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Sample records for kamairi-cha green tea

  1. Changes in the Composition of Raw Tea Leaves from the Korean Yabukida Plant during High-temperature Processing to Pan-Fried Kamairi-cha Green Tea

    Science.gov (United States)

    To develop a better understanding of compositional changes occurring during the production of commercial teas, we determined by high-performance liquid chromatography (HPLC) changes in ingredient levels during each of several manufacturing steps used to produce Kamairi-cha, a premium green tea. We ...

  2. Changes in the composition of raw tea leaves from the Korean Yabukida plant during high-temperature processing to pan-fried Kamairi-cha green tea.

    Science.gov (United States)

    Friedman, Mendel; Levin, Carol E; Choi, Suk-Hyun; Lee, Seung-Un; Kozukue, Nobuyuki

    2009-06-01

    To develop a better understanding of compositional changes occurring during the production of commercial teas, we determined by high-performance liquid chromatography (HPLC) changes in ingredient levels during each of several manufacturing steps used to produce Kamairi-cha, a premium green tea. Kamairi-cha uses pan-frying instead of the usual blanching technique to inactivate the enzymes responsible for producing traditional black tea. The resulting tea lacks the characteristic bitterness of green tea, producing a green tea that is described as sweet tasting. The processing steps used to produce this pan-fried tea were as follows: 1st roasting, 1st rolling, 2nd roasting, 2nd rolling, 1st firing, and 2nd firing. The results show that during production at temperatures up to 300 degrees C, raw leaves lost (in percent) 97.3 water, 94 two chlorophylls, 14.3 seven catechins, and 2.75 caffeine. A separate analysis showed that the final product contained 21.67 mg/g dry wt of the biologically active amino acid theanine. The results of this 1st report on changes in individual catechins and other tea ingredients in tea leaves during pan-frying make it possible to select production conditions that maximize levels of beneficial tea ingredients. The possible significance of the results for the human diet is discussed.

  3. GREEN TEA FESTIVAL

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ What is the green tea? The green tea belongs to the type of non-fermenting tea, with a quality feature of "clear tea infusion with green leaves"; this type of tea has the biggest output in China, and the basic processing procedure of the green tea is divided into three steps: heating, rubbing and drying. According to the different processing technologies, the green tea is divided into fried green tea, baked green tea, steamed green tea and dried green tea. The steamed green tea is to heat the tea by steaming; to heat the tea by pan-frying can be divided into frying, baking and drying, which is called heating by frying, heating by baking and heating by drying. West LakeLongjing, Xinyang Maojian, Bi Luochun, and Sanbeixiang belong to fried green tea; Mount Huang Maofeng, Youjiyuluo, and Luhai pekoe belong to baked green tea;Enshiyulu belongs to steamed green tea.

  4. Green tea and cancer prevention.

    Science.gov (United States)

    Yang, Chung S; Wang, Xin

    2010-01-01

    Extracts of green tea and green tea polyphenols have exhibited inhibitory effects against the formation and development of tumors at different organ sites in animals. These include animal models for skin, lung, oral cavity, esophagus, stomach, intestine, colon, liver, pancreas, bladder, mammary gland, and prostate cancers. In addition to suppressing cell proliferation, promoting apoptosis, and modulating signaling transduction, green tea polyphenols, especially (-)-epigallocatechin-3-gallate, also inhibit cell invasion, angiogenesis, and metastasis. This article reviews data on the cancer preventive activities of green tea polyphenols, possible mechanisms involved, and the relationship between green tea consumption and human cancer risk.

  5. Green tea and bone health

    Science.gov (United States)

    Osteoporosis is a major health problem in the elderly, particularly women. 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 mit...

  6. Green tea and bone metabolism.

    Science.gov (United States)

    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.

  7. Green Tea and Bone Metabolism

    Science.gov (United States)

    Osteoporosis is a major health problem in elderly men and women. Epidemiological evidence has shown association between tea consumption and age-related bone loss in elderly men and women. The aim of this review is to provide a systemic review of green tea and bone health to cover the following topi...

  8. Green tea and the skin.

    Science.gov (United States)

    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.

  9. Green Tea and Its Antioxidant Properties

    OpenAIRE

    Yeh, Jason

    1999-01-01

    Green tea contains antioxidants which have been implicated to contribute to reduced risk of cardiovascular disease. This may be explained in part by the green tea's antioxidant properties. Green tea is a rich source of flavonoids with high antioxidant activity both in vitro and in vivo. This includes the ability of green tea to lower the oxidizability of low-density lipoprotein (LDL) in vitro. In vivo lipid oxidation as measure by plasma lipid peroxides and LDL oxidizability are significantly...

  10. Green tea and tea polyphenols in cancer prevention.

    Science.gov (United States)

    Chen, Di; Daniel, Kenyon G; Kuhn, Deborah J; Kazi, Aslamuzzaman; Bhuiyan, Mohammad; Li, Lianhai; Wang, Zhigang; Wan, Sheng Biao; Lam, Wai Har; Chan, Tak Hang; Dou, Q Ping

    2004-09-01

    The cancer-preventive effects of green tea and its main constituent (-)-epigallocatechin gallate [(-)-EGCG] are widely supported by results from epidemiological, cell culture, animal and clinical studies in the recent decade. In vitro cell culture studies show that tea polyphenols potently induce apoptotic cell death and cell cycle arrest in tumor cells but not in their normal cell counterparts. Green tea polyphenols affect several signal transduction pathways, including growth factor-mediated, the mitogen-activated protein kinase (MAPK)-dependent, and ubiquitin/proteasome degradation pathways. Epidemiological studies have suggested that the consumption of green tea lowers the risk of cancer. Various animal studies have revealed that treatment by green tea inhibits tumor incidence and multiplicity in different organ sites such as skin, lung, liver, stomach, mammary gland and colon. Phase I and II clinical trials were carried out recently to explore the anticancer effects of green tea in patients with cancer. At this time, more mechanistic research, animal studies, and clinical trials are necessary to further evaluate the role of green tea in cancer prevention.

  11. Green tea and type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Jae-Hyung Park

    2014-03-01

    Full Text Available Green tea and coffee consumption have been widely popular worldwide. These beverages contain caffeine to activate the central nervous system by adenosine receptor blockade, and due to the caffeine, addiction or tolerance may occur. In addition to this caffeine effect, green tea and coffee consumption have always been at the center of discussions about human health, disease, and longevity. In particular, green tea catechins are involved in many biological activities such as antioxidation and modulation of various cellular lipid and proteins. Thus, they are beneficial against degenerative diseases, including obesity, cancer, cardiovascular diseases, and various inflammatory diseases. Some reports also suggest that daily consumption of tea catechins may help in controlling type 2 diabetes. However, other studies have reported that chronic consumption of green tea may result in hepatic failure, neuronal damage, and exacerbation of diabetes, suggesting that interindividual variations in the green tea effect are large. This review will focus on the effect of green tea catechins extracted from the Camellia sinensis plant on type 2 diabetes and obesity, and the possible mechanistic explanation for the experimental results mainly from our laboratory. It is hoped that green tea can be consumed in a suitable manner as a supplement to prevent the development of type 2 diabetes and obesity.

  12. Preparation of partially decaffeinated instant green tea.

    Science.gov (United States)

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

    2007-05-02

    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.

  13. Health potential for functional green teas?

    Science.gov (United States)

    Boon, Niels

    2008-12-01

    Obesity is a major health problem in the developed and developing world. Many "functional" foods and ingredients are advocated for their effects on body composition but few have consistent scientific support for their efficacy. However, an increasing amount of mechanistic and clinical evidence is building for green tea. The tea plant is naturally rich in a group of antioxidants known as catechins. Unlike black tea, green tea production involves little processing and fermentation and therefore, green tea brews are rich in catechins. Green tea has been suggested to have a number of potential health benefits in areas such as cardiovascular disease, cancer prevention, glucose homeostasis and dental health. Although there is some promising evidence in all of these areas, more data from human intervention trials are needed. A lot of attention has lately been focused on the beneficial effects of green tea on body composition and particularly visceral fat, which has been shown to have a strong link with different components of the metabolic syndrome such as cardiovascular disease and type 2 diabetes. Most, but not all, of the positive results come from a number Asian studies, in which overweight subjects (men and women) consumed green tea for approximately 12 weeks. Finally, green tea may also have measurable acute effects on energy metabolism and fat oxidation and in particular during physical activity, as evidenced by other studies specifically looking at these endpoints. Small cumulative effects on energy metabolism could also be responsible for the longer-tem effects of green tea on body composition, and these long-term effects may also be most apparent in the context of moderate physical activity. However, more research is needed to further clarify the exact mechanisms of action and to extrapolate these findings to non-Asian populations.

  14. Targeting DNA methylation with green tea catechins.

    Science.gov (United States)

    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.

  15. The antimicrobial possibilities of green tea

    Directory of Open Access Journals (Sweden)

    Wanda C Reygaert

    2014-08-01

    Full Text Available Green tea is a popular drink, especially in Asian countries, although its popularity continues to spread across the globe. The health benefits of green tea, derived from the leaves of the Camellia sinensis plant, have been studied for many years. Fairly recently, researchers have begun to look at the possibility of using green tea in antimicrobial therapy, and the potential prevention of infections. The particular properties of catechins found in the tea have shown promise for having antimicrobial effects. There are four main catechins (polyphenols found in green tea: (--epicatechin (EC, (--epicatechin-3-gallate (ECG, (--epigallocatechin (EGC, and (--epigallocatechin-3-gallate (EGCG. Three of these, ECG, EGC, and EGCG have been shown to have antimicrobial effects against a variety of organisms. These catechins have exhibited a variety of antimicrobial mechanisms. The results of studies on the antimicrobial effects of green tea have shown that the potential for preventive and therapeutic purposes is present. Further data collection on studies performed with human consumption during the course of infections, and studies on the occurrence of infections in populations that consume regular amounts of green tea will be necessary to complete the picture of its antimicrobial possibilities.

  16. THE COMAPARATIVE DATA BETWEEN VARIOUS BRANDS OF TEA POWDERS AND GREEN TEA

    Directory of Open Access Journals (Sweden)

    M.Kranthi Kumar

    2014-08-01

    Full Text Available Tea is composed of many compounds. These components have various Effects depending upon the amount of tea ingested and the quality of the tea .apart from that green tea having various useful properties which are helpful for human body .The present Communication Describes about the about the “THE COMAPARATIVE DATA BETWEEN VARIOUS BRANDS OF TEA POWDERS AND GREEN TEA by using U.V Spectrophotometer and TLC Procedure for the estimation of caffeine content in commercial available tea samples and Comparative data of caffeine content along with analysis of different brands of tea samples by Comparing with the green tea powder. The present methods shows a detailed description about the Difference between commercial brands of tea powders and Green tea. A possible explanation to Account for the variability in Green Tea and analysis of different samples is offered.

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

    Science.gov (United States)

    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.

  18. Effect of green tea phytochemicals on mood and cognition

    NARCIS (Netherlands)

    Dietz, Christina; Dekker, Matthijs

    2017-01-01

    Background: Green tea is traditionally known to induce mental clarity, cognitive function, physical activation and relaxation. Recently, a special green tea, matcha tea, is rapidly gaining popularity throughout the world and is frequently referred to as a mood- and brain food. Matcha tea

  19. Effect of green tea phytochemicals on mood and cognition

    NARCIS (Netherlands)

    Dietz, Christina; Dekker, Matthijs

    2017-01-01

    Background: Green tea is traditionally known to induce mental clarity, cognitive function, physical activation and relaxation. Recently, a special green tea, matcha tea, is rapidly gaining popularity throughout the world and is frequently referred to as a mood- and brain food. Matcha tea consumpt

  20. Green tea extract for periodontal health

    OpenAIRE

    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 chroni...

  1. Genotoxicity studies on green tea catechin.

    Science.gov (United States)

    Ogura, R; Ikeda, N; Yuki, K; Morita, O; Saigo, K; Blackstock, C; Nishiyama, N; Kasamatsu, T

    2008-06-01

    The beneficial effects of tea catechins are well documented. We evaluated the genotoxic potential of a green tea catechin preparation using established genotoxicity assays, including a bacterial reverse mutation assay (Ames test), a chromosomal aberration assay in cultured Chinese hamster lung cells (CHL/IU), a mouse lymphoma L5178Y/tk assay, and a bone marrow micronucleus (MN) assay in ICR CD mice and SD rats. No significant increases in the number of revertant colonies were observed in the Ames test, but positive responses were observed in two in vitro assays: the chromosomal aberration assay and mouse lymphoma L5178/tk assay. However, the in vivo study demonstrated no significant increase in micronucleated polychromatic erythrocytes (MNPCE) in the bone marrow of both ICR CD mice and SD rats administered a high dose of the green tea catechin preparation up to 2000mg/kg. Combined with favorable epidemiological information suggesting a chemopreventive effect of tea catechins on carcinogenesis, we conclude that green tea catechin presents no significant genotoxic concern under the anticipated conditions of use. These results are consistent with other genotoxicity studies of tea catechins, which show minimal, if any, genotoxic potential.

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

    Science.gov (United States)

    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.

  3. The cytogenetic effects of black tea and green tea on cultured human lymphocytes

    Directory of Open Access Journals (Sweden)

    Halil Erhan Eroğlu

    2011-12-01

    Full Text Available In this study, the cytogenetic effects of black tea and green tea were determined in cultured peripheral blood lymphocytes. Results showed that black tea and green tea induced the mitotic and replication indexes and decreased micronuclei. But these data were not statistically significant for green tea. The effects of black tea on the micronucleus formation and mitotic index were statistically significant. The decrease in micronucleus counts indicated that black tea and green tea had considerable anticlastogenic and antigenotoxic effects as observed in vitro in human lymphocytes. Thus, it could be concluded that tea polyphenols protected the normal cells from genotoxic or carcinogenic agents, which indicated the therapeutic and antioxidative role of catechins, flavonoids or other tea compounds.

  4. Oligomerization and hydroxylation of green tea catechins by oxidative enzymes

    OpenAIRE

    Verloop, J.W.

    2016-01-01

    Black teas are known for their characteristic brown colour, bitter taste and astringent mouth feel. These sensory characteristics are mainly influenced by the phenolic oxidation products present in black tea. The oxidation of phenolics from green tea leaves during black tea manufacturing is an uncontrolled process. With the objective to make tea oxidation a more controlled process, the aim of this thesis was to understand the enzymatic oxidation reactions occurring during tea oxidation, and t...

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

    Science.gov (United States)

    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.

  6. Cancer prevention by green tea: evidence from epidemiologic studies1234

    OpenAIRE

    Yuan, Jian-Min

    2013-01-01

    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 o...

  7. Association between green tea consumption and lung cancer risk.

    Science.gov (United States)

    Lee, Andy H; Liang, Wenbin; Hirayama, Fumi; Binns, Colin W

    2010-07-01

    Green tea is a popular beverage and its health benefits are well known. However, inconsistent results have been reported in observational studies concerning the association between green tea consumption and the lung cancer risk. In this commentary, several methodological issues underlying the measurement of tea exposure are highlighted. The recommendations should be useful for designing and planning prospective cohort studies to ascertain the protective effect of green tea against lung cancer.

  8. Green tea and prevention of esophageal and lung cancers

    OpenAIRE

    Yuan, Jian-Min

    2011-01-01

    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 enh...

  9. Green tea as a source of food antioxidants

    DEFF Research Database (Denmark)

    Yin, Jie

    as Safe” (GRAS-status). In this PhD project, green tea rich in polyphenol compounds catechins was selected as the natural source of antioxidants. The aim of the project was to investigate green tea as a source of natural antioxidants for use in processed foods. First of all, the antioxidant effects...... of green tea catechins and green tea extract were investigated in terms of scavenging efficiency of the food-derived free radicals. The relevant experimental methods were based on electrochemical detection of oxygen consumption, electron spin resonance (ESR) spectroscopy, Rancimat test and liposome...... oxidation test. In addition, antioxidant interactions for individual green tea catechins or green tea extract in combination with endogenous antioxidant, α-tocopherol, were studied. The results showed that green tea catechins possess excellent antioxidant activity against the oxidative damage of lipids...

  10. Oligomerization and hydroxylation of green tea catechins by oxidative enzymes

    NARCIS (Netherlands)

    Verloop, J.W.

    2016-01-01

    Black teas are known for their characteristic brown colour, bitter taste and astringent mouth feel. These sensory characteristics are mainly influenced by the phenolic oxidation products present in black tea. The oxidation of phenolics from green tea leaves during black tea manufacturing is an uncon

  11. Oligomerization and hydroxylation of green tea catechins by oxidative enzymes

    NARCIS (Netherlands)

    Verloop, J.W.

    2016-01-01

    Black teas are known for their characteristic brown colour, bitter taste and astringent mouth feel. These sensory characteristics are mainly influenced by the phenolic oxidation products present in black tea. The oxidation of phenolics from green tea leaves during black tea manufacturing is an

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  14. Green tea, black tea and breast cancer risk: a meta-analysis of epidemiological studies

    National Research Council Canada - National Science Library

    Sun, Can-Lan; Yuan, Jian-Min; Koh, Woon-Puay; Yu, Mimi C

    2006-01-01

    .... This meta-analysis included 13 papers which examined populations in eight countries and provided data on consumption of either green tea or black tea, or both in relation to breast cancer risk...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  17. PROTECTIVE EFFECT OF GREEN TEA FROM PAF-INDUCED NEUROTOXITY

    Institute of Scientific and Technical Information of China (English)

    Han Enji; Hah Xuefei; Joseph Rajiv

    2000-01-01

    Objective The protective effect of chinese green tea from PAF-induced neurotoxity was investigated Method LaN1 ( neuroblastoma cell line) was used as neuron. Lactate dehydrogenase (LDH) -release was an indicator of cell death. Cytoplasmic calcium was measured with Aequouin-loaded method. Results When applied to LaN1 cells, green tea in concentration 2mg/ml or stronger obviously damaged cells. If lower concentration (0. 5mg/ml and l.Omg/ml) of green tea were applied, green tea inhibited the elevation of intracellular calcium and reduced the cytotoxity induced by PAF in neurons. Conclusion PAF plays an important role in brain injury and stroke, the protective effect of green tea could be a basis to explore weather green tea or its derivative may have preventive and therapeutic potential for neuronal injury.

  18. Cardiovascular effects of green tea catechins: progress and promise.

    Science.gov (United States)

    Islam, Mohammed A

    2012-08-01

    Recently, there is a growing interest in the cardiovascular beneficial effects of green tea. Epidemiological and clinical studies have suggested that consumption of green tea is inversely associated with the risk of developing cardiovascular diseases. Catechins, the major flavonoid constituents of green tea, exert cardioprotective effects through diverse mechanisms that include reversal of endothelial dysfunctions, decreasing inflammatory biomarkers, and providing antioxidant, antiplatelet and antiproliferative effects. Moreover, dietary consumption of green tea catechins has beneficial effects on blood pressure and lipid parameters. This review will focus on discussing the latest research on the cardioprotective effects of green tea catechins and their underlying molecular mechanisms. Several recent patents pertinent to green tea and cardiovascular health will also be discussed. It is noteworthy that clinical studies involving green tea are fraught with multiple complexity and confounding factors. Therefore, a rigorous assessment of the effects of green tea catechins in well-controlled human trials will be required for better understanding of the effects of green tea in cardiovascular health.

  19. Effects of an Intensive Resistant Training Sessions and Green Tea

    Directory of Open Access Journals (Sweden)

    Mohammad Esmaeil Afzalpour

    2014-03-01

    Full Text Available Background: Intensive and acute exercise trainings may induce oxidative stress, but antioxidant supplements may attenuate its degenerative consequences. The aim of this research was to examine the effect of green tea supplementation on the oxidative stress indices after an intensive resistance training session. Materials and Methods: 40 non-athletes (without regular physical activity women were randomly divided into 4 equal (n=10 groups including green tea supplementation, green tea supplementation plus resistance training, resistance training, and control groups. After supplementation period (600 mg/day, 14 days, resistance training and green tea supplementation plus resistance training groups performed an intensive resistance training session at 75-85 % of one repetition maximum. The malondialdehyde and total thiol were measured as oxidative stress indices. Data were analyzed by using of repeated measure ANOVA and LSD tests at p<0.056T. Results: Results showed that after 14 days of green tea consumption, malondialdehyde significantly decreased in green tea supplementation (p=0.03 and green tea supplementation plus resistance training (p=0.01 groups, while total thiol increased significantly (p=0.01 in two green tea supplementation groups. However, an intensive resistance training session increased malondialdehyde (p=0.01 without any significantly changes in total thiol (p=0.426T. Conclusion: It seems that green tea supplementation can inhibit exercise-induced protein and lipid oxidation in non-athletes women via enhancement of antioxidant defense system of the body6T.6T

  20. Effects of Water Solutions on Extracting Green Tea Leaves

    Directory of Open Access Journals (Sweden)

    Wen-Ying Huang

    2013-01-01

    Full Text Available This study investigates the effects of water solutions on the antioxidant content of green tea leaf extracts. Green teas prepared with tap water and distilled water were compared with respect to four antioxidant assays: total phenol content, reducing power, DMPD assay, and trolox equivalent antioxidant capacity assay. The results indicate that green tea prepared with distilled water exhibits higher antioxidant activity than that made with tap water. The high performance liquid chromatography showed that major constituents of green tea were found in higher concentrations in tea made with distilled water than in that made with tap water. This could be due to less calcium fixation in leaves and small water clusters. Water solutions composed of less mineralisation are more effective in promoting the quality of green tea leaf extracts.

  1. Beneficial effects of green tea: A literature review

    Directory of Open Access Journals (Sweden)

    Kuttan Ramadasan

    2010-04-01

    Full Text Available Abstract The health benefits of green tea for a wide variety of ailments, including different types of cancer, heart disease, and liver disease, were reported. Many of these beneficial effects of green tea are related to its catechin, particularly (--epigallocatechin-3-gallate, content. There is evidence from in vitro and animal studies on the underlying mechanisms of green tea catechins and their biological actions. There are also human studies on using green tea catechins to treat metabolic syndrome, such as obesity, type II diabetes, and cardiovascular risk factors. Long-term consumption of tea catechins could be beneficial against high-fat diet-induced obesity and type II diabetes and could reduce the risk of coronary disease. Further research that conforms to international standards should be performed to monitor the pharmacological and clinical effects of green tea and to elucidate its mechanisms of action.

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

    Science.gov (United States)

    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.

  3. Antioxidant effects of green tea polyphenols

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The unprecedented interest in the antioxidant activity of green tea polyphenols (GTP) is due to the apparent health benefits of tea drinking and the experimental results with the polyphenols. The results suggest that the galloylated catechins show stronger antioxidant effect than that of nongalloylated catechins and the double bond in C ring also plays an important role in this effect. There are synergic effects between different catechins and the antioxidant effectof (+)-epimers is stronger than that of (-)-epimers. The active site to scavenge free radicals mainly locates in p-hydroxyl of phenol in gallic acid and hydroxyl of phenol in the pyrane also shows activity. The large π bond in chromane and benzene ring of catechin is the structure base for their antioxidant effects. The prevent effect of GTP against diseases and their redox regulation in cell signal pathway are very important to be studied in the future.

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

    Science.gov (United States)

    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.

  5. Role of green tea in reduction of cardiovascular risk factors

    OpenAIRE

    Vlachopoulos, Charalambos; Alexopoulos, Nikolaos; Stefanadis, C.

    2010-01-01

    Nikolaos Alexopoulos, Charalambos Vlachopoulos, Christodoulos Stefanadis1st Cardiology Department, Athens Medical School, Hippokration Hospital, Athens, GreeceAbstract: Tea is widely consumed worldwide. There is accumulating evidence that tea ­consumption may be associated with reduced cardiovascular risk, an association that could be attributed to its flavonoid content. Green tea, the most common type of tea consumed in Asia, contains a large amount of nonoxidized flavonoids, named c...

  6. [Cancer prevention with green tea: reality and wishful thinking].

    Science.gov (United States)

    Bertram, Barbara; Bartsch, H

    2002-01-01

    Different processing of the leaves of the tea plant Camellia sinensis yields green or black tea, the subject of numerous investigations on the preventive effects on chronic degenerative diseases. The tea polyphenols, in particular (-)-epigallocatechin gallate (EGCG) were found to account for most of the protective effects. Since the concentration of EGCG is 5 times higher in green than in black tea, it is assumed that green tea possesses a greater preventive potential. Protection against cancer and cardiovascular diseases are the most important biomedical effects. In experimental models the preventive activity of tea is well documented for tumors at many organ sites. In humans, tea was reported to be protective against tumors of the lung, the gastrointestinal tract and the liver. Tea polyphenols, especially EGCG, were shown to exert cancer-protective activity by the following mechanisms: they inhibit the metabolic activation of carcinogens and induce at the same time detoxifying enzymes. They inhibit signaling pathways controlling cell proliferation and tumor growth such as protein kinase C and the release of tumor necrose factor-alpha from cells. Tea polyphenols reactivate processes which are impaired in tumor cells, such as the programmed cell death and the tumorsuppressor gene p53. Finally, tea polyphenols can also block angiogenesis leading to a starvation of the tumor. By inactivation of proteolytic enzymes they inhibit the development of metastases. This short review summarizes relevant recent findings on the protective effects of green tea constituents.

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

    Science.gov (United States)

    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.

  8. Monitoring Chlorfenapyr in Green Tea during the Manufacturing Process

    Science.gov (United States)

    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.

  9. Green tea as a source of food antioxidants

    DEFF Research Database (Denmark)

    Yin, Jie

    and proteins. Lipid oxidation as well as the Maillard reactions can affect the quality of foods. An efficient way to retard or inhibit both types of reactions can be achieved by utilizing natural antioxidants, which are normally presumed to be safe when the source is plant material, “Generally Recognized...... as Safe” (GRAS-status). In this PhD project, green tea rich in polyphenol compounds catechins was selected as the natural source of antioxidants. The aim of the project was to investigate green tea as a source of natural antioxidants for use in processed foods. First of all, the antioxidant effects...... oxidation test. In addition, antioxidant interactions for individual green tea catechins or green tea extract in combination with endogenous antioxidant, α-tocopherol, were studied. The results showed that green tea catechins possess excellent antioxidant activity against the oxidative damage of lipids...

  10. Structural Properties of Green Tea Catechins.

    Science.gov (United States)

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

    2015-10-08

    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.

  11. Green Tea and Other Tea Polyphenols: Effects on Sebum Production and Acne Vulgaris.

    Science.gov (United States)

    Saric, Suzana; Notay, Manisha; Sivamani, Raja K

    2016-12-29

    Polyphenols are antioxidant molecules found in many foods including nuts, fruits, vegetables, chocolate, wine, and tea. Polyphenols have antimicrobial, anti-inflammatory, and antineoplastic properties. Recent studies suggest that tea polyphenols may be used for reducing sebum production in the skin and for treatment of acne vulgaris. This review examines the evidence for use of topically and orally ingested tea polyphenols against sebum production and for acne treatment and prevention. The PubMed database was searched for studies on tea polyphenols, sebum secretion, and acne vulgaris. Of the 59 studies found, eight met the inclusion criteria. Two studies evaluated tea polyphenol effects on sebum production; six studies examined tea polyphenol effects on acne vulgaris. Seven studies evaluated topical tea polyphenols; one study examined systemic tea polyphenols. None of the studies evaluated both topical and systemic tea polyphenols. Tea polyphenol sources included green tea (six studies) and tea, type not specified (two studies). Overall, there is some evidence that tea polyphenols in topical formulation may be beneficial in reducing sebum secretion and in treatment of acne. Research studies of high quality and with large sample sizes are needed to assess the efficacy of tea polyphenols in topical and oral prevention of acne vulgaris and lipid synthesis by the sebaceous glands.

  12. Green Tea and Other Tea Polyphenols: Effects on Sebum Production and Acne Vulgaris

    Directory of Open Access Journals (Sweden)

    Suzana Saric

    2016-12-01

    Full Text Available Polyphenols are antioxidant molecules found in many foods including nuts, fruits, vegetables, chocolate, wine, and tea. Polyphenols have antimicrobial, anti-inflammatory, and antineoplastic properties. Recent studies suggest that tea polyphenols may be used for reducing sebum production in the skin and for treatment of acne vulgaris. This review examines the evidence for use of topically and orally ingested tea polyphenols against sebum production and for acne treatment and prevention. The PubMed database was searched for studies on tea polyphenols, sebum secretion, and acne vulgaris. Of the 59 studies found, eight met the inclusion criteria. Two studies evaluated tea polyphenol effects on sebum production; six studies examined tea polyphenol effects on acne vulgaris. Seven studies evaluated topical tea polyphenols; one study examined systemic tea polyphenols. None of the studies evaluated both topical and systemic tea polyphenols. Tea polyphenol sources included green tea (six studies and tea, type not specified (two studies. Overall, there is some evidence that tea polyphenols in topical formulation may be beneficial in reducing sebum secretion and in treatment of acne. Research studies of high quality and with large sample sizes are needed to assess the efficacy of tea polyphenols in topical and oral prevention of acne vulgaris and lipid synthesis by the sebaceous glands.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  15. Evaluation of significant pigmets in green teas of different origin

    Directory of Open Access Journals (Sweden)

    Martina Ošťádalová

    2014-07-01

    Full Text Available This work monitors flavonoid pigments (theaflavins and thearubigins, and chlorophyll in green teas from different growing regions (India, China, Russia, Vietnam. These pigments affect the quality of the finished tea infusion and their quantity is affected by the way of tea processing (fermentation. 15 samples of green loose teas were selected for the analysis. The content of these pigments was determined using UV-Vis spectrophotometry, the concentration of flavonoid pigments was measured at a wavelength of 665 nm (theaflavins and 825 nm (thearubigins. Concentration of flavonoid pigments was determined using the standard conversion coefficients, which are 38.7 for TRs and 1.4 for TFs. Chlorophyll concentration was measured at 642.5 and 660 nm. Chlorophyll concentration was determined by the conversion using international standard conversion coefficients and calculation of linear regressions. The results were statistically processed and evaluated in the program of UNISTAT version 5.6. The total amount of chlorophyll ranged from 0.20 to 1.33 mg/L of tea. Concentrations of theaflavin ranged from 0.15 to 0.66 g/100 g of tea and TRs from 2.00 to 11.15 g/100 g of tea. The results showed that the amount of theaflavins, thearubigins and chlorophyll in green teas varied (P <0,05, especially in teas from lowlands in Vietnam and Krasnodar (Russia. Statistically demonstrable difference (P <0,05 in the content of pigments was also recorded in a group of Indian teas (from lowlands and, from a group of Chinese teas, a statistical difference (P <0,05 was demonstrated in the content of pigments in the mountain teas. On the basis of the results it can be concluded that the quality of green tea is mainly influenced by the processing method depending on the processing area (the factory, than by their country of origin.

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

    Science.gov (United States)

    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.

  17. Analysis of Key Odorants in Roasted Green Tea

    Science.gov (United States)

    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.

  18. Extraction of Catechins from Green Tea Using Ultrasound

    Science.gov (United States)

    Koiwai, Hitoshi; Masuzawa, Nobuyoshi

    2007-07-01

    Recently, hazardous properties of synthetic substances contained in foods and medicines have been observed. Therefore, the pharmacological actions of natural substances became the focus of attention. Catechins, which are polyphenols, are abundant in green tea. To extract green tea catechins, there are two types of method: extraction using hot water and organic solvents. In the extraction using hot water, green tea quality deteriorates and catechins are destroyed due to the heat applied. Accordingly, the extraction of catechins at low temperatures is appropriate, although the efficiency is low. Therefore, we attempted to increase the amount of catechins extracted with ultrasonic irradiation.

  19. Biophysical Approach to Mechanisms of Cancer Prevention and Treatment with Green Tea Catechins

    OpenAIRE

    Masami Suganuma; Atsushi Takahashi; Tatsuro Watanabe; Keisuke Iida; Takahisa Matsuzaki; Yoshikawa, Hiroshi Y.; Hirota Fujiki

    2016-01-01

    Green tea catechin and green tea extract are now recognized as non-toxic cancer preventives for humans. We first review our brief historical development of green tea cancer prevention. Based on exciting evidence that green tea catechin, (−)-epigallocatechin gallate (EGCG) in drinking water inhibited lung metastasis of B16 melanoma cells, we and other researchers have studied the inhibitory mechanisms of metastasis with green tea catechins using biomechanical tools, atomic force microscopy (AF...

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

    Science.gov (United States)

    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.

  1. Iron deficiency anemia due to excessive green tea drinking

    OpenAIRE

    Fan, Frank S.

    2016-01-01

    Key Clinical Message Tea interferes with iron absorption and can lead to iron deficiency anemia when consumed in large quantities. The rechallenge effect of green tea on anemia in a middle‐aged man emphasizes the potential causal role of this beverage. Lifestyle and dietary habits are important diagnostic considerations in diseases of this type.

  2. Evaluation of {gamma}-radiation on green tea odor volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Fanaro, G.B., E-mail: gbfanaro@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN)-Centro de Tecnologia das Radiacoes, Av. Professor Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil); Duarte, R.C., E-mail: renatocduarte@yahoo.com.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN)-Centro de Tecnologia das Radiacoes, Av. Professor Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil); Araujo, M.M., E-mail: mmozeika@yahoo.co [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN)-Centro de Tecnologia das Radiacoes, Av. Professor Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil); Purgatto, E., E-mail: epurgatt@usp.b [Universidade de Sao Paulo-Faculdade de Ciencias Farmaceuticas, FCF/USP, Departamento de Alimentos e Nutricao Experimental, Av. Prof. Lineu Prestes, 580 Bloco 14, 05508-900, Sao Paulo, SP (Brazil); Villavicencio, A.L.C.H., E-mail: villavic@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN)-Centro de Tecnologia das Radiacoes, Av. Professor Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil)

    2011-01-15

    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.

  3. Evaluation of γ-radiation on green tea odor volatiles

    Science.gov (United States)

    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.

  4. Green tea may protect brain cells against Parkinson's

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Does the consumption of green tea, widely touted to have beneficial effects on health, also protect brain cells? As reported in the 15 December, 2007 issue of Biological Psychiatry, studies by CAS researchers indicate this may be the case.

  5. Green tea polyphenol induces significant cell death in human lung ...

    African Journals Online (AJOL)

    Green tea polyphenol induces significant cell death in ... The dose-dependent effects of EGCG on H1155 xenograft tumor growth, as well as ..... of mitochondrial ROS and changes in .... ATM phosphorylates histone H2AX in response to DNA.

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

    Science.gov (United States)

    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.

  7. Green tea and the risk of gastric cancer: epidemiological evidence.

    Science.gov (United States)

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

    2013-06-28

    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.

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

    Science.gov (United States)

    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. An Update on the Health Benefits of Green Tea

    Directory of Open Access Journals (Sweden)

    Wanda C. Reygaert

    2017-01-01

    Full Text Available Green tea, which is produced from the leaves of the Camellia sinensis plant, is one of the most popular beverages worldwide. Over the past 30 years or more, scientists have studied this plant in respect to potential health benefits. Research has shown that the main components of green tea that are associated with health benefits are the catechins. The four main catechins found in green tea are: (−-epicatechin (EC, (−-epicatechin-3-gallate (ECG, (−-epigallocatechin (EGC, and (−-epigallocatechin-3-gallate (EGCG. Of these four, EGCG is present in the largest quantity, and so has been used in much of the research. Among the health benefits of green tea are: anticarcinogenic, anti-inflammatory, antimicrobial, and antioxidant properties, and benefits in cardiovascular disease and oral health. Research has been carried out using various animal models and cells lines, and is now more and more being carried out in humans. This type of research will help us to better understand the direct benefits of green tea. This review will focus primarily on research conducted using human subjects to investigate the health benefits of green tea.

  10. Metabolomics-driven nutraceutical evaluation of diverse green tea cultivars.

    Directory of Open Access Journals (Sweden)

    Yoshinori Fujimura

    Full Text Available BACKGROUND: Green tea has various health promotion effects. Although there are numerous tea cultivars, little is known about the differences in their nutraceutical properties. Metabolic profiling techniques can provide information on the relationship between the metabolome and factors such as phenotype or quality. Here, we performed metabolomic analyses to explore the relationship between the metabolome and health-promoting attributes (bioactivity of diverse Japanese green tea cultivars. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the ability of leaf extracts from 43 Japanese green tea cultivars to inhibit thrombin-induced phosphorylation of myosin regulatory light chain (MRLC in human umbilical vein endothelial cells (HUVECs. This thrombin-induced phosphorylation is a potential hallmark of vascular endothelial dysfunction. Among the tested cultivars, Cha Chuukanbohon Nou-6 (Nou-6 and Sunrouge (SR strongly inhibited MRLC phosphorylation. To evaluate the bioactivity of green tea cultivars using a metabolomics approach, the metabolite profiles of all tea extracts were determined by high-performance liquid chromatography-mass spectrometry (LC-MS. Multivariate statistical analyses, principal component analysis (PCA and orthogonal partial least-squares-discriminant analysis (OPLS-DA, revealed differences among green tea cultivars with respect to their ability to inhibit MRLC phosphorylation. In the SR cultivar, polyphenols were associated with its unique metabolic profile and its bioactivity. In addition, using partial least-squares (PLS regression analysis, we succeeded in constructing a reliable bioactivity-prediction model to predict the inhibitory effect of tea cultivars based on their metabolome. This model was based on certain identified metabolites that were associated with bioactivity. When added to an extract from the non-bioactive cultivar Yabukita, several metabolites enriched in SR were able to transform the extract into a bioactive

  11. Interactions between milk fat globules and green tea catechins.

    Science.gov (United States)

    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.

  12. GREEN TEA: A MAGICAL HERB WITH MIRACULOUS OUTCOMES

    Directory of Open Access Journals (Sweden)

    Anand Jigisha

    2012-05-01

    Full Text Available Green tea in its purest and most unadulterated form has always influenced human health from generations and day by day scientific evidences throughout the world are making people aware of health benefits associated with this herbal drink. Though Green Tea is not officially recognized as a medical agent, it is one of the most researched plant-based remedies whose possible benefits include promotion of cardio-vascular health, cancer prevention, skin protection, and antioxidant activity, to fight high cholesterol levels, infection, impaired immune function, diarrhoea, fatigue and many more. Laboratory findings have revealed that notable health benefit of green tea is its powerful antioxidants potential which at the molecular level, helps prevent cellular damage from certain oxidation reactions in the body. The credit for their useful antioxidant property lies with their huge collection of chemical substances called polyphenols and catechins make the major contribution of them. Though catechins have been found in other plants derivatives such as grapes, pomegranates, those found in tea have proven to be the most effective antioxidants known. The catechins epigallocatechin gallate (EGCG is found in the greatest concentration and most studied for its health benefits. There is an urgent need to check the efficacy, safety and translational guidelines for a green tea to be used as safe, effective drug. The main objective of this review is to enlighten some recent facts with relevance to the current status and advance in green tea benefits.

  13. Characterization of Black and Green Tea from Local Market

    Directory of Open Access Journals (Sweden)

    Sonia Ancuta Socaci

    2013-11-01

    Full Text Available The leaves from Camellia sinensis are used from ancient times for preparation of tea but also as raw material for different extracts which are used in food industry as well as in pharmaceutical or cosmetic products. Due to the increasing interest in tea health benefits, the aim of the present study was to characterize several brands of green and black tea found on local market, regarding their content in total phenolic compounds, flavonoids and antioxidant capacity. Total phenolics and flavonoids were determined spectrophotometrically using a modified Folin-Ciocalteu method, respectively a chromogenic system of NaNO2–Al(NO33–NaOH based method. The antioxidant capacity of each tea sample was assessed through the evaluation of free radical scavenging effect on 2,2-diphenyl-1-picrylhydrazyl. The results obtained for the green and black tea samples varied widely, depending on the tea variety. The antioxidant capacity of the analyzed teas ranged between 12.10 and 40.03%RSA, while the total phenolic content was within 2090 and 6080 mg GA/ 100g. The concentrantion in flavonoids was between 9.04 and 15.34 g/100g of tea.

  14. The Making of Transparent Soap from Green Tea Extract

    Directory of Open Access Journals (Sweden)

    Tuty Anggraini

    2015-01-01

    Full Text Available This study aims to determined the effect of green tea extract on the characteristics of transparent soap and antioxidant activity as well as to determine the best concentration of the addition of green tea extract. This study used a completely randomized design (CRD consisting of 5 treatments and 3 repetitions. Data were analyzed statistically using ANOVA followed by Duncan's test New Multiple Range Test (DNMRT at 5%. Treatment in this research were the addition of green tea extract  0%; 0.5%; 1%; 1.5%; and 2%. The analysis on the transparent soap product were sensory evaluation test, irritation test,  antimicrobial test, antioxidant activity, and chemical properties that include water content, pH, the amount of fatty acid, the saponified fraction, alkali-free / free fatty acids, and insoluble part in alcohol . The results showed that the difference in the concentration of green tea extract in a transparent soap significantly affect insoluble part in alcohol, antioxidant activity, and antimicrobial, but did not significantly affect to moisture content, the level of fatty acid ,  unsaponified fraction, free fatty acids, pH, hardness , and degree of foam. Effect of green tea extracts in the manufacture of transparent soap in treatment E (Addition of green tea extract 2% is the best product, the value for color was 25%, aroma was 50%, 20% transparency, hardness 35%, and degree of foam was 70while the hardness was 2,90 N / cm2; degree of foam 48.95%; the water content of 35.35%; 29.78% the amount of fatty acids; unsaponified fraction was 12.87%; free fatty acids 0,23%; pH was  9.78; Insoluble parts in alcohol 2.08%; irritation value 0; antioxidant activity of 15.21% and a diameter anti-microbial of 42 mm. A transparent soap with the addition of green tea extract deserves to be developed.

  15. Antiviral effects of green tea ( Camellia sinensis ) against pathogenic ...

    African Journals Online (AJOL)

    Log in or Register to get access to full text downloads. ... Materials and Methods: We performed a search using the key words “green tea” AND “antiviral” covering the last 10 years. ... Conclusion: A detailed information on the antiviral activity of green tea in a number of different viruses show a promising future as a popular ...

  16. Green tea formulations with vitamin C and xylitol on enhanced intestinal transport of green tea catechins.

    Science.gov (United States)

    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.

  17. Residue pattern of polycyclic aromatic hydrocarbons during green tea manufacturing and their transfer rates during tea brewing.

    Science.gov (United States)

    Gao, Guanwei; Chen, Hongping; Liu, Pingxiang; Hao, Zhenxia; Ma, Guicen; Chai, Yunfeng; Wang, Chen; Lu, Chengyin

    2017-06-01

    Residues of polycyclic aromatic hydrocarbons (PAHs) in green tea and tea infusion were determined using gas chromatography-tandem mass spectrometry to study their dissipation pattern during green tea processing and infusion. Concentration and evaporation of PAHs during tea processing were the key factors affecting PAH residue content in product intermediates and in green tea. PAH residues in tea leaves increased by 2.4-3.1 times during the manufacture of green tea using the electric heating model. After correction to dry weight, PAH residue concentrations decreased by 33.5-48.4% during green tea processing because of PAH evaporation. Moreover, spreading and drying reduced PAH concentrations. The transfer rates of PAH residues from green tea to infusion varied from 4.6% to 7.2%, and PAH leaching was higher in the first infusion than in the second infusion. These results are useful for assessing exposure to PAHs from green tea and in formulating controls for the maximum residue level of PAHs in green tea.

  18. Consumption of Green Tea, but Not Black Tea or Coffee, Is Associated with Reduced Risk of Cognitive Decline

    OpenAIRE

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

    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...

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

    Science.gov (United States)

    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.

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

    NARCIS (Netherlands)

    Verloop, A.J.W.; Gruppen, H.; Bisschop, Robbin; Vincken, Jean Paul

    2016-01-01

    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 toward

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

    NARCIS (Netherlands)

    Verloop, A.J.W.; Gruppen, H.; Bisschop, Robbin; Vincken, Jean Paul

    2016-01-01

    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

  2. Green tea catechins: defensive role in cardiovascular disorders

    Institute of Scientific and Technical Information of China (English)

    Pooja Bhardwaj; Deepa Khanna

    2013-01-01

    Green tea,Camellia sinensis (Theaeeae),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.

  3. Green tea (Camellia sinensis) catechins and vascular function.

    Science.gov (United States)

    Moore, Rosalind J; Jackson, Kim G; Minihane, Anne M

    2009-12-01

    The health benefits of green tea (Camellia sinensis) catechins are becoming increasingly recognised. Amongst the proposed benefits are the maintenance of endothelial function and vascular homeostasis and an associated reduction in atherogenesis and CVD risk. The mounting evidence for the influential effect of green tea catechins on vascular function from epidemiological, human intervention and animal studies is subject to review together with exploration of the potential mechanistic pathways involved. Epigallocatechin-3-gallate, one of the most abundant and widely studied catechin found in green tea, will be prominent in the present review. Since there is a substantial inconsistency in the published data with regards to the impact of green tea catechins on vascular function, evaluation and interpretation of the inter- and intra-study variability is included. In conclusion, a positive effect of green tea catechins on vascular function is becoming apparent. Further studies in animal and cell models using physiological concentrations of catechins and their metabolites are warranted in order to gain some insight into the physiology and molecular basis of the observed beneficial effects.

  4. Cancer chemoprevention with green tea catechins: from bench to bed.

    Science.gov (United States)

    Shirakami, Yohei; Shimizu, Masahito; Moriwaki, Hisataka

    2012-12-01

    Many epidemiological studies and a large number of experimental studies using a variety of animal models have observed that consumption or administration of green tea appears to exert cancer chemopreventive activity. Based on the results of numerous laboratory cell culture investigations, several mechanisms have been hypothesized to underlie the anti-cancer activity of green tea catechins, especially that of (-)-epigallocatechin-3-gallate (EGCG), the most abundant and active constituent in green tea. These mechanisms include promotion of anti-oxidant activity, inhibition of NF-κB and AP-1, regulation of the cell cycle, inhibition of receptor tyrosine kinase pathways, control of epigenetic modifications, and modulation of the immune system. Several recent interventional studies examining the anti-carcinogenic properties of green tea catechins in humans have yielded promising results that suggest the possibility of their application to human clinical trials. This review article analyzes the results of these studies to explicate the effects of consumption or administration of green tea and its constituents on malignancies observed to date and discuss future directions in this research field.

  5. Determination of catechins in matcha green tea by micellar electrokinetic chromatography.

    Science.gov (United States)

    Weiss, David J; Anderton, Christopher R

    2003-09-05

    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.

  6. Pharmacokinetics of Green Tea Catechins in Extract and Sustained-Release Preparations

    OpenAIRE

    Janle, Elsa M; Morré, Dorothy M.; Morré, D. James; Zhou, Qin; Zhu, Yongxin

    2008-01-01

    Catechins are a major constituent of green tea. For green tea to have cancer therapeutic benefit, catechin concentrations in the range of 100 nM are required continuously until apoptosis (programmed cell death) is induced. To prolong elevated plasma and interstitial concentrations of catechins, a sustained-release formulation of green tea extract was tested and compared to a commercial green tea extract (Tegreen97®). Sustained-release formulations are usually developed in the pharmaceutical i...

  7. Green Tea Extract-induced Acute Hepatotoxicity in Rats.

    Science.gov (United States)

    Emoto, Yuko; Yoshizawa, Katsuhiko; Kinoshita, Yuichi; Yuki, Michiko; Yuri, Takashi; Yoshikawa, Yutaka; Sayama, Kazutoshi; Tsubura, Airo

    2014-10-01

    Although green tea is considered to be a healthy beverage, hepatotoxicity associated with the consumption of green tea extract has been reported. In the present study, we characterized the hepatotoxicity of green tea extract in rats and explored the responsible mechanism. Six-week-old IGS rats received a single intraperitoneal (ip) injection of 200 mg/kg green tea extract (THEA-FLAN 90S). At 8, 24, 48 and 72 hrs and 1 and 3 months after exposure, liver damage was assessed by using blood-chemistry, histopathology, and immunohistochemistry to detect cell death (TUNEL and caspase-3) and proliferative activity (PCNA). Analyses of malondialdehyde (MDA) in serum and the liver and of MDA and thymidine glycol (TG) by immunohistochemistry, as oxidative stress markers, were performed. Placental glutathione S-transferase (GST-P), which is a marker of hepatocarcinogenesis, was also immunohistochemically stained. To examine toxicity at older ages, 200 mg/kg green tea extract was administered to 18-wk-old female rats. In 6-wk-old rats, 12% of males and 50% of females died within 72 hrs. In 18-wk-old rats, 88% died within 72 hrs. The serum levels of aspartate aminotransferase, alanine aminotransferase and/or total bilirubin increased in both males and females. Single-cell necrosis with positive signs of TUNEL and caspase-3 was seen in perilobular hepatocytes from 8 hrs onward in all lobular areas. PCNA-positive hepatocytes increased at 48 hrs. MDA levels in the serum and liver tended to increase, and MDA- and TG-positive hepatocytes were seen immunohistochemically. GST-P-positive hepatocellular altered foci were detected in one female rat at the 3-month time point. In conclusion, a single injection of green tea extract induced acute and severe hepatotoxicity, which might be associated with lipid peroxidation and DNA oxidative stress in hepatocytes.

  8. Pheophorbide a Content and Chlorophyllase Activity in Green Tea.

    Science.gov (United States)

    Kohata, K; Hanada, K; Yamauchi, Y; Horie, H

    1998-01-01

    We investigated the total content of pheophorbide a (PB a), which is sum of the contents of newly produced PB a, including PB a initially present and that converted from chlorophyllide a (Chd a) by the chlorophyllase reaction during incubation, in green tea samples, and found that the total content of PB a markedly increased in both Sencha and Matcha, compared with the initially present PB a content in each. This result demonstrates that chlorophyllase activity still remains in green tea, even after processing fresh green leaves. A comparison of the total contents of PB a produced during the incubation of chlorophyll a (Chl a) with Sencha and fresh green leaf acetone powder indicates that the ratio of chlorophyllase activity in Sencha and in fresh green leaves was about 1:20.

  9. Study Finds How Green Tea Might Fight Cancer

    Institute of Scientific and Technical Information of China (English)

    钱浩良

    1999-01-01

    人们对饮用绿茶的好处已有不少议论,但是,本篇视角独特,明确指出饮用绿茶能抗癌:Our research shows that green tea leaves are rich in thisanti-cancer compound,with concentrations high enough to induce anti-cancereffects in the body.但是,本文同时体现了极其严肃的科学态度:Now tests areneeded to see if EGCg is active in the bodies of people who drink green tea.

  10. Effect of Green Tea Phytochemicals on Mood and Cognition.

    Science.gov (United States)

    Dietz, Christina; Dekker, Matthijs

    2017-01-01

    Green tea is traditionally known to induce mental clarity, cognitive function, physical activation and relaxation. Recently, a special green tea, matcha tea, is rapidly gaining popularity throughout the world and is frequently referred to as a mood- and brain food. Matcha tea consumption leads to much higher intake of green tea phytochemicals compared to regular green tea. Previous research on tea constituents caffeine, L-theanine, and epigallocatechin gallate (EGCG) repeatedly demonstrated benefits on mood and cognitive performance. These effects were observed when these phytochemicals were consumed separately and in combination. A review was conducted on 49 human intervention studies to summarize the research on acute psychoactive effects of caffeine, L-theanine, and EGCG on different dimensions of mood and cognitive performance. Caffeine was found to mainly improve performance on demanding long-duration cognitive tasks and self-reported alertness, arousal, and vigor. Significant effects already occurred at low doses of 40 mg. L-theanine alone improved self-reported relaxation, tension, and calmness starting at 200 mg. L-theanine and caffeine combined were found to particularly improve performance in attention-switching tasks and alertness, but to a lesser extent than caffeine alone. No conclusive evidence relating to effects induced by EGCG could be given since the amount of intervention studies was limited. These studies provided reliable evidence showing that L-theanine and caffeine have clear beneficial effects on sustained attention, memory, and suppression of distraction. Moreover, L-theanine was found to lead to relaxation by reducing caffeine induced arousal. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  11. Anti-cancer properties of green Tea Probed viaquantum mechanics calculations

    Directory of Open Access Journals (Sweden)

    Azin Chitsazan

    2015-03-01

    Full Text Available 10.13005/ojc/310147Tea, from the plant camellia sinensis, is consumed in different parts of the world as green, black or oolong tea. Among all of these, however, the most significant effects on human health have been observed with the consumption of green tea. Green tea contains polyphenols, which include flavanols, flavandiols, flavonoids, and phenolic acids. Most of the green tea polyphenols (GTPs are flavonols, commonly known as catechins. There are four kinds of catechins mainly find in green tea: epicatechin, epigallocatechin, epicatechin-3-gallate, and EGCG. Green tea catechins have demonstrated significant antioxidant, anticarcinogenic, anti-inflammatory, thermogenic, probiotic, and antimicrobial properties in numerous human, animal, and in vitro studies. In the present study, four type catechins of green tea were studied. For each catechin ab initio method was employed for calculations and related parameters were computed.

  12. Bactericidal activity of green tea extracts: the importance of catechin containing nano particles.

    Science.gov (United States)

    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.

  13. Biological Effects of Green Tea Capsule Supplementation in Pre-surgery Postmenopausal Breast Cancer Patients

    Directory of Open Access Journals (Sweden)

    Steven S Yu

    2013-12-01

    Full Text Available Regular green tea intake has been associated with an inverse risk of breast cancer. There is compelling experimental evidence that green tea, particularly, epigallocatechin gallate, the most potent green tea catechin, possesses a range of anti-cancer properties. We conducted a pre-surgical study of green tea capsules versus no green tea in women with primary breast cancer to determine the effects of green tea supplementation on markers of biological response. Postmenopausal women with ductal carcinoma in situ (DCIS or stage I or II breast cancer took green tea capsules (940 mg per day for an average of 35 days prior to surgery (n=13 or received no green tea (n=18. Paired diagnostic core biopsy and surgical specimen samples were analyzed for cell proliferation (Ki-67, apoptosis (caspase 3 and angiogenesis (CD34 separately in benign and malignant cell components. There were no significant changes in caspase-3 and CD34 in the green tea and no green tea groups and there were no significant differences in the change in these markers between the two groups. However, Ki-67 levels declined in both benign and malignant cell components in the green tea group; the decline in Ki-67 positivity in malignant cells was not statistically significant (P=0.10 but was statistically significant in benign cells (P=0.007. Ki-67 levels in benign and malignant cells did not change significantly in the no green tea group. There was a statistically significant difference in the change in Ki-67 in benign cells (P=0.033 between the green tea and the no green tea groups. The trend of a consistent reduction in Ki-67 in both benign and malignant cells in the green tea group warrants further investigations in a larger study of breast cancer patients or high-risk women.

  14. Having a promising efficacy on type II diabetes, it's definitely a green tea time.

    Science.gov (United States)

    Jiao, Hen; Hu, Guohua; Gu, Dayong; Ni, Xiaoling

    2015-01-01

    The beneficial effects of green tea have been confirmed in various diseases, such as different types of cancer, heart disease, and liver disease. The effective components of green tea mainly include tea polysaccharides and tea polyphenols, such as catechin, particularly (-)-epigallocatechin-3-gallate. Increasing in vivo and in vitro evidences have explored the potential molecular mechanisms of green tea as well as the specific biological actions. Moreover, clinical trials have also explored the potential value of green tea components in treating metabolic syndromes, such as obesity, type II diabetes, and cardiovascular disease. This study explores the effects of the two major green tea components on the improvement of type II diabetes. It is concluded that regular consumption of green tea is beneficial for the improvement of high-fat dietary-induced obesity and type II diabetes.

  15. Prediction of Japanese green tea ranking by fourier transform near-infrared reflectance spectroscopy.

    Science.gov (United States)

    Ikeda, Tatsuhiko; Kanaya, Shigehiko; Yonetani, Tsutomu; Kobayashi, Akio; Fukusaki, Eiichiro

    2007-11-28

    A rapid and easy determination method of green tea's quality was developed by using Fourier transform near-infrared (FT-NIR) reflectance spectroscopy and metabolomics techniques. The method is applied to an online measurement and an online prediction of green tea's quality. FT-NIR was employed to measure green tea metabolites' alteration affected by green tea varieties and manufacturing processes. A set of ranked green tea samples from a Japanese commercial tea contest was analyzed to create a reliable quality-prediction model. As multivariate analyses, principal component analysis (PCA) and partial least-squares projections to latent structures (PLS) were used. It was indicated that the wavenumber region from 5500 to 5200 cm(-1) had high correlation with the quality of the tea. In this study, a reliable quality-prediction model of green tea has been achieved.

  16. Protective effect of green tea on dentin erosion and abrasion

    Directory of Open Access Journals (Sweden)

    Melissa Thiemi Kato

    2009-12-01

    Full Text Available 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.

  17. Green Tea and its Effect on Hemostasis Measured by Thrombelastography

    Directory of Open Access Journals (Sweden)

    Bryant Alyzandyr Eumhyn Chua

    2015-03-01

    Full Text Available Background: Increasing health problems may come from changes in lifestyle including stressful lifestyles, high calorie diets, and lack of physical activity. Those may also lead to an increase occurrence of abnormal hemostasis. Green tea has been well known for its many benefits, including its antithrombotic effect. The aim of this study was to determine whether the consumption of green tea actually affects hemostasis and to measure changes in hemostatic parameters after its consumption. Methods: A preliminary explorative study was conducted on 3 healthy female subjects aged between 21 to 22 years old for 8 weeks from October to November 2012 in Jatinangor, Sumedang, Indonesia. The subjects were subjected to initial thrombelastography analysis and started drinking green tea twice a day after meals. The solution was made by steeping a teabag in 250ml water of 70°C for 2 minutes. After 8 weeks, another thrombelastography analysis was performed to the subjects. Results: Pre- and post-intervention results of the analysis were averaged and compared according to the parameters. The results of this study showed prolonged R (Reaction-time and K (K-time, decreased α (angle and MA (Maximum Amplitude, and increased LY30 (lysis at 30 minutes, showing an overall reduction in coagulability. Conclusions: The consumption of green tea twice a day for 8 weeks affects hemostasis with hemostatic parameters measured by thrombelastography show differences before and after consumption.

  18. Green Tea Modulation of Obesity and Breast Cancer Risk

    Science.gov (United States)

    2013-04-01

    his doctorate degree program’s requirements including preliminary written and oral exams , teaching requirements for three academic semesters, as...Obesity 2009; 17(2):310-317. 5. Phung OJ, Baker WL, Matthews LJ, Lanosa M, Thorne A, Coleman CI. Effect of green tea catechins with or without caffeine

  19. Green Tea and Its Extracts in Cancer Prevention and Treatment

    Directory of Open Access Journals (Sweden)

    Johannes Schulze

    2017-03-01

    Full Text Available Green tea (GT and green tea extracts (GTE have been postulated to decrease cancer incidence. In vitro results indicate a possible effect; however, epidemiological data do not support cancer chemoprevention. We have performed a PubMED literature search for green tea consumption and the correlation to the common tumor types lung, colorectal, breast, prostate, esophageal and gastric cancer, with cohorts from both Western and Asian countries. We additionally included selected mechanistical studies for a possible mode of action. The comparability between studies was limited due to major differences in study outlines; a meta analysis was thus not possible and studies were evaluated individually. Only for breast cancer could a possible small protective effect be seen in Asian and Western cohorts, whereas for esophagus and stomach cancer, green tea increased the cancer incidence, possibly due to heat stress. No effect was found for colonic/colorectal and prostatic cancer in any country, for lung cancer Chinese studies found a protective effect, but not studies from outside China. Epidemiological studies thus do not support a cancer protective effect. GT as an indicator of as yet undefined parameters in lifestyle, environment and/or ethnicity may explain some of the observed differences between China and other countries.

  20. Synergistic antioxidant activity of green tea with some herbs

    Directory of Open Access Journals (Sweden)

    Dheeraj P Jain

    2011-01-01

    Full Text Available 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.

  1. [Identification of green tea brand based on hyperspectra imaging technology].

    Science.gov (United States)

    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.

  2. Improvement effect of green tea on hepatic dysfunction, lipid ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-01

    Sep 1, 2009 ... NBT/Riboflavin tests, green tea was extracted by ethanol. ... 3000. 3500. 4000. 4500. Control. Cd. Cd + GT. GT. Groups. L. D. H a c tiv ity. (IU. /l), ... infusion in the bilirubin level. Values .... Garret HE (1956) Elementary statistics.

  3. Green tea consumption and lung cancer risk: the Ohsaki study.

    Science.gov (United States)

    Li, Q; Kakizaki, M; Kuriyama, S; Sone, T; Yan, H; Nakaya, N; Mastuda-Ohmori, K; Tsuji, I

    2008-10-07

    We examined the risk of lung cancer in relation to green tea consumption in a population-based cohort study in Japan among 41,440 men and women, aged 40-79 years, who completed a questionnaire in 1994 regarding green tea consumption and other health-related lifestyle factors. During the follow-up period of 7 years (from 1995 to 2001), 302 cases of lung cancer were identified, and the Cox proportional hazards regression model was used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs). The multivariable-adjusted HRs of lung cancer incidence for green tea consumption of 1 or 2, 3 or 4, and 5 or more cups/day as compared to less than 1 cup/day were 1.14 (95% CI: 0.80-1.62), 1.18 (95% CI: 0.83-1.66), and 1.17 (95% CI: 0.85-1.61), respectively (P for trend=0.48). This cohort study has found no evidence that green tea consumption is associated with lung cancer.

  4. Green tea polyphenols require the mitochondrial iron transporter, mitoferrin, for lifespan extension in Drosophila melanogaster.

    Science.gov (United States)

    Lopez, Terry E; Pham, Hoang M; Nguyen, Benjamin V; Tahmasian, Yerazik; Ramsden, Shannon; Coskun, Volkan; Schriner, Samuel E; Jafari, Mahtab

    2016-12-01

    Green tea has been found to increase the lifespan of various experimental animal models including the fruit fly, Drosophila melanogaster. High in polyphenolic content, green tea has been shown to reduce oxidative stress in part by its ability to bind free iron, a micronutrient that is both essential for and toxic to all living organisms. Due to green tea's iron-binding properties, we questioned whether green tea acts to increase the lifespan of the fruit fly by modulating iron regulators, specifically, mitoferrin, a mitochondrial iron transporter, and transferrin, found in the hemolymph of flies. Publicly available hypomorph mutants for these iron regulators were utilized to investigate the effect of green tea on lifespan and fertility. We identified that green tea could not increase the lifespan of mitoferrin mutants but did rescue the reduced male fertility phenotype. The effect of green tea on transferrin mutant lifespan and fertility were comparable to w(1118) flies, as observed in our previous studies, in which green tea increased male fly lifespan and reduced male fertility. Expression levels in both w(1118) flies and mutant flies, supplemented with green tea, showed an upregulation of mitoferrin but not transferrin. Total body and mitochondrial iron levels were significantly reduced by green tea supplementation in w(1118) and mitoferrin mutants but not transferrin mutant flies. Our results demonstrate that green tea may act to increase the lifespan of Drosophila in part by the regulation of mitoferrin and reduction of mitochondrial iron. © 2016 Wiley Periodicals, Inc.

  5. Green tea polyphenols extend the lifespan of male drosophila melanogaster while impairing reproductive fitness.

    Science.gov (United States)

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

    Science.gov (United States)

    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.

  7. Weight control and prevention of metabolic syndrome by green tea.

    Science.gov (United States)

    Sae-tan, Sudathip; Grove, Kimberly A; Lambert, Joshua D

    2011-08-01

    Green tea (Camellia sinensis, Theaceace) is the second most popular beverage in the world and has been extensively studied for its putative disease preventive effects. Green tea is characterized by the presence of a high concentrations of polyphenolic compounds known as catechins, with (-)-epigallocatechin-3-gallate (EGCG) being the most abundant and most well-studied. Metabolic syndrome (MetS) is a complex condition that is defined by the presence of elevated waist circumference, dysglycemia, elevated blood pressure, decrease serum high-density lipoprotein-associated cholesterol, and increased serum triglycerides. Studies in both in vitro and laboratory animal models have examined the preventive effects of green tea and EGCG against the symptoms of MetS. Overall, the results of these studies have been promising and demonstrate that green tea and EGCG have preventive effects in both genetic and dietary models of obesity, insulin resistance, hypertension, and hypercholesterolemia. Various mechanisms have been proposed based on these studies and include: modulation of dietary fat absorption and metabolism, increased glucose utilization, decreased de novo lipogenesis, enhanced vascular responsiveness, and antioxidative effects. In the present review, we discuss the current state of the science with regard to laboratory studies on green tea and MetS. We attempt to critically evaluate the available data and point out areas for future research. Although there is a considerable amount of data available, questions remain in terms of the primary mechanism(s) of action, the dose-response relationships involved, and the best way to translate the results to human intervention studies.

  8. Both phenolic and non-phenolic green tea fractions inhibit migration of cancer cells

    Science.gov (United States)

    Green tea consumption is associated with chemoprevention of many cancer types. Fresh tea leaves are rich in polyphenolic catechins, which can constitute up to 30% of the dry leaf weight. While the polyphenols of green tea have been well investigated, it is still largely unknown, whether or not non-p...

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Moeko Noguchi-Shinohara

    Full Text Available 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.

  11. Bactericidal activity of green tea extracts: the importance of catechin containing nano particles

    OpenAIRE

    Judy Gopal; Manikandan Muthu; Diby Paul; Doo-Hwan Kim; Sechul Chun

    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 ...

  12. COMPARATIVE STUDY OF GREEN TEA POLYPHENOL AND FLUORIDE ON STREPTOCOCCUS MUTANS

    Institute of Scientific and Technical Information of China (English)

    李鸣宇; 刘正

    2000-01-01

    Objective To disclose the mechanism of green tea polyphenol in the prevention of dental caries.Methods Using sodium fluoride (highly effective anticaries agent) as control and Streptococcus mutans (carigenous microbe) as target, green tea polyphenol (potential bacterial inhibitor) was used to testify its action on the change of microbial morphology, extramicrobial sucrase, glucosyltransferase (GTF), lactate hydrogenase (LDH),protein and pH values of the culture media. Results GTF activities were inhibited both by green tea polyphenol and sodium fluoride, the inhibitory efficacy was stronger in green tea polyphenol. Morphologic changes consisted of membrane disruption in tea polyphenol treated microbes, and cytoplasmic vacuolization in fluoride treated bacteria.High protein level in fluoride treated culture media means cytoplasmic decomposition, intracellular protein leakage into media. Conclusion The inhibition of GTF activity was stronger in green tea polyphenol treated microbes.The target of action was cell membrane disruption in green tea polyphenol treated cell and cytoplasmic in fluoride treated microbes.

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

    Science.gov (United States)

    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.

  14. Skin photoprotection by green tea: antioxidant and immunomodulatory effects.

    Science.gov (United States)

    Katiyar, Santosh K

    2003-09-01

    Because of a characteristic aroma and health benefits, green tea is consumed worldwide as a popular beverage. The epicatechin derivatives, commonly called polyphenols, present in green tea possess antioxidant, anti-inflammatory and anti-carcinogenic properties. The major and most highly chemopreventive constituent in green tea responsible for the biochemical or pharmacological effects is (-)-epigallocatechin-3-gallate (EGCG). Epidemiological, clinical and biological studies have implicated that solar ultraviolet (UV) light is a complete carcinogen and repeated exposure can lead to the development of various skin disorders including melanoma and nonmelanoma skin cancers. We and others have shown that topical treatment or oral consumption of green tea polyphenols (GTP) inhibit chemical carcinogen- or UV radiation-induced skin carcinogenesis in different laboratory animal models. Topical treatment of GTP and EGCG or oral consumption of GTP resulted in prevention of UVB-induced inflammatory responses, immunosuppression and oxidative stress, which are the biomarkers of several skin disease states. Topical application of GTP and EGCG prior to exposure of UVB protects against UVB-induced local as well as systemic immune suppression in laboratory animals, which was associated with the inhibition of UVB-induced infiltration of inflammatory leukocytes. Prevention of UVB-induced suppression of immune responses by EGCG was also associated with the reduction in immunosuppressive cytokine interleukin (IL)-10 production at UV irradiated skin and draining lymph nodes, whereas IL-12 production was significantly enhanced in draining lymph nodes. Antioxidant and anti-inflammatory effects of green tea were also observed in human skin. Treatment of EGCG to human skin resulted in the inhibition of UVB-induced erythema, oxidative stress and infiltration of inflammatory leukocytes. We also showed that treatment of GTP to human skin prevents UVB-induced cyclobutane pyrimidine dimers

  15. DETERMINATION OF TOTAL ANTIOXIDANT CAPACITY OF GREEN TEAS BY THE FERRIC REDUCING/ANTIOXIDANT POWER ASSAY

    Directory of Open Access Journals (Sweden)

    M. Hajimahmoodi, M. Hanifeh, M. R. Oveisi, N. Sadeghi, B. Jannat

    2008-07-01

    Full Text Available Green tea is one of the important sources of bioactive compounds which have been used in folk medicine for many centuries. This study aimed to compare in vitro antioxidant power of different types of green tea (Camellia sinensis. Antioxidant activity of methanolic (50% extracts of five green tea samples was investigated according to Ferric reducing ability power method. Total phenolic contents were analyzed using a spectrophotometric technique, based on the Folin-ciocalteau reagent, and calculated as gallic acid equivalents per gram dry weight. Total flavonoid and antocyanidin were also investigated according to aluminum chloride and vanillin colorimetric assay respectively. Total antioxidant activity varied from 0.554±0.042 in Avicen green tea sample to 3.082±0.150 mmoL FeII/g in Chinas green tea and total phenolic content ranged from the 0.030±0.001 in Avicen green tea sample to 0.196±0.012 g gallic acid per gram dry weight in Ahmad green tea. A linear positive relationship existed between the antioxidant activity, total phenolic, flavonoid and antocyanidin content of the tested green tea samples. Green tea samples possess relatively high antioxidant activity due to contribution of phenolic compounds. The present study showed that green tea samples which are more frequently consumed in Iran are strong radical scavengers and can be considered as good sources of natural antioxidants for medicinal and commercial uses.

  16. A non-targeted approach to chemical discrimination between green tea extract-based dietary supplements and green tea leaves by LC/MS

    Science.gov (United States)

    Green tea extract-based dietary supplements (GTDS) have gained in popularity in the U.S. market in recent years. This study evaluated the phytochemical composition of several GTDS in comparison to the composition of green tea leaves using a LC-MS fingerprinting technique coupled with chemometric an...

  17. Data on green tea flavor determinantes as affected by cultivars and manufacturing processes.

    Science.gov (United States)

    Han, Zhuo-Xiao; Rana, Mohammad M; Liu, Guo-Feng; Gao, Ming-Jun; Li, Da-Xiang; Wu, Fu-Guang; Li, Xin-Bao; Wan, Xiao-Chun; Wei, Shu

    2017-02-01

    This paper presents data related to an article entitled "Green tea flavor determinants and their changes over manufacturing processes" (Han et al., 2016) [1]. Green tea samples were prepared with steaming and pan firing treatments from the tender leaves of tea cultivars 'Bai-Sang Cha' ('BAS') and 'Fuding-Dabai Cha' ('FUD'). Aroma compounds from the tea infusions were detected and quantified using HS-SPME coupled with GC/MS. Sensory evaluation was also made for characteristic tea flavor. The data shows the abundances of the detected aroma compounds, their threshold values and odor characteristics in the two differently processed tea samples as well as two different cultivars.

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

    Science.gov (United States)

    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.

  19. Antioxidant effect of green tea on polymer gel dosimeter

    Science.gov (United States)

    Samuel, E. J. J.; Sathiyaraj, P.; Deena, T.; Kumar, D. S.

    2015-01-01

    Extract from Green Tea (GTE) acts as an antioxidant in acrylamide based polymer gel dosimeter. In this work, PAGAT gel was used for investigation of antioxidant effect of GTE.PAGAT was called PAGTEG (Polyacrylamide green tea extract gel dosimeter) after adding GTE. Free radicals in water cause pre polymerization of polymer gel before irradiation. Polyphenols from GTE are highly effective to absorb the free radicals in water. THPC is used as an antioxidant in polymer gel dosimeter but here we were replaced it by GTE and investigated its effect by spectrophotometer. GTE added PAGAT samples response was lower compared to THPC added sample. To increase the sensitivity of the PAGTEG, sugar was added. This study confirmed that THPC was a good antioxidant for polymer gel dosimeter. However, GTE also can be used as an antioxidant in polymer gel if use less quantity (GTE) and add sugar as sensitivity enhancer.

  20. A new antioxidant beverage produced with green tea and apple.

    Science.gov (United States)

    Rubio-Perez, Jose M; Vidal-Guevara, Maria L; Zafrilla, Pilar; Morillas-Ruiz, Juana M

    2014-08-01

    Green tea and apple are natural products with health benefits. These healthy properties are linked closely to the antioxidant compounds, mainly phenolic compounds. These antioxidant compounds have a potential for preventing and treating cancer, cardiovascular, inflammatory and neurodegenerative diseases in humans. The aim of the present work was to design a new beverage with high antioxidant power combining extracts of green tea and apple, studying the antioxidant composition and activity, organoleptic properties (colour) and stability status during storage at different temperatures. The majority compounds identified in the beverage were flavan-3-ols, being the (-)-epigallocatechin-3-gallate which had the highest concentration. After storage, floridzine was the compound with lower decrease of concentration. The new designed beverage had a good colour, and high antioxidant activity and stability at room temperature, so that the beverage needs no refrigeration, showing potential for the development of new healthy functional beverages.

  1. Green Nanotechnology from Tea: Phytochemicals in Tea as Building Blocks for Production of Biocompatible Gold Nanoparticles.

    Science.gov (United States)

    Nune, Satish K; Chanda, Nripen; Shukla, Ravi; Katti, Kavita; Kulkarni, Rajesh R; Thilakavathi, Subramanian; Mekapothula, Swapna; Kannan, Raghuraman; Katti, Kattesh V

    2009-06-01

    Phytochemicals occluded in tea have been extensively used as dietary supplements and as natural pharmaceuticals in the treatment of various diseases including human cancer. Results on the reduction capabilities of phytochemicals present in tea to reduce gold salts to the corresponding gold nanoparticles are presented in this paper. The phytochemicals present in tea serve the dual roles as effective reducing agents to reduce gold and also as stabilizers to provide robust coating on the gold nanoparticles in a single step. The Tea-generated gold nanoparticles (T-AuNPs), have demonstrated remarkable in vitro stability in various buffers including saline, histidine, HSA, and cysteine solutions. T-AuNPs with phytochemical coatings have shown significant affinity toward prostate (PC-3) and breast (MCF-7) cancer cells. Results on the cellular internalization of T-AuNPs through endocytosis into the PC-3 and MCF-7 cells are presented. The generation of T-AuNPs follows all principles of green chemistry and have been found to be non toxic as assessed through MTT assays. No 'man made' chemicals, other than gold salts, are used in this true biogenic green nanotechnological process thus paving excellent opportunities for their applications in molecular imaging and therapy.

  2. Sustained Release Oral Nanoformulated Green Tea for Prostate Cancer

    Science.gov (United States)

    2011-05-01

    prostate cancer progression in humans and is being detected in the serum of patients with prostate diseases including prostatitis , benign prostatic ... hypertrophy , and prostate cancer (4). In our study, we found that there was significant inhibition of secreted PSA levels by 13-36%, 26-54% and 57-72% in...TITLE: Sustained Release Oral Nanoformulated Green Tea for Prostate Cancer PRINCIPAL INVESTIGATOR: Hasan Mukhtar, PhD

  3. Green tea and skin cancer: photoimmunology, angiogenesis and DNA repair.

    Science.gov (United States)

    Katiyar, Suchitra; Elmets, Craig A; Katiyar, Santosh K

    2007-05-01

    Human skin is constantly exposed to numerous noxious physical, chemical and environmental agents. Some of these agents directly or indirectly adversely affect the skin. Cutaneous overexposure to environmental solar ultraviolet (UV) radiation (290-400 nm) has a variety of adverse effects on human health, including the development of melanoma and nonmelanoma skin cancers. Therefore, there is a need to develop measures or strategies, and nutritional components are increasingly being explored for this purpose. The polyphenols present in green tea (Camellia sinensis) have been shown to have numerous health benefits, including protection from UV carcinogenesis. (-)-Epigallocatechin-3-gallate (EGCG) is the major and most photoprotective polyphenolic component of green tea. In this review article, we have discussed the most recent investigations and mechanistic studies that define and support the photoprotective efficacy of green tea polyphenols (GTPs) against UV carcinogenesis. The oral administration of GTPs in drinking water or the topical application of EGCG prevents UVB-induced skin tumor development in mice, and this prevention is mediated through: (a) the induction of immunoregulatory cytokine interleukin (IL) 12; (b) IL-12-dependent DNA repair following nucleotide excision repair mechanism; (c) the inhibition of UV-induced immunosuppression through IL-12-dependent DNA repair; (d) the inhibition of angiogenic factors; and (e) the stimulation of cytotoxic T cells in a tumor microenvironment. New mechanistic information strongly supports and explains the chemopreventive activity of GTPs against photocarcinogenesis.

  4. Occupational hypersensitivity pneumonitis in a green tea manufacturer.

    Science.gov (United States)

    Tanaka, Yuko; Shirai, Toshihiro; Enomoto, Noriyuki; Asada, Kazuhiro; Oyama, Yoshiyuki; Suda, Takafumi

    2016-04-01

    Hypersensitivity pneumonitis (HP) is caused by numerous agents, and one of its histopathological features is poorly formed granulomas. We report here a rare case of occupational HP caused by green tea, showing well-formed granulomas. The patient, a 54-year-old woman who had worked for 15 years in a green tea factory, was referred for abnormal chest X-ray shadows with cough and breathlessness over a 2-month period. The chest X-ray and high-resolution computed tomography showed diffuse bilateral ground-glass opacities and poorly defined centrilobular nodules. Histopathological examination of the thoracoscopic lung biopsy specimens showed bronchiolocentric interstitial pneumonia with well-formed granulomas. Although the form of granulomas were atypical, laboratory data, CT findings, and intradermal skin testing suggested the diagnosis of subacute HP caused by green tea. After transfer to a different department, her condition improved markedly. Taking a precise medical history and avoidance of the suspected environmental agent proved useful in diagnosing this condition. © 2016 The Authors. Respirology Case Reports published by John Wiley & Sons Australia, Ltd on behalf of The Asian Pacific Society of Respirology.

  5. Camellia sinensis (green tea) extract attenuate acrylamide induced testicular damage in albino rats.

    Science.gov (United States)

    Yassa, Heba A; George, Safaa M; Refaiy, Abeer El Refaiy M; Moneim, Effat M Abdel

    2014-10-01

    Acrylamide is a proved toxin for testicular function, found in food when heated for long period of time. Green tea (Camellia sinensis) is a potent antioxidant; the aim of this study was to investigate the protective effect of green tea extract against the toxic effects of acrylamide in rat testes. acrylamide was administered orally to rats in different doses and also the extract of green tea was administered orally to different groups of animals in combination with the acrylamide. The weight of animals, testosterone hormone level and histopathological effect upon testicles were evaluated. Testosterone hormone level in serum, and histopathological findings were significantly improved with the co-administration of green tea extract with the acrylamide. Green tea extract reversed all the toxic effects of acrylamide even in high dose for long period (90 days). Green tea extract is a potent antioxidant antidote for the acrylamide toxic effects upon testicular function. Copyright © 2013 Wiley Periodicals, Inc., a Wiley company.

  6. Green tea consumption affects cognitive dysfunction in the elderly: a pilot study.

    Science.gov (United States)

    Ide, Kazuki; Yamada, Hiroshi; Takuma, Norikata; Park, Mijong; Wakamiya, Noriko; Nakase, Junpei; Ukawa, Yuuichi; Sagesaka, Yuko M

    2014-09-29

    Green tea is known to have various health benefits for humans. However, the effect of green tea consumption on cognitive dysfunction remains to be clinically verified. We conducted a clinical study to investigate the effects of green tea consumption on cognitive dysfunction. Twelve elderly nursing home residents with cognitive dysfunction (Mini-Mental State Examination Japanese version (MMSE-J) score: green tea powder 2 g/day for 3 months. After three months of green tea consumption, the participants' MMSE-J scores were significantly improved (before, 15.3 ± 7.7; after, 17.0 ± 8.2; p = 0.03). This result suggests that green tea consumption may be effective in improving cognitive function or reducing the progression of cognitive dysfunction; however, long-term large-scale controlled studies are needed to further clarify the effect.

  7. Green Tea Consumption Affects Cognitive Dysfunction in the Elderly: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Kazuki Ide

    2014-09-01

    Full Text Available Green tea is known to have various health benefits for humans. However, the effect of green tea consumption on cognitive dysfunction remains to be clinically verified. We conducted a clinical study to investigate the effects of green tea consumption on cognitive dysfunction. Twelve elderly nursing home residents with cognitive dysfunction (Mini-Mental State Examination Japanese version (MMSE-J score: <28 participated in the study (2 men, 10 women; mean age, 88 years. The participants consumed green tea powder 2 g/day for 3 months. After three months of green tea consumption, the participants’ MMSE-J scores were significantly improved (before, 15.3 ± 7.7; after, 17.0 ± 8.2; p = 0.03. This result suggests that green tea consumption may be effective in improving cognitive function or reducing the progression of cognitive dysfunction; however, long-term large-scale controlled studies are needed to further clarify the effect.

  8. Interaction of green tea catechins with breast cancer endocrine treatment: a systematic review.

    Science.gov (United States)

    Yiannakopoulou, Eugenia C

    2014-01-01

    Recent data have shown strong chemopreventive and possibly cancer chemotherapeutic effects of green tea polyphenols and EGCG against breast cancer. This systematic review aims to synthesize data on the possible interaction of green tea catechins with breast cancer endocrine treatment. Electronic databases were searched with the appropriate search terms. Experimental trials suggest a synergistic interaction of green tea catechins with tamoxifen or raloxifene in the treatment of estrogen receptor-positive and estrogen receptor-negative breast cancer through estrogen receptor-dependent and -independent mechanisms. No evidence of an interaction of green tea catechins with aromatase inhibitors or fulvestrant has been reported. As green tea catechins are natural compounds with a rather favorable safety profile, the strategy of co-administrating green tea catechins with tamoxifen seems to be a rational approach in chemoprevention, adjuvant and metastatic breast cancer treatment that needs further investigation.

  9. DETERMINATION OF TOTAL ANTIOXIDANT CAPACITY OF GREEN TEAS BY THE FERRIC REDUCING/ANTIOXIDANT POWER ASSAY

    OpenAIRE

    M. Hajimahmoodi, M. Hanifeh, M. R. Oveisi, N. Sadeghi, B. Jannat

    2008-01-01

    Green tea is one of the important sources of bioactive compounds which have been used in folk medicine for many centuries. This study aimed to compare in vitro antioxidant power of different types of green tea (Camellia sinensis). Antioxidant activity of methanolic (50%) extracts of five green tea samples was investigated according to Ferric reducing ability power method. Total phenolic contents were analyzed using a spectrophotometric technique, based on the Folin-ciocalteau reagent, and cal...

  10. Evaluation of the antiviral activity of a green tea solution as a hand-wash disinfectant.

    Science.gov (United States)

    Shin, Woo-Jin; Kim, Young-Kyung; Lee, Kwang-Hee; Seong, Baik-Lin

    2012-01-01

    Based on the broad-spectrum antiviral effect of green tea catechins, we established an experimental skin contact model for influenza virus transmission and evaluated the use of a green tea solution as a first-hand disinfectant. The infectivity of the virus on the skin cell layer became obsolete when washed with the green tea solution. The skin contact model could be applied to develop non-pharmaceutical intervention measures for reducing human transmission of the influenza virus.

  11. Green tea and the risk of prostate cancer: A systematic review and meta-analysis.

    Science.gov (United States)

    Guo, Yuming; Zhi, Fan; Chen, Ping; Zhao, Keke; Xiang, Han; Mao, Qi; Wang, Xinghuan; Zhang, Xinhua

    2017-03-01

    Prostate cancer (PCa) now remains the 2nd most frequently diagnosed cancer. In recent years, chemoprevention for PCa becomes a possible concept. Especially, many phytochemicals rich foods are suggested to lower the risk of cancer. Among these foods, green tea is considered as effective prevention for various cancers. However, clinical trials and previous meta-analyses on the relationship between green tea consumption and the risk of PCa have produced inconsistent outcomes. This study aims to determine the dose-response association of green tea intake with PCa risk and the preventive effect of green tea catechins on PCa risk. Seven observational studies and 3 randomized controlled trials were retrieved from Cochrane Library, PubMed, Sciencedirect Online, and hand searching. The STATA (version 12.0) was applied to analyze the data. The relative risks (RRs) and 95% confidence intervals were pooled by fixed or random effect modeling. Dose-response relations were evaluated with categories of green tea intake. Although there was no statistical significance in the comparison of the highest versus lowest category, there was a trend of reduced incidence of PCa with each 1 cup/day increase of green tea (P = 0.08). Our dose-response meta-analysis further demonstrated that higher green tea consumption was linearly associated with a reduced risk of PCa with more than 7 cups/day. In addition, green tea catechins were effective for preventing PCa with an RR of 0.38 (P = 0.02). In conclusion, our dose-response meta-analysis evaluated the association of green tea intake with PCa risk systematically and quantitatively. And this is the first meta-analysis of green tea catechins consumption and PCa incidence. Our novel data demonstrated that higher green tea consumption was linearly reduced PCa risk with more than 7 cups/day and green tea catechins were effective for preventing PCa. However, further studies are required to substantiate these conclusions.

  12. Vascular and Metabolic Actions of the Green Tea Polyphenol Epigallocatechin Gallate

    OpenAIRE

    2015-01-01

    Epidemiological studies demonstrate robust correlations between green tea consumption and reduced risk of type 2 diabetes and its cardiovascular complications. However, underlying molecular, cellular, and physiological mechanisms remain incompletely understood. Health promoting actions of green tea are often attributed to epigallocatechin gallate (EGCG), the most abundant polyphenol in green tea. Insulin resistance and endothelial dysfunction play key roles in the pathogenesis of type 2 diabe...

  13. Antimutagenic activity of green tea and black tea extracts studied in a dynamic in vitro gastrointestinal model

    NARCIS (Netherlands)

    Krul, C.A.M.; Luiten-Schuite, A.; Tenfelde, A.; Ommen, B. van; Verhagen, H.; Havenaar, R.

    2001-01-01

    An in vitro gastrointestinal model, which simulates the conditions in the human digestive tract, was used to determine potential antimutagenic activity of extracts of black tea and green tea. In this paper, results are presented on the availability for absorption of potential antimutagenic compounds

  14. Antimutagenic activity of green tea and black tea extracts studied in a dynamic in vitro gastrointestinal model

    NARCIS (Netherlands)

    Krul, C.A.M.; Luiten-Schuite, A.; Tenfelde, A.; Ommen, B. van; Verhagen, H.; Havenaar, R.

    2001-01-01

    An in vitro gastrointestinal model, which simulates the conditions in the human digestive tract, was used to determine potential antimutagenic activity of extracts of black tea and green tea. In this paper, results are presented on the availability for absorption of potential antimutagenic compounds

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

    Science.gov (United States)

    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.

  16. Volatile and non-volatile compounds in green tea affected in harvesting time and their correlation to consumer preference.

    Science.gov (United States)

    Kim, Youngmok; Lee, Kwang-Geun; Kim, Mina K

    2016-10-01

    Current study was designed to find out how tea harvesting time affects the volatile and non-volatile compounds profiles of green tea. In addition, correlation of instrumental volatile and non-volatile compounds analyses to consumer perception were analyzed. Overall, earlier harvested green tea had stronger antioxidant capacity (~61.0%) due to the polyphenolic compounds from catechin (23,164 mg/L), in comparison to later harvested green teas (11,961 mg/L). However, high catechin content in green tea influenced negatively the consumer likings of green tea, due to high bitterness (27.6%) and astringency (13.4%). Volatile compounds drive consumer liking of green tea products were also identified, that included linalool, 2,3-methyl butanal, 2-heptanone, (E,E)-3,5-Octadien-2-one. Finding from current study are useful for green tea industry as it provide the difference in physiochemical properties of green tea harvested at different intervals.

  17. Prediction of Japanese green tea ranking by gas chromatography/mass spectrometry-based hydrophilic metabolite fingerprinting.

    Science.gov (United States)

    Pongsuwan, Wipawee; Fukusaki, Eiichiro; Bamba, Takeshi; Yonetani, Tsutomu; Yamahara, Toshiyaki; Kobayashi, Akio

    2007-01-24

    An innovative technique for green tea's quality determination was developed by means of metabolomics. Gas-chromatography coupled with time-of-flight mass spectrometry and multivariate data analysis was employed to evaluate the quality of green tea. Alteration of green tea varieties and manufacturing processes effects a variation in green tea metabolites, which leads to a classification of the green tea's grade. Therefore, metabolic fingerprinting of green tea samples of different qualities was studied. A set of ranked green tea samples from a Japanese commercial tea contest was analyzed with the aim of creating a reliable quality-prediction model. Several multivariate algorithms were performed. Among those, the partial least-squares projections to latent structures (PLS) analysis with the spectral filtering technique, orthogonal signal correction (OCS), was found to be the most practical approach. In addition, metabolites that play an important role in green tea's grade classification were identified.

  18. Green tea polyphenols protect spinal cord neurons against hydrogen peroxide-induced oxidative stress

    Institute of Scientific and Technical Information of China (English)

    Jianbo Zhao; Shiqiang Fang; Yajiang Yuan; Zhanpeng Guo; Jinhao Zeng; Yue Guo; Peifu Tang; Xifan Mei

    2014-01-01

    Green tea polyphenols are strong antioxidants and can reduce free radical damage. To investigate their neuroprotective potential, we induced oxidative damage in spinal cord neurons using hy-drogen peroxide, and applied different concentrations (50-200 µg/mL) of green tea polyphenol to the cell medium for 24 hours. Measurements of superoxide dismutase activity, malondial-dehyde content, and expression of apoptosis-related genes and proteins revealed that green tea polyphenol effectively alleviated oxidative stress. Our results indicate that green tea polyphenols play a protective role in spinal cord neurons under oxidative stress.

  19. Drug-delivery systems of green tea catechins for improved stability and bioavailability.

    Science.gov (United States)

    Rodrigues, C F; Ascenção, K; Silva, F A M; Sarmento, B; Oliveira, M B P P; Andrade, J C

    2013-01-01

    Numerous studies in humans, animal models and cell lines have suggested the potential benefits from the consumption of green tea polyphenols, including prevention of cancer and heart diseases. However these potential effects have been strongly limited by green tea catechins low bioavailability, which hinders the development of therapeutic applications. In this review formulations that are being proposed for delivery of green tea catechins are discussed. New delivery systems are presented as valid alternatives to overcome the limitations such as green tea catechins poor stability or intestinal absorption.

  20. Biophysical Approach to Mechanisms of Cancer Prevention and Treatment with Green Tea Catechins

    Directory of Open Access Journals (Sweden)

    Masami Suganuma

    2016-11-01

    Full Text Available Green tea catechin and green tea extract are now recognized as non-toxic cancer preventives for humans. We first review our brief historical development of green tea cancer prevention. Based on exciting evidence that green tea catechin, (−-epigallocatechin gallate (EGCG in drinking water inhibited lung metastasis of B16 melanoma cells, we and other researchers have studied the inhibitory mechanisms of metastasis with green tea catechins using biomechanical tools, atomic force microscopy (AFM and microfluidic optical stretcher. Specifically, determination of biophysical properties of cancer cells, low cell stiffness, and high deformability in relation to migration, along with biophysical effects, were studied by treatment with green tea catechins. The study with AFM revealed that low average values of Young’s moduli, indicating low cell stiffness, are closely associated with strong potential of cell migration and metastasis for various cancer cells. It is important to note that treatments with EGCG and green tea extract elevated the average values of Young’s moduli resulting in increased stiffness (large elasticity of melanomas and various cancer cells. We discuss here the biophysical basis of multifunctions of green tea catechins and green tea extract leading to beneficial effects for cancer prevention and treatment.

  1. Does green tea affect postprandial glucose, insulin and satiety in healthy subjects: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Lindstedt Sandra

    2010-11-01

    Full Text Available Abstract Background Results of epidemiological studies have suggested that consumption of green tea could lower the risk of type 2 diabetes. Intervention studies show that green tea may decrease blood glucose levels, and also increase satiety. This study was conducted to examine the postprandial effects of green tea on glucose levels, glycemic index, insulin levels and satiety in healthy individuals after the consumption of a meal including green tea. Methods The study was conducted on 14 healthy volunteers, with a crossover design. Participants were randomized to either 300 ml of green tea or water. This was consumed together with a breakfast consisting of white bread and sliced turkey. Blood samples were drawn at 0, 15, 30, 45, 60, 90, and 120 minutes. Participants completed several different satiety score scales at the same times. Results Plasma glucose levels were higher 120 min after ingestion of the meal with green tea than after the ingestion of the meal with water. No significant differences were found in serum insulin levels, or the area under the curve for glucose or insulin. Subjects reported significantly higher satiety, having a less strong desire to eat their favorite food and finding it less pleasant to eat another mouthful of the same food after drinking green tea compared to water. Conclusions Green tea showed no glucose or insulin-lowering effect. However, increased satiety and fullness were reported by the participants after the consumption of green tea. Trial registration number NCT01086189

  2. Biophysical Approach to Mechanisms of Cancer Prevention and Treatment with Green Tea Catechins.

    Science.gov (United States)

    Suganuma, Masami; Takahashi, Atsushi; Watanabe, Tatsuro; Iida, Keisuke; Matsuzaki, Takahisa; Yoshikawa, Hiroshi Y; Fujiki, Hirota

    2016-11-18

    Green tea catechin and green tea extract are now recognized as non-toxic cancer preventives for humans. We first review our brief historical development of green tea cancer prevention. Based on exciting evidence that green tea catechin, (-)-epigallocatechin gallate (EGCG) in drinking water inhibited lung metastasis of B16 melanoma cells, we and other researchers have studied the inhibitory mechanisms of metastasis with green tea catechins using biomechanical tools, atomic force microscopy (AFM) and microfluidic optical stretcher. Specifically, determination of biophysical properties of cancer cells, low cell stiffness, and high deformability in relation to migration, along with biophysical effects, were studied by treatment with green tea catechins. The study with AFM revealed that low average values of Young's moduli, indicating low cell stiffness, are closely associated with strong potential of cell migration and metastasis for various cancer cells. It is important to note that treatments with EGCG and green tea extract elevated the average values of Young's moduli resulting in increased stiffness (large elasticity) of melanomas and various cancer cells. We discuss here the biophysical basis of multifunctions of green tea catechins and green tea extract leading to beneficial effects for cancer prevention and treatment.

  3. 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.

    Science.gov (United States)

    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.

  4. In vivo evaluation of black and green tea dermal products against UV radiation.

    Science.gov (United States)

    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.

  5. Optimizing conditions for the extraction of catechins from green tea using hot water.

    Science.gov (United States)

    Vuong, Quan V; Golding, John B; Stathopoulos, Costas E; Nguyen, Minh H; Roach, Paul D

    2011-11-01

    Six different factors involved in the extraction of catechins from green tea using water were examined for their impact on the yield of catechins and on the efficiency of water use. The best temperature and time combination for catechin extraction was at 80°C for 30 min. The yield of catechins was also optimal with a tea particle size of 1 mm, a brewing solution pH tea-to-water ratio at 50:1 (mL/g). In terms of efficient use of water in a single extraction, a water-to-tea ratio of 20:1 (mL/g) gave the best results; 2.5 times less water was used per gram of green tea. At the water-to-tea ratio of 20:1 mL/g, the highest yield of catechins per gram of green tea was achieved by extracting the same sample of green tea twice. However, for the most efficient use of water, the best extraction was found to be once at a water-to-tea ratio of 12:1 (mL/g) and once at a water-to-tea ratio of 8:1 (mL/g). Therefore, all six of the factors investigated had an impact on the yield of catechins extracted from green tea using water and two had an impact on the efficiency of water use.

  6. Green tea flavour determinants and their changes over manufacturing processes.

    Science.gov (United States)

    Han, Zhuo-Xiao; Rana, Mohammad M; Liu, Guo-Feng; Gao, Ming-Jun; Li, Da-Xiang; Wu, Fu-Guang; Li, Xin-Bao; Wan, Xiao-Chun; Wei, Shu

    2016-12-01

    Flavour determinants in tea infusions and their changes during manufacturing processes were studied using Camellia sinensis cultivars 'Bai-Sang Cha' ('BAS') possessing significant floral scents and 'Fuding-Dabai Cha' ('FUD') with common green tea odour. Metabolite profiling based on odour activity threshold revealed that 'BAS' contained higher levels of the active odorants β-ionone, linalool and its two oxides, geraniol, epoxylinalool, decanal and taste determinant catechins than 'FUD' (pmanufacturing processes, the levels of linalool and geraniol decreased whereas those of β-ionone, linalool oxides, indole and cis-jasmone increased. Compared with pan-fire treatment, steam treatment reduced the levels of catechins and proportion of geraniol, linalool and its derivatives, consequently, reducing catechin-related astringency and monoterpenol-related floral scent. Our study suggests that flavour determinant targeted modulation could be made through genotype and manufacturing improvements.

  7. Determination of Lead in Saudi Arabian Imported Green Tea by ICP-MS

    Directory of Open Access Journals (Sweden)

    Ahmed Othman

    2012-01-01

    Full Text Available Lead (Pb in nine different Saudi Arabian imported green tea samples originated from China has been determined using inductively coupled plasma mass spectrometry (ICP-MS. Tea infusion and microwave acid digestion procedures are used for sample pre-treatment. The concentrations range of lead (total in the analyzed green tea samples is 0.231 – 6.340 mg/kg. The total concentration of lead released 3% – 19% into tea infusions with boiling water. The calculated average daily intakes of lead in tea infusions was low and within the bounds of safety (≤0.009 mg/day.

  8. Data on green tea flavor determinantes as affected by cultivars and manufacturing processes

    OpenAIRE

    Han, Zhuo-Xiao; Rana, Mohammad M.; Liu, Guo-Feng; Gao, Ming-Jun; Li, Da-Xiang; Wu, Fu-Guang; Li, Xin-Bao; Wan, Xiao-Chun; Wei, Shu

    2016-01-01

    This paper presents data related to an article entitled “Green tea flavor determinants and their changes over manufacturing processes” (Han et al., 2016) [1]. Green tea samples were prepared with steaming and pan firing treatments from the tender leaves of tea cultivars ‘Bai-Sang Cha’ (‘BAS’) and ‘Fuding-Dabai Cha’ (‘FUD’). Aroma compounds from the tea infusions were detected and quantified using HS-SPME coupled with GC/MS. Sensory evaluation was also made for characteristic tea flavor. The d...

  9. Data on green tea flavor determinantes as affected by cultivars and manufacturing processes

    OpenAIRE

    Zhuo-Xiao Han; Rana, Mohammad M.; Guo-Feng Liu; Ming-Jun Gao; Da-Xiang Li; Fu-Guang Wu; Xin-Bao Li; Xiao-Chun Wan; Shu Wei

    2017-01-01

    This paper presents data related to an article entitled “Green tea flavor determinants and their changes over manufacturing processes” (Han et al., 2016) [1]. Green tea samples were prepared with steaming and pan firing treatments from the tender leaves of tea cultivars ‘Bai-Sang Cha’ (‘BAS’) and ‘Fuding-Dabai Cha’ (‘FUD’). Aroma compounds from the tea infusions were detected and quantified using HS-SPME coupled with GC/MS. Sensory evaluation was also made for characteristic tea flavor. The d...

  10. Protective Mechanisms of Green Tea Polyphenols in Skin

    Directory of Open Access Journals (Sweden)

    Patricia OyetakinWhite

    2012-01-01

    Full Text Available Skin is frequently exposed to a variety of environmental, chemical, and genotoxic agents that contribute to disease and carcinogenesis. Ultraviolet light (UVR is the main external stress that leads to immunosuppresion, oxidative stress, premature aging, and tumor formation. Scientists and health professionals emphasize the importance of prevention strategies to circumvent such unfavorable outcomes. Plant polyphenols are a promising approach to disease prevention and treatment. Green tea is an abundant source of plant polyphenols that exhibit significant antioxidant, chemopreventive, and immunomodulatory effects in protecting the skin.

  11. Sustained Release Oral Nanoformulated Green Tea for Prostate Cancer Prevention

    Science.gov (United States)

    2013-05-01

    encap n establishe eventive/the trated the u he cost, we cility. Male aintained in nsin. We h emales (tra es to gener gene is det eeks of age he mice...disease. Clin Cancer Res. 2009;15:1947-53. 4. Gupta S, Adhami VM, Subbarayan M, MacLennan GT, Lewin JS, Hafeli UO, et al. Suppression of prostate...S, Hastak K, Ahmad N, Lewin JS, Mukhtar H. Inhibition of prostate carcinogenesis in TRAMP mice by oral infusion of green tea polyphenols. Proc Natl

  12. Fungal evaluation on green tea irradiated with different water activities

    Energy Technology Data Exchange (ETDEWEB)

    Fanaro, Gustavo B.; Duarte, Renato C.; Rodrigues, Flavio T.; Villavicencio, Anna Lucia C.H., E-mail: gbfanaro@ipen.b, E-mail: villavic@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (CTR/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes; Correa, Benedito, E-mail: correabe@usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Ciencias Biologicas. Dept. de Micologia

    2011-07-01

    The aim of this study was evaluate the fungal contamination in green tea irradiated with different radiation doses and water activities. Samples were irradiated in {sup 60}Co irradiator at doses of 0, 2.5, 5.0, 7.5 and 10.0kGy with three different water activities. In the sample with decreased water activity, the count of fungi was lower than others samples followed by original Aw and the samples with the higher water activity, however there is no difference between the increased and decreased water activities samples after the irradiation on fungi contamination at dose of 2.5 kGy. (author)

  13. Green Tea Leaves Extract: Microencapsulation, Physicochemical and Storage Stability Study

    Directory of Open Access Journals (Sweden)

    James A. Zokti

    2016-07-01

    Full Text Available Green tea polyphenols have been reported to possess many biological properties. Despite the many potential benefits of green tea extracts, their sensitivity to high temperature, pH and oxygen is a major disadvantage hindering their effective utilization in the food industry. Green tea leaves from the Cameron Highlands Malaysia were extracted using supercritical fluid extraction (SFE. To improve the stability, green tea extracts were encapsulated by spray-drying using different carrier materials including maltodextrin (MD, gum arabic (GA and chitosan (CTS and their combinations at different ratios. Encapsulation efficiency, total phenolic content and antioxidant capacity were determined and were found to be in the range of 71.41%–88.04%, 19.32–24.90 (g GAE/100 g, and 29.52%–38.05% respectively. Further analysis of moisture content, water activity, hygroscopicity, bulk density and mean particles size distribution of the microparticles were carried out and the results ranged from; 2.31%–5.11%, 0.28–0.36, 3.22%–4.71%, 0.22–0.28 g/cm3 and 40.43–225.64 µm respectively. The ability of the microparticles to swell in simulated gastric fluid (SGF and simulated intestinal fluid (SIF was determined as 142.00%–188.63% and 207.55%–231.77%, respectively. Release of catechin polyphenol from microparticles in SIF was higher comparable to that of SGF. Storage stability of encapsulated catechin extracts under different temperature conditions was remarkably improved compared to non-encapsulated extract powder. This study showed that total catechin, total phenolic content (TPC and antioxidant activity did not decrease significantly (p ≥ 0.05 under 4 °C storage conditions. The half-life study results were in the range of 35–60, 34–65 and 231–288 weeks at storage temperatures of 40 °C, 25 °C and 4 °C respectively, therefore, for improved shelf-life stability we recommend that microparticles should be stored at temperatures below 25 °C.

  14. Green Tea Leaves Extract: Microencapsulation, Physicochemical and Storage Stability Study.

    Science.gov (United States)

    Zokti, James A; Sham Baharin, Badlishah; Mohammed, Abdulkarim Sabo; Abas, Faridah

    2016-07-26

    Green tea polyphenols have been reported to possess many biological properties. Despite the many potential benefits of green tea extracts, their sensitivity to high temperature, pH and oxygen is a major disadvantage hindering their effective utilization in the food industry. Green tea leaves from the Cameron Highlands Malaysia were extracted using supercritical fluid extraction (SFE). To improve the stability, green tea extracts were encapsulated by spray-drying using different carrier materials including maltodextrin (MD), gum arabic (GA) and chitosan (CTS) and their combinations at different ratios. Encapsulation efficiency, total phenolic content and antioxidant capacity were determined and were found to be in the range of 71.41%-88.04%, 19.32-24.90 (g GAE/100 g), and 29.52%-38.05% respectively. Further analysis of moisture content, water activity, hygroscopicity, bulk density and mean particles size distribution of the microparticles were carried out and the results ranged from; 2.31%-5.11%, 0.28-0.36, 3.22%-4.71%, 0.22-0.28 g/cm³ and 40.43-225.64 µm respectively. The ability of the microparticles to swell in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) was determined as 142.00%-188.63% and 207.55%-231.77%, respectively. Release of catechin polyphenol from microparticles in SIF was higher comparable to that of SGF. Storage stability of encapsulated catechin extracts under different temperature conditions was remarkably improved compared to non-encapsulated extract powder. This study showed that total catechin, total phenolic content (TPC) and antioxidant activity did not decrease significantly (p ≥ 0.05) under 4 °C storage conditions. The half-life study results were in the range of 35-60, 34-65 and 231-288 weeks at storage temperatures of 40 °C, 25 °C and 4 °C respectively, therefore, for improved shelf-life stability we recommend that microparticles should be stored at temperatures below 25 °C.

  15. TIME INTENSITY (TI MEASUREMENTS OF SWEETENERS ON GREEN TEA CARRIER

    Directory of Open Access Journals (Sweden)

    Vladimir Vietoris

    2015-02-01

    Full Text Available Aim of the study was characterize sweet intensity profiles of natural and artificial sweeteners during time interval on taste carrier (green tea. For analysis was selected time intensity (TI methodology during 12 second time interval and assessors group was divided to male and female division. Difference between groups and sweeteners was investigated. Preference testing was done by CATA methodology and processed by correspondent analysis. During time intensity evaluation was observed similar profile shape of natural sweeteners. Different was performance of saccharin. During preference experiment was evaluated that all artificial sweeteners are associated with negative attributes of CATA questionnaire. Perception of sweeteners by male and female assessors was statistically significant.

  16. Comparison of fluoride concentration in several types of green tea consumed in Iran

    OpenAIRE

    S. Maleki Kambakhsh; Hejazi, M.; A. Rahmaninejad; S Babazadeh

    2016-01-01

    Background: Tea is known as a source of fluoride that not only can prevent tooth decay but also can increase the risk of dental fluorosis in overuse or in combination with other sources of fluoride. Objective: The aim of this study was to compare the fluoride concentration in three brands of green tea consumed in Iran. Methods: This experimental study was conducted in Qazvin University of medical Science during 2012. Three brands of green tea (bag type and packed type) were evaluated. T...

  17. Chinese green tea ameliorates lung injury in cigarette smoke-exposed rats

    OpenAIRE

    Koo, MWL; Ip, MSM; Man, RYK; Mak, JCW; Chan, KH; Ho, SP; Yeung, SC; So, WHL; Cho, CH; Lam, WK

    2009-01-01

    Background: Epigallocatechin-3-gallate (EGCG), which has been shown to have potent antioxidant effect, comprises 80% of catechins in Chinese green tea. This study was to investigate whether cigarette smoke (CS) exposure would induce lung morphological changes and oxidative stress in the CS-exposed rat model, and whether Chinese green tea (Lung Chen tea with EGCG as its main active ingredient) consumption would alter oxidative stress in sera and lung leading to protection of CS-induced lung da...

  18. Green Tea as Inhibitor of the Intestinal Absorption of Lipids: Potential Mechanism for its Lipid-Lowering Effect1

    OpenAIRE

    Koo, Sung I.; Noh, Sang K.

    2007-01-01

    Animal and epidemiological studies suggest that green tea catechins may reduce the risk of cardiovascular diseases (CHD). The health benefit of green tea has been attributed to its antioxidant and anti-inflammatory properties; however, considerable evidence suggests that green tea and its catechins may reduce the risk of CHD by lowering the plasma levels of cholesterol and triglyceride. Although the mechanism underlying such effect of green tea is yet to be determined, it is evident from in v...

  19. Green tea polyphenols avert chronic inflammation-induced myocardial fibrosis of female rats

    Science.gov (United States)

    Objective: Green tea proposes anti-inflammatory properties which may attenuate chronic inflammation-induced fibrosis of vessels. This study evaluated whether green tea polyphenols (GTP) can avert fibrosis or vascular disruption along with mechanisms in rats with chronic inflammation. Treatments: Fo...

  20. The potential role of green tea catechins in the prevention of the metabolic syndrome - a review.

    Science.gov (United States)

    Thielecke, Frank; Boschmann, Michael

    2009-01-01

    The metabolic syndrome (MetS) represents an emerging health burden for governments and health care providers. Particularly relevant for prevention and early management of MetS are lifestyle conditions including physical activity and the diet. It has been shown that green tea, when consumed on a daily basis, supports health. Many of the beneficial effects of green tea are related to its catechin, particularly (-)-epigallocatechin-3-gallate (EGCG), content. There is conclusive evidence from in vitro and animal studies which provide the concepts for underlying functional mechanisms of green tea catechins and their biological actions. An increasing number of human studies have explored the effects of green tea catechins on the major MetS conditions such as obesity, type-2 diabetes and cardiovascular risk factors. This article provides a comprehensive overview of the human studies addressing the potential benefits of green tea catechins on the MetS. The number of human studies in this field is still limited. However, the majority of human epidemiological and intervention studies demonstrate beneficial effects of green tea or green tea extracts, rich in EGCG on weight management, glucose control and cardiovascular risk factors. The optimal dose has not yet been established. The current body of evidence in humans warrants further attention. In particular, well-controlled long-term human studies would help to fully understand the protective effects of green tea catechins on parameters related to the MetS.

  1. Green tea EGCG suppresses T cell proliferation through impairment of IL-2/IL-2 receptor signaling

    Science.gov (United States)

    Studies have suggested a benefit of consuming green tea in promoting general health and reducing the risk of certain diseases. However, little is known about the effect of green tea on immune function. In this study we determined the effect of epigallocatechin-3-gallate (EGCG), the major active comp...

  2. Green tea ingestion greatly reduces plasma concentrations of nadolol in healthy subjects.

    Science.gov (United States)

    Misaka, S; Yatabe, J; Müller, F; Takano, K; Kawabe, K; Glaeser, H; Yatabe, M S; Onoue, S; Werba, J P; Watanabe, H; Yamada, S; Fromm, M F; Kimura, J

    2014-04-01

    This study aimed to evaluate the effects of green tea on the pharmacokinetics and pharmacodynamics of the β-blocker nadolol. Ten healthy volunteers received a single oral dose of 30 mg nadolol with green tea or water after repeated consumption of green tea (700 ml/day) or water for 14 days. Catechin concentrations in green tea and plasma were determined. Green tea markedly decreased the maximum plasma concentration (C(max)) and area under the plasma concentration-time curve (AUC(0-48)) of nadolol by 85.3% and 85.0%, respectively (P green tea. [(3)H]-Nadolol uptake assays in human embryonic kidney 293 cells stably expressing the organic anion-transporting polypeptides OATP1A2 and OATP2B1 revealed that nadolol is a substrate of OATP1A2 (Michaelis constant (K(m)) = 84.3 μmol/l) but not of OATP2B1. Moreover, green tea significantly inhibited OATP1A2-mediated nadolol uptake (half-maximal inhibitory concentration, IC(50) = 1.36%). These results suggest that green tea reduces plasma concentrations of nadolol possibly in part by inhibition of OATP1A2-mediated uptake of nadolol in the intestine.

  3. Goitrogenic/antithyroidal potential of green tea extract in relation to catechin in rats.

    Science.gov (United States)

    Chandra, Amar K; De, Neela

    2010-01-01

    Catechins are flavonoids found in abundance in green tea, have elicited high interest due to their beneficial effects on health. Though flavonoids have been reported to have an antithyroid effect and also to be goitrogenic there have been no reports about the effect of green tea on rat thyroid. The present study was designed to examine whether high doses of green tea has any harmful effect on thyroid physiology. For this purpose green tea extract was administered orally to male albino rats for 30 days at doses of 1.25 g%, 2.5 g% and 5.0 g%, respectively. Similarly, pure catechin was administered at doses of 25, 50 and 100mg/kg body weight which is equivalent to above doses of green tea extract. Lower body weight gain associated with marked hypertrophy and/or hyperplasia of the follicles was noted in the high dose of green tea and catechin treated groups. Decreased activity of thyroid peroxidase and 5'-deiodinase I and substantially elevated thyroidal Na,K+ATPase activity have been observed. Moreover, serum T3 and T4 levels were found to reduce followed by significant elevation of serum TSH. Taken together, these results suggest that catechin present in green tea extract might behave as antithyroid agent and possibly the consumption of green tea at high dose could alter thyroid function adversely.

  4. Interaction mechanism between green tea extract and human α-amylase for reducing starch digestion.

    Science.gov (United States)

    Miao, Ming; Jiang, Bo; Jiang, Huan; Zhang, Tao; Li, Xingfeng

    2015-11-01

    This study evaluated the inhibitory effects of the green tea extract on human pancreatic α-amylase activity and its molecular mechanism. The green tea extract was composed of epicatechin (59.2%), epigallocatechin gallate (14.6%) and epicatechin gallate (26.2%) as determined by HPLC analysis. Enzyme activity measurement showed that % inhibition and IC50 of the green tea extract (10%, based on starch) were 63.5% and 2.07 mg/ml, respectively. The Michaelis-Menten constant remained unchanged but the maximal velocity decreased from 0.43 (control) to 0.07 mg/(ml × min) (4 mg/ml of the green tea extract), indicating that the green tea extract was an effective inhibitor against α-amylase with a non-competitive mode. The fluorescence data revealed that the green tea extract bound with α-amylase to form a new complex with static quenching mechanism. Docking study showed the epicatechin gallate in the green tea extract presented stronger affinity than epigallocatechin gallate, with more number of amino acid residues involved in amylase binding with hydrogen bonds and Van der Waals forces. Thus, the green tea extract could be used to manipulate starch digestion for potential health benefits.

  5. Green tea supplementation increases glutathione and plasma antioxidant capacity in adults with the metabolic syndrome.

    Science.gov (United States)

    Basu, Arpita; Betts, Nancy M; Mulugeta, Afework; Tong, Capella; Newman, Emily; Lyons, Timothy J

    2013-03-01

    Green tea, a popular polyphenol-containing beverage, has been shown to alleviate clinical features of the metabolic syndrome. However, its effects in endogenous antioxidant biomarkers are not clearly understood. Thus, we tested the hypothesis that green tea supplementation will upregulate antioxidant parameters (enzymatic and nonenzymatic) in adults with the metabolic syndrome. Thirty-five obese participants with the metabolic syndrome were randomly assigned to receive one of the following for 8 weeks: green tea (4 cups per day), control (4 cups water per day), or green tea extract (2 capsules and 4 cups water per day). Blood samples and dietary information were collected at baseline (0 week) and 8 weeks of the study. Circulating carotenoids (α-carotene, β-carotene, lycopene) and tocopherols (α-tocopherol, γ-tocopherol) and trace elements were measured using high-performance liquid chromatography and inductively coupled plasma mass spectroscopy, respectively. Serum antioxidant enzymes (glutathione peroxidase, glutathione, catalase) and plasma antioxidant capacity were measured spectrophotometrically. Green tea beverage and green tea extract significantly increased plasma antioxidant capacity (1.5 to 2.3 μmol/L and 1.2 to 2.5 μmol/L, respectively; P glutathione (1783 to 2395 μg/g hemoglobin and 1905 to 2751 μg/g hemoglobin, respectively; P glutathione peroxidase and catalase activities. Green tea extract significantly reduced plasma iron vs baseline (128 to 92 μg/dL, P green tea may provide antioxidant protection in the metabolic syndrome.

  6. Application of far-infrared irradiation in the manufacturing process of green tea.

    Science.gov (United States)

    Kim, So-Young; Jeong, Seok-Moon; Jo, Seong-Chun; Lee, Seung-Cheol

    2006-12-27

    Seven kinds of green tea leaves were manufactured with far-infrared (FIR) irradiation, and the physicochemical characteristics of the green tea were determined. Appropriate FIR irradiation during the manufacturing process significantly increased the polyphenolic content of green tea. FIR irradiation at 90 degrees C for 10 min, replacing the roasting step, and of the fully processed green tea leaves (GTP3) increased the total phenol content of green tea from 475.6 to 811.1 mg/g and the total flavanol content from 175.7 to 208.7 mg/g, as compared to the control. Epigallocatechin and epigallocatechin gallate increased from 57.68 and 9.60 mg/g in a nonirradiated control to 89.88 and 16.33 mg/g in GTP3, respectively. Ascorbic acid, caffeine, and nitrite scavenging activities were also increased in GTP3. However, the overall color change of GTP3 was negligible. These results indicate that the chemical properties of green tea are significantly affected by FIR irradiation at specific stages of the manufacturing process of green tea leaves and that this FIR irradiation results in high-quality green tea.

  7. In vitro human skin permeation and cutaneous metabolism of catechins from green tea extract and green tea extract-loaded chitosan microparticles.

    Science.gov (United States)

    Wisuitiprot, W; Somsiri, A; Ingkaninan, K; Waranuch, N

    2011-12-01

    Catechins are major antioxidants in green tea (Camellia sinensis or Camellia assamica), but because they do not permeate the skin well, the application of green tea in cosmetic products has so far been limited. This study aims to evaluate the cutaneous absorption of catechins from an extract of green tea and from a green tea extract-loaded chitosan microparticle. The catechin skin metabolism was also examined. The results suggest that chitosan microparticles significantly improve the ability of catechins to permeate skin. The cutaneous metabolism of the catechins significantly affected their permeation profiles. Epicatechin (EC) and epigallocatechin (EGC) penetrated the skin more than epigallocatechin gallate (EGCG) and epicatechin gallate (ECG). The galloyl groups in EGCG and ECG were enzymatically hydrolysed to EGC and EC, respectively. Dehydroxylation of catechins was also observed. Chitosan microparticles effectively prevented enzymatic changes of the catechins; therefore, chitosan microparticles are here found to be the promising carriers for enhancing the skin permeation.

  8. A Non-targeted Approach to Chemical Discrimination Between Green Tea Dietary Supplements and Green Tea Leaves by HPLC/MS

    OpenAIRE

    Sun, Jianghao; Chen, Pei; Lin, Long-Ze; Harnly, James M.

    2011-01-01

    Green tea-based dietary supplements (GTDSs) have gained popularity in the U.S. market in recent years. This study evaluated the phytochemical composition difference of GTDS in comparison with green tea leaves using an HPLC/MS fingerprinting technique coupled with chemometric analysis. Five components that are most responsible for class separation among samples were identified as (−) epicatechin gallate, strictinin, trigalloylglucose, quercetin-3-O-glucosylrhamnosylglucoside, and kaempferol-3-...

  9. Effect of supercritical carbon dioxide decaffeination on volatile components of green teas.

    Science.gov (United States)

    Lee, S; Park, M K; Kim, K H; Kim, Y-S

    2007-09-01

    Volatile components in regular and decaffeinated green teas were isolated by simultaneous steam distillation and solvent extraction (SDE), and then analyzed by GC-MS. A total of 41 compounds, including 8 alcohols, 15 terpene-type compounds, 10 carbonyls, 4 N-containing compounds, and 4 miscellaneous compounds, were found in regular and decaffeinated green teas. Among them, linalool and phenylacetaldehyde were quantitatively dominant in both regular and decaffeinated green teas. By a decaffeination process using supercritical carbon dioxide, most volatile components decreased. The more caffeine was removed, the more volatile components were reduced in green teas. In particular, relatively nonpolar components such as terpene-type compounds gradually decreased according to the decaffeination process. Aroma-active compounds in regular and decaffeinated green teas were also determined and compared by aroma extract dilution analysis (AEDA). Most greenish and floral flavor compounds such as hexanal, (E)-2-hexenal, and some unknown compounds disappeared or decreased after the decaffeination process.

  10. Identification of Key Odorants in Withering-Flavored Green Tea by Aroma Extract Dilution Analysis

    Science.gov (United States)

    Mizukami, Yuzo; Yamaguchi, Yuichi

    This research aims to identify key odorants in withering-flavored green tea. Application of the aroma extract dilution analysis using the volatile fraction of green tea and withering-flavored green tea revealed 25 and 35 odor-active peaks with the flavor dilution factors of≥4, respectively. 4-mercapto-4-methylpentan-2-one, (E)-2-nonenal, linalool, (E,Z)-2,6-nonadienal and 3-methylnonane-2,4-dione were key odorants in green tea with the flavor dilution factor of≥16. As well as these 5 odorants, 1-octen-3-one, β-damascenone, geraniol, β-ionone, (Z)-methyljasmonate, indole and coumarine contributed to the withering flavor of green tea.

  11. Pharmacokinetics of green tea catechins in extract and sustained-release preparations.

    Science.gov (United States)

    Janle, Elsa M; Morré, Dorothy M; Morré, D James; Zhou, Qin; Zhu, Yongxin

    2008-01-01

    Catechins are a major constituent of green tea. For green tea to have cancer therapeutic benefit, catechin concentrations in the range of 100 nM are required continuously until apoptosis (programmed cell death) is induced. To prolong elevated plasma and interstitial concentrations of catechins, a sustained-release formulation of green tea extract was tested and compared to a commercial green tea extract (Tegreen97®). Sustained-release formulations are usually developed in the pharmaceutical industry to slowly deliver the compound over a period of time and increase the dosing interval. Plasma and interstitial fluid (ISF) pharmacokinetics of catechins were determined following an oral dose in the rat. The sustained-release formulation profile included multiple smaller peaks of total catechins in both plasma and ISF. Interstitial fluid profiles of green tea extract indicate that higher catechins concentration and longer duration in tissue than in blood may make a sustained-release form unnecessary.

  12. The Effects of Green Tea Consumption on Cardiometabolic Alterations Induced by Experimental Diabetes

    Directory of Open Access Journals (Sweden)

    Patricia Fiorino

    2012-01-01

    Full Text Available We evaluated cardiac autonomic modulation by heart rate (HRV, and arterial pressure variability (APV, and metabolic response in streptozotocin diabetic rats treated with green tea. Male Wistar rats were separated in groups: control, drinking tap water (C, green tea-treated (GT group, diabetic, drinking tap water (D, and diabetic, treated with green tea (DGT. Kidney mass was greater in D and DGT than in C and GT, but reduced in DGT compared to D. Green tea prevented the increase in creatinine clearance and reduced hyperglycemia in DGT compared to D. Arterial pressure was increased in GT and decreased in D compared to C. HRV was reduced in D compared with all groups. APV was decreased in D compared to C and recovery in DGT. Sympathetic modulation of APV was decreased in D compared with all groups. Green tea reduced hyperglycemia, prevented renal injury and autonomic dysfunction, suggesting reduced cardiovascular risk and target organ damage in diabetes.

  13. Both phenolic and non-phenolic green tea fractionsinhibit migration of cancer cells

    Directory of Open Access Journals (Sweden)

    Ean-Jeong Seo

    2016-11-01

    Full Text Available Green tea consumption is associated with chemoprevention of many cancer types. Fresh tea leaves are rich in polyphenolic catechins, which can constitute up to 30% of the dry leaf weight. While the polyphenols of green tea have been well investigated, it is still largely unknown, whether or not non-phenolic constituents also reveal chemopreventive and anti-metastatic effects.In this study, we investigated the effects of a fraction of green tea rich in phenolic compounds (PF, a non-phenolic fraction (NPF, which contains glyceroglycolipids (GGL, and a pure glyceroglycolipid compound isolated from the non-phenolic fraction in human cancer.Dried green tea leaves were extracted and applied to a Sephadex LH-20 column. The resazurin reduction assay was used to investigate the cytotoxicity of green tea samples towards human HepG2 hepatocellular carcinoma and normal AML12 hepatocytes cells. Gene expression profiling was performed by mRNA microarray hybridization and the microarray results were validated by RT-PCR. The scratch migration assay was used to investigate the effects of green tea samples on cell migration in vitro. The changes of microtubule dynamics were observed using fluorescence microscopy.PF and NPF were prepared from methanol extract of green tea. A GGL was isolated from NPF. All three green tea samples did not show significant cytotoxic activity up to 10 µg/mL in both HepG2 and AML12 cells, whereas cytotoxicity of the control drug doxorubicin was observed with both cell lines (IC50 on AML12: 0.024 µg/mL, IC50 on HepG2: 2.103 µg/mL. We identified three sets of genes differentially expressed upon treatment with the green tea samples. The genes were associated with cytoskeleton formation, cellular movement and morphology. The correlation coefficients between mRNA expression values determined by microarray and RT-PCR were R = 0.94. HepG2 and U2OS cells treated with green tea extracts showed the delayed closures. Besides, the number of

  14. Green Tea Polyphenols in drug discovery - a success or failure?

    Science.gov (United States)

    Smith, Thomas J.

    2011-01-01

    Green tea is made from unfermented dried leaves from Camellia sinensis and has been consumed by humans for thousands of years. For nearly as long, it has been used as a folk remedy for a wide array of diseases. More recently, a large number of in-vitro and in-vivo scientific studies have supported this ancient contention that the polyphenols from green tea can provide a number of health benefits. Since these compounds are clearly safe for human consumption and ubiquitous in the food supply, they are highly attractive as lead compounds for drug discovery programs. However, as drugs, they are far from optimum. They are relatively unstable, poorly absorbed, and readily undergo a number of metabolic transformations by intestinal microbiota and human enzymes. Further, since these compounds target a wide array of biological systems, in-vivo testing is rather difficult since effects on alternative pathways need to be carefully eliminated. The purpose of this review is to discuss some of the challenges and benefits of pursuing this family of compounds for drug discovery. PMID:21731575

  15. Text mining factor analysis (TFA) in green tea patent data

    Science.gov (United States)

    Rahmawati, Sela; Suprijadi, Jadi; Zulhanif

    2017-03-01

    Factor analysis has become one of the most widely used multivariate statistical procedures in applied research endeavors across a multitude of domains. There are two main types of analyses based on factor analysis: Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA). Both EFA and CFA aim to observed relationships among a group of indicators with a latent variable, but they differ fundamentally, a priori and restrictions made to the factor model. This method will be applied to patent data technology sector green tea to determine the development technology of green tea in the world. Patent analysis is useful in identifying the future technological trends in a specific field of technology. Database patent are obtained from agency European Patent Organization (EPO). In this paper, CFA model will be applied to the nominal data, which obtain from the presence absence matrix. While doing processing, analysis CFA for nominal data analysis was based on Tetrachoric matrix. Meanwhile, EFA model will be applied on a title from sector technology dominant. Title will be pre-processing first using text mining analysis.

  16. Green tea catechins: inhibitors of glycerol-3-phosphate dehydrogenase.

    Science.gov (United States)

    Kao, Chung-Cheng; Wu, Bo-Tsung; Tsuei, Yi-Wei; Shih, Li-Jane; Kuo, Yu-Liang; Kao, Yung-Hsi

    2010-05-01

    Green tea catechins, especially (-)-epigallocatechin-3-gallate (EGCG), are known to regulate obesity and fat accumulation. We performed a kinetic analysis in a cell-free system to determine the mode of inhibition of glycerol-3-phosphate dehydrogenase (GPDH; EC 1.1.1.8) by EGCG. GPDH catalyzes the beta-nicotinamide adenine dinucleotide (NADH)-dependent reduction of dihydroxyacetone phosphate (DHAP) to yield glycerol-3-phosphate, which serves as one of the major precursors of triacylglycerols. We found that EGCG dose-dependently inhibited GPDH activity at a concentration of approximately 20 muM for 50 % inhibition. The IC (50) values of other green tea catechins, such as (-)-epicatechin, (-)-epicatechin-3-gallate, and (-)-epigallocatechin, were all above 100 microM. This suggests a catechin type-dependent effect. Based on double-reciprocal plots of the kinetic data, EGCG was a noncompetitive inhibitor of the GPDH substrates, NADH and DHAP, with respective inhibition constants (Ki) of 18 and 31 microM. Results of this study possibly support previous studies that EGCG mediates fat content. Georg Thieme Verlag KG Stuttgart. New York.

  17. Differential Contribution of Jasmine Floral Volatiles to the Aroma of Scented Green Tea

    Directory of Open Access Journals (Sweden)

    Jian-Xia Shen

    2017-01-01

    Full Text Available Tea volatiles’ generation and retention over manufacturing processes are crucial for tea quality. In this study, floral volatile adsorption and retention in green tea scented with Jasminum sambac flowers were examined over the scenting process. Out of 34 enhanced volatiles in the scented tea, β-ionone, β-linalool, indole, and methyl anthranilate were the most potent odorants with 5.1–45.2-fold higher odor activity values than the corresponding controls in the nonscented tea. Scenting efficiencies for the floral volatiles retained in the scented tea (the percentage of volatile abundance over its corresponding amount in jasmine flowers ranged from 0.22% for α-farnesene to 75.5% for β-myrcene. Moreover, due to additional rounds of heat treatment for scented green tea manufacturing, some volatiles such as carotenoid-derived geraniol and β-ionone and lipid-derived (Z-jasmone were heat-enhanced and others such as nonanal were heat-desorbed in the scented green tea. Our study revealed that dynamic volatile absorption and desorption collectively determined tea volatile retention and tea aroma. Our findings may have a great potential for practical improvement of tea aroma.

  18. Oxidative deamination of benzylamine and lysine residue in bovine serum albumin by green tea, black tea, and coffee.

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    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.

  19. Comparison of fluoride concentration in several types of green tea consumed in Iran

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    S. Maleki Kambakhsh

    2016-04-01

    Full Text Available Background: Tea is known as a source of fluoride that not only can prevent tooth decay but also can increase the risk of dental fluorosis in overuse or in combination with other sources of fluoride. Objective: The aim of this study was to compare the fluoride concentration in three brands of green tea consumed in Iran. Methods: This experimental study was conducted in Qazvin University of medical Science during 2012. Three brands of green tea (bag type and packed type were evaluated. Two bags of every bag type and two 1-gram samples of every packed type were selected. Each time, the samples were placed in 100 ml distilled boiling water and were restored in an incubator at 80 ºC. Three and ten minutes after tea brewing, the fluoride concentration of filtrated water was measured by chromatography and was recorded in milligram per liter. Data were analyzed using ANOVA and repeated measures ANOVA. Findings: The fluoride concentration in bag type green tea was more than packed type. The fluoride concentration was not different among three brands of green tea. The fluoride concentration after ten minutes brewing was not significantly different from the concentration after three minutes brewing. Conclusion: With regards to the results, it seems that green tea brand and the brewing time does not affect fluoride release. The fluoride release in bag type green tea is more than packed type.

  20. Effect of gamma radiation on antioxidant capacity of green tea, yerba mate, and chamomile tea as evaluated by different methods

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    Gerolis, Luanai Grazieli Luquini; Lameiras, Fernando Soares; Krambrock, Klaus; Neves, Maria Jose.

    2017-01-01

    Tea is a traditional plant extract with important cultural ties. It is the most widely consumed beverage in the world. Tea consumption has some health benefits including antioxidant stimulus. Gamma radiation is currently used to control of postharvest pathogens on tea herb. However, free radicals can be generated, which consumes antioxidant molecules. A positive relation was found between radiation doses used and free radicals generation in green tea (Camellia sinensis), yerba mate (Ilex paraguariensis), and chamomile tea (Matricaria recutita). Total antioxidant capacity (TAC) of aqueous and methanol extracts of these herbs was determined by various methods to compare the effect of irradiation of herb on antioxidant capacity of the extracts. TAC was evaluated by measuring: total phenols (decreased with irradiation in mate and green teas), total flavonoids (stable in aqueous extracts and decreased with irradiation in methanol extract of mate and chamomile), Trolox equivalent or ABTS (unchanged under irradiation), DPPH* scavenging capacity (stable on aqueous extract but diminished in methanol extract after irradiation), β carotene/acid linoleic ability (stable with the exception of chamomile tea that increased after irradiation) and, capacity to chelate ferrous ions (unchanged with irradiation). In conclusion, gamma irradiation reduced the capacity of some antioxidants but preserved the capacity of others. This study showed that one isolated test does not suffice to perform this evaluation reliably, which is a reflection of the diversity and complexity of the effects of irradiation on antioxidant molecules present in different samples.

  1. Mast cell stabilizing and anti-anaphylactic activity of aqueous extract of green tea (Camellia sinensis

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    G. Balaji

    2014-06-01

    Full Text Available Green tea (Camellia sinensis is one of the most popular and widely consumed beverages in the world. In the current study, aqueous extract of green tea (C. sinensis was evaluated for mast cell stabilizing and anti-anaphylactic activities. Green tea extract (11, 13, 15 mg/ml significantly (P < 0.05 inhibited compound 48/80-induced rat mesentric mast cell degranulation in a dose dependent manner. Anti-anaphylactic activity of green tea extract was performed in female mice. At a dose of 400, 500, 600 mg/kg BW, green tea extract showed significant reduction in the mortality of mice subjected to anaphylactic shock by compound C48/80. Ketotifen was used for comparison. In addition, IR and UV–Visible spectroscopy analysis of green tea extract revealed the presence of functional groups of bioactive compounds. These results suggest that green tea could be useful in the treatment of asthma and allergic rhinitis.

  2. Effectiveness of Green Tea in a Randomized Human Cohort: Relevance to Diabetes and Its Complications

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    Naushad Ali Toolsee

    2013-01-01

    Full Text Available Epidemiological studies have argued that green tea could mitigate diabetes and its complications. This study investigated the phytophenolic profile of Mauritian green tea and its antioxidant propensity. The effect of green tea on the risk factors: waist-hip ratio, glucose level, arterial pressure, antioxidant status, and alanine aminotransferase (ALT in prediabetics was assessed. The experimental group consumed 3 cups of green tea daily for 14 weeks followed by a 2-week washout period. The control group followed a water regimen. Green tea contained high level of phenolics related to its antioxidant power. Green tea suppressed waist-hip ratio of women from a significant increase and suppressed mean arterial pressure of men and women from a significant decrease after week 14. It reduced ALT level in women by 13.0% (P<0.1 while increasing the antioxidant potential of men and women sera by 2.7% (P<0.1 and 5.1% (P<0.1. The study timescale may have been too short to enable demonstration of effects on fasting plasma glucose and HbA1c outcomes. Green tea regimen could form part of a healthy lifestyle that might ameliorate features of metabolic syndrome and subsequent risks for diabetes and its complications. This trial is registered with ClinicalTrials.gov NCT01248143.

  3. Application of Fourier transform near-infrared spectroscopy to optimization of green tea steaming process conditions.

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    Ono, Daiki; Bamba, Takeshi; Oku, Yuichi; Yonetani, Tsutomu; Fukusaki, Eiichiro

    2011-09-01

    In this study, we constructed prediction models by metabolic fingerprinting of fresh green tea leaves using Fourier transform near-infrared (FT-NIR) spectroscopy and partial least squares (PLS) regression analysis to objectively optimize of the steaming process conditions in green tea manufacture. The steaming process is the most important step for manufacturing high quality green tea products. However, the parameter setting of the steamer is currently determined subjectively by the manufacturer. Therefore, a simple and robust system that can be used to objectively set the steaming process parameters is necessary. We focused on FT-NIR spectroscopy because of its simple operation, quick measurement, and low running costs. After removal of noise in the spectral data by principal component analysis (PCA), PLS regression analysis was performed using spectral information as independent variables, and the steaming parameters set by experienced manufacturers as dependent variables. The prediction models were successfully constructed with satisfactory accuracy. Moreover, the results of the demonstrated experiment suggested that the green tea steaming process parameters could be predicted on a larger manufacturing scale. This technique will contribute to improvement of the quality and productivity of green tea because it can objectively optimize the complicated green tea steaming process and will be suitable for practical use in green tea manufacture.

  4. Assessment of Fluoride Levels in Different Brands of Black and Green Tea Consumed in Iran

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    F. Mojarad

    2013-01-01

    Full Text Available Introduction & Objective: Tea is one of the most commonly consumed drinks in the world. Tea is recognized as a source of fluoride whose intake may increase the risk of developing dental fluorosis, particularly if other sources of fluoride augment the intake. Since the amount of fluoride in different types of tea consumed in our country is unknown, the purpose of this study was to evaluate the fluoride level of 22 commercial brands of tea popular in Iran. Materials & Methods: This descriptive study was conducted to assess the fluoride content of black tea (10 brands, bagged black tea (9 brands, and green tea (3 brands. 2 g from three samples of each tea brand taken out randomly were added to 200 ml deionized water and boiled for 10 minutes. After the infusion temperature coming down to the room temperature, the infusion was filtered and its volume made up to 200 ml by adding deionized water. The fluoride levels were measured using ion-selective electrode, and reported as mg/lit. Data were analyzed by ANOVA and Tukey test. Results: The Fluoride content was found 1.51 mg/lit in black tea bag, 1.038 mg/lit in green tea and 0.869±0.360 mg/lit in black tea sticks. (P<0.05, However, there was no statistically sig-nificant difference of fluoride concentration between green tea and black tea sticks(P= 0.52. Conclusion: This study showed that fluoride content of some tea brands were so high that drinking a few cups daily may increase the risk of developing dental fluorosis. Therefore, their consumption must be limited particularly in children, and in all inhabitants of regions with high fluoride levels in water supply.(Sci J Hamadan Univ Med Sci 2013; 19 (4:36-42

  5. A gene expression signature that can predict green tea exposure and chemopreventive efficacy of lung cancer in mice.

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    Lu, Yan; Yao, Ruisheng; Yan, Ying; Wang, Yian; Hara, Yukihiko; Lubet, Ronald A; You, Ming

    2006-02-15

    Green tea has been shown to be a potent chemopreventive agent against lung tumorigenesis in animal models. Previously, we found that treatment of A/J mice with either green tea (0.6% in water) or a defined green tea catechin extract (polyphenon E; 2.0 g/kg in diet) inhibited lung tumor tumorigenesis. Here, we described expression profiling of lung tissues derived from these studies to determine the gene expression signature that can predict the exposure and efficacy of green tea in mice. We first profiled global gene expressions in normal lungs versus lung tumors to determine genes which might be associated with the tumorigenic process (TUM genes). Gene expression in control tumors and green tea-treated tumors (either green tea or polyphenon E) were compared to determine those TUM genes whose expression levels in green tea-treated tumors returned to levels seen in normal lungs. We established a 17-gene expression profile specific for exposure to effective doses of either green tea or polyphenon E. This gene expression signature was altered both in normal lungs and lung adenomas when mice were exposed to green tea or polyphenon E. These experiments identified patterns of gene expressions that both offer clues for green tea's potential mechanisms of action and provide a molecular signature specific for green tea exposure.

  6. Absorption and pharmacokinetics of green tea catechins in beagles.

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    Mata-Bilbao, Maria de Lourdes; Andrés-Lacueva, Cristina; Roura, Elena; Jáuregui, Olga; Escribano, Elvira; Torre, Celina; Lamuela-Raventós, Rosa M

    2008-09-01

    The present study evaluates for the first time in dogs, the kinetics of green tea catechins and their metabolic forms in plasma and urine. Ten beagles were administered 173 mg (12.35 mg/kg body weight) of catechins as a green tea extract, in capsules. Blood samples were collected during 24 h after intake and urine samples were collected during the following periods of time: 0-2, 2-6, 6-8 and 8-24 h. Two catechins with a galloyl moiety and three conjugated metabolites were detected in plasma. Most of the detected forms in plasma reached their maximum plasma concentration (Cmax) at around 1 h. Median Cmax for ( - )-epigallocatechin-3-gallate (EGCG), ( - )-epicatechin-3-gallate (ECG), ( - )-epigallocatechin glucuronide (EGC-glucuronide), ( - )-epicatechin glucuronide (EC-glucuronide), ( - )-epicatechin sulphate (EC-sulphate) were 0.3 (range 0.1-1.9), 0.1 (range 0-0.4), 0.8 (range 0.2-3.9), 0.2 (range 0.1-1.7) and 1 (range 0.3-3.4) micromol/l, respectively. The areas under the plasma concentration v. time curves (AUC0 --> 24) were 427 (range 102-1185) micromol/l x min for EGC-glucuronide, 112 (range 53-919) micromol/l x min for EC-sulphate, 71 (range 26-306) micromol/l x min for EGCG, 40 (range 12-258) micromol/l x min for EC-glucuronide and 14 (range 0.1-124) micromol/l x min for ECG. The values of mean residence time (MRT0 --> 24) were 5 (range 2-16), 2 (range 1-11), 10 (range 2-13), 3 (range 2-16) and 2.4 (range 1-18) h for EGCG, ECG, EGC-glucuronide, EC-glucuronide and EC-sulphate, respectively. In urine, catechins were present as conjugated forms, suggesting bile excretion of EGCG and ECG. Green tea catechins are absorbed following an oral administration and EGC-glucuronide is the metabolic form that remains in the organism for a longer period of time, suggesting that this compound could suffer an enterohepatic cycle.

  7. Polyphenol Bioaccessibility and Sugar Reducing Capacity of Black, Green, and White Teas

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    Shelly Coe

    2013-01-01

    Full Text Available 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 ( 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.

  8. Optimum conditions for the water extraction of L-theanine from green tea.

    Science.gov (United States)

    Vuong, Quan V; Stathopoulos, Costas E; Golding, John B; Nguyen, Minh H; Roach, Paul D

    2011-09-01

    Theanine is a unique non-protein amino acid found in tea (Camellia sinensis). It contributes to the favourable umami taste of tea and is linked to various beneficial effects in humans. There is an increasing interest in theanine as an important component of tea, as an ingredient for novel functional foods and as a dietary supplement. Therefore, optimal conditions for extracting theanine from tea are required for the accurate quantification of theanine in tea and as an efficient first step for its purification. This study examined the effects of four different extraction conditions on the yield of theanine from green tea using water and applied response surface methodology to further optimise the extraction conditions. The results showed that temperature, extraction time, ratio of water-to-tea and tea particle sizes had significant impacts on the extraction yield of theanine. The optimal conditions for extracting theanine from green tea using water were found to be extraction at 80 °C for 30 min with a water-to-tea ratio of 20:1 mL/g and a tea particle size of 0.5-1 mm. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. A new function of green tea: prevention of lifestyle-related diseases.

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    Sueoka, N; Suganuma, M; Sueoka, E; Okabe, S; Matsuyama, S; Imai, K; Nakachi, K; Fujiki, H

    2001-04-01

    In the normal human life span, there occur lifestyle-related diseases that may be preventable with nontoxic agents. This paper deals with the preventive activity of green tea in some lifestyle-related diseases. Green tea is one of the most practical cancer preventives, as we have shown in various in vitro and in vivo experiments, along with epidemiological studies. Among various biological effects of green tea, we have focused on its inhibitory effect on TNF-alpha gene expression mediated through inhibition of NF-kappaB and AP-1 activation. Based on our recent results with TNF-alpha-deficient mice, TNF-alpha is an endogenous tumor promoter. TNF-alpha is also known to be a central mediator in chronic inflammatory diseases such as rheumatoid arthritis and multiple sclerosis. We therefore hypothesized that green tea might be a preventive agent for chronic inflammatory diseases. To test this hypothesis, TNF-alpha transgenic mice, which overexpress TNF-alpha only in the lungs, were examined. The TNF-alpha transgenic mouse is an animal model of human idiopathic pulmonary fibrosis which also frequently develops lung cancer. Expressions of TNF-alpha and IL-6 were inhibited in the lungs of these mice after treatment with green tea in drinking water for 4 months. In addition, judging from the results of a prospective cohort study in Saitama Prefecture, Japan, green tea helps to prevent cardiovascular disease. In this study, a decreased relative risk of death from cardiovascular disease was found for people consuming over 10 cups of green tea a day, and green tea also had life-prolonging effects on cumulative survival. These data suggest that green tea has preventive effects on both chronic inflammatory diseases and lifestyle-related diseases (including cardiovascular disease and cancer), resulting in prolongation of life span.

  10. Data on green tea flavor determinantes as affected by cultivars and manufacturing processes

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    Zhuo-Xiao Han

    2017-02-01

    Full Text Available This paper presents data related to an article entitled “Green tea flavor determinants and their changes over manufacturing processes” (Han et al., 2016 [1]. Green tea samples were prepared with steaming and pan firing treatments from the tender leaves of tea cultivars ‘Bai-Sang Cha’ (‘BAS’ and ‘Fuding-Dabai Cha’ (‘FUD’. Aroma compounds from the tea infusions were detected and quantified using HS-SPME coupled with GC/MS. Sensory evaluation was also made for characteristic tea flavor. The data shows the abundances of the detected aroma compounds, their threshold values and odor characteristics in the two differently processed tea samples as well as two different cultivars.

  11. The green tea catechin, epigallocatechin gallate inhibits chikungunya virus infection.

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    Weber, Christopher; Sliva, Katja; von Rhein, Christine; Kümmerer, Beate M; Schnierle, Barbara S

    2015-01-01

    Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes chikungunya fever and has infected millions of people mainly in developing countries. The associated disease is characterized by rash, high fever and severe arthritis that can persist for years. CHIKV has adapted to Aedes albopictus, which also inhabits temperate regions, including Europe and the United States of America and might cause new, large outbreaks there. No treatment or licensed CHIKV vaccine exists. Epigallocatechin-3-gallate (EGCG), the major component of green tea, has, among other beneficial properties, antiviral activities. Therefore, we examined if EGCG has antiviral activity against CHIKV. EGCG inhibited CHIKV infection in vitro, blocked entry of CHIKV Env-pseudotyped lentiviral vectors and inhibited CHIKV attachment to target cells. Thus EGCG might be used as a lead structure to develop more effective antiviral drugs.

  12. Epigenetic effects of green tea polyphenols in cancer.

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    Henning, Susanne M; Wang, Piwen; Carpenter, Catherine L; Heber, David

    2013-12-01

    Epigenetics describes heritable alterations of gene expression and chromatin organization without changes in DNA sequence. Both hypermethylation and hypomethylation of DNA can affect gene expression and the multistep process of carcinogenesis. Epigenetic changes are reversible and may be targeted by dietary interventions. Bioactive compounds from green tea (GT) such as (-)-epigallocatechin gallate have been shown to alter DNA methyltransferase activity in studies of esophageal, oral, skin, Tregs, lung, breast and prostate cancer cells, which may contribute to the chemopreventive effect of GT. Three out of four mouse model studies have confirmed the inhibitory effect of (-)-epigallocatechin gallate on DNA methylation. A human study demonstrated that decreased methylation of CDX2 and BMP-2 in gastric carcinoma was associated with higher GT consumption. It is the goal of this review to summarize our current knowledge of the potential of GT to alter epigenetic processes, which may be useful in chemoprevention.

  13. Removal of caffeine from green tea by microwave-enhanced vacuum ice water extraction.

    Science.gov (United States)

    Lou, Zaixiang; Er, Chaojuan; Li, Jing; Wang, Hongxin; Zhu, Song; Sun, Juntao

    2012-02-24

    In order to selectively remove caffeine from green tea, a microwave-enhanced vacuum ice water extraction (MVIE) method was proposed. The effects of MVIE variables including extraction time, microwave power, and solvent to solid radio on the removal yield of caffeine and the loss of total phenolics (TP) from green tea were investigated. The optimized conditions were as follows: solvent (mL) to solid (g) ratio was 10:1, microwave extraction time was 6 min, microwave power was 350 W and 2.5 h of vacuum ice water extraction. The removal yield of caffeine by MVIE was 87.6%, which was significantly higher than that by hot water extraction, indicating a significant improvement of removal efficiency. Moreover, the loss of TP of green tea in the proposed method was much lower than that in the hot water extraction. After decaffeination by MVIE, the removal yield of TP tea was 36.2%, and the content of TP in green tea was still higher than 170 mg g(-1). Therefore, the proposed microwave-enhanced vacuum ice water extraction was selective, more efficient for the removal of caffeine. The main phenolic compounds of green tea were also determined, and the results indicated that the contents of several catechins were almost not changed in MVIE. This study suggests that MVIE is a new and good alternative for the removal of caffeine from green tea, with a great potential for industrial application. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Interaction of green tea polyphenols with dairy matrices in a simulated gastrointestinal environment.

    Science.gov (United States)

    Lamothe, Sophie; Azimy, Naheed; Bazinet, Laurent; Couillard, Charles; Britten, Michel

    2014-10-01

    The consumption of polyphenols in green tea has been associated with beneficial health effects. Although polyphenols are unstable in the intestinal environment, they may be protected by interactions with dairy proteins during digestion. The objectives of this study were to evaluate the effect of a green tea extract on the digestibility of different dairy matrices and to monitor the antioxidant activity of these matrices with or without the green tea extract during digestion in a simulated gastrointestinal environment. Milk, yogurt and cheese with similar fat-to-protein ratios were subjected to simulated digestion. Matrix degradation, protein and fat hydrolysis, polyphenol concentration and radical scavenging activity were analyzed during gastric and intestinal digestion phases. Cheese was the matrix most resistant to protein and fat digestion. The addition of the green tea extract significantly decreased proteolysis in the gastric phase but had no effect in the intestinal phase. The kinetics of fatty acid release was reduced by the presence of the green tea extract. Transition from the gastric phase to the intestinal phase induced a 50% decrease in the antioxidant activity of the control (tea extract dispersed in water) due to the degradation of polyphenols. The presence of dairy matrices significantly improved polyphenol stability in the intestinal phase and increased the antioxidant activity by 29% (cheese) to 42% (milk) compared to the control. These results suggest that simultaneous consumption of green tea and dairy products helps to maintain the integrity and antioxidant activity of polyphenols during digestion.

  15. Texture discrimination of green tea categories based on least squares support vector machine (LSSVM) classifier

    Science.gov (United States)

    Li, Xiaoli; He, Yong; Qiu, Zhengjun; Wu, Di

    2008-03-01

    This research aimed for development multi-spectral imaging technique for green tea categories discrimination based on texture analysis. Three key wavelengths of 550, 650 and 800 nm were implemented in a common-aperture multi-spectral charged coupled device camera, and images were acquired for 190 unique images in a four different kinds of green tea data set. An image data set consisting of 15 texture features for each image was generated based on texture analysis techniques including grey level co-occurrence method (GLCM) and texture filtering. For optimization the texture features, 5 features that weren't correlated with the category of tea were eliminated. Unsupervised cluster analysis was conducted using the optimized texture features based on principal component analysis. The cluster analysis showed that the four kinds of green tea could be separated in the first two principal components space, however there was overlapping phenomenon among the different kinds of green tea. To enhance the performance of discrimination, least squares support vector machine (LSSVM) classifier was developed based on the optimized texture features. The excellent discrimination performance for sample in prediction set was obtained with 100%, 100%, 75% and 100% for four kinds of green tea respectively. It can be concluded that texture discrimination of green tea categories based on multi-spectral image technology is feasible.

  16. Anti-melanogenic effects of black, green, and white tea extracts on immortalized melanocytes.

    Science.gov (United States)

    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. The effects of bathing in hot springs on the absorption of green tea catechin: a pilot study.

    Science.gov (United States)

    Hayasaka, Shinya; Goto, Yasuaki; Maeda-Yamamoto, Mari

    2013-11-01

    Japan is a major tea producing country, and green tea is known for its health benefits which are believed to be due to catechins. However, difficulties in maintaining an adequate amount of catechins in the blood have been reported. Another important health-promoting activity among the Japanese is bathing in hot springs. This pilot study examined whether the combined effects of green tea consumption and hot spring bathing improved absorption of green tea catechins. The study, with a comparative within-subject design involving two different intervention trials--green tea consumption with hot spring bathing and only green tea consumption--was conducted on 2 separate days. Plasma levels of catechin; (-)-epigallocatechin-3-O-gallate (EGCG) were analyzed from four volunteers. Plasma EGCG concentration was found to be higher for the combined trial of green tea consumption and hot spring bathing.

  18. Green and black tea consumption and risk of stroke: a meta-analysis.

    Science.gov (United States)

    Arab, Lenore; Liu, Weiqing; Elashoff, David

    2009-05-01

    Experimental models of stroke provide consistent evidence of smaller stroke volumes in animals ingesting tea components or tea extracts. To assess whether a similar association of black or green tea consumption with reduced risk is evident in human populations, we sought to identify and summarize all human clinical and observational data on tea and stroke. We searched PubMed and Web of Science for all studies on stroke and tea consumption in humans with original data, including estimation or measurement of tea consumption and outcomes of fatal or nonfatal stroke. Data from 9 studies involving 4378 strokes among 194 965 individuals were pooled. The main outcome was the occurrence of fatal or nonfatal stroke. We tested for heterogeneity and calculated the summary effect estimate associated with consumption of >or=3 cups of tea (green or black) per day using random-effects and fixed-effects models for the homogeneous studies. Publication bias was also evaluated. Regardless of their country of origin, individuals consuming >or=3 cups of tea per day had a 21% lower risk of stroke than those consuming risk reduction, 0.79; CI, 0.73 to 0.85). The proportion of heterogeneity not explained by chance alone was 23.8%. Although a randomized clinical trial would be necessary to confirm the effect, this meta-analysis suggests that daily consumption of either green or black tea equaling 3 cups per day could prevent the onset of ischemic stroke.

  19. Temperature and Time of Steeping Affect the Antioxidant Properties of White, Green, and Black Tea Infusions.

    Science.gov (United States)

    Hajiaghaalipour, Fatemeh; Sanusi, Junedah; Kanthimathi, M S

    2016-01-01

    Tea (Camellia sinensis) is the most highly consumed beverage in the world next to water. The common way of preparation is steeping in hot water which is varying for different type of tea. We investigated the antioxidant properties of 6 type of tea leaves under different time and temperatures of extraction method used. In general, all samples tested in this study demonstrated high levels of antioxidant capacity and antioxidant activity. The results indicate that the antioxidants activity is significantly affected by time and temperature of steeping and the highest was depending on the variety. White state values, green and black teas showed different levels of antioxidants under different extraction conditions. Overall, the highest activity for white tea was in prolonged hot and in some assays prolonged hot and cold extracts, whereas for green tea the highest activity observed in prolonged cold steeping while, for black tea was in short hot water infusion. The results of this study showed the antioxidant capacity of white and green tea was greater than black tea.

  20. Green tea for the prevention of cancer: evidence of field epidemiology

    Directory of Open Access Journals (Sweden)

    Min Zhang

    2012-10-01

    Full Text Available Background: Tea is derived from the leaf of Camellia sinensis, a natural beverage widely consumed around the world. Geological and botanical evidence suggests that the tea plant originated from China. Varying methods of processing tea leaves lead to green tea, black tea, or Oolong tea, which differ in their concentrations of polyphenols. Green tea polyphenols appear to have anti-tumorigenic properties, and form 30-40% of the dry weight of green tea compared with only 3-10% of black tea. Numerous studies in multiple animal models and different cancer cell lines have demonstrated the anti-tumorigenesis by green tea polyphenols. Despite the consistency of laboratory results, evidence of this effect occuring in humans has been inconclusive to date.Objective: To investigate if green tea consumption was associated with longer survival rates in ovarian cancer patients, and a lower risk of ovarian, breast, and colorectal cancer, in addition toadult leukemiaMethods: We have conducted one prospective cohort study in ovarian cancer patients, and fivecase-control studies in ovarian, breast, and colorectal cancers, and leukemia over the past decade. Tea consumption was measured using a structured questionnaire by face-to-face interviews. The validity and reliability of the questionnaire was assessed in a preliminary study, and then evaluated by a test–retest. Cox proportional hazards regression models were used to obtain hazard ratios(HRs, 95% confidence intervals(95% CIs, and were adjusted for age at diagnosis, locality, body mass index(BMI, parity, International Federation of Gynecology and Obstetrics(IFGO stage, histologic grade of differentiation, cytology of ascites, residual tumour, and chemotherapeutic status. Odds ratios(ORs and 95% CIs were obtained using logistic regression analyses, which accounted for demographic, lifestyle, hormonal and family cancer factors, and potential confounders.Functional Foods in Health and Disease 2012, 2

  1. Effect of different doses of un-fractionated green and black tea extracts on thyroid physiology.

    Science.gov (United States)

    Chandra, Amar K; De, Neela; Choudhury, Shyamosree Roy

    2011-08-01

    Tea is a rich source of polyphenolic flavonoids including catechins, which are thought to contribute to the health benefits of it. Flavonoids have been reported to have antithyroid and goitrogenic effect. The purpose of this study was to evaluate whether high doses of green and black tea have a harmful effect on thyroid physiology. Un-fractionated green and black tea extracts were administered orally to male rats for 30 days at doses of 1.25 g%, 2.5 g% and 5.0 g%. The results showed that green tea extract at 2.5 g% and 5.0 g% doses and black tea extract only at 5.0 g% dose have the potential to alter the thyroid gland physiology and architecture, that is, enlargement of thyroid gland as well as hypertrophy and/or hyperplasia of the thyroid follicles and inhibition of the activity of thyroid peroxidase and 5(')-deiodinase I with elevated thyroidal Na+, K+-ATPase activity along with significant decrease in serum T3 and T4, and a parallel increase in serum thyroid stimulating hormone (TSH). This study concludes that goitrogenic/antithyroidal potential of un-fractionated green tea extract is much more than black tea extract because of the differences in catechin contents in the tea extracts.

  2. Inhibition of urinary bladder tumors induced by N-butyl-N-(4-hydroxybutyl)-nitrosamine in rats by green tea.

    Science.gov (United States)

    Sato, D

    1999-02-01

    Recently, the anticarcinogenic effects of green tea have been studied in sites other than the urinary tract. The present study examined the inhibition by green tea of vesical tumors induced in rats by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN). In the first series of experiments, 0.05% BBN was added to the drinking water of rats and remained present for 5 weeks. In one experiment, six groups of animals received either tap water, green tea, matcha, hojicha, oolong tea or black tea from week 6. In a second experiment, three groups of rats received either tap water, green tea extract or powdered green tea mixed into a pellet diet from week 6. In a third experiment, five groups of rats were fed a pellet diet with addition of either 0, 0.15, 1.5 or 3.0% powdered green tea from week 6. All rats were killed and examined at 40 weeks. Green tea, particularly green tea leaves, dose-dependently inhibited the growth of BBN-induced urinary bladder tumors when given after the carcinogen. Green tea may inhibit bladder tumor growth.

  3. The use of green tea (Camellia sinensis) as a phytogenic substance in poultry diets.

    Science.gov (United States)

    Khan, Sohail H

    2014-01-01

    This review examined the use of green tea (Camellia sinensis) in the diets of poultry. Research findings were obtained from various recent studies, where much attention was focused on the role of green tea in the promotion of both animal and human health. The review involved some of the currently available information about green tea, pertaining to its chemical composition, anticoccidial and antimicrobial effect, effect on broiler and layer performance and on blood and egg yolk constituents. To the author's knowledge this is the first review paper on this topic. It will be helpful for poultry nutritionists and the poultry industry, although more detailed studies are still needed to elucidate the effects of green tea in poultry nutrition under various circumstances.

  4. Effects of green tea catechins on gramicidin channel function and inferred changes in bilayer properties

    NARCIS (Netherlands)

    Ingólfsson, Helgi I; Koeppe, Roger E; Andersen, Olaf S

    2011-01-01

    Green tea's health benefits have been attributed to its major polyphenols, the catechins: (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC), and epicatechin (EC). Catechins (especially EGCG) modulate a wide range of biologically important molecules, inclu

  5. Purification process influence on green tea extracts’ polyphenol content and antioxidant activity

    National Research Council Canada - National Science Library

    Anna Gramza-Michałowska; Józef Korczak; Marzanna Hęś

    2007-01-01

    The research examined green tea ethanol extract, subjected to different purification processes with use of active carbon, bleaching earth, and mixture of acetone, acetic acid, water, with or without...

  6. The use of green tea (Camellia sinensis as a phytogenic substance in poultry diets

    Directory of Open Access Journals (Sweden)

    Sohail H. Khan

    2014-02-01

    Full Text Available This review examined the use of green tea (Camellia sinensis in the diets of poultry. Research findings were obtained from various recent studies, where much attention was focused on the role of green tea in the promotion of both animal and human health. The review involved some of the currently available information about green tea, pertaining to its chemical composition, anticoccidial and antimicrobial effect, effect on broiler and layer performance and on blood and egg yolk constituents. To the author’s knowledge this is the first review paper on this topic. It will be helpful for poultry nutritionists and the poultry industry, although more detailed studies are still needed to elucidate the effects of green tea in poultry nutrition under various circumstances.

  7. Green and black tea consumption and risk of stroke: a meta-analysis

    National Research Council Canada - National Science Library

    Arab, Lenore; Liu, Weiqing; Elashoff, David

    2009-01-01

    .... To assess whether a similar association of black or green tea consumption with reduced risk is evident in human populations, we sought to identify and summarize all human clinical and observational...

  8. Factors affecting the caffeine and polyphenol contents of black and green tea infusions.

    Science.gov (United States)

    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.

  9. Green Tea Polyphenols Attenuated Glutamate Excitotoxicity via Antioxidative and Antiapoptotic Pathway in the Primary Cultured Cortical Neurons.

    Science.gov (United States)

    Cong, Lin; Cao, Chang; Cheng, Yong; Qin, Xiao-Yan

    2016-01-01

    Green tea polyphenols are a natural product which has antioxidative and antiapoptotic effects. It has been shown that glutamate excitotoxicity induced oxidative stress is linked to neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. In this study we explored the neuroprotective effect of green teen polyphenols against glutamate excitotoxicity in the primary cultured cortical neurons. We found that green tea polyphenols protected against glutamate induced neurotoxicity in the cortical neurons as measured by MTT and TUNEL assays. Green tea polyphenols were then showed to inhibit the glutamate induced ROS release and SOD activity reduction in the neurons. Furthermore, our results demonstrated that green tea polyphenols restored the dysfunction of mitochondrial pro- or antiapoptotic proteins Bax, Bcl-2, and caspase-3 caused by glutamate. Interestingly, the neuroprotective effect of green tea polyphenols was abrogated when the neurons were incubated with siBcl-2. Taken together, these results demonstrated that green tea polyphenols protected against glutamate excitotoxicity through antioxidative and antiapoptotic pathways.

  10. Design and in vivo evaluation of emulgel formulations including green tea extract and rose oil

    OpenAIRE

    YAPAR, EVREN ALGIN; İNAL, ÖZGE; Erdal, M. Sedef

    2013-01-01

    Prevention of skin aging and its treatment is an emerging field for development of new formulations in cosmetics. Accordingly, plant extracts with antioxidant properties are beneficial cosmetic ingredients for this purpose. This study was aimed at developing a stable and easily manufactured emulgel including green tea extract and rose oil that is effective on the barrier function and hydration of skin. An emulgel formulation containing 20 % green tea extract and 5 % rose oil was designed as a...

  11. Excessive Consumption of Green Tea as a Risk Factor for Periodontal Disease among Korean Adults

    OpenAIRE

    Kyungdo Han; Eunkyung Hwang; Jun-Beom Park

    2016-01-01

    This study was performed to assess the relationship between the amount of green tea that is consumed and periodontitis. It is based on data obtained from the Korea National Health and Nutrition Examination Survey, conducted between 2008 and 2010. A community periodontal index equal to code 3 was defined as moderate periodontitis, and code 4 was defined as severe periodontitis (n = 16,726). Consumption of green tea less than one cup per day was associated with a decreased prevalence of periodo...

  12. Can green tea protect against not only sunburn but also melanoma?

    Institute of Scientific and Technical Information of China (English)

    Tsung O.Cheng

    2006-01-01

    @@ To the Editor: I read with great interest the recent article by Song et al1 who showed that green tea may play a protective role from ultraviolet B (UVB)-induced skin damage and thus may be a therapeutically effective agent against sunburn.Since excessive exposure to the sun and frequent sunburns predispose to melanoma, one wonders if green tea can also protect against melanoma.

  13. Redox chemistry of green tea polyphenols: therapeutic benefits in neurodegenerative diseases.

    Science.gov (United States)

    Hügel, H M; Jackson, N

    2012-05-01

    Evidence for the medicinal and health benefits of polyphenols in green tea for the prevention of chronic diseases such as heart disease, various types of cancer and neurodegenerative diseases is advancing. Their in vivo effectiveness and molecular mechanisms are difficult to elucidate and remain a challenging task. We review the redox responsiveness and amyloid protein perturbation biophysical properties of the major green tea polyphenol constituent (-)- epigallocatechin-3-gallate [EGCG].

  14. Phenolic compounds of green tea: Health benefits and technological application in food

    Institute of Scientific and Technical Information of China (English)

    José Manuel Lorenzo; Paulo Eduardo Sichetti Munekata

    2016-01-01

    Green tea has been an important beverage for humans since ancient times, widely consumed and considered to have health benefits by traditional medicine in Asian countries. Green tea phenolic compounds are predominately composed of catechin derivatives, although other compounds such as flavonols and phenolic acids are also present in lower proportion. The bioactivity exerted by these compounds has been associated with reduced risk of severe illnesses such as cancer, cardiovascular and neurodegenerative diseases. Particularly, epigallocatechin gallate has been implicated in alteration mechanisms with protective effect in these diseases as indicated by several studies about the effect of green tea consumption and mechanistic explanation through in vitro and in vivo experiments. The biological activity of green tea phenolic compounds also promotes a protective effect by antioxidant mechanisms in biological and food systems, preventing the oxidative damage by acting over either precursors or reactive species. Extraction of phenolic compounds influences the antioxidant activity and promotes adequate separation from green tea leaves to enhance the yield and/or antioxidant activity. Application of green tea phenolic compounds is of great interest because the antioxidant status of the products is enhanced and provides the product with additional antioxidant activity or reduces the undesirable changes of oxidative reactions while processing or storing food.In this scenario, meat and meat products are greatly influenced by oxidative deterioration and microbial spoilage, leading to reduced shelf life. Green tea extracts rich in phenolic compounds have been applied to increase shelf life with comparable effect to synthetic compounds, commonly used by food industry. Green tea has great importance in general health in technological application, however more studies are necessary to elucidate the impact in pathways related to other diseases and food applications.

  15. Apoptosis-inducing activity of a driselase digest fraction of green tea residue.

    Science.gov (United States)

    Katsuno, Y; Koyama, Y; Saeki, K; Sazuka, M; Ookawa, K; Isemura, M

    2001-01-01

    We enzymatically digested green tea residue with Driselase, a crude preparation containing cellulase, pectinase and proteases, in order to examine the potential usefulness of the residue. A fraction of the digest soluble in 70% ethanol was found to induce the death of U937 human histiocytic lymphoma cells by apoptosis. Other enzyme preparations gave similar products with cell death-inducing activity of varing potency. The green tea residue may therefore be a useful source of potential agents with anti-cancer activity.

  16. Green tea consumption, genetic susceptibility, PAH-rich smoky coal, and the risk of lung cancer.

    Science.gov (United States)

    Bonner, Matthew R; Rothman, Nathaniel; Mumford, Judy L; He, Xingzhou; Shen, Min; Welch, Robert; Yeager, Meredith; Chanock, Stephen; Caporaso, Neil; Lan, Qing

    2005-04-04

    Experimental evidence suggests that green tea (Camellia sinesis) may reduce the risk of lung cancer through several hypothesized mechanisms including scavenging oxidative radicals, inhibition of tumor initiation, and modulation of detoxification enzymes. However, epidemiologic results have not been consistent as to the relationship between green tea consumption and lung caner prevention. We employed a population-based case-control study of 122 cases and 122 controls to investigate the effect that green tea consumption may have on the risk of lung cancer and whether polymorphisms in 8-oxoguanine-DNA glycosylase (OGG1), glutathione-S-transferase M1 (GSTM1), and aldo-keto reductase 1C3 (AKR1C3) modify such an association. Daily green tea consumption was associated with a non-significant reduction in lung cancer risk. However, the effect of smoky coal exposure was higher for non-drinkers (odds ratio (OR)=4.93; 95% confidence interval (95% CI)=1.27-19.13) than for drinkers (OR=1.88; 95% CI=1.01-3.48). Further, among individuals with the OGG1 Cys(326) allele, daily consumption was associated with a 72% reduction (95% CI=0.09-0.94). Among GSTM1 null homozygotes, those who consumed green tea daily had a non-significant reduction in risk compared with non-consumers. Green tea consumption had no effect among OGG1 Ser(326) homozygotes or GSTM1 carriers. In addition, AKR1C3 genotype did not modulate the effect of green tea consumption. The chemopreventive effects of green tea in this population may be restricted to individuals who are particularly susceptible to oxidative stress and oxidative DNA damage.

  17. Phenolic compounds of green tea: Health benefits and technological application in food

    Directory of Open Access Journals (Sweden)

    José Manuel Lorenzo

    2016-08-01

    Full Text Available Green tea has been an important beverage for humans since ancient times, widely consumed and considered to have health benefits by traditional medicine in Asian countries. Green tea phenolic compounds are predominately composed of catechin derivatives, although other compounds such as flavonols and phenolic acids are also present in lower proportion. The bioactivity exerted by these compounds has been associated with reduced risk of severe illnesses such as cancer, cardiovascular and neurodegenerative diseases. Particularly, epigallocatechin gallate has been implicated in alteration mechanisms with protective effect in these diseases as indicated by several studies about the effect of green tea consumption and mechanistic explanation through in vitro and in vivo experiments. The biological activity of green tea phenolic compounds also promotes a protective effect by antioxidant mechanisms in biological and food systems, preventing the oxidative damage by acting over either precursors or reactive species. Extraction of phenolic compounds influences the antioxidant activity and promotes adequate separation from green tea leaves to enhance the yield and/or antioxidant activity. Application of green tea phenolic compounds is of great interest because the antioxidant status of the products is enhanced and provides the product with additional antioxidant activity or reduces the undesirable changes of oxidative reactions while processing or storing food. In this scenario, meat and meat products are greatly influenced by oxidative deterioration and microbial spoilage, leading to reduced shelf life. Green tea extracts rich in phenolic compounds have been applied to increase shelf life with comparable effect to synthetic compounds, commonly used by food industry. Green tea has great importance in general health in technological application, however more studies are necessary to elucidate the impact in pathways related to other diseases and food

  18. Green tea infusion improves cyclophosphamide-induced damage on male mice reproductive system

    Directory of Open Access Journals (Sweden)

    Mariane Magalhães Zanchi

    2015-01-01

    Full Text Available Green tea presents catechins as its major components and it has a potential antioxidant activity. Cyclophosmamide (CP is an antineoplastic and immunosuppressive agent, known to reduce fertility. In the present study, we evaluated the effect of green tea infusion on cyclophosphamide-induced damage in male mice reproductive system. Mice received green tea infusion (250 mg/kg or vehicle by gavage for 14 days. Saline or CP were injected intraperitoneally at a single dose (100 mg/kg at the 14th day. Animals were euthanized 24 h after CP administration and testes and epididymis were removed for biochemical analysis and sperm evaluation. Catechins concentration in green tea infusion was evaluated by HPLC. CP increased lipid peroxidation, DNA damage and superoxide dismutase activity whereas sperm concentration, glutathione peroxidase (GPx, glutathione S-transferase (GST and 17β-hydroxysteroid (17β-HSD dehydrogenase activities were reduced in both tissues tested. Catalase activity and protein carbonyl levels were changed only in testes, after CP administration. Green tea pre-treatment reduced significantly lipid peroxidation, protein carbonylation, DNA damage and restored GPx and GST activity in testes. In epididymis, therapy significantly increased sperm concentration and restored GPx and 17β-HSD activity. Green tea improves CP-induced damage on reproductive system, probably due to their high catechins content.

  19. Systematic Analysis of the Multiple Bioactivities of Green Tea through a Network Pharmacology Approach

    Directory of Open Access Journals (Sweden)

    Shoude Zhang

    2014-01-01

    Full Text Available During the past decades, a number of studies have demonstrated multiple beneficial health effects of green tea. Polyphenolics are the most biologically active components of green tea. Many targets can be targeted or affected by polyphenolics. In this study, we excavated all of the targets of green tea polyphenolics (GTPs though literature mining and target calculation and analyzed the multiple pharmacology actions of green tea comprehensively through a network pharmacology approach. In the end, a total of 200 Homo sapiens targets were identified for fifteen GTPs. These targets were classified into six groups according to their related disease, which included cancer, diabetes, neurodegenerative disease, cardiovascular disease, muscular disease, and inflammation. Moreover, these targets mapped into 143 KEGG pathways, 26 of which were more enriched, as determined though pathway enrichment analysis and target-pathway network analysis. Among the identified pathways, 20 pathways were selected for analyzing the mechanisms of green tea in these diseases. Overall, this study systematically illustrated the mechanisms of the pleiotropic activity of green tea by analyzing the corresponding “drug-target-pathway-disease” interaction network.

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

    Science.gov (United States)

    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.

  1. [The fate of dioxins during green tea manufacture].

    Science.gov (United States)

    Uegaki, R; Eun, H; Kuwahara, M; Ishii, Y; Kobara, Y; Ueji, M; Nakamura, K; Narita, I

    2001-04-01

    Dioxin concentrations and homologue profiles were examined in plucked new shoots, crude tea and its hot water extracts, soils and atmosphere in tea orchards. The rate of dry provisions in crude tea has increased 4 times as that of the plucked new shoots. However, dioxin concentrations except O8CDD in crude tea have increased only 2 to 3 times as those of the plucked new shoots. O8CDD concentration increased remarkably during processing. Little dioxins were detected in hot water extracts of crude tea leaves.

  2. Optical Determination of Lead Chrome Green in Green Tea by Fourier Transform Infrared (FT-IR) Transmission Spectroscopy

    Science.gov (United States)

    Li, Xiaoli; Xu, Kaiwen; Zhang, Yuying; Sun, Chanjun; He, Yong

    2017-01-01

    The potential of Fourier transform infrared (FT-IR) transmission spectroscopy for determination of lead chrome green in green tea was investigated based on chemometric methods. Firstly, the qualitative analysis of lead chrome green in tea was performed based on partial least squares discriminant analysis (PLS-DA), and the correct rate of classification was 100%. And then, a hybrid method of interval partial least squares (iPLS) regression and successive projections algorithm (SPA) was proposed to select characteristic wavenumbers for the quantitative analysis of lead chrome green in green tea, and 19 wavenumbers were obtained finally. Among these wavenumbers, 1384 (C = C), 1456, 1438, 1419(C = N), and 1506 (CNH) cm-1 were the characteristic wavenumbers of lead chrome green. Then, these 19 wavenumbers were used to build determination models. The best model was achieved by least squares support vector machine (LS-SVM)algorithm with high coefficient of determination and low root-mean square error of prediction set (R2p = 0.864 and RMSEP = 0.291). All these results indicated the feasibility of IR spectra for detecting lead chrome green in green tea. PMID:28068348

  3. Effect of green tea catechins on breast carcinogenesis: a systematic review of in-vitro and in-vivo experimental studies.

    Science.gov (United States)

    Yiannakopoulou, Eugenia Ch

    2014-03-01

    Catechins (flavan-3-oils) are the main flavonoids present in green tea. The potential cancer chemopreventive and therapeutic properties of green tea catechins have been the focus of research efforts in the last two decades. This systematic review aims to generate in vitro and in vivo data on the effect of green tea catechins on breast carcinogenesis. Electronic databases were searched with the appropriate search terms. Existing evidence suggests that green tea catechins modulate breast cell carcinogenesis. The effect of green tea catechins on breast cell carcinogenesis has been investigated in different experimental models and under different experimental conditions, that is, carcinogen investigated, green tea catechin dosage regimen, treatment with green tea extract versus pure synthetic EGCG, and time point of treatment with green tea catechins in relation to the exposure to the carcinogen. Although the effect of green tea catechins was not always statistically significant, the protective effect of green tea catechins was demonstrated in all the trials, suggesting that treatment with green tea catechins should be further investigated in the clinical setting of chemoprevention of high-risk women. However, it should be emphasized that the reported actions of green tea catechins are observed in high concentrations that are difficult to achieve in the clinical setting. This drawback could be overcome by designing green tea catechins with better bioavailability and/or by cotreatment combining breast cancer endocrine treatment with green tea catechins.

  4. Behavioral responses for evaluating the attractiveness of specific tea shoot volatiles to the tea green leafhopper,Empoaca vitis

    Institute of Scientific and Technical Information of China (English)

    Dan Mu; Lin Cui; Jian Ge; Meng-Xin Wang; Li-Fang Liu; Xiao-Ping Yu; Qing-He Zhanga; Bao-Yu Han

    2012-01-01

    The tea green leafhopper,Empoasca vitis G(o)the,is one of the most serious insect pests of tea plantations in mainland China.Over the past decades,this pest has been controlled mainly by spraying pesticides.Insecticide applications not only have become less effective in controlling damage,but even more seriously,have caused high levels of toxic residues in teas,which ultimately threatens human health.Therefore,we should seek a safer biological control approach.In the present study,key components of tea shoot volatiles were identified and behaviorally tested as potential leathopper attractants.The following 13 volatile compounds were identified from aeration samples of tea shoots using gas chromatography-mass spectrometry (GC-MS):(E)-2-hexenal,(Z)-3-hexen-1-ol,(Z)-3-hexenyl acetate,2-ethyl-1-hexanol,(E)-ocimene,linalool,nonanol,(Z)-butanoic acid,3-hexenyl ester,decanal,tetradecane,β-caryophyllene,geraniol and hexadecane.In Y-tube olfactometer tests,the following individual compounds were identified:(E)-2-hexenal,(E)-ocimene,(Z)-3-hexenyl acetate and linalool,as well as two synthetic mixtures (called blend 1 and blend 2) elicited significant taxis,with blend 2 being the most attractive.Blend 1 included linalool,(Z)-3-hexen-l-ol and (E)-2-hexenal at a 1:1:1 ratio,whereas blend 2 was a mixture of eight compounds at the same loading ratio:(E)-2-hexenal,(Z)-3-hexen-1-ol,(Z)-3-hexenyl acetate,2-penten-1-ol,(E)-2-pentenal,pentanol,hexanol and l-penten-3-ol.In tea fields,the bud-green sticky board traps baited with blend 2,(E)-2-hexenal or hexane captured adults and nymphs of the leafhoppers,with blend 2 being the most attractive,followed by (E)-2-hexenal and hexane.Placing sticky traps baited with blend 2 or (E)-2-hexenal in the tea fields significantly reduced leafhopper populations.Our results indicate that the bud-green sticky traps baited with tea shoot volatiles can provide a new tool for monitoring and managing the tea leafhopper.

  5. An in vitro comparative antibacterial study of different concentrations of green tea extracts and 2% chlorhexidine on Enterococcus faecalis

    Directory of Open Access Journals (Sweden)

    Leena P Martina

    2013-01-01

    Full Text Available Aim : The purpose of this study was to comparatively evaluate the antibacterial property of various concentrations of green tea extracts and 2% chlorhexidine (CHX against Enterococcus faecalis 0(E. faecalis in vitro. Materials and Methods: The activity of green tea extract and CHX on E. faecalis was measured on agar plates using the agar diffusion method. In addition, the tube dilution method was used to determine the minimum inhibitory concentration (MIC and minimum bactericidal concentration of green tea extract against E. faecalis. Results: The MIC of green tea extract was found to be 3.5%. The zone of inhibition was found to be concentration dependent. The 2.5% concentration of green tea extract showed 20 mm zone of inhibition, while the 3% concentration demonstrated a 30 mm zone of inhibition. Two percent CHX showed 30 mm zone of inhibition. Conclusion: Three percent concentration of green tea extract showed an antibacterial activity equivalent to 2% CHX against E. faecalis.

  6. Survival of Salmonella on chamomile, peppermint, and green tea during storage and subsequent survival or growth following tea brewing.

    Science.gov (United States)

    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 (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.

  7. Green tea consumption after intense taekwondo training enhances salivary defense factors and antibacterial capacity.

    Directory of Open Access Journals (Sweden)

    Shiuan-Pey Lin

    Full Text Available The aim of this study was to investigate the short-term effects of green tea consumption on selected salivary defense proteins, antibacterial capacity and anti-oxidation activity in taekwondo (TKD athletes, following intensive training. Twenty-two TKD athletes performed a 2-hr TKD training session. After training, participants ingested green tea (T, caffeine 6 mg/kg and catechins 22 mg/kg or an equal volume of water (W. Saliva samples were collected at three time points: before training (BT-T; BT-W, immediately after training (AT-T; AT-W, and 30 min after drinking green tea or water (Rec-T; Rec-W. Salivary total protein, immunoglobulin A (SIgA, lactoferrin, α-amylase activity, free radical scavenger activity (FRSA and antibacterial capacity were measured. Salivary total protein, lactoferrin, SIgA concentrations and α-amylase activity increased significantly immediately after intensive TKD training. After tea drinking and 30 min rest, α-amylase activity and the ratio of α-amylase to total protein were significantly higher than before and after training. In addition, salivary antibacterial capacity was not affected by intense training, but green tea consumption after training enhanced salivary antibacterial capacity. Additionally, we observed that salivary FRSA was markedly suppressed immediately after training and quickly returned to pre-exercise values, regardless of which fluid was consumed. Our results show that green tea consumption significantly enhances the activity of α-amylase and salivary antibacterial capacity.

  8. Does the consumption of green tea reduce the risk of lung cancer among smokers?

    Science.gov (United States)

    Liang, Wenbin; Binns, Colin W; Jian, Le; Lee, Andy H

    2007-03-01

    Experimental and epidemiological studies were reviewed to assess whether the consumption of green tea could reduce the risk of lung cancer in smokers. Articles published since 1990 were located by searching electronic databases PubMed, Ovid and Science Direct, using keywords 'lung cancer', 'tea' and 'smoking' without any restriction on language. After relevant articles had been located, further papers were obtained from their reference lists. Evidence from experimental studies (in vitro animal and human trials) suggested that regular intake of green tea may be protective against tobacco carcinogens. However, the mechanism behind the protective effect is only partly understood. In most of the epidemiological studies reviewed, the green tea exposure was within 5 years of the interview or follow-up, which would coincide with the induction period and latent period of lung cancer. Longer term studies are thus needed to further quantify the cancer risk. There is some evidence suggesting regular intake of green tea at high level (>3 cups per day) may reduce the risk of smokers developing lung cancer. Improvement in measuring green tea intake is required in order to confirm the evidence from epidemiological studies.

  9. Toxicity of green tea extracts and their constituents in rat hepatocytes in primary culture.

    Science.gov (United States)

    Schmidt, M; Schmitz, H-J; Baumgart, A; Guédon, D; Netsch, M I; Kreuter, M-H; Schmidlin, C B; Schrenk, D

    2005-02-01

    Recent reports on sporadic cases of liver disorders (acute hepatitis, icterus, hepatocellular necrosis) after ingestion of dietary supplements based on hydro-alcoholic extracts from green tea leaves led to restrictions of the marketing of such products in certain countries of the EU. Since green tea is considered to exert a number of beneficial health effects, and, therefore, green tea products are widely used as dietary supplements, we were interested in the possible mechanism of hepatotoxicity of green tea extracts and in the components involved in such effects. Seven hours after seeding on collagen, rat hepatocytes in primary culture were treated with various hydro-alcoholic green tea extracts (two different native 80% ethanolic dry extracts and an 80% ethanolic dry extract cleared from lipophilic compounds). Cells were washed, and reduction of resazurin, used as a viability parameter monitoring intact mitochondrial function, was determined. It was found that all seven green tea extracts examined enhanced resazurin reduction significantly at a concentration range of 100-500 microg/ml medium, while a significant decrease was observed at 1-3mg/ml medium. Decreased levels were concomitant with abundant necrosis as observed by microscopic inspection of the cultures and with increased leakage of lactate dehydrogenase activity from the cells. In a separate series of experiments, the green tea constituents (-)-epicatechin, (-)-epigallocatechin-3-gallate, caffeine and theanine were tested at concentrations reflecting their levels in a typical green tea extract. Synthetic (+)-epigallocatechin (200 microM) was used for comparison. Cytotoxicity was found with (-)-epigallocatechin-3-gallate only. The concomitant addition of 0.25 mM ascorbate/0.05 mM alpha-tocopherol had no influence on cytotoxicity. In conclusion, our results suggest that high concentrations of green tea extract can exert acute toxicity in rat liver cells. (-)-Epigallocatechin-3-gallate seems to be a key

  10. Qualitative analysis of catechins from green tea GMB-4 clone using HPLC and LC-MS/MS

    OpenAIRE

    Erna Susanti; Ciptati; Retty Ratnawati; ., Aulanni'am; Achmad Rudijanto

    2015-01-01

    Objective: To identify the bioactive compounds in catechins isolation and its components from green tea GMB-4 clone. Methods: Green tea GMB-4 clones were extracted with distilled water at 90 °C. Samples were eluted into the column with 10% ethanol. Subsequently, the column was eluted with 95% ethanol and evaporated separately. Green tea extract was identified by thin layer chromatography. Catechins were separated by the stationary phase in column chromatography using polyamide with 10% eth...

  11. Chemopreventive Potential of Green Tea Catechins in Hepatocellular Carcinoma

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    Masahito Shimizu

    2015-03-01

    Full Text Available Hepatocellular carcinoma (HCC, which is a common malignancy worldwide, usually develops in a cirrhotic liver due to hepatitis virus infection. Metabolic syndrome, which is frequently complicated by obesity and diabetes mellitus, is also a critical risk factor for liver carcinogenesis. Green tea catechins (GTCs may possess potent anticancer and chemopreventive properties for a number of different malignancies, including liver cancer. Antioxidant and anti-inflammatory activities are key mechanisms through which GTCs prevent the development of neoplasms, and they also exert cancer chemopreventive effects by modulating several signaling transduction and metabolic pathways. Furthermore, GTCs are considered to be useful for the prevention of obesity- and metabolic syndrome-related carcinogenesis by improving metabolic disorders. Several interventional trials in humans have shown that GTCs may ameliorate metabolic abnormalities and prevent the development of precancerous lesions. The purpose of this article is to review the key mechanisms by which GTCs exert chemopreventive effects in liver carcinogenesis, focusing especially on their ability to inhibit receptor tyrosine kinases and improve metabolic abnormalities. We also review the evidence for GTCs acting to prevent metabolic syndrome-associated liver carcinogenesis.

  12. Effect of green tea consumption on blood pressure: a meta-analysis of 13 randomized controlled trials.

    Science.gov (United States)

    Peng, Xiaoli; Zhou, Rui; Wang, Bin; Yu, Xiaoping; Yang, Xiaohong; Liu, Kai; Mi, Mantian

    2014-09-01

    The studies investigating the effects of green tea on blood pressure (BP) have generated inconsistent results. The aim of this study is to quantitatively evaluate the effects of green tea on BP control. PubMed, Embase, and the Cochrane Library (updated to March 2014) were searched for randomized controlled trials evaluating the effects of green tea on BP. Pooled effect of green tea consumption on BP was evaluated using fixed-effects or random-effects model. Thirteen trials comprising a total of 1,367 subjects were included in the current meta-analysis. The overall outcome of the meta-analysis suggested that green tea consumption significantly decrease systolic blood pressure (SBP) level by -1.98 mmHg (95% CI: -2.94, -1.01 mmHg; P green tea also showed a significant lowering effect on diastolic blood pressure (DBP) in treatment group (-1.92 mmHg; 95% CI: -3.17, -0.68 mmHg; P = 0.002). Subgroup analyses further suggested that the positive effect of green tea polyphenols on BP was only showed in studies using a low-dose green tea polyphenol, with the long-term intervention duration or ruling out the confounding effects of caffeine. The meta-analysis suggested that green tea consumption had a favorable effect on decrease of BP.

  13. Green tea catechins: Proposed mechanisms of action in breast cancer focusing on the interplay between survival and apoptosis.

    Science.gov (United States)

    Yiannakopoulou, Eugenia Ch

    2014-02-01

    Recent data have shown strong chemopreventive and possibly cancer chemotherapeutic effects of green tea polyphenols against cancer. Despite advances in breast cancer treatment, mortality from breast cancer is still high. Undoubtedly novel treatment strategies are needed for chemoprevention of high risk women and for the treatment of receptor negative breast cancer. Green tea catechins have been shown to inhibit proliferation of breast cancer cells and to block carcinogenesis. This review attempts a critical presentation of the mechanisms of action of green tea catechins in breast cancer. Several mechanisms of action of green tea catechins in breast cancer have been proposed including modulation of extracellular signalling, induction of apoptosis through redox regulation, or through modulation of epigenetic alterations. A number of molecular targets of green tea catechins have been suggested i.e molecular chaperones, telomerase, apoptotic cascade. Although the molecular links among the proposed mechanisms of action of green tea catechins are often missing, it must be emphasized that all the proposed mechanisms indicate that green tea catechins inhibit growth and /or promote apoptosis. It would be interesting if future experimental trials could take into account that green tea catechins are multi-target agents and attempt to link every novel proposed target with the other already proposed targets of green tea catechins.

  14. Metabolomic unveiling of a diverse range of green tea (Camellia sinensis) metabolites dependent on geography.

    Science.gov (United States)

    Lee, Jang-Eun; Lee, Bum-Jin; Chung, Jin-Oh; Kim, Hak-Nam; Kim, Eun-Hee; Jung, Sungheuk; Lee, Hyosang; Lee, Sang-Jun; Hong, Young-Shick

    2015-05-01

    Numerous factors such as geographical origin, cultivar, climate, cultural practices, and manufacturing processes influence the chemical compositions of tea, in the same way as growing conditions and grape variety affect wine quality. However, the relationships between these factors and tea chemical compositions are not well understood. In this study, a new approach for non-targeted or global analysis, i.e., metabolomics, which is highly reproducible and statistically effective in analysing a diverse range of compounds, was used to better understand the metabolome of Camellia sinensis and determine the influence of environmental factors, including geography, climate, and cultural practices, on tea-making. We found a strong correlation between environmental factors and the metabolome of green, white, and oolong teas from China, Japan, and South Korea. In particular, multivariate statistical analysis revealed strong inter-country and inter-city relationships in the levels of theanine and catechin derivatives found in green and white teas. This information might be useful for assessing tea quality or producing distinct tea products across different locations, and highlights simultaneous identification of diverse tea metabolites through an NMR-based metabolomics approach. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Green Tea as an Agricultural Based Health Promoting Food: The Past Five to Ten Years

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    Qin-Yin Shi

    2012-12-01

    Full Text Available The consumption of tea originated in ancient China over 4000 years ago and is currently the second most popular beverage in the world after water. Tea is an aromatic beverage prepared by pouring hot water over cured leaves of the Camellia sinensis plant. The link between tea intake, most notably green tea, and health has resulted in intense research on the components responsible for preventing the onset of several chronic diseases, including atherosclerosis, cancer, obesity and diabetes. In particular, the high levels of chemically diverse phenols (e.g., phenolic acids, flavonoids present in tea exhibit potent protective properties against many of these diseases. Although health related research on green tea and its predominant phenol (catechins has been on-going for decades, major advances have occurred in the last 5–10 years. Therefore, this review focuses on seminal studies reported primarily within the last five years but not extending past ten years on the link between health and green tea with an emphasis on the catechins.

  16. Green tea and exercise interventions as nondrug remedies in geriatric patients with rheumatoid arthritis.

    Science.gov (United States)

    Alghadir, Ahmad H; Gabr, Sami A; Al-Eisa, Einas S

    2016-10-01

    This study aimed to evaluate the effects of green tea and supervised exercise training interventions on improvement of disease activity and bone metabolism markers in rheumatoid arthritis patients. [Subjects and Methods] One-hundred and twenty subjects who had a mean age of (60.7 ± 2.53 years) and had been diagnosed with rheumatoid arthritis at least ten years previously were randomly included in this study. Patients were treated with infliximab, green tea, or a supervised exercise program for six months. Disease activity markers as well as antioxidant activity of green tea extracts were estimated before supplementation using in vitro assays. [Results] Rheumatoid arthritis patients treated with green tea for 6 months alone or in combination with infliximab or an exercise program showed significant improvement in disease activity parameters, including C-reactive protein, and erythrocyte sedimentation rate, swollen and tender joints counts, and modified Stanford Health Assessment Questionnaire score, along with an increase in serum levels of bone resorption markers, i.e., deoxypyridinoline, amino-terminal telopeptide of type 1 collagen, and bone alkaline phosphatase, at 6 months of after initial treatment. The European League Against Rheumatism and American College of Rheumatology scores revealed more clinical improvement in the disease activity of rheumatoid arthritis patients treated with green tea along with exercise compared with rheumatoid arthritis patients treated with infliximab or exercise combinations. This may have been due to the higher potential antioxidant activity of green tea (89.6% to 96.5%). [Conclusion] Both exercise and green tea interventions appeared to be beneficial as nondrug modulates for rheumatoid arthritis disorders.

  17. Green tea catechins for well-being and therapy: prospects and opportunities

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    Miyoshi N

    2015-12-01

    Full Text Available Noriyuki Miyoshi,1 Monira Pervin,1 Takuji Suzuki,2 Keiko Unno,3 Mamoru Isemura,1 Yoriyuki Nakamura1 1School of Food and Nutritional Sciences, University of Shizuoka, Yada, Shizuoka, Japan; 2Faculty of Education, Art and Science, Yamagata University, Yamagata, Japan; 3School of Pharmaceutical Sciences, University of Shizuoka, Yada, Shizuoka, Japan Abstract: Tea is derived from the leaves and buds of Camellia sinensis (Theaceae plant, and is consumed worldwide. Green tea was discovered in the People's Republic of China approximately 3,000 BC. Lu Yu (733–803 published a book that describes the history of tea, the techniques, and utensils used for manufacturing, the method of preparation, and drinking of tea in the People's Republic of China. Green tea contains various components with specific health-promoting effects and is believed to exert protective effects against diseases such as cancer, obesity, diabetes, hepatitis, and neurodegenerative diseases. Of the various tea components, the polyphenol catechins have been the subject of extensive investigation. Among the catechins, (--epigallocatechin gallate has the strongest bioactivity in most cases. Caffeine induces alertness, decreases the sensation of fatigue, and has a diuretic effect. Theanine and -aminobutyric acid can lower the blood pressure and regulate brain function. Vitamin C exhibits antiscorbutic activity, prevents cataracts, and may boost the immune system. Majority of the scientific evidence based on cellular and animal experiments as well as a number of human epidemiological and intervention studies indicate that green tea and (--epigallocatechin gallate have beneficial health effects against various diseases. However, conflicting results have also been reported. Since confounding factors could affect the results, future studies should be designed to eliminate such factors for better understanding of the benefits of green tea on human health. Genetic and environmental factors

  18. A comparative study of the antioxidant scavenging activity of green tea, black tea and coffee extracts: a kinetic approach.

    Science.gov (United States)

    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)).

  19. Additional benefit of higher dose green tea in lowering postprandial blood glucose

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    Rita Lahirin

    2015-07-01

    Full Text Available Background: Green tea contains catechins that have inhibitory effects on amylase, sucrase, and sodium-dependent glucose transporter (SGLT which result in lowering of postprandial blood glucose (PBG. This beneficial effect has been widely demonstrated using the usual dose (UD of green tea preparation. Our study was aimed to explore futher lowering of PBG using high dose (HD of green tea in healthy adolescents.Methods: 24 subjects received 100 mL infusion of either 0.67 or 3.33 grams of green tea with test meal. Fasting, PBG at 30, 60, 120 minutes were measured. Subjects were cross-overed after wash out. PBG and its incremental area under the curve (IAUC difference between groups were analyzed with paired T-test. Cathecin contents of tea were measured using high-performance liquid chromatography (HPLC.Results: The PBG of HD group was lower compared to UD (at 60 minutes =113.70 ± 13.20 vs 124.16 ± 8.17 mg/dL, p = 0.005; at 120 minutes = 88.95 ± 6.13 vs 105.25 ± 13.85 mg/dL, p < 0.001. The IAUC of HD was also found to be lower compared to UD (2055.0 vs 3411.9 min.mg/dL, p < 0.001.Conclusion: Additional benefit of lowering PBG can be achieved by using higher dose of green tea. This study recommends preparing higher dose of green tea drinks for better control of PBG.

  20. An Appraisal of Drug-Drug Interactions with Green Tea (Camellia sinensis).

    Science.gov (United States)

    Albassam, Ahmed A; Markowitz, John S

    2017-01-24

    This review summarizes published in vitro, animal, and clinical studies investigating the effects of green tea (Camellia sinensis) extract and associated catechins on drug-metabolizing enzymes and drug transporters. In vitro studies suggest that green tea extract and its main catechin, (-)-epigallocatechin-3-gallate, to varying degrees, inhibit the activity of CYP1A1, CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2D6, and CYP3A4. UGT1A1 and UGT1A4 isoforms were also inhibited by (-)-epigallocatechin-3-gallate. Animal studies suggest green tea extract and/or (-)-epigallocatechin-3-gallate significantly increase the bioavailability of diltazem, verapamil, tamoxifen simvastatin, 5-fluorouracil, and nicardipine. Conversely, green tea extract and/or (-)-epigallocatechin-3-gallate reduce the bioavailability of quetiapine, sunitinib, clozapine, and nadolol. Of the few clinical studies available for review, it appears neither green tea extract nor (-)-epigallocatechin-3-gallate inhibit any major cytochrome P450 enzyme. Regarding drug transporters, in vitro studies indicate P-glycoprotein, organic anion transporting polypeptide 1A1, organic anion transporting polypeptide 1B1, organic anion transporting polypeptide 1B3, organic anion transporting polypeptide 2B1, organic cation transporter 1, organic cation transporter 2, multidrug and toxin extrusion 1, and multidrug and toxin extrusion 2-K are potentially inhibited by green tea extract. A clinical study indicates the organic anion transporting polypeptide 1A1 transporter is inhibited by (-)-epigallocatechin-3-gallate while P-glycoprotein is unaffected. In conclusion, the ingestion of green tea extract or its associated catechins is not expected to result in clinically significant influences on major cytochrome P450 or uridine 5'-diphospho-glucuronosyltransferase enzyme substrates or drugs serving as substrates of P-glycoprotein. However, some caution is advised in the consumption of significant amounts of green tea beverages or green

  1. The major factors influencing the formation of sediments in reconstituted green tea infusion.

    Science.gov (United States)

    Xu, Yong-Quan; Hu, Xiong-Fei; Tang, Ping; Jiang, Yong-Wen; Yuan, Hai-Bo; Du, Qi-Zhen; Yin, Jun-Feng

    2015-04-01

    The effects of Ca(2+), caffeine and polyphenols on the formation of reversible tea sediments (RTS) and irreversible tea sediments (IRS) in green tea infusion were studied. Adding Ca(2+) (2 mmol/l) was found to increase the formation of RTS by 8% and IRS by 92%, while adding chelating ions of Na2EDTA significantly decreased the amount of RTS by 14.6%, but not the amount of IRS. Under acid conditions, Ca(2+) combined with oxalic ions to form indissoluble oxalate that is the principal constituent of IRS, despite the existence of the chelating ions. Decaffeination largely inhibited the formation of RTS (73%) and IRS (60%), even in the presence of Ca(2+). The amount of sediment could be reduced by removing polyphenols using polyvinyl-polypyrrolidone. The results suggest that sediment formation in green tea infusions can be inhibited by lowering the concentration of Ca(2+), caffeine or polyphenols. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Molecular mechanisms of green tea polyphenols with protective effects against skin photoaging.

    Science.gov (United States)

    Roh, Eunmiri; Kim, Jong-Eun; Kwon, Jung Yeon; Park, Jun Seong; Bode, Ann M; Dong, Zigang; Lee, Ki Won

    2017-05-24

    Whereas green tea has historically been consumed in high quantities in Northeast Asia, its popularity is also increasing in many Western countries. Green tea is an abundant source of plant polyphenols exhibiting numerous effects that are potentially beneficial for human health. Accumulating evidence suggests that green tea polyphenols confer protective effects on the skin against ultraviolet (UV) irradiation-induced acceleration of skin aging, involving antimelanogenic, antiwrinkle, antioxidant, and anti-inflammatory effects as well as prevention of immunosuppression. Melanin pigmentation in the skin is a major defense mechanism against UV irradiation, but pigmentation abnormalities such as melasma, freckles, senile lentigines, and other forms of melanin hyperpigmentation can also cause serious health and aesthetic issues. Furthermore, UV irradiation initiates the degradation of fibrillar collagen and elastic fibers, promoting the process of skin aging through deep wrinkle formation and loss of tissue elasticity. UV irradiation-induced formation of free radicals also contributes to accelerated photoaging. Additionally, immunosuppression caused by UV irradiation plays an important role in photoaging and skin carcinogenesis. In this review, we summarize the current literature regarding the antimelanogenic, antiwrinkle, antioxidant, and immunosuppression preventive mechanisms of green tea polyphenols that have been demonstrated to protect against UV irradiation-stimulated skin photoaging, and gauge the quality of evidence supporting the need for clinical studies using green tea polyphenols as anti-photoaging agents in novel cosmeceuticals.

  3. Effect of green tea on the second degree burn wounds in rats

    Directory of Open Access Journals (Sweden)

    Mohammad Javad Fatemi

    2014-01-01

    Full Text Available Background: Various studies indicate that the green tea has anti-inflammatory and anti-oxidative properties. Moreover, a few studies have been carried out that demonstrate beneficial effects of green tea on burned patients. Materials and Methods: In this study, green tea, Vaseline, and silver sulfadiazine dressings were used as first-aid treatment to deep dermal contact burns in rats, compared with a control of nothing. After creating second-degree burn on the dorsum of rats, the treatments were applied for 15 min in four groups. Wound dressing changes were daily. Macroscopic study was performed on days 1, 3, 7, and 14 by using a digital camera and software processing of photos. Microscopic examination was done by pathologic evaluation of skin specimens on day 14. Results: We observed that green tea usage significantly decreased burn size in comparison to the control group (P = 0.004. Conclusion: Green tea is effective on healing process of second degree burn wounds.

  4. Effect of Green Tea Extract on the Treatment of Dentin Erosion: An in Vitro Study

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    M Mirkarimi

    2012-01-01

    Full Text Available Objective: The aim of this study was to analyze the impact of green tea on dentin erosion.Materials and Methods: Twelve extracted sound human premolars were immersed in Coca Cola with a pH of 2.8 for 5 minutes. The surface microhardness was measured with a Knoop diamond under a load of 50gr/10s. The teeth were immersed in green tea (Camellia sinensis solution for one minute. The microhardness values were measured again and compared with pretreatment values by the Wilcoxon test. Three eroded teeth, which were treated with green tea, were evaluated under scanning electron microscope.Results: The mean ± SD of microhardness values before and after immersion in green tea were 46.5±2.79 and 54.5±4.4, respectively with statistically significant differences between the two measurements (P<0.01. In SEM evaluation there was an improvement in eroded dentin appearance and there were deposits on the dentin surface.Conclusion: Green tea (Camellia sinensis increased the microhardness of eroded dentin and improved the eroded texture.

  5. Contents and compositions of policosanols in green tea (Camellia sinensis) leaves.

    Science.gov (United States)

    Choi, Sol Ji; Park, Su Yeon; Park, Ji Su; Park, Sang-Kyu; Jung, Mun Yhung

    2016-08-01

    Policosanol (PC) is a mixture of health promoting bioactive long-chain aliphatic alcohols. Here, we report that green tea (Camellia sinensis) leaves are the exceptionally rich plant-sources of PC. Young and tender leaves and old and turf leaves of C. sinensis were hand-picked in spring and autumn. The total contents of PC in the leaves were in the range of 726.2-1363.6mg/kg as determined by a GC-MS/MS. The compositions of PC in the leaves were different with harvest season and types. The total contents of PC in commercial green tea leaves were found to be in the range of 856.7-1435.1mg/kg. Interestingly, the infused green tea leaves contained the higher PC than the non-infused green tea product, reaching to 1629.4mg/kg. This represents the first report on the contents and compositions of PC in green tea leaves, showing unambiguous evidence of their potential as rich sources of PC.

  6. Validation of AN Hplc-Dad Method for the Classification of Green Teas

    Science.gov (United States)

    Yu, Jingbo; Ye, Nengsheng; Gu, Xuexin; Liu, Ni

    A reversed phase high performance liquid chromatography (RP-HPLC) separation coupled with diode array detection (DAD) and electrospray ionization mass spectrometer (ESI/MS) was developed and optimized for the classification of green teas. Five catechins [epigallocatechin (EGC), epigallocatechin gallate (EGCG), epicatechin (EC), gallocatechin gallate (GCG), epicatechin gallate (ECG)] had been identified and quantified by the HPLC-DAD-ESI/MS/MS method. The limit of detection (LOD) of five catechins was within the range of 1.25-15 ng. All the analytes exhibited good linearity up to 2500 ng. These compounds were considered as chemical descriptors to define groups of green teas. Chemometric methods including principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied for the purpose. Twelve green tea samples originating from different regions were subjected to reveal the natural groups. The results showed that the analyzed green teas were differentiated mainly by provenance; HCA afforded an excellent performance in terms of recognition and prediction abilities. This method was accurate and reproducible, providing a potential approach for authentication of green teas.

  7. The Effect of Mercury Vapor and the Role of Green Tea Extract on Brain Cells

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    Dhona Afriza

    2013-09-01

    Full Text Available Mercury is a wellknown toxic metal that is capable to induce free radical-induced oxidative stress. It can cause human disease including brain disorders. Objective: To identify the effect of mercury vapor inhalation on brain cells and the role of green tea extract (Camellia sinensis as antioxidant on the brain cells exposed to mercury. Methods: Fourty-eight male Mus musculus were divided into 8 groups, which were given treatment for 3 and 6 weeks. Group A did not receive any treatment and served as a negative control. Group B was a positive control exposed to Mercury. Group C was exposed to Mercury and treated with 26μg/g green tea extract. Group D was exposed to mercury and treated with 52μg/g green tea extract. All animals in the Group B, C, D were exposed to mercury through inhalation for 4 hours daily. The effect of mercury on the brain cells were examined histopathologically. Results: The numbers of necrotic cells counted in the green tea-treated mice group were significantly lower than those untreated group (p<0,05. Conclusion: Mercury vapor inhalation may cause necrosis on brain cells. Administration of green tea extract as an antioxidant reduced the amount of mercury-induced necrotic brain cells in mice.DOI: 10.14693/jdi.v20i2.151

  8. Green tea prevents non-melanoma skin cancer by enhancing DNA repair.

    Science.gov (United States)

    Katiyar, Santosh K

    2011-04-15

    Excessive exposure of the skin to solar ultraviolet (UV) radiation is one of the major factors for the development of skin cancers, including non-melanoma. For the last several centuries the consumption of dietary phytochemicals has been linked to numerous health benefits including the photoprotection of the skin. Green tea has been consumed as a popular beverage world-wide and skin photoprotection by green tea polyphenols (GTPs) has been widely investigated. In this article, we have discussed the recent investigations and mechanistic studies which define the potential efficacy of GTPs on the prevention of non-melanoma skin cancer. UV-induced DNA damage, particularly the formation of cyclobutane pyrimidine dimers, has been implicated in immunosuppression and initiation of skin cancer. Topical application or oral administration of green tea through drinking water of mice prevents UVB-induced skin tumor development, and this prevention is mediated, at least in part, through rapid repair of DNA. The DNA repair by GTPs is mediated through the induction of interleukin (IL)-12 which has been shown to have DNA repair ability. The new mechanistic investigations support and explain the anti-photocarcinogenic activity, in particular anti-non-melanoma skin cancer, of green tea and explain the benefits of green tea for human health.

  9. Does the Consumption of Green Tea Reduce the Risk of Lung Cancer among Smokers?

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    Wenbin Liang

    2007-01-01

    Full Text Available Experimental and epidemiological studies were reviewed to assess whether the consumption of green tea could reduce the risk of lung cancer in smokers. Articles published since 1990 were located by searching electronic databases PubMed, Ovid and Science Direct, using keywords ‘lung cancer’, ‘tea’ and ‘smoking’ without any restriction on language. After relevant articles had been located, further papers were obtained from their reference lists. Evidence from experimental studies (in vitro animal and human trials suggested that regular intake of green tea may be protective against tobacco carcinogens. However, the mechanism behind the protective effect is only partly understood. In most of the epidemiological studies reviewed, the green tea exposure was within 5 years of the interview or follow-up, which would coincide with the induction period and latent period of lung cancer. Longer term studies are thus needed to further quantify the cancer risk. There is some evidence suggesting regular intake of green tea at high level (>3 cups per day may reduce the risk of smokers developing lung cancer. Improvement in measuring green tea intake is required in order to confirm the evidence from epidemiological studies.

  10. A non-targeted approach to chemical discrimination between green tea dietary supplements and green tea leaves by HPLC/MS.

    Science.gov (United States)

    Sun, Jianghao; Chen, Pei; Lin, Long-Ze; Harnly, James M

    2011-01-01

    Green tea-based dietary supplements (GTDSs) have gained popularity in the U.S. market in recent years. This study evaluated the phytochemical composition difference of GTDS in comparison with green tea leaves using an HPLC/MS fingerprinting technique coupled with chemometric analysis. Five components that are most responsible for class separation among samples were identified as (-) epicatechin gallate, strictinin, trigalloylglucose, quercetin-3-O-glucosyl-rhamnosylglucoside, and kaempferol-3-O-galactosyl-rhamnosylglucoside, according to the accurate mass measurements and MS/MS data. The similarity coefficients between the GTDSs in solid form with green tea were 0.55 to 0.91, while for the GTDSs in liquid form they were 0.12 to 0.89, which suggested that chemical composition variance across the GTDSs was significant. Flavonol aglycone concentrations were higher in GTDSs than in tea leaves, indicating the degradation of flavonol glycosides or the oxidation of catechin during the manufacturing and storage processes. In some GTDS samples, compounds were identified that were on the label. The results demonstrate the urgency of QC for GTDS products.

  11. Quantification of catechins and caffeine from green tea (Camellia sinensis infusions, extract, and ready-to-drink beverages

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    Rafaela Macedo Mendes De Oliveira

    2012-03-01

    Full Text Available This study aimed to quantify the levels of catechins and caffeine in various forms of presentation of green tea: infusion tea bags, extract, and ready-to-drink beverage and, based on their content, identify the most suitable for consumption. High Performance Liquid Chromatography (HPLC analytical method was used for the quantification of catechins and caffeine. The tea bags had the highest concentration of total catechins with 5 to 9.5% followed by the extract with 3.64 to 4.88%, and ready-to-drink green tea beverage showed low levels of catechins, from 0.14 to 0.26%. As for caffeine content, green tea extract had higher concentration (1.96 to 3.54% compared to the tea bags (1.39 to 1.57%. Tea bags were found the most suitable for consumption because it contains higher amounts of catechins and smaller amounts of caffeine.

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

    Science.gov (United States)

    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...

  13. Green tea polyphenols inhibit testosterone production in rat Leydig cells

    Institute of Scientific and Technical Information of China (English)

    Marina S.Figueiroa; Juliany S.B.Cesar Vieira; Disleide S.Leite; Ruben C.O.Andrade Filho; Fabiano Ferreira; Patricia S.Gouveia; Daniel P.Udrisar; Maria I.Wanderley

    2009-01-01

    This study investigated the acute effects of green tea extract (GTE) and its polyphenol constituents, (-)-epigal-locatechin-3-gallate (EGCG) and (-)-epicatechin (EC), on basal and stimulated testosterone production by rat Leydig cells in vitro. Leydig cells purified in a Percoll gradient were incubated for 3 h with GTE, EGCG or EC and the testosterone precursor androstenedione, in the presence or absence of either protein kinase A (PKA) or protein kinase C (PKC) activators. The reversibility of the effect was studied by pretreating cells for 15 min with GTE or EGCG, allowing them to recover for 1 h and challenging them for 2 h with human chorionic gonadotropin (hCG), luteinizing hormone releasing hormone (LHRH), 22(R)-hydroxycholesterol or androstenedione. GTE and EGCG, but not EC, inhibited both basal and kinase-stimulated testosterone production. Under the pretreatment conditions, the inhibitory effect of the higher concentration of GTE/EGCG on hCG/LHRH-stimulated or 22(R)-hydroxycholesterol-induced testosterone production was maintained, whereas androstenedione-supported testosterone production returned to control levels. At the lower concentration of GTE/EGCG, the inhibitory effect of these polyphenols on 22(R)-hydroxycholesterol-supported testosterone production was reversed. The inhibitory effects of GTE may be explained by the action of its principal component, EGCG, and the presence of a gallate group in its structure seems important for its high efficacy in inhibiting testosterone production. The mechanisms underlying the effects of GTE and EGCG involve the inhibition of the PKA/PKC signalling pathways, as well as the inhibition of P450 side-chain cleavage enzyme and 17β-hydroxysteroid dehydrogenase function.

  14. Adsorption of Pb(II) on Spent Leaves of Green and Black Tea

    OpenAIRE

    Antonio Zuorro; Roberto Lavecchia

    2010-01-01

    Problem statement: In recent years much attention has been focused on the use of biomass residues as low-cost adsorbents for the removal of heavy metal ions from contaminated waters. Spent tea leaves, an abundantly available material that is currently disposed of as a solid waste, are potentially suitable for such applications. Approach: To provide some information on the adsorption properties of tea waste, we evaluated the removal efficiency of lead ions by spent leaves of green and black te...

  15. Green tea catechins for well-being and therapy: prospects and opportunities

    OpenAIRE

    Miyoshi N; Pervin M; Suzuki T.; Unno K; Isemura M; Nakamura Y.

    2015-01-01

    Noriyuki Miyoshi,1 Monira Pervin,1 Takuji Suzuki,2 Keiko Unno,3 Mamoru Isemura,1 Yoriyuki Nakamura1 1School of Food and Nutritional Sciences, University of Shizuoka, Yada, Shizuoka, Japan; 2Faculty of Education, Art and Science, Yamagata University, Yamagata, Japan; 3School of Pharmaceutical Sciences, University of Shizuoka, Yada, Shizuoka, Japan Abstract: Tea is derived from the leaves and buds of Camellia sinensis (Theaceae) plant, and is consumed worldwide. Green tea was discovered in the...

  16. Green tea aroma fraction reduces β-amyloid peptide-induced toxicity in Caenorhabditis elegans transfected with human β-amyloid minigene.

    Science.gov (United States)

    Takahashi, Atsushi; Watanabe, Tatsuro; Fujita, Takashi; Hasegawa, Toshio; Saito, Michio; Suganuma, Masami

    2014-01-01

    Green tea is a popular world-wide beverage with health benefits that include preventive effects on cancer as well as cardiovascular, liver and Alzheimer's diseases (AD). This study will examine the preventive effects on AD of a unique aroma of Japanese green tea. First, a transgenic Caenorhabditis elegans (C. elegans) CL4176 expressing human β-amyloid peptide (Aβ) was used as a model of AD. A hexane extract of processed green tea was further fractionated into volatile and non-volatile fractions, named roasty aroma and green tea aroma fractions depending on their aroma, by microscale distillation. Both hexane extract and green tea aroma fraction were found to inhibit Aβ-induced paralysis, while only green tea aroma fraction extended lifespan in CL4176. We also found that green tea aroma fraction has antioxidant activity. This paper indicates that the green tea aroma fraction is an additional component for prevention of AD.

  17. [Antioxidant activities of green and black teas determined by the cumene hydroperoxide/hemoglobin.methylene blue method].

    Science.gov (United States)

    Sugita, Osamu; Ishizawa, Nobuhito; Nakano, Masaharu; Matsuto, Takayuki; Okada, Masahiko

    2003-09-01

    Antioxidant activity in tea was measured by the new cumene hydroperoxide/hemoglobin.methylene blue(CHP/Hb.MB) method developed in our laboratory. Using the CHP/Hb.MB method, we investigated the activities of polyphenols(11 varieties) in order to determine their reactivity on CHP. According to the CHP/Hb.MB method, an increase in the number of hydroxyl groups in polyphenols induced high antioxidant activity. We found that this method was capable of measuring the antioxidant activity of polyphenols. Consequently, we were able to measure the antioxidant activities of heated, green, powdered and black teas by this method. The average of antioxidant activities of heated green tea was 207 nmol/ml, while that of green tea was 280 nmol/ml, powdered green tea was 481 nmol/ml and black tea was 215 nmol/ml respectively.

  18. Fermentation Characteristics, Tannin Contents and Ruminal Degradation of Green Tea and Black Tea By-products Ensiled at Different Temperatures

    Directory of Open Access Journals (Sweden)

    Makoto Kondo

    2014-07-01

    Full Text Available Green and black tea by-products, obtained from ready-made tea industry, were ensiled at 10°C, 20°C, and 30°C. Green tea by-product silage (GTS and black tea by-product silage (BTS were opened at 5, 10, 45 days after ensiling. Fermentation characteristics and nutrient composition, including tannins, were monitored and the silages on day 45 were subjected to in vitro ruminal fermentation to assess anti-nutritive effects of tannins using polyethylene glycol (PEG as a tannin-binding agent. Results showed that the GTS and BTS silages were stable and fermented slightly when ensiled at 10°C. The GTS stored at 20°C and 30°C showed rapid pH decline and high acetic acid concentration. The BTS was fermented gradually with moderate change of pH and acid concentration. Acetic acid was the main acid product of fermentation in both GTS and BTS. The contents of total extractable phenolics and total extractable tannins in both silages were unaffected by storage temperatures, but condensed tannins in GTS were less when stored at high temperature. The GTS showed no PEG response on in vitro gas production, and revealed only a small increase by PEG on NH3-N concentration. Storage temperature of GTS did not affect the extent of PEG response to both gas production and NH3-N concentration. On the other hand, addition of PEG on BTS markedly increased both the gas production and NH3-N concentration at any ensiled temperature. It can be concluded that tannins in both GTS and BTS suppressed rumen fermentation, and tannins in GTS did more weakly than that in BTS. Ensiling temperature for both tea by-products did not affect the tannin’s activity in the rumen.

  19. Characterization of EPG waveforms for the tea green leafhopper, Empoasca vitis Göthe (Hemiptera: Cicadellidae), on tea plants and their correlation with stylet activities

    Science.gov (United States)

    Stylet probing activities of the tea green leafhopper, Empoasca vitis Göthe (Hemiptera: Cicadellidae), were studied using the DC electrical penetration graph (EPG) technique. Seven different EPG waveforms (i.e., Np, E1, E2, E3, E4, E5 and E6) were identified and characterized on susceptible tea leav...

  20. Irradiation application for color removal and purification of green tea leaves extract

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Cheorun; Son, J.H.; Lee, H.J.; Byun, M.W. E-mail: mwbyun@kaeri.re.kr

    2003-02-01

    Gamma irradiation was introduced to develop a new processing method for brighter-colored green tea leaves extract without changes of physiological activities. Dried green tea leaves were purchased and extracted by 70% ethanol solution and irradiated at 0, 5, 10, and 20 kGy with gamma rays. Hunter color L-value increased and a- and b-value decreased by irradiation, resulting in bright yellow from dark brown. There was no difference in radical scavenging and tyrosinase inhibition effect by irradiation. The irradiation effect in the solution disappeared during storage for 3 weeks at room temperature but vitamin C addition was effective in reducing the color change. Results indicated that irradiation may be a good technology to remove undesirable color in green tea leaves extract.

  1. Green tea catechins reduced the glycaemic potential of bread: an in vitro digestibility study.

    Science.gov (United States)

    Goh, Royston; Gao, Jing; Ananingsih, Victoria K; Ranawana, Viren; Henry, Christiani Jeyakumar; Zhou, Weibiao

    2015-08-01

    Green tea catechins are potent inhibitors of enzymes for carbohydrate digestion. However, the potential of developing low glycaemic index bakery food using green tea extract has not been investigated. Results of this study showed that addition of green tea extract (GTE) at 0.45%, 1%, and 2% concentration levels significantly reduced the glycaemic potential of baked and steamed bread. The average retention levels of catechins in the baked and steamed bread were 75.3-89.5% and 81.4-99.3%, respectively. Bread fortified with 2% GTE showed a significantly lower level of glucose release during the first 90 min of pancreatic digestion as well as a lower content of rapidly digested starch (RDS) content. A significantly negative correlation was found between the catechin retention level and the RDS content of bread. The potential of transforming bread into a low GI food using GTE fortification was proven to be promising. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Black and green tea--how to make a perfect crime.

    Science.gov (United States)

    Bancirova, Martina

    2013-08-01

    The antioxidant properties of the black and green tea are well known. The latent bloodstains are detectable by luminol. The bloodstains also can be cover up by drinks and foods containing the antioxidants; thus their presence can cause a decrease of the luminol light emission (false-negative results). The aim of this study was to quantify the light emission decrease of the chemiluminescent mixture prepared according to Weber (containing NaOH) and the chemiluminescent mixture of pH 7.4 (for the determination of the total antioxidant capacity) for the open air-dried sample. The black and green teas and white wine were used as the antioxidant's samples (high and low total antioxidant capacity). The significant decrease of the luminol chemiluminescent emission caused by the presence of the black and green teas (and comparable for both of them) was observed in comparison with the presence of white wine.

  3. Inhibition of free radical induced oxidative hemolysis of red blood cells by green tea polyphenols

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The in vitro oxidative hemolysis of human red blood cells (RBC) was used as a model to study the free radical induced damage of biological membranes and the inhibitory effect of natural antioxidants. The hemolysis was induced by a water-soluble free radical initiator 2,2′-azo(2- asmidinopropane)dihydrochloride (AAPH) and inhibited by the principal polyphenolic components extracted from green tea leaves, i.e. (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicat- echin gallate (ECG), (-)-epigallocatechin gallate (EGCG) and gallic acid (GA). Addition of AAPH at 37°C caused fast hemolysis after a short period of inhibition period, while addition of the green tea polyphenols efficiently suppressed the hemolysis in the activity sequence of EGCG>EGC>ECG≈EC>GA, demonstrating that these green tea polyphenols are effective antioxidants which could protect biological membranes from free radical induced oxidative damage.

  4. A green tea catechin extract upregulates the hepatic low-density lipoprotein receptor in rats.

    Science.gov (United States)

    Bursill, Christina A; Roach, Paul D

    2007-07-01

    Green tea extracts have hypocholesterolaemic properties in epidemiological and animal intervention studies. Upregulation of the low-density lipoprotein (LDL) receptor may be one mechanism to explain this as it is the main way cholesterol is removed from the circulation. This study aimed to determine if a green tea extract could upregulate the hepatic LDL receptor in vivo in the rat. A green tea extract (GTE) enriched in its anti-oxidant constituents, the catechins, was fed to rats (n = 6) at concentrations of either 0, 0.5, 1.0 or 2.0% (w/w) mixed in with their normal chow along with 0.25% (w/w) cholesterol for 12 days. Administration of the GTE had no effect on plasma total or LDL cholesterol concentrations but high-density lipoprotein significantly increased (41%; p extract was able to increase the efflux of cholesterol from liver cells.

  5. The Place of Green Tea in the Prevention of Osteoporosis in Women

    Directory of Open Access Journals (Sweden)

    Gülbahtiyar Demirel

    2015-08-01

    Full Text Available Osteoporosis is one of the most important health-related problems in today’s world that it is increasing in incidence specifically after menopause in women. Various risk factors including genetic characteristics, Vitamin D deficiency, insufficient calcium intake, sedentary lifestyle and late menarche enable osteoporosis to be contained in terms of its progress and to be treated. The consumption of green tea is one of the non-pharmacological methods utilized in the prevention of osteoporosis in recent years. Studies conducted abroad with relation to this subject identified that the consumption of green tea is effective in the regulation of bone density and the protection of bone health. However, this finding lacks sufficient data at the national scale. The present review will provide healthcare professionals information on the necessity for the consumption of green tea in the prevention of osteoporosis in women. (Turkish Journal of Osteoporosis 2015;21: 84-6

  6. Honey and green/black tea consumption may reduce the risk of Helicobacter pylori infection.

    Science.gov (United States)

    Boyanova, Lyudmila; Ilieva, Juliana; Gergova, Galina; Vladimirov, Borislav; Nikolov, Rossen; Mitov, Ivan

    2015-05-01

    The aim of the study was to evaluate the influence of dietary and demographic factors and some habits on the prevalence of Helicobacter pylori infection in 150 dyspeptic patients examined endoscopically and by the urea breath test. Positivity rate was lower (50.6%) in patients consuming honey ≥1 day weekly compared with the remainder (70.8%) and in those consuming green/black tea ≥1 day weekly (45.2%) compared with the other patients (64.8%). Logistic regression confirmed that the factors associated with significantly lower H. pylori positivity rate were the consumption of honey (odds ratio [OR], 0.38; 95% confidence interval [CI], 0.19-0.78) and green/black tea (OR, 0.45; 95% CI, 0.21-0.95). In conclusion, honey and green/black tea intake is associated with reduced prevalence of H. pylori infection.

  7. Inhibition of proliferation of human lung cancer cells by green tea catechins is mediated by upregulation of let-7

    OpenAIRE

    ZHONG, ZHIWEI; Dong, Zhuo; Yang, Lihua; Chen, Xiaoqiang; Gong, Zhaohui

    2012-01-01

    Green tea catechins are known to function as anticancer agents via inhibition of carcinogenesis during the initiation, promotion and progression stages. Many potential mechanisms have been proposed, yet the precise mechanism of lung cancer prevention by green tea catechins remains unclear. microRNAs (miRs) are a class of 21–24 nucleotide small non-coding RNAs and play critical roles throughout cellular development and regulation. Emerging evidence demonstrates that tea catechins influence the...

  8. Green tea as inhibitor of the intestinal absorption of lipids: potential mechanism for its lipid-lowering effect.

    Science.gov (United States)

    Koo, Sung I; Noh, Sang K

    2007-03-01

    Animal and epidemiological studies suggest that green tea catechins may reduce the risk of cardiovascular diseases [e.g., coronary heart disease (CHD)]. The health benefit of green tea has been attributed to its antioxidant and anti-inflammatory properties; however, considerable evidence suggests that green tea and its catechins may reduce the risk of CHD by lowering the plasma levels of cholesterol and triglyceride. Although the mechanism underlying such effect of green tea is yet to be determined, it is evident from in vitro and in vivo studies that green tea or catechins inhibit the intestinal absorption of dietary lipids. Studies in vitro indicate that green tea catechins, particularly (-)-epigallocatechin gallate, interfere with the emulsification, digestion, and micellar solubilization of lipids, critical steps involved in the intestinal absorption of dietary fat, cholesterol, and other lipids. Based on the observations, it is likely that green tea or its catechins lower the absorption and tissue accumulation of other lipophilic organic compounds. The available information strongly suggests that green tea or its catechins may be used as safe and effective lipid-lowering therapeutic agents.

  9. Effects of Green Tea Extract on Learning, Memory, Behavior and Acetylcholinesterase Activity in Young and Old Male Rats

    Science.gov (United States)

    Kaur, Tranum; Pathak, C. M.; Pandhi, P.; Khanduja, K. L.

    2008-01-01

    Objective: To study the effects of green tea extract administration on age-related cognition in young and old male Wistar rats. Methods: Young and old rats were orally administered 0.5% green tea extract for a period of eight weeks and were evaluated by passive avoidance, elevated maze plus paradigm and changes in acetylcholinesterase activity.…

  10. Synergistic Effect of Green Tea Polyphenols and Vitamin D on Chronic Inflammation-Induced Bone Loss in Female Rats

    Science.gov (United States)

    Our recent study demonstrated a bone-protective role of green tea polyphenols (GTPs), extracted from green tea, in chronic inflammation-induced bone loss of female rats through reduction of inflammation and oxidative stress. This study further examines effects of GTPs in conjunction with vitamin D (...

  11. Effects of Green Tea Extract on Learning, Memory, Behavior and Acetylcholinesterase Activity in Young and Old Male Rats

    Science.gov (United States)

    Kaur, Tranum; Pathak, C. M.; Pandhi, P.; Khanduja, K. L.

    2008-01-01

    Objective: To study the effects of green tea extract administration on age-related cognition in young and old male Wistar rats. Methods: Young and old rats were orally administered 0.5% green tea extract for a period of eight weeks and were evaluated by passive avoidance, elevated maze plus paradigm and changes in acetylcholinesterase activity.…

  12. Green Tea Extract Improves the Post Prandial Overproduction of Intestinal Apolipoprotein B-containing Lipoproteins in Fructose Fed Hamsters

    Science.gov (United States)

    Green tea has putative medicinal properties that may be useful in preventing the metabolic syndrome. However, little is known of the effects of green tea extract (GTE) on postprandial apoB-48 containing lipoproteins and its molecular mechanisms. In a three-hour olive oil loading study, acute GTE ora...

  13. Green Tea Extract Improves the Postprandial Overproduction of Intestinal Apolipoprotein B-containing Lipoproteins in Fructose-Fed Hamsters

    Science.gov (United States)

    Green tea has putative medicinal properties that may be useful in preventing the metabolic syndrome since increased consumption of green tea extract (GTE) is associated with improved lipid and glucose homeostasis in human and animals. The acute effect of GTE on postprandial intestinal apoB48 product...

  14. Contribution of temporal dominance of sensations method to the sensory description of taste properties of commercial green tea brands

    Directory of Open Access Journals (Sweden)

    Noémi Dubová

    2013-03-01

    Full Text Available This paper aims to investigate the most dominant taste attributes of green tea samples in panelists perception over time. In order to assess the samples, a brand new method of sensory evaluation called „Temporal Dominance of Sensations“ was used. The five commercial green tea brands were evaluated by eight trained panelists (students. For each sample of green tea, curves of the dominance of each attribute over time were computed. The TDS curves provided information about the sequence of attributes that were dominant during degustation. This methodology was useful to characterize taste properties of green tea samples.doi:10.5219/274 Normal 0 false false false EN-US X-NONE X-NONE This paper aims to investigate the most dominant taste attributes of green tea samples in panelists perception over time. In order to assess the samples, a brand new method of sensory evaluation called „Temporal Dominance of Sensations“ was used. The five commercial green tea brands were evaluated by eight trained panelists (students. For each sample of green tea, curves of the dominance of each attribute over time were computed. The TDS curves provided information about the sequence of attributes that were dominant during degustation. This methodology was useful to characterize taste properties of green tea samples.doi:10.5219/274

  15. Green synthesis of iron nanoparticles by various tea extracts: Comparative study of the reactivity

    Science.gov (United States)

    Huang, Lanlan; Weng, Xiulan; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravendra

    2014-09-01

    Iron nanoparticles (Fe NPs) are often synthesized using sodium borohydride with aggregation, which is a high cost process and environmentally toxic. To address these issues, Fe NPs were synthesized using green methods based on tea extracts, including green, oolong and black teas. The best method for degrading malachite green (MG) was Fe NPs synthesized by green tea extracts because it contains a high concentration of caffeine/polyphenols which act as both reducing and capping agents in the synthesis of Fe NPs. These characteristics were confirmed by a scanning electron microscope (SEM), UV-visible (UV-vis) and specific surface area (BET). To understand the formation of Fe NPs using various tea extracts, the synthesized Fe NPs were characterized by SEM, X-ray energy-dispersive spectrometer (EDS), and X-ray diffraction (XRD). What emerged were different sizes and concentrations of Fe NPs being synthesized by tea extracts, leading to various degradations of MG. Furthermore, kinetics for the degradation of MG using these Fe NPs fitted well to the pseudo first-order reaction kinetics model with more than 20 kJ/mol activation energy, suggesting a chemically diffusion-controlled reaction. The degradation mechanism using these Fe NPs included adsorption of MG to Fe NPs, oxidation of iron, and cleaving the bond that was connected to the benzene ring.

  16. Green synthesis of iron nanoparticles by various tea extracts: comparative study of the reactivity.

    Science.gov (United States)

    Huang, Lanlan; Weng, Xiulan; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravendra

    2014-09-15

    Iron nanoparticles (Fe NPs) are often synthesized using sodium borohydride with aggregation, which is a high cost process and environmentally toxic. To address these issues, Fe NPs were synthesized using green methods based on tea extracts, including green, oolong and black teas. The best method for degrading malachite green (MG) was Fe NPs synthesized by green tea extracts because it contains a high concentration of caffeine/polyphenols which act as both reducing and capping agents in the synthesis of Fe NPs. These characteristics were confirmed by a scanning electron microscope (SEM), UV-visible (UV-vis) and specific surface area (BET). To understand the formation of Fe NPs using various tea extracts, the synthesized Fe NPs were characterized by SEM, X-ray energy-dispersive spectrometer (EDS), and X-ray diffraction (XRD). What emerged were different sizes and concentrations of Fe NPs being synthesized by tea extracts, leading to various degradations of MG. Furthermore, kinetics for the degradation of MG using these Fe NPs fitted well to the pseudo first-order reaction kinetics model with more than 20 kJ/mol activation energy, suggesting a chemically diffusion-controlled reaction. The degradation mechanism using these Fe NPs included adsorption of MG to Fe NPs, oxidation of iron, and cleaving the bond that was connected to the benzene ring. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Quantitative Analysis of Major Constituents in Green Tea with Different Plucking Periods and Their Antioxidant Activity

    Directory of Open Access Journals (Sweden)

    Lan-Sook Lee

    2014-07-01

    Full Text Available The objective of this study was to determine the relationship between the plucking periods and the major constituents and the antioxidant activity in green tea. Green tea was prepared from leaves plucked from the end of April 2013 to the end of May 2013 at intervals of one week or longer. The contents of theanine, theobromine, caffeine, catechin (C, and gallocatechin gallate (GCg were significantly decreased, whereas those of epicatechin (EC, epigallocatechin gallate (EGCg and epigallocatechin (EGC were significantly increased along with the period of tea leaf plucking. In addition, antioxidant activity of green tea and standard catechins was investigated using ABTS, FRAP and DPPH assays. The highest antioxidant activity was observed in relatively the oldest leaf, regardless of the assay methods used. Additionally, the order of antioxidant activity of standard catechins was as follows: EGCg ³ GCg ³ ECg > EGC ³ GC ³ EC ³ C. Moreover, the cis-catechins contents were the key factor affecting the antioxidant activity of green tea in all assays employed (ABTS, r = 0.731, p < 0.01; FRAP, r = 0.886, p < 0.01; DPPH, r = 0.778, p < 0.01.

  18. Green tea catechins and their metabolites in human skin before and after exposure to ultraviolet radiation.

    Science.gov (United States)

    Clarke, Kayleigh A; Dew, Tristan P; Watson, Rachel E B; Farrar, Mark D; Osman, Joanne E; Nicolaou, Anna; Rhodes, Lesley E; Williamson, Gary

    2016-01-01

    Dietary flavonoids may protect against sunburn inflammation in skin. Preliminary reports using less complete analysis suggest that certain catechins and their metabolites are found in skin biopsies and blister fluid after consumption of green tea; however, it is not known if they are affected by solar-simulated ultraviolet radiation (UVR) or whether conjugated forms, with consequently altered bioactivity, are present. The present study tested the hypothesis that UVR affects the catechin levels in the skin of healthy volunteers after consumption of green tea and how catechins in the plasma are related to their presence in skin tissue samples. In an open oral intervention study, 11 subjects consumed green tea and vitamin C supplements daily for 3months. Presupplementation and postsupplementation plasma samples, suction blister fluid and skin biopsies were collected; the latter two samples were collected both before and after UVR. A sensitive high-performance liquid chromatography/mass spectrometric assay was used to measure the intact catechin metabolites, conjugates and free forms. Seven green tea catechins and their corresponding metabolites were identified postsupplementation in skin biopsies, 20 in blister fluid and 26 in plasma, with 15 green tea catechin metabolites present in both blister fluid and plasma. The valerolactone, O-methyl-M4-O-sulfate, a gut microbiota metabolite of catechins, was significantly increased 1.6-fold by UVR in blister fluid samples. In conclusion, there were some common catechin metabolites in the plasma and blister fluid, and the concentration was always higher in plasma. The results suggest that green tea catechins and metabolites are bioavailable in skin and provide a novel link between catechin metabolites derived from the skin and gut microbiota. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Effect of Green Tea Extract in Reducing Genotoxic Injuries of Cell Phone Microwaves on Bone Marrow

    Directory of Open Access Journals (Sweden)

    Zahra Zahedifar

    2013-11-01

    Full Text Available Background: Green tea (Camellia sinensis extract is rich source of natural antioxidants specially catechin that is quickly absorbed into the body and it has cancer protective, anti microbial and anti inflammation effects. In this study has been studied role of green tea extract against genotoxic damage induced by cell phone microwaves on bone marrow polychromatic erythrocytes of adult male Balb/C mouse.Materials and Methods: In this experimental study 40 mouse were divided into five groups, control animals were located under natural condition, sham -exposed animals were prepared by experimental condition without cell phone waves radiation. Experimental 1 group that irradiated at cell phones for 4 days (3 hours/day and experimental 2 groups were injected intraperitoneal 100 mg/kg green tea extract for 5 days and experimental 3 group that irradiated at active mobile phones for 4 days (3 hours/day and were injected intraperitoneal 100 mg/kg green tea extract for 5 days. After treatment period micronucleus test was evaluated in polychromatic erythrocytes on bone marrow. The quantitative data was analyzed by ANOVA and Tukey test with using of SPSS-13 software at the level of p<0.05.Results: Based on this study, treatment with extracts of green tea decreased micronucleus frequency in bone marrow polychromatic erythrocytes of Balb/C mouse that irradiated at cell phone microwave (0.92±0.129, (p<0.001.Conclusion: Cell phone microwaves (940 MHz increased micronucleus on bone marrow polychromatic erythrocytes of male Balb/C mouse, but green tea had inhibitory effect and it decreased the average number of micronucleus.

  20. The prevention of lung cancer induced by a tobacco-specific carcinogen in rodents by green and black Tea.

    Science.gov (United States)

    Chung, F L

    1999-04-01

    A growing body of evidence from studies in laboratory animals indicates that green tea protects against cancer development at various organ sites. We have previously shown that green tea, administered as drinking water, inhibits lung tumor development in A/J mice treated with 4-(methylnitrosamino)-1-(3-pyridyl)-l-butanone (NNK), a potent nicotine-derived lung carcinogen found in tobacco. The inhibitory effect of green tea has been attributed to its major polyphenolic compound, epigallocatechin gallate (EGCG), and, to a lesser extent, to caffeine. We have also demonstrated that while levels of O6-methylguanine, a critical lesion in NNK lung tumorigenesis, were not affected in lung DNA. However, the levels of 8-hydroxydeoxyguanosine (8-OH-dG), a marker of oxidative DNA damage, were significantly suppressed in mice treated with green tea or EGCG. These studies underscore the importance of the antioxidant activity of green tea and EGCG for their inhibitory activity against lung tumorigenesis. Unlike green tea, the effect of black tea on carcinogenesis has been scarcely studied, even though the worldwide production and consumption of black tea far exceeds that of green tea. The oxidation products found in black tea, thearubigins and theaflavins, also possess antioxidant activity, suggesting that black tea may also inhibit NNK-induced lung tumorigenesis. Indeed, bioassays in A/J mice have shown that black tea given as drinking water retarded the development of lung cancer caused by NNK. However, data on the relationship of black tea consumption with the lung cancer risk in humans are limited and inconclusive. There is a need for additional tumor bioassays in animal models to better examine the protective role of black tea against lung cancer. The development of adenocarcinomas and adenosquamous carcinomas in F344 rats upon chronic administration of NNK provides an important and relevant model for lung carcinogenesis in smokers. Thus far, no information was previously

  1. Characterization of the constituents and antioxidant activity of Brazilian green tea (Camellia sinensis var. assamica IAC-259 cultivar) extracts.

    Science.gov (United States)

    Saito, Samuel T; Gosmann, Grace; Saffi, Jenifer; Presser, Márcio; Richter, Marc F; Bergold, Ana M

    2007-11-14

    Freeze-dried extracts from Camellia sinensis var. assamica IAC-259 cultivar named Brazilian green tea were prepared by hot water and ultrasound-assisted extractions using leaves harvested in spring and summer. Their caffeine and catechin contents were measured by high performance liquid chromatography-diode array detector. The antioxidant activity of the major green tea compounds and Brazilian green tea extracts was evaluated using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The levels of caffeine were higher in the summer samples (p extract not only epigallocatechin gallate but also epicatechin gallate (p Antioxidant activities of the Brazilian green tea extracts were not significantly different among seasons and extraction systems. The antioxidant data (IC50) of the Brazilian green tea extracts showed a significant correlation with their epigallocatechin gallate and epicatechin gallate contents (p < 0.05).

  2. Green tea and exercise interventions as nondrug remedies in geriatric patients with rheumatoid arthritis

    OpenAIRE

    2016-01-01

    This study aimed to evaluate the effects of green tea and supervised exercise training interventions on improvement of disease activity and bone metabolism markers in rheumatoid arthritis patients. [Subjects and Methods] One-hundred and twenty subjects who had a mean age of (60.7 ± 2.53 years) and had been diagnosed with rheumatoid arthritis at least ten years previously were randomly included in this study. Patients were treated with infliximab, green tea, or a supervised exercise program fo...

  3. Effect of the green tea on the formation of the bacterian plaque for Streptococcus mutans.

    OpenAIRE

    Moromi Nakata, Hilda; Departamento Académico de Ciencias Básicas; Facultad de Odontología; Universidad Nacional Mayor de San Marcos. Lima, Perú.; Martinez Cadillo, Elba; Departamento Académico de Ciencias Básicas; Facultad de Odontología; Universidad Nacional Mayor de San Marcos. Lima, Perú.

    2014-01-01

    In order to determine the effect of the infusion of the green tea to 10 % w/v in plaque formation for Streptococcus mutans ATCC 25175; carried out successive cultures every 24 hours, up to 7 days, in broth saccharose to 5 %. The results showed a notarial decrease and lack of adherence in the plaque formation at wiere of nichrone cultures with infusion of green tea with respect at control culture. Con el objetivo de determinar el efecto de la infusión del té verde al 10 % w/v en la formació...

  4. Associations of green tea and rock tea consumption with risk of impaired fasting glucose and impaired glucose tolerance in Chinese men and women.

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    Huibin Huang

    Full Text Available OBJECTIVE: To explore the associations of green tea and rock tea consumption with risk of impaired fasting glucose (IFG and impaired glucose tolerance (IGT. METHODS: A multistage, stratified, cluster, random-sampling method was used to select a representative sample from Fujian Province in China. In total, 4808 subjects without cardiovascular disease, hypertension, cancer, or pancreatic, liver, kidney, or gastrointestinal diseases were enrolled in the study. A standard questionnaire was used to gather data on tea (green, rock, and black consumption and other relevant factors. The assessment of impaired glucose regulation (IGR was using 75-g oral glucose tolerance test (OGTT, the diagnostic criteria of normal glucose tolerance was according to American Diabetes Association. RESULTS: Green tea consumption was associated with a lower risk of IFG, while rock tea consumption was associated with a lower risk of IGT. The adjusted odds ratios for IFG for green tea consumption of 30 cups per week were 1.0 (reference, 0.42 (95% confidence intervals (CI 0.27-0.65, 0.23 (95% CI, 0.12-0.46, and 0.41 (95% CI, 0.17-0.93, respectively. The adjusted odds ratios for IGT for rock tea consumption of 30 cups per week were 1.0 (reference, 0.69 (95% CI, 0.48-0.98, 0.59 (95% CI, 0.39-0.90, and 0.64 (95% CI, 0.43-0.97, respectively. A U-shaped association was observed, subjects who consumed 16-30 cups of green or rock tea per week having the lowest odds ratios for IFG or IGT. CONCLUSIONS: Consumption of green or rock tea may protect against the development of type 2 diabetes mellitus in Chinese men and women, particularly in those who drink 16-30 cups per week.

  5. Antioxidative potential, nutritional value and sensory profiles of confectionery fortified with green and yellow tea leaves (Camellia sinensis).

    Science.gov (United States)

    Gramza-Michałowska, Anna; Kobus-Cisowska, Joanna; Kmiecik, Dominik; Korczak, Józef; Helak, Barbara; Dziedzic, Krzysztof; Górecka, Danuta

    2016-11-15

    This paper presents a study on development of functional food products containing green and yellow tea leaves. The results indicated that green and yellow tea are significant tools in the creation of the nutritional value, antioxidative potential and stability of the lipid fraction of cookies. Tea-fortified cookies showed considerably higher contents of dietary fiber, especially hemicellulose and insoluble fractions, and were characterized by significantly higher antioxidant potential associated with their phenolics content. Results of ABTS, DPPH, ORACFL and PCL assay showed significantly higher antioxidant potential of tea cookies, highest for yellow tea. The antioxidative potential of applied teas was significant in terms of the inhibition of hydroperoxide content, while formation of secondary lipid oxidation products was less spectacular. It is concluded that tea leaves could be widely used as a source of polyphenols with high antioxidative potential, as well as fiber; thus introducing numerous health benefits for the consumer.

  6. Analysis of Green - tea Qualities in Rizhao Tea - planting Areas%日照茶叶生产基地绿茶品质评价分析

    Institute of Scientific and Technical Information of China (English)

    张伦; 张祖陆; 王学; 王茂香

    2011-01-01

    研究了日照茶叶生产基地BDC,BBSZ和BYQ3个茶园的福鼎大白、黄山群体和鸠坑3个绿茶品种主要生化成分的含量,并将其与浙江龙井、福建乌龙茶名种等南方优质绿茶的各生化成分进行对比分析。结果表明,3个绿茶品种中,鸠坑的品质最好,福鼎大白次之,黄山群体最差,但日照绿茶总体品质要.优于各南方绿茶。%The main biochemical components of three green- tea breeds are analyzed about three tea planta- tions in Rizhao tea- planting areas, and comparison was carried out with Zhejiang green- tea as well as Fu- jian oolong tea. The results turned out that according to comparison of tea breeds, the quality of Jiukeng breed is the best, and the next is Fudingdabai, while Huangshanquntea is poorest of all. Still and all, the total quality of Rizhao green - tea is superior to the southern tea.

  7. Flavonoids, total phenolics and antioxidant capacity: comparison between commercial green tea preparations

    Directory of Open Access Journals (Sweden)

    Débora Harumi Kodama

    2010-12-01

    Full Text Available The potential health benefits attributed to green tea and its catechins such as antioxidant effects, cancer chemoprevention, and weight loss have led to a huge increase of green tea products in the food market. The objectives of this work were to analyze and compare these products in terms of phenolic contents and in vitro antioxidant capacity including tea bags, dehydrated leaves, and ready-to-drink preparations after standardization of the infusion preparation procedure. Total phenolics content in 1 cup of the different teas varied from 90 to 341 mg of catechin equivalents, and the highest and the lowest values were both those of the ready-to-drink products. Infusions prepared from tea bags had contents varying from 96 to 201 mg.200 mL-1, and there were no significant differences among batches. The DPPH radical scavenging and the Oxygen Radical Absorbing Capacities (ORAC varied largely among the different tea preparations, from 23 to 131 mmoles of Trolox Equivalents (TE.200 mL-1 (DPPH, and from 1.2 to 5.1 mmoles of TE.200 mL-1 (ORAC, but again there were no differences among infusions or ready-to-drink commercial preparations. However, the antioxidant capacity of ready-to-drink products was partially due to the presence of other non-phenolic compounds such as ascorbic acid

  8. Identification of processed Japanese green tea based on polymorphisms generated by STS-RFLP analysis.

    Science.gov (United States)

    Kaundun, Shiv S; Matsumoto, Satoru

    2003-03-26

    In Japan, tea is generally sold blended, though 90% of the total production is clonal. Due to the increasingly strict consumer need and taste, however, more and more Japanese green teas are being sold under their particular cultivar name. Moreover, tea made from Yabukita, a much appreciated cultivar originally developed in Japan, has recently been produced and imported from a neighboring country. This paper describes a simple and inexpensive methodology capable of identifying fresh and processed Japanese green teas to discourage its fraudulent commercialization. The study was based on 46 main tea cultivars, and polymorphism detected through STS-RFLP analysis of the coding and noncoding DNA regions of three genes, namely phenylalanine ammonia-lyase, chalcone synthase, and dihydroflavonol 4-reductase, for which nucleotide information was available. All 46 tea cultivars analyzed could be easily distinguished using a combination of codominant DNA markers. Yabukita displayed a unique profile when PAL intron was digested with DdeI, thus allowing its rapid authentication at low cost.

  9. Coffee and green tea consumption is associated with upper aerodigestive tract cancer in Japan.

    Science.gov (United States)

    Oze, Isao; Matsuo, Keitaro; Kawakita, Daisuke; Hosono, Satoyo; Ito, Hidemi; Watanabe, Miki; Hatooka, Shunzo; Hasegawa, Yasuhisa; Shinoda, Masayuki; Tajima, Kazuo; Tanaka, Hideo

    2014-07-15

    The impact of coffee and green tea consumption on upper aerodigestive tract (UADT) cancer risk has not been established. Evaluation of the possible anticarcinogenic properties of their ingredients is confounded by the potential increase in risk owing to the high temperatures at which these beverages are generally consumed. We conducted a case-control study to evaluate the association between coffee and tea consumption and the risk of UADT cancer. The study enrolled 961 patients with UADT cancer and 2,883 noncancer outpatients who visited Aichi Cancer Center between 2001 and 2005. Information on coffee and green tea consumption and other lifestyle factors was collected via a self-administered questionnaire. Consumption of three or more cups of coffee per day had a significant inverse association with UADT cancer [odds ratio (OR) 0.73, 95% confidence interval (CI) 0.55-0.96]. In contrast, consumption of three or more cups of green tea per day had a significant positive association with UADT cancer (OR 1.39, 95% CI 1.13-1.70). These associations were evident for head and neck cancer but not for esophageal cancer. The association of coffee consumption with head and neck cancer was observed only among never smokers and alcohol drinkers. Similarly, the association of green tea consumption was observed among never smokers and never alcohol drinkers. No change in these associations was seen on stratification by each confounding factors. These findings suggest that consumption of coffee might be associated with a decreased risk of UADT cancer, whereas that of green tea might be associated with an increased risk.

  10. Determination of fluoride in black, green and herbal teas by ionselective electrode using a standard-addition method

    Directory of Open Access Journals (Sweden)

    Mochammad Yuwono

    2005-06-01

    Full Text Available Tea leaves are very rich in fluoride, since tea plants take up fluoride from the soil and accumulate in its leaves. Some of this fluoride is released into the infusion, which is drunk as tea. Fluoride in tea could be beneficial for the prevention of dental caries, but it may result in excessive intake and lead to enamel fluorosis. The purpose of this work was to determine the fluoride levels in 12 different brands and types of tea by means of a computer-controlled ion-selective electrode potentiometry using a standard-addition method. It is a rapid method which showed good accuracy and precision. Fluoride contents of tea infusions after 5 min ranged from 0.95 to 4.73 mg/l for black teas; from 0.70 to 1.00 mg/l for green teas, and from 0.26 to 0.27 mg/l for herbal teas. It was concluded that black teas and green teas examined may be important contributors to the total daily fluoride intake. However, the ingestion of some black teas that were found to have high fluoride content by children at the age of risk to dental fluorosis should be avoided.

  11. Application of microwave energy in the manufacture of enhanced-quality green tea.

    Science.gov (United States)

    Gulati, Ashu; Rawat, Renu; Singh, Brajinder; Ravindranath, S D

    2003-07-30

    Green tea manufacture was standardized with respect to the inactivation of polyphenol oxidase (PPO), rolling, and drying for quality manufacture. Inactivation of PPO by parching, steaming, microwave heating, and oven heating was monitored in tea shoots. The inactivated shoots were rolled under regimens of high and low pressures and dried by microwave heating, oven heating, or sun-drying; total phenols and catechins were estimated. Parched and sun-dried teas contained the lowest levels of total phenols and catechins, and their infusions were dull in color with a slightly burnt odor. Microwave-inactivated and-dried teas showed the highest levels of total phenols and catechins, and their infusions were bright in color and sweet in taste with a subtle pleasant odor. In steam-inactivated and oven/microwave-dried teas, total phenol and catechin contents were intermediate between parched and sun-dried teas and microwave-inactivated and microwave-dried teas, and their infusions were bright with a umami taste.

  12. Effects of brewing conditions on the antioxidant capacity of twenty-four commercial green tea varieties.

    Science.gov (United States)

    Sharpe, Erica; Hua, Fang; Schuckers, Stephanie; Andreescu, Silvana; Bradley, Ryan

    2016-02-01

    A novel paper-based Nanoceria Reducing Antioxidant Capacity (NanoCerac) assay for antioxidant detection (Sharpe, Frasco, Andreescu, & Andreescu, 2012), has been adapted for the first time as a high-throughput method, in order to measure the effect of brewing conditions and re-infusion on the antioxidant capacity of twenty-four commercial green teas. The oxygen radical absorbance capacity (ORAC) assay, frequently applied to complex foods and beverages, was used as a comparator measure of antioxidant capacity. A novel measure of sustained antioxidant capacity, the total inherent antioxidant capacity (TI-NanoCerac and TI-ORAC) was measured by infusing each tea six times. Effects of brewing conditions (temperature, brew time, etc.) were assessed using one popular tea as a standard. Both NanoCerac and ORAC assays correlated moderately (R(2) 0.80 ± 0.19). The average first-brew NanoCerac, TI-NanoCerac, first-brew ORAC and TI-ORAC were: 0.73 ± 0.1 GAE/g tea; 2.4 ± 0.70 mmolGAE/g tea; 1.0 ± 0.3 mmolTE/g tea and 2.1 ± 0.71 mmolTE/g tea respectively. Brewing conditions including water temperature and infusion time significantly affected antioxidant capacity. The high-throughput adaptation of the original NanoCerac assay tested here offered advantages over ORAC, including portability and rapid analysis.

  13. In Vitro Chemopreventive Properties of Green Tea, Rooibos and Honeybush Extracts in Skin Cells

    Directory of Open Access Journals (Sweden)

    Tandeka U. Magcwebeba

    2016-11-01

    Full Text Available The chemopreventive properties of the herbal teas rooibos (Aspalathus linearis and honeybush (Cyclopia spp. have been demonstrated on mouse skin in vivo but the underlying mechanisms are not clear. The aim of the current study was to determine the anti-proliferative and pro-apoptotic activity of methanol and aqueous extracts of rooibos and two Cyclopia species in different skin cells, using green tea (Camellia sinensis as a benchmark. Extracts were also characterised for their major individual polyphenols by high performance liquid chromatography and spectroscopically for the total polyphenol (TP groups. The methanol extract of rooibos, containing higher levels of polyphenols than its aqueous extract, displayed similar activity to green tea as it selectively targeted premalignant cells by inhibiting cell proliferation at lower concentrations whilst inducing apoptosis via membrane depolarisation at higher concentrations. Specific roles of the major rooibos dihydrochalcones and flavanol/proanthocyanidin-type (FLAVA compounds are likely to be involved. The aqueous extracts of the Cyclopia species were more active against cell proliferation and at inducing apoptosis which was associated with a higher FLAVA content and a reduced TP/FLAVA ratio. In contrast, their methanol extracts exhibited a cytoprotective effect against apoptosis which was related to their monomeric xanthone and flavanone content. The underlying chemopreventive properties of green tea and the herbal teas appear to be associated with diverse and complex monomeric/polymeric polyphenolic cell interactions.

  14. Green tea and diabetes mellitus%绿茶与糖尿病

    Institute of Scientific and Technical Information of China (English)

    狄红杰; 刘超

    2011-01-01

    Diabetes mellitus is one of the major and growing public health problems. Tea is the most commonly consumed soft drink in the world except for water. Green tea contains many components such as tea polyphenol, caffeine,theanine and vitamins. It can increase insulin sensitivity and regulate glucose metabo]ism. Epidemiological observations, laboratory studies and clinical trials have shown that green tea has an effect on glucose tolerance, resulting in the reduction of blood glucose and hemoglobin A 1 c. However, future studies are required to fully understand the beneficial effects of green tea on diabetic patients.%糖尿病日益成为严重的社会问题.茶是除了水之外最为广泛饮用的饮料.绿茶含绿茶多酚、咖啡因、维生素等有效成分,可以增加胰岛素的敏感性,调节糖代谢.流行病学研究、动物实验和临床研究均证明,饮用绿茶可降低糖尿病发病风险,改善糖耐量,降低血糖和糖化血红蛋白Alc,但还需要更多的研究进一步证实绿茶在糖尿病防治中的价值.

  15. Syneresis and rheological behaviors of set yogurt containing green tea and green coffee powders.

    Science.gov (United States)

    Dönmez, Özge; Mogol, Burçe Ataç; Gökmen, Vural

    2017-02-01

    This study aimed to investigate the effect of added green coffee powder (GCP) and green tea powder (GTP) on syneresis behavior and consistency of set yogurts. Adding GCP (1 or 2%) decreased syneresis rate. The effect of GTP on the syneresis rate was concentration dependent. In comparison to the control, GTP decreased syneresis rate when it was added at 0.02%, but it caused an increase when added at 2%. No significant difference was observed in the syneresis rates when GTP was added at 1 and 0.01%, until 14 and 7 d of storage, respectively. The Herschel-Bulkley model parameters indicated that the consistency of control was considerably lower than that of GCP yogurts during 14 d, whereas it was higher at the end of storage. The GTP yogurt results showed that the consistency coefficients of GTP yogurts were different from those of control samples until 14 d of storage. In conclusion, GTP and GCP behaved differently in acidified gel networks of set yogurt, modifying its rheological behavior, as they have different profiles and concentrations of polyphenols. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  16. Simulated gastrointestinal digestion, intestinal permeation and plasma protein interaction of white, green, and black tea polyphenols.

    Science.gov (United States)

    Tenore, Gian Carlo; Campiglia, Pietro; Giannetti, Daniela; Novellino, Ettore

    2015-02-15

    The gastrointestinal digestion, intestinal permeation, and plasma protein interaction of polyphenols from a single tea cultivar at different stages of processing (white, green, and black teas) were simulated. The salivary phase contained 74.8-99.5% of native polyphenols, suggesting potential bioavailability of significant amounts of antioxidants through the oral mucosal epithelium that might be gastric sensitive and/or poorly absorbed in the intestine. White tea had the highest content and provided the best intestinal bioaccessibility and bioavailability for catechins. Since most of native catechins were not absorbed, they were expected to accumulate in the intestinal lumen where a potential inhibition capacity of cellular glucose and cholesterol uptake was assumed. The permeated catechins (approximately, 2-15% of intestinal levels) significantly bound (about 37%) to plasma HDLs, suggesting a major role in cholesterol metabolism. White tea and its potential nutraceuticals could be effective in the regulation of plasma glucose and cholesterol levels.

  17. Adsorption of Pb(II on Spent Leaves of Green and Black Tea

    Directory of Open Access Journals (Sweden)

    Antonio Zuorro

    2010-01-01

    Full Text Available Problem statement: In recent years much attention has been focused on the use of biomass residues as low-cost adsorbents for the removal of heavy metal ions from contaminated waters. Spent tea leaves, an abundantly available material that is currently disposed of as a solid waste, are potentially suitable for such applications. Approach: To provide some information on the adsorption properties of tea waste, we evaluated the removal efficiency of lead ions by spent leaves of green and black tea. Batch adsorption experiments were made at 25 and 40°C at initial lead-ion concentrations between 0.01 and 2 g L-1. Equilibrium data were analyzed by the Langmuir equation to evaluate the maximum adsorption capacity and the equilibrium constant. The adsorption characteristics of the two materials were also compared with those of coffee grounds, activated carbon and Fullers earth. Results: Experimental data showed that removal efficiencies up to 98-99% can be achieved when using spent tea leaves as lead adsorbent. The results were only marginally affected by the type of tea waste. At low lead loading, the adsorption equilibrium was well described by the Langmuir equation, with a maximum adsorption capacity of 83-130 mg g-1 and an equilibrium constant ranging from 0.112-0.245 L mg-1. A comparison with other adsorbents provided the following order for lead removal efficiency: Black tea, coffee grounds > green tea > Fullers earth > activated carbon. Conclusion: The results from this study indicate that using spent tea leaves as an adsorbent may be an efficient and economical means for removing lead and, presumably, other heavy metal ions from aqueous solutions.

  18. Role of catechins in the antioxidant capacity of an active film containing green tea, green coffee, and grapefruit extracts.

    Science.gov (United States)

    Colon, M; Nerin, C

    2012-10-03

    The oxygen radical absorbance capacity (ORAC) method was used to characterize the antioxidant capacity of natural extracts of green tea, green coffee, and grapefruit. These natural extracts were incorporated into a plastic film layer, which was subsequently subjected to a free radical gas stream in order to determine the antioxidant capacity directly in the active film. The green tea extract (GTE) afforded the strongest antioxidant activity. To identify the active compounds in the extract, concentration of the diverse catechins in samples were determined by HPLC-UV analysis. The results showed that the content of catechins in the GTE is around 77% (w/w), the major components being (-)-epigallocatechin gallate, (-)-epicatechin gallate, and (-)-epicatechin. A variation in the concentration profile of catechins was detected during the oxidation process. The chromatographic study demonstrated that (-)-gallocatechin, (-)- epigallocatechin, (+)-catechin, and (-)-catechin gallate exhibited the most radical scavenging.

  19. The Effect of Green Tea versus Sour Tea on Insulin Resistance, Lipids Profiles and Oxidative Stress in Patients with Type 2 Diabetes Mellitus: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Hassan Mozaffari-Khosravi

    2014-09-01

    Full Text Available Background: By decreasing oxidative stress and whereby decreasing insulin resistance, it may be possible to decrease complications of Diabetes Mellitus (DM. Green tea and sour tea contain phytochemicals which have anti-oxidative function. The aim of this study is to compare the effect of sour and green tea consumption on insulin resistance and oxidative stress in DM. Methods: This study is a randomized clinical trial in which 100 type 2 diabetes patients were randomly assigned into sour tea group (ST and green tea group (GT. The patients were instructed to drink 150ml sour tea and green tea infusion, respectively, three times a day for 4 weeks. Fasting blood sugar (FBS, fructosamine, lipid profiles, fasting blood insulin (FBI, homeostasis model assessment of insulin resistance (HOMA-IR; beta cell function (b%, insulin sensitivity (S% and malondialdehyde (MDA were monitored. Results: HDL-c significantly increased in both groups. The median of FBI in GT showed significant decrease (8.5 to 6.6 μIU/mL unlike the ST which showed significant increase (8.2 to 16.3 μIU/mL. The median of HOMA-IR after the intervention in GT showed lower levels than the ST (1.1 vs. 1.6, P=0.004. The median of b% only in ST showed significant increase from 38.2% at the baseline to 47.7% after the intervention. The mean of S% only in ST showed significant decrease after the intervention. Conclusion: This study shows that the use of 150 ml infusion of green tea or sour tea, three times a day for four weeks, has positive effect on insulin resistance and certain lipoproteins in type 2 DM. Trial Registration Number: IRCT201107317161N1

  20. Green synthesis of tea Ag nanocomposite hydrogels via mint leaf extraction for effective antibacterial activity.

    Science.gov (United States)

    Jayaramudu, Tippabattini; Varaprasad, Kokkarachedu; Raghavendra, Gownolla Malegowd; Sadiku, E R; Mohana Raju, Konduru; Amalraj, John

    2017-10-01

    In this report, we investigated the swelling behavior and antibacterial property of nanosilver composite hydrogels made from tea with polyacrylamide via a free-radical polymerization and green process technique. This is probably for the first time; tea-based nano silver composite hydrogels were developed. The composite hydrogels comprise embedded nano silver particles in the tea hydrogel matrix via a green process with mint leaf extract. The size of the nano silver particles in the hydrogel matrix was found to be < 10 nm. The nano silver composite hydrogels formed and their blank hydrogels from the mint leaf were characterized by using ultraviolet-visible spectroscopy, scanning electron microscopy with energy dispersive spectroscopy, transmission electron microscopy, thermogravimetric analysis and X-ray diffraction studies. The nano silver composite hydrogels developed exhibit eminent antibacterial activity against Escherichia coli and Staphylococcus aureus. This clearly indicates that the nano silver composite hydrogels are potential candidates for antimicrobial applications.

  1. Chinese green tea and acute hepatitis: a rare yet recurring theme.

    Science.gov (United States)

    Lugg, Sebastian Thomas; Braganza Menezes, Darryl; Gompertz, Simon

    2015-09-23

    A previously healthy 16-year-old girl presented with signs of acute hepatitis. On initial enquiry, she had not taken any prescribed or 'over-the-counter' medications, and there was no recent travel history. Further investigations revealed no viral, autoimmune or metabolic cause of hepatitis. Only following specific questioning did she reveal that she had, in the preceding 3 months, regularly consumed internet ordered Chinese green tea, which contained Camellia sinensis. After ceasing green tea consumption, there was a rapid and sustained recovery of her hepatitis. The authors discuss the probable cause of herbal tea in this case of acute hepatitis, and the importance of awareness of this rare yet recurring theme for patients and clinicians alike.

  2. NMR Metabolic profiling of green tea (Camellia sinensis L.) leaves grown at Kemuning, Indonesia

    Science.gov (United States)

    Wahyuni, D. S. C.; Kristanti, M. W.; Putri, R. K.; Rinanto, Y.

    2017-01-01

    Green tea (Camellia sinensis L.) has been famous as a beverage and natural medicine. It contains a broad range of primary and secondary metabolites i.e. polyphenols. Nuclear Magnetic Resonance (NMR) has been widely used for metabolic profiling in medicinal plants. It provides a very fast and detailed analysis of the biomolecular composition of crude extracts. Moreover, an NMR spectrum is a physical characteristic of a compound and thus highly reproducible. Therefore, this study aims to profile metabolites of three different varieties of green tea C. Sinensis grown in Kemuning, Middle Java. Three varieties of green tea collected on Kemuning (TR1 2025, Gambung 4/5, and Chiaruan 143) were used in this study. 1H-NMR spectra were recorded at 230C on a 400 MHz Agilent WB (Widebore). The analysis was performed on dried green tea leaves and analyzed by 1H-NMR, 2D-J-resolved and 1H-1H correlated spectroscopy (COSY). MestRenova version 11.0.0 applied to identify metabolites in samples. A 1H-NMR spectrum of tea showed amino acids and organic acids signal at the area δ 0.8-4.0. These were theanine, alanine, threonine, succinic acid, aspartic acid, lactic acid. Anomeric protons of carbohydrate were shown by the region of β-glucose, α-glucose, fructose and sucrose. The phenolic region was depicted at area δ 5.5-8.5. Epigallocatechin derivates and caffeine were detected in the tea leaves. The detail compound identification was observed and discussed in the text.

  3. Green Tea Polyphenols Attenuated Glutamate Excitotoxicity via Antioxidative and Antiapoptotic Pathway in the Primary Cultured Cortical Neurons

    OpenAIRE

    Lin Cong; Chang Cao; Yong Cheng; Xiao-Yan Qin

    2016-01-01

    Green tea polyphenols are a natural product which has antioxidative and antiapoptotic effects. It has been shown that glutamate excitotoxicity induced oxidative stress is linked to neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. In this study we explored the neuroprotective effect of green teen polyphenols against glutamate excitotoxicity in the primary cultured cortical neurons. We found that green tea polyphenols protected against glutamate induced neurotox...

  4. Molecular Dynamics Study on the Biophysical Interactions of Seven Green Tea Catechins with Cell Membranes

    Science.gov (United States)

    Molecular dynamics simulations were performed to study the interactions of bioactive catechins (flavonoids) commonly found in green tea with lipid bilayers, as model for cell membranes. Previously, a number of experimental studies rationalized catechin’s anticarcinogenic, antibacterial, and other be...

  5. Excessive Consumption of Green Tea as a Risk Factor for Periodontal Disease among Korean Adults.

    Science.gov (United States)

    Han, Kyungdo; Hwang, Eunkyung; Park, Jun-Beom

    2016-07-02

    This study was performed to assess the relationship between the amount of green tea that is consumed and periodontitis. It is based on data obtained from the Korea National Health and Nutrition Examination Survey, conducted between 2008 and 2010. A community periodontal index equal to code 3 was defined as moderate periodontitis, and code 4 was defined as severe periodontitis (n = 16,726). Consumption of green tea less than one cup per day was associated with a decreased prevalence of periodontal disease among Korean adults. The association between the consumption of green tea and periodontal disease was independent of various potential confounding factors, such as age, sex, body mass index, smoking, drinking, exercise, metabolic syndrome, frequency of tooth brushing per day, use of secondary oral products, the number of dental examination per year, diabetes, hypertension, and white blood cell count. Adjusted odds ratio and 95% confidence interval of no consumption was 1.360 (1.156, 1.601) when participants with consumption of two times per week ≤ x green tea may be considered as a risk factor for periodontal disease among Korean adults.

  6. HEMATOLOGICAL AND IMMUNOBIOCHEMICAL STUDY OF GREEN TEA AND GINGER EXTRACTS IN EXPERIMENTALLY INDUCED DIABETIC RABBITS.

    Science.gov (United States)

    Elkirdasy, Ahmed; Shousha, Saad; Alrohaimi, Abdulmohsen H; Arshad, M Faiz

    2015-01-01

    The present study was designed to investigate the effects of the extract of green tea and/or ginger on some hematological and immunobiochemical profiles in alloxan-induced diabetic rabbits. The results revealed that treatment of diabetic animals with extract of green tea and/or ginger elevated the decreased HDL-c and LDL-c but significantly decreased triglycerides, the elevated glucose and GOT concentrations. The result also displayed a non-significant increase in the levels of CRP and fibrinogen. The experiment also revealed that the elevated MDA and GSH level fell down to the normal control group. The result also showed that after green tea and/or ginger extract treatment, the lowered RBC, WBC counts, PCV, percentage of neutrophils were increased and the elevated MCV, MCH, and MCHC of diabetic rabbits were decreased to normal levels. Thus, the overall results may indicate that green tea and/or ginger extracts have a significant hypoglycemic effect in diabetic rabbits. In addition, the extracts may be capable of improving hyperlipidemia, the impaired kidney function and hemogram in alloxan-induced diabetic rabbits.

  7. Green tea polyphenols attenuate deterioration of bone microarchitecture in female rats with systemic chronic inflammation

    Science.gov (United States)

    Introduction: Our previous study demonstrated that green tea polyphenols (GTP) benefit bone health in female rats with chronic inflammation, because of GTP’s antioxidant capacity. The current study further evaluates whether GTP can restore bone microstructure along with related mechanism in rats wit...

  8. Green Tea Polyphenols and Vitamin D3 Protect Bone Microarchitecture in Female Rats with Chronic Inflammation

    Science.gov (United States)

    Our recent study showed that green tea polyphenols (GTP) in conjunction with 1-a-OH¬vit-D3 (vitD3) treatment mitigates lipopolysaccharide (LPS)-induced bone mineral density loss in female rats. This study was undertaken to further explore the mechanism and bone microarchitecture of GTP plus vitD3 in...

  9. Supplementation with green tea polyphenols improves bone microstructure and quality in aged, orchidectomized rats

    Science.gov (United States)

    Recent studies show that green tea polyphenols (GTP) attenuate bone loss and microstructure deterioration in ovariectomized aged female rats, a model of postmenopausal osteoporosis. However, it is not known if such an osteo-protective role of GTP is demonstrable in androgen-deficient aged rats, a mo...

  10. Green Tea Catechin Consumption Enhances Exercise-Induced Abdominal Fat Loss

    Science.gov (United States)

    Aim: This study evaluated the influence of a green tea catechin beverage on body composition and fat distribution in overweight and obese adults during exercised-induced weight loss. Methods: Participants (N=132) were randomly assigned to receive a 500 mL beverage containing approximately 625 mg of...

  11. Green tea polyphenols attenuate glial swelling and mitochondrial dysfunction following oxygen-glucose deprivation in cultures

    Science.gov (United States)

    Astrocyte swelling is a major component of cytotoxic brain edema in ischemia. Oxidative stress and mitochondrial dysfunction have been hypothesized to contribute to such swelling in cultures. We investigated the protective effects of polyphenol-rich green tea extract (GTE) on key features of ischemi...

  12. Green tea polyphenols supplementation improves bone microstructure in orchidectomized middle-Aged rats

    Science.gov (United States)

    Our recent study shows that green tea polyphenols (GTP) attenuate trabecular bone loss in ovariectomized middle-aged female rats. To investigate whether GTP prevents bone loss in male rats, 40 rats with and without oriectomy (ORX) were assigned to 4 groups in a 2 (sham vs. ORX)× 2 (no GTP and 0.5% G...

  13. Green tea EGCG, T cells, and T cell-mediated autoimmune diseases

    Science.gov (United States)

    One of the proposed health benefits of consuming green tea is its protective effect on autoimmune diseases. Research on the immunopathogenesis of autoimmune diseases has made significant progression in the past few years and several key concepts have been revised. T cells, particularly CD4+ T helper...

  14. pH-dependent radical scavenging capacity of green tea catechins

    NARCIS (Netherlands)

    Muzolf, M.; Szymusiak, H.; Gliszczynska-Swiglo, A.; Rietjens, I.M.C.M.; Tyrakowska, B.

    2008-01-01

    The effect of pH on the radical scavenging capacity of green tea catechins was investigated using experimental as well as theoretical methods. It was shown that the radical scavenging capacity of the catechins, quantified by the TEAC value, increases with increasing pH of the medium. Comparison of t

  15. UHPLC determination of catechins for the quality control of green tea.

    Science.gov (United States)

    Naldi, Marina; Fiori, Jessica; Gotti, Roberto; Périat, Aurélie; Veuthey, Jean-Luc; Guillarme, Davy; Andrisano, Vincenza

    2014-01-01

    An ultra-high performance liquid chromatography (UHPLC) with UV detection method was developed for the fast quantitation of the most represented and biologically important green tea catechins and caffeine. UHPLC system was equipped with C18 analytical column (50mm×2.1mm, 1.8μm), utilizing a mobile phase composed of pH 2.5 triethanolamine phosphate buffer (0.1M) and acetonitrile in a gradient elution mode; under these conditions six major catechins and caffeine were separated in a 3min run. The method was fully validated in terms of precision, detection and quantification limits, linearity, accuracy, and it was applied to the identification and quantification of catechins and caffeine present in green tea infusions. In particular, commercially available green tea leaves samples of different geographical origin (Sencha, Ceylon Green and Lung Ching) were used for infusion preparations (water at 85°C for 15min). The selectivity of the developed UHPLC method was confirmed by comparison with UHPLC-MS/MS analysis. The recovery of the main six catechins and caffeine on the three analyzed commercial tea samples ranged from 94 to 108% (n=3). Limits of detection (LOD) were comprised in the range 0.1-0.4μgmL(-1). An orthogonal micellar electrokinetic (MEKC) method was applied for comparative purposes on selectivity and quantitative data. The combined use of the results obtained by the two techniques allowed for a fast confirmation on quantitative characterization of commercial samples.

  16. Effect of marinating chicken meat with lemon, green tea, and turmeric against foodborne bacterial pathogenss

    Science.gov (United States)

    Foodborne diseases affect millions of people each year. To reduce the incidence of bacterial foodborne pathogens more effective treatment methods are needed. In this study we evaluated the effect of marinating chicken breast fillets with extracts of lemon, green tea, and turmeric against Campylob...

  17. Excessive Consumption of Green Tea as a Risk Factor for Periodontal Disease among Korean Adults

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    Kyungdo Han

    2016-07-01

    Full Text Available This study was performed to assess the relationship between the amount of green tea that is consumed and periodontitis. It is based on data obtained from the Korea National Health and Nutrition Examination Survey, conducted between 2008 and 2010. A community periodontal index equal to code 3 was defined as moderate periodontitis, and code 4 was defined as severe periodontitis (n = 16,726. Consumption of green tea less than one cup per day was associated with a decreased prevalence of periodontal disease among Korean adults. The association between the consumption of green tea and periodontal disease was independent of various potential confounding factors, such as age, sex, body mass index, smoking, drinking, exercise, metabolic syndrome, frequency of tooth brushing per day, use of secondary oral products, the number of dental examination per year, diabetes, hypertension, and white blood cell count. Adjusted odds ratio and 95% confidence interval of no consumption was 1.360 (1.156, 1.601 when participants with consumption of two times per week ≤ x < 7 times per week was considered as a reference. However, consumption of one or more cups per day increased the prevalence of moderate and severe periodontitis. In conclusion, excessive consumption of green tea may be considered as a risk factor for periodontal disease among Korean adults.

  18. GREEN SYNTHESIS OF SILVER AND PALLADIUM NANOPARTICLES AT ROOM TEMPERATURE USING COFFEE AND TEA EXTRACT

    Science.gov (United States)

    An extremely simple green approach that generates bulk quantities of nanocrystals of noble metals such as silver (Ag) and palladium (Pd) using coffee and tea extract at room temperature is described. The single-pot method uses no surfactant, capping agent, and/or template. The ob...

  19. Green Tea Protects Testes against Atrazine-induced Toxicity in Rat

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    Reza Kheirandish

    2017-06-01

    Full Text Available Background: Atrazine (ATZ is a common herbicide in agriculture for control of grass and broad-leaved weeds. It persists in the environment and causes reproductive problems in both human and animals. The present study was aimed at protective effect of green tea against ATZ toxicity in the reproductive system of male rats. Methods: The present study was performed in Veterinary School, Shahid Bahonar University of Kerman in 2016. ATZ and treatment groups received ATZ daily 200 mg/kg BW orally for 14 d. In addition, 0.2% methanolic green tea extract was administrated in the treatment group. Results: In histopathologic investigation, number of germinal layers reduced in the most seminiferous tubules in the ATZ group and spermatids were absence. Necrotic spermatocytes, spermatids, and spermatozoa were evident in the testicular tubules. In the morphometric measurements, tubular diameter, germinal epithelium height, and meiosis index decreased significantly. Conclusion: Green tea extract had reduced testicular toxicity of atrazine significantly. ATZ induces toxicity through oxidative damage and green tea extract can protect the testes due to antioxidant activity of its polyphenols especially flavonoids.

  20. The effect of green tea on radiation-induced late biological effect in mice

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Ho; Kim, Se Ra; Lee, Hae June; Jo, Sung Kee [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2004-07-01

    This study was performed to determine the effect of Green tea on the late biological effect of mice irradiated with 3 Gy of gamma-radiation. There were various findings including hematopoietic and lymphoid tumor, lung cancer, ovarian cancer and cancer of other lesions. Further studies are needed to characterize better the protective nature of active compounds.

  1. FLUORIDE IN BLACK AND GREEN TEA (CAMELLIA SINENSIS ...

    African Journals Online (AJOL)

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    None of the 10 Ethiopian black tea leaf brands are safe for children but 30% of the ... Fluoride has also been used to treat osteoporosis [1, 2]. It is very characteristic that fluoride prevents tooth decay at about 1 mg/L but causes mottled teeth.

  2. Study on Flavour Volatiles of GABA Green Tea

    African Journals Online (AJOL)

    USER

    2012-06-26

    Jun 26, 2012 ... inhibitory neurotransmitters in the central nervous system and is known to ... units (Yao et al., 2005; Shimoda et al., 1995; Baptista et al., 1998; Kenji and ... This study took GABA tea through vacuum processing and water ...

  3. Green tea consumption and risk of esophageal cancer: a meta-analysis of epidemiologic studies

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    Zheng Ping

    2012-11-01

    Full Text Available Abstract Background Green tea has shown the role of chemoprevention for cancer. Recently, several studies suggested that green tea intake may have effect on esophageal cancer risk, whereas the results were inconsistent. Methods We performed a meta-analysis of all English and Chinese language studies of green tea consumption and esophageal cancer risk indexed in Medline, Embase, the Science Citation Index, the Chinese Biomedical Database and Wanfang Data from 1980 to June 2012. After reviewing each study, extracting data, and evaluating heterogeneity (Chi-square-based Q test and Ι2 and publication bias (Begg and Egger test, a meta-analysis was performed to evaluate the association between high/medium/low green tea consumption and non-drinking esophageal cancer risk. Pooled relative risk (RR or odds ratio (OR with 95% confidence intervals (CIs were calculated using the fixed- or random-effect models. Results Ten eligible epidemiologic studies including 33731 participants and 3557 cases for esophageal cancer were included. Eight of which were case–control studies, and two were cohort studies. Overall, there were no association between high/medium/low green tea consumption and non-drinking risk of esophageal cancer (High: highest vs non-drinker: RR/OR = 0.76, 95% CI: 0.49 to 1.02. Medium: drinker vs non-drinker: RR/OR = 0.86, 95% CI: 0.70 to 1.03. Low: lowest vs non-drinker: RR/OR = 0.83, 95% CI: 0.58 to 1.08. When stratified analyses according to study design (case–control and cohort studies, country (China and Japan, participates source (population-based and hospital-based case–control, and gender (female and male, there were significant association between high/medium/low green tea consumption and non-drinking risk of esophageal cancer among female (High: RR/OR = 0.32, 95% CI: 0.10 to 0.54. Medium: RR/OR = 0.43, 95% CI: 0.21 to 0.66. Low: RR/OR = 0.45, 95% CI: 0.10 to 0.79, but not the others. Conclusions We did not found significant

  4. Modification of lung cancer susceptibility by green tea extract as measured by the comet assay.

    Science.gov (United States)

    Zhang, Huifeng; Spitz, Margaret R; Tomlinson, Gail E; Schabath, Matthew B; Minna, John D; Wu, Xifeng

    2002-01-01

    Green tea is widely consumed throughout the world and is known to possess various beneficial properties that may affect carcinogen metabolism, free radical scavenging, or formation of DNA adducts. Therefore, it is plausible that green tea extract may modify BPDE-induced DNA damage. In this report, we utilized the comet assay to (1) evaluate BPDE-induced DNA damage as a potential marker of cancer susceptibility and (2) assess the ability of green tea to modify BPDE-induced DNA damage. DNA damage in individual comet cells was quantified by (1) visually measuring the proportion of cells exhibiting migration versus those without and (2) the length of damaged DNA migration (comet tail). We detected a dose-response between BDPE concentration and mean comet tail length in EBV-immortalized lymphoblastiod (lymphoid) cell lines. As the concentration of BPDE increased from 0.5 to 3 microM, the length of the mean comet tail length increased proportionally in the 3590P (derived from a healthy subject) and 3640P (derived from a patient with head and neck cancer) cell lines. In separate experiments using lymphoid cells from 21 lung cancer cases and 12 healthy subjects, the mean comet tail length was significantly higher in the lung cancer cases (80.19 +/- 15.55) versus the healthy subjects (59.94 +/- 14.23) (P green tea extract was added in conjunction with BPDE, there was a notable reduction of the mean comet tail length (13.29 +/- 0.97) as compared to BPDE treatment alone (80.19 +/- 15.55) (P lung cancer cases. There were no statistical differences between the baseline (no treatments) (12.74 +/- 0.63) and the green tea extract treatment (13.06 +/- 0.97) (P = 0.21). These data suggest the modification of lung cancer susceptibility by the green tea extract. Similar results were observed for the percentage of induced comet cells and the statistical trends were similar for the 12 healthy subjects. This preliminary study demonstrated that the detection of BPDE-induced DNA damage via

  5. Therapeutic potential of green tea on risk factors for type 2 diabetes in obese adults - a review.

    Science.gov (United States)

    Ferreira, M A; Silva, D M; de Morais, A C; Mota, J F; Botelho, P B

    2016-12-01

    Green tea has been associated with positive effects in the treatment of obesity and other associated comorbidities such as type 2 diabetes. These benefits are thought to be related to the anti-inflammatory and antioxidant effects of green tea and to the reduction in body fat percentage exhibited by its bioactive compounds. The predominant active compounds in green tea are flavonoid monomers known as catechins, in particular epigallocatechin-3-gallate, which is the most abundant and most effective catechin in metabolic care, particularly among obese patients. The objective of this review was to investigate the effects of green tea on body composition, oxidative stress, inflammation and insulin resistance, risk factors for the development of type 2 diabetes in obese individuals and the mechanisms that underlie the modulatory actions of green tea compounds on these risk factors. Although green tea has therapeutic potential in the treatment of obese individuals, the findings of this review demonstrate the need for a greater number of studies to confirm the positive effects of green tea, especially regarding the modulation of obesity. © 2016 World Obesity Federation.

  6. Interactive suppression of aberrant crypt foci induced by azoxymethane in rat colon by phytic acid and green tea.

    Science.gov (United States)

    Challa, A; Rao, D R; Reddy, B S

    1997-10-01

    Several epidemiological studies point to a strong correlation between nutrient composition of the diet and cancer of the colon. Phytic acid, present in grains, has been credited with reducing the risk of cancer of the colon. A number of reports are available indicating the benefits of green tea consumption in reducing the risk of stomach, lung and skin cancer, but little data are available on the effect of green tea in reducing the risk of colon cancer. Also, there are no studies on the combined effect of these compounds on colon tumorigenesis. Thus the primary objective of this investigation was to elucidate the combined effects of green tea and phytic acid on colonic preneoplastic lesions and the Phase II enzyme glutathione S-transferase. Fisher 344 male weanling rats were divided into nine groups of 15 rats each and fed the experimental diet for 13 weeks. Rats received two s.c. injections of azoxymethane in saline at 16 mg/kg body wt at 7 and 8 weeks of age. Rats received three levels (0, 1 and 2%) of phytic acid with three levels (0, 1 and 2%) of green tea within each phytic acid level in a 3 x 3 factorial experiment. Results indicate that while green tea had a marginal effect (P green tea and phytic acid was significant (P green tea and phytic acid.

  7. Allograft pretreatment for the repair of sciatic nerve defects:green tea polyphenolsversus radiation

    Institute of Scientific and Technical Information of China (English)

    Sheng-hu Zhou; Ping Zhen; Shen-song Li; Xiao-yan Liang; Ming-xuan Gao; Qi Tian; Xu-sheng Li

    2015-01-01

    Pretreatment of nerve allografts by exposure to irradiation or green tea polyphenols can elimi-nate neuroimmunogenicity, inhibit early immunological rejection, encourage nerve regeneration and functional recovery, improve tissue preservation, and minimize postoperative infection. In the present study, we investigate which intervention achieves better results. We produced a 1.0 cm sciatic nerve defect in rats, and divided the rats into four treatment groups: autograft, fresh nerve allograft, green tea polyphenol-pretreated (1 mg/mL, 4°C) nerve allograft, and irradiation-pre-treated nerve allograft (26.39 Gy/min for 12 hours; total 19 kGy). The animals were observed, and sciatic nerve electrophysiology, histology, and transmission electron microscopy were carried out at 6 and 12 weeks after grafting. The circumference and structure of the transplanted nerve in rats that received autografts or green tea polyphenol-pretreated nerve allografts were similar to those of the host sciatic nerve. Compared with the groups that received fresh or irradiation-pre-treated nerve allografts, motor nerve conduction velocity in the autograft and fresh nerve allograft groups was greater, more neurites grew into the allografts, Schwann cell proliferation was evident, and a large number of new blood vessels was observed; in addition, massive myelinated nerve ifbers formed, and abundant microiflaments and microtubules were present in the axoplasm. Our ifndings indicate that nerve allografts pretreated by green tea polyphenols are equivalent to trans-planting autologous nerves in the repair of sciatic nerve defects, and promote nerve regeneration. Pretreatment using green tea polyphenols is better than pretreatment with irradiation.

  8. Effect of green tea extracts on oxaliplatin-induced peripheral neuropathy in rats

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    Lee Jung

    2012-08-01

    Full Text Available Abstract Background A common side effect of oxaliplatin is peripheral neurotoxicity. Oxidative stress to dorsal root ganglion (DRG may be one of important pathogenic mechanisms. Green tea contains four polyphenol catechins, which are known to be potent antioxidants. The present work is aimed to determine whether green tea extracts have neuroproective or palliative effects on neurotoxicity symptoms induced by oxaliplatin. Methods We conducted behavioral tests including sensory and thermal thresholds, an electrophysiological study, and TUNEL staining to assess neurotoxicity during the experimental period using animal models. Results A total of 14 adult rats were randomly allocated into two groups. Oxaliplatin (4 mg/kg with or without green tea (300 mg/kg orally once daily was administered intraperitoneally twice per week for 6 weeks. At 4 and 6 weeks after oxaliplatin administration, sensory threshold values were significantly decreased and at 6 weeks after oxaliplatin administration, thermal threshold values were significantly increased in oxaliplatin-treated rats compared with those in rat treated with oxaliplatin and green tea extracts. The electrophysiological assessment, including sensory nerve conduction and H-reflex-related sensory nerve conduction velocity, revealed no significant changes in the two groups. TUNEL staining showed no significant difference in the number of apoptotic-featured cells between the two experimental groups in the DRG or peripheral nerves, but the number of apoptotic-featured cells in DRG was higher than that in sciatic nerves within each group. Conclusions Green tea extracts may be a useful adjuvant to alleviate sensory symptoms after oxaliplatin administration, such as allodynia, but did not prevent morphometric or electrophysiological alterations induced by oxaliplatin.

  9. New cancer treatment strategy using combination of green tea catechins and anticancer drugs.

    Science.gov (United States)

    Suganuma, Masami; Saha, Achinto; Fujiki, Hirota

    2011-02-01

    Green tea is now recognized as the most effective cancer preventive beverage. In one study, 10 Japanese-size cups of green tea daily supplemented with tablets of green tea extract limited the recurrence of colorectal polyps in humans to 50%. Thus, cancer patients who consume green tea and take anticancer drugs will have double prevention. We studied the effects of combining (-)-epigallocatechin gallate (EGCG) and anticancer drugs, focusing on inhibition of cell growth and induction of apoptosis. Numerous anticancer drugs, such as tamoxifen, COX-2 inhibitors, and retinoids were used for the experiments, and the combination of EGCG and COX-2 inhibitors consistently induced the enhancement of apoptosis. To study the mechanism of the enhancement, we paid special attention to the enhanced expressions of DDIT3 (growth arrest and DNA damage-inducible 153, GADD153), GADD45A, and CDKN1A (p21/WAF1/CIP1) genes, based on our previous evidence that a combination of EGCG and sulindac specifically induced upregulated expression of GADD153 and p21 genes in PC-9 lung cancer cells. The synergistic enhancements of apoptosis and GADD153 gene expression in human non-small cell lung cancer cells by the combination of EGCG and celecoxib were mediated through the activation of the MAPK signaling pathway. This article reviews the synergistic enhancement of apoptosis, gene expression, and anticancer effects using various combinations of EGCG and anticancer drugs, including the combination of (-)-epicatechin (EC) and curcumin. Based on the evidence, we present a new concept: green tea catechins as synergists with anticancer drugs.

  10. Effect of Eight Weeks of Aerobic Training and Green Tea Supplementation on Cardiovascular Risk Factors in Inactive Overweight Women

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    M. Fathei

    2016-09-01

    Full Text Available Aims: Physical activities, as well as diet, are known as the truest scientific methods to reduce the signs of the cardio-vascular diseases. The aim of this study was to investigate the effects of 8–week aerobic trainings and green tea supplementation on some of the cardio-vascular risk factors in the obese inactive women. Materials & Methods: In the semi-experimental study, 40 obese inactive women, who were residents of Mashhad Township, were studied in 2015. The subjects, selected via purposeful available sampling method, were randomly divided into 4 groups (n=10 per group. The groups were green tea, aerobic training, aerobic training and green tea supplementation, and control groups. 8-week training program consisted of three 45- to 60-minute sessions per week. Green tea was consumed by green tea group three times a day after each meal. The composed group underwent both interventions, while control group underwent no intervention. Data was analyzed by SPSS 15 software using correlated T test and one-way ANOVA. Findings: Mean total cholesterol level was significantly changed in green tea, aerobic training, and composed groups in the posttest stage compared to the pretest stage (p<0.05. Mean triglyceride level was significantly changed in green tea and aerobic training groups in the posttest stage compared to the pretest stage (p<0.05. Mean low density lipoprotein was significantly changed in green tea and composed groups in the posttest stage compared to the pretest stage (p<0.05. Mean high-density lipoprotein was significantly changed only in aerobic group in posttest stage compared to the pretest stage (p<0.05. In addition, mean concentration of C-reactive protein was significantly reduced in aerobic training (p=0.01 and composed (p=0.04 groups. Conclusion: 8 weeks aerobic training, green tea consumption, and their composition reduce the cardiovascular risk factors in inactive obese women in a relatively similar manner.

  11. The Powdering Process with a Set of Ceramic Mills for Green Tea Promoted Catechin Extraction and the ROS Inhibition Effect.

    Science.gov (United States)

    Fujioka, Kouki; Iwamoto, Takeo; Shima, Hidekazu; Tomaru, Keiko; Saito, Hideki; Ohtsuka, Masaki; Yoshidome, Akihiro; Kawamura, Yuri; Manome, Yoshinobu

    2016-04-11

    For serving green tea, there are two prominent methods: steeping the leaf or the powdered leaf (matcha style) in hot water. The purpose of the present study was to reveal chemical and functional differences before and after the powdering process of green tea leaf, since powdered green tea may contribute to expanding the functionality because of the different ingesting style. In this study, we revealed that the powdering process with a ceramic mill and stirring in hot water increased the average extracted concentration of epigallocatechin gallate (EGCG) by more than three times compared with that in leaf tea using high-performance liquid chromatography (HPLC) and liquid chromatography-tandem mass Spectrometry (LC-MS/MS) analyses. Moreover, powdered green tea has a higher inhibition effect of reactive oxygen species (ROS) production in vitro compared with the same amount of leaf tea. Our data suggest that powdered green tea might have a different function from leaf tea due to the higher catechin contents and particles.

  12. The Powdering Process with a Set of Ceramic Mills for Green Tea Promoted Catechin Extraction and the ROS Inhibition Effect

    Directory of Open Access Journals (Sweden)

    Kouki Fujioka

    2016-04-01

    Full Text Available For serving green tea, there are two prominent methods: steeping the leaf or the powdered leaf (matcha style in hot water. The purpose of the present study was to reveal chemical and functional differences before and after the powdering process of green tea leaf, since powdered green tea may contribute to expanding the functionality because of the different ingesting style. In this study, we revealed that the powdering process with a ceramic mill and stirring in hot water increased the average extracted concentration of epigallocatechin gallate (EGCG by more than three times compared with that in leaf tea using high-performance liquid chromatography (HPLC and liquid chromatography–tandem mass Spectrometry (LC-MS/MS analyses. Moreover, powdered green tea has a higher inhibition effect of reactive oxygen species (ROS production in vitro compared with the same amount of leaf tea. Our data suggest that powdered green tea might have a different function from leaf tea due to the higher catechin contents and particles.

  13. Interaction of environmental moisture with powdered green tea formulations: effect on catechin chemical stability.

    Science.gov (United States)

    Ortiz, J; Ferruzzi, M G; Taylor, L S; Mauer, L J

    2008-06-11

    Green tea and tea catechins must be stable in finished products to deliver health benefits; however, they may be adversely affected by tea processing/storage conditions and the presence of other components. The objective of this study was to determine the effects of storage relative humidity (RH) and addition of other ingredients on catechin stability in simulated dry beverage mixtures. Samples of green tea powder alone and mixed with sucrose, citric acid, and/or ascorbic acid were prepared and stored in desiccators at 22 degrees C and 0-85% RH for up to 3 months. Epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate were determined by high-performance liquid chromatography (HPLC). Formulation and the interaction of formulation and RH significantly promoted catechin degradation ( P or = 58% RH by the presence of powdered citric acid and at > or = 75% RH by the presence of ascorbic acid. Catechins degraded the most in formulations containing both acids. Although catechin chemical stability was maintained at < or = 43% RH in all samples stored at 22 degrees C for 3 months, caking was observed in samples at these relative humidities. These results are the first to demonstrate that addition of other dry components to tea powders may affect catechin stability in finished dry blends and highlight the importance of considering the complex interplay between a multicomponent system and its environment for developing stable products.

  14. Development of green tea scented with organic roses "Vitality" from Nevado Ecuador

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    Elena Beltrán

    2014-12-01

    Full Text Available (Received: 2014/11/03 - Accepted: 2014/12/15The aim of this study was to obtain a flavored green tea with organic rose petals "Vitality" from Nevado Ecuador. Green tea, purchased from a private company, it was subjected to analysis to verify compliance with the requirements of standard INEN 2381: 2005. The Characterization of fresh rose petals was to made and for the dehydration was used two temperatures and two geometries. Analysis of total polyphenol content (Folin-Ciocalteu and antioxidant capacity (TEACmethod were performed. The dried petals, with a higher content of polyphenols and antioxidant capacity, were used in the preparation to flavored tea. Three formulations with different amounts of dried rose petals (10, 17.5 and 25% were tested sensorially by 100 judges to determine the aroma rose in the tea. The final product was analyzed to determine compliance of the requirements of the standard INEN of the tea. Finally acceptability and purchase intention of the product is evaluated. The values of content total polyphenol in the extracts of rose petals were superior to fruits such as blackberries, and strawberries.

  15. Monitoring of essential and heavy metals in green tea from different geographical origins.

    Science.gov (United States)

    Brzezicha-Cirocka, Justyna; Grembecka, Małgorzata; Szefer, Piotr

    2016-03-01

    The present study measured the concentrations of toxic metals (Cd, Pb) and other elements (Ca, K, Mg, Na, P, Mn, Fe, Zn, Cu, Co, Cr, Ni) in tea leaves and their infusions. The total metal contents were determined by atomic absorption spectrometry. Phosphorus concentration was determined using an ultraviolet-visible spectrophotometer. Assessment of the mineral composition enabled determination of the leaching percentage and the risk of exceeding provisional tolerable weekly intake for Cd through daily tea consumption. The concentrations of bioelements were analyzed based on the recommended daily intake values for each. According to recently established standards, green tea was found to be a rich source of Mn. The average Pb and Cd levels in a 200-mL beverage were 0.002 and 0.003 mg, respectively. Indian teas had the highest percentage of Cd leaching (43.8%) and Chinese tea had the lowest (9.41%). Multivariate analysis techniques such as factor analysis and cluster analysis were used to differentiate samples according to geographical origin (China, India, or Japan). Potassium, P, Mn, Fe, Cu, Co, and Cd were effective descriptors for the identification of tea samples from China, India, and Japan.

  16. Smoking, green tea consumption, genetic polymorphisms in the insulin-like growth factors and lung cancer risk.

    Science.gov (United States)

    Lin, I-Hsin; Ho, Ming-Lin; Chen, Hsuan-Yu; Lee, Hong-Shen; Huang, Chia-Chen; Chu, Yin-Hung; Lin, Shiau-Yun; Deng, Ya-Ru; He, Yu-Hao; Lien, Yu-Hui; Hsu, Chi-Wen; Wong, Ruey-Hong

    2012-01-01

    Insulin-like growth factors (IGFs) are mediators of growth hormones; they have an influence on cell proliferation and differentiation. In addition, IGF-binding protein (IGFBP)-3 could suppress the mitogenic action of IGFs. Interestingly, tea polyphenols could substantially reduce IGF1 and increase IGFBP3. In this study, we evaluated the effects of smoking, green tea consumption, as well as IGF1, IGF2, and IGFBP3 polymorphisms, on lung cancer risk. Questionnaires were administered to obtain the subjects' characteristics, including smoking habits and green tea consumption from 170 primary lung cancer cases and 340 healthy controls. Genotypes for IGF1, IGF2, and IGFBP3 were identified by polymerase chain reaction. Lung cancer cases had a higher proportion of smoking, green tea consumption of less than one cup per day, exposure to cooking fumes, and family history of lung cancer than controls. After adjusting the confounding effect, an elevated risk was observed in smokers who never drank green tea, as compared to smokers who drank green tea more than one cup per day (odds ratio (OR) = 13.16, 95% confidence interval (CI) = 2.96-58.51). Interaction between smoking and green tea consumption on lung cancer risk was also observed. Among green tea drinkers who drank more than one cup per day, IGF1 (CA)(19)/(CA)(19) and (CA)(19)/X genotypes carriers had a significantly reduced risk of lung cancer (OR = 0.06, 95% CI = 0.01-0.44) compared with IGF1 X/X carriers. Smoking-induced pulmonary carcinogenesis could be modulated by green tea consumption and their growth factor environment.

  17. Smoking, green tea consumption, genetic polymorphisms in the insulin-like growth factors and lung cancer risk.

    Directory of Open Access Journals (Sweden)

    I-Hsin Lin

    Full Text Available Insulin-like growth factors (IGFs are mediators of growth hormones; they have an influence on cell proliferation and differentiation. In addition, IGF-binding protein (IGFBP-3 could suppress the mitogenic action of IGFs. Interestingly, tea polyphenols could substantially reduce IGF1 and increase IGFBP3. In this study, we evaluated the effects of smoking, green tea consumption, as well as IGF1, IGF2, and IGFBP3 polymorphisms, on lung cancer risk. Questionnaires were administered to obtain the subjects' characteristics, including smoking habits and green tea consumption from 170 primary lung cancer cases and 340 healthy controls. Genotypes for IGF1, IGF2, and IGFBP3 were identified by polymerase chain reaction. Lung cancer cases had a higher proportion of smoking, green tea consumption of less than one cup per day, exposure to cooking fumes, and family history of lung cancer than controls. After adjusting the confounding effect, an elevated risk was observed in smokers who never drank green tea, as compared to smokers who drank green tea more than one cup per day (odds ratio (OR = 13.16, 95% confidence interval (CI = 2.96-58.51. Interaction between smoking and green tea consumption on lung cancer risk was also observed. Among green tea drinkers who drank more than one cup per day, IGF1 (CA(19/(CA(19 and (CA(19/X genotypes carriers had a significantly reduced risk of lung cancer (OR = 0.06, 95% CI = 0.01-0.44 compared with IGF1 X/X carriers. Smoking-induced pulmonary carcinogenesis could be modulated by green tea consumption and their growth factor environment.

  18. Rapid detection of bacteria in green tea using a novel pretreatment method in a bioluminescence assay.

    Science.gov (United States)

    Shinozaki, Yohei; Harada, Yasuhiro

    2014-06-01

    Tea is one of the most popular beverages consumed in the world, and green tea has become a popular beverage in Western as well as Asian countries. A novel pretreatment method for a commercial bioluminescence assay to detect bacteria in green tea was developed and evaluated in this study. Pretreatment buffers with pH levels ranging from 6.0 to 9.0 were selected from MES (morpholineethanesulfonic acid), HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid), or Tricine buffers. To evaluate the effect of pretreatment and the performance of the assay, serially diluted cultures of Enterobacter cloacae, Escherichia coli, Bacillus subtilis, and Staphylococcus aureus were tested. The improved methods, which consisted of a pretreatment of the sample in alkaline buffer, significantly decreased the background bioluminescence intensity of green tea samples when compared with the conventional method. Pretreatment with alkaline buffers with pH levels ranging from 8.0 to 9.0 increased the bioluminescence intensities of cultures of E. cloacae and S. aureus. Strong log-linear relationships between the bioluminescence intensities and plate counts emerged for the tested strains. Furthermore, the microbial detection limit was 15 CFU in 500 ml of bottled green tea after an 8-h incubation at 35°C and an assay time of 1 h. The results showed that contaminated samples could be detected within 1 h of operation using our improved bioluminescence assay. This method could be used to test for contamination during the manufacturing process as well as for statistical sampling for quality control.

  19. Plasma appearance and correlation between coffee and green tea metabolites in human subjects.

    Science.gov (United States)

    Renouf, Mathieu; Guy, Philippe; Marmet, Cynthia; Longet, Karin; Fraering, Anne-Lise; Moulin, Julie; Barron, Denis; Dionisi, Fabiola; Cavin, Christophe; Steiling, Heike; Williamson, Gary

    2010-12-01

    Coffee and green tea are two of the most widely consumed hot beverages in the world. Their respective bioavailability has been studied separately, but absorption of their respective bioactive phenolics has not been compared. In a randomised cross-over design, nine healthy subjects drank instant coffee and green tea. Blood samples were collected over 12 h and at 24 h to assess return to baseline. After green tea consumption, (-)-epigallocatechin (EGC) was the major catechin, appearing rapidly in the plasma; (-)-EGC gallate (EGCg) and (-)-epicatechin (EC) were also present, but (-)-EC gallate and C were not detected. Dihydroferulic acid and dihydrocaffeic acid were the major metabolites that appeared after coffee consumption with a long time needed to reach maximum plasma concentration, suggesting metabolism and absorption in the colon. Other phenolic acid equivalents (caffeic acid (CA), ferulic acid (FA) and isoferulic acid (iFA)) were detected earlier, and they peaked at lower concentrations. Summations of the plasma area under the curves (AUC) for the measured metabolites showed 1.7-fold more coffee-derived phenolic acids than green tea-derived catechins (P = 0.0014). Furthermore, we found a significant correlation between coffee metabolites based on AUC. Inter-individual differences were observed, but individuals with a high level of CA also showed a correspondingly high level of FA. However, no such correlation was observed between the tea catechins and coffee phenolic acids. Correlation between AUC and maximum plasma concentration was also significant for CA, FA and iFA and for EGCg. This implies that the mechanisms of absorption for these two classes of compounds are different, and that a high absorber of phenolic acids is not necessarily a high absorber of catechins.

  20. Artificial neural network modeling and optimization of ultrahigh pressure extraction of green tea polyphenols.

    Science.gov (United States)

    Xi, Jun; Xue, Yujing; Xu, Yinxiang; Shen, Yuhong

    2013-11-01

    In this study, the ultrahigh pressure extraction of green tea polyphenols was modeled and optimized by a three-layer artificial neural network. A feed-forward neural network trained with an error back-propagation algorithm was used to evaluate the effects of pressure, liquid/solid ratio and ethanol concentration on the total phenolic content of green tea extracts. The neural network coupled with genetic algorithms was also used to optimize the conditions needed to obtain the highest yield of tea polyphenols. The obtained optimal architecture of artificial neural network model involved a feed-forward neural network with three input neurons, one hidden layer with eight neurons and one output layer including single neuron. The trained network gave the minimum value in the MSE of 0.03 and the maximum value in the R(2) of 0.9571, which implied a good agreement between the predicted value and the actual value, and confirmed a good generalization of the network. Based on the combination of neural network and genetic algorithms, the optimum extraction conditions for the highest yield of green tea polyphenols were determined as follows: 498.8 MPa for pressure, 20.8 mL/g for liquid/solid ratio and 53.6% for ethanol concentration. The total phenolic content of the actual measurement under the optimum predicated extraction conditions was 582.4 ± 0.63 mg/g DW, which was well matched with the predicted value (597.2mg/g DW). This suggests that the artificial neural network model described in this work is an efficient quantitative tool to predict the extraction efficiency of green tea polyphenols. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  1. Inhibition of proliferation of human lung cancer cells by green tea catechins is mediated by upregulation of let-7.

    Science.gov (United States)

    Zhong, Zhiwei; Dong, Zhuo; Yang, Lihua; Chen, Xiaoqiang; Gong, Zhaohui

    2012-08-01

    Green tea catechins are known to function as anticancer agents via inhibition of carcinogenesis during the initiation, promotion and progression stages. Many potential mechanisms have been proposed, yet the precise mechanism of lung cancer prevention by green tea catechins remains unclear. microRNAs (miRs) are a class of 21-24 nucleotide small non-coding RNAs and play critical roles throughout cellular development and regulation. Emerging evidence demonstrates that tea catechins influence the expression of miRs in human cancer cells to inhibit tumorigenesis. Both let-7a-1 and let-7g were detected in the human lung cancer cells treated with tea catechins. The cell viability and cell cycle were analyzed after tea catechins treatment. In the present study, we found that tea catechins upregulated the tumor-suppressor miRs, let-7a-1 and let-7g, in lung cancer cell lines. The upregulation of let-7a/7g repressed the expression of their targets, C-MYC and the regulatory protein of LIN-28, at the mRNA and protein levels. Moreover, the cell growth assay indicated that tea catechins significantly inhibited cell proliferation, and the flow cytometric analysis revealed an increase in the number of cells in the G2/M phase and a decrease in the number of cells in the S phase after treatment with tea catechins. These observations suggest that green tea catechins mediate the inhibition of proliferation of lung cancer cells through the let-7 signaling pathway.

  2. Green Tea Polyphenols Attenuated Glutamate Excitotoxicity via Antioxidative and Antiapoptotic Pathway in the Primary Cultured Cortical Neurons

    Directory of Open Access Journals (Sweden)

    Lin Cong

    2016-01-01

    Full Text Available Green tea polyphenols are a natural product which has antioxidative and antiapoptotic effects. It has been shown that glutamate excitotoxicity induced oxidative stress is linked to neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. In this study we explored the neuroprotective effect of green teen polyphenols against glutamate excitotoxicity in the primary cultured cortical neurons. We found that green tea polyphenols protected against glutamate induced neurotoxicity in the cortical neurons as measured by MTT and TUNEL assays. Green tea polyphenols were then showed to inhibit the glutamate induced ROS release and SOD activity reduction in the neurons. Furthermore, our results demonstrated that green tea polyphenols restored the dysfunction of mitochondrial pro- or antiapoptotic proteins Bax, Bcl-2, and caspase-3 caused by glutamate. Interestingly, the neuroprotective effect of green tea polyphenols was abrogated when the neurons were incubated with siBcl-2. Taken together, these results demonstrated that green tea polyphenols protected against glutamate excitotoxicity through antioxidative and antiapoptotic pathways.

  3. Green tea as an effective antimicrobial for urinary tract infections caused by Escherichia coli

    Directory of Open Access Journals (Sweden)

    Wanda eReygaert

    2013-06-01

    Full Text Available Background: Urinary tract infections (UTIs are a very most common type of infection worldwide, and result in billions of dollars in medical care costs. Escherichia coli is the infective agent for 80%-90% of all UTIs. Green tea, derived from leaves of the Camellia sinensis plant has been shown to have various potential health benefits (e.g. cardiovascular disease and cancer. The major beneficial components of green tea have been characterized, and are now known to be polyphenolic catechins. The main catechins in green tea are (--epicatechin-3-gallate (ECG, (--epigallocatechin (EGC, (--epicatechin (EC, and (--epigallocatechin-3-gallate (EGCG. EGCG and EGC have been shown to have antimicrobial effects, but only EGC has been shown to be excreted in urine. Isolates of E. coli from urinary tract infections collected between 2007-2008 were characterized for antimicrobial resistance to standard drugs. Then 80 of these isolates, representing a wide spectrum of antimicrobial susceptibility patterns, were selected for testing using an extract of green tea.Results: The concentrations of green tea extract tested were 0, 2.5, 3.0, 3.5, and 4.0 mg/ml. All of the strains tested, except one, had MICs of ≤4.0 mg/ml, with 40% of the isolates having an MIC of ≤2.5 mg/ml, 36% of the isolates having an MIC of ≤3.0 mg/ml, 18% of the isolates having an MIC of ≤3.5 mg/ml, and 5% of the isolates having an MIC of ≤4.0 mg/ml. Two control strains varied in susceptibility, one having an MIC of ≤2.5 mg/ml, another having an MIC of ≤3.5 mg/ml, and the third having an MIC of ≤4.0 mg/ml.Conclusion: Since EGC has been shown to have antimicrobial effects on E. coli, and EGC has been shown to be excreted in the urine in a high enough concentration to potentially be effective as an antimicrobial; these MIC results suggest that ingesting green tea could have potential antimicrobial effects on urinary tract infections caused by E. coli.

  4. In-vitro study investigating influence of toothpaste containing green tea extract on the microhardness of demineralized human enamel

    Science.gov (United States)

    Febrian, K.; Triaminingsih, S.; Indrani, DJ

    2017-08-01

    The aim of this study was to analyze the influence of toothpaste containing green tea extract on the microhardness of demineralized enamel. Human tooth, which was demineralised in citric acid solution, had a toothpaste containing green tea extract of concentration of 5, 10 or 15% application. Microhardness measurement was carried out on each enamel surface of the teeth for initial, after the demineralization and after application of the tooth pastes. It showed that there was significant decrease between enamel microhardness of the teeth at the initial condition and after demineralization. After application of the toothpaste containing green tea extract of each concentration the microhardnss increased significantly. However, there the microhardness was insignificant between the applications of each green tea concentration.

  5. Reduced Dental Plaque Formation in Dogs Drinking a Solution Containing Natural Antimicrobial Herbal Enzymes and Organic Matcha Green Tea

    National Research Council Canada - National Science Library

    Lindinger, Michael I

    2016-01-01

    ...) reduced the rate of plaque formation on teeth of dogs consuming the OCP (antimicrobial plant-derived enzymes, organic matcha green tea, cultured dextrose, sodium bicarbonate, and ascorbic acid...

  6. Free radical scavenging and cytotoxic activity of five commercial standardized extracts (red wine, green tea, pine bark, polygonum and pomegranate)

    National Research Council Canada - National Science Library

    García-Becerra Ledy; Leos-Rivas Catalina; Oranday-Cárdenas Azucena; Rivas-Morales Catalina

    2012-01-01

    ...) and cytotoxic activity in vitro on the cervical cancer cell line HeLa of five commercial standardized extracts rich in phenolic compounds: red wine (Vitis vinifera ), green tea (Camellia sinensis ), pine bark (Pinus maritime ), polygonum...

  7. Resistance to Citrus Canker in Key/Mexican Lime Induced by β-Aminobutyric Acid and Green Tea

    National Research Council Canada - National Science Library

    B. Beheshti; G. R. Sharifi-Sirchi; M. Mansouri; A. Hosseinipour; N. L. Schlaich

    2011-01-01

    .... To improve control of this disease, lime (Citrus aurantifolia) plants inoculated with Xcc were treated with β-Aminobutyric Acid (BABA), ascorbic acid (vitamin C), thiamin (vitamin B1), green tea (Camellia sinensis...

  8. Application of radiation technology to develop green tea leaf as a natural resource for the cosmetic industry

    Science.gov (United States)

    Byun, Myung Woo; Jo, Cheorun; Lee, Ju Woon; Jo, Sung Kee; Kim, Kwan Soo

    2004-09-01

    The irradiation of natural resources such as green tea leaf, persimmon leaf, licorice root and stolon or Lonicera japonica improved the color of the extract, resulting in a higher applicability without any adverse change to the beneficial functions such as the inhibitory effects of oxidation, melanin hyperpigmentation on the skin, and others. To investigate the application of irradiated natural resources for a real cosmetic composition, the physiological activities of irradiated green tea leaf extract powder dissolved in butylene glycol and ethanol were compared to a commercial green tea extract product. Furthermore, a cream lotion was manufactured using the powder and the physiological activities were compared. Results showed that the irradiation of the green tea leaf extract and the freeze-dried powder from the extract had the same physiological activities as the commercial product in a cosmetic composition.

  9. Correlation between catechin content and NF-κB inhibition by infusions of green and black tea.

    Science.gov (United States)

    Di Lorenzo, Chiara; Dell'Agli, Mario; Sangiovanni, Enrico; Dos Santos, Ariana; Uberti, Francesca; Moro, Enzo; Bosisio, Enrica; Restani, Patrizia

    2013-06-01

    This study investigates whether infusions of green and black tea inhibit the NF-κB driven transcription in human epithelial gastric AGS cells. Water extracts were prepared from different brands of green and black tea available on the Italian market. Teas with or without caffeine were studied. An industrially prepared freeze-dried water extract of green tea was also tested. Catechin and caffeine contents were measured by HPLC analysis. The decrease in phenol and catechin content three months after the expiry date was also investigated. The NF-κB driven transcription and the free radical scavenger activity were inhibited, and this effect was related to catechin levels. The potency of epigallocatechin 3-gallate in inhibiting NF-κB driven transcription is so great that tea extracts low in epigallocatechin 3-gallate are still highly active. In one decaffeinated sample of green tea, the phenol and catechin content was very low, probably as a consequence of caffeine removal. The decrease in catechin levels after 3 months did not reduce the inhibition of NF-κB driven transcription by tea infusions. This is the first paper reporting the inhibitory effect of NF-κB of commercial green and black infusions at the gastric level, evaluating their stability as well.

  10. Reduced Stress and Improved Sleep Quality Caused by Green Tea Are Associated with a Reduced Caffeine Content

    Directory of Open Access Journals (Sweden)

    Keiko Unno

    2017-07-01

    Full Text Available Caffeine, one of the main components in green tea, can interfere with sleep and block the effect of theanine. Since theanine, the main amino acid in tea leaves, has significant anti-stress effects in animals and humans, we examined the effects of green tea with lowered caffeine content, i.e., low-caffeine green tea (LCGT, on stress and quality of sleep of middle–aged individuals (n = 20, mean age 51.3 ± 6.7 years in a double-blind crossover design. Standard green tea (SGT was used as the control. These teas (≥300 mL/day, which were eluted with room temperature water, were consumed over a period of seven days after a single washout term. The level of salivary α-amylase activity (sAA, a stress marker, was significantly lower in participants that consumed LCGT (64.7 U/mL than in those that consumed SGT (73.9 U/mL. Sleep quality was higher in participants that consumed a larger quantity of LCGT. In addition, a self-diagnostic check for accumulated fatigue was significantly lower in those participants that consumed LCGT than SGT. These results indicate that LCGT intake can reduce stress in middle-aged individuals and improve their quality of sleep. The reduction in caffeine is suggested to be a valid reason for enhancing the anti-stress effect of green tea.

  11. Green Tea Consumption and Risk of Pancreatic Cancer: A Meta-analysis

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    Jin-Long Zeng

    2014-10-01

    Full Text Available Emerging laboratory and animal studies indicate that green tea inhibits development and progression of pancreatic cancer, but evidence from epidemiologic studies appears inconsistent and inconclusive. A meta-analysis summarizing published case-control and cohort studies was performed to evaluate the association of green tea consumption with risk of pancreatic cancer. Pertinent studies were identified by a search of PubMed and EMBASE up to April 2014. A random-effects model was assigned to compute summary risk estimates. A total of three case-control studies and five prospective studies were included, comprising 2317 incident cases and 288209 subjects. Of them, three studies were from China and the reminders were conducted in Japan. Overall, neither high vs. low green consumption (odds ratio (OR = 0.99, 95% confidence interval [CI] = 0.78–1.25, nor an increase in green tea consumption of two cups/day (OR = 0.95, 95% CI = 0.85–1.06 was associated with risk of pancreatic cancer. The null association persisted when the analysis was stratified by sex or restricted to non-smokers. In the stratification by study location, the summary OR for the studies from China and for those from Japan was 0.77 (95% CI = 0.60–0.99 and 1.21 (95% CI = 0.94–1.54, respectively (P for differences = 0.04. Cumulative epidemiologic evidence suggests that green tea consumption is not associated with pancreatic cancer.

  12. Green Tea Potentially Ameliorates Bisphenol A-Induced Oxidative Stress: An In Vitro and In Silico Study

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    Hiral Suthar

    2014-01-01

    . Concurrent addition of different concentrations (10–50 μg/mL of green tea extract to reaction mixture containing high dose of bisphenol A (250 μg/mL caused concentration-dependent amelioration in bisphenol A-induced hemolysis. The effect was significant (P<0.05. It is concluded that BPA-induced oxidative stress could be significantly mitigated by green tea extract.

  13. Qualitative analysis of catechins from green tea GMB-4 clone using HPLC and LC-MS/MS

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    Erna Susanti

    2015-12-01

    Conclusions: The HPLC and LC-MS/MS methods were successfully tuned for the qualitative analysis of green tea extract with EGCG and ECG. Four major catechins were separated and identified by LC-MS/MS, such as EGCG, epigallocatechin, ECG and epicatechin. The result of HPLC analysis showed that EGCG and ECG were main components from catechins isolation of green tea GMB-4 clone.

  14. Green tea extract as an anti-browning agent for cloudy apple juice.

    Science.gov (United States)

    Klimczak, Inga; Gliszczyńska-Świgło, Anna

    2017-03-01

    Enzymatic browning of fruits and vegetables and their products is an important factor worsening their quality. The influence of five green tea extracts at the concentrations of 1 g L(-1) , 2 g L(-1) and 3 g L(-1) on polyphenol oxidase (PPO) activity in fresh cloudy apple juice was investigated. Moreover, PPO inhibition by tea extract and colour stability of juice during short-time refrigerated storage was studied. The changes of juice colour during storage was expressed as the total colour differences (ΔE*), browning index (BI), yellowness index (YI), and the absorbance at 420 nm (A420 ). All extracts inhibited PPO activity in fresh apple juice in concentration-dependent manner. PPO activity in pure apple juice decreased by 7% after 48 h, whereas PPO activity in samples with 1 g L(-1) , 2 g L(-1) and 3 g L(-1) tea extract decreased by 53%, 74%, and 96%, respectively. Browning of apple juice during storage decreased with increased concentration of green tea extract. After 48 h, extract at 1 g L(-1) , 2 g L(-1) and 3 g L(-1) inhibited browning of juice expressed as BI by 48%, 60%, and 86%, respectively, comparing to pure apple juice. Green tea extract may be an effective anti-browning agent for short-time stored cloudy apple juices. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  15. Catechin and caffeine content of green tea dietary supplements and correlation with antioxidant capacity.

    Science.gov (United States)

    Seeram, Navindra P; Henning, Susanne M; Niu, Yantao; Lee, Rupo; Scheuller, H Samuel; Heber, David

    2006-03-08

    The health benefits associated with tea consumption have resulted in the wide inclusion of green tea extracts in botanical dietary supplements, which are widely consumed as adjuvants for complementary and alternative medicines. Tea contains polyphenols such as catechins or flavan-3-ols including epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate (EGCG), as well as the alkaloid, caffeine. Polyphenols are antioxidants, and EGCG, due to its high levels, is widely accepted as the major antioxidant in green tea. Therefore, commercial green tea dietary supplements (GTDS) may be chemically standardized to EGCG levels and/or biologically standardized to antioxidant capacity. However, label claims on GTDS may not correlate with actual phytochemical content or antioxidant capacity nor provide information about the presence and levels of caffeine. In the current study, 19 commonly available GTDS were evaluated for catechin and caffeine content (using high-performance liquid chromatography) and for antioxidative activity [using trolox equivalent antioxidant capacity (TEAC) and oxygen radical antioxidant capacity (ORAC) assays]. Product labels varied in the information provided and were inconsistent with actual phytochemical contents. Only seven of the GTDS studied made label claims of caffeine content, 11 made claims of EGCG content, and five specified total polyphenol content. Caffeine, EGCG, and total polyphenol contents in the GTDS varied from 28 to 183, 12-143, and 14-36% tablet or capsule weight, respectively. TEAC and ORAC values for GTDS ranged from 187 to 15340 and from 166 to 13690 mumol Trolox/g for tablet or capsule, respectively. The antioxidant activities for GTDS determined by TEAC and ORAC were well-correlated with each other and with the total polyphenol content. Reliable labeling information and standardized manufacturing practices, based on both chemical standardization and biological assays, are recommended for the quality

  16. Antioxidants from black and green tea: from dietary modulation of oxidative stress to pharmacological mechanisms.

    Science.gov (United States)

    Peluso, Ilaria; Serafini, Mauro

    2016-10-16

    The consumption of tea (Camellia sinensis) has been correlated with a low incidence of chronic pathologies, such as cardiovascular disease and cancer, in which oxidative stress plays a critical role. Tea catechins and theaflavins are, respectively, the bioactive phytochemicals responsible for the antioxidant activity of green tea (GT) and black tea (BT). In addition to their redox properties, tea catechins and theaflavins could have also pharmacological activities, such as the ability to lower glucose, lipid and uric acid (UA) levels. These activities are mediated by pharmacological mechanisms such as enzymatic inhibition and interaction with transporters. Epigallocatechin gallate is the most active compound at inhibiting the enzymes involved in cholesterol and UA metabolism (hydroxy-3-methyl-glutaryl-CoA reductase and xanthine oxidase respectively) and affecting glucose transporters. The structural features of catechins that significantly contribute to their pharmacological effect are the presence/absence of the galloyl moiety and the number and positions of the hydroxyl groups on the rings. Although the inhibitory effects on α-glucosidase, maltase, amylase and lipase, multidrug resistance 1, organic anion transporters and proton-coupled folate transport occur at higher concentrations than those apparent in the circulation, these effects could be relevant in the gut. In conclusion, despite the urgent need for further research in humans, the regular consumption of moderate quantities of GT and BT can effectively modulate their antioxidant capacity, mainly in people subjected to oxidative stress, and could improve the metabolism of glucose, lipid and UA.

  17. Differentiation of green tea samples by chiral CD-MEKC analysis of catechins content.

    Science.gov (United States)

    Gotti, Roberto; Furlanetto, Sandra; Lanteri, Silvia; Olmo, Stefano; Ragaini, Alessandro; Cavrini, Vanni

    2009-08-01

    A chiral CD-MEKC method, enantioselective for catechin and gallocatechin, was developed, validated and applied to the analysis of tea samples. The method was addressed to the fast and simultaneous quantitation of the most represented and biologically important green tea catechins and methylxanthines. The CD-MEKC was based on SDS as surfactant (90 mM) and hydroxypropyl-beta-CD (25 mM) as chiral selector, under acidic conditions (25 mM borate-phosphate buffer, pH 2.5). The method was first applied to study the thermal epimerisation of epi-structured catechins, (-)-epicatechin and (-)-epigallocatechin, to non-epi-structured (-)-catechin and (-)-gallocatechin. The latter compounds, being non-native molecules, were for the first time regarded as useful phytomarkers of tea samples subjected to thermal treatment. The proposed method was applied to the analysis of more than twenty tea samples of different geographical origins (China, Japan, Ceylon), having undergone different storage conditions and manufacturing processes. Finally, factor analysis was used to visualise the useful information contained in the data set, showing that it was possible to distinguish tea samples on the basis of their different contents of native and non-native catechins.

  18. Identification of potent odorants in Chinese jasmine green tea scented with flowers of Jasminum sambac.

    Science.gov (United States)

    Ito, Yuriko; Sugimoto, Akio; Kakuda, Takami; Kubota, Kikue

    2002-08-14

    The odorants in Chinese jasmine green tea scented with jasmine flowers (Jasminum sambac) were separated from the infusion by adsorption to Porapak Q resin. Among the 66 compounds identified by GC and GC/MS, linalool (floral), methyl anthranilate (grape-like), 4-hexanolide (sweet), 4-nonanolide (sweet), (E)-2-hexenyl hexanoate (green), and 4-hydroxy-2,5-dimethyl-3(2H)-furanone (sweet) were extracted as potent odorants by an aroma extract dilution analysis and sensory analysis. The enantiomeric ratios of linalool in jasmine tea and Jasminum sambac were determined by a chiral analysis for the first time in this study: 81.6% ee and 100% ee for the (R)-(-)-configuration, respectively. The jasmine tea flavor could be closely duplicated by a model mixture containing these six compounds on the basis of a sensory analysis. The omission of methyl anthranilate and the replacement of (R)-(-)-linalool by (S)-(+)-linalool led to great changes in the odor of the model. These two compounds were determined to be the key odorants of the jasmine tea flavor.

  19. Efficacy of chlorhexidine and green tea mouthwashes in the management of dental plaque-induced gingivitis: A comparative clinical study

    Directory of Open Access Journals (Sweden)

    Meena B Priya

    2015-01-01

    Full Text Available Background: The intake of green tea has been increased recently due to its medicinal values. The antibacterial and antioxidant properties of green tea were found to be beneficial in the treatment of gingival and periodontal diseases. The aim of this comparative study was to compare the efficacy of the mouthwash containing green tea and chlorhexidine in the management of dental plaque-induced gingivitis. Materials and Methods: Thirty patients who participated in the study were divided randomly into two groups, each group of 15 patients was prescribed with either chlorhexidine or green tea mouthwash. Turesky modification of Quigley-Hein plaque index, Löe and Silness gingival index, Ainamo and Bay bleeding index, tooth stain, and tongue stain (TS were recorded at baseline, 15 days, and 1 month. The subjects were asked to report any discomfort or alteration in taste. Results: There was a significant decrease in plaque index, gingival index, and bleeding index in both the groups. However, green tea mouthwash resulted in a statistically significant decrease in bleeding index compared to chlorhexidine group. There was no significant difference in tooth stain and TS in both the groups. Conclusion: The green tea-containing mouthwash is equally effective in reducing the gingival inflammation and plaque to chlorhexidine.

  20. Streptococcus Alpha growth in gingivitis patient’s dental plaque after rinsing with green tea extract (Camellia Sinensis

    Directory of Open Access Journals (Sweden)

    Isti Endah Kurniwati

    2007-03-01

    Full Text Available Green tea (Camellia sinensis has been widely known as a healthy drink since long time ago. One of the substances in green tea which can give health benefit is catechin, an antibacterial substance. The purpose of this research is to know the efficacy of rinsing with green tea extract to Streptococcus alpha growth on gingivitis patient’s dental plaque. The research subjects include 30 mild gingivitis patients, and these subjects are divided into two groups: treatment group (20 patients and control group (10 patients. Ten patients of treatment group rinse their mouth with 0.25% green tea extract and 10 other patients with 0.5% green tea extract. Meanwhile, control group use Bactidol (0.1% Hexetidine. Rinsing the mouth is performed every morning and night for five days. Sampling is conducted on the first and sixth day. Before rinsing data is analyzed using ANOVA and the result shows a significant difference. ANAVA testing then is done using proportion value. ANAVA Testing result shows that there is no significant difference among the patients in the treatment group. This result indicates that the effect of rinsing with 0.25% and 0.5% green tea extract is equivalent to the control (0.1% Hexetidine to inhibit S. alpha growth on mild gingivitis patient’s dental plaque. From these two concentrations, it has not been known which one is the most effective concentration to inhibit S. alpha growth on mild gingivitis patient.

  1. The Antioxidative Activity of Aqueous and Ethanolic Extracts of Rosemary and Green Tea Leaves: A Comparative Study

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    *N. M. Tariq

    2013-03-01

    Full Text Available The antioxidant activities of rosemary and green tea leaves, aqueous and ethanolic extracts, have been studied by using two different methods (reducing power and chelating ability. It was found that the total phenolic compounds in aqueous and ethanolic extracts of rosemary and green tea leaves were 13.44, 18.75, 39.38 and 48.44 mg/ 100 mg dry extract respectively. The flavonoids (which is a part of the phenolic compounds were found to be 9.54, 12.65, 17.69 and 22.70 mg/ 100 mg dry extract in aqueous and ethanolic extract of rosemary and green tea leaves respectively. The ethanolic extract shows high content of phenolic compounds and in turn highly antioxidative activiy for both rosemary and green tea leaves as compared with aqueous extract.The aqueous and ethanolic extracts of rosemary and green tea leaves show high reducing power ability comparing with their abilities as chelating agents. Although, the phenolic compounds of green tea leave almost about 3-fold as compared with rosemary leave in both aqueous and ethanolic extracts, their extracts show extremely the same mode of action in both methods of determination (the reducing power and chelating ability. Therefore, we are fully recommended the rosemary leave extracts as a potent food preservative.

  2. Acute ingestion of catechin-rich green tea improves postprandial glucose status and increases serum thioredoxin concentrations in postmenopausal women.

    Science.gov (United States)

    Takahashi, Masaki; Miyashita, Masashi; Suzuki, Katsuhiko; Bae, Seong-Ryu; Kim, Hyeon-Ki; Wakisaka, Takuya; Matsui, Yuji; Takeshita, Masao; Yasunaga, Koichi

    2014-11-14

    Elevated postprandial hyperglycaemia and oxidative stress increase the risks of type 2 diabetes and CVD. Green tea catechin possesses antidiabetic properties and antioxidant capacity. In the present study, we examined the acute and continuous effects of ingestion of catechin-rich green tea on postprandial hyperglycaemia and oxidative stress in healthy postmenopausal women. Participants were randomly assigned into the placebo (P, n 11) or green tea (GT, n 11) group. The GT group consumed a catechin-rich green tea (catechins 615 mg/350 ml) beverage per d for 4 weeks. The P group consumed a placebo (catechins 92 mg/350 ml) beverage per d for 4 weeks. At baseline and after 4 weeks, participants of each group consumed their designated beverages with breakfast and consumed lunch 3 h after breakfast. Venous blood samples were collected in the fasted state (0 h) and at 2, 4 and 6 h after breakfast. Postprandial glucose concentrations were 3 % lower in the GT group than in the P group (three-factor ANOVA, group × time interaction, Pcatechin-rich green tea intake was observed. Conversely, serum postprandial thioredoxin concentrations were 5 % higher in the GT group than in the P group (three-factor ANOVA, group × time interaction, Pcatechin-rich green tea has beneficial effects on postprandial glucose and redox homeostasis in postmenopausal women.

  3. Potential protection of green tea polyphenols against 1800 MHz electromagnetic radiation-induced injury on rat cortical neurons.

    Science.gov (United States)

    Liu, Mei-Li; Wen, Jian-Qiang; Fan, Yu-Bo

    2011-10-01

    Radiofrequency electromagnetic fields (EMF) are harmful to public health, but the certain anti-irradiation mechanism is not clear yet. The present study was performed to investigate the possible protective effects of green tea polyphenols against electromagnetic radiation-induced injury in the cultured rat cortical neurons. In this study, green tea polyphenols were used in the cultured cortical neurons exposed to 1800 MHz EMFs by the mobile phone. We found that the mobile phone irradiation for 24 h induced marked neuronal cell death in the MTT (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl-tetrazolium bromide) and TUNEL (TdT mediated biotin-dUTP nicked-end labeling) assay, and protective effects of green tea polyphenols on the injured cortical neurons were demonstrated by testing the content of Bcl-2 Assaciated X protein (Bax) in the immunoprecipitation assay and Western blot assay. In our study results, the mobile phone irradiation-induced increases in the content of active Bax were inhibited significantly by green tea polyphenols, while the contents of total Bax had no marked changes after the treatment of green tea polyphenols. Our results suggested a neuroprotective effect of green tea polyphenols against the mobile phone irradiation-induced injury on the cultured rat cortical neurons.

  4. Design and in vivo evaluation of emulgel formulations including green tea extract and rose oil.

    Science.gov (United States)

    Yapar, Evren Algin; Ynal, Ozge; Erdal, M Sedef

    2013-12-01

    Prevention of skin aging and its treatment is an emerging field for development of new formulations in cosmetics. Accordingly, plant extracts with antioxidant properties are beneficial cosmetic ingredients for this purpose. This study was aimed at developing a stable and easily manufactured emulgel including green tea extract and rose oil that is effective on the barrier function and hydration of the skin. An emulgel formulation containing 20 % green tea extract and 5 % rose oil was designed as a result of pre-formulation studies. Physicochemical characterization, in vitro stability studies, in vivo water content of the stratum corneum and transepidermal water loss studies were carried out afterwards. In vivo studies on ten female subjects were evaluated by using non-invasive skin bioengineering techniques. Finally, a cosmetically acceptable, stable and effective emulgel formulation for skin barrier function with good hydrating properties was obtained for skin hydration, protection and anti-aging purposes.

  5. Green tea: a novel functional food for the oral health of older adults.

    Science.gov (United States)

    Gaur, Sumit; Agnihotri, Rupali

    2014-04-01

    Functional foods are foods with positive health effects that extend beyond their nutritional value. They affect the function of the body and help in the management of specific health conditions. Green tea, a time-honoured Chinese herb, might be regarded as a functional food because of its inherent anti-oxidant, anti-inflammatory, antimicrobial and antimutagenic properties. They are attributed to its reservoir of polyphenols, particularly the catechin, epigallocatechin-3-gallate. Owing to these beneficial actions, this traditional beverage was used in the management of chronic systemic diseases including cancer. Recently, it has been emphasized that the host immuno-inflammatory reactions destroy the oral tissues to a greater extent than the microbial activity alone. Green tea with its wide spectrum of activities could be a healthy alternative for controlling these damaging reactions seen in oral diseases, specifically, chronic periodontitis, dental caries and oral cancer, which are a common occurrence in the elderly population.

  6. [Effects of green tea on growth inhibition and immune regulation of Lewis lung cancer in mice].

    Science.gov (United States)

    Zhu, M; Gong, Y; Ge, G

    1997-11-01

    C57/BL6J mice were inoculated with Lewis lung cancer cells as an experimental model to study the effects of green tea on cancer prevention, inhibition of tumor growth and immune regulation in mice with tumor. Results showed that weight of thymus in C57/BL6J mice and its index declined, proportion of positive CD4 subgroup of T lymphocyte and ratio of CD4+, to CD8+ reduced, baseline chemilumi-nescence decreased in peripheral white blood cells, yeast zymosan stimulated chemiluminescence increased, and number of immunoglobulin M formation cells decreased. It indicated that green tea had obvious inhibition in Lewis lung cancer and protective effects, to various extent, on adverse changes of above indices.

  7. Ameliorated Effects of Green Tea Extract on Lead Induced Kidney Toxicity in Rats

    Directory of Open Access Journals (Sweden)

    Nadia Ait Hamadouche

    2015-01-01

    Full Text Available In the present study, the protective effect of an aqueous extract of green tea (GTE against renal oxidative damage induced by lead was undertaken. Adult males rats were divided into 4 groups: Control group receives distilled water as sole drinking source. GTE group received green tea extract (6.6% w/v.Pb group received Pb at dose of 0.4 % w/v in distilled water. Pb + GTE group received mixture of Pb and GTE as sole drinking source. Renal oxidative damage was observed in Pb-treated rats as evidenced via augmentation in kidney lipid peroxidation (LPO as well as depletion in kidney antioxidant enzymes; catalase (CAT, superoxide dismutase (SOD and glutathione peroxidase (GPx. Histopathological analysis revealed degeneration in the endothelium of glomerular tuft and the epithelium of lining tubules. In conclusion, GTE appeared to be beneficial to rats, to a great extent by attenuating and restoring the damage sustained by lead exposure.

  8. Optimization of Ultrasonic Extraction of Phenolic Antioxidants from Green Tea Using Response Surface Methodology

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    Lan-Sook Lee

    2013-10-01

    Full Text Available Response surface methodology (RSM has been used to optimize the extraction conditions of antioxidants with relatively low caffeine content from green tea by using ultrasonic extraction. The predicted optimal conditions for the highest antioxidant activity and minimum caffeine level were found at 19.7% ethanol, 26.4 min extraction time, and 24.0 °C extraction temperature. In the predicted optimal conditions, the experimental values were very close to the predicted values. Moreover, the ratio of (EGCg + ECg/EGC was identified a major factor contributing to the antioxidant activity of green tea extracts. In this study, ultrasonic extraction showed that the ethanol concentration and extraction time used for antioxidant extraction could be remarkably reduced without a decrease in antioxidant activity compared to the conventional extraction conditions.

  9. Green tea catechins: biologic properties, proposed mechanisms of action, and clinical implications.

    Science.gov (United States)

    Rosen, Ted

    2012-11-01

    Botanical products, including and especially green tea leaves, have a wide range of both reputed and demonstrated health benefits and have been used medicinally for thousands of years. This paper focuses on green tea catechins, principally reviewing their known biologic properties and potential mechanisms of action (MOAs). The primary objective is to discuss the proposed antiviral, antiproliferative, and immunostimulatory activity of catechins based on strong evidence from in vitro and in vivo studies conducted to date, including two preclinical in vitro studies with sinecatechins, a proprietary mixture of catechins. This review also discusses the clinical implications of catechins for the treatment of external genital and perianal warts (EGWs) and other conditions caused by human papillomavirus (HPV). While the MOA of catechins in the treatment of EGWs and other HPV-related conditions may be related to or associated with postulated or proven antiviral and immunostimulatory activity, the precise clinical significance of the various in vitro findings remains largely unknown.

  10. CAM use in dermatology. Is there a potential role for honey, green tea, and vitamin C?

    Science.gov (United States)

    Barbosa, Naiara S; Kalaaji, Amer N

    2014-02-01

    Complementary and alternative medicine (CAM) is a group of non-traditional medical practices that includes natural products, manipulations, and mind and body medicine. CAM use has grown and become popular among patients. In dermatology, honey, green tea, and vitamin C have been used as topical treatments for a variety of diseases. We performed a systematic review to explore the cutaneous effects of each of these three products. Honey's unique antibacterial, anti-inflammatory, and antioxidant properties were shown to contribute to wound healing, especially in ulcers and burns. Green tea, among many health benefits, demonstrated protection from ultraviolet-induced events, such as photoimmunosuppression and skin cancer growth. Vitamin C, known for its antioxidant properties and key role in collagen production, has been shown to produce positive effects on skin hyperpigmentation and aging. Future large well-designed clinical trials are needed in order to further investigate the potential of these agents as dermatological therapies.

  11. Green tea cultivar 'Benifuuki' potentiates split vaccine-induced immunoglobulin A production.

    Science.gov (United States)

    Won, Yeong-Seon; Kumazoe, Motofumi; Takamatsu, Kanako; Shinoda, Yuki; Sonoda, Saki; Okada, Kenji; Okamoto, Takehisa; Tachibana, Hirofumi

    2017-01-01

    Influenza is a widespread disease caused by infection with the influenza virus. Vaccination is considered to be the main countermeasure against influenza. A split vaccine is widely used to avoid severe adverse events, and it induces strong humoral immunity. However, the split vaccine alone cannot elicit mucosal immunity, including IgA production, and its preventative effects are limited. Here, we show that the green tea cultivar 'Benifuuki' extract enhanced the effect of a split vaccine on mucosal immunity. The frequency of IgA(+) cells was increased in lung and Peyer's patch that received Benifuuki diet. Secretion of hemagglutinin-specific mucosal IgA, which is closely linked to the prevention of viral infection, was significantly increased in the bronchoalveolar lavage fluid of split vaccine-immunized BALB/c mice that were administered green tea Benifuuki extract. Our findings suggest that Benifuuki intake enhanced the effects of the split vaccine on mucosal immunity.

  12. Green tea catechins prevent obesity through modulation of peroxisome proliferator-activated receptors.

    Science.gov (United States)

    Yan, Jingqi; Zhao, Yan; Zhao, Baolu

    2013-09-01

    Epidemiological evidence and experimental studies suggest that drinking green tea is associated with a lower risk of obesity and related diseases. However, the mechanisms of these effects are not clear. In the present study, we investigated the anti-obesity mechanisms of green tea catechins (GTCs) through modulation of peroxisome proliferator activated-receptor (PPAR) pathways in high-fat diet-induced obesity in rats. GTC supplementation significantly attenuated the increased body and liver weights and the elevated serum and liver triglyceride levels. Meanwhile, GTCs increased the PPARγ levels in subcutaneous white adipose tissue (SWAT) and decreased the PPARγ levels in visceral white adipose tissue (VWAT). In addition, GTC treatment up-regulated the levels of PPARδ in SWAT, VWAT, and brown adipose tissue and increased the expression of genes involved in fatty acid oxidation in brown adipose tissue. Our results suggest that GTCs exert their anti-obesity mechanism in part by modulating PPAR signaling pathways.

  13. Preventive role of green tea catechins from obesity and related disorders especially hypercholesterolemia and hyperglycemia

    OpenAIRE

    Ahmad, Rabia Shabir; Butt, Masood Sadiq; Sultan, M Tauseef; Mushtaq, Zarina; Ahmad, Shakeel; Dewanjee, Saikat; De Feo, Vincenzo; Zia-Ul-Haq, Muhammad

    2015-01-01

    Background During the last few years, scientific investigations have proposed diet based regimens to prevent several health ailments including obesity, hypercholesterolemia and diabetes. In this regard, a promising tool is the use of functional foods/nutraceuticals. Present research project was an attempt to explore nutraceutical worth of locally grown green tea variety (Qi-Men) against lifestyle related disorders. Methods Functional drinks (T2 and T3) were prepared by adding catechins and ep...

  14. Systemic Absorption of Catechins after Intraruminal or Intraduodenal Application of a Green Tea Extract in Cows

    OpenAIRE

    Silvia Wein; Birgit Beyer; Annika Gohlke; Ralf Blank; Metges, Cornelia C.; Siegfried Wolffram

    2016-01-01

    Green tea catechins have various potential health benefits in humans including anti-inflammatory, anti-oxidative and hepato-protective effects. If present in the circulation, they might have similar effects in ruminants, which are exposed to oxidative stress and fatty liver disease such as dairy cows during the periparturient phase. However, the bioavailability of a substance is a prerequisite for any post absorptive effect in vivo. This study aimed to investigate the appearance of catechins ...

  15. Oral green tea catechins transiently lower plasma glucose concentrations in female db/db mice.

    Science.gov (United States)

    Wein, Silvia; Schrader, Eva; Rimbach, Gerald; Wolffram, Siegfried

    2013-04-01

    Polyphenols, including green tea catechins, are secondary plant compounds often discussed in the context of health-promoting potential. Evidence for such effects is mainly derived from epidemiological and cell culture studies. The aim of the present study was to investigate antidiabetic, antiadipogenic, and anti-inflammatory effects at nonpharmacological doses in an obese diabetic mouse model that exerts early relevant clinical signs of non-insulin-dependent diabetes mellitus. Female db/db mice received a flavonoid-poor diet either without additive, with rosiglitazone (RSG, 0.02 g/kg diet), or with green tea extract (low-dose green tea extract [LGTE] and high-dose green tea extract [HGTE], 0.1 and 1 g/kg diet). Food and water were freely available. The body weight was monitored weekly. Blood was sampled (12-h fasted) from the tail vein on day 28 and analyzed for glucose, cholesterol, triacylglycerol, nonesterified fatty acids, insulin, adiponectin, and soluble intercellular adhesion molecule-1 (sICAM-1). Blood glucose was also analyzed on day 14. Furthermore, sICAM-1 release was investigated in tumor necrosis factor alpha-stimulated EAhy926 cells. After 14 days, fasting glycemia was improved by RSG or HGTE supplementation compared to controls. However, at the end of the study (day 28), only RSG exhibited glucose-lowering effects and induced plasma adiponectin concentrations, paralleled by higher body weight gain and reduced periuterine fat pads compared to controls. However, only GTE treatment reduced sICAM-1 release in vitro and in vivo. Nonpharmacological HGTE supplementation in db/db mice caused (1) no adiponectin-inducing or antiadipogenic effects, (2) reduced sICAM-1 release, thereby potentially exerting anti-inflammatory effects in the progressive diabetic state, and (3) a transient improvement in glycemia.

  16. Ameliorative Effect of Green Tea Catechin Against Cadmium Chloride-Induced Testicular Toxicity in Mice.

    Science.gov (United States)

    Sharma, Priyanka; Goyal, Pradeep Kumar

    2015-01-01

    The present study was designed to evaluate the effect of green tea catechin (7500 µg/kg/animal/day) against cadmium-induced testicular dysfunctions and oxidative stress in the testes of mice. For this purpose, Swiss albino mice were divided into six groups: group I, negative control; group II, catechin-treated control; group III, cadmium chloride (CdCl2)-treated control; group IV, experimental group I; group V, experimental group II; and group VI, experimental group III. Animals from all of these groups were necropsied at various post-treatment intervals between 12 hours and 30 days for various biochemical alterations in the testes. CdCl2 intoxication resulted in a significant decline in testicular total proteins, cholesterol, and alkaline phosphatase, whereas acid phosphatase and lipid peroxidation exhibited a noticeable augmentation as compared to negative control. Catechin treatment effectively protected CdCl2-induced alterations in all such parameters throughout the experiment. Catechin was effective in reducing the CdCl2-induced augmentation of phase I (P450 and CYPB5) as well as phase II (DT-diaphorase and glutathione-S-transferase) enzymes in testes. Furthermore, CdCl2 intoxication was found to attenuate the antioxidant potential of testes, which was however augmented when supplemented with green tea extract. Compared to CdCl2-treated control mice, superoxide dismutase, glutathione peroxidase, glutathione, and catalase levels were significantly decreased in testes. Indeed, green tea catechin significantly increased testicular antioxidant enzymatic activities compared to those given CdCl2 alone. In conclusion, the use of green tea extract appeared to be beneficial to a great extent in inhibiting and restoring the testicular injuries induced by CdCl2 intoxication in mammals.

  17. Epigallocatechin-3-Gallate (EGCG), a Green Tea Polyphenol, Stimulates Hepatic Autophagy and Lipid Clearance

    OpenAIRE

    Jin Zhou; Benjamin Livingston Farah; Rohit Anthony Sinha; Yajun Wu; Brijesh Kumar Singh; Boon-Huat Bay; Yang, Chung S.; Paul Michael Yen

    2014-01-01

    Epigallocatechin gallate (EGCG) is a major polyphenol in green tea that has been shown to have anti-inflammatory, anti-cancer, anti-steatotic effects on the liver. Autophagy also mediates similar effects; however, it is not currently known whether EGCG can regulate hepatic autophagy. Here, we show that EGCG increases hepatic autophagy by promoting the formation of autophagosomes, increasing lysosomal acidification, and stimulating autophagic flux in hepatic cells and in vivo. EGCG also increa...

  18. Effect of aqueous extract of green tea on sexual efficiency in adult male rats

    Directory of Open Access Journals (Sweden)

    A. Y. Jasem

    2008-01-01

    Full Text Available This experiment was designed to study the effects of treatment with green tea (10 g /750ml deionized boiled water for 30 days on some physiological and histological changes of male reproductive system of rats exposed to oxidative stress induced by alloxan (100 mg/kg body weight. The study showed that treatment with alloxan (100 mg/kg body weight, caused a significant decrease in body weights, epididymal body and seminal vesicles weight. total number of epididymal sperm, percentage of live sperms, with significant increase in epididymal head,tail and prostate gland weight, percentage of dead sperms and sperm abnormalities, but there is no significant changes in the weight of the testes in the rats treated with alloxan.Treatment of rats exposed to oxidative stress induced by alloxan (100 mg/kg body weight with green tea (10 g/750ml deionized boiled water for 30 days in drinking water caused a significant increase in body weights, epididymal body & seminal vesicles, percentage of live sperms, with decrease in epididymal head, tail and prostate gland weights, percentage of dead sperms and sperm abnormalities as compared with alloxan treated group. With decrease in the total number of epididymal sperm count as compared with control. Histopathological changes observed in the testes of rats treated with alloxan (100 mg/kg included presence of abnormal spermatids with decrease in the number of sperms in the lumen of seminiferous tubules in addition to irregular division of germ cells.Treatment with green tea caused improvement in the histology of the testes. It was concluded that aqueous extract of green tea exerted an antioxidant effect on the histopathological aspects of the male reproductive system of rats exposed to oxidative stress induced by alloxan.

  19. Does the Consumption of Green Tea Reduce the Risk of Lung Cancer among Smokers?

    OpenAIRE

    Wenbin Liang; Binns, Colin W; Le Jian; Lee, Andy H

    2007-01-01

    Experimental and epidemiological studies were reviewed to assess whether the consumption of green tea could reduce the risk of lung cancer in smokers. Articles published since 1990 were located by searching electronic databases PubMed, Ovid and Science Direct, using keywords ‘lung cancer’, ‘tea’ and ‘smoking’ without any restriction on language. After relevant articles had been located, further papers were obtained from their reference lists. Evidence from experimental studies (in vitro anima...

  20. Effects of green tea compound epigallocatechin-3-gallate against Stenotrophomonas maltophilia infection and biofilm.

    OpenAIRE

    Vidigal, Pedrina G; Mathias Müsken; Becker, Katrin A.; Susanne Häussler; Jost Wingender; Eike Steinmann; Jan Kehrmann; Erich Gulbins; Jan Buer; Peter Michael Rath; Jörg Steinmann

    2014-01-01

    We investigated the in vitro and in vivo activities of epigallocatechin-3-gallate (EGCg), a green tea component, against Stenotrophomonas maltophilia (Sm) isolates from cystic fibrosis (CF) patients. In vitro effects of EGCg and the antibiotic colistin (COL) on growth inhibition, survival, and also against young and mature biofilms of S. maltophilia were determined. Qualitative and quantitative changes on the biofilms were assessed by confocal laser scanning microscopy (CLSM). Further, in viv...

  1. Do teas rich in antioxidants reduce the physicochemical and peroxidative risk factors for calcium oxalate nephrolithiasis in humans? Pilot studies with Rooibos herbal tea and Japanese green tea.

    Science.gov (United States)

    Rodgers, A; Mokoena, M; Durbach, I; Lazarus, J; de Jager, S; Ackermann, H; Breytenbach, I; Okada, A; Usami, M; Hirose, Y; Ando, R; Yasui, T; Kohri, K

    2016-08-01

    Several experimental and animal studies have demonstrated that substances rich in antioxidants can reduce the physicochemical and peroxidative risk factors for calcium oxalate (CaOx) renal stone formation in urine and blood. However, there are very few such investigations in humans. In the present pilot study, two varieties of tea, a green one from Japan (JGT) and a herbal one from South Africa (Rooibos) (RT), both rich in antioxidants, were administered to a group of CaOx stone formers (SF) (n = 8) for 30 days. Both teas were analysed for polyphenols by high-performance liquid chromatography and for minerals by plasma atomic and optical emission spectroscopy. 24 h urines (baseline and day 30) were analysed for lithogenic factors. CaOx metastable limits and crystal nucleation and growth kinetics were also determined in each urine sample. Deposited crystals were inspected by scanning electron microscopy. Blood samples were collected (baseline and day 30). Biomarkers of oxidative stress including plasma and urinary thiobarbituric acid reactive substances (TBARS) and urinary N-acetyl-β-D-glucosaminidase (NAG) were also determined. Urinary physicochemical risk factors were also investigated after ingestion of RT for 30 days in two control groups (CG1 and CG2), the latter one of which consisted of habitual JGT drinkers. Statistical analyses were performed using Wilcoxon signed rank tests and Mann-Whitney tests for paired and independent measurements, respectively. Several flavonoids and catechins were quantified in RT and JGT, respectively, confirming that both teas are rich sources of antioxidants. Mineral content was found to be far below dietary reference intakes. There were no significant changes in any of the urinary physicochemical or peroxidative risk factors in the control groups or in SF, except for the supersaturation (SS) of brushite (Bru) which decreased in the latter group after ingestion of JGT. Crystal morphology showed a tendency to change from

  2. Green tea, black tea, and oolong tea polyphenols reduce visceral fat and inflammation in mice fed high-fat, high-sucrose obesogenic diets.

    Science.gov (United States)

    Heber, David; Zhang, Yanjun; Yang, Jieping; Ma, Janice E; Henning, Susanne M; Li, Zhaoping

    2014-09-01

    Green tea (GT) and caffeine in combination were shown to increase energy expenditure and fat oxidation, but less is known about the effects of black tea (BT) and oolong tea (OT). This study investigated whether decaffeinated polyphenol extracts from GT, BT, and OT decrease body fat and inflammation in male C57BL/6J mice fed high-fat/high-sucrose [HF/HS (32% energy from fat, 25% energy from sucrose)] diets. Mice were fed either an HF/HS diet with 0.25% of polyphenol from GT, OT, or BT or a low-fat/high-sucrose [LF/HS (10.6% energy from fat, 25% energy from sucrose)] diet for 20 wk. Monomeric tea polyphenols were found in the liver and adipose tissue of mice fed the HF/HS diet with GT polyphenols (GTPs) and OT polyphenols (OTPs) but not BT polyphenols (BTPs). Treatment with GTPs, OTPs, BTPs, and an LF/HS diet led to significantly lower body weight, total visceral fat volume by MRI, and liver lipid weight compared with mice in the HF/HS control group. Only GTPs reduced food intake significantly by ∼10%. GTP, BTP, and LF/HS-diet treatments significantly reduced serum monocyte chemotactic protein-1 (MCP-1) compared with HF/HS controls. In mesenteric fat, monocyte chemotactic protein-1 (Mcp1) gene expression was significantly decreased by treatment with GTPs, BTPs, OTPs, and an LF/HS diet and in liver tissue by GTP and BTP treatments. Mcp1 gene expression in epididymal fat was significantly decreased by the BTP and LF/HS diet interventions. In epididymal fat, consistent with an anti-inflammatory effect, adiponectin gene expression was significantly increased by GTPs and OTPs. Angiogenesis during adipose tissue expansion is anti-inflammatory by maintaining adipocyte perfusion. We observed significantly increased gene expression of vascular endothelial growth factor A by GTPs and vascular endothelial growth factor receptor 2 by BTPs and the LF/HS diet and a decrease in pigment epithelium-derived factor gene expression by OTPs and BTPs. In summary, all 3 tea polyphenol

  3. Phenolic Antioxidants Identified by ESI-MS from Yerba Maté (Ilex paraguariensis and Green Tea (Camelia sinensis Extracts

    Directory of Open Access Journals (Sweden)

    Patricia O Carvalho

    2007-03-01

    Full Text Available Aqueous extracts of green yerba maté (Ilex paraguariensis and green tea (Camellia sinensis are good sources of phenolic antioxidants, as already described in the literature. The subject of this study were organic extracts from yerba maté, both green and roasted, and from green tea. Their phenolic profiles were characterized by direct infusion electrospray insertion mass spectrometry (ESI-MS and their free radical scavenging activity was determined by the DPPH assay. Organic extracts containing phenolic antioxidants might be used as natural antioxidants by the food industry, replacing the synthetic phenolic additives used nowadays. Ethanolic and aqueous extracts from green yerba maté, roasted yerba maté and green tea showed excellent DPPH scavenging activity (>89%. The ether extracts from green and roasted yerba maté displayed a weak scavenging activity, different from the behavior observed for the green tea ether extract. The main phenolic compounds identified in green yerba maté water and ethanolic extracts were: caffeic acid, quinic acid, caffeoyl glucose, caffeoylquinic acid, feruloylquinic acid, dicaffeoylquinic acid and rutin. After the roasting process two new compounds were formed: caffeoylshikimic acid and dicaffeoylshikimic acid. The ethanolic extracts from yerba maté, both roasted and green, with lower content of phenolic compounds (3.80 and 2.83 mg/mL presented high antioxidant activity and even at very low phenolic concentrations, ether extract from GT (0.07 mg/mL inhibited DPPH over 90%.

  4. The acute effects of green tea and carbohydrate coingestion on systemic inflammation and oxidative stress during sprint cycling.

    Science.gov (United States)

    Suzuki, Katsuhiko; Takahashi, Masaki; Li, Chia-Yang; Lin, Shiuan-Pey; Tomari, Miki; Shing, Cecilia M; Fang, Shih-Hua

    2015-10-01

    Green tea (Camellia sinensis) has anti-oxidative and anti-inflammatory effects, which may be beneficial to athletes performing high-intensity exercise. This study investigated the effects of carbohydrate and green tea coingestion on sprint cycling performance and associated oxidative stress and immunoendocrine responses to exercise. In a crossover design, 9 well-trained male cyclists completed 3 sets of 8 repetitions of 100-m uphill sprint cycling while ingesting green tea and carbohydrate (TEA) (22 mg/kg body mass catechins, 6 mg/kg body mass caffeine, 230 mg/kg glucose, and 110 mg/kg fructose) or carbohydrate only (CHO) (230 mg/kg body mass glucose and 110 mg/kg body mass fructose) during each 10-min recovery period between sets. Blood samples were collected before exercise, 10 min after exercise, and 14 h after exercise. There was no effect of acute TEA ingestion on cycling sprint performance (p = 0.29), although TEA maintained postexercise testosterone and lymphocyte concentrations, which decreased significantly in the CHO group (p 0.20), markers of oxidative stress and antioxidant capacity (p > 0.17), adiponectin concentration (p = 0.60), or muscle damage markers (p > 0.64). While acute green tea ingestion prevents the postexercise decrease in testosterone and lymphocytes, it does not appear to benefit cycling sprint performance or reduce markers of oxidation and inflammation when compared with carbohydrate alone.

  5. Comparative Analysis on Tea Polyphenols Extraction Rates of Four Kinds of Green Teas in Tongren%铜仁市四种绿茶茶多酚提取率的比较分析

    Institute of Scientific and Technical Information of China (English)

    鲁道旺; 鲁连芳; 罗磊

    2012-01-01

    To provide a scientific basis for tea quality and components in Tongren city, the experiment applied ferrous tartrate colorimetric method to compare the tea polyphenols extraction rates of four different green teas in Tongren city: Fanjing Mountain green tea from Yinjiang, ecological green tea from Songtao, Tai green tea from Shiqian, and the cloud green tea from Yanhe, which were picked in the same season and also in the same grade. The tea polyphenols extraction rates of Songtao ecological green teas from the same origin but in different picking seasons were also compared. The results showed that Tai green tea from Shiqian extracted the most, ecological green tea from Songtao, the cloud green tea from Yanhe, Fanjing Mountain green tea from Yinjiang progressively declinded. Meanwhile, among the Songtao ecological green teas in different picking seasons, the tea in Qingming season extracted the most, the tea before Qingming follows, then the tea in Guyu, the tea after Qingming the lest.%为对铜仁市茶叶品质成分提供科学依据,用酒石酸亚铁比色法对铜仁市的印江梵净山绿茶、松桃生态绿茶、石阡苔茶、沿河云雾绿茶四县同一季节同一等级茶叶中茶多酚提取率进行比较研究,同时对松桃生态绿茶同一产地不同采收时节茶叶中茶多酚的提取率进行比较研究。结果表明:茶多酚的提取率含量较高的是石阡苔茶,其次是松桃生态绿茶、沿河云雾绿茶、印江梵净山绿茶;松桃县云雾绿茶不同采收时节的茶叶中茶多酚提取率含量较高的是清明茶,其次是清明前茶、谷雨茶、清明后茶。

  6. Fermentation of Green Tea with 2% Aquilariae lignum Increases the Anti-Diabetic Activity of Green Tea Aqueous Extracts in the High Fat-Fed Mouse

    Directory of Open Access Journals (Sweden)

    Ji Eun Lee

    2015-11-01

    Full Text Available Anti-diabetic effects on the metabolomic differences between green tea (GT and Aquilariae lignum-fermented green tea (fGT were investigated in the high fat-fed mouse. To prove the differences, hypoglycemic (blood glucose, insulin and glycated hemoglobin levels, pancreas weights and histopathological-immunohistochemistrical analysis of pancreas–insulin/glucagon cells, hepato- and nephron-protective (the changes in liver and kidney weight, histopathology of liver and kidney, serum aminotransferases (AST and ALT levels, blood urea nitrogen, and serum creatinine levels, and hypolipidemic (the changes of serum total cholesterol, triglyceride, low- and high-density lipoprotein levels with fecal total cholesterol (TC and triglyceride (TG contents effects were evaluated. In addition, liver lipid peroxidation, the glutathione contents, and catalase and superoxide dismutase activities were measured according to the hepatic glucose-regulating enzyme activities of glucokinase (GK, glucose-6-phosphatase (G6pase and phosphoenolpyruvate carboxykinase (PEPCK for action mechanisms. As a result, fGT showed a stronger hypoglycemic, hepato- and nephron-protective, hypolipidemic, and anti-oxidant effect than GT in high fat-fed mice. In addition, fGT-treated mice exerted more favorable inhibitory activities against GK, G6pase, PERCK activities as compared to GT-treated mice. Taken together, fGT fermented with Aquilariae lignum, 1:49 (2%; g/g has a stronger effect compared with GT. Therefore, fGT has the potential to increase bioactivity against type 2 diabetics.

  7. Effects of Tannic Acid, Green Tea and Red Wine on hERG Channels Expressed in HEK293 Cells.

    Directory of Open Access Journals (Sweden)

    Xi Chu

    Full Text Available Tannic acid presents in varying concentrations in plant foods, and in relatively high concentrations in green teas and red wines. Human ether-à-go-go-related gene (hERG channels expressed in multiple tissues (e.g. heart, neurons, smooth muscle and cancer cells, and play important roles in modulating cardiac action potential repolarization and tumor cell biology. The present study investigated the effects of tannic acid, green teas and red wines on hERG currents. The effects of tannic acid, teas and red wines on hERG currents stably transfected in HEK293 cells were studied with a perforated patch clamp technique. In this study, we demonstrated that tannic acid inhibited hERG currents with an IC50 of 3.4 μM and ~100% inhibition at higher concentrations, and significantly shifted the voltage dependent activation to more positive potentials (Δ23.2 mV. Remarkably, a 100-fold dilution of multiple types of tea (green tea, oolong tea and black tea or red wine inhibited hERG currents by ~90%, and significantly shifted the voltage dependent activation to more positive potentials (Δ30.8 mV and Δ26.0 mV, respectively. Green tea Lung Ching and red wine inhibited hERG currents, with IC50 of 0.04% and 0.19%, respectively. The effects of tannic acid, teas and red wine on hERG currents were irreversible. These results suggest tannic acid is a novel hERG channel blocker and consequently provide a new mechanistic evidence for understanding the effects of tannic acid. They also revealed the potential pharmacological basis of tea- and red wine-induced biology activities.

  8. Effects of Tannic Acid, Green Tea and Red Wine on hERG Channels Expressed in HEK293 Cells.

    Science.gov (United States)

    Chu, Xi; Guo, Yusong; Xu, Bingyuan; Li, Wenya; Lin, Yue; Sun, Xiaorun; Ding, Chunhua; Zhang, Xuan

    2015-01-01

    Tannic acid presents in varying concentrations in plant foods, and in relatively high concentrations in green teas and red wines. Human ether-à-go-go-related gene (hERG) channels expressed in multiple tissues (e.g. heart, neurons, smooth muscle and cancer cells), and play important roles in modulating cardiac action potential repolarization and tumor cell biology. The present study investigated the effects of tannic acid, green teas and red wines on hERG currents. The effects of tannic acid, teas and red wines on hERG currents stably transfected in HEK293 cells were studied with a perforated patch clamp technique. In this study, we demonstrated that tannic acid inhibited hERG currents with an IC50 of 3.4 μM and ~100% inhibition at higher concentrations, and significantly shifted the voltage dependent activation to more positive potentials (Δ23.2 mV). Remarkably, a 100-fold dilution of multiple types of tea (green tea, oolong tea and black tea) or red wine inhibited hERG currents by ~90%, and significantly shifted the voltage dependent activation to more positive potentials (Δ30.8 mV and Δ26.0 mV, respectively). Green tea Lung Ching and red wine inhibited hERG currents, with IC50 of 0.04% and 0.19%, respectively. The effects of tannic acid, teas and red wine on hERG currents were irreversible. These results suggest tannic acid is a novel hERG channel blocker and consequently provide a new mechanistic evidence for understanding the effects of tannic acid. They also revealed the potential pharmacological basis of tea- and red wine-induced biology activities.

  9. Anticancer activity of grape and grape skin extracts alone and combined with green tea infusions.

    Science.gov (United States)

    Morré, Dorothy M; Morré, D James

    2006-07-18

    Grapes and grape extracts were compared for inhibition of a growth-related and cancer-specific form of cell surface NADH oxidase with protein disulfide-thiol interchange activity designated tNOX from human cervical carcinoma (HeLa) cells and growth of HeLa and mouse mammary 4T1 cells in culture and transplanted tumors in mice. Grapes and grape extracts of several varieties had activity. With an extracted grape preparation provided by the California Table Grape Commission, an active fraction was eluted with methanol from a Diaion HP-20 column after removal of inactive water-soluble materials. Grape skins were a much more potent source than either grape pulp, juice or seeds. Ethanol extracts of the ground freeze-dried pomace was an excellent source. The grape extracts interacted, often synergistically, with decaffeinated green tea extracts both in the inhibition of tNOX activity and in the inhibition of cancer cell growth. Intratumoral injections of a 25:1 mixture of a green tea extract plus ground freeze-dried pomace was nearly as effective as standard synergistic green tea-Capsicum mixtures in inhibiting growth of 4T1 mammary tumors in situ in mice.

  10. Periodontal Dressing-containing Green Tea Epigallocathechin gallate Increases Fibroblasts Number in Gingival Artifical Wound Model

    Directory of Open Access Journals (Sweden)

    Ardisa U. Pradita

    2014-04-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Green tea leaf (Camellia sinensis is one of herbal plants that is used for traditional medicine. Epigallocatechin gallate (EGCG in green tea is the most potential polyphenol component and has the strongest biological activity. It is known that EGCG has potential effect on wound healing. Objective: This study aimed to determine the effect of adding green tea EGCG into periodontal dressing on the number of fibroblasts after gingival artificial wound in animal model. Methods: Gingival artifical wound model was performed using 2mm punch biopsy on 24 rabbits (Oryctolagus cuniculus. The animals were divided into two groups. Periodontal dressing with EGCG and without EGCG was applied to the experimental and control group, respectively. Decapitation period was scheduled at day 3, 5, and 7 after treatment. Histological analysis to count the number of fibroblasts was performed. Results: Number of fibroblasts was significantly increased in time over the experimental group treated with EGCG periodontal dressing compared to control (p<0.05. Conclusion: EGCG periodontal dressing could increase the number of fibroblast, therefore having role in wound healing after periodontal surgery in animal model.DOI: 10.14693/jdi.v20i3.197

  11. Nutraceuticals for body-weight management: The role of green tea catechins.

    Science.gov (United States)

    Janssens, Pilou L H R; Hursel, Rick; Westerterp-Plantenga, Margriet S

    2016-08-01

    Green tea catechins mixed with caffeine have been proposed as adjuvants for maintaining or enhancing energy expenditure and for increasing fat oxidation, in the context of prevention and treatment of obesity. These catechins-caffeine mixtures seem to counteract the decrease in metabolic rate that occurs during weight loss. Their effects are of particular importance during weight maintenance after weight loss. Other metabolic targets may be fat absorption and the gut microbiota composition, but these effects still need further investigation in combination with weight loss. Limitations for the effects of green tea catechins are moderating factors such as genetic predisposition related to COMT-activity, habitual caffeine intake, and ingestion combined with dietary protein. In conclusion, a mixture of green tea catechins and caffeine has a beneficial effect on body-weight management, especially by sustained energy expenditure, fat oxidation, and preservation of fat free body-mass, after energy restriction induced body-weight loss, when taking the limitations into account. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Comparison of Some Extraction Methods for Isolation of Catechins and Caffeine from Turkish Green Tea

    Directory of Open Access Journals (Sweden)

    Ezgi DEMİR

    2015-07-01

    Full Text Available Effective extraction of anticancer and antioxidant principles from Turkish green tea were main purpose of this work. The pre-optimized experimental condition for liquid extraction was employed for comparative appraisal.  Not only extraction methods also nature of the green tea samples (fresh, dried or frozen and quantitative yields related to collection periods were investigated.  After extraction of the green tea with various techniques the extract was partitioned with chloroform to remove caffeine, after that the extract was partitioned with ethyl acetate to obtain catechin mixture. Quantification of individual catechins was carried out by HPLC and analysis results proved that epigallocatechin gallate (EGCG was main catechin specie present in all extracts. The results indicate that hot water extraction (at 80 0C provides higher catechin yield when compared to other methods. The highest extract yields were obtained with dried leaves collected in second collection period. The crude catechin mixture contains high amount of EGCG and might be used as raw material for production of plant remedies at industrial scale.

  13. Effects of green tea extract and (-)-epigallocatechin-3-gallate on pharmacokinetics of nadolol in rats.

    Science.gov (United States)

    Misaka, S; Miyazaki, N; Fukushima, T; Yamada, S; Kimura, J

    2013-11-15

    Green tea catechins have been shown to affect the activities of drug transporters in vitro, including P-glycoprotein and organic anion transporting polypeptides. However, it remains unclear whether catechins influence the in vivo disposition of substrate drugs for these transporters. In the present study, we investigated effects of green tea extract (GTE) and (-)-epigallocatechin-3-gallate (EGCG) on pharmacokinetics of a non-selective hydrophilic β-blocker nadolol, which is reported to be a substrate for several drug transporters and is not metabolized by cytochrome P450 enzymes. Male Sprague-Dawley rats received GTE (400 mg/kg), EGCG (150 mg/kg) or saline (control) by oral gavage, 30 min before a single intragastric administration of 10 mg/kg nadolol. Plasma and urinary concentrations of nadolol were determined using high performance liquid chromatography. Pharmacokinetic parameters were estimated by a noncompartmental analysis. Pretreatment with GTE resulted in marked reductions in the maximum concentration (Cmax) and area under the time-plasma concentration curve (AUC) of nadolol by 85% and 74%, respectively, as compared with control. In addition, EGCG alone significantly reduced Cmax and AUC of nadolol. Amounts of nadolol excreted into the urine were decreased by pretreatments with GTE and EGCG, while the terminal half-life of nadolol was not different among groups. These results suggest that the coadministration with green tea catechins, particularly EGCG, causes a significant alteration in the pharmacokinetics of nadolol, possibly through the inhibition of its intestinal absorption mediated by uptake transporters.

  14. Degradation kinetics of catechins in green tea powder: effects of temperature and relative humidity.

    Science.gov (United States)

    Li, Na; Taylor, Lynne S; Mauer, Lisa J

    2011-06-08

    The stability of catechins in green tea powders is important for product shelf life and delivering health benefits. Most published kinetic studies of catechin degradation have been conducted with dilute solutions and, therefore, are limited in applicability to powder systems. In this study, spray-dried green tea extract powders were stored under various relative humidity (RH) (43-97%) and temperature (25-60 °C) conditions for up to 16 weeks. High-performance liquid chromatography (HPLC) was used to determine catechin contents. Catechin degradation kinetics were affected by RH and temperature, but temperature was the dominant factor. Kinetic models as functions of RH and temperature for the individual 2,3-cis-configured catechins (EGCG, EGC, ECG, and EC) were established. The reaction rate constants of catechin degradation also followed the Williams-Landel-Ferry (WLF) relationship. This study provides a powerful prediction approach for the shelf life of green tea powder and highlights the importance of glass transition in solid state kinetics studies.

  15. Green tea catechins ameliorate adipose insulin resistance by improving oxidative stress.

    Science.gov (United States)

    Yan, Jingqi; Zhao, Yan; Suo, Siqingaowa; Liu, Yang; Zhao, Baolu

    2012-05-01

    Epidemiological data have suggested that drinking green tea is negatively associated with diabetes, and adipose oxidative stress may have a central role in causing insulin resistance, according to recent findings. The aim of this work is to elucidate a new mechanism for green tea's anti-insulin resistance effect. We used obese KK-ay mice, high-fat diet-induced obese rats, and induced insulin resistant 3T3-L1 adipocytes as models. Insulin sensitivity and adipose reactive oxidative species (ROS) levels were detected in animals and adipocytes. The oxidative stress assay and glucose uptake ability assay were performed, and the effects of EGCG on insulin signals were detected. Green tea catechins (GTCs) significantly decreased glucose levels and increased glucose tolerance in animals. GTCs reduced ROS content in both models of animal and adipocytes. EGCG attenuated dexamethasone and TNF-α promoted ROS generation and increased glucose uptake ability. EGCG also decreased JNK phosphorylation and promoted GLUT-4 translocation. EGCG and GTCs could improve adipose insulin resistance, and exact this effect on their ROS scavenging functions. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Comparative study of the growth-inhibitory and apoptosis-inducing activities of black tea theaflavins and green tea catechin on murine myeloid leukemia cells.

    Science.gov (United States)

    Lung, Hong-Lok; Ip, Wai-Ki; Chen, Zhen-Yu; Mak, Nai-Ki; Leung, Kwok-Nam

    2004-03-01

    Among the black tea polyphenols, theaflavins are generally considered to be the more effective components for the inhibition of carcinogenesis. In this study, we attempted to compare the growth-inhibitory and apoptosis-inducing activities of the four black tea theaflavins (TF-1, TF-2A, TF-2B and TF-3) with the major green tea catechin epigallocatechin-3-gallate (EGCG) on the murine myeloid leukemia WEHI-3B JCS cells. All the four black tea theaflavins were shown to exert potent anti-proliferative and cytotoxic effects on the leukemia WEHI-3B JCS cells in a dose-dependent manner. The observed anti-proliferative and cytotoxic effects were in the following order of potency: EGCG > TF-2B > TF-3 > TF-2A > TF-1. In addition, all theaflavins were capable of inducing apoptosis in the leukemia WEHI-3B JCS cells. Among the four theaflavins tested, TF-2B and TF-3 were found to be slightly more potent in inducing apoptosis of the WEHI-3B JCS cells than that of TF-2A and TF-1 but were comparable to the major green tea epicatechin EGCG. More interestingly, both TF-2B and TF-3 were found to be much more effective than TF-1 and TF-2B in reducing both the in vitro clonogenicity and in vivo tumorigenicity of the WEHI-3B JCS cells, suggesting that these two black tea theaflavins might represent potential candidates for the treatment of some forms of leukemia.

  17. In vitro antioxidant and anti-inflammatory properties of Limonium algarvense flowers' infusions and decoctions: A comparison with green tea (Camellia sinensis).

    Science.gov (United States)

    Rodrigues, Maria João; Neves, Vanessa; Martins, Alice; Rauter, Amélia P; Neng, Nuno R; Nogueira, José M F; Varela, João; Barreira, Luísa; Custódio, Luísa

    2016-06-01

    This work reports the in vitro antioxidant and anti-inflammatory activities and toxicity of infusions and decoctions of Limonium algarvense flowers, and green tea. The total contents in different phenolic groups and the quantification of individual phenolics by HPLC are also reported. L. algarvense and green tea had similar antioxidant properties, except for hydroxyl radical-scavenging activity, higher on green tea, and iron chelating potential, higher on L. algarvense. The later species also had the uppermost anti-inflammatory potential. Green tea decoction had the highest content of phenolic groups, but the infusion of L. algarvense had higher amounts of salicylic, gallic and coumaric acids. L. algarvense was not toxic, whereas green tea was toxic for S17 cells. Under our experimental conditions, infusions and decoctions of L. algarvense flowers had similar or higher antioxidant and anti-inflammatory properties than green tea, and thus, may be useful for alleviating symptoms associated with oxidative and inflammatory-related diseases.

  18. Spectroscopy Investigation on Conformational Transition of Tea Glycoconjugate from Green Tea

    Institute of Scientific and Technical Information of China (English)

    CHEN,Hai-Xia(陈海霞); ZHANG,Min(张民); XIE,Bi-Jun(谢笔钧)

    2004-01-01

    The conformational transition of a new glycoconjugate,tea glycoconjugate(TGC),was investigated by spectroscopy techniques including circular dichroism(CD)and ultraviolet(UV)spectroscopy.The solution behaviors of TGC inthe mediums of different temperature,pH value,and ions were compared.Results showed that the native conformation of TGC was partially ordered.The CD value and UV absorbance of TGC altered with the change of pH value,temperature,the addition of ions,and also accompanied order-disorder transition.Especially the conditions with temperature higher than the glasstransition temperature(Tg=62℃),higher pH value orlower pH value will have the most impact on the conformation of TGC,which will destroy the hydrogen bonds between the TGC molecules.The results indicated that the outside factors playimportant roles onthe stability of the conformation of TGC.

  19. A rapid green strategy for the synthesis of Au "meatball"-like nanoparticles using green tea for SERS applications

    Science.gov (United States)

    Wu, Shichao; Zhou, Xi; Yang, Xiangrui; Hou, Zhenqing; Shi, Yanfeng; Zhong, Lubin; Jiang, Qian; Zhang, Qiqing

    2014-09-01

    We report a simple and rapid biological approach to synthesize water-soluble and highly roughened "meatball"-like Au nanoparticles using green tea extract under microwave irradiation. The synthesized Au meatball-like nanoparticles possess excellent monodispersity and uniform size (250 nm in diameter). Raman measurements show that these tea-generated meatball-like gold nanostructures with high active surface areas exhibit a high enhancement of surface-enhanced Raman scattering. In addition, the Au meatball-like nanoparticles demonstrate good biocompatibility and remarkable in vitro stability at the biological temperature. Meanwhile, the factors that influence the Au meatball-like nanoparticles morphology are investigated, and the mechanisms behind the nonspherical shape evolution are discussed.

  20. Utilization of natural antioxidants: Green tea extract and Thymbra spicata oil in Turkish dry-fermented sausage.

    Science.gov (United States)

    Bozkurt, Hüseyin

    2006-07-01

    Effect of natural (green tea extract, Thymbra spicata oil) and synthetic antioxidants (buthylatedhydroxytoluene, BHT) on the safety (biogenic amine and TBARS values) and quality (pH, colour and sensory attributes) of sucuk (Turkish dry-fermented sausage) were investigated during the ripening periods. Addition of antioxidants decreased (Pgreen tea extract-T. spicata oil>T. spicata oil>BHT, and their mean values were 70.45, 76.05, 83.13, and 95.97mg/kg, respectively. The highest tyramine concentration was observed in control sucuk prepared without any antioxidants, while the lowest was in the recipe with green tea extract as their mean values were about 99.42 and 64.31mg/kg, respectively. The pH, L, b, and overall sensory quality were not significantly different (P>0.05) with the addition of green tea extract, T. spicata oil, green tea extract-T. spicata oil. These results indicated that the most effective antioxidant was found to be green tea extract. This study pointed out that natural antioxidants were more effective than synthetic antioxidants, so they could be easily utilized in sucuk to enhance quality and provide safer products.

  1. Preparation of Gold Nanoparticles Using Tea: A Green Chemistry Experiment

    Science.gov (United States)

    Sharma, R. K.; Gulati, Shikha; Mehta, Shilpa

    2012-01-01

    Assimilating green chemistry principles in nanotechnology is a developing area of nanoscience research nowadays. Thus, there is a growing demand to develop environmentally friendly and sustainable methods for the synthesis of nanoparticles that utilize nontoxic chemicals, environmentally benign solvents, and renewable materials to avoid their…

  2. Preparation of Gold Nanoparticles Using Tea: A Green Chemistry Experiment

    Science.gov (United States)

    Sharma, R. K.; Gulati, Shikha; Mehta, Shilpa

    2012-01-01

    Assimilating green chemistry principles in nanotechnology is a developing area of nanoscience research nowadays. Thus, there is a growing demand to develop environmentally friendly and sustainable methods for the synthesis of nanoparticles that utilize nontoxic chemicals, environmentally benign solvents, and renewable materials to avoid their…

  3. Coffee and green tea as a large source of antioxidant polyphenols in the Japanese population.

    Science.gov (United States)

    Fukushima, Yoichi; Ohie, Takashi; Yonekawa, Yasuhiko; Yonemoto, Kohei; Aizawa, Hiroki; Mori, Yoko; Watanabe, Makoto; Takeuchi, Masato; Hasegawa, Maiko; Taguchi, Chie; Kondo, Kazuo

    2009-02-25

    Food and beverages rich in polyphenols with antioxidant activity are highlighted as a potential factor for risk reduction of lifestyle related diseases. This study was conducted to elucidate total polyphenol consumption from beverages in Japanese people. Total polyphenol (TP) contents in beverages were measured using a modified Folin-Ciocalteu method removing the interference of reduced sugars by using reverse-phase column chromatography. A beverage consumption survey was conducted in the Tokyo and Osaka areas in 2004. Randomly selected male and female subjects (10-59 years old, n = 8768) recorded the amounts and types of all nonalcoholic beverages consumed in a week. Concentration of TP in coffee, green tea, black tea, Oolong tea, barley tea, fruit juice, tomato/vegetable juice, and cocoa drinks were at 200, 115, 96, 39, 9, 34, 69, and 62 mg/100 mL, respectively. Total consumption of beverages in a Japanese population was 1.11 +/- 0.51 L/day, and TP contents from beverages was 853 +/- 512 mg/day. Coffee and green tea shared 50% and 34% of TP consumption in beverages, respectively, and contribution of each of the other beverages was less than 10%. TP contents in 20 major vegetables and 5 fruits were 0-49 mg and 2-55 mg/100 g, respectively. Antioxidant activities, Cu reducing power, and scavenging activities for DPPH and superoxide, of those samples correlated to the TP contents (p coffee, contributed to a large share of the consumption of polyphenols, as antioxidants, in the Japanese diet.

  4. Consumption of coffee, green tea, oolong tea, black tea, chocolate snacks and the caffeine content in relation to risk of diabetes in Japanese men and women.

    Science.gov (United States)

    Oba, Shino; Nagata, Chisato; Nakamura, Kozue; Fujii, Kaori; Kawachi, Toshiaki; Takatsuka, Naoyoshi; Shimizu, Hiroyuki

    2010-02-01

    Although the inverse association between coffee consumption and risk of diabetes has been reported numerous times, the role of caffeine intake in this association has remained unclear. We evaluated the consumption of coffee and other beverages and food containing caffeine in relation to the incidence of diabetes. The study participants were 5897 men and 7643 women in a community-based cohort in Takayama, Japan. Consumption of coffee, green tea, oolong tea, black tea and chocolate snacks were measured with a semi-quantitative FFQ in 1992. At the follow-up survey in 2002, the development of diabetes and the time of diagnosis were reported. To assess the association, age, smoking status, BMI, physical activity, education in years, alcohol consumption, total energy intake, fat intake and women's menopausal status were adjusted. Among men who consumed one cup per month to six cups per week and among those who consumed one cup per d or more, the associated hazard ratios were 0.69 (95 % CI 0.50, 0.97) and 0.69 (95 % CI 0.49, 0.98) compared with those who drank little to no coffee, with a P value for trend of 0.32. The hazard ratios for women with the same coffee consumption patterns were 1.08 (95 % CI 0.74, 1.60) and 0.70 (95 % CI 0.44, 1.12), with a P value for trend of 0.03. The association between estimated total caffeine intake and risk of diabetes was insignificant both among men and among women. The results imply that coffee consumption decreased the risk of developing diabetes. The protective effect may exist aside from the influence of caffeine intake.

  5. Effect of Catechins, Green tea Extract and Methylxanthines in Combination with Gentamicin Against Staphylococcus aureus and Pseudomonas aeruginosa - Combination therapy against resistant bacteria -

    OpenAIRE

    Bibi Sedigheh Fazly Bazzaz; Sahar Sarabandi; Bahman Khameneh; Hossein Hosseinzadeh

    2016-01-01

    Objectives: Bacterial resistant infections have become a global health challenge and threaten the society’s health. Thus, an urgent need exists to find ways to combat resistant pathogens. One promising approach to overcoming bacterial resistance is the use of herbal products. Green tea catechins, the major green tea polyphenols, show antimicrobial activity against resistant pathogens. The present study aimed to investigate the effect of catechins, green tea extract, and methylxanthines in com...

  6. Pro-bone and antifat effects of green tea and its polyphenol, epigallocatechin, in rat mesenchymal stem cells in vitro.

    Science.gov (United States)

    Ko, Chun Hay; Siu, Wing Sum; Wong, Hing Lok; Shum, Wai Ting; Fung, Kwok Pui; San Lau, Clara Bik; Leung, Ping Chung

    2011-09-28

    Green tea has been demonstrated recently as a potent bone supportive agent. Our previous studies showed that green tea and its polyphenolic constituents can promote bone-forming osteoblast activities and inhibit the bone-resorpting osteoclast formation. The objective of the present study was to investigate whether green tea and its components can regulate the osteogenic and adipogenic differentiation in pluripotent rat mesenchymal stem cells (MSCs). The rat MSCs were isolated from the bone marrow of tibiae and femora. The cells were treated with decaffeinated green tea extract (GTE) and six tea polyphenols under osteogenic induction. The alkaline phosphatase (ALP) activities and matrix calcium (Ca) deposition were assessed after 7 and 14 days of treatment. Our results demonstrated that GTE could significantly increase ALP dose dependently in the concentrations without cytotoxicity (0-100 μg/mL). Among six tested tea polyphenols, epigallocatechin (EGC) was shown to be the most effective in promoting osteogenic differentiation. At 20 μM, EGC increased ALP levels and Ca deposition significantly by 2.3- and 1.7-fold, respectively, when compared with the control group. EGC also increased the mRNA expression of bone formation markers runt-related transcription factor 2, ALP, osteonectin, and osteopontin. Furthermore, EGC demonstrated its antiadipogenicity by decreasing the adipocyte formation and inhibiting the mRNA expression levels of the adipogenic markers peroxisome proliferator-activated receptor γ, ccaat/enhancer-binding protein β, and fatty acid binding protein 4. In conclusion, this is the first report of the dual action of green tea polyphenol EGC in promoting osteogenesis and inhibiting adipocyte formation in MSCs. Our results provide scientific evidence to support the potential use of green tea in supporting the bone against degenerative diseases such as osteoporosis.

  7. Coffee and green tea consumption in relation to brain tumor risk in a Japanese population.

    Science.gov (United States)

    Ogawa, Takahiro; Sawada, Norie; Iwasaki, Motoki; Budhathoki, Sanjeev; Hidaka, Akihisa; Yamaji, Taiki; Shimazu, Taichi; Sasazuki, Shizuka; Narita, Yoshitaka; Tsugane, Shoichiro

    2016-12-15

    Few prospective studies have investigated the etiology of brain tumor, especially among Asian populations. Both coffee and green tea are popular beverages, but their relation with brain tumor risk, particularly with glioma, has been inconsistent in epidemiological studies. In this study, we evaluated the association between coffee and greed tea intake and brain tumor risk in a Japanese population. We evaluated a cohort of 106,324 subjects (50,438 men and 55,886 women) in the Japan Public Health Center-Based Prospective Study (JPHC Study). Subjects were followed from 1990 for Cohort I and 1993 for Cohort II until December 31, 2012. One hundred and fifty-seven (70 men and 87 women) newly diagnosed cases of brain tumor were identified during the study period. Hazard ratio (HR) and 95% confidence intervals (95%CIs) for the association between coffee or green tea consumption and brain tumor risk were assessed using a Cox proportional hazards regression model. We found a significant inverse association between coffee consumption and brain tumor risk in both total subjects (≥3 cups/day; HR = 0.47, 95%CI = 0.22-0.98) and in women (≥3 cups/day; HR = 0.24, 95%CI = 0.06-0.99), although the number of cases in the highest category was small. Furthermore, glioma risk tended to decrease with higher coffee consumption (≥3 cups/day; HR = 0.54, 95%CI = 0.16-1.80). No association was seen between green tea and brain tumor risk. In conclusion, our study suggested that coffee consumption might reduce the risk of brain tumor, including that of glioma, in the Japanese population. © 2016 UICC.

  8. New Approaches for Effective Microwave Assisted Extraction of Caffeine and Catechins from Green Tea

    Directory of Open Access Journals (Sweden)

    Gönül SERDAR

    2016-01-01

    Full Text Available This study was designed to develop an effective microwave assisted extraction (MAE method for extraction of caffeine and catechins from green tea samples. A series of solvents (water, ethanol:water mixture or citric acid:water mixture were used for extraction of green tea samples (fresh, frozen or dried collected in three collection periods (first, second and third collection periods. Tea samples were extracted using water in a close microwave system under the certain extraction conditions. Extraction was carried out under a controlled 600 W microwave power at 80 oC temperature for 4 min irradiation time. Alternative to water, an ethanol-water mixture (1:1 or a citric acid-water (1:1 mixture was used as extracting solvent under the same conditions. After MAE crude aqueous extract was partitioned first with chloroform to separate caffeine then ethyl acetate for catechins.  Both caffeine and catechin extraction was quite successful with microwave assisted system employing only 4 minutes treatment. The highest caffeine yield was obtained in the second collection period using frozen green tea samples and ethanol-water as extracting solvent. The yield of catechin extracts was between 0.84-3.96% depending on the solvent system used for extraction. Ethanol-water mixture seems to be appropriate for effective extraction in the basis of extract yields. However, HPLC results showed that individual catechin content of each extraction is more important criteria for the evaluation of most effective extraction medium rather than the mass of the extract.  Using citric acid as extracting solvent in MAE seem to be more fruitful providing 100% catechin mixture with the highest EGCG content. 

  9. Green synthesis of silver nanoparticles using green tea leaves: Experimental study on the morphological, rheological and antibacterial behaviour

    Science.gov (United States)

    Nakhjavani, Maryam; Nikkhah, V.; Sarafraz, M. M.; Shoja, Saeed; Sarafraz, Marzieh

    2017-10-01

    In this paper, silver nanoparticles are produced via green synthesis method using green tea leaves. The introduced method is cost-effective and available, which provides condition to manipulate and control the average nanoparticle size. The produced particles were characterized using x-ray diffraction, scanning electron microscopic images, UV visualization, digital light scattering, zeta potential measurement and thermal conductivity measurement. Results demonstrated that the produced samples of silver nanoparticles are pure in structure (based on the x-ray diffraction test), almost identical in terms of morphology (spherical and to some extent cubic) and show longer stability when dispersed in deionized water. The UV-visualization showed a peak in 450 nm, which is in accordance with the previous studies reported in the literature. Results also showed that small particles have higher thermal and antimicrobial performance. As green tea leaves are used for extracting the silver nanoparticles, the method is eco-friendly. The thermal behaviour of silver nanoparticle was also analysed by dispersing the nanoparticles inside the deionized water. Results showed that thermal conductivity of the silver nano-fluid is higher than that of obtained for the deionized water. Activity of Ag nanoparticles against some bacteria was also examined to find the suitable antibacterial application for the produced particles.

  10. Green tea drinking, high tea temperature and esophageal cancer in high and low risk areas of Jiangsu Province, China: a population-based case-control study

    NARCIS (Netherlands)

    Wu, M.; Liu, A.; Kampman, E.; Zhang, Zuo-Feng; Veer, van 't P.; Wu, P.; Wang, P.; Kok, F.J.; Zhao, J.

    2009-01-01

    Epidemiological studies suggested drinking green tea is inversely associated with esophageal cancer but results remain inconclusive. Moreover, inconsistent observations found high temperature drinks are associated with esophageal cancer. A population-based case-control study was conducted in a high-

  11. Green tea drinking, high tea temperature and esophageal cancer in high- and low-risk areas of Jiangsu Province, China: a population-based case-control study.

    NARCIS (Netherlands)

    Wu, M.; Liu, A.M.; Kampman, E.; Zhang, Z.F.; Veer, P. van 't; Wu, D.L.; Wang, P.H.; Yang, J.; Qin, Y.; Mu, L.N.; Kok, F.J.; Zhao, J.K.

    2009-01-01

    Epidemiological studies suggested drinking green tea is inversely associated with esophageal cancer but results remain inconclusive. Moreover, inconsistent observations found high temperature drinks are associated with esophageal cancer. A population-based case-control study was conducted in a high-

  12. Green tea catechins enhance norepinephrine-induced lipolysis via a protein kinase A-dependent pathway in adipocytes.

    Science.gov (United States)

    Chen, Shu; Osaki, Noriko; Shimotoyodome, Akira

    2015-05-22

    Green tea catechins have been shown to attenuate obesity in animals and humans. The catechins activate adenosine monophosphate-activated protein kinase (AMPK), and thereby increase fatty acid oxidation in liver and skeletal muscles. Green tea catechins have also been shown to reduce body fat in humans. However, the effect of the catechins on lipolysis in adipose tissue has not been fully understood. The aim of this study was to clarify the effect of green tea catechins on lipolysis in adipocytes and to elucidate the underlying mechanism. Differentiated mouse adipocyte cell line (3T3-L1) was stimulated with green tea catechins in the presence or absence of norepinephrine. Glycerol and free fatty acids in the media were measured. Phosphorylation of hormone-sensitive lipase (HSL) was determined by Western blotting, and the mRNA expression levels of HSL, adipose triglyceride lipase (ATGL), and perilipin were determined by quantitative RT-PCR. The cells were treated with inhibitors of protein kinase A (PKA), protein kinase C (PKC), protein kinase G (PKG), or mitogen-activated protein kinase (MAPK) to determine the responsible pathway. Treatment of 3T3-L1 adipocytes with green tea catechins increased the level of glycerol and free fatty acids released into the media in the presence, but not absence, of norepinephrine, and increased the level of phosphorylated HSL in the cells. The catechins also increased mRNA and protein levels of HSL and ATGL. PKA inhibitor (H89) attenuated the catechin-induced increase in glycerol release and HSL phosphorylation. The results demonstrate that green tea catechins enhance lipolysis in the presence of norepinephrine via a PKA-dependent pathway in 3T3-L1 adipocytes, providing a potential mechanism by which green tea catechins could reduce body fat.

  13. Structural characteristics of green tea catechins for formation of protein carbonyl in human serum albumin.

    Science.gov (United States)

    Ishii, Takeshi; Mori, Taiki; Ichikawa, Tatsuya; Kaku, Maiko; Kusaka, Koji; Uekusa, Yoshinori; Akagawa, Mitsugu; Aihara, Yoshiyuki; Furuta, Takumi; Wakimoto, Toshiyuki; Kan, Toshiyuki; Nakayama, Tsutomu

    2010-07-15

    Catechins are polyphenolic antioxidants found in green tea leaves. Recent studies have reported that various polyphenolic compounds, including catechins, cause protein carbonyl formation in proteins via their pro-oxidant actions. In this study, we evaluate the formation of protein carbonyl in human serum albumin (HSA) by tea catechins and investigate the relationship between catechin chemical structure and its pro-oxidant property. To assess the formation of protein carbonyl in HSA, HSA was incubated with four individual catechins under physiological conditions to generate biotin-LC-hydrazide labeled protein carbonyls. Comparison of catechins using Western blotting revealed that the formation of protein carbonyl in HSA was higher for pyrogallol-type catechins than the corresponding catechol-type catechins. In addition, the formation of protein carbonyl was also found to be higher for the catechins having a galloyl group than the corresponding catechins lacking a galloyl group. The importance of the pyrogallol structural motif in the B-ring and the galloyl group was confirmed using methylated catechins and phenolic acids. These results indicate that the most important structural element contributing to the formation of protein carbonyl in HSA by tea catechins is the pyrogallol structural motif in the B-ring, followed by the galloyl group. The oxidation stability and binding affinity of tea catechins with proteins are responsible for the formation of protein carbonyl, and consequently the difference in these properties of each catechin may contribute to the magnitude of their biological activities.

  14. 绿茶和发酵茶的茶多酚组成比较%Comparison of the Composition of the Polyphenols in Green Tea and Fermented Tea

    Institute of Scientific and Technical Information of China (English)

    吴警; 刘春莹; 郭久宁; 杨刚; 鱼红闪; 金凤燮

    2011-01-01

    [ Objective ] To compare the composition of the polyphenols in green tea and fermented tea ( including Black tea, Dianhong and Pu-Er tea). [ Method] Liquid chromatography (HPLC) was used to the determination of the polyphenols. [ Result] Five catechins, GA( Gallic acid)and CAF(Caffeine) in commercial green tea and fermented tea (including Black tea, Dianhong and Pu-Er tea). The results showed that, five catechins such as GC (Gallocatechin), EGC ( Epigallocatechin), EGCG ( Epigallocatechin gallate), EC ( Epicatechin ), ECG ( Epicatechin gallate), Gallic acid and Caffeine were all contained in green tea. EGCG was the major active components. “Semi-fermented” tea Tieguanyin was all detected. The contents of EGCG was the highest, 16.610 mg/g. “Fermented” tea Black tea was degraded partly. The contents of GC, EGC, EGCG were low. The content of Caffeine in Black tea was high, 17. 304 mg/g. The content of EGCG and ECG were high in Dianhong, 4.588 mg/g and 3. 559 mg/g. The major components in Pu-Er tea were Gallic acid and Caffeine. Other five catechins could not be detected. [ Conclusion] According to the different fermentation process of tea, tea polyphenols were degraded to varying degrees.%[目的]比较市售4种绿茶和发酵茶(包括红茶、滇红茶和普洱茶)的茶多酚组成和比例.[方法]采用高效液相色谱法检测茶多酚种类和含量.[结果]市售绿茶均含有没食子儿茶素(GC)、表没食子儿荼素(EGC)和表没食子儿茶素没食子酸酯(EGCG)、表儿茶素(EC)和表儿茶素没食子酸酯(ECG)等茶多酚,以及没食子酸(GA)和咖啡因(CAF),EGCG为4种绿茶有效成分中的主要物质.半发酵茶铁观音7种有效成分全部检出,EGCG含量最高为16.610mg/s.发酵茶红茶中茶多酚(儿茶素)部分被降解,GC、EGC、EGCG含量低,咖啡因含量高为17.304 mg/g;滇红茶中EGCG和ECG含量最高,分别为4.588和3.559 mg/g;普洱荼主要有效成分为没食子酸和咖啡因,几乎测不出其他5

  15. Enhanced in vitro and in vivo cellular imaging with green tea coated water-soluble iron oxide nanocrystals

    NARCIS (Netherlands)

    Xiao, Lisong; Mertens, Marianne; Wortmann, Laura; Kremer, Silke; Valldor, Martin; Lammers, Twan; Kiessling, Fabian; Mathur, Sanjay

    2015-01-01

    Fully green and facile redox chemistry involving reduction of colloidal iron hydroxide (Fe(OH)3) through green tea (GT) polyphenols produced water-soluble Fe3O4 nanocrystals coated with GT extracts namely epigallocatechin gallate (EGCG) and epicatechin (EC). Electron donating polyphenols stoichiomet

  16. Characterization of Two Homogalacturonan Pectins with Immunomodulatory Activity from Green Tea

    Directory of Open Access Journals (Sweden)

    Huijun Wang

    2014-06-01

    Full Text Available Two natural homogalacturonan (HG pectins (MW ca. 20 kDa were isolated from green tea based on their immunomodulatory activity. The crude tea polysaccharides (TPS1 and TPS2 were obtained from green tea leaves by hot water extraction and followed by 40% and 70% ethanol precipitation, respectively. Two homogenous water soluble polysaccharides (TPS1-2a and TPS1-2b were obtained from TPS1 after purification with gel permeation, which gave a higher phagocytic effect than TPS2. A combination of composition, methylation and configuration analyses, as well as NMR (nuclear magnetic resonance spectroscopy revealed that TPS1-2a and TPS1-2b were homogalacturonan (HG pectins consisting of a backbone of 1,4-linked α-d-galacturonic acid (GalA residues with 28.4% and 26.1% of carboxyl groups as methyl ester, respectively. The immunological assay results demonstrated that TPS1-2, which consisted mainly of HG pectins, showed phagocytosis-enhancing activity in HL-60 cells.

  17. Characterization of two homogalacturonan pectins with immunomodulatory activity from green tea.

    Science.gov (United States)

    Wang, Huijun; Wei, Guodong; Liu, Fei; Banerjee, Gautam; Joshi, Manoj; Bligh, S W Annie; Shi, Songshan; Lian, Hui; Fan, Hongwei; Gu, Xuelan; Wang, Shunchun

    2014-06-04

    Two natural homogalacturonan (HG) pectins (MW ca. 20 kDa) were isolated from green tea based on their immunomodulatory activity. The crude tea polysaccharides (TPS1 and TPS2) were obtained from green tea leaves by hot water extraction and followed by 40% and 70% ethanol precipitation, respectively. Two homogenous water soluble polysaccharides (TPS1-2a and TPS1-2b) were obtained from TPS1 after purification with gel permeation, which gave a higher phagocytic effect than TPS2. A combination of composition, methylation and configuration analyses, as well as NMR (nuclear magnetic resonance) spectroscopy revealed that TPS1-2a and TPS1-2b were homogalacturonan (HG) pectins consisting of a backbone of 1,4-linked α-D-galacturonic acid (GalA) residues with 28.4% and 26.1% of carboxyl groups as methyl ester, respectively. The immunological assay results demonstrated that TPS1-2, which consisted mainly of HG pectins, showed phagocytosis-enhancing activity in HL-60 cells.

  18. Effects of different brewing conditions on catechin content and sensory acceptance in Turkish green tea infusions.

    Science.gov (United States)

    Saklar, Sena; Ertas, Erdal; Ozdemir, Ibrahim S; Karadeniz, Bulent

    2015-10-01

    The optimal brewing conditions for Turkish green tea were determined on the basis of extracted catechins and sensory attributes. Green tea infusions were prepared at 75, 85 and 95 °C with brewing times of 1, 2, 3, 5, 10, 20, 30 and 45 min. The amounts of epistructured catechins (EGCG, EGC, ECG, EC), non-epistructured catechins (C, GC, GCG) and caffeine in brewed tea samples were analysed. Sensory analyses were performed by nine trained panelists for infusion colour, taste, aroma and overall acceptability. Brewing at 85 °C for 3 min was found to be the optimal condition, where the EGCG content was at a maximum of 50.69 mg/100 ml with the highest sensory scores. It was observed that the yield of epistructured catechins increased rapidly for the first 3-5 min of brewing at 85 °C, and increased brewing time resulted in a decrease in the yield of epistructured catechins. The amount of nonepistructured catechins continued to increase with longer extraction times. Sensory scores for infusion colour, taste, aroma and overall acceptability were highest at 3 and 5 min brewing times at all temperatures. Sensory scores were very low for 30 and 45 min brewing at 85 and 95 °C due to the bitter taste and dark colour.

  19. Influence of Steep Time on Polyphenol Content and Antioxidant Capacity of Black, Green, Rooibos, and Herbal Teas

    Directory of Open Access Journals (Sweden)

    Michael D. McAlpine

    2016-07-01

    Full Text Available Potential health benefits of tea consumption are often attributed to the antioxidant activity of polyphenols. Whether steep time, often variable in a real-life situation, makes a biological difference in terms of polyphenol content and antioxidant activity is uncertain. The study objective was to characterize eight popular and commercially available teas for total polyphenol content (TPC and antioxidant capacity in relation to steep time. Dragonwell (DW, Sencha (S, English Breakfast (EB, Golden Monkey (GM, Green Rooibos (GR, Red Rooibos (RR, Chamomile (C, and Peppermint (P loose leaf teas were individually steeped in water for 1–10 min at 1 min intervals. TPC increased with longer durations of steep time; however, the majority of polyphenols observed after 10 minutes were extracted in the first 5 min regardless of tea type. After 5 min of steeping, differences (p < 0.05 in TPC were observed across teas (JS~EB~P > DW > GM~GR~RR > C. Different teas also varied in their ability to inhibit the free radical 2, 2-diphenyl-1-picrylhydrazyl (DPPH when normalized for polyphenol concentration (1 µg/mL and there was no effect due to steep time. Predicted antioxidant capacity of teas also demonstrated significant differences among teas after 5 and 10 min. In conclusion, steep time modulates TPC but not the antioxidative capacity of tea polyphenols.

  20. Research on Jasmine Tea Scented by Green Tea With Different Drying Methods%不同干燥方式茶坯窨制茉莉花茶的研究

    Institute of Scientific and Technical Information of China (English)

    郭春雨

    2013-01-01

    通过对5种干燥方式茶坯窨制成的茉莉花茶进行品质分析,结果发现:低温真空-热风联合干燥方式茶坯制成的茉莉花茶与冷冻真空干燥方式茶坯制成的茉莉花茶相比,其茶多酚、氨基酸、黄酮类化合物、水浸出物稍低,但比其他干燥方式(热风、微波、低温真空)茶坯制成的茉莉花茶相比含量相对较高;在感官品质方面,低温真空-热风联合干燥方式茶坯制成的茉莉花茶明显优于其他干燥方式茶坯制成的茉莉花茶。%Based on the analysis of the quality of jasmine tea scented by green tea with 5 drying methods ,the results showed that compared with the jasmine tea scented by freeze vacuum drying green tea,the tea polyphenols,amino acids,flavonoids,water extractslightly were lower than the jasmine tea scented by low-temperature and hot-air drying green tea ,but it was higher than the jasmine tea scented by other drying (hot-air drying;microwave drying;low-temperature vacuum drying )green tea;In the sensory quality ,the jasmine tea scented by low-temperature vacuum and hot-air drying green tea was obviously better than the jasmine tea scented by green tea with other drying methods.

  1. Anti-stress effects of drinking green tea with lowered caffeine and enriched theanine, epigallocatechin and arginine on psychosocial stress induced adrenal hypertrophy in mice.

    Science.gov (United States)

    Unno, Keiko; Hara, Ayane; Nakagawa, Aimi; Iguchi, Kazuaki; Ohshio, Megumi; Morita, Akio; Nakamura, Yoriyuki

    2016-11-15

    Theanine, an amino acid in tea, has significant anti-stress effects on animals and humans. However, the anti-stress effects of drinking green tea have not yet been elucidated. The present study aimed to explore anti-stress effects of green tea and roles of tea components in a mouse model of psychosocial stress. We examined anti-stress effects of three types of green teas, theanine-rich "Gyokuro", standard "Sencha", and Sencha with lowered caffeine (low-caffeine green tea). Furthermore, the roles of tea components such as caffeine, catechins, and other amino acids in anti-stress effects were examined. To prepare low-caffeine green tea, plucked new tea leaves were treated with a hot-water spray. Mice were psychosocially stressed from a conflict among male mice under confrontational housing. Mice consumed each tea that was eluted with room temperature water ad libitum. As a marker for the stress response, adrenal hypertrophy was compared with mice that ingested water. Caffeine was significantly lowered by spraying hot-water on tea leaves. While epigallocatechin gallate (EGCG) is the main catechin in tea leaves, epigallocatechin (EGC) was mainly infused into water at room temperature. Adrenal hypertrophy was significantly suppressed in mice that ingested theanine-rich and low-caffeine green tea that were eluted with water at room temperature. Caffeine and EGCG suppressed the anti-stress effects of theanine while EGC and arginine (Arg) retained these effects. These results suggest that drinking green tea exhibits anti-stress effects, where theanine, EGC and Arg cooperatively abolish the counter-effect of caffeine and EGCG on psychosocial stress induced adrenal hypertrophy in mice. Copyright © 2016 Elsevier GmbH. All rights reserved.

  2. Effects of green tea, black tea, and coffee consumption on the risk of esophageal cancer: a systematic review and meta-analysis of observational studies.

    Science.gov (United States)

    Zheng, Ju-Sheng; Yang, Jing; Fu, Yuan-Qing; Huang, Tao; Huang, Yu-Jing; Li, Duo

    2013-01-01

    Epidemiological studies regarding the associations of tea and coffee consumption with esophageal cancer (EC) risk are still inconsistent and this meta-analysis was conducted to examine these associations. PubMed, ISI -Web of Science, China National Knowledge Infrastructure (CNKI), and Chinese VIP database up to October 2011 were searched and manual search for reference lists of relevant studies were conducted. Random effects model was used to pool the odds ratios (OR). Twenty-four case-control and cohort studies with 7376 EC cases were included in this meta-analysis. The pooled OR of EC was 0.77 [95% confidence intervals (95% CI): 0.57, 1.04] for highest vs. non/lowest green tea consumption; but it was statistically significant for case-control studies (OR = 0.70; 95% CI: 0.51, 0.96) and for studies conducted in China (OR = 0.64; 95% CI: 0.44, 0.95). No significant association was observed for the highest vs. non/lowest black tea consumption against EC risk (OR = 1.35; 95% CI: 0.86, 2.11). A borderline significantly inverse association of highest vs. non/lowest coffee consumption against EC risk was found (OR = 0.88; 95% CI: 0.76, 1.01). In conclusion, our data showed that both green tea and coffee consumption, but not black tea consumption, have protective effects on EC.

  3. Inhibitory effects of (-)-epigallocatechin-3-gallate from green tea on the growth of Babesia parasites.

    Science.gov (United States)

    Aboulaila, M; Yokoyama, N; Igarashi, I

    2010-04-01

    (-)-Epigallocatechin-3-gallate (EGCG) is the major tea catechin and accounts for 50-80% of the total catechin in green tea. (-)-Epigallocatechin-3-gallate has antioxidant, anti-inflammatory, anti-microbial, anti-cancer, and anti-trypanocidal activities. This report describes the inhibitory effect of (-)-Epigallocatechin-3-gallate on the in vitro growth of bovine Babesia parasites and the in vivo growth of the mouse-adapted rodent babesia B. microti. The in vitro growth of the Babesia species was significantly (Pparasites showed no re-growth at 25 microM for B. bovis and B. bigemina in the subsequent viability test. The drug significantly (Pparasites completely cleared on day 14 and 16 post-inoculation in the 5 and 10 mg/kg treated groups, respectively. These findings highlight the potentiality of (-)-Epigallocatechin-3-gallate as a chemotherapeutic drug for the treatment of babesiosis.

  4. Chiral cyclodextrin-modified micellar electrokinetic chromatography and chemometric techniques for green tea samples origin discrimination.

    Science.gov (United States)

    Pasquini, Benedetta; Orlandini, Serena; Goodarzi, Mohammad; Caprini, Claudia; Gotti, Roberto; Furlanetto, Sandra

    2016-04-01

    Catechins and methylxanthines were determined in 92 green tea (GT) samples originating from Japan and China by using micellar electrokinetic chromatography with the addition of (2-hydroxypropyl)-β-cyclodextrin. GT samples showed high concentrations of (-)-epigallocatechin gallate and caffeine, with (-)-epigallocatechin, (-)-epicatechin gallate and (-)-epicatechin in relevant content and (+)-catechin, (-)-catechin and theobromine in much lower amounts. The amount of all the considered compounds was higher for Chinese GTs, with the exception of (-)-epicatechin gallate. Pattern recognition methods were applied to discriminate GTs according to geographical origin, which is an important factor to determine quality and reputation of a commercial tea product. Data analysis was performed by principal component analysis and hierarchical cluster analysis as exploratory techniques. Linear discriminant analysis and quadratic discriminant analysis were utilized as discrimination techniques, obtaining a very good rate of correct classification and prediction.

  5. Determination of the inhibitory effect of green tea extract on glucose-6-phosphate dehydrogenase based on multilayer capillary enzyme microreactor.

    Science.gov (United States)

    Camara, Mohamed Amara; Tian, Miaomiao; Liu, Xiaoxia; Liu, Xin; Wang, Yujia; Yang, Jiqing; Yang, Li

    2016-08-01

    Natural herbal medicines are an important source of enzyme inhibitors for the discovery of new drugs. A number of natural extracts such as green tea have been used in prevention and treatment of diseases due to their low-cost, low toxicity and good performance. The present study reports an online assay of the activity and inhibition of the green tea extract of the Glucose 6-phosphate dehydrogenase (G6PDH) enzyme using multilayer capillary electrophoresis based immobilized enzyme microreactors (CE-IMERs). The multilayer CE-IMERs were produced with layer-by-layer electrostatic assembly, which can easily enhance the enzyme loading capacity of the microreactor. The activity of the G6PDH enzyme was determined and the enzyme inhibition by the inhibitors from green tea extract was investigated using online assay of the multilayer CE-IMERs. The Michaelis constant (Km ) of the enzyme, the IC50 and Ki values of the inhibitors were achieved and found to agree with those obtained using offline assays. The results show a competitive inhibition of green tea extract on the G6PDH enzyme. The present study provides an efficient and easy-to-operate approach for determining G6PDH enzyme reaction and the inhibition of green tea extract, which may be beneficial in research and the development of natural herbal medicines. Copyright © 2016 John Wiley & Sons, Ltd.

  6. Role of Green Tea in Reducing Epidermal Thickness upon Ultraviolet Light-B Injury in BALB/c Mice

    Directory of Open Access Journals (Sweden)

    Snur M. A. Hassan

    2015-01-01

    Full Text Available The main environmental source for skin damage is ultraviolet (UV radiation. Many adverse effects have been recognized as the result of prolonged cutaneous exposure to solar ultraviolet radiation, such as erythema, edema, apoptosis, hyperplastic responses, photo-aging, and skin cancer development. Green tea provides photo-protection against UV radiation through many mechanisms including anti-inflammatory, immunomodulatory, and antioxidant properties. The aim of this study was to evaluate the effect of green tea in reducing epidermal thickness on mouse’s skin exposed to UVB irradiation. Thirty mice (Mus musculus species, BALB/c strain underwent this study and were divided into 3 groups: control group (n=10 mice, without UVB exposure and green tea administration; exposure group (n=10 mice, which were exposed to UVB light only; and treatment group (n=10 mice, which were exposed to UVB light and treated with 1 mL of green tea through oral gavage. Mice from both groups (exposure and treatment were subjected to UVB irradiation 4 days/week (20 minutes/day, 4 weeks. It concluded that oral administration of green tea was provided photo-protection against UVB induced hyperplasia; therefore, it can be regarded as a natural alternative for photo-protection.

  7. Red wine and green tea reduce H pylori- or VacA-induced gastritis in a mouse model

    Institute of Scientific and Technical Information of China (English)

    Paolo Ruggiero; Giacomo Rossi; Francesco Tombola; Laura Pancotto; Laura Lauretti; Giuseppe Del Giudice; Mario Zoratti

    2007-01-01

    AIM: To investigate whether red wine and green tea could exert anti-H pylori or anti-VacA activity in vivo in a mouse model of experimental infection.METHODS: Ethanol-free red wine and green tea concentrates were administered orally as a mixture of the two beverages to H pylori infected mice, or separately to VacA-treated mice. Gastric colonization and gastric inflammation were quantified by microbiological,histopathological, and immunohistochemical analyses.RESULTS: In H pylori-infected mice, the red wine and green tea mixture significantly prevented gastritis and limited the localization of bacteria and VacA to the surface of the gastric epithelium. Similarly, both beverages significantly prevented gastric epithelium damage in VacA-treated mice; green tea, but not red wine, also altered the VacA localization in the gastric epithelium.CONCLUSION: Red wine and green tea are able to prevent H pylori-induced gastric epithelium damage,possibly involving VacA inhibition. This observation supports the possible relevance of diet on the pathological outcome of H pylori infection.

  8. Green tea catechins prevent low-density lipoprotein oxidation via their accumulation in low-density lipoprotein particles in humans.

    Science.gov (United States)

    Suzuki-Sugihara, Norie; Kishimoto, Yoshimi; Saita, Emi; Taguchi, Chie; Kobayashi, Makoto; Ichitani, Masaki; Ukawa, Yuuichi; Sagesaka, Yuko M; Suzuki, Emiko; Kondo, Kazuo

    2016-01-01

    Green tea is rich in polyphenols, including catechins which have antioxidant activities and are considered to have beneficial effects on cardiovascular health. In the present study, we investigated the effects of green tea catechins on low-density lipoprotein (LDL) oxidation in vitro and in human studies to test the hypothesis that catechins are incorporated into LDL particles and exert antioxidant properties. In a randomized, placebo-controlled, double-blind, crossover trial, 19 healthy men ingested green tea extract (GTE) in the form of capsules at a dose of 1 g total catechin, of which most (>99%) was the gallated type. At 1 hour after ingestion, marked increases of the plasma concentrations of (-)-epigallocatechin gallate and (-)-epicatechin gallate were observed. Accordingly, the plasma total antioxidant capacity was increased, and the LDL oxidizability was significantly reduced by the ingestion of GTE. We found that gallated catechins were incorporated into LDL particles in nonconjugated forms after the incubation of GTE with plasma in vitro. Moreover, the catechin-incorporated LDL was highly resistant to radical-induced oxidation in vitro. An additional human study with 5 healthy women confirmed that GTE intake sufficiently increased the concentration of gallated catechins, mainly in nonconjugated forms in LDL particles, and reduced the oxidizability of LDL. In conclusion, green tea catechins are rapidly incorporated into LDL particles and play a role in reducing LDL oxidation in humans, which suggests that taking green tea catechins is effective in reducing atherosclerosis risk associated with oxidative stress.

  9. Effect of coffee and green tea consumption on the risk of liver cancer: cohort analysis by hepatitis virus infection status.

    Science.gov (United States)

    Inoue, Manami; Kurahashi, Norie; Iwasaki, Motoki; Shimazu, Taichi; Tanaka, Yasuhito; Mizokami, Masashi; Tsugane, Shoichiro

    2009-06-01

    In spite of their anticarcinogenic potential, the effect of coffee and green tea consumption on the risk of liver cancer has not been clarified prospectively in consideration of hepatitis C (HCV) and B virus (HBV) infection. We examined whether coffee and green tea consumption was associated with a reduced risk of liver cancer by hepatitis virus infection status in the Japan Public Health Center-Based Prospective Study Cohort II. A total of 18,815 subjects ages 40 to 69 years participating in a questionnaire and health checkup survey in 1993 to 1994 were followed for the incidence of liver cancer through 2006. A total of 110 cases of liver cancer were newly documented. Hazard ratios for coffee and green tea consumption categories were calculated with a Cox proportional hazards model. Compared with almost never drinkers, increased coffee consumption was associated with a reduced risk of liver cancer in all subjects (hazard ratio for or=3 cups/d; P(trend) = 0.67, 0.49, 0.54, and 0.025). A similar risk tendency was observed in those with either or both HCV and HBV infection. In contrast, no association was observed between green tea consumption and the risk of liver cancer in all subjects. Our results suggest that coffee consumption may reduce the risk of liver cancer regardless of HCV and HBV infection status, whereas green tea may not reduce this risk

  10. Green tea polyphenol extract attenuates lung injury in experimental model of carrageenan-induced pleurisy in mice.

    Science.gov (United States)

    Di Paola, Rosanna; Mazzon, Emanuela; Muià, Carmelo; Genovese, Tiziana; Menegazzi, Marta; Zaffini, Raffaela; Suzuki, Hisanory; Cuzzocrea, Salvatore

    2005-06-29

    Here we investigate the effects of the green tea extract in an animal model of acute inflammation, carrageenan-induced pleurisy. We report here that green tea extract (given at 25 mg/kg i.p. bolus 1 h prior to carrageenan), exerts potent anti-inflammatory effects in an animal model of acute inflammation in vivo. Injection of carrageenan (2%) into the pleural cavity of mice elicited an acute inflammatory response characterized by fluid accumulation in the pleural cavity that contained many neutrophils (PMNs), an infiltration of PMNs in lung tissues and increased production of nitrite/nitrate, tumour necrosis factor alpha. All parameters of inflammation were attenuated by green tea extract treatment. Furthermore, carrageenan induced an up-regulation of the adhesion molecule ICAM-1, as well as nitrotyrosine and poly (ADP-ribose) synthetase (PARS) formation, as determined by immunohistochemical analysis of lung tissues. Staining for the ICAM-1, nitrotyrosine, and PARS was reduced by green tea extract. Our results clearly demonstrate that treatment with green tea extract exerts a protective effect and offers a novel therapeutic approach for the management of lung injury.

  11. Green tea polyphenol extract attenuates lung injury in experimental model of carrageenan-induced pleurisy in mice

    Directory of Open Access Journals (Sweden)

    Suzuki Hisanory

    2005-06-01

    Full Text Available Abstract Here we investigate the effects of the green tea extract in an animal model of acute inflammation, carrageenan-induced pleurisy. We report here that green tea extract (given at 25 mg/kg i.p. bolus 1 h prior to carrageenan, exerts potent anti-inflammatory effects in an animal model of acute inflammation in vivo. Injection of carrageenan (2% into the pleural cavity of mice elicited an acute inflammatory response characterized by fluid accumulation in the pleural cavity that contained many neutrophils (PMNs, an infiltration of PMNs in lung tissues and increased production of nitrite/nitrate, tumour necrosis factor alpha. All parameters of inflammation were attenuated by green tea extract treatment. Furthermore, carrageenan induced an up-regulation of the adhesion molecule ICAM-1, as well as nitrotyrosine and poly (ADP-ribose synthetase (PARS formation, as determined by immunohistochemical analysis of lung tissues. Staining for the ICAM-1, nitrotyrosine, and PARS was reduced by green tea extract. Our results clearly demonstrate that treatment with green tea extract exerts a protective effect and offers a novel therapeutic approach for the management of lung injury.

  12. Green tea polyphenol blocks h(2)o(2)-induced interleukin-8 production from human alveolar epithelial cells.

    Science.gov (United States)

    Matsuoka, Katsunari; Isowa, Noritaka; Yoshimura, Takashi; Liu, Mingyao; Wada, Hiromi

    2002-06-07

    Reactive oxygen species (ROS) play crucial roles in ischemia-reperfusion (IR) injury of lung transplants. Reactive oxygen species may stimulate the production of neutrophil chemotactic factors such as interleukin-8 (IL-8), from alveolar epithelial cells, causing recruitment and activation of neutrophils in the reperfused tissue. Green tea polyphenol has potent anti-oxidative activities and anti-inflammatory effects by decreasing cytokine production. In the present study, we found that green tea polyphenol significantly inhibited IL-8 production induced by hydrogen peroxide (H(2)O(2)) in human lung alveolar epithelial cells (A549 line). It has been shown that mitogen activated protein kinases, such as Jun N-terminal kinase (JNK), p38 and p44/42, could mediate IL-8 production from a variety of cell types. We further investigated the effect of green tea polyphenol on these protein kinases, and demonstrated that H(2)O(2)-induced phosphorylation of JNK and p38 but not p44/42 was inhibited by green tea polyphenol in A549 cells. We speculate that green tea polyphenol may inhibit H(2)O(2)-induced IL-8 production from A549 cells through inactivation of JNK and p38.

  13. Smoking, Green Tea Consumption, Genetic Polymorphisms in the Insulin-Like Growth Factors and Lung Cancer Risk

    OpenAIRE

    I-Hsin Lin; Ming-Lin Ho; Hsuan-Yu Chen; Hong-Shen Lee; Chia-Chen Huang; Yin-Hung Chu; Shiau-Yun Lin; Ya-Ru Deng; Yu-Hao He; Yu-Hui Lien; Chi-Wen Hsu; Ruey-Hong Wong

    2012-01-01

    Insulin-like growth factors (IGFs) are mediators of growth hormones; they have an influence on cell proliferation and differentiation. In addition, IGF-binding protein (IGFBP)-3 could suppress the mitogenic action of IGFs. Interestingly, tea polyphenols could substantially reduce IGF1 and increase IGFBP3. In this study, we evaluated the effects of smoking, green tea consumption, as well as IGF1, IGF2, and IGFBP3 polymorphisms, on lung cancer risk. Questionnaires were administered to obtain th...

  14. Quantification of catechins and caffeine from green tea (Camellia sinensis) infusions, extract, and ready-to-drink beverages

    OpenAIRE

    Rafaela Macedo Mendes De Oliveira

    2012-01-01

    This study aimed to quantify the levels of catechins and caffeine in various forms of presentation of green tea: infusion tea bags, extract, and ready-to-drink beverage and, based on their content, identify the most suitable for consumption. High Performance Liquid Chromatography (HPLC) analytical method was used for the quantification of catechins and caffeine. The tea bags had the highest concentration of total catechins with 5 to 9.5% followed by the extract with 3.64 to 4.88%, and ready-t...

  15. Can green tea be used to reverse compromised bond strength after bleaching?

    Science.gov (United States)

    Berger, Sandrine B; De Souza Carreira, Renata P; Guiraldo, Ricardo D; Lopes, Murilo B; Pavan, Sabrina; Giannini, Marcelo; Bedran-Russo, Ana K

    2013-08-01

    The objective of this study was to evaluate the antioxidant effect of green tea on microtensile bond strength (μTBS) to bleached enamel. Forty-two human third molars were randomly divided into six experimental groups (n = 7 each group): group 1, no treatment; group 2, bleaching (10% carbamide peroxide); group 3, bleaching + 10% sodium ascorbate gel (SA); group 4, bleaching + 10% green tea gel (GT); group 5, SA; and group 6, GT. In groups 2, 3, and 4, bleach was applied onto the enamel surface for 6 h, every day for 14 d. In groups 3 and 5, SA was applied for 1 h; and in groups 4 and 6, GT was applied for 1 h. Immediately after treatment, the specimens were bonded with Adper Single Bond 2 and Filtek Z350 XT. The μTBS of the specimens was tested using a universal testing machine. Fracture mode analysis of the bonded enamel surface was performed using scanning electron microscopy. The mean μTBS values for each group were: group 1, 33.2 ± 5.8 MPa; group 2, 22.6 ± 5.5 MPa; group 3, 30.0 ± 5.2 MPa; group 4, 31.6 ± 3.8 MPa; group 5, 29.1 ± 4.2 MPa; and group 6, 32.2 ± 4.5 MPa. All groups had a higher percentage of mixed failures. In conclusion, green tea can be used as an alternative antioxidant on bleached enamel before bonding procedures. © 2013 Eur J Oral Sci.

  16. Green Tea Extract Induces the Resistance of Caenorhabditis elegans against Oxidative Stress

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    Sami Abbas

    2014-03-01

    Full Text Available Epidemiological studies on the effects of green tea consumption (Camellia sinensis have demonstrated a reduction for the risk of age-related diseases. The investigation of the in vivo and in vitro antioxidant properties of an aqueous extract of green tea (GTE was the aim of the current study. 2,2-Diphenyl-1-picrylhydrazyl (DPPH• and superoxide anion radical (O2•− assays were used to estimate the GTE antioxidant activity. To investigate the protective effects of GTE against oxidative stress, wild-type N2 and transgenic strains (TJ374, hsp-16.2/GFP of the model organism, Caenorhabditis elegans (C. elegans, were chosen. In the current study, the following catechins were identified by LC/ESI-MS: catechin, epicatechin, epicatechin gallate, gallocatechin, epigallocatechin and epigallocatechin gallate. GTE exhibited a free radical scavenging activity of DPPH• and O2•− with IC50 8.37 and 91.34 µg/mL, respectively. In the C. elegans strain (TJ374, hsp-16.2/GFP, the expression of hsp-16.2/GFP was induced by a nonlethal dose of juglone, and the fluorescence density of hsp-16.2/GFP was measured. The hsp-16.2/GFP was reduced by 68.43% in the worms pretreated with 100 µg/mL GTE. N2 worms pretreated with 100 µg/mL GTE exhibited an increased survival rate of 48.31% after a lethal dose application of juglone. The results suggest that some green tea constituents are absorbed by the worms and play a substantial role to enhance oxidative stress resistance in C. elegans.

  17. The Potential Therapeutic Effect of Green Tea in Treatment of Vernal Keratoconjunctivitis

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    Mahnaz Mosallaei

    2008-05-01

    Full Text Available Vernal keratoconjunctivitis is a chronic, recurrent and severe ocular allergic disease, which is characterized by persistent allergic inflammation of the conjunctiva. It can be accompanied by ocular discomfort and visual disturbance. All forms are characterized by intense itching, tearing, mucous secretions and a severe photophobia, which often forces children to live virtually in dark places. Conjunctival proliferative changes, such as the formation of giant papillae are the characteristic findings of affected individuals. Giant papillae develop as a result of infiltration of inflammatory cells, changes in the epithelial layer, and increased deposition of extracellular matrix molecules such as collagen and proliferation of conjunctival fibroblasts. Currently several therapeutic options such as corticosteroids, mast cell stabilizers and cyclosporine are applied for treatment of Vernal keratoconjunctivitis but in long-term, the chronic and recurrent nature of this problem leads to failure or appearance of side effects of current treatment in many patients. Recently, Green tea extract and its principal active ingredient, epigallocatechin gallate , are gaining attention and increased usage due to its healthful properties. It has considerable anticatactogenic effect by inducing apoptosis in lens epithelial cells and antioxidant effects. Also its great benefits were achieved in attenuation of damaging influences to the retina caused by ischemia/reperfusion. Based on evidences supported beneficial effects of green tea, we hypothesize that local administration of green tea and its extract seems to be a proper substitute or adjunct to current treatments of Vernal keratoconjunctivitis. This plant contains a series of antioxidants that can abolish the process of allergic cascade. Moreover, by suppressing TNF-alpha potentially, it can reduce proinflammatory reaction, as well as fibroblast proliferation and subsequently decrease giant papilla formation

  18. Content Variation of Catechin Markers, Total Phenolics and Caffeine in Green Tea Dietary Supplements.

    Science.gov (United States)

    Abourashed, Ehab A; Roberson, Cindy Leslie A; Elsharkawy, Nancy

    2016-01-01

    Green tea (Camellia sinensis) preparations are among the top selling products in the United States dietary supplements market. Numerous manufacturers claim different levels of specific catechin markers in their products while many others use total phenolic concentration instead, or not at all. Limited quality control results have been published for green tea dietary supplements over the past seven years. Thus, the goal of this work was to correlate determined levels of phenolics, catechins, and caffeine with manufacturer label claims for selected dietary supplement products (26 total) purchased in the United States. The Folin-Ciocalteu (FC) method was used to determine the total phenolic content while reversed-phase (RP) HPLC was used to quantify the major catechins: epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG), epigallocatechin gallate (EGCG). The developed HPLC method was validated for accuracy and precision. It utilized a C8 column with gradient elution of acetonitrile in 0.1% aqueous formic acid over 11 min total run time. Peak detection was performed at 280 nm. Caffeine was also included in the HPLC method as another non-phenolic alkaloid marker commonly found in green tea. Both methods showed a good correlation between the content of catechins and polyphenolic compounds in the selected products. The ranges of total catechins and polyphenol concentrations were 3.8-70.2% and 3.6-95.8%, respectively, while that of caffeine was 0.8-11.2%. The selected products displayed a wide range of marker levels. A lack of conformity in disclosing the actual levels of marker compounds was also noticed in the labeling of many products.

  19. Consumption of Milk-Protein Combined with Green Tea Modulates Diet-Induced Thermogenesis

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    Margriet S. Westerterp-Plantenga

    2011-07-01

    Full Text Available Green tea and protein separately are able to increase diet-induced thermogenesis. Although their effects on long-term weight-maintenance were present separately, they were not additive. Therefore, the effect of milk-protein (MP in combination with green tea on diet-induced thermogenesis (DIT was examined in 18 subjects (aged 18–60 years; BMI: 23.0 ± 2.1 kg/m2. They participated in an experiment with a randomized, 6 arms, crossover design, where energy expenditure and respiratory quotient (RQ were measured. Green tea (GT vs. placebo (PL capsules were either given in combination with water or with breakfasts containing milk protein in two different dosages: 15 g (15 MP (energy% P/C/F: 15/47/38; 1.7 MJ/500 mL, and 3.5 g (3.5 MP (energy% P/C/F: 41/59/0; 146.4 kJ/100 mL. After measuring resting energy expenditure (REE for 30 min, diet-induced energy expenditure was measured for another 3.5 h after the intervention. There was an overall significant difference observed between conditions (p < 0.001. Post-hoc, areas under the curve (AUCs for diet-induced energy expenditure were significantly different (P ≤ 0.001 for GT + water (41.11 [91.72] kJ·3.5 h vs. PL + water (10.86 [28.13] kJ·3.5 h, GT + 3.5 MP (10.14 [54.59] kJ·3.5 h and PL + 3.5 MP (12.03 [34.09] kJ·3.5 h, but not between GT + 3.5 MP, PL + 3.5 MP and PL + water, indicating that MP inhibited DIT following GT. DIT after GT + 15 MP (167.69 [141.56] kJ·3.5 h and PL + 15 MP (168.99 [186.56] kJ·3.5 h was significantly increased vs. PL + water (P < 0.001, but these were not different from each other indicating that 15 g MP stimulated DIT, but inhibited the GT effect on DIT. No significant differences in RQ were seen between conditions for baseline and post-treatment. In conclusion, consumption of milk-protein inhibits the effect of green tea on DIT.

  20. The green tea extract epigallocatechin-3-gallate inhibits irradiation-induced pulmonary fibrosis in adult rats

    OpenAIRE

    You, Hua; Wei, Li; Sun, Wan-Liang; Wang, Lei; YANG, ZAI-LIANG; Liu, Yuan; Zheng, Ke; Wang, Ying; Zhang, Wei-Jing

    2014-01-01

    The present study evaluated the effect of epigallocatechin-3-gallate (EGCG), the most abundant catechin in green tea, on irradiation-induced pulmonary fibrosis and elucidated its mechanism of action. A rat model of irradiation-induced pulmonary fibrosis was generated using a 60Co irradiator and a dose of 22 Gy. Rats were intraperitoneally injected with EGCG (25 mg/kg) or dexamethasone (DEX; 5 mg/kg) daily for 30 days. Mortality rates and lung index values were calculated. The severity of fibr...

  1. Inhibition of MMP-9 by green tea catechins and prediction of their interaction by molecular docking analysis.

    Science.gov (United States)

    Sarkar, Jaganmay; Nandy, Suman Kumar; Chowdhury, Animesh; Chakraborti, Tapati; Chakraborti, Sajal

    2016-12-01

    Green tea polyphenolic catechins have been shown to prevent various types of diseases such as pulmonary hypertension (PAH), cancer and cardiac and neurological disorders. Matrix metalloproteinases (MMPs) play an important role in the development of PAH. The present study demonstrated that among the four green tea catechins (EGCG, ECG, EC and EGC), EGCG and ECG inhibit pro-/active MMP-9 activities in pulmonary artery smooth muscle cell culture supernatant. Based on the above, we investigated the interactions of pro-/active MMP-9 with the green tea catechins by computational methods. In silico molecular docking analysis revealed a strong interaction between pro-/active MMP-9 and EGCG/ECG, and galloyl group appears to be responsible for this enhanced interaction. The molecular docking studies corroborate our experimental observation that EGCG and ECG are mainly active in preventing both the proMMP-9 and MMP-9 activities.

  2. Molecular interactions between green tea catechins and cheese fat studied by solid-state nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Rashidinejad, Ali; Birch, Edward J; Hindmarsh, Jason; Everett, David W

    2017-01-15

    Molecular integrations between green tea catechins and milk fat globules in a cheese matrix were investigated using solid-state magic angle spinning nuclear magnetic resonance spectroscopy. Full-fat cheeses were manufactured containing free catechin or free green tea extract (GTE), and liposomal encapsulated catechin or liposomal encapsulated GTE. Molecular mobility of the carbon species in the cheeses was measured by a wide-line separation technique. The (1)H evolution frequency profile of the (13)C peak at 16ppm obtained for the control cheese and cheeses containing encapsulated polyphenols (catechin or GTE) were similar, however, the spectrum was narrower for cheeses containing free polyphenols. Differences in spectral width indicates changes in the molecular mobility of --CH3- or -C-C-PO4- species through hydrophobic and/or cation-π associations between green tea catechins and cheese fat components. However, the similar spectral profile suggests that encapsulation protects cheese fat from interaction with catechins.

  3. The behaviour of green tea catechins in a full-fat milk system under conditions mimicking the cheesemaking process.

    Science.gov (United States)

    Rashidinejad, Ali; Birch, E John; Everett, David W

    2016-09-01

    Due to their well-known health benefits, green tea catechins have received recent attention as natural additives in foods such as dairy products. However, they may present some irreversible associations with milk components (e.g. protein and milk fat globules). To investigate the behaviour of two important green tea catechins, (+)-catechin (C) and (-)-epigallocatechin gallate (EGCG), in a standard whole milk system under the conditions of cheesemaking, 250 and 500 ppm of each catechin were added to whole milk (3.3% fat). Although both C and EGCG at either concentration increased both total phenolic content and total antioxidant capacity of the subnatants obtained from the milk system, there was a less linear increase when the concentration of the catechins was doubled, whereas C or EGCG were recovered (measured by HPLC) differently. Overall, these results suggest a degree of associations between green tea catechins with milk proteins and milk fat.

  4. AKTIVITAS ANTIOKSIDATIF DAN HIPOKOLESTEROLEMIK EKSTRAK TEH HIJAU DAN TEH WANGI PADA TIKUS YANG DIBERI RANSUM KAYA ASAM LEMAK TIDAK JENUH GANDA [Antioxidative and Hipocholesterolemic Activity of Green Tea and Jasmine Green Tea Extracts in Rats Fed with High Polyunsaturated Fatty Acids (PUFA

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    Mary Astuti 2

    2002-04-01

    Full Text Available The aim of this study was to evaluate in-vivo the antioxidative and hipocholesterolemic activity of green tea and jasmine green tea extracts in 3.5-month-old Sprague Dawley male rats given high PUFA diet for 4 weeks. In rats fed with (adlibidom or forcely adted high PUFA diet supplemented with green tea extract, serum and liver homogenate malondialdehyde level and the liver homogenate cholesterol level were greater than rats fed with the high PUFA diet supplemented with jasmine green tea extract pn the control. In contrast, no change was observed in serum cholesterol level in rats fed with the high PUFA diet containing green tea or jasmine green tea extract as compared with the high PUFA diet.

  5. Green Tea Extract Supplementation Induces the Lipolytic Pathway, Attenuates Obesity, and Reduces Low-Grade Inflammation in Mice Fed a High-Fat Diet

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    Cláudio A. Cunha

    2013-01-01

    Full Text Available The aim of this study was to evaluate the effects of green tea Camellia sinensis extract on proinflammatory molecules and lipolytic protein levels in adipose tissue of diet-induced obese mice. Animals were randomized into four groups: CW (chow diet and water; CG (chow diet and water + green tea extract; HW (high-fat diet and water; HG (high-fat diet and water + green tea extract. The mice were fed ad libitum with chow or high-fat diet and concomitantly supplemented (oral gavage with 400 mg/kg body weight/day of green tea extract (CG and HG, resp.. The treatments were performed for eight weeks. UPLC showed that in 10 mg/mL green tea extract, there were 15 μg/mg epigallocatechin, 95 μg/mg epigallocatechin gallate, 20.8 μg/mg epicatechin gallate, and 4.9 μg/mg gallocatechin gallate. Green tea administered concomitantly with a high-fat diet increased HSL, ABHD5, and perilipin in mesenteric adipose tissue, and this was associated with reduced body weight and adipose tissue gain. Further, we observed that green tea supplementation reduced inflammatory cytokine TNFα levels, as well as TLR4, MYD88, and TRAF6 proinflammatory signalling. Our results show that green tea increases the lipolytic pathway and reduces adipose tissue, and this may explain the attenuation of low-grade inflammation in obese mice.

  6. Green tea Improves Carbohydrate and Lipid Metabolism and Regulates Cardiac mRNA Expression Related to Insulin, Lipid and Inflammatory Signaling Pathways

    Science.gov (United States)

    Green tea has multiple benefits to human health. Epidemiologic studies demonstrate that the consumption of green tea polyphenols (GTP) reduces the risk of coronary artery disease and cardiac events. To explore the underlying mechanisms of action at a molecular level, we examined the effects of GTP o...

  7. Combination of selenium and green tea improves the efficacy of chemoprevention in a rat colorectal cancer model by modulating genetic and epigenetic biomarkers.

    Science.gov (United States)

    Hu, Ying; McIntosh, Graeme H; Le Leu, Richard K; Nyskohus, Laura S; Woodman, Richard J; Young, Graeme P

    2013-01-01

    Dietary supplementation of selenium and green tea holds promise in cancer prevention. In this study, we evaluated the efficacies of selenium and green tea administered individually and in combination against colorectal cancer in an azoxymethane (AOM)-induced rat colonic carcinogenesis model and determined the underlying mechanisms of the protection. Four-week old Sprague-Dawley male rats were fed with diets containing 0.5% green tea extract, 1 ppm selenium as selenium-enriched milk protein, or combination of 1 ppm selenium and 0.5% green tea extract. Animals received 2 AOM (15 mg/kg) treatments to induce colonic oncogenesis. Rats were killed 8 or 30 wk later after the last AOM to examine the effect of dietary intervention on aberrant crypt foci (ACF) formation or tumor development. On sacrifice, colons were examined for ACF and tumors, the mRNA levels of SFRP5 and Cyclin D1, and the proteins levels of ß-catenin, COX-2, Ki-67, DNMT1 and acetyl histone H3. The combination of selenium and green tea resulted in a significant additive inhibition of large ACF formation, this effect was greater than either selenium or green tea alone, Pselenium or green tea alone, Pselenium and green tea is more effective in suppressing colorectal oncogenesis than either agent alone. The preventive effect is associated with regulation of genetic and epigenetic biomarkers implicated in colonic carcinogenesis.

  8. Effect of green tea extract on advanced glycation and cross-linking of tail tendon collagen in streptozotocin induced diabetic rats.

    Science.gov (United States)

    Babu, Pon Velayutham Anandh; Sabitha, Kuruvimalai Ekambaram; Shyamaladevi, Chennam Srinivasulu

    2008-01-01

    Diabetes leads to modification of collagen such as advanced glycation and cross-linking which play an important role in the pathogenesis of diabetes mellitus. We have investigated the effect of green tea on modification of collagen in streptozotocin (60 mg/kg body weight) induced diabetic rats. To investigate the therapeutic effect of green tea, treatment was begun six weeks after the onset of diabetes and green tea extract (300 mg/kg body weight) was given orally for 4 weeks. The collagen content, extent of advanced glycation, advanced glycation end products (AGE) and cross-linking of tail tendon collagen were investigated. Green tea reduced the tail tendon collagen content which increased in diabetic rats. Accelerated advanced glycation and AGE in diabetic animals, as detected by Ehrlich's-positive material and collagen linked fluorescence respectively were reduced significantly by green tea. The solubility of tail tendon collagen decreased significantly in diabetic rats indicating a remarkable increase in the cross-linking, whereas green tea increases the solubility of collagen in diabetic rats. The present study reveals that green tea is effective in reducing the modification of tail tendon collagen in diabetic rats. Thus green tea may have a therapeutic effect in the treatment of glycation induced complications of diabetes.

  9. 论安化黑茶的绿色包装%Talk about the Green Packaging of Anhua Black Tea

    Institute of Scientific and Technical Information of China (English)

    庞野营

    2011-01-01

    通过对绿色包装的内涵及原则的论述,结合安化黑茶包装材料的发展现状,分析了绿色包装材料在安化黑茶包装设计中的重要性。在此基础上,进一步提出了安化黑茶包装材料基于地域资源、地域文化之上的绿色发展方向,提高了安化黑茶包装与社会、自然相互协调、共生互补的境界,确保绿色设计思想在黑茶包装中的可行性。%Through discussion of the connotation and principle of green packaging, combined with the development situation of Anhua black tea packaging materials, it analyzed the importance of green packaging materials in packaging design of Anhua black tea. Based on this, it further proposed the green development orientation of packaging materials of Anhua black tea based on region resources and culture. Finally, it enhanced the anhua black tea packaging to achieve sustainable development with the society and nature, which guaranteed the feasibility of green design ideas in the black tea packaging.

  10. Study of the protection of polysaccharide and polyphenols of black tea,green tea and Oolong tea on DNA%红茶、绿茶和乌龙茶多糖及多酚对DNA的保护作用研究

    Institute of Scientific and Technical Information of China (English)

    陈金娥; 张海容

    2011-01-01

    The protection action of tea polysaccharide and polyphenols on DNA are investigated using EB as a fluorescent probe in the work. The fluoresence integral intensity of DNA and EB mixture are determined in the presence of polysaccharide and polyphenols in extracts of 8 Chinese teas, such as Longjing tea, Puer tea and Oolong tea etc. D is defined as the interaction constant of different teas with DNA. According to the size of D, the impaction of protection action of tea polysaccharide and polyphenols on DNA was discussed. The result shown that the 8 kinds of teas can interact with DNA,but the degree of interaction is different.The bigger the D was,the stronger the interaction of teas and DNA was. The order of protection action of tae polysaccharide was Qimen black tea > Green tea (An-hui) > Puer tea > Oolong tea > Black tea of Fujian Zhenghe > Shouning green tea > Xinyang needle tea > Longjing tea.The order of protection action of tea polyphenols was Qimen black tea > Black tea of Fujian Zhenghe > Shouning green tea > Longjing tea > Oolong tea > Green tea ( Anhui) > Xinyang needle tea > Puer tea.%用溴化乙锭(EB)作为荧光探针研究了各种茶叶多糖、多酚类化合物对DNA的保护作用.测定了龙井、普耳茶、乌龙茶等8种茶叶中多糖和多酚类提取物存在下DNA与EB混合液的荧光积分强度,并把不同茶叶与DNA相互作用的常数定义为结合常数D,根据D的大小讨论了多糖及多酚类化合物的存在DNA保护作用的影响.结果表明,8种茶叶与DNA有较好的作用,但作用程度不同.D值越大,茶叶对DNA的保护作用越好.多糖保护作用顺序如下:祁门红茶>绿茶(安徽)>普尔茶>乌龙茶>福建政和红茶>寿宁绿茶>信阳毛尖>龙井;多酚保护作用顺序如下:祁门红茶>福建政和红茶>寿宁绿茶>龙井>乌龙茶>绿茶(安徽)>信阳毛尖>普尔茶.

  11. Prevention of chinese green tea on 3,4-benzopyrene-induced lung cancer and its mechanism in animal model

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    Qihua GU

    2008-08-01

    Full Text Available Background and objective Chinese green tea is one of the daily consumption beverages in the world and is considered a promising cancer chemopreventive agent. In the present study, we investigate the role of lung cancer prevention by green tea and its mechanism. Methods Three groups of female SD rats were kept with the same feed. Rats in group A were administrated with 1% green tea drinking, while in group B and group C with water only. Animals in group A and group B were given 3,4-benzopyrene-corn oil mixture pulmonary injection fortnightly for 4 times, while in group C corn oil only. Rats were sacrificed 1 year after the first injection under narcotism. Lung tumors and lung tissues were performed H&E staining for cancer identification. Each case of lung cancer was examined for expression of p53 and Bcl-2 with in situ hybridization analysis and immunohistochemistry staining. Results No cancer was found in rats in group C. However, in group B, 15 out of 20 rats were found generating lung cancer, and in group A, 6 out of 20 rats inducing lung cancer were recorded. The rate of lung carcinogenesis in rats was decreased from 75% to 30% by 1% chinese green tea oral administration (χ2=8.12, P0.05. However, significantly lower level of Bcl-2 expression was found in lung cancer tissues of group A than that of group B (P<0.05. Conclusion The results indicate that chinese green tea inhibits lung carcinogenesis. Chinese green tea can slightly upregulate expression of p53, but significantly downregulate expression of Bcl-2 in lung cancer, and this may be related to the mechanism of lung cancer prevention.

  12. Association between green tea/coffee consumption and biliary tract cancer: A population-based cohort study in Japan.

    Science.gov (United States)

    Makiuchi, Takeshi; Sobue, Tomotaka; Kitamura, Tetsuhisa; Ishihara, Junko; Sawada, Norie; Iwasaki, Motoki; Sasazuki, Shizuka; Yamaji, Taiki; Shimazu, Taichi; Tsugane, Shoichiro

    2016-01-01

    Green tea and coffee consumption may decrease the risk of some types of cancers. However, their effects on biliary tract cancer (BTC) have been poorly understood. In this population-based prospective cohort study in Japan, we investigated the association of green tea (total green tea, Sencha, and Bancha/Genmaicha) and coffee consumption with the risk for BTC and its subtypes, gallbladder cancer, and extrahepatic bile duct cancer. The hazard ratios and 95% confidence intervals were calculated using the Cox proportional hazard model. A total of 89 555 people aged 45-74 years were enrolled between 1995 and 1999 and followed up for 1 138 623 person-years until 2010, during which 284 cases of BTC were identified. Consumption of >720 mL/day green tea was significantly associated with decreased risk compared with consumption of ≤120 mL/day (hazard ratio = 0.67 [95% confidence interval, 0.46-0.97]), and a non-significant trend of decreased risk associated with increased consumption was observed (P-trend = 0.095). In the analysis according to the location of the primary tumor, consuming >120 mL green tea tended to be associated with decreased risk of gallbladder cancer and extrahepatic bile duct cancer. When Sencha and Bancha/Genmaicha were analyzed separately, we observed a non-significant trend of decreased risk of BTC associated with Sencha but no association with Bancha/Genmaicha. For coffee, there was no clear association with biliary tract, gallbladder, or extrahepatic bile duct cancer. Our findings suggest that high green tea consumption may lower the risk of BTC, and the effect may be attributable to Sencha consumption.

  13. Comparison of the Inhibition of Monoamine Oxidase and Butyrylcholinesterase Activities by Infusions from Green Tea and Some Citrus Peels

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    Ayokunle O. Ademosun

    2014-01-01

    Full Text Available This study sought to investigate the effect of infusions from green tea (Camellia sinensis and some citrus peels [shaddock (Citrus maxima, grapefruit (Citrus paradisi, and orange (Citrus sinensis] on key enzymes relevant to the management of neurodegenerative conditions [monoamine oxidase (MAO and butyrylcholinesterase (BChE]. The total phenol contents and antioxidant activities as typified by their 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid (ABTS radicals scavenging abilities, ferric reducing antioxidant properties, and Fe2+ chelating abilities were also investigated. Green tea had the highest total phenol (43.3 mg/g and total flavonoid (16.4 mg/g contents, when compared to orange [total phenol (19.6 mg/g, total flavonoid (6.5 mg/g], shaddock [total phenol (16.3 mg/g, total flavonoid (5.2 mg/g], and grapefruit [total phenol (17.7 mg/g, total flavonoid (5.9 mg/g]. Orange (EC50 = 1.78 mg/mL had the highest MAO inhibitory ability, while green tea had the least MAO inhibitory ability (EC50 = 2.56 mg/mL. Similarly, green tea had the least BChE inhibitory ability (EC50 = 5.43 mg/mL when compared to the citrus peels’ infusions. However, green tea infusions had the strongest highest ABTS radical scavenging ability, reducing power, and Fe2+ chelating ability. The inhibition of MAO and BChE activities by the green tea and citrus peels infusions could make them good dietary means for the prevention/management of neurodegenerative conditions.

  14. The Peroxidation of Leukocytes Index Ratio Reveals the Prooxidant Effect of Green Tea Extract.

    Science.gov (United States)

    Peluso, Ilaria; Manafikhi, Husseen; Raguzzini, Anna; Longhitano, Yaroslava; Reggi, Raffaella; Zanza, Christian; Palmery, Maura

    2016-01-01

    Despite tea increased plasma nonenzymatic antioxidant capacity, the European Food Safety Administration (EFSA) denied claims related to tea and its protection from oxidative damage. Furthermore, the Supplement Information Expert Committee (DSI EC) expressed some doubts on the safety of green tea extract (GTE). We performed a pilot study in order to evaluate the effect of a single dose of two capsules of a GTE supplement (200 mg × 2) on the peroxidation of leukocytes index ratio (PLIR) in relation to uric acid (UA) and ferric reducing antioxidant potential (FRAP), as well as the sample size to reach statistical significance. GTE induced a prooxidant effect on leukocytes, whereas FRAP did not change, in agreement with the EFSA and the DSI EC conclusions. Besides, our results confirm the primary role of UA in the antioxidant defences. The ratio based calculation of the PLIR reduced the sample size to reach statistical significance, compared to the resistance to an exogenous oxidative stress and to the functional capacity of oxidative burst. Therefore, PLIR could be a sensitive marker of redox status.

  15. The Peroxidation of Leukocytes Index Ratio Reveals the Prooxidant Effect of Green Tea Extract

    Directory of Open Access Journals (Sweden)

    Ilaria Peluso

    2016-01-01

    Full Text Available Despite tea increased plasma nonenzymatic antioxidant capacity, the European Food Safety Administration (EFSA denied claims related to tea and its protection from oxidative damage. Furthermore, the Supplement Information Expert Committee (DSI EC expressed some doubts on the safety of green tea extract (GTE. We performed a pilot study in order to evaluate the effect of a single dose of two capsules of a GTE supplement (200 mg × 2 on the peroxidation of leukocytes index ratio (PLIR in relation to uric acid (UA and ferric reducing antioxidant potential (FRAP, as well as the sample size to reach statistical significance. GTE induced a prooxidant effect on leukocytes, whereas FRAP did not change, in agreement with the EFSA and the DSI EC conclusions. Besides, our results confirm the primary role of UA in the antioxidant defences. The ratio based calculation of the PLIR reduced the sample size to reach statistical significance, compared to the resistance to an exogenous oxidative stress and to the functional capacity of oxidative burst. Therefore, PLIR could be a sensitive marker of redox status.

  16. The Choice of China Tea

    Institute of Scientific and Technical Information of China (English)

    YuLiejiang; LiuHuadong

    2004-01-01

    THERE are three broad categories of China tea: green,black and oolong.Green tea is unfermented, and grows best in Zhejiang. According to Traditional Chinese Medicine it relieves internal heat. Black tea is

  17. Discrimination of Chinese green tea according to varieties and grade levels using artificial nose and tongue based on colorimetric sensor arrays.

    Science.gov (United States)

    Huo, Danqun; Wu, Yu; Yang, Mei; Fa, Huanbao; Luo, Xiaogang; Hou, Changjun

    2014-02-15

    Colorimetric artificial tongue and nose were used to discriminate nine Chinese green teas from different geographical origins and grade levels. Printing nanoporous porphyrin, dimeric metalloporphyrins, metallosalophen complexes and chemically responsive dyes on a hydrophobic membrane, the developed sensor array of artificial tongue and nose showed a unique pattern of colorimetric change upon exposure to green tea liquids or gases. All green tea samples, both in liquid and gas analysis, gave distinct patterns according to geographical origin and grade level, thus resulting in their facile identification. The good reproducibility of colorimetric artificial tongue and nose was proved. Data analysis was performed by chemometric techniques: hierarchical cluster analysis (HCA), and principal component analysis (PCA). Chinese green tea from the same geographical origin could cluster together in PCA score plot. No errors in classification by HCA were observed in 90 trials. The colorimetric artificial tongue and nose can be used to discriminate Chinese green tea according to geographical origin and grade level.

  18. Green tea polyphenol extract attenuates lung injury in experimental model of carrageenan-induced pleurisy in mice

    OpenAIRE

    Suzuki Hisanory; Zaffini Raffaela; Menegazzi Marta; Genovese Tiziana; Muià Carmelo; Mazzon Emanuela; Di Paola Rosanna; Cuzzocrea Salvatore

    2005-01-01

    Abstract Here we investigate the effects of the green tea extract in an animal model of acute inflammation, carrageenan-induced pleurisy. We report here that green tea extract (given at 25 mg/kg i.p. bolus 1 h prior to carrageenan), exerts potent anti-inflammatory effects in an animal model of acute inflammation in vivo. Injection of carrageenan (2%) into the pleural cavity of mice elicited an acute inflammatory response characterized by fluid accumulation in the pleural cavity that contained...

  19. A Laboratory Method for Rearing Tea Green Leafhopper, Empoasca onukii Matsuda by Using Tea Seedlings as Oviposition Sites and as Food

    Science.gov (United States)

    Kosugi, Yukio

    In this study,I have developed a method for rearing tea green leafhopper, Empoasca onukii Matsuda by using tea seedlings. Tea seeds were prepared by incubating tea seeds at 5 ℃ for 30 daysand planted these seeds in agar gel.The germination rate of the seedlings on the 28th postincubation (at 25 ℃) days was 89.5%. When the length of new shoots was 7-8 cm, the seedlings were replanted in a cup containing agar gel. The cups were covered with a plastic cap and used as a rearing case. One adult female was captured from the tea fields and reared on the rearing case. On an average, 34.7 nymphs were found to breed on this rearing case. However, when the number of adult females in the rearing case was increased, the number of nymphs tended to decrease. Rearing of 1-2 adult males and females resulted in the breeding of more than 20 nymphs, ranging from the first to the fifth generation.

  20. Synthesis of iron-based nanoparticles using oolong tea extract for the degradation of malachite green

    Science.gov (United States)

    Huang, Lanlan; Weng, Xiulan; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravendra

    2014-01-01

    Iron-based nanoparticles (OT-FeNP) were synthesized using oolong tea extracts. Their morphology, structure and size were confirmed by scanning electron microscopy (SEM), X-ray energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), UV-visible (UV-vis) and Fourier Transform Infrared spectroscopy (FTIR). Formation of FeNP results in mostly spherical particles with diameters ranging from 40 to 50 nm. Degradation of malachite green (MG) using OT-FeNP demonstrated that kinetics fitted well to the pseudo first-order reaction by removing 75.5% of MG (50 mg/L). This indicated that OT-FeNP has the potential to serve as a green nanomaterial for environmental remediation.

  1. Metabolomics evaluation of the effects of green tea extract on acetaminophen-induced hepatotoxicity in mice.

    Science.gov (United States)

    Lu, Yihong; Sun, Jinchun; Petrova, Katya; Yang, Xi; Greenhaw, James; Salminen, William F; Beger, Richard D; Schnackenberg, Laura K

    2013-12-01

    Green tea has been purported to have beneficial health effects including protective effects against oxidative stress. Acetaminophen (APAP) is a widely used analgesic drug that can cause acute liver injury in overdose situations. These studies explored the effects of green tea extract (GTE) on APAP-induced hepatotoxicity in liver tissue extracts using ultra performance liquid chromatography/quadrupole time-of-flight mass spectrometry and nuclear magnetic resonance spectroscopy. Mice were orally administered GTE, APAP or GTE and APAP under three scenarios. APAP alone caused a high degree of hepatocyte necrosis associated with increases in serum transaminases and alterations in multiple metabolic pathways. The time of GTE oral administration relative to APAP either protected against or potentiated the APAP-induced hepatotoxicity. Dose dependent decreases in histopathology scores and serum transaminases were noted when GTE was administered prior to APAP; whereas, the opposite occurred when GTE was administered after APAP. Similarly, metabolites altered by APAP alone were less changed when GTE was given prior to APAP. Significantly altered pathways included fatty acid metabolism, glycerophospholipid metabolism, glutathione metabolism, and energy pathways. These studies demonstrate the complex interaction between GTE and APAP and the need to employ novel analytical strategies to understand the effects of dietary supplements on pharmaceutical compounds.

  2. The green tea catechin epigallocatechin gallate (EGCG blocks cell motility, chemotaxis and development in Dictyostelium discoideum.

    Directory of Open Access Journals (Sweden)

    Kyle J McQuade

    Full Text Available Catechins, flavanols found at high levels in green tea, have received significant attention due to their potential health benefits related to cancer, autoimmunity and metabolic disease, but little is known about the mechanisms by which these compounds affect cellular behavior. Here, we assess whether the model organism Dictyostelium discoideum is a useful tool with which to characterize the effects of catechins. Epigallocatechin gallate (EGCG, the most abundant and potent catechin in green tea, has significant effects on the Dictyostelium life cycle. In the presence of EGCG aggregation is delayed, cells do not stream and development is typically stalled at the loose aggregate stage. The developmental effects very likely result from defects in motility, as EGCG reduces both random movement and chemotaxis of Dictyostelium amoebae. These results suggest that catechins and their derivatives may be useful tools with which to better understand cell motility and development in Dictyostelium and that this organism is a useful model to further characterize the activities of catechins.

  3. Analysis of Trace Ingredients in Green Tea by Capillary Electrophoresis with Amperometric Detection

    Institute of Scientific and Technical Information of China (English)

    LI Ping; DONG Shu-Qing; WANG Qing-Jiang; FANG Yu-Zhi

    2008-01-01

    In this paper, four trace ingredients (rutin, gallic acid, quercetin, chlorogenic acid) in green tea were simultaneously determined by capillary electrophoresis coupled with amperometric detection (CE-AD). Effects of several important factors such as the pH and concentration of running buffer, separation voltage, injection time and detection potential were investigated to acquire the optimum conditions. Under the optimum conditions, the analytes could be separated within 20 min at a separation voltage of 18 kV in a 60 mmol/L borate buffer (pH 8.7). A 300 μmdiameter carbon disk electrode generated good responses at 950 mV (vs. SCE) for all analytes. The relationship between the peak currents and concentrations of the analytes was linear over about three orders of magnitude with demonstrated long-term stability and reproducibility with relative standard deviations less than 3% for both migration time and peak current (n=7), which could be successfully used for the determination of the analytes in green tea with satisfactory assay results.

  4. Antihemolytic Activities of Green Tea, Safflower, and Mulberry Extracts during Plasmodium berghei Infection in Mice

    Directory of Open Access Journals (Sweden)

    Suthin Audomkasok

    2014-01-01

    Full Text Available Malaria-associated hemolysis is associated with mortality in adult patients. It has been speculated that oxidative stress and inflammation induced by malaria parasite are involved in its pathophysiology. Hence, we aimed to investigate the antihemolytic effect of green tea, safflower, and mulberry extracts against Plasmodium berghei infection. Aqueous crude extracts of these plants were prepared using hot water method and used for oral treatment in mice. Groups of ICR mice were infected with 6 × 106 infected red blood cells of P. berghei ANKA by intraperitoneal injection and given the extracts (500, 1500, and 3000 mg/kg twice a day for 4 consecutive days. To assess hemolysis, hematocrit levels were then evaluated. Malaria infection resulted in hemolysis. However, antihemolytic effects were observed in infected mice treated with these extracts at dose-dependent manners. In conclusion, aqueous crude extracts of green tea, safflower, and mulberry exerted antihemolysis induced by malaria infection. These plants may work as potential source in the development of variety of herbal formulations for malarial treatment.

  5. Thrombolytic Potential of Aqueous and Methanolic Crude Extracts of Camellia sinensis (Green Tea: In vitro study

    Directory of Open Access Journals (Sweden)

    Muhammad Ajmal Shah

    2013-05-01

    Full Text Available Investigation of thrombolytic activityof crude extracts ofCamellia sinensis (Green tea using in-vitrothrombolytic model which is very simple, rapid and easy to do method. Both aqueous crude and methanolic extracts were studied however; the results of methanolic extract were more promising which exhibited maximum 95. 24% clot lysis as compared to aqueous one i.e. 90.34% at 800 μg/ml concentration in 72 hrs of incubation. Various concentrations of leaf extract i.e. 200μg/ml, 400μg/ml, 600ug/ml and 800μg/ml were tested at different time intervals including; 24hrs, 48hrs and 72hrs duration of incubation at 370 C for observing maximum clot lysis. The result indicated that concentrations of leaf extract enhanced the percentage of clot lysis in dose dependent manner. On the other hand, Streptokinase SK, a reference standard and water were used as a positive and negative control showed clot lysis maximum 96.63% and 41.32% in 72 hrs of incubation respectively. From results, it can be concluded that if further studies reveals the exact molecule from green tea diverse composition, an effective thromolytic candidate can be achieved for the improvement of the patients suffering from Atherothrombotic diseases.

  6. Effect of Additional Information on Consumer Acceptance: An Example with Pomegranate Juice and Green Tea Blends

    Directory of Open Access Journals (Sweden)

    Federica Higa

    2017-07-01

    Full Text Available Pomegranate Juice (PJ and Green Tea (GT products have increased in popularity because of their beneficial health properties. Consumers look for healthier beverages, and rely on labels, claims, and product packaging when choosing a product. The objectives of this study were to determine (1 the sensory profiles and acceptance of PJ and GT blends; (2 whether additional information would have an effect on consumer acceptance; and (3 the total phenolic content (TPC of the samples. Six PJ and GT blends were evaluated by a descriptive panel in order to explore sensory differences in flavor characteristics. A consumer panel (n = 100 evaluated the samples before and after beneficial health information about the samples was provided to them. The blends that were higher in tea concentration were higher in Green and GT-like flavors, and lower in berry, beet, floral, sweetness, and cherry flavors. The overall liking scores of all of the samples increased after the information was provided to the consumers. The sample highest in PJ and lowest in GT blend was liked the most. In addition, as the samples increased in PJ, the TPC content increased. These results may be of interest to the beverage industry, providing information of consumer liking of beverage blends, and how information on health related claims affects consumer acceptance.

  7. Inhibition of FLT3 expression by green tea catechins in FLT3 mutated-AML cells.

    Directory of Open Access Journals (Sweden)

    Bui Thi Kim Ly

    Full Text Available Acute myeloid leukemia (AML is a heterogeneous disease characterized by a block in differentiation and uncontrolled proliferation. FLT3 is a commonly mutated gene found in AML patients. In clinical trials, the presence of a FLT3-ITD mutation significantly correlates with an increased risk of relapse and dismal overall survival. Therefore, activated FLT3 is a promising molecular target for AML therapies. In this study, we have shown that green tea polyphenols including (--epigallocatechin-3-gallate (EGCG, (--epigallocatechin (EGC, and (--epicatechin-3-gallate (ECG suppress the proliferation of AML cells. Interestingly, EGCG, EGC and ECG showed the inhibition of FLT3 expression in cell lines harboring FLT3 mutations. In the THP-1 cells harboring FLT3 wild-type, EGCG showed the suppression of cell proliferation but did not suppress the expression of FLT3 even at the concentration that suppress 100% cell proliferation. Moreover, EGCG-, EGC-and ECG-treated cells showed the suppression of MAPK, AKT and STAT5 phosphorylation. Altogether, we suggest that green tea polyphenols could serve as reagents for treatment or prevention of leukemia harboring FLT3 mutations.

  8. Green tea catechins and their oxidative protection in the rat eye.

    Science.gov (United States)

    Chu, Kai On; Chan, Kwok Ping; Wang, Chi Chiu; Chu, Ching Yan; Li, Wai Ying; Choy, Kwong Wai; Rogers, Michael Scott; Pang, Chi Pui

    2010-02-10

    Catechins, active constituents of green tea, are well-known antioxidative natural products. It was proposed that green tea extract (GTE) consumption could benefit the eye, and the pharmacokinetics of catechins and oxidation status in rat eye were investigated after oral administration. Sprague-Dawley rats were fed GTE and sacrificed at different time intervals. Their eyes were dissected into cornea, lens, retina, choroid-sclera, vitreous humor, and aqueous humor for analysis of catechins and 8-epi-isoprostane by HPLC-ECD and GC-NCI-MS, respectively. Catechins were differentially distributed in eye tissues. Gallocatechin was present at the highest concentration in the retina, 22729.4 +/- 4229.4 pmol/g, and epigallocatechin in aqueous humor at 602.9 +/- 116.7 nM. The corresponding area-under-curves were 207,000 pmol x h/g and 2035.0 +/- 531.7 nM x h, respectively. The time of maximum concentration of the catechins varied from 0.5 to 12.2 h. Significant reductions in 8-epi-isoprostane levels were found in the compartments except the choroid-sclera or plasma, indicating antioxidative activities of catechins in these tissues.

  9. Green tea extract ingestion, fat oxidation, and glucose tolerance in healthy humans.

    Science.gov (United States)

    Venables, Michelle C; Hulston, Carl J; Cox, Hannah R; Jeukendrup, Asker E

    2008-03-01

    Green tea consumption is reportedly associated with various health-promoting properties. For example, it has been shown to promote fat oxidation in humans at rest and to prevent obesity and improve insulin sensitivity in mice. We investigated the effects of acute ingestion of green tea extract (GTE) on glucose tolerance and fat oxidation during moderate-intensity exercise in humans. Two studies were performed, both with a counter-balanced crossover design. In study A, 12 healthy men performed a 30-min cycling exercise at 60% of maximal oxygen consumption (VO2max) before and after supplementation. In study B, 11 healthy men took an oral-glucose-tolerance test before and after supplementation. In the 24-h period before the experimental trials, participants ingested 3 capsules containing either GTE (total: 890 +/- 13 mg polyphenols and 366 +/- 5 mg EGCG) or a corn-flour placebo (total: 1729 +/- 22 mg). Average fat oxidation rates were 17% higher after ingestion of GTE than after ingestion of placebo (0.41 +/- 0.03 and 0.35 +/- 0.03 g/min, respectively; P fat oxidation to total energy expenditure was also significantly higher, by a similar percentage, after GTE supplementation. The insulin area under the curve decreased in both the GTE and placebo trials (3612 +/- 301 and 4280 +/- 309 microIU/dL . 120 min, respectively; P fat oxidation during moderate-intensity exercise and can improve insulin sensitivity and glucose tolerance in healthy young men.

  10. Inhibition of HMGB1 Translocation by Green Tea Extract in Rats Exposed to Environmental Tobacco Smoke

    Directory of Open Access Journals (Sweden)

    Sirintip Chaichalotornkul

    2012-01-01

    Full Text Available Environmental tobacco smoke (ETS exposure is linked to carcinogenic, oxidative and inflammatory cellular reactions. Green tea polyphenol reportedly plays a role in the prevention of inflammation-related diseases. To evaluate the effects of green tea extract (GTE on cellular location of High Mobility Group Box-1 (HMGB1 protein, we studied the lung tissue in rats exposed to cigarette smoke (CS. Rats were divided into three groups; CS, CSG, and C, which were groups of CS-treated only, CS-treated with GTE dietary supplement, and the control, respectively. Our findings by immunocytochemistry showed that abundant HMGB1 translocated from the nucleus to the cytoplasm in the lung tissues of rats that were exposed to CS, whereas HMGB1 was localized to the nuclei of CSG and C group. For in vitro studies, cotinine stimulated the secretion of HMGB1 in a dose and time dependent manner and the HMGB1 level was suppressed by GTE in murine macrophage cell lines. Our results could suggest that GTE supplementation which could suppress HMGB1 may offer a beneficial effect against diseases.

  11. Construction Technology of Ecological Tea Plantation in Mindong Black-green Tea Area%闽东红绿茶产区生态茶园建设技术

    Institute of Scientific and Technical Information of China (English)

    杨如兴; 张磊; 陈芝芝; 吴志丹

    2014-01-01

    阐述了闽东生态茶园建设措施和目标,总结出适合闽东红绿茶生产的新垦茶园、茶林嵌合型和纯茶种植老茶园生态建设技术。%In this paper, construction measures and objectives of ecological tea plantation in Mindong area were elaborated, and thus construction technology of ecological tea plantation was suggested for the newly-reclaimed young tea plantation, mosaic type plantation of tea and woods, and ageing single-tea plantation, to be proper for the production of black tea and green tea in Mindong area.

  12. Green Tea Catechin Metabolites Exert Immunoregulatory Effects on CD4(+) T Cell and Natural Killer Cell Activities.

    Science.gov (United States)

    Kim, Yoon Hee; Won, Yeong-Seon; Yang, Xue; Kumazoe, Motofumi; Yamashita, Shuya; Hara, Aya; Takagaki, Akiko; Goto, Keiichi; Nanjo, Fumio; Tachibana, Hirofumi

    2016-05-11

    Tea catechins, such as (-)-epigallocatechin-3-O-gallate (EGCG), have been shown to effectively enhance immune activity and prevent cancer, although the underlying mechanism is unclear. Green tea catechins are instead converted to catechin metabolites in the intestine. Here, we show that these green tea catechin metabolites enhance CD4(+) T cell activity as well as natural killer (NK) cell activity. Our data suggest that the absence of a 4'-hydroxyl on this phenyl group (B ring) is important for the effect on immune activity. In particular, 5-(3',5'-dihydroxyphenyl)-γ-valerolactone (EGC-M5), a major metabolite of EGCG, not only increased the activity of CD4(+) T cells but also enhanced the cytotoxic activity of NK cells in vivo. These data suggest that EGC-M5 might show immunostimulatory activity.

  13. Analysis of some selected catechins and caffeine in green tea by high performance liquid chromatography.

    Science.gov (United States)

    El-Shahawi, M S; Hamza, A; Bahaffi, S O; Al-Sibaai, A A; Abduljabbar, T N

    2012-10-15

    Green tea seems to have a positive impact on health due to the catechins-found as flavanols. Thus, the present study was aimed to develop a low cost reversed phase high performance liquid chromatographic (HPLC) method for simultaneous determination of flavanol contents, namely catechin (C), epicatechin (EC), epigallocatechin (EGC), epicatechin 3-gallate (ECG) and epigallocatechin 3-gallate (EGCG) and caffeine in 29 commercial green tea samples available in a Saudi Arabian local market. A C-18 reversed-phase column, acetonitrile-trifluoroacetic acid as a mobile phase, coupled with UV detector at 205 nm, was successfully used for precise analysis of the tested analytes in boiled water of digested tea leaves. The average values of N (No. of theoretical plates), HETP (height equivalent of theoretical plates) and R(s) (separation factor) (at 10 μg ml(-1) of the catechins EC, EGC, EGCG and ECG) were 2.6×10(3)±1.2×10(3), 1.7×10(-3)±4.7×10(-4) cm and 1.7±5.53×10(-2), respectively. The developed HPLC method demonstrated excellent performance, with low limits of detection (LOD) and quantification (LOQ) of the tested catechins of 0.004-0.05 μg ml(-1) and 0.01-0.17 μg ml(-1), respectively, and recovery percentages of 96-101%. The influence of infusion time (5-30 min) and temperature on the content of the flavanols was investigated by HPLC. After a 5 min infusion of the tea leaves, the average concentrations of caffeine, catechin, EC, EGC, ECG and EGCG were found to be in the ranges 0.086-2.23, 0.113-2.94, 0.58-10.22, 0.19-24.9, 0.22-13.9 and 1.01-43.3 mg g(-1), respectively. The contents of caffeine and catechins followed the sequence: EGCG>EGC>ECG>EC>C>caffeine. The method was applied satisfactorily for the analysis of (+)-catechin, even at trace and ultra trace concentrations of catechins. The method was rapid, accurate, reproducible and ideal for routine analysis.

  14. Green Tea

    Science.gov (United States)

    60040 ... https://nccih.nih.gov/health/greentea ... us ... 60040 ... https://nccih.nih.gov/health/greentea ... Herbal Medicine ... Herbal Medicine/Specifics ... us ... 60040 ... https://nccih.nih. ...

  15. Antioxidant properties of green tea extract protect reduced fat soft cheese against oxidation induced by light exposure

    DEFF Research Database (Denmark)

    Huvaere, Kevin; Nielsen, Jacob Holm; Bakman, Mette

    2011-01-01

    The effect of two different antioxidants, EDTA and green tea extract (GTE), used individually or in combination, on the light-induced oxidation of reduced fat soft cheeses (0.2 and 6% fat) was investigated. In samples with 0.2% fat, lipid hydroperoxides as primary lipid oxidation products were...

  16. How Does Alkali Aid Protein Extraction in Green Tea Leaf Residue: A Basis for Integrated Biorefinery of Leaves

    NARCIS (Netherlands)

    Zhang, C.; Sanders, J.P.M.; Xiao, T.T.; Bruins, M.E.

    2015-01-01

    Leaf protein can be obtained cost-efficiently by alkaline extraction, but overuse of chemicals and low quality of (denatured) protein limits its application. The research objective was to investigate how alkali aids protein extraction of green tea leaf residue, and use these results for further impr

  17. The Impact of Green Tea Supplementation on Anthropometric Indices and Inflammatory Cytokines in Women with Polycystic Ovary Syndrome.

    Science.gov (United States)

    Mombaini, Esmat; Jafarirad, Sima; Husain, Durdana; Haghighizadeh, Mohammad Hossein; Padfar, Parivash

    2017-02-28

    The present study aimed to determine the effect of a green tea supplement on anthropometric indices and inflammatory factors in women with polycystic ovary syndrome (PCOS). In this randomized clinical trial, 45 women with PCOS were randomly allocated into two groups receiving green tea tablets or placebo. The period of intervention was 45 days. The serum levels of interleukin 6, high-sensitivity C-reactive protein, and tumor necrosis factor α were measured before and after intervention period using the related kits. Anthropometric indices also were measured. The mean of body mass index, weight, waist circumference, and body fat percentage in the green tea group were reduced significantly. However, no significant difference was observed between the two groups. Also, there was no significant effect on the levels of inflammatory factors. The present results suggest that daily consumption of green tea tablets did not cause any effect on inflammation biomarkers in PCOS women. However, it may be effective as a complementary treatment for weight control in these women. Copyright © 2017 John Wiley & Sons, Ltd.

  18. Synergistic effects of green tea polyphenols and alphacalcidol on chronic inflammation-induced bone loss in female rats

    Science.gov (United States)

    Summary: Studies suggest that green tea polyphenols (GTP) or alphacalcidol is promising agent for preventing bone loss. Findings that GTP supplementation in the drinking water plus alphacalcidol administration resulted in increased bone mass via a decrease of oxidative stress and inflammation sugges...

  19. Protective actions of green tea polyphenols and alfacalcidol on bone microstructure in female rats with chronic inflammation

    Science.gov (United States)

    This study investigated the effects of green tea polyphenols (GTP) and alfacalcidol on bone microstructure and strength along with possible mechanisms in rats with chronic inflammation. A 12-week study using a 2 (no GTP vs. 0.5%, w/v GTP in drinking water) × 2 (no alfacalcidol vs. 0.05 ug/kg alfacal...

  20. Green tea polyphenols mitigate bone loss of female rats in a chronic inflammation-induced bone loss model

    Science.gov (United States)

    The purpose of this study was to explore bioavailability, efficacy, and molecular mechanisms of green tea polyphenols (GTP) related to preventing bone loss in rats with chronic inflammation. A 2 (placebo vs. lipopolysaccharide, LPS) × 2 (no GTP vs. 0.5% GTP in drinking water) factorial design using ...

  1. How Does Alkali Aid Protein Extraction in Green Tea Leaf Residue: A Basis for Integrated Biorefinery of Leaves

    NARCIS (Netherlands)

    Zhang, C.; Sanders, J.P.M.; Xiao, T.T.; Bruins, M.E.

    2015-01-01

    Leaf protein can be obtained cost-efficiently by alkaline extraction, but overuse of chemicals and low quality of (denatured) protein limits its application. The research objective was to investigate how alkali aids protein extraction of green tea leaf residue, and use these results for further

  2. Effectiveness of green tea mouthwash in comparison to chlorhexidine mouthwash in patients with acute pericoronitis: a randomized clinical trial.

    Science.gov (United States)

    Shahakbari, R; Eshghpour, M; Rajaei, A; Rezaei, N M; Golfakhrabadi, P; Nejat, A

    2014-11-01

    The objective of this study was to evaluate the effectiveness of green tea mouthwash in controlling the pain and trismus associated with acute pericoronitis in comparison to chlorhexidine (CHX) mouthwash. Ninety-seven patients with acute pericoronitis underwent debridement and received 5% green tea mouthwash (study group) or 0.12% CHX mouth rinse (control group). Pain (visual analogue scale; VAS), number of analgesics, maximum mouth opening (MMO), and number of patients with trismus were determined. There were no significant differences in demographic variables (P>0.05), or baseline VAS (P>0.006), MMO (P>0.017) or number of patients with trismus (P>0.017) between the two groups. The mean VAS score of the study group was statistically lower than that of the control group between post-treatment days 3 and 5 (P0.017). Fewer of the patients rinsing with green tea had trismus on days 3 and 7, but the difference was non-significant (P>0.017). Hence, green tea mouth rinse could be an appropriate and effective choice for the control of pain and trismus in acute pericoronitis. Copyright © 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  3. Green tea extract only affects markers of oxidative status postprandially: lasting antioxidant effect of flavonoid-free diet

    DEFF Research Database (Denmark)

    Young, J.F.; Dragsted, Lars Ove; Haraldsdottir, J.

    2002-01-01

    Epidemiological studies suggest that foods rich in flavonoids might reduce the risk of cardiovascular disease and cancer. The objective of the present study was to investigate the effect of green tea extract (GTE) used as a food antioxidant on markers of oxidative status after dietary depletion...... in flavonoids. GTE intervention increased plasma antioxidant capacity from 1.35 to 1.56 (P...

  4. Inhibition of pro-/active MMP-2 by green tea catechins and prediction of their interaction by molecular docking studies.

    Science.gov (United States)

    Chowdhury, Animesh; Nandy, Suman Kumar; Sarkar, Jaganmay; Chakraborti, Tapati; Chakraborti, Sajal

    2017-03-01

    Matrix metalloproteinases (MMPs) play a crucial role in developing different types of lung diseases, e.g., pulmonary arterial hypertension (PAH). Green tea polyphenolic catechins such as EGCG and ECG have been shown to ameliorate various types of diseases including PAH. Our present study revealed that among the four green tea catechins (EGCG, ECG, EC, and EGC), EGCG and ECG inhibit pro-/active MMP-2 activities in pulmonary artery smooth muscle cell (PASMC) culture supernatant. Based on the above, we investigated the interactions of pro-/active MMP-2 with the green tea catechins by computational methods. In silico analysis revealed a strong interaction of pro-/active MMP-2 with EGCG/ECG, and galloyl group has been observed to be responsible for this interaction. The in silico analysis corroborated our experimental observation that EGCG and ECG are active in preventing both the proMMP-2 and MMP-2 activities. Importantly, these two catechins appeared to be better inhibitors for proMMP-2 in comparison to MMP-2 as revealed by gelatin zymogram and also by molecular docking studies. In many type of cells, activation of proMMP-2 occurs via an increase in the level of MT1-MMP (MMP-14). We, therefore, determined the interactions of MT1-MMP with the green tea catechins by molecular docking analysis. The study revealed a strong interaction of MT1-MMP with EGCG/ECG, and galloyl group has been observed to be responsible for the interaction.

  5. How Does Alkali Aid Protein Extraction in Green Tea Leaf Residue: A Basis for Integrated Biorefinery of Leaves

    NARCIS (Netherlands)

    Zhang, C.; Sanders, J.P.M.; Xiao, T.T.; Bruins, M.E.

    2015-01-01

    Leaf protein can be obtained cost-efficiently by alkaline extraction, but overuse of chemicals and low quality of (denatured) protein limits its application. The research objective was to investigate how alkali aids protein extraction of green tea leaf residue, and use these results for further impr

  6. Effects of green tea and its epigallocatechin (EGCG) content on body weight and fat mass in humans: a systematic review

    Science.gov (United States)

    Vázquez Cisneros, Lucía Cristina; López-Uriarte, Patricia; López-Espinoza, Antonio; Navarro Meza, Mónica; Espinoza-Gallardo, Ana Cristina; Guzmán Aburto, Martha Beatriz

    2017-06-05

    The prevalence and incidence of overweight and obesity worldwide continues to increase, as well as diseases related to these conditions. This is attributed to an increase in energy intake and a decrease in energy expenditure. Consumption of green tea has been linked to a reduction in body fat and body weight. However, research on green tea has been very diverse. This review assesses the investigations that have been made with green tea and its epigallocatechin gallato (EGCG) content, evaluating its effect on body fat and body weight in humans. A search was made in the PubMed and Web of the Science databases that gave a first total result of 424 potential articles; 409 were excluded and 15 articles were used for this systematic review. Research has been very varied, however, daily consumption of green tea with doses of EGCG between 100 and 460 mg/day has shown greater effectiveness on body fat and body weight reduction in intervention periods of 12 weeks or more. In addition, the use of caffeine doses between 80 and 300 mg/day has been shown to be an important factor for this effects, when the participants did not have a high caffeine intake (> 300 mg/day) prior to the intervention.

  7. Green tea polyphenols block the anticancer effects of bortezomib and other boronic acid-based proteasome inhibitors.

    Science.gov (United States)

    Golden, Encouse B; Lam, Philip Y; Kardosh, Adel; Gaffney, Kevin J; Cadenas, Enrique; Louie, Stan G; Petasis, Nicos A; Chen, Thomas C; Schönthal, Axel H

    2009-06-04

    The anticancer potency of green tea and its individual components is being intensely investigated, and some cancer patients already self-medicate with this "miracle herb" in hopes of augmenting the anticancer outcome of their chemotherapy. Bortezomib (BZM) is a proteasome inhibitor in clinical use for multiple myeloma. Here, we investigated whether the combination of these compounds would yield increased antitumor efficacy in multiple myeloma and glioblastoma cell lines in vitro and in vivo. Unexpectedly, we discovered that various green tea constituents, in particular (-)-epigallocatechin gallate (EGCG) and other polyphenols with 1,2-benzenediol moieties, effectively prevented tumor cell death induced by BZM in vitro and in vivo. This pronounced antagonistic function of EGCG was evident only with boronic acid-based proteasome inhibitors (BZM, MG-262, PS-IX), but not with several non-boronic acid proteasome inhibitors (MG-132, PS-I, nelfinavir). EGCG directly reacted with BZM and blocked its proteasome inhibitory function; as a consequence, BZM could not trigger endoplasmic reticulum stress or caspase-7 activation, and did not induce tumor cell death. Taken together, our results indicate that green tea polyphenols may have the potential to negate the therapeutic efficacy of BZM and suggest that consumption of green tea products may be contraindicated during cancer therapy with BZM.

  8. Resistance to Citrus Canker in Key/Mexican Lime Induced by β-Aminobutyric Acid and Green Tea

    Directory of Open Access Journals (Sweden)

    B. Beheshti

    2011-01-01

    Full Text Available Citrus bacterial canker, caused by Xanthomonas citri subsp. citri (Xcc, is a destructive disease. So far used chemicals to control this pathogen are either not effective or have harmful effects on the environment. To improve control of this disease, lime (Citrus aurantifolia plants inoculated with Xcc were treated with β-Aminobutyric Acid (BABA, ascorbic acid (vitamin C, thiamin (vitamin B1, green tea (Camellia sinensis, copper oxychloride and distilled water. Lesion diameters of inoculated leaves were evaluated twenty days after treatment. The results showed that BABA and green tea had inhibitory effects on disease development. None of the agents used for plant treatment had direct antimicrobial activity on Xcc, except copper oxychloride. This indicated that the inhibitory effects of BABA and green tea resulted from strengthening the defense capacities of the plant. To support this claim, partial coding sequences of Pathogenesis-Related (PR genes from lime were cloned and sequenced. Analysis of PR gene expression showed increased mRNA levels of β-1,3-glucanase and chitinase, during disease development. Reduction in lesion size and lack of antimicrobial activity indicate that BABA and green tea might be useful treatments against Xcc infection.

  9. Comparative evaluation of Green Tea- Aloe Vera mouthwash and chlorhexidine 0.2% on gingival indices (A randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Naser Sargolzaie

    2015-12-01

    Full Text Available Introduction: Nowadays in the field of dentistry, there is a trend to encourage the use of herbal and natural products. The high level of clinical research in terms of considering green tea and aloe vera, with various functionality for individual use is a typical example. The purpose of this randomized, controlled, and double-blind study was to evaluate comparative evaluation of green tea-aloe vera mouthwash and chlorhexidine 0.2% on gingival indices. Methods: A total of 60 patients (26 women and 34 men with periodontal disease were randomly allocated into one of the three double blind groups, 20 in each, to receive the following treatments :(1 0.2% chlorhexidine, (2 green tea-aloe vera and  (3 distilled water. Plaque and gingival indices were evaluated on the day of the beginning of the experiment and 14 days postoperative. Subjects were asked to rinse their mouth with the mouth rinse, twice a day, during a 14-day period. Paired t-test was used to test the mean difference on 0 and 14 days, respectively. One way analysis of variance (ANOVA was used to compare the mean difference between the groups while Tukey test was used for multiple comparisons. Results: Chlorhexidine 0.2%, green tea - aloe vera and placebo reduced the plaque index by 0.17±0.14, 0.10±0/08 and 0.02±0.18, respectively, with a statistical significance of p=0.008. This difference was related to Chlorhexidine 0.2% and green tea - aloe vera with Placebo. There exist a significant difference of p=0.001 in the bleeding index  between the three groups, and this difference was related to Chlorhexidine 0.2% and green tea - aloe vera with placebo. Conclusion: Green tea –aloe vera   mouthwash improves periodontal health status. Therefore, it can be used to improve oral and dental health status.

  10. Effects of green tea gargling on the prevention of influenza infection in high school students: a randomized controlled study.

    Directory of Open Access Journals (Sweden)

    Kazuki Ide

    Full Text Available BACKGROUND: The anti-influenza virus activity of green tea catechins has been demonstrated in experimental studies, but clinical evidence has been inconclusive. School-aged children play an important role in the infection and spread of influenza in the form of school-based outbreaks. Preventing influenza infection among students is essential for reducing the frequency of epidemics and pandemics. As a non-pharmaceutical intervention against infection, gargling is also commonly performed in Asian countries but has not yet been extensively studied. METHODS AND FINDINGS: A randomized, open label, 2-group parallel study of 757 high school students (15 to 17 years of age was conducted for 90 days during the influenza epidemic season from December 1st, 2011 to February 28th, 2012, in 6 high schools in Shizuoka Prefecture, Japan. The green tea gargling group gargled 3 times a day with bottled green tea, and the water gargling group did the same with tap water. The water group was restricted from gargling with green tea. The primary outcome measure was the incidence of laboratory-confirmed influenza using immunochromatographic assay for antigen detection. 757 participants were enrolled and 747 participants completed the study (384 in the green tea group and 363 in the water group. Multivariate logistic regression indicated no significant difference in the incidence of laboratory-confirmed influenza between the green tea group (19 participants; 4.9% and the water group (25 participants; 6.9% (adjusted OR, 0.69; 95%CI, 0.37 to 1.28; P = 0.24. The main limitation of the study is the adherence rate among high school students was lower than expected. CONCLUSIONS: Among high school students, gargling with green tea three times a day was not significantly more efficacious than gargling with water for the prevention of influenza infection. In order to adequately assess the effectiveness of such gargling, additional large-scale randomized studies are needed

  11. Green Tea Modulates Cytokine Expression in the Periodontium and Attenuates Alveolar Bone Resorption in Type 1 Diabetic Rats.

    Directory of Open Access Journals (Sweden)

    Gabriela Gennaro

    Full Text Available Diabetes mellitus comprises a heterogeneous group of disorders with the main feature of hyperglycemia. Chronic hyperglycemia increases the severity of periodontal disease via an exacerbated inflammatory response, activated by advanced glycation end products and their receptor, RAGE. Therefore, anti-inflammatory agents represent potential inhibitors of this pathological interaction. In particular, green tea has been shown to possess anti-inflammatory properties mediated by its polyphenol content.This study investigated the mechanisms by which green tea attenuates the spontaneous onset of diabetes-induced periodontitis.Diabetes was induced in rats via a single intraperitoneal injection of streptozotocin (STZ. Diabetic and control animals were divided into water-treated and green tea-treated subgroups and were analyzed at 15, 30, 60 and 90 days after diabetes induction. Immunohistochemistry was performed to quantitatively evaluate tumor necrosis factor-α (TNF-α, receptor activator of nuclear factor kappa-B ligand (RANKL, osteoprotegerin (OPG, interleukin-10 (IL-10 and runt-related transcription factor 2 (RUNX-2 expression in serial sections of each hemimaxilla. Morphometric measurements of the distance from the cementum-enamel junction (CEJ of the superior distal root of the first molar to the alveolar bone crest (ABC were performed to assess bone loss.Diabetes resulted in significant bone loss and alterations in the number of cells that stained positive for inflammatory mediators. In the diabetic rats treated with green tea,