Special Issue "Antioxidants"

Guest Editor
Prof. Dr. Mike Gordon
Department of Food and Nutritional Sciences, University of Reading, Whiteknights PO Box 226, Reading RG6 6AP, UK
E-Mail:
Phone: 0118-3786723
Fax: 0118-3787708

Dear Colleagues,

The subject of antioxidants has developed by leaps and bounds since the studies in the late 19th and early 20th centuries into the compounds that could retard or prevent the effects of oxidation of industrial polymers such as rubber and the mechanisms of their action. The subject was given a strong boost in the mid 20th century when it was realised that the deterioration of lipid-containing foods could be retarded by the use of antioxidants, and again in the late 20th century, when the importance of radical reactions in the degradation of biological molecules and the significance for human health was recognised. Although it is now recognised that phytochemicals have a range of bioactivities including effects on cell signalling and gene expression, the bioavailability, activity, and effects of antioxidants on physiological processes continues to be an important area of study. The topic of antioxidants also remains an important subject for research in the optimisation of the stability of a range of industrial products and foods. The development of natural antioxidants to allow food manufacturers to replace synthetic antioxidants, the activity of antioxidants in polymers such as food packaging, and migration of the antioxidants from polymers into liquids in contact with them are other important areas. This special issue contains a range of papers reporting some of the interesting developments in this area.

Prof. Dr. Mike Gordon
Guest Editor

Related Special Issues in Other Journals

• Antioxidants in Molecules
• Dietary Antioxidants in Nutrients

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• antioxidants
• activity
• bioavailability
• food
• health
• mechanisms
• nutrition
• packaging
• polymers

Type of Paper: Article
Title: The Protective Role of Hsp27 Protein in Ovarian Cancer Cell Line (OvBH-1) after Chemotherapy
Authors: Jolanta Saczko ¹, Iwona Kamińska ², Julita Kulbacka ¹, Anna Choromańska ¹, Nina Skołucka ¹ and Julia Bar ²
Affilitions: ¹ Department of Medical Biochemistry, Medical University, Chalubinskiego 10 St., 50-368 Wroclaw, Poland; E-Mail: michal@ak.am.wroc.pl (J.S.)
² Department of Pathomorphology and Clinical cytology, Medical University, Borowska 213 St., 50-556 Wroclaw, Poland
Abstract: The successful treatment of ovarian cancer is dependent upon the effectiveness of cytotoxic anticancer drugs either alone or in combination with other ways of treatment. Heat-shock proteins seem to play a still indeterminate role in cancer. One of them mainly, the low molecular weight Hsp27, seems to be involved in resistance to chemotherapy. Drugs used in chemotherapy of cancer disease work in different ways to stop proliferation of tumor cells or induce cell death. Some drugs used in chemotherapy like doxorubicin induce synthesis of HSP 27 and additionally reduce the sensitivity of cancer cells to drugs, particularly in breast and ovarian carcinoma. Hsp27 protein may protect cancer cells by inhibiting apoptosis, or act as chaperone proteins. The aim of the study was to investigate the expression of Hsp27 protein in ovarian clear carcinoma cell line (OvBH-1) before and after chemotherapy as well as chemotherapy connected with electroporation. The OvBH-1 cells were treated with 5-Fluoroacyl in different concentration and with 5-Fluoroacyl after electroporation in different conditions. MTT assay was performed to examine the cells viability as a mitochondria metabolic function after the drugs uptake. The expression of Hsp27 was estimated by immunohistochemical assay. The high expression of Hsp27 was observed after 5-Fluoroacyl treatment compared to non treated OvBH-1 cells. The elevated viability was observed after chemotherapy and also after electrochemotherapy. We suggest that 5-fluoroacyl may affect the increased expression of Hsp27, which affects the efficiency of these cells lack the applied therapy revealed.

Type of Paper: Review
Title: Antioxidant-Induced Stress
Authors: Cleva Villanueva ¹ and Robert David Kross ²
Affiliations: ¹ Escuela Superior de Medicina IPN, Mexico D.F., Mexico; E-Mail: cleva_villanueva@yahoo.com.mx
² Kross-Link Laboratories, New York, USA
Abstract: Antioxidants are among the most popular health-protecting products, sold worldwide without prescription. Indeed, there are many reports showing the benefits of antioxidants but a few questioning the possible harmful effects of these “drugs”. The normal balance between antioxidants and free radicals in the body is offset when either of these forces prevails. The available evidence of the harmful effects of antioxidants is analyzed in this review. In summary, a hypothesis is presented that “antioxidant-induced stress” results when antioxidants overwhelm the body’s free radicals.

Type of Paper: Article
Title: Recovery and Concentration Antioxidants from Wine Distilleries Byproducts
Authors: María Luisa Soto, Noelia González-López, María Jesús Conde, Andrés Moure, Herminia Domínguez and Juan Carlos Parajó
Affiliation: Departamento de Enxeñería Química, Universidade de Vigo (Campus Ourense), Edificio Politécnico, As Lagoas, 32004 Ourense, Spain; E-Mail: herminia@uvigo.es (H.D.)
Abstract: Grape and wine byproducts have been extensively studied for the recovery of phenolic compounds with antioxidant properties and a variety of biological actions. The utilization of the aqueous phase embebing the distilled fermented grape pomace would allow the valorization of this solid residue, sparing the use of water as extracting solvent. The recovery and concentration of the phenolic compounds from this stream has been proposed using non ionic polymeric commercial resins and further desorption of the active compounds in ethanolic solutions. A screening of the potential of several resins has been addressed with the aim of selecting the most suited adsorbents for the practical recovery of the target active compounds. Aspects related to the adsorption equilibrium and kinetics and to the selection of the optimal operation conditions for the efficient adsorption and desorption stages have been addressed.

Type of Paper: Review
Title: Significance of Dietary Antioxidants for Health–A Review
Author: Michael H. Gordon
Affiliation: Institute of Cardiovascular and Metabolic Research, University of Reading, UK; E-Mail: m.h.gordon@reading.ac.uk
Abstract: Since evidence became available that free radicals were involved in mechanisms for the development of major diseases including cardiovascular disease and cancer, there has been considerable research into the properties of natural dietary antioxidants. However, it has become clear that dietary antioxidants can only have beneficial effects in vivo by radical scavenging or effects on redox potential if they are present in tissues or bodily fluids at sufficient concentrations. For many dietary components, absorption is limited or metabolism into derivatives reduces the antioxidant capacity. Other effects of phytochemicals including effects on cell signalling or gene expression are likely to be more significant for health than their antioxidant effects in vivo.

Type of Paper: Article
Title: 10-Shogaol, One Antioxidant from Zingiber officinale for Cell Proliferation and Migration Enhancer
Author: Hui-Min Wang
Affiliation: Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, 100, Shih-Chuan 1st Road, San-Ming District, Kaohsiung 80708, Taiwan; E-Mail: davidw@kmu.edu.tw
Abstract: Antioxidants are used widely for the prevention of a variety of diseases. In this work, one of Zingiber officinale compounds, 10-shogaol, as tested with 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method, ABTS radical scavenging assay, metal chelating ability, and reducing power to show antioxidant activity. 10-shogaol promoted human normal epidermal keratinocytes and dermal fibroblasts cell growth. In the in vitro wound healing assay for 12 or 24 h, with 10-shogaol, the fibroblasts and keratinocytes migrated rapider than the vehicle groups. Thus, this study reported the target compound, 10-shogaol, as antioxidant for human skin cell growth and migration enhancer with potential to be one novel wound repair agent.
Keywords: ginger; antioxidant; 10-shogaol; cell proliferation; cell migration

Title: Supplementation with Antioxidants in Middle Class Cardiovascular Patients in Argentina
Authors: Matilde Otero-Losada, Susana Vila, Daniel R Grana and José Milei
Afiliation: Instituto de Investigaciones Cardiológicas (ININCA). University of Buenos Aires – National Research Council (UBA-CONICET), Buenos Aires, Argentina; E-Mail: mol@fmed.uba.ar
Abstract: The effectiveness of antioxidants’ supplementation (2 months’ daily, α-tocopherol 400 mg, beta-carotene 40 mg, and vitamin C 1000 mg). to induce changes in oxidative metabolism were evaluated in 112 middle-class cardiovascular patients (29% smokers, 18% hypertensives, 63% sedentary, 23% subjects with atherosclerotic cardiovascular disease ,ACVD) in Buenos Aires, Argentina. 1) Basal levels of antioxidants or thiobarbituric acid reactive substances (TBARS) across subjects was not related to age (F_4,95 = 1.34, p< 0.26, N:S.), diabetes (F_4,95 = 1.41, p< 0.23, N.S.), ACVD (F_4,95 = 1.45, p< 0.22, N.S.) or sedentarism (F_4,95 = 0.78, p< 0.54, N.S.). 2) Smoking status was strongly associated with ACVD: 42% of smokers had ACVD compared to a 16% of ACVD cases observed in non smokers (r= 0.87, p<0.0001) as expected. 3) Basal thiobarbituric acid reactive substances (TBARS) / α-TP ratio was higher in smokers vs. non-smokers: 0.11 ± 0.02 vs. 0.06 ± 0.01 respectively (F_32,80= 1.63, p<0.04). α-tocopherol (αTP), β-carotene (βC), glutathione and ubiquinol levels were dissociated from smoking. 4) Supplementation was effective only in patients with basal levels lower than either 18µM for α-TP (p<0.01.) or 0.30µM for βC (p<0.02). 6) The magnitude of oxidative metabolism decreased after treatment: 5.3% vs. 14.6% before treatment (F_1,110 = 9.21, p<0.0003). Antioxidants in excess are not free from adverse effects. Present findings emphasize on the need to measure plasma antioxidants’ levels prior to antioxidants’ supplementation.

Title: Synergism, Antagonism and Additivism of Binary and Triple Mixtures of Phenolic Antioxidants
Author: Vessela D. Kancheva
Affiliation: Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria; E-Mail: vedeka@abv.bg
Abstract: In this study different effects of binary and triple mixtures of various phenolic antioxidants  - synthetic and of natural origin were compared and discussed. Binary mixtures with alpha-tocopherol (TOH) of flavonoids [1], standard antioxidants and cinnamic acids [2], simple hydroxy-coumarins [3] and bis-coumarins [4], benzo[kl]xanthene lignans and dihydrobenzofuran neolignans [5] biphenyls and their monomers and some other new synthesized compounds with different structures were selected for this study.  Triple mixtures with TOH and ascorbic acid (AscH) were created with compounds demonstrated a synergism in binary mixtures with TOH. If two or more antioxidants are added to oxidizing lipid substrates, their combined inhibitory effect can be additive, antagonistic, or synergistic. Synergism – the inhibiting effect of the mixtures (IP_S) is higher than the sum of the induction periods of the individual phenolic antioxidants SIP_i (IP_S > SIP_i) and the percent of the synergism was calculated as %Syn = [(IP_S - SIP_i)/ SIP_i]x100, %. Additivism - the inhibiting effect of the mixtures (IP_S) is equal to the sum of the induction periods of the individual phenolic antioxidants SIP_i (IP_S = SIP_i). Antagonism - the inhibiting effect of the mixtures (IP_S) is lower than the sum of the induction periods of the individual phenolic antioxidants (IP_S < SIP_i) and the percent of antagonism was calculated as %Ant = [(SIP_i - IP_S )/ SIP_S]x100, %. On the base of results obtained new effective powerful complex bio-antioxidants can be created for the practical purpose.

Type of Paper: Review
Title: Glutathione is a Key Player in Metal-induced Oxidative Stress Defences
Authors: Marijke Jozefczak, Tony Remans, Jaco Vangronsveld and Ann Cuypers
Affiliations: Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium; E-Mail: marijke.jozefczak@uhasselt.be
Abstract: Over the past two centuries, advanced industrial and agricultural activities have led to high emissions of toxic metals into the environment at concentrations significantly exceeding those from origin. Metals display a diverse array of physio-chemical properties such as essential versus non-essential and redox-active versus non-redox-active. In general, all metals can produce toxicity and oxidative stress when taken up in sufficient quantities, imposing a serious threat to the environment and human health. In order to cope with different kinds of metals, plants have a common defence strategy in which glutathione (GSH; g-glu-cys-gly) plays a central role. Therefore, this review highlights on GSH and its role in (1) metal homeostasis, (2) redox homeostasis and (3) signal transduction under metal stress. To maintain metal homeostasis, the synthesis of specific chelators and sequestration of metal complexes are of major importance. Due to the high affinity of metals to thiols and as a precursor of phytochelatins, GSH is a key component in metal scavenging. Besides metal homeostasis, plants posses a well-equipped antioxidative defence system to manage the metal-imposed oxidative challenge. GSH is an important antioxidant that, in addition to its primary antioxidant capacities, acts as a substrate in the ascorbate-glutathione cycle and is essential for the regeneration of the redoxin pool in plants. Via GSH, metal and redox homeostasis are directly linked, having their impact on the cellular redox state of GSH, i.e. reduced versus oxidised [glutathione disulphide (GSSG)]. This redox balance transmits specific information in order to fine tune cellular signalling pathways under environmental stress conditions. The underlying regulation of these systems as a result of metal-induced cellular redox imbalance is currently under intense investigation and will provide essential information to understand the cellular responses to metal toxicity.
Keywords: metals; cellular redox state; glutathione; chelation