Leading Edge Antioxidants Research

279 Pages·2006·3.62 MB·English

by  Harold V. Panglossi

L E
EADING DGE
A R
NTIOXIDANTS ESEARCH

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.

L E
EADING DGE
A R
NTIOXIDANTS ESEARCH

HAROLD V. PANGLOSSI
EDITOR

Nova Science Publishers, Inc.
New York
Copyright © 2007 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 [phone]; Fax [phone]
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.

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 cover herein. It is sold with the clear understanding that the Publisher is not
engaged in rendering legal or any other professional services. If legal, medical 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
Leading edge antioxidants research / Harold V. Panglossi (editor).
p. ; cm.
Includes bibliographical references and index.
ISBN: 978-1-61324-512-5 (eBook)
1. Antioxidants--Research. 2. Antioxidants--Therapeutic use. I. Panglossi, Harold V.
[DNLM: 1. Antioxidants--therapeutic use. QV 325 L434 2006]
RB170.L43 2006
613.2'8072--dc22 2006017578

Published by Nova Science Publishers, Inc. New York
CONTENTS

Preface vii

Chapter 1 Anti- and Prooxidative Effects of Flavonoids 1
Wim Wätjen, Yvonni Chovolou, Andreas Kampkötter and Regine Kahl

Chapter 2 Comparison of Antioxidative Properties of Green and Black Tea 17
Agnieszka Augustyniak, Justyna Ostrowska, Wojciech Luczaj
and Elzbieta Skrzydlewska

Chapter 3 Antioxidants in Foods: A New Challenge for Food Processors 35
G. Oboh and J. B. T. Rocha

Chapter 4 Are Teas the Universal Antioxidants 65
Justyna Ostrowska, Wojciech Luczaj and Elzbieta Skrzydlewska

Chapter 5 Radioprotective Effects of Antioxidants 89
Mustafa Vecdi Ertekin and Orhan Sezen

Chapter 6 Antioxidant Therapy for Chronic Inflammatory Diseases 145
Jayraz Luchoomun, Dominic Sinibaldi and Xi-Lin Chen

Chapter 7 Impact of Oxidative Stress on Diabetes Mellitus
and Inflammatory Bowel Diseases 179
Jana Varvařovská, Rudolf Štětina, Josef Sýkora Zdeněk Rušavý,
Jaroslav Racek, Silva Lacigová and Konrad Siala

Index 247

PREFACE

In biological systems, the normal processes of oxidation (plus a minor contribution from
ionizing radiation) produce highly reactive free radicals. These can readily react with and
damage other molecules. In some cases the body uses free radicals to destroy foreign or
unwanted objects, such as in an infection. However, in the wrong place, the body's own cells
may become damaged. Should the damage occur to DNA, the result could be cancer.
Antioxidants decrease the damage done to cells by reducing oxidants before they can damage
the cell. Virtually all studies of mammals have concluded that a restricted calorie diet extends
the lifespan of mammals by as much as 100%. This remarkable finding suggests that food is
actually more damaging than smoking. As food produces free radicals (oxidants) when
metabolized, antioxidant-rich diets are thought to stave off the effects of aging significantly
better than diets lacking in antioxidants. The reduced levels of free radicals, resulting from a
reduction in their production by metabolism, is thought to be a major cause of the success of
caloric restriction in increasing life span. Antioxidants consist of a group of vitamins
including vitamin C, vitamin E, selenium and carotenoids (such as beta-carotene, lycopene,
and lutein). This new book brings together the latest research in this dynamic field.
Chapter 1 - Flavonoids are polyphenolic compounds that occur ubiquitously in foods of
plant origin. This class of compounds has become increasingly popular in terms of health
protection because they possess a remarkable spectrum of biochemical and pharmacological
activities. Flavonoids affect basic cell functions such as growth, differentiation and apoptosis.
Epidemiological studies have suggested that flavonoids may protect against various stages of
the cancer process and are associated with a reduced incidence of coronary heart disease.
Flavonoids have been shown to be potent antioxidants because of their radical scavenging
activity. Furthermore, flavonoids are able to complex heavy metal ions, e.g. iron and copper
which are involved in Fenton-like reactions. The biological actions of flavonoids have long
been thought to be due to their antioxidant potential but at present it is by no means clear
whether other mechanisms of action contribute to their overall effect or are even more
important than their radical scavenging properties. Although some flavonoids act as powerful
antioxidants it was also shown that in high concentrations they can generate reactive oxygen
species and induce apoptosis. Hydroxyl radicals generated by autoxidation and redox-cycling
of the polyphenolic flavonoids may initiate peroxidation of the lipids in cellular membranes.
Furthermore, flavonoids can cause an impairment of antioxidative defense systems consisting
e.g. of glutathione and glutathione-S-transferase, which in this way indirectly induces
oxidative stress in the cell.
viii Harold V. Panglossi
For a number of flavonoids cytoprotective, antioxidative and antiapoptotic as well as
cytotoxic, prooxidative and proapoptotic effects have been shown in various cell culture
models. Given this wide spectrum of biological actions, it is quite understandable that
numerous health claims which are in part mutually exclusive have been linked with
flavonoids. Notably in cancer, but also in infections or autoimmune disease, a deficiency in
apoptosis is one of the key events. On the other hand, overefficient apoptosis, as observed in
fulminant liver failure, or the long term accumulation of apoptotic events in
neurodegenerative disorders may be equally harmful for the organism. Given that both
beneficial and adverse effects can in principle be caused by flavonoids it must be assumed
that – in addition to the cell type or tissue involved and to the presence or absence of a
stressor - it depends on dose which action prevails.
Chapter 2 - Green tea has been proved to possess antioxidative properties whereas black
tea antioxidant properties in vivo have been questioned, considering its components. The aim
of this study has been to compare the antioxidative properties of black and green tea
manifested by their protective action on the liver, brain and serum antioxidants of two months
old rats chronically (4 weeks) intoxicated with ethanol. In order to estimate the intensity of
black and green tea action the activity of antioxidant enzymes – superoxide dismutase,
catalase, glutathione peroxidase and reductase as well as GSH level were measured by
spectrophotometric methods while the levels of vitamin C and E were measured by HPLC
methods. Teas antioxidant efficiency was evaluated by lipid peroxidation process intensity
estimated as TBARS level. It has been shown that ethanol caused decrease in the
activity/level of the examined antioxidants in the liver, brain and serum except glutathione
reductase whose activity increased in the liver and serum. Disturbances in antioxidant
abilities led to oxidative stress formation manifested by the rice of the level of lipid
peroxidation products. Green tea as well as black tea partially prevented changes in the
activity/level of antioxidants of all examined tissues caused by ethanol intoxication and
significantly protected phospholipids against oxidative modifications. Green tea as well as
black tea given to rats receiving alcohol caused significant increase in the activity of all
examined enzymes in the brain. Moreover green tea enhanced the activity of superoxide
dismutase, glutathione peroxidase and catalase, while black tea increased only glutathione
peroxidase and catalase activities in the liver. Serum of alcohol intoxicated and drinking tea
rats was characterized by increase in the activity of superoxide dismutase after green tea and
in superoxide dismutase and glutathione peroxidase after black tea. Both teas caused
significant increased in the liver, brain and serum levels of GSH, vitamin C and E in
comparison to alcohol group. However green tea action was a little more effective than that of
black tea. In consequence both teas significantly protected phospholipids against oxidative
modifications caused by ethanol. The above results clearly indicate beneficial effect of green
as well as black tea on antioxidant system and prevention against oxidative stress formation
after ethanol intoxication.
Chapter 3 - In recent years, human health has assumed an unprecedented important
status. A new diet-health paradigm is everlasting which places more emphasis on the positive
aspects of diet. Foods have now assumed the status of functional foods, which should be
capable of providing additional physiological benefit, such as prevent or delaying onset of
chronic diseases, as well as meeting basic nutritional requirements. Recently phytochemicals
in fruits and vegetables have attracted a great deal of attention mainly concentrated on their
role in preventing diseases caused as a result of oxidative stress. The regular consumption of
Preface ix
foods that are naturally high in antioxidants (fruits, vegetables, whole grains, nuts and seeds,
legumes and herbal seasonings) is associated with substantial health benefits. Although some
of this food are eaten raw without processing, but many of them are subjected to one or more
forms of post-harvest food processing techniques such as blanching, cooking, sun drying,
frying, soaking, irridation, fermentation, coagulation and baking. Apart from Vitamin C and E
that are already established food nutrient with antioxidant properties, other phytochemicals in
foods with antioxidant properties includes: Ally sulphide, carotenoids, curcumins, flavonoids,
gingerols, indoles and isothiocyanates, isoflavones, lignans, liminoids, phenolic acids,
phthalides polyacetylenes, phytates, saponins and terpenes. This phytochemicals varies in
their quantities and physico-chemical properties, and their activities in food are either additive
or synergistic. Since most of the methods employed in foods processing both at household
levels or during the unit operations in food processing industry will bring about a change in
quantities and physico-chemicals properties of the food phytochemicals, and this could effect
individual / or gross antioxidant properties of the food. In this article, the effect of the various
post-harvest food processing techniques popularly employed both at the household or
industrial levels on the antioxidant phytochemicals and activity of some commonly consumed
plant foods, and the possible remedy is highlighted.
Chapter 4 - Cellular metabolism is accompanied by generation of free radicals, which
also play pivotal role in the action of numerous xenobiotics. Their increased production is a
primary event in many human diseases progression or a secondary consequence of tissue
injury. Detoxification of radicals in the cell is provided by the antioxidant defense system.
Many synthetic and natural antioxidants are useful when antioxidant systems are no able to
cope with radicals action. Among natural antioxidants, the most popular beverage consumed
worldwide is tea. Tea is manufactured in three basic forms: green, oolong and black, which
are non-, partially- and full-fermented/oxidized, respectively. Therefore, green tea
composition is very similar to that of the fresh leaves and contains considerable amount of
monomeric polyphenols, particularly catechins. The major components of black tea are
multimeric polyphenols - theaflavins and thearubinins – the oxidation products and
condensates of catechins. Considerable amount of the original polyphenolic compounds are
contained in oolong tea. Monomeric polyphenols possess proved antioxidant properties wich
are manifested in the ability to prevent oxygen radical formation, by inhibiting the activity of
enzymes participating in their generation as well as in the ability to scavenge free radicals and
to chelate transition metal ions. Recently, antioxidant properties of multimeric polyphenols of
black tea have also been proved. The antioxidant properties of teas polyphenolic compounds
have led to considerable interest in the potential health benefits resulting from teas
consumption. Evidence has been collected that teas polyphenols are metabolized extensively
and are distributed to all tissues in animal organisms. Metabolites of catechins and their
condensates have been also revealed to possess antioxidant properties comparable to their
parent compounds. Significant enhancement in tissues antioxidant capacity has been
demonstrated following the consumption of teas by animals and humans. In consequence the
protective effect of teas polyphenols on DNA, lipids and proteins appears to be very
promising in reducing the incidence of many diseases. It was indicated that tea consumption
leads among others to decrease in cancer risk but its mode of action is still unclear. Teas
polyphenols can block the formation of mutagens and carcinogens from precursor and
increase their detoxification. Moreover they influence molecular events at the gene level.
However, despite of proved antioxidant and cancer chemoprotective properties of tea