology for remodeling the aroma of preharvest tea leaves. Furthermore, our study provided evidence that light wavelength can activate the expression of key genes involved in formation of plant volatiles for the first time.

  1. Regulation of formation of volatile compounds of tea (Camellia sinensis) leaves by single light wavelength

    PubMed Central

    Fu, Xiumin; Chen, Yiyong; Mei, Xin; Katsuno, Tsuyoshi; Kobayashi, Eiji; Dong, Fang; Watanabe, Naoharu; Yang, Ziyin

    2015-01-01

    Regulation of plant growth and development by light wavelength has been extensively studied. Less attention has been paid to effect of light wavelength on formation of plant metabolites. The objective of this study was to investigate whether formation of volatiles in preharvest and postharvest tea (Camellia sinensis) leaves can be regulated by light wavelength. In the present study, in contrast to the natural light or dark treatment, blue light (470 nm) and red light (660 nm) significantly increased most endogenous volatiles including volatile fatty acid derivatives (VFADs), volatile phenylpropanoids/benzenoids (VPBs), and volatile terpenes (VTs) in the preharvest tea leaves. Furthermore, blue and red lights significantly up-regulated the expression levels of 9/13-lipoxygenases involved in VFADs formation, phenylalanine ammonialyase involved in VPBs formation, and terpene synthases involved in VTs formation. Single light wavelength had less remarkable influences on formation of volatiles in the postharvest leaves compared with the preharvest leaves. These results suggest that blue and red lights can be promising technology for remodeling the aroma of preharvest tea leaves. Furthermore, our study provided evidence that light wavelength can activate the expression of key genes involved in formation of plant volatiles for the first time. PMID:26567525

  2. TEA: A Code Calculating Thermochemical Equilibrium Abundances

    NASA Astrophysics Data System (ADS)

    Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver

    2016-07-01

    We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. and Eriksson. It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature-pressure pairs. We tested the code against the method of Burrows & Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows & Sharp. Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via https://github.com/dzesmin/TEA.

  3. TEA: A Code Calculating Thermochemical Equilibrium Abundances

    NASA Astrophysics Data System (ADS)

    Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver

    2016-07-01

    We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. and Eriksson. It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature–pressure pairs. We tested the code against the method of Burrows & Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows & Sharp. Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via https://github.com/dzesmin/TEA.

  4. Irreversible sediment formation in green tea infusions.

    PubMed

    Xu, Yong-Quan; Chen, Gen-Sheng; Wang, Qiu-Shuang; Yuan, Hai-Bo; Feng, Chun-Hong; Yin, Jun-Feng

    2012-03-01

    The formation of irreversible tea sediment (IRS) and its chemical components in green tea infusions were investigated. The results showed that the amounts of IRS in the green tea infusions from various tea cultivars ranged from 0.10 to 1.47 mg/mL. The amount of IRS was influenced remarkably by the chemical components in the green tea infusion. Principal component analysis and regression analysis indicated that gallated catechins, Mn, Ca, caffeine, Na, and (-)-gallocatechin gallate (GCG) were the principal components. IRS (mg/mL) = -4.226 + 0.275 gallated catechins + 79.551 Na + 7.321 Mn + 21.055 Ca + 0.513 caffeine - 0.129 GCG (R2 = 0.697). The contents of the main chemical components in the reversible tea sediment (RTS) and IRS were markedly different, especially the minerals. Large amount of minerals participated in the formation of irreversible green tea sediment. The amount of IRS increased with the extraction temperature. PMID:22329921

  5. Targeting DNA methylation with green tea catechins.

    PubMed

    Yiannakopoulou, Eugenia C

    2015-01-01

    Aberrant epigenetic alterations in the genome such as DNA methylation play a significant role in cancer development. Green tea catechins have been reported to modulate epigenetic processes. This review aims to synthesize evidence on the modulation of DNA methylation by green tea catechins. Green tea catechins have been reported to reverse DNA methylation of tumor suppressor genes and increase transcription of these genes. Green tea catechins and especially epigallocatechin gallate modulate DNA methylation by attenuating the effect of DNA methyltransferase 1 (DNMT1). However, the exact mechanism of DNMT1 inhibition is not delineated. Suggested mechanisms include direct enzymatic inhibition, indirect enzymatic inhibition, reduced DNMT1 expression and translation. The possible effect of green tea catechins on other pathways of DNA methylation, i.e. methyl-CpG binding domain proteins, has not been investigated. Furthermore, the link between redox properties and epigenetic modulation by green tea catechins has not been defined either. Since green tea catechins are natural compounds with a rather acceptable safety profile, further research on their action as inhibitors of DNA methylation seems worthwhile.

  6. Spectroscopic fingerprint of tea varieties by surface enhanced Raman spectroscopy.

    PubMed

    Buyukgoz, Guluzar Gorkem; Soforoglu, Mehmet; Basaran Akgul, Nese; Boyaci, Ismail Hakki

    2016-03-01

    The fingerprinting method is generally performed to determine specific molecules or the behavior of specific molecular bonds in the desired sample content. A novel, robust and simple method based on surface enhanced Raman spectroscopy (SERS) was developed to obtain the full spectrum of tea varieties for detection of the purity of the samples based on the type of processing and cultivation. For this purpose, the fingerprint of seven different varieties of tea samples (herbal tea (rose hip, chamomile, linden, green and sage tea), black tea and earl grey tea) combined with silver colloids was obtained by SERS in the range of 200-2000 cm(-1) with an analysis time of 20 s. Each of the thirty-nine tea samples tested showed its own specific SERS spectra. Principal Component Analysis (PCA) was also applied to separate of each tea variety and different models developed for tea samples including three different models for the herbal teas and two different models for black and earl grey tea samples. Herbal tea samples were separated using mean centering, smoothing and median centering pre-processing steps while baselining and derivatisation pre-processing steps were applied to SERS data of black and earl grey tea. The novel spectroscopic fingerprinting technique combined with PCA is an accurate, rapid and simple methodology for the assessment of tea types based on the type of processing and cultivation differences. This method is proposed as an alternative tool in order to determine the characteristics of tea varieties. PMID:27570296

  7. [Residual pesticide concentrations after processing various types of tea and tea infusions].

    PubMed

    Kondo, Takahide; Watanabe, Ayaka; Shitara, Hiroshi; Kaburagi, Yasuo; Shibata, Masahisa; Kanda, Noriko; Kurokawa, Chieko; Inoue, Yutaka; Miyazaki, Motonobu; Togawa, Masayuki; Ozawa, Akihito; Uchiyama, Toru; Koizumi, Yutaka; Nakamura, Yoriyuki; Masuda, Shuichi; Maitani, Tamio

    2013-01-01

    The effects of processing to produce various types of tea or infusion on the levels of pesticide residues in tea were investigated for three insecticides (chlorfenapyr, pyrimiphos-methyl, and clothianidin). Tea plants were sprayed with one of the three pesticides and cultivated under cover. The levels of pesticide residues in tea decreased after processing according to the time and temperature of heating, as well as fermentation. Although significant differences were not observed among the three pesticides in the ratio of decreased of pesticide concentration after processing to green tea, clothianidin, which is a neonicotinoid insecticide and has a lower log Pow value, tended to be transferred more than the other two insecticides into infusions. However, no significant difference in the ratios of clothianidin transferred to infusions was observed among green tea with three different leaf sizes. PMID:24025203

  8. Genetics Home Reference: GM3 synthase deficiency

    MedlinePlus

    ... GM3 synthase deficiency is characterized by recurrent seizures (epilepsy) and problems with brain development. Within the first ... diagnosis or management of GM3 synthase deficiency: American Epilepsy Society: Find a Doctor Clinic for Special Children ( ...

  9. S-Carvone Suppresses Cellulase-Induced Capsidiol Production in Nicotiana tabacum by Interfering with Protein Isoprenylation1[C][W

    PubMed Central

    Huchelmann, Alexandre; Gastaldo, Clément; Veinante, Mickaël; Zeng, Ying; Heintz, Dimitri; Tritsch, Denis; Schaller, Hubert; Rohmer, Michel; Bach, Thomas J.; Hemmerlin, Andréa

    2014-01-01

    S-Carvone has been described as a negative regulator of mevalonic acid (MVA) production by interfering with 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMGR) activity, a key player in isoprenoid biosynthesis. The impact of this monoterpene on the production of capsidiol in Nicotiana tabacum, an assumed MVA-derived sesquiterpenoid phytoalexin produced in response to elicitation by cellulase, was investigated. As expected, capsidiol production, as well as early stages of elicitation such as hydrogen peroxide production or stimulation of 5-epi-aristolochene synthase activity, were repressed. Despite the lack of capsidiol synthesis, apparent HMGR activity was boosted. Feeding experiments using (1-13C)Glc followed by analysis of labeling patterns by 13C-NMR, confirmed an MVA-dependent biosynthesis; however, treatments with fosmidomycin, an inhibitor of the MVA-independent 2-C-methyl-d-erythritol 4-phosphate (MEP) isoprenoid pathway, unexpectedly down-regulated the biosynthesis of this sesquiterpene as well. We postulated that S-carvone does not directly inhibit the production of MVA by inactivating HMGR, but possibly targets an MEP-derived isoprenoid involved in the early steps of the elicitation process. A new model is proposed in which the monoterpene blocks an MEP pathway–dependent protein geranylgeranylation necessary for the signaling cascade. The production of capsidiol was inhibited when plants were treated with some inhibitors of protein prenylation or by further monoterpenes. Moreover, S-carvone hindered isoprenylation of a prenylable GFP indicator protein expressed in N. tabacum cell lines, which can be chemically complemented with geranylgeraniol. The model was further validated using N. tabacum cell extracts or recombinant N. tabacum protein prenyltransferases expressed in Escherichia coli. Our study endorsed a reevaluation of the effect of S-carvone on plant isoprenoid metabolism. PMID:24367019

  10. Determination of pesticide residue transfer rates (percent) from dried tea leaves to brewed tea.

    PubMed

    Wang, Jian; Cheung, Wendy; Leung, Daniel

    2014-01-29

    This paper presents a study on pesticide residue transfer rates (%) from dried tea leaves to brewed tea. In the study, a brewing procedure simulated the preparation of a hot tea drink as in routine. After brewing, pesticide residues were extracted from brewed tea using a method known as QuEChERS (quick, easy, cheap, effective, rugged, and safe). An UHPLC/ESI-MS/MS method was developed and validated to identify and quantify up to 172 pesticides in both tea leaves and brewed tea samples. Quantification was achieved using matrix-matched standard calibration curves with isotopically labeled standards or a chemical analogue as internal standards, and the calibration curves consisted of six points (0.4, 2.0, 8.0, 16.0, 24.0, and 40.0 μg/L equivalent in sample). The method was validated at four concentration levels (4.0, 12, 20.0, and 32.0 μg/L equivalent in sample) using five different brewed tea matrices on two separate days per matrix. Method performance parameters included overall recovery, intermediate precision, and measurement uncertainty, which were evaluated according to a nested experimental design. Approximately, 95% of the pesticides studied had recoveries between 81 and 110%, intermediate precision ≤20%, and measurement uncertainty ≤40%. From a pilot study of 44 incurred tea samples, pesticide residues were examined for their ability to transfer from dried tea leaves to brewed tea. Each sample, both tea leaves and brewed tea, was analyzed in duplicate. Pesticides were found to have different transfer rates (%). For example, imidacloprid, methomyl, and carbendazim had transfer rates of 84.9, 83.4, and 92.4%, respectively.

  11. Cancer Prevention by Tocopherols and Tea Polyphenols

    PubMed Central

    Yang, Chung S.; Li, Guangxun; Yang, Zhihong; Guan, Fei; Chen, Amber; Ju, Jihyeung

    2013-01-01

    Tocopherols (vitamin E) and tea polyphenols have been reported to have cancer preventive activities. Large-scale human trials with high doses of alpha-tocopherol, however, have produced disappointing results. This review presents data showing that γ- and δ-tocopherols inhibit colon, lung, mammary and prostate carcinogenesis in animal models, whereas α-tocopherol is ineffective in animal and human studies. Possible mechanisms of action are discussed. A broad cancer preventive activity of green tea polyphenols has been demonstrated in animal models, and many mechanisms have been proposed. The cancer preventive activity of green tea in humans, however, has not been conclusively demonstrated and remains to be further investigated. PMID:23403075

  12. Cancer prevention by tocopherols and tea polyphenols.

    PubMed

    Yang, Chung S; Li, Guangxun; Yang, Zhihong; Guan, Fei; Chen, Amber; Ju, Jihyeung

    2013-06-28

    Tocopherols (vitamin E) and tea polyphenols have been reported to have cancer preventive activities. Large-scale human trials with high doses of alpha-tocopherol, however, have produced disappointing results. This review presents data showing that - and -tocopherols inhibit colon, lung, mammary and prostate carcinogenesis in animal models, whereas -tocopherol is ineffective in animal and human studies. Possible mechanisms of action are discussed. A broad cancer preventive activity of green tea polyphenols has been demonstrated in animal models, and many mechanisms have been proposed. The cancer preventive activity of green tea in humans, however, has not been conclusively demonstrated and remains to be further investigated. PMID:23403075

  13. Effect of Tea Catechins on Folate Analysis in Green Tea by Microbiological Assay.

    PubMed

    Umegaki, Keizo; Sekine, Yuki; Sato, Yoko; Chiba, Tsuyoshi; Sonoda, Masaru

    2016-01-01

    Green tea is thought to be a primary source of folate in the Japanese diet, based on folate content analyzed by a microbiological assay. Green tea also contains high amount of catechins, in particular, epigallocatechin gallate (EGCg), which was demonstrated to be able to inhibit the digestive enzyme activities and microbial growth in the folate assay. In the present study, we examined whether tea catechins interfered with components of the folate assay for green tea. A marked inhibitory effect of EGCg on microbial growth was observed at an inhibitory concentration of higher than 10 μg/mL. Tea catechins without the galloyl moiety did not show an inhibitory effect. EGCg inhibited the activity of the three enzymes used for assay sample preparation at an inhibitory concentration of higher than 750 μg/mL for α-amylase, 1,000 μg/mL for protease, and 50 μg/mL for conjugase. However, with each step of the assay, the actual concentration of EGCg was decreased to below the inhibitory concentration of each analytical step. Lack of influence of EGCg on green tea folate assay was confirmed by an addition of folate standard in tea infusion. These results suggested that tea catechins have no practical impact on folate analysis in green tea, using the general microbiological assay.

  14. Mycocerosic acid synthase exemplifies the architecture of reducing polyketide synthases.

    PubMed

    Herbst, Dominik A; Jakob, Roman P; Zähringer, Franziska; Maier, Timm

    2016-03-24

    Polyketide synthases (PKSs) are biosynthetic factories that produce natural products with important biological and pharmacological activities. Their exceptional product diversity is encoded in a modular architecture. Modular PKSs (modPKSs) catalyse reactions colinear to the order of modules in an assembly line, whereas iterative PKSs (iPKSs) use a single module iteratively as exemplified by fungal iPKSs (fiPKSs). However, in some cases non-colinear iterative action is also observed for modPKSs modules and is controlled by the assembly line environment. PKSs feature a structural and functional separation into a condensing and a modifying region as observed for fatty acid synthases. Despite the outstanding relevance of PKSs, the detailed organization of PKSs with complete fully reducing modifying regions remains elusive. Here we report a hybrid crystal structure of Mycobacterium smegmatis mycocerosic acid synthase based on structures of its condensing and modifying regions. Mycocerosic acid synthase is a fully reducing iPKS, closely related to modPKSs, and the prototype of mycobacterial mycocerosic acid synthase-like PKSs. It is involved in the biosynthesis of C20-C28 branched-chain fatty acids, which are important virulence factors of mycobacteria. Our structural data reveal a dimeric linker-based organization of the modifying region and visualize dynamics and conformational coupling in PKSs. On the basis of comparative small-angle X-ray scattering, the observed modifying region architecture may be common also in modPKSs. The linker-based organization provides a rationale for the characteristic variability of PKS modules as a main contributor to product diversity. The comprehensive architectural model enables functional dissection and re-engineering of PKSs.

  15. Chemopreventive Effects of Tea in Prostate Cancer: Green Tea vs. Black Tea

    PubMed Central

    Henning, Susanne M.; Wang, Piwen; Heber, David

    2011-01-01

    The polyphenol compositions of green tea (GT) and black tea (BT) are very different due to post-harvest processing. GT contains higher concentrations of monomeric polyphenols, which affect numerous intracellular signaling pathways involved in prostate cancer (CaP) development. BT polymers, on the other hand, are poorly absorbed and are converted to phenolic acids by the colonic microflora. Therefore, after consumption of GT higher concentrations of polyphenols are found in the circulation while after BT consumption the phenolic acid levels in the circulation are higher. The majority of in vitro cell culture, in vivo animal, and clinical intervention studies examine the effects of extracts of GT or purified (-)-epigallocatechin-3-gallate (EGCG) on prostate carcinogenesis. These studies provide strong evidence supporting a chemopreventive effect of GT, but results from epidemiological studies of GT consumption are mixed. While the evidence for a chemopreventive effect of BT is much weaker than the body of evidence with regard to GT, there are several animal BT intervention studies demonstrating inhibition of CaP growth. This article will review in detail the available epidemiological and human clinical studies, as well as animal and basic mechanistic studies on GT and BT supporting a chemopreventive role in CaP. PMID:21538852

  16. The Chemopreventive and Chemotherapeutic Potentials of Tea Polyphenols

    PubMed Central

    Thakur, Vijay S; Gupta, Karishma; Gupta, Sanjay

    2011-01-01

    Tea is the second most consumed beverage in the world reported to have multiple health benefits. Preventive and therapeutic benefits of tea polyphenols include enhanced general well being and anti-neoplastic effects. The pharmacologic action of tea is often attributed to various catechins present therein. Experiments conducted in cancer cell lines and animal models demonstrate that tea polyphenols protect against cellular damage caused by oxidative stress and altered immunity. Tea polyphenols modify various metabolic and signaling pathways in the regulation of proliferation, apoptosis, angiogenesis, and metastasis and therefore restrict clonal expansion of cancer cells. Tea polyphenols have been shown to reactivate tumor suppressors, block the unlimited replicative potential of cancer cells, and physically bind to nucleic acids involved in epigenetic alterations of gene regulation. Remarkable interest in green tea as a potential chemopreventive agent has been generated since recent epigenetic data showed that tea polyphenols have the potential to reverse epigenetic modifications which might otherwise be carcinogenic. Like green tea, black tea may also possess chemopreventive and chemotherapeutic potential; however, there is still not enough evidence available to make any conclusive statements. Here we present a brief description of tea polyphenols and discuss the findings of various in vitro and in vivo studies of the anticancer effects of tea polyphenols. Detailed discussion of various studies related to epigenetic changes caused by tea polyphenols leading to prevention of oncogenesis or cancer progression is included. Finally, we discuss on the scope and development of tea polyphenols in cancer prevention and therapy. PMID:21466438

  17. Drinking green tea modestly reduces breast cancer risk.

    PubMed

    Shrubsole, Martha J; Lu, Wei; Chen, Zhi; Shu, Xiao Ou; Zheng, Ying; Dai, Qi; Cai, Qiuyin; Gu, Kai; Ruan, Zhi Xian; Gao, Yu-Tang; Zheng, Wei

    2009-02-01

    Green tea is a commonly consumed beverage in China. Epidemiological and animal data suggest tea and tea polyphenols may be preventive against various cancers, including breast cancer. Catechol-O-methyltransferase (COMT) catalyzes catechol estrogens and tea polyphenols. The COMT rs4680 AA genotype leads to lower COMT activity, which may affect the relationship between green tea consumption and breast cancer risk. We evaluated whether regular green tea consumption was associated with breast cancer risk among 3454 incident cases and 3474 controls aged 20-74 y in a population-based case-control study conducted in Shanghai, China during 1996-2005. All participants were interviewed in person about green tea consumption habits, including age of initiation, duration of use, brew strength, and quantity of tea. Odds ratios (OR) and 95% CI were calculated for green tea consumption measures and adjusted for age and other confounding factors. Compared with nondrinkers, regular drinking of green tea was associated with a slightly decreased risk for breast cancer (OR, 0.88; 95% CI, 0.79-0.98). Among premenopausal women, reduced risk was observed for years of green tea drinking (P-trend = 0.02) and a dose-response relationship with the amount of tea consumed per month was also observed (P-trend = 0.046). COMT rs4680 genotypes did not have a modifying effect on the association of green tea intake with breast cancer risk. Drinking green tea may be weakly associated with a decreased risk of breast cancer.

  18. Black tea polyphenols inhibit tumor proteasome activity.

    PubMed

    Mujtaba, Taskeen; Dou, Q Ping

    2012-01-01

    Tea is a widely consumed beverage and its constituent polyphenols have been associated with potential health benefits. Although black tea polyphenols have been reported to possess potent anticancer activities, the effect of its polyphenols, theaflavins on the tumor's cellular proteasome function, an important biological target in cancer prevention, has not been carefully studied. Here black tea extract (T5550) enriched in theaflavins inhibited the chymotrypsin-like (CT) activity of the proteasome and proliferation of human multiple myeloma cells in a dose-dependent manner. Also an isolated theaflavin (TF-1) can bind to, and inhibit the purified 20S proteasome, accompanied by suppression of tumor cell proliferation, suggesting that the tumor proteasome is an important target whose inhibition is at least partially responsible for the anticancer effects of black tea.

  19. Green tea extract for periodontal health

    PubMed Central

    Venkateswara, Babu; Sirisha, K.; Chava, Vijay K.

    2011-01-01

    Tea, the commonly consumed beverage, is gaining increased attention in promoting overall health. In specific, green tea is considered a healthful beverage due to the biological activity of its polyphenols namely catechins. Among the polyphenols Epigallo catechin 3 gallate and Epicatechin 3 Gallate are the most predominant catechins. The antioxidant, antimicrobial, anticollagenase, antimutagenic, and c hemopreventive properties of these catechins proved to be helpful in the treatment of chronic diseases like periodontal disease. Studies have demonstrated that the type of processing mainly effects the concentration of catechins. Several epidemiological studies have proved that green tea also has some general health benefitting properties like antihypertensive, reduction of cardiovascular risk, antibacterial, antiviral, and antifungal activity. The present review concentrates on the effects of green tea in periodontal and general health. PMID:21772716

  20. Sweeteners: consumer acceptance in tea.

    PubMed

    Sprowl, D J; Ehrcke, L A

    1984-09-01

    Sucrose, fructose, aspartame, and saccharin were compared for consumer preference, aftertaste, and cost to determine acceptability of the sweeteners. A 23-member taste panel evaluated tea samples for preference and aftertaste. Mean retail cost of the sweeteners were calculated and adjusted to take sweetening power into consideration. Sucrose was the least expensive and most preferred sweetener. No significant difference in preference for fructose and aspartame was found, but both sweeteners were rated significantly lower than sucrose. Saccharin was the most disliked sweetener. Fructose was the most expensive sweetener and aspartame the next most expensive. Scores for aftertaste followed the same pattern as those for preference. Thus, a strong, unpleasant aftertaste seems to be associated with a dislike for a sweetener. From the results of this study, it seems that there is no completely acceptable low-calorie substitute for sucrose available to consumers.

  1. Antioxidant screening of medicinal herbal teas.

    PubMed

    Speisky, Hernán; Rocco, Claudia; Carrasco, Catalina; Lissi, Eduardo A; López-Alarcón, Camilo

    2006-06-01

    Herbal tea consumption is deeply and widely rooted amongst South-American populations. In view of the involvement of oxygen- and nitrogen-reactive species in the ethiogenesis of several diseases, the antioxidant properties of some of the herbal teas most commonly consumed in the southern regions was assessed in vitro. Around one-third of the 13 examined herbs, displayed a substantially higher ability to scavenge ABTS(+.) radicals (TEAC assay), and to quench the pro-oxidant species, hypochlorite (HClO) and peroxynitrite (ONOO(-)). Amongst the tested herbs, teas prepared from Haplopappus baylahuen, Rosa moschata and Peumus boldus showed the highest TEAC and HClO-quenching activities. These herbs were around 5- to 7-fold more potent than the least active herbs. Based on the TEAC assay, 150 mL of tea prepared from H. baylahuen, R. moschata and P. boldus would be equivalent to around 200 mg of Trolox). Teas from H. baylahuen and P. boldus were also found to be particularly potent in quenching HClO. In the ONOO(-) assay, H. baylahuen and Buddleia globosa showed the highest activities. The results obtained suggest that the regular consumption of teas prepared from some of these herbs may be useful potentially to provide the organism with molecules capable of protecting the gastrointestinal tract against certain pathologically relevant oxidant species. PMID:16619353

  2. [Determination of elements related to reducing blood sugar (ERBS) in tea and tea polysaccharide by ICP-MS].

    PubMed

    Xie, Ming-Yong; Nie, Shao-Ping; Fu, Bo-Qiang; Wang, Xiao-Ru

    2006-09-01

    Contents of elements related to reducing blood sugar (ERBS) in several kinds of green tea of Wuyuan county, their tea infusion extracted by warm water and boiling water and tea polysaccharide (TP) were determined by ICP-MS, after the samples were digested with acids by microwave method. The relation between the amount of ERBS and tea quality and the relation between the content of ERBS in TP and the total content in tea were discussed. The results showed that the amounts of ERBS in tea and TP are different in various samples. The amount of ERBS in TP extracted from coarse tea was higher than that from fresh tea. The percentage of certain ERBS in TP accounting for the ERBS in tea ranged from 0.03% to 9.57%. As to the total ERBS in TP extracted from Mt. Zhang super grade tea and grade 5 tea, the percentages were 1.11% and 2.10% respectively. As to Mt. Gu old tea, it was 0.85%. The results could provide data for selecting tea material used to extracting tea polysaccharide and for studying the mechanism of reducing blood sugar. PMID:17112052

  3. Suppressive Effects of Tea Catechins on Breast Cancer

    PubMed Central

    Xiang, Li-Ping; Wang, Ao; Ye, Jian-Hui; Zheng, Xin-Qiang; Polito, Curt Anthony; Lu, Jian-Liang; Li, Qing-Sheng; Liang, Yue-Rong

    2016-01-01

    Tea leaf (Camellia sinensis) is rich in catechins, which endow tea with various health benefits. There are more than ten catechin compounds in tea, among which epigallocatechingallate (EGCG) is the most abundant. Epidemiological studies on the association between tea consumption and the risk of breast cancer were summarized, and the inhibitory effects of tea catechins on breast cancer, with EGCG as a representative compound, were reviewed in the present paper. The controversial results regarding the role of tea in breast cancer and areas for further study were discussed. PMID:27483305

  4. Suppressive Effects of Tea Catechins on Breast Cancer.

    PubMed

    Xiang, Li-Ping; Wang, Ao; Ye, Jian-Hui; Zheng, Xin-Qiang; Polito, Curt Anthony; Lu, Jian-Liang; Li, Qing-Sheng; Liang, Yue-Rong

    2016-01-01

    Tea leaf (Camellia sinensis) is rich in catechins, which endow tea with various health benefits. There are more than ten catechin compounds in tea, among which epigallocatechingallate (EGCG) is the most abundant. Epidemiological studies on the association between tea consumption and the risk of breast cancer were summarized, and the inhibitory effects of tea catechins on breast cancer, with EGCG as a representative compound, were reviewed in the present paper. The controversial results regarding the role of tea in breast cancer and areas for further study were discussed. PMID:27483305

  5. Interactions among chemical components of Cocoa tea (Camellia ptilophylla Chang), a naturally low caffeine-containing tea species.

    PubMed

    Lin, Xiaorong; Chen, Zhongzheng; Zhang, Yuanyuan; Gao, Xiong; Luo, Wei; Li, Bin

    2014-06-01

    In the 1980s, a novel tea species, Cocoa tea (Camellia ptilophylla Chang), was discovered in Southern China with surprisingly low caffeine content (0.2% by dry weight). Although its health promoting characteristics have been known for a while, a very limited amount of scientific research has been focused on Cocoa tea. Herein, a systematic study on Cocoa tea and its chemical components, interactions and bioactivities was performed. YD tea (Yunnan Daye tea, Camellia sinensis), a tea species with a high caffeine content (5.8% by dry weight), was used as a control. By UV-Vis spectrometry, High Performance Liquid Chromatography (HPLC), and Flame Atomic Absorption Spectrometry (FAAS) for chemical composition analysis, C-2 epimeric isomers of tea catechins and theobromine were found to be the major catechins and methylxanthine in Cocoa tea, respectively. More gallated catechins, methylxanthines, and proteins were detected in Cocoa tea compared with YD tea. Moreover, the tendency of major components in Cocoa tea for precipitation was significantly higher than that in YD tea. Catechins, methylxanthines, proteins, iron, calcium, and copper were presumed to be the origins of molecular interactions in Cocoa tea and YD tea. The interactions between catechins and methylxanthines were highly related to the galloyl moiety in catechins and methyl groups in methylxanthines. In vitro anti-inflammatory activity assays revealed that Cocoa tea was a more potent inhibitor of nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated macrophage cells (RAW 264.7) than YD tea. This study constructs a solid phytochemical foundation for further research on the mechanisms of molecular interactions and the integrated functions of Cocoa tea.

  6. Stability of Green Tea Catechins in Commercial Tea Leaves during Storage for 6 Months

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To help meet the needs of consumers, producers of dietary tea products, and researchers for information on health-promoting tea ingredients, we determined by HPLC seven catechins [(–)-epigallocatechin (EGC), (–)-catechin (C), (+)-epicatechin (EC), (–)-epigallocatechin 3-gallate (EGCG), (–)-gallocate...

  7. Overview of antibacterial, antitoxin, antiviral, and antifungal activities of tea flavonoids and teas.

    PubMed

    Friedman, Mendel

    2007-01-01

    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 leaves results in the formation of four theaflavins as well as polymeric thearubigins. These substances impart the black color to black teas. Black and partly fermented oolong teas contain both classes of phenolic compounds. A need exists to develop a better understanding of the roles of polyphenolic tea compounds in food and medical microbiology. This overview surveys and interprets our present knowledge of activities of tea flavonoids and teas against foodborne and other pathogenic bacteria, virulent protein toxins produced by some of the bacteria, virulent bacteriophages, pathogenic viruses and fungi. Also covered are synergistic, mechanistic, and bioavailability aspects of the antimicrobial effects. Further research is suggested for each of these categories. The herein described findings are not only of fundamental interest, but also have practical implications for nutrition, food safety, and animal and human health. PMID:17195249

  8. Factors affecting transfer of polycyclic aromatic hydrocarbons from made tea to tea infusion.

    PubMed

    Lin, Daohui; Zhu, Lizhong; Luo, Lan

    2006-06-14

    Factors affecting transfer percentages of 12 polycyclic aromatic hydrocarbons (PAHs) were investigated, including tea variety, tea/water ratio (TWR, g/mL), brewing times, washed tea or unwashed tea, and covered cup or uncovered cup. It was observed that %PAH transfer varied with tea variety and increased with the decrease of TWR. The mean %PAH transfer with TWR = 1/150 was 1.12 and 1.65 times higher than that with TWR = 1/100 and 1/50, respectively. %PAH transfer reduced greatly as the brewing times increased. The mean %PAH transfer in the first brewing time occupied 51.6% of the total three mean %PAH transfers in the three brewing times. The mean %PAH transfer decreased by 30.4% after the tea had been washed immediately before brewing. Brewing the tea within uncovered cup diminished %PAH transfer by a degree of 4.31-31.7% compared to brewing the tea within a covered cup. PMID:16756366

  9. Determination of polycyclic aromatic hydrocarbons in smoked and non-smoked black teas and tea infusions.

    PubMed

    Pincemaille, Justine; Schummer, Claude; Heinen, Eric; Moris, Gilbert

    2014-02-15

    This study describes the occurrence of polycyclic aromatic hydrocarbons (PAHs) in smoked tea and tea infusions, via the monitoring of benzo(a)anthracene, chrysene, benzo(b)fluoranthene and benzo(a)pyrene (PAH4) that have been chosen as indicators for the occurrence of PAHs in food by the European Food Safety Agency. The concentrations ranged from 1.2 μg/kg for benzo(b)fluoranthene to 125.0 μg/kg for benzo(a)anthracene in smoked tea leaves, and from 0.6 μg/L for benzo(a)anthracene to 1.2 μg/L for benzo(b)fluoranthene in smoked tea infusions. Benzo(a)pyrene was never detected in infusions. The concentrations in non-smoked tea leaves ranged from 0.6 μg/kg for benzo(a)anthracene to 10.8 μg/kg for benzo(b)fluoranthene. It was shown that the concentrations of benzo(a)anthracene and chrysene were higher in smoked tea than in non-smoked tea while no difference was observed for benzo(b)fluoranthene and benzo(a)pyrene. The concentrations of PAHs in tea infusions are low compared to other foodstuffs, but the migration rates from leaves into water are high (82-123%).

  10. Aroma changes of black tea prepared from methyl jasmonate treated tea plants.

    PubMed

    Shi, Jiang; Wang, Li; Ma, Cheng-ying; Lv, Hai-peng; Chen, Zong-mao; Lin, Zhi

    2014-04-01

    Methyl jasmonate (MeJA) was widely applied in promoting food quality. Aroma is one of the key indicators in judging the quality of tea. This study examined the effect of exogenous MeJA treatment on tea aroma. The aroma components in black tea prepared from MeJA-treated fresh tea leaves were extracted using headspace solid-phase microextraction (HS-SPME) and were analyzed using gas chromatography-mass spectrometry (GC-MS) and GC-olfactometry (GC-O). Forty-five volatile compounds were identified. The results revealed that the MeJA-treated black tea had higher levels of terpene alcohols and hexenyl esters than the untreated tea. Moreover, several newly components, including copaene, cubenol, and indole, were induced by the MeJA treatment. The activities of polyphenol oxidase and β-glucosidase in fresh tea leaves changed after the MeJA treatment. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis indicated that the gene expression levels of polyphenol oxidase and β-primeverosidase were upregulated by two and three folds, respectively, by the MeJA treatment (P<0.01); however, the gene expression of β-glucosidase was downregulated to a half level. In general, the aroma quality of the MeJA-treated black tea was clearly improved.

  11. Monitoring Chlorfenapyr in Green Tea during the Manufacturing Process

    NASA Astrophysics Data System (ADS)

    Takahashi, Atsushi; Kishi, Yasuhiro; Ogawa, Hideyuki; Nakajima, Kenta

    In order to clarify the change in the leaves of agricultural chemicals during the green tea manufacturing process, we analyzed chlorfenapyr in tea leaves obtained at each processing stage by using an immunoassay. Chlorfenapyr is a novel broad-spectrum insecticide-miticide registered in many countries for the control of various insects and mite pests. Chlorfenapyr is stable and persistent in the environment. Furthermore, it is widely applied for tea cultivation in Japan. Therefore, we selected chlorfenapyr for analysis in this study. In the unrefined tea (Aracha) manufacturing process, the highest level of chlorfenapyr was 16.5 ppm, which was obtained in tea powder separated from leaves at the secondary drying stage. However, the level at the other processing stages in tea leaves was approximately 9 ppm, and no significant difference in the chlorfenapyr level was detected between the processing stages. After Aracha processing, tea leaves are classified on the basis of their size, shape and color; this is the refined tea (Shiagecha) manufacturing process. After this process, although a high level of chlorfenapyr was detected in bud tea (8.1 ppm) and honcha (on-grade tea; 6.2 ppm), the level in the other classified teas was approximately 4.0 ppm. Thus, this paper shows the difference in the chlorfenapyr level in tea leaves obtained at each processing stage. This indicated that there are significant differences in the agricultural chemical levels between the green tea processing stages.

  12. STRUCTURAL ENZYMOLOGY OF POLYKETIDE SYNTHASES

    PubMed Central

    Tsai, Shiou-Chuan (Sheryl); Ames, Brian Douglas

    2010-01-01

    This chapter describes structural and associated enzymological studies of polyketide synthases, including isolated single domains and multidomain fragments. The sequence–structure–function relationship of polyketide biosynthesis, compared with homologous fatty acid synthesis, is discussed in detail. Structural enzymology sheds light on sequence and structural motifs that are important for the precise timing, substrate recognition, enzyme catalysis, and protein–protein interactions leading to the extraordinary structural diversity of naturally occurring polyketides. PMID:19362634

  13. Swelling kinetics of tea in hot water.

    PubMed

    Joshi, Bhushan S; Farakte, Raosaheb A; Yadav, Geeta U; Patwardhan, Ashwin W; Singh, Gurmeet

    2016-01-01

    In this study, the swelling kinetics of individual tea particles as well as bed of tea granules were investigated for different types of teas. The swelling experiments involved image analysis and volume measurements of tea particles. Each individual particle shows different swelling characteristics. Separating funnels and cylindrical columns of varying sizes were used to study the changes in volume of tea bed. Swelling in separating funnel was observed to be more than that in column. The effect of temperature, particle size, bed height and vessel diameter were investigated. The extent as well as the rate of swelling is found to increase with rise in temperature (60 to 80 °C) and reduction in particle size. A decrease in swelling is observed with increase in bed height as well as decrease in vessel diameter and vice a versa. About 70 to 75 % swelling occurs in the first 40 to 45 s. Two empirical models viz. Weibull and Peleg were used to fit the experimental data. The rate parameters obtained for a sample T5 at different temperatures were in the range of 0.012 to 0.016. The volume changes of all the teas were compared with their elution behavior, by measuring the absorbance of a diluted sample of brew at 272 nm. The activation energies for the process of tea swelling calculated for T1 (1.2 mm), T5 (2.2 mm) and T5 (0.72 mm) were 14.156, 8.37 and 13.42 kJ/mol respectively. PMID:26787951

  14. Swelling kinetics of tea in hot water.

    PubMed

    Joshi, Bhushan S; Farakte, Raosaheb A; Yadav, Geeta U; Patwardhan, Ashwin W; Singh, Gurmeet

    2016-01-01

    In this study, the swelling kinetics of individual tea particles as well as bed of tea granules were investigated for different types of teas. The swelling experiments involved image analysis and volume measurements of tea particles. Each individual particle shows different swelling characteristics. Separating funnels and cylindrical columns of varying sizes were used to study the changes in volume of tea bed. Swelling in separating funnel was observed to be more than that in column. The effect of temperature, particle size, bed height and vessel diameter were investigated. The extent as well as the rate of swelling is found to increase with rise in temperature (60 to 80 °C) and reduction in particle size. A decrease in swelling is observed with increase in bed height as well as decrease in vessel diameter and vice a versa. About 70 to 75 % swelling occurs in the first 40 to 45 s. Two empirical models viz. Weibull and Peleg were used to fit the experimental data. The rate parameters obtained for a sample T5 at different temperatures were in the range of 0.012 to 0.016. The volume changes of all the teas were compared with their elution behavior, by measuring the absorbance of a diluted sample of brew at 272 nm. The activation energies for the process of tea swelling calculated for T1 (1.2 mm), T5 (2.2 mm) and T5 (0.72 mm) were 14.156, 8.37 and 13.42 kJ/mol respectively.

  15. Green tea: nature's defense against malignancies.

    PubMed

    Butt, Masood Sadiq; Sultan, Muhammad Tauseef

    2009-05-01

    The current practice of introducing phytochemicals to support the immune system or fight against diseases is based on centuries old traditions. Nutritional support is a recent advancement in the domain of diet-based therapies; green tea and its constituents are one of the important components of these strategies to prevent and cure various malignancies. The anti-carcinogenic and anti-mutagenic activities of green tea were highlighted some years ago suggesting that it could reduce the prevalence of cancer and even provide protection. The pharmacological actions of green tea are mainly attributed to polyphenols that includes epigallocatechin-3-gallate (EGCG), epicatechin, epicatechin-3-gallate, epigallocatechin. Green tea and its components effectively mitigate cellular damage arising due to oxidative stress. Green tea is supposed to enhance humoral and cell-mediated immunity, decreasing the risk of certain cancers, and may have certain advantage in treating inflammatory disorders. Much of the cancer chemopreventive properties of green tea are mediated by EGCG that induces apoptosis and promotes cell growth arrest, by altering the expression of cell cycle regulatory proteins, activating killer caspases, and suppressing nuclear factor kappa-B activation. Besides, it regulates and promotes IL-23 dependent DNA repair and stimulates cytotoxic T cells activities in a tumor microenvironment. It also blocks carcinogenesis by modulating the signal transduction pathways involved in cell proliferation, transformation, inflammation and metastasis. The review is intended to highlight the chemistry of green tea, its antioxidant potential, its immunopotentiating properties and mode of action against various cancer cell lines that showed its potential as a chemopreventive agent against colon, skin, lung, prostate, and breast cancer.

  16. Determination of pyrrolizidine alkaloids in tea, herbal drugs and honey.

    PubMed

    Bodi, Dorina; Ronczka, Stefan; Gottschalk, Christoph; Behr, Nastassja; Skibba, Anne; Wagner, Matthias; Lahrssen-Wiederholt, Monika; Preiss-Weigert, Angelika; These, Anja

    2014-01-01

    Honey was previously considered to be one of the main food sources of human pyrrolizidine alkaloid (PA) exposure in Europe. However, comprehensive analyses of honey and tea sampled in the Berlin retail market revealed unexpected high PA amounts in teas. This study comprised the analysis of 87 honey as well as 274 tea samples including black, green, rooibos, melissa, peppermint, chamomile, fennel, nettle, and mixed herbal tea or fruit tea. Total PA concentrations in tea ranged from < LOD to 5647 µg kg(-1), while a mean value of about 10 µg kg(-1) was found in honey samples. Additionally, herbal drugs were investigated to identify the source of PA in teas. Results suggest that PA in tea samples are most likely a contamination caused by co-harvesting of PA-producing plants. In some cases such as fennel, anise or caraway, it cannot be excluded that these plants are able to produce PA themselves.

  17. Antimicrobial activity of different tea varieties available in Pakistan.

    PubMed

    Zakir, Muhammad; Sultan, Khush Bakht; Khan, Haroon; Ihsaanullah; Khan, Murad Ali; Fazal, Hina; Rauf, Abdur

    2015-11-01

    In this antimicrobial study, various extracts of Green and Black tea (Camellia sinensis) and Lemon grass (Cymbopogon citrates) were evaluated for antimicrobial activities against six bacterial strains including both human pathogenic bacteria (Escherichia coli, Pseudomonas aeuroginosa, Staphylococcus aureus and Salmonella typhi) and plant pathogenic bacteria (Erwinia carotovora, Agro bacterium tumifaciens) and one fungal strain Candida albicans by disc diffusion susceptibility method. Of human pathogens, P. aeruginosa was most susceptible to all three different tea varieties; though rest of the strains also demonstrated prominent sensitivity. In comparison, black tea extracts were less activities than green tea and lemon grass. However, all the three tea varieties illustrated profound activity against plant pathogenic bacteria. Similarly, when extracts of tea were tested against C. albicans, green tea and lemon grass exhibited significant activity while black tea was mostly inactive.

  18. Efficient extraction strategies of tea (Camellia sinensis) biomolecules.

    PubMed

    Banerjee, Satarupa; Chatterjee, Jyotirmoy

    2015-06-01

    Tea is a popular daily beverage worldwide. Modulation and modifications of its basic components like catechins, alkaloids, proteins and carbohydrate during fermentation or extraction process changes organoleptic, gustatory and medicinal properties of tea. Through these processes increase or decrease in yield of desired components are evident. Considering the varied impacts of parameters in tea production, storage and processes that affect the yield, extraction of tea biomolecules at optimized condition is thought to be challenging. Implementation of technological advancements in green chemistry approaches can minimize the deviation retaining maximum qualitative properties in environment friendly way. Existed extraction processes with optimization parameters of tea have been discussed in this paper including its prospects and limitations. This exhaustive review of various extraction parameters, decaffeination process of tea and large scale cost effective isolation of tea components with aid of modern technology can assist people to choose extraction condition of tea according to necessity.

  19. Fluoride in Ceylon tea and its implications to dental health.

    PubMed

    Chandrajith, Rohana; Abeypala, Uthpala; Dissanayake, C B; Tobschall, H J

    2007-10-01

    The purpose of this study was to assess the fluoride content of Ceylon Tea, which is a popular beverage throughout the world. The fluoride content of tea infusions prepared from different grades of tea leaves collected from different parts of the tea-growing regions (25 samples) of Sri Lanka was measured using a fluoride-selective electrode. Fluoride leaching was found to vary from 0.32 to 1.69 mg F/l, but there were no significant differences in terms of fluoride leaching between tea from different tea-growing regions or between tea of different grades. Dental fluorosis is widespread throughout the dry zone of Sri Lanka, and drinking water has traditionally been considered to be the main contributory factor to the development of fluorosis. However, diet, the consumption of tea in particular, may also contribute to the manifestation of dental diseases.

  20. Antimicrobial activity of different tea varieties available in Pakistan.

    PubMed

    Zakir, Muhammad; Sultan, Khush Bakht; Khan, Haroon; Ihsaanullah; Khan, Murad Ali; Fazal, Hina; Rauf, Abdur

    2015-11-01

    In this antimicrobial study, various extracts of Green and Black tea (Camellia sinensis) and Lemon grass (Cymbopogon citrates) were evaluated for antimicrobial activities against six bacterial strains including both human pathogenic bacteria (Escherichia coli, Pseudomonas aeuroginosa, Staphylococcus aureus and Salmonella typhi) and plant pathogenic bacteria (Erwinia carotovora, Agro bacterium tumifaciens) and one fungal strain Candida albicans by disc diffusion susceptibility method. Of human pathogens, P. aeruginosa was most susceptible to all three different tea varieties; though rest of the strains also demonstrated prominent sensitivity. In comparison, black tea extracts were less activities than green tea and lemon grass. However, all the three tea varieties illustrated profound activity against plant pathogenic bacteria. Similarly, when extracts of tea were tested against C. albicans, green tea and lemon grass exhibited significant activity while black tea was mostly inactive. PMID:26639502

  1. Determination of pyrrolizidine alkaloids in tea, herbal drugs and honey.

    PubMed

    Bodi, Dorina; Ronczka, Stefan; Gottschalk, Christoph; Behr, Nastassja; Skibba, Anne; Wagner, Matthias; Lahrssen-Wiederholt, Monika; Preiss-Weigert, Angelika; These, Anja

    2014-01-01

    Honey was previously considered to be one of the main food sources of human pyrrolizidine alkaloid (PA) exposure in Europe. However, comprehensive analyses of honey and tea sampled in the Berlin retail market revealed unexpected high PA amounts in teas. This study comprised the analysis of 87 honey as well as 274 tea samples including black, green, rooibos, melissa, peppermint, chamomile, fennel, nettle, and mixed herbal tea or fruit tea. Total PA concentrations in tea ranged from < LOD to 5647 µg kg(-1), while a mean value of about 10 µg kg(-1) was found in honey samples. Additionally, herbal drugs were investigated to identify the source of PA in teas. Results suggest that PA in tea samples are most likely a contamination caused by co-harvesting of PA-producing plants. In some cases such as fennel, anise or caraway, it cannot be excluded that these plants are able to produce PA themselves. PMID:25222912

  2. Antimutagenicity and catechin content of soluble instant teas.

    PubMed

    Constable, A; Varga, N; Richoz, J; Stadler, R H

    1996-03-01

    The antimutagenic properties of soluble instant teas were examined using the bacterial Ames assay. Inhibition of the numbers of revertants induced from a number of known mutagens indicates that aqueous extracts of instant teas have antimutagenic activity and antioxidative properties, and can inhibit nitrosation reactions. Despite a significant reduction in the amounts of major green tea catechins, quantified using reversed-phase HPLC with electro-chemical detection, no differences in antimutagenicity were observed between the instant teas, a black fermented tea and a green tea. Oxidation of polyphenolic compounds which occurs during the production of instant tea does not therefore decrease the antioxidant, free radical scavenging and antimutagenic properties. This suggests that catechins are not the only compounds responsible for the protective effects of teas. PMID:8671737

  3. Efficient extraction strategies of tea (Camellia sinensis) biomolecules.

    PubMed

    Banerjee, Satarupa; Chatterjee, Jyotirmoy

    2015-06-01

    Tea is a popular daily beverage worldwide. Modulation and modifications of its basic components like catechins, alkaloids, proteins and carbohydrate during fermentation or extraction process changes organoleptic, gustatory and medicinal properties of tea. Through these processes increase or decrease in yield of desired components are evident. Considering the varied impacts of parameters in tea production, storage and processes that affect the yield, extraction of tea biomolecules at optimized condition is thought to be challenging. Implementation of technological advancements in green chemistry approaches can minimize the deviation retaining maximum qualitative properties in environment friendly way. Existed extraction processes with optimization parameters of tea have been discussed in this paper including its prospects and limitations. This exhaustive review of various extraction parameters, decaffeination process of tea and large scale cost effective isolation of tea components with aid of modern technology can assist people to choose extraction condition of tea according to necessity. PMID:26028699

  4. [Selection of reference genes for quantitative real-time PCR in six oil-tea camellia based on RNA].

    PubMed

    Zhou, C F; Lin, P; Yao, X H; Wang, K L; Chang, J; Han, X J

    2013-01-01

    qRT-PCR is becoming a routine tool in molecular biology to study gene expression. It is nec- essary to find stable reference genes when performing qRT-PCR. The expression of genes cloned in oil-tea camellia currently can't be accurately analyzed because of a lack of suitable reference genes. We collected different tissues (including roots, stems, leaves, flowers and seeds) from six oil-tea camellia species to determine stable reference genes. Five novel and ten traditional reference gene sequences were selected from the RNA-seq database of Camellia oleifera C. Abel seeds and specific PCR primers were designed for each. Cycle threshold (Ct) data were obtained from each reaction for all samples. Three different software tools, geNorm, NormFinder and BestKeeper were applied to calculate the expression stability of the candidate reference genes according to the Ct values. The results were similar between analyzed by the three software packages, and indicated that the traditional gene TUBa-3, AC17a and the novel gene CESA were relatively stable in all species and tissues. However, no genes were sufficiently stable across all species and tissues, thus the optimal number of reference genes required for accurate normalization varied from two to six. Finally, the relative expression ofsqualene synthase (SQS) and squalene epoxidase (SQE) genes related to important ingredients squalene and tea saponin in oil-tea camellia seeds were compared by using stable to less stable reference genes. The comparison results validated the selection of reference genes in the current study. In summary, different optimal numbers of suitable reference genes were found for the different tissues of six oil-tea camellia species. PMID:25509858

  5. Antioxidants of the beverage tea in promotion of human health.

    PubMed

    Siddiqui, Imtiaz A; Afaq, Farrukh; Adhami, Vaqar M; Ahmad, Nihal; Mukhtar, Hasan

    2004-06-01

    Tea that contains many antioxidants is a pleasant and safe drink that is enjoyed by people across the globe. Tea leaves are manufactured as black, green, or oolong. Black tea represents approximately 78% of total consumed tea in the world, whereas green tea accounts for approximately 20% of tea consumed. The concept of "use of tea for promotion of human health and prevention and cure of diseases" has become a subject of intense research in the last decade. Diseases for which tea drinkers appear to have lower risk are simple infections, like bacterial and viral, to chronic debilitating diseases, including cancer, coronary heart disease, stroke, and osteoporosis. Initial work on green tea suggested that it possesses human health-promoting effects. In recent years, the research efforts have been expanded to black tea as well. Research conducted in recent years reveals that both black and green tea have very similar beneficial attributes in lowering the risk of many human diseases, including several types of cancer and heart diseases. For cancer prevention, evidence is so overwhelming that the Chemoprevention Branch of the National Cancer Institute has initiated a plan for developing tea compounds as cancer-chemopreventive agents in human trials. Thus, modern medical research is confirming the ancient wisdom that therapy of many diseases may reside in an inexpensive beverage in a "teapot."

  6. Antioxidants of the beverage tea in promotion of human health.

    PubMed

    Siddiqui, Imtiaz A; Afaq, Farrukh; Adhami, Vaqar M; Ahmad, Nihal; Mukhtar, Hasan

    2004-06-01

    Tea that contains many antioxidants is a pleasant and safe drink that is enjoyed by people across the globe. Tea leaves are manufactured as black, green, or oolong. Black tea represents approximately 78% of total consumed tea in the world, whereas green tea accounts for approximately 20% of tea consumed. The concept of "use of tea for promotion of human health and prevention and cure of diseases" has become a subject of intense research in the last decade. Diseases for which tea drinkers appear to have lower risk are simple infections, like bacterial and viral, to chronic debilitating diseases, including cancer, coronary heart disease, stroke, and osteoporosis. Initial work on green tea suggested that it possesses human health-promoting effects. In recent years, the research efforts have been expanded to black tea as well. Research conducted in recent years reveals that both black and green tea have very similar beneficial attributes in lowering the risk of many human diseases, including several types of cancer and heart diseases. For cancer prevention, evidence is so overwhelming that the Chemoprevention Branch of the National Cancer Institute has initiated a plan for developing tea compounds as cancer-chemopreventive agents in human trials. Thus, modern medical research is confirming the ancient wisdom that therapy of many diseases may reside in an inexpensive beverage in a "teapot." PMID:15130283

  7. Cancer prevention by green tea: evidence from epidemiologic studies.

    PubMed

    Yuan, Jian-Min

    2013-12-01

    In contrast to the consistent results of an inhibitory effect of green tea extracts and tea polyphenols on the development and growth of carcinogen-induced tumors in experimental animal models, results from human studies are mixed. Both observational and intervention studies have provided evidence in support of a protective role of green tea intake in the development of oral-digestive tract cancer or an inhibitory role of oral supplementation of green tea extract on a precancerous lesion of oral cavity. Evidence in support of green tea intake against the development of liver cancer risk is limited and inconsistent. An inverse association between green tea intake and lung cancer risk has been observed among never smokers but not among smokers. Although observational studies do not support a beneficial role of tea intake against the development of prostate cancer, several phase 2 clinical trials have shown an inhibitory effect of green tea extract against the progression of prostate premalignant lesions to malignant tumors. Prospective epidemiologic studies so far have not provided evidence for a protective effect of green tea consumption on breast cancer development. Current data neither confirm nor refute a definitive cancer-preventive role of green tea intake. Large randomized intervention trials on the efficacy of green tea polyphenols or extracts are required before a recommendation for green tea consumption for cancer prevention should be made.

  8. Antiradical and tea polyphenol-stabilizing ability of functional fermented soymilk-tea beverage.

    PubMed

    Zhao, Danyue; Shah, Nagendra P

    2014-09-01

    This study examined the potential of two-step fermentation to preserve TPs in functional soy-tea beverage. Fermented soymilk-tea (FST) was produced by culturing Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus and Bifidobacterium longum in soymilk supplemented with tea extract (TE). Total phenolic content (TPC) and anti-radical activities were determined for FSTs and fermented soymilk (FS). A HPLC method was employed to quantify nine major tea phenolics in FST products. TPC was significantly higher (p<0.05) in FST than FS, in the order of green tea>oolong tea>black tea>soymilk. The FSTs were effective at scavenging DPPH-radical rather than hydroxyl radical. Optimal pH to stabilize TPs in SMT was ca. 5.7, which reduced total TP loss by ca. 40% compared with that obtained from products with TE supplemented at the beginning of fermentation. A gradual decrease in TPs was observed during storage (4 °C), with more than half of total TPs remained in FST after 8 weeks.

  9. Changes in flavor volatile composition of oolong tea after panning during tea processing.

    PubMed

    Sheibani, Ershad; Duncan, Susan E; Kuhn, David D; Dietrich, Andrea M; Newkirk, Jordan J; O'Keefe, Sean F

    2016-05-01

    Panning is a processing step used in manufacturing of some varieties of oolong tea. There is limited information available on effects of panning on oolong tea flavors. The goal of this study was to determine effects of panning on flavor volatile compositions of oolong using Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Olfactometry (GC-O). SDE and SPME techniques were applied for extraction of volatiles in panned and unpanned teas. A total of 190 volatiles were identified from SDE and SPME extractions using GC-MS and GC-O. There were no significant differences (P > 0.05) in aldehyde or terpene contents of unpanned and panned tea. However, alcohols, ketones, acids and esters contents were significantly reduced by panning. Among 12 major volatiles previously used for identification and quality assessment of oolong tea, trans nerolidol, 2- hexenal, benzaldehyde, indole, gernaiol, and benzenacetaldehyde contents were significantly decreased (P < 0.05) by panning. Panning increased (P < 0.05) contents of linalool oxide, cis jasmone, and methyl salicylate. The GC-O study also showed an increase of aroma active compounds with sweet descriptions and decrease of aroma active compounds with fruity and smoky descriptions after panning. Panning significantly changes the volatile compositions of the tea and created new aroma active compounds. Results from this study can be used in quality assessment of panned oolong tea. PMID:27247775

  10. Pyrrolizidine and tropane alkaloids in teas and the herbal teas peppermint, rooibos and chamomile in the Israeli market.

    PubMed

    Shimshoni, Jakob Avi; Duebecke, Arne; Mulder, Patrick P J; Cuneah, Olga; Barel, Shimon

    2015-01-01

    Dehydro pyrrolizidine alkaloids (dehydro PAs) are carcinogenic phytotoxins prevalent in the Boraginaceae, Asteraceae and Fabaceae families. Dehydro PAs enter the food and feed chain by co-harvesting of crops intended for human and animal consumption as well as by carry-over into animal-based products such as milk, eggs and honey. Recently the occurrence of dehydro PAs in teas and herbal teas has gained increasing attention from the EU, due to the high levels of dehydro PAs found in commercially available teas and herbal teas in Germany and Switzerland. Furthermore, several tropane alkaloids (TAs, e.g. scopolamine and hyoscyamine) intoxications due to the consumption of contaminated herbal teas were reported in the literature. The aim of the present study was to determine the dehydro PAs and TAs levels in 70 pre-packed teabags of herbal and non-herbal tea types sold in supermarkets in Israel. Chamomile, peppermint and rooibos teas contained high dehydro PAs levels in almost all samples analysed. Lower amounts were detected in black and green teas, while no dehydro PAs were found in fennel and melissa herbal teas. Total dehydro PAs concentrations in chamomile, peppermint and rooibos teas ranged from 20 to 1729 μg/kg. Except for black tea containing only mono-ester retrorsine-type dehydro PAs, all other teas and herbal teas showed mixed patterns of dehydro PA ester types, indicating a contamination by various weed species during harvesting and/or production. The TA levels per teabag were below the recommended acute reference dose; however, the positive findings of TAs in all peppermint tea samples warrant a more extensive survey. The partially high levels of dehydro PAs found in teas and herbal teas present an urgent warning letter to the regulatory authorities to perform routine quality control analysis and implement maximum residual levels for dehydro PAs. PMID:26365752

  11. Acetohydroxyacid synthases: evolution, structure, and function.

    PubMed

    Liu, Yadi; Li, Yanyan; Wang, Xiaoyuan

    2016-10-01

    Acetohydroxyacid synthase, a thiamine diphosphate-dependent enzyme, can condense either two pyruvate molecules to form acetolactate for synthesizing L-valine and L-leucine or pyruvate with 2-ketobutyrate to form acetohydroxybutyrate for synthesizing L-isoleucine. Because the key reaction catalyzed by acetohydroxyacid synthase in the biosynthetic pathways of branched-chain amino acids exists in plants, fungi, archaea, and bacteria, but not in animals, acetohydroxyacid synthase becomes a potential target for developing novel herbicides and antimicrobial compounds. In this article, the evolution, structure, and catalytic mechanism of acetohydroxyacid synthase are summarized. PMID:27576495

  12. [Genetic diversity of ancient tea gardens and tableland tea gardens from Yunnan Province as revealed by AFLP marker].

    PubMed

    Ji, Peng-Zhang; Jiang, Hui-Bing; Huang, Xing-Qi; Zhang, Jun; Liang, Min-Zhi; Wang, Ping-Sheng

    2009-01-01

    This study was conducted to evaluate the genetic diversity within and among the plants of four ancient tea gardens and two tableland tea gardens form Yunnan Province, China by AFLP technique. The percentage of polymorphic loci (P) of the plants from six tea gardens was 92.31%. The genetic diversity within the six gardens demonstrated by Nei cents genetic diversity (He) was estimated to be 0.1366, while Shannon indices (Ho) were 0.2323. The percentage of polymorphic loci of the four ancient tea populations was 45.55% on average, with a range of 36.44% (Mengsong) to 59.11% (Mengla). But the percentages of polymorphic loci of the plants from two tableland gardens were 13.77% (Yunkang 10) and 24.2% (Menghai Daye), respectively. There was a great genetic difference between ancient tea gardens and tableland tea gardens. The genetic diversity among the plants of the ancient tea garden was higher than those of the sexual tableland tea garden and the clone tableland tea garden based on P valve. The four ancient tea gardens and two tableland gardens could be differentiated with AFLP markers. The results show that AFLP marker is an effective tool in the discrimination of tea germplasm, as well as sundried green tea.

  13. Green tea and black tea consumption and prostate cancer risk: an exploratory meta-analysis of observational studies.

    PubMed

    Zheng, Jusheng; Yang, Bin; Huang, Tao; Yu, Yinghua; Yang, Jing; Li, Duo

    2011-01-01

    Observational studies on tea consumption and prostate cancer (PCa) risk are still inconsistent. The authors conducted a meta-analysis to investigate the association between green tea and black tea consumption with PCa risk. Thirteen studies providing data on green tea or black tea consumption were identified by searching PubMed and ISI Web of Science databases and secondary referencing qualified for inclusion. A random-effects model was used to calculate the summary odds ratios (OR) and their corresponding 95% confidence intervals (CIs). For green tea, the summary OR of PCa indicated a borderline significant association in Asian populations for highest green tea consumption vs. non/lowest (OR = 0.62; 95% CI: 0.38-1.01); and the pooled estimate reached statistically significant level for case-control studies (OR = 0.43; 95% CI: 0.25-0.73), but not for prospective cohort studies (OR = 1.00; 95% CI: 0.66-1.53). For black tea, no statistically significant association was observed for the highest vs. non/lowest black tea consumption (OR = 0.99; 95% CI: 0.82-1.20). In conclusion, this meta-analysis supported that green tea but not black tea may have a protective effect on PCa, especially in Asian populations. Further research regarding green tea consumption across different regions apart from Asia is needed.

  14. Green tea extract for external anogenital warts.

    PubMed

    2015-10-01

    Catephen (Kora Corporation Ltd) is a herbal medicinal product consisting predominantly of catechins (sinecatechins) extracted from Camellia sinensis (L.) O. Kuntze folium (green tea leaf) formulated as a topical preparation for the treatment of external genital and perianal warts (condylomata acuminata).(1) Marketing authorisation for an ointment containing 0.1g of green tea extract per gram (10%) was granted by the Medicines and Healthcare products Regulatory Agency (MHRA) under the mutual recognition procedure in February 2015.(2) Here, we consider the evidence for Catephen ointment in the management of external genital and perianal warts and its place within current management strategies. PMID:26471269

  15. Green tea extract for external anogenital warts.

    PubMed

    2015-10-01

    Catephen (Kora Corporation Ltd) is a herbal medicinal product consisting predominantly of catechins (sinecatechins) extracted from Camellia sinensis (L.) O. Kuntze folium (green tea leaf) formulated as a topical preparation for the treatment of external genital and perianal warts (condylomata acuminata).(1) Marketing authorisation for an ointment containing 0.1g of green tea extract per gram (10%) was granted by the Medicines and Healthcare products Regulatory Agency (MHRA) under the mutual recognition procedure in February 2015.(2) Here, we consider the evidence for Catephen ointment in the management of external genital and perianal warts and its place within current management strategies.

  16. Aflatoxins in black tea in Iran.

    PubMed

    Pouretedal, Zohreh; Mazaheri, Mansooreh

    2013-01-01

    Aflatoxins (AFs) are highly toxic, and carcinogenic secondary fungal metabolites and have been detected in various food commodities. In this regard, 40 black tea samples including domestic and imported black tea were analysed for aflatoxin contamination by high-performance liquid chromatography using a post-column derivatisation procedure (Kobra cell) with fluorescence detection. Samples were randomly collected in 2010 from Tehran markets. The results revealed that 30 among 40 samples were contaminated with aflatoxins (27.5% of the total). Mean AFB1 content was 10.0 ng/g and mean of aflatoxin total was 12.07 ng/g for the 11 contaminated samples.

  17. Oolong tea made from tea plants from different locations in Yunnan and Fujian, China showed similar aroma but different taste characteristics.

    PubMed

    Wang, Chen; Lv, Shidong; Wu, Yuanshuang; Gao, Xuemei; Li, Jiangbing; Zhang, Wenrui; Meng, Qingxiong

    2016-01-01

    Consistent aroma characteristics are important for tea products. However, understanding the formation of tea aroma flavor and correspondingly proposing applicable protocols to control tea quality and consistency remain major challenges. Oolong tea is one of the most popular teas with a distinct flavor. Generally, oolong tea is processed with the leaves of tea trees belonging to different subspecies and grown in significantly different regions. In this study, Yunnan and Fujian oolong teas, green tea, black tea, and Pu-erh tea were collected from major tea estates across China. Their sensory evaluation, main water-soluble and volatile compounds were identified and measured. The sensory evaluation, total polysaccharide, caffeine, and catechin content of Yunnan oolong tea was found to be different from that of Fujian oolong tea, a result suggesting that the kinds of tea leaves used in Yunnan and Fujian oolong teas were naturally different. However, according to their aroma compounds, principal component analysis (PCA) and cluster analysis (CA) of the volatile compounds showed that the two types of oolong teas were similar and cannot be clearly distinguished from each other; they are also different from green, black, and Pu-erh teas, a result indicating that the same oolong tea processing technology applied to different tea leaves results in consistent aroma characteristics. The PCA analysis results also indicated that benzylalcohol, indole, safranal, linalool oxides, β-ionone, and hexadecanoic acid methyl ester highly contributed to the distinct aroma of oolong tea compared with the other three types of teas. This study proved that the use of the same processing technology on two kinds of tea leaves resulted in a highly consistent tea aroma. PMID:27247873

  18. Oolong tea made from tea plants from different locations in Yunnan and Fujian, China showed similar aroma but different taste characteristics.

    PubMed

    Wang, Chen; Lv, Shidong; Wu, Yuanshuang; Gao, Xuemei; Li, Jiangbing; Zhang, Wenrui; Meng, Qingxiong

    2016-01-01

    Consistent aroma characteristics are important for tea products. However, understanding the formation of tea aroma flavor and correspondingly proposing applicable protocols to control tea quality and consistency remain major challenges. Oolong tea is one of the most popular teas with a distinct flavor. Generally, oolong tea is processed with the leaves of tea trees belonging to different subspecies and grown in significantly different regions. In this study, Yunnan and Fujian oolong teas, green tea, black tea, and Pu-erh tea were collected from major tea estates across China. Their sensory evaluation, main water-soluble and volatile compounds were identified and measured. The sensory evaluation, total polysaccharide, caffeine, and catechin content of Yunnan oolong tea was found to be different from that of Fujian oolong tea, a result suggesting that the kinds of tea leaves used in Yunnan and Fujian oolong teas were naturally different. However, according to their aroma compounds, principal component analysis (PCA) and cluster analysis (CA) of the volatile compounds showed that the two types of oolong teas were similar and cannot be clearly distinguished from each other; they are also different from green, black, and Pu-erh teas, a result indicating that the same oolong tea processing technology applied to different tea leaves results in consistent aroma characteristics. The PCA analysis results also indicated that benzylalcohol, indole, safranal, linalool oxides, β-ionone, and hexadecanoic acid methyl ester highly contributed to the distinct aroma of oolong tea compared with the other three types of teas. This study proved that the use of the same processing technology on two kinds of tea leaves resulted in a highly consistent tea aroma.

  19. Producing biofuels using polyketide synthases

    SciTech Connect

    Katz, Leonard; Fortman, Jeffrey L; Keasling, Jay D

    2013-04-16

    The present invention provides for a non-naturally occurring polyketide synthase (PKS) capable of synthesizing a carboxylic acid or a lactone, and a composition such that a carboxylic acid or lactone is included. The carboxylic acid or lactone, or derivative thereof, is useful as a biofuel. The present invention also provides for a recombinant nucleic acid or vector that encodes such a PKS, and host cells which also have such a recombinant nucleic acid or vector. The present invention also provides for a method of producing such carboxylic acids or lactones using such a PKS.

  20. Increase of theaflavin gallates and thearubigins by acceleration of catechin oxidation in a new fermented tea product obtained by the tea-rolling processing of loquat ( Eriobotrya japonica ) and green tea leaves.

    PubMed

    Tanaka, Takashi; Miyata, Yuji; Tamaya, Kei; Kusano, Rie; Matsuo, Yosuke; Tamaru, Shizuka; Tanaka, Kazunari; Matsui, Toshiro; Maeda, Masamichi; Kouno, Isao

    2009-07-01

    In a project to produce a new fermented tea product from non-used tea leaves harvested in the summer, we found that kneading tea leaves ( Camellia sinensis ) with fresh loquat leaves ( Eriobotrya japonica ) accelerated the enzymatic oxidation of tea catechins. The fermented tea obtained by tea-rolling processing of tea and loquat leaves had a strong, distinctive flavor and a plain aftertaste, which differed from usual black, green, and oolong teas. The phenolic constituents were similar to those of black tea. However, the concentrations of theaflavin 3-O-gallate, theaflavin 3,3'-di-O-gallate, and thearubigins were higher in the tea leaves kneaded with loquat leaves than in tea leaves kneaded without loquat leaves. The results from in vitro experiments suggested that acceleration of catechin oxidation was caused by the strong oxidation activity of loquat leaf enzymes and a coupled oxidation mechanism with caffeoyl quinic acids, which are the major phenolic constituents of loquat leaves.

  1. Utilization of tea grounds as feedstuff for ruminant

    PubMed Central

    2013-01-01

    Researches on tea have been developed for decades, which prove that tea, especially green tea, has multiple functional components. With the rapid development of beverage industry, the resultant large amounts of tea grounds attract great attention. However, unreasonable utilization of tea grounds would lead to great waste and environmental pollution, especially in summer. In view of the high nutritive value and multiple functional components, tea grounds could be used as feedstuff. By now, researches of tea grounds as feedstuff are mainly on ruminant, as the utilization on other animals is limited to lower level due to high fiber content. Therefore, the following review will begin with a brief introduction of tea grounds and the possible utilization of tea grounds as feedstuff, and then elaborate on the application of ensiling and total mixed ration on ruminant. Apart from the fermentation quality, nutritive value is also provided to assess feasibilities of using tea grounds as feedstuff resources. Finally, a summary on the utilization situation and future direction of using tea grounds as feedstuff is provided in this review. PMID:24369099

  2. Persistence behaviour of deltamethrin on tea and its transfer from processed tea to infusion.

    PubMed

    Paramasivam, M; Chandrasekaran, S

    2014-09-01

    The dynamics and residues of deltamethrin in a tea grown in an open field ecosystem were investigated. The quantification was performed using gas chromatography-electron capture detection (GC-ECD) and confirmed by gas chromatograph-mass spectrometry (GC-MS) in selective ion monitoring (SIM) mode. The method was validated using blank samples spiked at three levels and the results showed that recoveries ranged from 87% to 101% with relative standard deviations (RSD) ranging of 0.7-7.1%. The residues of deltamethrin were found to dissipate following first order kinetics with half-life ranging between 3.04 and 3.54d for two different rates of foliar application. The deltamethrin residues are present in the processed tea are not transferred into the tea infusion during the infusion process, since their water solubility is extremely low. These results can be utilized in formulating the spray schedule and safety evaluation on deltamethrin tea crop.

  3. [Genetic diversity of microbial communities in tea orchard soil].

    PubMed

    Xue, Dong; Yao, Huai-Ying; Huang, Chang-Yong

    2007-04-01

    In this paper, the total microbial DNA was extracted from the soils in 8-, 50- and 90 years old tea orchards, adjacent wasteland, and 90 years old forestland in Meijiawu tea area of Hangzhou. The 16S rDNA V3 fragment was amplified by PCR, and the polymorphism of this fragment was analyzed by DGGE. The results indicated that both the tea orchard age and the land use type had significant effects on soil microbial genetic diversity. There was a significant difference (P < 0.05) in the microbial genetic diversity index among wasteland, tea orchards and forestland, which was decreased in the order of wasteland > tea orchard > forestland. For the tea orchards of different ages, the soil microbial genetic diversity index, microbial biomass C, and basal respiration were significantly higher in 50 years old than in 8 and 90 years old tea orchards.

  4. Inhibition of wheat starch retrogradation by tea derivatives.

    PubMed

    Zhang, Haihua; Sun, Binghua; Zhang, Shikang; Zhu, Yuejin; Tian, Yaoqi

    2015-12-10

    The effect of four industrial tea derivatives (tea polyphenols [TPS], tea water-soluble extracts [TSE], tea polysaccharides [TSS], and green tea powder [GTP]), on the retrogradation of wheat starch was investigated using texture profile analysis (TPA), differential scanning calorimetry (DSC), rapid viscosity analysis (RVA), and the α-amylase-iodine method. The addition of the four tea derivatives resulted in decreased hardness and increased cohesiveness of the starch gel as shown by the TPA test. The DSC data demonstrated an increase in the enthalpy change of starch gelatinization and a decrease in the enthalpy change of starch recrystallite dissociation. The RVA results indicated that the peak viscosity, representing the intermolecular forces of wheat starch, was reduced after addition of TPS, TSE, and TSS, respectively, but was increased by GTP. Furthermore, the half crystallization time in the Avrami equation almost doubled after the separate addition of the tea derivatives. PMID:26428142

  5. Green Tea (Camellia Sinensis): Chemistry and Oral Health.

    PubMed

    Khurshid, Zohaib; Zafar, Muhammad S; Zohaib, Sana; Najeeb, Shariq; Naseem, Mustafa

    2016-01-01

    Green tea is a widely consumed beverage worldwide. Numerous studies have suggested about the beneficial effects of green tea on oral conditions such as dental caries, periodontal diseases and halitosis. However, to date there have not been many review articles published that focus on beneficial effects of green tea on oral disease. The aim of this publication is to summarize the research conducted on the effects of green tea on oral cavity. Green tea might help reduce the bacterial activity in the oral cavity that in turn, can reduce the aforementioned oral afflictions. Furthermore, the antioxidant effect of the tea may reduce the chances of oral cancer. However, more clinical data is required to ascertain the possible benefits of green tea consumption on oral health. PMID:27386001

  6. Fluoride content in caffeinated, decaffeinated and herbal teas.

    PubMed

    Chan, J T; Koh, S H

    1996-01-01

    The fluoride contents of infusions prepared from 44 different brands and types of teas were measured. Fluoride concentrations ranged from 0.34 to 3.71 ppm (mean = 1.50 ppm) in caffeinated tea infusions, 0.02-0.14 ppm (mean = 0.05 ppm) in herbal tea infusions, and 1.01-5.20 ppm (mean = 3.19) in decaffeinated tea infusions. This is the first report of the fluoride content of decaffeinated teas. The mean fluoride content of decaffeinated tea infusions is significantly (p < 0.01) higher than the corresponding caffeinated tea. The use of mineral water containing a naturally high fluoride level during the process of decaffeination is the most likely explanation of the above observation.

  7. Inhibition of wheat starch retrogradation by tea derivatives.

    PubMed

    Zhang, Haihua; Sun, Binghua; Zhang, Shikang; Zhu, Yuejin; Tian, Yaoqi

    2015-12-10

    The effect of four industrial tea derivatives (tea polyphenols [TPS], tea water-soluble extracts [TSE], tea polysaccharides [TSS], and green tea powder [GTP]), on the retrogradation of wheat starch was investigated using texture profile analysis (TPA), differential scanning calorimetry (DSC), rapid viscosity analysis (RVA), and the α-amylase-iodine method. The addition of the four tea derivatives resulted in decreased hardness and increased cohesiveness of the starch gel as shown by the TPA test. The DSC data demonstrated an increase in the enthalpy change of starch gelatinization and a decrease in the enthalpy change of starch recrystallite dissociation. The RVA results indicated that the peak viscosity, representing the intermolecular forces of wheat starch, was reduced after addition of TPS, TSE, and TSS, respectively, but was increased by GTP. Furthermore, the half crystallization time in the Avrami equation almost doubled after the separate addition of the tea derivatives.

  8. Fluoride content in caffeinated, decaffeinated and herbal teas.

    PubMed

    Chan, J T; Koh, S H

    1996-01-01

    The fluoride contents of infusions prepared from 44 different brands and types of teas were measured. Fluoride concentrations ranged from 0.34 to 3.71 ppm (mean = 1.50 ppm) in caffeinated tea infusions, 0.02-0.14 ppm (mean = 0.05 ppm) in herbal tea infusions, and 1.01-5.20 ppm (mean = 3.19) in decaffeinated tea infusions. This is the first report of the fluoride content of decaffeinated teas. The mean fluoride content of decaffeinated tea infusions is significantly (p < 0.01) higher than the corresponding caffeinated tea. The use of mineral water containing a naturally high fluoride level during the process of decaffeination is the most likely explanation of the above observation. PMID:8850589

  9. Effect of physicochemical parameters on enzymatic biodecaffeination during tea fermentation.

    PubMed

    Babu, V R Sarath; Thakur, M S; Patra, Sanjukta

    2012-01-01

    We report for the first time the development of a biodecaffeination process for tea synchronised with tea fermentation process using enzymes isolated from Pseudomonas alcaligenes. Cell-free extract was used for biodecaffeination of tea during fermentation of tea and 80% of the caffeine in the tea dhool was degraded within 90 min of incubation. Several factors that tend to effect the biodecaffeination during this stage, like moisture, aeration, intermittent enzyme addition and mixing, were optimized, and inhibitory interactions of proteins with polyphenols, caffeine-polyphenol interactions, which directly influence the biodecaffeination process were prevented by the use of glycine (5% w/w) in the dhool. Tea decaffeinated through the enzymatic route retained the original flavor and aroma, and there was an increase in the total polyphenol content of the tea. PMID:22116671

  10. Green Tea (Camellia Sinensis): Chemistry and Oral Health

    PubMed Central

    Khurshid, Zohaib; Zafar, Muhammad S.; Zohaib, Sana; Najeeb, Shariq; Naseem, Mustafa

    2016-01-01

    Green tea is a widely consumed beverage worldwide. Numerous studies have suggested about the beneficial effects of green tea on oral conditions such as dental caries, periodontal diseases and halitosis. However, to date there have not been many review articles published that focus on beneficial effects of green tea on oral disease. The aim of this publication is to summarize the research conducted on the effects of green tea on oral cavity. Green tea might help reduce the bacterial activity in the oral cavity that in turn, can reduce the aforementioned oral afflictions. Furthermore, the antioxidant effect of the tea may reduce the chances of oral cancer. However, more clinical data is required to ascertain the possible benefits of green tea consumption on oral health. PMID:27386001

  11. Green Tea (Camellia Sinensis): Chemistry and Oral Health.

    PubMed

    Khurshid, Zohaib; Zafar, Muhammad S; Zohaib, Sana; Najeeb, Shariq; Naseem, Mustafa

    2016-01-01

    Green tea is a widely consumed beverage worldwide. Numerous studies have suggested about the beneficial effects of green tea on oral conditions such as dental caries, periodontal diseases and halitosis. However, to date there have not been many review articles published that focus on beneficial effects of green tea on oral disease. The aim of this publication is to summarize the research conducted on the effects of green tea on oral cavity. Green tea might help reduce the bacterial activity in the oral cavity that in turn, can reduce the aforementioned oral afflictions. Furthermore, the antioxidant effect of the tea may reduce the chances of oral cancer. However, more clinical data is required to ascertain the possible benefits of green tea consumption on oral health.

  12. Are odorant constituents of herbal tea transferred into human milk?

    PubMed

    Denzer, Melanie Y; Kirsch, Frauke; Buettner, Andrea

    2015-01-14

    The present study investigates aroma transfer from commercial nursing tea, consumed in the maternal diet, into human milk by correlating sensory assessments with quantitative analytical data. The target terpenes were quantified in milk (expressed before and after tea consumption) and tea samples via gas chromatography–mass spectrometry (GC-MS) using stable isotope dilution assays (volunteer donors n = 5). Sensory analyses were carried out on different milk samples from a single donor, sampled before (blank) and at different times after tea ingestion. Quantitative analysis revealed that no significant odorant transfer into milk was observed after lactating women drank the tea. The comparative sensorial analysis of milk samples expressed before and after tea consumption confirmed that tea ingestion had no significant influence on the odor profile of human milk.

  13. Are odorant constituents of herbal tea transferred into human milk?

    PubMed

    Denzer, Melanie Y; Kirsch, Frauke; Buettner, Andrea

    2015-01-14

    The present study investigates aroma transfer from commercial nursing tea, consumed in the maternal diet, into human milk by correlating sensory assessments with quantitative analytical data. The target terpenes were quantified in milk (expressed before and after tea consumption) and tea samples via gas chromatography–mass spectrometry (GC-MS) using stable isotope dilution assays (volunteer donors n = 5). Sensory analyses were carried out on different milk samples from a single donor, sampled before (blank) and at different times after tea ingestion. Quantitative analysis revealed that no significant odorant transfer into milk was observed after lactating women drank the tea. The comparative sensorial analysis of milk samples expressed before and after tea consumption confirmed that tea ingestion had no significant influence on the odor profile of human milk. PMID:25436940

  14. A comparison of the potential health risk of aluminum and heavy metals in tea leaves and tea infusion of commercially available green tea in Jiangxi, China.

    PubMed

    Li, Lanhai; Fu, Qing-Long; Achal, Varenyam; Liu, Yonglin

    2015-05-01

    Heavy metals and Al in tea products are of increasing concern. In this study, contents of Al, Cd, Co, Cr, Cu, Ni, and Pb in commercially available green tea and its infusions were measured by ICP-MS and ICP-AES. Both target hazard quotient (THQ) and hazard index (HI) were employed to assess the potential health risk of studied metals in tea leaves and infusions to drinkers. Results showed that the average contents of Al, Cd, Co, Cr, Cu, Ni, and Pb in tea leaves were 487.57, 0.055, 0.29, 1.63, 17.04, 7.71, and 0.92 mg/kg, respectively. Except for Cu, metal contents were within their maximum limits (1, 5, 30, and 5 mg/kg for Cd, Cr, Cu, and Pb, respectively) of current standards for tea products. Concentrations of metals in tea infusions were all below their maximum limits (0.2, 0.005, 0.05, 1.0, 0.02, and 0.01 mg/L for Al, Cd, Cr(VI), Cu, Ni, and Pb, respectively) for drinking water, and decreased with the increase of infusion times. Pb, Cd, Cu, and Al mainly remained in tea leaves. The THQ from 2.33 × 10(-5) to 1.47 × 10(-1) and HI from1.41 × 10(-2) to 3.45 × 10(-1) values in tea infusions were all less than 1, suggesting that consumption of tea infusions would not cause significant health risks for consumers. More attention should be paid to monitor Co content in green tea. Both THQ and HI values decreased with the increase of infusion times. Results of this study suggest that tea drinkers should discard the first tea infusion and drink the following infusions.

  15. Curcuminoids Extract, Hydrolyzed Collagen and Green Tea Extract Synergically Inhibit Inflammatory and Catabolic Mediator’s Synthesis by Normal Bovine and Osteoarthritic Human Chondrocytes in Monolayer

    PubMed Central

    Comblain, Fanny; Sanchez, Christelle; Lesponne, Isabelle; Balligand, Marc; Serisier, Samuel; Henrotin, Yves

    2015-01-01

    The main objective of this study was to assess the in vitro effects of curcuminoids extract, hydrolyzed collagen and green tea extract in normal bovine chondrocytes and osteoarthritic human chondrocytes cultured in monolayer. This study also investigated the synergic or additive effects of these compounds. Enzymatically isolated primary bovine or human chondrocytes were cultured in monolayer until confluence and then incubated for 24 hours or 48 hours in the absence or in the presence of interleukin-1β and with or without curcuminoids extract, hydrolyzed collagen or green tea extract, added alone or in combination, at different concentrations. Cell viability was neither affected by these compounds, nor by interleukin 1β. In the absence of interleukin-1β, compounds did not significantly affect bovine chondrocytes metabolism. In human chondrocytes and in the absence of interleukin 1β, curcuminoids extract alone or in combination with hydrolyzed collagen and green tea extract significantly inhibited matrix metalloproteinase-3 production. In interleukin-1β-stimulated bovine chondrocytes, interleukin-6, inducible nitric oxide synthase, cyclooxygenase2, matrix metalloproteinase 3, a disintegrin and metalloproteinase with thrombospondin type I motifs 4 and a disintegrin and metalloproteinase with thrombospondin type I motifs 5 expressions were decreased by curcuminoids extract alone or in combination with hydrolyzed collagen and green tea extract. The combination of the three compounds was significantly more efficient to inhibit interleukin-1β stimulated matrix metalloproteinase-3 expression than curcuminoids extract alone. In interleukin-1β-stimulated human chondrocytes, nitric oxide, interleukin-6 and matrix metalloproteinase 3 productions were significantly reduced by curcuminoids extract alone or in combination with hydrolyzed collagen and green tea extract. These findings indicate that a mixture of curcuminoids extract, hydrolyzed collagen and green tea

  16. Curcuminoids extract, hydrolyzed collagen and green tea extract synergically inhibit inflammatory and catabolic mediator's synthesis by normal bovine and osteoarthritic human chondrocytes in monolayer.

    PubMed

    Comblain, Fanny; Sanchez, Christelle; Lesponne, Isabelle; Balligand, Marc; Serisier, Samuel; Henrotin, Yves

    2015-01-01

    The main objective of this study was to assess the in vitro effects of curcuminoids extract, hydrolyzed collagen and green tea extract in normal bovine chondrocytes and osteoarthritic human chondrocytes cultured in monolayer. This study also investigated the synergic or additive effects of these compounds. Enzymatically isolated primary bovine or human chondrocytes were cultured in monolayer until confluence and then incubated for 24 hours or 48 hours in the absence or in the presence of interleukin-1β and with or without curcuminoids extract, hydrolyzed collagen or green tea extract, added alone or in combination, at different concentrations. Cell viability was neither affected by these compounds, nor by interleukin 1β. In the absence of interleukin-1β, compounds did not significantly affect bovine chondrocytes metabolism. In human chondrocytes and in the absence of interleukin 1β, curcuminoids extract alone or in combination with hydrolyzed collagen and green tea extract significantly inhibited matrix metalloproteinase-3 production. In interleukin-1β-stimulated bovine chondrocytes, interleukin-6, inducible nitric oxide synthase, cyclooxygenase2, matrix metalloproteinase 3, a disintegrin and metalloproteinase with thrombospondin type I motifs 4 and a disintegrin and metalloproteinase with thrombospondin type I motifs 5 expressions were decreased by curcuminoids extract alone or in combination with hydrolyzed collagen and green tea extract. The combination of the three compounds was significantly more efficient to inhibit interleukin-1β stimulated matrix metalloproteinase-3 expression than curcuminoids extract alone. In interleukin-1β-stimulated human chondrocytes, nitric oxide, interleukin-6 and matrix metalloproteinase 3 productions were significantly reduced by curcuminoids extract alone or in combination with hydrolyzed collagen and green tea extract. These findings indicate that a mixture of curcuminoids extract, hydrolyzed collagen and green tea

  17. Molecular evolution and sequence divergence of plant chalcone synthase and chalcone synthase-Like genes.

    PubMed

    Han, Yingying; Zhao, Wenwen; Wang, Zhicui; Zhu, Jingying; Liu, Qisong

    2014-06-01

    Plant chalcone synthase (CHS) and CHS-Like (CHSL) proteins are polyketide synthases. In this study, we evaluated the molecular evolution of this gene family using representative types of CHSL genes, including stilbene synthase (STS), 2-pyrone synthase (2-PS), bibenzyl synthase (BBS), acridone synthase (ACS), biphenyl synthase (BIS), benzalacetone synthase, coumaroyl triacetic acid synthase (CTAS), and benzophenone synthase (BPS), along with their CHS homologs from the same species of both angiosperms and gymnosperms. A cDNA-based phylogeny indicated that CHSLs had diverse evolutionary patterns. STS, ACS, and 2-PS clustered with CHSs from the same species (late diverged pattern), while CTAS, BBS, BPS, and BIS were distant from their CHS homologs (early diverged pattern). The amino-acid phylogeny suggested that CHS and CHSL proteins formed clades according to enzyme function. The CHSs and CHSLs from Polygonaceae and Arachis had unique evolutionary histories. Synonymous mutation rates were lower in late diverged CHSLs than in early diverged ones, indicating that gene duplications occurred more recently in late diverged CHSLs than in early diverged ones. Relative rate tests proved that late diverged CHSLs had unequal rates to CHSs from the same species when using fatty acid synthase, which evolved from the common ancestor with the CHS superfamily, as the outgroup, while the early diverged lineages had equal rates. This indicated that late diverged CHSLs experienced more frequent mutation than early diverged CHSLs after gene duplication, allowing obtaining new functions in relatively short period of time.

  18. Determination of essential and non-essential elements in various tea leaves and tea infusions consumed in Turkey.

    PubMed

    Aksuner, Nur; Henden, Emur; Aker, Zehra; Engin, Esra; Satik, Samet

    2012-01-01

    Tea is one of the most popular beverages in the world. Thus, the chemical components in tea are of great interest, especially in relation to health. In this study, 12 tea samples (10 black, 1 white and 1 green) and 5 herbal tea samples were purchased from supermarkets in Izmir, Turkey. Sample preparation has been performed using wet and microwave digestion procedures. The elemental content (Fe, Zn, Cu, Mn, Ni, Na and K) in the digests and infusions has been analysed. Generally, elemental contents in tea leaves were found to be higher than those in tea infusions. The accuracy of the method was checked and confirmed by standard reference material analyses. The comparison of wet and microwave digestion has not shown significantly different results. Therefore, the microwave digestion procedure was preferred because it is less laborious. The elemental intake related to tea consumption has also been studied. PMID:24779742

  19. Trichodiene synthase. Substrate specificity and inhibition.

    PubMed

    Cane, D E; Yang, G; Xue, Q; Shim, J H

    1995-02-28

    The substrate specificity of the sesquiterpene synthase trichodiene synthase was examined by determining the Vmax and Km parameters for the natural substrate, trans,trans-farnesyl diphosphate (1), its stereoisomer, cis,trans-farnesyl diphosphate, and the tertiary allylic isomer, (3R)-nerolidyl diphosphate (3), using both the native fungal and recombinant enzymes. A series of farnesyl diphosphate analogs, 15, 16, 20, 7, 8, and 9, was also tested as inhibitors of trichodiene synthase. 10-Fluorofarnesyl diphosphate (15) was the most effective competitive inhibitor, with a K1 of 16 nM compared to the Km for 1 of 87 nM, while the ether analog of farnesyl diphosphate, 8, an extremely potent inhibitor of squalene synthase, showed only modest inhibition of trichodiene synthase, with a K1/Km of 70. PMID:7873526

  20. The Other Boston Tea Party. Teacher's Guide.

    ERIC Educational Resources Information Center

    Rosal, Lorenca Consuelo; And Others

    A teachers' guide is presented that accompanies the video production of "The Other Boston Tea Party," a play used to teach about the U.S. Constitution and American legal and political systems. The play combines a comedy of manners with an historical approach to the issues surrounding the Federalist/Anti-Federalist debate over ratification of the…

  1. Dramatizing History With A Victorian Tea.

    ERIC Educational Resources Information Center

    Dyson, Pauline Ucci

    1986-01-01

    Describes how a role-playing approach may be used to capture the style, flavor, and conversation of nineteenth-century British life through the staging of a Victorian tea. Examines the economic, social, and cultural questions addressed through the technique. Also discusses evaluation and student impact and recommends the activity for any…

  2. 'The English Drink a Lot of Tea!

    ERIC Educational Resources Information Center

    Taborn, Stretton

    1981-01-01

    Presents statistics on the most commonly held stereotypes in Germany of Britain and the British including drinking a lot of tea, eating bacon and eggs for breakfast, consumption of whiskey and beer, and the occurrence of fog in England. Suggests these stereotypes were developed in the early 1950s and are not as prevalent today. (BK)

  3. Hypotriglyceridemic potential of fermented mixed tea made with third-crop green tea leaves and camellia (Camellia japonica) leaves in Sprague-Dawley rats.

    PubMed

    Tamaru, Shizuka; Ohmachi, Kazuhiro; Miyata, Yuji; Tanaka, Takashi; Kubayasi, Takashi; Nagata, Yasuo; Tanaka, Kazunari

    2013-06-19

    Fermented mixed tea made with third-crop green tea leaves and camellia leaves by a tea-rolling process has been developed. The objective of this study was to investigate hypotriglyceridemic potential of the mixed tea in rats. The mixed tea contained theasinensins and theaflavins. Rats fed the mixed tea extract at the level of 1% exerted significantly lower body weight and adipose tissue weight compared to animals fed third-crop green tea or camellia tea extract alone for 4 weeks. Serum and hepatic triglyceride was significantly and dose-dependently decreased by the mixed tea. This decrease was associated with lowered lipogenic enzyme activities in the liver. Furthermore, an oral administration of 4 or 8% of the mixed tea extract followed by fat emulsion suppressed the increment of serum triglyceride level. These results suggest that the mixed tea has hypotriglyceridemic action, partially via delaying triglyceride absorption in the small intestine and repressing hepatic lipogenic enzymes.

  4. Clinical application of therapeutic erythrocytapheresis (TEA).

    PubMed

    Valbonesi, M; Bruni, R

    2000-06-01

    Therapeutic erythrocytapheresis (TEA) has been used in different diseases such as polycythemia vera (PV), secondary erythrocytosis or hemochromatosis as a process of the less cumbersome but more expensive phlebotomy. TEA is preferred in emergency conditions such as thrombocytosis or in conditions such as porphyria cutanea tarda (PCT) or erythropoietic porphyria when plasma exchange (PEX) is often combined with TEA to reduce extracellular levels of uroporphyrin which contribute to plasma hyperviscosity. TEA is often combined with drug therapy that varies from etoposide in PV to EPO and desferoxamine which are used to mobilize and reduce iron stores in hemochromatosis. Benefits from this combination may be more long lasting than expected. Nonetheless for TEA, there is no standard protocol and, clinical experience with this therapy remains highly anecdotal. Therapeutic red cell-exchange (TREX) has been used with much interest over the years, starting with the management of hemolytic disease of the newborn and later used to correct severe anemia in thalassemia patients thereby preventing iron overload. It has also been used for the management of complications of sickle cell disease such as priapism, chest syndrome, stroke, retinal, bone, splenic and hepatic infarction or in preparation for surgery by reducing HbS to less than 30%. Automated apheresis has also favored the use of TREX in conditions such as paroxysmal nocturnal hemoglobinuria and aniline poisoning, arsenic poisoning, Na chlorate intoxications and CO intoxications, hemoglobinopathies, autoimmune hemolytic anemia, reactions due to ABO incompatibility, in preparation for ABO incompatible bone marrow transplantation or for preventing anti-D immunization after the transfusion of D(+) cells to D(-) recipients. Another field of application has been in the emergency management of intraerythrocytic parasite infections such as malaria and babesiosis. Application of TREX may be wide but its real use remains limited

  5. Protective effects of green tea polyphenol extracts against ethanol-induced gastric mucosal damages in rats: stress-responsive transcription factors and MAP kinases as potential targets.

    PubMed

    Lee, Jeong-Sang; Oh, Tae-Young; Kim, Young-Kyung; Baik, Joo-Hyun; So, Sung; Hahm, Ki-Baik; Surh, Young-Joon

    2005-11-11

    There are multiple lines of compelling evidence from epidemiologic and laboratory studies supporting that frequent consumption of green tea is inversely associated with the risk of chronic human diseases including cancer. The chemopreventive and chemoprotective effects of green tea have been largely attributed to antioxidative and anti-inflammatory activities of its polyphenolic constituents, such as epigallocatechin gallate. The present study was designed to evaluate the efficacy of green tea polyphenols in protecting against alcohol-induced gastric damage and to elucidate the underlying mechanisms. Intragastric administration of ethanol to male Sprague-Dawley rats caused significant gastric mucosal damage, which was accompanied by elevated expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) as well as transient activation of redox-sensitive transcription factors, such as NF-kappaB and AP-1, and mitogen-activated protein kinases (MAPKs). Oral administration of the green tea polyphenolic extract (GTE) significantly ameliorated mucosal damages induced by ethanol and also attenuated the ethanol-induced expression of COX-2 and iNOS. Inactivation of MAPKs, especially p38 and ERKl/2, by GTE might be responsible for inhibition of ethanol-induced expression of COX-2 and iNOS.

  6. Black tea improves attention and self-reported alertness.

    PubMed

    De Bruin, E A; Rowson, M J; Van Buren, L; Rycroft, J A; Owen, G N

    2011-04-01

    Tea has previously been demonstrated to better help sustain alertness throughout the day in open-label studies. We investigated whether tea improves attention and self-reported alertness in two double-blind, randomised, placebo-controlled, crossover studies. Participants received black tea (made from commercially available tea bags) in one condition and placebo tea (hot water with food colours and flavours) similar in taste and appearance to real tea in the other condition. Attention was measured objectively with attention tests (the switch task and the intersensory-attention test) and subjectively with a self-report questionnaire (Bond-Lader visual analogue scales). In both studies, black tea significantly enhanced accuracy on the switch task (study 1 p<.002, study 2 p=.007) and self-reported alertness on the Bond-Lader questionnaire (study 1 p<.001, study 2 p=.021). The first study also demonstrated better auditory (p<.001) and visual (p=.030) intersensory attention after black tea compared to placebo. Simulation of theanine and caffeine plasma time-concentration curves indicated higher levels in the first study compared to the second, which supports the finding that tea effects on attention were strongest in the first study. Being the second most widely consumed beverage in the world after water, tea is a relevant contributor to our daily cognitive functioning.

  7. Transfer of ochratoxin A into tea and coffee beverages.

    PubMed

    Malir, Frantisek; Ostry, Vladimir; Pfohl-Leszkowicz, Annie; Toman, Jakub; Bazin, Ingrid; Roubal, Tomas

    2014-01-01

    Ochratoxin A (OTA) is nephrotoxic, hepatotoxic, immunotoxic, neurotoxic, reprotoxic, teratogenic, and carcinogenic (group 2B), being characterized by species and sex differences in sensitivity. Despite the fact that OTA is in some aspects a controversial topic, OTA is the most powerful renal carcinogen. The aim of this study was to make a small survey concerning OTA content in black tea, fruit tea, and ground roasted coffee, and to assess OTA transfer into beverages. OTA content was measured using a validated and accredited HPLC-FLD method with a limit of quantification (LOQ) of 0.35 ng/g. The OTA amount ranged from LOQ up to 250 ng/g in black tea and up to 104 ng/g in fruit tea. Black tea and fruit tea, naturally contaminated, were used to prepare tea infusions. The transfer from black tea to the infusion was 34.8% ± 1.3% and from fruit tea 4.1% ± 0.2%. Ground roasted coffee naturally contaminated at 0.92 ng/g was used to prepare seven kinds of coffee beverages. Depending on the type of process used, OTA transfer into coffee ranged from 22.3% to 66.1%. OTA intakes from fruit and black tea or coffee represent a non-negligible human source.

  8. Tea and cancer: a review of the epidemiological evidence.

    PubMed

    Blot, W J; Chow, W H; McLaughlin, J K

    1996-12-01

    Numerous recent reports of inhibition of carcinogenesis in experimental animals by tea or tea compounds raise the possibility that tea drinking may lower cancer risk in humans. Thus, studies around the world were reviewed to evaluate whether there is a consensus of epidemiologic evidence on the relation of tea drinking to cancer overall or to specific cancers. Ecological data suggest at most a modest benefit, since there is considerable international variation in tea consumption but generally small differences in cancer rates. More relevant case-control and cohort studies show mixed results. Detailed data from these studies on cancer risks according to amount and duration of tea intake are quite limited, and consistent dose-related patterns. have yet to emerge. Nevertheless, several investigations point to the possibility of lowered risks of digestive tract cancers among tea drinkers, especially those consuming green tea. Further research, particularly in population with wide ranges of tea consumption, is needed before definitive conclusions on tea's impact upon cancer risk can be reached. PMID:9061273

  9. Green tea and prevention of esophageal and lung cancers.

    PubMed

    Yuan, Jian-Min

    2011-06-01

    Green tea contains high concentrations of tea polyphenols that have shown inhibitory effects against the development, progress, and growth of carcinogen-induced tumors in animal models at different organ sites, including the esophagus and lung. Green tea polyphenols also have shown to suppress cell proliferation and induce apoptosis. Besides antioxidative property, green tea polyphenols have pro-oxidative activities under certain conditions and modulate phase II metabolic enzymes that can enhance the detoxification pathway of environmental toxicants and carcinogens. Although epidemiological studies have provided inconclusive results on the effect of green tea consumption against the development of esophageal and lung cancers in humans overall, the inverse association between green tea intake and risk of esophageal cancer risk is more consistently observed in studies with adequate control for potential confounders. Epidemiological studies also have demonstrated an inverse, albeit moderate, association between green tea consumption and lung cancer, especially in non-smokers. This article reviews data on the cancer-preventive activities of green tea extract and green tea polyphenols and possible mechanisms against the esophageal and lung carcinogenesis in experimental animals, and summarizes the current knowledge from epidemiological studies on the relationship between green tea consumption and esophageal and lung cancer risk in humans.

  10. Transfer of ochratoxin A into tea and coffee beverages.

    PubMed

    Malir, Frantisek; Ostry, Vladimir; Pfohl-Leszkowicz, Annie; Toman, Jakub; Bazin, Ingrid; Roubal, Tomas

    2014-01-01

    Ochratoxin A (OTA) is nephrotoxic, hepatotoxic, immunotoxic, neurotoxic, reprotoxic, teratogenic, and carcinogenic (group 2B), being characterized by species and sex differences in sensitivity. Despite the fact that OTA is in some aspects a controversial topic, OTA is the most powerful renal carcinogen. The aim of this study was to make a small survey concerning OTA content in black tea, fruit tea, and ground roasted coffee, and to assess OTA transfer into beverages. OTA content was measured using a validated and accredited HPLC-FLD method with a limit of quantification (LOQ) of 0.35 ng/g. The OTA amount ranged from LOQ up to 250 ng/g in black tea and up to 104 ng/g in fruit tea. Black tea and fruit tea, naturally contaminated, were used to prepare tea infusions. The transfer from black tea to the infusion was 34.8% ± 1.3% and from fruit tea 4.1% ± 0.2%. Ground roasted coffee naturally contaminated at 0.92 ng/g was used to prepare seven kinds of coffee beverages. Depending on the type of process used, OTA transfer into coffee ranged from 22.3% to 66.1%. OTA intakes from fruit and black tea or coffee represent a non-negligible human source. PMID:25525684

  11. Transfer of Ochratoxin A into Tea and Coffee Beverages

    PubMed Central

    Malir, Frantisek; Ostry, Vladimir; Pfohl-Leszkowicz, Annie; Toman, Jakub; Bazin, Ingrid; Roubal, Tomas

    2014-01-01

    Ochratoxin A (OTA) is nephrotoxic, hepatotoxic, immunotoxic, neurotoxic, reprotoxic, teratogenic, and carcinogenic (group 2B), being characterized by species and sex differences in sensitivity. Despite the fact that OTA is in some aspects a controversial topic, OTA is the most powerful renal carcinogen. The aim of this study was to make a small survey concerning OTA content in black tea, fruit tea, and ground roasted coffee, and to assess OTA transfer into beverages. OTA content was measured using a validated and accredited HPLC-FLD method with a limit of quantification (LOQ) of 0.35 ng/g. The OTA amount ranged from LOQ up to 250 ng/g in black tea and up to 104 ng/g in fruit tea. Black tea and fruit tea, naturally contaminated, were used to prepare tea infusions. The transfer from black tea to the infusion was 34.8% ± 1.3% and from fruit tea 4.1% ± 0.2%. Ground roasted coffee naturally contaminated at 0.92 ng/g was used to prepare seven kinds of coffee beverages. Depending on the type of process used, OTA transfer into coffee ranged from 22.3% to 66.1%. OTA intakes from fruit and black tea or coffee represent a non-negligible human source. PMID:25525684

  12. Stability of tea catechins in the breadmaking process.

    PubMed

    Wang, Rong; Zhou, Weibiao

    2004-12-29

    A green tea extract (GTE) was incorporated into bread as a source of tea catechins. The stability of tea catechins in the breadmaking process including unfrozen and frozen dough was studied. A method was developed for the separation and quantification of tea catechins in GTE, dough, and bread samples using a RP-HPLC system. The separation system consisted of a C18 reversed-phase column, a gradient elution system of water/methanol and formic acid, and a photodiode array UV detector. Tea catechins were detected at 275 nm. GTEs at 50, 100, and 150 mg per 100 g of flour were formulated. The results obtained showed that green tea catechins were relatively stable in dough during freezing and frozen storage at -20 degrees C for up to 9 weeks. There were no further detectable losses of tea catechins in bread during a storage of 4 days at room temperature. It was also revealed that (-)-epigallocatechin gallate (EGCG) and (-)-epigallocatechin (EGC) were more susceptible to degradation than (-)-epicatechin gallate (ECG) and (-)-epicatechin (EC). (-)-EGCG and (-)-ECG were normally selected as the quality indices of green tea catechins, and their retention levels in freshly baked bread were ca. 83 and 91%, respectively. One piece of bread (53 g) containing 150 mg of GTE/100 g of flour will provide 28 mg of tea catechins, which is approximately 35% of those infused from one green tea bag (2 g). PMID:15612821

  13. The effects of tea extracts on proinflammatory signaling

    PubMed Central

    Pajonk, Frank; Riedisser, Anja; Henke, Michael; McBride, William H; Fiebich, Bernd

    2006-01-01

    Background 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 epigallocatechin-gallate, the proposed most-active moiety of green tea. Methods Data from 60 patients with cancer of the head and neck or pelvic region topically treated with green or black tea extracts were analyzed retrospectively. Tea extracts were compared for their ability to modulate IL-1β, IL-6, IL-8, TNFα and PGE2 release from human monocytes. Effects of tea extracts on 26S proteasome function were assessed. NF-κB activity was monitored by EMSAs. Viability and radiation response of macrophages after exposure to tea extracts was measured by MTT assays. Results Tea extracts supported the restitution of skin integrity. Tea extracts inhibited proteasome function and suppressed cytokine release. NF-κB activity was altered by tea extracts in a complex, caspase-dependent manner, which differed from the effects of epigallocatechin-gallate. Additionally, both tea extracts, as well as epigallocatechin-gallate, slightly protected macrophages from ionizing radiation Conclusion Tea extracts are an efficient, broadly available treatment option for patients suffering from acute radiation-induced skin toxicity. The molecular mechanisms underlying the beneficial effects are complex, and most likely not exclusively dependent on effects of tea polyphenols such as epigallocatechin-gallate. PMID:17140430

  14. Sensory characteristics and consumer acceptability of decaffeinated green teas.

    PubMed

    Lee, S M; Lee, H-S; Kim, K-H; Kim, K-O

    2009-04-01

    Green tea has been widely consumed for its mild flavors and its health benefits, yet caffeine in green tea has been a limitation for those who want to avoid it. The limitation brought increase in need for decaffeinated products in the green tea market. Most of the conventional decaffeination techniques applied in food use organic solvents. However, supercritical carbon dioxide fluid extraction (SC-CO2) method is gaining its intension as one of the future decaffeination methods that overcomes the problems of conventional methods. The purpose of this study was to identify sensory characteristics of decaffeinated green teas applied with SC-CO2 method and to observe the relationship with consumer acceptability to elucidate the potentiality of applying SC-CO2 technique in decaffeinated green tea market. Descriptive analysis was performed on 8 samples: green teas containing 4 caffeine levels (10%, 35%, 60%, and 100%) infused at 2 infusing periods (1 or 2 min). It was found that the SC-CO2 process not only reduced caffeine but also decreased some important features of original tea flavors. Two groups were recruited for consumer acceptability test: one (GP I, N = 52), consuming all types of green teas including hot/cold canned teas; and the other (GP II, N = 40), only consuming the loose type. While GP II liked original green tea the most, GP I liked highly decaffeinated green teas. Although the SC-CO2 method had limitations of losing complex flavors of green teas, it appeared to have future potential in the decaffeinated green tea market within or without the addition of desirable flavors. PMID:19397734

  15. Sensory characteristics and consumer acceptability of decaffeinated green teas.

    PubMed

    Lee, S M; Lee, H-S; Kim, K-H; Kim, K-O

    2009-04-01

    Green tea has been widely consumed for its mild flavors and its health benefits, yet caffeine in green tea has been a limitation for those who want to avoid it. The limitation brought increase in need for decaffeinated products in the green tea market. Most of the conventional decaffeination techniques applied in food use organic solvents. However, supercritical carbon dioxide fluid extraction (SC-CO2) method is gaining its intension as one of the future decaffeination methods that overcomes the problems of conventional methods. The purpose of this study was to identify sensory characteristics of decaffeinated green teas applied with SC-CO2 method and to observe the relationship with consumer acceptability to elucidate the potentiality of applying SC-CO2 technique in decaffeinated green tea market. Descriptive analysis was performed on 8 samples: green teas containing 4 caffeine levels (10%, 35%, 60%, and 100%) infused at 2 infusing periods (1 or 2 min). It was found that the SC-CO2 process not only reduced caffeine but also decreased some important features of original tea flavors. Two groups were recruited for consumer acceptability test: one (GP I, N = 52), consuming all types of green teas including hot/cold canned teas; and the other (GP II, N = 40), only consuming the loose type. While GP II liked original green tea the most, GP I liked highly decaffeinated green teas. Although the SC-CO2 method had limitations of losing complex flavors of green teas, it appeared to have future potential in the decaffeinated green tea market within or without the addition of desirable flavors.

  16. Crystal structure of riboflavin synthase

    SciTech Connect

    Liao, D.-I.; Wawrzak, Z.; Calabrese, J.C.; Viitanen, P.V.; Jordan, D.B.

    2010-03-05

    Riboflavin synthase catalyzes the dismutation of two molecules of 6,7-dimethyl-8-(1'-D-ribityl)-lumazine to yield riboflavin and 4-ribitylamino-5-amino-2,6-dihydroxypyrimidine. The homotrimer of 23 kDa subunits has no cofactor requirements for catalysis. The enzyme is nonexistent in humans and is an attractive target for antimicrobial agents of organisms whose pathogenicity depends on their ability to biosynthesize riboflavin. The first three-dimensional structure of the enzyme was determined at 2.0 {angstrom} resolution using the multiwavelength anomalous diffraction (MAD) method on the Escherichia coli protein containing selenomethionine residues. The homotrimer consists of an asymmetric assembly of monomers, each of which comprises two similar {beta} barrels and a C-terminal {alpha} helix. The similar {beta} barrels within the monomer confirm a prediction of pseudo two-fold symmetry that is inferred from the sequence similarity between the two halves of the protein. The {beta} barrels closely resemble folds found in phthalate dioxygenase reductase and other flavoproteins. The three active sites of the trimer are proposed to lie between pairs of monomers in which residues conserved among species reside, including two Asp-His-Ser triads and dyads of Cys-Ser and His-Thr. The proposed active sites are located where FMN (an analog of riboflavin) is modeled from an overlay of the {beta} barrels of phthalate dioxygenase reductase and riboflavin synthase. In the trimer, one active site is formed, and the other two active sites are wide open and exposed to solvent. The nature of the trimer configuration suggests that only one active site can be formed and be catalytically competent at a time.

  17. [Content of soil heavy metals and characteristics of environmental quality in tea plantations of Changsha Baili Tea Zone].

    PubMed

    Guo, Hai-yan; Zhou, Wei-jun; Zhang, Yang-zhu; Huang, Yun-xiang; Zhou, Qing; Yan, Xiong; Zhang, Jian-xin; Chen, Qiang-chun; Mao, Chang-ming

    2008-08-01

    The distributing and changing characteristics and content of soil heavy metals was studied using methods of field survey and sampling, indoor analysis, and pollution index were used to investigate the soil environmental quality in the tea plantations of Changsha Baili Tea Zone. The results showed that the content of soil total Pb, Hg, Cd, Cr, As, Ni basically was in the soil background value, their averages were 42.7, 0.068, 0.074, 92.2, 12.4 and 19.5 mg/kg respectively. The content of heavy metals was lower than the standard of Environmental Qualification of Nuisance Free Tea Producing Area (NY 5020-2001). Simultaneity, soil environmental quality in tea plantations of Baili Tea Zone, it answered for the second grade of State Environmental Quality Standard for Soils (GB 15618-1995), achieved safe class, and the content of soil Hg, Cd, Ni accorded to the first grade of GB 15618-1995, these results showed the Changsha Baili Tea Zone were propitious to develop nuisance free tea production. Besides the single pollution index of Cr was 0.837 and in warning class at the tea plantation of Xiangfeng, the others were all less than 0.7, and in the safe class. The integrated index of 6 tea bases was all less than 0.7, in the safe class, the soil environmental quality was cleanness on the whole at Changsha Baili Tea Zone, and the soils were suitable for non-polluted agricultural production.

  18. HPLC ANALYSIS OF CATECHINS, THERAFLAVINS, AND ALKALOIDS IN COMMERCIAL TEAS AND GREEN TEA DIETARY SUPPLEMENTS: COMARARISON OF WATER AND 80% ETHANOL/WATER EXTRACTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To help meet the needs of consumers, producers of dietary tea supplements, and researchers for information on health-promoting tea compounds, we compared the following conditions for the extraction of tea leaves and green tea-containing dietary supplements: 80% ethanol/water at 60 'C for 15 min and ...

  19. The fortification of tea with sweeteners and milk and its effect on in vitro antioxidant potential of tea product and glutathione levels in an animal model.

    PubMed

    Korir, M W; Wachira, F N; Wanyoko, J K; Ngure, R M; Khalid, R

    2014-02-15

    Several studies have demonstrated that tea flavonoids protect cells and tissues against free radicals which have been implicated in the etiology of oxidative stress-related disease disorders. However, black tea is commonly consumed with additives that could otherwise affect the bioavailability of the active tea molecules. In this study, the biochemical parameters of Kenyan teas were determined and the effect of added milk and sweeteners on the antioxidant activity of Kenyan teas was investigated. The effect of tea antioxidants on glutathione (GSH) was also evaluated in vivo in a time series study using Swiss mice. Green teas had the highest levels of total polyphenols, total and individual catechins, while black teas had high levels of total thearubigins, total theaflavins and theaflavin fractions. The antioxidant activity was high in green teas though some of the black teas were as efficacious as the green teas. The addition of milk, sugar and honey significantly (p<0.05) decreased the antioxidant activity of tea in a concentration-dependent manner. Addition of the sweetener, stevia (Stevia rebaudiana Bertoni), showed no significant (p>0.05) influence on the antioxidant activity of tea and therefore can be recommended as a preferred sweetener for tea. Significantly (p<0.001) higher levels of GSH were observed in plasma than in other tissues. GSH levels were generally highest 2h after tea consumption, which indicates the need to repeatedly take tea every 2h to maximise its potential health benefits.

  20. Acute effects of tea consumption on attention and mood.

    PubMed

    Einöther, Suzanne J; Martens, Vanessa E

    2013-12-01

    Tea has historically been associated with mood and performance benefits, such as relaxation and concentration. This review summarizes the research on the acute effects of tea, and its ingredients theanine and caffeine, on attention and mood. Consistent with abundant research on the benefits of caffeine, the performance benefits of tea were identified in a number of studies, with particularly consistent evidence for improved attention. Tea consumption also consistently improved self-reported alertness and arousal, whereas effects on pleasure or relaxation were less consistent. In addition to the research on caffeine in real-life performance, 2 recent studies have provided a broader perspective on tea's effects on psychological function in that they showed beneficial effects in related areas such as work performance and creativity. These studies showed the validity of laboratory findings by supporting the idea that tea consumption has acute benefits on both mood and performance in real-life situations.

  1. Polyphenolic chemistry of tea and coffee: a century of progress.

    PubMed

    Wang, Yu; Ho, Chi-Tang

    2009-09-23

    Tea and coffee, the most popular beverages in the world, have been consumed for thousands of years for their alluring flavors and health benefits. Polyphenols, particularly flavonoids and phenolic acids, are of great abundance in tea and coffee and contribute a lot to their flavor and health properties. This paper reviews the polyphenol chemistry of tea and coffee, specifically their stability, and scavenging ability of reactive oxygen species (ROS) and reactive carbonyl species (RCS). During the manufacturing and brewing process, green tea and black tea polyphenols undergo epimerization and oxidation, respectively. Meanwhile, the lactonization and the polymerization of chlorogenic acid are the major causes for the degradation of polyphenols in coffee. Tea catechins, besides having antioxidant properties, have the novel characteristic of trapping reactive carbonyl species. The A ring of the catechins is the binding site for RCS trapping, whereas the B ring is the preferred site for antioxidation.

  2. Characterization of novel small RNAs from tea (Camellia sinensis L.).

    PubMed

    Mohanpuria, Prashant; Yadav, Sudesh Kumar

    2012-04-01

    Small RNAs play important roles in plant development, metabolism, signal transduction and responses to biotic and abiotic stresses by affecting gene expression. Tea (Camellia sinensis L.) is an important commercial crop in the world. To understand the regulatory mechanisms involving small RNAs in tea metabolism, we constructed a small RNA (sRNA) library from its tea drink manufacturing tissue part i.e. topmost two leaves and a bud. For the first time, we isolated and cloned six novel small RNAs candidates from tea. These were predicted to target 67 genes responsible for various important plant functions. Isolated small RNAs were validated through expression analysis in young leaf and old leaf during non-dormant and dormant growth phases of tea. Results suggest the probable role of isolated small RNAs in development and seasonal variations of tea.

  3. Commercial Teas Highlight Plant DNA Barcode Identification Successes and Obstacles

    PubMed Central

    Stoeckle, Mark Y.; Gamble, Catherine C.; Kirpekar, Rohan; Young, Grace; Ahmed, Selena; Little, Damon P.

    2011-01-01

    Appearance does not easily identify the dried plant fragments used to prepare teas to species. Here we test recovery of standard DNA barcodes for land plants from a large array of commercial tea products and analyze their performance in identifying tea constituents using existing databases. Most (90%) of 146 tea products yielded rbcL or matK barcodes using a standard protocol. Matching DNA identifications to listed ingredients was limited by incomplete databases for the two markers, shared or nearly identical barcodes among some species, and lack of standard common names for plant species. About 1/3 of herbal teas generated DNA identifications not found on labels. Broad scale adoption of plant DNA barcoding may require algorithms that place search results in context of standard plant names and character-based keys for distinguishing closely-related species. Demonstrating the importance of accessible plant barcoding, our findings indicate unlisted ingredients are common in herbal teas. PMID:22355561

  4. Antioxidant activity of polyphenols from green and toasted mate tea.

    PubMed

    Coentrão, Patricia de Abreu Marques; Teixeira, Valéria Laneuville; Netto, Annibal Duarte Pereira

    2011-05-01

    The production and distribution of toasted mate tea in Brazil has increased, which has resulted in its greater consumption. Mate tea is obtained by roasting non-fermented erva-mate in order to produce toasted erva-mate or toasted mate tea. However, although the product is much appreciated, studies of its chemical composition and the concentration of polyphenols, particularly flavonols present in toasted mate tea, are few and often controversial. This paper elucidates some misunderstandings involving the nomenclature of erva-mate and toasted mate, and mainly provides an overview of the composition of polyphenols and antioxidant capacity of toasted mate tea and its raw material, erva-mate, in comparison with other teas, the compositions of which were found in the literature. PMID:21615026

  5. Fate of imidacloprid and acetamiprid residues during black tea manufacture and transfer into tea infusion.

    PubMed

    Gupta, M; Shanker, A

    2009-02-01

    The objective of this paper is to investigate the loss/stability of neonicotinoids (imidacloprid and acetamiprid) residues during the manufacture of black tea and to study the transfer of these pesticides from made tea to its infusion. For orthodox black tea, the manufacturing process involves leaf harvesting (plucking two leaves and a bud), withering, rolling, fermentation (oxidation), and drying. Initial withering and final drying resulted in the loss of pesticide residues, but no significant reduction in residue levels resulted from the rolling and fermentation steps. The drying process resulted in a residue transfer of 64-70% and 69-74% of the initial level, whereas the brewing process resulted in a residue transfer of 37-39% and 45-49% of imidacloprid and acetamiprid, respectively, from dried tea into the infusion. The decrease in acetamiprid levels during drying was also significant (8-13%), whereas the total loss during the manufacturing process ranged from 26 to 31%. Further, brewing for longer periods (an extended brewing time) resulted in higher transfer (up to 44% for imidacloprid and 53% for acetamiprid) of pesticides to tea infusion. Further, the extent of pesticide leaching depends on its water solubility, partition coefficient, and the brewing time. PMID:19680885

  6. TEA (CAMELIA THEA): BOON OR CURSE FOR HUMAN BEING

    PubMed Central

    Singh, O.P; Hazra, J.; Pathak, N.N.

    2001-01-01

    Drinking some types of tea and other caffaeinated drink is a part of our culture and everyday life. It is contained from the leaves and seeds of evergreen plant (Camelia thea). It is caffeine contained in so many drinks which really plays havoc with our body and mind. It is only when man exceeds they tea drinking that he experiences the ill effects. When taken in limited quantity tea is indeed very good for health. PMID:22557043

  7. The emission spectra of Ar, Kr and Xe + TEA

    NASA Astrophysics Data System (ADS)

    Suzuki, Masayo; Strock, Pierre; Sauli, Fabio; Charpak, Georges

    1987-03-01

    The emission spectra of Ar, Kr and Xe + 6% TEA gas mixtures are measured by using a single wire proportional counter as the emission source. Asymmetric emission bands are observed in the range of 270 to 350 nm, which can be attributed to the radiative deexcitation of excited TEA molecules. For the practical application of optical readout of avalanche chambers, the Ar + 2.0% TEA + 20% isobutane gas mixture is also examined, and nearly the same emission band is observed.

  8. Arsenic species and leaching characters in tea (Camellia sinensis).

    PubMed

    Yuan, Chungang; Gao, Erle; He, Bin; Jiang, Guibin

    2007-12-01

    Tea is one of the most popular non-alcoholic beverages consumed in the world. Arsenic including species totalling to 47 Chinese tea samples from 18 tea-producing provinces in China were analyzed. By simulating the infusion process, leaching characters, effects of extraction time and temperature on arsenic extraction were investigated. Total amount of arsenic in tea leaf samples was in the range below the detection limit to 4.81 microg/g. Leaching of arsenic was strongly affected by extraction time and temperature. Because arsenic leaching ability by hot water was low and most of the arsenic was left in tea leaf residues after infusion, the concentration of arsenic in tea infusion was low even when some original tea leaf samples contained high level of arsenic. The major species in tea infusion were inorganic arsenic form (arsenite As(III) and arsenate As(V)). Compared with the amount of arsenic in infusion, more organic arsenic species were found in the original tea leaf samples. The contents of extractable inorganic arsenic in tea leaf samples were in the range below the detection limit to 226 ng/g. Considering ingestion dose and assuming one person (60 kg body weight) consumes 10 g of Chinese tea per day, the maximum inorganic arsenic contribution from tea infusion is 2.26 microg, which is equal to 0.038 microg/kg/d excluding water contribution. This value only accounts for 1.8% of provisional tolerable weekly intake (PTWI) (2.1 microg/kg/d) recommended by the Food and Agriculture Organization/World Health Organization [FAO/WHO, 1989. Evaluation of certain food additives and contaminants. Thirty-third Report of the Joint FAO/WHO Expert Committee on Food Additives. WHO Technical Report Series No. 776, Geneva, World Health Organization]. PMID:17892910

  9. Catechins are not major components responsible for anti-genotoxic effects of tea extracts against nitroarenes.

    PubMed

    Ohe, T; Marutani, K; Nakase, S

    2001-09-20

    The anti-genotoxic properties of tea leaf extracts were examined in a Salmonella umu-test. Seven non-fermented teas (green tea), one semi-fermented tea (oolong tea), two fermented teas (black tea and Chinese pu er tea) and two other teas were examined for their anti-genotoxic abilities and for their catechins contents. This was to study the relationship between catechins contents and anti-genotoxic activity of various tea leaf extracts. All types of tea extracts showed more potent suppressive effects against umu gene expression of the SOS response in Salmonella typhimurium TA1535/pSK 1002 induced by four nitroarenes (1-nitropyrene, 2-nitrofluorene, 3-nitrofluoranthene and a mixture of 1,6- and 1,8-dinitropyrene) rather than 4-NQO, AF-2 and MNNG. The anti-genotoxic effect of 12 tea leaf extracts on 1-NP, 2-NF, 3-NF and DNP decreased in the order: oolong tea (semi-fermented tea)>black tea (fermented tea)>sencha (non-fermented tea, an ordinary grade green tea)>tocyucya (other tea)>Chinese pu er tea (fermented tea). The amount of catechins (EGC, C, EGCG, EC and ECG) in various teas in decreasing order was non-fermented tea>semi-fermented tea>fermented tea>other tea. A remarkable feature was the effectiveness of black tea and Chinese pu er tea in suppressing the genotoxicity induced by nitroarenes, in spite of the fact that these fermented teas do not have high catechins contents. Statistical analysis showed that no significant (P<0.01) correlation was found between the anti-genotoxicity of tea extracts against nitroarenes and the catechins contents in tea leaf extracts. In further experiment, fractionation of sencha extract by HPLC revealed that anti-genotoxicity of the peak fraction corresponding to catechins accounted for <10% of the total anti-genotoxic activity of sencha extract against for 1-nitropyrene. These results suggest that catechins are not major components responsible for the anti-genotoxic effects of tea leaf extracts against direct-acting nitroarenes

  10. Photoprotective effects of green tea polyphenols.

    PubMed

    Yusuf, Nabiha; Irby, Cynthia; Katiyar, Santosh K; Elmets, Craig A

    2007-02-01

    Non-melanoma skin cancer is the most common malignancy in humans and is equivalent to the incidence of malignancies in all other organs combined in the United States. Current methods of prevention depend on sunscreens in humans, efficacy of which is largely undetermined for non-melanoma skin cancers. Green tea polyphenols have the greatest effect with respect to chemoprevention and have been found to be most potent at suppressing the carcinogenic activity of UV radiation. They protect against many of the other damaging effects of UV radiation such as UV-induced sunburn response, UV-induced immunosuppression and photoaging of the skin. They exert their photoprotective effects by various cellular, molecular and biochemical mechanisms in in vitro and in vivo systems. Green tea polyphenols thus have the potential, when used in conjunction with traditional sunscreens, to further protect the skin against the adverse effects of ultraviolet radiation.

  11. Green tea and bone health: Evidence from laboratory studies.

    PubMed

    Shen, Chwan-Li; Yeh, James K; Cao, Jay J; Chyu, Ming-Chien; Wang, Jia-Sheng

    2011-08-01

    Osteoporosis is a major health problem in the elderly. Epidemiological evidence has shown an association between tea consumption and the prevention of bone loss in the elderly population. Ingestion of green tea and green tea bioactive compounds may be beneficial in mitigating bone loss of this population and decreasing their risk of osteoporotic fractures. This review describes the effect of green tea with its bioactive components on bone health with an emphasis on the following: (i) the etiology of osteoporosis, (ii) evidence of osteo-protective impacts of green tea on bone mass and microarchitecture in various bone loss models in which induced by aging, sex hormone deficiency, and chronic inflammation, (iii) discussion of impacts of green tea on bone mass in two obesity models, (iv) observation of short-term green tea supplementation given to postmenopausal women with low bone mass, (v) possible mechanisms for the osteo-protective effects of green tea bioactive compounds, and (vi) a summary and future research direction of green tea and bone health.

  12. Commercialized non-Camellia tea: traditional function and molecular identification

    PubMed Central

    Long, Ping; Cui, Zhanhu; Wang, Yingli; Zhang, Chunhong; Zhang, Na; Li, Minhui; Xiao, Peigen

    2014-01-01

    Non-Camellia tea is a part of the colorful Chinese tea culture, and is also widely used as beverage and medicine in folk for disease prevention and treatment. In this study, 37 samples were collected, including 33 kinds of non-Camellia teas and 4 kinds of teas (Camellia). Traditional functions of non-Camellia teas were investigated. Furthermore, non-Camellia teas of original plants were characterized and identified by molecular methods. Four candidate regions (rbcL, matK, ITS2, psbA-trnH) were amplified by polymerase chain reaction. In addition, DNA barcodes were used for the first time to discriminate the commercial non-Camellia tea and their adulterants, and to evaluate their safety. This study showed that BLASTN and the relevant phylogenetic tree are efficient tools for identification of the commercial non-Camellia tea and their adulterants. However, some sequences from original plants have not been found and there is a limitation of sequence number of original plants in GenBank. Submitting more original plant sequences to the GenBank will be helpful for evaluating the safety of non-Camellia teas. PMID:26579387

  13. Strontium-90 and caesium-137 in Indian tea.

    PubMed

    Lalit, B Y; Ramachandran, T V; Rajan, S

    1983-01-01

    The paper presents results of measurements made on tea samples, collected during 1961-1979 period for their strontium-90 and caesium-137 content. Tea was found to contain higher concentration of these radioisotopes compared to other food-stuffs having vegetative origin. Levels in tea are compared with those in leafy vegetables from both India and Japan. Interpretation for higher concentrations in tea compared to leafy vegetables is briefly given on the basis of agro-climatic conditions. The levels are also considered from the point of view of health hazard.

  14. Green tea: A boon for periodontal and general health

    PubMed Central

    Chatterjee, Anirban; Saluja, Mini; Agarwal, Gunjan; Alam, Mahtab

    2012-01-01

    Green tea is particularly rich in health-promoting flavonoids (which account for 30% of the dry weight of a leaf), including catechins and their derivatives. The most abundant catechin in green tea is epigallocatechin-3-gallate, which is thought to play a pivotal role in the green tea's anticancer and antioxidant effects. Catechins should be considered right alongside of the better-known antioxidants like vitamins E and C as potent free radical scavengers and health-supportive for this reason. It has been suggested that green tea also promotes periodontal health by reducing inflammation, preventing bone resorption and limiting the growth of certain bacteria associated with periodontal diseases. PMID:23055579

  15. Effect of different brewing times on soluble oxalate content of loose-packed black teas and tea bags.

    PubMed

    Mahdavi, Reza; Lotfi Yagin, Neda; Liebman, Michael; Nikniaz, Zeinab

    2013-02-01

    Because of the postulated role of increased dietary oxalate intake in calcium oxalate stone formation, the effect of different brewing times on soluble oxalate contents of loose-packed black tea and tea bags was studied. The oxalate content of 25 different samples of loose-packed black teas after brewing at 5, 10, 15, 30, and 60 min and of ten brands of tea bags after infusion for 1, 2, 3, 4, and 5 min was measured by enzymatic assay. The oxalate concentration resulting from different brewing times ranged from 4.3 to 6.2 mg/240 ml for loose-packed black teas and from 2.7 to 4.8 mg/240 ml for tea bags. There was a stepwise increase in oxalate concentration associated with increased brewing times.

  16. The lumazine synthase/riboflavin synthase complex: shapes and functions of a highly variable enzyme system.

    PubMed

    Ladenstein, Rudolf; Fischer, Markus; Bacher, Adelbert

    2013-06-01

    The xylene ring of riboflavin (vitamin B2 ) is assembled from two molecules of 3,4-dihydroxy-2-butanone 4-phosphate by a mechanistically complex process that is jointly catalyzed by lumazine synthase and riboflavin synthase. In Bacillaceae, these enzymes form a structurally unique complex comprising an icosahedral shell of 60 lumazine synthase subunits and a core of three riboflavin synthase subunits, whereas many other bacteria have empty lumazine synthase capsids, fungi, Archaea and some eubacteria have pentameric lumazine synthases, and the riboflavin synthases of Archaea are paralogs of lumazine synthase. The structures of the molecular ensembles have been studied in considerable detail by X-ray crystallography, X-ray small-angle scattering and electron microscopy. However, certain mechanistic aspects remain unknown. Surprisingly, the quaternary structure of the icosahedral β subunit capsids undergoes drastic changes, resulting in formation of large, quasi-spherical capsids; this process is modulated by sequence mutations. The occurrence of large shells consisting of 180 or more lumazine synthase subunits has recently generated interest for protein engineering topics, particularly the construction of encapsulation systems.

  17. Assessment of Culturable Tea Rhizobacteria Isolated from Tea Estates of Assam, India for Growth Promotion in Commercial Tea Cultivars.

    PubMed

    Dutta, Jintu; Handique, Pratap J; Thakur, Debajit

    2015-01-01

    In the present study, 217 rhizobacterial isolates were obtained from six different tea estates of Assam, India and subjected to preliminary in vitro plant growth promotion (PGP) screening for indole acetic acid (IAA) production, phosphate solubilization, siderophore production and ammonia production. Fifty isolates showed all the PGP traits and five isolates did not exhibit any PGP traits. These 50 potential isolates were further analyzed for quantitative estimation of the PGP traits along with the aminocyclopropane-1-carboxylate (ACC) deaminase, protease and cellulose production. After several rounds of screening, four rhizobacteria were selected based on their maximum ability to produce in vitro PGP traits and their partial 16S rRNA gene sequence analysis revealed that they belong to Enterobacter lignolyticus strain TG1, Burkholderia sp. stain TT6, Bacillus pseudomycoides strain SN29 and Pseudomonas aeruginosa strain KH45. To evaluate the efficacy of these four rhizobacteria as plant growth promoters, three different commercially important tea clones TV1, TV19, and TV20 plants were inoculated with these rhizobacteria in greenhouse condition and compared to the uninoculated control plants. Though, all the rhizobacterial treatments showed an increase in plant growth compared to control but the multivariate PCA analysis confirmed more growth promotion by TG1 and SN29 strains than the other treatments in all three clones. To validate this result, the fold change analysis was performed and it revealed that the tea clone TV19 plants inoculated with the E. lignolyticus strain TG1 showed maximum root biomass production with an increase in 4.3-fold, shoot biomass with increase in 3.1-fold, root length by 2.2-fold and shoot length by 1.6-fold. Moreover, two way ANOVA analysis also revealed that rhizobacterial treatment in different tea clones showed the significant increase (P < 0.05) in growth promotion compared to the control. Thus, this study indicates that the

  18. Assessment of Culturable Tea Rhizobacteria Isolated from Tea Estates of Assam, India for Growth Promotion in Commercial Tea Cultivars

    PubMed Central

    Dutta, Jintu; Handique, Pratap J.; Thakur, Debajit

    2015-01-01

    In the present study, 217 rhizobacterial isolates were obtained from six different tea estates of Assam, India and subjected to preliminary in vitro plant growth promotion (PGP) screening for indole acetic acid (IAA) production, phosphate solubilization, siderophore production and ammonia production. Fifty isolates showed all the PGP traits and five isolates did not exhibit any PGP traits. These 50 potential isolates were further analyzed for quantitative estimation of the PGP traits along with the aminocyclopropane-1-carboxylate (ACC) deaminase, protease and cellulose production. After several rounds of screening, four rhizobacteria were selected based on their maximum ability to produce in vitro PGP traits and their partial 16S rRNA gene sequence analysis revealed that they belong to Enterobacter lignolyticus strain TG1, Burkholderia sp. stain TT6, Bacillus pseudomycoides strain SN29 and Pseudomonas aeruginosa strain KH45. To evaluate the efficacy of these four rhizobacteria as plant growth promoters, three different commercially important tea clones TV1, TV19, and TV20 plants were inoculated with these rhizobacteria in greenhouse condition and compared to the uninoculated control plants. Though, all the rhizobacterial treatments showed an increase in plant growth compared to control but the multivariate PCA analysis confirmed more growth promotion by TG1 and SN29 strains than the other treatments in all three clones. To validate this result, the fold change analysis was performed and it revealed that the tea clone TV19 plants inoculated with the E. lignolyticus strain TG1 showed maximum root biomass production with an increase in 4.3-fold, shoot biomass with increase in 3.1-fold, root length by 2.2-fold and shoot length by 1.6-fold. Moreover, two way ANOVA analysis also revealed that rhizobacterial treatment in different tea clones showed the significant increase (P < 0.05) in growth promotion compared to the control. Thus, this study indicates that the

  19. Tea and Recurrent Clostridium difficile Infection

    PubMed Central

    Starley, Brad; Galagan, Jack Carl; Yabes, Joseph Michael; Evans, Sara

    2016-01-01

    Background and Aims. Studies have shown effects of diet on gut microbiota. We aimed to identify foods associated with recurrent Clostridium difficile infection (CDI). Methods. In this cross-sectional survey, consecutive patients diagnosed with CDI were identified by electronic medical records. Colitis symptoms and positive Clostridium difficile assay were confirmed. Health-care onset-health-care facility associated CDI was excluded. Food surveys were mailed to 411 patients. Survey responses served as the primary outcome measure. Spearman's rank correlation identified risk factors for CDI recurrence. Results. Surveys were returned by 68 patients. Nineteen patients experienced CDI recurrence. Compared to patients without CDI recurrence, patients with CDI recurrence had more antibiotics prescribed preceding their infection (p = 0.003). Greater numbers of the latter also listed tea (p = 0.002), coffee (p = 0.013), and eggs (p = 0.013), on their 24-hour food recall. Logistic regression identified tea as the only food risk factor for CDI recurrence (adjusted OR: 5.71; 95% CI: 1.26–25.89). Conclusion. The present results indicate a possible association between tea and CDI recurrence. Additional studies are needed to characterize and confirm this association. PMID:27651790

  20. Tea and Recurrent Clostridium difficile Infection.

    PubMed

    Oman Evans Ii, Martin; Starley, Brad; Galagan, Jack Carl; Yabes, Joseph Michael; Evans, Sara; Salama, Joseph John

    2016-01-01

    Background and Aims. Studies have shown effects of diet on gut microbiota. We aimed to identify foods associated with recurrent Clostridium difficile infection (CDI). Methods. In this cross-sectional survey, consecutive patients diagnosed with CDI were identified by electronic medical records. Colitis symptoms and positive Clostridium difficile assay were confirmed. Health-care onset-health-care facility associated CDI was excluded. Food surveys were mailed to 411 patients. Survey responses served as the primary outcome measure. Spearman's rank correlation identified risk factors for CDI recurrence. Results. Surveys were returned by 68 patients. Nineteen patients experienced CDI recurrence. Compared to patients without CDI recurrence, patients with CDI recurrence had more antibiotics prescribed preceding their infection (p = 0.003). Greater numbers of the latter also listed tea (p = 0.002), coffee (p = 0.013), and eggs (p = 0.013), on their 24-hour food recall. Logistic regression identified tea as the only food risk factor for CDI recurrence (adjusted OR: 5.71; 95% CI: 1.26-25.89). Conclusion. The present results indicate a possible association between tea and CDI recurrence. Additional studies are needed to characterize and confirm this association.

  1. Guaianolides and volatile compounds in chamomile tea.

    PubMed

    Tschiggerl, Christine; Bucar, Franz

    2012-06-01

    Chamomile (German Chamomile, Matricaria recutita L., Asteraceae) is one of the most popular medicinal plants in use as an herbal tea for food purposes and in folk medicine. Qualitative and semi-quantitative analyses of the volatile fraction of chamomile herbal tea were performed. Volatile constituents of the infusion were isolated by two different methods, namely hydrodistillation and solid phase extraction (SPE), and analysed by GC-MS. The relative proportions of particular chemical classes, present in the essential oil and volatile fractions of the infusion showed remarkable differences. The proportion of mono- and sesquiterpene hydrocarbons in the infusion, as compared to the essential oil, was significantly lower. Strikingly, the dichloromethane extract of the infusion contained a lower amount of bisabolol oxides and chamazulene, but higher amounts of spiroethers, sesquiterpene lactones and coumarins, as compared to the hydrodistillates of the herbal drug and the infusion. In addition to the previously known guaianolides matricarin and achillin, acetoxyachillin and leucodin (= desacetoxymatricarin), corresponding C-11 stereoisomers with various biological activities typically occurring in Achillea species, were identified in the dichloromethane extract of chamomile tea for the first time. PMID:22410959

  2. Tea and Recurrent Clostridium difficile Infection.

    PubMed

    Oman Evans Ii, Martin; Starley, Brad; Galagan, Jack Carl; Yabes, Joseph Michael; Evans, Sara; Salama, Joseph John

    2016-01-01

    Background and Aims. Studies have shown effects of diet on gut microbiota. We aimed to identify foods associated with recurrent Clostridium difficile infection (CDI). Methods. In this cross-sectional survey, consecutive patients diagnosed with CDI were identified by electronic medical records. Colitis symptoms and positive Clostridium difficile assay were confirmed. Health-care onset-health-care facility associated CDI was excluded. Food surveys were mailed to 411 patients. Survey responses served as the primary outcome measure. Spearman's rank correlation identified risk factors for CDI recurrence. Results. Surveys were returned by 68 patients. Nineteen patients experienced CDI recurrence. Compared to patients without CDI recurrence, patients with CDI recurrence had more antibiotics prescribed preceding their infection (p = 0.003). Greater numbers of the latter also listed tea (p = 0.002), coffee (p = 0.013), and eggs (p = 0.013), on their 24-hour food recall. Logistic regression identified tea as the only food risk factor for CDI recurrence (adjusted OR: 5.71; 95% CI: 1.26-25.89). Conclusion. The present results indicate a possible association between tea and CDI recurrence. Additional studies are needed to characterize and confirm this association. PMID:27651790

  3. [Development of cough-relieving herbal teas].

    PubMed

    Puodziūniene, Gene; Janulis, Valdimaras; Milasius, Arvydas; Budnikas, Vytautas

    2005-01-01

    Cough-relieving medicinal herbs in tea are used from ancient times. Mucilage present in them or secretion produced under the influence of the active substances covers the oral and throat mucosa soothing its irritability and relieving dry, tiresome cough. It is known that the mixtures of medicinal herbs (Specias) have a complex influence on the human organism and the rational combination of medicinal herbs can improve their curative action and decrease the undesirable side effects. Having summarized the properties of those medicinal herbs we decided to create two formulations of cough-relieving herbal tea. The first formulation consists of marshmallow roots, liquorice roots and lime flowers, the second -- of marshmallow roots, Iceland moss and lime flowers. The methods for identification and assay of the active substances in the compounds were applied. The purity of the mixtures was regulated by limitation of the loss on drying, total ash, microbial contamination, contamination with radionuclides, heavy metals, pesticides and foreign matter. The expiry date of both cough-relieving herbal teas was approved to be 2 years.

  4. Tea and Recurrent Clostridium difficile Infection

    PubMed Central

    Starley, Brad; Galagan, Jack Carl; Yabes, Joseph Michael; Evans, Sara

    2016-01-01

    Background and Aims. Studies have shown effects of diet on gut microbiota. We aimed to identify foods associated with recurrent Clostridium difficile infection (CDI). Methods. In this cross-sectional survey, consecutive patients diagnosed with CDI were identified by electronic medical records. Colitis symptoms and positive Clostridium difficile assay were confirmed. Health-care onset-health-care facility associated CDI was excluded. Food surveys were mailed to 411 patients. Survey responses served as the primary outcome measure. Spearman's rank correlation identified risk factors for CDI recurrence. Results. Surveys were returned by 68 patients. Nineteen patients experienced CDI recurrence. Compared to patients without CDI recurrence, patients with CDI recurrence had more antibiotics prescribed preceding their infection (p = 0.003). Greater numbers of the latter also listed tea (p = 0.002), coffee (p = 0.013), and eggs (p = 0.013), on their 24-hour food recall. Logistic regression identified tea as the only food risk factor for CDI recurrence (adjusted OR: 5.71; 95% CI: 1.26–25.89). Conclusion. The present results indicate a possible association between tea and CDI recurrence. Additional studies are needed to characterize and confirm this association.

  5. Green tea polyphenols: DNA photodamage and photoimmunology.

    PubMed

    Katiyar, S K; Bergamo, B M; Vyalil, P K; Elmets, C A

    2001-12-31

    Green tea is a popular beverage consumed worldwide. The epicatechin derivatives, which are commonly called 'polyphenols', are the active ingredients in green tea and possess antioxidant, anti-inflammatory and anti-carcinogenic properties. Studies conducted by our group on human skin have demonstrated that green tea polyphenols (GTP) prevent ultraviolet (UV)-B-induced cyclobutane pyrimidine dimers (CPD), which are considered to be mediators of UVB-induced immune suppression and skin cancer induction. GTP treated human skin prevented penetration of UV radiation, which was demonstrated by the absence of immunostaining for CPD in the reticular dermis. The topical application of GTP or its most potent chemopreventive constituent (-)-epigallocatechin-3-gallate (EGCG) prior to exposure to UVB protects against UVB-induced local as well as systemic immune suppression in laboratory animals. Additionally, studies have shown that EGCG treatment of mouse skin inhibits UVB-induced infiltration of CD11b+ cells. CD11b is a cell surface marker for activated macrophages and neutrophils, which are associated with induction of UVB-induced suppression of contact hypersensitivity responses. EGCG treatment also results in reduction of the UVB-induced immunoregulatory cytokine interleukin (IL)-10 in skin as well as in draining lymph nodes, and an elevated amount of IL-12 in draining lymph nodes. These in vivo observations suggest that GTPs are photoprotective, and can be used as pharmacological agents for the prevention of solar UVB light-induced skin disorders associated with immune suppression and DNA damage.

  6. Hyperbranched acidic polysaccharide from green tea.

    PubMed

    Yang, Liqun; Fu, Shanshan; Zhu, Xiane; Zhang, Li-Ming; Yang, Yanrui; Yang, Xiaomin; Liu, Hui

    2010-12-13

    An acidic tea polysaccharide (ALTPS), isolated from green tea ( Camellia sinensis ), was characterized as a hyperbranched glycoprotein containing the acidic heteropolysaccharide chains and the protein residues from the results of UV-vis, FTIR, one- and two-dimensional NMR, GC, GC-MS, and amino acid analyses. Solution properties of ALTPS were investigated by static and dynamic light scattering analyses and viscometry. The results indicated that the viscosity behavior of ALTPS exhibited a typical polyelectrolyte effect in distilled water, which may be avoided by adding salts. The low intrinsic viscosity of ALTPS in the solutions (8-15 mL/g) is attributed to its hyperbranched structure. By application of the polymer solution theory, it was revealed that ALTPS was present in a sphere-like conformation in the solutions as a result of the hyperbranched structure. The TEM image further confirmed that ALTPS existed in a spherical conformation in aqueous NaCl solution. Glucose was absorbed by ALTPS, which may be one of blood glucose lowering mechanisms of tea polysaccharides.

  7. [Effects of different tillage methods on tea garden soil physical characteristics and tea yield].

    PubMed

    Su, You-jian; Wang, Ye-jun; Zhang, Yong-li; Ding, Yong; Luo, Yi; Song, Li; Liao, Wan-you

    2015-12-01

    The effects of three tillage methods, i.e., no tillage, rotary tillage, deep tillage, on tea garden soil compaction, soil moisture, soil bulk density, yield component factors and tea yield were studied through field experiments in Langxi Country of Anhui Province. The results indicated that the effects of three tillage methods on soil bulk density and soil compaction were in order of deep tillage>rotary tillage>no tillage. Deep tillage and rotary tillage could effectively break the argillic horizon layer and decrease the soil compaction. Compared with no tillage, soil compaction and soil bulk density (0-30 cm) under deep tillage decreased 16.4% and 13.4%-27.5%, respectively. Deep tillage could significantly increase soil water storage space and enhance the water holding capacity of the soil. Compared with no tillage, the soil moisture of 15-30 cm soil layer was increased by 7.7% under deep tillage. The different tillage methods had little effect on soil porosity. Rotary tillage and deep tillage could increase soil specific surface area and the ratios of soil gas and soil liquid. The diurnal changes of photosynthetic rate and transpiration rate of tea both exhibited double-peak pattern. There was a significant midday depression caused principally by stomatal factors. Under deep tillage, the tea leaf transpiration rate decreased, shoot density increased, 100-bud dry mass and water use efficiency increased significantly, and the tea yield increased by 17.6% and 6.8% compared with no tillage and rotary tillage, respectively. Deep tillage was the most appropriate tillage practice in tea garden of east Anhui Province. PMID:27112011

  8. [Effects of different tillage methods on tea garden soil physical characteristics and tea yield].

    PubMed

    Su, You-jian; Wang, Ye-jun; Zhang, Yong-li; Ding, Yong; Luo, Yi; Song, Li; Liao, Wan-you

    2015-12-01

    The effects of three tillage methods, i.e., no tillage, rotary tillage, deep tillage, on tea garden soil compaction, soil moisture, soil bulk density, yield component factors and tea yield were studied through field experiments in Langxi Country of Anhui Province. The results indicated that the effects of three tillage methods on soil bulk density and soil compaction were in order of deep tillage>rotary tillage>no tillage. Deep tillage and rotary tillage could effectively break the argillic horizon layer and decrease the soil compaction. Compared with no tillage, soil compaction and soil bulk density (0-30 cm) under deep tillage decreased 16.4% and 13.4%-27.5%, respectively. Deep tillage could significantly increase soil water storage space and enhance the water holding capacity of the soil. Compared with no tillage, the soil moisture of 15-30 cm soil layer was increased by 7.7% under deep tillage. The different tillage methods had little effect on soil porosity. Rotary tillage and deep tillage could increase soil specific surface area and the ratios of soil gas and soil liquid. The diurnal changes of photosynthetic rate and transpiration rate of tea both exhibited double-peak pattern. There was a significant midday depression caused principally by stomatal factors. Under deep tillage, the tea leaf transpiration rate decreased, shoot density increased, 100-bud dry mass and water use efficiency increased significantly, and the tea yield increased by 17.6% and 6.8% compared with no tillage and rotary tillage, respectively. Deep tillage was the most appropriate tillage practice in tea garden of east Anhui Province.

  9. Unique animal prenyltransferase with monoterpene synthase activity

    NASA Astrophysics Data System (ADS)

    Gilg, Anna B.; Tittiger, Claus; Blomquist, Gary J.

    2009-06-01

    Monoterpenes are structurally diverse natural compounds that play an essential role in the chemical ecology of a wide array of organisms. A key enzyme in monoterpene biosynthesis is geranyl diphosphate synthase (GPPS). GPPS is an isoprenyl diphosphate synthase that catalyzes a single electrophilic condensation reaction between dimethylallyl diphosphate (C5) and isopentenyl diphosphate (C5) to produce geranyl diphosphate (GDP; C10). GDP is the universal precursor to all monoterpenes. Subsequently, monoterpene synthases are responsible for the transformation of GDP to a variety of acyclic, monocyclic, and bicyclic monoterpene products. In pheromone-producing male Ips pini bark beetles (Coleoptera: Scolytidae), the acyclic monoterpene myrcene is required for the production of the major aggregation pheromone component, ipsdienol. Here, we report monoterpene synthase activity associated with GPPS of I. pini. Enzyme assays were performed on recombinant GPPS to determine the presence of monoterpene synthase activity, and the reaction products were analyzed by coupled gas chromatography-mass spectrometry. The functionally expressed recombinant enzyme produced both GDP and myrcene, making GPPS of I. pini a bifunctional enzyme. This unique insect isoprenyl diphosphate synthase possesses the functional plasticity that is characteristic of terpene biosynthetic enzymes of plants, contributing toward the current understanding of product specificity of the isoprenoid pathway.

  10. Nitric oxide synthases in pregnant rat uterus.

    PubMed

    Farina, M; Ribeiro, M L; Franchi, A

    2001-03-01

    The conversion of [14C]arginine into [14C]citrulline as an indicator of nitric oxide synthesis was studied in uteri isolated from rats on different days of gestation, after labour and during dioestrus. Nitric oxide synthesis was present in uterine tissues isolated at each stage of gestation and also in tissues collected during dioestrus and after labour. Expression of neuronal nitric oxide synthase was not detectable at any of the stages studied. Endothelial nitric oxide synthase was present at all the stages studied, but there was a significant increase on day 13 of gestation and a decrease thereafter, with the lowest expression recorded on the day after labour. Inducible nitric oxide synthase expression in rat uteri increased substantially during pregnancy, with the highest expression on day 13 of gestation; expression decreased at term and after labour. The changes in expression of inducible nitric oxide synthase were coincident with the changes in nitric oxide synthase activity in uteri treated with aminoguanidine. Thus, these findings indicate that an increase in expression of inducible nitric oxide synthase in the uterus may be important for maintenance of uterine quiescence during pregnancy and its decrease near the time of labour could have an effect on the start of uterine contractility. PMID:11226066

  11. Comparison of the level of boron concentrations in black teas with fruit teas available on the Polish market.

    PubMed

    Zioła-Frankowska, Anetta; Frankowski, Marcin; Novotny, Karel; Kanicky, Viktor

    2014-01-01

    The determination of boron by inductively coupled plasma-atomic emission spectrometry has been carried in water-soluble and acid soluble (total content) fractions of 36 samples of traditional black tea and fruit brew. The estimation of the impact of the type of tea on the concentration of boron in water-soluble and acid extracts and potential human health risk from the daily intake of boron was carried out in this study. The levels of boron differed significantly in black and fruit tea types. The mean total content of boron ranged from 8.31 to 18.40 mg/kg in black teas, from 12.85 to 15.13 mg/kg in black tea with fruit flavor, and from 12.09 to 22.77 mg/kg in fruit brews. The degree of extraction of boron in black tea ranged from 8% to 27% and for fruit tea from 17% to 69%. In addition, the values below 25% were of black teas with fruit flavors. The daily intake of B from tea infusions (three cups/day) is still within the average daily intake except for some of the fruit brews which exceed acceptable regulations of the daily intake of total boron by humans. Hence, it may not produce any health risks for human consumption, if other sources of metal contaminated food are not taken at the same time. PMID:25379551

  12. Comparison of the Level of Boron Concentrations in Black Teas with Fruit Teas Available on the Polish Market

    PubMed Central

    Zioła-Frankowska, Anetta; Frankowski, Marcin; Novotny, Karel; Kanicky, Viktor

    2014-01-01

    The determination of boron by inductively coupled plasma-atomic emission spectrometry has been carried in water-soluble and acid soluble (total content) fractions of 36 samples of traditional black tea and fruit brew. The estimation of the impact of the type of tea on the concentration of boron in water-soluble and acid extracts and potential human health risk from the daily intake of boron was carried out in this study. The levels of boron differed significantly in black and fruit tea types. The mean total content of boron ranged from 8.31 to 18.40 mg/kg in black teas, from 12.85 to 15.13 mg/kg in black tea with fruit flavor, and from 12.09 to 22.77 mg/kg in fruit brews. The degree of extraction of boron in black tea ranged from 8% to 27% and for fruit tea from 17% to 69%. In addition, the values below 25% were of black teas with fruit flavors. The daily intake of B from tea infusions (three cups/day) is still within the average daily intake except for some of the fruit brews which exceed acceptable regulations of the daily intake of total boron by humans. Hence, it may not produce any health risks for human consumption, if other sources of metal contaminated food are not taken at the same time. PMID:25379551

  13. Malate synthase a membrane protein

    SciTech Connect

    Chapman, K.D.; Turley, R.B.; Hermerath, C.A.; Carrapico, F.; Trelease, R.N.

    1987-04-01

    Malate synthase (MS) is generally regarded as a peripheral membrane protein, and believed by some to be ontogenetically associated with ER. However, immuno- and cyto-chemical in situ localizations show MS throughout the matrix of cotton (and cucumber) glyoxysomes, not specifically near their boundary membranes, nor in ER. Only a maximum of 50% MS can be solubilized from cotton glyoxysomes with 1% Triton X-100, 2mM Zwittergen 14, or 10mM DOC +/- salts. Cotton MS does not incorporate /sup 3/H-glucosamine in vivo, nor does it react with Con A on columns or blots. Cotton MS banded with ER in sucrose gradients (20-40%) in Tricine after 3h, but not after 22h in Tricine or Hepes, or after 3h in Hepes or K-phosphate. Collectively the authors data are inconsistent with physiologically meaningful MS-membrane associations in ER or glyoxysomes. It appears that experimentally-induced aggregates of MS migrate in ER gradients and occur in isolated glyoxysomes. These data indicate that ER is not involved in synthesis or modification of cottonseed MS prior to its import into the glyoxysomal matrix.

  14. Dihydrodipicolinate synthase from Thermotoga maritima.

    PubMed

    Pearce, F Grant; Perugini, Matthew A; McKerchar, Hannah J; Gerrard, Juliet A

    2006-12-01

    DHDPS (dihydrodipicolinate synthase) catalyses the branch point in lysine biosynthesis in bacteria and plants and is feedback inhibited by lysine. DHDPS from the thermophilic bacterium Thermotoga maritima shows a high level of heat and chemical stability. When incubated at 90 degrees C or in 8 M urea, the enzyme showed little or no loss of activity, unlike the Escherichia coli enzyme. The active site is very similar to that of the E. coli enzyme, and at mesophilic temperatures the two enzymes have similar kinetic constants. Like other forms of the enzyme, T. maritima DHDPS is a tetramer in solution, with a sedimentation coefficient of 7.2 S and molar mass of 133 kDa. However, the residues involved in the interface between different subunits in the tetramer differ from those of E. coli and include two cysteine residues poised to form a disulfide bond. Thus the increased heat and chemical stability of the T. maritima DHDPS enzyme is, at least in part, explained by an increased number of inter-subunit contacts. Unlike the plant or E. coli enzyme, the thermophilic DHDPS enzyme is not inhibited by (S)-lysine, suggesting that feedback control of the lysine biosynthetic pathway evolved later in the bacterial lineage. PMID:16872276

  15. Identification of avian wax synthases

    PubMed Central

    2012-01-01

    Background Bird species show a high degree of variation in the composition of their preen gland waxes. For instance, galliform birds like chicken contain fatty acid esters of 2,3-alkanediols, while Anseriformes like goose or Strigiformes like barn owl contain wax monoesters in their preen gland secretions. The final biosynthetic step is catalyzed by wax synthases (WS) which have been identified in pro- and eukaryotic organisms. Results Sequence similarities enabled us to identify six cDNAs encoding putative wax synthesizing proteins in chicken and two from barn owl and goose. Expression studies in yeast under in vivo and in vitro conditions showed that three proteins from chicken performed WS activity while a sequence from chicken, goose and barn owl encoded a bifunctional enzyme catalyzing both wax ester and triacylglycerol synthesis. Mono- and bifunctional WS were found to differ in their substrate specificities especially with regard to branched-chain alcohols and acyl-CoA thioesters. According to the expression patterns of their transcripts and the properties of the enzymes, avian WS proteins might not be confined to preen glands. Conclusions We provide direct evidence that avian preen glands possess both monofunctional and bifunctional WS proteins which have different expression patterns and WS activities with different substrate specificities. PMID:22305293

  16. Energy transduction in ATP synthase

    NASA Astrophysics Data System (ADS)

    Elston, Timothy; Wang, Hongyun; Oster, George

    1998-01-01

    Mitochondria, bacteria and chloroplasts use the free energy stored in transmembrane ion gradients to manufacture ATP by the action of ATP synthase. This enzyme consists of two principal domains. The asymmetric membrane-spanning Fo portion contains the proton channel, and the soluble F1 portion contains three catalytic sites which cooperate in the synthetic reactions. The flow of protons through Fo is thought to generate a torque which is transmitted to F1 by an asymmetric shaft, the coiled-coil γ-subunit. This acts as a rotating `cam' within F1, sequentially releasing ATPs from the three active sites. The free-energy difference across the inner membrane of mitochondria and bacteria is sufficient to produce three ATPs per twelve protons passing through the motor. It has been suggested that this protonmotive force biases the rotor's diffusion so that Fo constitutes a rotary motor turning the γ shaft. Here we show that biased diffusion, augmented by electrostatic forces, does indeed generate sufficient torque to account for ATP production. Moreover, the motor's reversibility - supplying torque from ATP hydrolysis in F1 converts the motor into an efficient proton pump - can also be explained by our model.

  17. Kombucha tea fermentation: Microbial and biochemical dynamics.

    PubMed

    Chakravorty, Somnath; Bhattacharya, Semantee; Chatzinotas, Antonis; Chakraborty, Writachit; Bhattacharya, Debanjana; Gachhui, Ratan

    2016-03-01

    Kombucha tea, a non-alcoholic beverage, is acquiring significant interest due to its claimed beneficial properties. The microbial community of Kombucha tea consists of bacteria and yeast which thrive in two mutually non-exclusive compartments: the soup or the beverage and the biofilm floating on it. The microbial community and the biochemical properties of the beverage have so far mostly been described in separate studies. This, however, may prevent understanding the causal links between the microbial communities and the beneficial properties of Kombucha tea. Moreover, an extensive study into the microbial and biochemical dynamics has also been missing. In this study, we thus explored the structure and dynamics of the microbial community along with the biochemical properties of Kombucha tea at different time points up to 21 days of fermentation. We hypothesized that several biochemical properties will change during the course of fermentation along with the shifts in the yeast and bacterial communities. The yeast community of the biofilm did not show much variation over time and was dominated by Candida sp. (73.5-83%). The soup however, showed a significant shift in dominance from Candida sp. to Lachancea sp. on the 7th day of fermentation. This is the first report showing Candida as the most dominating yeast genus during Kombucha fermentation. Komagateibacter was identified as the single largest bacterial genus present in both the biofilm and the soup (~50%). The bacterial diversity was higher in the soup than in the biofilm with a peak on the seventh day of fermentation. The biochemical properties changed with the progression of the fermentation, i.e., beneficial properties of the beverage such as the radical scavenging ability increased significantly with a maximum increase at day 7. We further observed a significantly higher D-saccharic acid-1,4-lactone content and caffeine degradation property compared to previously described Kombucha tea fermentations. Our

  18. Kombucha tea fermentation: Microbial and biochemical dynamics.

    PubMed

    Chakravorty, Somnath; Bhattacharya, Semantee; Chatzinotas, Antonis; Chakraborty, Writachit; Bhattacharya, Debanjana; Gachhui, Ratan

    2016-03-01

    Kombucha tea, a non-alcoholic beverage, is acquiring significant interest due to its claimed beneficial properties. The microbial community of Kombucha tea consists of bacteria and yeast which thrive in two mutually non-exclusive compartments: the soup or the beverage and the biofilm floating on it. The microbial community and the biochemical properties of the beverage have so far mostly been described in separate studies. This, however, may prevent understanding the causal links between the microbial communities and the beneficial properties of Kombucha tea. Moreover, an extensive study into the microbial and biochemical dynamics has also been missing. In this study, we thus explored the structure and dynamics of the microbial community along with the biochemical properties of Kombucha tea at different time points up to 21 days of fermentation. We hypothesized that several biochemical properties will change during the course of fermentation along with the shifts in the yeast and bacterial communities. The yeast community of the biofilm did not show much variation over time and was dominated by Candida sp. (73.5-83%). The soup however, showed a significant shift in dominance from Candida sp. to Lachancea sp. on the 7th day of fermentation. This is the first report showing Candida as the most dominating yeast genus during Kombucha fermentation. Komagateibacter was identified as the single largest bacterial genus present in both the biofilm and the soup (~50%). The bacterial diversity was higher in the soup than in the biofilm with a peak on the seventh day of fermentation. The biochemical properties changed with the progression of the fermentation, i.e., beneficial properties of the beverage such as the radical scavenging ability increased significantly with a maximum increase at day 7. We further observed a significantly higher D-saccharic acid-1,4-lactone content and caffeine degradation property compared to previously described Kombucha tea fermentations. Our

  19. Green tea polyphenolic antioxidants and skin photoprotection (Review).

    PubMed

    Katiyar, S K; Elmets, C A

    2001-06-01

    Green tea is consumed as a popular beverage worldwide particularly in Asian countries like China, Korea, Japan and India. It contains polyphenolic compounds also known as epicatechins, which are antioxidant in nature. Many laboratories have shown that topical treatment or oral consumption of green tea polyphenols inhibits chemical carcinogen- or ultraviolet radiation-induced skin tumorigenesis in different animal models. Studies have shown that green tea extract also possesses anti-inflammatory activity. These anti-inflammatory and anti-carcinogenic properties of green tea are due to their polyphenolic constituents present therein. The major and most chemopreventive constituent in green tea responsible for these biochemical or pharmacological effects is (-)-epigallocatechin-3-gallate (EGCG). Understanding the molecular mechanisms of these effects of green tea is a subject of investigation in many laboratories. Treatment of green tea polyphenols to skin has been shown to modulate the biochemical pathways involved in inflammatory responses, cell proliferation and responses of chemical tumor promoters as well as ultraviolet (UV) light-induced inflammatory markers of skin inflammation. Topical treatment with EGCG on mouse skin also results in prevention of UVB-induced immunosuppression, and oxidative stress. The protective effects of green tea treatment on human skin either topically or consumed orally against UV light-induced inflammatory or carcinogenic responses are not well understood. Based on documented extensive beneficial effects of green tea on mouse skin models and very little in human skin, many pharmaceutical and cosmetic companies are supplementing their skin care products with green tea extracts. Therefore, the focus of this communication is to review and analyze the photoprotective effects of green tea polyphenols to skin.

  20. Body fat accumulation in zebrafish is induced by a diet rich in fat and reduced by supplementation with green tea extract.

    PubMed

    Meguro, Shinichi; Hasumura, Takahiro; Hase, Tadashi

    2015-01-01

    Fat-rich diets not only induce obesity in humans but also make animals obese. Therefore, animals that accumulate body fat in response to a high-fat diet (especially rodents) are commonly used in obesity research. The effect of dietary fat on body fat accumulation is not fully understood in zebrafish, an excellent model of vertebrate lipid metabolism. Here, we explored the effects of dietary fat and green tea extract, which has anti-obesity properties, on body fat accumulation in zebrafish. Adult zebrafish were allocated to four diet groups and over 6 weeks were fed a high-fat diet containing basal diet plus two types of fat or a low-fat diet containing basal diet plus carbohydrate or protein. Another group of adult zebrafish was fed a high-fat diet with or without 5% green tea extract supplementation. Zebrafish fed the high-fat diets had nearly twice the body fat (visceral, subcutaneous, and total fat) volume and body fat volume ratio (body fat volume/body weight) of those fed low-fat diets. There were no differences in body fat accumulation between the two high-fat groups, nor were there any differences between the two low-fat groups. Adding green tea extract to the high-fat diet significantly suppressed body weight, body fat volume, and body fat volume ratio compared with the same diet lacking green tea extract. 3-Hydroxyacyl-coenzyme A dehydrogenase and citrate synthase activity in the liver and skeletal muscle were significantly higher in fish fed the diet supplemented with green tea extract than in those fed the unsupplemented diet. Our results suggest that a diet rich in fat, instead of protein or carbohydrate, induced body fat accumulation in zebrafish with mechanisms that might be similar to those in mammals. Consequently, zebrafish might serve as a good animal model for research into obesity induced by high-fat diets.

  1. Dissipation behavior of octachlorodipropyl ether residues during tea planting and brewing process.

    PubMed

    Liao, Min; Shi, Yanhong; Cao, Haiqun; Hua, Rimao; Tang, Feng; Wu, Xiangwei; Tang, Jun

    2015-10-01

    The dissipation behavior of octachlorodipropyl ether (OCDPE) residues in fresh tea shoots and in tea prepared under field conditions was investigated, and the transfer of residues from brewed tea to tea infusion was determined. OCDPE levels in tea shoots, prepared tea, tea infusion, and spent tea leaves were determined using a sensitive and simple method. The dissipation of OCDPE is fairly slow in tea shoots and prepared tea, with half-life values of 5.10 and 5.46 days, respectively. The degradation rates of OCDPE residues in tea processing were 23.9-43.1 %. The terminal residues of OCDPE in tea shoots and prepared tea samples after 20 and 30 days of OCDPE application were higher than 0.01 mg/kg. However, OCDPE's transfer rates from brewed tea to tea infusion were only 6.0-14.8 %. Further studies on risk assessment of OCDPE residue in tea on the basis of the relationship of OCDPE in prepared tea and infusion are warranted. PMID:27604890

  2. Selected tea and tea pomace extracts inhibit intestinal α-glucosidase activity in vitro and postprandial hyperglycemia in vivo.

    PubMed

    Oh, Jungbae; Jo, Sung-Hoon; Kim, Justin S; Ha, Kyoung-Soo; Lee, Jung-Yun; Choi, Hwang-Yong; Yu, Seok-Yeong; Kwon, Young-In; Kim, Young-Cheul

    2015-01-01

    Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by postprandial hyperglycemia, which is an early defect of T2DM and thus a primary target for anti-diabetic drugs. A therapeutic approach is to inhibit intestinal α-glucosidase, the key enzyme for dietary carbohydrate digestion, resulting in delayed rate of glucose absorption. Although tea extracts have been reported to have anti-diabetic effects, the potential bioactivity of tea pomace, the main bio waste of tea beverage processing, is largely unknown. We evaluated the anti-diabetic effects of three selected tea water extracts (TWE) and tea pomace extracts (TPE) by determining the relative potency of extracts on rat intestinal α-glucosidase activity in vitro as well as hypoglycemic effects in vivo. Green, oolong, and black tea bags were extracted in hot water and the remaining tea pomace were dried and further extracted in 70% ethanol. The extracts were determined for intestinal rat α-glucosidases activity, radical scavenging activity, and total phenolic content. The postprandial glucose-lowering effects of TWE and TPE of green and black tea were assessed in male Sprague-Dawley (SD) rats and compared to acarbose, a known pharmacological α-glucosidase inhibitor. The IC50 values of all three tea extracts against mammalian α-glucosidase were lower or similar in TPE groups than those of TWE groups. TWE and TPE of green tea exhibited the highest inhibitory effects against α-glucosidase activity with the IC50 of 2.04 ± 0.31 and 1.95 ± 0.37 mg/mL respectively. Among the specific enzymes tested, the IC50 values for TWE (0.16 ± 0.01 mg/mL) and TPE (0.13 ± 0.01 mg/mL) of green tea against sucrase activity were the lowest compared to those on maltase and glucoamylase activities. In the animal study, the blood glucose level at 30 min after oral intake (0.5 g/kg body wt) of TPE and TWE of both green and black tea was significantly reduced compared to the control in sucrose-loaded SD rats. The TPE

  3. Selected Tea and Tea Pomace Extracts Inhibit Intestinal α-Glucosidase Activity in Vitro and Postprandial Hyperglycemia in Vivo

    PubMed Central

    Oh, Jungbae; Jo, Sung-Hoon; Kim, Justin S.; Ha, Kyoung-Soo; Lee, Jung-Yun; Choi, Hwang-Yong; Yu, Seok-Yeong; Kwon, Young-In; Kim, Young-Cheul

    2015-01-01

    Type 2 diabetes mellitus (T2DM) is a metabolic disorder characterized by postprandial hyperglycemia, which is an early defect of T2DM and thus a primary target for anti-diabetic drugs. A therapeutic approach is to inhibit intestinal α-glucosidase, the key enzyme for dietary carbohydrate digestion, resulting in delayed rate of glucose absorption. Although tea extracts have been reported to have anti-diabetic effects, the potential bioactivity of tea pomace, the main bio waste of tea beverage processing, is largely unknown. We evaluated the anti-diabetic effects of three selected tea water extracts (TWE) and tea pomace extracts (TPE) by determining the relative potency of extracts on rat intestinal α-glucosidase activity in vitro as well as hypoglycemic effects in vivo. Green, oolong, and black tea bags were extracted in hot water and the remaining tea pomace were dried and further extracted in 70% ethanol. The extracts were determined for intestinal rat α-glucosidases activity, radical scavenging activity, and total phenolic content. The postprandial glucose-lowering effects of TWE and TPE of green and black tea were assessed in male Sprague-Dawley (SD) rats and compared to acarbose, a known pharmacological α-glucosidase inhibitor. The IC50 values of all three tea extracts against mammalian α-glucosidase were lower or similar in TPE groups than those of TWE groups. TWE and TPE of green tea exhibited the highest inhibitory effects against α-glucosidase activity with the IC50 of 2.04 ± 0.31 and 1.95 ± 0.37 mg/mL respectively. Among the specific enzymes tested, the IC50 values for TWE (0.16 ± 0.01 mg/mL) and TPE (0.13 ± 0.01 mg/mL) of green tea against sucrase activity were the lowest compared to those on maltase and glucoamylase activities. In the animal study, the blood glucose level at 30 min after oral intake (0.5 g/kg body wt) of TPE and TWE of both green and black tea was significantly reduced compared to the control in sucrose-loaded SD rats. The TPE

  4. Consumption of green tea, but not black tea or coffee, is associated with reduced risk of cognitive decline.

    PubMed

    Noguchi-Shinohara, Moeko; Yuki, Sohshi; Dohmoto, Chiaki; Ikeda, Yoshihisa; Samuraki, Miharu; Iwasa, Kazuo; Yokogawa, Masami; Asai, Kimiko; Komai, Kiyonobu; Nakamura, Hiroyuki; Yamada, Masahito

    2014-01-01

    Our objective was to determine whether the consumption of green tea, coffee, or black tea influences the incidence of dementia and mild cognitive impairment (MCI) in older people. We conducted a population-based prospective study with Japanese residents aged >60 years from Nakajima, Japan (the Nakajima Project). Participants received an evaluation of cognitive function and blood tests. The consumption of green tea, coffee, and black tea was also evaluated at baseline. Of 723 participants with normal cognitive function at a baseline survey (2007-2008), 490 completed the follow up survey in 2011-2013. The incidence of dementia during the follow-up period (mean ± SD: 4.9 ± 0.9 years) was 5.3%, and that of MCI was 13.1%. The multiple-adjusted odds ratio for the incidence of overall cognitive decline (dementia or MCI) was 0.32 (95% CI: 0.16-0.64) among individuals who consumed green tea every day and 0.47 (95% CI: 0.25-0.86) among those who consumed green tea 1-6 days per week compared with individuals who did not consume green tea at all. The multiple-adjusted odds ratio for the incidence of dementia was 0.26 (95% CI: 0.06-1.06) among individuals who consumed green tea every day compared with those who did not consume green tea at all. No association was found between coffee or black tea consumption and the incidence of dementia or MCI. Our results indicate that green tea consumption is significantly associated with reduced risk of cognitive decline, even after adjustment for possible confounding factors.

  5. Critical aspartic acid residues in pseudouridine synthases.

    PubMed

    Ramamurthy, V; Swann, S L; Paulson, J L; Spedaliere, C J; Mueller, E G

    1999-08-01

    The pseudouridine synthases catalyze the isomerization of uridine to pseudouridine at particular positions in certain RNA molecules. Genomic data base searches and sequence alignments using the first four identified pseudouridine synthases led Koonin (Koonin, E. V. (1996) Nucleic Acids Res. 24, 2411-2415) and, independently, Santi and co-workers (Gustafsson, C., Reid, R., Greene, P. J., and Santi, D. V. (1996) Nucleic Acids Res. 24, 3756-3762) to group this class of enzyme into four families, which display no statistically significant global sequence similarity to each other. Upon further scrutiny (Huang, H. L., Pookanjanatavip, M., Gu, X. G., and Santi, D. V. (1998) Biochemistry 37, 344-351), the Santi group discovered that a single aspartic acid residue is the only amino acid present in all of the aligned sequences; they then demonstrated that this aspartic acid residue is catalytically essential in one pseudouridine synthase. To test the functional significance of the sequence alignments in light of the global dissimilarity between the pseudouridine synthase families, we changed the aspartic acid residue in representatives of two additional families to both alanine and cysteine: the mutant enzymes are catalytically inactive but retain the ability to bind tRNA substrate. We have also verified that the mutant enzymes do not release uracil from the substrate at a rate significant relative to turnover by the wild-type pseudouridine synthases. Our results clearly show that the aligned aspartic acid residue is critical for the catalytic activity of pseudouridine synthases from two additional families of these enzymes, supporting the predictive power of the sequence alignments and suggesting that the sequence motif containing the aligned aspartic acid residue might be a prerequisite for pseudouridine synthase function.

  6. Terpene synthases are widely distributed in bacteria

    PubMed Central

    Yamada, Yuuki; Kuzuyama, Tomohisa; Komatsu, Mamoru; Shin-ya, Kazuo; Omura, Satoshi; Cane, David E.; Ikeda, Haruo

    2015-01-01

    Odoriferous terpene metabolites of bacterial origin have been known for many years. In genome-sequenced Streptomycetaceae microorganisms, the vast majority produces the degraded sesquiterpene alcohol geosmin. Two minor groups of bacteria do not produce geosmin, with one of these groups instead producing other sesquiterpene alcohols, whereas members of the remaining group do not produce any detectable terpenoid metabolites. Because bacterial terpene synthases typically show no significant overall sequence similarity to any other known fungal or plant terpene synthases and usually exhibit relatively low levels of mutual sequence similarity with other bacterial synthases, simple correlation of protein sequence data with the structure of the cyclized terpene product has been precluded. We have previously described a powerful search method based on the use of hidden Markov models (HMMs) and protein families database (Pfam) search that has allowed the discovery of monoterpene synthases of bacterial origin. Using an enhanced set of HMM parameters generated using a training set of 140 previously identified bacterial terpene synthase sequences, a Pfam search of 8,759,463 predicted bacterial proteins from public databases and in-house draft genome data has now revealed 262 presumptive terpene synthases. The biochemical function of a considerable number of these presumptive terpene synthase genes could be determined by expression in a specially engineered heterologous Streptomyces host and spectroscopic identification of the resulting terpene products. In addition to a wide variety of terpenes that had been previously reported from fungal or plant sources, we have isolated and determined the complete structures of 13 previously unidentified cyclic sesquiterpenes and diterpenes. PMID:25535391

  7. Properties of phosphorylated thymidylate synthase.

    PubMed

    Frączyk, Tomasz; Ruman, Tomasz; Wilk, Piotr; Palmowski, Paweł; Rogowska-Wrzesinska, Adelina; Cieśla, Joanna; Zieliński, Zbigniew; Nizioł, Joanna; Jarmuła, Adam; Maj, Piotr; Gołos, Barbara; Wińska, Patrycja; Ostafil, Sylwia; Wałajtys-Rode, Elżbieta; Shugar, David; Rode, Wojciech

    2015-12-01

    Thymidylate synthase (TS) may undergo phosphorylation endogenously in mammalian cells, and as a recombinant protein expressed in bacterial cells, as indicated by the reaction of purified enzyme protein with Pro-Q® Diamond Phosphoprotein Gel Stain (PGS). With recombinant human, mouse, rat, Trichinella spiralis and Caenorhabditis elegans TSs, expressed in Escherichia coli, the phosphorylated, compared to non-phosphorylated recombinant enzyme forms, showed a decrease in Vmax(app), bound their cognate mRNA (only rat enzyme studied), and repressed translation of their own and several heterologous mRNAs (human, rat and mouse enzymes studied). However, attempts to determine the modification site(s), whether endogenously expressed in mammalian cells, or recombinant proteins, did not lead to unequivocal results. Comparative ESI-MS/analysis of IEF fractions of TS preparations from parental and FdUrd-resistant mouse leukemia L1210 cells, differing in sensitivity to inactivation by FdUMP, demonstrated phosphorylation of Ser(10) and Ser(16) in the resistant enzyme only, although PGS staining pointed to the modification of both L1210 TS proteins. The TS proteins phosphorylated in bacterial cells were shown by (31)P NMR to be modified only on histidine residues, like potassium phosphoramidate (KPA)-phosphorylated TS proteins. NanoLC-MS/MS, enabling the use of CID and ETD peptide fragmentation methods, identified several phosphohistidine residues, but certain phosphoserine and phosphothreonine residues were also implicated. Molecular dynamics studies, based on the mouse TS crystal structure, allowed one to assess potential of several phosphorylated histidine residues to affect catalytic activity, the effect being phosphorylation site dependent.

  8. Tea flavonoids for bone health: from animals to humans.

    PubMed

    Shen, Chwan-Li; Chyu, Ming-Chien

    2016-10-01

    Osteoporosis is a skeletal disease characterized by a deterioration of bone mass and bone quality that predisposes an individual to a higher risk of fragility fractures. Emerging evidence has shown that the risk for low bone mass and osteoporosis-related fractures can be reduced by nutritional approaches aiming to improve bone microstructure, bone mineral density, and strength. Tea and its flavonoids, especially those of black tea and green tea, have been suggested to protect against bone loss and to reduce risk of fracture, due to tea's antioxidant and anti-inflammatory properties. Based on the results of animal studies, moderate intake of tea has shown to benefit bone health as shown by mitigation of bone loss and microstructural deterioration as well as improvement of bone strength and quality. Epidemiological studies have reported positive, insignificant, and negative impacts on bone mineral density at multiple skeletal sites and risk of fracture in humans with habitual tea consumption. There are limited human clinical trials that objectively and quantitatively assessed tea consumption and bone efficacy using validated outcome measures in a population at high risk for osteoporosis, along with safety monitoring approach. This review summarizes the current state of knowledge of laboratory animal research, epidemiological observational studies, and clinical trials assessing the skeletal effects of tea and its active flavonoids, along with discussion of relevant future directions in translational research.

  9. Einstein's Tea Leaves and Pressure Systems in the Atmosphere

    ERIC Educational Resources Information Center

    Tandon, Amit; Marshall, John

    2010-01-01

    Tea leaves gather in the center of the cup when the tea is stirred. In 1926 Einstein explained the phenomenon in terms of a secondary, rim-to-center circulation caused by the fluid rubbing against the bottom of the cup. This explanation can be connected to air movement in atmospheric pressure systems to explore, for example, why low-pressure…

  10. Green tea compounds in breast cancer prevention and treatment

    PubMed Central

    Li, Min-Jing; Yin, Yan-Cun; Wang, Jiao; Jiang, Yang-Fu

    2014-01-01

    Breast cancer is the most common cancer among women. In recent years, many in vitro and in vivo studies indicate that green tea possesses anti-cancer effects. The epidemiological studies, however, have produced inconclusive results in humans. Likewise, results from animal models about the preventive or therapeutic effects of green tea components are inconclusive. The mechanisms by which green tea intake may influence the risk of breast cancer in humans remain elusive mechanisms by which green tea intake may influence. Here, we review recent studies of green tea polyphenols and their applications in the prevention and treatment of breast cancer. Furthermore, we discuss the effect of green tea components on breast cancer by reviewing epidemiological studies, animal model studies and clinical trials. At last, we discuss the mechanisms by which green tea components suppress the development and recurrence of breast cancer. A better understanding of the mechanisms will improve the utilization of green tea in breast cancer prevention and therapy and pave the way to novel prevention and treatment strategies for breast cancer. PMID:25114865

  11. Green tea compounds in breast cancer prevention and treatment.

    PubMed

    Li, Min-Jing; Yin, Yan-Cun; Wang, Jiao; Jiang, Yang-Fu

    2014-08-10

    Breast cancer is the most common cancer among women. In recent years, many in vitro and in vivo studies indicate that green tea possesses anti-cancer effects. The epidemiological studies, however, have produced inconclusive results in humans. Likewise, results from animal models about the preventive or therapeutic effects of green tea components are inconclusive. The mechanisms by which green tea intake may influence the risk of breast cancer in humans remain elusive mechanisms by which green tea intake may influence. Here, we review recent studies of green tea polyphenols and their applications in the prevention and treatment of breast cancer. Furthermore, we discuss the effect of green tea components on breast cancer by reviewing epidemiological studies, animal model studies and clinical trials. At last, we discuss the mechanisms by which green tea components suppress the development and recurrence of breast cancer. A better understanding of the mechanisms will improve the utilization of green tea in breast cancer prevention and therapy and pave the way to novel prevention and treatment strategies for breast cancer. PMID:25114865

  12. [Climate suitability for tea growing in Zhejiang Province].

    PubMed

    Jin, Zhi-Feng; Ye, Jian-Gang; Yang, Zai-Qiang; Sun, Rui; Hu, Bo; Li, Ren-Zhong

    2014-04-01

    It is important to quantitatively assess the climate suitability of tea and its response to climate change. Based on meteorological indices of tea growth and daily meteorological data from 1971 to 2010 in Zhejiang Province, three climate suitability models for single climate factors, including temperature, precipitation and sunshine, were established at a 10-day scale by using the fuzzy mathematics method, and a comprehensive climate suitability model was established with the geometric average method. The results indicated that the climate suitability was high in the tea growth season in Zhejiang Province, and the three kinds of climate suitability were all higher than 0.6. As for the single factor climate suitability, temperature suitability was the highest and sunshine suitability was the lowest. There were obvious inter-annual variations of tea climate suitability, with a decline trend in the 1970s, less variation in the 1980s, and an obvious incline trend after the 1990s. The change tendency of climate suitability for spring tea was similar with that of annual climate suitability, lower in the 1980s, higher in the 1970s and after the 1990s. However, the variation amplitude of the climate suitability for spring tea was larger. The climate suitability for summer tea and autumn tea showed a decline trend from 1971 to 2010.

  13. Tea and health: preventive and therapeutic usefulness in the elderly?

    PubMed Central

    Bolling, Bradley W.; Chen, Chung-Yen Oliver; Blumberg, Jeffrey B.

    2016-01-01

    Purpose of review To update the growing literature suggesting that tea and its constituent flavonoids are inversely related to the risk of chronic diseases common among the elderly. Recent findings Results are provided from recent observational studies and clinical trials on the relationship of tea and tea catechins to body weight control and energy metabolism, impaired glucose tolerance and diabetes, cardiovascular disease, bone mineral density, cognitive function and neurodegenerative disease, and cancer. The evidence for the efficacy and potency of tea and tea extracts in benefiting these outcomes ranges from compelling for cardiovascular disease to equivocal at best for some forms of cancer. Summary Although randomized clinical trials of tea have generally been of short duration and with small sample sizes, together with experimental and epidemiological studies, the totality of the data suggests a role for tea in health promotion as a beverage absent in calories and rich in phytochemicals. Further research is warranted on the putative benefits of tea and the potential for synergy among its constituent flavonoids, l-theanine, and caffeine. PMID:19057186

  14. Green tea in dermatology--myths and facts.

    PubMed

    Zink, Alexander; Traidl-Hoffmann, Claudia

    2015-08-01

    Green tea consumption has a long tradition in Asian countries--especially China. The epidemiologically and experimentally observed anticarcinogenic and antiinflammatory effects of green tea have led to the implementation of green tea extracts in multiple therapeutic applications - both in dermatological and cosmeceutical preparations. The most abundant evidence exists for the anticarcinogenic and chemopreventive effect of green tea or its major constituent epigallocatechin-3-gallate. Almost equally evident is the effect in infectious diseases such as cutaneous viral infections. For external genital warts, a topical ointment with green tea extracts was licensed in the USA in 2010, and recently also in Europe. Experimental evidence pinpointing the block of central signal transduction factors in inflammatory mechanisms has led to the evaluation of catechins in inflammatory disorders such as atopic dermatitis. The belief of green tea as a "wonder weapon" against diseases dates back thousands of years. According to a Chinese legend, ancient Emperor Shen Nung noted a delightful aroma after some leaves of a nearby tree had fallen into boiling water. He immediately proclaimed the new "drink" as "heaven-sent", starting the belief - persisting until today - of green tea as a medication from nature against many different diseases. This review summarizes biological effects and clinical implications of green tea.

  15. Antiobesity effects of Chinese black tea (Pu-erh tea) extract and gallic acid.

    PubMed

    Oi, Yasuyuki; Hou, I-Ching; Fujita, Hiroyuki; Yazawa, Kazunaga

    2012-04-01

    The antiobesity effects of Chinese black tea (Pu-erh tea) and of gallic acid (GA) were investigated using in vitro and in vivo assays. Chinese black tea extract (BTE) and GA inhibited pancreatic lipase activity in a dose-dependent manner in vitro; the IC(inhibitory concentration)(50) values were 101.6 and 9.2 µg/mL, respectively. Black tea extract (50, 100 mg/kg body weight (b.w.)) and GA (15, 45 mg/kg b.w.) significantly suppressed the elevation of blood triglyceride after oral administration of a corn oil emulsion (8 mL oil/kg b.w.) to male ddY mice. Moreover, the antiobesity effects of BTE and GA were also evaluated in a mouse model of diet-induced obesity. Female ddY mice were divided into seven groups; normal diet (ND) group, high fat diet (HFD) group, BTE (0.2% and 0.6% of diets) groups, and GA (0.007%, 0.02% and 0.1% of diets) groups; the experimental groups were fed the test diets for 12 weeks. The BTE 0.6% and GA 0.1% groups showed significant suppression of weight gain. The weight of parametrial adipose tissue was strongly correlated with the body weight. These results suggest that GA contributes to the antiobesity effect of BTE as an active constituent by inhibiting pancreatic lipase activity.

  16. Tea and Parkinson's disease: Constituents of tea synergize with antiparkinsonian drugs to provide better therapeutic benefits.

    PubMed

    Dutta, Debashis; Mohanakumar, Kochupurackal P

    2015-10-01

    The major neurodegenerative movement disorder Parkinson's disease (PD) is characterized by rest-tremor, akinesia, rigidity and inability to initiate movements. PD syndromes result from excessive loss of dopamine from the forebrain striatal region, due to dopaminergic neuronal death in the midbrain substantia nigra pars compacta. PD with multifactorial etiology is believed to ideally require a drug or different drugs that act(s) at multiple sites of action for symptomatic relief. Replenishing striatal dopamine by providing L-3,4-dihydroxyphenylalanine (l-DOPA) along with a peripheral aromatic amino acid decarboxylase inhibitor is the mainstay treatment for PD. Such prolonged therapy leads to debilitating effects, often worsening the affection. Interestingly some under-appreciated pharmaceutical compounds, including constituents of plants and nutraceuticals can synergize with l-DOPA to support mitochondrial function, suppress inflammation, ease oxidative stress, and in turn slow the progression of the disease. Tea and other dietary polyphenols are shown to provide relief to the disease syndromes and provide neuroprotection in cellular and animal models of PD. At par with these findings, random epidemiological studies in certain populations of the world support habitual tea drinking to reduce the risk of PD. The present review addresses how these tea constituents work at the cellular level to render effective control of the disease syndromes and suggests that tea synergizes with established drugs, such as l-DOPA to maximize their effects at certain levels in the disease phenotype-inducing canonical pathways of PD. PMID:26271432

  17. Tea and Parkinson's disease: Constituents of tea synergize with antiparkinsonian drugs to provide better therapeutic benefits.

    PubMed

    Dutta, Debashis; Mohanakumar, Kochupurackal P

    2015-10-01

    The major neurodegenerative movement disorder Parkinson's disease (PD) is characterized by rest-tremor, akinesia, rigidity and inability to initiate movements. PD syndromes result from excessive loss of dopamine from the forebrain striatal region, due to dopaminergic neuronal death in the midbrain substantia nigra pars compacta. PD with multifactorial etiology is believed to ideally require a drug or different drugs that act(s) at multiple sites of action for symptomatic relief. Replenishing striatal dopamine by providing L-3,4-dihydroxyphenylalanine (l-DOPA) along with a peripheral aromatic amino acid decarboxylase inhibitor is the mainstay treatment for PD. Such prolonged therapy leads to debilitating effects, often worsening the affection. Interestingly some under-appreciated pharmaceutical compounds, including constituents of plants and nutraceuticals can synergize with l-DOPA to support mitochondrial function, suppress inflammation, ease oxidative stress, and in turn slow the progression of the disease. Tea and other dietary polyphenols are shown to provide relief to the disease syndromes and provide neuroprotection in cellular and animal models of PD. At par with these findings, random epidemiological studies in certain populations of the world support habitual tea drinking to reduce the risk of PD. The present review addresses how these tea constituents work at the cellular level to render effective control of the disease syndromes and suggests that tea synergizes with established drugs, such as l-DOPA to maximize their effects at certain levels in the disease phenotype-inducing canonical pathways of PD.

  18. Effect of microbial fermentation on caffeine content of tea leaves.

    PubMed

    Wang, Xiaogang; Hu, Shuxia; Wan, Xiaochun; Pan, Caiyuan

    2005-09-01

    Caffeine is widely used in the food and pharmaceutical industries. For safety concerns, natural caffeine is preferred over synthetic products despite of its high cost. To explore more economical methods of acquiring natural caffeine, we adopted a microbial fermentation technique to increase the caffeine content of tea leaves. Our studies showed that the caffeine content in tea leaves increased reasonably after treating leaves with microorganisms for a period of time (i.e. orthodox pile-fermentation), and the amount of caffeine content increase varied significantly between black and green teas (27.57% and 86.41%). These results suggested that the change of caffeine content in tea leaves during the pile-fermentation depended not only on the growth and reproduction of microorganisms, but also on the tea composition.

  19. Coffee, tea, and cocoa and risk of stroke.

    PubMed

    Larsson, Susanna C

    2014-01-01

    Current evidence from experimental studies in animals and humans along with findings from prospective studies indicates beneficial effects of green and black tea as well as chocolate on cardiovascular health, and that tea and chocolate consumption may reduce the risk of stroke. The strongest evidence exists for beneficial effects of tea and cocoa on endothelial function, total and LDL cholesterol (tea only), and insulin sensitivity (cocoa only). The majority of prospective studies have reported a weak inverse association between moderate consumption of coffee and risk of stroke. However, there are yet no clear biological mechanisms whereby coffee might provide cardiovascular health benefits. Awaiting the results from further long-term RCTs and prospective studies, moderate consumption of filtered coffee, tea, and dark chocolate seems prudent.

  20. Green tea catechins: a fresh flavor to anticancer therapy.

    PubMed

    Yu, Yang; Deng, Yuan; Lu, Bang-Min; Liu, Yong-Xi; Li, Jian; Bao, Jin-Ku

    2014-01-01

    Green tea catechins have been extensively studied for their cancer preventive effects. Accumulating evidence has shown that green tea catechins, like (-)-epigallocatechin-3-gallate, have strong anti-oxidant activity and affect several signal transduction pathways relevant to cancer development. Here, we review the biological properties of green tea catechins and the molecular mechanisms of their anticancer effects, including the suppression of cancer cell proliferation, induction of apoptosis, and inhibition of tumor metastasis and angiogenesis. We summarize the efficacy of a single catechin and the synergetic effects of multiple catechins. We also discuss the enhanced anticancer effects of green tea catechins when they are combined with anticancer drugs. The information present in this review might promote the development of strategy for the co-administration of green tea catechins with other anticancer drugs to increase the potency of currently available anticancer medicine. This new strategy should in turn lower the cytotoxicity and cost of anticancer treatment.

  1. Nuclear genetic defects of mitochondrial ATP synthase.

    PubMed

    Hejzlarová, K; Mráček, T; Vrbacký, M; Kaplanová, V; Karbanová, V; Nůsková, H; Pecina, P; Houštěk, J

    2014-01-01

    Disorders of ATP synthase, the key enzyme of mitochondrial energy provision belong to the most severe metabolic diseases presenting as early-onset mitochondrial encephalo-cardiomyopathies. Up to now, mutations in four nuclear genes were associated with isolated deficiency of ATP synthase. Two of them, ATP5A1 and ATP5E encode enzyme's structural subunits alpha and epsilon, respectively, while the other two ATPAF2 and TMEM70 encode specific ancillary factors that facilitate the biogenesis of ATP synthase. All these defects share a similar biochemical phenotype with pronounced decrease in the content of fully assembled and functional ATP synthase complex. However, substantial differences can be found in their frequency, molecular mechanism of pathogenesis, clinical manifestation as well as the course of the disease progression. While for TMEM70 the number of reported patients as well as spectrum of the mutations is steadily increasing, mutations in ATP5A1, ATP5E and ATPAF2 genes are very rare. Apparently, TMEM70 gene is highly prone to mutagenesis and this type of a rare mitochondrial disease has a rather frequent incidence. Here we present overview of individual reported cases of nuclear mutations in ATP synthase and discuss, how their analysis can improve our understanding of the enzyme biogenesis.

  2. An investigation into eukaryotic pseudouridine synthases.

    PubMed

    King, Ross D; Lu, Chuan

    2014-08-01

    A common post-transcriptional modification of RNA is the conversion of uridine to its isomer pseudouridine. We investigated the biological significance of eukaryotic pseudouridine synthases using the yeast Saccharomyces cerevisiae. We conducted a comprehensive statistical analysis on growth data from automated perturbation (gene deletion) experiments, and used bi-logistic curve analysis to characterise the yeast phenotypes. The deletant strains displayed different alteration in growth properties, including in some cases enhanced growth and/or biphasic growth curves not seen in wild-type strains under matched conditions. These results demonstrate that disrupting pseudouridine synthases can have a significant qualitative effect on growth. We further investigated the significance of post-transcriptional pseudouridine modification through investigation of the scientific literature. We found that (1) In Toxoplasma gondii, a pseudouridine synthase gene is critical in cellular differentiation between the two asexual forms: Tachyzoites and bradyzoites; (2) Mutation of pseudouridine synthase genes has also been implicated in human diseases (mitochondrial myopathy and sideroblastic anemia (MLASA); dyskeratosis congenita). Taken together, these results are consistent with pseudouridine synthases having a Gene Ontology function of "biological regulation".

  3. 19 CFR 12.33 - Importation of tea; entry; examination for customs purposes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 1 2013-04-01 2013-04-01 false Importation of tea; entry; examination for customs... SECURITY; DEPARTMENT OF THE TREASURY SPECIAL CLASSES OF MERCHANDISE Tea § 12.33 Importation of tea; entry; examination for customs purposes. (a) The importation of any merchandise as tea which is inferior in...

  4. 19 CFR 12.33 - Importation of tea; entry; examination for customs purposes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 1 2012-04-01 2012-04-01 false Importation of tea; entry; examination for customs... SECURITY; DEPARTMENT OF THE TREASURY SPECIAL CLASSES OF MERCHANDISE Tea § 12.33 Importation of tea; entry; examination for customs purposes. (a) The importation of any merchandise as tea which is inferior in...

  5. 19 CFR 12.33 - Importation of tea; entry; examination for customs purposes.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 1 2014-04-01 2014-04-01 false Importation of tea; entry; examination for customs... SECURITY; DEPARTMENT OF THE TREASURY SPECIAL CLASSES OF MERCHANDISE Tea § 12.33 Importation of tea; entry; examination for customs purposes. (a) The importation of any merchandise as tea which is inferior in...

  6. 19 CFR 12.33 - Importation of tea; entry; examination for customs purposes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Importation of tea; entry; examination for customs... SECURITY; DEPARTMENT OF THE TREASURY SPECIAL CLASSES OF MERCHANDISE Tea § 12.33 Importation of tea; entry; examination for customs purposes. (a) The importation of any merchandise as tea which is inferior in...

  7. 19 CFR 12.33 - Importation of tea; entry; examination for customs purposes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Importation of tea; entry; examination for customs... SECURITY; DEPARTMENT OF THE TREASURY SPECIAL CLASSES OF MERCHANDISE Tea § 12.33 Importation of tea; entry; examination for customs purposes. (a) The importation of any merchandise as tea which is inferior in...

  8. Molecular and Clinical Effects of Green Tea and Fermented Papaya Preparation on Diabetes and Cardiovascular Diseases

    ClinicalTrials.gov

    2014-11-14

    Assess the Effect of Green Tea on Diabetes; Assess the Effect of Fermented Papaya Pretration on Diabetes; Effects of Green Tea and FPP on C-reactive Proteins; Effects of Green Tea and FPP of Lipid Profiles in Diabetes; Effect of Green Tea and FPP on Atheroma Formation

  9. Medicinal benefits of green tea: Part I. Review of noncancer health benefits.

    PubMed

    Cooper, Raymond; Morré, D James; Morré, Dorothy M

    2005-06-01

    Tea, in the form of green or black tea, is one of the most widely consumed beverages in the world. Extracts of tea leaves also are sold as dietary supplements. However, with the increasing interest in the health properties of tea and a significant rise in scientific investigation, this review covers recent findings on the medicinal properties and noncancer health benefits of both green and black tea. In Part II, a review of anticancer properties of green tea extracts is presented. Green tea contains a unique set of catechins that possess biological activity in antioxidant, anti-angiogenesis, and antiproliferative assays potentially relevant to the prevention and treatment of various forms of cancer. Although there has been much focus on the biological properties of the major tea catechin epigallocatechin gallate (EGCg) and its antitumor properties, tea offers other health benefits; some due to the presence of other important constituents. Characteristics unrelated to the antioxidant properties of green and black teas may be responsible for tea's anticancer activity and improvement in cardiac health and atherosclerosis. Theanine in green tea may play a role in reducing stress. Oxidized catechins (theaflavins in black tea) may reduce cholesterol levels in blood. Synergistic properties of green tea extracts with other sources of polyphenolic constituents are increasingly recognized as being potentially important to the medicinal benefits of black and green teas. Furthermore, due to presumed antioxidant and antiaging properties, tea is now finding its way into topical preparations. Each of these aspects is surveyed.

  10. Tea and flavonoids: where we are, where to go next.

    PubMed

    Dwyer, Johanna T; Peterson, Julia

    2013-12-01

    There is a need to evaluate the evidence about the health effects of tea flavonoids and to provide valid, specific, and actionable tea consumption information to consumers. Emerging evidence suggests that the flavonoids in tea may be associated with beneficial health outcomes, whereas the benefits and risks of tea extracts and supplements are less well known. The next steps in developing tea science should include a focus on the most promising leads, such as reducing the risk of cardiovascular disease and stroke, rather than pursuing smaller, more diffuse studies of many different health outcomes. Future tea research should also include the use of common reference standards, better characterization of intervention products, and application of batteries of biomarkers of intakes and outcomes across studies, which will allow a common body of evidence to be developed. Mechanistic studies should determine which tea bioactive constituents have effects, whether they act alone or in combination, and how they influence health. Clinical studies should use well-characterized test products, better descriptions of baseline diets, and validated biomarkers of intake and disease risk reduction. There should be more attention to careful safety monitoring and adverse event reporting. Epidemiologic investigations should be of sufficient size and duration to detect small effects, involve populations most likely to benefit, use more complete tea exposure assessment, and include both intermediary markers of risk as well as morbidity and mortality outcomes. The construction of a strong foundation of scientific evidence on tea and health outcomes is essential for developing more specific and actionable messages on tea for consumers.

  11. Mechanistic findings of green tea as cancer preventive for humans.

    PubMed

    Fujiki, H; Suganuma, M; Okabe, S; Sueoka, E; Suga, K; Imai, K; Nakachi, K; Kimura, S

    1999-04-01

    Based on our initial work with green tea, in which repeated topical applications of (-)-epigallocatechin gallate (EGCG), the main green tea polyphenol, inhibited tumor promotion in a two-stage carcinogenesis experiment on mouse skin (Phytother Res 1, 44-47, 1987), numerous scientists have since provided so much additional evidence of the benefits of drinking green tea that it is now an acknowledged cancer preventive in Japan, and will possibly soon be recognized as such in other countries. Our work has so far produced several important results with EGCG and green tea: a wide range of target organs in animal experiments for cancer prevention, wide bioavailability of 3H-EGCG in various organs of mice, delayed cancer onset of patients with a history of consuming over 10 cups of green tea per day, and absence of any severe adverse effects among volunteers who took 15 green tea tablets per day (2.25 g green tea extracts, 337.5 mg EGCG, and 135 mg caffeine) for 6 months. This paper introduces three new findings: 1) EGCG interacted with the phospholipid bilayer membrane resulting in confirmation of the sealing effect of EGCG; 2) EGCG inhibited TNF-alpha gene expression in the cells and TNF-alpha release from the cells; 3) high consumption of green tea was closely associated with decreased numbers of axillary lymph node metastases among premenopausal Stage I and II breast cancer patients, and with increased expression of progesterone and estrogen receptors among postmenopausal ones. These results provide new insights into our understanding of the mechanisms of action of tea polyphenols and green tea extract as a cancer preventive.

  12. Tea Consumption and Mortality Among Oldest-Old Chinese

    PubMed Central

    Ruan, Rongping; Feng, Lei; Li, Jialiang; Ng, Tze-Pin; Zeng, Yi

    2013-01-01

    Objectives To investigate the association between tea consumption and mortality among oldest-old Chinese. Design Population-based longitudinal data from The Chinese Longitudinal Healthy Longevity Survey (CLHLS) was analyzed using Cox semi-parametric proportional hazard model. Setting 631 randomly selected counties and cities of China’s 22 provinces. Participants 9,093 old adults aged 80 and above who provided complete data at baseline survey (year 1998). Measurements Self-reported current frequency of tea drinking and past frequency around age 60 were ascertained at baseline survey, and follow-up survey was conducted respectively in years 2000, 2002 and 2005. Results Among oldest-old Chinese, tea consumption was associated with reduced risk of mortality after adjusting for demographic characteristics, socioeconomic status, health practices, and health status. Compared with non-tea drinkers, the adjusted hazard ratio (HR) was 0.90 (95% CI 0.84–0.96) for daily tea drinkers (at the baseline survey, 1998) and 1.00 (95% CI 1.01–1.07) for occasional tea drinkers respectively (P for linear trend=0.003). Similar results were found when tea drinking status around age 60 was used in analysis. Further analysis showed that compared to consistently infrequent tea drinkers, subjects who reported frequent tea drinking at both age 60 and at baseline survey had a 10% reduction in mortality (HR=0.90, 95%CI 0.84–0.97). Conclusion Tea consumption is associated reduced risk of mortality among oldest-old Chinese. PMID:24117374

  13. Tea, Coffee, and Milk Consumption and Colorectal Cancer Risk

    PubMed Central

    Green, Chadwick John; de Dauwe, Palina; Boyle, Terry; Tabatabaei, Seyed Mehdi; Fritschi, Lin; Heyworth, Jane Shirley

    2014-01-01

    Background Data regarding the effects of tea, coffee, and milk on the risk of colorectal cancer are inconsistent. We investigated associations of tea, coffee, and milk consumption with colorectal cancer risk and attempted to determine if these exposures were differentially associated with the risks of proximal colon, distal colon, and rectal cancers. Methods Data from 854 incident cases and 948 controls were analyzed in a case-control study of colorectal cancer in Western Australia during 2005–07. Multivariable logistic regression was used to analyze the associations of black tea (with and without milk), green tea, herbal tea, hot coffee, iced coffee, and milk with colorectal cancer. Results Consumption of 1 or more cups of herbal tea per week was associated with a significantly decreased risk of distal colon cancer (adjusted odds ratio, 0.37; 95% CI, 0.16–0.82; PTrend = 0.044), and consumption of 1 or more cups of iced coffee per week was associated with increased risk of rectal cancer (adjusted odds ratio, 1.52; 95% CI, 0.91–2.54; PTrend = 0.004). Neither herbal tea nor iced coffee was associated with the risk of proximal colon cancer. Hot coffee was associated with a possible increased risk of distal colon cancer. Black tea (with or without milk), green tea, decaffeinated coffee, and milk were not significantly associated with colorectal cancer risk. Conclusions Consumption of herbal tea was associated with reduced risk of distal colon cancer, and consumption of iced coffee was associated with increased rectal cancer risk. PMID:24531002

  14. Inhibition of gastrointestinal lipolysis by green tea, coffee, and gomchui (Ligularia fischeri) tea polyphenols during simulated digestion.

    PubMed

    Cha, Kwang Hyun; Song, Dae-Geun; Kim, Sang Min; Pan, Cheol-Ho

    2012-07-25

    Green tea, coffee, and gomchui (Ligularia fischeri) tea, which are rich in polyphenols, may exhibit antiobesity effects by inhibiting pancreatic lipase. However, the bioavailability of some polyphenols is poor due to either degradation or absorption difficulties in the gastrointestinal tract, thus making their beneficial effects doubtful. This study was conducted to evaluate the inhibitory effect of three beverages on lipolysis and the contribution of their major polyphenols during simulated digestion. During simulated digestion, gomchui tea was the most potent at inhibiting gastrointestinal lipolysis, whereas green tea was the least potent. The strongest lipase inhibitor among purified major polyphenols was a green tea polyphenol, (-)-epigallocatechin gallate (EGCG, IC(50) = 1.8 ± 0.57 μM), followed by di-O-caffeoylquinic acid isomers (DCQA, IC(50) from 12.7 ± 4.5 to 40.4 ± 2.3 μM), which are gomchui tea polyphenols. However, the stability of DCQA was greater than that of EGCG when subjected to simulated digestion. Taken together, gomchui tea, which has DCQA as the major polyphenol, showed stronger lipolysis inhibitory activity during simulated digestion compared to both green tea and coffee.

  15. Regurgitant derived from the tea geometrid Ectropis obliqua suppresses wound-induced polyphenol oxidases activity in tea plants.

    PubMed

    Yang, Zi-Wei; Duan, Xiao-Na; Jin, Shan; Li, Xi-Wang; Chen, Zong-Mao; Ren, Bing-Zhong; Sun, Xiao-Ling

    2013-06-01

    Polyphenol oxidases (PPOs) have been reported to play an important role in protecting plants from attack by herbivores. However, little is known about their role in tea. Here, we investigated the effect of PPOs on interactions between tea plants and the tea geometrid Ectropis obliqua, one of the most important insect pests of tea. Jasmonic acid (JA) treatment resulted in increases in PPO activity, and the effect of JA was dose dependent. Ectropis obliqua caterpillars grew and developed more slowly on JA-treated tea plants than on control plants, and larval weight gains depended on the JA dosage. Artificial diet complemented with PPOs reduced the growth and survival rate of E. obliqua caterpillars, and there was a negative relationship between PPO level and larval growth and survival. Unlike mechanical wounding, which is an effective inducer of tea plant PPO activity, wounding plus the herbivore regurgitant or herbivore infestation suppressed the wound-induced PPO activities, especially at 4 days after treatment. These results suggest that PPOs are an important anti-herbivore factor in tea plants, defending them against E. obliqua larvae, and that E. obliqua larvae have evolved to elude the tea plant's defense by inhibiting the production of PPOs.

  16. Inhibition of gastrointestinal lipolysis by green tea, coffee, and gomchui (Ligularia fischeri) tea polyphenols during simulated digestion.

    PubMed

    Cha, Kwang Hyun; Song, Dae-Geun; Kim, Sang Min; Pan, Cheol-Ho

    2012-07-25

    Green tea, coffee, and gomchui (Ligularia fischeri) tea, which are rich in polyphenols, may exhibit antiobesity effects by inhibiting pancreatic lipase. However, the bioavailability of some polyphenols is poor due to either degradation or absorption difficulties in the gastrointestinal tract, thus making their beneficial effects doubtful. This study was conducted to evaluate the inhibitory effect of three beverages on lipolysis and the contribution of their major polyphenols during simulated digestion. During simulated digestion, gomchui tea was the most potent at inhibiting gastrointestinal lipolysis, whereas green tea was the least potent. The strongest lipase inhibitor among purified major polyphenols was a green tea polyphenol, (-)-epigallocatechin gallate (EGCG, IC(50) = 1.8 ± 0.57 μM), followed by di-O-caffeoylquinic acid isomers (DCQA, IC(50) from 12.7 ± 4.5 to 40.4 ± 2.3 μM), which are gomchui tea polyphenols. However, the stability of DCQA was greater than that of EGCG when subjected to simulated digestion. Taken together, gomchui tea, which has DCQA as the major polyphenol, showed stronger lipolysis inhibitory activity during simulated digestion compared to both green tea and coffee. PMID:22730927

  17. (17)O NMR and Raman Spectroscopies of Green Tea Infusion with Nanomaterial to Investigate Their Properties.

    PubMed

    Zhou, Changyan; Zhang, Huiping; Yan, Ying; Zhang, Xinya

    2016-09-01

    (17)O NMR and Raman spectrograms of green tea infusions with nanomaterial were investigated. Different green tea infusions were prepared by steeping tea powder with different concentrations of nanomaterial aqueous solution. The tea infusions were tested with (17)O NMR and Raman spectroscopies. The (17)O NMR results showed that line width increased to 90 in the tea infusions after nanomaterial was added as a result of the effects of the self-association of Ca(2+) and tea polyphenol. The results of Raman spectroscopy showed that, in tea infusions, the enhancement of C─C and C─O stretching vibrations suggest an increase in the number of effective components in water.

  18. Exploring biosynthetic diversity with trichodiene synthase.

    PubMed

    Vedula, L Sangeetha; Zhao, Yuxin; Coates, Robert M; Koyama, Tanetoshi; Cane, David E; Christianson, David W

    2007-10-15

    Trichodiene synthase is a terpenoid cyclase that catalyzes the cyclization of farnesyl diphosphate (FPP) to form the bicyclic sesquiterpene hydrocarbon trichodiene (89%), at least five sesquiterpene side products (11%), and inorganic pyrophosphate (PP(i)). Incubation of trichodiene synthase with 2-fluorofarnesyl diphosphate or 4-methylfarnesyl diphosphate similarly yields sesquiterpene mixtures despite the electronic effects or steric bulk introduced by substrate derivatization. The versatility of the enzyme is also demonstrated in the 2.85A resolution X-ray crystal structure of the complex with Mg(2+) (3)-PP(i) and the benzyl triethylammonium cation, which is a bulkier mimic of the bisabolyl carbocation intermediate in catalysis. Taken together, these findings show that the active site of trichodiene synthase is sufficiently flexible to accommodate bulkier and electronically-diverse substrates and intermediates, which could indicate additional potential for the biosynthetic utility of this terpenoid cyclase. PMID:17678871

  19. Cellulose Synthase Complexes: Composition and Regulation

    PubMed Central

    Lei, Lei; Li, Shundai; Gu, Ying

    2012-01-01

    Live cell imaging has greatly advanced our knowledge on the molecular mechanism by which cellulose is deposited. Both the actin and microtubule cytoskeleton are involved in assuring the proper distribution, organization, and dynamics of cellulose synthase complexes (CSCs). This review is an update on the most recent progress on the characterization of the composition, regulation, and trafficking of CSCs. With the newly identified cellulose synthase interactive protein 1 (CSI1) on hand, we begin to unveil the mystery of an intimate relationship between cellulose microfibrils and microtubules. PMID:22639663

  20. Capillary electrophoretic determination of theanine, caffeine, and catechins in fresh tea leaves and oolong tea and their effects on rat neurosphere adhesion and migration.

    PubMed

    Chen, Chia-Nan; Liang, Chia-Min; Lai, Jueng-Rong; Tsai, Yao-Jen; Tsay, Jyh-Shyan; Lin, Jen-Kun

    2003-12-01

    Theanine, caffeine, and catechins in fresh tea leaves and oolong tea were determined by using capillary electrophoresis (CE). CE separated these tea polyphenols from three other tea ingredients, namely, caffeine, theophylline, and theanine, within 8 min. The young leaves (apical bud and the two youngest leaves) were found to be richer in caffeine, (-)-epigallocatechin gallate (EGCg), and (-)-epicatechin gallate (ECg) than old leaves (from 5th to 7th leaves). On the other hand, the old leaves (from 8th to 10th leaves) contained higher levels of theanine, (-)-epigallocatechin (EGC), and (-)-epicatechin (EC). Results from a comparison of fresh young tea and oolong tea compositions indicated oolong tea contained more theanine and catechins than fresh young tea. Furthermore, it was found that the levels of theanine, EGC, and EGCg in young leaves rose markedly with the withering process. Caffeine did not markedly change. However, fully or partially fermented teas (oolong tea or pauchong tea) have a common initial step in the withering process. Fresh tea leaves or oolong tea extract (0.1%, w/v) markedly inhibited neurosphere adhesion, cell migration, and neurite outgrowth in rat neurospheres. Theanine (348 micrograms/mL) and caffeine at high concentration (50 micrograms/mL) did not inhibit neurosphere adhesion or migration activities, but EGCg at 20 micrograms/mL effectively inhibited neurosphere adhesion for 24 h. These results indicated that EGCg might affect neural stem cell survival or differentiation.

  1. Homology study of two polyhydroxyalkanoate (PHA) synthases from Pseudomonas aureofaciens.

    PubMed

    Umeda, F; Nishikawa, T; Miyasaka, H; Maeda, I; Kawase, M; Yagi, K

    2001-11-01

    Recently, we have cloned and analyzed two polyhydroxyalkanoate (PHA) synthase genes (phaC1 and phaC2 in the pha cluster) from Pseudomonas aureofaciens. In this report, the deduced amino acid (AA) sequences of PHA synthase 1 and PHA synthase 2 from P. aureofaciens are compared with those from three other bacterial strains (Pseudomonas sp. 61-3, P. oleovorans and P. aeruginosa) containing the homologous pha cluster. The level of homology of either PHA synthase 1 or PHA synthase 2 was high with each enzyme from these three bacterial strains. Furthermore, multialignment of PHA synthase AA sequences implied that both enzymes of PHA synthase 1 and PHA synthase 2 were highly conserved in the four strains including P. aureofaciens. PMID:11916262

  2. Structural Properties of Green Tea Catechins.

    PubMed

    Botten, Dominic; Fugallo, Giorgia; Fraternali, Franca; Molteni, Carla

    2015-10-01

    Green tea catechins are polyphenols which are believed to provide health benefits; they are marketed as health supplements and are studied for their potential effects on a variety of medical conditions. However, their mechanisms of action and interaction with the environment at the molecular level are still not well-understood. Here, by means of atomistic simulations, we explore the structural properties of four green tea catechins, in the gas phase and water solution: specifically, (-)-epigallocatechin-3-gallate, which is the most abundant, (-)-epicatechin-3-gallate, (-)-epigallocatechin-3-O-(3-O-methyl)-gallate, and (-)-epigallocatechin. We characterize the free energy conformational landscapes of these catechins at ambient conditions, as a function of the torsional degrees of freedom of the pholyphenolic rings, determining the stable conformers and their connections. We show that these free energy landscapes are only subtly influenced by the interactions with the solvent and by the structural details of the polyphenolic rings. However, the number and position of the hydroxyl groups (or their sustituents) and the presence/absence of the galloyl moiety have significant impact on the selected catechin solvation shells and hydrogen bond capabilities, which are ultimately linked to their ability to interact with and affect the biological environment. PMID:26369298

  3. Tea and bone health: steps forward in translational nutrition.

    PubMed

    Shen, Chwan-Li; Chyu, Ming-Chien; Wang, Jia-Sheng

    2013-12-01

    Osteoporosis is a major health problem in the aging population worldwide. Cross-sectional and retrospective evidence indicates that tea consumption may be a promising approach in mitigating bone loss and in reducing risk of osteoporotic fractures among older adults. Tea polyphenols enhance osteoblastogenesis and suppress osteoclastogenesis in vitro. Animal studies reveal that intake of tea polyphenols have pronounced positive effects on bone as shown by higher bone mass and trabecular bone volume, number, and thickness and lower trabecular separation via increasing bone formation and inhibition of bone resorption, resulting in greater bone strength. These osteoprotective effects appear to be mediated through antioxidant or antiinflammatory pathways along with their downstream signaling mechanisms. A short-term clinical trial of green tea polyphenols has translated the findings from ovariectomized animals to postmenopausal osteopenic women through evaluation of bioavailability, safety, bone turnover markers, muscle strength, and quality of life. For future studies, preclinical animal studies to optimize the dose of tea polyphenols for maximum osteoprotective efficacy and a follow-up short-term dose-response trial in postmenopausal osteopenic women are necessary to inform the design of randomized controlled studies in at-risk populations. Advanced imaging technology should also contribute to determining the effective dose of tea polyphenols in achieving better bone mass, microarchitecture integrity, and bone strength, which are critical steps for translating the putative benefit of tea consumption in osteoporosis management into clinical practice and dietary guidelines.

  4. Associations of tea and coffee consumption with prostate cancer risk

    PubMed Central

    Geybels, Milan S.; Neuhouser, Marian L.; Stanford, Janet L.

    2013-01-01

    Purpose: Tea and coffee contain bioactive compounds and both beverages have recently been associated with a reduced risk of prostate cancer (PCa). Methods: We studied associations of tea and coffee consumption with PCa risk in a population-based case-control study from King County, Washington, US. Prostate cancer cases were diagnosed in 2002-2005 and matched to controls by five-year age groups. Logistic regression was used to generate odds ratios (ORs) and 95% confidence intervals (CIs). Results: Among controls, 19% and 58% consumed at least one cup per day of tea and coffee, respectively. The analysis of tea included 892 cases and 863 controls and tea consumption was associated with a reduced overall PCa risk with an adjusted OR of 0.63 (95% CI: 0.45, 0.90; P for trend = 0.02) for men in the highest compared to lowest category of tea intake (≥2 cups/day versus ≤1 cup/week). Risk estimates did not vary substantially by Gleason grade or disease stage. Coffee consumption was not associated with risk of overall PCa or PCa in subgroups defined by tumor grade or stage. Conclusions: Our results contribute further evidence that tea consumption may be a modifiable exposure that reduces PCa risk. PMID:23412806

  5. Green tea and anticancer perspectives: updates from last decade.

    PubMed

    Butt, Masood Sadiq; Ahmad, Rabia Shabir; Sultan, M Tauseef; Qayyum, Mir M Nasir; Naz, Ambreen

    2015-01-01

    Green tea is the most widely consumed beverage besides water and has attained significant attention owing to health benefits against array of maladies, e.g., obesity, diabetes mellitus, cardiovascular disorders, and cancer insurgence. The major bioactive molecules are epigallocatechin-3-gallate, epicatechin, epicatechin-3-gallate, epigallocatechin, etc. The anticarcinogenic and antimutagenic activities of green tea were highlighted some years ago. Several cohort studies and controlled randomized trials suggested the inverse association of green tea consumption and cancer prevalence. Cell culture and animal studies depicted the mechanisms of green tea to control cancer insurgence, i.e., induction of apoptosis to control cell growth arrest, altered expression of cell-cycle regulatory proteins, activation of killer caspases, and suppression of nuclear factor kappa-B activation. It acts as carcinoma blocker by modulating the signal transduction pathways involved in cell proliferation, transformation, inflammation, and metastasis. However, results generated from some research interventions conducted in different groups like smokers and nonsmokers, etc. contradicted with aforementioned anticancer perspectives. In this review paper, anticancer perspectives of green tea and its components have been described. Recent findings and literature have been surfed and arguments are presented to clarify the ambiguities regarding anticancer perspectives of green tea and its component especially against colon, skin, lung, prostate, and breast cancer. The heading of discussion and future trends is limelight of the manuscript. The compiled manuscript provides new avenues for researchers to be explored in relation to green tea and its bioactive components.

  6. Pyridine metabolism in tea plants: salvage, conjugate formation and catabolism.

    PubMed

    Ashihara, Hiroshi; Deng, Wei-Wei

    2012-11-01

    Pyridine compounds, including nicotinic acid and nicotinamide, are key metabolites of both the salvage pathway for NAD and the biosynthesis of related secondary compounds. We examined the in situ metabolic fate of [carbonyl-(14)C]nicotinamide, [2-(14)C]nicotinic acid and [carboxyl-(14)C]nicotinic acid riboside in tissue segments of tea (Camellia sinensis) plants, and determined the activity of enzymes involved in pyridine metabolism in protein extracts from young tea leaves. Exogenously supplied (14)C-labelled nicotinamide was readily converted to nicotinic acid, and some nicotinic acid was salvaged to nicotinic acid mononucleotide and then utilized for the synthesis of NAD and NADP. The nicotinic acid riboside salvage pathway discovered recently in mungbean cotyledons is also operative in tea leaves. Nicotinic acid was converted to nicotinic acid N-glucoside, but not to trigonelline (N-methylnicotinic acid), in any part of tea seedlings. Active catabolism of nicotinic acid was observed in tea leaves. The fate of [2-(14)C]nicotinic acid indicates that glutaric acid is a major catabolite of nicotinic acid; it was further metabolised, and carbon atoms were finally released as CO(2). The catabolic pathway observed in tea leaves appears to start with the nicotinic acid N-glucoside formation; this pathway differs from catabolic pathways observed in microorganisms. Profiles of pyridine metabolism in tea plants are discussed. PMID:22527843

  7. Race, ideology, and the tea party: a longitudinal study.

    PubMed

    Knowles, Eric D; Lowery, Brian S; Shulman, Elizabeth P; Schaumberg, Rebecca L

    2013-01-01

    The Tea Party movement, which rose to prominence in the United States after the election of President Barack Obama, provides an ideal context in which to examine the roles of racial concerns and ideology in politics. A three-wave longitudinal study tracked changes in White Americans' self-identification with the Tea Party, racial concerns (prejudice and racial identification), and ideologies (libertarianism and social conservatism) over nine months. Latent Growth Modeling (LGM) was used to evaluate potential causal relationships between Tea Party identification and these factors. Across time points, racial prejudice was indirectly associated with movement identification through Whites' assertions of national decline. Although initial levels of White identity did not predict change in Tea Party identification, initial levels of Tea Party identification predicted increases in White identity over the study period. Across the three assessments, support for the Tea Party fell among libertarians, but rose among social conservatives. Results are discussed in terms of legitimation theories of prejudice, the "racializing" power of political judgments, and the ideological dynamics of the Tea Party.

  8. Green tea and the risk of gastric cancer: Epidemiological evidence

    PubMed Central

    Hou, I-Chun; Amarnani, Saral; Chong, Mok T; Bishayee, Anupam

    2013-01-01

    Gastric cancer (GC) is one of the leading causes of cancer death in the world. Numerous efforts are being made to find chemoprotective agents able to reduce its risk. Amongst these, green tea has been reported to have a protective effect against stomach cancer. This article aims to critically evaluate all epidemiological studies reporting an association between green tea consumption and GC risk. MEDLINE, EBSCOHOST and Google Scholar were used to search for clinical trials of green tea and its correlation to stomach cancer. Studies include cohort and case-control studies. Outcome of interests are inverse association, no association, and positive association. Seventeen epidemiologic studies were reviewed. Eleven studies were conducted in Japan, five in China, and one with Japanese descendent in Hawaii. Ten case-control studies and seven cohort studies were included. The relative risks or odds ratio of GC for the highest level of green tea consumption was compared. Seven studies suggested no association, eight an inverse association, and one a positive association. One study had shown a significantly lowered GC risk when tea was served warm to cold. Another study also showed a significantly risk with lukewarm tea. All studies that analyzed men and women separately have suggested a reduced risk in women than in men, albeit no significant difference. This review demonstrates that there is insufficient information to support green tea consumption reduces the risk of GC. More studies on the subject matter are warranted. PMID:23840110

  9. Race, Ideology, and the Tea Party: A Longitudinal Study

    PubMed Central

    Knowles, Eric D.; Lowery, Brian S.; Shulman, Elizabeth P.; Schaumberg, Rebecca L.

    2013-01-01

    The Tea Party movement, which rose to prominence in the United States after the election of President Barack Obama, provides an ideal context in which to examine the roles of racial concerns and ideology in politics. A three-wave longitudinal study tracked changes in White Americans’ self-identification with the Tea Party, racial concerns (prejudice and racial identification), and ideologies (libertarianism and social conservatism) over nine months. Latent Growth Modeling (LGM) was used to evaluate potential causal relationships between Tea Party identification and these factors. Across time points, racial prejudice was indirectly associated with movement identification through Whites’ assertions of national decline. Although initial levels of White identity did not predict change in Tea Party identification, initial levels of Tea Party identification predicted increases in White identity over the study period. Across the three assessments, support for the Tea Party fell among libertarians, but rose among social conservatives. Results are discussed in terms of legitimation theories of prejudice, the “racializing” power of political judgments, and the ideological dynamics of the Tea Party. PMID:23825630

  10. Race, ideology, and the tea party: a longitudinal study.

    PubMed

    Knowles, Eric D; Lowery, Brian S; Shulman, Elizabeth P; Schaumberg, Rebecca L

    2013-01-01

    The Tea Party movement, which rose to prominence in the United States after the election of President Barack Obama, provides an ideal context in which to examine the roles of racial concerns and ideology in politics. A three-wave longitudinal study tracked changes in White Americans' self-identification with the Tea Party, racial concerns (prejudice and racial identification), and ideologies (libertarianism and social conservatism) over nine months. Latent Growth Modeling (LGM) was used to evaluate potential causal relationships between Tea Party identification and these factors. Across time points, racial prejudice was indirectly associated with movement identification through Whites' assertions of national decline. Although initial levels of White identity did not predict change in Tea Party identification, initial levels of Tea Party identification predicted increases in White identity over the study period. Across the three assessments, support for the Tea Party fell among libertarians, but rose among social conservatives. Results are discussed in terms of legitimation theories of prejudice, the "racializing" power of political judgments, and the ideological dynamics of the Tea Party. PMID:23825630

  11. Radical scavenging conserves from unused fresh green tea leaves.

    PubMed

    Borse, B B; Kumar, H Vijay; Rao, L Jagan Mohan

    2007-03-01

    Green teas were made by inactivating the enzymes present in fresh leaves of coarse/pruned (unused) and normal (used for tea) grades using different sources of thermal energies. Green teas were extracted in a Soxhlet using different solvents. The obtained miscella was subjected to concentration to give the extract. The extract was subjected to solvent-solvent extraction. Solvent extract was concentrated to obtain conserve. The yields of conserves are 17 +/- 0.8 and 15 +/- 0.8% from green teas of normal and coarse tea leaves, respectively. The radical scavenging activity of these extracts was evaluated using a DPPH in vitro model system. The total polyphenol content was also determined and found to be higher in conserves from normal tea leaves. However, radical scavenging activity of conserves from coarse and normal green tea leaves was found to be >90% at 15 ppm concentration. The HPLC profiles of these conserves were used to quantify the total catechin content with the help of calibration curves prepared using authentic samples at known concentrations. The total catechin content is found to be in the range of 55-85%. Results indicated that the extracts from coarse leaves also possess potential biological activity and could be used as nutraceuticals as well as for preservation purposes in food formulations.

  12. Tea and bone health: steps forward in translational nutrition12345

    PubMed Central

    Chyu, Ming-Chien; Wang, Jia-Sheng

    2013-01-01

    Osteoporosis is a major health problem in the aging population worldwide. Cross-sectional and retrospective evidence indicates that tea consumption may be a promising approach in mitigating bone loss and in reducing risk of osteoporotic fractures among older adults. Tea polyphenols enhance osteoblastogenesis and suppress osteoclastogenesis in vitro. Animal studies reveal that intake of tea polyphenols have pronounced positive effects on bone as shown by higher bone mass and trabecular bone volume, number, and thickness and lower trabecular separation via increasing bone formation and inhibition of bone resorption, resulting in greater bone strength. These osteoprotective effects appear to be mediated through antioxidant or antiinflammatory pathways along with their downstream signaling mechanisms. A short-term clinical trial of green tea polyphenols has translated the findings from ovariectomized animals to postmenopausal osteopenic women through evaluation of bioavailability, safety, bone turnover markers, muscle strength, and quality of life. For future studies, preclinical animal studies to optimize the dose of tea polyphenols for maximum osteoprotective efficacy and a follow-up short-term dose-response trial in postmenopausal osteopenic women are necessary to inform the design of randomized controlled studies in at-risk populations. Advanced imaging technology should also contribute to determining the effective dose of tea polyphenols in achieving better bone mass, microarchitecture integrity, and bone strength, which are critical steps for translating the putative benefit of tea consumption in osteoporosis management into clinical practice and dietary guidelines. PMID:24172296

  13. Factors affecting tea consumption pattern in an urban society in Isfahan, Iran

    PubMed Central

    Rezaee, Elahe; Mirlohi, Maryam; Hassanzadeh, Akbar; Fallah, Azizolah

    2016-01-01

    Objective: To determine the tea consumption pattern in an urban society in Isfahan. Methods: A descriptive, cross-sectional survey was carried out using questioner among 664 households who were selected by two steps cluster sampling. A questionnaire was developed including demographic questions, information on the quantity of tea intake by every member of the family, tea type, and tea brand preference. Results: The individuals who prioritized black tea as their 1st choice were 90.1% of the total surveyed community. The average amount of tea consumed was calculated as 1243 ± 530 ml/day. The individuals who were between 36 and 45 and <15 years old were shown as the highest and the lowest tea consumers, respectively. Men significantly consumed more amount of tea than women did and married participants significantly used more amount of tea than singles (P < 0.05). The number of the family members, though, had no impact on tea consumption (P > 0.05). Brand preference of tea showed that the individuals who prioritized Ahmed brand as their 1st choice constituted 44% of the total participants. Conclusion: Tea consumption pattern in an Iranian sample is specific. Despite of the huge evidence on the green tea benefits, this type of tea has very low popularity and among the available black tea brands, the imported ones are the most preferred. PMID:27500166

  14. Trace element content in tea brewed in traditional metallic and stainless steel teapots.

    PubMed

    Petit, D; El Houari, W; Jacobs, K; Baeyens, W; Leermakers, M

    2013-11-01

    The migration of metals in tea brewed in metallic teapots was investigated. The teapots were obtained from North Africa stores in Brussels in 2005-2006 and in 2011. Chinese gunpowder green tea, the most commonly used tea in the Moroccan community, was used to prepare the tea. Tea brewed in metallic teapots was compared to tea brewed in a glass vessel in order to evaluate the contribution of the tea and the teapots to the metal concentrations in the brewed tea. Tea samples were also collected in Moroccan households and in tearooms in Brussels. The elements As, Cd, Pb, Sn, Mn, Fe, Cr, Co, Ni, Cr, Cu, Zn, and Al were analyzed by high-resolution sector field inductively coupled mass spectrometry. The relationship between the metal composition of the alloy of the teapot and the metal concentration in tea was also investigated. Migration of Pb and to a lesser amount Ni, Cu, and Zn was observed in brass teapots and migration of Cd from a number of stainless steel teapots was observed. The soldering connecting the sprout to the teapot was shown to be an important source of Pb to the tea. High levels of Mn and Al were also observed in the brewed tea and these elements where shown to originate from the tea itself. Metal exposure from tea drinking was calculated for different tea consumption levels and different metal concentration levels and compared to toxicological reference values.

  15. Correlation of In Vivo and In Vitro Assay Results for Assessment of Free Radical Scavenging Activity of Green Tea Nutraceuticals.

    PubMed

    Abd-ElSalam, Heba-Alla H; Al-Ghobashy, Medhat A; Al-Shorbagy, Muhammad; Nassar, Noha; Zaazaa, Hala E; Ibrahim, Mohamed A

    2016-07-01

    Green tea (GT)-derived catechins; epigallocatechin gallate (EGCG) in particular are commonly used nutraceuticals for their free-radical scavenging activity (FRSA). The influence of photodegradation on the protective power of GT nutracenticals against oxidative stress was thoroughly explored. Photodegradation of GT extracts was carried out and monitored using orthogonal stability-indicating testing protocol; in vitro and in vivo assays. Total polyphenol content (TPC) and FRSA were determined spectrophotometrically while EGCG was selectively monitored using SPE-HPLC. In vivo assessment of photodegraded samples was investigated via measuring a number of biomarkers for hepatic oxidative stress and apoptosis (caspase-3, inducible nitric oxide synthase, nitric oxide, mitogen-activated protein kinase, glutathione, thiobarbituric acid reactive substances, nuclear factor kappa beta, and nuclear factor erythroid 2-related factor) as well as liver damage (alanine transaminase and aspartate transaminase) in serum of rats previously subjected to oxidative stress. Results showed complete degradation of EGCG in photodegraded green tea samples with no correlation with either TPC or FRSA. On the other hand, in vivo assay results revealed not only loss of activity but formation of harmful pro-oxidants. Photostability was found crucial for the protective effect of GT extract against lead acetate insult. Results confirmed that careful design of quality control protocols requires correlation of chemical assays to bioassays to verify efficacy, stability, and most importantly safety of nutraceuticals.

  16. Molecular Cloning and Characterization of Spermine Synthesis Gene Associated with Cold Tolerance in Tea Plant (Camellia sinensis).

    PubMed

    Zhu, Xujun; Li, Qinghui; Hu, Jingyan; Wang, Mingle; Li, Xinghui

    2015-11-01

    Spermine synthase (SPMS, EC 2.5.1.22), enzyme of spermine (Spm) biosynthesis, has been shown to be related to stress response. In this study, attempts were made to clone and characterize a gene encoding SPMS from tea plant (Camellia sinensis). The effect of exogenous application of Spm in C. sinensis subjected to low-temperature stress was also investigated. A full-length SPMS complementary DNA (cDNA) (CsSPMS) with an open reading frame of 1113 bp was cloned using reverse transcription-PCR and rapid amplification of cDNA ends (RACE) techniques from cultivar "Yingshuang". The CsSPMS gene, which encoded a 371 amino acid polypeptide, in four cultivars is highly homologous. Quantitative real-time PCR indicated that the CsSPMS gene shows tissue-specific expression, mainly in the leaf and root of tea plant. The expression analysis demonstrated that the CsSPMS gene is quickly induced by cold stress and had similar trends in four cultivars. Spm-supplemented "Baicha" cultivar contains higher endogenous polyamines compared to the control, coupling with higher expression levels of ADC and SPMS. In addition, activities of peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), as well as free proline content in the Spm-supplemented samples were higher than the control during the experiment course or at a given time point, indicating that Spm exerted a positive effect on antioxidant systems. Moreover, Agrobacterium-mediated expression of CsSPMS in tobacco leaves showed relatively higher cold tolerance. Taken together, these findings will enhance the understanding of the relationships among CsSPMS gene regulatory, polyamines accumulation, and cold tolerance in tea plant.

  17. Molecular Cloning and Characterization of Spermine Synthesis Gene Associated with Cold Tolerance in Tea Plant (Camellia sinensis).

    PubMed

    Zhu, Xujun; Li, Qinghui; Hu, Jingyan; Wang, Mingle; Li, Xinghui

    2015-11-01

    Spermine synthase (SPMS, EC 2.5.1.22), enzyme of spermine (Spm) biosynthesis, has been shown to be related to stress response. In this study, attempts were made to clone and characterize a gene encoding SPMS from tea plant (Camellia sinensis). The effect of exogenous application of Spm in C. sinensis subjected to low-temperature stress was also investigated. A full-length SPMS complementary DNA (cDNA) (CsSPMS) with an open reading frame of 1113 bp was cloned using reverse transcription-PCR and rapid amplification of cDNA ends (RACE) techniques from cultivar "Yingshuang". The CsSPMS gene, which encoded a 371 amino acid polypeptide, in four cultivars is highly homologous. Quantitative real-time PCR indicated that the CsSPMS gene shows tissue-specific expression, mainly in the leaf and root of tea plant. The expression analysis demonstrated that the CsSPMS gene is quickly induced by cold stress and had similar trends in four cultivars. Spm-supplemented "Baicha" cultivar contains higher endogenous polyamines compared to the control, coupling with higher expression levels of ADC and SPMS. In addition, activities of peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), as well as free proline content in the Spm-supplemented samples were higher than the control during the experiment course or at a given time point, indicating that Spm exerted a positive effect on antioxidant systems. Moreover, Agrobacterium-mediated expression of CsSPMS in tobacco leaves showed relatively higher cold tolerance. Taken together, these findings will enhance the understanding of the relationships among CsSPMS gene regulatory, polyamines accumulation, and cold tolerance in tea plant. PMID:26276446

  18. Identification of the varietal origin of loose leaf tea based on analysis of a single leaf by SNP nanofluidic array

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tea [Camellia sinensis (L.) O Kuntze] is an economically important crop cultivated in more than 50 countries. Production and marketing of premium specialty tea products provides opportunities for tea growers, the tea industry and consumers. Rapid market segmentation in the tea industry has resulted ...

  19. Identification of novel sesterterpene/triterpene synthase from Bacillus clausii.

    PubMed

    Sato, Tsutomu; Yamaga, Hiroaki; Kashima, Shoji; Murata, Yusuke; Shinada, Tetsuro; Nakano, Chiaki; Hoshino, Tsutomu

    2013-05-10

    Basic enzyme: The tetraprenyl-β-curcumene synthase homologue from the alkalophilic Bacillus clausii catalyses conversions of a geranylfarnesyl diphosphate and a hexaprenyl diphosphate into novel head-to-tail acyclic sesterterpene and triterpene. Tetraprenyl-β-curcumene synthase homologues represent a new family of terpene synthases that form not only sesquarterpene but also sesterterpene and triterpene. PMID:23554321

  20. Use of plant extracts for tea pest management in India.

    PubMed

    Roy, Somnath; Handique, Gautam; Muraleedharan, Narayanannair; Dashora, Kavya; Roy, Sudipta Mukhopadhyay; Mukhopadhyay, Ananda; Babu, Azariah

    2016-06-01

    India is the second largest producer of black tea in the world. The biggest challenge for tea growers of India nowadays is to combat pests and diseases. Tea crop in India is infested by not less than 720 insect and mite species. At least four sucking pests and six chewing pests have well established themselves as regular pests causing substantial damage to this foliage crop. Various synthetic pesticides are widely used for the management of tea pests in India. Applications of such large quantity of pesticides could cause various problems such as development of resistance, deleterious effects on non-target organisms such as insect predators and parasitoids, upsetting the ecological balance, and accumulation of pesticide residues on tea leaves. There is a growing demand for organic tea or at least pesticide residue free tea in the international market which affects the export price. There is also a higher emphasis of implementation of new regulations on internationally traded foods and implementation of Plant Protection Code (PPC) for tea by the Government of India. This necessitates a relook into the usage pattern of synthetic pesticides on this crop. There are various non-chemical interventions which are being worked out for their sustainability, compatibility, and eco-friendly properties which can gradually replace the use of toxic chemicals. The application of plant extracts with insecticidal properties provides an alternative to the synthetic pesticides. Botanical products, especially neem-based products, have made a relatively moderate impact in tea pest control. Research has also demonstrated the potential of 67 plant species as botanical insecticides against tea pests. The majority of plant products used in pest management of tea in India are in the form of crude extracts prepared locally in tea garden itself, and commercial standardized formulations are not available for most of the plants due to lack of scientific research in the area. Apart from systematic

  1. Mortality among female practitioners of Chanoyu (Japanese "tea-ceremony").

    PubMed

    Sadakata, S; Fukao, A; Hisamichi, S

    1992-04-01

    A cohort study aimed to evaluate the effect of drinking green tea on longevity was performed. Three thousand three hundred and eighty female practitioners of chanoyu (Japanese tea-ceremony), living in Tokyo, were followed from 1980 to 1988, and 280 were dead during this period. Standardized mortality ratios were estimated 0.55 when all Japanese women was used as standard population and 0.57 when women living in Tokyo was used, indicating the possibility that green tea is a protective factor for several fatal diseases. PMID:1502694

  2. A Case of Hepatotoxicity Related to Kombucha Tea Consumption.

    PubMed

    Gedela, Maheedhar; Potu, Kalyan Chakravarthy; Gali, Vasantha L; Alyamany, Kimberlee; Jha, Lokesh K

    2016-01-01

    The use of herbal and dietary supplements (HDSs) is widespread and growing due to the popular notion that these products are of natural origins and safe. Kombucha (or "mushroom") tea is one HDS that is consumed by people for various perceived health benefits. Kombucha tea is a well-known health beverage made by fermenting sweet black tea with a round, flat, gray fungus for a week or longer. There is concern, however, from the evidence of a few case reports currently available, that it may pose life-threatening and/or adverse effects for users. PMID:26882579

  3. Mortality among female practitioners of Chanoyu (Japanese "tea-ceremony").

    PubMed

    Sadakata, S; Fukao, A; Hisamichi, S

    1992-04-01

    A cohort study aimed to evaluate the effect of drinking green tea on longevity was performed. Three thousand three hundred and eighty female practitioners of chanoyu (Japanese tea-ceremony), living in Tokyo, were followed from 1980 to 1988, and 280 were dead during this period. Standardized mortality ratios were estimated 0.55 when all Japanese women was used as standard population and 0.57 when women living in Tokyo was used, indicating the possibility that green tea is a protective factor for several fatal diseases.

  4. Green tea catechins for treatment of external genital warts.

    PubMed

    Meltzer, Sara M; Monk, Bradley J; Tewari, Krishnansu S

    2009-03-01

    This review evaluates the antiviral, antioxidant, and immunostimulatory properties of green tea catechins. Two randomized trials evaluating the activity and efficacy of green tea catechins in the management of external genital warts are presented, and the reported side effects associated with this topical treatment modality are outlined. Finally, the mechanism of action, percent of wart clearance, time to clearance, and toxicity profile of green tea catechins are compared with those of podofilox and imiquimod, 2 other patient-administered topical agents approved for treatment of anogenital warts.

  5. Analysis of Key Odorants in Roasted Green Tea

    NASA Astrophysics Data System (ADS)

    Mizukami, Yuzo; Sawai, Yusuke; Yamaguchi, Yuichi

    This research aims to identify key odorants in roasted green tea. The aroma extract dilution analysis revealed 25 odor-active peaks with the flavor dilution factors of ≥ 16. We identified 2-ethyl-3,5-dimethylpyrazine as the most important odorant in roasted green tea with the highest flavor dilution factor of 4096. In addition, tetramethylpyrazine, 2,3-diethyl-5- methylpyrazine were also detected as potent odorants with the high flavor dilution factors. These three alkylpyrazines would be key contributors to aroma of roasted green tea.

  6. Lessons from 455 Fusarium polyketide synthases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In fungi, polyketide synthases (PKSs) synthesize a structurally diverse array of secondary metabolites (SMs) with a range of biological activities. The most studied SMs are toxic to animals and/or plants, alter plant growth, have beneficial pharmaceutical activities, and/or are brightly colored pigm...

  7. Producing dicarboxylic acids using polyketide synthases

    SciTech Connect

    Katz, Leonard; Fortman, Jeffrey L; Keasling, Jay D

    2013-10-29

    The present invention provides for a polyketide synthase (PKS) capable of synthesizing a dicarboxylic acid (diacid). Such diacids include diketide-diacids and triketide-diacids. The invention includes recombinant nucleic acid encoding the PKS, and host cells comprising the PKS. The invention also includes methods for producing the diacids.

  8. Producing dicarboxylic acids using polyketide synthases

    SciTech Connect

    Katz, Leonard; Fortman, Jeffrey L.; Keasling, Jay D.

    2015-05-26

    The present invention provides for a polyketide synthase (PKS) capable of synthesizing a dicarboxylic acid (diacid). Such diacids include diketide-diacids and triketide-diacids. The invention includes recombinant nucleic acid encoding the PKS, and host cells comprising the PKS. The invention also includes methods for producing the diacids.

  9. Fluorescent Staining of Tea Pathogenic Fungi in Tea Leaves Using Fluorescein-labeled Lectin

    NASA Astrophysics Data System (ADS)

    Yamada, Kengo; Yoshida, Katsuyuki; Sonoda, Ryoichi

    Fluorochrome-labeled lectin, fluorescein conjugated wheat germ agglutinin (F-WGA) was applied to stain tea pathogenic fungi in tea leaf tissue. Infected leaves were fixed and decolorized with a mixture of ethanol and acetic acid, and cleared with 10% KOH for whole mount before staining with F-WGA. Hyphae of Pestalotiopsis longiseta, Pseudocercospora ocellata, Botrytis cinerea and Colletotrichum theae-sinensis fluoresced brightly in whole mount and sectioned samples of infected leaf tissue. In browned tissue, hyphae did not fluoresce frequently in whole mount sample. Autofluorescence of leaf tissue was strong in browned tissue of sections, it was removed by 10% KOH treatment before staining. Penetration hyphae of C. theae-sinensis in cell wall of trichome and hyphae in basal part of trichome did not fluoresced frequently. In whole mount samples of tea leaf infected with Exobasidium vexans and E. reticulatum, hymenia appeared on leaf surface fluoresced, but hyphae in leaf tissue did not fluoresce. In sectioned samples, hyphae fluoresced brightly when sections were treated with 10% KOH before staining.

  10. A review on the structure-function relationship aspect of polysaccharides from tea materials.

    PubMed

    Xiao, Jian Bo; Jiang, Huixian

    2015-01-01

    Tea (Camellia sinensis) has a long history of medicinal use in the world. The chemical components of tea mainly consist of polyphenols (TPP), proteins, polysaccharides (TPS), chlorophyll, alkaloids, and so on. Great advances have been made in chemical and bioactive studies of catechins and TPP from tea in recent decades. However, the TPS from tea materials have received much less consideration than that of TPP. The number of relevant publications on the TPS from tea leaves and flowers has increased rapidly in recent years. This mini-review summarizes the structure-function relationship of TPS from tea leaves and flowers. The application of purified TPS from tea material as functional or nutritional foods was still little. It will help to develop the function foods with tea TPS and better understand the structure-bioactivity relationship of tea TPS.

  11. Characterization of pu-erh tea using chemical and metabolic profiling approaches.

    PubMed

    Xie, Guoxiang; Ye, Mao; Wang, Yungang; Ni, Yan; Su, Mingming; Huang, Hua; Qiu, Mingfeng; Zhao, Aihua; Zheng, Xiaojiao; Chen, Tianlu; Jia, Wei

    2009-04-22

    In this study, the chemical constituents of pu-erh tea, black tea, and green tea, as well as those of pu-erh tea products of different ages, were analyzed and compared using a chemical profiling approach. Differences in tea processing resulted in differences in the chemical constituents and the color of tea infusions. Human biological responses to pu-erh tea ingestion were also studied by using ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOFMS) in conjunction with multivariate statistical techniques. Metabolic alterations during and after pu-erh tea ingestion were characterized by increased urinary excretion of 5-hydroxytryptophan, inositol, and 4-methoxyphenylacetic acid, along with reduced excretion of 3-chlorotyrosine and creatinine. This study highlights the potential for metabonomic technology to assess nutritional interventions and is an important step toward a full understanding of pu-erh tea and its influence on human metabolism. PMID:19320437

  12. Altering the phenolics profile of a green tea leaves extract using exogenous oxidases.

    PubMed

    Verloop, Annewieke J W; Gruppen, Harry; Bisschop, Robbin; Vincken, Jean-Paul

    2016-04-01

    Transformation from green tea leaves into black tea involves oxidation of catechins into theaflavins and other complex phenolics by endogenous enzymes in tea leaves. By employing tyrosinase and laccase, both from Agaricus bisporus, on green tea catechins, the oxidation process was directed towards a higher theaflavins content, which is considered an important quality parameter in tea. The main tea catechins were incubated with tyrosinase and laccase, and product formation was monitored by RP-UHPLC-PDA-ESI-MS. The kind of catechin, their substitution with a galloyl group, and the type of oxidase used were important factors determining theaflavin concentrations. In particular, incubation of epicatechin with epigallocatechin with tyrosinase gave a high, stable theaflavin content. In a green tea extract, tyrosinase increased the proportion of theaflavins by twofold compared to black tea. Laccase mainly formed insoluble complexes. Our results indicate that the phenolic profile of tea can be modulated by using commercially available exogenous oxidases.

  13. Comparative studies on the physicochemical and antioxidant properties of different tea extracts.

    PubMed

    Chen, Haixia; Zhang, Yu; Lu, Xueming; Qu, Zhishuang

    2012-06-01

    Tea is one of the most popular drinks next to water. Tea polyphenol is one of the main bioactive constituents of tea with health functions. In order to find the most bioactive tea polyphynols, polyphenol extracts from green tea, black tea and chemical oxidation products of green tea extracts were comparatively studied on the physicochemical and antioxidant properties. Results showed physicochemical and antioxidant properties of polyphenol extracts changed greatly after the chemical oxidation. Hydrogen peroxide induced oxidation products (HOP) possessed the highest antioxidant ability among the four tea polyphenol extracts. Thirteen phenolic compounds and one alkaloid in HOP were identified by reversed phase high-performance liquid chromatography coupled to diode array detection and electrospray ionization mass spectrometry (RP-HPLC-DAD-ESI-MS). Hydrogen peroxide induced oxidation of tea polyphenol extracts could improve the antioxidant activity and could be used to produce antioxidants for food industry. PMID:23729856

  14. Metabolic dependence of green tea on plucking positions revisited: a metabolomic study.

    PubMed

    Lee, Jang-Eun; Lee, Bum-Jin; Hwang, Jeong-Ah; Ko, Kwang-Sup; Chung, Jin-Oh; Kim, Eun-Hee; Lee, Sang-Jun; Hong, Young-Shick

    2011-10-12

    The dependence of global green tea metabolome on plucking positions was investigated through (1)H nuclear magnetic resonance (NMR) analysis coupled with multivariate statistical data set. Pattern recognition methods, such as principal component analysis (PCA) and orthogonal projection on latent structure-discriminant analysis (OPLS-DA), were employed for a finding metabolic discrimination among fresh green tea leaves plucked at different positions from young to old leaves. In addition to clear metabolic discrimination among green tea leaves, elevations in theanine, caffeine, and gallic acid levels but reductions in catechins, such as epicatechin (EC), epigallocatechin (EGC), epicatechin-3-gallate (ECG), and epigallocatechin-3-gallate (EGCG), glucose, and sucrose levels were observed, as the green tea plant grows up. On the other hand, the younger the green tea leaf is, the more theanine, caffeine, and gallic acid but the lesser catechins accumlated in the green tea leaf, revealing a reverse assocation between theanine and catechins levels due to incorporaton of theanine into catechins with growing up green tea plant. Moreover, as compared to the tea leaf, the observation of marked high levels of theanine and low levels of catechins in green tea stems exhibited a distinct tea plant metabolism between the tea leaf and the stem. This metabolomic approach highlights taking insight to global metabolic dependence of green tea leaf on plucking position, thereby providing distinct information on green tea production with specific tea quality.

  15. The Benefits and Risks of Consuming Brewed Tea: Beware of Toxic Element Contamination

    PubMed Central

    Schwalfenberg, Gerry; Genuis, Stephen J.; Rodushkin, Ilia

    2013-01-01

    Background. Increasing concern is evident about contamination of foodstuffs and natural health products. Methods. Common off-the-shelf varieties of black, green, white, and oolong teas sold in tea bags were used for analysis in this study. Toxic element testing was performed on 30 different teas by analyzing (i) tea leaves, (ii) tea steeped for 3-4 minutes, and (iii) tea steeped for 15–17 minutes. Results were compared to existing preferred endpoints. Results. All brewed teas contained lead with 73% of teas brewed for 3 minutes and 83% brewed for 15 minutes having lead levels considered unsafe for consumption during pregnancy and lactation. Aluminum levels were above recommended guidelines in 20% of brewed teas. No mercury was found at detectable levels in any brewed tea samples. Teas contained several beneficial elements such as magnesium, calcium, potassium, and phosphorus. Of trace minerals, only manganese levels were found to be excessive in some black teas. Conclusions. Toxic contamination by heavy metals was found in most of the teas sampled. Some tea samples are considered unsafe. There are no existing guidelines for routine testing or reporting of toxicant levels in “naturally” occurring products. Public health warnings or industry regulation might be indicated to protect consumer safety. PMID:24260033

  16. Metabolic dependence of green tea on plucking positions revisited: a metabolomic study.

    PubMed

    Lee, Jang-Eun; Lee, Bum-Jin; Hwang, Jeong-Ah; Ko, Kwang-Sup; Chung, Jin-Oh; Kim, Eun-Hee; Lee, Sang-Jun; Hong, Young-Shick

    2011-10-12

    The dependence of global green tea metabolome on plucking positions was investigated through (1)H nuclear magnetic resonance (NMR) analysis coupled with multivariate statistical data set. Pattern recognition methods, such as principal component analysis (PCA) and orthogonal projection on latent structure-discriminant analysis (OPLS-DA), were employed for a finding metabolic discrimination among fresh green tea leaves plucked at different positions from young to old leaves. In addition to clear metabolic discrimination among green tea leaves, elevations in theanine, caffeine, and gallic acid levels but reductions in catechins, such as epicatechin (EC), epigallocatechin (EGC), epicatechin-3-gallate (ECG), and epigallocatechin-3-gallate (EGCG), glucose, and sucrose levels were observed, as the green tea plant grows up. On the other hand, the younger the green tea leaf is, the more theanine, caffeine, and gallic acid but the lesser catechins accumlated in the green tea leaf, revealing a reverse assocation between theanine and catechins levels due to incorporaton of theanine into catechins with growing up green tea plant. Moreover, as compared to the tea leaf, the observation of marked high levels of theanine and low levels of catechins in green tea stems exhibited a distinct tea plant metabolism between the tea leaf and the stem. This metabolomic approach highlights taking insight to global metabolic dependence of green tea leaf on plucking position, thereby providing distinct information on green tea production with specific tea quality. PMID:21899366

  17. Safety and anti-hyperglycemic efficacy of various tea types in mice.

    PubMed

    Han, Manman; Zhao, Guangshan; Wang, Yijun; Wang, Dongxu; Sun, Feng; Ning, Jingming; Wan, Xiachun; Zhang, Jinsong

    2016-01-01

    Tea, a beverage consumed worldwide, has proven anti-hyperglycemic effects in animal models. Better efficacies of tea beverages are frequently associated with high-dose levels, whose safety attracts considerable attention. Based on the inherent nature of tea catechin oxidation, fresh tea leaves are manufactured into diverse tea types by modulating the oxidation degree of catechins. The present study aimed to assess various tea types for their safety properties and anti-hyperglycemic effects. Mice were allowed free access to tea infusion (1:30, w/v) for one week, and the rare smoked tea caused salient adverse reactions, including hepatic and gastrointestinal toxicities; meanwhile, the widely-consumed green and black teas, unlike the rare yellow tea, suppressed growth in fast-growing healthy mice. When mice were fed a high-fat diet and allowed free access to tea infusion (1:30, w/v) for 25 days, only yellow tea significantly reduced blood glucose. Therefore, various teas showed different safety profiles as well as anti-hyperglycemic efficacy strengths. To achieve an effective and safe anti-hyperglycemic outcome, yellow tea, which effectively suppressed high-fat diet-induced early elevation of hepatic thioredoxin-interacting protein, is an optimal choice. PMID:27531374

  18. Exploring the nutraceutical potential of polyphenols from black, green and white tea infusions - an overview.

    PubMed

    Tenore, Gian C; Daglia, Maria; Ciampaglia, Roberto; Novellino, Ettore

    2015-01-01

    Black, green, and white teas are the main commercial teas obtained from buds and leaves of Camellia sinensis (L.). The postharvest processing treatments, together with genotype and growing techniques, may strongly affect the chemical composition of the tea infusion and, thereby, its potential effects on health. Catechins constituted up to 30% of tea leaves dry weight. During fermentation, polyphenols undergo enzymatic oxidation, leading to the formation of condensed polymeric compounds regarded as responsible for the typical organoleptic properties of black tea leaves and related infusions. Scientific studies has been recently focusing on the possibility that tea polyphenols, particularly those of black and green tea, may lead to healthy properties in individuals affected by diseases correlated to metabolic syndrome. In vivo experiments reveal that green and black tea polyphenols may be able to reduce hyperglycemia and insulin resistance. Other works suggest that black tea polymeric products may be effective in decreasing blood cholesterol levels and hypertriacylglycerolemia. To this regard, very few data about white tea, being the rarest and the least handled tea, are available so far. It has been reported that white tea could show higher antioxidative capacity than green tea and to exert in vitro lipolytic activity. Considering the increasing interest towards healthy potential through diet and natural medicaments, the aim of the present review was to overview the nutraceutical potential of polyphenols from tea after various degrees of fermentation. PMID:25601602

  19. Safety and anti-hyperglycemic efficacy of various tea types in mice

    PubMed Central

    Han, Manman; Zhao, Guangshan; Wang, Yijun; Wang, Dongxu; Sun, Feng; Ning, Jingming; Wan, Xiachun; Zhang, Jinsong

    2016-01-01

    Tea, a beverage consumed worldwide, has proven anti-hyperglycemic effects in animal models. Better efficacies of tea beverages are frequently associated with high-dose levels, whose safety attracts considerable attention. Based on the inherent nature of tea catechin oxidation, fresh tea leaves are manufactured into diverse tea types by modulating the oxidation degree of catechins. The present study aimed to assess various tea types for their safety properties and anti-hyperglycemic effects. Mice were allowed free access to tea infusion (1:30, w/v) for one week, and the rare smoked tea caused salient adverse reactions, including hepatic and gastrointestinal toxicities; meanwhile, the widely-consumed green and black teas, unlike the rare yellow tea, suppressed growth in fast-growing healthy mice. When mice were fed a high-fat diet and allowed free access to tea infusion (1:30, w/v) for 25 days, only yellow tea significantly reduced blood glucose. Therefore, various teas showed different safety profiles as well as anti-hyperglycemic efficacy strengths. To achieve an effective and safe anti-hyperglycemic outcome, yellow tea, which effectively suppressed high-fat diet-induced early elevation of hepatic thioredoxin-interacting protein, is an optimal choice. PMID:27531374

  20. Exploring the nutraceutical potential of polyphenols from black, green and white tea infusions - an overview.

    PubMed

    Tenore, Gian C; Daglia, Maria; Ciampaglia, Roberto; Novellino, Ettore

    2015-01-01

    Black, green, and white teas are the main commercial teas obtained from buds and leaves of Camellia sinensis (L.). The postharvest processing treatments, together with genotype and growing techniques, may strongly affect the chemical composition of the tea infusion and, thereby, its potential effects on health. Catechins constituted up to 30% of tea leaves dry weight. During fermentation, polyphenols undergo enzymatic oxidation, leading to the formation of condensed polymeric compounds regarded as responsible for the typical organoleptic properties of black tea leaves and related infusions. Scientific studies has been recently focusing on the possibility that tea polyphenols, particularly those of black and green tea, may lead to healthy properties in individuals affected by diseases correlated to metabolic syndrome. In vivo experiments reveal that green and black tea polyphenols may be able to reduce hyperglycemia and insulin resistance. Other works suggest that black tea polymeric products may be effective in decreasing blood cholesterol levels and hypertriacylglycerolemia. To this regard, very few data about white tea, being the rarest and the least handled tea, are available so far. It has been reported that white tea could show higher antioxidative capacity than green tea and to exert in vitro lipolytic activity. Considering the increasing interest towards healthy potential through diet and natural medicaments, the aim of the present review was to overview the nutraceutical potential of polyphenols from tea after various degrees of fermentation.

  1. Re-Citrate Synthase from Clostridium kluyveri Is Phylogenetically Related to Homocitrate Synthase and Isopropylmalate Synthase Rather Than to Si-Citrate Synthase† ▿

    PubMed Central

    Li, Fuli; Hagemeier, Christoph H.; Seedorf, Henning; Gottschalk, Gerhard; Thauer, Rudolf K.

    2007-01-01

    The synthesis of citrate from acetyl-coenzyme A and oxaloacetate is catalyzed in most organisms by a Si-citrate synthase, which is Si-face stereospecific with respect to C-2 of oxaloacetate. However, in Clostridium kluyveri and some other strictly anaerobic bacteria, the reaction is catalyzed by a Re-citrate synthase, whose primary structure has remained elusive. We report here that Re-citrate synthase from C. kluyveri is the product of a gene predicted to encode isopropylmalate synthase. C. kluyveri is also shown to contain a gene for Si-citrate synthase, which explains why cell extracts of the organism always exhibit some Si-citrate synthase activity. PMID:17400742

  2. Molecular interactions between caffeine and catechins in green tea.

    PubMed

    Colon, Marta; Nerin, Cristina

    2014-07-16

    Migration of green tea components from an active packaging material containing green tea extract was performed in water and 3% acetic acid in water. The migration values for acid simulant were much higher than the values obtained in water. The influence of the acidic media in solutions of catechin standards and green tea extract was evaluated by liquid chromatography. Catechin, epicatechin, and caffeine from the green tea extract exhibited major variation in their concentrations values, with increases of 29.90, 20.75, and 15.95%, respectively, in acidic medium. The results suggested that catechins and caffeine form complexes through intermolecular interactions in neutral media and that these interactions are broken in acidic media. The continuous variation method was also performed to confirm the stoichiometry of the complexes between catechins and caffeine. Finally, a computer simulation was applied by Chem Pro 12.0, and the energies involved were calculated to confirm the experimental results obtained.

  3. Improving the sweet aftertaste of green tea infusion with tannase.

    PubMed

    Zhang, Ying-Na; Yin, Jun-Feng; Chen, Jian-Xin; Wang, Fang; Du, Qi-Zhen; Jiang, Yong-Wen; Xu, Yong-Quan

    2016-02-01

    The present study aims to improve the sweet aftertaste and overall acceptability of green tea infusion by hydrolyzing (-)-epigallocatechin gallate (EGCG) and (-)-epicatechin gallate (ECG) with tannase. The results showed that the intensity of the sweet aftertaste and the score of overall acceptability of the green tea infusion significantly increased with the extension of the hydrolyzing treatment. (-)-Epigallocatechin (EGC) and (-)-epicatechin (EC) were found to be the main contributors for the sweet aftertaste, based on a trial compatibility with EGCG, ECG, EGC, and EC monomers, and a synergistic action between EGC and EC to sweet aftertaste was observed. A 2.5:1 (EGC/EC) ratio with a total concentration of 3.5 mmol/L gave the most satisfying sweet aftertaste, and the astringency significantly inhibited the development of the sweet aftertaste. These results can help us to produce a tea beverage with excellent sweet aftertaste by hydrolyzing the green tea infusion with tannase.

  4. LOOKING NORTHEAST TOWARD NORTHERN AVE. SWING BRIDGE. BOSTON TEA PARTY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LOOKING NORTHEAST TOWARD NORTHERN AVE. SWING BRIDGE. BOSTON TEA PARTY SHIP AT ANCHOR IN FOREGROUND. - Northern Avenue Swing Bridge, Spanning Fort Point Channel at boundary between Boston & South Boston, Boston, Suffolk County, MA

  5. Tea and Cancer Prevention: Strengths and Limits of the Evidence

    MedlinePlus

    ... supplements for tea catechin and caffeine content, the product labels varied in their presentation of catechin and caffeine information, and some values reported on product labels were inconsistent with analyzed values ( 1 ). How might ...

  6. Interactions between milk fat globules and green tea catechins.

    PubMed

    Rashidinejad, Ali; Birch, E John; Everett, David W

    2016-05-15

    The determination of putative chemical interactions between the milk fat globule membrane and green tea catechins provided useful information about the role of milk fat globules (MFGs) in high-fat dairy systems, such as cheese, and containing bioactive compounds, such as tea catechins. Catechins from green tea (125-1,000 ppm), including (+)-catechin, (-)-epigallocatechin gallate, and green tea extract were added to washed MFGs to examine possible interactions. The addition of catechins gave a significant change in the size and ζ-potential of MFGs. The recovery of different catechins from the milk fat globule suspensions was found to vary, suggesting selective association with the milk fat globule membranes. The interactions were further investigated using transmission electron microscopy and Fourier transform infra-red spectroscopy. It is suggested that catechins are localised in association with milk fat globule membrane domains as they contain both hydrophobic and hydrophilic moieties with potential points of molecular interaction. PMID:26775981

  7. Interactions between milk fat globules and green tea catechins.

    PubMed

    Rashidinejad, Ali; Birch, E John; Everett, David W

    2016-05-15

    The determination of putative chemical interactions between the milk fat globule membrane and green tea catechins provided useful information about the role of milk fat globules (MFGs) in high-fat dairy systems, such as cheese, and containing bioactive compounds, such as tea catechins. Catechins from green tea (125-1,000 ppm), including (+)-catechin, (-)-epigallocatechin gallate, and green tea extract were added to washed MFGs to examine possible interactions. The addition of catechins gave a significant change in the size and ζ-potential of MFGs. The recovery of different catechins from the milk fat globule suspensions was found to vary, suggesting selective association with the milk fat globule membranes. The interactions were further investigated using transmission electron microscopy and Fourier transform infra-red spectroscopy. It is suggested that catechins are localised in association with milk fat globule membrane domains as they contain both hydrophobic and hydrophilic moieties with potential points of molecular interaction.

  8. Evaluation of γ-radiation on green tea odor volatiles

    NASA Astrophysics Data System (ADS)

    Fanaro, G. B.; Duarte, R. C.; Araújo, M. M.; Purgatto, E.; Villavicencio, A. L. C. H.

    2011-01-01

    The aim of this study was to evaluate the gamma radiation effects on green tea odor volatiles in green tea at doses of 0, 5, 10, 15 and 20 kGy. The volatile organic compounds were extracted by hydrodistillation and analyzed by GC/MS. The green tea had a large influence on radiation effects, increasing the identified volatiles in relation to control samples. The dose of 10 kGy was responsible to form the majority of new odor compounds following by 5 and 20 kGy. However, the dose of 5 kGy was the dose that degraded the majority of volatiles in non-irradiated samples, following by 20 kGy. The dose of 15 kGy showed has no effect on odor volatiles. The gamma radiation, at dose up to 20 kGy, showed statistically no difference between irradiated and non irradiated green tea on odors compounds.

  9. [Determination of azoxystrobin in tea by HPLC].

    PubMed

    Chonan, T

    2001-08-01

    A determination method has been developed for azoxystrobin in tea by HPLC. Azoxystrobin was extracted from a sample with acetone, and the extract was passed through an alumina column to remove tannin. The eluate was concentrated to ca. 25 mL and passed through a Sep-Pak Vac tC18 to remove pigments. The eluate was cleaned-up by using liquid-liquid partition, and Florisil and silica-gel columns. The HPLC analysis for azoxystrobin was carried out on a C18 column with acetonitrile-water (9:11) as the mobile phase, with ultraviolet detection at 260 nm. The recovery of azoxystrobin fortified at the level of 0.4 microgram/g was 90.2% and the limit of determination was 0.2 microgram/g.

  10. Ultraviolet photoionization in CO2 TEA lasers

    NASA Astrophysics Data System (ADS)

    Scott, S. J.; Smith, A. L. S.

    1988-07-01

    The effects of gas composition and spark parameters on the UV emission in CO2 TEA laser gas mixtures were investigated together with the nature of photoionization process and the photoelectron-loss mechanism. A linear relationship was found between N2 concentration and photoionization (with no such dependence on C concentration, from CO and CO2), but the increases in photoionization that could be effected by optimizing the spark discharge circuit parameters were much higher than those produced by changes in gas composition. UV emission was directly proportional to the amount of stored electrical energy in the spark-discharge circuit and to the cube of the peak current produced in the spark by the discharge of this energy. Photoionization was also found to be proportional to the spark electrode gap. It was found that free-space sparks gave a considerably broader emission pattern than a surface-guided notched spark.

  11. [Fast Detection of Camellia Sinensis Growth Process and Tea Quality Informations with Spectral Technology: A Review].

    PubMed

    Peng, Ji-yu; Song, Xing-lin; Liu, Fei; Bao, Yi-dan; He, Yong

    2016-03-01

    The research achievements and trends of spectral technology in fast detection of Camellia sinensis growth process information and tea quality information were being reviewed. Spectral technology is a kind of fast, nondestructive, efficient detection technology, which mainly contains infrared spectroscopy, fluorescence spectroscopy, Raman spectroscopy and mass spectroscopy. The rapid detection of Camellia sinensis growth process information and tea quality is helpful to realize the informatization and automation of tea production and ensure the tea quality and safety. This paper provides a review on its applications containing the detection of tea (Camellia sinensis) growing status(nitrogen, chlorophyll, diseases and insect pest), the discrimination of tea varieties, the grade discrimination of tea, the detection of tea internal quality (catechins, total polyphenols, caffeine, amino acid, pesticide residual and so on), the quality evaluation of tea beverage and tea by-product, the machinery of tea quality determination and discrimination. This paper briefly introduces the trends of the technology of the determination of tea growth process information, sensor and industrial application. In conclusion, spectral technology showed high potential to detect Camellia sinensis growth process information, to predict tea internal quality and to classify tea varieties and grades. Suitable chemometrics and preprocessing methods is helpful to improve the performance of the model and get rid of redundancy, which provides the possibility to develop the portable machinery. Future work is to develop the portable machinery and on-line detection system is recommended to improve the further application. The application and research achievement of spectral technology concerning about tea were outlined in this paper for the first time, which contained Camellia sinensis growth, tea production, the quality and safety of tea and by-produce and so on, as well as some problems to be solved

  12. [Fast Detection of Camellia Sinensis Growth Process and Tea Quality Informations with Spectral Technology: A Review].

    PubMed

    Peng, Ji-yu; Song, Xing-lin; Liu, Fei; Bao, Yi-dan; He, Yong

    2016-03-01

    The research achievements and trends of spectral technology in fast detection of Camellia sinensis growth process information and tea quality information were being reviewed. Spectral technology is a kind of fast, nondestructive, efficient detection technology, which mainly contains infrared spectroscopy, fluorescence spectroscopy, Raman spectroscopy and mass spectroscopy. The rapid detection of Camellia sinensis growth process information and tea quality is helpful to realize the informatization and automation of tea production and ensure the tea quality and safety. This paper provides a review on its applications containing the detection of tea (Camellia sinensis) growing status(nitrogen, chlorophyll, diseases and insect pest), the discrimination of tea varieties, the grade discrimination of tea, the detection of tea internal quality (catechins, total polyphenols, caffeine, amino acid, pesticide residual and so on), the quality evaluation of tea beverage and tea by-product, the machinery of tea quality determination and discrimination. This paper briefly introduces the trends of the technology of the determination of tea growth process information, sensor and industrial application. In conclusion, spectral technology showed high potential to detect Camellia sinensis growth process information, to predict tea internal quality and to classify tea varieties and grades. Suitable chemometrics and preprocessing methods is helpful to improve the performance of the model and get rid of redundancy, which provides the possibility to develop the portable machinery. Future work is to develop the portable machinery and on-line detection system is recommended to improve the further application. The application and research achievement of spectral technology concerning about tea were outlined in this paper for the first time, which contained Camellia sinensis growth, tea production, the quality and safety of tea and by-produce and so on, as well as some problems to be solved

  13. Geranyl diphosphate synthase large subunit, and methods of use

    DOEpatents

    Croteau, Rodney B.; Burke, Charles C.; Wildung, Mark R.

    2001-10-16

    A cDNA encoding geranyl diphosphate synthase large subunit from peppermint has been isolated and sequenced, and the corresponding amino acid sequence has been determined. Replicable recombinant cloning vehicles are provided which code for geranyl diphosphate synthase large subunit). In another aspect, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding geranyl diphosphate synthase large subunit. In yet another aspect, the present invention provides isolated, recombinant geranyl diphosphate synthase protein comprising an isolated, recombinant geranyl diphosphate synthase large subunit protein and an isolated, recombinant geranyl diphosphate synthase small subunit protein. Thus, systems and methods are provided for the recombinant expression of geranyl diphosphate synthase.

  14. Character impact odorants of fennel fruits and fennel tea.

    PubMed

    Zeller, Annette; Rychlik, Michael

    2006-05-17

    The flavor of fennel fruits and fennel tea was examined by aroma extract dilution analysis of the respective dichloromethane extracts. In both fennel fruits and tea, trans-anethole, anisaldehyde, and trans-4,5-epoxy-2(E)-decenal showed high flavor dilution (FD) factors followed by fenchone, 1,8-cineole, (R)-alpha-pinene, estragole, and beta-myrcene. On the basis of these results, the odorants showing higher FD factors were quantified in tea as well as in fruits, and odor activity values (OAV) in tea were calculated by dividing the concentration of the compound by its recognition threshold in water. The highest OAV was found for trans-anethole, followed by estragole, fenchone, 1,8-cineole, (R)-alpha-pinene, beta-myrcene, and anisaldehyde. From a comparison of the concentrations of odorants in fruits and tea, trans-anethole and estragole showed similar extraction rates of approximately 10-15%, whereas the extraction rates for (R)-alpha-pinene, beta-myrcene, and limonene were below 2%. In contrast to this, fenchone, camphor, linalool, and carvone showed higher extraction rates (26-50%), whereas the high apparent extraction rates of anisalcohol (393%) and vanilline (480%) were attributed to the formation from precursors. Sensory studies of aqueous models containing odorants in the amounts quantified in fennel teas revealed high similarity of the models with the tea and proved that all impact odorants had been identified in their correct concentrations. Further sensory experiments showed that estragole had no odor impact on the overall flavor of fennel tea, and, therefore, a reduction of estragole in fennel products would have no negative impact on their sensoric quality. In contrast to this, trans-anethole and fenchone were found to be character impact compounds of fennel.

  15. Coffee, tea, and melanoma risk among postmenopausal women.

    PubMed

    Wu, Haotian; Reeves, Katherine W; Qian, Jing; Sturgeon, Susan R

    2015-07-01

    Laboratory research suggests that components in coffee and tea may have anticarcinogenic effects. Some epidemiologic studies have reported that women who consume coffee and tea have a lower risk for melanoma. We assessed coffee, tea, and melanoma risk prospectively in the Women's Health Initiative - Observational Study cohort of 66,484 postmenopausal women, followed for an average of 7.7 years. Coffee and tea intakes were measured through self-administered questionnaires at baseline and at year 3 of follow-up. Self-reported incident melanomas were adjudicated using medical records. Cox proportional hazard models were used to estimate risk, adjusting for covariates, with person-time accumulation until melanoma diagnosis (n=398), death, loss to follow-up, or through 2005. Daily coffee [hazard ratio (HR)=0.87, 95% confidence interval (CI) 0.68-1.12] and tea (HR=1.03, 95% CI 0.81-1.31) intakes were not significantly associated with melanoma risk compared with nondaily intake of each beverage. No significant trends were observed between melanoma risk and increasing intakes of coffee (P for trend=0.38) or tea (P for trend=0.22). Women who reported daily coffee intake at both baseline and year 3 had a significantly decreased risk compared with women who reported nondaily intake at both time points (HR=0.68, 95% CI 0.48-0.97). Consistent daily tea intake was not associated with decreased melanoma risk. Overall, there is no strong evidence that increasing coffee or tea consumption can lead to a lower melanoma risk. We observed a decrease in melanoma risk among long-term coffee drinkers, but the lack of consistency in the results by dose and type cautioned against overinterpretation of the results.

  16. Bioconversion of tea polyphenols to bioactive theabrownins by Aspergillus fumigatus.

    PubMed

    Wang, Qiuping; Gong, Jiashun; Chisti, Yusuf; Sirisansaneeyakul, Sarote

    2014-12-01

    Theabrownins (TB) are water-soluble phenolic compounds associated with the various health benefits of Pu-erh tea, a post-fermented Chinese dark tea. This work reports on the production of theabrownins from infusions of sun-dried green tea leaves using a pure culture of Aspergillus fumigatus isolated from a solid-state Pu-erh tea fermentation. A theabrownins yield of 158 g kg(-1) sun-dried green tea leaves was obtained in 6 days at 45 °C in an aerobic fermentation. In a 2 l fermenter, the yield of theabrownins was 151 g kg(-1) sun-dried green tea leaves in 48 h of aerobic culture (45 °C, 1 vvm aeration rate, 250 rpm agitation speed). Extracellular polyphenol oxidase and peroxidase of A. fumigatus contributed to this bioconversion. Repeated batch fermentation process was used for producing theabrownins but was less productive than the batch process.

  17. Tea and cancer prevention: Molecular mechanisms and human relevance

    SciTech Connect

    Yang, Chung S. Lambert, Joshua D.; Ju Jihyeung; Lu Gang; Sang Shengmin

    2007-11-01

    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, small intestine, colon, bladder, prostate, and mammary gland. The major active constituents are polyphenols, of which (-)-epigallocatechin-3-gallate (EGCG) is most abundant, most active, and most studied, and caffeine. The molecular mechanisms of the cancer-preventive action, however, are just beginning to be understood. Studies in cell lines led to the proposal of many mechanisms on the action of EGCG. However, mechanisms based on studies with very high concentrations of EGCG may not be relevant to cancer prevention in vivo. The autooxidation of EGCG in cell culture may also produce activities that do not occur in many internal organs. In contrast to the cancer prevention activity demonstrated in different animal models, no such conclusion can be convincingly drawn from epidemiological studies on tea consumption and human cancers. Even though the human data are inconclusive, tea constituents may still be used for the prevention of cancer at selected organ sites if sufficient concentrations of the agent can be delivered to these organs. Some interesting examples in this area are discussed.

  18. Gene expression analysis of bud and leaf color in tea.

    PubMed

    Wei, Kang; Zhang, Yazhen; Wu, Liyun; Li, Hailin; Ruan, Li; Bai, Peixian; Zhang, Chengcai; Zhang, Fen; Xu, Liyi; Wang, Liyuan; Cheng, Hao

    2016-10-01

    Purple shoot tea attributing to the high anthocyanin accumulation is of great interest for its wide health benefits. To better understand potential mechanisms involved in purple buds and leaves formation in tea plants, we performed transcriptome analysis of six green or purple shoot tea individuals from a F1 population using the Illumina sequencing method. Totally 292 million RNA-Seq reads were obtained and assembled into 112,233 unigenes, with an average length of 759 bp and an N50 of 1081 bp. Moreover, totally 2193 unigenes showed significant differences in expression levels between green and purple tea samples, with 1143 up- and 1050 down-regulated in the purple teas. Further real time PCR analysis confirmed RNA-Seq results. Our study identified 28 differentially expressed transcriptional factors and A CsMYB gene was found to be highly similar to AtPAP1 in Arabidopsis. Further analysis of differentially expressed genes involved in anthocyanin biosynthesis and transportation showed that the late biosynthetic genes and genes involved in anthocyanin transportation were largely affected but the early biosynthetic genes were less or none affected. Overall, the identification of a large number of differentially expressed genes offers a global view of the potential mechanisms associated with purple buds and leaves formation, which will facilitate molecular breeding in tea plants. PMID:27362295

  19. Metabolism of methylamine in the tea plant (Thea sinensis L.)

    PubMed Central

    Suzuki, Takeo

    1973-01-01

    1. The metabolism of methylamine in excised shoot tips of tea was studied with micromolar amounts of [14C]methylamine. Of the [14C]methylamine supplied 57% was utilized by tea shoots during the 10h experimental period. 2. The main products of [14C]methylamine metabolism in tea shoots were serine, γ-glutamylmethylamide, theobromine, caffeine and CO2. There was also incorporation of the label into glutamate, aspartate, RNA purine nucleotides and S-adenosylmethionine. 3. The formation of methylamine from γ-glutamylmethylamide was confirmed by feeding tea shoots with γ-glutamyl[14C]methylamide. The products of γ-glutamyl[14C]methylamide metabolism in tea plants were serine, theobromine, caffeine, glutamate and aspartate. 4. The results indicate that the oxidation of methylamine to formaldehyde is the first step of methylamine utilization. Labelled formaldehyde released by the metabolism of methylamine leads to the incorporation of the label into metabolites on the C1 pathways of this compound. It is also suggested that formaldehyde is further oxidized via formate to CO2. 5. The role of γ-glutamylmethylamide in methylamine metabolism in tea plants is discussed. 6. Results support the view that theobromine is the immediate precursor of caffeine. PMID:4721610

  20. The influence of Goishi tea on adipocytokines in obese mice.

    PubMed

    Yokota, Junko; Jobu, Kohei; Yoshioka, Saburo; Kashiwagi, Takehiro; Shimamura, Tomoko; Moriyama, Hironori; Murata, Shuzo; Ohishi, Masao; Ukeda, Hiroyuki; Miyamura, Mitsuhiko

    2013-06-15

    This study investigated the influence of Goishi-tea on visceral fat weight in induced obese mice. Mice were divided into two main groups, normal and obesity. In obesity group, mice were fed with high-fat diet. Goishi-tea including its fractions (ethyl-acetate layer and water layer) was administrated in normal and obesity three sub-groups. Results showed no influence of Goishi-tea in normal group. However, visceral fat weight, size of adipose cell and cholesterol level were significantly decreased in obesity group fed Goishi-tea compared to control group. Moreover, adiponectin levels tended to increase and adipocytokines has significant values lower in obesity group fed Goishi-tea compared to control group. Interestingly, Goishi tea involved in the high-fat diet induced-obese mice can inhibit fat accumulation and maintain adiponectins without increasing tumor necrosis factor-alpha and interleukin-6. It would be beneficial for the prevention of metabolic syndrome and obesity-related disorder.

  1. Volatile aroma compounds in various brewed green teas.

    PubMed

    Lee, Jeehyun; Chambers, Delores H; Chambers, Edgar; Adhikari, Koushik; Yoon, Youngmo

    2013-08-20

    This study identifies and semi-quantifies aroma volatiles in brewed green tea samples. The objectives of this study were to identify using a gas chromatograph-mass spectrometer (GC-MS) paired with a headspace solid-phase micro-extraction (HS-SPME) the common volatile compounds that may be responsible for aroma/flavor of the brewed liquor of a range of green tea samples from various countries as consumed and to determine if green teas from the same region have similarities in volatile composition when green tea samples are prepared for consumption. Twenty-four green tea samples from eight different countries were brewed as recommended for consumer brewing. The aroma volatiles were extracted by HS-SPME, separated on a gas chromatograph and identified using a mass spectrometer. Thirty-eight compounds were identified and the concentrations were semi-quantified. The concentrations were lower than those reported by other researchers, probably because this research examined headspace volatiles from brewed tea rather than solvent extraction of leaves. No relationship to country of origin was found, which indicates that other factors have a greater influence than country of origin on aroma.

  2. Anticariogenic Activity of Black Tea - An Invivo Study

    PubMed Central

    Arya, Vishal; Srivastava, Ankit; Nandlal, Swati

    2016-01-01

    Introduction Teas is known for its anticariogenic properties and various mechanisms have been invoked to explain this effect. One such proposed mechanism is inhibition of salivary alpha amylase activity by endogenous tannins present in tea. Aim The objective of the present study was to determine whether or not the ingestion of black tea decoction inhibits the enzyme salivary amylase and thus interferes with the release of maltose from intraoral entrapped particles of food. Materials and Methods A total of 30 children in the age group of 12 - 15 years were selected for the study. After two hours of fasting subjects consumed two salted crackers for 60 second following which they rinsed with water (control solution) and then with 1.5% black tea decoction (test solution) next day. Retained food particles were recovered from buccal aspect of left mandibular premolar and salivary amylase activity was noted via chromatography. Paired t-test was applied for statistical analysis. Results Maltose to Sucrose ratio was used to evaluate the result. The average ratio was 3.27 for control solution and 1.82 for test solution. The results were statistically highly significant (p <0.005). Conclusion Tea inhibited the activity of salivary amylase and this inhibition assumes a special significance when it is considered that the effect of tea could be manifested over a prolonged period of time, as in a real life situation. PMID:27135007

  3. Oxidative deamination of benzylamine and lysine residue in bovine serum albumin by green tea, black tea, and coffee.

    PubMed

    Akagawa, Mitsugu; Shigemitsu, Tomoko; Suyama, Kyozo

    2005-10-01

    Oxidative deamination by various polyphenolic compounds is presumed to be due to the oxidative conversion of polyphenols to the corresponding quinones through autoxidation. Here we examined the oxidative deamination by the polyphenol-rich beverages green tea, black tea, and coffee at a physiological pH and temperature. Green tea, black tea, and coffee extracts oxidatively deaminated benzylamine and the lysine residues of bovine serum albumin to benzaldehyde and alpha-aminoadipic delta-semialdehyde residues, respectively, in sodium phosphate buffer (pH 7.4) at 37 degrees C in both the presence and absence of Cu2+, indicating the occurrence of an amine (lysyl) oxidase-like reaction. We also examined the effects of pH and metal ions on the reaction. The possible biological effects of drinking polyphenol-rich beverages on human are also discussed.

  4. Survival of Salmonella on chamomile, peppermint, and green tea during storage and subsequent survival or growth following tea brewing.

    PubMed

    Keller, Susanne E; Stam, Christina N; Gradl, Dana R; Chen, Zhengzai; Larkin, Emily L; Pickens, Shannon R; Chirtel, Stuart J

    2015-04-01

    The survival of Salmonella on dried chamomile flowers, peppermint leaves, and green tea leaves stored under different conditions was examined. Survival and growth of Salmonella was also assessed after subsequent brewing using dried inoculated teas. A Salmonella enterica serovar cocktail was inoculated onto different dried tea leaves or flowers to give starting populations of approximately 10 log CFU/g. The inoculum was allowed to dry (at ambient temperature for 24 h) onto the dried leaves or flowers prior to storage under 25 and 35 °C at low (<30% relative humidity [RH]) and high (>90% RH) humidity levels. Under the four storage conditions tested, survival followed the order 25 °C with low RH > 35 °C with low RH > 25 °C with high RH > 35 °C with high RH. Salmonella losses at 25 °C with low RH occurred primarily during drying, after which populations showed little decline over 6 months. In contrast, Salmonella decreased below detection after 45 days at 35 °C and high RH in all teas tested. The thermal resistance of Salmonella was assessed at 55 °C immediately after inoculation of tea leaves or flowers, after drying (24 h) onto tea leaves or flowers, and after 28 days of storage at 25 °C with low RH. All conditions resulted in similar D-values (2.78 ± 0.12, 3.04 ± 0.07, and 2.78 ± 0.56, at 0 h, 24 h, and 28 days, respectively), indicating thermal resistance of Salmonella in brewed tea did not change after desiccation and 28 days of storage. In addition, all brewed teas tested supported the growth of Salmonella. If Salmonella survives after storage, it may also survive and grow after a home brewing process.

  5. [Effects of ground surface mulching in tea garden on soil water and nutrient dynamics and tea plant growth].

    PubMed

    Sun, Li-tao; Wang, Yu; Ding, Zhao-tang

    2011-09-01

    Taking a 2-year-old tea garden in Qingdao of Shandong Province as test object, this paper studied the effects of different mulching modes on the soil water and nutrient dynamics and tea plant growth. Four treatments were installed, i.e., no mulching (CK), straw mulching (T1), plastic film mulching (T2), and straw plus plastic film mulching (T3). Comparing with CK, mulching could keep the soil water content at a higher level, and enhance the water use efficiency. In treatments T1 and T3, the tea growth water use efficiency and yield water use efficiency increased by 43%-48% and 7%-13%, respectively, compared with CK. Also in treatments T1 and T3, the contents of soil organic matter, available-N, nitrate-N, and ammonium-N increased significantly, with the soil fertility improved, and the leaf nitrate-N content and nitrate reductase activity increased, which promoted the tea growth and yield (12%-13% higher than CK) and made the peak period of bud growth appeared earlier. Considering the tea growth and yield, water and nutrient use efficiency, environment safety and economic benefit, straw mulching could be an effective ground surface mulching mode for young tea garden.

  6. Inhibition of attachment of oral bacteria to immortalized human gingival fibroblasts (HGF-1) by tea extracts and tea components

    PubMed Central

    2013-01-01

    Background Tea has been suggested to promote oral health by inhibiting bacterial attachment to the oral cavity. Most studies have focused on prevention of bacterial attachment to hard surfaces such as enamel. Findings This study investigated the effect of five commercial tea (green, oolong, black, pu-erh and chrysanthemum) extracts and tea components (epigallocatechin gallate and gallic acid) on the attachment of five oral pathogens (Streptococcus mutans ATCC 25175, Streptococcus mutans ATCC 35668, Streptococcus mitis ATCC 49456, Streptococcus salivarius ATCC 13419 and Actinomyces naeslundii ATCC 51655) to the HGF-1 gingival cell line. Extracts of two of the teas (pu-erh and chrysanthemum) significantly (p < 0.05) reduced attachment of all the Streptococcus strains by up to 4 log CFU/well but effects of other teas and components were small. Conclusions Pu-erh and chrysanthemum tea may have the potential to reduce attachment of oral pathogens to gingival tissue and improve the health of oral soft tissues. PMID:23578062

  7. Fungal isolates from a Pu-erh type tea fermentation and their ability to convert tea polyphenols to theabrownins.

    PubMed

    Wang, Qiuping; Gong, Jiashun; Chisti, Yusuf; Sirisansaneeyakul, Sarote

    2015-04-01

    The natural microbiota involved in the fermentation influence the quality and taste of fully postfermented teas such as China's Pu-erh tea. Ten microbial isolates representing 6 species were recovered from a solid-state fermentation of a Pu-erh type tea. The isolates were Aspergillus tubingensis, Aspergillus marvanovae, Rhizomucor pusillus, Rhizomucor tauricus, Aspergillus fumigatus, and Candida mogii. With the exception of A. marvanovae and C. mogii, all these microorganisms have been previously reported in solid-state fermentations of native Pu-erh tea. The ability of the isolates for converting the tea polyphenols to bioactive theabrownins in infusions of sun-dried green tea leaves in a submerged fermentation process was subsequently investigated. All isolates except C. mogii TISTR 5938 effectively produced theabrownins in a 4-d fermentation in shake flasks at 40 °C, 250 rpm. A. tubingensis TISTR 3646, A. tubingensis TISTR 3647, A. marvanovae TISTR 3648, and A. fumigatus TISTR 3654 produced theabrownins at particularly high levels of 6.5, 12.4, 11.1, and 8.4 g/L, respectively.

  8. Caffeine is responsible for the bloodglucose-lowering effects of green tea and Puer tea extractsin BALB/c mice.

    PubMed

    Fang, Chong-Ye; Wang, Xuan-Jun; Huang, Ye-Wei; Hao, Shu-Mei; Sheng, Jun

    2015-08-01

    The present study was designed to determine the effects of Puer tea and green tea on blood glucose level. Male BALB/c mice were administered green tea extract (GTE) or Puer tea extract (PTE), either intragastrically or in their drinking water. The major components of these teas are epigallocatechin gallate (EGCG) and caffeine, respectively. Blood glucose measurement results showed that mice fed intragastrically or mice that drank GTE, PTE or caffeine showed significantly lower blood glucose levels compared to the control group. However, EGCG exhibited no influence on the blood glucose levels. When caffeine was eliminated from the GTE and PTE, the effect on the blood glucose levels was abolished, but the effect was recovered when caffeine was re-introduced into the extracts. Evaluation of hematological and biochemical indices at the time of the greatest caffeine-induced decrease in blood glucose levels showed that the effect of caffeine was specific. Microarray analyses were performed in 3T3-L1 preadipocytes and mature adipocytes treated with 0.1 mg · mL(-1) caffeine to identify factors that might be involved in the mechanisms underlying these effects. The results showed that few genes were changed after caffeine treatment in adipocytes, and of them only phospholipid transfer protein (PLTP) may be ralated to blood glucose. In conclusion, this study indicates that caffeine may be the key constituent of tea that decreases blood glucose levels, and it may be used to treat type 2 diabetes.

  9. [Effects of ground surface mulching in tea garden on soil water and nutrient dynamics and tea plant growth].

    PubMed

    Sun, Li-tao; Wang, Yu; Ding, Zhao-tang

    2011-09-01

    Taking a 2-year-old tea garden in Qingdao of Shandong Province as test object, this paper studied the effects of different mulching modes on the soil water and nutrient dynamics and tea plant growth. Four treatments were installed, i.e., no mulching (CK), straw mulching (T1), plastic film mulching (T2), and straw plus plastic film mulching (T3). Comparing with CK, mulching could keep the soil water content at a higher level, and enhance the water use efficiency. In treatments T1 and T3, the tea growth water use efficiency and yield water use efficiency increased by 43%-48% and 7%-13%, respectively, compared with CK. Also in treatments T1 and T3, the contents of soil organic matter, available-N, nitrate-N, and ammonium-N increased significantly, with the soil fertility improved, and the leaf nitrate-N content and nitrate reductase activity increased, which promoted the tea growth and yield (12%-13% higher than CK) and made the peak period of bud growth appeared earlier. Considering the tea growth and yield, water and nutrient use efficiency, environment safety and economic benefit, straw mulching could be an effective ground surface mulching mode for young tea garden. PMID:22126038

  10. Benzophenone synthase from Garcinia mangostana L. pericarps.

    PubMed

    Nualkaew, Natsajee; Morita, Hiroyuki; Shimokawa, Yoshihiko; Kinjo, Keishi; Kushiro, Tetsuo; De-Eknamkul, Wanchai; Ebizuka, Yutaka; Abe, Ikuro

    2012-05-01

    The cDNA of a benzophenone synthase (BPS), a type III polyketide synthase (PKS), was cloned and the recombinant protein expressed from the fruit pericarps of Garcinia mangostana L., which contains mainly prenylated xanthones. The obtained GmBPS showed an amino acid sequence identity of 77-78% with other plant BPSs belonging to the same family (Clusiaceae). The recombinant enzyme produced 2,4,6-trihydroxybenzophenone as the predominant product with benzoyl CoA as substrate. It also accepted other substrates, such as other plant PKSs, and used 1-3 molecules of malonyl CoA to form various phloroglucinol-type and polyketide lactone-type compounds. Thus, providing GmBPS with various substrates in vivo might redirect the xanthone biosynthetic pathway.

  11. Using UV-Vis spectroscopy for simultaneous geographical and varietal classification of tea infusions simulating a home-made tea cup.

    PubMed

    Diniz, Paulo Henrique Gonçalves Dias; Barbosa, Mayara Ferreira; de Melo Milanez, Karla Danielle Tavares; Pistonesi, Marcelo Fabián; de Araújo, Mário César Ugulino

    2016-02-01

    In this work we proposed a method to verify the differentiating characteristics of simple tea infusions prepared in boiling water alone (simulating a home-made tea cup), which represents the final product as ingested by the consumers. For this purpose we used UV-Vis spectroscopy and variable selection through the Successive Projections Algorithm associated with Linear Discriminant Analysis (SPA-LDA) for simultaneous classification of the teas according to their variety and geographic origin. For comparison, KNN, CART, SIMCA, PLS-DA and PCA-LDA were also used. SPA-LDA and PCA-LDA provided significantly better results for tea classification of the five studied classes (Argentinean green tea; Brazilian green tea; Argentinean black tea; Brazilian black tea; and Sri Lankan black tea). The proposed methodology provides a simpler, faster and more affordable classification of simple tea infusions, and can be used as an alternative approach to traditional tea quality evaluation as made by skilful tasters, which is evidently partial and cannot assess geographic origins.

  12. Assessment of fluoride concentration and daily intake by human from tea and herbal infusions.

    PubMed

    Malinowska, E; Inkielewicz, I; Czarnowski, W; Szefer, P

    2008-03-01

    The fluoride content in infusions of commercially available black, green, oolong, pu-erh and white teas was determined by ion-selective electrode. Herbal infusions as well as instant tea and ready-to-drink tea beverages were also examined. It is found that brewing time (5, 10 and 30 min) does increase the fluoride content, which in infusions of black tea (5 min brewing) was higher than that in the other types of tea, with contents ranging between 0.32 and 4.54 mg/l for black tea to 0.37-0.54 mg/l for white tea and with even lower values for herbal tea infusions of 0.02-0.09 mg/l. On the basis of the results obtained, the daily intake of fluoride provided from tea and herbal beverages was estimated for an adult person and for children in comparison with the Polish SAI (Safe and Adequate Daily Intake) of fluoride which is strictly attributable to ADI (Acceptable Daily Intake). The fluoride intake resulted from the regular consumption of black tea infusions was raised as compared to the other types of teas as well as herbal teas. For adult and children tea drinkers consuming five cups of black tea per day the intake of fluoride will be in the range of 8.0-303% and 12-303% of the SAI, respectively. People are often exposed to multiple sources of fluoride, such as in food, water, air and excessive use of toothpaste. The control of tea quality is important to protect human against too high uptake of this element from black tea, which is the most popular beverage. Excessive intake of fluoride with black tea, especially in the regions with its high level in the drinking water, increases the risk of dental fluorosis in children during the years of tooth development. The long-term exposure to large amounts of fluoride can lead to potentially skeletal fluorosis (WHO, 1984).

  13. Screening lactic acid bacteria with high yielding-acid capacity from pickled tea for their potential uses of inoculating to ferment tea products.

    PubMed

    Xiao, Ping; Huang, Youyi; Yang, Wenpeng; Zhang, Bowei; Quan, Xiaoxia

    2015-10-01

    For there were very short of excellent strains inoculated to ferment tea products, the lactic acid bacteria from pickled tea were isolated, characterized and identified, and the acid production capacity of part better strains was determined. There are only 22 strains isolated from pickled tea, and 2 of them were yeast, and 8 strains selected from the other 20 strains all were identified as Lactobacillus plantarum. A1, L2 and L5 of L. plantarum with a high acid production capacity were screened out and could obviously shorten the fermentation time of pickled tea by the verification, which suggests that they have a potential use of inoculating to ferment tea products. It was the first report on screening lactic acid bacteria with high yielding-acid capacity from pickled tea, which will bring benefits to fermenting tea products by artificial inoculation. PMID:26396422

  14. Monoterpene synthases from grand fir (Abies grandis). cDNA isolation, characterization, and functional expression of myrcene synthase, (-)-(4S)-limonene synthase, and (-)-(1S,5S)-pinene synthase.

    PubMed

    Bohlmann, J; Steele, C L; Croteau, R

    1997-08-29

    Grand fir (Abies grandis) has been developed as a model system for studying defensive oleoresin formation in conifers in response to insect attack or other injury. The turpentine fraction of the oleoresin is a complex mixture of monoterpene (C10) olefins in which (-)-limonene and (-)-alpha- and (-)-beta-pinene are prominent components; (-)-limonene and (-)-pinene synthase activities are also induced upon stem wounding. A similarity based cloning strategy yielded three new cDNA species from a wounded stem cDNA library that appeared to encode three distinct monoterpene synthases. After expression in Escherichia coli and enzyme assay with geranyl diphosphate as substrate, subsequent analysis of the terpene products by chiral phase gas chromatography and mass spectrometry showed that these sequences encoded a (-)-limonene synthase, a myrcene synthase, and a (-)-pinene synthase that produces both alpha-pinene and beta-pinene. In properties and reaction stereochemistry, the recombinant enzymes resemble the corresponding native monoterpene synthases of wound-induced grand fir stem. The deduced amino acid sequences indicated the limonene synthase to be 637 residues in length (73.5 kDa), the myrcene synthase to be 627 residues in length (72.5 kDa), and the pinene synthase to be 628 residues in length (71.5 kDa); all of these monoterpene synthases appear to be translated as preproteins bearing an amino-terminal plastid targeting sequence. Sequence comparison revealed that these monoterpene synthases from grand fir resemble sesquiterpene (C15) synthases and diterpene (C20) synthases from conifers more closely than other monoterpene synthases from angiosperm species. This similarity between extant monoterpene, sesquiterpene, and diterpene synthases of gymnosperms is surprising since functional diversification of this enzyme class is assumed to have occurred over 300 million years ago. Wound-induced accumulation of transcripts for monoterpene synthases was demonstrated by RNA

  15. Bactericidal activity of green tea extracts: the importance of catechin containing nano particles

    PubMed Central

    Gopal, Judy; Muthu, Manikandan; Paul, Diby; Kim, Doo-Hwan; Chun, Sechul

    2016-01-01

    When we drink green tea infusion, we believe we are drinking the extract of the green tea leaves. While practically each tea bag infused in 300 mL water contains about 50 mg of suspended green tea leaf particles. What is the role of these particles in the green tea effect is the objective of this study. These particles (three different size ranges) were isolated via varying speed centrifugation and their respective inputs evaluated. Live oral bacterial samples from human volunteers have been screened against green tea extracts and macro, micro and nano sized green tea particles. The results showed that the presence/absence of the macro and mico sized tea particles in the green tea extract did not contribute much. However, the nano sized particles were characterized to be nature’s nano stores of the bioactive catechins. Eradication of these nano tea particles resulted in decrease in the bactericidal property of the green tea extracts. This is a curtain raiser investigation, busting the nano as well as green tea leaf particle contribution in green tea extracts. PMID:26818408

  16. Bactericidal activity of green tea extracts: the importance of catechin containing nano particles.

    PubMed

    Gopal, Judy; Muthu, Manikandan; Paul, Diby; Kim, Doo-Hwan; Chun, Sechul

    2016-01-28

    When we drink green tea infusion, we believe we are drinking the extract of the green tea leaves. While practically each tea bag infused in 300 mL water contains about 50 mg of suspended green tea leaf particles. What is the role of these particles in the green tea effect is the objective of this study. These particles (three different size ranges) were isolated via varying speed centrifugation and their respective inputs evaluated. Live oral bacterial samples from human volunteers have been screened against green tea extracts and macro, micro and nano sized green tea particles. The results showed that the presence/absence of the macro and mico sized tea particles in the green tea extract did not contribute much. However, the nano sized particles were characterized to be nature's nano stores of the bioactive catechins. Eradication of these nano tea particles resulted in decrease in the bactericidal property of the green tea extracts. This is a curtain raiser investigation, busting the nano as well as green tea leaf particle contribution in green tea extracts.

  17. Building-block selectivity of polyketide synthases.

    PubMed

    Liou, Grace F; Khosla, Chaitan

    2003-04-01

    For the past decade, polyketide synthases have presented an exciting paradigm for the controlled manipulation of complex natural product structure. These multifunctional enzymes catalyze the biosynthesis of polyketide natural products by stepwise condensation and modification of metabolically derived building blocks. In particular, regioselective modification of polyketide structure is possible by alterations in either intracellular acyl-CoA pools or, more commonly, by manipulation of acyl transferases that act as the primary gatekeepers for building blocks.

  18. Chrysanthemyl diphosphate synthase operates in planta as a bifunctional enzyme with chrysanthemol synthase activity.

    PubMed

    Yang, Ting; Gao, Liping; Hu, Hao; Stoopen, Geert; Wang, Caiyun; Jongsma, Maarten A

    2014-12-26

    Chrysanthemyl diphosphate synthase (CDS) is the first pathway-specific enzyme in the biosynthesis of pyrethrins, the most widely used plant-derived pesticide. CDS catalyzes c1'-2-3 cyclopropanation reactions of two molecules of dimethylallyl diphosphate (DMAPP) to yield chrysanthemyl diphosphate (CPP). Three proteins are known to catalyze this cyclopropanation reaction of terpene precursors. Two of them, phytoene and squalene synthase, are bifunctional enzymes with both prenyltransferase and terpene synthase activity. CDS, the other member, has been reported to perform only the prenyltransferase step. Here we show that the NDXXD catalytic motif of CDS, under the lower substrate conditions prevalent in plants, also catalyzes the next step, converting CPP into chrysanthemol by hydrolyzing the diphosphate moiety. The enzymatic hydrolysis reaction followed conventional Michaelis-Menten kinetics, with a Km value for CPP of 196 μm. For the chrysanthemol synthase activity, DMAPP competed with CPP as substrate. The DMAPP concentration required for half-maximal activity to produce chrysanthemol was ∼100 μm, and significant substrate inhibition was observed at elevated DMAPP concentrations. The N-terminal peptide of CDS was identified as a plastid-targeting peptide. Transgenic tobacco plants overexpressing CDS emitted chrysanthemol at a rate of 0.12-0.16 μg h(-1) g(-1) fresh weight. We propose that CDS should be renamed a chrysanthemol synthase utilizing DMAPP as substrate.

  19. Chrysanthemyl Diphosphate Synthase Operates in Planta as a Bifunctional Enzyme with Chrysanthemol Synthase Activity*

    PubMed Central

    Yang, Ting; Gao, Liping; Hu, Hao; Stoopen, Geert; Wang, Caiyun; Jongsma, Maarten A.

    2014-01-01

    Chrysanthemyl diphosphate synthase (CDS) is the first pathway-specific enzyme in the biosynthesis of pyrethrins, the most widely used plant-derived pesticide. CDS catalyzes c1′-2-3 cyclopropanation reactions of two molecules of dimethylallyl diphosphate (DMAPP) to yield chrysanthemyl diphosphate (CPP). Three proteins are known to catalyze this cyclopropanation reaction of terpene precursors. Two of them, phytoene and squalene synthase, are bifunctional enzymes with both prenyltransferase and terpene synthase activity. CDS, the other member, has been reported to perform only the prenyltransferase step. Here we show that the NDXXD catalytic motif of CDS, under the lower substrate conditions prevalent in plants, also catalyzes the next step, converting CPP into chrysanthemol by hydrolyzing the diphosphate moiety. The enzymatic hydrolysis reaction followed conventional Michaelis-Menten kinetics, with a Km value for CPP of 196 μm. For the chrysanthemol synthase activity, DMAPP competed with CPP as substrate. The DMAPP concentration required for half-maximal activity to produce chrysanthemol was ∼100 μm, and significant substrate inhibition was observed at elevated DMAPP concentrations. The N-terminal peptide of CDS was identified as a plastid-targeting peptide. Transgenic tobacco plants overexpressing CDS emitted chrysanthemol at a rate of 0.12–0.16 μg h−1 g−1 fresh weight. We propose that CDS should be renamed a chrysanthemol synthase utilizing DMAPP as substrate. PMID:25378387

  20. All members in the sphingomyelin synthase gene family have ceramide phosphoethanolamine synthase activity[S

    PubMed Central

    Ding, Tingbo; Kabir, Inamul; Li, Yue; Lou, Caixia; Yazdanyar, Amirfarbod; Xu, Jiachen; Dong, Jibin; Zhou, Hongwen; Park, Taesik; Boutjdir, Mohamed; Li, Zhiqiang; Jiang, Xian-Cheng

    2015-01-01

    Sphingomyelin synthase-related protein (SMSr) synthesizes the sphingomyelin analog ceramide phosphoethanolamine (CPE) in cells. Previous cell studies indicated that SMSr is involved in ceramide homeostasis and is crucial for cell function. To further examine SMSr function in vivo, we generated Smsr KO mice that were fertile and had no obvious phenotypic alterations. Quantitative MS analyses of plasma, liver, and macrophages from the KO mice revealed only marginal changes in CPE and ceramide as well as other sphingolipid levels. Because SMS2 also has CPE synthase activity, we prepared Smsr/Sms2 double KO mice. We found that CPE levels were not significantly changed in macrophages, suggesting that CPE levels are not exclusively dependent on SMSr and SMS2 activities. We then measured CPE levels in Sms1 KO mice and found that Sms1 deficiency also reduced plasma CPE levels. Importantly, we found that expression of Sms1 or Sms2 in SF9 insect cells significantly increased not only SM but also CPE formation, indicating that SMS1 also has CPE synthase activity. Moreover, we measured CPE synthase Km and Vmax for SMS1, SMS2, and SMSr using different NBD ceramides. Our study reveals that all mouse SMS family members (SMSr, SMS1, and SMS2) have CPE synthase activity. However, neither CPE nor SMSr appears to be a critical regulator of ceramide levels in vivo. PMID:25605874

  1. Antioxidant potential of green and black tea determined using the ferric reducing power (FRAP) assay.

    PubMed

    Langley-Evans, S C

    2000-05-01

    Tea is one of the most commonly consumed beverages in the world and is rich in polyphenolic compounds collectively known as the tea flavonoids. Tea flavonoids possess antioxidant properties in vitro and have been proposed as key protective dietary components, reducing risk of coronary heart disease and some cancers. The present study aimed to evaluate the possible effects of different preparation methods on the antioxidant properties of green and black tea. Antioxidant potentials of tea infusates were assessed using an assay based upon the reduction of ferric chloride linked to a chromophore. Green tea, black leaf tea and black tea in tea bags were infused with water at 90 degrees C for time periods ranging from 0.25 to 15 min. Green tea infusates possessed approximately 2.5-fold greater antioxidant capacity than both types of black tea infusates. Both green and black teas released significant levels of antioxidants into the hot water within 2 min of infusion. Preparation of teas across a range of temperatures between 20 and 90 degrees C revealed that although antioxidants were liberated from the leaves into the water in cooler infusions, increasing the temperature could increase antioxidant potential by 4 to 9.5-fold. Black tea prepared using tea bags had significantly lower antioxidant capacity than black leaf tea at temperatures between 20 and 70 degrees C, suggesting that tea bag materials may prevent some extraction of flavonoids into the tea solution. The addition of milk appeared to diminish the antioxidant potential of black tea preparations. This effect was greatest where whole cow's milk was used and appeared to be primarily related to the fat content of the added milk. These experiments have considered the effects of commonly used domestic methods of preparation on the in vitro antioxidant potential of tea. It is concluded that maximum antioxidant capacity and hence maximal health benefit may be derived from green tea or from black leaf tea prepared by

  2. CTP synthase forms cytoophidia in the cytoplasm and nucleus

    SciTech Connect

    Gou, Ke-Mian; Chang, Chia-Chun; Shen, Qing-Ji; Sung, Li-Ying; Liu, Ji-Long

    2014-04-15

    CTP synthase is an essential metabolic enzyme responsible for the de novo synthesis of CTP. Multiple studies have recently showed that CTP synthase protein molecules form filamentous structures termed cytoophidia or CTP synthase filaments in the cytoplasm of eukaryotic cells, as well as in bacteria. Here we report that CTP synthase can form cytoophidia not only in the cytoplasm, but also in the nucleus of eukaryotic cells. Both glutamine deprivation and glutamine analog treatment promote formation of cytoplasmic cytoophidia (C-cytoophidia) and nuclear cytoophidia (N-cytoophidia). N-cytoophidia are generally shorter and thinner than their cytoplasmic counterparts. In mammalian cells, both CTP synthase 1 and CTP synthase 2 can form cytoophidia. Using live imaging, we have observed that both C-cytoophidia and N-cytoophidia undergo multiple rounds of fusion upon glutamine analog treatment. Our study reveals the coexistence of cytoophidia in the cytoplasm and nucleus, therefore providing a good opportunity to investigate the intracellular compartmentation of CTP synthase. - Highlights: • CTP synthase forms cytoophidia not only in the cytoplasm but also in the nucleus. • Glutamine deprivation and Glutamine analogs promotes cytoophidium formation. • N-cytoophidia exhibit distinct morphology when compared to C-cytoophidia. • Both CTP synthase 1 and CTP synthase 2 form cytoophidia in mammalian cells. • Fusions of cytoophidia occur in the cytoplasm and nucleus.

  3. Oligosaccharide Binding in Escherichia coli Glycogen Synthase

    SciTech Connect

    Sheng, Fang; Yep, Alejandra; Feng, Lei; Preiss, Jack; Geiger, James H.

    2010-11-17

    Glycogen/starch synthase elongates glucan chains and is the key enzyme in the synthesis of glycogen in bacteria and starch in plants. Cocrystallization of Escherichia coli wild-type glycogen synthase (GS) with substrate ADPGlc and the glucan acceptor mimic HEPPSO produced a closed form of GS and suggests that domain-domain closure accompanies glycogen synthesis. Cocrystallization of the inactive GS mutant E377A with substrate ADPGlc and oligosaccharide results in the first oligosaccharide-bound glycogen synthase structure. Four bound oligosaccharides are observed, one in the interdomain cleft (G6a) and three on the N-terminal domain surface (G6b, G6c, and G6d). Extending from the center of the enzyme to the interdomain cleft opening, G6a mostly interacts with the highly conserved N-terminal domain residues lining the cleft of GS. The surface-bound oligosaccharides G6c and G6d have less interaction with enzyme and exhibit a more curled, helixlike structural arrangement. The observation that oligosaccharides bind only to the N-terminal domain of GS suggests that glycogen in vivo probably binds to only one side of the enzyme to ensure unencumbered interdomain movement, which is required for efficient, continuous glucan-chain synthesis.

  4. Determination of catechins in matcha green tea by micellar electrokinetic chromatography.

    PubMed

    Weiss, David J; Anderton, Christopher R

    2003-09-01

    Catechins in green tea are known to have many beneficial health properties. Recently, it has been suggested that matcha has greater potential health benefits than other green teas. Matcha is a special powdered green tea used in the Japanese tea ceremony. However, there has been no investigation to quantitate the catechin intake from matcha compared to common green teas. We have developed a rapid method of analysis of five catechins and caffeine in matcha using micellar electrokinetic chromatography. Results are presented for water and methanol extractions of matcha compared with water extraction of a popular green tea. Using a mg catechin/g of dry leaf comparison, results indicate that the concentration of epigallocatechin gallate (EGCG) available from drinking matcha is 137 times greater than the amount of EGCG available from China Green Tips green tea, and at least three times higher than the largest literature value for other green teas. PMID:14518774

  5. 5. NORTHWEST FACADE OF JAPANESE TEA HOUSE, 1950s, BY YOSHIMIERA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. NORTHWEST FACADE OF JAPANESE TEA HOUSE, 1950s, BY YOSHIMIERA IN SUKIYA SHOIN STYLE AFTER THE KATSURA IMPERIAL VILLA - Kykuit, Japanese Tea House, 200 Lake Road, Pocantico Hills, Westchester County, NY

  6. Determination of catechins in matcha green tea by micellar electrokinetic chromatography.

    PubMed

    Weiss, David J; Anderton, Christopher R

    2003-09-01

    Catechins in green tea are known to have many beneficial health properties. Recently, it has been suggested that matcha has greater potential health benefits than other green teas. Matcha is a special powdered green tea used in the Japanese tea ceremony. However, there has been no investigation to quantitate the catechin intake from matcha compared to common green teas. We have developed a rapid method of analysis of five catechins and caffeine in matcha using micellar electrokinetic chromatography. Results are presented for water and methanol extractions of matcha compared with water extraction of a popular green tea. Using a mg catechin/g of dry leaf comparison, results indicate that the concentration of epigallocatechin gallate (EGCG) available from drinking matcha is 137 times greater than the amount of EGCG available from China Green Tips green tea, and at least three times higher than the largest literature value for other green teas.

  7. New phenylpropanoid-substituted flavan-3-ols from Pu-er ripe tea.

    PubMed

    Tao, Mu-Ke; Xu, Min; Zhu, Hong-Tao; Cheng, Rong-Rong; Wang, Dong; Yang, Chong-Ren; Zhang, Ying-Jun

    2014-08-01

    Pu-er ripe tea is a special microbial post-fermented tea made from Pu-er raw tea, a kind of green tea produced from the leaves of Camellia sinensis var. assamica. It is one of the most consumed teas in the past two decades in China, due to its special flavor, taste, and beneficial effects. This work aimed to obtain diverse catechin structures from Pu-er ripe tea, which led to the isolation of four new phenylpropanoid-substituted flavan-3-ols, puerins C-F (1-4), together with four known flavan-3-ols, (+)-catechin (5), (-)-epicatechin (6), (+/-)-gallocatechin (7), and (-)-epigallocatechin (8). Their structures were elucidated on the basis of detailed spectroscopic analysis, including 1D and 2D NMR, mass and CD spectra. Compounds 1-4, which could be formed in the post-fermentative process of Pu-er tea, were isolated for the first time from tea and Theaceae plant.

  8. Mutational analysis of a monoterpene synthase reaction: altered catalysis through directed mutagenesis of (-)-pinene synthase from Abies grandis.

    PubMed

    Hyatt, David C; Croteau, Rodney

    2005-07-15

    Two monoterpene synthases, (-)-pinene synthase and (-)-camphene synthase, from grand fir (Abies grandis) produce different product mixtures despite having highly homologous amino acid sequences and, presumably, very similar three-dimensional structures. The major product of (-)-camphene synthase, (-)-camphene, and the major products of (-)-pinene synthase, (-)-alpha-pinene, and (-)-beta-pinene, arise through distinct mechanistic variations of the electrophilic reaction cascade that is common to terpenoid synthases. Structural modeling followed by directed mutagenesis in (-)-pinene synthase was used to replace selected amino acid residues with the corresponding residues from (-)-camphene synthase in an effort to identify the amino acids responsible for the catalytic differences. This approach produced an enzyme in which more than half of the product was channeled through an alternative pathway. It was also shown that several (-)-pinene synthase to (-)-camphene synthase amino acid substitutions were necessary before catalysis was significantly altered. The data support a model in which the collective action of many key amino acids, located both in and distant from the active site pocket, regulate the course of the electrophilic reaction cascade.

  9. White and green teas (Camellia sinensis var. sinensis): variation in phenolic, methylxanthine, and antioxidant profiles.

    PubMed

    Unachukwu, Uchenna J; Ahmed, Selena; Kavalier, Adam; Lyles, James T; Kennelly, Edward J

    2010-08-01

    Recent investigations have associated white teas with anti-carcinogenic, immune-boosting, and antioxidative properties that may impact human health in a manner comparable to green teas. An in-depth chemical analysis of white tea types was conducted to quantify polyphenols and antioxidant potential of 8 commercially available white teas, and compare them to green tea. Extraction and HPLC protocols were optimized and validated for the quantification of 9 phenolic and 3 methylxanthine compounds to examine inter- and intra-variation in white and green tea types and subtypes. A sampling strategy was devised to assess various subtypes procured from different commercial sources. Variation in antioxidant activity and total phenolic content (TPC) of both tea types was further assessed by the 1-1-diphenyl-2-picrylhydrazyl (DPPH) and Folin-Ciocalteau (F-C) assays, respectively. Total catechin content (TCC) for white teas ranged widely from 14.40 to 369.60 mg/g of dry plant material for water extracts and 47.16 to 163.94 mg/g for methanol extracts. TCC for green teas also ranged more than 10-fold, from 21.38 to 228.20 mg/g of dry plant material for water extracts and 32.23 to 141.24 mg/g for methanol extracts. These findings indicate that statements suggesting a hierarchical order of catechin content among tea types are inconclusive and should be made with attention to a sampling strategy that specifies the tea subtype and its source. Certain white teas have comparable quantities of total catechins to some green teas, but lesser antioxidant capacity, suggesting that white teas have fewer non-catechin antioxidants present. Practical Application: In this investigation white and green teas were extracted in ways that mimic common tea preparation practices, and their chemical profiles were determined using validated analytical chemistry methods. The results suggest certain green and white tea types have comparable levels of catechins with potential health promoting qualities

  10. Determination of in vitro antidiabetic effects, antioxidant activities and phenol contents of some herbal teas.

    PubMed

    Büyükbalci, Aynur; El, Sedef Nehir

    2008-03-01

    In this research, some herbal teas and infusions traditionally used in the treatment of diabetes in Turkey, have been studied for their antidiabetic effects on in vitro glucose diffusion and phenolic contents and antioxidant activities. Ten aqueous herbal tea extracts were examined using an in vitro method to determine their effects on glucose movement across the gastrointestinal tract. Total phenol content of herbal teas was analyzed by Folin-Ciocalteu's procedure. Antioxidant activities of herbal teas were evaluated by the effect of extracts on DPPH radical and hydrogen peroxide scavenging. Antioxidant activity was defined as the amount of the sample to decrease the initial DPPH concentration by 50% as efficient concentration, EC50. Antiradical activity [AE] was calculated as 1/EC50. Values were evaluated statistically. Results support the view that none of the herbal teas showed antidiabetic effect on glucose diffusion using in vitro model glucose absorption. Teas were arranged in the order of green tea > peppermint > thyme > black tea > relax tea > absinthium > shrubby blackberry > sage > roselle > olive leaves according to their total phenol contents. Among ten herbal teas, green tea had the highest hydrogen-donating capacity against to DPPH radical. Ranking of the herbal teas with respect to their DPPH radical scavenging activity were green tea > peppermint > black tea > thyme > relax tea > absinthium > roselle > olive leaves > sage > shrubby blackberry. It was determined that adding flavoring substances such as lemon, bergamot, clove and cinnamon, which are commonly used in preparation of black tea in Turkey resulted to have synergistic effect on total antioxidant activities of black and peppermint teas. The highest hydrogen peroxide inhibition value (65.50%) was obtained for green tea at a 250 microl/ml concentration. The H2O2 scavenging activity of herbal teas decreased in the order green tea > peppermint > relax tea > black tea > thyme > olive leaves

  11. Regulation of mitochondrial ATP synthase in cardiac pathophysiology.

    PubMed

    Long, Qinqiang; Yang, Kevin; Yang, Qinglin

    2015-01-01

    Mitochondrial function is paramount to energy homeostasis, metabolism, signaling, and apoptosis in cells. Mitochondrial complex V (ATP synthase), a molecular motor, is the ultimate ATP generator and a key determinant of mitochondrial function. ATP synthase catalyzes the final coupling step of oxidative phosphorylation to supply energy in the form of ATP. Alterations at this step will crucially impact mitochondrial respiration and hence cardiac performance. It is well established that cardiac contractility is strongly dependent on the mitochondria, and that myocardial ATP depletion is a key feature of heart failure. ATP synthase dysfunction can cause and exacerbate human diseases, such as cardiomyopathy and heart failure. While ATP synthase has been extensively studied, essential questions related to how the regulation of ATP synthase determines energy metabolism in the heart linger and therapies targeting this important mechanism remain scarce. This review will visit the main findings, identify unsolved issues and provide insights into potential future perspectives related to the regulation of ATP synthase and cardiac pathophysiology.

  12. Geranyl diphosphate synthase molecules, and nucleic acid molecules encoding same

    DOEpatents

    Croteau, Rodney Bruce; Burke, Charles Cullen

    2008-06-24

    In one aspect, the present invention provides isolated nucleic acid molecules that each encode a geranyl diphosphate synthase protein, wherein each isolated nucleic acid molecule hybridizes to a nucleic acid molecule consisting of the sequence set forth in SEQ ID NO:1 under conditions of 5.times.SSC at 45.degree. C. for one hour. The present invention also provides isolated geranyl diphosphate synthase proteins, and methods for altering the level of expression of geranyl diphosphate synthase protein in a host cell.

  13. Green tea extract: A potential cause of acute liver failure

    PubMed Central

    Patel, Shreena S; Beer, Stacey; Kearney, Debra L; Phillips, Garrett; Carter, Beth A

    2013-01-01

    The use of herbal products has increased significantly in recent years. Because these products are not subject to regulation by the Food and Drug Administration and are often used without supervision by a healthcare provider, the indication for and consumption of these supplements is quite variable. Moreover, their use is generally regarded as safe and natural by the lay-public. Unfortunately, there has been an increase in the number of reported adverse events occurring with the use of herbal products. We present a case of acute impending liver failure in an adolescent male using a weight-loss product containing green tea extract. Our case adds to the growing concern surrounding the ingestion of green tea extract and serves to heighten healthcare provider awareness of a potential green tea extract hepatotoxicity. Despite the generally touted benefits of green tea as a whole, clinical concern regarding its use is emerging and has been linked to its concentration in multiple herbal supplements. Interestingly, the suspected harmful compounds are those previously proposed to be advantageous for weight-loss, cancer remedy, and anti-inflammatory purposes. Yet, we emphasize the need to be aware of not just green tea extract, but the importance of monitoring patient use of all dietary supplements and herbal products. PMID:23964154

  14. Green tea catechins: defensive role in cardiovascular disorders.

    PubMed

    Bhardwaj, Pooja; Khanna, Deepa

    2013-07-01

    Green tea, Camellia sinensis (Theaceae), a major source of flavonoids such as catechins, has recently shown multiple cardiovascular health benefits through various experimental and clinical studies. These studies suggest that green tea catechins prevent the incidence of detrimental cardiovascular events, and also lower the cardiovascular mortality rate. Catechins present in green tea have the ability to prevent atherosclerosis, hypertension, endothelial dysfunction, ischemic heart diseases, cardiomyopathy, cardiac hypertrophy and congestive heart failure by decreasing oxidative stress, preventing inflammatory events, reducing platelet aggregation and halting the proliferation of vascular smooth muscle cells. Catechins afford an anti-oxidant effect by inducing anti-oxidant enzymes, inhibiting pro-oxidant enzymes and scavenging free radicals. Catechins present anti-inflammatory activity through the inhibition of transcriptional factor NF-κB-mediated production of cytokines and adhesion molecules. Green tea catechins interfere with vascular growth factors and thus inhibit vascular smooth muscle cell proliferation, and also inhibit thrombogenesis by suppressing platelet adhesion. Additionally, catechins could protect vascular endothelial cells and enhance vascular integrity and regulate blood pressure. In this review various experimental and clinical studies suggesting the role of green tea catechins against the markers of cardiovascular disorders and the underlying mechanisms for these actions are discussed.

  15. Green tea polyphenols for prostate cancer chemoprevention: A translational perspective

    PubMed Central

    Johnson, J.J.; Bailey, H.H.; Mukhtar, H.

    2009-01-01

    Every year nearly 200,000 men in the United States are diagnosed with prostate cancer (PCa), and another 29,000 men succumb to the disease. Within certain regions of the world population based studies have identified a possible role for green tea in the prevention of certain cancers, especially PCa. One constituent in particular, epigallocatechin-3-gallate also known as EGCG has been shown in cell culture models to decrease cell viability and promote apoptosis in multiple cancer cell lines including PCa with no effect on non-cancerous cell lines. In addition, animal models have consistently shown that standardized green tea polyphenols when administered in drinking water delay the development and progression of PCa. Altogether, three clinical trials have been performed in PCa patients and suggest that green tea may have a distinct role as a chemopreventive agent. This review will present the available data for standardized green tea polyphenols in regard to PCa chemoprevention that will include epidemiological, mechanism based studies, safety, pharmacokinetics, and applicable clinical trials. The data that has been collected so far suggests that green tea may be a promising agent for PCa chemoprevention and further clinical trials of participants at risk of PCa or early stage PCa are warranted. PMID:19959000

  16. Brick tea fluoride as a main source of adult fluorosis.

    PubMed

    Cao, Jin; Zhao, Yan; Liu, Jianwei; Xirao, Ruoden; Danzeng, Sangbu; Daji, Dawei; Yan, Yu

    2003-04-01

    An epidemiological survey was conducted in Naqu County, Tibet in September 2001 to investigate the manifestations of fluorosis in adults caused by the habitual consumption of brick tea. Profiles were obtained for the total daily fluoride intake, environmental fluoride levels and average urinary fluoride concentration, and a physical examination and a skeletal radiographic study were conducted. One hundred and eleven 30-78-year-old adults were enrolled. It was found that the fluoride level of water sources in Naqu County was 0.10+/-0.03 mg/l; no evidence of fluoride air pollution was found, but the brick tea water processed foods--zamba and buttered tea--had fluoride contents of 4.52+/-0.74 mg/kg and 3.21+/-0.65 mg/l, respectively. The adult daily fluoride intake reached 12 mg, of which 99% originated from the brick tea-containing foods. The positive rate of clinical symptoms by physical examination was 89%; furthermore, 42 of the 111 subjects were diagnosed by X-ray. The positive examination rate was 83%. Although the osteosclerosis-type skeletal fluorosis (overall increased bone matrix density) affected 74%, arthropathy and arthritis affected a significant number of the patients, resulting in functional disability. The results suggest that this brick tea-type fluorosis had even more severe adverse effects on human health compared with both the water-type and coal combustion-type fluorosis that occurred in other areas of China.

  17. Green tea yogurt: major phenolic compounds and microbial growth.

    PubMed

    Amirdivani, Shabboo; Baba, Ahmad Salihin Hj

    2015-07-01

    The purpose of this study was to evaluate fermentation of milk in the presence of green tea (Camellia sinensis) with respect to changes in antioxidant activity, phenolic compounds and the growth of lactic acid bacteria. Pasteurized full fat cow's milk and starter culture were incubated at 41 °C in the presence of two different types of green tea extracts. The yogurts formed were refrigerated (4 °C) for further analysis. The total phenolic content was highest (p < 0.05) in air-dried green tea-yogurt (MGT) followed by steam-treated green tea (JGT) and plain yogurts. Four major compounds in MGTY and JGTY were detected. The highest concentration of major phenolic compounds in both samples was related to quercetin-rhamnosylgalactoside and quercetin-3-O-galactosyl-rhamnosyl-glucoside for MGTY and JGTY respectively during first 7 day of storage. Diphenyl picrylhydrazyl and ferric reducing antioxidant power methods showed highest antioxidant capacity in MGTY, JGTY and PY. Streptococcus thermophillus and Lactobacillus spp. were highest in MGTY followed by JGTY and PY. This paper evaluates the implementation of green tea yogurt as a new product with functional properties and valuable component to promote the growth of beneficial yogurt bacteria and prevention of oxidative stress by enhancing the antioxidant activity of yogurt. PMID:26139940

  18. Transient Ejector Analysis (TEA) code user's guide

    NASA Technical Reports Server (NTRS)

    Drummond, Colin K.

    1993-01-01

    A FORTRAN computer program for the semi analytic prediction of unsteady thrust augmenting ejector performance has been developed, based on a theoretical analysis for ejectors. That analysis blends classic self-similar turbulent jet descriptions with control-volume mixing region elements. Division of the ejector into an inlet, diffuser, and mixing region allowed flexibility in the modeling of the physics for each region. In particular, the inlet and diffuser analyses are simplified by a quasi-steady-analysis, justified by the assumption that pressure is the forcing function in those regions. Only the mixing region is assumed to be dominated by viscous effects. The present work provides an overview of the code structure, a description of the required input and output data file formats, and the results for a test case. Since there are limitations to the code for applications outside the bounds of the test case, the user should consider TEA as a research code (not as a production code), designed specifically as an implementation of the proposed ejector theory. Program error flags are discussed, and some diagnostic routines are presented.

  19. Varietal identification of tea (Camellia sinensis) using nanofluidic array of single nucleotide polymorphism (SNP) markers

    PubMed Central

    Fang, Wan-Ping; Meinhardt, Lyndel W; Tan, Hua-Wei; Zhou, Lin; Mischke, Sue; Zhang, Dapeng

    2014-01-01

    Apart from water, tea is the world’s most widely consumed beverage. Tea is produced in more than 50 countries with an annual production of approximately 4.7 million tons. The market segment for specialty tea has been expanding rapidly owing to increased demand, resulting in higher revenues and profits for tea growers and the industry. Accurate varietal identification is critically important to ensure traceability and authentication of premium tea products, which in turn contribute to on-farm conservation of tea genetic diversity. Using a set of single nucleotide polymorphism (SNP) markers developed from the expressed sequence tag (EST) database of Camilla senensis, we genotyped deoxyribonucleic acid (DNA) samples extracted from a diverse group of tea varieties, including both fresh and processed commercial loose-leaf teas. The validation led to the designation of 60 SNPs that unambiguously identified all 40 tested tea varieties with high statistical rigor (p<0.0001). Varietal authenticity and genetic relationships among the analyzed cultivars were further characterized by ordination and Bayesian clustering analysis. These SNP markers, in combination with a high-throughput genotyping protocol, effectively established and verified specific DNA fingerprints for all tested tea varieties. This method provides a powerful tool for variety authentication and quality control for the tea industry. It is also highly useful for the management of tea genetic resources and breeding, where accurate and efficient genotype identification is essential. PMID:26504544

  20. 37 CFR 2.53 - Requirements for drawings filed through the TEAS.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... filed through the TEAS. 2.53 Section 2.53 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND... for drawings filed through the TEAS. The drawing must meet the requirements of § 2.52. In addition, in a TEAS submission, the drawing must meet the following requirements: (a) Standard character...

  1. 37 CFR 2.23 - Additional requirements for TEAS Plus application.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... TEAS Plus application. 2.23 Section 2.23 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND... § 2.23 Additional requirements for TEAS Plus application. (a) In addition to the filing requirements under § 2.22(a), the applicant must: (1) File the following communications through TEAS: (i)...

  2. 37 CFR 2.53 - Requirements for drawings filed through the TEAS.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... filed through the TEAS. 2.53 Section 2.53 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND... for drawings filed through the TEAS. The drawing must meet the requirements of § 2.52. In addition, in a TEAS submission, the drawing must meet the following requirements: (a) Standard character...

  3. 37 CFR 2.23 - Additional requirements for TEAS Plus application.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... TEAS Plus application. 2.23 Section 2.23 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND... § 2.23 Additional requirements for TEAS Plus application. (a) In addition to the filing requirements under § 2.22(a), the applicant must: (1) File the following communications through TEAS: (i)...

  4. 37 CFR 2.23 - Additional requirements for TEAS Plus application.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... TEAS Plus application. 2.23 Section 2.23 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND... § 2.23 Additional requirements for TEAS Plus application. (a) In addition to the filing requirements under § 2.22(a), the applicant must: (1) File the following communications through TEAS: (i)...

  5. 37 CFR 2.53 - Requirements for drawings filed through the TEAS.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... filed through the TEAS. 2.53 Section 2.53 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND... for drawings filed through the TEAS. The drawing must meet the requirements of § 2.52. In addition, in a TEAS submission, the drawing must meet the following requirements: (a) Standard character...

  6. 37 CFR 2.23 - Additional requirements for TEAS Plus application.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... TEAS Plus application. 2.23 Section 2.23 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND... § 2.23 Additional requirements for TEAS Plus application. (a) In addition to the filing requirements under § 2.22(a), the applicant must: (1) File the following communications through TEAS: (i)...

  7. 37 CFR 2.53 - Requirements for drawings filed through the TEAS.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... filed through the TEAS. 2.53 Section 2.53 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND... for drawings filed through the TEAS. The drawing must meet the requirements of § 2.52. In addition, in a TEAS submission, the drawing must meet the following requirements: (a) Standard character...

  8. 37 CFR 2.23 - Additional requirements for TEAS Plus application.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... TEAS Plus application. 2.23 Section 2.23 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND... § 2.23 Additional requirements for TEAS Plus application. (a) In addition to the filing requirements under § 2.22(a), the applicant must: (1) File the following communications through TEAS: (i)...

  9. Integrated Emergy and Economic Evaluation of Tea Production Chains in Anxi, China

    EPA Science Inventory

    Emergy and economic methods were used to evaluate and compare tea production systems in Anxi, China. Tea production was classified into three phases, i.e., the nursery, the plantation and tea processing, and each phase was evaluated. The results showed that the nursery subsystems...

  10. Green tea formulations with vitamin C and xylitol on enhanced intestinal transport of green tea catechins.

    PubMed

    Chung, Jae-Hwan; Kim, Sol; Lee, Sang-Jun; Chung, Jin-Oh; Oh, Yu-Jin; Shim, Soon-Mi

    2013-05-01

    The effect of green tea formulated with vitamin C and xylitol on intestinal cell transport of gallated and nongallated catechin was studied. The transport of catechins from both apical to basolateral and basolateral to apical directions was measured. The effect of vitamin C (4, 10, 20 ppm), xylitol (11, 27.5, 55 ppm), and combinations of both on the intestinal transport rate of catechins was examined. The efflux value (Pb→a/Pa→b) of (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCG), (-)-epicatechin (EC), and (-)-epicatechin gallate (ECG) was 0.26, 0.22, 1.22, and 0.17, respectively, indicating that EC appeared to be less absorbed compared with other catechins. The addition of xylitol (11, 27.5, 55 ppm) and vitamin C (4, 10, 20 ppm) and in combination enhanced transport rate of nongallated catechins such as EC and EGC. For EC, vitamin C was revealed to be the most effective on intestinal transport, implying the inhibition of the efflux transport mechanism of EC. Intestinal transport of gallated catechins significantly increased from catechins formulated with vitamin C and xylitol in a dose-dependent manner compared to the catechin-only formulation. Results provide a potential strategy to enhance the delivery and bioavailability of catechins in humans by modulating green tea formulation with vitamin C and xylitol.

  11. Vitis vinifera terpenoid cyclases: functional identification of two sesquiterpene synthase cDNAs encoding (+)-valencene synthase and (-)-germacrene D synthase and expression of mono- and sesquiterpene synthases in grapevine flowers and berries.

    PubMed

    Lücker, Joost; Bowen, Pat; Bohlmann, Jörg

    2004-10-01

    Valencene is a volatile sesquiterpene emitted from flowers of grapevine, Vitis vinifera L. A full-length cDNA from the cultivar Gewürztraminer was functionally expressed in Escherichia coli and found to encode valencene synthase (VvVal). The two major products formed by recombinant VvVal enzyme activity with farnesyl diphosphate (FPP) as substrate are (+)-valencene and (-)-7-epi-alpha-selinene. Grapevine valencene synthase is closely related to a second sesquiterpene synthase from this species, (-)-germacrene D synthase (VvGerD). VvVal and VvGerD cDNA probes revealed strong signals in Northern hybridizations with RNA isolated from grapevine flower buds. Transcript levels were lower in open pre-anthesis flowers, flowers after anthesis, or at early onset of fruit development. Similar results were obtained using a third probe, (-)-alpha-terpineol synthase, a monoterpenol synthase. Sesquiterpene synthase and monoterpene synthase transcripts were not detected in the mesocarp and exocarp during early stages of fruit development, but transcripts hybridizing with VvVal appeared during late ripening of the berries. Sesquiterpene synthase transcripts were also detected in young seeds. PMID:15464152

  12. Divinyl ether synthase gene, and protein and uses thereof

    DOEpatents

    Howe, Gregg A.; Itoh, Aya

    2006-12-26

    The present invention relates to divinyl ether synthase genes, proteins, and methods of their use. The present invention encompasses both native and recombinant wild-type forms of the synthase, as well as mutants and variant forms, some of which possess altered characteristics relative to the wild-type synthase. The present invention also relates to methods of using divinyl ether synthase genes and proteins, including in their expression in transgenic organisms and in the production of divinyl ether fatty acids, and to methods of suing divinyl ether fatty acids, including in the protection of plants from pathogens.

  13. Divinyl ether synthase gene and protein, and uses thereof

    DOEpatents

    Howe, Gregg A.; Itoh, Aya

    2011-09-13

    The present invention relates to divinyl ether synthase genes, proteins, and methods of their use. The present invention encompasses both native and recombinant wild-type forms of the synthase, as well as mutants and variant forms, some of which possess altered characteristics relative to the wild-type synthase. The present invention also relates to methods of using divinyl ether synthase genes and proteins, including in their expression in transgenic organisms and in the production of divinyl ether fatty acids, and to methods of suing divinyl ether fatty acids, including in the protection of plants from pathogens.

  14. Molecular characterization of the homo-phytochelatin synthase of soybean Glycine max: relation to phytochelatin synthase.

    PubMed

    Oven, Matjaz; Page, Jonathan E; Zenk, Meinhart H; Kutchan, Toni M

    2002-02-15

    The phytochelatin homologs homo-phytochelatins are heavy metal-binding peptides present in many legumes. To study the biosynthesis of these compounds, we have isolated and functionally expressed a cDNA GmhPCS1 encoding homo-phytochelatin synthase from Glycine max, a plant known to accumulate homo-phytochelatins rather than phytochelatins upon the exposure to heavy metals. The catalytic properties of GmhPCS1 were compared with the phytochelatin synthase AtPCS1 from Arabidopsis thaliana. When assayed only in the presence of glutathione, both enzymes catalyzed phytochelatin formation. GmhPCS1 accepted homoglutathione as the sole substrate for the synthesis of homo-phytochelatins whereas AtPCS1 did not. Homo-phytochelatin synthesis activity of both recombinant enzymes was significantly higher when glutathione was included in the reaction mixture. The incorporation of both glutathione and homoglutathione into homo-phytochelatin, n = 2, was demonstrated using GmhPCS1 and AtPCS1. In addition to bis(glutathionato)-metal complexes, various other metal-thiolates were shown to contribute to the activation of phytochelatin synthase. These complexes were not accepted as substrates by the enzyme, thereby suggesting that a recently proposed model of activation cannot fully explain the catalytic mechanism of phytochelatin synthase (Vatamaniuk, O. K., Mari, S., Lu, Y. P., and Rea, P. A. (2000) J. Biol. Chem. 275, 31451-31459). PMID:11706029

  15. Design Of High Power CO2 TEA Lasers And Applications

    NASA Astrophysics Data System (ADS)

    Von Bergmann, H. M.

    2008-09-01

    There are a number of key technologies involved in the successful design and construction of high power, Carbon Dioxide TEA lasers (Transverse Excitation Atmospheric). These include uniform field electrodes, excitation circuit design including high voltage switching, discharge preionisation and for high repetition, high power applications fast transverse gas flow and the management of acoustic waves. This paper provides a summary of the design aspects of high repetition rate, high average power CO2 TEA lasers. Experimental data measured on high power CO2 TEA laser systems delivering average outputs of several kW and kHz repetition rates will be reported showing the detrimental effect of acoustic waves on laser performance and the improvement that can be achieved through effective acoustic damping measures.

  16. MULTITARGETED THERAPY OF CANCER BY GREEN TEA POLYPHENOLS

    PubMed Central

    Khan, Naghma; Mukhtar, Hasan

    2010-01-01

    Tea ranks second only to water as a major component of fluid intake worldwide and has been considered a health-promoting beverage since ancient times. For the past two decades, we and others have been investigating the potential cancer preventive and therapeutic effects of green tea and its polyphenolic mixture termed GTP. It has become clear that much of these effects of GTP are mediated by its most abundant catechin, epigallocatechin gallate (EGCG). Large amount of encouraging data from in vitro and animal models have emerged making clear that green tea is a nature's gift molecule endowed with anticancer effects. Epidemiological and geographical observations suggest that these laboratory data may be applicable to human population. Clinical trials of GTP, especially in prostate cancer patients have yielded encouraging results. This article briefly reviews properties of GTP, especially EGCG with reference to multitargeted therapy of cancer. PMID:18501505

  17. Efficacy of green tea extract in two exercise models.

    PubMed

    Novozhilov, A V; Tavrovskaya, T V; Voitenko, N G; Maslova, M N; Goncharov, N V; Morozov, V I

    2015-01-01

    Oral administration of green tea extract in a dose of 6 mg/kg twice a day (before and after exercise) over 2 weeks significantly increased swimming times on week 1 and 2 in comparison with control animals receiving water. The 7-day and final exhaustive running in rats was accompanied by a significant decrease in spleen weight and iron serum levels associated with developed reticulocytosis. Administration of green tea extract in a dose of 12 mg/kg once a day (before exercise) for 2 weeks did not affect the duration of the running, but prevented the decrease in serum iron and spleen weight, that, along with a significantly increased concentration of reduced glutathione in erythrocytes, can indicate a normalizing effect of green tea extract on hemopoiesis and stimulating effect on the antioxidant system of erythrocytes.

  18. Green tea modulates reserpine toxicity in animal models.

    PubMed

    Al-Bloushi, Shaima; Safer, Abdel-Majeed; Afzal, Mohammed; Mousa, Shaker A

    2009-02-01

    Reserpine, a natural product extracted from Rauwolfia serpintina or Rauwolfia vomitoria, is a known dopamine depleter that inhibits several neurotransmitters. Reserpine has been used clinically to control hypertension, schizophrenia, insomnia and insanity. The use of this drug, however, has been limited because of its side effects which include oxidative damage to organs, including the liver. Green tea catechins are potent antioxidants that have the potential to counteract reserpine induced oxidative stress. This study investigated the merits of administering green tea concurrently with reserpine to prevent oxidative hepatic damage in Sprague-Dawely (SD) rats. Reserpine was found to cause hepatic damage, with elevated levels of oxidative stress markers, such as Thiobarbituric Acid Reactive Substances (TBARS), transaminases and cholesterol. Reserpine also induced hepatic ultra-structural damage in the cytoplasmic membrane, nuclear envelope, endoplasmic reticulum (rER), ribosomal stripping and mitochondria. Electron microscopy examination showed revival of liver cells as a result of green tea extract administration to experimental rats.

  19. Aflatoxin in detannin coffee and tea and its destruction.

    PubMed

    Hasan, H A H

    2002-05-01

    The aflatoxins produced byAspergillus parasiticus var. globosus IMI 12090 in detannin-caffeinated coffee and black tea were five times more concentrated than in regular coffee and tea. The activity of caffeine and tannin on the fungus growth and aflatoxin production in liquid broth was tested at three levels: viz. 0.1, 0.3, and 0.6%. Tannin and caffeine induced 95% inhibition in aflatoxins at 0.3% and 0.6%, respectively. The antiaflatoxigenic properties of regular coffee and tea appear to be due to tannin, followed by caffeine. The roasting of contaminated coffee beans at 200 degrees C for 20 min is effective in the destruction of aflatoxins.

  20. The content of artemisinin in the Artemisia annua tea infusion.

    PubMed

    van der Kooy, Frank; Verpoorte, Robert

    2011-10-01

    The traditional use of the medicinal plant Artemisia annua for the treatment of malaria entails the preparation of a tea infusion. In the scientific literature there have been some discrepancies on the quantity of the active principle, artemisinin, in the tea infusion. Due to these discrepancies, we decided to quantify artemisinin in tea infusions prepared according to different methods. We also studied the water solubility of pure artemisinin at room temperature and at 100  °C and compared it to the solubility of artemisinin from the plant material. We found that the extraction efficiency is very sensitive to temperature and that efficiencies of above 90 % can be reached. We also showed that the solubility of artemisinin is not improved by other components in the extract but that a supersaturated solution of artemisinin might be formed, which is stable for at least 24 hours. PMID:21544776

  1. Engineering of chimeric class II polyhydroxyalkanoate synthases.

    PubMed

    Niamsiri, Nuttawee; Delamarre, Soazig C; Kim, Young-Rok; Batt, Carl A

    2004-11-01

    PHA synthase is a key enzyme involved in the biosynthesis of polyhydroxyalkanoates (PHAs). Using a combinatorial genetic strategy to create unique chimeric class II PHA synthases, we have obtained a number of novel chimeras which display improved catalytic properties. To engineer the chimeric PHA synthases, we constructed a synthetic phaC gene from Pseudomonas oleovorans (phaC1Po) that was devoid of an internal 540-bp fragment. Randomly amplified PCR products (created with primers based on conserved phaC sequences flanking the deleted internal fragment) were generated using genomic DNA isolated from soil and were substituted for the 540-bp internal region. The chimeric genes were expressed in a PHA-negative strain of Ralstonia eutropha, PHB(-)4 (DSM 541). Out of 1,478 recombinant clones screened for PHA production, we obtained five different chimeric phaC1Po genes that produced more PHA than the native phaC1Po. Chimeras S1-71, S4-8, S5-58, S3-69, and S3-44 exhibited 1.3-, 1.4-, 2.0-, 2.1-, and 3.0-fold-increased levels of in vivo activity, respectively. All of the mutants mediated the synthesis of PHAs with a slightly increased molar fraction of 3-hydroxyoctanoate; however, the weight-average molecular weights (Mw) of the PHAs in all cases remained almost the same. Based upon DNA sequence analyses, the various phaC fragments appear to have originated from Pseudomonas fluorescens and Pseudomonas aureofaciens. The amino acid sequence analyses showed that the chimeric proteins had 17 to 20 amino acid differences from the wild-type phaC1Po, and these differences were clustered in the same positions in the five chimeric clones. A threading model of PhaC1Po, developed based on homology of the enzyme to the Burkholderia glumae lipase, suggested that the amino acid substitutions found in the active chimeras were located mostly on the protein model surface. Thus, our combinatorial genetic engineering strategy proved to be broadly useful for improving the catalytic

  2. TEA DRINKING AND COGNITIVE FUNCTION IN OLDEST-OLD CHINESE

    PubMed Central

    Feng, L.; Li, J.; Ng, T.-P.; Lee, T.-S.; Kua, E.-H.; Zeng, Y.

    2013-01-01

    Objective We examined the longitudinal association between tea drinking frequency and cognitive function in a large sample of oldest-old Chinese. Design population-based longitudinal cohort study. Setting The Chinese Longitudinal Healthy Longevity Survey (CLHLS). Participants 7139 participants aged 80 to 115 (mean age 91.4 years) who provided complete data at baseline (year 1998). Measurements Current frequency of tea drinking and past frequency at age 60 were ascertained at baseline, and baseline and follow-up cognitive assessments were performed in the years 1998 (n=7139), 2000 (n=4081), 2002 (n=2288) and 2005 (n=913) respectively. Verbal fluency test was used as measure of cognitive function. Results Tea drinking was associated at baseline with higher mean (SD) verbal fluency scores: daily=10.7 (6.6), occasional=9.2 (5.8), non-drinker=9.0 (5.5). In linear mixed effects model that adjusted for age, gender, years of schooling, physical exercise and activities score, the regression coefficient for daily drinking (at age 60) and occasional drinking was 0.72 (P<0.0001) and 0.41(P=0.01) respectively. Tea drinkers had higher verbal fluency scores throughout the follow-up period but concurrently had a steeper slope of cognitive decline as compared with non-drinkers (coefficient for the interaction term Time*Daily drinking= −0.12, P=0.02; ‘Time’ was defined as the time interval from baseline to follow-up assessments in years). Similar results were found for current tea drinking status at study baseline year (1998) as predictor variable. Conclusion Regular tea drinking is associated with better cognitive function in oldest-old Chinese. PMID:23131816

  3. Green Tea Catechins and Cardiovascular Health: An Update

    PubMed Central

    Velayutham, Pon; Babu, Anandh; Liu, Dongmin

    2009-01-01

    Epidemiological, clinical and experimental studies have established a positive correlation between green tea consumption and cardiovascular health. Catechins, the major polyphenolic compounds in green tea, exert vascular protective effects through multiple mechanisms, including antioxidative, anti-hypertensive, anti-inflammatory, anti-proliferative, anti-thrombogenic, and lipid lowering effects. (1) Tea catechins present antioxidant activity by scavenging free radicals, chelating redox active transition-metal ions, inhibiting redox active transcription factors, inhibiting pro-oxidant enzymes and inducing antioxidant enzymes. (2) Tea catechins inhibit the key enzymes involved in lipid biosynthesis and reduce intestinal lipid absorption, thereby improving blood lipid profile. (3) Catechins regulate vascular tone by activating endothelial nitric oxide. (4) Catechins prevent vascular inflammation that plays a critical role in the progression of atherosclerotic lesions. The anti-inflammatory activities of catechins may be due to their suppression of leukocyte adhesion to endothelium and subsequent transmigration through inhibition of transcriptional factor NF-kB-mediated production of cytokines and adhesion molecules both in endothelial cells and inflammatory cells. (5) Catechins inhibit proliferation of vascular smooth muscle cells by interfering with vascular cell growth factors involved in atherogenesis. (6) Catechins suppress platelet adhesion, thereby inhibiting thrombogenesis. Taken together, catechins may be novel plant-derived small molecules for the prevention and treatment of cardiovascular diseases. This review highlights current developments in green tea extracts and vascular health, focusing specifically on the role of tea catechins in the prevention of various vascular diseases and the underlying mechanisms for these actions. In addition, the possible structure-activity relationship of catechins is discussed. PMID:18691042

  4. Novel family of terpene synthases evolved from trans-isoprenyl diphosphate synthases in a flea beetle.

    PubMed

    Beran, Franziska; Rahfeld, Peter; Luck, Katrin; Nagel, Raimund; Vogel, Heiko; Wielsch, Natalie; Irmisch, Sandra; Ramasamy, Srinivasan; Gershenzon, Jonathan; Heckel, David G; Köllner, Tobias G

    2016-03-15

    Sesquiterpenes play important roles in insect communication, for example as pheromones. However, no sesquiterpene synthases, the enzymes involved in construction of the basic carbon skeleton, have been identified in insects to date. We investigated the biosynthesis of the sesquiterpene (6R,7S)-himachala-9,11-diene in the crucifer flea beetle Phyllotreta striolata, a compound previously identified as a male-produced aggregation pheromone in several Phyllotreta species. A (6R,7S)-himachala-9,11-diene-producing sesquiterpene synthase activity was detected in crude beetle protein extracts, but only when (Z,E)-farnesyl diphosphate [(Z,E)-FPP] was offered as a substrate. No sequences resembling sesquiterpene synthases from plants, fungi, or bacteria were found in the P. striolata transcriptome, but we identified nine divergent putative trans-isoprenyl diphosphate synthase (trans-IDS) transcripts. Four of these putative trans-IDSs exhibited terpene synthase (TPS) activity when heterologously expressed. Recombinant PsTPS1 converted (Z,E)-FPP to (6R,7S)-himachala-9,11-diene and other sesquiterpenes observed in beetle extracts. RNAi-mediated knockdown of PsTPS1 mRNA in P. striolata males led to reduced emission of aggregation pheromone, confirming a significant role of PsTPS1 in pheromone biosynthesis. Two expressed enzymes showed genuine IDS activity, with PsIDS1 synthesizing (E,E)-FPP, whereas PsIDS3 produced neryl diphosphate, (Z,Z)-FPP, and (Z,E)-FPP. In a phylogenetic analysis, the PsTPS enzymes and PsIDS3 were clearly separated from a clade of known coleopteran trans-IDS enzymes including PsIDS1 and PsIDS2. However, the exon-intron structures of IDS and TPS genes in P. striolata are conserved, suggesting that this TPS gene family evolved from trans-IDS ancestors. PMID:26936952

  5. Novel family of terpene synthases evolved from trans-isoprenyl diphosphate synthases in a flea beetle.

    PubMed

    Beran, Franziska; Rahfeld, Peter; Luck, Katrin; Nagel, Raimund; Vogel, Heiko; Wielsch, Natalie; Irmisch, Sandra; Ramasamy, Srinivasan; Gershenzon, Jonathan; Heckel, David G; Köllner, Tobias G

    2016-03-15

    Sesquiterpenes play important roles in insect communication, for example as pheromones. However, no sesquiterpene synthases, the enzymes involved in construction of the basic carbon skeleton, have been identified in insects to date. We investigated the biosynthesis of the sesquiterpene (6R,7S)-himachala-9,11-diene in the crucifer flea beetle Phyllotreta striolata, a compound previously identified as a male-produced aggregation pheromone in several Phyllotreta species. A (6R,7S)-himachala-9,11-diene-producing sesquiterpene synthase activity was detected in crude beetle protein extracts, but only when (Z,E)-farnesyl diphosphate [(Z,E)-FPP] was offered as a substrate. No sequences resembling sesquiterpene synthases from plants, fungi, or bacteria were found in the P. striolata transcriptome, but we identified nine divergent putative trans-isoprenyl diphosphate synthase (trans-IDS) transcripts. Four of these putative trans-IDSs exhibited terpene synthase (TPS) activity when heterologously expressed. Recombinant PsTPS1 converted (Z,E)-FPP to (6R,7S)-himachala-9,11-diene and other sesquiterpenes observed in beetle extracts. RNAi-mediated knockdown of PsTPS1 mRNA in P. striolata males led to reduced emission of aggregation pheromone, confirming a significant role of PsTPS1 in pheromone biosynthesis. Two expressed enzymes showed genuine IDS activity, with PsIDS1 synthesizing (E,E)-FPP, whereas PsIDS3 produced neryl diphosphate, (Z,Z)-FPP, and (Z,E)-FPP. In a phylogenetic analysis, the PsTPS enzymes and PsIDS3 were clearly separated from a clade of known coleopteran trans-IDS enzymes including PsIDS1 and PsIDS2. However, the exon-intron structures of IDS and TPS genes in P. striolata are conserved, suggesting that this TPS gene family evolved from trans-IDS ancestors.

  6. Novel family of terpene synthases evolved from trans-isoprenyl diphosphate synthases in a flea beetle

    PubMed Central

    Beran, Franziska; Rahfeld, Peter; Luck, Katrin; Nagel, Raimund; Vogel, Heiko; Wielsch, Natalie; Irmisch, Sandra; Ramasamy, Srinivasan; Gershenzon, Jonathan; Heckel, David G.; Köllner, Tobias G.

    2016-01-01

    Sesquiterpenes play important roles in insect communication, for example as pheromones. However, no sesquiterpene synthases, the enzymes involved in construction of the basic carbon skeleton, have been identified in insects to date. We investigated the biosynthesis of the sesquiterpene (6R,7S)-himachala-9,11-diene in the crucifer flea beetle Phyllotreta striolata, a compound previously identified as a male-produced aggregation pheromone in several Phyllotreta species. A (6R,7S)-himachala-9,11-diene–producing sesquiterpene synthase activity was detected in crude beetle protein extracts, but only when (Z,E)-farnesyl diphosphate [(Z,E)-FPP] was offered as a substrate. No sequences resembling sesquiterpene synthases from plants, fungi, or bacteria were found in the P. striolata transcriptome, but we identified nine divergent putative trans-isoprenyl diphosphate synthase (trans-IDS) transcripts. Four of these putative trans-IDSs exhibited terpene synthase (TPS) activity when heterologously expressed. Recombinant PsTPS1 converted (Z,E)-FPP to (6R,7S)-himachala-9,11-diene and other sesquiterpenes observed in beetle extracts. RNAi-mediated knockdown of PsTPS1 mRNA in P. striolata males led to reduced emission of aggregation pheromone, confirming a significant role of PsTPS1 in pheromone biosynthesis. Two expressed enzymes showed genuine IDS activity, with PsIDS1 synthesizing (E,E)-FPP, whereas PsIDS3 produced neryl diphosphate, (Z,Z)-FPP, and (Z,E)-FPP. In a phylogenetic analysis, the PsTPS enzymes and PsIDS3 were clearly separated from a clade of known coleopteran trans-IDS enzymes including PsIDS1 and PsIDS2. However, the exon–intron structures of IDS and TPS genes in P. striolata are conserved, suggesting that this TPS gene family evolved from trans-IDS ancestors. PMID:26936952

  7. Determination of polycyclic aromatic hydrocarbons in dry tea.

    PubMed

    Adisa, Afolabi; Jimenez, Angelica; Woodham, Cara; Anthony, Kevin; Nguyen, Thao; Saleh, Mahmoud A

    2015-01-01

    Twenty-eight different tea samples sold in the United States were evaluated using high-performance liquid chromatography (HPLC) with fluorescence detection (FLD) for their contamination with polycyclic aromatic hydrocarbons (PAHs). Many PAHs exhibit carcinogenic, mutagenic, and teratogenic properties and have been related to several kinds of cancer in man and experimental animals. The presence of PAHs in environmental samples such as water, sediments, and particulate air has been extensively studied, but food samples have received little attention. Eighteen PAHs congeners were analyzed, with percentage recovery higher than 85%. Contamination expressed as the sum of the 18 analyzed PAHs was between 101 and 1337 μg/kg on dry mass and the average contents in all of the 28 examined samples was 300 μg/kg on dry mass. Seven of the congeners were found in all samples with wide ranges of concentrations as follows: fluorene (7-48 μg/kg), anthracene (1-31 μg/kg), pyrene (1-970 μg/kg), benzo(a)anthracene (1-18 μg/kg) chrysene (17-365 μg/kg), benzo(a)pyrene (1-29 μg/kg), and indeno(1,2,3-cd)pyrene (4-119 μg/kg). The two most toxic congeners benzo(a)pyrene and dibenzo(a,h)anthracene were found at high concentrations only in Earl Grey Twinnings, Earl Grey Harney& Sons Fine Teas, and Chai Ultra Spice Black Tea Twinnings. Six PAH congeners are considered as suspected carcinogens (U.S.EPA), formed the basis of the estimation of the toxic equivalent (TEQ), Chai Ultra-Spice Black Tea Twinnings had the highest TEQ (110.9) followed by two grey tea samples, Earl Grey Harney & Sons Fine Tea (57.7) and Earl Grey Twinnings (54.5). Decaffeinated grey teas had the lowest TEQs, decaffeinated Earl Grey Bigelow (9.4) and Green Tea Honey Lemon Decaffeinated Lipton (9.6).

  8. Potent inhibitors of anthrax lethal factor from green tea

    PubMed Central

    Dell'Aica, Isabella; Donà, Massimo; Tonello, Fiorella; Piris, Alejandro; Mock, Michèle; Montecucco, Cesare; Garbisa, Spiridione

    2004-01-01

    The anthrax lethal factor (LF) has a major role in the development of anthrax. LF is delivered by the protective antigen (PA) inside the cell, where it exerts its metalloprotease activity on the N-terminus of MAPK-kinases. PA+LF are cytotoxic to macrophages in culture and kill the Fischer 344 rat when injected intravenously. We describe here the properties of some polyphenols contained in green tea as powerful inhibitors of LF metalloproteolytic activity, and how the main catechin of green tea, (−)epigallocatechin-3-gallate, prevents the LF-induced death of macrophages and Fischer 344 rats. PMID:15031715

  9. Determination of polycyclic aromatic hydrocarbons in dry tea

    PubMed Central

    ADISA, AFOLABI; JIMENEZ, ANGELICA; WOODHAM, CARA; ANTHONY, KEVIN; NGUYEN, THAO; SALEH, MAHMOUD A.

    2016-01-01

    Twenty-eight different tea samples sold in the United States were evaluated using high-performance liquid chromatography (HPLC) with fluorescence detection (FLD) for their contamination with polycyclic aromatic hydrocarbons (PAHs). Many PAHs exhibit carcinogenic, mutagenic, and teratogenic properties and have been related to several kinds of cancer in man and experimental animals. The presence of PAHs in environmental samples such as water, sediments, and particulate air has been extensively studied, but food samples have received little attention. Eighteen PAHs congeners were analyzed, with percentage recovery higher than 85%. Contamination expressed as the sum of the 18 analyzed PAHs was between 101 and 1337 μg/kg on dry mass and the average contents in all of the 28 examined samples was 300 μg/kg on dry mass. Seven of the congeners were found in all samples with wide ranges of concentrations as follows: fluorene (7–48 μg/kg), anthracene (1–31 μg/kg), pyrene (1–970 μg/kg), benzo(a)anthracene (1–18 μg/kg) chrysene (17–365 μg/kg), benzo(a)pyrene (1–29 μg/kg), and indeno(1,2,3-cd)pyrene (4–119 μg/kg). The two most toxic congeners benzo(a)pyrene and dibenzo(a,h)anthracene were found at high concentrations only in Earl Grey Twinnings, Earl Grey Harney& Sons Fine Teas, and Chai Ultra Spice Black Tea Twinnings. Six PAH congeners are considered as suspected carcinogens (U.S.EPA), formed the basis of the estimation of the toxic equivalent (TEQ), Chai Ultra-Spice Black Tea Twinnings had the highest TEQ (110.9) followed by two grey tea samples, Earl Grey Harney & Sons Fine Tea (57.7) and Earl Grey Twinnings (54.5). Decaffeinated grey teas had the lowest TEQs, decaffeinated Earl Grey Bigelow (9.4) and Green Tea Honey Lemon Decaffeinated Lipton (9.6). PMID:26065515

  10. A minireview of analytical methods for the geographical origin analysis of teas (Camellia sinensis).

    PubMed

    Ye, N S

    2012-01-01

    Chemical compositions in tea leaves are influenced by their growing surrounding, and the content of these components are related to the quality of teas. The determination of the concentration of chemical composition in teas will predict the ranking of teas and indicate the geographical origins. This overview concerns an investigation of analytical methods that are being used for the determination of the geographical origin of tea. The analytical approaches have been subdivided into three groups: spectroscopic techniques, chromatographic techniques, and other techniques. The advantages, drawbacks, and reported applications concerning geographical authenticity are discussed.

  11. White tea as a promising antioxidant medium additive for sperm storage at room temperature: a comparative study with green tea.

    PubMed

    Dias, Tânia R; Alves, Marco G; Tomás, Gonçalo D; Socorro, Sílvia; Silva, Branca M; Oliveira, Pedro F

    2014-01-22

    Storage of sperm under refrigeration reduces its viability, due to oxidative unbalance. Unfermented teas present high levels of catechin derivatives, known to reduce oxidative stress. This study investigated the effect of white tea (WTEA) on epididymal spermatozoa survival at room temperature (RT), using green tea (GTEA) for comparative purposes. The chemical profiles of WTEA and GTEA aqueous extracts were evaluated by (1)H NMR. (-)-Epigallocatechin-3-gallate was the most abundant catechin, being twice as abundant in WTEA extract. The antioxidant power of storage media was evaluated. Spermatozoa antioxidant potential, lipid peroxidation, and viability were assessed. The media antioxidant potential increased the most with WTEA supplementation, which was concomitant with the highest increase in sperm antioxidant potential and lipid peroxidation decrease. WTEA supplementation restored spermatozoa viability to values similar to those obtained at collection time. These findings provide evidence that WTEA extract is an excellent media additive for RT sperm storage, to facilitate transport and avoid the deleterious effects of refrigeration.

  12. Heavy metal content in tea soils and their distribution in different parts of tea plants, Camellia sinensis (L). O. Kuntze.

    PubMed

    Seenivasan, Subbiah; Anderson, Todd Alan; Muraleedharan, Narayanannair

    2016-07-01

    Soils contaminated with heavy metals may pose a threat to environment and human health if metals enter the food chain over and above threshold levels. In general, there is a lack of information on the presence of heavy metals in tea [Camellia sinensis (L). O. Kuntze] plants and the soils in which they are grown. Therefore, an attempt was made to establish a database on the important heavy metals: cadmium (Cd), chromium (Cr), nickel (Ni), and lead (Pb). For an initial survey on heavy metals, soil samples were collected randomly from tea-growing areas of Tamil Nadu, Kerala, and Karnataka, India. Parallel studies were conducted in the greenhouse on uptake of Pb, Cd, and Ni from soils supplemented with these metals at different concentrations. Finally, metal distribution in the tea plants under field conditions was also documented to assess the accumulation potential and critical limit of uptake by plants. PMID:27334344

  13. White tea as a promising antioxidant medium additive for sperm storage at room temperature: a comparative study with green tea.

    PubMed

    Dias, Tânia R; Alves, Marco G; Tomás, Gonçalo D; Socorro, Sílvia; Silva, Branca M; Oliveira, Pedro F

    2014-01-22

    Storage of sperm under refrigeration reduces its viability, due to oxidative unbalance. Unfermented teas present high levels of catechin derivatives, known to reduce oxidative stress. This study investigated the effect of white tea (WTEA) on epididymal spermatozoa survival at room temperature (RT), using green tea (GTEA) for comparative purposes. The chemical profiles of WTEA and GTEA aqueous extracts were evaluated by (1)H NMR. (-)-Epigallocatechin-3-gallate was the most abundant catechin, being twice as abundant in WTEA extract. The antioxidant power of storage media was evaluated. Spermatozoa antioxidant potential, lipid peroxidation, and viability were assessed. The media antioxidant potential increased the most with WTEA supplementation, which was concomitant with the highest increase in sperm antioxidant potential and lipid peroxidation decrease. WTEA supplementation restored spermatozoa viability to values similar to those obtained at collection time. These findings provide evidence that WTEA extract is an excellent media additive for RT sperm storage, to facilitate transport and avoid the deleterious effects of refrigeration. PMID:24372402

  14. Evolution and function of phytochelatin synthases.

    PubMed

    Clemens, Stephan

    2006-02-01

    Both essential and non-essential transition metal ions can easily be toxic to cells. The physiological range for essential metals between deficiency and toxicity is therefore extremely narrow and a tightly controlled metal homeostasis network to adjust to fluctuations in micronutrient availability is a necessity for all organisms. One protective strategy against metal excess is the expression of high-affinity binding sites to suppress uncontrolled binding of metal ions to physiologically important functional groups. The synthesis of phytochelatins, glutathione-derived metal binding peptides, represents the major detoxification mechanism for cadmium and arsenic in plants and an unknown range of other organisms. A few years ago genes encoding phytochelatin synthases (PCS) were cloned from plants, fungi and nematodes. Since then it has become apparent that PCS genes are far more widespread than ever anticipated. Searches in sequence databases indicate PCS expression in representatives of all eukaryotic kingdoms and the presence of PCS-like proteins in several prokaryotes. The almost ubiquitous presence in the plant kingdom and beyond as well as the constitutive expression of PCS genes and PCS activity in all major plant tissues are still mysterious. It is unclear, how the extremely rare need to cope with an excess of cadmium or arsenic ions could explain the evolution and distribution of PCS genes. Possible answers to this question are discussed. Also, the molecular characterization of phytochelatin synthases and our current knowledge about the enzymology of phytochelatin synthesis are reviewed.

  15. Activities and regulation of peptidoglycan synthases

    PubMed Central

    Egan, Alexander J. F.; Biboy, Jacob; van't Veer, Inge; Breukink, Eefjan; Vollmer, Waldemar

    2015-01-01

    Peptidoglycan (PG) is an essential component in the cell wall of nearly all bacteria, forming a continuous, mesh-like structure, called the sacculus, around the cytoplasmic membrane to protect the cell from bursting by its turgor. Although PG synthases, the penicillin-binding proteins (PBPs), have been studied for 70 years, useful in vitro assays for measuring their activities were established only recently, and these provided the first insights into the regulation of these enzymes. Here, we review the current knowledge on the glycosyltransferase and transpeptidase activities of PG synthases. We provide new data showing that the bifunctional PBP1A and PBP1B from Escherichia coli are active upon reconstitution into the membrane environment of proteoliposomes, and that these enzymes also exhibit DD-carboxypeptidase activity in certain conditions. Both novel features are relevant for their functioning within the cell. We also review recent data on the impact of protein–protein interactions and other factors on the activities of PBPs. As an example, we demonstrate a synergistic effect of multiple protein–protein interactions on the glycosyltransferase activity of PBP1B, by its cognate lipoprotein activator LpoB and the essential cell division protein FtsN. PMID:26370943

  16. ATP synthase: a tentative structural model.

    PubMed

    Engelbrecht, S; Junge, W

    1997-09-15

    Adenosine triphosphate (ATP) synthase produces ATP from ADP and inorganic phosphate at the expense of proton- or sodium-motive force across the respective coupling membrane in Archaea, Bacteria and Eucarya. Cation flow through the intrinsic membrane portion of this enzyme (Fo, subunits ab2c9-12) and substrate turnover in the headpiece (F1, subunits alpha3beta3 gammadeltaepsilon) are mechanically coupled by the rotation of subunit gamma in the center of the catalytic hexagon of subunits (alphabeta)3 in F1. ATP synthase is the smallest rotatory engine in nature. With respect to the headpiece alone, it probably operates with three steps. Partial structures of six out of its at least eight different subunits have been published and a 3-dimensional structure is available for the assembly (alphabeta)3gamma. In this article, we review the available structural data and build a tentative topological model of the holoenzyme. The rotor portion is proposed to consist of a wheel of at least nine copies of subunits c, epsilon and a portion of gamma as a spoke, and another portion of gamma as a crankshaft. The stator is made up from a, the transmembrane portion of b2, delta and the catalytic hexagon of (alphabeta)3. As an educated guess, the model may be of heuristic value for ongoing studies on this fascinating electrochemical-to-mechanical-to-chemical transducer. PMID:9323021

  17. Torque generation mechanism of ATP synthase

    NASA Astrophysics Data System (ADS)

    Miller, John; Maric, Sladjana; Scoppa, M.; Cheung, M.

    2010-03-01

    ATP synthase is a rotary motor that produces adenosine triphosphate (ATP), the chemical currency of life. Our proposed electric field driven torque (EFT) model of FoF1-ATP synthase describes how torque, which scales with the number of c-ring proton binding sites, is generated by the proton motive force (pmf) across the mitochondrial inner membrane. When Fo is coupled to F1, the model predicts a critical pmf to drive ATP production. In order to fully understand how the electric field resulting from the pmf drives the c-ring to rotate, it is important to examine the charge distributions in the protonated c-ring and a-subunit containing the proton channels. Our calculations use a self-consistent field approach based on a refinement of reported structural data. The results reveal changes in pKa for key residues on the a-subunit and c-ring, as well as titration curves and protonation state energy diagrams. Health implications will be briefly discussed.

  18. Factors affecting the caffeine and polyphenol contents of black and green tea infusions.

    PubMed

    Astill, C; Birch, M R; Dacombe, C; Humphrey, P G; Martin, P T

    2001-11-01

    The effects of product and preparation variables on the in-cup chemical composition of tea extracts is of interest because the appearance and taste characteristics and the possible health effects of a tea liquor arise from the chemical components extracted from the leaf during tea preparation. A comprehensive study was therefore undertaken to determine the contributions of product and preparation variables on the total soluble solids, caffeine, and polyphenol contents of tea extracts. The results of this study show that the variety, growing environment, manufacturing conditions, and grade (particle size) of the tea leaves each influence the tea leaf and final infusion compositions. In addition, the composition of the tea infusion was shown to be influenced by whether the tea was contained in a teabag and, if so, the size and material of construction of the bag. Finally, the preparation method, including the amounts of tea and water used, infusion time, and amount of agitation, was shown to be a major determinant of the component concentrations of tea beverages as consumed. An illustration of the variation introduced by these product and preparation factors is provided by comparing solids, caffeine, and polyphenol contents of green and black tea infusions when commercial products are prepared according to the instructions given on their packaging. PMID:11714326

  19. Estimating Biochemical Parameters of Tea (camellia Sinensis (L.)) Using Hyperspectral Techniques

    NASA Astrophysics Data System (ADS)

    Bian, M.; Skidmore, A. K.; Schlerf, M.; Liu, Y.; Wang, T.

    2012-07-01

    Tea (Camellia Sinensis (L.)) is an important economic crop and the market price of tea depends largely on its quality. This research aims to explore the potential of hyperspectral remote sensing on predicting the concentration of biochemical components, namely total tea polyphenols, as indicators of tea quality at canopy scale. Experiments were carried out for tea plants growing in the field and greenhouse. Partial least squares regression (PLSR), which has proven to be the one of the most successful empirical approach, was performed to establish the relationship between reflectance and biochemical concentration across six tea varieties in the field. Moreover, a novel integrated approach involving successive projections algorithms as band selection method and neural networks was developed and applied to detect the concentration of total tea polyphenols for one tea variety, in order to explore and model complex nonlinearity relationships between independent (wavebands) and dependent (biochemicals) variables. The good prediction accuracies (r2 > 0.8 and relative RMSEP < 10 %) achieved for tea plants using both linear (partial lease squares regress) and nonlinear (artificial neural networks) modelling approaches in this study demonstrates the feasibility of using airborne and spaceborne sensors to cover wide areas of tea plantation for in situ monitoring of tea quality cheaply and rapidly.

  20. Polyphenol Bioaccessibility and Sugar Reducing Capacity of Black, Green, and White Teas

    PubMed Central

    Coe, Shelly; Ryan, Lisa

    2013-01-01

    Tea (Camellia sinensis) is a widely consumed beverage and recognised for its potential enhancing effect on human health due to its rich polyphenol content. While a number of studies have investigated the quantity and type of polyphenols present in different tea samples, no study has reported the potential effect of digestive enzymes on the availability of tea polyphenols for human absorption or the subsequent impact on glycaemic response. The objectives of the present study were to assess the total polyphenol content of different teas, to assess the bioaccessibility of polyphenols in whole and bagged teas, and to determine the effect of black, white, and green tea infusions on sugar release. All of the teas were a significant source of polyphenols (10–116 mg Gallic acid equivalents/g). There was an overall increase in the release of polyphenols from both the bagged and the whole teas following in vitro digestion. Bagged green tea significantly (P < 0.05) reduced rapidly digestible starch from white bread samples compared to control and black and white bagged teas. The present study confirms that tea is a rich source of polyphenols and highlights the potential benefits it may have on modulating glycaemic response in humans. PMID:26904591

  1. Infusing pleasure: Mood effects of the consumption of a single cup of tea.

    PubMed

    Einöther, Suzanne J L; Rowson, Matthew; Ramaekers, Johannes G; Giesbrecht, Timo

    2016-08-01

    Tea has historically been associated with mood benefits. Nevertheless, few studies have empirically investigated mood changes after tea consumption. We explored immediate effects of a single cup of tea up to an hour post-consumption on self-reported valence, arousal, discrete emotions, and implicit measures of mood. In a parallel group design, 153 participants received a cup of tea or placebo tea, or a glass of water. Immediately (i.e. 5 min) after consumption, tea increased valence but reduced arousal, as compared to the placebo. There were no differences at later time points. Discrete emotions did not differ significantly between conditions, immediately or over time. Water consumption increased implicit positivity as compared to placebo. Finally, consumption of tea and water resulted in higher interest in activities overall and in specific activity types compared to placebo. The present study shows that effects of a single cup of tea may be limited to an immediate increase in pleasure and decrease in arousal, which can increase interest in activities. Differences between tea and water were not significant, while differences between water and placebo on implicit measures were unexpected. More servings over a longer time may be required to evoke tea's arousing effects and appropriate tea consumption settings may evoke more enduring valence effects. PMID:27059832

  2. Green Tea Polyphenols Extend the Lifespan of Male Drosophila melanogaster While Impairing Reproductive Fitness

    PubMed Central

    Lopez, Terry; Schriner, Samuel E.; Okoro, Michael; Lu, David; Chiang, Beatrice T.; Huey, Jocelyn

    2014-01-01

    Abstract Green tea is a popular beverage believed to have many health benefits, including a reduction in the risks of heart disease and cancer. Rich in polyphenolic compounds known as catechins, green tea and its components have been shown to increase the lifespan of various animal models, including Drosophila melanogaster. Here, we investigated the gender-specific effects of green tea on the lifespan of fruit flies and observed that green tea extended the lifespan of male flies only. This effect was found to be independent of typical aging interventions, such as dietary restriction, modulation of oxidative energy metabolism, and improved tolerance to environmental stresses. The one exception was that green tea did protect male flies against iron toxicity. Since there is an inverse correlation between lifespan and reproduction, the impact of green tea on male reproductive fitness was also investigated. We found that green tea negatively impacted male fertility as shown by a reduced number of offspring produced and increased mating latency. We further identified that the lifespan extension properties of green tea was only observed in the presence of females which alludes to a reproductive (or mating) dependent mechanism. Our findings suggest that green tea extends the lifespan of male flies by inhibiting reproductive potential, possibly by limiting iron uptake. To our knowledge, our study is the first to report the negative impact of green tea on Drosophila male reproduction. Our results also support previous studies that suggest that green tea might have a negative effect on reproductive fitness in humans. PMID:25058464

  3. Fluoride levels in various black tea, herbal and fruit infusions consumed in Turkey.

    PubMed

    Emekli-Alturfan, Ebru; Yarat, Aysen; Akyuz, Serap

    2009-07-01

    The fluoride contents were determined by ion-selective electrode in 26 black tea samples originally produced in Turkey, Sri Lanka, India and Kenya, and in 14 herbal and seven fruit infusions originated from Turkey. Fluoride content in black tea infusions ranged from 0.57 to 3.72 mg/L after 5 min of brewing. Higher fluoride levels were found in black teas originated from Turkey when compared with teas originated from Sri Lanka. Moreover higher fluoride levels were determined in black tea bags compared with granular and stick-shaped black teas. However, herbal and fruit infusions were characterized by low values of fluoride (0.02-0.04 mg/L) after 5 min of brewing and increasing brewing time to 10 min caused only slight increases in some infusions. As a result, consuming tea infusions prepared from some black tea available in Turkish market, especially black tea bags, in large quantities may lead to exposion to a high amount of fluoride which may cause dental fluorosis. Although fruit and herbal infusions are safer to consume their fluoride contents are too low for caries prevention. In countries such as Turkey where tea is traditionally consumed, the fluoride concentration and daily safety precautions should be indicated on tea products.

  4. Effect of green tea supplementation on insulin sensitivity in Sprague-Dawley rats.

    PubMed

    Wu, Liang-Yi; Juan, Chi-Chang; Ho, Low-Tone; Hsu, Yung-Pei; Hwang, Lucy Sun

    2004-02-11

    Epidemiological observations and laboratory studies have shown that green tea has a variety of health effects, including antitumor, antioxidative, and hypolipidemic activities. The aim of this study was to examine whether it had an effect on glucose tolerance and insulin sensitivity in Sprague-Dawley rats. In experiment 1 (in vivo study), rats were divided into two groups: a control group fed standard chow and deionized distilled water and a "green tea" group fed the same chow diet but with green tea instead of water (0.5 g of lyophilized green tea powder dissolved in 100 mL of deionized distilled water). After 12 weeks of green tea supplementation, the green tea group had lower fasting plasma levels of glucose, insulin, triglyceride, and free fatty acid than the control rats. Insulin-stimulated glucose uptake of, and insulin binding to, adipocytes were significantly increased in the green tea group. In experiment 2 (in vitro study), a tea polyphenol extract was used to determine its effect on insulin activity in vitro. Green tea polyphenols (0.075%) significantly increased basal and insulin-stimulated glucose uptake of adipocytes. Results demonstrated that green tea increases insulin sensitivity in Sprague-Dawley rats and that green tea polyphenol is one of the active components.

  5. Green tea polyphenols extend the lifespan of male drosophila melanogaster while impairing reproductive fitness.

    PubMed

    Lopez, Terry; Schriner, Samuel E; Okoro, Michael; Lu, David; Chiang, Beatrice T; Huey, Jocelyn; Jafari, Mahtab

    2014-12-01

    Green tea is a popular beverage believed to have many health benefits, including a reduction in the risks of heart disease and cancer. Rich in polyphenolic compounds known as catechins, green tea and its components have been shown to increase the lifespan of various animal models, including Drosophila melanogaster. Here, we investigated the gender-specific effects of green tea on the lifespan of fruit flies and observed that green tea extended the lifespan of male flies only. This effect was found to be independent of typical aging interventions, such as dietary restriction, modulation of oxidative energy metabolism, and improved tolerance to environmental stresses. The one exception was that green tea did protect male flies against iron toxicity. Since there is an inverse correlation between lifespan and reproduction, the impact of green tea on male reproductive fitness was also investigated. We found that green tea negatively impacted male fertility as shown by a reduced number of offspring produced and increased mating latency. We further identified that the lifespan extension properties of green tea was only observed in the presence of females which alludes to a reproductive (or mating) dependent mechanism. Our findings suggest that green tea extends the lifespan of male flies by inhibiting reproductive potential, possibly by limiting iron uptake. To our knowledge, our study is the first to report the negative impact of green tea on Drosophila male reproduction. Our results also support previous studies that suggest that green tea might have a negative effect on reproductive fitness in humans.

  6. ATP synthases from archaea: the beauty of a molecular motor.

    PubMed

    Grüber, Gerhard; Manimekalai, Malathy Sony Subramanian; Mayer, Florian; Müller, Volker

    2014-06-01

    Archaea live under different environmental conditions, such as high salinity, extreme pHs and cold or hot temperatures. How energy is conserved under such harsh environmental conditions is a major question in cellular bioenergetics of archaea. The key enzymes in energy conservation are the archaeal A1AO ATP synthases, a class of ATP synthases distinct from the F1FO ATP synthase ATP synthase found in bacteria, mitochondria and chloroplasts and the V1VO ATPases of eukaryotes. A1AO ATP synthases have distinct structural features such as a collar-like structure, an extended central stalk, and two peripheral stalks possibly stabilizing the A1AO ATP synthase during rotation in ATP synthesis/hydrolysis at high temperatures as well as to provide the storage of transient elastic energy during ion-pumping and ATP synthesis/-hydrolysis. High resolution structures of individual subunits and subcomplexes have been obtained in recent years that shed new light on the function and mechanism of this unique class of ATP synthases. An outstanding feature of archaeal A1AO ATP synthases is their diversity in size of rotor subunits and the coupling ion used for ATP synthesis with H(+), Na(+) or even H(+) and Na(+) using enzymes. The evolution of the H(+) binding site to a Na(+) binding site and its implications for the energy metabolism and physiology of the cell are discussed.

  7. Characteristic Fluctuations in Glycosidically Bound Volatiles during Tea Processing and Identification of Their Unstable Derivatives.

    PubMed

    Cui, Jilai; Katsuno, Tsuyoshi; Totsuka, Kojiro; Ohnishi, Toshiyuki; Takemoto, Hiroyuki; Mase, Nobuyuki; Toda, Mitsuo; Narumi, Tetsuo; Sato, Kohei; Matsuo, Testuaki; Mizutani, Kenta; Yang, Ziyin; Watanabe, Naoharu; Tong, Huarong

    2016-02-10

    A recently developed method enabled us to simultaneously characterize and quantitate glycosidically bound volatiles (GBVs) at picomole levels using liquid chromatography-mass spectrometry (LC-MS). On the basis of the analytical data it is possible to screen tea varieties most suitable for black tea processing, in which higher concentrations of primeverosides accumulate. The primeverosides decreased at the rolling step in black tea processing, whereas the glucopyranosides did not change much. The total contents of GBVs gradually increased at the withering steps and then remarkably increased after the fixing step at 230 °C, during oolong tea processing. The presence of 6'-O-malonyl ester type β-D-glucopyranosides in the tea samples suggested a contribution to the increment in glucopyranosides during oolong tea processing. The method was also used to analyze GBVs and their derivatives to understand their possible role in the metabolic pathway of tea.

  8. 2-DE combined with two-layer feature selection accurately establishes the origin of oolong tea.

    PubMed

    Chien, Han-Ju; Chu, Yen-Wei; Chen, Chi-Wei; Juang, Yu-Min; Chien, Min-Wei; Liu, Chih-Wei; Wu, Chia-Chang; Tzen, Jason T C; Lai, Chien-Chen

    2016-11-15

    Taiwan is known for its high quality oolong tea. Because of high consumer demand, some tea manufactures mix lower quality leaves with genuine Taiwan oolong tea in order to increase profits. Robust scientific methods are, therefore, needed to verify the origin and quality of tea leaves. In this study, we investigated whether two-dimensional gel electrophoresis (2-DE) and nanoscale liquid chromatography/tandem mass spectroscopy (nano-LC/MS/MS) coupled with a two-layer feature selection mechanism comprising information gain attribute evaluation (IGAE) and support vector machine feature selection (SVM-FS) are useful in identifying characteristic proteins that can be used as markers of the original source of oolong tea. Samples in this study included oolong tea leaves from 23 different sources. We found that our method had an accuracy of 95.5% in correctly identifying the origin of the leaves. Overall, our method is a novel approach for determining the origin of oolong tea leaves.

  9. Comparison of the effects of internal TEA+ and Cs+ on potassium current in squid giant axons.

    PubMed Central

    Clay, J R

    1985-01-01

    Internal tetraethylammonium (TEA) and cesium ions block outward potassium current in nerve membrane in a voltage-dependent manner. Blockade with Cs+ occurs virtually instantaneously after membrane depolarization, whereas blockade with TEA+ occurs after a delay. The latter result suggested to Armstrong (1966, J. Gen. Physiol., 50:279-293; 1969, J. Gen. Physiol., 54:553-575) that potassium channels must open before TEA+ blockade can occur, which is in contrast to Cs+ blockade, which appears to be independent of channel gating. The results in this study concerning the effect of TEA+ on inward (tail) current argue against the Armstrong model. Specifically, TEA+ (partially) blocks inward current without altering the tail current time constant. This result indicates that TEA+ can occupy its binding site within the channel whether or not the channel gates are open. This alternative hypothesis can describe both the steady-state and time-dependent components of TEA+ blockade. PMID:2418889

  10. Spatial variability of theaflavins and thearubigins fractions and their impact on black tea quality.

    PubMed

    Bhuyan, Lakshi Prasad; Borah, Paban; Sabhapondit, Santanu; Gogoi, Ramen; Bhattacharyya, Pradip

    2015-12-01

    The spatial distribution of theaflavin and thearubigin fractions and their impact on black tea quality were investigated using multivariate and geostatistics techniques. Black tea samples were collected from tea gardens of six geographical regions of Assam and West Bengal, India. Total theaflavin (TF) and its four fractions of upper Assam, south bank and North Bank teas were higher than the other regions. Simple theaflavin showed highest significant correlation with tasters' quality. Low molecular weight thearubigins of south bank and North Bank were significantly higher than other regions. Total thearubigin (TR) and its fractions revealed significant positive correlation with tasters' organoleptic valuations. Tea tasters' parameters were significantly and positively correlated with each other. The semivariogram for quality parameters were best represented by gaussian models. The nugget/sill ratio indicated a strong/moderate spatial dependence of the studied parameters. Spatial variation of tea quality parameters may be used for quality assessment in the tea growing areas of India. PMID:26604370

  11. [Analysis of rare earth elements in pu'er tea of Yunnan by ICP-AES].

    PubMed

    Ning, Peng-bo; Gong, Chun-mei; Zhang, Yan-ming; Guo, Kang-kang

    2010-10-01

    The 150 samples of pu'er tea collected from the main producing area of Yunnan were detected by ICP-AES method, to investigate the current safety status of pu'er tea rare earth elements. The rare earth elements contents were found to be in the range 0.26-4.07 mg x kg(-1) in all detected samples, with the 43.0% samples exceeding the maximum levels of contaminants of 2 mg x kg(-1) set by GB 2762-2005 "Maximum levels of contaminants in foods". There was a significant difference between ripened tea rare earth elements and raw tea's from the same sources, which affected some ripened tea quality at last. There was a significant difference among the rare earth elements contents of the pu'er tea main producing areas, and the condition of pu'er tea quality and safety controlling was not optimistic at individual producing areas.

  12. (17)O NMR and Raman Spectroscopies of Green Tea Infusion with Nanomaterial to Investigate Their Properties.

    PubMed

    Zhou, Changyan; Zhang, Huiping; Yan, Ying; Zhang, Xinya

    2016-09-01

    (17)O NMR and Raman spectrograms of green tea infusions with nanomaterial were investigated. Different green tea infusions were prepared by steeping tea powder with different concentrations of nanomaterial aqueous solution. The tea infusions were tested with (17)O NMR and Raman spectroscopies. The (17)O NMR results showed that line width increased to 90 in the tea infusions after nanomaterial was added as a result of the effects of the self-association of Ca(2+) and tea polyphenol. The results of Raman spectroscopy showed that, in tea infusions, the enhancement of C─C and C─O stretching vibrations suggest an increase in the number of effective components in water. PMID:27461881

  13. Determination of quality constituents in the young leaves of albino tea cultivars.

    PubMed

    Feng, Lin; Gao, Ming-Jun; Hou, Ru-Yan; Hu, Xiao-Yi; Zhang, Liang; Wan, Xiao-Chun; Wei, Shu

    2014-07-15

    Albino tea has received increased attention due to its brisk flavour. To identify changes in the key chemical constituents conveying important qualities to albino tea, the metabolite profiles of four albino cultivars and one green tea cultivar were analysed. Compared to the green tea control, significantly decreased contents of chlorophyll (Chl) (p<0.01), total carotenoids (p<0.05), caffeine (p<0.01), and total catechins (p<0.05) were found in albino tea leaves with a few exceptions, whereas increases were noted in the Chl a/b ratio and the contents of both zeaxanthin and free amino acids, including theanine. Multivariate analysis identified catechins and carotenoids as the most important contributors to the metabolic profile variance between the albino and green tea cultivars. High levels of amino acids, along with low levels of chlorophylls, catechins and caffeine, contribute to the qualities of albino tea, which include reduced astringency and bitterness, along with a strong umami taste.

  14. Differentiation of tea (Camellia sinensis) varieties and their geographical origin according to their metal content.

    PubMed

    Fernández-Cáceres, P L; Martín, M J; Pablos, F; González, A G

    2001-10-01

    The metal content of 46 tea samples, including green, black, and instant teas, was analyzed. Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Sr, Ti, and Zn were determined by ICP-AES. Potassium, with an average content of 15145.4 mg kg(-1) was the metal with major content. Calcium, magnesium, and aluminum had average contents of 4252.4, 1978.2, and 1074.0 mg kg(-1), respectively. The average amount of manganese was 824.8 mg kg(-1). There were no clear differences between the metal contents of green and black teas. Pattern recognition methods such as principal component analysis (PCA), linear discriminant analysis (LDA), and artificial neural networks (ANN), were applied to differentiate the tea types. LDA and ANN provided the best results in the classification of tea varieties. These chemometric procedures were also useful for distinguishing between Asian and African teas and between the geographical origin of different Asian teas. PMID:11600020

  15. Determination of minerals extracted from several commercial teas (Camellia sinensis) to hot water (infusion).

    PubMed

    Gezgin, Sait; Ozcan, Mehmet Musa; Atalay, Emine

    2006-01-01

    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. In addition, the health benefits of teas and knowledge of their mineral contents are of great interest and may be useful for further study of enzyme systems and vital biochemical functions. PMID:16579740

  16. Anti-melanogenic effects of black, green, and white tea extracts on immortalized melanocytes.

    PubMed

    Kim, Young Chul; Choi, So Young; Park, Eun Ye

    2015-01-01

    Tea contains polyphenols and is one of the most popular beverages consumed worldwide. Because most tyrosinase inhibitors that regulate melanogenesis are phenol/catechol derivatives, this study investigated the inhibitory effects of Camellia sinensis water extracts (CSWEs), including black tea, green tea, and white tea extracts, on melanogenesis using immortalized melanocytes. CSWEs inhibited melanin accumulation and melanin synthesis along with tyrosinase activity in a concentration-dependent manner. These inhibitory effects were superior to those of arbutin, a well-known depigmenting agent. The anti-melanogenic activity of black (fermented) tea was higher than that of a predominant tea catecholamine, epigallocatechin gallate. CSWEs, especially black tea extract, decreased tyrosinase protein levels in a concentration-dependent manner. These results suggest that the anti-melanogenic effect of CSWEs is mediated by a decrease in both tyrosinase activity and protein expression, and may be augmented by fermentation. Thus, CSWEs could be useful skin-whitening agents in the cosmetic industry.

  17. [Four cases of aldosterone synthase deficiency in childhood].

    PubMed

    Collinet, E; Pelissier, P; Richard, O; Gay, C; Pugeat, M; Morel, Y; Stephan, J-L

    2012-11-01

    Neonatal salt-wasting syndromes are rare but potentially serious conditions. Isolated hypoaldosteronism is an autosomal recessive inherited disorder of terminal aldosterone synthesis, leading to selective aldosterone deficiency. Two different biochemical forms of this disease have been described, called aldosterone synthase deficiency or corticosterone methyl oxydase, types I and II. In type I, there is no aldosterone synthase activity and the 18 hydroxycorticosterone (18 OHB) level is low, whereas in type II, a residual activity of aldosterone synthase persists and 18 OHB is overproduced. We report on four patients with isolated hypoaldosteronism. In 2 of them, who were recently diagnosed with aldosterone synthase deficit, we discuss the symptoms and treatment. The 2 other patients are now adults. We discuss the long-term outcome, the quality of adult life, aldosterone synthase deficits, as well as the pathophysiology and molecular analysis.

  18. Ubiquitination and filamentous structure of cytidine triphosphate synthase

    PubMed Central

    Pai, Li-Mei; Wang, Pei-Yu; Lin, Wei-Cheng; Chakraborty, Archan; Yeh, Chau-Ting; Lin, Yu-Hung

    2016-01-01

    ABSTRACT Living organisms respond to nutrient availability by regulating the activity of metabolic enzymes. Therefore, the reversible post-translational modification of an enzyme is a common regulatory mechanism for energy conservation. Recently, cytidine-5′-triphosphate (CTP) synthase was discovered to form a filamentous structure that is evolutionarily conserved from flies to humans. Interestingly, induction of the formation of CTP synthase filament is responsive to starvation or glutamine depletion. However, the biological roles of this structure remain elusive. We have recently shown that ubiquitination regulates CTP synthase activity by promoting filament formation in Drosophila ovaries during endocycles. Intriguingly, although the ubiquitination process was required for filament formation induced by glutamine depletion, CTP synthase ubiquitination was found to be inversely correlated with filament formation in Drosophila and human cell lines. In this article, we discuss the putative dual roles of ubiquitination, as well as its physiological implications, in the regulation of CTP synthase structure. PMID:27116391

  19. Trinuclear Metal Clusters in Catalysis by Terpenoid Synthases.

    PubMed

    Aaron, Julie A; Christianson, David W

    2010-01-01

    Terpenoid synthases are ubiquitous enzymes that catalyze the formation of structurally and stereochemically diverse isoprenoid natural products. Many isoprenoid coupling enzymes and terpenoid cyclases from bacteria, fungi, protists, plants, and animals share the class I terpenoid synthase fold. Despite generally low amino acid sequence identity among these examples, class I terpenoid synthases contain conserved metal binding motifs that coordinate to a trinuclear metal cluster. This cluster not only serves to bind and orient the flexible isoprenoid substrate in the precatalytic Michaelis complex, but it also triggers the departure of the diphosphate leaving group to generate a carbocation that initiates catalysis. Additional conserved hydrogen bond donors assist the metal cluster in this function. Crystal structure analysis reveals that the constellation of three metal ions required for terpenoid synthase catalysis is generally identical among all class I terpenoid synthases of known structure.

  20. Changes of Constituents and Activity to Apoptosis and Cell Cycle During Fermentation of Tea

    PubMed Central

    Zhao, Hang; Zhang, Min; Zhao, Lu; Ge, Ya-kun; Sheng, Jun; Shi, Wei

    2011-01-01

    Tea is believed to be beneficial for health, and the effects of the fermentation process on its contributions to apoptosis and cell cycle arrest of gastric cancer cells have not been completely investigated. In this study, the chemical components in green tea, black tea and pu-erh tea aqueous extracts were analyzed and compared. The polysaccharide and caffeine levels were substantially higher in the fermented black tea and pu-erh tea, while the polyphenol level was higher in the unfermented green tea. Hence, a treatment of tea aqueous extract and the components, which are emerging as promising anticancer agents, were pursued to determine whether this treatment could lead to enhance apoptosis and cell cycle arrest. In the human gastric cancer cell line SGC-7901, the cell viability and flow cytometry analysis for apoptotic cells indicated effects in a dose-dependent inhibition manner for the three tea treatment groups. The apoptosis rates were found to be elevated after 48 h of treatment with 31.2, 125, and 500 μg/mL of green tea extract, the higher catechins content may be involved in the mechanism. Cell cycle was arrested in S phase in the fermented black tea and pu-erh tea, and the populations were significantly decreased in G2/M phases, possibly due to the oxidation of tea polyphenols, which causes an increase of theabrownins. CCC-HEL-1 normal cells were not sensitive to tea extract. These findings suggest that the fermentation process causes changes of the compounds which might be involved in the changes of cell proliferation inhibition, apoptosis induction and cell cycle arrest. PMID:21673927

  1. Structure-activity relationships of tea compounds against human cancer cells.

    PubMed

    Friedman, Mendel; Mackey, Bruce E; Kim, Hyun-Jeong; Lee, In-Seon; Lee, Kap-Rang; Lee, Seung-Un; Kozukue, Etsuko; Kozukue, Nobuyuki

    2007-01-24

    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 human cancer and normal cells using a tetrazolium microculture (MTT) assay. Compared to untreated controls, most catechins, theaflavins, theanine, and all tea extracts reduced the numbers of the following human cancer cell lines: breast (MCF-7), colon (HT-29), hepatoma (liver) (HepG2), and prostate (PC-3) as well as normal human liver cells (Chang). The growth of normal human lung (HEL299) cells was not inhibited. The destruction of cancer cells was also observed visually by reverse phase microscopy. Statistical analysis of the data showed that (a) the anticarcinogenic effects of tea compounds and of tea leaf extracts varied widely and were concentration dependent over the ranges from 50 to 400 microg/mL of tea compound and from 50 to 400 microg/g of tea solids; (b) the different cancer cells varied in their susceptibilities to destruction; (c) 80% ethanol/water extracts with higher levels of flavonoids determined by HPLC were in most cases more active than the corresponding water extracts; and (d) flavonoid levels of the teas did not directly correlate with anticarcinogenic activities. The findings extend related observations on the anticarcinogenic potential of tea ingredients and suggest that consumers may benefit more by drinking both green and black teas. PMID:17227049

  2. The effect of drinking tea at high altitude on hydration status and mood.

    PubMed

    Scott, David; Rycroft, Jane A; Aspen, Jennifer; Chapman, Clare; Brown, Bryce

    2004-04-01

    The effect of drinking tea on hydration status and mood was studied in nine male and four female members of expeditions based at Mt. Everest base camp at an altitude of 5,345 m. Whilst exposed to altitude-cold diuresis, participants were subjected to a crossover experimental design comprising two 24-h dietary interventions. In the "tea" condition, hot brewed tea formed a major part of fluid intake, whereas in the "no-tea" condition tea was excluded from the diet. Subjects were prohibited in both cases from consuming other caffeinated beverages, caffeinated foods, and alcoholic drinks. Mean fluids ingested [mean (SE); tea=3,193 (259) ml versus no tea=3,108 (269) ml] and urine volume (tea=2,686 (276) ml versus no tea=2,625 (342) ml] were similar under both conditions. Statistical analysis found no difference in urine stimulated as a result of the tea intervention (P=0.81). Several markers of hydration status were also taken immediately pre and post each condition, including measures of urine specific gravity, urine electrolyte balance (K+, Na+), and urine colour. None of these measures indicated a difference in hydration status as a result of the dietary intervention in either the control or tea condition. A difference was, however, found in mood, with subjects reporting reduced fatigue when tea was included in the diet (P=0.005). The study shows therefore that even when drunk at high altitude where fluid balance is stressed, there is no evidence that tea acts as a diuretic when consumed through natural routes of ingestion by regular tea drinkers, but that it does have a positive effect on mood. PMID:14872247

  3. In vivo evaluation of black and green tea dermal products against UV radiation.

    PubMed

    Türkoğlu, M; Uğurlu, T; Gedik, G; Yılmaz, A M; Süha Yalçin, A

    2010-10-01

    Aqueous extracts of black and green tea (Camellia sinensis) were obtained by freeze-drying for this study. The extracts were evaluated based on tea quality control tests, UV, IR scans, and in vitro antioxidant capacity tests. Dermal products from the tea extracts were designed and manufactured. Black and green tea gels were tested in vivo in the forearms of six subjects using an artifical UV (200-400 nm) source. The tested formulations were green tea gel, black tea gel, 0.3% caffeine gel, carbomer gel base, and a control. Depending on tea quality, the samples resulted in water soluble fractions of 24.5-39.5%. UV and IR scans specifically showed peaks for alkaloids like caffeine, catechins such as epigallocatechin gallate, and polyphenols with dimeric and polymeric structures such as theaflavins (TFs) and thearubigins (TRs). Antioxidant and free radical scavenging activities of black and green tea samples were found to be high and comparable; activity levels for black tea, green tea, high quality black tea, and L-ascorbic acid were 0.48, 0.50, 0.82, and 1.32 mM TR/mg, respectively. No UV-induced erythema was observed at the black and green tea gel sites in any of the subjects. UV-induced erythema was consistently present in various grades at caffeine gel, carbomer gel, and control sites. Results led to the conclusion that freeze-dried black and green tea extracts had strong UV absorbance. Formulating those extracts into dermal gels protected the skin against UV-induced erythema. Therefore, tea extracts were found to be promising candidates for their ability to protect against the harmful effects of UV radiation, such as erythema and premature aging of the skin.

  4. Descriptive analysis and U.S. consumer acceptability of 6 green tea samples from China, Japan, and Korea.

    PubMed

    Lee, Jeehyun; Chambers, Delores H

    2010-03-01

    In the past, green tea has been one of the least popular nonalcoholic beverages for U.S. consumers. However, green tea has been receiving attention because of its potential health benefits. Knowing which green tea flavor attributes contribute to consumer liking will help the fast growing green tea business including green tea importers, tea shops, and beverage companies to understand which characteristics are most accepted by U.S. consumers. The objectives of this study were (1) to examine differences in acceptability of commonly available loose leaf and bagged green teas available from the major exporters to the U.S. (Japan, Korea, and China) and (2) to determine which green tea flavor characteristics are related to consumers' liking. In the study, consumers from the U.S. evaluated 6 green tea samples from China, Japan, and Korea for acceptability. A highly trained panel also evaluated the green tea samples to provide descriptive sensory attributes that might be related to acceptability. We found that U.S. consumers liked green tea samples with lower flavor intensity and lower bitterness intensity. Consumers' acceptability of green tea was negatively correlated with spinach and animalic flavor and bitterness and astringency of green teas evaluated using descriptive sensory analysis, but the correlation was only moderate. To learn what green tea flavor characteristics influence consumers' liking, future studies using more green tea samples with different flavor profiles are needed.

  5. Functional Contribution of Chorismate Synthase, Anthranilate Synthase, and Chorismate Mutase to Penetration Resistance in Barley-Powdery Mildew Interactions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant processes resulting from primary or secondary metabolism have been hypothesized to contribute to defense against microbial attack. Barley chorismate synthase (HvCS), anthranilate synthase alpha subunit 2 (HvASa2) and chorismate mutase 1 (HvCM1) occupy pivotal branch-points downstream of the s...

  6. A Comparison of the Effects of Neuronal Nitric Oxide Synthase and Inducible Nitric Oxide Synthase Inhibition on Cartilage Damage

    PubMed Central

    Gokay, Nevzat Selim; Yilmaz, Ibrahim; Demiroz, Ahu Senem; Gokce, Alper; Dervisoglu, Sergülen; Gokay, Banu Vural

    2016-01-01

    The objective of this study was to investigate the effects of selective inducible nitric oxide synthase and neuronal nitric oxide synthase inhibitors on cartilage regeneration. The study involved 27 Wistar rats that were divided into five groups. On Day 1, both knees of 3 rats were resected and placed in a formalin solution as a control group. The remaining 24 rats were separated into 4 groups, and their right knees were surgically damaged. Depending on the groups, the rats were injected with intra-articular normal saline solution, neuronal nitric oxide synthase inhibitor 7-nitroindazole (50 mg/kg), inducible nitric oxide synthase inhibitor amino-guanidine (30 mg/kg), or nitric oxide precursor L-arginine (200 mg/kg). After 21 days, the right and left knees of the rats were resected and placed in formalin solution. The samples were histopathologically examined by a blinded evaluator and scored on 8 parameters. Although selective neuronal nitric oxide synthase inhibition exhibited significant (P = 0.044) positive effects on cartilage regeneration following cartilage damage, it was determined that inducible nitric oxide synthase inhibition had no statistically significant effect on cartilage regeneration. It was observed that the nitric oxide synthase activation triggered advanced arthrosis symptoms, such as osteophyte formation. The fact that selective neuronal nitric oxide synthase inhibitors were observed to have mitigating effects on the severity of the damage may, in the future, influence the development of new agents to be used in the treatment of cartilage disorders. PMID:27382570

  7. Pseudouridines and pseudouridine synthases of the ribosome.

    PubMed

    Ofengand, J; Malhotra, A; Remme, J; Gutgsell, N S; Del Campo, M; Jean-Charles, S; Peil, L; Kaya, Y

    2001-01-01

    psi are ubiquitous in ribosomal RNA. Eubacteria, Archaea, and eukaryotes all contain psi, although their number varies widely, with eukaryotes having the most. The small ribosomal subunit can apparently do without psi in some organisms, even though others have as many as 40 or more. Large subunits appear to need at least one psi but can have up to 50-60. psi is made by a set of site-specific enzymes in eubacteria, and in eukaryotes by a single enzyme complexed with auxiliary proteins and specificity-conferring guide RNAs. The mechanism is not known in Archaea, but based on an analysis of the kinds of psi synthases found in sequenced archaeal genomes, it is likely to involve use of guide RNAs. All psi synthases can be classified into one of four related groups, virtually all of which have a conserved aspartate residue in a conserved sequence motif. The aspartate is essential for psi formation in all twelve synthases examined so far. When the need for psi in E. coli was examined, the only synthase whose absence caused a major decrease in growth rate under normal conditions was RluD, the synthase that makes psi 1911, psi 1915, and psi 1917 in the helix 69 end-loop. This growth defect was the result of a major failure in assembly of the large ribosomal subunit. The defect could be prevented by supplying the rluD structural gene in trans, and also by providing a point mutant gene that made a synthase unable to make psi. Therefore, the RluD synthase protein appears to be directly involved in 50S subunit assembly, possibly as an RNA chaperone, and this activity is independent of its ability to form psi. This result is not without precedent. Depletion of PET56, a 2'-O-methyltransferase specific for G2251 (E. coli numbering) in yeast mitochondria virtually blocks 50S subunit assembly and mitochondrial function (Sirum-Connolly et al. 1995), but the methylation activity of the enzyme is not required (T. Mason, pers. comm.). The absence of FtsJ, a heat shock protein that makes

  8. Wavelength measurement of tunable TEA CO2 laser

    NASA Astrophysics Data System (ADS)

    Qu, Yanchen; Ren, Deming; Hu, Xiaoyong; Liu, Fengmei; Zhang, Lili; Chen, Chunyu

    2005-01-01

    Due to their interesting physical and chemical parameters, tunable transversely excited atmospheric-pressure(TEA) CO2 lasers are widely utilized in scientific and industrial applications. The CO2 differential absorption lidar (DIAL) is an effective tool for remote measurement of pollutant gaseous concentration of the atmosphere over large areas. Many pollutant gases have strong absorption lines within the spectral range of CO2 laser wavelength tuning. In addition, the radiation of CO2 laser is well distributed in the atmosphere, coinciding with the "transparency window" of the atmosphere. Therefore the wavelength tunable TEA CO2 laser is an ideal optical source for DIAL. Most existing instruments for measuring the laser wavelength are only suitable for the measurement of continuous wave and stable frequency output. With the attempt of measuring the wavelength of pulsed TEA CO2 laser, an experimental setup is established which consists of two main portions, namely auto-scanning grating monochromator as the color dispersion system and Boxcar integrator. In the experiment of tuning TEA CO2 laser, the wavelength of CO2 laser is observed and measured by means of integrating method. The accuracy of measurement in the mid-infrared region attains 1nm.

  9. PROTECTIVE EFFECT OF GREEN TEA ON DENTIN EROSION AND ABRASION

    PubMed Central

    Kato, Melissa Thiemi; Magalhães, Ana Carolina; Rios, Daniela; Hannas, Angélica Reis; Attin, Thomas; Buzalaf, Marília Afonso Rabelo

    2009-01-01

    Objective: This in situ study evaluated the protective effect of green tea on dentin erosion (ERO) and erosion-abrasion (ABR). Material and methods: Ten volunteers wore intraoral palatal appliances with bovine dentin specimens subjected to ERO or ERO + toothbrushing abrasion performed immediately (ERO+I-ABR) or 30 min after erosion (ERO+30-min-ABR). During 2 experimental 5-day crossover phases, the volunteers rinsed with green tea or water (control, 1 min) between each erosive (5 min, cola drink) and abrasive challenge (30 s, toothbrushing), 4x/day. Dentin wear was measured by profilometry. Results: The green tea reduced the dentin wear significantly for all conditions compared to control. ERO+I-ABR led to significantly higher wear than ERO, but it was not significantly different from ERO+30-min-ABR. ERO+30-min-ABR provoked significant higher wear than ERO, only for the placebo treatment. Conclusions: From the results of the present study, it may be concluded that green tea reduces the dentin wear under erosive/abrasive conditions. PMID:20027426

  10. Reading the tea leaves: anticarcinogenic properties of (-)-epigallocatechin-3-gallate.

    PubMed

    Carlson, Jennifer R; Bauer, Brent A; Vincent, Ann; Limburg, Paul J; Wilson, Ted

    2007-06-01

    Green tea is an extremely popular beverage worldwide. Derivatives of green tea, particularly (-)-epigallocatechin-3-gallate (EGCG), have been proposed to have anticarcinogenic properties based on preclinical, observational, and clinical trial data. To summarize, clarify, and extend current knowledge, we conducted a comprehensive search of the PubMed database and other secondary data sources, as appropriate, regarding the chemopreventive potential of EGCG. Apparently, EGCG functions as an antioxidant, preventing oxidative damage in healthy cells, but also as an antiangiogenic agent, preventing tumors from developing a blood supply needed to grow larger. Furthermore, EGCG may stimulate apoptosis in cancerous cells by negatively regulating the cell cycle to prevent continued division. Finally, EGCG exhibits antibacterial activity, which may be implicated in the prevention of gastric cancer. Although in vitro research of the anticarcinogenic properties of EGCG seems promising, many diverse and unknown factors may influence its in vivo activity in animal and human models. Some epidemiological studies suggest that green tea compounds could protect against cancer, but existing data are inconsistent, and limitations in study design hinder full interpretation and generalizability of the published observational findings. Several clinical trials with green tea derivatives are ongoing, and further research should help to clarify the clinical potential of EGCG for chemoprevention and/or chemotherapy applications. PMID:17550753

  11. Identification Guide for Diseases of Tea (Camellia sinensis)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of this guide on diseases associated with tea (Camellia sinensis) is to assist with p;roblem identification and raise awareness of serious plant disease pathogens not yet present in Hawaii. Blister bligtht, horse-hair blight, and twig dieback/stem canker are very destructive diseases fo...

  12. Quantification of Tea Flavonoids by High Performance Liquid Chromatography

    ERIC Educational Resources Information Center

    Freeman, Jessica D.; Niemeyer, Emily D.

    2008-01-01

    We have developed a laboratory experiment that uses high performance liquid chromatography (HPLC) to quantify flavonoid levels in a variety of commercial teas. Specifically, this experiment analyzes a group of flavonoids known as catechins, plant-derived polyphenolic compounds commonly found in many foods and beverages, including green and black…

  13. The Secret between Storytelling and Retelling: Tea, School, & Narrative

    ERIC Educational Resources Information Center

    Yu, Jie

    2014-01-01

    In this paper, I will tell two of my personal stories to try to explore the secret or opaque space between the original telling and retelling of stories in narrative inquiry. Based upon my difficult struggles with the two stories of tea, school, and narrative, I suggest that narrative inquiry has to be a complex loop of relationship, reflexivity,…

  14. [Identification of green tea brand based on hyperspectra imaging technology].

    PubMed

    Zhang, Hai-Liang; Liu, Xiao-Li; Zhu, Feng-Le; He, Yong

    2014-05-01

    Hyperspectral imaging technology was developed to identify different brand famous green tea based on PCA information and image information fusion. First 512 spectral images of six brands of famous green tea in the 380 approximately 1 023 nm wavelength range were collected and principal component analysis (PCA) was performed with the goal of selecting two characteristic bands (545 and 611 nm) that could potentially be used for classification system. Then, 12 gray level co-occurrence matrix (GLCM) features (i. e., mean, covariance, homogeneity, energy, contrast, correlation, entropy, inverse gap, contrast, difference from the second-order and autocorrelation) based on the statistical moment were extracted from each characteristic band image. Finally, integration of the 12 texture features and three PCA spectral characteristics for each green tea sample were extracted as the input of LS-SVM. Experimental results showed that discriminating rate was 100% in the prediction set. The receiver operating characteristic curve (ROC) assessment methods were used to evaluate the LS-SVM classification algorithm. Overall results sufficiently demonstrate that hyperspectral imaging technology can be used to perform classification of green tea.

  15. Antimicrobial polyphenols from small tropical fruits, tea and spice oilseeds.

    PubMed

    Aman, Sahar; Naim, Asma; Siddiqi, Rahmanullah; Naz, Shahina

    2014-06-01

    The polyphenolic fractions of fruits: Terminalia catappa, Carissa carandas, Ziziphus nummularia; spice oilseeds: thymol, mustard, fenugreek and poppy seeds; and herb: green and black teas were analyzed for their total phenolics, flavonoids and antimicrobial potential. All fractions from fruits, except anthocyanin of C. carandas, displayed substantial antibacterial activity in accordance to their phenolic contents, the difference in activity being quite significant (p < 0.05), highest for T. catappa (minimum inhibitory concentration, MIC: 7.8-1000 microg/mL) and lowest for C. carandas (MIC: 62.5-1000 microg/mL). With few exceptions, both green and black teas' fractions inhibited the tested strains, however, green tea fractions (MIC: 15.63-125 microg/mL) were more active than black (MIC: 31.25-1000 microg/mL) and neutral were more active than their corresponding acidic fractions. Oil fractions of all oilseeds were found to be more active than their polyphenolic fractions, their antibacterial action decreased in the order thymol > mustard > fenugreek > poppy seeds (p < 0.05). Though the fruits used for the study are underutilized and have been emphasized for processed products, they may potentially be important to fight against pathogenic bacteria in view of their MICs. The teas and oilseeds, though a small part of total food intake, are more functional and active against the tested bacterial species and may find potential applications in therapeutics and food preservation.

  16. Arsenic removal from groundwater by pretreated waste tea fungal biomass.

    PubMed

    Murugesan, G S; Sathishkumar, M; Swaminathan, K

    2006-02-01

    Arsenic contamination in ground water poses a serious threat on human health. The tea fungus, a waste produced during black tea fermentation has been examined for its capacity to sequester the metal ions from ground water samples. Autoclaved tea fungal mat and autoclaving followed by FeCl3 pretreated tea fungal mat were exploited for removal of As(III), As(V) and Fe(II) from ground water sample collected from Kolkata, West Bengal, India. The biosorption rate tends to increase with the increase in contact time and adsorbent dosage. FeCl3 pretreated and autoclaved fungal mats removed 100% of As(III) and Fe(II) after 30 min contact time and 77% of As(V) after 90 min contact time. The optimum adsorbent dosage was 1.0 g/50 mL of water sample. The results revealed that the FeCl3 pretreated fungal mat could be used as an effective biosorbent for As(III) and As(V); autoclaved fungal mat for Fe(II) removal from ground water sample.

  17. Tea Time: Raising Awareness and Support for Extension

    ERIC Educational Resources Information Center

    Franz, Nancy K.; Fahey, Chris

    2012-01-01

    In a time of reliance on electronic media for information, chaotic programming environments, and declining public resources, Extension workers need to find unique ways to connect with stakeholders to maintain and increase support for programming. To address this need, we developed, conducted, and evaluated a series of stakeholder teas. We found…

  18. Synergistic antioxidant activity of green tea with some herbs

    PubMed Central

    Jain, Dheeraj P.; Pancholi, Shyam S.; Patel, Rakesh

    2011-01-01

    Cardiovascular diseases, cancer, arthritis, etc. are caused by free radicals that are byproducts of metabolic pathways. Selected plants namely Vitis vinifera, Phyllanthus emblica L., Punica granatum, Cinnamomum cassia, Ginkgo biloba L., and Camellia sinensis Linn. are reported to produce antioxidant property. This study is undertaken to support the hypothesis that formulation of a polyherbal combination of these plants shows a synergistic effect with green tea. The extracts of each drug were characterized by phytochemical studies and tests for phenolics and flavonoids. In vitro antioxidant activity for individual drug and its combination was determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide, and nitric oxide free radical scavenging methods. Our results suggest that a combination of all these herbs with green tea can synergistically enhance antioxidant activity and thus lower doses of each herb with green tea may be used. Antioxidant potential of polyherbal combination was also comparable to that of standard ascorbic acid. Studies showed that selected individual plants contained abundant quantity of phenolics and flavonoids and their polyherbal combination with green tea was found to produce best antioxidant activity among all individual extracts. This will help in avoiding undesirable side effects due to higher doses of single herb. PMID:22171315

  19. Haemolytic anaemia after ingestion of Neem (Azadirachta indica) tea

    PubMed Central

    Page, Cristy; Hawes, Emily M

    2013-01-01

    The authors report a clinically relevant and possible cause of haemolytic anaemia from ingestion of a Mexican tea from the Neem tree, also known as Azadirachta indica, in a 35-year-old Hispanic man who was found to have glucose-6-phosphate dehydrogenase deficiency. PMID:24136910

  20. Hyaluronan synthases and hyaluronidases in nasal polyps.

    PubMed

    Panogeorgou, T; Tserbini, E; Filou, S; Vynios, D H; Naxakis, S S; Papadas, T A; Goumas, P D; Mastronikolis, N S

    2016-07-01

    Nasal polyps (NPs) are benign lesions of nasal and paranasal sinuses mucosa affecting 1-4 % of all adults. Nasal polyposis affects the quality of patient's life as it causes nasal obstruction, postnasal drainage, purulent nasal discharge, hyposmia or anosmia, chronic sinusitis, facial pain and snoring. Without treatment, the disease can alter the craniofacial skeleton in cases of extended growth of polyps. The development of NPs is caused by the hyperplasia of nasal or paranasal sinuses mucosa, and edema of extracellular matrix. This is usually the result of high concentration of high molecular mass hyaluronan (HA) which is either overproduced or accumulated from blood supply. The size of HA presents high diversity and, especially in pathologic conditions, chains of low molecular mass can be observed. In NPs, chains of about 200 kDa have been identified and considered to be responsible for the inflammation. The purpose of the present study was the investigation, in NPs and normal nasal mucosa (NM), of the expression of the wild-type and alternatively spliced forms of hyaluronidases, their immunolocalization, and the expression of HA synthases to examine the isoform(s) responsible for the increased amounts of HA in NPs. Hyaluronidases' presence was examined on mRNA (RT-PCR analysis) and protein (immunohistochemistry) levels. Hyaluronan synthases' presence was examined on mRNA levels. Hyaluronidases were localized in the cytoplasm of epithelial and inflammatory cells, as well as in the matrix. On mRNA level, it was found that hyal-1-wt was decreased in NPs compared to NM and hyal-1-v3, -v4 and -v5 were substantially increased. Moreover, HAS2 and HAS3 were the only hyaluronan synthases detected, the expression of which was almost similar in NPs and NM. Overall, the results of the present study support that hyaluronidases are the main enzymes responsible for the decreased size of hyaluronan observed in NPs; thus they behave as inflammatory agents. Therefore, they

  1. Structure of Aminodeoxychorismate Synthase from Stenotrophomonas maltophilia†

    PubMed Central

    Bera, Asim K.; Atanasova, Vesna; Dhanda, Anjali; Ladner, Jane E.; Parsons, James F.

    2012-01-01

    PabB, aminodeoxychorismate synthase, is the chorismic acid binding component of the heterodimeric PabAB complex that converts chorismic acid to 4-amino-4-deoxychorismate, a precursor of p-aminobenzoate and folic acid in microorganisms. The second component, a glutamine amidotransferase subunit, PabA, generates ammonia that is channeled to the PabB active site where it attacks the C4 carbon of a chorismate derived intermediate that is covalently bound, through C2, to an active site lysine residue. The presence of a PIKGT motif was, until recently, believed to be discriminate PabB enzymes from the closely related enzyme anthranilate synthase, which typically contains a PIAGT active site motif and does not form a covalent enzyme-substrate intermediate with chorismate. A subclass of PabB enzymes that employ an alternative mechanism requiring two equivalents of ammonia from glutamine and that feature a noncovalently bound 2-amino-2-deoxyisochorismate intermediate was recently identified. Here we report the 2.25 Å crystal structure of PabB from the emerging pathogen Stenotrophomonas maltophilia. It is the first reported structure of a PabB that features the PIAGT motif. Surprisingly, no dedicated pabA is evident in the genome of S. maltophilia suggesting that another cellular amidotransferase is able to fulfill the role of PabA in this organism. Evaluation of the ammonia-dependent aminodeoxychorismate synthase activity of S. maltophilia PabB alone revealed that it is virtually inactive. However, in the presence of a heterologous PabA surrogate, typical levels of activity were observed using either glutamine or ammonia as the nitrogen source. Additionally, the structure suggests that a key segment of the polypeptide can remodel itself to interact with a nonspecialized or shared amidotransferase partner in vivo. The structure and mass spectral analysis further suggest that S. maltophilia PabB, like Escherichia coli PabB, binds tryptophan in a vestigial regulatory site

  2. Conversion of anthranilate synthase into isochorismate synthase: implications for the evolution of chorismate-utilizing enzymes.

    PubMed

    Plach, Maximilian G; Löffler, Patrick; Merkl, Rainer; Sterner, Reinhard

    2015-09-14

    Chorismate-utilizing enzymes play a vital role in the biosynthesis of metabolites in plants as well as free-living and infectious microorganisms. Among these enzymes are the homologous primary metabolic anthranilate synthase (AS) and secondary metabolic isochorismate synthase (ICS). Both catalyze mechanistically related reactions by using ammonia and water as nucleophiles, respectively. We report that the nucleophile specificity of AS can be extended from ammonia to water by just two amino acid exchanges in a channel leading to the active site. The observed ICS/AS bifunctionality demonstrates that a secondary metabolic enzyme can readily evolve from a primary metabolic enzyme without requiring an initial gene duplication event. In a general sense, these findings add to our understanding how nature has used the structurally predetermined features of enzyme superfamilies to evolve new reactions.

  3. Identification of cystathionine γ-synthase and threonine synthase from Cicer arietinum and Lens culinaris.

    PubMed

    Morneau, Dominique J K; Jaworski, Allison F; Aitken, Susan M

    2013-04-01

    In plants, cystathionine γ-synthase (CGS) and threonine synthase (TS) compete for the branch-point metabolite O-phospho-L-homoserine. These enzymes are potential targets for metabolic engineering studies, aiming to alter the flux through the competing methionine and threonine biosynthetic pathways, with the goal of increasing methionine production. Although CGS and TS have been characterized in the model organisms Escherichia coli and Arabidopsis thaliana, little information is available on these enzymes in other, particularly plant, species. The functional CGS and TS coding sequences from the grain legumes Cicer arietinum (chickpea) and Lens culinaris (lentil) identified in this study share approximately 80% amino acid sequence identity with the corresponding sequences from Glycine max. At least 7 active-site residues of grain legume CGS and TS are conserved in the model bacterial enzymes, including the catalytic base. Putative processing sites that remove the targeting sequence and result in functional TS were identified in the target species.

  4. Effects of aqueous extracts of raw pu-erh tea and ripened pu-erh tea on proliferation and differentiation of 3T3-L1 preadipocytes.

    PubMed

    Cao, Zhen-Hui; Yang, Hui; He, Zhan-Long; Luo, Cheng; Xu, Zhi-Qiang; Gu, Da-Hai; Jia, Jun-Jing; Ge, Chang-Rong; Lin, Qiu-Ye

    2013-08-01

    Pu-erh tea has shown anti-obesity effects but little is known about its effect on proliferation and differentiation of preadipocytes. This study investigated the effects of the aqueous extracts of raw pu-erh tea and ripened pu-erh tea on proliferation and differentiation of murine 3T3-L1 preadiopocytes. We examined dose and time effects of both aqueous extracts on proliferation of 3T3-L1 preadipocytes. The contents of triglycerides in cytoplasm and the mRNA expression of critical transcriptional factors involved in differentiation were determined. Cytotoxicity and apoptosis rate of preadipocytes by pu-erh tea extracts treatment were test for toxic and pro-apoptotic effects. Both aqueous extracts of pu-erh tea inhibited the proliferation of 3T3-L1 preadipocytes at the selected time points. At lower concentration of raw pu-erh tea extracts (less than 300 µg/ml) and ripened pu-erh tea extracts (less than 350 µg/ml), no significant cytotoxic and pro-apoptotic were observed. Ripened pu-erh tea was more effective with lower IC50 than raw pu-erh tea. Both extracts suppressed the differentiation and down-regulated the gene expression of peroxisome proliferator-activated receptor-γ and CCAAT/enhancer binding proteins-α. Therefore, these results indicate that both aqueous extracts of pu-erh tea can inhibit proliferation and differentiation with ripened pu-erh tea more potent. Polyphenol rich in both extracts may play a role in the inhibition of proliferation and differentiation of 3T3-L1 preadipocytes.

  5. Determination and comparison of γ-aminobutyric acid (GABA) content in pu-erh and other types of Chinese tea.

    PubMed

    Zhao, Ming; Ma, Yan; Wei, Zhen-zhen; Yuan, Wen-xia; Li, Ya-li; Zhang, Chun-hua; Xue, Xiao-ting; Zhou, Hong-jie

    2011-04-27

    Two previous studies have reported that pu-erh tea contains a high level of γ-aminobutyric acid (GABA), which is the major inhibitory neurotransmitter in the central nervous system and has several physiological functions. However, two other researchers have demonstrated that the GABA content of several pu-erh teas was low. Due to the high value and health benefits of GABA, analysis of mass-produced pu-erh tea is necessary to determine whether it is actually enriched with GABA. A high-performance liquid chromatography (HPLC) method was developed for the determination of GABA in tea, the results of which were verified by amino acid analysis using an Amino Acid Analyzer (AAA). A total of 114 samples of various types of Chinese tea, including 62 pu-erh teas, 13 green teas, 8 oolong teas, 8 black teas, 3 white teas, 4 GABA teas, and 16 process samples from two industrial fermentations of pu-erh tea (including the raw material and the first to seventh turnings), were analyzed using HPLC. Statistical analysis demonstrated that the GABA content in pu-erh tea was significantly lower than that in other types of tea (p < 0.05) and that the GABA content decreased during industrial fermentation of pu-erh tea (p < 0.05). This mass analysis and comparison suggested GABA was not a major bioactive constituent and resolved the disagreement GABA content in pu-erh tea. In addition, the GABA content in white tea was found to be significantly higher than that in the other types of tea (p < 0.05), leading to the possibility of producing GABA-enriched white tea.

  6. Endothelial nitric oxide synthase in the microcirculation.

    PubMed

    Shu, Xiaohong; Keller, T C Stevenson; Begandt, Daniela; Butcher, Joshua T; Biwer, Lauren; Keller, Alexander S; Columbus, Linda; Isakson, Brant E

    2015-12-01

    Endothelial nitric oxide synthase (eNOS, NOS3) is responsible for producing nitric oxide (NO)--a key molecule that can directly (or indirectly) act as a vasodilator and anti-inflammatory mediator. In this review, we examine the structural effects of regulation of the eNOS enzyme, including post-translational modifications and subcellular localization. After production, NO diffuses to surrounding cells with a variety of effects. We focus on the physiological role of NO and NO-derived molecules, including microvascular effects on vessel tone and immune response. Regulation of eNOS and NO action is complicated; we address endogenous and exogenous mechanisms of NO regulation with a discussion of pharmacological agents used in clinical and laboratory settings and a proposed role for eNOS in circulating red blood cells.

  7. The Rotary Mechanism of the ATP Synthase

    PubMed Central

    Nakamoto, Robert K.; Scanlon, Joanne A. Baylis; Al-Shawi, Marwan K.

    2008-01-01

    The FOF1 ATP synthase is a large complex of at least 22 subunits, more than half of which are in the membranous FO sector. This nearly ubiquitous transporter is responsible for the majority of ATP synthesis in oxidative and photo-phosphorylation, and its overall structure and mechanism have remained conserved throughout evolution. Most examples utilize the proton motive force to drive ATP synthesis except for a few bacteria, which use a sodium motive force. A remarkable feature of the complex is the rotary movement of an assembly of subunits that plays essential roles in both transport and catalytic mechanisms. This review addresses the role of rotation in catalysis of ATP synthesis/hydrolysis and the transport of protons or sodium. PMID:18515057

  8. Transfer RNA pseudouridine synthases in Saccharomyces cerevisiae.

    PubMed

    Samuelsson, T; Olsson, M

    1990-05-25

    A transfer RNA lacking modified nucleosides was produced by transcription in vitro of a cloned gene that encodes a Saccharomyces cerevisiae glycine tRNA. At least three different uridines (in nucleotide positions 13, 32, and 55) of this transcript tRNA are modified to pseudouridine by an extract of S. cerevisiae. Variants of the RNA substrate were also constructed that each had only one of these sites, thus allowing specific monitoring of pseudouridylation at different nucleotide positions. Using such RNAs to assay pseudouridine synthesis, enzymes producing this nucleoside were purified from an extract of S. cerevisiae. The activities corresponding to positions 13, 32, and 55 in the tRNA substrate could all be separated chromatographically, indicating that there is a separate enzyme for each of these sites. The enzyme specific for position 55 (denoted pseudouridine synthase 55) was purified approximately 4000-fold using a combination of DEAE-Sepharose, heparin-Sepharose, and hydroxylapatite.

  9. Prenyltransferases of the dimethylallyltryptophan synthase superfamily.

    PubMed

    Yu, Xia; Li, Shu-Ming

    2012-01-01

    Prenylated natural products often have interesting biological and pharmacological activities clearly distinct from their nonprenylated precursors. Prenyltransferases are responsible for the attachment of prenyl moieties to a number of acceptors and contribute significantly to structural and biological diversity of these compounds in nature. In the past 8 years, significant progress has been achieved in the molecular biological, biochemical, and structural biological investigation of the prenyltransferases of the dimethylallyltryptophan synthase (DMATS) superfamily. These soluble enzymes are involved in the biosynthesis of fungal secondary metabolites and mainly catalyze prenylation of diverse indole derivatives, including tryptophan and tryptophan-containing cyclic dipeptides. The members of the DMATS superfamily show promising flexibility toward their aromatic substrates and catalyze highly regio- and stereoselective prenyltransfer reactions. These features were successfully used for chemoenzymatic synthesis, not only for production of prenylated simple indoles and cyclic dipeptides but also for prenylated hydroxynaphthalenes and flavonoids, which are usually found in bacteria and plants, respectively.

  10. Design, formulation and evaluation of green tea chewing gum

    PubMed Central

    Aslani, Abolfazl; Ghannadi, Alireza; Khalafi, Zeinab

    2014-01-01

    Background: The main purpose of this study is to design, formulate and evaluate the green tea gums with a suitable taste and quality in order to produce an anti-oxidant chewing gum. Materials and Methods: Fresh green tea leaves obtained from Northern Iran for extraction. Maceration is the extraction method that is used in this study. The contents of caffeine, catechin and flavonoids of the hydro alcoholic extract were measured. Various formulations of the 120 mg green tea extract chewing gums with different sweeteners, flavoring agents and various gum bases were prepared afterward release pattern, content uniformity, organoleptic results and other properties were characterized. Results: The contents of caffeine, catechin and flavonoid of the hydro alcoholic extraction were 207.32 mg/g, 130.00 mg/g and 200.82 mg/g, respectively. Release pattern of green tea chewing gum with different gum base ratios and various sweeteners in phosphate buffer were prepared. A total of 60 persons who were 20-30 years of age, participated in our panel test for organoleptic properties such as taste, stiffness, stickiness, etc., Acceptable gum was the one with the same ratio of the used rubber bases. Cinnamon selected as the preferred taste by volunteers. Combination of aspartame, sugar and maltitol has appropriate taste. The effect of various sweetener on release pattern was negligible, on the other hand rubber bases ratio variation, changed the release pattern obviously. Conclusion: The green tea chewing gum with sugar, maltitol and aspartame sweeteners and cinnamon flavor, using the same rubber bases ratio may be a desirable antioxidant product. PMID:25161989

  11. Milk β-lactoglobulin complexes with tea polyphenols.

    PubMed

    Kanakis, C D; Hasni, Imed; Bourassa, Philippe; Tarantilis, P A; Polissiou, M G; Tajmir-Riahi, Heidar-Ali

    2011-08-01

    The effect of milk on the antioxidant capacity of tea polyphenols is not fully understood. The complexation of tea polyphenols with milk proteins can alter the antioxidant activity of tea compounds and the protein secondary structure. This study was designed to examine the interaction of β-lactogolobulin (β-LG) with tea polyphenols (+)-catechin (C), (-)-epicatechin (EC), (-)-epicatechin gallate (ECG) and (-)-epigallocatechin gallate (EGCG) at molecular level, using FTIR, CD and fluorescence spectroscopic methods as well as molecular modelling. The polyphenol binding mode, the binding constant and the effects of polyphenol complexation on β-LG stability and secondary structure were determined. Structural analysis showed that polyphenols bind β-LG via both hydrophilic and hydrophobic interactions with overall binding constants of KC-β-LG=2.2 (±0.8)×10(3)M(-1), KEC-β-LG=3.2 (±1)×10(3)M(-1), KECG-β-LG=1.1 (±0.6)×10(4)M(-1) and KEGCG-β-LG=1.3 (±0.8)×10(4)M(-1). The number of polyphenols bound per protein molecule (n) was 1.1 (C), 0.9 (EC), 0.9 (ECG) and 1.3 (EGCG). Molecular modelling showed the participation of several amino acid residues in polyphenol-protein complexation with extended H-bonding network. The β-LG conformation was altered in the presence of polyphenols with an increase in β-sheet and α-helix suggesting protein structural stabilisation. These data can be used to explain the mechanism by which the antioxidant activity of tea compounds is affected by the addition of milk. PMID:25214095

  12. Tea category classification using morphological characteristics and support vector machines

    NASA Astrophysics Data System (ADS)

    Li, X. L.; He, Y.; Qiu, Z. J.; Bao, Y. D.

    2008-11-01

    Tea categories classification is an importance task for quality inspection. And traditional way for doing this by human is time-consuming, requirement of too much manual labor. This study proposed a method for discriminating green tea categories based on multi-spectral images technique. Four tea categories were selected for this study, and total of 243 multi-spectral images were collected using a common-aperture multi-spectral charged coupled device camera with three channels (550, 660 and 800 nm). A compound image which has the clearest outline of samples was process by combination of the three monochrome images (550, 660 and 800 nm). After image preprocessing, 18 morphometry parameters were obtained for each samples. The 18 parameters used including area, perimeter, centroid and eccentricity et al. To better understanding these parameters, principal component analysis was conducted on them, and score plot of the first three independent components was obtained. The first three components accounted for 99.02% of the variation of original 18 parameters. It can be found that the four tea categories were distributed in dense clusters respectively in score plot. But the boundaries among them were not clear, so a further discrimination must be developed. Three algorithms including support vector machines, artificial neural network and linear discriminant analysis were adopted for developed classification models based on the optimized 9 features. Wonderful result was obtained by support vector machines model with accuracy of 93.75% for prediction unknown samples in testing set. It can be concluded that it is an effective method to classification tea categories based on computer vision, and support vector machines is very specialized for development of classification model.

  13. Fluoride concentration and pH of iced tea products.

    PubMed

    Behrendt, Annekathrin; Oberste, Volker; Wetzel, Willi Eckhard

    2002-01-01

    The objective of this study was to determine the fluoride concentration and pH of 44 iced tea samples and hence to assess the possible role of these beverages as systemic fluoride source as well as their potential cariogenic and erosive character. Ten tea samples were available as a granular instant powder, and 34 as ready-to-drink liquid products. The iced teas contained different types of sugar alone or in combination with maltodextrin, glucose syrup and noncaloric sweeteners. In one product, only acesulfame and aspartame were established. All samples contained lemon juice or citric acid as an additive. The pH ranged from 4.04 to 2.63 and the titrated amount of base to pH 7.0 from 0.75 to 2.39 mmol NaOH/50 ml. The fluoride concentrations measured were <0.6 ppm in 14 products, 0.6-1.0 ppm in 10 products, 1.1-1.5 ppm in 16 products, 1.6-2.0 ppm in 2, and >2.0 ppm in another 2 products. In conclusion, most of the iced teas studied contained considerable fluoride concentrations. If infants ingest larger amounts of them because of their sweet taste, there is a risk of uncontrolled overdosing as a result of additional fluoride intake from other sources at the same time. Furthermore, the majority of the products revealed a highly cariogenic character and finally, all the iced teas appear to be acidic enough to cause dental erosion if these refreshments were excessively consumed from nursing bottles.

  14. Structure and Function of Fusicoccadiene Synthase, a Hexameric Bifunctional Diterpene Synthase.

    PubMed

    Chen, Mengbin; Chou, Wayne K W; Toyomasu, Tomonobu; Cane, David E; Christianson, David W

    2016-04-15

    Fusicoccin A is a diterpene glucoside phytotoxin generated by the fungal pathogen Phomopsis amygdali that causes the plant disease constriction canker, first discovered in New Jersey peach orchards in the 1930s. Fusicoccin A is also an emerging new lead in cancer chemotherapy. The hydrocarbon precursor of fusicoccin A is the tricyclic diterpene fusicoccadiene, which is generated by a bifunctional terpenoid synthase. Here, we report X-ray crystal structures of the individual catalytic domains of fusicoccadiene synthase: the C-terminal domain is a chain elongation enzyme that generates geranylgeranyl diphosphate, and the N-terminal domain catalyzes the cyclization of geranylgeranyl diphosphate to form fusicoccadiene. Crystal structures of each domain complexed with bisphosphonate substrate analogues suggest that three metal ions and three positively charged amino acid side chains trigger substrate ionization in each active site. While in vitro incubations reveal that the cyclase domain can utilize farnesyl diphosphate and geranyl diphosphate as surrogate substrates, these shorter isoprenoid diphosphates are mainly converted into acyclic alcohol or hydrocarbon products. Gel filtration chromatography and analytical ultracentrifugation experiments indicate that full-length fusicoccadiene synthase adopts hexameric quaternary structure, and small-angle X-ray scattering data yield a well-defined molecular envelope illustrating a plausible model for hexamer assembly.

  15. CLYBL is a polymorphic human enzyme with malate synthase and β-methylmalate synthase activity

    PubMed Central

    Strittmatter, Laura; Li, Yang; Nakatsuka, Nathan J.; Calvo, Sarah E.; Grabarek, Zenon; Mootha, Vamsi K.

    2014-01-01

    CLYBL is a human mitochondrial enzyme of unknown function that is found in multiple eukaryotic taxa and conserved to bacteria. The protein is expressed in the mitochondria of all mammalian organs, with highest expression in brown fat and kidney. Approximately 5% of all humans harbor a premature stop polymorphism in CLYBL that has been associated with reduced levels of circulating vitamin B12. Using comparative genomics, we now show that CLYBL is strongly co-expressed with and co-evolved specifically with other components of the mitochondrial B12 pathway. We confirm that the premature stop polymorphism in CLYBL leads to a loss of protein expression. To elucidate the molecular function of CLYBL, we used comparative operon analysis, structural modeling and enzyme kinetics. We report that CLYBL encodes a malate/β-methylmalate synthase, converting glyoxylate and acetyl-CoA to malate, or glyoxylate and propionyl-CoA to β-methylmalate. Malate synthases are best known for their established role in the glyoxylate shunt of plants and lower organisms and are traditionally described as not occurring in humans. The broader role of a malate/β-methylmalate synthase in human physiology and its mechanistic link to vitamin B12 metabolism remain unknown. PMID:24334609

  16. Pesticide usage pattern in tea ecosystem, their retrospects and alternative measures.

    PubMed

    Gurusubramanian, G; Rahman, A; Sarmah, M; Ray, Somnath; Bora, S

    2008-11-01

    Tea is a perennial plantation crop grown under monoculture providing favorable conditions for a variety of pests. The concept of pest control has undergone a considerable change over the past few decades. In recent years there has been a greater dependence on the use of pesticides (7.35-16.75 kgha(-1)) with little importance laid on other safe control methods for the management of tea pests. Due to this practice, the tea pests showed a higher tolerance/ resistance status due to formation of greater amount of esterases, glutathione S-transferase and acetylcholinesterase. Thus, over reliance on pesticides end up with pesticide residue in made tea (DDT - 10.4-47.1%; endosulfan - 41.1-98.0%; dicofol- 0.0-82.4%; ethion - 0.0-36.2%; cypermethrin - 6.0- 45.1%). The growing concern about the pesticide residue in made tea, its toxicity hazards to consumers, the spiraling cost of pesticides and their application have necessitated a suitable planning which will ensure a safe, economic as well as effective pest management in tea. At present it is a global concern to minimize chemical residue in tea and European union and German law imposed stringent measures for the application of chemicals in tea and fixed MRL values at < or = 0. 1 mgkg(-1) for the most commonly used pesticides which will not be met out in the real practice and has been a major constraint to tea exporting countries like India. In order to regulate the situation of the Indian market at global level, central insecticide board and prevention of food adulteration regulation committee have reviewed the MRL position for tea and has recommended 10 insecticides, 5 acaricides, 9 herbicides and 5 fungicides for use in tea and issued the tea distribution and export control order 2005 which will help the country to limit the presence of undesirable substances in tea. This review attempts to provide the readers with a comprehensive account of pesticide use in North East in tea, surveillance report of the European

  17. Application of the Kombucha 'tea fungus' for the enhancement of antioxidant and starch hydrolase inhibitory properties of ten herbal teas.

    PubMed

    Watawana, Mindani I; Jayawardena, Nilakshi; Choo, Candy; Waisundara, Viduranga Y

    2016-03-01

    Ten herbal teas (Acacia arabica, Aegle marmelos flower, A. marmelos root bark, Aerva lanata, Asteracantha longifolia, Cassia auriculata, Hemidesmus indicus, Hordeum vulgare, Phyllanthus emblica, Tinospora cordifolia) were fermented with the Kombucha 'tea fungus'. The pH values of the fermented beverages ranged from 4.0 to 6.0 by day 7, while the titratable acidity ranged from 2.5 to 5.0g/mL (P<0.05). Gallic acid had statistically significantly increased (P<0.05) in almost all the samples by day 7. The Oxygen radical absorbance capacity assay indicated 5 of the Kombucha beverages to have statistically significant increases (P<0.05) by day 7. The α-amylase inhibitory activities ranged from 52.5 to 67.2μg/mL in terms of IC50 values following fermentation, while the α-glucosidase inhibitory activities ranged from 95.2 to 196.1μg/mL. In conclusion, an enhancement of the antioxidant and starch hydrolase inhibitory potential of the herbal teas was observed by adding the tea fungus.

  18. Preparation of Herbal Tea as Infusion or by Maceration at Room Temperature Using Mistletoe Tea as an Example

    PubMed Central

    Jäger, Sebastian; Beffert, Markus; Hoppe, Katharina; Nadberezny, Dominik; Frank, Bruno; Scheffler, Armin

    2011-01-01

    Herbal tea can be prepared by infusion or maceration at room temperature resulting in different compositions of extractable constituents, which possibly influences the mode of action or safety profile. Knowledge on this topic is limited. The aim of this study was to investigate the substantial differences between infusion and maceration as recommended preparation methods for the preparation of herbal mistletoe tea, a traditional remedy against cardiovascular diseases. No active substances are known but analytical marker substances such as proteins, triterpenoids, phenylpropane derivatives and flavonoids can be quantified within the herb and the different herbal tea preparations. Whereas phenylpropane derivatives were completely extracted by infusion and maceration, neither method dissolved viscotoxins. 43% of mistletoe lectins were extracted by maceration, whereas by infusion they are inactivated by thermal degradation. By contrast, oleanolic acid and betulinic acid are present in higher concentrations in infusates compared with macerates, but even infusion extracted less than 2%. Infusion extracted 43% of flavonoid-like substances and maceration only 31%. In conclusion this study determines some differences between both extraction methods on the profile of solved substances. The relevance of it should be determined in studies dealing with the efficacy of herbal mistletoe tea. PMID:21617779

  19. Preparation of herbal tea as infusion or by maceration at room temperature using mistletoe tea as an example.

    PubMed

    Jäger, Sebastian; Beffert, Markus; Hoppe, Katharina; Nadberezny, Dominik; Frank, Bruno; Scheffler, Armin

    2011-03-01

    Herbal tea can be prepared by infusion or maceration at room temperature resulting in different compositions of extractable constituents, which possibly influences the mode of action or safety profile. Knowledge on this topic is limited. The aim of this study was to investigate the substantial differences between infusion and maceration as recommended preparation methods for the preparation of herbal mistletoe tea, a traditional remedy against cardiovascular diseases. No active substances are known but analytical marker substances such as proteins, triterpenoids, phenylpropane derivatives and flavonoids can be quantified within the herb and the different herbal tea preparations. Whereas phenylpropane derivatives were completely extracted by infusion and maceration, neither method dissolved viscotoxins. 43% of mistletoe lectins were extracted by maceration, whereas by infusion they are inactivated by thermal degradation. By contrast, oleanolic acid and betulinic acid are present in higher concentrations in infusates compared with macerates, but even infusion extracted less than 2%. Infusion extracted 43% of flavonoid-like substances and maceration only 31%. In conclusion this study determines some differences between both extraction methods on the profile of solved substances. The relevance of it should be determined in studies dealing with the efficacy of herbal mistletoe tea. PMID:21617779

  20. A comparative study of the antioxidant scavenging activity of green tea, black tea and coffee extracts: a kinetic approach.

    PubMed

    Anissi, Jaouad; El Hassouni, Mohammed; Ouardaoui, Abdelkrim; Sendide, Khalid

    2014-05-01

    The antioxidant activities of three beverages, coffee, black tea and green tea, along with their major components, were investigated in terms of their reaction with the stable radical 2,2'-diphenyl-2-picrylhydrazyl (DPPH). We used a kinetic approach in parallel with quantification methods based on a fixed end-point to determine the scavenging efficiency of compounds abundant in these beverages during their reaction with DPPH using a stopped-flow spectrophotometer-based method. Ascorbic acid, (+)-catechin, (-)-epigallocatechin, tannic acid, and caffeic acid were selected as model antioxidants to study in coffee, black tea and green tea. We applied a second-order model to demonstrate similarities in the kinetics behavior of beverages and related compounds. Our findings showed the slopes k2(')((mol/L)(-1)s(-1)) and k2max(')((mol/L)(1)s(-1)) exhibited similar and correlated values; we suggest the variation in k2(') as a function of time is more informative about antioxidant properties than reaction with DPPH alone. We also used IC100 to test the reliability of the relative stoichiometry using a new comparative parameter "n", which was calculated as: n=c0DPPHIC100 (mol/L(mol/L)(-1), (mol/L)mlmg(-1) or molg(-1)).