Free Radicals, Oxidative Stress, and Diseases Associated with Them

Volume 62 2015 Number 1

JOURNAL OF THE BULGARIAN PHARMACEUTICAL SCIENTIFIC SOCIETY

Editorial Board

Alexander Zlatkov (Faculty of Pharmacy MU Sofia Bulgaria)Bojka Tzvetkova (Faculty of Pharmacy MU Sofia Bulgaria)Christo Tsvetanov (Institute of Polymers BAS Sofia Bulgaria)Darvin Ivanov (Faculty of Pharmacy MU Sofia Bulgaria)Danka Obreshkova (Faculty of Pharmacy MU Sofia Bulgaria)Georgi Momekov (Faculty of Pharmacy MU Sofia Bulgaria)Guenka Petrova (Faculty of Pharmacy MU Sofia Bulgaria)Ilijana Jonkova (Faculty of Pharmacy MU Sofia Bulgaria)Nikolai Lambov (Faculty of Pharmacy MU Sofia Bulgaria)Nikolai Danchev (Faculty of Pharmacy MU Sofia Bulgaria)Stefan Nikolov (Faculty of Pharmacy MU Sofia Bulgaria)Bistra Angelovska (Goce Delcev University Skopje Macedonia)Ebba Holme Hansen (University of Koslashbenhavns Koslashbenhavn Denmark)Fabrice Clerfeuille (University of Nantes Nantes France)Georg Heun (University of Applied Sciences Koetten Germany) Luisa Pistelli (University of Pisa Pisa Italy)Marion Schaefer (Institute of Clinical Pharmacology and Toxcology Berlin Germany)Mecedes Unzeta (Autonomic University of Barselona Barcelona Spain) Ruediger Groening (University of Muenster Muenster Germany)Svjetlana Luterotti (University of Zagreb Zagreb Croatia) Danijel Kikelj (University of Ljubljana Ljubljana Slovenia)

Editor in Chief P Peikov

Secretary M Georgieva

Indexed in MEDLINE CAplusSMChemical Abstracts TOXCENTER EMBASEExcerpta Medica PASCAL BIOTECHNOBASE ExtraMEDTM SCOPUS

Elsevier impact metrics SJR for Pharmacia for 2011 0122

Editorialpublishing policy Manuscripts submitted to PHARMACIA are only accepted on the understanding that they are subject to editorial review and review of at least two independent referees that they have not been and will not be bublished whole or in part in any other journal and that recommendations to comply with with ethycal standards when performing clinical and other biological experiments have been adhered to

Publishing frequency is four times a year (volume) Only abstracts published in the Journal may be reproduced without prior permission reproduction of other materials requires publisherrsquos consent

Address of Editorial Board

Faculty of Pharmacy Editor in Chief (+359 2) 9236 5052 Dunav str Sofia 1000 E-mail pharmacia_editorpharmfacnetFax (02) 987 987 4 Secretary (02) 9236 515

E-mail pharmacia_secretarypharmfacnet

Number 2

PPHHAARRMMAAccIIAAVolume 60 2013 Number 1

c o N t e N t s

original articles

I Todorov M Christov K Stanoeva K Yakimova Leptin and GABA interactions on body temperature of rats00

S Harkov D Havrylyuk V Atamanyuk B Zimenkovsky R Lesyk Synthesis and biological activity of isatines bearing thiazolidinone and pyrazoline moietieshelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip00

L Peikova B Tsvetkova RP-HPLC method for simultaneous determination of Amlodipine besylate and Valsartan in pharmaceutical dosage form helliphelliphelliphelliphellip00

Review articles

Georgi Momekov Niko Benbassat Pharmacological properties of Hawthorn leaf and flower as a cardiovascular agenthellip00

L Peikova B Tsvetkova Amide-based prodrugs of nonsteroidal anti-inflammatory drugshelliphelliphelliphellip00

L Andonova M Georgieva Al Zlatkov Arylpiperazine derivatives ndash new agents affecting mood disordershelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip00

Georgi Momekov Iliana Ionkova Paraskev Nedialkov Zlatina Kokanova-Nedialkova Dimitrina Zheleva-Dimitrova Ilina Krasteva Yohana Ilieva Ilina Dineva Gerassim Kitanov Stefan Nikolov Spiro Konstantinov Overview of the oncopharmacological studies of plant-derived natural products conducted at the Faculty of Pharmacy (MU-Sofia) helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 00

D Obreshkova Reactive oxygen species induced neurodegeneration in Alzheimerrsquos diseasehelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip00

Instructions to authorshelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip00

c o N t e N t s

original articles

St Pankova D Tsvetkova K Ivanov St Papanov St Ivanova Validation of TLC ndash densitometric method for identification and determination of estradiol 3

A Kougioumtzoglou L Peikova M Georgieva Al Zlatkov Evaluation of the stability of indomethacin substance under a model of physiological conditions using modified and validated RP-HPLC method 10

Kr Makukh T Ryvak O Lopatynska Patientsrsquo compliance to phytotherapy prescribed and self-medicated with herbal medicines in Ukraine 18

Review articles

L Andonova M Georgieva Al Zlatkov Free radicals oxidative stress and diseases associated with them 26

St Ivanova K Ivanov St Pankova Br Zlatkov K Stoychev Sport supplementation beneficial effects of vitamin E and creatine on exercise performance 40

E Drakalska D Momekova S Rangelov N Lambov Nanoparticles as platforms for delivery of curcumin 50

From the editorial board

Instructions to authors 58


26

IntroductionOxygen is one of the most important molecules on

Earth mainly because of the biochemical symmetry of oxygenic photosynthesis and aerobic respiration that can maintain homeostasis within our planetrsquos biosphere The paradox of aerobic life is the fact that the higher aerobic eukaryotes can not live without ox-ygen but in its essence it is dangerous for their life At the end of the 18th century oxygen is described as a model among the elements constituting life that contributes to physical health and stimulates mental strength But too much of even the best can be wrong as said from Paul Bert in 1878 describing the oxygen in high concentrations as harmful to the brain lungs and other organs [1]

The initial studies suggest that at high concentra-tions oxygen inactivate cellular enzymes However in vitro experiments show that the enzyme deacti-vation is too low to develop toxic effects In 1954 Gershman and Gilbert suggest that the known neg-ative effects of oxygen are due to formation of free radicals thereof [2] In the same year Commoner Townsend and Pake in studies of various freeze-dried biological materials using electron paramagnetic resonance observe weak signals due to the presence of free radicals [3] The work of Denham Harman in

1956 [4] described the assumptions about the role of free radicals in the aging process gradually increased the depth of research on free radicals in biological systems Gershman theory was not fully accepted until the detection of the superoxide dismutase en-zyme in 1969 an enzyme catalyzing the conversion of superoxide radicals to hydrogen peroxide Thus McCord and Fridovich launched the second era in the study of free radicals [5-8] The third era dates from 1977 When Mittal and Murad provide evidence for hydroxyl radical which stimulates the activation of guanylate cyclase and formation of a bdquosecond mes-sengerldquo ndash cyclic guanosine monophosphate (cGMF) [9] In 1978 Erwin Schauenstein and Hermann Es-terbauer [10] found that some aldehydes such as acrolein and 4-hydroxy-2-alkenals easily react with sulfhydryl groups via thioether linkages to form sta-ble complexes They probably lead to inhibition of certain metabolic processes including glycolysis protein synthesis and respiration In the same year they also expressed the hypothesis that lipid peroxi-dation leads to formation of various α β-unsaturated aldehydes In 1980 Benedetti et al found that one of these aldehydes 4-hydroxy-2-nonenal exhibit cy-totoxicity on liver cells [11] In the 80s of the 20th century greatly increased research on lipid peroxida-

Review Articles

FRee RADIcALs oXIDAtIVe stRess AND DIseAses AssocIAteD WItH tHeM

L Andonova M Georgieva Al Zlatkov

Department of Pharmaceutical chemistry Faculty of Pharmacy Medical University ndash Sofia Bulgaria

Abstract Oxygen is one of the most important and indispensable elements since life molecules on Earth can under certain situations produce from it constantly in the human body toxic mol-ecules called free radicals andor other reactive oxygen species (ROS) ROS play a dual role in biological systems since they can be either harmful or beneficial to living systems These highly reactive species capable of wide spread indiscriminate oxidation and peroxidation of proteins lipids and DNA which can lead to significant cellular damage and even tissue andor organ fail-ure However it is well known fact that many of the ROS-mediated responses actually protect the cells against oxidative stress On the other hand over-production of ROS has the potential to cause damage In addition currently some increasing evidence appeared showing that oxidative stress is associated with the pathogenesis of number diseases like neurodegenerative disorders cardiovascular diseases neuropsychiatric disorders cancer diabetes cataract etc

Key words Oxidative stress Free radicals Reactive oxygen species (ROS) Reactive nitrogen species (RNS) Lipid peroxidation

PHARMACIA vol 62 No 22015 27Free radicals oxidative stress and diseases associated with them

tion [12 13] The main findings concerning hydroxy alkenyls include inhibition of DNA and RNA syn-thesis inhibitory effects on the DNA polymerase and adenylate cyclase enzymes quantification by HPLC and etc [14]

1 oxygen free radicals ndash sources and typesFree radical is a chemical particle that contains of

one or more unpaired electrons Free radicals are ex-tremely reactive and therefore have a very short half-life and low concentration of the stable state

Sources of oxygen free radicalsReactive oxygen species (ROS) are generated

continuously by the oxygen in all aerobic organisms during the intracellular metabolism in response to an external stimulus ROS are generated in many compartments and numerous enzymes in the cells However at this point it is well known that the largest source of ROS is the mitochondrial electron trans-port chain whereat the monoamine oxidase system may also contribute During inflammation the pres-ence of ROS in some cells is also increased result-ing in a highly specialized NADPH oxidase-depen-dent system NADPH oxidase (NOX) is a complex enzyme All enzymes of the family of NOX carried out transmembrane electron transport using NADPH as a source of electrons and molecular oxygen scav-enger Additional sources of ROS are cytoplasmic cytochrome P450 cyclooxygenase lipoxygenase [15] The molecular oxygen is biradical as it has one unpaired electron in each of the two frontier π an-ti-bonding orbitals The reactivity of the molecular oxygen is extremely low which is due to the parallel spin of these electrons

bull Singlet oxygenUpon introduction of energy in an oxygen mol-

ecule the spin of the electrons changes to antiparal-lel which leads to the formation of so called singlet oxygen with high reactivity Singlet oxygen has two forms - delta singlet oxygen and sigma singlet oxy-gen (Fig 1) the first has significantly important bio-logical role as a result of its long half-life But he is not a free radical as there is no unpaired electrons On the other hand the sigma singlet oxygen has sig-ma electrons with antiparallel spins which are lo-cated in different orbitals These particles have very high reactivity but a short half-life since it is decom-posed as soon as they are formed and transforms in delta singlet oxygen

bull Superoxide radicalsSuperoxide radical (O2

-bull) is a free radical formed upon addition of single electron to an oxygen mole-cule [16] This radical is unstable in aqueous solu-tions since it reacts spontaneously with himself in the presence of hydrogen ions and forms hydrogen peroxide and molecular oxygen which is also its ca-tabolism [17]

O2 O2+ + 2H H2O2 +O2 (1)

Superoxide radicals are generated by autooxidation of the oxygen molecule during the metabolic process-es also known as mitochondrial electron transport re-actions It can also occur in the cytosol or mitochondria in enzymatic reactions catalyzed by xanthine oxidase and cytochrome P450 Superoxide radical is the least reactive of all types of oxygen radicals and is the most observed in humans It is defined as ldquoprimaryrdquo ROS because once formed enters the cascade of reactions with other molecules to form other ldquosecondaryrdquo ROS This process can be carried out directly or can be cata-lyzed by metal ions or enzymes [18 19]

Superoxide radical may also be in a protonated form as perhydroxyl radical (HO2

bull) which shows a seven-fold higher reactivity but at physiological pH dominate the non-protonated form [20] Superoxide radicals react with halogens (chlorinechloride ion) released from leukocytes to obtain hypochloric acid which is cytotoxic free radical The hypohalogenic acids are obtained in reactions catalyzed by haloper-oxidase enzymes [19 21-23]

bull Hydrogen peroxideAfter reduction of two electrons in the molecule

of oxygen a peroxide ion (O22-) is formed with hydro-

gen peroxide as its protonated form It is not regarded as a free radical but has a strong detrimental impact on the cells as it can cross the cell membranes cause synthesis of highly reactive hydroxyl radical (OHbull)

Ground state

Delta singlet oxygen

sigma singlet oxygen

Fig 1 Distribution of electrons in π anti-bonding orbitals

28 PHARMACIA vol 62 No 22015 L Andonova M Georgieva Al Zlatkov

bull Hydroxyl radicalsHydroxyl radical is a product of reduction of

three electrons of molecular oxygen It is the most reactive free radical and can react with any biologi-cal molecule [23] As a result has a very short half-life about 9-10 sec [24] Superoxide and peroxide radicals are less reactive but have a longer half-life allowing them to react with molecules which are lo-cated further from the place of formation [25 26] The main source of hydroxyl radicals is the iron-cat-alyzed Haber-Weiss reaction (reaction 4) which gen-erates bullOH (hydroxyl radicals) from H2O2 (hydrogen peroxide) and superoxide (bullO2

minus) This reaction is very slow and can occur in cells and is therefore a possible source for oxidative stress The first step of the cata-lytic cycle involves reduction of ferric ion to ferrous (reaction 2) followed by a Fenton reaction (reaction 3) [17 23]

O2 + Fe3+ O2 + Fe2+

Fe2+ + H2O2 Fe3+ + OH- + OHO2 + H2O2 O2 + OH- + OH

(2)

(3)

(4)

2 Nitrogen free radicals (RNs) ndash sources and types

Nitrogen monoxide (nitric oxide) may be pro-duced by a number of cells (endothelial neuronal

(2)

(3)

(4)

macrophages etc) It has been found that in vivo it is formed by the oxidation of arginine by oxygen cata-lyzed by the enzyme nitric oxide synthase Nitrogen monoxide acts as a messenger when it forms a ni-trosyl complex with the haem of guanylate cyclase and initiates the formation of cyclic GMP NO also functions in the immunological response by produc-ing in combination with superoxide radical a potent oxidant and nitrating agent peroxynitrite (ONOOminus) able to damage cellular macromolecules (including DNA and proteins) In many aspects this oxidant cre-ates the same damage as the hydroxyl radical [23 27-30] Peroxynitrite is an unstable structural isomer of nitrate NO3

minus Although its conjugate acid is high-ly reactive peroxynitrite is stable in alkali solutions

[31] Formation of peroxynitrite in vivo has been as-cribed to the reaction of the free radical superoxide with the free radical nitric oxide [3233]

middoto2 + middotNo oNo2 (5)

The resultant pairing of these two free radicals re-sults in peroxynitrite a molecule that is itself not a free radical but that is a powerful oxidant

3 Lipid peroxidationLipids (cholesterol polyunsaturated fatty acids

(PUFAs)) are a main target of oxidative attack Lipid

C5H11 (CH2)7COOH

H

C5H11 (CH2)7COOH C5H11 (CH2)7COOH


O2 O2OO O O


OHO O OH+LH-L

+LH-L


HO OHReduction Reduction

Fig 2 Removal of hydrogen from PUFA and their transformation into two stereo isomers of LOOH molecules


hydroperoxides (LOOHs) and their products of de-composition are generated by the processes of lipid peroxidation of PUFAs They are characterized by the presence of one or more structural elements con-taining a methylene (CH2) group between the double bonds

bull Processes of non-enzymatic lipid peroxida-tion

The hydrogen atoms of the double allyl-activated methylene group can be replaced easily The process requires a very small amount of energy including UV light addition of divalent ions such as iron for exam-ple and other processes which generate radicals Ob-tained dienyl radical (LS Fig 2) immediately reacts with oxygen to form peroxidienyl radicals (LOOS) They are able to remove hydrogen from a methylene group of another PUFA thus forming a lipid hydrop-eroxide and a new dienyl radical and thereby initiate the chain reaction [34]

bull Enzymatic lipid peroxidationThe energy which is necessary for the removal of

hydrogen from a double-activated methylene allyl group in PUFA is even lower when the process is activated by enzymes of the group of lipoxygenas-es [35-37] After hydrogen removing it turns into a proton To the resultant dienyl residue oxygen in stereo specific reaction is added The resulting per-oxidienyl radical is transformed into an anion The reaction is terminated by the reverse transfer of the protons produced in the first stage of the process Thus forming a chiral lipid hydroperoxides (Fig 3) and during these events the radical is not leaving the enzyme complex [38 39]

Summarizing the above may be indicated that free radicals and other reactive species are derived either from normal essential metabolic processes as well as from not mentioned so far external sources As one of the most important internal factors must be identified the enzymatic reactions which serve as a source of free radicals These include those reactions involved in the respiratory chain in phagocytosis in prostaglandin synthesis and in the cytochrome P450 system Some internal sources of generation of free radicals are mitochondria xanthine oxidase phago-cytes reactions involving iron and other transition metals inflammation External sources of free rad-icals include in general non-enzymatic reactions of the oxygen with organic compounds Free radicals are also produced in reactions which are initiated by ionizing radiations Some external sources of free

radicals not mentioned above are cigarette smoke environmental pollutant radiations ultraviolet light ozone certain drugs pesticides anesthetics and in-dustrial solvents Last but not least some physio-logical factors such as stress emotion and disease conditions are also responsible for the formation of free radicals

4 Protection of the organism from free radicals

Mammalians have evolved a defense system against free radicals in which many antioxidants per-form different roles These anti-free-radical defense systems control the levels of free radicals and other lsquoreactive speciesrsquo by a complex web of antioxidant defences which minimize (but do not completely prevent) oxidative damage to biomolecules In human disease this lsquooxidantndashantioxidantrsquo balance is tilted in favour of the reactive species so that oxidative dam-age levels increase In some diseases this makes a significant contribution to tissue injury giving rise to prospects for therapeutic intervention with rationally designed antioxidant drugs The antioxidant system of the organism is complex and can be separated as follows (Table 1)

Fig 3 Generation of LOOH molecules by lipoxygenase

C5H11 (CH2)7COOH

H H

C5H11 (CH2)7COOH

H

C5H11 (CH2)7COOH

C5H11 (CH2)7COOH

OO

C5H11 (CH2)7COOH

OHO

Fe3+

Fe2+ + H+

Fe3+Fe2+ + H+


bull enzymatic (endogenous) antioxidants super-oxide dismutase catalase glutathione reduc-tase and glutathione peroxidase The defense enzyme superoxide dismutase (SOD) takes hold of molecules of superoxide ndash a partic-ularly destructive free radical-and changes them to a much less reactive form SOD and another important antioxidant enzyme set the glutathione system work within the cell Circulating biochemicalrsquos like uric acid and ceruloplasmin react with free radicals in the intercellular spaces and bloodstream

bull non-enzymatic antioxidant1) Metabolic (endogenous) glutamine L-ar-ginine CoQ10 melatonin uric acid2) Food antioxidants (exogenous) ndash vitamins (A E and C) zinc magnesium omegandash3 and omegandash6 fatty acids carotenoids and poly-phenols (flavonoids curcumin resveratrol etc) [23 40 41]

Antioxidants are substances that slow or prevent the oxidation other chemicals and in this way are ca-pable of counteracting the damaging effects of oxida-tion in body tissue Oxidation reactions can involve the production of free radicals which can form dan-gerous chain reactions Antioxidants can terminate

Table 1 Various types of free radicals and their corresponding antioxidant systems [42]

Type of free radical or oxidant Antioxidant system

superoxide anion superoxide dismutase

hydroxide radical SOD Mn-SOD Cu Zn-SOD glutathione

singlet oxygen Tocopherols ubiquinone

peroxide radical carotenoids

hydrogen peroxide Catalase Se-glutathione peroxidase

hydroperoxides Glutathione peroxidase reductase

transition metals chelators

these chain reactions by removing radical intermedi-ates and can inhibit other oxidation reactions by be-ing oxidized themselves Although there are several enzyme systems within the body that scavenge free radicals the principle micronutrient (vitamin) anti-oxidants are vitamin E beta-carotene and vitamin C Additionally selenium a trace metal that is required for proper function of one of the bodylsquos antioxidant enzyme systems is sometimes included in this cate-gory The body cannot manufacture these micronutri-ents so they must be supplied in the diet

The antioxidant reacts with the radical by one of the following mechanisms (Fig 4)

In functional aspect the biological protection against free radical processes could be provisionally separated in three consecutive protective levels

Factors acting at the first level decrease to possi-ble minimum of endogenous radical formation Here could be considered the factors which function is to prevent as much as possible endogenous formation of free radicals

At the second ndash main level of antioxidant protec-tion of organism interception and disposal of already formed free radicals is performed It is realized main-ly through antioxidant components

Some enzymes which partially recreate damages caused by free radicals are classified as third level

(1) Cleavage of hydrogen

(2) Addition

(3) Electron transfer

X + IH XH + I

X + C C X C CX + IH X- + IH X- + I + H+

Fig 4 Mechanism of the reaction between the antioxidant and a free radical [43]


of antioxidant protection For example such effects have phospholipase A2 some proteolytic enzymes methionine ndashsulfoxide reductase DNA reparative enzymes and others [44]

5 Diseases associated with free radicals and oxi-dative stress

Oxygen free radicals or more generally reactive oxygen species (ROS) as well as reactive nitrogen species (RNS) are products of normal cellular me-tabolism ROS and RNS are well recognised for playing a dual role as both deleterious and beneficial species since they can be either harmful or benefi-cial to living systems Free radicals and other reactive species have been implicated in the pathology of over 100 human diseases ranging from ulcerative colitis and haemorrhagic shock to cystic fibrosis and AIDS Some human diseases may be caused by oxidative stress For example ionizing radiation generates OH by splitting water molecules and many of the biolog-ical consequences of excess radiation exposure are probably due to oxidative damage to proteins DNA and lipids Injuries caused by free radicals are an im-portant factor in many pathological and toxicological processes [45] In recent decades more and more talk about oxidative stress which is defined as an imbal-ance between the formation of reactive oxygen and nitrogen particles (ROSRNS) and antioxidant pro-tection Oxidative stress is characterized by the in-ability of endogenous antioxidants to counteract ox-idative damage to biomolecules and also plays a key role in the pathophysiology of a variety of diseases [46-48] While excess of ROS strongly damages the nucleinic acids lipids and proteins low levels of ROS affect cell signaling mainly at the level of the redox modulation Considerable evidence suggests that the role of ROS is quite complex it seems that is crucial in the intracellular signal transduction in many cellu-lar responses such as inflammation proliferation dif-ferentiation angiogenesis aging and apoptosis [40] The beneficial role of free radicals consists in the fact that they perform many critical functions in our bodies in controlling the flow of blood through our arteries to fight infection to keep our brain alert and in focus Phagocytic cells involved in body defense produce and mobilize oxygen free radicals to destroy the bacteria and other cells of foreign matter which they ingest Similar to antioxidants some free radi-cals at low levels are signaling molecules ie they are responsible for turning on and off of genes Some free radicals such as nitric oxide and superoxide are

produced in very high amount by immune cells to poison viruses and bacteria Some free radicals kill cancer cells In fact certain cancer drugs aim in in-creasing the free radical amount in body The excess of free radicals is also responsible for causing athero-sclerosis cardiovascular diseases cancer alcohol-in-duced liver diseases depression ulcerogenic colitis etc [41 49]

51 schizophrenia and oxidative stressSchizophrenia is a severe neuro psychiatric disor-

der which according to WHO data affects 24 million people of the world population One of the factors which contribute to the development of schizophre-nia is oxidative damage to nerve cells The brain is particularly vulnerable to oxidative stress resulting in relatively low levels of antioxidants high levels of polyunsaturated fatty acids and increased oxygen consumption Established a very strong relationship between oxidative stress and the pathophysiology of schizophrenia In plasma and erythrocytes of patients with schizophrenia increased levels of products of lipid peroxidation were observed as well as enzy-matic and non-enzymatic antioxidants [50]

52 oxidative stress and cardiovascular diseaseCardiovascular diseases are the most common

cause of death in developed countries Although atherosclerosis was initially considered a common disorder thought to result from the accumulation of lipids in the arterial wall it is clear today that it leads to a series of inflammatory processes The initiating step in the development of atherosclerotic lesion is the damaging of the endothelium Oxidative stress may contribute to endothelial dysfunction andor cell death Furthermore many types of ROS are re-sponsible for the migration of smooth muscle cells in the intima and also regulate their proliferation Macrophages are able to form ROS which play an important role in inflammation in the injured en-dothelium and cause oxidative modification of low density lipoproteins Platelets may themselves form or may be activated by the superoxide and other rad-icals resulting in increased aggregation and throm-bogenesis [51]

53 oxidative stress and neurodegenerative dis-eases

Parkinson disease (PD) is the second most com-mon neurodegenerative disease after Alzheimerrsquos disease (AD) prevailing in industrialized countries and the WHO estimates affects between 7 and 10


million people worldwide PD is a complex neurode-generative disease with motor and non-motor symp-toms which results in the loss of neurons in the brain Currently there is only a symptomatic treatment and no way to control the degenerative process that re-mains not quite clear Aging genetic predisposition and environmental factors are considered as risk fac-tors There is a significant progress in understanding the mechanisms that contribute to dopaminergic cell death in the substantia nigra including mitochon-drial dysfunction inflammation oxidative narrow-ing Oxidative stress remains the main element in the concept of loss of dopaminergic neurons in PD Since 1980 the publications that determine the for-mation of ROS as the last step of neuronal death of any origin significantly increase Starting from the idea of forming free radicals by high chemical and enzymatic oxidation of dopamine in the mechanism of action of some toxins such as 6-hydroxydopamine (6-OHDA) and paraquat (NNprime-dimethyl-44prime-bi-pyridinium dichloride) and ending with evidence of clinical and postmortem studies oxidative stress and damage that causes emerge [52] Lipid peroxi-dation is strongly associated with some neurodegen-erative diseases such as PD [53] Huntington disease [54] amyotrophic lateral sclerosis and AD [55-59] During the enzymatic and non-enzymatic reactions induced lipid peroxidation LOOS are prepared as in-termediates Radicals LOOS obtained by enzymatic reactions have been disabled by the enzyme complex and are much less reactive than LOOH On the other hand LOOS generated with non-enzymatic reactions can react with surrounding molecules by attacking all molecules with double bonds by epoxidation As a result important brain compounds such as sphin-gomyelins cholesterol esters and unsaturated fatty acids are converted into epoxides In turn epoxides are also reactive and may react with nucleophiles LOOS radical attack also the amino acid residues of the proteins thereby inducing plaque formation which is the basis for neurodegenerative diseases Since the presented sequence of events (changes in cellular structure influx of Ca2+ ions the activation of enzymes generating LOOH molecules and their final cleavage with release of the divalent metal ions from enzymes induces the generation of peroxyl rad-icals and their attack on proteins) requires much less amount of energy than the direct oxidation of the pro-teins it can be concluded that the formation of plaque is the result of processes of lipid peroxidation [34] It was reported also for lipid peroxidation in the phos-pholipids The oxidized phosphatidylcholine is used

as a marker of inflammation and is set at high levels in stroke and multiple sclerosis [60 61]

The improved understanding of the disease the discovery of the relationship between lipid peroxi-dation and neurodegenerative diseases increased sig-nificantly over the past 20 years So this new field of science provides essential information for modifica-tions to macromolecules not only on neurodegenera-tive diseases and cancer These new knowledge offer much insight into the mechanisms of disease and can be considered as potential targets for development of new therapeutic strategies [14]

54 oxidative stress and cancerCancer is the biggest health problem in the world

Despite the progress in prevention and treatment tumors are still the second most common cause of death [62] The development of cancer is a multistep process which is mediated by complex molecular and cellular changes caused by various endogenous and exogenous stimuli

Although the mechanisms of antioxidant defense cellular damage from ROS are ubiquitous and even not cause cell death can stimulate the development of cancer There are many hypotheses that mutagen-esis caused by oxidative changes in the structure of DNA is common in normal human cell A large num-ber of evidence confirm the essential role of ROS in the expansion of tumor cells and their acquisition of malignant properties therefore they define as an es-sential factor in the development of carcinogenesis For this reason the inefficiency of preventive anti-oxidant therapy studied in clinical trials is very sur-prising Ultimately the difficulties in antioxidant in-tervention can be explained by the complexity of the chemistry of free radicals and cancer Hence today it is assumed that it is best to reduce the causes leading to oxidative stress [63]

Oxidative stress is a key component in the rela-tionship between the toxicity of the environment and the multistep process of carcinogenesis ROS are formed in response to endogenous and exogenous stimuli There is a lot of evidence of in vivo and in vitro studies that determine external factors such as radiation xenobiotics and chlorinated agents as sig-nificant inducers of cell damage by ROS-mediated toxicity

Chronic accumulation and oxidative stress induc-es harmful modifications in many macromolecules such as DNA proteins and lipids ROS attack DNA indirectly by reacting with other cellular components such as phospholipids Phospholipid residues are in


much higher concentrations and are the first targets of ROS As a result of passed lipid peroxidation a broad range of reactive carbonyl intermediates such as αβ-unsaturated aldehydes like 4-hydroxynonenal (4-HNE) and acrolein dialdehydes such as malond-ialdehyde (MDA) and glyoxal and keto-aldehydes like 4-oxo-trans-2-nonenal (4-ONE) are obtained (Fig 5) These carbonyl compounds generated in bi-ological systems have unique properties contrasted with free radicals Further the non-charged structure of aldehydes allows them to migrate with relative ease through hydrophobic membranes and hydrophil-ic cytosolic media thereby extending the migration distance far from the production site Based on these features alone these carbonyl compounds can be more destructive than ROS and may have far-reach-ing damaging effects on target sites within or outside membranes as they react with nucleophilic groups in macromolecules like proteins DNA and aminophos-pholipids among others resulting in their chemical non-enzymatic and irreversible modification [64]

4-HNE is found throughout animal tissues and in higher quantities during oxidative stress due to the increase in the lipid peroxidation chain reaction upon increase in stress events It has been hypothe-sized to play a key role in cell signal transduction in a variety of pathways from cell cycle events to cel-lular adhesion [65] There seems to be a dual action of 4-HNE on the health of cells lower intracellular concentrations seem to be beneficial to cells promot-ing proliferation differentiation antioxidant defence and compensatory mechanism while higher concen-trations have been shown to trigger well-known toxic pathways such as the induction of caspase enzymes the laddering of genomic DNA the release of cyto-chrome C from mitochondria with the eventual out-

come of cell death (through both apoptosis and ne-crosis depending on concentration) 4-HNE has been linked in the pathology of several diseases such as Alzheimerlsquos disease cataract atherosclerosis diabe-tes and cancer [64]

Both of malondialdehyde and 4-hydroxynonenal can bind irreversibly to nitrogen containing bases of DNA thus forming DNA-adducts This determines their central role in carcinogenesis because the over-coming of the mechanisms of cell protection and continuing to persist would lead to the formation of mutations [65-71] Oxidative changes are not only part of the etiology of cancer and even developed a critical biomarker (8-oxo-dG) determining DNA damage [72-76]

bull Mode of carcinogenic action of ROSROS are involved in all three stages of the de-

velopment of cancer initiation promotion and pro-gression The effect of oxidative stress on the cor-responding stage of carcinogenesis is directly pro-portional to the type and reactivity of the radical Initiation is the result of a mutation in the DNA and normal cell after fixation of the mutation resulting from cleavage of DNA damage was prepared trig-gering cell [77] Promotion step is characterized by clonal expansion of mutated initiating cells by induction of cell proliferation andor inhibition of apoptosis [68] Oxidative stress is closely related to this stage as ROS stimulate proliferation of mutant cells by continuing to modulate genes related to pro-liferation or cell death [78] and regulate the activity of certain transcription factors involved in the con-trol of cell growth and oncogenesis [79 80] This leads to activation and secondary induction of genes encoding proteins that inhibit apoptosis [81] It has

O OH

H H

O O

H H

OH

O

malondialdehyde (β-hydroxyacroleine) 4-hydroxynonenal (4-HNE)O

OO H

H H

OO

H

H

acroleine glyoxal 4-oxo-trans-2-nonenal

Fig 5 Products of lipid peroxidation


been found that even very low levels of oxidative stress stimulate cell division at this stage and lead to tumor growth as this determines the production of ROS as a major mechanism of tumor promotion [82] ROS play an important role in the final stage of carcinogenesis progression The generation of large amounts of ROS contributes to new mutations inhibit antiproteases and cytoplasmic metallopro-teinases [83 84] and affect local tissues [85] El-evated levels of oxidatively modified DNA bases lead to genetic instability and metastatic potential of tumor cells [86]

bull ROS mediated damage in biomolecules and their role in carcinogenesis

Oxidative changes in nuclear and mitochondrial DNA are expressed mainly in increased levels of ox-idative DNA changes reported in studies of different types of tumors highlighting their role in the etiolo-gy of cancer [87-89] ROS RNS cause these DNA changes [90]

(1) structural changes in DNA including muta-tions in the databases such as deletions insertions duplications inversions Thus ROS induce chromo-somal changes that lead to inactivation or loss of al-leles of tumor suppressor genes and developing steps promotion andor progression by expression of the mutant phenotype

(2) affection on the nuclear and cytoplasmatic sig-nal transduction pathways

(3) modulation of the activity of the genes and proteins in an environment of oxidative stress regu-lating genes associated with cell proliferation differ-entiation and apoptosis

(4) RNS as NO2 ONOOndash N2O3 and HNO2 are mutagenic Have the potential to produce reactions of nitration nitrosation and deamination in DNA bases [91 92]

(5) exposure of cells to H2O2 and other oxidants inhibits DNA repair which leads to an increase in disability and increased risk of disease [93]

bull Damage to mitochondrial DNAROS mediated deletions and mutations in mito-

chondrial DNA (mtDNA) with age are accumulat-ed to a greater extent than in the nuclear DNA [94] MtDNA is much more susceptible to radical attack due to the large amount of histones and the proxim-ity of the respiratory chain Moreover the reparation of the mtDNA is significantly reduced compared to chromosomal DNA which significantly contributes to carcinogenesis [95]

bull Oxidative damage to proteinsMany studies show that the proteins are the main

cellular target of ROS [96 97] Oxidative changes in proteins include loss of histidine residues oxidative cleavage of the polypeptide chain introducing car-boxyl and other groups [98] Radical ndash protein inter-actions violate the very important functions of certain proteins such as enzymes involved in DNA repair which often leads to increased incidence of muta-tions The products of proteins oxidation such as NO or H2O2 may cause cascading effects that potentially can damage cellular macromolecules

bull Oxidative changes in lipidsCell membranes are very sensitive to radical at-

tack [99] ROS-induced lipid peroxidation in cell membranes was associated with malignant transfor-mation [100]

Mechanism of carcinogenic action of the RNS NO mediated DNA damage via formation of carcino-genic nitrosamines RNS formation and inhibition mechanisms of DNA repair which defined itself as a tumor-initiating agent [101] It can also have an im-pact on other stages of cancer development by inhib-iting apoptosis promoting angiogenesis modulation of defense mechanisms It was found that NO and NOS enzymes are elevated in the blood and tissues of patients with cancer of the oral cavity [102]

In the treatment of cancer are used radiation ther-apy and chemotherapy which themselves induce the formation of free radicals Radiation therapy based on the irradiation of X and γ-rays to destroy tumor cells even in the deeper tissues is actually causing direct damage to DNA and thereby impairing cell division The primary mechanism of action of many of the drugs used in chemotherapy is the formation of ROS-alkylating agents (Melphalan Cyclophos-phamide) anthracycline antibiotics (Doxorubicin Epirubicin) podophyllinic derivatives (Etoposide) platinum complexes (Cisplatin Carboplatin) and camptothecins (Topocan Irinotecan) Ultimately the generated free radicals in the therapy often lead to side effects such as nephrotoxicity ototoxicity car-diotoxicity and etc

Some studies have shown decreased anti-oxidant status and increased oxidative stress observed in pa-tients even before the start of oncotherapy [103]

Enzymatic and non-enzymatic antioxidant sys-tems act as synergists to protect cells and organs from the radical damage and therefore cancer Their inhib-itory effects on cancer are based on

1) Immune mechanisms increased immune re-


sponse by stimulating cytotoxic cytokines that de-stroy tumor cells

2) Molecular and genetic pathways3) Inhibition of tumor angiogenesis4) Stimulation of cell differentiationAntioxidants are used in the treatment of cancer

and to enhance the effects of chemotherapy and ra-diotherapy Yet the use of antioxidants in cancer ther-apy is debatable There is evidence that antioxidants may reduce the effectiveness of drugs that affect the tumor cells by generating free radicals Although an-tioxidant protection is extremely important the anti-oxidant therapy should be administered with caution and given the stage which includes as when used in the phase of progression of cancer can stimulate tumor growth by increasing resilience of tumor cells Also should be considered carefully and pro-oxidant states effect of some antioxidants [104]

conclusionReactive oxygen species (ROS) as well as reactive

nitrogen species (RNS) are products of normal cellu-lar metabolism ROS and RNS are well recognised for playing a dual role as both deleterious and beneficial species since they can be either harmful or beneficial to living systems Overproduction of ROS and other free radicals result in oxidative stress Oxidative stress has been implicated in the etiology of large number of major diseases and plays a major role in the pathogen-esis of many disorders including neurodegenerative processes (including cell death motor neuron diseases and axonal injury) neuropsychiatric disorders cardio-vascular diseases neuropsychiatric disorders diabe-tes cataract cancer as well as aging viral infections (that cause airway epithelial inflammation) etc

References1 C h o u d h a r i SK Chaudhary M Gadbail AR

Sharma A Tekade S Oxidative and antioxidative mechanisms in oral cancer and precancer A re-view Oral Oncology 2014 50 10ndash18

2 G e r s c h m a n R Gilbert Dl Nye Sw Dwyer P Fenn Wo Oxygen poisoning and x-irradia-tion a mechanism in common Science 1954 119(3097) 623-6

3 C o m m o n e r B Townsend J Pake Ge Free radicals in biological materials Nature 1954 174(4432) 689ndash691

4 H a r m a n D Aging a theory based on free rad-ical and radiation chemistry Journal of Gerontol-ogy 1956 11 298-300

5 F r i d o v i c h I Superoxide dismutases Annu Rev Biochem 1975 44 147-159

6 F r i d o v i c h I The biology of oxygen radicals Science 1978 201 875-880

7 F r i d o v i c h I Superoxide radical An endog-enous toxicant Annu Rev Pharmacol toxicol 1983 23 239-257

8 M c C o r d JM Fridovich I Superoxide dis-mutase An enzymic function for erythrocupre-in (hemocuprein) J Biol Chem 1969 244(22) 6049-55

9 M i t t a l CK Murad F Activation of guanylate cyclase by superoxide dismutase and hydroxyl radical a physiological regulator of guanosine 3lsquo5lsquo-monophosphate formation Proc Natl Acad Sci USA 1977 74(10) 4360ndash4364

10 S c h a u e n s t e i n E Esterbauer H Forma-tion and properties of reactive aldehydes Ciba Found Symp 1978 67 225ndash244

11 B e n e d e t t i A Comporti M Esterbauer H Identification of 4-hydroxynonenal as a cytotox-ic product originating from the peroxidation of liver microsomal lipids Biochim Biophys Acta 1980 620 281ndash296

12 E s t e r b a u e r H Cheeseman KH Determi-nation of aldehydic lipid peroxidation products malonaldehyde and 4-hydroxynonenal Methods Enzymol 1990 186 407-421

13 E s t e r b a u e r H Schaur RJ Zollner H Chem-istry and biochemistry of 4-hydroxynonenal malonaldehyde and related aldehydes Free Rad-ic Biol Med 1991 11 81-128

14 T a n e a T Reed Lipid peroxidation and neu-rodegenerative disease Free Radical Biology amp Medicine 2011 51 1302ndash1319

15 L e o n a r d u z z i G Sottero B Poli G Target-ing tissue oxidative damage by means of cell signaling modulators The antioxidant concept revisited Pharmacology amp Therapeutics 2010 128 336ndash374

16 M i l l e r DM Buettner GR Aust SD Transition metals as catalysts of ldquoautoxidationrdquo reactions Free Radic Biol Med 1990 8 95ndash108

17 M a r t i n e z - C a y u e l a M Oxygen free rad-icals and human disease Biochimie 1995 77 47-16

18 Va l k o M Morris H Cronin MTD (2005) Metals toxicity and oxidative stress Curr Med Chem 2005 12 1161ndash1208


19 R a o PS Kalva S Yerramilli A Mamidi A Free Radicals and Tissue Damage Role of Antiox-idants Free Radicals and Antioxidants 2011 1(4) 2-7

20 A i k e n s J Dix TA Perhydroxyl radical (HOObull) Initiated lipid- peroxidationmdashThe role of fatty-acid hydroperoxides J Biol Chem 1991 266 15091ndash15098

21 M o r r i s o n M Schonbaum GR Peroxi-dase-catalyzed halogenation Annu Rev Bio-chem 1976 45 861ndash888

22 C l i f f o r d DP Repine JE Hydrogen peroxide mediated killing of bacteria Mol Cell Biochem 1982 49 143ndash149

23 C h a n d l e r JD Day BJ Thiocyanate a poten-tially useful therapeutic agent with host defense and antioxidant properties Biochem Pharmacol 2012 84 1381ndash1387

24 P a s t o r N Weinstein H Jamison E Brenowitz M A detailed interpretation of OH radical foot-prints in a TBP DNA complex reveals the role of dynamics in the mechanism of sequence-specific binding J Mol Biol 2000 304 55ndash68

25 H a l l i w e l l B Gulteridgе JMC Oxygen tox-icity oxygen radicals transition metals and dis-ease Biochem J 1984 219 1-14

26 P r y o r WA Oxy-radicals and related species Their formation life-limes and reactions Annu rev Physiol 1986 148 657-667

27 M o n c a d a S Palmer RM Higgs EA Nitric oxide physiology pathophysiology and phar-macology Pharmacol Rev 1991 43 109ndash142

28 D a y BJ Patel M Calavetta L Chang LY Stam-ler JS A mechanism of paraquat toxicity involv-ing nitric oxide synthase Proc Natl Acad Sci USA 1996 96 12760ndash12765

29 B e c k m a n JS Koppenol WH Nitric oxide superoxide and peroxynitrite the good the bad and ugly Am J Physiol 1996 271 C1424ndash1437

30 B e c k m a n JS Beckman TW Chen J Marshall PA Freeman BA Apparent hydroxyl radical pro-duction by peroxynitrite implications for endo-thelial injury from nitric oxide and superoxide Proc Natl Acad Sci USA 1990 87 1620ndash1624

31 K o p p e n o l WH The chemistry of peroxyni-trite a biological toxin Quiacutemica nova 1998 21(3) 326-331

32 P a c h e r P Beckman JS Liaudet L Nitric oxide and peroxynitrite in health and disease Physio-logical Reviews 2007 87(1) 315-424

33 S z a b oacute C Ischiropoulos H Radi R Peroxyni-trite biochemistry pathophysiology and devel-opment of therapeutics Nature Reviews Drug Discovery 2007 6 662-680

34 S p i t e l l e r G Peroxyl radicals Inductors of neurodegenerative and other inflammatory diseases Their origin and how they transform cholesterol phospholipids plasmalogens poly-unsaturated fatty acids sugars and proteins into deleterious products Free Radical Biology amp Medicine 2006 41 362ndash387

35 Ya m a m o t o S Suzuki H Ueda N Takahashi Y Yoshimoto T Mammalian lipoxygenases In Curtis-Prior P (Ed) Eicosanoids Wiley Chich-ester 2004 53ndash59

36 S c h w a r z K Anton M Kuumlhn H Sequence determinants for the positional specificity of lip-oxygenases Advances in medicine and biology Eicosanoids and other bioactive lipids in cancer inflammation and radiation injury New York Kluwer AcademyPlenum Publishers 2002 507(5) 55ndash60

37 K uuml h n H Roumlmisch I Belkner J The role of li-poxygenase-isoforms in atherogenesis Mol Nutr Food Res 2005 49 1014ndash1029

38 D e G r o o t JJMC Veldink GA Vliegenthart JFG Boldingh J Wever R Van B Gelder F Demonstration by EPR spectroscopy of the func-tional role of iron in soybean lipoxygenase-1 Biochim BiophysActa 1975 377 71ndash79

39 P e r c i v a l MD Human 5-lipoxygenase con-tains an essential iron J Biol Chem 1991 266 10058ndash10061


41 A l a m N Bristi NJ Rafiquzzaman Review on in vivo and in vitro methods evaluation of an-tioxidant activity Saudi Pharmaceutical Journal 2013 21(2) 143ndash152

42 S i r e e s h a K Evaluation of Adaptogenic ac-tivity of Ocimum Sanctum by invivo and invitro methods MPharm Thesis Dept of Pharmacolo-gy Roland Institute of Pharmaceutical Sciences Berhampur Orissa (2006)

43 E t s u o N Role of vitamin E as a lipid-soluble peroxyl radical scavenger in vitro and in vivo evidence Free Radical Biology and Medicine 2014 66 3ndash12


44 P a n k o v a St Zhelev Il Peykova L Pupanov St Ivanov V Andonova V Penkov D Kasuro-va D Obreshkova D Petkova Ek Antioxidation against free rtadicals In Public health and health care in Greece and Bulgaria the challenge of the cross-border collaboration in times of financial crisis Kyriopoulos J Dimitrova D EdsPapa-zissis Publishers Athens 2011 pp335-338

45 H a g e m a n JJ Bast A Vermeulen NPE Mon-itoring of oxidative free radical damage in vivo Analytical aspects Chemico-Biological Interac-tions 1992 82(3) 243ndash293

46 L oacute p e z - A l a r c oacute n C Denicola A Evaluating the antioxidant capacity of natural products A review on chemical and cellular-based assays Analytica Chimica Acta 2013 763 1ndash10

47 K o v a c i c P Jacintho JD Mechanisms of car-cinogenesis Focus on oxidative stress and elec-tron transfer Curr Med Chem 2001 8 773ndash796

48 R i d n o u r LA Isenberg JS Espey MG Thom-as DD Roberts DD Wink DA Nitric oxide reg-ulates angiogenesis through a functional switch involving thrombo spondin-1 Proc Natl Acad Sci USA 2005 102 13147ndash13152

49 M o h s i n S Mahadevan R Muraleedhara Ku-rup G Free-radical-scavenging activity and anti-oxidant effect of ascophyllan from marine brown algae Padina tetrastromatica Biomedicine amp Preventive Nutrition 2014 4 75-79

50 M a b r o u k H Houas I Mechria H Mechri A Douki W Gaha L Najjar MF Oxidative stress markers in schizophrenic patients Immuno-anal-yse et biologie speacutecialiseacutee 2013 28 51-56

51 F e a r o n IM Faux SP Oxidative stress and car-diovascular disease Novel tools give (free) rad-ical insight Journal of Molecular and Cellular Cardiology 2009 47 372-381

52 D e x t e r DT Jenner P Parkinson disease from pathology to molecular disease mechanisms Free Radical Biology and Medicine 2013 62 132ndash144

53 T s a n g AH Chung KK Oxidative and nitrosa-tive stress in Parkinsonrsquos disease Biochim Bio-phys Acta 2009 1792 643ndash650

54 P e r e z - D e La Cruz V Elinos-Calderon D Robledo-Arratia Y Medina-Campos ON Pedra-za-Chaverri J Ali SF Santamaria A Targeting oxidativenitrergic stress ameliorates motor im-pairment and attenuates synaptic mitochondrial dysfunction and lipid peroxidation in two models

of Huntingtonrsquos disease Behav Brain Res 2009 199 210ndash217

55 G a l a s k o D Montine TJ Biomarkers of oxi-dative damage and inflammation in Alzheimerrsquos disease Biomark Med 2010 4 27ndash36

56 P i c k l o MJ Montine TJ Amarnath V Neely MD Carbonyl toxicology and Alzheimerrsquos dis-ease Toxicol Appl Pharmacol 2002 184 187ndash197

57 N e e l y MD Montine TJ CSF lipoproteins and Alzheimerrsquos disease J Nutr Health Aging 2002 6 383ndash391

58 R e e d T Perluigi M Sultana R Pierce WM Klein JB Turner DM Coccia R Markesbery WR Butterfield DA Redox proteomic identifi-cation of 4- hydroxy-2-nonenal-modi fi ed brain proteins in amnestic mild cognitive impairment insight into the role of lipid peroxidation in the progression and pathogenesis of Alzheimerrsquos dis-ease Neurobiol Dis 2008 30 107ndash120

59 A l u i s e CD Robinson RA Beckett TL Mur-phy MP Cai J Pierce WM Markesbery WR Butterfield DA Preclinical Alzheimer disease brain oxidative stress A beta peptide and pro-teomics Neurobiol Dis 2010 39 221ndash228

60 A d i b h a t l a RM Hatcher JF Phospholipase A(2) reactive oxygen species and lipid peroxi-dation in CNS pathologies BMB Rep 2008 41 560ndash567

61 Q i n J Goswami R Balabanov R Dawson G Oxidized phosphatidylcholine is a marker for neuroin fl ammation in multiple sclerosis brain J Neurosci Res 2007 85 977ndash984

62 Aw a d a l l a h FM Piazza GA Gary BD Kee-ton AB Canzoneri JC Synthesis of some dihy-dropyrimidine-based compounds bearing pyra-zoline moiety and evaluation of their antiprolif-erative activity European Journal of Medicinal Chemistry 2013 70 273-279

63 D r e h e r D Junod AF Role of oxygen free rad-icals in cancer development European Journal of Cancer 1996 32 30ndash38

64 N e g r e - S a l v a y r e A Auge N Ayala V Basaga H Boada J Brenke R Chapple S Co-hen G Feher J Grune T Lengyel G Mann GE Pamplona R Poli G Portero-Otin M Riahi Y Salvayre R Sasson S Serrano J Shamni O Siems W Siow RCM Wiswedel I Zarkovic K Zarkovic N Pathological aspects of lipid per-oxidation Free Radical Research 2010 44(10) 1125ndash1171


65 Aw a s t h i YC Yang Y Tiwari NK Patrick B Sharma A Li J Awasthi S Regulation of 4-hy-droxynonenal-mediated signaling by glutathione S-transferases Free Radical Biology and Medi-cine 2004 37(5) 607ndash619

66 M a r n e t t e LJ Oxyradicals and DNA damage Carcinogenesis 2000 21 361ndash70

67 Wo g a n GN Hecht SS Felton JS Conney AH Loeb LA Environmental and chemical carcino-genesis Semin Cancer Biol 2004 14 437ndash86

68 Va l k o M Rhodes CJ Moncol J Izakovik M Mazure M Free radicals metals and antioxidants in oxidative stress-induced cancer Chemico Biol Inter 2006 160 1ndash40

69 G o n z a l e z RA Free radicals oxidative stress and DNA metabolism in human cancer Cancer Invest 1999 17 376ndash7

70 U c h i d a K 4-Hydroxy-2-nonenal a product and mediator of oxidative stress Prog Lipid Res 2003 42(4) 318ndash43

71 B o n t RD Larebeke NV Endogenous DNA damage in humans a review of quantitative data Mutagenesis 2004 19(3) 169ndash85

72 C o o k e MS Evans MD Dizardaroglu M Lunec J Oxidative DNA damage mechanisms mutation and disease FASEB J 2003 17 1195ndash214

73 E v a n s MD Dizardaroglu M Cooke MS Ox-idative DNA damage and disease induction repair and signi fi cance Mutat Res 2004 567 1ndash61

74 D i z a r d a r o g l u M Kirkali G Jaruge P For-mamidopyrimidines in DNA mechanisms of formation repair and biological effects Free Radic Biol Med 2008 45 1610ndash21

75 V i n e i s P Pursianinen KP Air pollution and cancer biomarker studies in human populations Carcinogenesis 2005 26 1846ndash55

76 Va l k o M Izakovic M Mazur M Christopher J Rhodes C Telser J Role of oxygen radicals in DNA damage and cancer incidence Mol Cell Biochem 2004 266 37ndash56

77 P o u l s e n HE Prieme H Loft S Role of oxi-dative DNA damage in cancer initiation and pro-motion Eur J Cancer Prev 1998 7(1) 9ndash16

78 T r u e b a GP Saacutenchez GM Giuliani A Oxygen free radical and antioxidant defence mechanism in cancer Front Biosci 2004 9 2029ndash44

79 T r a c h o o t h a m D Lu W Ogasawara MA Nilsa RD Huang P Redox regulation of cell sur-vival Antioxid Redox Signal 2008 10 1343ndash74

80 M a r t y WM Baldwin AS The transcription factor NF-jB control of oncogenesis and cancer therapy resistance BBA 2000 1470 M55ndash62

81 K a r i n M Lin A NF-kappaB at the crossroads of life and death Nat Immunol 2002 3 221ndash7

82 D r e h e r D Junod AF Role of oxygen free rad-icals in cancer development Eur J Cancer 1996 32A 30ndash8

83 M o r i K Shibanuma M Nose K Invasive po-tential induced under long-term oxidative stress in mammary epithelial cells Cancer Res 2004 64 7464ndash72

84 S h i n o h a r a M Adachi Y Mitsushita J Kuwa-bara M Nagasawa A Harada S Furuta S Zhang Y Seheli K Miyazaki H Kamata T Reactive oxygen generated by NADPH oxidase 1 (nox1) contributes to cell invasion by regulating matrix metalloprotease-9 production and cell migration J Biol Chem 2009 285 4481ndash8

85 M a l i n s DC Polissar NL Gunselman SJ Pro-gression of human breast cancer to the metastatic state is linked to hydroxyl radical-induced DNA damage Proc Natl Acad Sci USA 1996 93 2557ndash63

86 S c h m i e l a u J Finn OJ Activated granulo-cytes and granulocyte-derived hydrogen perox-ide are the underlying mechanism of suppression of t-cell function in advanced cancer patients Cancer Res 2001 61 4756ndash60

87 B r e e n AP Murphy JA Reactions of oxyl rad-icals with DNA Free Rad Biol Med 1995 18 1033ndash77

88 Wa n g D Kreutzer DA Essigmann JM Muta-genicity and repair of oxidative DNA damage insights from studies using defined lesions Mu-tat Res 1998 400 99-115

89 C o o k e MS Evans MD Dizdaroglu M Lunec J Oxidative DNA damage mechanisms muta-tion and disease FASEB J 2003 17 1195ndash214

90 W i s e m a n H Halliwell B Damage to DNA by reactive oxygen and nitrogen species role in inflammatory disease and progression to cancer Biochem J 1996 313 17ndash29

91 O h s h i m a H Bartsch H Chronic infections and inflammatory processes as cancer risk fac-tors possible role of nitric oxide in carcinogene-sis Mutat Res 1994 305 253ndash64


92 R o u t l e d g e MN Wink DA Keefer LK Dip-ple A Mutations induced the by the nitric oxide generators SPERNO and DEANO in the SUPF assay Chem Res Toxicol 1994 7 628ndash32

93 F r u e h a u g JP Meyskens FL Reactive oxygen species a breath of life of death Clin Cancer Res 2007 13 789ndash94

94 A r n h e i m N Cortopassi G Deleterious mito-chondrial DNA mutations accumulate in aging human tissues Mutat Res 1992 275 157ndash67

95 F r u e h a u JP Meyskens FL Reactive oxygen species a breath of life of deathClin Cancer Res 2007 13 789ndash94

96 G i e s e g S Duggan S Gebicki JM Peroxida-tion of proteins before lipids in U937 cells ex-posed to peroxyl radicals Biochem J 2000 350 215ndash8

97 D u J Gebicki JM Proteins are major initial cell targets of hydroxyl free radicals Int J Biochem Cell Biol 2004 36 2334ndash43

98 S t a d t m a n ER Metal ion-catalyzed oxidation of proteins-biochemical- mechanism and biolog-

ical consequences Free Rad Biol Med 1990 9 315ndash25

99 G r o g o r o v B Reactive oxygen species and their relation to carcinogenesis Trakia J Sci 2012 10 83ndash92


101 L i RH Hotchkiss JH Potential genotoxicity of chronically elevated nitric oxide a review Mu-tat Res 1995 339 73ndash89

102 K o r d e (Choudhari) S Sridharan G Gadbail A Poornima V Nitric oxide and oral cancer a review Oral Oncol 2012 48 475ndash83

103 F u c h s - T a r l o v s k y V Role of antioxidants in cancer therapy Nutrition 2013 29 15ndash21

104 C h o u d h a r i SK Chaudhary M Gadbail AR Sharma A Tekade S Oxidative and antioxida-tive mechanisms in oral cancer and precancer A review Oral Oncology 2014 50 10ndash18

corresponding authorMaya GeorgievaFaculty of Pharmacy Medical University-Sofia2 ldquoDunavrdquo str 1000 Sofia BulgariaPhone +359 2 9236 515e-mail georgmmailbg

PPHHAARRMMAAccIIAAVolume 60 2013 Number 1

c o N t e N t s

original articles

I Todorov M Christov K Stanoeva K Yakimova Leptin and GABA interactions on body temperature of rats00

S Harkov D Havrylyuk V Atamanyuk B Zimenkovsky R Lesyk Synthesis and biological activity of isatines bearing thiazolidinone and pyrazoline moietieshelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip00

L Peikova B Tsvetkova RP-HPLC method for simultaneous determination of Amlodipine besylate and Valsartan in pharmaceutical dosage form helliphelliphelliphelliphellip00

Review articles

Georgi Momekov Niko Benbassat Pharmacological properties of Hawthorn leaf and flower as a cardiovascular agenthellip00

L Peikova B Tsvetkova Amide-based prodrugs of nonsteroidal anti-inflammatory drugshelliphelliphelliphellip00

L Andonova M Georgieva Al Zlatkov Arylpiperazine derivatives ndash new agents affecting mood disordershelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip00

Georgi Momekov Iliana Ionkova Paraskev Nedialkov Zlatina Kokanova-Nedialkova Dimitrina Zheleva-Dimitrova Ilina Krasteva Yohana Ilieva Ilina Dineva Gerassim Kitanov Stefan Nikolov Spiro Konstantinov Overview of the oncopharmacological studies of plant-derived natural products conducted at the Faculty of Pharmacy (MU-Sofia) helliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip 00

D Obreshkova Reactive oxygen species induced neurodegeneration in Alzheimerrsquos diseasehelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip00

Instructions to authorshelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphelliphellip00

c o N t e N t s

original articles

St Pankova D Tsvetkova K Ivanov St Papanov St Ivanova Validation of TLC ndash densitometric method for identification and determination of estradiol 3

A Kougioumtzoglou L Peikova M Georgieva Al Zlatkov Evaluation of the stability of indomethacin substance under a model of physiological conditions using modified and validated RP-HPLC method 10

Kr Makukh T Ryvak O Lopatynska Patientsrsquo compliance to phytotherapy prescribed and self-medicated with herbal medicines in Ukraine 18

Review articles

L Andonova M Georgieva Al Zlatkov Free radicals oxidative stress and diseases associated with them 26

St Ivanova K Ivanov St Pankova Br Zlatkov K Stoychev Sport supplementation beneficial effects of vitamin E and creatine on exercise performance 40

E Drakalska D Momekova S Rangelov N Lambov Nanoparticles as platforms for delivery of curcumin 50

From the editorial board

Instructions to authors 58


26





Review Articles
















O2 O2+ + 2H H2O2 +O2 (1)







Ground state








O2 + Fe3+ O2 + Fe2+


(2)

(3)

(4)



(2)

(3)

(4)








C5H11 (CH2)7COOH

H



O2 O2OO O O


OHO O OH+LH-L

+LH-L















C5H11 (CH2)7COOH

H H

C5H11 (CH2)7COOH

H

C5H11 (CH2)7COOH

C5H11 (CH2)7COOH

OO

C5H11 (CH2)7COOH

OHO

Fe3+

Fe2+ + H+

Fe3+Fe2+ + H+





















(2) Addition


X + IH XH + I






























O OH

H H

O O

H H

OH

O


OO H

H H

OO

H

H













































































































































26





Review Articles
















O2 O2+ + 2H H2O2 +O2 (1)







Ground state








O2 + Fe3+ O2 + Fe2+


(2)

(3)

(4)



(2)

(3)

(4)








C5H11 (CH2)7COOH

H



O2 O2OO O O


OHO O OH+LH-L

+LH-L















C5H11 (CH2)7COOH

H H

C5H11 (CH2)7COOH

H

C5H11 (CH2)7COOH

C5H11 (CH2)7COOH

OO

C5H11 (CH2)7COOH

OHO

Fe3+

Fe2+ + H+

Fe3+Fe2+ + H+





















(2) Addition


X + IH XH + I






























O OH

H H

O O

H H

OH

O


OO H

H H

OO

H

H























































































































































O2 O2+ + 2H H2O2 +O2 (1)







Ground state








O2 + Fe3+ O2 + Fe2+


(2)

(3)

(4)



(2)

(3)

(4)








C5H11 (CH2)7COOH

H



O2 O2OO O O


OHO O OH+LH-L

+LH-L















C5H11 (CH2)7COOH

H H

C5H11 (CH2)7COOH

H

C5H11 (CH2)7COOH

C5H11 (CH2)7COOH

OO

C5H11 (CH2)7COOH

OHO

Fe3+

Fe2+ + H+

Fe3+Fe2+ + H+





















(2) Addition


X + IH XH + I






























O OH

H H

O O

H H

OH

O


OO H

H H

OO

H

H

















































































































































O2 + Fe3+ O2 + Fe2+


(2)

(3)

(4)



(2)

(3)

(4)








C5H11 (CH2)7COOH

H



O2 O2OO O O


OHO O OH+LH-L

+LH-L















C5H11 (CH2)7COOH

H H

C5H11 (CH2)7COOH

H

C5H11 (CH2)7COOH

C5H11 (CH2)7COOH

OO

C5H11 (CH2)7COOH

OHO

Fe3+

Fe2+ + H+

Fe3+Fe2+ + H+





















(2) Addition


X + IH XH + I






























O OH

H H

O O

H H

OH

O


OO H

H H

OO

H

H
























































































































































C5H11 (CH2)7COOH

H H

C5H11 (CH2)7COOH

H

C5H11 (CH2)7COOH

C5H11 (CH2)7COOH

OO

C5H11 (CH2)7COOH

OHO

Fe3+

Fe2+ + H+

Fe3+Fe2+ + H+





















(2) Addition


X + IH XH + I






























O OH

H H

O O

H H

OH

O


OO H

H H

OO

H

H

































































































































































(2) Addition


X + IH XH + I






























O OH

H H

O O

H H

OH

O


OO H

H H

OO

H

H








































































































































































O OH

H H

O O

H H

OH

O


OO H

H H

OO

H

H





























































































































































O OH

H H

O O

H H

OH

O


OO H

H H

OO

H

H




















































































































































O OH

H H

O O

H H

OH

O


OO H

H H

OO

H

H









































































































































































































































































































































































































































































































































































































































Documents

Free Radicals, Oxidative Stress, and Diseases Associated with Them