Effects of cigarette smoking on the antioxidant defence in young healthy male volunteers

β-Escin and Chokeberry Fruit Extract Supplementation in Smokers as Potential anti-Inflammatory Protection-a Pilot Proof-of-Concept Study

Despite the well-recognized risks associated with cigarette smoking, exposure to tobacco smoke remains one of the most serious public health threats worldwide. The aim of the study was to evaluate the potential of β-escin combined with chokeberry fruit extract as anti-inflammatory intervention for tobacco smokers. In addition, mechanisms of the observed effects were investigated. Nine smoking volunteers received 10 mg of water soluble β-escin combined with 5 mg of chokeberry fruit juice concentrate daily for 7 days. The effects of β-escin and chokeberry fruit extract on neutrophil number, IL-6 and IL-8 concentration in induced sputum, antioxidant capacity in induced sputum and saliva as well as on alehyde dehydrogenase (ALDH) activity in PBMC in vitro and in vivo were evaluated. Simultaneously, IL-6, IL-8 and neutrophil number in day 0 and 7 was analyzed in sputum from control subject without β-escin and chokeberry fruit extract intervention. Short, 7-day treatment led to a considerable decrease in neutrophil and increase in macrophage concentration in smokers' sputum as well as significant rise in antioxidant capacity of induced sputum and saliva. The observed reduction in IL-6 and IL-8 concentration did not reach statistical significance. β-escin and chokeberry fruit extract induced a strong upregulation of ALDH activity in PBMC in vitro and in vivo. This pilot proof-of-concept study suggests that by increasing ALDH activity and antioxidant capacity, β-escin and chokeberry fruit extract may effectively lower the inflammation associated with tobacco smoking and contribute to toxicity reduction in the airways exposed to cigarette smoke.

Risk Stratification and Clinical Characteristics of Patients with Late Recurrence of Melanoma (>10 Years)

Background: Most patients with high-risk melanomas develop metastasis within the first few years after diagnosis. However, late recurrence of melanoma is seen in patients that metastasize more than 10 years after the primary diagnosis; a metastasis after 15 years is considered an ultra-late recurrence. It is critical to better understand the clinical and biological characteristics of this subset of melanoma patients in order to offer an individual treatment plan and prevent metastasis. Methods: We retrospectively analyzed melanoma patients with recurrence ≥10 years after a primary diagnosis documented between 1993 and 2012 at the skin cancer center of the University Medical Center Leipzig, Germany. We conducted a comprehensive review of the literature and compared the results with our data. Available archived primary melanoma tissue was investigated with a seven-marker immunohistochemical signature (immunoprint^®) previously validated to reliably identify high-risk patients within stages IB-III. Results: Out of 36 analyzed patients, a third metastasized ultra-late (≥15 years). The mean age at initial diagnosis was 51 years, with women being diagnosed comparatively younger than men. The largest proportion of patients with late recurrence had primary melanomas located on the trunk. The immunoprint^® signature of the available primary melanomas allowed the accurate prediction of a high risk. However, it is difficult to draw a definitive conclusion from the small number of cases that could be analyzed with immunoprint^® (n = 2) in this study. Apart from the primary tumor characteristics, the laboratory values at time of metastasis, comorbidities and outcome are also shown. Conclusion: Late and ultra-late recurrent melanomas seem not to differ from melanomas in general, apart from a distinctly higher proportion of lower leg localizations in ultra-late recurrent melanomas. The immunoprint^® signature may help to identify high-risk primary tumors at the time of initial diagnosis. However, apart from the risk profile of the primary tumor, it seems that individual immune surveillance can control residual tumor cells for more than a decade. Advanced age and increasing comorbidities may contribute to a disturbed immunological balance.

Ethanol- and Cigarette Smoke-Related Alternations in Oral Redox Homeostasis

Alcohol abuse as well as smoking cigarettes has been proven to negatively affect the oral environment. The aim of this work was to provide a systematic review of the literature on the influence of ethanol and cigarette smoking on oral redox homeostasis. A search was performed for scientific articles indexed in the PubMed, Medline and Web of Science databases. We identified 32,300 articles, of which 54 were used for the final review, including the results from 2000 to 2021. Among the publications used to write this article, n = 14 were related to the influence of alcohol consumption (clinical studies n = 6, experimental studies n = 8) and n = 40 were related to the influence of smoking (clinical studies n = 33, experimental studies n = 7) on oral redox homeostasis. The reviewed literature indicates that alcohol abusers and smokers are more likely to suffer from salivary gland dysfunction, as well as develop precancerous lesions due to DNA damage. Compared to alcohol abstainers and non-smokers, alcohol drinkers and smokers are also characterized by a deterioration in periodontal health measured by various indicators of periodontal status. In summary, alcohol abuse and smoking are associated with disrupted oral redox homeostasis, which may lead not only to tooth loss, but also contribute to various adverse effects related to mental health, digestive processes and chronic inflammation throughout the human body.

Electronic and Tobacco Cigarettes Alter Polyunsaturated Fatty Acids and Oxidative Biomarkers

[Figure: see text].

Impaired High-Density Lipoprotein Function in Patients With Heart Failure

Background

We recently showed that, in patients with heart failure, lower high‐density lipoprotein (HDL) cholesterol concentration was a strong predictor of death or hospitalization for heart failure. In a follow‐up study, we suggested that this association could be partly explained by HDL proteome composition. However, whether the emerging concept of HDL function contributes to the prognosis of patients with heart failure has not been addressed.

Methods and Results

We measured 3 key protective HDL function metrics, namely, cholesterol efflux, antioxidative capacity, and anti‐inflammatory capacity, at baseline and after 9 months in 446 randomly selected patients with heart failure from BIOSTAT‐CHF (A Systems Biology Study to Tailored Treatment in Chronic Heart Failure). Additionally, the relationship between HDL functionality and HDL proteome composition was determined in 86 patients with heart failure. From baseline to 9 months, HDL cholesterol concentrations were unchanged, but HDL cholesterol efflux and anti‐inflammatory capacity declined (both P<0.001). In contrast, antioxidative capacity increased (P<0.001). Higher HDL cholesterol efflux was associated with lower mortality after adjusting for BIOSTAT‐CHF risk models and log HDL cholesterol (hazard ratio, 0.81; 95% CI, 0.71–0.92; P=0.001). Other functionality measures were not associated with outcome. Several HDL proteins correlated with HDL functionality, mainly with cholesterol efflux. Apolipoprotein A1 emerged as the main protein associated with all 3 HDL functionality measures.

Conclusions

Better HDL cholesterol efflux at baseline was associated with lower mortality during follow‐up, independent of HDL cholesterol. HDL cholesterol efflux and anti‐inflammatory capacity declined during follow‐up in patients with heart failure. Measures of HDL function may provide clinical information in addition to HDL cholesterol concentration in patients with heart failure.

Evaluation of Antioxidant Capacity and Cotinine Levels of Saliva in Male Smokers and Non-smokers

Background

The cigarette compounds are associated with the increase in the incidence of oral cancer and precancerous lesions. Salivary antioxidant system plays an important role in anti-carcinogenic capacity of saliva. Cotinine, a nicotine metabolite, has a longer half-life in comparison with nicotine and is a suitable marker for exposure to cigarette smoke. This study aims to measure total antioxidant capacity (TAC) and cotinine level in saliva of smokers and non-smokers and compare salivary cotinine level and TAC in each group.

Methods

In this cross-sectional study, 32 smokers and 34 non-smokers were recruited by consecutive sampling from Department of Oral Medicine, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran. Salivary cotinine and TAC concentrations were determined using the enzyme-linked immunosorbent assay (ELISA) technique. For data analysis, correlation tests of Spearman, Mann-Whitney U, and independent samples t-test were used.

Findings

A significant difference was observed between the two groups in the mean cotinine level and in the mean TAC (P = 0.015, P = 0.027, respectively). TAC showed a weak negative correlation with the cotinine level, but the difference was not significant (P = 0.651).

Conclusion

Antioxidants are of great importance to smokers because antioxidants are able to scavenge free radicals found in cigarette smoke. According to the results of present study, the salivary TAC in smokers was lower than that of non-smokers, and the salivary cotinine level in smokers was higher than non-smokers. Therefore, smoking endangers the oral cavity health by reducing the salivary TAC. Further studies with a higher sample size and other factors affecting the salivary TAC are needed for definitive comment.

Anti-oxidative function of follicular fluid HDL and outcomes of modified natural cycle-IVF

High density lipoproteins (HDL) are the main cholesterol carriers in follicular fluid (FF), the natural environment of oocyte development. Additionally, HDL have critical biological functions such as anti-oxidative capacity, which have not been studied in reproduction. Therefore, this study aimed to investigate whether the anti-oxidative function of FF-HDL is associated with fertility outcomes. From 253 women undergoing modified natural cycle (MNC)- IVF at a single academic centre FF and plasma were collected (n = 375 cycles). Anti-oxidative function of FF was mainly attributable to HDL (n = 8; 83%). FF-HDL had a higher anti-oxidative function than plasma HDL (n = 19, P < 0.001) coinciding with increased vitamin E and sphingosine 1 phosphate content (P = 0.028 each). Proteomic analysis indicated no significant differences in major anti-oxidative proteins such as paraoxonase 1, apolipoprotein (apo) A-I or apoA-IV between FF-HDL and matched plasma-HDL (n = 5), while apoC-III, apoE and apoC-II were relatively lower in FF-HDL. Finally, FF-HDL anti-oxidative function was related to a decrease in the odds of the oocyte undergoing normal fertilization, an association that persisted after adjustment for confounders (odds ratio 0.97 (0.93–1), P = 0.041). In conclusion, FF-HDL has considerable anti-oxidative properties that might be relevant for embryo quality.

The relationship between examination-related academic stress, salivary antioxidant capacity and exercise patterns of final-year Saudi dental students

OBJECTIVE

To study the impact of examination stress on the total antioxidant capacity (TAC) of senior dental students and compare changes in TAC between students who exercise regularly and those who do not.

METHODS

A questionnaire designed to evaluate physical activity levels, body mass index (BMI) and academic performance was distributed to 325 senior dental students. Of the 312 who responded, a total of 70 were enrolled in the study, of whom 60 completed the study. The students were composed of a low-activity group (n = 30), who had a Goddard-Sheppard (GS) exercise score of <25, and a high-exercise group (n = 30), who had a GS score >60. Dental Environment Stress (DES) questionnaires and salivary samples were collected at the first week of the semester and at the week of the examinations. Salivary TAC was measured using a commercially available Radical Absorbance Antioxidant Assay measurement kit (Zen-Bio ORAC™, AMS Biotechnology, Abington UK). A total of 60 students completed the study.

RESULTS

A significant increase in DES values and a significant reduction in salivary TAC values were observed in the week of the examination compared to baseline scores. Although no differences were observed in the DES scores between the high-exercise and low-exercise groups, the high-exercise group showed a significantly lower reduction in examination week salivary TAC compared to their counterparts in the low-exercise group. Regression models showed a significant association between the TAC, exercise scores and DES scores in the week of the examinations.

CONCLUSION

Regular exercise may help protect students against the oxidative stress associated with academic stress.

The predictive value of the antioxidative function of HDL for cardiovascular disease and graft failure in renal transplant recipients

BACKGROUND

Protection of low-density lipoproteins (LDL) against oxidative modification is a key anti-atherosclerotic property of high-density lipoproteins (HDL). This study evaluated the predictive value of the HDL antioxidative function for cardiovascular mortality, all-cause mortality and chronic graft failure in renal transplant recipients (RTR).

METHODS

The capacity of HDL to inhibit native LDL oxidation was determined in vitro in a prospective cohort of renal transplant recipients (RTR, n = 495, median follow-up 7.0 years).

RESULTS

The HDL antioxidative functionality was significantly higher in patients experiencing graft failure (57.4 ± 9.7%) than in those without (54.2 ± 11.3%; P = 0.039), while there were no differences for cardiovascular and all-cause mortality. Specifically glomerular filtration rate (P = 0.001) and C-reactive protein levels (P = 0.006) associated independently with antioxidative functionality in multivariate linear regression analyses. Cox regression analysis demonstrated a significant relationship between antioxidative functionality of HDL and graft failure in age-adjusted analyses, but significance was lost following adjustment for baseline kidney function and inflammatory load. No significant association was found between HDL antioxidative functionality and cardiovascular and all-cause mortality.

CONCLUSION

This study demonstrates that the antioxidative function of HDL (i) does not predict cardiovascular or all-cause mortality in RTR, but (ii) conceivably contributes to the development of graft failure, however, not independent of baseline kidney function and inflammatory load.

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

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

Total Antioxidant Capacity and Total Oxidant Status in Saliva of Periodontitis Patients in Relation to Bacterial Load

The detection of salivary biomarkers has a potential application in early diagnosis and monitoring of periodontal inflammation. However, searching sensitive salivary biomarkers for periodontitis is still ongoing. Oxidative stress is supposed to play an important role in periodontitis progression and tissue destruction. In this cross-sectional study, we investigated total antioxidant capacity (TAC) and total oxidant status (TOS) in saliva of periodontitis patients compared to healthy controls and their relationship with periodontopathic bacteria and periodontal disease severity. Unstimulated saliva was collected from 45 patients with generalized severe periodontitis and 37 healthy individuals and the TAC/TOS were measured. In addition, salivary levels of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Fusobacterium nucleatum in saliva were measured. Salivary TAC was lower in periodontitis patients compared to healthy controls. Moreover, a significant negative correlation of salivary TAC with clinical attachment loss was observed in periodontitis patients. No significant difference in the salivary TOS was observed between periodontitis patients and healthy controls. Bacterial load was enhanced in periodontitis patients and exhibited correlation with periodontal disease severity but not with salivary TAC/TOS. Our data suggest that changes in antioxidant capacity in periodontitis patients are not associated with increased bacterial load and are probably due to a dysregulated immune response.

Evaluation of the Effect of Passive Smoking on Lactoferrin and AST on 12 - 15 Years Old Children and Adolescents

BACKGROUND

Passive smokers are involuntarily exposed to cigarette or tobacco smoke and as known, inhalation of environmental tobacco smoke is a serious threat. There is little information about the effect of passive smoking on salivary markers and periodontal indices.

OBJECTIVES

This study investigated the effect of passive smoking on lactoferrin and AST in 12 - 15 years old children and adolescents.

PATIENTS AND METHODS

This case-control analytic correlation type study with no-convenience random sampling method was performed on 160 children aged 12 - 15 who had smokers in their families. The eligible children were divided into two equal groups; 80 cot(+) children as case group and 80 cot(-) children as control group, matched according to age, sex and plaque index. Plaque index was obtained from all subjects. 2 cc unstimulated salivary samples were collected by spitting method. The collected specimens were tested by lactoferrin and AST kits in biochemistry were measured on the day of sampling laboratory. Gingival index Loe and Silness (GI) and Probing Pocket Depth (PPD).

RESULTS

Mean and Standard Deviation of PPD and GI was 2.01 ± 0.077 and 1.53 ± 0.055 in experimental group and 1.93 ± 0.073 and 1.49 ± 0.046 in control group respectively (P < 0.001). The Mean and Standard Deviation parameters of lactoferrin and AST, in the experimental group was 38.66 ± 25.15 and 13.45 ± 6.33 and in the control group 10.18 ± 6.82 and 6.53 ± 2.65 group, respectively (P < 0.001).

CONCLUSIONS

Passive smoking can be effective on inflammatory process of periodontal and salivary biomarkers related to inflammation. Lactoferrin was 11 - 104 in case group and 0.5 - 38 in control group. Aspartat aminotransferase in case group was 2.64 - 30.43 and in control group it was 2.16 - 12.02.

High sensitivity detection of salivary 8-hydroxy deoxyguanosine levels in patients with chronic periodontitis

BACKGROUND

Inflammation is associated with hydroxyl radical damage to DNA as a result of oxidative stress. 8-Hydroxy deoxyguanosine (8-OHdG) is a marker of this process and its levels in saliva could be linked to the severity of periodontal inflammation. The aim of this study was to test the sensitivity of liquid chromatography with tandem mass spectrometry (LC-MS/MS) in comparison to enzyme-linked immune sorbent assay (ELISA) for the detection of 8-OHdG in saliva in patients with chronic periodontitis before and after periodontal treatment.

METHODS

Saliva samples were collected from 23 patients (eight females and 15 males; 46.1 ± 5.1 years of age) with generalized chronic periodontitis and 25 (15 females and 10 males; 44.9 ± 6.8 years of age) periodontally healthy individuals. Patients received initial periodontal treatment consisting of scaling and root planing and were evaluated at baseline and after 6 wk of completion of non-surgical therapy. Salivary 8-OHdG levels were measured using ELISA and LC-MS/MS before and after the treatment. Clinically, plaque index, gingival index, clinical attachment level, bleeding on probing, gingival recession and probing pocket depth were measured at baseline and after 6 wk.

RESULTS

Salivary levels of 8-OHdG decreased significantly after the non-surgical periodontal treatment (p < 0.001). Statistically significant positive correlations were observed between plaque index, gingival index, probing pocket depth, clinical attachment level, bleeding on probing values and LC-MS/MS and ELISA levels of 8-OHdG (p < 0.001).

CONCLUSION

LC-MS/MS is a reliable and sensitive method for evaluating salivary 8-OHdG levels to monitor the treatment response of periodontitis.

Investigation on the mechanisms of genotoxicity of butadiene, styrene and their combination in human lymphocytes using the Comet assay

The toxicity of butadiene and styrene is exerted by their metabolites. Such metabolites have been extensively scrutinized at the in vitro level demonstrating evident genotoxic properties. In monitoring, a diverse range of outcomes has been produced. Additionally, epidemiological studies in rubber workers face difficulties of data interpretation due to the changeability and multiple exposures of the workers as well as to confounding factors inherent to the cohorts. Nevertheless, toxicity has been associated with a significant trend of increasing the risk of leukaemia in employees at the styrene-butadiene rubber industry. Thus, further effort must be made to distinguish the exposures to each chemical over time and to characterize their interrelationships. The present investigation focuses on the effects and mechanisms of damage of the mixture styrene-butadiene by examining its metabolites: styrene oxide (SO), butadiene monoepoxide (BME) and butadiene diepoxide (BDE) respectively. The in vitro Comet assay on frozen lymphocytes has been employed to ascertain the DNA damage patterns for the styrene-butadiene metabolites combined and on their own. Different patterns were observed for the mixture and each of its components. This study has also led to determining the mechanism of damage of the mixture and the compounds. With regard to the presence of reactive oxygen species (ROS), co-treatment with catalase does not modulate the genotoxicity of the mixture but it does modulate its components. The outcomes also indicate that the mixture induces cross-links and this is due to the influence of BDE in the mixture, being more evident as the concentration of BDE increases. An investigation on the sensitivity of lymphocytes from occupationally un/exposed subjects to in vitro exposure of the mixture and its components revealed that occupationally exposed subjects had a substantially higher background of DNA damage and a lower sensitivity to the metabolites of styrene, 1,3-butadiene and its mixture.

Efficient assay for total antioxidant capacity in human plasma using a 96-well microplate

In the present study, we tried to establish an efficient assay for total antioxidant capacity (TAC) in human plasma using a 96-well microplate. TAC was assessed using lag time by antioxidants against the myoglobin-induced oxidation of 2,2'-azino-di(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) with hydrogen peroxide, and expressed as Trolox equivalent. The linearity of the calibration curve with Trolox was maintained with the Trolox concentration range from 2.5 µM to 25 µM (R² = 0.997). The assay was applied to the measurement of TAC in healthy human plasma. Coefficient of variation in intraday assay was 2.4%. Difference was not observed in interday assay. Plasma TAC of men ((569 ± 41) µM Trolox equivalent; n = 6) was higher than that of women ((430 ± 28) µM Trolox equivalent; n = 4). After the vegetable juice was drunk for 1 week, the increase in plasma TAC was observed in almost all the volunteers. In summary, we developed the efficient assay for plasma TAC using a 96-well microplate.

Oxidative stress in smokers and non-smokers

Oxidative stress plays an important role in the pathogenesis of some diseases such as lung cancer, chronic obstructive pulmonary disease, and atheroscleorosis. Smoking may enhance oxidative stress not only through the production of reactive oxygen radicals in smoke but also through weakening of the antioxidant defense systems. In this study, we investigated the effects of smoking on lipid peroxidation and paraoxonase activity in a healthy population. The study consisted of (n = 30) smokers and (n = 30) nonsmokers. The age of the population which is studied was 44.74 +/- 10.59 yr. The levels of serum malondialdehyde (MDA) and paraoxonase (PON1) activities were measured by the modified Buege method and the Eckerson method, respectively. Student's t-test was used to analyze the data. The serum MDA levels were significantly higher (p < .05) and serum PON1 activities were significantly lower (p < .001) in smokers than in nonsmokers. Thus, increased levels of serum MDA and decreased PON1 activities may be important in determining the oxidant/antioxidant imbalance in smokers.

Dental students' attitude towards anti-smoking programmes: a study in Flanders, Belgium

OBJECTIVE

The aim of the study was to assess the dental students' attitude towards tobacco cessation counselling in the dental setting and to explore the influence of knowledge, belief in effectiveness, smoking status, gender and curriculum.

MATERIAL AND METHODS

The study group consisted of all undergraduate students from the 2002-2003 classes of the Ghent University (n = 96). A validated questionnaire was administered to all students involving four different sections: demographic characteristics, attitude related to tobacco cessation programmes in the dental setting, belief in their effectiveness and knowledge concerning tobacco health effects. Statistical analysis included simple univariate nonparametric tests for evaluating differences in attitude towards tobacco cessation programmes, belief in effectiveness of tobacco cessation programmes in the dental setting and knowledge of students concerning tobacco health effects by year of graduation, smoking status and gender. Multiple logistic regression was chosen to calculate adjusted odds ratios and 95% confidence intervals.

RESULTS

Students view willingness to advise individual patients to quit using tobacco. Yet only 51.3% are willing to co-operate in anti-tobacco programmes at the community level, and the perception of students of the effectiveness of smoking cessation counselling in the dental setting is low. The variance of attitude towards tobacco cessation programmes was significantly affected by knowledge and the belief in effectiveness of tobacco cessation programmes in the dental setting. Better knowledge and belief in effectiveness of tobacco cessation counselling was associated with an increasing positive attitude towards tobacco cessation programmes expressed by an odds ratio of 3.12 (95% CI 1.00-9.67) and 1.17 (95% CI 1.00-1.37) respectively.

CONCLUSION

Belief in effectiveness and knowledge seem to influence the attitude of students towards tobacco cessation counselling.

PRACTICE IMPLICATIONS

Besides imparting knowledge, the attitude of newly graduated dentists could be improved by stressing the effectiveness of smoking cessation activities during lectures and integrated training modules in the undergraduate education.

Effect of cigarette smoking on the oxidant/antioxidant balance in healthy subjects

BACKGROUND AND PURPOSE

Cigarette smoking has been associated with the development of cardiovascular disease and cancer. Even though the molecular mechanism(s) are not clear, the pathology has been related to oxygen free radicals present in cigarette smoke. Thus, the main objective of this study was to establish the changes in the oxidation/antioxidation balance induced by cigarette smoking.

METHODS

Thirty healthy subjects (15 smokers and 15 nonsmokers) of both sexes were studied. The smokers group had smoked a mean of 14 cigarettes per day for an average of 4.5 years. Fasting serum levels of malondialdehyde (MDA), a marker of oxidative stress, nitric oxide (NO), reduced glutathione (GSH), and vitamin C (ascorbic and dehydroascorbic acids) were measured.

RESULTS

Fasting NO concentration was significantly higher in smokers (51.3 +/- 5.3 microM) than in nonsmokers (35.2 +/- 4.8 microM, P < 0.05). The smokers had significantly higher serum dehydroascorbic acid levels (2.4 +/- 0.5 mg/dL, P < 0.03) than the nonsmokers (1.08 +/- 0.08 mg/dL). No significant differences were observed in the levels of ascorbic acid, MDA, and GSH between the smokers and nonsmokers.

CONCLUSIONS

Our results suggest that exposure to cigarette smoke increases NO synthesis, such that NO may act in a compensatory way as an inhibitor of lipid peroxidation. Smoking also activates other antioxidative mechanisms such as involving vitamin C. These protective mechanisms appear to be enough in preventing accumulation of oxidative products such as MDA and avoiding oxidative damage.

Effects of smoking and gingival inflammation on salivary antioxidant capacity

AIM

This study evaluated possible effects of smoking and gingival inflammation on salivary antioxidants in gingivitis patients.

METHODS

Twenty otherwise healthy gingivitis patients (10 self-reported smokers) and 20 periodontally and systemically healthy volunteer subjects were enrolled in the study. Whole saliva samples and full-mouth clinical periodontal recordings were obtained at baseline and one month following initial phase of treatment in gingivitis patients. Salivary cotinine, glutathione and ascorbic acid concentrations, and total antioxidant capacity were determined, and the data generated were tested by non-parametric tests.

RESULTS

Salivary cotinine measurements resulted in re-classification of three self-reported non-smokers as smokers. Smoker patients revealed significantly higher probing depths but lower bleeding values than non-smoker patients (p=0.044 and 0.001, respectively). Significant reductions in clinical recordings were obtained in non-smoker (all p<0.05) and smoker (all p<0.01) patients following periodontal treatment. Salivary total glutathione concentrations were reduced following therapy in gingivitis patients who smoke (p<0.01). Otherwise, no statistically significant differences were found between the groups in biochemical parameters at baseline or following treatment (p>0.05).

CONCLUSIONS

Within the limits of this study, neither smoking nor gingival inflammation compromised the antioxidant capacity of saliva in systemically healthy gingivitis patients.

The effect of smoking on DNA effects in the comet assay: a meta-analysis

The comet assay (alkaline single-cell gel electrophoresis, SCG or SCGE) is frequently used in biomonitoring to detect genotoxic effects in humans exposed at the workplace or in their environment. Because of its ready accessibility, blood is most frequently used in such studies. Many studies investigated cigarette smoking either as a genotoxic exposure itself or as a potential confounding factor in occupational studies. However, although smoking is considered to be a relevant exposure towards various genotoxins, conflicting results have been reported in the comet assay studies. The actual reasons for this discrepancy are not known. To further evaluate evidence for smoking-related DNA effects in the comet assay, we now used a meta-analysis approach based on a literature search. We identified 38 studies from 37 publications which were suited for a formal meta-analysis based on the standardized mean difference (SMD) between the study groups. The evaluation of these 38 studies indicated higher levels of DNA damage in smokers than in non-smokers [under a random effects model, SMD = 0.55, 95% confidence interval = (0.16-0.93)]. Subdividing these studies into studies investigating the effect of smoking as a genotoxic exposure (Type A studies, n = 12) and studies investigating smoking as a potential confounder in occupational studies (Type B, n = 26) indicated a significant difference only in Type A studies but not in Type B studies. Furthermore, studies using image analysis or image length measurements (n = 23) only indicated a tendency for a genotoxic effect of smoking, whereas studies using an arbitrary score (n = 15) found a significantly higher level of DNA damage in smokers.