8-hydroxy-2' -deoxyguanosine (8-OHdG): A critical biomarker of oxidative stress and carcinogenesis

CaMKII as a pathological mediator of ER stress, oxidative stress, and mitochondrial dysfunction in a murine model of nephronophthisis

Polycystic kidney diseases (PKDs) are genetic diseases characterized by renal cyst formation with increased cell proliferation, apoptosis, and transition to a secretory phenotype at the expense of terminal differentiation. Despite recent progress in understanding PKD pathogenesis and the emergence of potential therapies, the key molecular mechanisms promoting cystogenesis are not well understood. Here, we demonstrate that mechanisms including endoplasmic reticulum stress, oxidative damage, and compromised mitochondrial function all contribute to nephronophthisis-associated PKD. Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) is emerging as a critical mediator of these cellular processes. Therefore, we reasoned that pharmacological targeting of CaMKII may translate into effective inhibition of PKD in jck mice. Our data demonstrate that CaMKII is activated within cystic kidney epithelia in jck mice. Blockade of CaMKII with a selective inhibitor results in effective inhibition of PKD in jck mice. Mechanistic experiments in vitro and in vivo demonstrated that CaMKII inhibition relieves endoplasmic reticulum stress and oxidative damage and improves mitochondrial integrity and membrane potential. Taken together, our data support CaMKII inhibition as a new and effective therapeutic avenue for the treatment of cystic diseases.

Acute crack cocaine exposure induces genetic damage in multiple organs of rats

Crack cocaine is a very toxic product derived from cocaine. The aim of this study was to evaluate genetic damage in multiple organs of rats following acute exposure to crack cocaine. A total of 20 Wistar rats were distributed into four groups (n = 5), as follows: 0, 4.5, 9, and 18 mg/kg body weight (b.w.) of crack cocaine administered by intraperitoneal route (i.p.). All animals were killed 24 h after intraperitoneal (i.p.) injection. The results showed that crack cocaine increased the number of micronucleated cells in bone marrow cells exposed to 18 mg/kg crack cocaine (p < 0.05). Peripheral blood and liver cells presented genetic damage as depicted by single cell gel (comet) assay at 9 and 18 mg/kg doses (p < 0.05). Immunohistochemistry data revealed significant increase in 8-hydroxy-20-deoxyguanosine (8-OHdG) immunoexpression in hepatocytes of animals exposed to crack cocaine at 9 and 18 mg/kg (p < 0.05) when compared with negative controls. Taken together, our results demonstrate that crack cocaine is able to induce genomic damage in multiple organs of Wistar rats.

Hepatoprotective Effects of Chinese Medicinal Herbs: A Focus on Anti-Inflammatory and Anti-Oxidative Activities

The liver is intimately connected to inflammation, which is the innate defense system of the body for removing harmful stimuli and participates in the hepatic wound-healing response. Sustained inflammation and the corresponding regenerative wound-healing response can induce the development of fibrosis, cirrhosis and eventually hepatocellular carcinoma. Oxidative stress is associated with the activation of inflammatory pathways, while chronic inflammation is found associated with some human cancers. Inflammation and cancer may be connected by the effect of the inflammation-fibrosis-cancer (IFC) axis. Chinese medicinal herbs display abilities in protecting the liver compared to conventional therapies, as many herbal medicines have been shown as effective anti-inflammatory and anti-oxidative agents. We review the relationship between oxidative stress and inflammation, the development of hepatic diseases, and the hepatoprotective effects of Chinese medicinal herbs via anti-inflammatory and anti-oxidative mechanisms. Moreover, several Chinese medicinal herbs and composite formulae, which have been commonly used for preventing and treating hepatic diseases, including Andrographis Herba, Glycyrrhizae Radix et Rhizoma, Ginseng Radix et Rhizoma, Lycii Fructus, Coptidis Rhizoma, curcumin, xiao-cha-hu-tang and shi-quan-da-bu-tang, were selected for reviewing their hepatoprotective effects with focus on their anti-oxidative and ant-inflammatory activities. This review aims to provide new insight into how Chinese medicinal herbs work in therapeutic strategies for liver diseases.

Effect of alpha-lipoic acid on radiation-induced small intestine injury in mice

PURPOSE

Radiation therapy is a highly effective treatment for patients with solid tumors. However, it can cause damage and inflammation in normal tissues. Here, we investigated the effects of alpha-lipoic acid (ALA) as radioprotection agent for the small intestine in a mouse model.

MATERIALS AND METHODS

Whole abdomen was evenly irradiated with total a dose of 15 Gy. Mice were treated with either ALA (100 mg/kg, intraperitoneal injection [i.p.]) or saline (equal volume, i.p.) the prior to radiation as 100 mg/kg/day for 3 days. Body weight, food intake, histopathology, and biochemical parameters were evaluated.

RESULTS

Significant differences in body weight and food intake were observed between the radiation (RT) and ALA + RT groups. Moreover, the number of crypt cells was higher in the ALA + RT group. Inflammation was decreased and recovery time was shortened in the ALA + RT group compared with the RT group. The levels of inflammation-related factors (i.e., phosphorylated nuclear factor kappa B and matrix metalloproteinase-9) and mitogen-activated protein kinases were significantly decreased in the ALA + RT group compared with those in the RT group.

CONCLUSIONS

ALA treatment prior to radiation decreases the severity and duration of radiation-induced enteritis by reducing inflammation, oxidative stress, and cell death.

Methacryloxylethyl Cetyl Ammonium Chloride Induces DNA Damage and Apoptosis in Human Dental Pulp Cells via Generation of Oxidative Stress

The polymerizable antibacterial monomer methacryloxylethyl cetyl ammonium chloride (DMAE-CB) has provided an effective strategy to combat dental caries. However, the application of such material raises the question about the biological safety and the question remains open. The mechanism of this toxic action, however, is not yet clearly understood. The present study aims at providing novel insight into the possible causal link between cellular oxidative stress and DNA damage, as well as apoptosis in human dental pulp cells exposed to DMAE-CB. The enhanced formation of reactive oxygen species and depletion of glutathione, as well as differential changes in activities of superoxide dismutase, glutathione peroxidase, and catalase in DMAE-CB-treated cells indicated oxidative stress. By using substances that can alter GSH synthesis, we found that GSH was the key component in the regulation of cell response towards oxidative stress induced by DMAE-CB. The increase in oxidative stress-sensitive 8-Oxo-2'-deoxyguanosine (8-OHdG) content, formation of γ-H2AX and cell cycle G1 phase arrest indicated that DNA damage occurred as a result of the interaction between DNA base and ROS beyond the capacities of antioxidant mechanisms in cells exposed to DMAE-CB. Such oxidative DNA damage thus triggers the activation of ataxia telangiectasia-mutated (ATM) signaling, the intrinsic apoptotic pathway, and destruction of mitochondrial morphology and function.

Burn injury induces skeletal muscle degeneration, inflammatory host response, and oxidative stress in wistar rats

Burn injuries (BIs) result in both local and systemic responses distant from the site of thermal injury, such as skeletal muscle. The purpose of this study was to investigate the expression of cyclooxygenase-2 (COX-2) and hydroxy-2'-deoxyguanosine (8-OHdG) as a result of inflammation and reactive oxygen species production, respectively. A total of 16 male rats were distributed into two groups: control (C) and submitted to BI. The medial part of gastrocnemius muscle formed the specimens, which were stained with hematoxylin and eosin and were evaluated. COX-2 and 8-OHdG expressions were assessed by immunohistochemistry, and cell profile area and density of muscle fibers (number of fibers per square millimeter) were evaluated by morphometric methods. The results revealed inflammatory infiltrate associated with COX-2 immunoexpression in BI-gastrocnemius muscle. Furthermore, a substantial decrease in the muscle cell profile area of BI group was noticed when compared with the control group, whereas the density of muscle fibers was higher in the BI group. 8-OHdG expression in numerous skeletal muscle nuclei was detected in the BI group. In conclusion, the BI group is able to induce skeletal muscle degeneration as a result of systemic host response closely related to reactive oxygen species production and inflammatory process.

Lack of p47(phox) in Akita Diabetic Mice Is Associated with Interstitial Pneumonia, Fibrosis, and Oral Inflammation

Excess reactive oxygen species production is central to the development of diabetic complications. The contribution of leukocyte reactive oxygen species produced by the NADPH oxidase to altered inflammatory responses associated with uncontrolled hyperglycemia is poorly understood. To get insight into the role of phagocytic superoxide in the onset of diabetic complications, we used a model of periodontitis in mice with chronic hyperglycemia and lack of leukocyte p47(phox) (Akita/Ncf1) bred from C57BL/6-Ins2(Akita)/J (Akita) and neutrophil cytosolic factor 1 knockout (Ncf1) mice. Akita/Nfc1 mice showed progressive cachexia starting at early age and increased mortality by six months. Their lungs developed infiltrative interstitial lesions that obliterated air spaces as early as 12 weeks when fungal colonization of lungs also was observed. Neutrophils of Akita/Ncf1 mice had normal degranulation and phagocytic efficiency when compared with wild-type mice. Although Akita/Ncf1 mice had increased prevalence of oral infections and more severe periodontitis compared with wild-type mice, bone loss was only marginally higher compared with Akita and Ncf1 null mice. Altogether these results indicate that lack of leukocyte superoxide production in mice with chronic hyperglycemia results in interstitial pneumonia and increased susceptibility to infections.

Sociodemographic and Lifestyle Determinants of Plasma Oxidative Stress Markers 8-OHdG and F2-Isoprostanes and Associations with Metabolic Syndrome

Background. Oxidative stress is increasingly important in health research. Therefore, it is necessary to understand which factors determine basal oxidative stress. This study examines the associations of various determinants with markers of oxidative DNA and lipid damage: 8-hydroxy-2'-deoxyguanosine (8-OHdG) and F2-isoprostanes. Methods. Data are from the Netherlands Study of Depression and Anxiety; 1117 subjects (18-65 years) without a current psychiatric diagnosis. Multivariable regression analyses were conducted with plasma levels of 8-OHdG and F2-isoprostanes (measured by LC/MS-MS) including sociodemographic, lifestyle, and sampling variables. Associations with metabolic syndrome (MetS) and chronic disease were examined. Results. 8-OHdG and F2-isoprostanes were weakly correlated (r = 0.06, p = 0.045). Both were positively associated with age and cotinine (cigarette exposure); 8-OHdG was lower in females and after longer sample storage. F2-isoprostanes were higher in females, alcohol users, and in samples collected in spring and lower in supplement users and those with more education. Both markers were lower in fasting subjects. F2-isoprostanes, not 8-OHdG, were positively associated with MetS. Conclusion. The weak correlation between 8-OHdG and F2-isoprostanes suggests they reflect specific aspects of oxidative stress. Both markers are associated with a range of sociodemographic, lifestyle, and sampling determinants which should be considered in future research. F2-isoprostanes are associated with MetS.

Oxidative mitochondrial DNA damage in peripheral blood mononuclear cells is associated with reduced volumes of hippocampus and subcortical gray matter in chronically HIV-infected patients

Cross-sectional relationships were examined between regional brain volumes and mitochondrial DNA (mtDNA) 8-hydroxy-2-deoxyguanosine (8-oxo-dG) in peripheral blood mononuclear cells (PBMCs) of 47 HIV patients [mean age 51years; 81% with HIV RNA ≤50copies/mL] on combination antiretroviral therapy. The gene-specific DNA damage and repair assay measured mtDNA 8-oxo-dG break frequency. Magnetic resonance imaging was performed at 3T. Higher mtDNA 8-oxo-dG was associated with lateral ventricular enlargement and with decreased volumes of hippocampus, pallidum, and total subcortical gray matter, suggesting the involvement of systemic mitochondrial-specific oxidative stress in chronic HIV-related structural brain changes and cognitive difficulties. Clarification of the mechanism may provide potential therapeutic targets.

Bioanalytical techniques for detecting biomarkers of response to human asbestos exposure

Asbestos exposure is known to cause lung cancer and mesothelioma and its health and economic impacts have been well documented. The exceptionally long latency periods of most asbestos-related diseases have hampered preventative and precautionary steps thus far. We aimed to summarize the state of knowledge on biomarkers of response to asbestos exposure. Asbestos is not present in human biological fluids; rather it is inhaled and trapped in lung tissue. Biomarkers of response, which reflect a change in biologic function in response to asbestos exposure, are analyzed. Several classes of molecules have been studied and evaluated for their potential utility as biomarkers of asbestos exposure. These studies range from small molecule oxidative stress biomarkers to proteins involved in immune responses.

Stress, nutrition and parental care in a teleost fish: exploring mechanisms with supplemental feeding and cortisol manipulation

Parental care is an essential life-history component of reproduction for many animal species, and it entails a suite of behavioural and physiological investments to enhance offspring survival. These investments can incur costs to the parent, reducing their energetic and physiological condition, future reproductive capabilities and survival. In fishes, relatively few studies have focused on how these physiological costs are mediated. Male smallmouth bass provide parental care for developing offspring until the brood reaches independence. During this energetically demanding life stage, males cease active foraging as they vigorously defend their offspring. Experimental manipulation of cortisol levels (via implantation) and food (via supplemental feeding) in parental males was used to investigate the fitness consequences of parental care. Improving the nutritional condition of nest-guarding males increased their reproductive success by reducing premature nest abandonment. However, supplemental feeding and cortisol treatment had no effect on parental care behaviours. Cortisol treatment reduced plasma lymphocyte numbers, but increased neutrophil and monocyte concentrations, indicating a shift in immune function. Supplemental feeding improved the physiological condition of parental fish by reducing the accumulation of oxidative injury. Specifically, supplemental feeding reduced the formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) on DNA nucleotides. Increasing the nutritional condition of parental fish can reduce the physiological cost associated with intensive parental activity and improve overall reproductive success, illustrating the importance of nutritional condition as a key modulator of parental fitness.

Recent advances in salivary cancer diagnostics enabled by biosensors and bioelectronics

There is a high demand for a non-invasive, rapid, and highly accurate tool for disease diagnostics. Recently, saliva based diagnostics for the detection of specific biomarkers has drawn significant attention since the sample extraction is simple, cost-effective, and precise. Compared to blood, saliva contains a similar variety of DNA, RNA, proteins, metabolites, and microbiota that can be compiled into a multiplex of cancer detection markers. The salivary diagnostic method holds great potential for early-stage cancer diagnostics without any complicated and expensive procedures. Here, we review various cancer biomarkers in saliva and compare the biomarkers efficacy with traditional diagnostics and state-of-the-art bioelectronics. We summarize biomarkers in four major groups: genomics, transcriptomics, proteomics, and metabolomics/microbiota. Representative bioelectronic systems for each group are summarized based on various stages of a cancer. Systematic study of oxidative stress establishes the relationship between macromolecules and cancer biomarkers in saliva. We also introduce the most recent examples of salivary diagnostic electronics based on nanotechnologies that can offer rapid, yet highly accurate detection of biomarkers. A concluding section highlights areas of opportunity in the further development and applications of these technologies.

Integrating Multiple Biomarkers of Fish Health: A Case Study of Fish Health in Ports

Biomarkers of fish health are recognised as valuable biomonitoring tools that inform on the impact of pollution on biota. The integration of a suite of biomarkers in a statistical analysis that better illustrates the effects of exposure to xenobiotics on living organisms is most informative; however, most published ecotoxicological studies base the interpretation of results on individual biomarkers rather than on the information they carry as a set. To compare the interpretation of results from individual biomarkers with an interpretation based on multivariate analysis, a case study was selected where fish health was examined in two species of fish captured in two ports located in Western Australia. The suite of variables selected included chemical analysis of white muscle, body condition index, liver somatic index (LSI), hepatic ethoxyresorufin-O-deethylase activity, serum sorbitol dehydrogenase activity, biliary polycyclic aromatic hydrocarbon metabolites, oxidative DNA damage as measured by serum 8-oxo-dG, and stress protein HSP70 measured on gill tissue. Statistical analysis of individual biomarkers suggested little consistent evidence of the effects of contaminants on fish health. However, when biomarkers were integrated as a set by principal component analysis, there was evidence that the health status of fish in Fremantle port was compromised mainly due to increased LSI and greater oxidative DNA damage in fish captured within the port area relative to fish captured at a remote site. The conclusions achieved using the integrated set of biomarkers show the importance of viewing biomarkers of fish health as a set of variables rather than as isolated biomarkers of fish health.

8-Hydroxy-2'-deoxyguanosine as a biomarker of oxidative DNA damage induced by perfluorinated compounds in TK6 cells

8-Hydroxy-2'-deoxyguanosine (8-OHdG) is the most common biomarker of oxidative DNA damage, it is formed by chemical carcinogens and can be measured in any species. Perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA) are suspected genotoxic carcinogens through induction of reactive oxygen species that are responsible for oxidative DNA damage. This study was conducted to investigate the in vitro genotoxicity of PFOA and PFNA in human lymphoblastoid (TK6) cell line. TK6 cells were exposed to PFOA at 0, 125, 250, and 500 ppm and PFNA at 125 and 250 ppm for 2 h. Single cell gel electrophoresis (comet assay) was used to measure DNA damage; at least 50 cells per sample were analyzed using comet Assay Software Project (CASP). 8-OHdG was measured in DNA of exposed cells using high-performance liquid chromatography (HPLC)-mass spectrometry (MS)/MS. Results showed that both PFOA and PFNA induced DNA damage indicated by increased tail length (DNA migration). The level of 8-OHdG was increased in a dose-dependent manner in both PFOA and PFNA exposure. We concluded that PFOA and PFNA induced DNA damage and the biomarker of oxidative DNA damage (8-OHdG) could be measured by HPLC-MS/MS. In addition, PFNA produced high level of 8-OHdG at concentrations lower than PFOA, this may indicate that PFNA is more potent genotoxicant for TK6 cells than PFOA.

Aeroparticles, Composition, and Lung Diseases

Urban air pollution is a serious worldwide problem due to its impact on human health. In the past 60 years, growing evidence established a correlation between exposure to air pollutants and the developing of severe respiratory diseases. Recently particulate matter (PM) is drawing more public attention to various aspects including historical backgrounds, physicochemical characteristics, and its pathological role. Therefore, this review is focused on these aspects. The most famous air pollution disaster happened in London on December 1952; it has been calculated that more than 4,000 deaths occurred during this event. Air pollution is a complex mix of gases and particles. Gaseous pollutants disseminate deeply into the alveoli, allowing its diffusion through the blood-air barrier to several organs. Meanwhile, PM is a mix of solid or liquid particles suspended in the air. PM is deposited at different levels of the respiratory tract, depending on its size: coarse particles (PM10) in upper airways and fine particles (PM2.5) can be accumulated in the lung parenchyma, inducing several respiratory diseases. Additionally to size, the composition of PM has been associated with different toxicological outcomes on clinical and epidemiological, as well as in vivo and in vitro animal and human studies. PM can be constituted by organic, inorganic, and biological compounds. All these compounds are capable of modifying several biological activities, including alterations in cytokine production, coagulation factors balance, pulmonary function, respiratory symptoms, and cardiac function. It can also generate different modifications during its passage through the airways, like inflammatory cells recruitment, with the release of cytokines and reactive oxygen species (ROS). These inflammatory mediators can activate different pathways, such as MAP kinases, NF-κB, and Stat-1, or induce DNA adducts. All these alterations can mediate obstructive or restrictive respiratory diseases like asthma, COPD, pulmonary fibrosis, and even cancer. In 2013, outdoor air pollution was classified as Group 1 by IARC based on all research studies data about air pollution effects. Therefore, it is important to understand how PM composition can generate several pulmonary pathologies.

Protocatechualdehyde Protects Against Cerebral Ischemia-Reperfusion-Induced Oxidative Injury Via Protein Kinase Cε/Nrf2/HO-1 Pathway

Oxidative stress is closely related to the pathogenesis of ischemic stroke. Protocatechualdehyde (PCA) is a phenolic acid compound that has the putative antioxidant activities. The present study was aimed to investigate the molecular mechanisms involved in the antioxidative effect of PCA against cerebral ischemia/reperfusion (I/R) injury. The experiment stroke model was produced in Sprague-Dawley rats via middle cerebral artery occlusion (MCAO). To model ischemia-like conditions in vitro, differentiated SH-SY5Y cells were exposed to transient oxygen and glucose deprivation (OGD). Treatment with PCA significantly improved neurologic score, reduced infarct volume and necrotic neurons, and also decreased reactive oxygen species (ROS) production, 4-hydroxynonenal (4-HNE), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) contents at 24 h after reperfusion. Meanwhile, PCA significantly increased the transcription nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expressions in the ischemic cerebral cortex as shown by immunofluorescence staining and Western blot analysis. In vitro experiment showed that PCA protected differentiated SH-SY5Y cells against OGD-induced injury. Likewise, PCA also increased markedly the Nrf2 and HO-1 expressions in a dose-dependent manner. The neuroprotection effect of PCA was abolished by knockdown of Nrf2 and HO-1. Moreover, knockdown of protein kinase Cε (PKCε) also blocked PCA-induced Nfr2 nuclear translocation, HO-1 expression, and neuroprotection. Taken together, these results provide evidences that PCA can protect against cerebral ischemia-reperfusion-induced oxidative injury, and the neuroprotective effect involves the PKCε/Nrf2/HO-1 pathway.

Evidence for the Cost of Reproduction in Humans: High Lifetime Reproductive Effort Is Associated with Greater Oxidative Stress in Post-Menopausal Women

Life history theory predicts trade-offs between reproductive effort and maternal survivorship in energy-restricted environments. However, empirical evidence for the positive association between maternal mortality and reproductive effort from energetically challenged human populations are mixed and physiological mechanisms that may underlie this association are poorly understood. We hypothesized that increases in aerobic metabolism during repeated periods of pregnancy and lactation result in increased oxidative stress that may contribute to somatic deterioration, vulnerability to illness, and accelerated aging. We therefore predicted that lifetime gravidity and parity would be related to levels of biomarkers of oxidative stress, as well as antioxidative defence enzymes in post-menopausal women. Our hypothesis was supported by positive linear associations between levels of 8-OHdG, a biomarker of DNA oxidative damage (β = 0.21, p<0.05), levels of antioxidative defence enzyme Cu-Zn SOD (β = 0.25, p<0.05), and number of lifetime pregnancies. Furthermore, independent of age and health status, post-menopausal women with higher gravidity and parity (> = 4 pregnancies per lifetime) had 20% higher levels of 8-OHdG and 60% higher levels of Cu-Zn SOD compared to women with lower gravidity and parity (<4 pregnancies per lifetime). Our results present the first evidence for oxidative stress as a possible cost of reproductive effort in humans.

The 2100MHz radiofrequency radiation of a 3G-mobile phone and the DNA oxidative damage in brain

We aimed to evaluate the effect of 2100MHz radiofrequency radiation emitted by a generator, simulating a 3G-mobile phone on the brain of rats during 10 and 40 days of exposure. The female rats were randomly divided into four groups. Group I; exposed to 3G modulated 2100MHz RFR signal for 6h/day, 5 consecutive days/wk for 2 weeks, group II; control 10 days, were kept in an inactive exposure set-up for 6h/day, 5 consecutive days/wk for 2 weeks, group III; exposed to 3G modulated 2100MHz RFR signal for 6h/day, 5 consecutive days/wk for 8 weeks and group IV; control 40 days, were kept in an inactive exposure set-up for 6h/day, 5 consecutive days/wk for 8 weeks. After the genomic DNA content of brain was extracted, oxidative DNA damage (8-hydroxy-2'deoxyguanosine, pg/mL) and malondialdehyde (MDA, nmoL/g tissue) levels were determined. Our main finding was the increased oxidative DNA damage to brain after 10 days of exposure with the decreased oxidative DNA damage following 40 days of exposure compared to their control groups. Besides decreased lipid peroxidation end product, MDA, was observed after 40 days of exposure. The measured decreased quantities of damage during the 40 days of exposure could be the means of adapted and increased DNA repair mechanisms.

Electrochemiluminescent Array to Detect Oxidative Damage in ds-DNA Using [Os(bpy)2(phen-benz-COOH)]2+/Nafion/Graphene Films

Reactive oxygen species (ROS) oxidize guanosines in DNA to form 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxodG), a biomarker for oxidative stress. Herein we describe a novel 64-microwell electrochemiluminescent (ECL) array enabling sensitive multiplexed detection of 8-oxodG in ds-DNA without hydrolysis. Films of Nafion and reduced graphene oxide containing ECL dye [Os(bpy)₂(phen-benz-COOH)]²⁺ (OsNG, {bpy= 2,2'-bipyridine and phen-benz-COOH = (4-(1,10-phenanthrolin-6-yl) benzoic acid)}) were assembled into microwells on a pyrolytic graphite wafer to detect 8-oxodG in oligonucleotides by electrochemiluminescence (ECL). DNA oxidation by Fenton's reagent or by ROS formation during redox cycles involving NADPH, Cu^II, and model metabolites was monitored. UPLC-MS/MS of oxidized DNA samples were used for calibration. Detection limit for the fluidic arrays was one 8-oxodG per 670 intact nucleobases, or 0.15%. The method is sensitive enough to evaluate DNA oxidation from biologically relevant ROS-generating reactions of Cu^II, NADPH, and model metabolites.

Biomarkers of PAH exposure and hematologic effects in subjects exposed to combustion emission during residential (and professional) cooking practices in Pakistan

The aim of this study was to evaluate and compare the exposure of household women and professional male workers to combustion emission in the indoor and semi-outdoor environments, respectively, by using biochemical parameters and the biomarkers of exposure to polycyclic aromatic hydrocarbon (PAH). Female (WR n = 60) and male "cooks" (WC n = 60) exposed to the combustion emission of fuel wood and coal in rural/suburban areas of Pakistan were recruited in this study and compared to non-exposed female (CF) and male (CM) groups (n = 32 and 34, respectively). Urinary biomarkers of PAH exposure including 1-hyroxypyrene (1-OHPyr), α-naphthol, and β-naphthol were analyzed together with the biomarkers of effect, including the serum c-reactive proteins (CRP), white blood cells (WBCs), hemoglobin (Hb), red blood cells (RBC), and platelet (PLT) count. In addition, blood superoxide dismutase (SOD) and urinary level of 8-hydroxydeoxyguanosine (8-OHdG) were evaluated to determine the oxidative stress and DNA damage, respectively. A questionnaire was used to document demographic-, health-, and exposure-related information. The results showed that urinary β-naphthol was almost 44% higher in WR subjects than WC (median 7.69 vs. 3.39 μmol/mol-Cr, respectively; p = 0.01) and respective controls (CF). Higher urinary 8-OHdG were observed in WR (71.1 ng/mg-Cr) than WC (56.37 ng/mg-Cr) (p < 0.001), and lower life status and higher degree of headache were observed in WR than WC. In WCs, however, a low Hb and high WBC (8.29 × 10(3) μL(-1), ranging between 6.1 and 10.6 × 10(3) μL(-1)) were observed in comparison with CM. The study shows that WC subjects used larger amount of fuel and were subjected to prolonged exposure. It was concluded that the role of ventilation is fundamental and WR were more exposed to PAHs despite the fact that WC spent more time in cooking (due to occupational requirement) than WR.

Electrochemical investigations of 8-hydroxydeoxyguanosine and its determination at an edge plane pyrolytic graphite electrode

Electrochemical oxidation of 8-hydroxydeoxyguanosine (8-OHdG) and its detection with low detection limit is reported at pyrolytic graphite electrode.

Approaches to prevent the patients with chronic airway diseases from exacerbation in the haze weather

Haze weather is becoming one of the biggest problems in many big cities in China. It triggers both public anxiety and official concerns. Particulate matter (PM) plays the most important role in causing the adverse health effects. Chemical composition of PM2.5 includes primary particles and secondary particles. The toxicological mechanisms of PM2.5 to the human body include the oxidative stress, inflammation and carcinogenesis. Short or long-term exposure to PM (especially PM2.5) can cause a series of symptoms including respiratory symptoms such as cough, wheezing and dyspnea as well as other symptoms. There are positive associations between PM2.5 and mortality due to a number of causes. PM2.5 is considered to contribute to the onset of asthma, the exacerbation of chronic obstructive pulmonary disease (COPD) in haze weather. Some approaches including outdoor health care, indoor health care and preventive medications can prevent the patients with chronic airway diseases from exacerbations.

Oxidative stress promotes benign prostatic hyperplasia

BACKGROUND

Benign prostatic hyperplasia (BPH) is characterized by increased tissue mass in the transition zone of the prostate, which leads to obstruction of urine outflow and significant morbidity in the majority of older men. Plasma markers of oxidative stress are increased in men with BPH but it is unclear whether oxidative stress and/or oxidative DNA damage are causal in the pathogenesis of BPH.

METHODS

Levels of 8-OH deoxyguanosine (8-OH dG), a marker of oxidative stress, were measured in prostate tissues from normal transition zone and BPH by ELISA. 8-OH dG was also detected in tissues by immunohistochemistry and staining quantitated by image analysis. Nox4 promotes the formation of reactive oxygen species. We therefore created and characterized transgenic mice with prostate specific expression of Nox4 under the control of the prostate specific ARR2PB promoter.

RESULTS

Human BPH tissues contained significantly higher levels of 8-OH dG than control transition zone tissues and the levels of 8-OH dG were correlated with prostate weight. Cells with 8-OH dG staining were predominantly in the epithelium and were present in a patchy distribution. The total fraction of epithelial staining with 8-OH dG was significantly increased in BPH tissues by image analysis. The ARR2PB-Nox4 mice had increased oxidative DNA damage in the prostate, increased prostate weight, increased epithelial proliferation, and histological changes including epithelial proliferation, stromal thickening, and fibrosis when compared to wild type controls.

CONCLUSIONS

Oxidative stress and oxidative DNA damage are important in the pathogenesis of BPH.

Purple carrot extract protects against cadmium intoxication in multiple organs of rats: Genotoxicity, oxidative stress and tissue morphology analyses

The aim of this study was to investigate if purple carrot extract is able to protect against the noxious activities induced by cadmium exposure in multiple organs of rats. For this purpose, histopathological analysis, genotoxicity and oxidative status were investigated in this setting. A total of twenty Wistar rats weighing 250g on the average, and 8 weeks age were distributed into four groups (n=5), as follows: Control group (non-treated group, CTRL); Cadmium group (Cd) and Purple carrot extract groups at 400mg/L or 800mg/L. Histopathological analysis revealed that liver from animals treated with purple carrot extract improved tissue degeneration induced by cadmium intoxication. Genetic damage was reduced in blood and hepatocytes as depicted by comet and micronucleus assays in animals treated with purple carrot extract. SOD-CuZn and cytocrome C gene expression increased in groups treated with purple carrot extract. Purple carrot extract also reduced the 8OHdG levels in liver cells when compared to cadmium group. Taken together, our results demonstrate that purple carrot extract is able to protect against cadmium intoxication by means of reducing tissue regeneration, genotoxicity and oxidative stress in multiple organs of Wistar rats.

Electrochemical sensing of guanine, adenine and 8-hydroxy-2′-deoxyguanosine at glassy carbon modified with single-walled carbon nanotubes covalently functionalized with lysine

Synthesis and characterization of l-lysine covalently functionalized SWCNT and analytical application for the highly sensitive quantification of guanine, adenine and 8-hydroxy-2′-deoxyguanosine.

ZnO Nanoparticles: A Promising Anticancer Agent

Nanoparticles, with their selective targeting capabilities and superior efficacy, are becoming increasingly important in modern cancer therapy and starting to overshadow traditional cancer therapies such as chemotherapy radiation and surgery. ZnO nanoparticles, with their unique properties such as biocompatibility, high selectivity, enhanced cytotoxicity and easy synthesis, may be a promising anticancer agent. Zinc, as one of the major trace elements of the human body and co-factor of more than 300 mammalian enzymes, plays an important role in maintaining crucial cellular processes including oxidative stress, DNA replication, DNA repair, cell cycle progression and apoptosis. Thus, it is evident that an alteration in zinc levels in cancer cells can cause a deleterious effect. Research has shown that low zinc concentration in cells leads to the initiation and progression of cancer and high zinc concentration shows toxic effects. Zinc-mediated protein activity disequilibrium and oxidative stress through reactive oxygen species (ROS) may be the probable mechanism of this cytotoxic effect. The selective localization of ZnO nanoparticles towards cancer cells due to enhanced permeability and retention (EPR) effect and electrostatic interaction and selective cytotoxicity due to increased ROS present in cancer cells show that ZnO nanoparticles can selectively target and kill cancer cells, making them a promising anticancer agent.

Possible Biomarkers in Blood for Crohn's Disease: Oxidative Stress and MicroRNAs-Current Evidences and Further Aspects to Unravel

Crohn's disease (CD) is an inflammatory disorder characterised by a transmural inflammation of the intestinal wall. Although the physiopathology of the disease is not yet fully understood, it is clear that the immune response plays an important role in it. This hyperreactive immune system is accompanied by the presence of unregulated reactive oxygen species (ROS). These elements are modulated in normal conditions by different elements, including enzymes that function as antioxidant defences preventing the harmful effects of ROS. However, in CD there is an imbalance between ROS production and these antioxidant elements, resulting in oxidative stress (OxS) phenomena. In fact, now OxS is being considered more a potential etiological factor for Crohn's disease rather than a concomitant effect in the disease. The persistence of the OxS can also be influencing the evolution of the disease. Furthermore, the epigenetic mechanisms, above all microRNAs, are being considered key elements in the pathogenesis of CD. These elements and the presence of OxS have also been linked to several diseases. We, therefore, describe in this review the most significant findings related to oxidative stress and microRNAs profiles in the peripheral blood of CD patients.

Methane-rich saline protects against concanavalin A-induced autoimmune hepatitis in mice through anti-inflammatory and anti-oxidative pathways

Methane is a common gas which has been reported to play a protective role in organ injury and presents an anti-inflammatory property. However, its effects on Concanavalin A (Con A)-induced autoimmune hepatitis (AIH) remain unknown. Thus, the aim of this study was to investigate the effects of methane on Con A-induced autoimmune hepatitis in mice and its underlying mechanism. Autoimmune hepatitis was induced by Con A (15 mg/kg) in healthy C57BL/6 mice and methane-rich saline (MS) (20 ml/kg) was intraperitoneally injected 30 min after the challenge with Con A. We found that methane treatment significantly reduced the elevated serum aminotransferase levels and ameliorated liver pathological damage. Furthermore, methane treatment obviously suppressed the secretion of proinflammatory cytokines including tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-6 (IL-6) and interleukin-1β (IL-1β) and increased anti-inflammatory cytokine interleukin-10 (IL-10). Moreover, we found that the levels of malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were highly increased while the activities of superoxide dismutase (SOD) and catalase (CAT) were decreased in liver with the injection of Con A, which was reversed by methane. Also, the data demonstrated that the phosphorylated IκB, NF-κB and P38 MAPK in liver were significantly down-regulated by methane. These results suggested that methane protected liver against Con A-induced injury through anti-inflammatory and anti-oxidative pathways.

Oxidative Stress and Inflammation in Hepatic Diseases: Therapeutic Possibilities of N-Acetylcysteine

Liver disease is highly prevalent in the world. Oxidative stress (OS) and inflammation are the most important pathogenetic events in liver diseases, regardless the different etiology and natural course. N-acetyl-l-cysteine (the active form) (NAC) is being studied in diseases characterized by increased OS or decreased glutathione (GSH) level. NAC acts mainly on the supply of cysteine for GSH synthesis. The objective of this review is to examine experimental and clinical studies that evaluate the antioxidant and anti-inflammatory roles of NAC in attenuating markers of inflammation and OS in hepatic damage. The results related to the supplementation of NAC in any form of administration and type of study are satisfactory in 85.5% (n = 59) of the cases evaluated (n = 69, 100%). Within this percentage, the dosage of NAC utilized in studies in vivo varied from 0.204 up to 2 g/kg/day. A standard experimental design of protection and treatment as well as the choice of the route of administration, with a broader evaluation of OS and inflammation markers in the serum or other biological matrixes, in animal models, are necessary. Clinical studies are urgently required, to have a clear view, so that, the professionals can be sure about the effectiveness and safety of NAC prescription.

Impact of dexrazoxane on doxorubicin-induced aneuploidy in somatic and germinal cells of male mice

PURPOSE

Despite dexrazoxane's increasing use in mitigating doxorubicin-induced cardiotoxicity, no data are available in the literature on the potential aneugenicity of drug combination. Therefore, detailed evaluation of aneugenic potential of this combination is essential to provide more insights into aneuploidy induction that may play a role in the development of secondary malignancies and reproductive toxicity after treatment with doxorubicin. Thus, our aim was to determine whether dexrazoxane has influence on the aneuploidy induced by doxorubicin in germinal and somatic cells of male mice.

METHODS

Sperm BrdU-incorporation assay, sperm FISH assay and the bone marrow micronucleus test complemented by FISH assay were used to determine aneuoploidy. Moreover, the formation of 8-OHdG, one of the oxidative DNA damage by-products, has been evaluated.

RESULTS

Dexrazoxane was not aneugenic at the doses tested. Pre-treatment of mice with dexrazoxane significantly reduced doxorubicin-induced aneuploidy in a dose-dependent manner. Doxorubicin induced marked biochemical alterations characteristic of oxidative DNA damage, and prior administration of dexrazoxane before doxorubicin challenge ameliorated this biochemical marker.

CONCLUSION

This study provides evidence that dexrazoxane has a protective role in the abatement of doxorubicin-induced aneuploidy. This activity resides, at least in part, in its radical scavenger activity. Thus, dexrazoxane can avert secondary malignancies and abnormal reproductive outcomes in cured cancer patients exposed to doxorubicin.

Distribution and biomarkers of carbon-14-labeled fullerene C60 ([(14) C(U)]C60 ) in female rats and mice for up to 30 days after intravenous exposure

A comprehensive distribution study was conducted in female rats and mice exposed to a suspension of uniformly carbon-14-labeled C60 ([(14) C(U)]C60 ). Rodents were administered [(14) C(U)]C60 (~0.9 mg kg(-1) body weight) or 5% polyvinylpyrrolidone-saline vehicle alone via a single tail vein injection. Tissues were collected at 1 h and 1, 7, 14 and 30 days after administration. A separate group of rodents received five daily injections of suspensions of either [(14) C(U)]C60 or vehicle with tissue collection 14 days post exposure. Radioactivity was detected in over 20 tissues at all time points. The highest concentration of radioactivity in rodents at each time point was in liver, lungs and spleen. Elimination of [(14) C(U)]C60 was < 2% in urine and feces at any 24 h time points. [(14) C(U)]C60 and [(14) C(U)]C60 -retinol were detected in liver of rats and together accounted for ~99% and ~56% of the total recovered at 1 and 30 days postexposure, respectively. The blood radioactivity at 1 h after [(14) C(U)]C60 exposure was fourfold higher in rats than in mice; blood radioactivity was still in circulation at 30 days post [(14) C(U)]C60 exposure in both species (<1%). Levels of oxidative stress markers increased by 5 days after exposure and remained elevated, while levels of inflammation markers initially increased and then returned to control values. The level of cardiovascular marker von Willebrand factor, increased in rats, but remained at control levels in mice. This study demonstrates that [(14) C(U)]C60 is retained in female rodents with little elimination by 30 days after i.v. exposure, and leads to systemic oxidative stress.

Gum acacia mitigates genetic damage in adenine-induced chronic renal failure in rats

BACKGROUND

Subjects with chronic renal failure (CRF) exhibit oxidative genome damage, which may predispose to carcinogenesis, and Gum acacia (GumA) ameliorates this condition in humans and animals. We evaluated here renal DNA damage and urinary excretion of four nucleic acid oxidation adducts namely 8-oxoguanine (8-oxoGua), 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), 8-oxoguanosine (8-oxoGuo) and 8-hydroxy-2-deoxyguanisone (8-OHdg) in rats with adenine (ADE)-induced CRF with and without GumA treatment.

MATERIALS AND METHODS

Twenty-four rats were divided into four equal groups and treated for 4 weeks. The first group was given normal food and water (control). The second group was given normal food and GumA (15% w/v) in drinking water. The third group was fed powder diet containing adenine (ADE) (0·75% w/w in feed). The fourth group was fed like in the third group, plus GumA in drinking water (15%, w/v).

RESULTS

ADE feeding induced CRF (as measured by several physiological, biochemical and histological indices) and also caused a significant genetic damage and significant decreases in urinary 8-oxo Gua and 8-oxoGuo, but not in the other nucleic acids. However, concomitant GumA treatment reduced the level of genetic damage in kidney cells as detected by Comet assay and significantly reversed the effect of adenine on urinary 8-oxoGuo.

CONCLUSIONS

Treatment with GumA is able to mitigate genetic damage in renal tissues of rats with ADE-induced CRF.

Ameliorative Influence of Green Tea Extract on Copper Nanoparticle-Induced Hepatotoxicity in Rats

The potential toxicity of copper nanoparticles (CNPs) to the human health and environment remains a critical issue. In the present study, we investigated the protective influence of an aqueous extract of green tea leaves (GTE) against CNPs-induced (20-30 nm) hepatotoxicity. Four different groups of rats were used: group I was the control, group II received CNPs (40 mg/kg BW), group III received CNPs plus GTE, and group IV received GTE alone. We highlighted the hepatoprotective effect of GTE against CNPs toxicity through monitoring the alteration of liver enzyme activity, antioxidant defense mechanism, histopathological alterations, and DNA damage evaluation. The rats that were given CNPs only had a highly significant elevation in liver enzymes, alteration in oxidant-antioxidant balance, and severe pathological changes. In addition, we detected a significant elevation of DNA fragmentation percentage, marked DNA laddering, and significance over expression of both caspase-3 and Bax proteins. The findings for group III clarify the efficacy of GTE as a hepatoprotectant on CNPs through improving the liver enzyme activity, antioxidant status, as well as suppressing DNA fragmentation and the expression of the caspase-3 and Bax proteins. In conclusion, GTE was proved to be a potential hepatoprotective additive as it significantly ameliorates the hepatotoxicity and apoptosis induced by CNPs.

The role of base excision repair in pathogenesis of breast cancer in the Polish population

Breast cancer (BC) is leading type of cancer among group of women, which determines almost 23% of invasive cancers. It has been reported repeatedly that the level of oxidative stress is higher for BC in comparison to cancer-free woman. The goal of the present study was to evaluate the role of base excision repair (BER) pathway in the development of BC. One-hundred seventy-one women with confirmed BC and 222 healthy controls were enrolled in presented study. The level of oxidative DNA damage and the kinetic of their repair were analyzed by the modified alkaline comet assay. The efficiency of BER pathway was evaluated by BER assay. The presence of the 326Cys/Cys genotype and 326Cys allele of OGG1 gene and the 324His/His of MUTYH gene are associated with increased risk of BC development. Moreover, correlation between clinical parameter with selected genes has shown increased risk of BC progression. The survival analysis has shown a significant lower DFS for individuals with the 762Ala/Ala genotype compared to 762Val/Vla carriers and the 762Val/Ala genotype in relation to concomitant chemotherapy and radiotherapy. In subgroup of patients with alone chemotherapy and alone radiotherapy, the 762Val/Val genotype was significantly associated with lower overall survival. Furthermore, we also elevated the level of basal and oxidative DNA damage in a group of patients with BC in relation to healthy controls. We also observed the difference in effectiveness of DNA damage repair. The results of present studies suggested the important role of BER pathway in BC development. © 2015 Wiley Periodicals, Inc.

Adenosine A1 receptor activation attenuates cardiac hypertrophy and fibrosis in response to α1 -adrenoceptor stimulation in vivo

BACKGROUND AND PURPOSE

Adenosine has been proposed to exert anti-hypertrophic effects. However, the precise regulation and the role of the different adenosine receptor subtypes in the heart and their effects on hypertrophic signalling are largely unknown. We aimed to characterize expression and function of adenosine A1 receptors following hypertrophic stimulation in vitro and in vivo.

EXPERIMENTAL APPROACH

Pro-hypertrophic stimuli and adenosine A1 receptor stimulation of neonatal rat cardiomyocytes and male C57/Bl6 mice, sc. drug administration, real-time PCR, (3) [H]-leucine-incorporation assay, immunostaining, tissue staining, Western blots, gravimetric analyses and echocardiography were applied in this study.

KEY RESULTS

In neonatal rat cardiomyocyte cultures, phenylephrine, but not angiotensin II or insulin-like growth factor 1 (IGF1), up-regulated adenosine A1 receptors concentration-dependently. The hypertrophic phenotype (cardiomyocyte size, sarcomeric organization, total protein synthesis, c-fos expression) mediated by phenylephrine (10 μM), but not that by angiotensinII (1 μM) or IGF1 (20 ng·mL(-1) ), was counteracted by the selective A1 receptor agonist, N6-cyclopentyladenosine. In C57/BL6 mice, continuous N6-cyclopentyladenosine infusion (2 mg·kg(-1) ·day(-1) ; 21 days) blunted phenylephrine (120 mg·kg(-1) ·day(-1) ; 21 days) induced hypertrophy (heart weight, cardiomyocyte size and fetal genes), fibrosis, MMP 2 up-regulation and generation of oxidative stress - all hallmarks of maladaptive remodelling. Concurrently, phenylephrine administration increased expression of adenosine A1 receptors.

CONCLUSIONS AND IMPLICATIONS

We have presented evidence for a negative feedback mechanism attenuating pathological myocardial hypertrophy following α1 -adrenoceptor stimulation. Our results suggest adenosine A1 receptors as potential targets for therapeutic strategies to prevent transition from compensated myocardial hypertrophy to decompensated heart failure due to chronic cardiac pressure overload.

Efficiency of Base Excision Repair of Oxidative DNA Damage and Its Impact on the Risk of Colorectal Cancer in the Polish Population

DNA oxidative lesions are widely considered as a potential risk factor for colorectal cancer development. The aim of this work was to determine the role of the efficiency of base excision repair, both in lymphocytes and in epithelial tissue, in patients with CRC and healthy subjects. SNPs were identified within genes responsible for steps following glycosylase action in BER, and patients and healthy subjects were genotyped. A radioisotopic BER assay was used for assessing repair efficiency and TaqMan for genotyping. Decreased BER activity was observed in lymphocyte extract from CRC patients and in cancer tissue extract, compared to healthy subjects. In addition, polymorphisms of EXO1, LIG3, and PolB may modulate the risk of colorectal cancer by decreasing (PolB) or increasing (LIG3 and EXO1) the chance of malignant transformation.

Gingival fibroblasts resist apoptosis in response to oxidative stress in a model of periodontal diseases

Periodontal diseases are classified as inflammation affecting the supporting tissue of teeth, which eventually leads to tooth loss. Mild reversible gingivitis and severe irreversible periodontitis are the most common periodontal diseases. Periodontal pathogens initiate the diseases. The bacterial toxin, lipopolysaccharide (LPS), triggers the inflammatory response and leads to oxidative stress. However, the progress of oxidative stress in periodontal diseases is unknown. The purpose of this study is to examine oxidative stress and cell damage in gingivitis and periodontitis. Our results showed that LPS increases reactive oxygen species (ROS) accumulation in gingival fibroblast (GF). However, oxidative stress resulting from excessive ROS did not influence DNA damage and cell apoptosis within 24 h. The mechanism may be related to the increased expression of DNA repair genes, Ogg1, Neil1 and Rad50. Detection of apoptosis-related proteins also showed anti-apoptotic effects and pro-apoptotic effects were balanced. The earliest damage appeared in DNA when increased γH2AX, an early biomarker for DNA damage, was detected in the LPS group after 48 h. Later, when recurrent inflammation persisted, 8-OHdG, a biomarker for oxidative stress was much higher in periodontitis model compared to the control in vivo. Staining of 8-OHdG in human periodontitis specimens confirmed the results. Furthermore, TUNEL staining of apoptotic cells indicated that the periodontitis model induced more cell apoptosis in gingival tissue. This suggested GF could resist early and acute inflammation (gingivitis), which was regarded as reversible, but recurrent and chronic inflammation (periodontitis) led to permanent cell damage and death.

Protective Effect of Folic Acid on Oxidative DNA Damage: A Randomized, Double-Blind, and Placebo Controlled Clinical Trial

Although previous reports have linked DNA damage with both transmissions across generations as well as our own survival, it is unknown how to reverse the lesion. Based on the data from a Randomized, Double-blind, Placebo Controlled Clinical Trial, this study aimed to assess the efficacy of folic acid supplementation (FAS) on DNA oxidative damage reversal.In this randomized clinical trial (RCT), a total of 450 participants were enrolled and randomly assigned to 3 groups to receive folic acid (FA) 0.4 mg/day (low-FA), 0.8 mg/day (high-FA), or placebo (control) for 8 weeks. The urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and creatinine (Cr) concentration at pre- and post-FAS were measured with modified enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC), respectively. A multivariate general linear model was applied to assess the individual effects of FAS and the joint effects between FAS and hypercholesterolemia on oxidative DNA damage improvement. This clinical trial was registered with ClinicalTrials.gov, number NCT02235948.Of the 438 subjects that received FA fortification or placebo, the median (first quartile, third quartile) of urinary 8-OHdG/Cr for placebo, low-FA, and high-FA groups were 58.19 (43.90, 82.26), 53.51 (38.97, 72.74), 54.73 (39.58, 76.63) ng/mg at baseline and 57.77 (44.35, 81.33), 51.73 (38.20, 71.30), and 50.65 (37.64, 76.17) ng/mg at the 56th day, respectively. A significant decrease of urinary 8-OHdG was observed after 56 days FA fortification (P < 0.001). Compared with the placebo, after adjusting for some potential confounding factors, including the baseline urinary 8-OHdG/Cr, the urinary 8-OHdG/Cr concentration significantly decreased after 56 days FAS [β (95% confidence interval) = -0.88 (-1.62, -0.14) and P = 0.020 for low-FA; and β (95% confidence interval) = -2.68 (-3.42, -1.94) and P < 0.001 for high-FA] in a dose-response fashion (Ptrend < 0.001). Test of interaction between hypercholesterolemia and FA supplementation on urinary 8-OHdG reduction was significant (P = 0.001).The present study demonstrates that FA fortification is independently linked to the reduction of urinary 8-OHdG/Cr in a dose-related pattern, which suggests that FA is beneficial to protect against oxidative damage to DNA. This effect is apparently stronger in those with hypercholesterolemia. The authors provide a new insight into the prevention and reversal of oxidative DNA damage.

Ameliorative effect of naringin against doxorubicin-induced acute cardiac toxicity in rats

CONTEXT

Doxorubicin (Dox) is one of the most active chemotherapeutic agents used to treat various types of cancers. Its clinical utility is compromised due to fatal cardiac toxicity characterized by an irreversible cardiomyopathy.

OBJECTIVE

This study evaluates the cardioprotective potential of naringin (NR) against Dox-induced acute cardiac toxicity in rats.

MATERIALS AND METHODS

Male Wistar rats were randomly divided into five groups. NR (50 and 100 mg/kg) was administered intraperitoneally (i.p.) daily from 0 to 14 d. Doxorubicin (15 mg/kg, i.p.) was given as a single dose on the 10th day. On the 14th day, all animals were sacrificed and oxidative stress parameters that include malondialdehyde (MDA), glutathione (GSH) level, superoxide dismutase (SOD), catalase (CAT) activities, and all mitochondrial complexes (I-IV) activities were evaluated along with histopathological studies of the heart.

RESULTS

Doxorubicin-induced cardiotoxicity was confirmed by increased (p < 0.05) MDA, decreased (p < 0.05) GSH levels, SOD, and CAT activities, mitochondrial complexes (I-IV) activities in the heart tissue. NR (100 mg/kg) showed cardioprotection as evident from significant decreased MDA (p < 0.001) level, raised (p < 0.001) GSH level, SOD and CAT activities and increased mitochondrial complexes I (p < 0.01), II (p < 0.001), III (p < 0.001), and IV (p < 0.05) activities. Further, Dox-induced cardiotoxicity was confirmed by histopathological studies. These obtained results indicated the protective role of NR against Dox-induced cardiac toxicity in rats.

CONCLUSION

NR can be used in combination with Dox due to its high cardioprotective effect against Dox-induced cardiomyopathy.

Apple juice attenuates genotoxicity and oxidative stress induced by cadmium exposure in multiple organs of rats

The aim of this study was to evaluate the health benefits associated with apple consumption following cadmium exposure. A total of 15 Wistar rats were distributed into three groups (n=5), as follows: control group (non-treated group, CTRL); cadmium group (Cd) and apple juice group (Cd+AJ). The results showed a decrease in the frequency micronucleated cells in bone marrow and hepatocytes in the group exposed to cadmium and treated with apple juice. Apple juice was also able to reduce the 8OHdG levels and to decrease genetic damage in liver and peripheral blood cells. Catalase (CAT) was decreased following apple juice intake. Taken together, our results demonstrate that apple juice seems to be able to prevent genotoxicity and oxidative stress induced by cadmium exposure in multiple organs of Wistar rats.

Mutagenic Effects of Iron Oxide Nanoparticles on Biological Cells

In recent years, there has been an increased interest in the design and use of iron oxide materials with nanoscale dimensions for magnetic, catalytic, biomedical, and electronic applications. The increased manufacture and use of iron oxide nanoparticles (IONPs) in consumer products as well as industrial processes is expected to lead to the unintentional release of IONPs into the environment. The impact of IONPs on the environment and on biological species is not well understood but remains a concern due to the increased chemical reactivity of nanoparticles relative to their bulk counterparts. This review article describes the impact of IONPs on cellular genetic components. The mutagenic impact of IONPs may damage an organism's ability to develop or reproduce. To date, there has been experimental evidence of IONPs having mutagenic interactions on human cell lines including lymphoblastoids, fibroblasts, microvascular endothelial cells, bone marrow cells, lung epithelial cells, alveolar type II like epithelial cells, bronchial fibroblasts, skin epithelial cells, hepatocytes, cerebral endothelial cells, fibrosarcoma cells, breast carcinoma cells, lung carcinoma cells, and cervix carcinoma cells. Other cell lines including the Chinese hamster ovary cells, mouse fibroblast cells, murine fibroblast cells, Mytilus galloprovincialis sperm cells, mice lung cells, murine alveolar macrophages, mice hepatic and renal tissue cells, and vero cells have also shown mutagenic effects upon exposure to IONPs. We further show the influence of IONPs on microorganisms in the presence and absence of dissolved organic carbon. The results shed light on the OPEN ACCESS Int. J. Mol. Sci. 2015, 16 23483 transformations IONPs undergo in the environment and the nature of the potential mutagenic impact on biological cells.

Renal Protective Effect of Probucol in Rats with Contrast-Induced Nephropathy and its Underlying Mechanism

Background

Contrast-induced nephropathy (CIN) refers to acute renal damage that occurs after the use of contrast agents. This study investigated the renal protective effect of probucol in a rat model of contrast-induced nephropathy and the mechanism of its effect.

Material/Methods

Twenty-eight Wistar rats were randomly divided into the control group, model group, N-acetylcysteine(NAC) group, and probucol group. We used a rat model of iopromide-induced CIN. One day prior to modeling, the rats received gavage. At 24 h after the modeling, blood biochemistry and urine protein were assessed. Malondialdehyde (MDA) and superoxide dismutase (SOD) were measured in renal tissue. Kidney sections were created for histopathological examination.

Results

The model group of rats showed significantly elevated levels of blood creatinine, urea nitrogen, 24-h urine protein, histopathological scores, and parameters of oxidative stress (P<0.05). Both the NAC and probucol groups demonstrated significantly lower Scr, BUN, and urine protein levels compared to the model group (P<0.05), with no significant difference between these 2 groups. The NAC group and the probucol group had significantly lower MDA and higher SOD than the model group at 24 h after modeling (P<0.05). The 8-OHdG-positive tubule of the probucol group and NAC group were significantly lower than those of the model group (p=0.046, P=0.0008), with significant difference between these 2 groups (P=0.024).

Conclusions

Probucol can effectively reduce kidney damage caused by contrast agent. The underlying mechanism may be that probucol accelerates the recovery of renal function and renal pathology by reducing local renal oxidative stress.

Enhanced oxidative stress by alcohol use in HIV+ patients: possible involvement of cytochrome P450 2E1 and antioxidant enzymes

Background

Alcohol consumption is prevalent amongst HIV positive population. Importantly, chronic alcohol use is reported to exacerbate HIV pathogenesis. Although alcohol is known to increase oxidative stress, especially in the liver, there is no clinical evidence that alcohol increases oxidative stress in HIV positive patients. The mechanism by which alcohol increases oxidative stress in HIV positive patients is also unknown.

Methods

To examine the effects of alcohol use on oxidative stress we recruited HIV+ patients who reported mild-to-moderate alcohol use. Strict inclusion and exclusion criteria were applied to reduce the effect of other therapeutic drugs metabolized via the hepatic system as well as the effect of co-morbidities such as active tuberculosis on the interaction between alcohol and HIV infection, respectively. Blood samples were collected from HIV-negative alcohol-users and HIV positive alcohol-users followed by collection of plasma and isolation and fractionation of monocytes from peripheral blood. We then determined oxidative DNA damage, glutathione level, alcohol level, transcriptional level of cytochrome P450 2E1 (CYP2E1) and several antioxidant enzymes, and plasma level of cytokines.

Results

Compared to HIV-negative alcohol users, HIV-positive alcohol users demonstrated an increase in oxidative DNA damage in both plasma and CD14+ monocytes, as well as, a relative increase in oxidized/reduced glutathione (GSSG/GSH) in plasma samples. These results suggest an increase in oxidative stress in HIV-positive alcohol users compared with HIV-negative alcohol users. We also examined whether alcohol metabolism, perhaps by CYP2E1, and antioxidant enzymes are involved in alcohol-mediated increased oxidative stress in HIV-positive patients. The results showed a lower plasma alcohol level, which was associated with an increased level of CYP2E1 mRNA in monocytes, in HIV-positive alcohol users compared with HIV-negative alcohol users. Furthermore, the transcription of major antioxidants enzymes (catalase, SOD1, SOD2, GSTK1), and their transcription factor, Nrf2, were reduced in monocytes obtained from HIV positive alcohol users compared to the HIV-negative alcohol user group. However, no significant change in levels of five major cytokines/chemokines were observed between the two groups.

Conclusions

The data suggests that alcohol increases oxidative stress in HIV+ patients, perhaps through CYP2E1- and antioxidant enzymes-mediated pathways. The enhanced oxidative stress is accompanied by a failure of cellular antioxidant mechanisms to maintain redox homeostasis. Overall, the enhanced oxidative stress in monocytes may exacerbate HIV pathogenesis in HIV positive alcohol users.

Mono(2-ethylhexyl) phthalate induces apoptosis in p53-silenced L02 cells via activation of both mitochondrial and death receptor pathways

Mono(2-ethylhexyl) phthalate (MEHP) is one of the main metabolites of di(2-ethylhexyl) phthalate. The evidence shows that DEHP may exert its toxic effects primarily via MEHP, which is 10-fold more potent than its parent compound in toxicity in vitro. MEHP-induced apoptosis is mediated by either p53-dependent or -independent pathway. However, the detailed mechanism of its toxicity remains unclear. In this study, immortalized normal human liver cell line L02 was chosen, as an in vitro model of nonmalignant liver, to elucidate the role of p53 in MEHP-induced apoptosis. The cells were treated with MEHP (6.25, 12.50, 25.00, 50.00, and 100.00 μM) for 24 and 36 h, then small interfering RNA (siRNA) was used to specifically silence p53 gene of L02 cells. The results indicated that MEHP caused oxidative DNA damage and apoptosis in L02 cells were associated with the p53 signaling pathway. Further study found that MEHP (50.00 and 100.00 μM) induced apoptosis in p53-silenced L02 cells, along with the up-regulations of Fas and FasL proteins as well as increased the Bax/Bcl-2 ratio and Caspase 3, 8, and 9 activities. Additionally, both FasL inhibitor (AF-016) and Caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp- fluoromethylketone (Z-VAD-FMK) could prevent the cell apoptosis induced by MEHP. The findings suggested that MEHP-induced apoptosis in L02 cells involving a Caspases-mediated mitochondrial signaling pathway and/or death receptor pathway. p53 was not absolutely necessary for MEHP-induced L02 cell apoptosis.