Main Free radicals in biology and medicine

Free radicals in biology and medicine

, , ,
0 / 0
How much do you like this book?
What’s the quality of the file?
Download the book for quality assessment
What’s the quality of the downloaded files?
Free Radicals in Biology and Medicine has become a classic text in the field of free radical and antioxidant research. Now in its fifth edition, the book has been comprehensively rewritten and updated whilst maintaining the clarity of its predecessors. Two new chapters discuss 'in vivo' and 'dietary' antioxidants, the first emphasising the role of peroxiredoxins and integrated defence mechanisms which allow useful roles for ROS, and the second containing new information on the role of fruits, vegetables, and vitamins in health and disease. This new edition also contains expanded coverage of the mechanisms of oxidative damage to lipids, DNA, and proteins (and the repair of such damage), and the roles played by reactive species in signal transduction, cell survival, death, human reproduction, defence mechanisms of animals and plants against pathogens, and other important biological events. The methodologies available to measure reactive species and oxidative damage (and their potential pitfalls) have been fully updated, as have the topics of phagocyte ROS production, NADPH oxidase enzymes, and toxicology. There is a detailed and critical evaluation of the role of free radicals and other reactive species in human diseases, especially cancer, cardiovascular, chronic inflammatory and neurodegenerative diseases. New aspects of ageing are discussed in the context of the free radical theory of ageing.

This book is recommended as a comprehensive introduction to the field for students, educators, clinicians, and researchers. It will also be an invaluable companion to all those interested in the role of free radicals in the life and biomedical sciences.
Categories:
Year:
2015
Edition:
5th ed
Publisher:
Oxford University Press
Language:
english
Pages:
905 / 961
ISBN 10:
0198717482
ISBN 13:
9780198717485
File:
PDF, 34.82 MB
Download (pdf, 34.82 MB)
Conversion to is in progress
Conversion to is failed

Most frequent terms

 
0 comments
 

To post a review, please sign in or sign up
You can write a book review and share your experiences. Other readers will always be interested in your opinion of the books you've read. Whether you've loved the book or not, if you give your honest and detailed thoughts then people will find new books that are right for them.
Free Radicals in Biology and Medicine

Free Radicals in
Biology and Medicine
FIFTH EDITION

Barry Halliwell
B.A. (OXON), D.Phil. (OXON), D.SC (LOND)
and

John M.C. Gutteridge
PHD (LOND), D.Sc (LOND)

Do not follow where the path may lead. Go instead where there is no path and leave
a trail.
Muriel Strode

3
Free Radicals in Biology and Medicine. Fifth Edition. Barry Halliwell and John M.C. Gutteridge.
© Barry Halliwell and John M.C. Gutteridge 2015. Published in 2015 by Oxford University Press.

3

Great Clarendon Street, Oxford, OX2 6DP,
United Kingdom
Oxford University Press is a department of the University of Oxford.
It furthers the University’s objective of excellence in research, scholarship,
and education by publishing worldwide. Oxford is a registered trade mark of
Oxford University Press in the UK and in certain other countries
© Barry Halliwell and John M.C. Gutteridge 2015
The moral rights of the authors have been asserted
First Edition published in 1985
Second Edition published in 1989
Third Edition published in 1999
Fourth Edition published in 2007
Fifth Edition published in 2015
Impression: 1
All rights reserved. No part of this publication may be reproduced, stored in
a retrieval system, or transmitted, in any form or by any means, without the
prior permission in writing of Oxford University Press, or as expressly permitted
by law, by licence or under terms agreed with the appropriate reprographics
rights organization. Enquiries concerning reproduction outside the scope of the
above should be sent to the Rights Department, Oxford University Press, at the
address above
You must not circulate this work in any other form
and you must impose this same condition on any acquirer
Published in the United States of America by Oxford University Press
198 Madison Avenue, New York, NY 10016, United States of America
British Library Cataloguing in Publication Data
Data available
Library of Congress Control Number: 2014955109
ISBN 978–0–19–871747–8 (hbk.)
ISBN 978–0–19–871748–5 (pbk.)
Printed and bound;  by
CPI Group (UK) Ltd, Croydon, CR0 4YY
Links to third party websites are provided by Oxford in good faith and
for information only. Oxford disclaims any responsibility for the materials
contained in any third party website referenced in this work.

Preface to the fifth edition

When the first edition of Free Radicals in Biology and
Medicine appeared in 1985, free radicals were mainly
studied by radiation chemists and those involved in
industrial processes and research relating to rubber,
plastics, oils, paint, and food (table below). These are
still key research areas. Two major scientific advances
broadened the spectrum: the discovery of CuZnSOD
by Joe McCord and Irwin Fridovich in 1968, and the
report by Bernie Babior in 1973 that activated neutrophils produce superoxide for microbicidal purposes.
At this time, most of our indirect methodology for
measuring the damage caused by free radicals came
from the food industry, where the thiobarbituric acid
(TBA) assay was widely used to detect and measure
lipid rancidity. In hindsight, this simple-to-do but misleading test distorted our interpretations by focusing
excessive attention on ‘lipid peroxidation’ in biology
and medicine at the expense of understanding better
how proteins, DNA, and individual lipids are damaged by reactive oxygen species (ROS), what products
are generated, and what biological effects they exert
(good, bad, or indifferent). It also triggered a corresponding rush to find antioxidants that would protect
against ‘peroxidation’. The explosive growth of interest
that followed this realization of the biological relevance of free radicals necessitated the writing of a
second edition four years later (1989). Our third edition (1999) reflected an enormous expansion in new
methodologies to detect and measure oxidative damage to proteins, carbohydrates, DNA, and lipids, which
helped to place these processes in better physiological
and pathological context. These changes quickly led
to the realization that free radicals and other reactive
species are consequential to most (but not all) disease
processes, and that, by implication, antioxidants would
usually be limited and selective in their efficacy, as
indeed they are.
The present (fifth) edition expands this area to take
in recent advances in research methodologies, their application and limitations, and the findings of clinical
and nutritional intervention studies. Precise molecular

characterization of oxidative damage is gradually replacing TBA and carbonyl assays, and revealing a
wealth of new information about molecular processes
in ageing and disease.
After 1987, a new free radical, nitric oxide (NO• ),
gained prominence, some of the discoverers of its
biological role being awarded Nobel Prizes. Nitric
oxide research reinforced the increasingly recognized
concept that free radicals and other ROS have purposeful and beneficial roles to play in biology. Far
fewer scientists are now sceptical about the role of
free radicals and antioxidants in living organisms. The
authors are convinced that these agents permeate the
whole of biology and that knowledge of them is essential to understand how aerobic life evolved and works.
In edition five we have expanded coverage of the biological roles of oxygen-derived species and other free
radicals and placed these roles in a clearer biological
context. Superoxide, NO• , and hydrogen peroxide are
poorly reactive (see editions 1, 2, and 3) and (unlike
OH• ) better suited to signalling functions than to
destructive chemical reactions. Nevertheless, their
potential for selective cytotoxicity is clear. In addition,
we are learning how antioxidant defence systems are
carefully co-ordinated to allow signalling roles for
ROS, an area also expanded. To keep the book from
growing too large, much older and now less-relevant
material has been omitted.
We hope that the fifth edition will again serve to
bridge the gap between experts and novices. We have
tried to keep the text chatty and readable. Will we need
a sixth edition, and when? We think so, this is a field
that isn’t going away!
B.H.
Tan Chin Tuan Centennial Professor
National University of Singapore, Singapore
J.M.C.G
Retired Scientist
UK
v

vi

P R E FA C E TO T H E F I F T H E D I T I O N
Milestones in free radical research.
Discovery

Year

Discovery of oxygen (Scheele discovered it in 1772.
Priestley published it first in 1775, Lavoisier clarified its nature∗ ).
Priestley also discovered seven other gases, namely NO• , N2 O, NO•2 ,
SO2 , HCl, CO, and NH3 .
Demonstration of oxygen toxicity
Discovery of selenium
Discovery of hydrogen peroxide (eau oxygénée )
First attempts to study oil oxidation by O2 uptake
Oxygen causes rancidification of natural oils
Fenton reaction described
First report of a free radical (triphenylmethyl)
Discovery of vitamin E
Isolation of vitamin C
Fungal glucose oxidase the first enzyme found to produce H2 O2
Postulation of the Haber–Weiss reaction
Catalase purified from bovine liver
Basic mechanism of lipid peroxidation elucidated
Sperm discovered to be susceptible to oxidative damage
Discovery of electron spin resonance
Proposal that free radicals account for damage by ionizing radiation
Identification of retinopathy of prematurity as an O2 toxicity
Proposal that free radicals cause ageing
Use of ESR to discover paramagnetic [Fe-S] proteins
Discovery of glutathione peroxidase
Phagocytes shown to produce H2 O2
Myeloperoxidase found to oxidize Cl– to a bactericidal product
Synergy between ascorbate and α-tocopherol suggested
Spin traps first developed
Discovery of the SOD activity of CuZnSOD
First identification of O•–
2 production by an enzyme
First description of phagocyte O•–
2 production
Phagocytes from patients with chronic granulomatous disease found to
be deficient in O•–
2 production
Aromatic hydroxylation introduced as an in vivo assay for OH•
First description of the effects of oxygen-derived species on the vascular
system
FIRST EDITION OF THIS BOOK
Term ‘oxidative stress’ introduced
Identification of nitric oxide as the endothelium-derived relaxing factor
Links made between human plasma/serum antioxidant levels and lower
disease risk
SECOND EDITION OF THIS BOOK
Discovery of OxyR and SoxR
Introduction of the isoprostanes as an assay for lipid peroxidation
Oxygen-derived species reported to activate the transcription factor
NF-κB in some systems
Detailed characterization of peroxiredoxins
THIRD EDITION OF THIS BOOK
FOURTH EDITION OF THIS BOOK

1775–1778

1775 (Joseph Priestley)
1817
1818
1820
1822
1876
1900 (by Gomberg)
1922
1928
1928
1934
1937
1940s
1943
1944
1954
1954
1956
1957
1957
1961
1967
1968
1968
1968–69
1969
1973
1974
1975
1981
1985
1985
1987
1987 onwards
1989
1990
1991
1991
1994 onwards
1999
2007

∗ Free Radicals can kill you: Lavoisier’s Oxygen Revolution. FASEB J. 24, 649–52 (2010); also see Am. J. Physiol. 306, L111, 2014.

Acknowledgements

Production of the fifth edition was aided by advice and/or permission to reproduce their published material from
the following experts, acknowledged in alphabetical order of surname. We are most grateful for their help, but the
responsibility for any errors in the text is solely ours.
Doris Abele (Germany)
John R. Aitken (Australia)
Peter Andersen (Sweden)
Shannon M Bailey (USA)
Neil R. Baker (UK)
Carolina Barillas (USA)
Ines Batinic-Haberle (USA)
Jeffrey Blumberg (USA)
Susan Brain (UK)
Regina Brigelius-Flohé (Germany)
Gary Buettner (USA)
Graham Burton (UK)
Allan Butterfield (USA)
Ioav Cabantchik (Israel)
Jean Cadet (France)
Kate Carroll (USA)
Christopher Chang (USA)
Christopher Chen (Singapore)
Kee Seng Chia (Singapore)
Marie Véronique Clement (Singapore)
James Cobley (UK)
Andrew R. Collins (Norway)
Marcus S. Cooke (USA)
Morton J. Cowan (USA)
Diane Critchlow (UK)
Carroll Cross (USA)
Andrew Das (New Zealand)
Michael Davies (Australia)
Peter Dedon (USA)
Jean-Charles Deybach (France)
Bryan Dickinson (USA)
Miral Dizdaroglu (USA)
Lawrence A Donehower (USA)
Joël R. Drevet (France)
Grant Drummond (Australia)
Gregory Dusting (Australia)

Gerard Evan (UK)
Philip Evans (UK)
Toren Finkel (USA)
Lisa Folkes (UK)
Christine Foyer (UK)
Errol Friedberg (USA)
Xin-Yuan Fu (Singapore)
Nicholas R.J. Gascoigne (Singapore)
David Gems (UK)
German Nutrition Society
Elizabeth Getzoff (USA)
Michael Goodman (USA)
Govindjee (USA)
Jan Gruber (Singapore)
Tomasz Guzik (Poland)
Vincent Hearing (USA)
Harri Hemilä (Finland)
Russell Hepple (Canada)
Cecilia Hidalgo (Chile)
Ralph Hueckelhoven (Germany)
Dora Ilyasova (USA)
Shosuke Ito (Japan)
Yoshiaki Ito (Singapore)
Balaraman Kalyanaraman (USA)
Frank Kelly (UK)
Jan F. Kern (USA)
Sashi Kesavapany (Singapore)
Anthony Kettle (New Zealand)
Tom Kirkwood (UK)
William H. Koppenol (Switzerland)
Paul Kubes (Canada)
David Lambeth (USA)
Nick Lane (UK)
Henry Leese (UK)
Kah-Leong Lim (Singapore)
Stefan Liochev (USA)

vii

viii

ACKNOWLEDGEMENTS

Valter Longo (USA)
Alvin Loo (Singapore)
Jon O. Lundberg (Sweden)
Paul Macary (Singapore)
Danny Manor (USA)
Stefan Marklund (Sweden)
Jenny Martin (Australia)
Ronald Mason (USA)
Johannes Messinger (Sweden)
Ginger Milne (USA)
Ron Mittler (USA)
Alvaro Molina-Cruz (USA)
Vincent Monnier (USA)
Philip Keith Moore (Singapore)
Richard I. Morimoto (USA)
Martin Mueller (Germany)
Mahdi Najafpour (Iran)
Philipp Niethammer (USA)
Etsuo Niki (Japan)
Graham Noctor (UK)
Vesa Olkkonen (Finland)
Sten Orrenius (Sweden)
Sampath Parthasarathy (USA)
Riccardo Percudani (Italy)
Shazib Pervaiz (Singapore)
Alfonso Pompella (Italy)
Henrik E. Poulsen (Denmark)
Christopher Putnam (USA)
Gregory J. Quinlan (UK)
Rafael Radi (Uruguay)
Roxana Radu (USA)
Sue Goo Rhee (Korea)
David Ross (USA)

Ji-Hwan Ryu (Korea)
Sebastian Schaffer (Singapore)
Raymond Seet (Singapore)
Sason Shaik (Israel)
Shen Han Ming (Singapore)
David Shin (USA)
Helmut Sies (Germany)
Vladimir Skulachev (Russia)
Alan J. Slusarenko (Germany)
William L. Smith (USA)
Soong Tuck Wah (Singapore)
Ivan Spasojevic (Serbia)
Wilhelm Stahl (Germany)
Roland Stocker (Australia)
JoAnne Stubbe (USA)
Roger G. Sturmey (UK)
John Tainer (USA)
Paul Talalay (USA)
Mauro M. Teixeira (Brazil)
Vinay Tergaonkar (Singapore)
Paul J. Thornalley (UK)
Artak Tovmasyan (USA)
Shinya Toyokuni (Japan)
Maret G. Traber (USA)
Gabriel Travis (USA)
Albert van der Vliet (USA)
Markus Wenk (Singapore)
John Whitmarsh (USA)
Christine Winterbourn (New Zealand)
Paul Winyard (UK)
Khay Guan Yeoh (Singapore)
Juyoung Yoon (Korea)
Yongliang Zhang (Singapore)

Contents

Abbreviations

xxxii

1 Oxygen: boon yet bane—introducing oxygen toxicity and reactive species

1

1.1 The history of oxygen: an essential air pollutant
1.1.1 The paradox of photosynthesis
1.1.2 Hyperoxia in history?
1.1.3 Oxygen in solution
1.2 Oxygen and anaerobes
1.2.1 Why does oxygen injure anaerobes?
1.3 Oxygen and aerobes
1.3.1 Oxygen transport in mammals
1.3.2 Oxygen sensing
1.3.3 Mitochondrial electron transport
1.3.4 The evolution of mitochondria
1.3.5 Nicotinamide nucleotide reduction
1.3.6 Bacterial electron transport chains
1.4 Oxidases and oxygenases in aerobes
1.4.1 Cytochromes P450
1.5 Oxygen toxicity in aerobes
1.5.1 Bacteria, plants, insects, and alligators
1.5.2 Mammals
1.5.2.1 Retinopathy of prematurity and brain damage
1.5.2.2 Resuscitation of newborns
1.5.2.3 Factors affecting oxygen toxicity
1.6 What causes the toxic effects of oxygen?
1.7 So free radicals contribute to oxygen toxicity and oxygen is one of
them? What then are free radicals?
1.8 Oxygen and its radicals
1.8.1 Singlet oxygen
1.8.2 Superoxide radical
1.9 How to describe them: oxygen radicals, oxygen-derived species,
reactive oxygen species, or oxidants?
1.10 Sources of superoxide in aerobes
1.10.1 Enzymes
1.10.2 Auto-oxidation reactions
1.10.3 Haem proteins
1.10.4 Mitochondrial electron transport
1.10.4.1 Mitochondrial DNA (mtDNA)

1
4
4
5
7
7
8
8
8
9
13
14
14
14
15
16
16
18
19
19
19
20
20
22
22
23
23
23
24
24
25
25
26
ix

x

CONTENTS

1.10.5 Uncoupling proteins as antioxidants?
1.10.6 Endoplasmic reticulum (ER)
1.10.7 Nuclear and plasma membranes
1.10.8 Bacterial superoxide production and biofilms
1.11 Thinking about cell culture
1.12 Some numbers
2 Redox chemistry: the essentials
2.1 Introduction
2.2 How do free radicals react?
2.3 Radical chemistry: thermodynamics versus kinetics
2.3.1 Redox chemistry
2.3.1.1 Caveats
2.3.1.2 Thermodynamics of oxygen reduction
2.3.2 Reaction rates and rate constants
2.3.3 Measuring reaction rates and rate constants
2.3.3.1 Pulse radiolysis
2.3.3.2 Stopped-flow methods
2.4 Transition metals: biocatalytic free radicals
2.4.1 Iron
2.4.2 Copper
2.4.3 Manganese
2.4.4 The Fenton reaction
2.4.5 Iron chelators and Fenton chemistry: speed it up or slow it down?
2.4.6 Reaction of copper ions with H2 O2
2.5 Chemistry of other biologically important radicals
2.5.1 Hydroxyl radical
2.5.1.1 Generation
2.5.1.2 Chemistry
2.5.2 Carbonate radical
2.5.3 Superoxide radical
2.5.3.1 Making superoxide in the laboratory
2.5.3.2 Reactions of superoxide
2.5.3.3 Superoxide–iron interactions
2.5.3.4 Reductants and Fenton chemistry
2.5.3.5 Semiquinones and quinones
2.5.3.6 Superoxide in hydrophobic environments
2.5.4 Peroxyl and alkoxyl radicals
2.5.4.1 Chemistry
2.5.4.2 Generation of RO2 • /RO• radicals
2.5.5 Sulphur radicals
2.5.5.1 Formation
2.5.5.2 Reactions
2.5.5.3 Artefacts involving sulphur compounds
2.5.5.4 The perils of dithiothreitol, thiourea, and N-acetylcysteine
2.5.6 Nitric oxide
2.5.6.1 Basic chemistry
2.5.6.2 Nitric oxide as a free radical scavenger
2.5.6.3 Physiological roles

27
27
27
27
28
29
30
30
30
32
32
33
33
34
35
35
36
36
36
37
38
38
39
39
40
40
40
41
43
43
45
46
46
47
47
48
48
48
49
50
50
50
51
52
52
52
53
53

CONTENTS

2.5.6.4
2.5.6.5
2.5.6.6

Synthesis of nitric oxide
Removal of NO• in vivo
Nitrate and nitrite: inert end-products or
physiologically important sources of NO• ?
2.5.6.7 Nitric oxide donors
2.6 Chemistry of biologically important non-radicals
2.6.1 Peroxynitrite
2.6.1.1 How does peroxynitrite cause damage?
2.6.1.2 Toxicity of nitrotyrosine and nitrated proteins?
2.6.1.3 Nitric oxide, superoxide, peroxynitrite, and nitrated
lipids: a balance
2.6.1.4 Can peroxynitrite be antioxidant?
2.6.1.5 More things to beware of
2.6.2 Hydrogen peroxide
2.6.2.1 Production of H2 O2
2.6.2.2 Chemistry of H2 O2
2.6.3 Hypohalous acids and their derivatives
2.6.3.1 Chlorhydrins, chloramines, and hydroxyl radical
from HOCl
2.6.3.2 Atomic chlorine
2.6.4 Singlet oxygen
2.6.4.1 Singlet O2 from photosensitization
2.6.4.2 Type I and II reactions
2.6.4.3 Biological damage by photosensitization
2.6.4.4 Uses of photosensitization
2.6.4.5 Other sources of singlet O2
2.6.4.6 Reactions of singlet oxygen
2.6.5 Ozone, a radical or not?
3 Antioxidant defences synthesized in vivo
3.1
3.2
3.3
3.4

Introduction
What is an antioxidant?
Antioxidant defences: general principles
The simplest antioxidant defence: minimize exposure to oxygen
3.4.1 Protecting nitrogenases
3.4.2 Stem cells
3.5 Antioxidant defence enzymes: superoxide dismutases (SODs)
3.5.1 Copper–zinc SOD
3.5.1.1 CuZnSOD in eukaryotes and prokaryotes
3.5.1.2 Catalytic ability of CuZnSOD
3.5.1.3 CuZnSOD structure
3.5.1.4 Inhibitors of CuZnSOD
3.5.1.5 Isoenzymes of CuZnSOD
3.5.1.6 Pro-oxidant effects of CuZnSOD?
3.5.2 Manganese SOD
3.5.2.1 Where is MnSOD found?
3.5.2.2 Regulation of MnSOD activity
3.5.2.3 Structure of MnSOD
3.5.3 Iron and cambialistic SODs
3.5.3.1 Distribution of FeSODs

xi

53
55
55
56
58
58
61
62
62
63
63
63
63
64
65
66
67
67
67
67
67
69
71
71
75
77
77
77
78
78
79
79
79
79
79
80
81
81
82
84
85
85
85
85
86
87

xii

CONTENTS

3.5.4
3.5.5
3.5.6

3.6
3.7

3.8

3.9

3.10

3.11
3.12
3.13

3.14

3.15

3.16

Evolution of SODs
Nickel-containing SODs
Assaying SOD
3.5.6.1 Distinguishing between different types of SOD
3.5.7 Using SOD enzymes to implicate superoxide
Superoxide reductases
Superoxide dismutases: evidence for their role in vivo?
3.7.1 Gene knockout in bacteria and yeasts
3.7.2 Transgenic animals
3.7.2.1 Caveats about transgenic animals
3.7.3 RNA interference
3.7.4 Induction experiments
3.7.5 SOD and oxygen toxicity in animals
3.7.6 SOD and hibernation
The superoxide theory of oxygen toxicity: variations and anomalies
3.8.1 Anaerobes with SOD and aerobes without SOD
3.8.2 Manganese can replace SOD
Why is superoxide cytotoxic?
3.9.1 Direct damage by superoxide or HO2 • ?
3.9.2 Cytotoxicity of superoxide-derived species
3.9.2.1 Hydrogen peroxide and peroxynitrite
3.9.2.2 Hydroxyl radical
Glutathione in metabolism and cellular redox state
3.10.1 GSH as a direct antioxidant
3.10.2 Glutathione reductase
3.10.2.1 Sources of NADPH
3.10.3 Glutathione biosynthesis and degradation
3.10.4 Defects in GSH metabolism: humans and other organisms
Glutathionylation: pathological or protective?
Protein-disulphide isomerase
Peroxiredoxins: leaders in peroxide metabolism
3.13.1 Introducing thioredoxins, cofactors of peroxiredoxins
3.13.2 The peroxiredoxins themselves
3.13.2.1 Reaction with peroxynitrite
3.13.2.2 Hyperoxidation
3.13.2.3 Circadian rhythms
Antioxidant defence enzymes: the glutathione peroxidase family
3.14.1 A family of enzymes
3.14.2 The role of selenium
3.14.3 Watching GPx in action
3.14.4 Consequences of GPx deficiency
Other enzymes using glutathione
3.15.1 Glyoxalases
3.15.2 The glutathione S-transferase superfamily
3.15.2.1 Subclasses of GST
3.15.2.2 GSTs and lipid peroxidation
Other sulphur-containing compounds and antioxidant defence
3.16.1 Trypanothione: an antioxidant defence in some parasites
3.16.2 Ergothioneine

87
87
87
89
90
90
91
91
91
93
94
94
94
95
95
95
95
96
96
96
96
97
99
100
100
101
102
103
105
106
106
106
108
109
109
109
109
110
110
111
111
111
111
112
112
113
113
113
115

CONTENTS

3.17 Antioxidant defence enzymes: catalases
3.17.1 Catalase structure
3.17.2 The reaction mechanism of catalase
3.17.3 Catalase inhibitors
3.17.4 Peroxidatic activity of catalase
3.17.5 Subcellular location of catalase: the peroxisome
3.17.6 Manganese-containing catalases
3.17.7 Does catalase matter? Acatalasaemia
3.18 NADH oxidases
3.19 Antioxidant defence enzymes: an assortment of other peroxidases
3.19.1 Cytochrome c peroxidase: another specific peroxidase
3.19.2 ‘Non-specific’ peroxidases
3.19.3 Horseradish peroxidase
3.19.4 Why do plants have so much peroxidase?
3.19.5 Chloroperoxidase and bromoperoxidase
3.19.6 Ascorbate peroxidase
3.19.7 Peroxidase ‘mimetics’
3.20 Making sense of it all. What fits where in peroxide metabolism?
3.20.1 Peroxisomes and mitochondria
3.20.2 Erythrocytes, lung, and yeast
3.20.3 Allowing redox signalling?
3.20.4 Bacteria
3.20.5 Selenium deficiency: reinterpretation of an old paradigm
3.20.5.1 Human selenium deficiency
3.20.5.2 Selenium deficiency and antioxidant defences
3.21 Further co-operation
3.21.1 Superoxide dismutases and peroxide-metabolizing enzymes
3.21.2 Down syndrome
3.22 Antioxidant defence: sequestration of metal ions
3.22.1 Iron metabolism
3.22.1.1 Transferrin
3.22.1.2 Other iron-binding proteins
3.22.1.3 Iron within cells
3.22.1.4 Ferritin
3.22.1.5 Regulation of cellular iron balance
3.22.2 Copper metabolism
3.22.2.1 Caeruloplasmin and copper chaperones
3.22.2.2 A phantom copper pool?
3.22.2.3 Caeruloplasmin as an oxidase
3.22.2.4 Caeruloplasmin as a peroxidase
3.22.3 Haem and haem proteins: powerful pro-oxidants
3.22.4 Metal ion sequestration: why do it?
3.22.4.1 Keeping micro-organisms at bay
3.22.4.2 Diminishing free-radical reactions
3.22.5 Metal ion sequestration: when it goes wrong
3.22.5.1 Iron overload: diet-derived
3.22.5.2 Iron overload: genetic
3.22.5.3 Thalassaemias
3.22.5.4 Non-transferrin-bound iron: is it pro-oxidant?
3.22.5.5 Copper overload

xiii

115
115
116
117
117
118
118
119
119
119
119
120
120
121
121
122
122
122
122
122
123
123
123
123
124
124
124
125
125
126
127
127
128
128
130
131
131
131
131
132
132
133
133
133
134
134
134
135
136
136

xiv

CONTENTS

3.23 Metal ions and antioxidant defence: comparing intracellular and
extracellular strategies
3.23.1 The intracellular environment: metals and oxidative damage
3.23.2 Metallothioneins
3.23.3 Extracellular antioxidant defence
3.23.3.1 Low antioxidant defence enzymes and limited metal
ion availability
3.23.3.2 Extracellular superoxide dismutase
3.23.3.3 Other extracellular SODs
3.23.3.4 Binding haem and haemoglobin
3.23.3.5 Albumin
3.23.3.6 Artefacts with albumin
3.24 Haem oxygenase
3.25 Antioxidant protection by low-molecular-mass agents
synthesized in vivo
3.25.1 Bilirubin
3.25.2 α-Keto acids
3.25.3 Melatonin
3.25.4 Lipoic acid
3.25.5 Coenzyme Q
3.25.6 Uric acid
3.25.7 Histidine-containing dipeptides
3.25.8 Trehalose (α-D-glucopyranosyl-(1→1)-α-D-glucopyranoside)
3.25.9 Melanins: hair, skin, corals, fungi, and fish
3.26 Antioxidant defence: a question of sex
4 Antioxidants from the diet
4.1 Introduction
4.2 Ascorbic acid (vitamin C)
4.2.1 Ascorbate as an antioxidant
4.2.2 ‘Recycling’ of ascorbate
4.2.3 Pro-oxidant effects of ascorbate
4.2.4 Taking ascorbate supplements?
4.3 Vitamin E
4.3.1 Its physiological role
4.3.2 What is vitamin E?
4.3.3 Chemistry of vitamin E
4.3.4 Recycling of α-tocopheryl radicals
4.3.5 Pro-oxidant effects of α-tocopherol?
4.3.6 Processing of dietary vitamin E
4.3.7 The fate of γ -tocopherol
4.3.8 α-Tocopherol deficiency
4.3.9 Vitamin E: only an antioxidant, or something else as well?
4.4 Carotenoids
4.4.1 Carotenoid chemistry
4.4.2 Metabolic roles of carotenoids
4.4.3 Carotenoids and vitamin A as antioxidants?
4.4.3.1 Do carotenoids react with radicals?
4.4.3.2 Stability of carotenoids
4.4.3.3 The interesting case of lycopene

137
137
137
138
138
138
140
140
141
141
142
143
143
144
144
144
146
146
148
149
149
151
153
153
155
157
159
160
161
161
161
161
162
162
165
165
167
167
169
170
170
171
171
172
173
173

CONTENTS

4.5 Flavonoids and other phenols
4.5.1 Phenols in the diet
4.5.1.1 Do humans and other animals absorb phenols?
4.5.2 Are phenols antioxidants in vivo?
4.5.2.1 More than antioxidants
4.5.3 Pro-oxidant effects of phenols?
4.5.4 Herbal medicine
4.6 Dietary antioxidants: insights from epidemiology
4.6.1 Problems of interpretation
4.6.2 The gold standard of intervention trials: hope unfulfilled
4.6.3 The need for biomarkers
4.6.3.1 Do fruits and vegetables decrease the risk of disease by
lowering oxidative damage?
4.6.4 Cardiovascular intervention trials
4.6.5 Cancer prevention by antioxidants?
4.6.5.1 The Finnish study (α-tocopherol/β-carotene [ATBC]
cancer prevention study) and CARET
4.6.6 Some rays of hope and a gender bias
4.6.7 Lycopene, other carotenoids, and human disease
4.6.8 Antioxidants and neuroprotection; insights from epidemiology?
4.7 Other dietary constituents and oxidative damage
4.8 What does it all mean? What should we poor mortals eat?

xv

173
175
176
177
178
178
179
180
182
183
185
187
188
189
189
190
190
190
196
197

5 Oxidative stress and redox regulation: adaptation, damage, repair,
senescence, and death

199

5.1 Introduction
5.1.1 Defining oxidative stress and oxidative damage
5.2 Consequences of oxidative stress
5.2.1 Proliferation
5.2.2 Adaptation
5.2.3 Migration and adhesion
5.2.4 Cell injury and senescence
5.2.5 Poly(ADP–ribose)polymerase
5.3 Oxidative stress causes changes in cellular ion metabolism
5.3.1 Basic principles
5.3.1.1 Cell volume changes
5.3.2 Calcium
5.3.2.1 Keeping it low
5.3.2.2 Oxidative stress raises Ca2+ levels
5.3.2.3 Ca2+ and mitochondria
5.3.3 Oxidative stress and transition metal ion mobilization
5.3.3.1 Demonstrating iron mobilization
5.3.4 Copper
5.4 Consequences of oxidative stress: cell death
5.4.1 Basic definitions
5.4.2 Apoptosis
5.4.2.1 Molecular mechanisms of apoptosis
5.4.2.2 Reactive species and apoptosis
5.5 Redox regulation
5.5.1 What is it and how does it work?

199
199
200
200
201
202
202
203
204
204
204
204
204
206
207
208
208
209
212
212
215
215
218
219
219

xvi

CONTENTS

5.5.2

5.6
5.7

5.8

5.9

5.10

Bacterial redox regulation: oxyR, soxRS and HOCl-sensitive
transcription factors
5.5.3 Redox regulation in yeast
5.5.4 Redox regulation in animals: kinases and phosphatases
5.5.4.1 What is it about?
5.5.4.2 Protein kinases
5.5.4.3 How do RS modulate signalling?
5.5.4.4 Reactive species as mediators of the actions of
signalling molecules?
5.5.5 Mitochondrial communication by ROS?
5.5.6 NF-κB
5.5.6.1 ROS or no ROS?
5.5.7 AP-1
5.5.8 The antioxidant response element and Nrf2
5.5.9 Co-operation and combination
5.5.10 Physiological significance of redox regulation in animals
5.5.11 Lessons from an amoeba
Heat-shock and related ‘stress-induced’ proteins; cross-talk with ROS
Cytokines, hormones, and redox-regulation of the organism
5.7.1 TNF-α
5.7.2 Interleukins
5.7.3 Transforming growth factors β
5.7.4 The acute-phase response
Mechanisms of damage to cellular targets by oxidative stress: DNA
5.8.1 DNA structure
5.8.2 Damage to DNA by reactive species
5.8.2.1 Hydroxyl radical
5.8.2.2 Hydrogen peroxide and the role of transition metals
5.8.2.3 Use of iron and hydrogen peroxide for oxidative
‘footprinting’
5.8.2.4 Singlet oxygen
5.8.2.5 Carbonate radical anion
5.8.2.6 Peroxyl and alkoxyl radicals
5.8.2.7 Hypohalous acids
5.8.2.8 Ozone
5.8.2.9 Reactive nitrogen species
5.8.2.10 Ultraviolet light
5.8.2.11 Oxidation of oxidation products
5.8.3 Damage to mitochondrial and chloroplast DNA
Consequences of damage to DNA and RNA by reactive species
5.9.1 Mutation
5.9.2 Slowing protein synthesis
5.9.3 Misincorporation
5.9.4 Changes in gene expression
5.9.5 Having sex
Repair of oxidative DNA damage
5.10.1 Reversing the chemical change
5.10.2 Don’t let it in: sanitization of the nucleotide pool
5.10.3 Cut it out: excision repair
5.10.4 Mismatch repair
5.10.5 Repair of 8-hydroxyguanine (8OHG)

220
221
221
221
221
224
225
225
226
228
229
229
230
230
231
231
234
235
235
236
236
236
236
238
238
240
244
244
244
244
244
244
244
245
245
245
245
245
246
246
247
247
247
247
248
248
250
250

CONTENTS

xvii

Repair of double-strand breaks
Mitochondrial DNA repair
Is DNA repair important?
5.10.8.1 Bacteria to mice
5.10.8.2 Mice to men
5.10.9 Polymorphisms in genes encoding antioxidant and repair enzymes
5.10.10 Dealing with oxidative RNA damage
5.11 Mechanisms of damage to cellular targets by oxidative stress: lipid
peroxidation
5.11.1 A history of peroxidation: from oils and textiles to breast
implants, fish meal, and plastic wrapping
5.11.2 Targets of attack: membrane lipids and proteins
5.11.2.1 What’s in a membrane?
5.11.2.2 Membrane structure
5.11.3 Targets of attack: dietary lipids and lipoproteins
5.11.4 How does lipid peroxidation begin?
5.11.5 Propagation of lipid peroxidation
5.11.6 Transition metals and lipid peroxidation
5.11.6.1 Iron
5.11.6.2 Copper
5.11.6.3 Other metals
5.11.7 Microsomal lipid peroxidation
5.11.8 Acceleration of lipid peroxidation by species other than
oxygen radicals
5.11.8.1 Singlet oxygen
5.11.8.2 Reactive halogen species
5.11.8.3 Adding organic peroxides or azo initiators
5.12 Lipid peroxidation products: bad, good, or indifferent?
5.12.1 General effects
5.12.2 Lipid hydroperoxides (ROOH)
5.12.3 Isoprostanes, isoketals, and cyclopentenone compounds
5.12.4 Cholesterol oxidation products (COPs)
5.12.5 Decomposition products of lipid peroxides: yet more
bioactive products
5.12.5.1 Ethane and pentane
5.12.5.2 Malondialdehyde
5.12.5.3 4-Hydroxy-2-trans-nonenal (HNE), acrolein, and
other unsaturated aldehydes
5.12.6 Peroxidation of other molecules
5.12.7 Repairing oxidized lipids?
5.12.8 Lipids as antioxidants?
5.12.8.1 The plasmalogens
5.13 Mechanisms of damage to cellular targets by oxidative stress:
protein damage
5.13.1 Does protein damage matter?
5.13.2 How does protein damage occur?
5.13.3 Chemistry of protein damage
5.13.4 Damage to specific amino acid residues
5.13.4.1 Cysteine and methionine

250
250
251
251
251
252
252

5.10.6
5.10.7
5.10.8

252
252
253
253
253
256
256
257
259
259
263
263
264
264
264
265
265
265
265
266
267
268
269
269
270
270
274
274
274
274
275
275
275
276
276
276

xviii

CONTENTS

5.13.4.2 Histidine
5.13.4.3 Proline, lysine, and arginine
5.13.4.4 Tryptophan
5.13.4.5 Tyrosine and phenylalanine
5.13.4.6 Valine, leucine, and other aliphatic amino acids
5.13.4.7 Hydroxy-amino acids (serine and threonine)
5.14 Dealing with oxidative protein damage
5.14.1 Repair of methionine residues
5.14.1.1 A methionine cycle?
5.14.2 Removal: spatial segregation
5.14.3 Removal: proteolysis
5.14.3.1 Autophagy
5.14.3.2 Lon proteinase and the proteasome
5.14.3.3 Any role for ubiquitin?
5.14.3.4 Clogging up the proteasome
5.15 Summary: oxidative stress and cell injury
6 Measurement of reactive species
6.1 Introduction
6.1.1 Trapping
6.1.2 Fingerprinting: the biomarker concept
6.2 ESR and spin trapping
6.2.1 What is ESR?
6.2.2 Measurement of oxygen
6.2.3 Spin trapping
6.2.4 DMPO, DEPMO, and PBN
6.2.5 Ex vivo trapping in humans
6.2.6 Cautions in the use of spin traps
6.2.7 Trapping thiyl radicals
6.2.8 Spin trapping without ESR?
6.3 Other trapping methods, as exemplified by hydroxyl radical
trapping
6.3.1 Aromatic hydroxylation
6.3.1.1 Aromatic hydroxylation in vivo
6.3.2 Use of hydroxyl radical scavengers
6.3.3 The deoxyribose assay
6.3.4 Measurement of rate constants for OH• reactions
6.3.5 Other trapping methods for hydroxyl radical
6.4 Detection of superoxide
6.4.1 The aconitase assay for superoxide
6.4.2 Rate constants for reactions with O•–
2
6.4.3 Triphenyl radical-based probes
6.4.4 Histochemical detection
6.5 Detection of nitric oxide
6.5.1 Calibration
6.6 Detection of peroxynitrite
6.6.1 Probes for peroxynitrite
6.6.2 Nitration assays
6.6.2.1 Specificity for peroxynitrite?
6.6.2.2 Accuracy of nitration assays?

277
277
277
277
277
277
280
280
280
280
280
280
281
282
282
283
284
284
284
284
285
285
287
287
289
290
291
292
293
293
293
294
296
296
296
299
299
300
300
300
300
302
302
302
302
302
306
306

CONTENTS

6.7 Detection of reactive halogen species
6.8 Detection of singlet oxygen
6.8.1
Direct detection
6.8.2
Use of scavengers and traps
6.8.3
Deuterium oxide (D2 O)
6.9 Studies of ‘generalized’ light emission (luminescence/fluorescence)
6.10 Changes in gene expression: ROS biosensors?
6.11 Detection of hydrogen peroxide
6.11.1 Fluorescent ‘probes’ for H2 O2
6.12 Other methods to measure reactive species in cultured cells: be wary
of DCFHDA!
6.12.1 2’,7’-Dichlorodihydrofluorescein diacetate
6.12.2 Dihydrorhodamine 123 (DHR)
6.12.3 Dihydroethidium
6.12.4 Luminol, lucigenin, and L-012
6.12.5 Alternative luminescent probes for superoxide
6.12.6 Effects of reactive species on other probes
6.13 Biomarkers: oxidation of bilirubin and of urate
6.14 Biomarkers: oxidative DNA damage
6.14.1 DNA damage: why measure it?
6.14.2 Characterizing DNA damage: what to measure?
6.14.3 Characterizing DNA damage: how to measure it
6.14.4 Steady-state damage: the artefact problem
6.14.5 Overcoming the artefact
6.14.5.1 The comet assay
6.14.6 Interpreting the results: measure DNA levels or urinary
excretion? What do the levels mean?
6.14.7 Reactive nitrogen and chlorine species
6.14.8 Gene-specific oxidative damage
6.14.9 RNA oxidation
6.14.10 DNA–aldehyde adducts
6.15 Biomarkers of lipid peroxidation
6.15.1 Why measure lipid peroxidation?
6.15.2 Measurement of peroxidation and peroxidizability
6.15.3 Loss of substrates
6.15.4 Measurement of intermediates
6.15.4.1 Radicals
6.15.4.2 Diene conjugates
6.15.5 Measurement of end-products: peroxides
6.15.6 Measurement of end-products: isoprostanes (IsoPs),
isofurans (IsoFs), and isoketals (IsoKs)
6.15.7 Measurement of end products: aldehydes
6.15.8 The thiobarbituric acid (TBA) assay
6.15.8.1 Problem 1: most TBARS (TBA-reactive substances)
are generated during the assay
6.15.8.2 Problem 2: false chromogens
6.15.8.3 Problem 3: real chromogens but not from lipids
6.15.8.4 Urinary TBARS
6.15.8.5 Should the TBA assay be abandoned?

xix

307
307
307
307
309
309
309
310
310
316
316
320
320
321
321
321
321
322
322
322
323
325
325
326
326
328
328
328
328
329
329
329
329
330
330
330
331
331
335
337
337
338
338
338
338

xx

CONTENTS

6.15.9 Measurement of end-products: breath analysis
6.15.10 Measuring lipid peroxidation: light emission
6.15.11 What is the best method to measure lipid peroxidation in
tissues, cells, and body fluids?
6.15.12 Visualizing lipid peroxidation
6.16 Biomarkers of protein damage by reactive species
6.16.1 Damage by reactive oxygen species
6.16.2 Damage by reactive halogen and nitrogen species
6.16.3 The carbonyl assay
6.16.4 Glutathione oxidation and synthesis
6.16.5 γ -Glutamyltranspeptidase
6.16.6 The ‘thiol-ome’
6.16.7 Advanced oxidation products and modified albumin
6.17 ‘Indirect’ approaches
6.17.1 Erythrocyte and plasma enzymes
6.17.2 Vascular reactivity
6.17.3 Assays of total (‘non-enzymic’) antioxidant capacity
6.17.3.1 What do changes in total antioxidant capacity mean?
6.18 Is there a single biomarker of oxidative stress or oxidative damage?

339
339
340
341
343
343
344
346
347
348
348
348
348
348
349
349
352
353

7 Reactive species can pose special problems needing special solutions:
some examples

354

7.1 Introduction
7.2 The gastrointestinal tract
7.2.1
The threats it faces
7.2.2
Defence systems
7.2.2.1 Saliva
7.2.2.2 Antioxidants from diet?
7.3 The respiratory tract
7.3.1
The challenges
7.3.2
Defending the respiratory tract
7.3.3
Asthma and antioxidants
7.4 Erythrocytes
7.4.1
What problems do erythrocytes face?
7.4.2
Solutions: antioxidant defence enzymes
7.4.3
Solutions: diet-derived antioxidants
7.4.4
Erythrocyte peroxidation in health and disease
7.4.4.1 Problems in blood transfusion
7.4.5
Glucose-6-phosphate dehydrogenase (G6PDH) deficiency
7.4.6
Solutions: destruction
7.5 Erythrocytes as targets for toxins
7.5.1
Hydrazines
7.5.2
Sulphur-containing haemolytic drugs
7.5.3
Favism
7.5.4
Erythrocyte apoptosis
7.6 Bloodthirsty parasites: problems for them and for us
7.6.1
Malaria, oxidative stress, and an ancient Chinese herb
7.7 The problems of plants

354
354
354
355
355
356
357
357
358
359
360
360
360
361
362
362
363
363
363
363
366
366
366
367
367
369

CONTENTS

7.8 The key to life: photosynthetic oxygen production
7.8.1 Trapping of light energy
7.8.2 The water splitting mechanism: a radical process and the
reason for this book
7.8.3 What problems do green leaves face?
7.8.4 Solutions: minimizing the problem
7.8.5 The xanthophyll cycle
7.8.6 Solutions: antioxidant defence enzymes control, but do not
eliminate, reactive species
7.8.6.1 Superoxide dismutases
7.8.6.2 Removal of hydrogen peroxide
7.8.6.3 Redox signalling in plants
7.8.7 Ascorbate and glutathione
7.8.8 Plant tocopherols
7.8.9 Solutions: sequestering transition metal ions
7.8.10 Solutions: repair and replacement
7.8.11 The special case of the root nodule
7.9 Plants as targets for stress and toxins
7.9.1 Inhibition of electron transport and carotenoid synthesis
7.9.2 Bipyridyl herbicides
7.9.2.1 Redox cycling
7.9.2.2 Evidence that ROS are important in paraquat toxicity
7.9.3 Environmental stress: air pollutants (ozone, sulphur dioxide,
nitrogen dioxide)
7.9.4 Environmental stress: heat, cold, and drought
7.9.5 Coral reef bleaching and toxic algal blooms: examples of
plant-dependent oxidative stress?
7.10 The eye
7.10.1 What problems does the eye face?
7.10.1.1 Macular degeneration, lipofuscin, and singlet oxygen
7.10.2 Protecting the eye
7.10.2.1 Screening, prevention, and crying
7.10.2.2 Antioxidants in the eye
7.10.2.3 Sequestration of metal ions
7.10.2.4 Repair of damage
7.10.3 Toxins, inflammation and the eye
7.10.4 Ocular carotenoids: a Chinese herb good for the eyes?
7.10.5 Antioxidants, cataract and macular degeneration
7.11 Reproduction and oxidative stress
7.11.1 Pre-conception: spermatozoa face problems
7.11.2 Spermatozoa: the solutions
7.11.3 Spermatozoa as targets for toxins
7.11.4 The female story
7.11.5 Problems of the embryo
7.11.6 Problems of pregnancy: normal and abnormal O2 levels
7.11.6.1 Endometriosis
7.11.7 The embryo/foetus as a target for toxins
7.11.8 Birth
7.11.8.1 A cold hyperoxic shock

xxi

369
370
374
374
377
378
379
379
379
380
380
381
381
382
382
382
382
383
383
384
384
385
386
386
387
388
390
390
391
392
392
393
393
393
394
394
395
395
395
396
397
398
398
399
399

xxii

CONTENTS

7.11.8.2 Prematurity
7.11.8.3 Antioxidants and babies
7.11.8.4 Iron metabolism in the newborn
7.11.8.5 Parenteral nutrition
7.11.8.6 Antioxidants, PUFAs and iron
7.12 The ear
7.13 The skin
7.13.1 What problems does the skin face?
7.13.1.1 Photosensitization
7.13.1.2 Ultraviolet light
7.13.1.3 Inflammation
7.13.1.4 Air pollutants
7.13.2 Protecting the skin
7.13.3 Wounds and burns
7.14 Skeletal muscle: is exercise a cause of or a protection against
oxidative stress?
7.14.1 Exercise, lack of exercise and oxidative damage
7.14.1.1 Antioxidant supplements and exercise
7.14.2 Exercise, health and free radicals
8 Reactive species can be useful: some more examples
8.1 Introduction
8.2 Radical enzymes: ribonucleotide reductase and its colleagues
8.2.1 The enzyme mechanism
8.2.2 Inhibitors of RNRs
8.2.3 Class III ribonucleotide reductases and other ‘sons of SAM’ enzymes
8.2.4 Class II ribonucleotide reductases and other cobalamin
radical enzymes
8.3 Pyruvate–formate lyase: a similar mechanism
8.3.1 Pyruvate–ferredoxin oxidoreductase
8.4 Assorted oxidases
8.4.1 Galactose oxidase
8.4.2 Indoleamine and tryptophan dioxygenases
8.5 Useful peroxidases
8.5.1 An ‘antimolestation’ spray
8.5.2 Sea urchins and brine shrimp
8.5.3 Making and degrading lignin
8.5.3.1 Making lignin
8.5.3.2 Breaking lignin down
8.5.3.3 A role for hydroxyl radical?
8.6 Light production
8.6.1 Green fluorescent protein: another example of autocatalytic oxidation
8.7 Phagocytosis
8.7.1 Setting the scene
8.7.2 Neutrophils, monocytes, and macrophages
8.7.3 Phagocyte recruitment, adhesion, activation, and disappearance
8.7.3.1 Getting to the right place
8.7.3.2 What must neutrophils do?

399
400
400
401
401
401
402
402
403
404
405
406
406
407
408
408
409
410
411
411
411
411
412
413
413
413
413
414
414
415
415
415
415
417
417
419
420
420
420
421
421
421
427
427
430

CONTENTS

8.8
8.9

8.10

8.11

8.12

8.7.4 How do phagocytes kill?
8.7.4.1 Phagocytes show a respiratory burst
8.7.4.2 Priming of the respiratory burst
8.7.4.3 The respiratory burst makes superoxide
8.7.4.4 Superoxide is required to kill some bacteria
8.7.4.5 So how does superoxide kill? Via H2 O2 ?
8.7.4.6 Via hydroxyl radical?
8.7.4.7 Via singlet O2 ?
8.7.4.8 Via peroxynitrite?
8.7.4.9 By facilitating the action of other microbicidal agents?
8.7.4.10 Interference with quorum sensing
8.7.4.11 By NETs formation
8.7.4.12 Fitting it together
8.7.5 Myeloperoxidase (MPO)
8.7.5.1 Hypochlorous acid production
8.7.5.2 The MPO reaction mechanism
8.7.5.3 Singlet O2 from MPO?
8.7.5.4 The enigma of MPO
8.7.5.5 Nitration by MPO
8.7.5.6 Peroxidasins
8.7.5.7 Other defensive peroxidases
8.7.5.8 Fitting it together (part 2)
Other phagocytes: similar but different
What do phagocyte-derived reactive species (RS) do to the host?
8.9.1 Extracellular RS: what can they do?
8.9.2 Signalling
8.9.3 Damage to the phagocyte
8.9.4 RS: promoters or suppressors of chronic inflammation?
8.9.5 What does it all mean? Are RS both pro- and anti-inflammatory?
8.9.6 Defeating the defences: bacterial and fungal avoidance strategies
NADPH oxidases in other cell types
8.10.1 The gastrointestinal and respiratory tracts
8.10.2 Thyroid hormone synthesis
8.10.2.1 Iodide as an antioxidant
8.10.3 C. elegans
8.10.4 Blood vessel walls and the regulation of blood pressure
8.10.5 Lymphocytes
8.10.6 Renal function and oxygen sensing
8.10.7 Platelets
8.10.8 Bone formation and degradation
8.10.9 Other redox systems
Plants use reactive species for defence and regulation
8.11.1 Plant NOXes
8.11.2 The hypersensitive response
8.11.3 Plant lipoxygenases
8.11.4 The injury response and oxylipin signalling
8.11.5 Germination and senescence
Animal lipoxygenases and cyclooxygenases: stereospecific lipid
peroxidation
8.12.1 Oxidation of PUFAs by enzymes

xxiii

431
431
432
432
433
434
435
435
435
435
436
436
436
436
436
438
438
439
439
439
440
440
440
441
441
442
442
443
444
444
445
447
447
448
448
448
449
449
450
451
451
451
451
452
453
455
455
456
456

xxiv

CONTENTS

8.12.2
8.12.3
8.12.4
8.12.5
8.12.6
8.12.7
8.12.8
8.12.9

Eicosanoids: prostaglandins and leukotrienes
Prostaglandins and thromboxanes
Prostaglandin synthesis
Regulation by ‘peroxide tone’
Prostaglandins from isoprostanes? Cross-talk of the systems
Levuglandins
Prostacyclins and thromboxanes
Leukotrienes and other lipoxygenase products

9 Reactive species can be poisonous: their role in toxicology
9.1 Introduction
9.1.1 What is toxicology?
9.1.2 Principles of toxin metabolism
9.1.3 How can reactive species contribute to toxicity?
9.2 Carbon tetrachloride
9.2.1 Carbon tetrachloride synthesis: a free-radical chain reaction
9.2.2 Toxicity of CCl4
9.2.3 How does CCl4 cause damage?
9.3 Other halogenated hydrocarbons
9.3.1 Chloroform and bromotrichloromethane
9.3.2 Pentachlorophenol and related environmental pollutants
9.4 Redox-cycling toxins: bipyridyl herbicides
9.4.1 Toxicity to bacteria
9.4.2 Toxicity to animals
9.4.3 Why is paraquat toxic to the lung?
9.5 Redox-cycling toxins: diphenols, quinones, and related molecules
9.5.1 Interaction with O2 and superoxide
9.5.2 Interaction with metals
9.5.3 Mechanisms of toxicity
9.5.4 Quinone reductase
9.5.5 Catechol oestrogens
9.5.6 Substituted dihydroxyphenylalanines and ‘manganese madness’
9.5.7 Neurotoxicity of 6-hydroxydopamine
9.5.8 Benzene and its derivatives
9.5.9 Toxic-oil syndrome and a new Society
9.6 Redox-cycling agents: toxins derived from Pseudomonas aeruginosa
9.7 Diabetogenic drugs
9.7.1 Alloxan
9.7.2 Streptozotocin
9.8 Alcohols
9.8.1 Ethanol
9.8.1.1 Ethanol metabolism and CYP2E1
9.8.1.2 Ethanol toxicity
9.8.1.3 Does ethanol increase RS formation?
9.8.1.4 How does ethanol cause oxidative stress?
9.8.1.5 Does oxidative damage explain ethanol toxicity?
9.8.1.6 Other liver diseases
9.8.1.7 Therapeutic options?
9.8.2 Allyl alcohol and acrolein
9.9 Other recreational drugs

456
456
458
458
460
460
460
462
463
463
463
463
464
465
465
466
467
468
469
469
470
470
470
470
471
471
471
473
474
475
475
475
476
476
477
477
477
478
479
479
480
481
482
482
482
483
483
483
484

CONTENTS

9.10 Paracetamol (acetaminophen) and naphthalene, glutathionedepleting toxins
9.11 Chlorine gas
9.12 Air pollutants
9.12.1 Ozone
9.12.2 Nitrogen dioxide
9.12.2.1 Nitrogen dioxide as a free radical
9.12.2.2 Antioxidants and nitrogen dioxide
9.12.3 Sulphur dioxide
9.13 Toxicity of mixtures: ‘real’ air pollution, cigarette smoke, and other
toxic smokes
9.13.1 Chemistry of tobacco smoke
9.13.2 Mechanisms of damage by cigarette smoke
9.13.3 How does the respiratory tract defend itself?
9.13.4 Adaptation
9.13.5 Environmental tobacco smoke (ETS)
9.13.6 Other tobacco usage
9.13.7 Other smokes, fumes, and dusts
9.14 Diesel exhaust and airborne particulates
9.14.1 Nanoparticles
9.15 Toxicity of asbestos and silica
9.16 Toxicity of metals
9.16.1 Cause or consequence?
9.16.2 Arsenic
9.16.3 Nickel
9.16.4 Chromium
9.16.5 Cobalt
9.16.6 Cadmium
9.16.7 Mercury
9.16.8 Lead
9.16.9 Vanadium
9.16.10 Titanium
9.16.11 Aluminium
9.16.12 Zinc
9.17 Antibiotics
9.17.1 Tetracyclines as pro- and antioxidants
9.17.2 Quinone antibiotics
9.17.3 Aminoglycoside nephrotoxicity
9.18 Stress
9.19 Nitro and azo compounds
9.19.1 Nitro radicals and redox cycling
9.19.2 Further reduction of nitro radicals
9.19.3 Azo compounds
9.20 Ionizing radiation
9.20.1 The oxygen effect
9.20.1.1 A role for superoxide?
9.20.2 Antioxidants and radiotherapy
9.20.3 Hypoxic cell sensitizers
9.20.4 Food irradiation
9.21 Summary and conclusion

xxv

484
487
487
487
488
488
489
489
490
491
492
493
494
494
494
495
495
496
496
497
497
497
498
498
499
499
499
500
500
500
501
501
502
502
502
503
503
505
505
505
505
507
507
508
509
509
509
510

xxvi

CONTENTS

10 Reactive species in disease: friends or foes?
10.1 Setting the scene
10.2 Does oxidative stress matter?
10.2.1 Establishing importance
10.3 Atherosclerosis
10.3.1 What is atherosclerosis?
10.3.2 Predictors of atherosclerosis
10.3.3 What initiates atherosclerosis?
10.3.4 LDL oxidation and the foam cell
10.3.5 Mechanisms of LDL oxidation
10.3.5.1 Reactive nitrogen and chlorine species
10.3.5.2 Metal ions
10.3.5.3 Lipoxygenases
10.3.5.4 Summing it up: which pro-oxidant(s) oxidize
LDL in vivo?
10.3.6 Other aspects of the involvement of RS in atherosclerosis
10.3.7 Does evidence support the ‘oxidative modification
hypothesis’ of atherosclerosis?
10.3.8 Chemistry of LDL oxidation: is in vitro LDL oxidation a
relevant model?
10.3.8.1 The role of ‘seeding peroxides’
10.3.8.2 Antioxidants and LDL oxidation
10.3.8.3 Pro-oxidant effects of antioxidants
10.3.8.4 Relevance of the model
10.3.8.5 An artefact of eating?
10.3.8.6 Subclasses of LDL
10.3.9 The role of high-density lipoproteins (HDL)
10.3.10 Lipoprotein(a)
10.3.11 Unanswered questions
10.4 Obesity and its opposite
10.5 Diabetes
10.5.1 Can oxidative stress cause diabetes?
10.5.2 ROS in normal insulin function and insulin resistance
10.5.3 Oxidative stress in diabetic patients
10.5.4 How does the oxidative stress originate?
10.5.5 Non-enzymatic glycation and glycoxidation
10.5.5.1 Reversing AGEing?
10.5.6 Other mechanisms of glucose toxicity
10.5.7 A summary: how important is oxidative stress in diabetes?
10.5.7.1 Do antioxidant supplements help diabetic patients?
10.6 Ischaemia–reperfusion
10.6.1 Reoxygenation injury
10.6.2 A role for xanthine oxidase?
10.6.3 Intestinal ischaemia–reoxygenation
10.6.4 Cardiac ischaemia–reoxygenation
10.6.4.1 The phenomenon
10.6.4.2 Importance of the model used
10.6.4.3 The relevance of xanthine oxidase
10.6.4.4 The relevance of transition metals

511
511
511
514
516
516
517
517
519
520
521
521
522
523
523
523
525
526
526
528
529
529
530
530
531
531
531
532
533
533
534
535
535
538
538
539
539
539
540
541
541
542
542
543
544
544

10.7

10.8
10.9
10.10

10.11

10.12

10.13

10.14

CONTENTS

xxvii

10.6.4.5 Nitric oxide: good or bad?
10.6.4.6 Heart failure
10.6.4.7 Clinical relevance
10.6.4.8 Cardiopulmonary bypass
10.6.5 Angioplasty, restenosis, and bypass grafting
10.6.6 Ischaemic preconditioning
10.6.7 Shock- and sepsis-related ischaemia–reoxygenation
10.6.7.1 Aneurysm
10.6.8 The eye
10.6.9 Chemical ischaemia–reperfusion: carbon monoxide poisoning
10.6.10 Cold and freezing injury: the enigma of biopsies
10.6.11 Sleep apnoea
Organ preservation, transplantation, and reattachment of severed tissues
10.7.1 Heart
10.7.2 Kidney
10.7.3 Liver and pancreas
10.7.4 Limbs, digits, and sex organs
10.7.5 Organ preservation fluids
10.7.6 Other examples
Lung transplants, shock, and ARDS
10.8.1 Oxidative stress in ARDS: does it occur and does it matter?
Cystic fibrosis
10.9.1 Cystic fibrosis and carotenoids
Some autoimmune diseases
10.10.1 Adverse drug reactions
10.10.2 Are RS important mediators of autoimmune diseases?
10.10.2.1 Artefacts to watch for: contamination of
commercial antioxidants and oxidation on sample
storage
10.10.2.2 Periodontal disease: a missed opportunity?
Rheumatoid arthritis
10.11.1 The normal joint
10.11.2 The RA joint
10.11.3 How does increased oxidative damage arise in RA?
10.11.4 Does oxidative damage matter in RA?
10.11.5 Drugs to treat RA: antioxidant, pro-oxidant, or neither?
10.11.6 Iron and rheumatoid arthritis
Inflammatory bowel disease
10.12.1 The salazines
10.12.2 Coeliac disease
Inflammation of other parts of the gastrointestinal tract
10.13.1 Pancreas
10.13.2 Oesophagus and stomach
10.13.3 Liver
Oxidative stress and cancer: a complex relationship
10.14.1 The cell cycle
10.14.2 Tumours
10.14.3 Carcinogenesis
10.14.3.1 Initiation
10.14.3.2 Tumour promoters
10.14.3.3 Progression

545
545
545
546
546
546
547
548
548
549
549
549
550
550
550
551
551
552
552
553
554
554
555
556
557
557

557
558
558
558
558
560
561
562
565
565
566
566
567
567
567
567
568
568
569
570
570
571
572

xxviii

CONTENTS

10.14.4

Genes and cancer
10.14.4.1 Oncogenes
10.14.4.2 Tumour suppressor genes
10.14.4.3 Stability genes
10.14.4.4 Angiogenesis and cancer
10.14.5 Reactive species and carcinogenesis: basic concepts
10.14.6 p53 and ROS
10.14.7 Changes in antioxidant defences in cancer
10.14.8 ROS and cancer
10.14.8.1 DNA damage by RS
10.14.8.2 Is there increased oxidative DNA damage in cancer?
10.14.8.3 A role for reactive nitrogen and chlorine species
10.14.8.4 Epigenetics, cell proliferation, and HIF-1α
10.14.8.5 Intercellular communication
10.14.8.6 Suppressing apoptosis
10.14.8.7 Metastasis and angiogenesis
10.14.8.8 Affecting stem cells
10.14.9 Cancer and cachexia
10.14.10 Are malignant cells truly under oxidative stress?
10.14.11 Chronic inflammation and cancer: a close link but is it
due to reactive species?
10.14.12 Transition metals and cancer
10.15 Carcinogens: oxygen and others
10.15.1 Carcinogen metabolism
10.15.1.1 Carcinogens can make RS
10.15.2 Carcinogens and oxidative DNA damage
10.15.2.1 Peroxisome proliferators
10.15.3 Carcinogenic reactive nitrogen species?
10.16 Cancer chemotherapy and reactive oxygen species
10.16.1 Oxidative stress and chemotherapy
10.16.2 The anthracyclines and other quinones
10.16.2.1 Mechanisms of cardiotoxicity: redox cycling
and others
10.16.2.2 Iron and anthracyclines
10.16.3 Bleomycin
10.16.3.1 Side-effects of bleomycin
10.16.4 Should cancer patients consume antioxidants?
10.17 Oxidative stress and disorders of the nervous system: setting the scene
10.17.1 Introduction to the brain
10.17.2 Energy metabolism in the brain
10.17.3 Glutamate, calcium, and nitric oxide
10.17.4 Excitotoxicity
10.17.5 Why should the brain be prone to oxidative stress? ROS
are both useful and deleterious
10.17.6 Antioxidant defences in the brain
10.17.6.1 Keeping oxygen low
10.17.6.2 Superoxide dismutases and peroxide-removing
enzymes
10.17.6.3 Glutathione and ergothioneine
10.17.6.4 Protecting brain mitochondria
10.17.6.5 Ascorbate

572
572
573
574
574
574
575
576
577
577
577
579
579
581
581
581
581
582
582
582
583
584
584
584
587
587
588
588
590
591
592
592
593
594
595
595
595
598
599
599
600
603
603
603
603
604
604

CONTENTS

10.18

10.19

10.20

10.21

10.22

10.23

10.24
10.25

10.17.6.6 Vitamin E
10.17.6.7 Coenzyme Q
10.17.6.8 Histidine-containing dipeptides
10.17.6.9 Plasmalogens
10.17.6.10 Carotenoids and flavonoids
10.17.6.11 Metal-binding and related protective proteins
10.17.6.12 Repair of oxidative damage
10.17.6.13 Defence of the blood–brain barrier
Oxidative stress in ischaemia, inflammation, and trauma in the
nervous system
10.18.1 Inflammation: a common feature
10.18.2 Multiple sclerosis
10.18.3 Brain injury: stroke
10.18.3.1 Mediators of damage
10.18.3.2 Therapeutic interventions?
10.18.4 Traumatic injury
Oxidative stress and neurodegenerative diseases: some general concepts
10.19.1 The role of iron
10.19.2 Are aggregates toxic?
Parkinson disease
10.20.1 Genetics or environment?
10.20.2 Treatment
10.20.3 Environmental toxins and PD
10.20.4 The vicious cycle: proteasomal dysfunction, oxidative
stress, and mitochondrial defects in PD
10.20.4.1 Early or late?
10.20.5 Summing it up; insights from PINK1 and DJ-1
Alzheimer disease
10.21.1 Definition and pathology
10.21.2 Genetics of AD
10.21.3 Mechanisms of neurodegeneration
10.21.4 Oxidative damage in AD: cause or consequence?
10.21.5 Impairment of proteolysis
10.21.6 An old red herring: aluminium in AD
10.21.7 Diet, lifestyle, and AD
10.21.8 Other amyloid diseases
10.21.9 Prion diseases
Amyotrophic lateral sclerosis (ALS)
10.22.1 Familial ALS (FALS) and superoxide dismutase
10.22.2 Oxidative damage and excitotoxicity in ALS
10.22.2.1 Therapies
Other diseases of the brain and nervous system
10.23.1 Friedreich ataxia
10.23.2 Huntington disease
10.23.3 Neuronal ceroid lipofuscinoses
Pain
Oxidative stress and viral infections
10.25.1 Reactive species, antioxidants, and HIV
10.25.1.1 Changes in glutathione?
10.25.2 Redox regulation of viral expression
10.25.3 Side-effects of therapy

xxix

604
605
605
605
605
605
606
606
606
606
607
607
608
610
611
611
614
615
615
616
616
617
620
621
621
622
622
624
625
627
628
628
628
629
629
630
631
632
632
633
633
633
635
635
636
637
637
638
638

xxx

CONTENTS

11 Ageing, nutrition, disease, and therapy: a role for antioxidants?
11.1 Introduction
11.2 Theories of ageing; the basics
11.2.1 General principles
11.2.2 What features of ageing must theories explain?
11.2.2.1 Caloric restriction (CR)
11.2.2.2 Obesity, oxidative stress, and CR
11.3 What theories of ageing exist?
11.3.1 Do genes influence ageing? The story of C. elegans
11.3.1.1 What about mammals?
11.3.2 Genes and human longevity
11.3.3 Premature human ageing
11.3.4 Mechanisms of caloric restriction; learning from yeast
11.3.5 Telomeres and cellular senescence
11.3.5.1 An artefact of cell culture?
11.4 Oxidative damage: a link between the theories of ageing?
11.4.1 Introduction to the free-radical theory of ageing
11.4.2 Do ROS production and oxidative damage increase with age?
11.4.2.1 Be cautious with global biomarkers
11.4.3 Is the rise in oxidative damage due to failure of antioxidant
protection with age?
11.4.4 Is there a failure to repair oxidative damage with age?
11.4.5 Testing the free-radical theory of ageing: altering
antioxidant levels
11.4.5.1 Transgenic organisms: a confusing picture
11.4.6 ‘Rapidly ageing’ rodents
11.4.7 Lipofuscin and ceroid; fluorescent ‘red herrings’?
11.4.8 Is the oxidative damage theory of ageing ageing badly?
11.4.9 How to live a long time
11.4.10 Iron, ageing, and disease: another gender gap
11.5 Antioxidants to treat disease
11.5.1 Therapeutic antioxidants
11.5.2 Approaches to antioxidant characterization
11.5.3 Superoxide dismutases, catalases, and nanoparticles
11.5.3.1 Viral vectors
11.5.4 SOD mimetics and related redox-active molecules
11.5.5 Spin traps/nitroxides
11.5.6 Vitamins C and E, carnosine, and their derivatives
11.5.7 Coenzyme Q and synthetic chain-breaking antioxidants
11.5.8 Dual action molecules and edaravone
11.5.9 Thiol compounds
11.5.9.1 Glutathione
11.5.9.2 N-Acetylcysteine
11.5.9.3 Other thiols
11.5.9.4 Thiols as radioprotectors
11.5.10 Glutathione peroxidase ‘mimetics’
11.5.11 ‘Pro-oxidants’ and Nrf2 activators
11.5.12 Mitochondrially targeted antioxidants

639
639
639
639
640
640
640
641
641
642
645
645
646
647
648
649
649
653
654
654
655
655
656
658
658
659
659
660
660
661
663
663
665
666
669
672
673
680
680
681
681
682
682
683
683
684

CONTENTS

11.6 Iron and copper ion chelators
11.6.1 Desferrioxamine
11.6.2 Other iron-chelating agents
11.7 Inhibitors of the generation of reactive species
11.7.1 Xanthine oxidase (XO) inhibitors
11.7.2 Myeloperoxidase inhibitors
11.7.3 Inhibitors of phagocyte action
11.7.4 NADPH oxidase inhibitors
11.8 Agents to watch
Appendix: Some basic chemistry
A1 Atomic structure
A2 Bonding between atoms
A2.1 Ionic bonding
A2.2 Covalent bonding
A2.3 Non-ideal character of bonds
A2.4 Hydrocarbons and electron delocalization
A3 Moles and molarity
A4 pH and pKa
References
Index

xxxi

686
686
692
693
693
694
694
694
695
697
697
702
702
702
703
704
705
705
707
823

Abbreviations

Where the same abbreviation is used for more than one item, the one listed first is that most commonly used in this book.
AA
A2E
A2PE-H2
AAPH
Aβ
ABAD
ABTS
ACE
AD
AdhE
ADMA
AEOL
AGE
AHPR
AHR
AHSP
AIDS
AIPH
ALA
ALS
AMD
AMPA
AMPK
AMVN
AOC
AOPP
AOS
AP
α 1 -AP
AP-1
APAF-1
APE1

xxxii

Arachidonic acid
N-retinylidene-N-retinylethanolamine
Dihydro-N-retinylidene-N-retinylphosphatidylethanolamine
2,2 -Azobis(2-amidinopropane)
dihydrochloride
Beta-amyloid peptides
Amyloid β-binding alcohol
dehydrogenase
2,2 -Azinobis
(3-ethylbenzothiazoline-6-sulphonic acid)
Angiotensin converting enzyme
Alzheimer disease
Alcohol dehydrogenase E (E. coli)
N G ,NG dimethyl-L-arginine
Aeolus (pharmaceuticals)
Advanced glycation end-product
Alkyl hydroperoxide reductase
Aryl hydrocarbon receptor
α-Haemoglobin stabilizing protein
Acquired immunodeficiency syndrome
2,2 -Azobis[2-(2-imidazolin-2-yl) propane]
dihydrochloride
5-Aminolaevulinic acid
Amyotrophic lateral sclerosis
Age-related macular degeneration
α-Amino-3-hydroxy-5-methyl-4-isoxazole
propionate
AMP-activated protein kinase
2,2 -Azobis(2,4-dimethylvaleronitrile)
Allene oxide cyclase
Advanced oxidation protein products
Allene oxide synthase
Apurinic/apyrimidinic (site) or alternative
pathway
α 1 -Antiproteinase
Activator protein 1
Apoptotic proteinase activating factor 1
Apurinic/apyrimidinic endonuclease 1

APF

apoA1
apoA2
apoB
apoE
APP
APS
ARDS
ARE
AREDS
ARP
ASAP
ASK
At
ATBC
ATM
ATP
ATR
AVED
AZN
AZT
BAL
BAT
BB
BCDO2
BCI
BCMO1
BCNU
BDNF
BER
BH•3
BH4
BHA
BHF
BHT

2-[6-(4 -Amino)
phenoxy-3H-xanthen-3-on-9-yl] benzoic
acid
Apolipoprotein A1
Apolipoprotein A2
Apolipoprotein B
Apolipoprotein E
Amyloid precursor protein
Antiphospholipid syndrome
Acute respiratory distress syndrome
Antioxidant response element
Age-related eye disease study
Aldehyde-reactive probe
Antioxidant supplementation in
atherosclerosis prevention (trial)
Apoptosis signal-regulating kinase
Arabidopsis thaliana
α-Tocopherol/β-carotene cancer
prevention study
Ataxia telangiectasia mutated
Adenosine-5 -triphosphate
ATM and Rad-3 related
Ataxia with isolated vitamin E deficiency
Azulenylnitrone
Azidodeoxythymidine
British anti-lewisite
Brown adipose tissue
Biobreeding (rat)
β-Carotene dioxygenase 2
Bleomycin-chelatable iron
β-Carotene monooxygenase enzyme
N,N-Bis(2-chloroethyl)-N- nitrosourea
Brain-derived neurotrophic factor
Base excision repair
Trihydrobiopterin radical
Tetrahydrobiopterin
Butylated hydroxyanisole
British Heart Foundation
Butylated hydroxytoluene

A B B R E V I AT I O N S
BLM
Bleomycin
BM
Basement membrane
BNB
tert-Butylnitrosobenzene
BOSS
Biomarkers of oxidative stress
BPD
Bronchopulmonary dysplasia
BPDS
Bathophenanthroline disulphonate
BrdU
5-Bromo-2 -deoxyuridine
BSD
Bypass SOD deficiency (gene)
BSE
Bovine spongiform encephalopathy
BSO
Buthionine sulphoximine
C11-BODIPY581/591
4,4-Difluoro-5-(4-phenyl-1,3-butadienyl)-4bora-3a,4a-diaza-s-indacene-3-undecanoic
acid
CAD
Caspase-activated deoxyribonuclease
CAL
Calcein
CALPAIN
Calcium-activated non-lysosomal
proteinase
CaMKII
Calcium-calmodulin dependent kinase II
CARET
β-Carotene and retinol efficiency trial
CARS
Compensatory anti-inflammatory
response syndrome
CASPASE
Cysteine-aspartyl-specific protease
CBA
Coumarin-7-boronate
CBD
Cannabidiol
CCA
Coumarin-3-carboxylic acid
CCP
Cytochrome c peroxidase
CCS
Copper chaperone for SOD
CD
Cluster of differentiation
2-S-CD
2-S-Cysteinyldopa
5-S-CD
5-S-Cysteinyldopa
CdK
Cyclin-dependent protein kinase
CDNB
1-Chloro-2,4-dinitrobenzene
α-CEHC
2,5,7,8-Tetramethyl-2-(2 -carboxyethyl)-6hydroxychroman
γ -CEHC
2,7,8-Trimethyl-2-(2
carboxyethyl)-6-hydroxychroman
CEP
Carboxyethylpyrrole
CF
Cystic fibrosis
CFTR
Cystic fibrosis transmembrane
conductance regulator
CGD
Chronic granulomatous disease
CHAOS
Cambridge heart antioxidant study
CHD
Coronary heart disease
CHO
Chinese hamster ovary
CJD
Creutzfeldt–Jakob disease
vCJD
Variant Creutzfeldt–Jakob disease
CK
Creatine kinase
CLA
Conjugated linoleic acid
CLAS
Cholesterol lowering atherosclerosis study
Clk-1
Clock-1 (gene)
CNS
Central nervous system
CNTF
Ciliary neurotrophic factor
COMT
Catechol-O-methyltransferase
COPD
Chronic obstructive pulmonary disease

COPs
CoQ
CoQH2
COX
CP
CR
CRP
11cRAL
11cROL
CS
CSF
CuZnSOD
CUPRAC
CyclodA
CyclodG
CYP
DAB
DABCO
DAF-2DA
DAG
DAMP
DBNBS
DCF
DCFH
DCFHDA
DCT
ddC
ddI
DDTC
DED
DEPMPO
DETAPAC
DFO
DHA
2,3-DHB
2,5-DHB
DHE
DHF
DHI
DHICA
DHLA
DHR
DIABLO
DISC
DMEM
DMF
DMPO
DMSO
DMT1

xxxiii

Cholesterol oxidation products
Coenzyme Q (ubiquinone)
Reduced coenzyme Q (ubiquinol)
Cyclooxygenase
Classical pathway
Caloric restriction
C-reactive protein
11-cis-Retinal
11-cis-Retinol
Cockayne syndrome or Cigarette smoke
Cerebrospinal fluid or Colony-stimulating
factor
Copper-and-zinc-containing superoxide
dismutase
Cupric reducing antioxidant capacity
8,5 -Cyclo-2 -deoxyadenosine
8,5 -Cyclo-2 -deoxyguanosine
Cytochrome P450
Diaminobenzidine
1,4-Diazabicyclooctane
4,5-Diaminofluorescein diacetate
Diacylglycerol
Damage-associated molecular pattern
3,5-Dibromo-4-nitroso-benzene-sulphonic
acid
2 ,7 -Dichlorofluorescein
2 ,7 -Dichlorodihydrofluorescein
2 ,7 -Dichlorodihydrofluorescein diacetate
DOPAchrome tautomerase
Dideoxycytidine
Dideoxyinosine
Diethyldithiocarbamate
Death effector domain
5-Diethoxyphosphoryl-5-methyl-1pyrroline-N-oxide
Diethylenetriaminepenta-acetic acid
Desferrioxamine
Dehydroascorbate or Docosahexaenoic
acid
2,3-Dihydroxybenzoate
2,5-Dihydroxybenzoate
Dihydroethidium
Dihydroxyfumarate
5,6-Dihydroxyindole
5,6-Dihydroxyindole-2-carboxylic acid
Dihydrolipoate
Dihydrorhodamine 123
Direct inhibitor of apoptosis protein
binding protein with low pI
Death-induced signalling complex
Dulbecco’s Modified Eagle’s Medium
Dimethylformamide
5,5-Dimethylpyrroline-N-oxide
Dimethylsulphoxide
Divalent metal transporter-1

xxxiv

A B B R E V I AT I O N S

DMTU
DNPH
DOD-8C

DOPA
DOPAC
DPI
DPPD
DPPH
Dpr
Dps
DQ
DS
DTNB
DUOX
EBV
EC-SOD
EDRF
EDTA
EGF
EGFR
EL
EMPO
EPA
EPO
EPR
ER
ERK
Ero
ESR
ETS
ETYA
EUK
EURAMIC

FA
FAD
FADH2
FAK
FALS
FAPyG
Fas
FAS
FGF
FMN
FMNH2
FOXO
Fur
γ GCS
γ GGT

Dimethylthiourea
2,4-Dinitrophenylhydrazine
(N-[4-dodecyloxy-2-(7 -carboxy-hept-1 yloxy)benzylidene]-N-tert-butylamine
N-oxide)
L -Dihydroxyphenylalanine
3,4-Dihydroxyphenylacetic acid
Diphenylene iodonium
N,N -Diphenyl-p-phenylenediamine
1,1-Diphenyl-2-picrylhydrazyl
Dps-like peroxide resistance protein
DNA binding protein during stationary
phase
Dopaquinone
Down syndrome
5,5 -Dithiobis(2-nitrobenzoic acid)
Dual oxidase
Epstein–Barr virus
Extracellular superoxide dismutase
Endothelium-derived relaxing factor
Ethylenediamine tetraacetic acid
Epidermal growth factor
Epidermal growth factor receptor
Ethyl linoleate
5-Ethoxycarbonyl-5-methyl-1-pyrroline-Noxide
Eicosapentaenoic acid
Eosinophil peroxidase
Electron paramagnetic resonance
Endoplasmic reticulum
Extracellular signal related kinase
Endoplasmic reticulum oxidoreductase
Electron spin resonance
Environmental tobacco smoke
5,8,11,14-Eicosatetraynoic acid
Eukarion (company)
European Community multicentre study
on antioxidants, myocardial infarction and
breast cancer
Freidreich ataxia or Fanconi anaemia
Flavin adenine dinucleotide
Reduced flavin adenine dinucleotide
Focal adhesion kinase
Familial amyotrophic lateral sclerosis
2,6-Diamino-4-hydroxy-5formamidopyrimidine
Fibroblast-associated cell surface
Foetal alcohol syndrome
Fibroblast growth factor
Flavin mononucleotide
Reduced flavin mononucleotide
Forkhead transcription factor, class O
Ferric uptake regulator
γ -Glutamylcysteine synthetase
γ -Glutamyl transferase

G3PDH
G6PDH
GA
GABA
GADD
GC
GFP
GHz
GI-GPx
GI tract
GM-CSF
GO
GOT
GPx
GPx2
GPx3
GPx4
GPT
GR
GSH
GSSG
GST
Gy
HATS
HBED
HBO
HBV
HCS
HCV
HD
HDC
HDL
12-HETE
HGF
HHE
HHT
HIF
HIU
HIV
HL
HMGB1
HNE
HNF-1α
HO
HOPE
HPI
HPII
HPD

Glyceraldehyde-3-phosphate
dehydrogenase
Glucose-6-phosphate dehydrogenase
Glucuronic acid
γ -Aminobutyrate
Growth arrest on DNA damage
Gas chromatography
Green fluorescent protein
Gigahertz
Intestinal glutathione peroxidase (see
GPx2)
Gastrointestinal tract
Granulocyte-macrophage colony
stimulating factor
Galactose oxidase
Glutamate-oxaloacetate transaminase
Glutathione peroxidase
Intestinal glutathione peroxidase
(see GI-GPx)
Extracellular glutathione peroxidase
Phospholipid hydroperoxide glutathione
peroxidase
Glutamate-pyruvate transaminase
Glutathione reductase
Reduced glutathione
Oxidized glutathione
Glutathione-S-transferase
Gray (radiation dose)
HDL-atherosclerosis treatment study
N,N-bis(2-hydroxybenzyl)
ethylenediamine-N,N-diacetic acid
Hyperbaric oxygen
Hepatitis B virus
Hypoxic cell sensitizer
Hepatitis C virus
Huntington disease
6-Hydroxy-1,4-dimethylcarbazole
High-density lipoproteins
12-Hydroxy-5,8,10,14-eicosatetraenoic acid
Hepatocyte growth factor
Trans-4-Hydroxy-2-hexenal
12-Hydroxy-5,8,10-heptadecatrienoic acid
Hypoxia inducible factor
5-Hydroxyisourate
Human immunodeficiency virus
Hydroperoxide lyase
High mobility group 1 protein
4-Hydroxy-2-trans-nonenal
Hepatic nuclear factor 1α
Haem oxygenase
Heart outcomes prevention evaluation
(study)
Hydroperoxidase I
Hydroperoxidase II
Haematoporphyin derivative

A B B R E V I AT I O N S
12-HPETE
HPF
HPLC
HPO
HPS
HRP
HSF
HSP
5-HT
HTGL
HTLV
HX
IAP
IBD
ICAD
ICAM
ICE
IDO
IEISS
IgA
IgE
IGF-1
IgG
IgM
IL-1
ILBD
IMA
IMT
IP-10
IP3
IRE
IRP
IsoP
I-TAC
JNK
KA
Keap1
αKGDH
KGF
kJ
LA
LCAT
LDH
LDL
LEC
LFA
LGD2
LGE2
LHON
LIP

12-Hydroperoxy-5,8,10,14-eicosatetraenoic
acid
2-[6-(4 -Hydroxyl)phenoxyl-3H-xanthen-3on-9-yl]benzoic acid
High-performance liquid chromatography
High-pressure oxygen
Heart protection study
Horseradish peroxidase
Heat-shock transcription factor
Heat-shock protein
5-Hydroxytryptamine
Hepatic triglyceride lipase
Human T-cell leukaemia virus
Hypoxanthine
Inhibitor of apoptosis protein
Inflammatory bowel disease
Inhibitor of caspase-activated
deoxyribonuclease
Intercellular adhesion molecule
Interleukin-1β converting enzyme
Indoleamine dioxygenase
Indian experiment of infarct survival study
Immunoglobulin A
Immunoglobulin E
Insulin-like growth factor 1
Immunoglobulin G
Immunoglobulin M
Interleukin-1
Incidental Lewy body disease
Ischaemia-modified albumin
Intima-media thickness
Inducible protein 10
Inositol triphosphate
Iron responsive element
Iron regulatory protein
Isoprostane
Interferon-inducible T-cell
α-chemoattractant
c-Jun N-terminal kinase
Kainic acid
Kelch-like (erythroid cell-derived protein
with CNC homology)-associated protein-1
α-Ketoglutarate dehydrogenase
Keratinocyte growth factor
Kilojoule
Lipoic acid
Lecithin-cholesterol acyltransferase
Lactate dehydrogenase
Low-density lipoproteins
Long–Evans Cinnamon (rat)
Lymphocyte function antigen
Levuglandin D2
Levuglandin E2
Leber hereditary optic neuropathy
Labile iron pool

LOX
LOX-1

xxxv

Lipoxygenase
Lipoxygenase-1 or Lectin-like oxidized low
density lipoprotein receptor-1
LP
Lectin pathway
LPL
Lipoprotein lipase
LPO
Lactoperoxidase
LPS
Lipopolysaccharide
LRAT
Lecithin retinol acyltransferase
LRP1
LDL receptor-related protein 1
LTA4
Leukotriene A4
LTB4
Leukotriene B4
LTC4
Leukotriene C4
LTD4
Leukotriene D4
LTE4
Leukotriene E4
M
Molar
μM
Micromolar
mM
Millimolar
nM
Nanomolar
pM
Picomolar
M1 G
Pyrimido[1,2α]purine-10(3H)-one
MAC
Membrane attack complex
MAO-A
Monoamine oxidase A
MAO-B
Monoamine oxidase B
MAP
Mitogen activated protein (kinase)
MAT
Methionine adenosyltransferase
MBL
Mannose binding lectin
MCI
Mild cognitive impairment
MCLA
2-Methyl-6-(4-methoxyphenyl)-3,7dihydroimidazo[1,2-α] pyrazin-3-one
MCP-1
Monocyte chemoattractant protein 1
MCSF
Macrophage colony-stimulating factor
MDA
Malondialdehyde or
3,4-Methylenedioxyamphetamine
MDMA
3,4-Methylenedioxymethylamphetamine
MDT
Marine-derived tocopherol
MEG
Mercaptoethylguanidine
MELAS
Mitochondrial encephalomyopathy, lactic
acidosis and stroke-like episodes
MEOS
Microsomal ethanol-oxidizing system
fMet-leu-phe N-formylmethionylleucylphenylalanine
MI
Myocardial infarction
MICRO-HOPE Microalbuminuria, cardiovascular, and
renal outcomes in the HOPE study
Mig
Monokine induced by interferon-γ
MIP
Monocyte inflammatory protein
MMP
Matrix metalloproteinase
MnSOD
Manganese-containing superoxide
dismutase
MODS
Multiple organ dysfunction syndrome
MODY
Maturity onset diabetes of the young
MOG
Myelin oligodendrocyte glycoprotein
MOX
Mitogenic oxidase
MPB
3-(N-maleimidylpropionyl) biocytin
MPDP+
1-Methyl-4-phenyl-2,3-dihydropyridine
ion

xxxvi

A B B R E V I AT I O N S

MPG
MPO
MPP+
MPT
MPTP
MR
MRC
MRI
MS
Msr
MT
MTH1
MTT
MVP
MYA
hMYH
NAAQS
NAc
NAD+
NADH
NADP+
NADPH
NAFLD
NAG
NASH
NBT
NCL
NDGA
NER
NETs
8-NG
NGF
NHANES
NHPA
NIA
NiSOD
NIST
NK
NMDA
NMMA
NMP
NNK
NNO
NOD
NOS

Mercaptopropionylglycine
Myeloperoxidase
1-Methyl-4-phenylpyridinium ion
Mitochondrial permeability transition
1-Methyl-4-phenyl-1,2,3,6tetrahydropyridine
Methaemoglobin reductase
Medical Research Council (UK)
Magnetic resonance imaging
Multiple sclerosis
Methionine sulphoxide reductase
Metallothionein
Mut T homologue one
3-(4,5 Dimethylthiazol-2-yl)-2,5-diphenyl
tetrazolium bromide
Multivitamins and probucol trial
Million years ago
Human mut Y analogue
National ambient air quality
standard (USA)
N-acetylcysteine
Nicotinamide adenine dinucleotide
Reduced nicotinamide adenine
dinucleotide
Nicotinamide adenine dinucleotide
phosphate
Reduced nicotinamide adenine
dinucleotide phosphate
Non-alcoholic fatty liver disease
N-Acetylglucosamine
Non-alcoholic steatohepatitis
Nitroblue tetrazolium
Neuronal ceroid lipofuscinoses
Nordihydroguaiaretic acid
Nucleotide excision repair
Neutrophil extracellular traps
8-Nitroguanine
Nerve growth factor
National Health and Nutrition
Examination Survey
3-Nitro-4-hydroxyphenylacetate
National Institute of Aging (USA)
Nickel-containing superoxide
dismutase
National Institute of Standards and
Technology (USA)
Natural killer (cell)
N-Methyl- D-aspartate
N G -Monomethyl- L-arginine
3-Nitratomethyl-PROXYL
4-(Methylnitrosamine)-1-(3-pyridyl)-1butanone
Nitronylnitroxide
Non-obese diabetic (mouse)
Nitric oxide synthase

eNOS
iNOS
nNOS
NP
NQO
Nramp1
N-ret-PE
NRF1
Nrf2
NRF2
NSAID
Nt
NTA
NTBI
ODS
OHCU
6-OHDA
8OHdG
8OHG
8OHGua
ORAC
OTC
OxLDL
8oxodG
OxPAPC
PAF
PAL
PAMP
PAPC
PARP
PBG
PBN
PC
PCC
PCD
PCP
PCR
PD
PDGF
PDH
PDI
PDK
PE
PECAM
PEG
PFL
PFOR
PG

Endothelial nitric oxide synthase
Inducible nitric oxide synthase
Neuronal nitric oxide synthase
Neuroprostane
NAD(P)H-quinone oxidoreductase
Natural murine resistance associated
macrophage protein-1
N-Retinylidenephosphatidylethanolamine
Nuclear respiratory factor 1
Nuclear factor erythroid 2 p4–5-related
factor 2
Nuclear respiratory factor 2
Non-steroidal anti-inflammatory drug
Nicotiana tabacum
Nitrilotriacetate
Non-transferrin-bound iron
Osteogenic disorder Shionogi (rat)
2-Oxo-4-hydroxy-4-carboxy-5ureidoimidazoline
6-Hydroxydopamine
8-Hydroxy-2 -deoxyguanosine
8-Hydroxyguanine
8-Hydroxyguanosine
(8-hydroxyguanine-ribose)
Oxygen radical absorbance capacity
L -2-Oxothiazolidine-4-carboxylate
Oxidized low-density lipoprotein
8-Oxo-7-hydro-2 -deoxyguanosine
Oxidized 1-palmitoyl-2-arachidonoyl-snglycero-3-phosphorylcholine
Platelet-activating factor
Present atmospheric level
Pathogen-associated molecular pattern
1-Palmitoyl-2-arachidonoyl-sn-glycero-3phosphorylcholine
Poly(ADP-ribose) polymerase
Porphobilinogen
α-Phenyl-tert-butylnitrone
Plastocyanin or Phosphatidylcholine
Phenanthroline-chelatable copper
Programmed cell death
Pentachlorophenol
Polymerase chain reaction
Parkinson disease
Platelet-derived growth factor
Pyruvate dehydrogenase
Protein disulphide isomerase
Phosphoinositide-dependent kinase
Phosphatidylethanolamine
Platelet-endothelial cell adhesion molecule
Polyethylene glycol
Pyruvate–formate lyase
Pyruvate–ferredoxin oxidoreductase
Prostaglandin

A B B R E V I AT I O N S
PGC-1α
pGPx
PHGPx
Phox
PHS
PI
PIH
PKA
PKB
PKC
PLC
PLD
PMA
4-POBN
Pol γ
PON-1
POP
PP
PPAR
PPP
PQ
PR
Prx
PS
PSI
PSII
PTEN
PUFA
PUVA
PVC
QR
RA
RAGE
atRAL
RANK
RANKL
RANTES
RBOH
RBS
RCS
RDA
atRE
Ref-1
RIP1
RNR
RNS
atROL
ROS
ROP

Peroxisome-proliferator-activated-receptor
γ co-activator-1α
Plasma glutathione peroxidase
(also see GPx3)
Phospholipid hydroperoxide glutathione
peroxidase (also see GPx4)
Phagocyte oxidase
Physicians‘ health study
Propidium iodide
Pyridoxal isonicotinoyl hydrazone
Protein kinase A
Protein kinase B
Protein kinase C
Phospholipase C
Phospholipase D
Phorbol myristate acetate
α-(4-Pyridyl-1-oxide)-N-tert-butylnitrone
DNA polymerase γ
Paraoxonase-1
Phytosterol oxidation product
Peroxisome proliferator
Peroxisome proliferator activated receptor
Pentose phosphate pathway
Plastoquinone
Promethazine
Peroxiredoxin
Phosphatidylserine
Photosystem I
Photosystem II
Phosphatase and tensin homologue
deleted on chromosome 10
Polyunsaturated fatty acid
Psoralen ultraviolet A (therapy)
Polyvinyl chloride
Quinone reductase
Rheumatoid arthritis
Receptor for advanced glycation
end-products
all-trans-Retinal
Receptor for activator of NF-κB
Receptor for activator of NF-κB, ligand
Regulation upon activation, normal T-cell
expressed and secreted
Respiratory burst oxidase homologue
Reactive bromine species
Reactive chlorine species
Recommended dietary allowance
all-trans-Retinyl esters
Redox effector factor 1
Receptor interacting protein-1
Ribonucleotide reductase
Reactive nitrogen species
all-trans-Retinol
Reactive oxygen species
Retinopathy of prematurity

RPE
RS
RSS
RSV
RTK
SAA
SAM
SAP
SAR
SCA
SCID
SCPS
SDA
SDS
SELECT
SERPIN
SF
SFRR
SHEEP
SHR
SIH
Sir
SIRS
SIRT
Sirtuin
SMAC
SLE
SLOS
SN
SNAP
SNP
SOD
SOR
SOTS
SPACE

SPL
SRA
SREBP
SS
STAZN
SUVIMAX
SVCT
TAC
Tat
TBA
TBARS
TBHQ
TCBQ
TCDD

xxxvii

Retinal pigment epithelium
Reactive species
Reactive sulphur species
Respiratory syncytial virus
Receptor tyrosine kinase
Serum amyloid A protein
S-Adenosyl methionine
Serum amyloid P protein
Systemic acquired resistance
Senescent cell antigen
Severe combined immunodeficient
Skin cancer prevention study
Semidehydroascorbate
Sodium dodecyl sulphate
Selenium and vitamin E cancer prevention
trial
Serine proteinase inhibitor
Synovial fluid
Society for Free Radical Research
Stockholm heart epidemiology programme
Spontaneously hypertensive rat
Salicylaldehyde isonicotinoylhydrazone
Silent information regulator
Systemic inflammatory response
syndrome
Sirtuin
Silent information regulator-like protein
Second mitochondria-derived activator of
caspases
Systemic lupus erythematosus
Smith-Lemli-Opitz syndrome
Substantia nigra
S-nitroso-N-acetyl-DL -penicillamine
Sodium nitroprusside
Superoxide dismutase
Superoxide reductase
Di-(4-carboxybenzyl) hyponitrite
Secondary prevention with antioxidants of
cardiovascular disease in endstage renal
disease
Spore photoproduct lyase
Scavenger receptors A
Sterol regulatory element binding protein
Szeto-Schiller
Stilbazulenyl nitrone
Supplementation en vitamins et mineraux
antioxidant
Sodium-vitamin C transporter
Total antioxidant capacity
Transactivator of transcription
Thiobarbituric acid
Thiobarbituric acid-reactive substances
tert-Butylhydroquinone
Tetrachlorobenzoquinone
2,3,7,8-Tetrachlorodibenzo-p-dioxin

xxxviii

A B B R E V I AT I O N S

TCHQ
TCR
TDO
TDS
TdT
TEAC
TGF-β
THC
THF
THOX
TIBS
TIC
TIMP
TiP
TLR
TMINO
tNB (NtB)
TNB
TNF
TPO
TPP
TRADD
TRAP
TRAIL
TRBP
TRPM
Trx

Tetrachlorohydroquinone
Transcription-coupled repair
Tryptophan 2,3-dioxygenase
Translesional DNA synthesis
Terminal deoxynucleotidyl transferase
Trolox equivalent antioxidant capacity
Transforming growth factor β
Tetrahydrocannabinol
Tetrahydrofolate
Thyroid oxidase
Trends in Biochemical Sciences
Tumour initiating cell
Tissue inhibitor of metalloproteinases
Thioredoxin interacting protein
Toll-like receptors
1,1,3-Trimethyl-isoindole N-oxide
tert-Nitrosobutane (nitroso-tert-butane)
Thionitrobenzoate
Tumour necrosis factor
Thyroid peroxidase
Thiamine pyrophosphate or
Triphenylphosphonium
Tumour necrosis factor receptor-associated
death domain
Total (peroxyl) radical trapping
antioxidant parameter
Tumour necrosis factor related apoptosis
inducing ligand
Telomere repeat binding protein
Transient receptor potential
melastatin-related (ion channels)
Thioredoxin

α-TTP
TUNEL
TX
TXNIP
UCHL1
UV
VA
VAP
VCAM
VDAC
VEAPS
VEGF
VHL
VITAL
VLDL
Vtc-mutant
WACS
WAVE
WR
XDH
XIAP
XO
XOR
XP
XTT

ZDF

α-Tocopherol transfer protein
TdT-mediated X-dUTP nick end-labelling
Thromboxane
Thioredoxin-interacting protein
Ubiquitin carboxy-terminal hydrolase L1
Ultraviolet
Veratryl alcohol
Vascular adhesion protein
Vascular cell adhesion molecule
Voltage-dependent anion-selective
channel
Vitamin E atherosclerosis prevention
study
Vascular endothelial growth factor
von Hippel-Lindau
Vitamins and lifestyle study
Very low-density lipoproteins
Vitamin C mutant (in Arabidopsis)
Women’s antioxidant and cardiovascular
study
Women’s angiographic vitamin and
oestrogen (trial)
Walter Reed (army hospital, USA)
Xanthine dehydrogenase
X-linked inhibitor of apoptosis
Xanthine oxidase
Xanthine oxidoreductase
Xeroderma pigmentosum
2,3-bis(2-Methoxy-4-nitro-5sulphophenyl)-2H-tetrazolium
5-carboxyanilide
Zucker diabetic fat (rat)

Sarcomere
SR

A

LD

B

C

Mitochondrion

1
4

2

3

Cytoskeleton

3D mitochondrial
reticular network
around sarcomeres

Plate 1 See Figure 1.8.

Transient membrane
rupture during
mitochondrial isolation

Uniform fragmented
morphology

Plate 2 See Figure 2.13.

Plate 3 See Figure 3.3.

(a)

(c)

Plate 4 See Figure 3.4.

(b)

(d)

(a)

(b)

Plate 5 See Figure 3.6.

Plate 6 See Figure 3.7.

Plate 7 See Figure 3.11.

(a)

(b)
His75

Phe153

water

Arg112
Asn148
Trp186

Val116
Va174

Phe154

haem

Phe153

Arg365
Arg354

Tyr358

Tyr358

Plate 8 See Figure 3.17.

A

BEFORE STRETCH

B

AFTER STRETCH

Sarcolemma

Sarcolemma

p47

T-T

p22

p40

phox

gp91

SR

p22

p47

SR

p40
phox p67
gp91

p67

rac1

rac1

VGCC

VGCC
RyR2

ROS
Ca2+

Plate 9 See Figure 5.4.

T-T

RyR2

(a)

(b)

(c)

(d)

(e)

(f)

(g)

Plate 10 See Figure 6.7.

3 days after fertilization

(c) Average arrival of first
leukocyte (+s.d.
)
–

(d)

HyPer ratio

HyPer ratio

3 min after wounding
17 min after wounding
61 min after wounding

7

5.5
4.5
3.5
2.5

5
3
1

3

23

43

63

0

Time after wounding (min)
3 min after
wounding

19 min after
wounding

35 min after
wounding

100
200
Distance from wound
margin (μm)
51 min after
wounding

300

DsRED2
HyPer ratio

0.5

Plate 11 See Figure 6.9.

Plate 12 See Figure 6.14.

YFP500

3.5

YFP500/YFP420

YFP420

YFP500

8.0

YFP500/YFP420

YFP420

YFP500

YFP500/YFP420
0.5

YFP420

67 min after
wounding

Trans

(e)

Cut tail fin

17 min after wounding

1-cell stage
HyPer mRNA

3 min after wounding

(b)

61 min after wounding

(a)

83 min after
wounding

99 min after
wounding

(a)

(b)

(c)

(d)

Plate 13 See Figure 6.18.

(a)

(b)

Plate 14 See Figure 6.21.

(a)

(b)

(c)

(d)

0.5

10

20

30

Time (min)
% oxidized
0
Plate 15 See Figure 6.22.

50

100

Plate 16 See Figure 6.24.

3 H+

ATP

ATP + Pi

hv
hv
NADP+
LHCII

P680
YZ

PQH2

PQH2

Cyt b6

A0

PQ
PQH2

YD

FeS
P700

Mn4

Cyt f

Lumen
2 H2O

(a)

A1

CF0

PQ

LHCI

4 nm

Pheo

Fd

FeS

FNR

QB

LHCI

QA

NADPH

2 H+

2 H+

Cyt b559

Stroma

CF1

H+

+
O2 4 H

PC

PC
3 H+

4 H+

Cytochrome b6f

Photosystem II

Photosystem I

ATP synthase

–1.6
P700*
–1.2

A0
Photosystem II

–0.8

P680°

Em (volts)

–0.4

QA

100–600 μs

0.4

hv

QB
1 ms

PQ

Mn4
YZ

1.6

Plate 17 See Figure 7.10.

20 ns–35 μs

FeS Cyt f
< 1 ms

P680

2 NADPH
Fd

– 1ms

FNR
2 NADP+

PC
200 μs

P700
Photosystem I

2 H2O 50 μs–1.5 ms

O2
+
4 H+

hv

Cyt b6f
Complex

1–20 ms

1.2

(b)

< 1–125 μs

Pheo

0.0

40–200 ps

A115–200 ns
Fx 200–500 ns
FAB

10 ps

200 ps

0.8

–1 ps

Plate 18 See Figure 7.12.

(c)
Vessel Lumen
3

Inflamed tissue

2

11

Draining
Lymph node
4

sue
Tis jury
in

te

cy
ko
eu

-

3

1

5

L

2

in

9

6

9

7

12

ux

fl

M1

Productive phase

Production of inflammatory mediators (1)
Vessel permeability
Vasodilation
Blood flow
Oedema
Beginning of leukocyte recruitment (2,3)
Monocytes Macrophages (4)
PMN and macrophage effector function (5)

Plate 19 See Figure 8.9.

10

8
M2

Transition phase
- PMN and monocyte recruitment (2,3)
- PMN and macrophage effector function (5)
- PMN apoptosis (6) - ‘Find-me’ and ‘eat-me’
signals on apoptotic PMN
- Efferocytosis (7)
- M1 M2 transition (8)
- M2 production of anti-inflammatory
molecules (IL-10 and TGF-β)

Mres

Resolving phase
- M2 Mres transition (10)
- Production of resolution mediators:Lipoxins, resolvins, protections, IL-10 etc. by
Mres (9)
- Lymphocyte repopulation (11)
- Macrophages apoptosis or lymphatic
drainage (12)

Plate 20 See Figure 8.10.

Airway epithelium (DUOX1/2, NOX2)
Beneficial role: Defence against infection
in airways and alveoli
Potential deleterious role: Mucus metaplasia,
chronic epithelial wound response and inflammation
Dendritic cells (NOX2)
Antigen processing,
inflammasome signalling

Lymphocytes (NOX2, DUOX1)
Beneficial role: T and B cell signalling
and proliferation
Potential deleterious role:
Participation in chronic
inflammation

Airway smooth muscle (NOX4)
Beneficial role: Helps control pulmonary vessel tone
Potential deleterious role: Smooth muscle
hyperplasia, airway hyper-responsiveness
(e.g. in asthma)

Neutrophils/Eosinophils (NOX2)
Beneficial role: Pathogen killing,
regulation of apoptosis
Potential deleterious role: Pro-inflammatory
signalling, extracellular oxidative injury

Pulmonary fibroblasts (NOX4)
Beneficial role: Regulation of
proliferation and differentiation
Potential deleterious role: Fibrosis

Plate 21 See Figure 8.16.

Plate 22 See Figure 8.18.

(a)
Normal p53
p53

Antioxidant
genes

ROS Prevention or repair
of mutations

No stress/mild
reversible damage
Normal cell growth
(b)

Normal p53
p53 p53
p53 Pro-oxidant
genes
p53

ROS

Elimination of cells
with mutations

Extended stress/
irreparable damage

Cell death

(c)
Mutant p53

Accumulation
of mutations

p53
ROS

Tumorigenesis

Plate 23 See Figure 10.17.

Ubiquitin-activating enzyme (E1)
ATP

Ubiquitin carboxyterminal hydrolase
(UCHL1 missense
mutation causes
familial PD)

Monomeric
ubiquitin

Ubiquitin-conjugating
enzyme (E2)

Polyubiquitin
chain
Short
peptide
fragments

Activated
ublquitin/E2

ATP

26S proteasome
(inhibited in sporadic PD)

Plate 24 See Figure 10.30.

Activated
ubiquitin

Polyubiquitin-protein
conjugate

Abnormal/
damaged/mutant
proteins
( -synuclein
missense
mutations cause
familial PD)

Ubiquitin ligase (E3)
(parkin deletions and point
mutations cause juvenile PD)

Plate 25 See Figure 11.3.

Plate 26 See Figure 11.4.

CHAPTER 1

Oxygen: boon yet bane—introducing
oxygen toxicity and reactive species

Oxygen has been a trouble-maker since the very beginning.
Doris Abele1

1.1 The history of oxygen: an essential
air pollutant
The element oxygen (chemical symbol O) surrounds
us as a diatomic molecule, O2 .1–5 Over 99% of the O2
in the atmosphere (about 3.7 × 109 moles in total!)2
is the isotope oxygen-16, but there are also traces
of oxygen-17 and oxygen-18 (see the Appendix for
details). Except for some anaerobic and aerotolerant
species, all organisms require O2 for efficient production of energy, by the use of electron transport chains
that ultimately donate electrons to O2 , such as those in
the mitochondria of eukaryotic cells and the cell membranes of many bacteria. This need for O2 obscures the
fact that it is a toxic, mutagenic gas and a serious fire
risk; aerobes survive only because they have evolved
antioxidant defences, which are explored in Chapter 3.
Oxygen appeared in significant amounts in the
Earth’s atmosphere over 2.2 billion years ago (Figs 1.1
and 1.2), almost entirely due to the evolution of photosynthesis by cyanobacteria,a using energy from the sun
to split water. Thereby, they gained reducing power
(hydrogen atoms) to drive their metabolism, but the
by-product, O2 , was discarded into the atmosphere.
Initially, most of this O2 was consumed by the formation of the metal oxide deposits that exist in rocks
and ores today, and by other ‘O2 sinks’ (Fig. 1.1).4,5
Only when this was largely complete did O2 build up
in the atmosphere. The rise in atmospheric O2 was
advantageous to life on Earth in at least two ways: it
a Cyanobacteria (previously called blue–green algae) are
prokaryotes that combine plant-type photosynthesis and cytochrome oxidase-based respiration in the same cell. A good review of how present-day cyanobacteria resist oxidative stress
may be found in ref6 .

led to formation of the ozone (O3 ) layer in the stratosphere and it removed ferrous (Fe2+ ) iron from aqueous
environments, helping to prevent Fenton chemistry
(Section 2.4.4). Ferrous iron was abundant at the time,
which helps to explain why organisms used it so much
(e.g. in Fe-S clusters) to catalyse redox reactions. When
O2 came, free Fe2+ posed a threat, as did the vulnerability of iron-containing enzymes to O2 and its
derivatives (Section 3.9). Iron is the fourth most abundant element on the Earth, and by forming insoluble,
unreactive ferric complexes, most Fe2+ was precipitated from solution, leaving sea water today containing
only trace amounts of soluble iron. The ability of O3
and O2 to filter out much of the intense solar ultraviolet
(UV-C) radiation bombarding the Earth helped living
organisms to leave the sea and colonize the land.
Yet the increasing O2 posed problems. When living
organisms first appeared on Earth, they did so under
an atmosphere containing much N2 and CO2 , but very
little O2 , i.e. they were anaerobes. Anaerobes still exist
today, but usually their growth is inhibited and often
they are killed by exposure to 21% O2 , the current
atmospheric level. As the O2 content of the atmosphere rose, many such species must have died out.
Present-day anaerobes are mostly the descendants of
organisms that followed the evolutionary path of ‘adapting’ to rising atmospheric O2 levels by restricting
themselves to environments from which O2 is absent
(Fig. 1.3). Other organisms instead began to develop
antioxidant defences (evolving new ones as well as
realigning ancient molecules to new functions) to protect against O2 toxicity. In retrospect, this was a fruitful
path to follow. Organisms that tolerated O2 could
also evolve to use it for metabolic transformations
catalysed by oxidase, oxygenase, and hydroxylase

Free Radicals in Biology and Medicine. Fifth Edition. Barry Halliwell and John M.C. Gutteridge.
© Barry Halliwell and John M.C. Gutteridge 2015. Published in 2015 by Oxford University Press.

FREE RADICALS IN BIOLOGY AND MEDICINE

0

500

1000

Present day

Rise in O2 to
about 5–18%
of present
Cambrian atmospheric
explosion level deduced
from oxidized
minerals and
sulphate-reducing
bacteria

1900
2000
2100
2200
2300

Uranium reactors
First multicellular algae

First eukaryotes with mitochondria?
Oxidized fossil soils
First eukaryotic fossils?
Global tectonic activity
Snowball Earth

2400
2500

1500

2000

2500

Rise in O2
to about 1%
of present
atmospheric
level deduced
from sulphatereducing bacteria

Banded-iron formations

Million
years ago
1800

Red-beds

2

2600
2700
2800
2900
3000

3000

3100
3200

3500

3300
3400

4000

3500

Fossil stromatolites
Fossil photosynthetic bacteria

3600
4500

3700
3800
3900

Carbon signatures
in Greenland rocks

Figure 1.1 Geological timeline expanding the mid-Precambrian period (Archaean and early Proterozoic). Note the burst of evolutionary activity in
the period 2.3 to 2 billion years ago, as oxygen levels rose to about 5–18% of present atmospheric levels; in spite of O2 toxicity, its presence
triggered the rapid evolution of an ‘explosion’ of different life forms. Oxygen may have eliminated many anaerobes but it also provided the means
for multicellular organisms to evolve. ‘Snowball Earth’ refers to an ice age. It has been suggested that the rise in O2 contributed to this by removing
some of the ‘greenhouse gas’ methane (CH4 ) from the atmosphere, so promoting global cooling. Diagram adapted from Oxygen, the Molecule that
Made the World, Oxford University Press, 2002 by courtesy of Dr Nick Lane and Oxford University Press. It should be noted that these timelines
remain a topic of controversy.2,5

O X Y G E N : B O O N Y E T B A N E — I N T R O D U C I N G O X Y G E N TO X I C I T Y A N D R E A C T I V E S P E C I E S

3

Million
years ago
500
0

500

Present day

Cambrian
explosion

Cambrian explosion
Oxygenation of deep waters
Vendobionts and worms

O2 levels reach
100% of present
atmospheric level
600

Radiation of sulphur bacteria
First fossil metazoans

1000

1500

Alternating isotope
patterns implying
oxygenation of air
and surface waters

Snowball Earth period
3 worldwide glaciations
700

2000

2500

800
3000
First metazoans?
(deduced from molecular clocks)
3500

4000

900

4500

1000
Figure 1.2 Geological timeline expanding the late Precambrian period and Cambrian explosion. Diagram adapted from Oxygen, the Molecule
that Made the World, Oxford University Press, 2002 by courtesy of Dr Nick Lane and Oxford University Press. The exact timelines remain a topic of
controversy.2,5

enzymes, such as tyrosine hydroxylase, cytochromes
P450, enzymes that demethylate DNA (essential for
epigenetic signalling), and the proline (often written
as prolyl) and lysine (lysyl) hydroxylases needed for
collagen biosynthesis and O2 sensing. In several cases,
these O2 -requiring enzymes replaced less efficient
older enzymes that took oxygen atoms from H2 O.7
In others (e.g. collagen hydroxylases and DNA demethylases), the biochemistry was completely novel.

Best of all, O2 could facilitate efficient energy production, employing electron transport chains with O2
as the terminal electron acceptor, the rudiments of
which may already have been present, but maybe using other electron acceptors such as NO–2 or NO–3 .3 This
switch to aerobic metabolism substantially increased
the yield of ATP that could be made from food molecules, such as glucose. Mitochondria, a word arising
from the Greek words mitos (thread-like) and khondros

4

FREE RADICALS IN BIOLOGY AND MEDICINE

First living organisms
Anaerobes
(very limited exposure to oxidative stress, e.g. H2O2 in rainwater, trace levels (<<0.1%) of O2 in air)

Stress with oxygen at increasing levels

Evolve antioxidant
defences

Die

Restrict to anaerobic
environments

Figure 1.3 Evolutionary adaptations to the appearance of O2 . Development of antioxidant defences allowed evolution of O2 -using enzymes and
electron-transport chains, enabling oxidation of food material more efficiently. Aerobic respiration produces more energy per unit mass of food,
facilitating the development of complex multicellular organisms. The bigger organisms then have to develop mechanisms for delivering O2 at the
right level to their cells, so that many cells are shielded from the full brunt of 21% O2 ; perhaps a driving force for the evolution of multicellularity.

(granule), make 80% or more of the ATP needed by
almost all animal cells, and the lethal effects of inhibiting this, for example by cyanide, show how important mitochondria now are. Another effect, the use
of O2 -containing signalling molecules (e.g. nitric oxide and H2 O2 ) became increasingly important as cells
evolved and became compartmentalized, and when
multicellularity arose.8
Evolution of efficient energy production allowed the
development of complex multicellular organisms with
increased body size,9 which then also needed systems
to ensure that O2 could be distributed throughout the
organism (Fig. 1.3). A further advantage of evolving
such systems is that delivery of O2 can be controlled;
most cells in the human body are never exposed to
the full force of atmospheric O2 (Fig. 1.4). Mechanisms for monitoring O2 levels in the body and altering
respiration rate and blood flow to control O2 supply are then needed. As multicellular organisms became bigger, they needed structural support: skeletons
and connective tissue. Hence collagen biosynthesis (an
O2 -requiring process) came into prominence, since collagen is a major protein in connective tissue and bone.

1.1.1 The paradox of photosynthesis
Since O2 is poisonous and photosynthetic organisms
expose themselves to high O2 levels, how was it possible for cyanobacteria to evolve photosynthesis in a
‘pre-antioxidant’ world? Even in present-day plants,
much of the protein synthesis in illuminated chloroplasts is used to repair the oxidative damage being done (Section 7.8.10). Were some antioxidants in
place already? It has been speculated (although hard

evidence is lacking) that the part of the photosynthetic
system that splits water, photosystem II (Section 7.8.2),
could have evolved from a manganese-containing
form of the enzyme catalase.2,3,10 If true, then catalaselike enzymes must have been present prior to a rise
in atmospheric O2 levels. How can this be? Catalase
is specific for H2 O2 ; was H2 O2 present to drive its
evolution? Maybe it was.
Under an atmosphere mainly composed of N2 and
CO2 with no O3 screen, UV radiation must have bombarded the face of the Earth. Even at the low O2 levels
present 3.5 billion years ago (< 0.1%), there could have
been substantial H2 O2 levels in rainwater generated
by photochemical reactions with traces of O2 .3 In addition, it would have taken a substantial time to form
the O3 layer when O2 began to rise. Iron was freely
available then in a soluble form, Fe2+ . Hence Fenton
chemistry (Section 2.4.4) was a threat, so H2 O2 must
be eliminated. One suggestion is that the evolutionary
precursors of photosystem II used H2 O2 as a substrate,10 and only later evolved the increased chemical
ferocity needed to split water. Do remember, however,
that decomposition of H2 O2 by catalase generates O2
(Section 3.17).

1.1.2 Hyperoxia in history?
Oxygen is now the commonest element in the Earth’s
crust (atomic abundance 53.8%) and is 21% of the atmosphere. The barometric pressure of dry air at sea
level is 760 mm mercury,b giving an O2 partial pressure
of about 159 mmHg.
b

1 atmosphere = 760 mmHg = 0.1013 megapascals.

O X Y G E N : B O O N Y E T B A N E — I N T R O D U C I N G O X Y G E N TO X I C I T Y A N D R E A C T I V E S P E C I E S

5

Hyperoxia and
oxygen toxicity

O2
100 Normal lung
capillaries

Red blood cells (Hb 95% saturated)
Aorta

90

80
Oxygen partial
pressure
(mmHg)

Arterioles
70

60
(Hb 70% saturated)
50

Capillary
pO2

Oxygen diffusion to cells
maintaining intracellular oxygen
tension of ~1–20 mmHg (0.5 mmHg
in mitochondria)

40
Hypoxia with
loss of consciousness
30

Figure 1.4 Approximate O2 concentrations in the human body. Most cells are only exposed to fairly low O2 concentrations; this may be regarded
as an antioxidant defence mechanism, although it also renders aerobic cells vulnerable to interruptions of the O2 transport mechanism. The cornea
and respiratory tract are obvious exceptions, but the skin is somewhat shielded by its outer layer of dead cells (Section 7.13.1). Cells circulating in
the blood (except erythrocytes) and cells in the vessel walls (especially vascular endothelium, which has a high metabolic activity) will consume
some of the O2 unloaded from haemoglobin (Hb) before it diffuses into the tissues.

Oxygen levels may have been even higher at periods in the Earth’s history.2 In the mid to late Devonian
period, O2 increased from about 18% to 20%, but then
rose sharply to ~30% by the late Carboniferous as
plant life flourished, CO2 levels fell drastically, and
huge deposits of coal and oil formed (Fig. 1.5). This
increased O2 concentration may have permitted insects (whose O2 distribution system depends largely
on diffusion) to become larger.11 For example the giant Carboniferous dragonfly Meganeura monyi had a
wingspan of up to 75 cm and a thoracic diameter of
about 2.8 cm, compared with about 10 cm and 1 cm,
respectively, for present-day dragonflies. Most of the
insects that attained exceptionally large body sizes during the Carboniferous did not persist after the Permian,
when O2 concentrations fell again, perhaps because
they could not develop a sufficient distribution system

at lower O2 levels.11 The plants and animals existing
in Carboniferous times must presumably have had
enhanced antioxidant defences, which would be fascinating to study if they could be resurrected. High
O2 levels would also be expected to increase the number and severity of wildfires, another contributor to
evolution (Fig. 1.5).

1.1.3 Oxygen in solution
Oxygen is also found dissolved in seas, lakes, rivers,
and other bodies of water. The solubility of O2 in
sea water exposed to air at 10 ◦ C is about 0.284 millimolar (mM), and decreases at higher temperatures
(e.g. 0.212 mM at 25 ◦ C), e.g. Arctic and Antarctic waters dissolve more O2 than temperate waters. Oxygen
is more soluble in fresh water, e.g. in distilled water its

6

FREE RADICALS IN BIOLOGY AND MEDICINE

(a)

Oxygen

35

% oxygen

30
25
PAL

20
15
10
5
C

O

S

D

C

P

Tr

(b)

J

K

T

Carbon dioxide

% carbon dioxide

0.5
0.4
0.3
0.2
0.1
PAL

O

C
–600

–500

S

D

C

–400

P

–300

Tr
–200

J

K
–100

T
0

Time (mya)
Figure 1.5 Changes in O2 and CO2 during the Earth’s history. (a) Calculated palaeoatmospheric O2 concentration showing the estimate (solid
line) and its range (dashed lines). Between the mid to late Devonian (380–360 million years ago (mya)), O2 increased from ~18 to 20%, and then
rose sharply to 30% or more by late Carboniferous (286 mya), probably mainly due to the evolution of large land plants with high photosynthetic
activity. The present atmospheric level (PAL) of 21% is indicated. Oxygen steadily declined throughout the Permian (286–250 mya) and dropped to
about 15% by the end of the Palaeozoic (250 mya), causing many species ‘adapted’ to high O2 to die out (Science 308, 398, 2005; ref11 ). This
drop in O2 seems to be related to decreases in the numbers of forests, perhaps due to aridity, fires, and some loss of wetlands (Geochim.
Cosmochim. Acta 69, 3211, 2005). (b) Palaeozoic atmospheric CO2 model. This gas was present in relatively large amounts in the
Ordovician–Silurian, fell precipitously during the Devonian–Carboniferous, and increased in the late Permian. The minimum value shown for the late
Carboniferous and early Permian approximates present CO2 levels (about 0.036%; dotted line). Data from Nature 375, 118, 1995, by courtesy
of Dr J.B. Graham and his colleagues and the publishers. Note that the exact timings of these changes remain a subject of controversy.2,5

solubility is 0.258 mM at 25 ◦ C and 0.355 mM at 10 ◦ C.c
The O2 concentration experienced by cells within a
multicellular organism will depend on how far the O2
has to move to reach them, as well as on how quickly
it is consumed by them and other cells around them.
Mitochondrial respiration can function well at low O2 ,
c For a detailed discussion of O solubility, see Geochim.
2
Cosmochim. Acta 74, 5631, 2010.

so one way of diminishing O2 toxicity has been to
decrease the concentration to which cells within the
body are exposed (Fig. 1.4). Within most or all eukaryotic cells, there is an O2 gradient, decreasing in concentration from the cell membrane to the O2 -consuming
mitochondria (Fig. 1.4).
However, O2 is much more soluble in organic solvents than in water (about tenfold for hydrocarbon
solvents and even greater for fluorocarbons), a point

O X Y G E N : B O O N Y E T B A N E — I N T R O D U C I N G O X Y G E N TO X I C I T Y A N D R E A C T I V E S P E C I E S

to consider when exploring oxidative damage to the
hydrophobic interior of biological membranes (Section 5.11). One practical consequence of this is the
inability of some plastic culture vessels to maintain
anoxia in laboratory experiments; O2 can pass through
many types of plastic.12 A related phenomenon often
overlooked, antioxidants and other chemicals can leach
from plastic tubes, syringes, dishes, and pipes and thus
confuse experimental results.13,14 However, the obvious biological advantage is that O2 readily diffuses
across membranes, an essential ability as internally
compartmentalized eukaryotic cells and multicellular
organisms evolved.

1.2 Oxygen and anaerobes
As O2 levels rose in the atmosphere, living organisms
began to experience O2 toxicity: oxidations of key molecules essential to the organism which halted growth
and were in some cases lethal. This created pressure
to evolve protective mechanisms and/or to retreat to
anoxic environments (Fig. 1.3).
The term ‘anaerobic organism’ covers a wide range
of biological variation.2,15–19 There are ‘strict’ anaerobes, such as the bacteria Treponema denticola, Prevotella
melaninogenica, and several Clostridium spp., that will
grow only if O2 is absent (or at least as absent as
it can ever be; it is almost impossible to eliminate it
completely in the laboratory). Indeed, the treatment of
gangrene due to Clostridium infections by exposing patients to pure O2 at pressures higher than atmospheric
(hyperbaric oxygen (HBO) therapy) is in part based
on the sensitivity of Clostridium spp. to O2 . Hyperbaric
treatment is not without problems, however (Section
1.5.2). The so-called strict anaerobe Bacteroides fragilis
even seems to benefit from nanomolar (10–9 M) levels
of O2 , and has been called a nanaerobe, although it
cannot grow at higher O2 levels.18 The difficulty in
maintaining very low O2 levels in the laboratory suggests that much early work on the O2 tolerance of
bacteria needs re-ev