Use of conventional and -omics based methods for health claims of dietary antioxidants: a critical overview

Inflammageing and Cardiovascular System: Focus on Cardiokines and Cardiac-Specific Biomarkers

The term "inflammageing" was introduced in 2000, with the aim of describing the chronic inflammatory state typical of elderly individuals, which is characterized by a combination of elevated levels of inflammatory biomarkers, a high burden of comorbidities, an elevated risk of disability, frailty, and premature death. Inflammageing is a hallmark of various cardiovascular diseases, including atherosclerosis, hypertension, and rapid progression to heart failure. The great experimental and clinical evidence accumulated in recent years has clearly demonstrated that early detection and counteraction of inflammageing is a promising strategy not only to prevent cardiovascular disease, but also to slow down the progressive decline of health that occurs with ageing. It is conceivable that beneficial effects of counteracting inflammageing should be most effective if implemented in the early stages, when the compensatory capacity of the organism is not completely exhausted. Early interventions and treatments require early diagnosis using reliable and cost-effective biomarkers. Indeed, recent clinical studies have demonstrated that cardiac-specific biomarkers (i.e., cardiac natriuretic peptides and cardiac troponins) are able to identify, even in the general population, the individuals at highest risk of progression to heart failure. However, further clinical studies are needed to better understand the usefulness and cost/benefit ratio of cardiac-specific biomarkers as potential targets in preventive and therapeutic strategies for early detection and counteraction of inflammageing mechanisms and in this way slowing the progressive decline of health that occurs with ageing.

A comparative study on the effect of blood collection tubes on stress oxidative markers

Oxidative stress has a major role in disease pathogenesis. However, limited studies have investigated the effect of various sample collection tubes on oxidative biomarkers. The present study aimed to evaluate the effect of different collection tubes on the variation of malondialdehyde (MDA), nitric oxide (NO), total thiol (t-SH), and ferric reducing ability of plasma (FRAP) levels. A total of 35 individuals participated in this study and each collected sample was separated into three different tubes: glass tubes (GTs), plain plastic tubes (PTs), and gel separator tubes (GSTs). The results of PTs and GSTs were compared to those of GTs as the reference tube. The comparison between the means of biomarkers in various tubes indicated that there was no significant difference in MDA results between tubes. In contrast, t-SH and NO content were significantly decreased in GSTs and PTs compared to GTs. However, the Bland-Altman analysis showed an acceptable concordance for the mentioned analytes and the statistically significant differences were not clinically significant for NO, MDA, and t-SH antioxidant parameters. Moreover, the FRAP level was considerably lower in GSTs compared to GTs. Nevertheless, the Bland-Altman analysis showed a high bias percentage for the FRAP assay when using PTs and GSTs. According to the present results, it can be concluded that switching to plastic blood collection tubes or serum separation tubes could influence the FRAP results. However, there was no interference for the interpretation of other antioxidant assays in different types of collection tubes. Hence, it is suggested to use GTs for total antioxidant capacity evaluations, especially the FRAP assay.

Genotoxicity of Mercury and Its Derivatives Demonstrated In Vitro and In Vivo in Human Populations Studies. Systematic Review

Beside partial coverage in three reviews so far (1994, 2009, 2019), there is no review on genotoxic studies dealing with mercury (Hg) and human exposure using the most usual genotoxic assays: sister chromatid exchanges (SCE), chromosomal aberrations (CA), cytochalasin B blocked micronucleus assay (CBMN), and single-cell gel electrophoresis (SCGE or alkaline comet assay). Fifty years from the first Hg genotoxicity study and with the Minamata Convention in force, the genotoxic potential of Hg and its derivatives is still controversial. Considering these antecedents, we present this first systematic literature overview of genotoxic studies dealing with Hg and human exposure that used the standard genotoxic assays. To date, there is not sufficient evidence for Hg human carcinogen classification, so the new data collections can be of great help. A review was made of the studies available (those published before the end of October 2021 on PubMed or Web of Science in English or Spanish language) in the scientific literature dealing with genotoxic assays and human sample exposure ex vivo, in vivo, and in vitro. Results from a total of 66 articles selected are presented. Organic (o)Hg compounds were more toxic than inorganic and/or elemental ones, without ruling out that all represent a risk. The most studied inorganic (i)Hg compounds in populations exposed accidentally, occupationally, or iatrogenically, and/or in human cells, were Hg chloride and Hg nitrate and of the organic compounds, were methylmercury, thimerosal, methylmercury chloride, phenylmercuric acetate, and methylmercury hydroxide.

The Impact of Oxidative Stress in Human Pathology: Focus on Gastrointestinal Disorders

Accumulating evidence shows that oxidative stress plays an essential role in the pathogenesis and progression of many diseases. The imbalance between the production of reactive oxygen species (ROS) and the antioxidant systems has been extensively studied in pulmonary, neurodegenerative cardiovascular disorders; however, its contribution is still debated in gastrointestinal disorders. Evidence suggests that oxidative stress affects gastrointestinal motility in obesity, and post-infectious disorders by favoring the smooth muscle phenotypic switch toward a synthetic phenotype. The aim of this review is to gain insight into the role played by oxidative stress in gastrointestinal pathologies (GIT), and the involvement of ROS in the signaling underlying the muscular alterations of the gastrointestinal tract (GIT). In addition, potential therapeutic strategies based on the use of antioxidants for the treatment of inflammatory gastrointestinal diseases are reviewed and discussed. Although substantial progress has been made in identifying new techniques capable of assessing the presence of oxidative stress in humans, the biochemical-molecular mechanisms underlying GIT mucosal disorders are not yet well defined. Therefore, further studies are needed to clarify the mechanisms through which oxidative stress-related signaling can contribute to the alteration of the GIT mucosa in order to devise effective preventive and curative therapeutic strategies.

Oxidative Stress and Non-Alcoholic Fatty Liver Disease: Effects of Omega-3 Fatty Acid Supplementation

Aging is a complex phenomenon characterized by the progressive loss of tissue and organ function. The oxidative-stress theory of aging postulates that age-associated functional losses are due to the accumulation of ROS-induced damage. Liver function impairment and non-alcoholic fatty liver disease (NAFLD) are common among the elderly. NAFLD can progress to non-alcoholic steatohepatitis (NASH) and evolve to hepatic cirrhosis or hepatic carcinoma. Oxidative stress, lipotoxicity, and inflammation play a key role in the progression of NAFLD. A growing body of evidence supports the therapeutic potential of omega-3 polyunsaturated fatty acids (n-3 PUFA), mainly docosahaexenoic (DHA) and eicosapentaenoic acid (EPA), on metabolic diseases based on their antioxidant and anti-inflammatory properties. Here, we performed a systematic review of clinical trials analyzing the efficacy of n-3 PUFA on both systemic oxidative stress and on NAFLD/NASH features in adults. As a matter of fact, it remains controversial whether n-3 PUFA are effective to counteract oxidative stress. On the other hand, data suggest that n-3 PUFA supplementation may be effective in the early stages of NAFLD, but not in patients with more severe NAFLD or NASH. Future perspectives and relevant aspects that should be considered when planning new randomized controlled trials are also discussed.

Impact of extended working periods on genomic and telomeric DNA and on inflammatory markers: Results of an intervention study with office workers and carpenters

Aim of this study was to clarify if extension of the work phase has an impact on DNA- stability, telomere lengths and inflammatory markers. We conducted an intervention trial with office workers (n = 24) and carpenters (n = 10), who changed their working schedule from 8 to 12 h per day over a period of 3 months. The work of both groups involved only moderate physical activity. We found no evidence for induction of double strand breaks (measured in γH2AX assays) and relative telomere lengths (relTL_36B4 and ALB) in lymphocytes in the two study groups. Furthermore, no overall changes of the levels of C-reactive protein (CRP), interleukin-6 (IL-6) and thiobarbituric acid reactive substances (TBARS) in plasma were detected. However, we found in agreement with earlier investigations a moderate (not significant) increase of the CRP levels with age. Furthermore, significant higher CRP concentrations (P = 0.03) were detected in young individuals (21-30 years) as a consequence of the extended working period. Taken together our findings indicate that prolongation of the working hours has no pronounced impact on DNA stability, telomere shortening and inflammatory markers; but the increase of the CRP concentrations in young workers may be indicative for adverse health effects in this subgroup.

Gallic acid, a common dietary phenolic protects against high fat diet induced DNA damage

Purpose

Aim of the study was to find out if gallic acid (GA), a common phenolic in plant foods, prevents obesity induced DNA damage which plays a key role in the induction of overweight associated cancer.

Methods

Male and female C57BL6/J mice were fed with a low fat or a high fat diet (HFD). The HFD group received different doses GA (0, 2.6–20 mg/kg b.w./day) in the drinking water for 1 week. Subsequently, alterations of the genetic stability in blood and inner organs were monitored in single cell gel electrophoresis assays. To elucidate the underlying molecular mechanisms: oxidized DNA bases, alterations of the redox status, lipid and glucose metabolism, cytokine levels and hepatic NF-κB activity were monitored.

Results

HFD fed animals had higher body weights; increased DNA damage and oxidation of DNA bases damage were detected in colon, liver and brain but not in blood and white adipose tissue. Furthermore, elevated concentrations of insulin, glucose, triglycerides, MCP-1, TNF-α and NF-κB activity were observed in this group. Small amounts of GA, in the range of human consumption, caused DNA protection and reduced oxidation of DNA bases, as well as biochemical and inflammatory parameters.

Conclusions

Obese animals have increased DNA damage due to oxidation of DNA bases. This effect is probably caused by increased levels of glucose and insulin. The effects of GA can be explained by its hypoglycaemic properties and indicate that the consumption of GA-rich foods prevents adverse health effects in obese individuals.

Electronic supplementary material

The online version of this article (10.1007/s00394-018-1782-2) contains supplementary material, which is available to authorized users.

The Effect of MitoQ on Aging-Related Biomarkers: A Systematic Review and Meta-Analysis

Mitochondria are metabolically active organelles that produce significant reactive oxygen species, linked with aging and degenerative diseases. In recent years, particular focus has been put on mitochondria-targeted antioxidants, to decrease the concentration of reactive oxygen species and help alleviate the accumulation of oxidative damage and associated aging. MitoQ is a mitochondria-targeted antioxidant of which is reported to support healthy aging. The aim of this systematic review is to investigate the effects of MitoQ on oxidative outcomes related to the aging process. A predeveloped search strategy was run against MEDLINE (Ovid), EMBASE (Ovid), and CINAHL databases, which identified 10,255 articles of interest, with 27 of these finalised for use after screening. Three outcomes had sufficient data to meta-analyse nitrotyrosine concentration (190 animals, SMD -0.67, 95% CI (-1.30, -0.05), p = 0.04), membrane potential (63 animals, MD 11.44, 95% CI (1.28-21.60), p = 0.03), and protein carbonyl concentration (182 animals, SMD -0.13, 95% CI (-0.44, 0.18), p = 0.41). MitoQ intervention produced a statistically significant reduction in nitrotyrosine concentration and increased membrane potential. MitoQ may be of some benefit in alleviating oxidative stress related to aging.

Impact of obesity and overweight on DNA stability: Few facts and many hypotheses

Health authorities are alarmed worldwide about the increase of obesity and overweight in the last decades which lead to adverse health effects including inflammation, cancer, accelerated aging and infertility. We evaluated the state of knowledge concerning the impact of elevated body mass on genomic instability. Results of investigations with humans (39 studies) in which DNA damage was monitored in lymphocytes and sperm cells, are conflicting and probably as a consequence of heterogeneous study designs and confounding factors (e.g. uncontrolled intake of vitamins and minerals and consumption of different food types). Results of animal studies with defined diets (23 studies) are more consistent and show that excess body fat causes DNA damage in multiple organs including brain, liver, colon and testes. Different molecular mechanisms may cause genetic instability in overweight/obese individuals. ROS formation and lipid peroxidation were found in several investigations and may be caused by increased insulin, fatty acid and glucose levels or indirectly via inflammation. Also reduced DNA repair and formation of advanced glycation end products may play a role but more data are required to draw firm conclusions. Reduction of telomere lengths and hormonal imbalances are characteristic for overweight/obesity but the former effects are delayed and moderate and hormonal effects were not investigated in regard to genomic instability in obese individuals. Increased BMI values affect also the activities of drug metabolizing enzymes which activate/detoxify genotoxic carcinogens, but no studies concerning the impact of these alterations of DNA damage in obese individuals are available. Overall, the knowledge concerning the impact of increased body weight and DNA damage is poor and further research is warranted to shed light on this important issue.

Use of HuH6 and other human-derived hepatoma lines for the detection of genotoxins: a new hope for laboratory animals?

Cell lines which are currently used in genotoxicity tests lack enzymes which activate/detoxify mutagens. Therefore, rodent-derived liver preparations are used which reflect their metabolism in humans only partly; as a consequence misleading results are often obtained. Previous findings suggest that certain liver cell lines express phase I/II enzymes and detect promutagens without activation; however, their use is hampered by different shortcomings. The aim of this study was the identification of a suitable cell line. The sensitivity of twelve hepatic cell lines was investigated in single cell gel electrophoresis assays. Furthermore, characteristics of these lines were studied which are relevant for their use in genotoxicity assays (mitotic activity, p53 status, chromosome number, and stability). Three lines (HuH6, HCC1.2, and HepG2) detected representatives of five classes of promutagens, namely, IQ and PhIP (HAAs), B(a)P (PAH), NDMA (nitrosamine), and AFB₁ (aflatoxin), and were sensitive towards reactive oxygen species (ROS). In contrast, the commercially available line HepaRG, postulated to be a surrogate for hepatocytes and an ideal tool for mutagenicity tests, did not detect IQ and was relatively insensitive towards ROS. All other lines failed to detect two or more compounds. HCC1.2 cells have a high and unstable chromosome number and mutated p53, these features distract from its use in routine screening. HepG2 was frequently employed in earlier studies, but pronounced inter-laboratory variations were observed. HuH6 was never used in genotoxicity experiments and is highly promising, it has a stable karyotype and we demonstrated that the results of genotoxicity experiments are reproducible.

Low-density lipoprotein oxidation biomarkers in human health and disease and effects of bioactive compounds

Based on the significance of oxidized low-density lipoprotein (LDL) in health and disease, this review focuses on human studies addressing oxidation of LDL, including three lines of biomarkers, (i) ex vivo LDL resistance to oxidation, a "challenge test" model, (ii) circulating oxidized LDL, indicating the "current in vivo status", and (iii) autoantibodies against oxidized LDL as fingerprints of an immune response to oxidized LDL, along with circulating oxysterols and 4-hydroxynonenal as biomarkers of lipid peroxidation. Lipid peroxidation and oxidized LDL are hallmarks in the development of various metabolic, cardiovascular and other diseases. Changes further occur across life stages from infancy to older age as well as in athletes and smokers. Given their responsiveness to targeted nutritional interventions, markers of LDL oxidation have been employed in a rapidly growing number of human studies for more than 2 decades. There is growing interest in foods, which, besides providing energy and nutrients, exert beneficial effects on human health, such as protection of DNA, proteins and lipids from oxidative damage. Any health claim, however, needs to be substantiated by supportive evidence derived from human studies, using reliable biomarkers to demonstrate such beneficial effects. A large body of evidence has accumulated, demonstrating protection of LDL from oxidation by bioactive food compounds, including vitamins, other micronutrients and secondary plant ingredients, which will facilitate the selection of oxidation biomarkers for future human intervention studies and health claim support.

Measurement and Clinical Significance of Biomarkers of Oxidative Stress in Humans

Oxidative stress is the result of the imbalance between reactive oxygen species (ROS) formation and enzymatic and nonenzymatic antioxidants. Biomarkers of oxidative stress are relevant in the evaluation of the disease status and of the health-enhancing effects of antioxidants. We aim to discuss the major methodological bias of methods used for the evaluation of oxidative stress in humans. There is a lack of consensus concerning the validation, standardization, and reproducibility of methods for the measurement of the following: (1) ROS in leukocytes and platelets by flow cytometry, (2) markers based on ROS-induced modifications of lipids, DNA, and proteins, (3) enzymatic players of redox status, and (4) total antioxidant capacity of human body fluids. It has been suggested that the bias of each method could be overcome by using indexes of oxidative stress that include more than one marker. However, the choice of the markers considered in the global index should be dictated by the aim of the study and its design, as well as by the clinical relevance in the selected subjects. In conclusion, the clinical significance of biomarkers of oxidative stress in humans must come from a critical analysis of the markers that should give an overall index of redox status in particular conditions.

The Role of Biomarkers of Oxidative Stress in Breast Cancer Risk and Prognosis: A Systematic Review of the Epidemiologic Literature

BACKGROUND

Oxidative stress may play an important role in both initiation and progression of breast cancer. We conducted the first systematic epidemiologic review to summarize the published literature on oxidative stress biomarkers and breast cancer.

MATERIALS AND METHODS

We implemented systematic search strategies to identify published studies of oxidative stress biomarkers and (1) risk of developing breast cancer and (2) breast cancer prognosis using the PRISMA statement guidelines.

RESULTS

We identified eleven case-control studies of oxidative stress biomarkers and breast cancer. Biomarkers utilized varied and menopausal status was a key modifying factor. Across three nested case-control studies with biomarkers measured before diagnosis, one reported increased risk of postmenopausal breast cancer in association with 8-oxodG (DNA damage biomarker), while two (one of F₂-isoprostanes and one of fluorescent oxidation products) reported inverse associations for premenopausal breast cancer only. We identified eight prognostic studies. Two reported associations for lipid peroxidation and breast cancer prognosis; results for other studies were null.

CONCLUSIONS

DNA damage may increase risk of breast cancer among postmenopausal women, while lipid peroxidation may be inversely associated with premenopausal breast cancer. Lipid peroxidation may be associated with survival after breast cancer diagnosis; however, results require evaluation in large, prospective cohort studies.

The Peroxidation of Leukocytes Index Ratio Reveals the Prooxidant Effect of Green Tea Extract

Despite tea increased plasma nonenzymatic antioxidant capacity, the European Food Safety Administration (EFSA) denied claims related to tea and its protection from oxidative damage. Furthermore, the Supplement Information Expert Committee (DSI EC) expressed some doubts on the safety of green tea extract (GTE). We performed a pilot study in order to evaluate the effect of a single dose of two capsules of a GTE supplement (200 mg × 2) on the peroxidation of leukocytes index ratio (PLIR) in relation to uric acid (UA) and ferric reducing antioxidant potential (FRAP), as well as the sample size to reach statistical significance. GTE induced a prooxidant effect on leukocytes, whereas FRAP did not change, in agreement with the EFSA and the DSI EC conclusions. Besides, our results confirm the primary role of UA in the antioxidant defences. The ratio based calculation of the PLIR reduced the sample size to reach statistical significance, compared to the resistance to an exogenous oxidative stress and to the functional capacity of oxidative burst. Therefore, PLIR could be a sensitive marker of redox status.

Total Antioxidant Capacity in beta-thalassemia: A systematic review and meta-analysis of case-control studies

Total Antioxidant Capacity (TAC), a biomarker measuring the antioxidant potential of body fluids, including redox synergistic interactions, is influenced by the presence of products of catabolism such as bilirubin (BR) and uric acid (UA). Hyperuricaemia and increased BR levels were observed in thalassemia. In order to evaluate the differences in TAC values between thalassemic patients and healthy subjects, we performed a systematic review and meta-analysis of case-control studies. After the exclusion of data deemed unsuitable for meta-analysis inclusion and a study imputed of bias by Trim-and-fill analysis, mean difference (MD) and confidence intervals 95% (CI 95%) were calculated by the random effect model for beta-thalassemia major (BTM) (1351 subjects: 770 thalassemic and 581 controls, from 15 studies) and Trait (BTT) or Hemoglobin E (BTE) (475 subjects: 165 thalassemic and 310 controls, from 5 studies). Despite the differences in clinical symptoms and severity, similar decreased levels of TAC were found in BTM [MD -0.22 (-0.35 -0.09) p<0.001] and BTT or BTE [MD -0.22 (-0.44 -0.01) p<0.05]. In conclusion, UA and BR interference on TAC suggests that corrected TAC and in particular the UA-independent TAC, considering the prominent influence of UA, might be the better approach to evaluate body antioxidant status.

Use of Single-cell Gel Electrophoresis Assays in Dietary Intervention Trials

The single-cell gel electrophoresis (SCGE) technique has been frequently used to investigate the impact of consumption of complex foods and individual constituents on DNA stability in humans. Since no division or cultivation of the indicator cells (in most studies lymphocytes) is required, this approach is less costly and time consuming than cytogenetic methods. Apart from single- and double-stand breaks and apurinic sites, which can be detected under standard conditions, it is also possible to assess the formation of oxidized DNA bases and alterations of DNA repair as well as protection of the DNA against chemical carcinogens. In total, 93 studies have been published since the first use of the Comet assay in this field in 1997. The results which emerged from these studies show that human foods contain specific highly protective components (e.g. gallic acid, xanthohumol, isoflavones); promising results were also obtained with beverages (coffee and other drinks), while mixed diets with vegetables and fruits conferred no or moderate protection; however, individual plant foods (e.g. kiwis and specific cruciferous vegetables) were highly protective. It is notable that prevention of DNA damage was rarely detected under standard conditions while evidence for reduced formation of oxidized DNA bases was found in approximately 30% of the trials. In some investigations it was possible to identify the modes of action by which specific compounds prevented damage of the genetic material in additional mechanistic experiments. The currently available data show that SCGE assays are a valuable tool for identifying dietary factors which improve the stability of the genetic material and prevent adverse health effects which are causally related to DNA damage.

Going retro: Oxidative stress biomarkers in modern redox biology

The field of redox biology is inherently intertwined with oxidative stress biomarkers. Oxidative stress biomarkers have been utilized for many different objectives. Our analysis indicates that oxidative stress biomarkers have several salient applications: (1) diagnosing oxidative stress, (2) pinpointing likely redox components in a physiological or pathological process and (3) estimating the severity, progression and/or regression of a disease. On the contrary, oxidative stress biomarkers do not report on redox signaling. Alternative approaches to gain more mechanistic insights are: (1) measuring molecules that are integrated in pathways linking redox biochemistry with physiology, (2) using the exomarker approach and (3) exploiting -omics techniques. More sophisticated approaches and large trials are needed to establish oxidative stress biomarkers in the clinical setting.

Plasma total antioxidant capacity and peroxidation biomarkers in psoriasis

Systemic biomarkers of oxidative stress can be relevant for assessment of psoriasis severity, for prediction of the outcome of therapy and of the development of comorbidities. In this review we aimed to evaluate the relationship between plasma total antioxidant capacity (TAC) and peroxidation biomarkers, as well as their association with dyslipidemia and systemic inflammation in psoriasis. The review of 59 case–control comparisons (from 41 studies) and 17 interventions (from 13 studies) suggests that peroxidation markers are more sensitive than TAC in the evaluation of oxidative stress in psoriasis. Although few studies investigated the effect of treatment on oxidative stress, it seems that biological drugs could be the better choice in the treatment of psoriasis. However, considering the limitations of TAC and plasma peroxidation markers, this review suggests that new methods should be developed in order to evaluate systemic oxidative stress in psoriasis.

Antioxidant capacity of foods for scavenging reactive oxidants and inhibition of plasma lipid oxidation induced by multiple oxidants

Unregulated oxidation of biological molecules induced by multiple oxidants has been implicated in the pathogenesis of various diseases. Consequently, the effects of antioxidants contained in foods, beverages and supplements on the maintenance of health and prevention of diseases have attracted much attention of the public as well as scientists. However, recent human studies have shown inconsistent results and failed to demonstrate the beneficial effects of antioxidants. The mechanisms and dynamics of antioxidant action and assessment of antioxidant capacity have been the subject of extensive studies and arguments. In the present article, the antioxidant capacity has been reviewed focusing on two main issues: the capacity of antioxidants to scavenge multiple reactive oxidants and to inhibit plasma lipid oxidation induced by different biological oxidants. It is emphasized that the capacity of antioxidants to scavenge reactive oxidants does not always correlate linearly with the capacity to inhibit lipid oxidation and that it is necessary to specify the oxidant to assess the efficacy of antioxidants, since multiple oxidants contribute to oxidative damage in vivo and the effects of antioxidants depend on the nature of oxidants. A convenient and rapid method using a microplate reader is discussed for assessing the antioxidant capacity against plasma lipid oxidation induced by multiple oxidants including peroxyl radicals, peroxynitrite, hypochlorite, 15-lipoxygenase, and singlet oxygen.

Results of micronucleus assays with individuals who are occupationally and environmentally exposed to mercury, lead and cadmium

Millions of humans are exposed occupationally and environmentally to lead, mercury and cadmium compounds. Mercury compounds are less abundant but some of them belong to the most toxic chemicals which are known. We evaluated the literature to find out if these metals act in humans as genotoxic carcinogens and if their health effects can be predicted by use of micronucleus (MN) assays with lymphocytes and/or with other genotoxicity tests. Numerous studies showed that lead and mercury induce cancer in humans and also in animals, in vitro experiments with cultured cells indicate that they cause DNA damage via different molecular mechanisms including release of reactive oxygen species and interactions with DNA repair processes. Also in most human studies, positive results were obtained in MN tests with lymphocytes (all 15 occupational studies with lead yielded positive results, with mercury 6 out of 7 investigations were positive). For cadmium, there is clear evidence that it causes cancer in humans; however, induction of chromosomal damage was only seen in high dose experiments with mammalian cells while results of animal and human studies yielded conflicting results (only in 2 of 5MN trials with humans positive findings were reported). Possibly, non-genotoxic mechanisms such as inhibition of apoptosis and interaction with signaling pathways account for the carcinogenic properties of cadmium species. The findings of MN studies with lead and mercury are in excellent agreement with results which were obtained with other endpoints (e.g. chromosomal aberrations and comet formations) and it is evident that this approach can be used for occupational and environmental monitoring of exposed individuals. Important future tasks will be the realization of larger studies with a uniform standardized protocol, the additional evaluation of anomalies other than MN (nuclear buds and bridges) and the combination of such trials with investigations which allow to define the molecular mechanisms relevant for exposed humans.

Antioxidant Activity/Capacity Measurement. 2. Hydrogen Atom Transfer (HAT)-Based, Mixed-Mode (Electron Transfer (ET)/HAT), and Lipid Peroxidation Assays

Measuring the antioxidant activity/capacity levels of food extracts and biological fluids is useful for determining the nutritional value of foodstuffs and for the diagnosis, treatment, and follow-up of numerous oxidative stress-related diseases. Biologically, antioxidants play their health-beneficial roles via transferring a hydrogen (H) atom or an electron (e(-)) to reactive species, thereby deactivating them. Antioxidant activity assays imitate this action; that is, antioxidants are measured by their H atom transfer (HAT) or e(-) transfer (ET) to probe molecules. Antioxidant activity/capacity can be monitored by a wide variety of assays with different mechanisms, including HAT, ET, and mixed-mode (ET/HAT) assays, generally without distinct boundaries between them. Understanding the principal mechanisms, advantages, and disadvantages of the measurement assays is important for proper selection of method for valid evaluation of antioxidant properties in desired applications. This work provides a general and up-to-date overview of HAT-based, mixed-mode (ET/HAT), and lipid peroxidation assays available for measuring antioxidant activity/capacity and the chemistry behind them, including a critical evaluation of their advantages and drawbacks.

Salivary and Urinary Total Antioxidant Capacity as Biomarkers of Oxidative Stress in Humans

Total Antioxidant Capacity (TAC) is a biomarker often used in order to investigate oxidative stress in many pathological conditions. Saliva and urine can be collected noninvasively and represent attractive diagnostic fluids for detecting biomarkers of various pathological conditions. The reviewed case-control and intervention studies that measured salivary or urinary TAC revealed that diseases, antioxidant foods, or supplements and age, gender, and lifestyle factors influenced salivary or urinary TAC. Salivary and urinary TAC were particularly affected by oral or renal status, respectively, as well as by infection; therefore these factors must be taken into account in both case-control and intervention studies. Furthermore, some considerations on sample collection and normalization strategies could be made. In particular, unstimulated saliva could be the better approach to measure salivary TAC, whereas 24 h or spontaneous urine collection should be chosen on the basis of the study outcome and of the creatinine clearance. Finally, the uric acid-independent TAC could be the better approach to evaluate red-ox status of body, in particular after nutritional interventions and in diseases associated with hyperuricaemia.

A Case-Control Study of Involvement of Oxidative DNA Damage and Alteration of Antioxidant Defense System in Patients with Basal Cell Carcinoma: Modulation by Tumor Removal

Oxidative damage has been suggested to play a role in the pathogenesis of basal cell carcinoma (BCC). This study illustrated an involvement of oxidative DNA damage and changes in antioxidant defenses in BCC by conducting a case-control study (24 controls and 24 BCC patients) and assessing urinary 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-oxo-dGuo), plasma antioxidant defenses including catalase (CAT), glutathione peroxidase (GPx), NQO1, and total superoxide dismutase (SOD) activities, and glutathione (GSH) levels before surgery and 1 month after surgery. 8-oxo-dGuo expressions as well as protein and mRNA expressions of DNA repair enzyme hOGG1 and antioxidant defenses (CAT, GCLC, GPx, Nrf2, and MnSOD) in nonneoplastic epidermis of control and BCC tissues were also determined. This study observed induction in urinary 8-oxo-dGuo, increased 8-oxo-dGuo expression, and reduced hOGG1 protein and mRNA in BCC tissues, decreased activities of CAT, GPx, and NQO1, but elevated SOD activities and GSH levels in BCC patients and reduction of all antioxidant proteins and genes studied in BCC tissues. Furthermore, decreased plasma antioxidant activities in BCC patients were restored at 1 month after operation compared with preoperative levels. Herein, we concluded that BCC patients were associated with oxidative DNA damage and depletion of antioxidant defenses and surgical removal of BCC correlated with improved redox status.

Structure-Functional Study of Tyrosine and Methionine Dipeptides: An Approach to Antioxidant Activity Prediction

Quantum chemical methods allow screening and prediction of peptide antioxidant activity on the basis of known experimental data. It can be used to design the selective proteolysis of protein sources in order to obtain products with antioxidant activity. Molecular geometry and electronic descriptors of redox-active amino acids, as well as tyrosine and methionine-containing dipeptides, were studied by Density Functional Theory method. The calculated data was used to reveal several descriptors responsible for the antioxidant capacities of the model compounds based on their experimentally obtained antioxidant capacities against ABTS (2,2'-Azino-bis-(3-ethyl-benzothiazoline-6-sulfonate)) and peroxyl radical. A formula to predict antioxidant activity of peptides was proposed.

Looking to the horizon: the role of bilirubin in the development and prevention of age-related chronic diseases

Bilirubin, the principal tetrapyrrole, bile pigment and catabolite of haem, is an emerging biomarker of disease resistance, which may be related to several recently documented biological functions. Initially believed to be toxic in infants, the perception of bilirubin has undergone a transformation: it is now considered to be a molecule that may promote health in adults. Data from the last decade demonstrate that mildly elevated serum bilirubin levels are strongly associated with reduced prevalence of chronic diseases, particularly cardiovascular diseases (CVDs), as well as CVD-related mortality and risk factors. Recent data also link bilirubin to other chronic diseases, including cancer and Type 2 diabetes mellitus, and to all-cause mortality. Therefore, there is evidence to suggest that bilirubin is a biomarker for reduced chronic disease prevalence and a predictor of all-cause mortality, which is of important clinical significance. In the present review, detailed information on the association between bilirubin and all-cause mortality, as well as the pathological conditions of CVD, cancer, diabetes and neurodegenerative diseases, is provided. The mechanistic background concerning how bilirubin and its metabolism may influence disease prevention and its clinical relevance is also discussed. Given that the search for novel biomarkers of these diseases, as well as for novel therapeutic modalities, is a key research objective for the near future, bilirubin represents a promising candidate, meeting the criteria of a biomarker, and should be considered more carefully in clinical practice as a molecule that might provide insights into disease resistance. Clearly, however, greater molecular insight is warranted to support and strengthen the conclusion that bilirubin can prevent disease, with future research directions also proposed.

Effects of red wine on postprandial stress: potential implication in non-alcoholic fatty liver disease development

INTRODUCTION

Red wine consumption is considered to be protective against oxidative stress. Diet strongly influences non-alcoholic fatty liver disease, which is associated with oxidative stress and is considered the hepatic manifestation of the metabolic syndrome.

METHODS

We reviewed the available evidence that investigated the effects of red wine on the postprandial-induced metabolic and oxidative stress in humans.

RESULTS

After red wine consumption with meal, despite the improvement in non-enzymatic antioxidant capacity and lipoperoxidation markers, the influence of confounding factors such as uric acid should be taken into account. Both uric acid and triglycerides increases, induced by ethanol, could cause liver damage. On the other hand, further researches are required in order to understand the meaning of the induction of antioxidant enzymes by red wine and red wine polyphenols in the context of non-alcoholic fatty liver disease.

CONCLUSION

In conclusion, inconsistent and contrasting findings exist regarding the potential benefits of red wine consumption against postprandial stress.

Targeted mass spectrometry for the analysis of nutritive modulation of catalase and heme oxygenase-1 expression

Comprehensive physiological food assessment requires recording of activity profiles. To elucidate the nutritive regulation of antioxidant enzymes, a generally applicable targeted MS method was established for the expression analysis of catalase and then adapted to heme oxygenase-1. Before tryptic digestion, target proteins were prefractionated by off-gel IEF of stimulated and control cell lysate. Targeted proteome analysis was achieved by LC coupled with scheduled selected reaction monitoring MS using 2 proteotypic peptides per protein and 3-4 transitions per peptide. Relative quantification was performed by stable isotope labeling by amino acids in cell culture (SILAC). The assay showed good correlation with results by Western blot. Linearity, precision, and sensitivity were even improved (LC/SRM vs. Western blot: 3 vs. 1 orders of magnitude, RSD 3.7-13.7% vs. 18.4%, LOD 0.2 vs. 1.6μg/mL). The developed method indicated that coffee does not modulate catalase expression in macrophages (T7cat 103±22%, T17cat 103±16%, p>0.05 vs. control), but leads to a highly significant increase of heme oxygenase-1 expression (T15Ho-1 420±24%, T22Ho-1 364±37%, p<0.001 vs. control, p>0.05 T15Ho-1 vs. T22Ho-1). In regard to multiplex options of the method, targeted proteome analysis can be a valuable tool for the comprehensive analysis of cellular effects of food components.

BIOLOGICAL SIGNIFICANCE

In the present study, targeted mass spectrometry was applied to determine the influence of food components on the expression of antioxidative enzymes. The results implicate that targeted proteomics may develop into a valuable tool in food science and nutrition to determine the physiological effects of nutrients. In contrast to conventional methods for expression analysis, targeted proteome analysis can be applied to monitor the effects of a food component on a broad range of cellular targets in parallel. Additionally, proteins or protein modifications can be addressed which elude immunochemical methods.

The effect of sample storage on the Peroxidation of Leukocytes Index Ratio (PLIR) measure

Delays in processing are frequent because of problems associated with transporting the samples to the laboratory. Thus, we aimed to evaluate the effect of sample storage on the Peroxidation of Leukocytes Index Ratio (PLIR). Differences between PLIR values of lymphocytes (PLIR-L), monocytes (PLIR-M) and granulocytes (PLIR-G) were observed in fresh samples. Sample storage affected the evaluation of PLIR. In particular, PLIR-L was lower in stored samples compared to fresh samples. In conclusion, our results suggest that fresh samples are recommended for assessing the PLIR.

Evaluation of the antiradical properties of phenolic acids

Antioxidant capacity (AOC) against peroxyl radical and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical cation was measured for a series of p-hydroxybenzoic (HB) and p-hydroxycinnamic (HC) acids at different pH. Quantum-chemical computation was performed using Gaussian 3.0 software package to calculate the geometry and energy parameters of the same compounds. Significant correlations were revealed between AOC and a number of calculated parameters. The most significant AOC descriptors for the studied compounds against peroxyl radical were found to be HOMO energy, rigidity (η) and Mulliken charge on the carbon atom in m-position to the phenolic hydroxyl. The most significant descriptor of the antioxidant properties against the ABTS radical cation at рН 7.40 is electron transfer enthalpy from the phenolate ion. The mechanism of AOC realization has been proposed for HB and HC acids against both radicals.

Oxidative stress--implications, source and its prevention

Oxidative stress has been a major predicament of present day living. It has been the product of imbalance between the processes involved in free radical generation and their neutralization by enzymatic and non-enzymatic defence mechanisms. The oxidative stress has been contributed by numerous factors including heavy metals, organic compound-rich industrial effluents, air pollutants and changing lifestyle pattern focussing mainly on alcohol consumption, dietary habits, sun exposure, nuclear emissions, etc. The most common outcome of oxidative stress is the increased damage of lipid, DNA and proteins that resulted in the development of different pathologies. Among these pathologies, cancer is the most devastating and linked to multiple mutations arising due to oxidative DNA and protein damage that ultimately affect the integrity of the genome. The chemopreventive agents particularly nutraceuticals are found to be effective in reducing cancer incidences as these components have immense antioxidative, antimutagenic and antiproliferative potentials and are an important part of our dietary components. These secondary metabolites, due to their unique chemical structure, facilitate cell-to-cell communication, repair DNA damage by the downregulation of transcription factors and inhibit the activity of protein kinases and cytochrome P450-dependent mixed function oxidases. These phytochemicals, therefore, are most appropriate in combating oxidative stress-related disorders due to their tendency to exert better protective effect without having any distinct side effect.

Skin tumorigenic potential of benzanthrone: prevention by ascorbic acid

Benzanthrone (BA) exposed occupational workers have been found to exhibit toxicological manifestations in the skin, thus it is quite likely that long term exposure may lead to skin tumorigenicity. Thus, attempts were made to elucidate the tumor initiating and promoting potentials of pure (PBA) and commercial benzanthrone (CBA). Additionally, the preventive role of ascorbic acid (AsA) was also assessed. PBA showed tumor initiating activity while CBA demonstrated tumor initiating as well as promoting activities in two-stage mouse skin tumor protocol. Further, prior treatment of AsA to PBA and CBA followed by twice weekly application of 12-o-tetradecanoyl phorbal myristate acetate (TPA) resulted into delayed onset of tumor formation and similarly single application of 7,12-dimethylbenz [α] anthracene (DMBA) followed by twice weekly application of AsA and CBA showed an increase in the latency period. Thus, AsA showed a protective effect against CBA promoted skin tumor. Furthermore, the topical application of CBA significantly increased the levels of xenobiotic enzymes. The animals topically treated with AsA along with topical application of CBA, restored all the impairment observed in enzyme activities. Thus, this study suggested that AsA can be useful in preventing PBA and CBA induced skin tumorigenicity.

On the methodological limitations of detecting oxidative stress: effects of paraquat on measures of oxidative status in greenfinches

Oxidative stress (OS) is widely believed to be responsible for generation of trade-offs in evolutionary ecology by means of constraining investment into a number of components of fitness. Yet the progress in understanding the true role of OS in ecology and evolution has remained elusive. Interpretation of current findings is particularly hampered by the scarcity of experiments demonstrating which of the many available parameters of oxidative status respond most sensitively to and are relevant for measuring OS. We addressed these questions in wild-caught captive greenfinches (Carduelis chloris) by experimental induction of OS by administration of the pro-oxidant compound paraquat with drinking water. Treatment induced 50% of mortality and a significant drop in body mass and an increase in oxidative DNA damage and glutathione levels in erythrocytes among the survivors of the high paraquat (0.2 g/L during 7 days) group. Three days after the end of the treatment, paraquat had no effect on peroxidation of lipids (plasma malondialdehyde), carbonylation of proteins (in erythrocytes), parameters of plasma antioxidant protection (TAC and OXY), uric acid or carotenoids. Our findings of an increase in one marker of damage and one marker of protection from the multitude of measured variables indicate that detection of OS is difficult even under most stringent experimental induction of oxidative insult. We hope that this study highlights the need for reconsideration of over-simplistic models of OS and draws attention to the limitations of detection of OS due to time-lagged and hormetic up-regulation of protective mechanisms. This study also underpins the diagnostic value of measurement of oxidative damage to DNA bases and assessment of erythrocyte glutathione levels.

Healthy and adverse effects of plant-derived functional metabolites: the need of revealing their content and bioactivity in a complex food matrix

In recent years, both food quality and its effect on human health have become a fundamental issue all over the world. As a consequence of this new and increased awareness, American, European, and Asian policymakers have strongly encouraged the research programs on food quality and safety thematic. Attempts to improve human health and to satisfy people's desire for healthcare without intake of pharmaceuticals, has led the food industry to focus attention on functional or nutraceutical food. For a long time, compounds with nutraceutical activity have been produced chemically, but the new demands for a sustainable life have gradually led the food industry to move towards natural compounds, mainly those derived from plants. Many phytochemicals are known to promote good health, but, sometimes, undesirable effects are also reported. Furthermore, several products present on the market show few benefits and sometimes even the reverse - unhealthy effects; the evidence of efficacy is often unconvincing and epidemiological studies are necessary to prove the truth of their claims. Therefore, there is a need for reliable analytical control systems to measure the bioactivity, content, and quality of these additives in the complex food matrix. This review describes the most widespread nutraceutics and an analytical control of the same using recently developed biosensors which are promising candidates for routine control of functional foods.

In vitro antioxidant capacity and antigenotoxic properties of protoporphyrin and structurally related tetrapyrroles

The antioxidant properties of protoporphyrin IX and related tetrapyrroles are poorly characterized. Therefore, eight tetrapyrroles, five of which are produced in vivo, were tested to assess their antioxidant capacities in the Salmonella reverse mutation, TEAC, FRAP and ORAC assays. Tertiary-butyl hydroperoxide (tert-BOOH) in the presence or absence of metabolic activation (±S9) was added to Salmonella strain TA102 together with the test compounds. In the absence of metabolic activation, the order of effectiveness was protoporphyrin > biliverdin > bilirubin ditaurate > bilirubin > biliverdin dimethyl ester > stercobilin > bilirubin dimethyl ester > urobilin. In the presence of S9, the effectiveness was reversed, with urobilin > biliverdin dimethyl ester > bilirubin dimethyl ester > stercobilin > biliverdin > bilirubin > bilirubin ditaurate > protoporphyrin. In the antioxidant capacity assays FRAP, TEAC and ORAC, mainly bilirubin, bilirubin ditaurate, biliverdin and protoporphyrin showed antioxidant activity. This study reports that previously untested tetrapyrroles of related structure prevent oxidatively induced genotoxicity, and for some, novel underlying mechanisms of antioxidant action were revealed. These results support the physiological importance and biological relevance of tetrapyrroles including protoporphyrin that might act as antioxidants, protecting from oxidatively induced DNA damage, particularly in the tissues/organs where they accumulate.

Formation of micronuclei and other nuclear anomalies in exfoliated nasal and oral cells: results of a human study with workers in a power plant processing poultry litter

Handling of chicken litter leads to exposure to toxic gases, endotoxins and airborne microorganisms. Aim of this study was to investigate if this results in acute cytotoxicity and to damage of the genetic material which is involved in the etiology of various diseases including cancer. Nuclear anomalies which reflect genotoxic and cytotoxic effects were monitored in exfoliated buccal and nasal cells which were collected from workers (n = 25) of a power plant which processes chicken manure and from controls (n = 21). Furthermore, biochemical parameters of the redox status (malondialdehyde, oxLDL and TEAC) and C-reactive protein (CRP) in plasma and the concentrations of toxic gases and endotoxins in the air were determined. No increase of anomalies which reflect chromosomal damage (micronuclei, binucleates, nuclear buds) but significantly higher rates of nuclear aberrations which are indicative for cytotoxicity (karyolysis, karyorrhexis, condensed chromatin) were found in the workers. These effects were in nasal cells more pronounced as in buccal cells. MDA, oxLDL and CRC levels were in both study groups similar. Chemical analyses show that the workers are exposed to high concentrations of NO and endotoxins, while the levels of NO2, NH3 and H2S were below the MAK levels. Taken together, the results show that anomalies that are due to cytotoxicity are increased in the workers and suggest that the exposure may lead to inflammations in the respiratory tract. However, the lack of induction of anomalies that reflect chromosomal damage indicate that no health effects will take place which are due to instability of the genetic material.

Review of current and "omics" methods for assessing the toxicity (genotoxicity, teratogenicity and nephrotoxicity) of herbal medicines and mushrooms

ETHNOPHARMACOLOGICAL RELEVANCE

The increasing use of traditional herbal medicines around the world requires more scientific evidence for their putative harmlessness. To this end, a plethora of methods exist, more or less satisfying. In this post-genome era, recent reviews are however scarce, not only on the use of new "omics" methods (transcriptomics, proteomics, metabonomics) for genotoxicity, teratogenicity, and nephrotoxicity assessment, but also on conventional ones.

METHODS

The present work aims (i) to review conventional methods used to assess genotoxicity, teratogenicity and nephrotoxicity of medicinal plants and mushrooms; (ii) to report recent progress in the use of "omics" technologies in this field; (iii) to underline advantages and limitations of promising methods; and lastly (iv) to suggest ways whereby the genotoxicity, teratogenicity, and nephrotoxicity assessment of traditional herbal medicines could be more predictive.

RESULTS

Literature and safety reports show that structural alerts, in silico and classical in vitro and in vivo predictive methods are often used. The current trend to develop "omics" technologies to assess genotoxicity, teratogenicity and nephrotoxicity is promising but most often relies on methods that are still not standardized and validated.

CONCLUSION

Hence, it is critical that toxicologists in industry, regulatory agencies and academic institutions develop a consensus, based on rigorous methods, about the reliability and interpretation of endpoints. It will also be important to regulate the integration of conventional methods for toxicity assessments with new "omics" technologies.

Protection by flavanol-rich foods against vascular dysfunction and oxidative damage: 27th Hohenheim Consensus Conference

Criteria for assessing the purported protection by flavanol-rich foods against vascular dysfunction and oxidative damage to biomolecules was the subject of the 27th Hohenheim Consensus Conference held on July 11, 2011. State-of-the-art evidence was put into perspective, focusing on several questions that were followed by a consensus answer. Among the topics addressed were the major sources of flavanols in the human diet, the bioavailability of flavanols, biomarkers for "health benefit," and the biological function of flavanols. Consensus was reached on these topics. No conclusion was reached on the design of randomized, controlled trials for substantiation of health claims for flavanol-rich foods as to the necessity of a study arm with an isolated pharmacologically active compound, e.g., (-)-epicatechin.

Potent protection of gallic acid against DNA oxidation: results of human and animal experiments

Gallic acid (3,4,5-trihydroxybenzoic acid, GA) is a constituent of plant derived foods, beverages and herbal remedies. We investigated its DNA protective properties in a placebo controlled human intervention trial in single cell gel electrophoresis experiments. Supplementation of drinking water with GA (12.8 mg/person/d) for three days led to a significant reduction of DNA migration attributable to oxidised pyrimidines (endonuclease III sensitive sites) and oxidised purines (formamidopyrimidine glycosylase sensitive sites) in lymphocytes of healthy individuals by 75% and 64% respectively. Also DNA damage caused by treatment of the cells with reactive oxygen species (ROS) was reduced after GA consumption (by 41%). These effects were paralleled by an increase of the activities of antioxidant enzymes (superoxide dismutase, glutathione peroxidase and glutathion-S-transferase-π) and a decrease of intracellular ROS concentrations in lymphocytes, while no alterations of the total antioxidant capacity (TAC), of malondialdehyde levels in serum and of the urinary excretion of isoprostanes were found. Experiments with rats showed that GA reduces oxidatively damaged DNA in lymphocytes, liver, colon and lungs and protects these organs against γ-irradiation-induced strand breaks and formation of oxidatively damaged DNA-bases. Furthermore, the number of radiation-induced preneoplastic hepatic foci was decreased by 43% after oral administration of the phenolic. Since we did not find alterations of the TAC in plasma and lipid peroxidation of cell membranes but intracellular effects it is likely that the antioxidant properties of GA seen in vivo are not due to direct scavenging of radicals but rather to indirect mechanisms (e.g. protection against ROS via activation of transcription factors). As the amount of GA used in the intervention trial is similar to the daily intake in Middle Europe (18 mg/person/day), our findings indicate that it may contribute to prevention of formation of oxidatively damaged DNA in humans.

Instant coffee with high chlorogenic acid levels protects humans against oxidative damage of macromolecules

SCOPE

Coffee is among the most frequently consumed beverages. Its consumption is inversely associated to the incidence of diseases related to reactive oxygen species; the phenomenon may be due to its antioxidant properties. Our primary objective was to investigate the impact of consumption of a coffee containing high levels of chlorogenic acids on the oxidation of proteins, DNA and membrane lipids; additionally, other redox biomarkers were monitored in an intervention trial.

METHODS AND RESULTS

The treatment group (n=36) consumed instant coffee co-extracted from green and roasted beans, whereas the control consumed water (800 mL/P/day, 5 days). A global statistical analysis of four main biomarkers selected as primary outcomes showed that the overall changes are significant. 8-Isoprostaglandin F2α in urine declined by 15.3%, 3-nitrotyrosine was decreased by 16.1%, DNA migration due to oxidized purines and pyrimidines was (not significantly) reduced in lymphocytes by 12.5 and 14.1%. Other markers such as the total antioxidant capacity were moderately increased; e.g. LDL and malondialdehyde were shifted towards a non-significant reduction.

CONCLUSION

The oxidation of DNA, lipids and proteins associated with the incidence of various diseases and the protection against their oxidative damage may be indicative for beneficial health effects of coffee.