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Objectives: 8-hydroxydeoxyguanosine (8-OHdG) and Malondialdehyde (MDA) are commonly used as markers to evaluate oxidative DNA and Lipid damage in disorders including chronic inflammatory diseases. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) protect tissues against oxidative injury from free oxygen radicals generated by various metabolic processes. The aim of this study was to evaluate 8-OHdG and MDA levels, and SOD and GPx activities in whole saliva of patients with peri-implant diseases., Materials and Methods: A cross-sectional study was conducted on a sum of 60 age gender balanced; peri-implantitis (n = 20), peri-mucositis (n = 20) and healthy (n = 20) individuals. Unstimulated whole saliva samples were collected and to determine the clinical condition of each subject; the plaque index (PI), gingival index (GI), peri-implant probing pocket depth (PIPD), peri-implant presence of bleeding on probing (BOP) (with/without suppuration) and radiographic signs of crestal bone loss (BL) were measured. The salivary 8-OHdG level was measured using the ELISA method. SOD, GPx activities and MDA levels were determined spectrophotometrically., Results: A total of 60 individuals had evaluations of 318 implants. In comparison to the peri-mucositis and peri-implantitis groups, the healthy group had significantly lower PI and GI scores (p < 0.001). The PIPD value differed amongst the groups, with the peri-implantitis group having the highest value (p < 0.001). Compared to the peri-mucositis and control groups, the peri-implantitis group had a significantly higher BL score (p < 0.001 and p < 0.001, respectively). The peri-implantitis group showed a significantly higher 8-OHdG level (p < 0.001; p < 0.001 respectively) than the peri-mucositis and control groups. Compared to the peri-mucositis and control groups, the peri-implantitis group had a significantly higher MDA level (p < 0.001 and p < 0.001, respectively). The peri-implantitis group had a significantly higher SOD level (p < 0.001 and p < 0.001, respectively) in comparison to the peri-mucositis and control groups. There was no significant difference in GPx levels between the peri-mucositis and control groups (p > 0.05), while the peri-implantitis group had significantly lower GPx levels than the peri-mucositis and control groups (p < 0.001 and p < 0.001, respectively)., Conclusions: Elevated levels of oxidative stress in saliva may indicate the onset of pathological bone loss surrounding the implant and may be an indication of peri-implantitis., Clinical Relevance: In peri-implant diseases, changes may occur in the levels of 8-OHdG, MDA, SOD and GPx in saliva, which may lead to a deterioration in the oxidant/antioxidant balance., (© 2024. The Author(s).)

8-Oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) base is the predominant form of commonly observed DNA oxidative damage. DNA impairment profoundly impacts gene expression and serves as a pivotal factor in stimulating neurodegenerative disorders, cancer, and aging. Therefore, precise quantification of 8-oxoG has clinical significance in the investigation of DNA damage detection methodologies. However, at present, the existing approaches for 8-oxoG detection pose challenges in terms of convenience, expediency, affordability, and heightened sensitivity. We employed the sandwich enzyme-linked immunosorbent assay (ELISA) technique, a highly efficient and swift colorimetric method, to detect variations in 8-oxo-dG content in MCF-7 cell samples stimulated with different concentrations of hydrogen peroxide (H2O2). We determined the concentration of H2O2 that induced oxidative damage in MCF-7 cells by detecting its IC50 value in MCF-7 cells. Subsequently, we treated MCF-7 cells with 0, 0.25, and 0.75 mM H2O2 for 12 h and extracted 8-oxo-dG from the cells. Finally, the samples were subjected to ELISA. Following a series of steps, including plate spreading, washing, incubation, color development, termination of the reaction, and data collection, we successfully detected changes in the 8-oxo-dG content in MCF-7 cells induced by H2O2. Through such endeavors, we aim to establish a method to evaluate the degree of DNA oxidative damage within cell samples and, in doing so, advance the development of more expedient and convenient approaches for DNA damage detection. This endeavor is poised to make a meaningful contribution to the exploration of associative analyses between DNA oxidative damage and various domains, including clinical research on diseases and the detection of toxic substances.

Background: Regular sleep is very important for human health; however, the short-term and long-term effects of nightshift with sleep deprivation and disturbance on human metabolism, such as oxidative stress, have not been effectively evaluated based on a realistic cohort. We conducted the first long-term follow-up cohort study to evaluate the effect of nightshift work on DNA damage., Methods: We recruited 16 healthy volunteers (aged 33 ± 5 years) working night shifts at the Department of Laboratory Medicine at a local hospital. Their matched serum and urine samples were collected at four time points: before, during (twice), and after the nightshift period. The levels of 8-oxo-7,8-dihydroguanosine (8-oxoG) and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), two important nucleic-acid damage markers, were accurately determined based on a robust self-established LC‒MS/MS method. The Mann-Whitney U or Kruskal-Wallis test was used for comparisons, and Pearson's or Spearman's correlation analysis was used to calculate the correlation coefficients., Results: The levels of serum 8-oxodG, estimated glomerular filtration rate-corrected serum 8-oxodG, and the serum-to-urine 8-oxodG ratio significantly increased during the nightshift period. These levels were significantly higher than pre-nightshift work level even after 1 month of discontinuation, but no such significant change was found for 8-oxoG. Moreover, 8-oxoG and 8-oxodG levels were significantly positively associated with many routine biomarkers, such as total bilirubin and urea levels, and significantly negatively associated with serum lipids, such as total cholesterol levels., Conclusion: The results of our cohort study suggested that working night shifts may increase oxidative DNA damage even after a month of discontinuing nightshift work. Further studies with large-scale cohorts, different nightshift modes, and longer follow-up times are needed to clarify the short- and long-term effects of night shifts on DNA damage and find effective solutions to combat the negative effects., (© 2023. The Author(s).)

In nuclear and mitochondrial DNA, 8-hydroxy-2 ' -deoxyguanosine (8-OHdG) is one of the predominant forms of reactive oxygen species (ROSs) lesions, which commonly used as a biomarker for oxidative stress. Studies showed that the different nanomaterials can induce toxicity by ROSs in human body. So, this study is going to review the studies about oxidative DNA damage caused by occupational exposure to nanomaterials, using 8-OHdG biomarker.Systematic review was managed based on Cochrane systematic review guideline. Literature search was conducted in scientific databases with the main terms of "biomarkers," "biological markers," combined with "occupational exposure" and "nanomaterials." All papers in the field of occupational exposure to nanomaterials until 2020 December were included. To evaluate the quality and bias of studies, GRADE method (Grading of Recommendations, Assessment, Development, and Evaluation) was used.Two hundred twenty-six studies were primarily achieved. By considering the inclusion criteria, overall 8 articles were selected. The majority of the studies were classified as the moderate quality studies (six studies). Also, the study-level bias was critical. This review shows that there is a significant relationship between job title and amount of produced nanomaterials and the existence of 8-OHdG. Also, the levels of 8-OHdG can be measured in urine, blood, and inhalation samples by instrumental procedures.Oxidative damages are an important threat for workers exposed to nanomaterial. Blood and EBC 8-OHdG level can be introduced as a biomarker for metal nanomaterials, but urinary 8-OHdG needs to be taken with caution. So, it is recommended that evaluation not be solely based on one biomarker.

Alcoholic beverages are a well-known risk factor for cancer. N 2 -Ethyl-2'-deoxyguanosine (N 2 -Et-dG) is a promising biomarker for alcohol-associated cancers. However, the lack of a convenient detection method for N 2 -Et-dG hinders the development of practical DNA damage markers. Herein, we develop a detection method for N 2 -Et-dG using a single-molecule quantum sequencing (SMQS) method and machine learning analysis. Our method succeeded in discriminating between N 2 -Et-dG and dG with an accuracy of 99%, using 20 signals. Our developed method quantified the mixing ratio of N 2 -Et-dG from a mixed solution of N 2 -Et-dG and dG. It is shown that our method has the potential to facilitate the development of DNA damage markers, and thus the early detection and prevention of cancers.

Guanine radicals are important reactive intermediates in DNA damage. Hydroxyl radical (HO . ) has long been believed to react with 2'-deoxyguanosine (dG) generating 2'-deoxyguanosin-N1-yl radical (dG(N1-H) . ) via addition to the nucleobase π-system and subsequent dehydration. This basic tenet was challenged by an alternative mechanism, in which the major reaction of HO . with dG was proposed to involve hydrogen atom abstraction from the N2-amine. The 2'-deoxyguanosin-N2-yl radical (dG(N2-H) . ) formed was proposed to rapidly tautomerize to dG(N1-H) . . We report the first independent generation of dG(N2-H) . in high yield via photolysis of 1. dG(N2-H) . is directly observed upon nanosecond laser flash photolysis (LFP) of 1. The absorption spectrum of dG(N2-H) . is corroborated by DFT studies, and anti- and syn-dG(N2-H) . are resolved for the first time. The LFP experiments showed no evidence for tautomerization of dG(N2-H) . to dG(N1-H) . within hundreds of microseconds. This observation suggests that the generation of dG(N1-H) . via dG(N2-H) . following hydrogen atom abstraction from dG is unlikely to be a major pathway when HO . reacts with dG., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Exogenous and endogenous chemicals can react with DNA to produce DNA lesions that may block DNA replication. Not much is known about the roles of polymerase (Pol) ν and Pol θ in translesion synthesis (TLS) in cells. Here we examined the functions of these two polymerases in bypassing major-groove O 6 -alkyl-2'-deoxyguanosine ( O 6 -alkyl-dG) and minor-groove N 2 -alkyl-dG lesions in human cells, where the alkyl groups are ethyl, n -butyl ( n Bu), and, for O 6 -alkyl-dG, pyridyloxobutyl. We found that Pol ν and Pol θ promote TLS across major-groove O 6 -alkyl-dG lesions. O 6 -alkyl-dG lesions mainly induced G→A mutations that were modulated by the two TLS polymerases and the structures of the alkyl groups. Simultaneous ablation of Pol ν and Pol θ resulted in diminished mutation frequencies for all three O 6 -alkyl-dG lesions. Depletion of Pol ν alone reduced mutations only for O 6 - n Bu-dG, and sole loss of Pol θ attenuated the mutation rates for O 6 - n Bu-dG and O 6 -pyridyloxobutyl-dG. Replication across the two N 2 -alkyl-dG lesions was error-free, and Pol ν and Pol θ were dispensable for their replicative bypass. Together, our results provide critical knowledge about the involvement of Pol ν and Pol θ in bypassing alkylated guanine lesions in human cells., (© 2020 Du et al.)

In this work, an electrochemical method for sensitive analysis of 8-hydroxy-2'-deoxyguanosine, a key biomarker that is widely used to study oxidative injury-related diseases, is proposed based on exonuclease-mediated functional nucleic acid. In the design, exonuclease can not only distinguish the existence of target, but also suppress the background noise, thus the sensitivity can be enhanced. Moreover, DNAzyme designed in the functional nucleic acid can further improve the sensitivity of the analysis during signal generation process. Therefore, exonuclease-mediated functional nucleic acid may ensure high sensitivity of the assay. Further studies reveal that the detection of 8-hydroxy-2'-deoxyguanosine can be achieved with a linearity from 0.01 nM to 7.0 μM and a detection limit of 6.82 pM. The new method has also been successfully applied to the determination of 8-OHdG in urine with good results, indicating its great potential for practical use., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background/aim: The effects of oxidative stress on various carcinomas were reported in previous studies, but those in intrahepatic cholangiocarcinoma (ICC) have not been fully elucidated. The purpose of this study was, thus, to reveal the effects of oxidative DNA damage and repair enzymes on ICC., Materials and Methods: The levels of 8-hydroxydeoxyguanosine (8-OHdG) and 8-OHdG DNA glycosylase (OGG1) were immunohistochemically evaluated in specimens resected from 63 patients with ICC., Results: Low OGG1 expression was related to tumour depth T4 (p=0.04), venous invasion (p=0.0005), lymphatic vessel invasion (p=0.03), and perineural invasion (p=0.03). Compared to the high-OGG1-expression group, patients with low OGG1 expression had a significantly poorer prognosis (overall survival: p=0.04, recurrence-free survival: p=0.02). Unlike for OGG1, the expression levels of 8-OHdG showed no association with prognosis., Conclusion: Oxidative DNA damage and DNA repair enzymes may be closely related to ICC progression., (Copyright© 2019, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Reactive oxygen species (ROS) accumulation is known to induce carcinogenesis and accelerate cancer progression. 8‑Hydroxydeoxyguanosine (8‑OHdG) is a specific marker of ROS‑mediated DNA damage. Therefore, we analysed 8‑OHdG levels in cancerous and normal tissue DNA via enzyme‑linked immunosorbent assay (ELISA) using 97 tissue specimens obtained from surgically‑treated patients with stage II/III colorectal cancer (CRC). Additionally, 8‑OHdG levels in these tissues were also assessed via quantitative immunohistochemistry (qIHC). To eliminate individual background variables, the ratio of 8‑OHdG levels between cancerous and normal tissues was calculated using both techniques. A comparative analysis demonstrated that the 8‑OHdG ratio in DNA was significantly correlated with both lymph node metastasis and lymphatic invasion. Multivariate analysis revealed that a high 8‑OHdG ratio in DNA was independently correlated with poor prognosis. These results suggest that the 8‑OHdG ratio in DNA reflects ROS‑induced cancer progression. Conversely, a low 8‑OHdG ratio as estimated via qIHC was an independent factor for poor prognosis. In Kaplan‑Meier analysis, the combination of a high 8‑OHdG ratio in DNA (ELISA) and a low 8‑OHdG ratio in cytoplasm (qIHC) was associated with markedly worse patient prognosis than other combinations. Combined evaluation of the 8‑OHdG ratio using ELISA and qIHC may be pivotal for predicting surgical outcomes for patients with stage II/III CRC.

Reported herein is the development of an analytical method for the detection of four oxidative stress biomarkers in wastewater using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) and solid phase extraction (SPE). The following four biomarkers of oxidative stress and lipid peroxidation have been investigated: hydroxynonenal-mercapturic acid (HNE-MA), 8-iso-prostglandin F2beta (8-iso-PGF 2β ), 8-nitroguanine (8-NO 2 Gua) and 8-hydroxy-2-deoxyguanosine (8-OHdG). The method showed very good performance: accuracy (> 87%), precision (> 90%), method quantification limits (1.3-3.0 ng L -1 ) and biomarker stability in wastewater in the case of HNE-MA, 8-OHdG and 8-iso-PGF 2β . In contrast, 8-NO 2 Gua was found to be less stable in wastewater, which affected its method performance: accuracy (> 63%), precision (> 91%) and method quantification limits (85.3 ng L -1 ). Application of the developed method resulted in, for the first time, HNE-MA being successfully observed and quantified within wastewater over a study period of a week (displayed average daily loads per capita of 48.9 ± 4.1 mg/1000/people/day). 8-iso-PGF 2β was detected with good intensity but could not be quantified due to co-elution with other isomers. 8-OHdG was detected, albeit at < MQL. This study demonstrates the potential for expanding on the possible endogenous biomarkers of health used in urban water fingerprinting to aid in measuring health in near-real time on a community-wide scale.

The aim of this study was to investigate neurophysiological responses in rainbow trout brain tissue exposed to natural/botanical pesticides. Fish were exposed to botanical and synthetic pesticides over a 21-day period. At the end of the treatment period, oxidative DNA damage (indicated by 8-OHdG (8-hydroxy-2'-deoxyguanosine), AChE activity (acetylcholinesterase) and transcriptional parameters (gpx (glutathione peroxidase), sod (superoxide dismutase), cat (catalase), HSP70 (heat shock protein 70) and CYP1A (cytochromes P450)) was investigated in control and application groups. Our results indicated that brain AChE activities decreased very significantly in fish treated with both insecticide types when compared with control (p < 0.05). 8-OHdG activity increased in a dose/time-dependent situation in the brain tissues of Oncorhynchus mykiss (p < 0.05). In addition, with regards to gene expression, gpx sod and, cat expressions were down-regulated, whereas CYP1A and HSP70 gene expression were up-regulated in fish treated with both insecticides when compared to the control group (p < 0.05). The data for this study suggests that bio-pesticides can cause neurophysiological changes in fish brain tissue.

Objective: This study aims to evaluate the clinical and biochemical (oxidative stress and pro-inflammatory mediators) effects of the gaseous ozone use accompanied by scaling and root planning (SRP) in periodontal treatment., Material and Methods: The study population consisted of 40 patients with chronic periodontitis (CP) randomly sorted into two groups of 20. The experimental group received SRP plus 3 watts gaseous ozone in two separate applications five days apart, whereas the control group received SRP plus placebo. Clinical periodontal parameters were assayed and saliva samples were taken before the initial and one month after the second treatment. Periodontal examination assessed plaque index (PI), gingival index (GI), probing depth, and clinical attachment level (CAL). Total antioxidant status (TAS), total oxidant status (TOS), nitric oxide (NO), 8-hydroxy-2'-deoxyguanosine (8-OHdG), myeloperoxidase (MPO), glutathione (GSH), malondialdehyde (MDA), and transforming growth factor-beta (TGF-β) levels were evaluated from saliva samples., Results: Changes following treatment in PI, GI, probing depth, and CAL scores were similar for both groups (p>0.05). Of note, TGF-β levels were observed to be higher in the treatment group than in controls (p<0.05). Changes in 8-OHdG, TAS, TOS, NO, MPO, GSH and MDA levels, however, were not significantly different between groups (p>0.05)., Conclusion: The findings of this study indicate that SRP plus gaseous ozone versus SRP alone does not correlate to a significant improvement in periodontal recovery.

Background and Objective: Levosimendan is a positive inotropic and a vasodilator agent with pleotropic characteristics that include antioxidation, anti-inflammation and smooth muscle vasodilation., Methods: In this study, the effects of levosimendan (0, 0.1, 1, 10, and 20 µg/ml) on oxidative DNA damage and sister-chromatid exchanges (SCEs) were evaluated in human cultured lymphocytes., Results: The results showed that levosimendan increased the frequency of SCEs in all examined concentrations (P<0.01) except for 0.1 µg/ml. On the other hand, levosimendan did not induce oxidative DNA damage as measured by the 8-OHdG biomarker (P > 0.05). In addition, neither mitotic arrest nor proliferation index was affected by levosimendan at all examined doses (P > 0.05)., Conclusion: In conclusion, levosimendan might be associated with increases in sister-chromatid exchanges in cultured human lymphocytes. In vivo studies are required to confirm the present findings., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Hypobromous acid (HOBr) is generated not only by eosinophils but also by neutrophils in the presence of Br - at the plasma concentration. Reactivity of HOBr is greatly modulated by coexistent compounds such as amines and amides. In this study, we investigated effects of urea in the reaction of nucleosides with HOBr. When nucleosides were incubated with HOBr without urea in potassium phosphate buffer at pH 7.4 and 37°C, the reactions almost completed within 10 min, with consumptions in the order of 2'-deoxyguanosine > 2'-deoxycytidine > 2'-deoxythymidine > 2'-deoxyadenosine, generating 8-bromo-2'-deoxyguanosine and 5-bromo-2'-deoxycytidine. In the presence of urea, the reaction of nucleosides with HOBr was relatively slow, continuing over several hours. When HOBr was preincubated without urea in potassium phosphate buffer at pH 7.4 and 37°C for 48 h, the preincubated HOBr solution did not react with nucleosides. However, a similar preincubated solution of HOBr with urea reacted with nucleosides to generate 8-bromo-2'-deoxyguanosine and 5-bromo-2'-deoxycytidine. These results imply that a reactive bromine compound with a long life, probably bromourea, is generated by HOBr in neutral urea solution and reacts with nucleosides, resulting in brominated nucleosides.

Polybrominated diphenyl ethers (PBDEs) are emerging organic environmental pollutants, which were accused of various toxic effects. Here, we studied the role of a potential PBDEs quinone metabolite, PBDEQ, on cytotoxicity, oxidative DNA damage, and the alterations of signal cascade in HeLa cells. PBDEQ exposure leads to reactive oxygen species (ROS) accumulation, mitochondrial membrane potential (MMP) loss, lactate dehydrogenase (LDH) release, increasing terminal transferase-mediated dUTP-biotin nick end labeling (TUNEL) positive foci, and the elevation of apoptosis rate. Furthermore, we showed PBDEQ exposure result in increased DNA migration, micronucleus frequency, and the promotion of 8-OHdG and phosphorylation of histone H2AX (γ-H2AX) levels. Mechanism study indicated that PBDEQ caused poly(ADP-ribose) polymerase 1 (PARP-1) activation and apoptosis-inducing factor (AIF) nuclear translocation. All together, these results confirmed the occurrence of parthanatos-like cell death upon PBDEQ exposure.

Bladder cancer risk is 3-4 times higher in men than women, but the reason is poorly understood. In mice, male bladder is also more susceptible than female bladder to 4-aminobiphenyl (ABP), a major human bladder carcinogen; however, female liver is more susceptible than male liver to ABP. We investigated the role of sulfotransferase (Sult) in gender-related bladder and liver susceptibility to ABP. Sulfation reactions of aromatic amine bladder carcinogens catalyzed by Sult may generate highly unstable and toxic metabolites. Therefore, liver Sult may decrease bladder exposure to carcinogens by promoting their toxic reactions in the liver. Notably, the expression of several liver Sults is suppressed by androgen in male mice. Here, we show that two Sults are critical for gender-related bladder susceptibility to ABP in mice. We measured tissue level of N-(deoxyguanosin-8-yl)-4-aminobiphenyl (dG-C8-ABP), a principal ABP-DNA adduct, as readout of tissue susceptibility to ABP. We identified Sutl1a1 and to a lesser extent Sult1d1 as Sults that promote dG-C8-ABP formation in hepatic cells. In mice, gender gap in bladder susceptibility to ABP was narrowed by knocking out Sult1a1 and was almost totally eliminated by knocking out both Sutl1a1 and Sult1d1. This was accompanied by dramatic decrease in ABP genotoxicity in the liver (>97%). These results show the strong impact of the Sults on bladder and liver susceptibility to a human carcinogen. Because liver expression of both Sult1a1 and Sutl1d1 is suppressed by androgen in male mice, our results suggest that androgen renders bladder more exposed to ABP in male mice by suppressing Sult-mediated ABP metabolism in liver, which increases bladder delivery of carcinogenic metabolites., (© 2018 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

The authors describe a fluorometric method for improving the determination of the cancer biomarker 8-hydroxy-2'-deoxyguanosine (8-OHdG). A nicking endonuclease (NEase)-powered 3-D DNA nanomachine was constructed by assembling hundreds of carboxyfluorescein-labeled single strand oligonucleotides (acting as signal reporter) and tens of swing arms (acting as single-foot DNA walkers) on a gold nanoparticle (AuNP). The activity of this DNA nanomachine was controlled by introducing the protecting oligonucleotides. In the presence of aptamer against 8-OHdG, the protecting oligonucleotides are removed from the swing arms by toehold-mediated strand displacement reaction. In the next step, detached DNA walker hybridizes to the labelled DNA so that the DNA nanomachine becomes activated. Special sequences of signal reporter in the formed duplex can be recognized and cleaved by NEase. As a result, the DNA walker autonomously and progressively moves along the surface of the AuNP, thereby releasing hundreds of signal reporters and causing a rapid increase in green fluorescence. This 3-D nanomachine is highly efficient because one aptamer can release hundreds of signal reporters. These unique properties allowed for the construction of a DNA nanomachine-based method for sensitively detecting 8-OHdG in concentrations as low as 4 pM. This is three orders of magnitude lower compared to previously reported methods. Graphical abstract Schematic of a fluorometric method for determination of the cancer biomarker 8-hydroxy-2'-deoxyguanosine. A nicking endonuclease powered 3D-DNA nanomachine was used to improve the sensitivity. Limit of detection is three orders of magnitude lower than reported methods.

We hypothesised that copper nanoparticles (NanoCu), because of their high physicochemical reactivity and bioavailability, could be used in much smaller quantities than bulk Cu, consequently reducing excretion of Cu into the environment. The objective of the study was to evaluate the effects of various levels of NanoCu on the development and growth of broiler chickens, in order to establish an optimum level of NanoCu dietary supplementation. Broiler chickens were randomly divided into five groups of 10 birds each. The control group received 7.5 mg Cu/kg feed (standard level) as CuSO 4 , while groups fed with complexes of NanoCu and starch received 25%, 50%, 75% and 100% of the standard level of Cu used in the control group. Chicken growth and excretion of Cu, Fe and Zn were measured during the growth period from d 7 to 42. At d 42, the slaughter characteristics, the content of Cu, Fe and Zn in the breast muscle and liver, and the oxidative status were analysed. The results indicate that using NanoCu can reduce the standard level of Cu from CuSO 4 supplementation by 75% without jeopardising animal growth, and at the same time significantly decreasing Cu excretion into the environment.

Alkylphenols, a nonionic surface-active agent group, such as nonylphenol (NP) and octylphenol (OP) are important endocrine-disrupting chemicals (EDC). In this study, the dose- and time-dependent effects of NP and OP were investigated in the primary hepatocyte culture of Van Fish. In this study, samples were taken at different times and biochemical parameters were studied separately. The effects of the chemicals used on SOD, CAT, GSH-Px, MDA, and 8-OHdG were investigated in hepatocyte culture. The antioxidants SOD and CAT were observed to increase in all groups in the primary hepatocyte cultures at the 24th hour after NP and OP administration, whereas the GSH-Px level was observed to increase with OP at the 24th hour and with NP at the 48th hour. The MDA level was observed to reach its highest value for both chemicals in the 24th hour, and the 8-OHdG level was observed to increase toward the end of the follow-up time, compared to the control group (p < 0.05). In conclusion, different doses of NP and OP were found to induce an increase in the levels of antioxidants and the MDA level in Van Fish primary hepatocyte culture. DNA damage, on the other hand, may be considered to appear after longer-term exposure to NP and OP.

Rats with a normal birth weight (NBW) or intra-uterine growth retardation (IUGR) were fed basic diets (NBW and IUGR groups) or basic diets supplemented with curcumin (NC and IC groups) from 6 to 12 weeks. The body weight of IUGR rats was lower (P<0·05) than that of the controls. Rats with IUGR showed higher (P<0·05) concentrations of TNF-α, IL-1β and IL-6; higher (P<0·05) activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in their serum; and increased (P<0·05) concentrations of malondialdehyde (MDA), protein carbonyl (PC) and 8-hydroxy-2'-deoxyguanosine (8-OHDG) in the liver compared with the NBW rats. The livers of IUGR rats exhibited a lower (P<0·05) superoxide dismutase activity and decreased (P<0·05) metabolic efficiency of the hepatic glutathione redox cycle compared with those of the NBW rats. In response to dietary curcumin supplementation, concentrations of inflammatory cytokines and activities of AST and ALT in the serum and MDA, PC and 8-OHDG in the liver were lower (P<0·05), and the hepatic glutathione redox cycle in the liver was improved (P<0·05) in the IC group than in the IUGR group. These results were associated with lower (P<0·05) phosphorylated levels of the NF-κB pathway and Janus kinase 2 (JAK2) and higher (P<0·05) mRNA expression of genes involved in the nuclear factor, erythroid 2-like 2 (Nfe2l2)/antioxidant response element (ARE) pathway in the liver of the IC rats than that of the IUGR rats. Maternal undernutrition decreased birth weight and led to inflammation, oxidative damage and injury in rats. Curcumin appeared to be beneficial in preventing IUGR-induced inflammation, oxidative damage and injury by activating the expression of the NF-κB, JAK/STAT and Nfe2l2/ARE pathways in the liver.

The present study aims at assessing the efficacies of olivetoric acid (OA) and physodic acid (PA) isolated from Pseudevernia furfuracea (L.) Zopf (Parmeliaceae) in human lymphocytes (HLs) in vitro. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assays were performed to establish cytotoxicity in HLs. Besides, oxidative stress and genotoxicity were monitored by estimating the changes of total oxidative stress (TOS) and 8-hydroxy-2'-deoxyguanosine (8-OH-dG) levels, respectively, in HLs. At the same time, OA- and PA-induced total antioxidant capacity (TAC) levels in HLs were determined. Although especially low concentrations of OA (IC50=109.94 mg/L) and PA (IC50=665.49 mg/L) did not show cytotoxic effect at high levels in HLs, it was revealed that cytotoxicity was significantly (p<0.05) associated with oxidative stress and genotoxicity via correlation analysis. While TOS level in HLs did not statistically (p>0.05) increase in the presence of all treatments (0.5-100 mg/L) of PA, TAC level was increased by PA applications in certain concentrations (0.5-10 mg/L). Overall, the obtained data indicate that OA and especially PA as lichen compounds that do not cause oxidative stress can be a new resource of therapeutics as recognized in the present study with their high antioxidant features.

4-Aminobiphenyl (4-ABP) which is primarily formed during tobacco combustion and overheated meat is a major carcinogen responsible for various cancers. Its adducted form, N-deoxyguanosine-C8-4-aminobiphenyl (dG-C8-4-ABP), has long been employed as a biomarker for assessment of the risk for cancer. In this review, the metabolism and carcinogenisity of 4-ABP will be discussed, followed by a discussion of the current common approaches of analyzing dG-C8-4-ABP. The major part of this review will be on the history and recent development of key methods for detection and quantitation of dG-C8-4-ABP in complex biological samples and their biological applications, from the traditional 2 P-postlabelling and immunoassay methods to modern liquid chromatography-mass spectrometry (LC-MS) with the latter as the focus. Many vital biological discoveries based on dG-C8-4-ABP have been published by using the nanoLC-MS with column switching platform in our laboratory, which has also been adopted and further improved by many other researchers. We hope this review can provide a perspective of the challenges that had to be addressed in reaching our present goals and possibly bring new ideas for those who are still working on the frontline of DNA adducts area., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objectives: 4'-cyano-2'-deoxyguanosine (CdG), a novel nucleoside analogue, has a high degree of antiviral activity against the chronic hepatitis B virus (HBV). The objective of this study was to develop an analytical method for quantitatively determining CdG levels in biological samples by liquid chromatography-mass spectrometry (LC/MS) and to investigate the pharmacokinetic properties of CdG in rats after intravenous and oral administration., Methods: An analytical method using a UPLC system interfaced with a TOF-MS system was developed and validated. The pharmacokinetic properties after the intravenous and oral administration of CdG to rats were evaluated. In vivo pharmacokinetic interactions between CdG and entecavir were also investigated., Key Findings: A rapid, simple and selective method for the quantification of CdG in biological samples was established using LC/MS with solid-phase extraction. In vivo pharmacokinetic studies of CdG in rats demonstrated that CdG is highly bioavailable, is rapidly absorbed from the intestinal tract, is then distributed to the liver rather than kidney and is ultimately excreted via the urine in an unchanged form. The co-administration of CdG and entecavir led to pharmacokinetic interactions with each other., Conclusions: The data generated in this study provide support for the clinical development of CdG for use in the treatment of HBV., (© 2018 Royal Pharmaceutical Society.)

Regulation of oxidative stress and redox systems has important roles in carcinogenesis and cancer progression, and for this reason has attracted much attention as a new area of cancer therapeutic targets. Glutathione peroxidase 4 (GPX4), an antioxidant enzyme, has biological important functions such as signaling cell death by suppressing peroxidation of membrane phospholipids. However, few studies exist on the expression and clinical relevance of GPX4 in malignant lymphomas such as diffuse large B-cell lymphoma. In this study, we assessed the expression of GPX4 immunohistochemically. GPX4 was expressed in 35.5% (33/93) cases of diffuse large B-cell lymphoma. The GPX4-positive group had poor overall survival (P = 0.0032) and progression-free survival (P = 0.0004) compared with those of the GPX4-negative group. In a combined analysis of GPX4 and 8-hydroxydeoxyguanosine (8-OHdG), an oxidative stress marker, there was a negative correlation between GPX4 and 8-hydroxydeoxyguanosine (P = 0.0009). The GPX4-positive and 8-hydroxydeoxyguanosine-negative groups had a significantly worse prognosis than the other groups in both overall survival (P = 0.0170) and progression-free survival (P = 0.0005). These results suggest that the overexpression of GPX4 is an independent prognostic predictor in diffuse large B-cell lymphoma. Furthermore, in vitro analysis demonstrated that GPX4-overexpressing cells were resistant to reactive oxygen species-induced cell death (P = 0.0360). Conversely, GPX4-knockdown cells were sensitive to reactive oxygen species-induced cell death (P = 0.0111). From these data, we conclude that GPX4 regulates reactive oxygen species-induced cell death. Our results suggest a novel therapeutic strategy using the mechanism of ferroptosis, as well as a novel prognostic predictor of diffuse large B-cell lymphoma.

Particulate matter (PM), broadly defined as coarse (2.5-10 μm), fine (0.1-2.5 μm) and ultrafine particles (≤0.1 μm), is a major constituent of ambient air pollution. Recent studies have linked PM exposure (coarse and fine particles) with several human diseases including cancer. However, the molecular mechanisms underlying ultrafine PM exposure induced cellular and sub-cellular repercussions are ill-defined. Since mitochondria are one of the major targets of different environmental pollutants, we herein aimed to understand the molecular repercussion of ultrafine PM exposure on mitochondrial machinery in peripheral blood lymphocytes. Upon comparative analysis, a significantly higher DCF fluorescence was observed in ultrafine PM exposed cells that confirmed the strong pro-oxidant nature of these particles. In addition, the depleted activity of antioxidant enzymes, glutathione reductase and superoxide dismutase suggested the strong association of ultrafine PM with oxidative stress. These results further coincided with mitochondrial membrane depolarization, altered mitochondrial respiratory chain enzyme activity and decline in mtDNA copy number. Moreover, the higher accumulation of DNA damage response proteins (γH2AX, pATM, p-p53), suggested that exposure to ultrafine PM induces DNA damage and triggers phosphatidylinositol 3 kinase mediated response pathway. Further, the alterations in mitochondrial machinery and redox balance among ultrafine PM exposed cells were accompanied by a considerably elevated pro-inflammatory cytokine response. Interestingly, the lower apoptosis levels observed in ultrafine particle treated cells suggest the possibility that the marked alterations may lead to the impairment of mitochondrial-nuclear cross talk. Together, our results showed that ultrafine PM, because of their smaller size possesses significant ability to disturb mitochondrial redox homeostasis and activates phosphatidylinositol 3 kinase mediated DNA damage response pathway, an unknown molecular paradigm of ultrafine PM exposure. Our findings also indicate that maneuvering through the mitochondrial function might be a viable, indirect method to modulate lymphocyte homeostasis in air pollution associated immune disorders., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objective: Impairment of the lipid metabolism could affect the periodontal disease; increased oxidative stress may have a role in this relationship. The aim of the present study was to evaluate the role of menopause in the relationship between hyperlipidemia and periodontal disease via oxidative stress markers in saliva., Materials and Methods: Sixty-seven women were enrolled in the study and divided into four groups as systemically healthy and premenopause (C) (n = 18), hyperlipidemia and premenopause (H) (n = 16), systemically healthy and postmenopause (M) (n = 17), and hyperlipidemia and postmenopause (MH) (n = 16). Sociodemographics, periodontal and metabolic parameters, and saliva oxidative markers (myeloperoxidase [MPO] and 8-hydroxy-2'-deoxyguanosine [8-OHdG]) were evaluated., Results: Menopause and/or hyperlipidemia were associated with an increase in all evaluated periodontal parameters. Saliva 8-OHdG and MPO levels were higher in menopausal groups (M and MH). Multivariate linear regression analyses revealed that hyperlipidemia was related to an increase in periodontal parameters. Salivary oxidative stress markers and periodontal parameters were also positively associated with menopause and hyperlipidemia., Conclusion: Saliva 8-OHdG and MPO levels may indicate that the relationship between periodontal disease and hyperlipidemia is aggravated by menopause.

Natural selection over billions of years has developed highly effective in vivo signal transduction that is often governed by a series of competitive multiple mechanisms. Several artificial signal transduction pathways have inspired numerous biosensing systems, but most of these are driven by a single mechanism. Herein we describe a multiple-mechanism-driven electrochemiluminescent (ECL) biosensor that utilizes competitive catalytic and steric hindrance effects by assembling hemin/G-quadruplex on carbon nitride nanosheets. Taking the detection of 8-hydroxy-2'-deoxyguanosine (8-OHdG) as example, the dynamic ranges of the detectable concentrations from the different mechanisms were integrated into a single sensor interface. Moreover, the detection sensitivity was more precisely controlled by the competition between the two mechanisms and inherently boosted compared with that of single-mechanism-driven detection. Going beyond the conventional single-mechanism-driven biosensing, the elaborate biomimetic coupling of multiple mechanisms in a single interface may open a new approach for future multiplexed biosensing.

Background/aims: Cigarette smoke exposure (CSE) during pregnancy is a well-recognized health hazard that causes placental damage. Hydrogen sulfide (H2S) has been reported to protect multiple organs from injury. However, the protective effects of H2S have not been tested in the placenta. This study aimed to explore the potential of H2S in protecting placenta against oxidative injury induced by CSE during pregnancy and the possible underlying mechanisms., Methods: Pregnant SD rats were randomly divided into 4 groups: NaCl, NaHS (a donor of H2S), CSE and CSE+NaHS. Placental oxidative damage was detected by 8-hydroxy-2-deoxyguanosine (8-OHdG) stain and malondialdehyde (MDA) assay. Placental redox status was assessed by measuring reactive oxygen species (ROS), total antioxidant capacity (T-AOC) and glutathione (GSH) levels, as well as copper/zinc SOD (SOD1), manganese SOD (SOD2), catalase (CAT) and glutathione peroxidase (GPx) activities and expressions. Meanwhile, nuclear factor erythroid 2-related factor 2 (Nrf2) was analyzed by immunohistochemistry, real-time PCR and Western blot., Results: We found that NaHS markedly reduced the elevated levels of 8-OHdG and MDA induced by CSE. Further, NaHS treatment effectively mitigated CSE-induced placental redox imbalance by inhibiting ROS production, restoring T-AOC level, increasing GSH/GSSG ratio, and augmenting SOD1 SOD2, CAT and GPx activities and expressions. More notably, NaHS administration also reversed the aberrant decrease of Nrf2 due to CSE in rat placentas., Conclusion: Our data demonstrate that H2S can protect against CSE-induced placental oxidative damage probably by alleviating redox imbalance via Nrf2 pathway., (© 2018 The Author(s). Published by S. Karger AG, Basel.)

Objective: To study the correlation of leukocyte subsets with sperm DNA damage in the semen of infertile men with asymptomatic genital tract infection (AGTI)., Methods: This study included 111 infertile males with AGTI. After routine semen analysis, we determined the concentration of CD45+ leukocytes in the semen by immunocytochemistry, measured the concentrations of CD14+ cells of the mononuclear / macrophagic system and activated macrophages and HLA-DR+ cells in the semen by flow cytometry, and examined the sperm DNA fragmentation index (DFI) and the expression of 8-hydroxy-2'-deoxyguanosine (8-OHdG) by TUNEL assay. Then we analyzed the correlation of seminal leukocyte subsets with sperm DNA damage and routine semen parameters., Results: The concentration of CD45+ leukocytes was correlated significantly with those of CD14+ and HLA-DR+ cells in the semen (P <0.01), but not that of leukocyte subsets with routine semen parameters, sperm DFI, or the percentage of 8-OHdG-positive cells. The percentage of 8-OHdG-positive sperm was correlated positively with the sperm DFI (r = 0.48, P<0.01) but negatively with sperm concentration (r = －0.44, P <0.01). After adjusted for age, abstinence time and cigarette smoking, the percentage of 8-OHdG-positive sperm was correlated independently with sperm concentration (β = －0.25, P = 0.008) and DFI (β = 0.23, P = 0.05)., Conclusions: Sperm DNA damage is associated with poor semen quality but not with seminal leukocyte subsets in infertile males with asymptomatic genital tract infection.

Benzo[a]pyrene (BaP), an archetypical polycyclic aromatic hydrocarbon, is classified as "carcinogenic to humans" and is ubiquitous in the environment, as evident by the measurable levels of BaP metabolites in virtually all human urine samples examined. BaP carcinogenicity is believed to occur mainly through its covalent modification of DNA, resulting in the formation of BPDE-N 2 -dG, an adduct formed between deoxyguanosine and a diol epoxide metabolite of BaP, with subsequent mutation of critical growth control genes. In spite of the liquid chromatography-mass spectrometry (LC-MS)-based detection of BPDE-N 2 -dG in BaP-treated rodents, and indirectly through high-performance liquid chromatography (HPLC)-fluorescence detection of BaP-7,8,9,10-tetraols released from human DNA upon acid hydrolysis, BPDE-N 2 -dG adducts have rarely if ever been observed directly in human samples using LC-MS techniques, even though sophisticated methodologies have been employed which should have had sufficient sensitivity. With this in mind, we developed a liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) methodology employing high-resolution/accurate mass analysis for detecting ultratrace levels of these adducts. These efforts are directly translatable to the development of sensitive detection of other small molecules using trap-based LC-ESI-MS/MS detection. The developed methodology had a limit of detection (LOD) of 1 amol of BPDE-N 2 -dG on-column, corresponding to 1 BPDE-N 2 -dG adduct per 10 11 nucleotides (1 adduct per 10 human lung cells) using 40 μg of human lung DNA. To our knowledge, this is the most sensitive DNA adduct quantitation method yet reported, exceeding the sensitivity of the 32 P-postlabeling assay (∼1 adduct per 10 10 nucleotides). Twenty-nine human lung DNA samples resulted in 20 positive measurements above the LOD, with smoker and nonsmoker DNA containing 3.1 and 1.3 BPDE-N 2 -dG adducts per 10 11 nucleotides, respectively.

Context: Ganoderma lucidum (Leyss: Fr) Karst. (Polyporaceae) is an oriental medicinal fungus, commonly used in traditional Chinese medicine (TCM) for treating various condition or diseases such as hypertension, hyperglycaemia, hepatitis and cancer., Objective: The current study examines whether triterpenoids and polysaccharide-enriched G. lucidum (GL) influence antioxidation and hepatoprotective efficacy by suppressing oxidative stress., Materials and Methods: Forty-two healthy subjects (22 male and 20 female) were recruited and segregated into two groups as experimental or placebo and requested to intake GL (n = 21) or placebo (n = 21) capsule (225 mg; after lunch or dinner) for six consecutive months and vice versa with one month washout period in between. The anthropometric analysis and biochemical assays, as well as abdominal ultrasonic examination were performed., Results: Consumption of GL substantially improved (p < 0.05) the total antioxidant capacity (TEAC; 79.33-84.04), total thiols and glutathione content (6-8.05) in plasma as well as significant (p < 0.05) enhanced the activities of antioxidant enzymes. Whereas, the levels of thiobarbituric acid reactive substances (TBARS; 3.37-2.47), 8-hydroxy-deoxy-guanosine (8-OH-dG; 15.99-11.98) and hepatic marker enzymes (glutamic-oxaloacetic transaminase; GOT and glutamic-pyruvic transaminase; GPT) were concomitantly reduced (42 and 27%) on treatment with GL. Furthermore, the abdominal ultrasonic examination in GL subjects displayed a notable alteration on hepatic condition by reversing from mild fatty liver condition (initial) to normal condition., Discussion and Conclusion: The outcome of the present intervention demonstrated the antioxidation, anti-aging and hepatoprotective nature of GL by effectively curbing oxidative stress.

An increased understanding is needed of the physiological effects and plausible biological mechanisms that link PM 2.5 (particulate matter with an aerodynamic diameter below 2.5μm) exposure to mortality and morbidities such as atherosclerosis and respiratory disease. PM 2.5 causes carcinogenic health effects. Biomonitoring in humans has suggested that 8-oxo-7, 8-dihydro-2-deoxyguanosine (8-oxodG) and N7-methylguanine (N7-MeG) are correlated with oxidative and methylated DNA damage. Thus, it is meaningful to explore the mechanisms of mutagenesis and carcinogenesis associated with oxidative and methylated DNA damage by simultaneously measuring these two markers. We recruited 72 participants from 2 areas (residential and commercial as well as residential and industrial) in the greater Taipei metropolitan area at baseline. Personal samplers were used to collect 24-hour PM 2.5 -integrated samples. All participants completed an interview, and blood and urine samples were collected the next morning. All collection procedures were repeated twice after a two-month follow-up period. Urinary 8-oxodG and N7-MeG were assayed as biomarkers of oxidative and methylated DNA damage, respectively. Plasma superoxide dismutase (SOD) and glutathione peroxidase-1 (GPX-1) were measured as biomarkers of antioxidants. Urinary 1-hydroxypyrene (1-OHP) was used as a biomarker of exposure to polycyclic aromatic hydrocarbons (PAHs). The mean PM 2.5 level was 37.3μg/m 3 at baseline. PM 2.5 concentrations were higher during winter than during spring and summer. After adjusting for confounds through a generalized estimating equation (GEE) analysis, N7-MeG was significantly increased by 8.1% (β=0.034, 95% CIs=0.001-0.068) per 10μg/m 3 increment in PM 2.5 . 8-oxodG levels were positively correlated with N7-MeG according to both cross-sectional and longitudinal analyses, and 1-OHP was significantly associated with increasing 8-oxodG and N7-MeG concentrations. Exposure to PM 2.5 increases methylated DNA damage. The mean level of urinary N7-MeG was 1000-fold higher than that of 8-oxodG., (Copyright © 2017 Elsevier B.V. All rights reserved.)

This work presents a cost-effective, label-free in point-of-care (POC) biosensor for the sensitive detection of 8-hydroxy-2'-deoxyguanosine (8-OHdG), the most abundant oxidative product of DNA, that may allow a premature assessment of cancer disease, thereby improving diagnosis, prognostics and survival rates. The device targets the direct detection of 8-OHdG by using for the first time a carbon-ink 3-electrode on a paper substrate coupled to Differential Pulse Voltammetry readings. This design was optimized by adding nanostructured carbon materials to the ink and the conducting polymer PEDOT, enhancing the electrocatalytic properties of the sensor towards 8-OHdG detection. Meanwhile, the ability of this oxidative stress biomarker to undertake an oxidation reaction enabled the development of the sensing electrochemical device without the need of chemical probes and long incubation periods. This paper-modified sensor presented high electrochemical performance on the oxidation of 8-OHdG with a wide linear range (50-1000 ng/ml) and a low detection limit (14.4 ng/ml). Thus, our results showed the development of a direct and facile sensor with good reproducibility, stability, sensitivity and more importantly, selectivity. The proposed carbon-based electrochemical sensor is a potential candidate to be miniaturized to small portable size, which make it applicable for in-situ 8-OHdG sensing in real biological samples.

Background: High glucose concentrations influence the functional and structural development of the peritoneal membrane. We previously reported that the oral administration of astaxanthin (AST) suppressed peritoneal fibrosis (PF) as well as inhibited oxidative stress, inflammation, and epithelial-mesenchymal transition (EMT) of peritoneal mesothelial cells (PMCs) in a chlorhexidine-induced PF rat model. This suggests that oxidative stress induction of EMT is a key event during peritoneal damage. The present study evaluated the therapeutic effect of AST in suppressing EMT, in response to glucose-induced oxidative stress., Methods: Temperature-sensitive mesothelial cells (TSMCs) were cultured in the presence or absence of AST and then treated with 140 mM glucose for 3 or 12 hours. Expression levels of TNF-α, TGF-β, and VEGF were determined at the mRNA and protein levels, and nuclear factor kappa B (NF-κB) activity was evaluated. We measured NO2-/NO3- concentrations in cellular supernatants and determined 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in mitochondrial and nuclear DNA. The expressions of E-cadherin and alpha-smooth muscle actin (α-SMA) were evaluated by double immunofluorescence and protein levels., Results: High glucose concentrations induced overproduction of reactive oxidative species (ROS), increasing 8-OHdG mitochondrial DNA and cytokine levels. The NF-κB pathway was activated in response to high glucose concentrations, whereas de novo α-SMA expression was observed with decreased E-cadherin expression. AST treatment attenuated ROS production, inflammatory cytokine production, NF-κB activation, and EMT., Conclusion: The findings of the present study indicate that AST may have an anti-EMT effect due to anti-oxidative and anti-inflammatory activities by scavenging glucose-induced ROS from mitochondria in PMCs. AST may be an efficacious treatment for PF.

Objectives: The aim of this study was to estimate tissue and gingival crevicular fluid (GCF) levels of the oxidative stress marker 8-hydroxy-2'-deoxyguanosine (8-OHdG) in premenopausal, perimenopausal and postmenopausal women with chronic periodontitis., Background: Oxidative stress has been implicated in the etiopathogenesis of periodontitis and menopause induces oxidative stress., Materials and Methods: According to Stages of Reproductive Aging Workshop (STRAW) criteria, women diagnosed with periodontitis were subdivided into three groups of 31 participants each 1. Premenopausal 2. Perimenopausal and 3. Postmenopausal. GCF and gingival tissue samples were collected from sites with maximum probing depth. Tissue DNA was extracted from the gingival sample and 8-OHdG in the extracted DNA, and GCF samples were measured using ELISA., Results: There was a highly significant difference in the overall GCF 8-OHdG levels among the three groups with the pairwise difference being highly significant between the premenopausal-postmenopausal groups and perimenopausal-postmenopausal groups. However, no overall significant differences in tissue 8-OHdG levels were found among the three groups. Pairwise, highly significant differences were found between the premenopausal-postmenopausal groups and perimenopausal-postmenopausal groups for tissue 8-OHdG levels. No significant correlations were found between various measure of periodontal disease and GCF/tissue 8-OHdG levels among all the groups., Conclusion: Premenopausal-postmenopausal and perimenopausal-postmenopausal transition resulted in significant increase in tissue and GCF 8-OHdG levels. However, no association was found between stages of reproductive ageing and tissue levels of 8-OHdG., (© 2017 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.)

Mutagenic modifications of nucleotides or DNA lesions that result from environmental stress have proven to be associated with a variety of diseases, particularly cancer. The method for accurately detecting the lesions is therefore of great importance for biomedical research and toxicity study. We develop a sensitive and low-cost bulge-enhanced coamplification at lower denaturation temperature polymerase chain reaction (COLD-PCR) method for detecting DNA lesions (uracil and 8-oxoguanine) by combining an in vitro base excision repair (BER) pathway and COLD-PCR. The modified bases are converted to bulge via the BER pathway involving converting modified bases to an apurinic/apyrimidinic (AP) site, cleavage at the AP site, and break ligation. The presence of the bulge induces a large change of the hybridization thermodynamics of double-stranded DNA, eventually enhancing the specificity of COLD-PCR. Besides, we used the free energy of hybridization as a reference to optimize the critical denaturation temperature (T c ) of COLD-PCR obtaining more specific amplification than empirical T c . Taking advantage of the proposed bulge-enhanced COLD-PCR, we are able to identify the presence of DNA lesion-containing strands at low abundance down to 0.01%. This method also exhibits high sensitivity for glycosylase with a detection limit of 10 -4 U/mL [3 S/N (signal-to-noise ratio)] that is superior than some recently reported methods. With the design of the repair guide probe, the level of oxidative damage in genomic DNA caused by chemicals and photodynamic therapy (PDT) can be evaluated, heralding more applications in clinical diagnosis and epigenetic study.

Objective: The purpose of this study was to determine the effect of non-surgical periodontal treatment on markers of oxidative stress in saliva and serum in patients with chronic periodontitis., Materials and Methods: In total, 25 patients, who were diagnosed with generalized chronic periodontitis (11 females and 14 males), and 26 systemically and periodontally healthy individuals (15 females and 11 males) were included. The plaque index (PI), gingival index (GI), probing pocket depth (PPD), attachment loss (AL), gingival recession (GR), and bleeding on probing (BOP) were recorded at baseline and 6 weeks later. Malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), and 4-hydroxy-2-nonenal (4-HNE) were assessed in saliva and serum samples before and after the non-surgical treatment by enzyme-linked immune sorbent assay (ELISA)., Results: In the group with chronic periodontitis, all clinical parameters were significantly higher compared to the control group at baseline (p < 0.001). Periodontal treatment reduced plaque, gingival inflammation, and pocket depth significantly (p < 0.001). At baseline, salivary 8-OHdG was significantly higher in chronic periodontitis (p < 0.001) and reduced significantly subsequent to the periodontal treatment (p < 0.001). Salivary MDA and serum 4-HNE were significantly higher in the patients with periodontitis compared to the control group (p < 0.001). Periodontal treatment did not significantly change the levels of 4-HNE and salivary MDA (p = 0.503, p = 0.093)., Conclusions: Salivary 8-OHdG and MDA may be associated with local impact of periodontal disease, while 4-HNE may be associated with systemic impact of chronic periodontitis., Clinical Relevance: Clinical intervention in periodontitis may be beneficial for periodontitis patients' systemic oxidative stress control, and using lipidic agents for the use of anti-inflammatory/pro-resolving processes for blocking the actions of arachidonic acid cascade can enable some late therapeutic strategies in order to lead oxidative stress-induced inflammation.

Background and Objective: The role of oxidative stress in the process of cardiac remodeling, hypertrophy and heart failure is a current topic. The purpose of this experimental study was to investigate the influences of periodontitis on levels of cardiac oxidative stress., Material and Methods: Twenty rats were separated into two groups: control and experimental periodontitis (EP). Periodontitis was induced by placing a 3.0 silk suture in the cervix of the left and right mandibular first molar teeth for 5 wk. At the end of the experiment, the animals were killed and blood samples and mandibular and ventricular cardiac tissue samples were collected. Levels of alveolar bone loss were determined using measurements performed on histological slices and radiographies. Left ventricular tissue 8-hydroxy-2'-deoxyguanosine, malonylaldehyde, glutathione peroxidase, total oxidant status, total antioxidant status (TAS) levels and serum paraoxonase-1 activity were evaluated biochemically., Results: Measurements performed on the histological slices and radiographies demonstrated that applying the ligature caused obvious alveolar bone loss. Oxidative damage markers (malonylaldehyde, 8-hydroxy-2'-deoxyguanosine, oxidative stress index: total oxidant status/TAS) were significantly higher, and antioxidant markers (glutathione peroxidase, TAS) were statistically insignificantly higher, in the hearts of rats with EP when compared to the controls. In addition, reduced serum paraoxonase-1 activity was also detected in the EP group., Conclusion: The pronounced increase in cardiac oxidative stress caused by periodontitis was due to an excessive increase in the production of reactive oxygen species, rather than due to decreased antioxidant capacity. The results indicate that periodontitis-related cardiac oxidative stress might be one of the mechanisms that contribute to the pathological process that leads to heart failure., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Recent studies demonstrated that protease-activated receptor-2 (PAR-2) correlates with tumor progression in various tissues. On the other hand, oxidative stress arising from endometriosis has been considered a cause of carcinogenesis in ovarian clear cell carcinoma (OCCC). We previously demonstrated that oxidative stress up-regulates PAR-2 expression, and we conducted the present study to investigate the PAR-2 expression and its relation to clinicopathological factors and oxidative stress in OCCC. We performed an immunohistochemical evaluation in 95 cases of OCCC. For the evaluation of oxidative stress markers, 31 cases of ovarian endometrioid carcinoma (OEC) were also examined. No significant differences in the expression of cyclooxygenase-2 and inducible nitric oxide synthase were observed between OCCC and OEC. Sixty-two percent of the OCCC cases showed high 8-hydroxydeoxyguanosine expression, whereas all of the OEC cases showed almost negative immunoreactivities. The presence of endometriosis did not affect the expression of these oxidative stress markers or prognosis. High PAR-2 expression was observed in 20% (14/71) of the early International Federation of Gynecology and Obstetrics (FIGO) stage cases and 58% (14/24) of the advanced FIGO stage cases. High PAR-2 expression was significantly correlated with advanced FIGO stage and shorter overall survival. We found no correlations between PAR-2 expression and oxidative stress in OCCC. Our results suggest that PAR-2 plays an important role in the progression of OCCC. The expression of 8-hydroxydeoxyguanosine is a characteristic finding of OCCC, indicating that the injury of DNA by oxidative stress may be involved in the carcinogenesis of OCCC., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Increased activity of the three major physiological stress systems (immune-inflammatory system, hypothalamic-pituitary-adrenal-axis [HPA-axis], and autonomic nervous system [ANS]) is part of the pathophysiology of various somatic and psychiatric diseases. Oxidative damage is a key mechanism in both ageing and disease. Elucidating the relationship between these stress systems and oxidative damage would contribute to the understanding of the role of physiological stress in disease. This study therefore investigates associations between various measures of physiological stress and oxidative DNA (8-hydroxy-2'-deoxyguanosine, 8-OHdG) and lipid (F2-isoprostanes) damage., Methods: Plasma 8-OHdG and F2-isoprostanes were measured using LC-MS/MS in 2858 subjects (aged 18-65). Plasma inflammation markers, salivary cortisol and ANS markers (three for each stress system) were determined. Linear regression analyses were adjusted for sociodemographics, sampling factors and medication., Results: 8-OHdG was positively associated with all inflammation markers (β=0.047-0.050, p<0.01), evening cortisol (β=0.073, p<0.001), and unexpectedly with low respiratory sinus arrhythmia (RSA) reflecting low ANS stress (β=0.073, p<0.001). F2-isoprostanes were associated with higher C-reactive protein (β=0.072, p<0.001), high ANS stress reflected in heart rate (β=0.064, p<0.001) and RSA (β=-0.076, p=0.001), but not with cortisol. Analyses investigating the cumulative impact of the stress systems demonstrated that the number of systems with ≥1 marker in the high risk quartile showed a positive linear trend with both 8-OHdG (p=0.030) and F2-isoprostanes (p=0.009)., Conclusion: This large-scale study showed that markers of inflammation, the HPA-axis and ANS are associated with oxidative DNA damage. Oxidative lipid damage is associated with inflammation and the ANS. Increased physiological stress across systems is associated with increasing oxidative damage in a dose-response fashion., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Purpose: We evaluate feasibility and repeatability of measures for lipid peroxidation and DNA oxidation in human tears, as well as relationships between outcome variables, and compared our findings to previously reported methods of evaluation for ocular sun exposure., Methods: A total of 50 volunteers were seen for 2 visits 14 ± 2 days apart. Tear samples were collected from the inferior tear meniscus using a glass microcapillary tube. Oxidative stress biomarkers were quantified using enzyme-linked immunosorbent assay (ELISA): lipid peroxidation by measurement of hexanoyl-lysine (HEL) expression; DNA oxidation by measurement of 8-oxo-2'-deoxyguinosone (8OHdG) expression. Descriptive statistics were generated. Repeatability estimates were made using Bland-Altman plots with mean differences and 95% limits of agreement were calculated. Linear regression was conducted to evaluate relationships between measures., Results: Mean (±SD) values for tear HEL and 8OHdG expression were 17368.02 (±9878.42) nmol/L and 66.13 (±19.99) ng/mL, respectively. Repeatability was found to be acceptable for both HEL and 8OHdG expression. Univariate linear regression supported tear 8OHdG expression and spring season of collection to be predictors of higher tear HEL expression; tear HEL expression was confirmed as a predictor of higher tear 8OHdG expression., Conclusions: We demonstrate feasibility and repeatability of estimating previously unreported tear 8OHdG expression. Seasonal temperature variation and other factors may influence tear lipid peroxidation. Support is demonstrated to suggest lipid damage and DNA damage occur concurrently on the human ocular surface.

Phosphorothioated DNA (PT-DNA) exhibits a mild anti-oxidant property both in vivo and in vitro. It was found that 8-OHdG and ROS levels were significantly lower in dnd+ (i.e. S + ) E. coli., compared to a dnd- (i.e. S - ) strain. Furthermore, different from traditional antioxidants, phosphorothioate compound presents an unexpectedly high capacity to quench hydroxyl radical. Oxidative product analysis by liquid chromatography-mass spectrometry and quantum mechanistic computation supported its unique anti-oxidant characteristic of the hydroxyl selectivity: phosphorothioate donates an electron to either hydroxyl radical or guanine radical derived from hydroxyl radical, leading to a PS • radical; a complex of PS • radical and OH - (i.e. the reductive product of hydroxyl radical) releases a highly reductive HS • radical, which scavenges more equivalents of oxidants in the way to high-covalent sulphur compounds such as sulphur, sulphite and sulphate. The PS-PO conversion (PS and PO denote phosphorus-sulphur and phosphorus-oxygen compounds, respectively) made a switch of extremely oxidative OH • to highly reductive HS • species, endowing PT-DNA with the observed high capacity in hydroxyl-radical neutralization. This plausible mechanism provides partial rationale as to why bacteria develop the resource-demanding PT modification on guanine-neighboring phosphates in genome.

Non-glucose biomarker-DNA oxidative damage biomarker 8-hydroxy-2'-deoxyguanosine (8-OHdG) has been successfully detected using a smartphone-enabled glucose meter. Through a series of immune reactions and enzymatic reactions on a solid lateral flow platform, 8-OHdG concentration has been converted to a relative amount of glucose, and therefore can be detected by conventional glucose meter directly. The device was able to detect 8-OHdG concentrations in phosphate buffer saline as low as 1.73 ng mL -1 with a dynamic range of 1-200 ng mL -1 . Considering the inherent advantages of the personal glucose meter, the demonstration of this device, therefore, should provide new opportunities for the monitoring of a wide range of biomarkers and various target analytes in connection with different molecular recognition events., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Purpose: The aim of study was to evaluate reactive oxygen species (ROS), total antioxidant capacity (TAC) andROS-TAC score as indicator for oxidative stress status as well as 8-hydrodeoxyguanosine (8-OHdG) levels as amarker for DNA damage in the seminal plasma of asthenozoospermia patients compared to normozoospermiasamples., Materials and Methods: The semen samples of 28 fertile normozoospermic donors and 25 infertile men withasthenozoospermia were analyzed according to World Health Organization (WHO) criteria. ROS production wasmeasured in neat semen samples by the chemiluminescent assay. Plasma levels of TAC was measured by commercially available colorimetric assays. The levels of DNA oxidative damage were measured by seminal plasma levelsof 8-OHdG using ELISA method. ROS-TAC score was measured using principal component analysis., Results: Asthenozoospermic men had a higher ROS levels compared to the normozoospermic men (P = .01).However, no significant difference was observed in TAC levels between the groups. ROS-TAC score in asthenozoospermicmen was lower than normozoospermic men (P = .02). The levels of 8-OHdG in the asthenozoospermicmen were higher than normozoospermic men (P = .01)., Conclusion: The present study demonstrated a decrease in ROS-TAC score and, a high DNA damage in asthenozoospermiacompared to normozoospermia. ROS-TAC score can predict the oxidative damage of semen samplesof astenozoospermic infertile males.

Ultraviolet B (UVB) irradiation has been known to cause skin damage, which is associated with oxidative stress, DNA damage, and apoptosis. Echinacoside is a phenylethanoid glycoside isolated from Herba Cistanches , which exhibits strong antioxidant activity. In this study, we evaluate the photoprotective effect of echinacoside on UVB-induced skin damage and explore the potential molecular mechanism. BALB/c mice and HaCaT cells were treated with echinacoside before UVB exposure. Histopathological examination was used to evaluate the skin damage. Cell viability, lactate dehydrogenase (LDH) levels, antioxidant enzyme activities, reactive oxygen species (ROS) generation, DNA damage, and apoptosis were measured as well. Western blot was used to measure the expression of related proteins. The results revealed that pretreatment of echinacoside ameliorated the skin injury; attenuated oxidative stress, DNA damage, and apoptosis caused by UVB exposure; and normalized the protein levels of ATR, p53, PIAS3, hnRNP K, PARP, and XPA. To summarize, echinacoside is beneficial in the prevention of UVB-induced DNA damage and apoptosis of the skin in vivo and in vitro.

Under homeostatic conditions, an equilibrium state between amounts of free radicals formed and their scavenging is observed. Free radicals are destructive only when present in excess. Pathological changes within cells and tissues can result from a persistent excess of free radicals. Living organisms are increasingly exposed to oxidative stress, resulting in oxidative DNA modifications. One such modification is 8-hydroxy-2'-deoxyguanosine (8-OHdG). It is considered a biomarker of oxidative stress and oxidative DNA damage. It has been found both in physiological fluids and in cells. This paper presents methods found in the literature for determining 8-OHdG expression in various kinds of biological material - blood, urine or liver homogenates. Methods for determining the biomarker expression have been grouped into direct and indirect methods, and the various levels of 8-hydroxy-2'-deoxyguanosine that can be determined by the different techniques are presented. The basic pros and cons of the various techniques are also discussed.

To evaluate RNA oxidation in the early stage of diabetic nephropathy, we applied an accurate method based on isotope dilution high-performance liquid chromatography-triple quadruple mass spectrometry to analyze the oxidatively generated guanine nucleosides in renal tissue and urine from db/db mice of different ages. We further investigated the relationship between these oxidative stress markers, microalbumin excretion, and histological changes. We found that the levels of 8-oxo-7,8-dihydroguanosine (8-oxoGuo) and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) were increased in the urine and renal tissue of db/db mice and db/db mice with early symptoms of diabetic nephropathy suffered from more extensive oxidative damage than lean littermate control db/m mice. Importantly, in contrast to the findings in db/m mice, the 8-oxoGuo levels in the urine and renal tissue of db/db mice were higher than those of 8-oxodGuo at four weeks. These results indicate that RNA oxidation is more apparent than DNA oxidation in the early stage of diabetic nephropathy. RNA oxidation may provide new insight into the pathogenesis of diabetic nephropathy, and urinary 8-oxoGuo may represent a novel, noninvasive, and easily detected biomarker of diabetic kidney diseases if further study could clarify its source and confirm these results in a large population study.