Book of Green Tea and Health Research

In: Food and Beverage Consumption and Health Series

HANDBOOK OF GREEN TEA AND HEALTH RESEARCH No part of this digital document may be reproduced, stored in a retrieval system or transmitted in any form or by any means. The publisher has taken reasonable care in the preparation of this digital document, but makes no expressed or implied warranty of any kind and assumes no responsibility for any errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of information contained herein. This digital document is sold with the clear understanding that the publisher is not engaged in rendering legal, medical or any other professional services.

FOOD AND BEVERAGE CONSUMPTION AND HEALTH SERIES

Handbook of Green Tea and Health Research Helen McKinley and Mark Jamieson 2009. ISBN 978-1-60741-045-4

In: Food and Beverage Consumption and Health Series

HANDBOOK OF GREEN TEA AND HEALTH RESEARCH

HELEN MCKINLEY AND

MARK JAMIESON EDITORS

Nova Science Publishers, Inc. New York

Copyright © 2009 by Nova Science Publishers, Inc.

All rights reserved. No part of this book may be reproduced, stored in a retrieval system or transmitted in any form or by any means: electronic, electrostatic, magnetic, tape, mechanical photocopying, recording or otherwise without the written permission of the Publisher. For permission to use material from this book please contact us: Telephone 631-231-7269; Fax 631-231-8175 Web Site: http://www.novapublishers.com NOTICE TO THE READER The Publisher has taken reasonable care in the preparation of this book, but makes no expressed or implied warranty of any kind and assumes no responsibility for any errors or omissions. No liability is assumed for incidental or consequential damages in connection with or arising out of information contained in this book. The Publisher shall not be liable for any special, consequential, or exemplary damages resulting, in whole or in part, from the readers’ use of, or reliance upon, this material. Any parts of this book based on government reports are so indicated and copyright is claimed for those parts to the extent applicable to compilations of such works. Independent verification should be sought for any data, advice or recommendations contained in this book. In addition, no responsibility is assumed by the publisher for any injury and/or damage to persons or property arising from any methods, products, instructions, ideas or otherwise contained in this publication. This publication is designed to provide accurate and authoritative information with regard to the subject matter covered herein. It is sold with the clear understanding that the Publisher is not engaged in rendering legal or any other professional services. If legal or any other expert assistance is required, the services of a competent person should be sought. FROM A DECLARATION OF PARTICIPANTS JOINTLY ADOPTED BY A COMMITTEE OF THE AMERICAN BAR ASSOCIATION AND A COMMITTEE OF PUBLISHERS.

LIBRARY OF CONGRESS CATALOGING-IN-PUBLICATION DATA Handbook of green tea and health research / [edited by] Helen McKinley and Mark Jamieson. p. ; cm. -- (Food and beverage consumption and health) Includes bibliographical references and index. ISBN 978-1-60876-202-6 (E-Book) 1. Green tea--Health aspects. I. McKinley, Helen. II. Jamieson, Mark. III. Series: Food and beverage consumption and health. [DNLM: 1. Tea. 2. Camellia sinensis. 3. Catechin--analogs & derivatives. 4. Phytotherapy--methods. WB 438 H236 2009] RM251.H36 2009 615'.321--dc22 2009000178

Published by Nova Science Publishers, Inc. Ô New York

ebooksdownloadrace.blogspot.in

CONTENTS Preface

ix

Chapter 1

Central Functions of Green Tea Components M. Furuse,, N. Adachi, S. Tomonaga, H. Yamane and D. M. Denbow

Chapter 2

Green Tea Catechins: A Class of Molecules with Antimicrobial Activity P. Buzzini, P. Vignolini, M. Goretti, B. Turchetti, E. Branda, E. Marchegiani, P. Pinelli and A. Romani

Chapter 3

Chapter 4

Chapter 5

Chapter 6

Chapter 7

1

23

Lipid-soluble Green Tea Polyphenols: Stabilized for Effective Formulation Ping Chen, Douglas Dickinson and Stephen Hsu

45

Assessment of the Antioxidant Capacity of Green Teas: A Critical Review Camilo López-Alarcón and Eduardo Lissi

63

Design and Assessment of the in Vitro Anti-oxidant Capacity of a Beverage Composed of Green Tea (Camellia Sinensis L.) and Lemongrass (Cymbopogon Citratus Stap) D. Fernando Ramos Escudero, Luis Alberto Condezo Hoyos, Mónica Ramos Escudero and Jaime A. Yáñez

81

Teas Are not All the Same: In Vitro and in Vivo Antioxidant Activity and Appetite Modulation in Rats of Green Teas with High and Low Levels of Organic Selenium Abdul L. Molan, Zhuojian Liu and Wenhua Wei Anti-obesity Effects of (-)-Epigallocathchin-3-gallate and its Molecular Mechanism Cheol-Heui Yun, Gi Rak Kim, Min Ji Seo, Hyun-Seuk Moon and Chong-Su Cho

103

125

vi Chapter 8

Chapter 9

Contents Green Tea: Protective Action against Pesticides and other Xenobiotics Present in Human Diet Geetanjali Kaushik, Poonam Kaushik and Shivani Chaturvedi

157

New Method to Improve the Function and Industrial Applicability of Green Tea and Its Byproducts Using Irradiation Technology Cheorun Jo and Myung Woo Byun

177

Chapter 10

Green Tea Catechin as Angiogenesis Inhibitor Kiminori Matsubara and Yoshiyuki Mizushina

197

Chapter 11

Neuroprotective Effect of Theanine on Cerebral Ischemia Nobuaki Egashira,, Kenichi Mishima, Katsunori Iwasaki, Ryozo Oishi and Michihiro Fujiwara

207

Chapter 12

Characterization of the Neuroprotective Activity of the Polyphenol (-)-Epigallocatechin-3-gallate in the Brain Orly Weinreb, Tamar Amit, Moussa B. H. Youdim and Silvia Mandel

219

Chapter 13

Cardiovascular and Metabolic Effects of Green Tea Kamilla Kelemen

Chapter 14

Molecular Basis for the Anti-cancer Activity of EGCG in Vivo: Molecular-Targeting Prevention of Cancer by Green Tea Catechin Yoshinori Fujimura and Hirofumi Tachibana

257

Utility of Epigallocatechin Gallate in the Treatment and Prevention of Breast Cancer: Molecular Mechanisms for Tumor Suppression R. J. Rosengren

301

Chapter 15

Chapter 16

Green Tea Catechins in Colorectal Cancer Seung Joon Baek and Mugdha Sukhthankar

Chapter 17

Inhibitory Effect of Catechin Derivatives from Green Tea on DNA Polymerase Activity, Human Cancer Cell Growth, and TPA (12-O-tetradecanoylphorbol-13-acetate) -induced Inflammation Yuko Kumamoto-Yonezawa, Hiromi Yoshida and Yoshiyuki Mizushina

Chapter 18

Telomerase Regulation in Response to Green Tea Huaping Chen and Trygve O. Tollefsbol

Chapter 19

Green Tea and Chronic Obstructive Pulmonary Disease: A Casecontrol Study in Japan Fumi Hirayama and Andy H. Lee

243

325

347

363

383

Chapter 20

Green Tea and Diabetes Dongfeng Wang, Linge Wang and Li Zhang

393

Chapter 21

Green Tea and Type 2 Diabetes Jae-Hyung Park, Hye-Young Sung and Dae-Kyu Song

411

Contents Chapter 22

Chapter 23

Biocatalytic Conversion of Green Tea Catechins to Epitheaflagallin, Epitheaflagallin, 3-O-gallate, and Theaflavins: Production of Promising Functional Foods Nobuya Itoh and Yuji Katsube Preventive Effects of Green Tea Catechins on Dementia Michio Hashimoto, Md Abdul Haque, Kohinoor Begum Himi and Yukihiko Hara

vii

419 429

Short Commentary Green Tea and Potential Human Health Effects James E. Trosko Index

451 463

PREFACE After water, tea signifies the second most frequently consumed beverage worldwide. Teas are not all the same; among the many areas of research that are included in this book are the effects of selenium-containing green tea on food consumption and body weight gain. Research shows that tea consumption may have its strongest effect among patients with cardiovascular disease. A specific chapter investigates whether green tea intake can reduce the risk of chronic obstructive pulmonary disease. Research is presented to show that green tea and its major constituent epigallocatechin gallate (EGCG) have a potential chemopreventative and/or treatment for a variety of diseases including breast cancer. Other research sheds new light on the molecular basis for the cancerpreventive activity of EGCG in vivo and helps in the design of new strategies to prevent cancer. A further study presents an analysis assessing the progress of research on the mechanisms pertaining to how telomerase activity is regulated by green tea in cancer cells. Further chapters look at the relationship of tea to diabetes and a description of the beneficial effects of green tea catechins on neuronal functions and neuronal diseases such as dementia. To improve biological functions and industrial applicability of green tea and its byproducts, research is presented showing irradiation as a useful method. Chapter 1 - Tea (Camellia sinensis) is widely consumed throughout the world and has a number of biologically active substances such as caffeine, catechins, and L-theanine (γglutamylethylamide). Tea consumption is generally known to induce a feeling of relaxation which may be mediated by either catechins, L-theanine, or both, since caffeine stimulates locomotor activities. The catechin (-)-epigallocatechin gallate (EGCG) occurs abundantly in tea. Moreover, frequent consumption of green tea results in high levels of EGCG in the blood and brain. Catechins, which are flavonoids, affect the central nervous system (CNS). The therapeutic effects of flavonoids may involve their binding to γ-aminobutyric acid (GABA)A receptors, which is a major inhibitory neurotransmission system. Recently, EGCG was shown to bind to GABAA receptors in vitro and to induce a sedative effect through GABAA, but not GABAB, receptors in the brain. L-Theanine, a derivative of glutamate, is a unique amino acid occurring only in green tea and a few other plants. After administration L-theanine concentrations were increased in serum, liver and brain, suggesting that L-theanine can cross the blood-brain barrier. Intravenous administration of L-theanine was shown to affect the cortex, hippocampus and amygdala, and increase the alpha-band component of electroencephalograms in rats. More

x

Helen McKinley and Mark Jamieson

recently, it was shown that L-theanine could reduce stress via either inhibiting cortical neuron excitation in human subjects or influencing the secretion and function of neurotransmitters in the CNS. We discuss the central functions of green tea components such as EGCG and Ltheanine in the CNS. Chapter 2 - A significant part of scientific interest of academy or industry is focused on discovering novel natural antimicrobial drugs. This attention is essentially justified by the expectation that a few of them could play a role in supporting (or even in substituting) some antibiotics of current use. It has been estimated that, although about some tens of novel antimicrobial drugs (either of biological or synthetic origin) are currently launched each year, due to the increasing development of resistant microbial genotypes, their downturn is becoming very rapid. Taking into account these considerations, the enormous scientific and commercial interest in discovering and developing novel classes of molecules exhibiting more or less pronounced antimicrobial properties has oriented the work of a growing part of the scientific community toward large-scale screening programs aimed at discovering novel classes of bioactive molecules. The occurrence in some plants of secondary metabolites exhibiting a more or less pronounced antimicrobial activity is a well-known phenomenon. Among them, green tea polyphenols represent a reservoir of molecules characterized by antioxidant, antiradical and antimicrobial activity. In particular, catechins have proven to be effective towards both prokaryotic and eukaryotic microorganisms. Despite the large number of studies published so far, their actual potentialities and limitations as antimicrobial (mainly antibacterial and antimycotic) drugs have not been critically evaluated. The present chapter represents an overview of the recent literature on the antiviral and antimicrobial properties exhibited by polyphenols, particularly catechins, occurring in green tea composition. Chapter 3 - Green tea polyphenols (GTPs), also referred to as green tea catechins, possess properties that can provide unique health benefits to humans. As indicated in other chapters of this book, studies using molecular, cellular, and animal models, and in human subjects, have demonstrated that these phytochemicals from non-oxidized tea leaves have anti-cancer, antioxidant, anti-microbial, and anti-inflammatory properties. Recently, investigations in our and other laboratories indicated that topical application of GTPs could protect the epidermis against autoimmune disorders, such as psoriasis, prevent or repair UV-induced damage, and suppress scar tissue overgrowth. In addition, specific gene regulation by GTPs, especially epigallocatechin-3-gallate (EGCG), promotes skin cell differentiation, which could lead to improved homeostasis of the skin. Based on these facts, the topical use of products containing GTPs has become more popular, and manufacturers of cosmetic, health care, and household products are adding GTPs or EGCG to their formulations. However, it is important to note that studies described in this book always use “freshly prepared” GTPs or green tea, instead of “pre-prepared” materials. This is because GTPs are potent antioxidants that react rapidly with reactive oxygen species (ROS). As a result, GTPs in most commercially available products have been oxidized and/or epimerized; the biological effects of the resulting compounds are largely unknown. In addition, due to the highly water-soluble nature of these compounds, GTPs in their original form are not lipid-soluble, and therefore not permeable to the skin, a water-proof barrier. Another problem with formulation of GTPs for topical application is the coloration change and precipitation caused by oxidation. Thus, GTPs for topical application (e.g., on skin and

Preface

xi

mucous membranes) must be prepared and used immediately prior to oxidation, coloration and precipitation. These properties of GTPs make it difficult to formulate products containing them that have a reasonable shelf life and maintain their activity and effectiveness. In other words, most of the commercially available “green tea”–containing products are without the full benefits of green tea or GTPs. Therefore, strategies to stabilize and increase the bioavailability of GTPs are needed to provide the full benefits of GTPs to consumers or patients. Recently, it has been shown that lipid esters of GTPs can be formed either enzymatically or chemically. These green tea polyphenol-lipid esters, also referred to as lipid-soluble tea polyphenols (LTPs), could significantly improve formulations of consumer or health care products. We hypothesized that fatty acyl esterification of green tea polyphenol would protect the hydroxyl groups from oxidation and improve skin permeability. In the current study, we compared the activities of LTPs to GTPs for their anti-cancer and gene regulation properties. We examined whether LTPs can be converted into a free GTP (EGCG) in human skin keratinocyte cultures. In addition, the effects of LTPs in a mouse model for psoriasis were evaluated. The results indicate that LTPs effectively cause cancer cell death, induce caspase 14 gene expression both in vitro and in vivo, and improve the skin condition in an animal model for psoriasis. Consistent with these observations, HPLC analysis demonstrated that EGCG in its original form was released from LTPs in situ by human epidermal keratinocytes. These results suggest that LTPs, under appropriate conditions, function similarly to GTPs. More importantly, since the most reactive hydroxyl group(s) is/are protected, and the lipid solubility is dramatically increased by the fatty acyl groups, the biological activity of these compounds can be stabilized, and their bioavailability increased significantly. In conclusion, LTPs are a novel and more effective form of green tea polyphenols for topical applications and other purposes, especially in formulations that require a reasonable shelf life. In addition, LTPs can be a natural additive to consumable products such as salad oil, fish oil, and cooking oil as antioxidants. Chapter 4 - In the last decades, the beneficial influence of green tea on human health has been related to the antioxidant capacity (AC) of its phenolic constituents. The latter has originated systematic studies of the AC of green tea and/or its pure antioxidants. Different methodologies have been used with this purpose. The methods are based on: (1) Estimation of the consumption by additives of stable free radicals (DPPH, and ABTS radical cation); (2) Evaluation of the protection given by antioxidants to a target being oxidized by free radicals (ORAC, TOSC, LDL oxidation assay); (3) Estimation of the steady state of free radicals before and after addition of additives (TAR); (4)Estimation of the reducing power capacity of the additives (FRAP, CUPRAC). The assays differ in the experimental conditions and their chemistry. Therefore, different conclusions could be obtained depending on the methodology used. For example, green tea presents a lower AC than peumus boldus by ORAC (oxygen radical absorbance capacity) method when fluorescein is used as target molecule. However, if pyrogallol red is used as probe, green tea appears with an ORAC index six times higher than peumus boldus. In the present review, we discuss the advantages, and disadvantages of the different methodologies employed to evaluate the AC of green tea. Chapter 5 - Tea is one of the most popular and widely consumed beverages in the world and it is derived from the infusion of tea leaves (Camellia sinensis L.). Different commercial types of tea are available, including black tea, oolong tea (semi-fermented) and green tea,

xii

Helen McKinley and Mark Jamieson

which differ on their processing and chemical composition. All these types of tea have been reported to prevent multiple diseases such as cancer, heart conditions, among others. On the other hand, lemongrass (Cymbopogon citratus Stap) is a rich source of essential oils, widely employed in infusions, soaps, and perfumes, and it has been reported to possess gastrointestinal and analgesic properties. In the present study, green tea (Camellia sinensis L.) and lemongrass (Cymbopogon citratus Stap) leaves were collected from Río Azul and Porvenir de Marona, Perú. The anti-oxidant capacity of green tea and lemongrass extracts was evaluated using the DPPH method and it was observed that the IC50 values for green tea was 32.4 ± 0.39 μg/mL and 1350 ± 47 μg/mL for lemongrass. These two plants (green tea and lemongrass) were employed to design multiple infused beverages and it was determined that an infused beverage containing 10 mg/mL total extract (50% green tea and 50% lemongrass) reported a total catechin content of 24.4 ± 0.65 mg/100mL, a DPPH inhibition percentage of 88.6%, and exhibited the greatest acceptance for sensory attributes such as flavor, color, and aroma (values of 6.8, 9.0, and 8.0 respectively) based on Friedman Multiple Comparisons test. The taste panel results also indicated that the optimized acidity and sweetness were to be set at pH 3.1 and 11°Brix, while the optimum infusion time based on the total catechin content was 7 minutes. The pasteurization profile at 90°C for 5 minutes achieved mesophilic microorganisms counts of 2 cups/d

1.40

P for trend = 0.0006

1.20 1.00 0.80

*

0.60 0.40 0.20 0.00 n=170

n=108

n=725

Figure 2. Odds ratios (ORs) for the association between different frequencies of green tea consumption and cognitive impairment. The bars indicate adjusted ORs for the association between green tea consumption frequencies and cognitive impairment; error bar represent the corresponding 95% CIs. Multivariate logistic regression analysis was used to calculate ORs for cognitive impairment relative to the consumption frequencies of green tea, with the lowest frequency category (≤3 cups/wk) treated as the reference group. Cognitive impairment was defined as a Mini-Mental State Examination score < 26. *P< 0.001. 1 cup = 0.1L. Data from Kuriyama et al., (2006).

GREEN TEA CATECHINS AND BRAIN FUNCTION Influence of Green Tea Catechins on Cognitive Function Green tea catechins currently show a profound beneficial effect on cognitive function both in animal and humans. An epidemiological cross-sectional study involving 1003 Japanese subjects 70 years old or older, demonstrated the relationship between the consumption of green tea and cognitive function. The study clearly showed that a higher consumption of green tea is associated with lower prevalence of cognitive impairment in humans [Kuriyama et al., 2006]. Drinking more than 2 cups a day of green tea slashed odds of cognitive impairment in elderly Japanese men and women by 64% (Figure 2). The results might partly explain the relatively lower prevalence of dementia, especially AD, in Japan compared to Europe and North America [Ritchie and Lovestone, 2002].

Preventive Effects of Green Tea Catechins on Dementia A

B

4

Control (n=8)

4

3

2

a b

1

0

Working Memory Errors

Reference Memory Errors

435

Catechins (n=9) 3

2

1

a b

0 0

2

4

6

8

Blocks of Six Trials

10

0

2

4

6

8

10

Blocks of Six Trials

Figure 3. Reference (A) and working (B) memory-related learning ability in the radial maze task of rats administered water alone (control, n = 8), or green tea catechins (0.5% polyphenon E; n = 9) for 26 wk. Values are means ± SEM in each block of six trials. Groups without a common letter differ, P < 0.05. Data from Haque et al., (2006).

In animal experiments with rats, long-term administration of green tea catechins in the form of Polyphenon E (PE: EGCG 63%; EC 11%; EGC 6%; ECG 6%) mixed with water (0.5% w/v) improved spatial cognition learning ability when measuring eight-arm radial maze task (Figure 3). The radial maze estimates two types of memory function, reference and working memory without any harmful stress to the rats. Reference memory involves utilizing information that remains constant over time whereas working memory involves holding information that is pertinent only within a short period of time. The lower numbers of reference memory errors (RMEs; entry into unbaited arm within one trial) and working memory errors (WMEs; repeated entry into arms that had already been visited within same trial) implies a higher acquisition of spatial learning ability in rats. 0.5% PE-administered rats had significantly lower LPO levels both in plasma and hippocampus and higher ferric reducing antioxidant power (FRAP) levels (an indicator of plasma antioxidant status) (Table 2). A significant positive correlation between the hippocampal LPO levels and the number of RMEs, and a negative correlation between plasma FRAP levels and the number of RMEs were observed in block 10 of the radial maze task in controls and in 0.5% PE-administered rats (Figure 4). These results indicate that the lower LPO and higher FRAP levels, combined with higher acquisition of memory performance, are likely to be the effects of PE on scavenging and/or preventing radical formation at the neuronal level. Similarly, it is reported that dietary administration of green tea catechins prevents memory regression and DNA oxidative damage in aged mice [Unno et al., 2007]. Thus, these findings suggest that continued intake of green tea catechins might promote healthy ageing of the brain in older persons.

Michio Hashimoto, Md Abdul Haque, Kohinoor Begum Himi et al.

A r = - 0.570 p = 0.017

r = 0.520 p = 0.032

3.0 Reference M emory Errors

B 3.0.

2.0

2.0

1.0

1.0 Control (n=8) Catechins (n=9)

0.0 0

0.25

0.50

1

0.75

150

TBARS levels in hippocampus (nmol/mg protein)

Reference M emory Errors

436

0.0 200

250

300

350

FRAP levels in plasma ( mol/L)

Figure 4. Correlations between the numbers of reference memory errors and each of the hippocampal TBARS (Figure 4A) and the plasma FRAP (Figure 4B) levels in controls and green tea catechinsadministered rats. (o), control rats; (●), green tea catechins (0.5% polyphenon E)-administered rats. Data from Haque et al., (2006).

Table 2. Effects of green tea catechins (0.5% PE) administration on oxidative status of plasma, cerebral cortex and hippocampus in rats Plasma

Cerebral cortex

Hippocampus

TBARS

FRAP

TBARS

ROS

TBARS

ROS

Control (n=8)

4.0 ± 0.1

224 ± 10

1.45 ± 0.10

0.21 ± 0.03

0.63 ± 0.09

0.13 ± 0.03

Catechins (n=9)

3.0 ± 0.1*

271 ± 11*

1.27 ± 0.08

0.19 ± 0.04

0.33 ± 0.03*

0.05 ± 0.01*

Values are means ± SEM. Rats were orally administered either water (control rats) or green tea catechins (Polyphenon E, PE: EGCG 63%; EC 11%; EGC 6%; ECG 6%, catechins rats) for 26 weeks. The levels of lipid peroxide were measured as TBARS (thiobarbituric acid reactive substance) indicated in nmol malondialdehyde/mL for plasma and nmol malondialdehyde/mg protein for brain tissues. Reactive oxygen species (ROS) is indicated in pmol/min/mg protein. The antioxidant potential of plasma was mesured as ferric reducing antioxidation power of plasma (FRAP) is indicated in μmol/L. *P