The impact of smoking status on antioxidant enzyme activity and malondialdehyde levels in chronic periodontitis

Evaluating the Efficacy of Resveratrol-Containing Mouthwash as an Adjunct Treatment for Periodontitis: A Randomized Clinical Trial

OBJECTIVES

 To evaluate the effectiveness of resveratrol mouthwash as an adjunct to nonsurgical periodontal treatment of periodontitis.

MATERIALS AND METHODS

 This study was a randomized, double-blind clinical trial study. The study included 57 participants with periodontitis. Clinical parameters (plaque index [PI], bleeding on probing [BOP], probing pocket depth [PPD], and clinical attachment loss [CAL]) were examined at the baseline visit, after 7 days, and after 30 days of using resveratrol mouthwash as an adjunct to nonsurgical periodontal treatment. The salivary levels of (interleukin [IL]-6) and RANKL (receptor activator of nuclear factor-kappa B ligand) were measured and compared before and after treatment. The participants answered the visual analog scale-based assessment questionnaire at the last visit.

STATISTICAL ANALYSIS

 A one-way ANOVA (analysis of variance) test was used to compare the means of multiple groups (test, positive control, negative control) at baseline and after treatment. A paired t-test was also used to compare the means of a single group before and after treatment. In addition, Tukey's multiple comparisons test was used to identify specific pairwise differences between the three groups after finding significant differences with ANOVA. The Chi-square test was also used to compare the distribution of categorical variables like sex between the groups.

RESULTS

 All interventions significantly reduced PI, BOP, PPD, and CAL, but resveratrol and chlorhexidine had a higher significant effect than placebo except for CAL without a significant difference between them. All mouthwashes significantly reduced the salivary concentration of IL-6. However, resveratrol and chlorhexidine had a significantly higher effect than placebo, while the concentration of RANKL was decreased in all groups without a significant difference between them. The participants' responses to the mouthwash questionnaire showed that resveratrol and chlorhexidine had the same feedback without significant differences.

CONCLUSION

 Resveratrol-containing mouthwash could be used as an alternative to chlorhexidine as an adjunct to nonsurgical periodontal treatment of periodontitis.

Improvement of post-periodontitis-therapy inflammatory state in diabetics: a meta-analysis of randomized controlled trials

OBJECTIVES

This systematic review aimed to evaluate the impact of periodontal therapy on systemic biomarkers of inflammation and oxidative stress in patients with type 2 diabetes mellitus (T2DM) and periodontitis.

MATERIALS AND METHODS

An electronic search without restriction on dates or languages was performed in six electronic databases, protocol records and other sources until May 2024. To develop the search strategy, clinical question was formulated using the PICOD method. Eligibility criteria included randomized controlled trials on the effects of periodontitis-therapy on the inflammatory parameters of T2DM patients. Risk of bias and certainty of evidence were assessed by RoB2 and GRADE tools, respectively. The review protocol was registered in PROSPERO platform (CRD42020206295).

RESULTS

Of 1,062 records screened, the authors determined that 14 studies enrolling 1223 participants proved eligible. Moderate-quality evidence suggested a positive effect of periodontitis-therapy on serum levels of c-reactive protein [0.39 (CI95%: 0.27-0.5)], even without the use of antibiotics [0.34 (CI95%: 0.22-0.46)], in T2DM patients. The significant reduction in C-reactive protein (CRP) among smokers in favor of periodontitis-therapy was greatest at six months of follow-up.

CONCLUSIONS

Non-surgical periodontal therapy improved short-term biomarkers of systemic inflammation in T2DM patients, with moderate evidence of improvement in serum levels of high sensitivity-CRP.

CLINICAL RELEVANCE

Systemic inflammation in T2DM patients can be reduced after non-surgical periodontal therapy, which also has the potential to reduce the risk of other important systemic outcomes, such as cardiovascular disease.

The assessment of glutathione, glutathione peroxidase, glutathione reductase, and oxidized glutathione in patients with periodontitis-A systematic review and meta-analysis

OBJECTIVE

The present systematic review explored the involvement of enzymatic and nonenzymatic antioxidants in periodontitis, drawing from established literature.

MATERIALS AND METHODS

The research approach encompassed an extensive electronic search from 2000 to 2023 across databases such as PubMed, Science Direct, and Wiley Online Library and cross-referencing using specific keywords.

RESULTS

The initial literature exploration generated a total of 766 articles. After thoroughly examining the abstracts, 693 articles were excluded from consideration due to duplication and lack of relevance to the central research inquiry. Following that, 73 articles were left for in-depth evaluation. Following a qualitative assessment, 35 studies that satisfied the inclusion criteria were chosen, while 38 were removed for not meeting the necessary standards. Within this selection, a meta-analysis was conducted on 11 articles that provided consistent data for quantitative synthesis. Specifically, the analysis of glutathione (GSH) levels in serum samples revealed a standardized mean difference (SMD) of -5.552 µg/mL (CI 95%: -9.078 to -2.026; P-0.002). In contrast, the analysis of glutathione peroxidase (GPx) enzymes in gingival crevicular fluid (GCF) samples displayed an overall SMD of 2.918 ng/µL (CI 95%: 0.372-5.465; P-0.025), while salivary samples exhibited an overall SMD value of 0.709 U/l (95% CI: -1.907-3.325; P-0.596) which is of insignificant.

CONCLUSION

The systematic review findings suggest a notable decrease in antioxidant enzymes across various systemic biological samples among patients with periodontitis, contrasting with the results from gingival tissue samples meta-analysis of GPx enzyme.

Advances of Oxidative Stress Impact in Periodontitis: Biomarkers and Effective Targeting Options

Periodontitis is the most common inflammatory oral disease that affects around 15% of adults and contributes to severe periodontal tissue destruction with subsequent tooth loosening and loss. Among the main pathogenic mechanisms underlying periodontitis, excessive reactive oxygen species production and oxidative stress play a predominant role in inducing both local and systemic damage. Current therapeutic approaches have expanded the conventional methods combined with herbal antioxidant compounds to free radical-scavenging nanomaterials and infrared laser therapy, offering promising pre-clinical evidence in periodontitis management. Herein, we review the pathogenic mechanisms of reactive oxygen species tissue damage, along with recent advances in oxidative stress biomarkers and novel targeting options.

Enzymatic antioxidants activity in gingival crevicular fluid and saliva in advanced periodontitis

AIM

Enzymatic antioxidants are the primary line of defense against oxidative and nitrosative stress. However, their involvement in the progression of periodontitis is still not well understood. The study aimed to determine the activity of enzymatic antioxidants in the gingival crevicular fluid (GCF) and saliva of patients with periodontitis.

MATERIALS AND METHODS

The study group of 56 patients with periodontitis (stage III and IV) and 28 healthy controls were involved. The modified plaque index, probing depth, the clinical attachment level, the percentage of sites with bleeding on probing, papilla bleeding index, and maximum value of tooth mobility (Periotest®) were tested. Saliva (stimulated and non-stimulated) and GCF were collected from the participants, and activity of peroxidase, catalase, superoxide dismutase, and glutathione reductase were determined colorimetrically.

RESULTS

Lower activity of peroxidase (p < 0.0001), catalase (p < 0.0001), superoxide dismutase (p = 0.0188), and glutathione reductase (p < 0.0001) was noted in non-stimulated saliva of patients with periodontitis compared to healthy subjects. Peroxidase (p < 0.0001), catalase (p < 0.0001) and superoxide dismutase (p < 0.0001) showed lower activity in stimulated saliva of patients with periodontitis compared to healthy subjects. The peroxidase (p < 0.0029), catalase (p < 0.0001), and glutathione reductase (p = 0.0028) activity in GCF of stage III + IV were significantly higher compared to healthy controls. Superoxide dismutase (p < 0.0001) showed lower activity in GCF of patients with periodontitis.

CONCLUSIONS

The demonstrated decrease in activity of all analyzed enzymatic antioxidants in non-stimulated saliva may result from long-lasting periodontitis and exhaustion of the safeguard mechanism against reactive oxygen species.

Bifidobacterium animalis subspecies lactis HN019 can reduce the sequelae of experimental periodontitis in rats modulating intestinal parameters, expression of lipogenic genes, and levels of hepatic steatosis

OBJECTIVE

To determine whether Bifidobacterium animalis subspecies lactis HN019 (B. lactis HN019) can reduce the sequelae of experimental periodontitis (EP) in rats modulating systemic parameters.

BACKGROUND

This study evaluated the effects of probiotic therapy (PROB) in the prevention of local and systemic damage resulting from EP.

METHODS

Forty-eight rats were allocated into four groups: C (control), PROB, EP, and EP-PROB. PROB (1 × 1010  CFU/mL) administration lasted 8 weeks and PE was induced on the 7th week by placing ligature on the animals' lower first molars. All animals were euthanized in the 9th week of the experiment. Biomolecular analyses, RT-PCR, and histomorphometric analyses were performed. The data obtained were analyzed statistically (ANOVA, Tukey, p < .05).

RESULTS

The EP group had higher dyslipidemia when compared to the C group, as well as higher levels of insulin resistance, proteinuria levels, percentages of systolic blood pressure, percentage of fatty hepatocytes in the liver, and expression of adipokines was up-regulated (LEPR, NAMPT, and FABP4). All these parameters (except insulin resistance, systolic blood pressure, LEPR and FABP4 gene expression) were reduced in the EP-PROB group when compared to the EP group. The EP group had lower villus height and crypt depth, as well as a greater reduction in Bacteroidetes and a greater increase in Firmicutes when compared to the EP-PROB group. Greater alveolar bone loss was observed in the EP group when compared to the EP-PROB group.

CONCLUSION

Bifidobacterium lactis HN019 can reduce the sequelae of EP in rats modulating intestinal parameters, attenuating expression of lipogenic genes and hepatic steatosis.

Assessment of Oxidative Stress by the Estimation of Lipid Peroxidation Marker Malondialdehyde (MDA) in Patients with Chronic Periodontitis: A Systematic Review and Meta-Analysis

Objective

The present systematic review and meta-analysis aimed to assess the oxidative stress-mediated lipid peroxidation end product malondialdehyde (MDA) in periodontitis using the available literature.

Materials and Methods

An electronic literature search was performed for the published articles from 2000 to 2022 in PubMed (MeSH), Science Direct, Wiley Online library, and cross-reference using specific keywords.

Results

The literature search identified 1,166 articles. After analyzing the abstracts of the obtained articles, the articles were excluded for the following reasons: duplicate studies (n = 395) and not relevant to the research question (n = 726). The remaining 45 articles were chosen for full-text evaluation. Finally, the present qualitative synthesis selected 34 articles that met the inclusion criteria for evaluation and removed the articles which did not meet the required criteria (n = 11). Out of these, 16 articles had coherent data for quantitative synthesis. The meta-analysis used the standardized mean differences method at a 95% confidence interval by random-effects model. The periodontitis group displayed significantly higher MDA levels (P < 0.001) in gingival crevicular fluid, saliva, and serum samples of the studies analyzed than the healthy control.

Conclusion

The analyzed studies showed significantly higher MDA levels in various biological samples of patients with periodontitis, supporting the role of elevated oxidative stress and consequent lipid peroxidation in periodontitis.

Evaluation of Lipid Peroxidation in the Saliva of Diabetes Mellitus Type 2 Patients with Periodontal Disease

As oxidative stress has been implicated in the pathogenesis of diabetes mellitus and periodontitis, it may serve as a link between these conditions. Therefore, as a part of the present study, salivary lipid peroxidation (LP) in periodontitis patients with and without diabetes mellitus type 2 (DM2) was evaluated, along with the periodontal therapy effectiveness. The study sample comprised of 71 DM2 patients with periodontitis and 31 systemically healthy controls suffering from periodontitis of comparable severity. In all participants, periodontal indices—plaque index (PI), gingival index (GI), papilla bleeding index (PBI), probing pocket depth (PPD), and clinical attachment level (CAL)—were recorded, and salivary LP was measured using a spectrophotometric method prior to treatment initiation and three months post-treatment. At baseline, mean salivary LP in DM2 patients was higher than that measured for the control group, but the difference did not reach statistical significance (p > 0.05), whereas a positive significant correlation was found between PPD and LP in both groups. Three months after nonsurgical periodontal therapy, clinical periodontal parameters and salivary LP levels were significantly reduced in both groups (p < 0.05). These findings indicate that the improvement in clinical periodontal status following nonsurgical periodontal therapy is accompanied by a significant decrease in salivary LP in DM2 patients, suggesting that periodontitis, rather than diabetes, is the primary driver of the elevated salivary LP in this group.

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.

Resveratrol prevents inflammation and oxidative stress response in LPS-induced human gingival fibroblasts by targeting the PI3K/AKT and Wnt/β-catenin signaling pathways

This study aimed to elucidate the anti-inflammatory and antioxidant properties of resveratrol (RSV) in human gingival fibroblasts (HGFs) following stimulation by P. gingivalis lipopolysaccharide (LPS). The levels of the inflammatory cytokines IL-1β, IL-6, IL-8 and TNFα, the activity of the antioxidant enzymes SOD and GSH-Px, and the levels of MDA, were evaluated by ELISA. It was observed that the expression of IL-1β, IL-6, IL-8 and TNFα in LPS-induced HGFs was significantly downregulated by RSV in a dose-dependent manner. RSV also partly increased oxidative stress (OS)-related factors, including SOD and GSH-Px, which was accompanied by a decrease in MDA production, although the results were not statistically significant. Additionally, RSV-induced deactivation of the PI3K/AKT and Wnt/β-catenin pathways in LPS-induced HGFs was observed by western blot analysis. Subsequently, it was demonstrated treatment with PI3K/AKT pathway inhibitor (LY294002) or Wnt/β-catenin pathway inhibitor (Dickkopf-1, DKK-1) could further enhance the anti-inflammatory and antioxidant effects of RSV by downregulating the expression of IL-1β, IL-6, IL-8 and TNFα, and the production of MDA, and increasing the activity of SOD and GSH-Px in LPS-induced HGFs. These results suggested RSV attenuated the inflammation and OS injury of P. gingivalis LPS-treated HGFs by deactivating the PI3K/AKT and Wnt/β-catenin signaling pathways.

Tobacco Use and Periodontal Disease-The Role of Microvascular Dysfunction

Periodontal disease consists in highly prevalent wide-ranging inflammatory conditions that affect the supporting apparatus of teeth. Tobacco use is the most important risk factor for periodontal disease as it increases disease severity and periodontal surgery complications. Tobacco use is harmful for the vasculature by causing microvascular dysfunction, which is known to negatively affect periodontal disease. To the author's knowledge this paper is the first comprehensive review on the mechanisms by which tobacco use affects oral microcirculation and impacts the pathophysiology of periodontal disease. In healthy subjects, acute nicotine administration or tobacco use (smoking/smokeless forms) increases the blood flow in the oral mucosa due to local irritation and increased blood pressure, which overcome neural- and endocrine-mediated vasoconstriction. Chronic tobacco smokers display an increased gingival microvascular density, which is attributed to an increased capillary recruitment, however, these microcirculatory units show higher tortuosity and lower caliber. These morphological changes, together with the repetitive vasoconstrictive insults, contribute to lower gingival perfusion in chronic smokers and do not completely regress upon smoking cessation. In periodontal disease there is considerable gingival inflammation and angiogenesis in non-smokers which, in chronic smokers, are considerably suppressed, in part due to local immune suppression and oxidative stress. Tobacco exposure, irrespective of the form of use, causes long-term microvascular dysfunction that increases the risk of complications due to the natural disease course or secondary therapeutic strategies.

Metabolomics of gingival crevicular fluid to identify biomarkers for periodontitis: A systematic review with meta-analysis

The present systematic review aimed to examine periodontitis-specific biomarkers in the gingival crevicular fluid (GCF) that could have a diagnostic relevance, and to provide a qualitative assessment of the current literature. Metabolites are reliable indicators of pathophysiological statuses, and their quantification in the GCF can provide an outlook of the changes associated with periodontitis and have diagnostic value. Relevant studies identified from PubMed, Embase, Cochrane Library, and Scopus databases were examined to answer the following PECO question: "In systemically healthy individuals, can concentration of specific metabolites in the GCF be used to discriminate subjects with healthy periodontium (H) or gingivitis from patients with periodontitis (P) and which is the diagnostic accuracy?" Quality of included studies was rated using a modified version of the QUADOMICS tool. Meta-analysis was conducted whenever possible. After the screening of 1,554 titles, 15 studies were selected, with sample size ranging from 30 to 93 subjects. Eleven studies performed targeted metabolomics analysis and provided data for 10 metabolites. Among the most consistent markers, malondialdehyde levels were found higher in the P group compared with H group (SMD = 2.86; 95% CI: 1.64, 4.08). Also, a significant increase of 8-hydroxy-deoxyguanosine, 4-hydroxynonenal, and neopterin was detected in periodontally diseased sites, while glutathione showed an inverse trend. When considering data from untargeted metabolomic analysis in four studies, more than 40 metabolites were found significantly discriminant, mainly related to amino acids and lipids degradation pathways. Notably, only one study reported measures of diagnostic accuracy. Several metabolites were differentially expressed in GCF of subjects across different periodontal conditions, having a major potential for investigating periodontal pathophysiology and for site-specific diagnosis. Oxidative stress-related molecules, such as malondialdehyde and 8-hydroxy-deoxyguanosine, were the most consistently associated to periodontitis (PROSPERO CRD42020188482).

Metallothionein levels in gingival crevicular fluid, saliva and serum of smokers and non-smokers with chronic periodontitis

BACKGROUND

Metallothionein (MT), a cysteine rich protein is involved as a radical scavenger in several pathological conditions associated with oxidative stress; however, its role in periodontal disease still remains elusive. The aim of this cross-sectional study is to determine the serum, saliva and gingival crevicular fluid (GCF) levels of MT in smokers (S) and non-smokers (NS) with chronic periodontitis (CP), and compare them with those of periodontally healthy (PH) individuals.

METHODS

A total of 85 participants were enrolled: 45 patients with CP (23 S [CP+S] and 22 NS [CP+NS]) and 40 PH individuals (20 S [PH+S] and 20 NS [PH+NS]). In all the study participants, clinical periodontal parameters (plaque index, gingival index, sulcus bleeding index, probing depth, and clinical attachment level) were recorded and samples of serum, saliva and GCF were collected. Enzyme-linked immunosorbent assay was used to determine the levels of MT in the samples.

RESULTS

All periodontal clinical parameters were significantly higher in the CP groups as compared to PH groups (P < 0.05). MT levels in CP+S group were significantly raised in comparison to other three groups. There was no statistically significant difference in MT levels among CP+NS and PH+S groups (P > 0.05); however, relatively higher levels were observed in GCF and saliva in CP+NS group. When all the study groups were observed together, MT levels were positively correlated with clinical parameters.

CONCLUSIONS

Results of present study suggest that smoking and CP can induce the synthesis of MT owing to increased oxidative stress and heavy metals intoxication. Further longitudinal studies with large sample size and an interventional arm are needed to substantiate the role of MT as a potential biomarker in periodontitis.

Periodontitis is an inflammatory disease of oxidative stress: We should treat it that way

Periodontitis is a highly prevalent disease. As it progresses, it causes serious morbidity in the form of periodontal abscesses and tooth loss and, in the latter stages, pain. It is also now known that periodontitis is strongly associated with several nonoral diseases. Thus, patients with periodontitis are at greater risk for the development and/or exacerbation of diabetes, chronic obstructive pulmonary disease, and cardiovascular diseases, among other conditions. Although it is without question that specific groups of oral bacteria which populate dental plaque play a causative role in the development of periodontitis, it is now thought that once this disease has been triggered, other factors play an equal, and possibly more important, role in its progression, particularly in severe cases or in cases that prove difficult to treat. In this regard, we allude to the host response, specifically the notion that the host, once infected with oral periodontal pathogenic bacteria, will mount a defense response mediated largely through the innate immune system. The most abundant cell type of the innate immune system - polymorphonuclear neutrophils - can, when protecting the host from microbial invasion, mount a response that includes upregulation of proinflammatory cytokines, matrix metalloproteinases, and reactive oxygen species, all of which then contribute to the tissue damage and loss of teeth commonly associated with periodontitis. Of the mechanisms referred to here, we suggest that upregulation of reactive oxygen species might play one of the most important roles in the establishment and progression of periodontitis (as well as in other diseases of inflammation) through the development of oxidative stress. In this overview, we discuss both innate and epigenetic factors (eg, diabetes, smoking) that lead to the development of oxidative stress. This oxidative stress then provides an environment conducive to the destructive processes observed in periodontitis. Therefore, we shall describe some of the fundamental characteristics of oxidative stress and its effects on the periodontium, discuss the diseases and other factors that cause oxidative stress, and, finally, review potentially novel therapeutic approaches for the management (and possibly even the reversal) of periodontitis, which rely on the use of therapies, such as resveratrol and other antioxidants, that provide increased antioxidant activity in the host.

Evaluation of salivary biomarkers of periodontitis among smokers and nonsmokers: A novel study

Background:

The analysis of salivary enzymes contributes to the clarification of pathogenesis and improvement in the diagnosis of periodontal disease. The present study aimed to examine the prospective association between smoking and periodontal disease progression and the effects of smoking on the following salivary biomarkers related to periodontitis: Alkaline phosphatase (ALP), acid phosphatase (ACP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), creatinine (CRE), blood urea nitrogen (BUN), urea (UA), free-hemoglobin (f-Hb), and neopterin.

Materials and Methods:

A total of 64 male patients aged 21–60 years were recruited and grouped as Group 1: 16 healthy nonsmokers, who had never smoked. Group 2: 16 smokers with gingivitis. Group 3: 16 smokers with moderate periodontitis. Group 4: 16 smokers with severe periodontitis. Stimulated saliva was collected for at least 5 min and clinical measurements; salivary biomarkers were assessed in automated analyzer.

Results:

Data showed significant correlation among salivary ACP, AST, LDH, CRE, BUN, UA, and f-Hb and neopterin levels showed higher in group 4 compared with other groups.

Conclusion:

This study indicated that smoking has several detrimental effects on periodontal tissues. A higher level of salivary biomarkers was seen in smokers with severe periodontitis. Hence, these biomarkers are helpful in future for the earlier detection of periodontal diseases progression and can also be used as potential salivary biomarkers for assessing smoking status and severity in chronic periodontitis.

Selenium-associated DNA methylation modifications in placenta and neurobehavioral development of newborns: An epigenome-wide study of two U.S. birth cohorts

BACKGROUND/AIM

Selenium (Se) levels in pregnancy have been linked to neurobehavioral development of the offspring. DNA methylation is a potential mechanism underlying the impacts of environmental exposures on fetal development; however, very few studies have been done elucidating the role of DNA methylation linking prenatal Se and child neurobehavior. We aimed to investigate the associations between placental Se concentration and epigenome-wide DNA methylation in two U.S. cohorts, and to assess the association between Se-related DNA methylation modifications and newborns' neurobehavior.

METHODS

We measured placental Se concentrations in 343 newborns enrolled in the New Hampshire Birth Cohort Study and in 141 newborns in the Rhode Island Child Health Study. Genome-wide placental DNA methylation was measured by HumanMethylation450 BeadChip, and newborn neurobehavioral development was assessed by the NICU Network Neurobehavioral Scales (NNNS). We meta-analyzed the associations between placental Se concentration and DNA methylation in each cohort, adjusting for covariates. We also fit multiple linear regression and ordinal logistic regression for methylation and newborn NNNS summary scores.

RESULTS

We identified five Se-related differentially methylated CpG sites. Among them was cg09674502 (GFI1), where selenium concentration was positively associated with methylation (β-coefficient = 1.11, FDR-adjusted p-value = 0.045), and where we observed that a one percent methylation level increase was associated with a 15% reduced odds of higher muscle tone in the arms, legs and trunk of newborns, (OR [95% Confidence Interval, CI] = 0.85 [0.77, 0.95]). We also observed for each interquartile range (IQR) increase in selenium concentration in the placenta, there was 1.76 times greater odds of higher hypotonicity (OR [95% CI] = 1.76 [1.12, 2.82]).

CONCLUSIONS

Placental selenium concentration was inversely associated with muscle tone of newborns, and hypermethylation of GFI1 could be a potential mechanism underlying this association.

Oxidative stress-related biomarkers in saliva and gingival crevicular fluid associated with chronic periodontitis: A systematic review and meta-analysis

AIM

Oxidative stress (OS) biomarkers have been detected in saliva and gingival crevicular fluid (GCF) during chronic periodontitis (CP) progression; however, the relationship between OS biomarkers and CP progression remains elusive. The purpose of this meta-analysis is to investigate the relationship between local OS biomarkers and CP.

METHODS

This review was conducted through a systematic search from three databases. Studies on CP participants were included as an experimental group, and studies on periodontally healthy (PH) participants were included as a control. Mean effects were expressed as standardized mean difference with their associated 95% confidence intervals.

RESULTS

From a total of 2,972 articles, 32 articles fulfilled the inclusion criteria. We found a significant decrease of total antioxidant capacity and a significant increase of malondialdehyde (MDA), nitric oxide, total oxidant status (TOS), and 8-hydroxy-deoxyguanosine levels in the saliva of CP patients. Moreover, we also found an elevation of MDA level in GCF of CP group when compared with the PH group. There were no significant differences of salivary and GCF superoxide dismutase levels, salivary glutathione peroxidase level, and GCF TOS level between two groups. However, a high heterogeneity was observed among evaluated studies.

CONCLUSIONS

Despite the limitations of this study, the result of our meta-analysis supported the rationale that there was a direct link between CP and OS-related biomarkers' levels in the local site, indicating the important role of OS in the onset and development of CP.

Salivary antioxidant enzymes and lipid peroxidation product malondialdehyde and sialic acid levels among smokers and non-smokers with chronic periodontitis-A clinico-biochemical study

Background

Pathogenesis of most of the inflammatory process are associated with reactive oxygen species (ROS), derived from various metabolic sources and which may lead to direct or indirect tissue damage due to oxidative stress, resulting in periodontal diseases. Usually antioxidant systems are capable of removing free radicals, thereby preventing tissue damage from free radical. ROS can result in tissue damage, involving lipid peroxidation. The aim of this study was to evaluate and compare the levels of superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA), and sialic acid (SA) in periodontally healthy and chronic periodontitis among nonsmokers and smokers and to determine their value as diagnostic markers for chronic periodontitis.

Materials and Methods

A total of 90 male patients aged 20--60 years were recruited and grouped as Group 1: 30 Healthy nonsmokers, who had never smoked. Group 2: 30 nonsmokers with chronic periodontitis. Group 3: 30 smokers with chronic periodontitis. Unstimulated saliva was collected for at least 5 min and clinical measurements; SOD, GPx, MDA and SA were assessed using a spectrophotometric method.

Results

Data showed a significant correlation between salivary SOD, GPx, MDA, and SA in group 1, group 2, and group 3. SOD and GPx were found to be lower and MDA and SA levels were found to be higher among smokers with chronic periodontitis.

Conclusion

Reduced levels of antioxidant enzymes SOD and GPx and elevated levels of lipid peroxidation product MDA as well as increased levels of SA could be used as diagnostic markers to measure oxidative stress in periodontal disease associated with risk factor such as smoking.

Protein carbonyl levels in serum, saliva and gingival crevicular fluid in patients with chronic and aggressive periodontitis

Objective

This study aims at evaluating the degree of protein carbonyl (PC) levels in serum, gingival crevicular fluid (GCF) and saliva in patients who suffer from chronic periodontitis (CP) and generalized aggressive periodontitis (GAP).

Materials and methods

A total of 110 individuals took part in the study. Of this number, 35 were CP patients, 43 GAP patients, and the remaining 32 were healthy controls. Measurements regarding the serum, saliva and GCF PC levels were obtained by high-performance liquid chromatography.

Results

No statistically significant difference was found in serum PC levels between the groups (P > 0.05). In terms of salivary levels, the CP group demonstrated a significantly higher level (P < 0.05) of PC level compared to the GAP group. However, the difference was not found statistically significant when the comparison was drawn with the control group (p > 0.05).

The GCF PC level in the CP group had a significantly higher level of concentration compared to the other groups (P < 0.05), whereas the relevant values in the control group were higher than the values in the GAP group (P < 0.05). GCF PC total values (/30 s) were higher in the CP group than the remaining groups (P < 0.05), whereas the relevant values in the GAP group were higher than the values in the control group (P < 0.05). It could be stated that GCF PC levels were significantly correlated, either positively or negatively, with all clinical periodontal parameters (p < 0.05).

Conclusions

The results obtained suggest that PC levels of serum and salivary in periodontitis, when compared to periodontal health, do not seem to change considerably. However, in the CP group, a statistically significant increase in PC levels of GCF was observed. This finding suggests the salient role of local protein carbonylation in the periodontal area in CP. That the CP group had a higher level of PC level than the GAP group underscores the higher protein oxidation levels in CP patients.

Tobacco-induced suppression of the vascular response to dental plaque

Cigarette smoking presents oral health professionals with a clinical and research conundrum: reduced periodontal vascular responsiveness to the oral biofilm accompanied by increased susceptibility to destructive periodontal diseases. This presents a significant problem, hampering diagnosis and complicating treatment planning. The aim of this review is to summarize contemporary hypotheses that help to explain mechanistically the phenomenon of a suppressed bleeding response to dysbiotic plaque in the periodontia of smokers. The influence of smoke exposure on angiogenesis, innate cell function, the production of inflammatory mediators including cytokines and proteases, tobacco-bacteria interactions, and potential genetic predisposition are discussed.

Oxidative Stress and Antioxidants in the Diagnosis and Therapy of Periodontitis

Oxidative stress has been implicated in the pathogenesis of numerous diseases. However, large interventional studies with antioxidants failed to show benefits in the prevention or treatment of cardiovascular diseases, cancer, or diabetes mellitus. Numerous clinical studies have confirmed the association of oxidative stress markers and periodontitis. Technical and biological variability is high for most of the analyzed markers and none of them seems to be optimal for routine clinical use. In a research setting, analysis of a palette of oxidative stress markers is needed to cover lipid peroxidation, protein oxidation, and the antioxidant status. The source of reactive oxygen species and their role in the pathogenesis of periodontitis remains unclear. Interventional experiments indicate that oxidative stress might be more than just a simple consequence of the inflammation. Small studies have confirmed that some antioxidants could have therapeutic value at least as an addition to the standard non-surgical treatment of periodontitis. A clear evidence for the efficiency of antioxidant treatment in large patient cohorts is lacking. Potentially, because lowering of oxidative stress markers might be a secondary effect of anti-inflammatory or antibacterial agents. As the field of research of oxidative stress in periodontitis gains attraction and the number of relevant published papers is increasing a systematic overview of the conducted observational and interventional studies is needed. This review summarizes the currently available literature linking oxidative stress and periodontitis and points toward the potential of adjuvant antioxidant treatment, especially in cases where standard treatment fails to improve the periodontal status.

Oxidative Stress and Antioxidant System in Periodontitis

Periodontitis is a common inflammatory disease, which is initiated by bacterial infection and subsequently progressed by aberrant host response. It can result in the destruction of teeth supporting tissues and have an influence on systemic health. When periodontitis occurs, reactive oxygen species, which are overproduced mostly by hyperactive neutrophils, could not be balanced by antioxidant defense system and cause tissues damage. This is characterized by increased metabolites of lipid peroxidation, DNA damage and protein damage. Local and systemic activities of antioxidants can also be influenced by periodontitis. Total antioxidant capacity, total oxidant status and oxidative stress index have been used to evaluate the oxidative stress associated with periodontitis. Studies have confirmed that inflammatory response in periodontitis is associated with an increased local and systemic oxidative stress and compromised antioxidant capacity. Our review focuses on increased oxidative stress in periodontal disease, specifically, on the relationship between the local and systemic biomarkers of oxidative stress and periodontitis and their association with the pathogenesis of periodontitis. Also, the relationship between periodontitis and systemic inflammation, and the effects of periodontal therapy on oxidative stress parameters will be discussed.

Treatment of experimental periodontal disease by laser therapy in simvastatin-modified rats

Low intensity laser can be used as a promising alternative in the treatment of periodontal disease.

Antioxidant enzymes in periodontitis

Periodontitis is basically an inflammatory disease initiated by the subgingival biofilm and modified by the individual's aberrant inflammatory/immune response. Various studies have pointed toward the role of oxidative stress in periodontitis. As the reactive oxygen species and antioxidants are in dynamic equilibrium, any disturbance in one would lead to changes in the other. As studying, individual antioxidants is a vast field, this review focuses on the role of antioxidant enzymes in periodontitis and in other related systemic conditions. It is highlighted that oxidative stress may be the missing link in these associations of periodontitis and other conditions. Also, the antioxidant enzymes may be considered a useful biomarker for periodontal diseases and antioxidant supplementation may be of help to reduce the burden of periodontal destruction without having much extra effort.

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.

Decrease of Pericytes is Associated With Liver Disease Caused by Ligature-Induced Periodontitis in Rats

BACKGROUND

Damage caused by periodontitis not only affects periodontal tissues, but also increases the severity of various illnesses such as rheumatoid arthritis, diabetes, and liver diseases. The aim of this study is to investigate the association between induced periodontitis and damage caused through its systemic effects on the liver.

METHODS

Twenty rats were divided into two groups: control and periodontitis. The following parameters were evaluated: gingival bleeding index (GBI), probing depth (PD), myeloperoxidase (MPO) activity, alveolar bone loss (ABL) for periodontal tissues; histopathologic examination of gingival and liver tissues; immunohistochemistry to cells positive for neural/glial antigen 2 (NG2) expressed in hepatic pericytes, glutathione (GSH), and malondialdehyde (MDA) concentrations in liver; and serum levels of alanine aminotransferase and aspartate aminotransferase.

RESULTS

GBI, PD, MPO, ABL, and histopathologic examinations demonstrated the development of periodontitis. There was a significant increase in microvesicular steatosis accompanied by a marked reduction in NG2+ pericytes in the periodontitis group compared with the control group. The periodontitis group had significantly lower GSH and higher MDA concentration in the liver compared with the control group.

CONCLUSIONS

The present study results link the systemic effects of induced periodontitis with changes in hepatic tissues such as microvesicular steatosis, likely caused by an increase in oxidative stress and lipid peroxidation. The findings from the present study implicate an association between a decrease of pericytes and liver disease caused by ligature-induced periodontitis in rats.

Malondialdehyde, superoxide dismutase and melatonin levels in gingival crevicular fluid of aggressive and chronic periodontitis patients

BACKGROUND

The aim of this study was to investigate malondialdehyde (MDA), superoxide dismutase (SOD) and melatonin levels in the gingival crevicular fluid (GCF) of patients with chronic periodontitis (CP) and generalized aggressive periodontitis (GAgP) as biomarkers for oxidative stress.

METHODS

The study comprised 65 subjects: 15 healthy individuals, 25 CP patients and 25 GAgP patients. Plaque index, gingival index, pocket depth, clinical attachment level measurements and GCF samples were obtained from all subjects. MDA, SOD and melatonin levels were determined utilizing enzyme-linked immunosorbent assay.

RESULTS

GCF-MDA levels were significantly higher in the GAgP group compared to the CP and control groups (p < 0.001) and significantly higher in the CP group than the C group (p < 0.001). SOD and melatonin GCF levels were significantly higher in the control than the GAgP and CP groups (p < 0.05), and significantly lower in the GAgP than the CP group (p < 0.05). The CP group demonstrated a significant negative correlation between GCF-MDA and melatonin concentrations. A positive correlation was observed between SOD and CAL in the CP group and PD in the GAgP group.

CONCLUSIONS

MDA, melatonin and SOD could be considered as biomarkers for oxidative stress in periodontal diseases and might be useful diagnostic aids in distinguishing CP and GAgP patients.

Hydrogen Sulfide, Oxidative Stress and Periodontal Diseases: A Concise Review

In the past years, biomedical research has recognized hydrogen sulfide (H₂S) not only as an environmental pollutant but also, along with nitric oxide and carbon monoxide, as an important biological gastransmitter with paramount roles in health and disease. Current research focuses on several aspects of H₂S biology such as the biochemical pathways that generate the compound and its functions in human pathology or drug synthesis that block or stimulate its biosynthesis. The present work addresses the knowledge we have to date on H₂S production and its biological roles in the general human environment with a special focus on the oral cavity and its involvement in the initiation and development of periodontal diseases.

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.

Association between catalase gene polymorphisms and risk of chronic hepatitis B, hepatitis B virus-related liver cirrhosis and hepatocellular carcinoma in Guangxi population: a case-control study

Reactive oxygen species (ROS) play critical roles in hepatocarcinogenesis. The catalase (CAT) enzyme is involved in the repair of ROS. Therefore, we investigate the association between CAT gene polymorphisms and the risk of hepatocellular carcinoma (HCC). A total of 715 subjects were divided into 4 groups: 111 chronic hepatitis B (CHB) patients, 90 hepatitis B virus (HBV)-related liver cirrhosis (LC) patients, 266 HBV-HCC patients, and 248 healthy controls. The polymerase chain reaction-restriction fragment length polymorphism strategy was used to detect CAT gene rs1001179, rs769217, and rs7943316 polymorphisms. Binary logistic regression analyses adjusting for sex, age, ethnicity, smoking and alcohol consumption, and body mass index suggested that subjects carrying the rs769217 T allele were at marginally increased risk of CHB, LC, and HCC, with adjusted odds ratios (ORs) of 1.51 (95% confidence interval [CI] = 1.04-2.20, P = 0.029), 1.48 (95% CI = 1.03-2.14, P = 0.035), and 1.51 (95% CI = 1.14-1.98, P = 0.004), respectively. Similarly, those individuals carrying the rs769217 TT genotype had a moderately increased risk of CHB, LC, and HCC, with adjusted ORs of 2.11 (95% CI = 1.05-4.22, P = 0.035), 2.00 (95% CI, 1.01-3.95, P = 0.047), and 1.93 (95% CI = 1.14-3.28, P = 0.015), respectively. Moreover, subjects carrying the rs769217 CT genotype and at least 1 copy of the T allele (dominant model) were 1.78 times and 1.83 times more likely to develop HCC, respectively (OR = 1.78, 95% CI = 1.16-2.73, P = 0.009 and OR = 1.83, 95% CI = 1.23-2.71, P = 0.003). This association between CAT rs769217 T alleles and HCC risk is significantly strengthened among men, nonsmokers, nondrinkers, and among individuals <50 years of age. Furthermore, we found 1 high-risk haplotype GTA for CHB (OR = 1.45, 95% CI = 1.05-2.01) and 1 protective haplotype GCA for HCC risk (OR = 0.67, 95% CI = 0.52-0.87). We did not found any significant difference in CAT rs1001179 and rs7943316 polymorphisms between controls and cases. Our findings suggest that the CAT rs769217 T allele is associated with increased risk of CHB, HBV-LC, and HBV-HCC in Guangxi population.

The influence of cigarette smoking on blood and salivary super oxide dismutase enzyme levels among smokers and nonsmokers-A cross sectional study

To determine the influence of smoking on blood and salivary superoxide dismutase enzyme levels among smokers, and to demonstrate the significant alterations in the levels of superoxide dismutase in association with patient age, periodontal disease status, smoking duration, and smoking frequency. This study also aimed to evaluate the use of saliva as a biological fluid for disease diagnosis.

Ninety males aged 25–56 years were selected and included 30 smokers, 30 nonsmokers with chronic periodontitis, and 30 healthy controls. Clinical parameters such as the gingival index, pocket depth, and clinical attachment loss were recorded. Blood and saliva samples were collected and superoxide dismutase enzyme levels were analyzed using spectrophotometric assay.

Superoxide dismutase enzyme levels in the blood and saliva were significantly higher in smokers than in nonsmokers and the controls (p < 0.05). A significant correlation existed between superoxide dismutase levels and clinical parameters. There was also a significant positive correlation between blood and salivary superoxide dismutase levels among the three groups.

Systemic and local antioxidant status is affected by periodontal disease and by the impact of smoking. The increased blood and salivary superoxide dismutase enzyme levels in smokers may be an adaptive defense mechanism to counteract the increased reactive oxygen species production induced by smoking. This study emphasizes the importance of saliva as an easy noninvasive tool in diagnosing patients who are more prone to precancerous lesions and conditions, and its importance in patient education and motivation programs for smoking cessation.

Determining the Effect of Gutkha on Serum Levels of Vitamin B12 and Folic Acid as Compared to Smoking among Chronic Periodontitis Subjects : A Cross-Sectional Study

BACKGROUND

Periodontitis, being a common inflammatory disease has a multifactorial origin , with smoking and gutkha as few of the causative entities. The role of smoking as a risk factor for periodontitis is been well documented in literature. Cigarette smoke also affects vitamin B12 and folic acid mechanisms. Nutritionally derived vitamin B12 occurs mainly as either hydroxycobalamin or deoxyadenosycobalmin. Folic acid is also heat sensitive and water soluble, closely linked to vitamin B12 in its metabolism. However, effect of smokeless tobacco in form of gutkha on serum levels of vitamin B12 and folic acid is yet to be explored.

AIMS AND OBJECTIVES

To estimate and correlate serum vitamin B12 (VB12) and folic acid (FA) levels among periodontally healthy subjects and Chronic Periodontitis (CP) subjects with habit of smoking and gutkha chewing.

MATERIALS AND METHODS

The study included 111 subjects ranging in age from 18 to 60 y. Participants were divided into four groups: 30 healthy subjects (Group I), 29 subjects with CP (Group II), 25 smokers with CP (Group III) and 27 gutkha chewers with CP (Group IV). Clinical parameters included pocket probing depth (PPD), clinical attachment level (CAL) & gingival index (GI) following which VB12 and FA levels were estimated through UV-spectrophotometry method and data was analysed using Statistical Package for Social Scientists software, Mann-Whitney U-test and Pearson correlation coefficient. p-values less than 0.05 were considered as significant. Results : Pairwise comparison by Mann-Whitney U-test showed an increase in the serum VB12 in Group IV when compared to Group I (p=0.01) and Group II (p=0.01). Although serum FA levels were found to be low in Group III (7.61 ug/ml) & Group IV (8.64 ug/ml), Group III was found to be statistically significant (P=0.046). The clinical parameters GI, PPD and CAL among the four groups of patients were also statistically significant (p < 0.05).

CONCLUSION

The study results suggested that among the patients with periodontal disease, serum VB12 levels are directly related while serum FA levels are inversely related to inflammation and tissue destruction in periodontium as occurred in Group IV.

Effect of initial periodontal therapy on oxidative stress markers in gingival crevicular fluid, saliva, and serum in smokers and non-smokers with chronic periodontitis

BACKGROUND

The aim of this case-control study with an intervention arm is to determine the effect of initial periodontal treatment on oxidative stress biomarkers in smokers and non-smokers with chronic periodontitis (CP).

METHODS

The study included 47 patients with CP (24 smokers [S+P+] and 23 non-smokers [S-P+]) and 46 periodontally healthy individuals (23 smokers [S+P-] and 23 non-smokers [S-P-]) for a total of 93 participants. Gingival crevicular fluid (GCF), serum, and saliva samples were obtained and clinical periodontal measurements were recorded at baseline and at the first and third months after periodontal therapy. 8-hydroxydeoxyguanosine (OHdG) and 4-hydroxynonenal (HNE) and enzyme activity of glutathione peroxidase (GSH-Px) were analyzed with enzyme-linked immunosorbent assay.

RESULTS

The level of 8-OHdD in GCF was found to be significantly higher in both periodontitis groups compared with both periodontally healthy groups. 8-OHdG and GSH-Px in saliva in both periodontitis groups were significantly increased compared with the S-P- group. In the S+P+ group, 4-HNE in GCF was found to be significantly higher than in periodontally healthy participants. After initial periodontal treatment, the levels of 8-OHdG in GCF and saliva were significantly decreased in both periodontitis groups.

CONCLUSION

Initial periodontal therapy may be helpful for diminishing oxidative stress in periodontitis.

LPS from P. gingivalis and hypoxia increases oxidative stress in periodontal ligament fibroblasts and contributes to periodontitis

Oxidative stress is characterized by an accumulation of reactive oxygen species (ROS) and plays a key role in the progression of inflammatory diseases. We hypothesize that hypoxic and inflammatory events induce oxidative stress in the periodontal ligament (PDL) by activating NOX4. Human primary PDL fibroblasts were stimulated with lipopolysaccharide from Porphyromonas gingivalis (LPS-PG), a periodontal pathogen bacterium under normoxic and hypoxic conditions. By quantitative PCR, immunoblot, immunostaining, and a specific ROS assay we determined the amount of NOX4, ROS, and several redox systems. Healthy and inflamed periodontal tissues were collected to evaluate NOX4 and redox systems by immunohistochemistry. We found significantly increased NOX4 levels after hypoxic or inflammatory stimulation in PDL cells (P < 0.001) which was even more pronounced after combination of the stimuli. This was accompanied by a significant upregulation of ROS and catalase (P < 0.001). However, prolonged incubation with both stimuli induced a reduction of catalase indicating a collapse of the protective machinery favoring ROS increase and the progression of inflammatory oral diseases. Analysis of inflamed tissues confirmed our hypothesis. In conclusion, we demonstrated that the interplay of NOX4 and redox systems is crucial for ROS formation which plays a pivotal role during oral diseases.

Lipid peroxidation levels and total oxidant/antioxidant status in serum and saliva from patients with chronic and aggressive periodontitis. Oxidative stress index: a new biomarker for periodontal disease?

BACKGROUND

In this study, levels of malondialdehyde (MDA), which is a significant product of lipid peroxidation (LPO), total oxidant status (TOS), total antioxidant capacity (TAOC), and the oxidative stress index (OSI), a novel value as a marker of periodontal disease activity, are investigated in serum and saliva from patients with chronic (CP) and generalized aggressive (GAgP) periodontitis.

METHODS

A total of 98 patients (33 with CP, 35 patients with GAgP, and 30 periodontally healthy controls) enrolled in the study. After clinical measurements and sample collection, the MDA level, TOS, and TAOC were measured by high-performance liquid chromatography and a novel automatic colorimetric method. The OSI was calculated as [(TOS/TAOC) × 100].

RESULTS

Although the salivary MDA levels and serum and salivary TOS and OSI values were significantly higher in the periodontitis groups than in the control group (P <0.05), the serum and salivary TAOC levels were significantly lower, and no significant difference in serum MDA levels was found (P >0.05). Furthermore, oxidative stress parameters were higher in the GAgP group than in the CP group (except the serum and salivary MDA levels and serum TAOC). Significant positive and negative correlations were observed between periodontal parameters and the MDA levels and TOS, TAOC, and OSI values (except serum MDA) (P <0.05).

CONCLUSIONS

The present findings suggest that an increased TOS and decreased TAOC, rather than LPO, play important roles in the pathology of periodontitis and are closely associated with clinical periodontal status. Furthermore, the OSI may be a useful and practical parameter for evaluating periodontal disease activity.

Effects of non-surgical periodontal treatment on the L-arginine-nitric oxide pathway and oxidative status in platelets

Several studies have suggested an increase of cardiovascular disease (CVD) risk on periodontitis patients. An enhancement has been demonstrated on both platelet activation and oxidative stress on periodontitis patients, which may contribute for this association. Therefore, the aim of this study was to evaluate the effects of non-surgical periodontal treatment on the l-arginine-nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) pathway and oxidative status in platelets. A total of eight periodontitis patients and eight controls were included in this study. Clinical, laboratory and experimental evaluations were performed on baseline and 90 days after periodontal treatment (except for western blot analysis). The clinical periodontal evaluation included measurements of probing pocket depth (PPD), clinical attachment loss (CAL), % of sites with plaque and % of sites with bleeding on probing. We evaluated: l-[(3)H]arginine influx; nitric oxide synthase (NOS) and arginase enzymes activity and expression; expression of guanylate cyclase and phosphodiesterase-5 enzymes; cGMP levels; platelet aggregation; oxidative status through superoxide dismutase (SOD) and catalase activities, and measurement of reactive oxygen species (ROS) levels and C-reactive protein (CRP) levels. The initial results showed an activation of both l-arginine influx and via system y (+ )L associated with reduced intraplatelet cGMP levels in periodontitis patients and increased systemic levels of CRP. After periodontal treatment, there was a significant reduction of the % of sites with PPD 4-5mm, % of sites with CAL 4-5 mm, and an enhancement in cGMP levels and SOD activity. Moreover, CRP levels were reduced after treatment. Therefore, alterations in the intraplatelet l-arginine-NO-cGMP pathway and oxidant-antioxidant balance associated with a systemic inflammatory response may lead to platelet dysfunction, which may contribute to a higher risk of CVD in periodontitis.

Evaluation of antioxidant enzymes activity and malondialdehyde levels in patients with chronic periodontitis and diabetes mellitus

BACKGROUND

The aim of this study is to investigate the impact of diabetes, a known risk factor for periodontitis, on activities of antioxidant enzymes superoxide dismutase (SOD), glutathione reductase (GR), and catalase (CAT) as well as levels of free radical damage marker malondialdehyde (MDA) in blood and saliva of individuals with chronic periodontitis (CP).

METHODS

Sixty patients with CP (30 patients with type 2 diabetes mellitus [DMCP] and 30 systemically healthy patients [CP]) and 60 periodontally healthy individuals (30 patients with type 2 diabetes mellitus and 30 systemically healthy patients [PH]) were included in this study. After clinical measurements, blood and saliva samples were collected. SOD, GR, and CAT activities in red blood cell lysate and saliva and MDA levels in plasma and saliva samples were spectrophotometrically assayed. An analysis of variance test followed by a post hoc test was used to compare the intragroup and intergroup variances among the study groups.

RESULTS

MDA levels in both the periodontitis groups were higher than in the periodontally healthy groups, but the difference between the CP and DMCP groups did not reach statistical significance (P >0.05). There was a highly significant difference between the CP and PH groups for all the enzymes studied except for SOD in blood. Only salivary SOD and GR activities were significantly different in the CP and DMCP groups.

CONCLUSIONS

This study favors the role of oxidative stress in both diabetes and periodontitis. It shows that the compensatory mechanism of the body is partially collapsed because of excessive production of free radicals during periodontitis and is not able to cope with increased free radical generation attributable to diabetes, thereby worsening the situation.