The effect of menopause on the relationship between hyperlipidemia and periodontal disease via salivary 8-hydroxy-2'-deoxyguanosine and myeloperoxidase levels.

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.

Influence of experimental periodontitis on cardiac oxidative stress in rats: a biochemical and histomorphometric study.

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.

Impact of non-surgical periodontal therapy on saliva and serum levels of markers of oxidative stress.

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.

Estimation of tissue and crevicular fluid oxidative stress marker in premenopausal, perimenopausal and postmenopausal women with chronic periodontitis.

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.

Increased levels of the acetaldehyde-derived DNA adduct N 2-ethyldeoxyguanosine in oral mucosa DNA from Rhesus monkeys exposed to alcohol.

Alcohol is a human carcinogen. A causal link has been established between alcohol drinking and cancers of the upper aerodigestive tract, colon, liver and breast. Despite this established association, the underlying mechanisms of alcohol-induced carcinogenesis remain unclear. Various mechanisms may come into play depending on the type of cancer; however, convincing evidence supports the concept that ethanol's major metabolite acetaldehyde may play a major role. Acetaldehyde can react with DNA forming adducts which can serve as biomarkers of carcinogen exposure and potentially of cancer risk. The major DNA adduct formed from this reaction is N (2)-ethylidenedeoxyguanosine, which can be quantified as its reduced form N (2)-ethyl-dG by LC-ESI-MS/MS. To investigate the potential use of N (2)-ethyl-dG as a biomarker of alcohol-induced DNA damage, we quantified this adduct in DNA from the oral, oesophageal and mammary gland tissues from rhesus monkeys exposed to alcohol drinking over their lifetimes and compared it to controls. N (2)-Ethyl-dG levels were significantly higher in the oral mucosa DNA of the exposed animals. Levels of the DNA adduct measured in the oesophageal mucosa of exposed animals were not significantly different from controls. A correlation between the levels measured in the oral and oesophageal DNA, however, was observed, suggesting a common source of formation of the DNA adducts. N (2) -Ethyl-dG was measured in mammary gland DNA from a small cohort of female animals, but no difference was observed between exposed animals and controls. These results support the hypothesis that acetaldehyde induces DNA damage in the oral mucosa of alcohol-exposed animals and that it may play role in the alcohol-induced carcinogenic process. The decrease of N (2)-ethyl-dG levels in exposed tissues further removed from the mouth also suggests a role of alcohol metabolism in the oral cavity, which may be considered separately from ethanol liver metabolism in the investigation of ethanol-related cancer risk.

Increased micronuclei and nuclear abnormalities in buccal mucosa and oxidative damage in saliva from patients with chronic and aggressive periodontal diseases.

BACKGROUND AND OBJECTIVE: Periodontal disease is a chronic bacterial infection characterized by connective tissue breakdown and alveolar bone destruction because of inflammatory and immune response caused by periodontopathogens and long-term release of reactive oxygen species. A high number of reactive oxygen species result in periodontal tissue damage through multiple mechanisms such as lipid peroxidation, protein denaturation and DNA damage. The aim of this study was to evaluate DNA and oxidative damage in subjects with chronic or aggressive periodontitis and healthy controls. MATERIAL AND METHODS: Buccal mucosa cells and whole saliva were collected from 160 subjects, who were divided into three groups: subjects with chronic periodontitis (CP) (n = 58), subjects with aggressive periodontitis (AgP) (n = 42) and a control group (n = 60). DNA damage was determined by counting micronuclei (MN) and nuclear abnormalities (NAs) in exfoliated cells, including binucleated cells, cells with nuclear buds and karyolitic, karyorrhectic, condensed chromatin and pyknotic cells. The degree of oxidative stress was determined by quantifying 8-hydroxy-2'-deoxyguanosine (8-OHdG) in whole saliva. RESULTS: Subjects with CP or AgP presented significantly more ( p < 0.05) MN and NAs and higher levels of 8-OHdG ( p < 0.05) compared with the control group. CONCLUSION: Our results indicate that subjects with periodontitis (CP or AgP) exhibited an increase in the frequency of MN, NAs and 8-OHdG, which is directly related to DNA damage. In addition, a positive correlation exists between oxidative stress produced by periodontitis disease and MN.

Oxidative stress in bisphosphonate-related osteonecrosis of the jaws.

OBJECTIVES: To analyze whether oxidative stress (OS) changes are present in patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ) versus controls. MATERIALS AND METHODS: Oxidative stress was analyzed in serum and unstimulated saliva of three groups: Group 1 consisted of 24 patients who had been treated with intravenous bisphosphonates (ivBPs) and developed BRONJ, group 2 consisted of 20 patients who had received ivBPs and did not develop BRONJ, and group 3 comprised 17 control subjects. Reduced glutathione (GSH), malondialdehyde (MDA), oxidized glutathione (GSSG), and 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxo-dG) levels, as well as the GSSG/GSH ratio, were measured. RESULTS: Mean serum and saliva levels of MDA, GSSG, and 8-oxo-dG and the GSSG/GSH ratio were significantly higher in patients with BRONJ than in controls. We found no significant difference in OS according to BRONJ stage, sex, or location in the jaws. Logistic regression analysis revealed that the GSSG/GSH ratio was a significant factor predicting the development of BRONJ (P = 0.01). CONCLUSIONS: Oxidative stress was detected in patients with BRONJ, and the GSSG/GSH ratio was the most significant OS variable found; it was a significant factor predicting the development of BRONJ.

Analysis of mitochondrial DNA damage using 8-hydroxy 2'deoxyguanosine on in vitro and in vivo exposure of biomaterials.

The present study was carried out to evaluate the effect of HAP-EVA, fibrin glue, HA-BG, Latex and Dental material on oxidative stress related mtDNA damage by in vitro and in vivo methods. In vivo studies of these biomaterials were carried out by implanting biomaterials (five materials) on animals for period of 1, 4, 12, 26 and 52 weeks. At the end of observations, animals were anesthetized, sacrificed and tissues surrounding the implanted materials were collected. Brain, bone and muscles were used for the extraction of mtDNA. Similarly mtDNA was extracted from the homogenate of fresh brain, bone and muscles on exposure to the physiological saline extract of all the above five biomaterials (In vitro). The extracted mtDNA were subjected to analyse the presence of 8-OHdG. The results of study indicated that there was no significant increase in the level of 8-OHdG and thereby does not influence on the GC-TA transversions.

Altered redox homeostasis in human diabetes saliva.

BACKGROUND: Oxidative stress has been implicated in the pathogenesis of diabetes mellitus (DM). Levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), 8-epi-prostaglandin-F(2α) (8-epi-PGF2α), and total protein carbonyls were measured to assess whether DM is associated with altered salivary redox homeostasis. METHODS: A total of 215 patients with diabetes and 481 healthy controls were recruited from the Department of Endocrinology at the Jewish General Hospital in Montreal. Levels of oxidative biomarkers were assayed using enzyme-linked immunosorbent assay (ELISA) in whole unstimulated saliva. Associations of the redox data with exposure to insulin, metformin and dietary control were assessed by logistic regression analyses. RESULTS: We observed (i) significantly higher mean levels of 8-OHdG and protein carbonyls in whole unstimulated saliva of patients with diabetes compared to controls, (ii) higher mean levels of protein carbonyls in type 1 diabetes as well as higher mean levels of 8-OHdG and protein carbonyls in type 2 diabetes compared to controls, (iii) elevated levels of protein carbonyls in diet-controlled patients and in patients with diabetes on insulin and metformin, (iv) elevated levels of 8-OHdG in patients on metformin, and (v) significant associations between subjects with DM and salivary 8-OHdG and protein carbonyls. CONCLUSION: DM is associated with increased oxidative modification of salivary DNA and proteins. Salivary redox homeostasis is perturbed in DM and may inform on the presence of the disease and efficacy of therapeutic interventions.

Identification of carcinogen DNA adducts in human saliva by linear quadrupole ion trap/multistage tandem mass spectrometry.

DNA adducts of carcinogens derived from tobacco smoke and cooked meat were identified by liquid chromatography-electrospray ionization/multistage tandem mass spectrometry (LC-ESI/MS/MS(n)) in saliva samples from 37 human volunteers on unrestricted diets. The N-(deoxyguanosin-8-yl) (dG-C8) adducts of the heterocyclic aromatic amines 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-9H-pyrido[2,3-b]indole (AalphaC), 2-amino-3,8-dimethylmidazo[4,5-f]quinoxaline (MeIQx), and the aromatic amine, 4-aminobiphenyl (4-ABP), were characterized and quantified by LC-ESI/MS/MS(n), employing consecutive reaction monitoring at the MS(3) scan stage mode with a linear quadrupole ion trap (LIT) mass spectrometer (MS). DNA adducts of PhIP were found most frequently: dG-C8-PhIP was detected in saliva samples from 13 of 29 ever-smokers and in saliva samples from 2 of 8 never-smokers. dG-C8-AalphaC and dG-C8-MeIQx were identified solely in saliva samples of three current smokers, and dG-C8-4-ABP was detected in saliva from two current smokers. The levels of these different adducts ranged from 1 to 9 adducts per 10(8) DNA bases. These findings demonstrate that PhIP is a significant DNA-damaging agent in humans. Saliva appears to be a promising biological fluid in which to assay DNA adducts of tobacco and dietary carcinogens by selective LIT MS techniques.

Effects of topical application of lipopolysaccharide and proteases on hepatic injury induced by high-cholesterol diet in rats.

BACKGROUND AND OBJECTIVE: Topical application of lipopolysaccharide and proteases to the gingival sulcus induced not only periodontal inflammation but also detectable liver changes in rats fed a normal diet. However, these changes in the liver were not sufficient to induce pathological consequences. The purpose of the present study was to investigate whether gingival inflammation-induced liver change would have more dramatic pathological consequences in rats fed a high-cholesterol diet compared with the effect of the high-cholesterol diet alone. MATERIAL AND METHODS: Twenty-four male Wistar rats were divided into four groups. During an 8 week experimental period, two groups were fed a normal diet and the other two were fed a high-cholesterol diet containing 1% cholesterol (w/w) and 0.5% cholic acid (w/w). Four weeks prior to the end of the experimental period, one of each of the dietary groups received daily topical application of lipopolysaccharide and proteases to the gingival sulcus, while the other was treated with pyrogen-free water. RESULTS: In the rats without application of lipopolysaccharide and proteases, the serum level of hexanoyl-lysine, scores of steatosis and inflammation, and concentration of 8-hydroxydeoxyguanosine in liver of rats fed a high-cholesterol diet were higher than in those fed a normal diet. In rats fed a high-cholesterol diet, the scores of steatosis and inflammation and the concentration of 8-hydroxydeoxyguanosine in the liver of rats with application of lipopolysaccharide and proteases were higher than in those without. CONCLUSION: In a rat model, application of lipopolysaccharide and proteases to the gingival sulcus augmented the effect of a high-cholesterol diet on steatosis, inflammation and oxidative damage in the liver.

Ability of orally administered IFN-α4 to inhibit naturally occurring gingival inflammation in dogs.

It has been reported that type I interferons (IFN-α/ß) play an important role in innate immune responses against viral and bacterial infections. In this study, we used and examined naturally occurred canine periodontal disease to show the therapeutic efficacy of low dose oral administration (LDOA) of canine IFN-α subtype 4 (CaIFN-α4). We administered purified recombinant CaIFN-α4 expressed in a baculovirus system to dogs with or without gingival inflammation. We found that LDOA of CaIFN-α4 reduce periodontopathic bacterial counts. LDOA induced improvement of naturally occurring gingival inflammation, and reduction of the stress marker responses was also observed after LDOA. These results suggest that LDOA of CaIFN-α4 has effectiveness for improvement of naturally occurring gingival inflammation in dogs.

Effects of obesity on gingival oxidative stress in a rat model.

BACKGROUND: Studies indicate a correlation between obesity and periodontitis. Oxidative stress is involved in the progression of periodontitis. The purpose of this study was to investigate the effects of obesity on gingival oxidative stress in a rat periodontitis model. METHODS: The obese Zucker rats (n = 14) and their lean littermates (n = 14) were each divided into two groups of seven rats. In one of each group, periodontitis was induced by ligature for 4 weeks, whereas the other group was left unligated. The level of 8-hydroxydeoxyguanosine and the ratio of reduced/oxidized glutathione were determined to examine gingival oxidative stress. The serum level of reactive oxygen metabolites and the gingival gene-expression pattern related to oxidative/metabolic stress, inflammation, and cell behavior were also evaluated. RESULTS: The obese rats weighed more than the lean rats at 4 weeks. Compared to lean rats, obese rats had enhanced gingival 8-hydroxydeoxyguanosine levels and a decreased ratio of reduced/oxidized glutathione in the gingival tissue, with increasing serum reactive oxygen metabolites. However, there were no significant differences in the degree of alveolar bone loss between lean and obese rats, except for teeth with and without ligatures in both rats. In addition, the periodontal lesion in obese rats showed higher 8-hydroxydeoxyguanosine levels and polymorphonuclear leukocyte infiltration than the inflamed ones in lean rats, with downregulation of multiple cytochrome P450 gene expression. CONCLUSIONS: Obesity induced gingival oxidative stress with increasing serum reactive oxygen metabolites in rats. In the periodontal lesion, gene expressions related to a capacity for xenobiotic detoxification were downregulated in the obese model.

Evaluating clinical and laboratory effects of ozone in non-surgical periodontal treatment: a randomized controlled trial.

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-ß) 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-ß 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.

Effect of a hemodiafiltration session with on-line regeneration of the ultrafiltrate on oxidative stress. Comparative study with conventional hemodialysis with polysulfone.

BACKGROUND: The influence of a dialysis session using hemodiafiltration with on-line regeneration of the ultrafiltrate (HFR) is compared with that of a conventional hemodialysis session with polysulfone (HD-PS) and with a group of healthy individuals. METHODS: Total antioxidant capacity (TAC), antioxidants, i.e., superoxide dismutase (SOD) glutathione peroxidase (GPX), reduced glutathione (GSH) and catalase, and biomarkers of oxidative stress were evaluated in plasma, whole blood and lymphocytes. RESULTS: The study showed decreased plasma TAC, decreased activities of antioxidant enzymes and decreased GSH levels along with increased thiobarbituric-acid-reactive substances and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels in lymphocytes. The antioxidants and biomarkers of lipid and protein damage after dialysis sessions with HFR were similar or better than following HD-PS. Thus, the blood GPX activity was comparable to that of healthy controls and significantly better than following HD-PS. An increase in 8-OHdG levels was observed in the HD-PS group after dialysis but not in the HFR group. CONCLUSIONS: These results show that HFR induces less oxidative stress than HD-PS.

Electrochemical performance of 8-hydroxy-2'-deoxyguanosine and its detection at poly(3-methylthiophene) modified glassy carbon electrode.

8-Hydroxy-2'-deoxyguanosine (8-OH-dG) has attracted enormous attention in recent years because it has been acknowledged as a typical biomarker of oxidative DNA damage. In this paper, the electrochemical performance of 8-OH-dG at the poly(3-methylthiophene) (P3MT) modified glassy carbon electrode (GCE) was investigated by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). The conducting polymer P3MT can effectively decrease the oxidation peak potential of 8-OH-dG and greatly enhance its peak current. In 0.1 M pH 7.0 phosphate buffer solution (PBS), the anodic peak currents of cyclic voltammograms are linear with the 8-OH-dG concentration in two intervals, viz. 0.700-35.0 microM and 35.0-70.0 microM, with the correlative coefficients of 0.9992 and 0.9995, respectively. The detection limit of 8-OH-dG can be estimated to be 0.100 microM (S/N=3). This modified electrode can be used to detect the amount of 8-OH-dG in human urine. Furthermore, the effects of scan rate, pH, and interference of uric acid (UA) for the voltammetric behavior and detection of 8-OH-dG are also discussed. This proposed modified electrode also shows excellent reproducibility and stability that makes it an ideal candidate for amperometric detection of 8-OH-dG in flow injection analysis (FIA) and high performance liquid chromatography (HPLC).

The association between three major physiological stress systems and oxidative DNA and lipid damage.

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 (ß=0.047-0.050, p<0.01), evening cortisol (ß=0.073, p<0.001), and unexpectedly with low respiratory sinus arrhythmia (RSA) reflecting low ANS stress (ß=0.073, p<0.001). F2-isoprostanes were associated with higher C-reactive protein (ß=0.072, p<0.001), high ANS stress reflected in heart rate (ß=0.064, p<0.001) and RSA (ß=-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.

Evaluation of enzyme-linked immunosorbent assay and liquid chromatography-tandem mass spectrometry methodology for the analysis of 8-oxo-7,8-dihydro-2'-deoxyguanosine in saliva and urine.

While ELISA is a frequently used means of assessing 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxodG) in biological fluids, differences in baseline urinary 8-oxodG levels, compared to chromatographic techniques, have raised questions regarding the specificity of immunoassays. Recently, ELISA of salivary 8-oxodG has been used to report on periodontal disease. We compared salivary 8-oxodG levels, determined by two commercial ELISA kits, to liquid chromatography-tandem mass spectrometry (LC-MS/MS) with prior purification using solid-phase extraction. While values were obtained with both ELISA kits, salivary 8-oxodG values were below or around the limit of detection of our LC-MS/MS assay. As the limit of detection for the LC-MS/MS procedure is much lower than ELISA, we concluded that the assessment of salivary 8-oxodG by ELISA is not accurate. In contrast to previous studies, ELISA levels of urinary 8-oxodG (1.67 +/- 0.53 pmol/mumol creatinine) were within the range reported previously only for chromatographic assays, although still significantly different than LC-MS/MS (0.41 +/- 0.39 pmol/mumol creatinine; p = 0.002). Furthermore, no correlation with LC-MS/MS was seen. These results question the ability of ELISA approaches, at present, to specifically determine absolute levels of 8-oxodG in saliva and urine. Ongoing investigation in our laboratories aims to identify the basis of the discrepancy between ELISA and LC-MS/MS.

1,N2-propanodeoxyguanosine adducts: potential new biomarkers of smoking-induced DNA damage in human oral tissue.

Highly DNA-reactive alpha,beta-unsaturated aldehydes such as acrolein and crotonaldehyde are common environmental pollutants present in cigarette smoke and automobile exhaust and are also released endogenously by lipid peroxidation. Acrolein- and crotonaldehyde-derived 1,N2-propanodeoxyguanosine (AdG and CdG, respectively) have been detected in the tissues of carcinogen-treated rodents and as background lesions in DNA from humans and untreated rodents. To determine whether cigarette smoking increases the levels of AdG and CdG, gingival tissue DNA from 11 smokers (4 males and 7 females; 30-58 years old) and 12 nonsmokers (8 males and 4 females; 21-66 years old) was analyzed using a previously described 32P-postlabeling high-performance liquid chromatography method. The results showed that the mean AdG levels in smokers were significantly higher than those in nonsmokers (1.36 +/- 0.90 micromol/mol guanine in smokers versus 0.46 +/- 0.26 micromol/mol guanine in nonsmokers; P = 0.003). The mean CdG 1 levels in smokers and nonsmokers were 0.53 +/- 0.44 and 0.06 +/- 0.07 micromol/mol guanine, respectively, corresponding to an 8.8-fold increase for smokers (P = 0.0015). Similar to CdG 1, levels of CdG 2 were increased 5.5-fold in smokers as compared to nonsmokers, from 0.31 +/- 0.40 to 1.72 +/- 1.26 micromol/mol guanine (P = 0.0014). Furthermore, the total levels of cyclic adduct (AdG and CdG) in smokers were 4.4-fold greater than those in nonsmokers (P = 0.0003). This study shows the detection of the potentially promutagenic 1,N2-propanoguanine adducts in human oral tissues and demonstrates for the first time an increase of structurally identified adducts in oral tissue DNA by cigarette smoking.

Association between periodontitis and salivary 8-hydroxydeoxyguanosine among Korean rural adults.

OBJECTIVES: This study aimed to evaluate the association between salivary 8-hydroxydeoxyguanosine (8-OHdG) and periodontitis among community-dwelling Korean adults. METHODS: A total of 211 adults (80 men and 131 women) were cross-sectionally surveyed from the Sunchang Longevity Cohort. Periodontitis was defined as having at least 30% of teeth with proximal attachment loss ≥5 mm. The salivary 8-OHdG level was categorized into tertiles: low (<0.916 ng/ml), medium (0.916 to <2.675 ng/ml) and high (≥2.675 ng/ml). Sociodemographic, habitual and systemic health-related factors were controlled for. Logistic regression analysis was performed for the outcome of severe periodontitis. Analysis of covariance in general linear model was performed for the outcome of 8-OHdG. RESULTS: The high 8-OHdG level showed a significant association with periodontitis. The odds ratio (95% confidence interval) was 2.40 (1.05-5.51), and it was highlighted by adding the interaction term with drinking and smoking. The adjusted mean log-transformed value of 8-OHdG was significantly higher in the severe periodontitis group (1.40 ng/ml) than in the control group (1.02 ng/ml) (ancova, P = 0.028). CONCLUSIONS: 8-OHdG was associated with periodontitis. Thus, salivary 8-OHdG could be a useful marker for periodontitis.