Reactive oxygen species in periodontitis

The Promising Role of Antioxidant Phytochemicals in the Prevention and Treatment of Periodontal Disease via the Inhibition of Oxidative Stress Pathways: Updated Insights

There is growing evidence on the involvement of oxidative stress, which is simply described as the imbalance between oxidants and antioxidants in favor of the former, in the development of periodontal disease that is the most common inflammatory disease in the oral cavity. Thus, the potential of antioxidant phytochemicals as adjunctively preventive and therapeutic agents against the initiation and progression of periodontal disease is a topic of great interest. The current review firstly aims to provide updated insights about the immuno-inflammatory pathway regulated by oxidative stress in periodontal pathology. Then, this work further presents the systemic knowledge of antioxidant phytochemicals, particularly the pharmacological activities, which can be utilized in the prevention and treatment of periodontal disease. Additionally, the challenges and future prospects regarding such a scope are figured out.

Evaluation of biochemical and clinical effects of hyaluronic acid on non-surgical periodontal treatment: a randomized controlled trial

BACKGROUND

Recent studies reported that hyaluronic acid (HA) has anti-inflammatory, anti-edematous, and anti-bacterial activities in dentistry, particularly in gingival disorders caused by subgingival plaque microorganisms.

AIMS

This study aimed to evaluate the early term effects of HA as an adjunct to scaling and root planing (SRP) on clinical parameters, periodontal inflamed surface area (PISA), and adenosine deaminase (ADA), catalase (CAT), and glutathione (GSH) levels in gingival crevicular fluid (GCF) in periodontitis.

METHODS

A total of 24 periodontitis patients per group were included in this randomized-controlled study. The study population was divided into four groups: in Group 1: SRP+ saline; in Group 2: SRP + HA gel; in Group 3: SRP+ HA mouth rinse; and in Group 4: SRP + HA mouth rinse + HA gingival gel were applied. At baseline and week 4, clinical parameters and PISA were calculated. Also, biochemicals' (ADA, CAT, and GSH) levels were determined by spectrophotometric analysis.

RESULTS

There was a statistically significant improvement in clinical parameters and PISA in all four groups in control sessions (p < 0.05). There was a significant decrease in ADA in GCF and significant increases in CAT and GSH levels after SRP (p < 0.05) in all four groups. The groups that were administered only gel (2nd and 4th) were different from other groups in terms of ADA, CAT, and GSH levels at 1st week (p < 0.05).

CONCLUSION

HA application as an adjunct to SRP did not affect the clinical results, although, in the control sessions following the application, the results were favorable for the biochemical data in gel-applied groups.

TRIAL REGISTRATION

ClinicalTrials.gov.tr (NCT03754010).

Oral manifestations of inflammatory bowel disease: the neglected piece of the puzzle

Inflammatory bowel disease (IBD) is a chronic relapsing remitting autoimmune disease including Crohn's disease and ulcerative colitis. IBD is associated with various extra-intestinal manifestations including oral manifestation. To date, only limited studies addressing the characteristics of the oral manifestations are available. The aim of the present review is to report the oral manifestations and their characteristics in IBD. A Medline/PubMed and Embase databases search were conducted and all relevant studies were extracted and analyzed. Overall, the oral manifestations in IBD were mostly associated with Crohn's disease rather than Ulcerative colitis where their prevalence ranged from 8 to 50%. Specific lesions for Crohn's disease include mucosal tags, cobblestoning and deep linear ulcerations with vertical fissures, while for ulcerative colitis, pyostomatisis vegetans was more disease specific. Notably, most of the oral manifestations were unrelated to disease activity, however more data are needed to accurately assess this correlation. Oral manifestations among IBD patients are not uncommon as Crohn's disease account for most of them. More data are warranted to precisely characterize their prevalence and association to intestinal activity.

Phelligridin D maintains the function of periodontal ligament cells through autophagy in glucose-induced oxidative stress

Purpose

The objective of this study was to investigate whether phelligridin D could reduce glucose-induced oxidative stress, attenuate the resulting inflammatory response, and restore the function of human periodontal ligament cells (HPDLCs).

Methods

Primary HPDLCs were isolated from healthy human teeth and cultured. To investigate the effect of phelligridin D on glucose-induced oxidative stress, HPDLCs were treated with phelligridin D, various concentrations of glucose, and glucose oxidase. Glucose-induced oxidative stress, inflammatory molecules, osteoblast differentiation, and mineralization of the HPDLCs were measured by hydrogen peroxide (H₂O₂) generation, cellular viability, alkaline phosphatase (ALP) activity, alizarin red staining, and western blot analyses.

Results

Glucose-induced oxidative stress led to increased production of H₂O₂, with negative impacts on cellular viability, ALP activity, and calcium deposition in HPDLCs. Furthermore, HPDLCs under glucose-induced oxidative stress showed induction of inflammatory molecules (intercellular adhesion molecule-1, vascular cell adhesion protein-1, tumor necrosis factor-alpha, interleukin-1-beta) and disturbances of osteogenic differentiation (bone morphogenetic protein-2, and -7, runt-related transcription factor-2), cementogenesis (cementum protein-1), and autophagy-related molecules (autophagy related 5, light chain 3 I/II, beclin-1). Phelligridin D restored all these molecules and maintained the function of HPDLCs even under glucose-induced oxidative stress.

Conclusions

This study suggests that phelligridin D reduces the inflammation that results from glucose-induced oxidative stress and restores the function of HPDLCs (e.g., osteoblast differentiation) by upregulating autophagy.

Potential effects of noxious chemical-containing fine particulate matter on oral health through reactive oxygen species-mediated oxidative stress: Promising clues

Nowadays, air pollution which is dominated by fine particulate matter with aerodynamic diameter less than or equal to 2.5 µm resulting from rapid industrialization and urbanization combined with population explosion has become more and more severe problem to mankind and the whole planet because of its diversity of deleterious effects. The latest data estimated that exposure to fine particulate matter, or PM2.5, contributes to approximately 4 million deaths worldwide due to cardiopulmonary conditions such as heart disease and stroke, respiratory infections, chronic lung disease and lung cancer. During recent years, there has been growing concern about the adverse effects of this global threat on oral health which is one of key components of general health and quality of life. Although a few studies have reported such possible association, the findings are still far from conclusion. Moreover, the underlying mechanisms remain unclear. To our knowledge, the analysis of literature regarding this scope has yet been published. Thus, current work systematically assesses existing evidences on the potential association between exposure to PM2.5 and the development of various oral diseases as well as figures out the plausible paradigm of PM2.5-induced damages in the oral cavity through its toxic chemical constituents along with its ability to induce oxidative stress via reactive oxygen species production. This might partially provide the clues for new research ideas and progression in the field of oral health.

Evaluation of Efficacy of Coenzyme Q10 as an Adjunct to Nonsurgical Periodontal Therapy and Its Effect on Crevicular Superoxide Dismutase in Patients with Chronic Periodontitis

OBJECTIVES

 To assess the efficacy of coenzyme Q10 (CoQ10) as an adjunct to nonsurgical periodontal therapy and its effect on superoxide dismutase (SOD) in gingival crevicular fluid (GCF) in patients with chronic periodontitis (CP).

MATERIALS AND METHODS

 A total of 16 patients aged between 30 and 50 years having mild to moderate CP of both sexes having pocket depth of 5 to 7 mm in four nonadjacent interproximal sites were selected. The sites were randomized and divided into treatment and control groups. CoQ10 and a placebo gel were administered in the treatment and control sites, respectively, at baseline after scaling and root planing (SRP). GCF was collected using microcapillary method at baseline and 3 months and was assessed for SOD using enzyme-linked immunosorbent assay reader at 450 nm wavelength. Probing pocket depth, gingival index, and plaque index were assessed at baseline, 1 month, and 3 months, respectively.

STATISTICAL ANALYSIS

 For each assessment point, data were statistically analyzed using Student's t-test and paired t-test. Level of significance was set at p < 0.05.

RESULTS

 On intergroup comparison, there was no statistically significant difference between the clinical parameters of both the groups at all the time intervals (p > 0.05), but there was a significant increase in the level of SOD in the test group (p > 0.05) compared with the control group at 3 months.

CONCLUSIONS

 Adjunctive use of CoQ10 with SRP can boost the antioxidant concentration, but it is not superior to SRP in the treatment of CP.

Assessment of Salivary Flow Rate in Patients with Chronic Periodontitis

Background:

Chronic periodontitis (CP) is an infectious disease, primarily affecting the attachment apparatus of the dentition, and is categorized into mild, moderate, and severe periodontitis on the basis of its severity. It is a well-established and proven fact that an adequate level of saliva is essential for maintaining the integrity of oral tissues including the periodontium. Although various factors, such as stimulation, circadian rhythm, diet, age, and drugs, can affect the salivary flow rate, many recent studies have provided evidence that it can be altered by pathological inflammatory conditions such as periodontal diseases. Therefore, this study has been undertaken to assess the unstimulated and stimulated salivary flow rate in the different clinical stages of chronic periodontitis.

Materials and Methods:

This study comprised 60 study participants, who were divided into four groups depending on clinical attachment level (CAL). In all, both unstimulated and stimulated saliva were collected, and the flow rate was expressed in milliliter per minute.

Results:

Statistical analysis was accomplished with Statistical Package for the Social Sciences (SPSS) software. One-way analysis of variance (ANOVA) was used to analyze differences in salivary flow rate among the groups. Statistical significance was set at P < 0.05. The amount of unstimulated saliva in healthy subjects, in mild, moderate, and severe periodontitis was 0.766, 0.400, 0.270, and 0.146 mL/min, respectively. Likewise, the amount of stimulated saliva in healthy subjects, in mild, moderate, and severe periodontitis was 1.017, 0.494, 0.347, and 0.236 mL/min, respectively.

Conclusion:

The study identified a significant decrease in both unstimulated and stimulated salivary flow rate with the severity of progression of chronic periodontitis.

Ethanol binge drinking exposure affects alveolar bone quality and aggravates bone loss in experimentally-induced periodontitis

Background

Periodontitis is a multifactorial inflammatory disease of tooth supporting tissues caused by oral biofilms, influenced by environmental and genetic factors, among others. Ethanol consumption has been considered a factor that enhances alveolar bone loss, especially in high doses. The present study aims to investigate the changes promoted by ethanol binge drinking per se or associated with ligature-induced periodontal breakdown on alveolar bone loss.

Materials and methods

Thirty-two Wistar rats were randomly allocated into four groups: control (C), ethanol (3g/kg/day; 3 days On-4 days Off protocol by gavage for 28 days, EtOH), experimental periodontitis (EP) and experimental periodontitis plus ethanol administration (EP+EtOH). On day 14^th, periodontitis was induced by ligatures that were placed around the lower first molars. On day 28^th, the animals were euthanized and mandibles were submitted to stereomicroscopy for exposed root area analysis and micro-computed tomography (micro-CT) for the evaluation of alveolar bone loss and microstructural parameters.

Results

The results revealed that ligature-induced alveolar bone loss is aggravated by ethanol binge drinking compared to controls (1.06 ± 0.10 vs 0.77 ± 0.04; p<0.0001). In addition, binge drinking per se altered the alveolar bone quality and density demonstrating a reduction in trabecular thickness, trabecular number parameter and bone density percentual. Periodontal disorder plus ethanol binge drinking group also demonstrated reduction of the quality of bone measured by trabecular thickness.

Conclusions

In conclusion, intense and episodic ethanol intake decreased alveolar bone quality in all microstructural parameters analyzed which may be considered a modifying factor of periodontitis, intensifying the already installed disease.

The events that may contribute to subgingival dysbiosis: a focus on the interplay between iron, sulfide and oxygen

This minireview considers the disruption of the host–microbiota harmless symbiosis in the subgingival niche. The establishment of a chronic infection by subversion of a commensal microbiota results from a complex and multiparametric sequence of events. This review narrows down to the interplay between oxygen, iron and sulfide that can result in a vicious cycle that would favor peroxygenic and glutathione producing streptococci as well as sulfidogenic anaerobic pathogens in the subgingival niche. We propose hypothesis and discuss strategies for the therapeutic modulation of the microbiota to prevent periodontitis and promote oral health.

Effect of smokeless tobacco use on salivary glutathione levels among chronic periodontitis patients before and after non-surgical periodontal therapy

INTRODUCTION

Smokeless tobacco (SLT) jeopardizes periodontal health and also produces an imbalance between reactive oxygen species (ROS) and antioxidants (AO) such as glutathione. Glutathione is an important redox regulator in saliva and its maintenance is essential for periodontal health. Periodontitis patients have a reduced total AO capacity in whole saliva, and periodontal therapy restores the redox balance. Hence, the purpose of this study was to investigate the effects of smokeless tobacco use on saliva glutathione levels in patients with chronic periodontitis and to evaluate these effects after non-surgical periodontal therapy.

METHODS

The study included 100 subjects in four groups; healthy, gingivitis, and chronic periodontitis (CP) patients with and without SLT use. Saliva samples were collected, and clinical periodontal parameters were recorded at baseline and at one month after non-surgical periodontal therapy. Glutathione levels were analyzed using spectrophotometry at 412 nm. Statistical analysis was carried out using paired t-test, chi-squared, and analysis of variance (ANOVA).

RESULTS

Mean glutathione values in saliva were found to be lower in periodontitis patients compared to SLT users at baseline and at 1 month post non-surgical periodontal therapy (p<0.001) In addition, non-surgical therapy leads to a highly significant improvement in the glutathione levels in gingivitis, in the CP with and without ST groups (p<0.001).

CONCLUSIONS

Successful non-surgical periodontal therapy leads to considerable progress in the redox balance, thus regulating glutathione levels and reducing the effects of SLT on the periodontium. This emphasises the importance of non-surgical therapy, especially among SLT users.

Research Advances in the Use of Bioactive Compounds from Vitis vinifera By-Products in Oral Care

Oral health is considered an important factor of general health and it contributes to the quality of life. Despite the raising awareness of preventive measures, the prevalence of oral health conditions continues to increase. In this context, a growing interest in investigating natural resources like Vitis vinifera (V. vinifera) phenolic compounds (PhCs) as oral health promoters has emerged. This paper aims to review the evidence about the bioactivities of V. vinifera by-products in oral health. Up to date, a high number of studies have thoroughly reported the antimicrobial and antiplaque activity of V. vinifera extracts against S. mutans or in multi-species biofilms. Moreover, the bioactive compounds from V. vinifera by-products have been shown to modulate the periodontal inflammatory response and the underlying oxidative stress imbalance induced by the pathogenic bacteria. Considering these beneficial effects, the utility of V. vinifera by-products in the maintaining of oral health and the necessary steps towards the development of oral care products were emphasized. In conclusion, the high potential of V. vinifera by-products could be valorized in the development of oral hygiene products with multi-target actions in the prevention and progression of several oral conditions.

Uncoupling protein-2 regulates M1 macrophage infiltration of gingiva with periodontitis

Periodontitis is an inflammatory disease accompanied by alveolar bone loss. Moreover, M1 macrophages play a critical role in the development of periodontal disease. Uncoupling protein-2 (UCP2) is a mitochondrial transporter protein that controls M1 macrophage activation by modulating reactive oxygen species (ROS) production. We investigated the role of UCP2 in M1 macrophage infiltration in gingival tissues with periodontitis. We found that the expression of UCP2 was upregulated in M1 macrophages infiltrating human periodontal tissues with periodontitis. Macrophage-specific knockout of UCP2 could increase the infiltration of macrophage and exacerbate inflammatory response in a mouse gingiva affected with periodontitis, induced by Porphyromonas gingivalis-LPS (Pg-LPS) injection. The loss of UCP2 may contribute to the enhanced abilities of proliferation, migration, pro-inflammatory cytokine secretion, and ROS production in Pg-LPS-treated macrophages. Our results indicate that UCP2 has an important role in M1 macrophage polarization in the periodontal tissue with periodontitis. It might be helpful to provide theoretical basis for design of new therapeutic strategies for periodontitis.

A review of the association between oral bacterial flora and obstructive sleep apnea-hypopnea syndrome comorbid with cardiovascular disease

PURPOSE

Obstructive sleep apnea-hypopnea syndrome (OSAHS), a common sleep disorder, has been shown to be an independent risk factor for cardiovascular disease (CVD). Recent studies have focused on the important roles of microorganisms in human health; for example, microorganisms are reportedly associated with obesity, metabolic disorders, and CVD. The number of oral bacteria in patients with OSAHS is considerably higher than that in healthy individuals, and infection with oral bacterial pathogens is associated with the development of CVD. However, whether changes in the oral microbiota mediate the development of OSAHS and CVD remains unknown.

METHODS

Therefore, we attempted to review the association between changes in oral microbiota in patients with OSAHS and the development of CVD.

RESULTS

Oral microbiota possibly acts via multiple pathways including direct invasion, platelet aggregation, immune response, inflammatory response, and oxidative stress response, leading to the development of CVD in patients with OSAHS. In particular, the strains Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia have demonstrated profound effects. OSAHS leads to changes in the oral bacterial flora and thus may facilitate the occurrence and development of CVD.

CONCLUSION

We propose that the underlying mechanism of CVDs resulting from oral microbiota in patients with OSAHS should be elucidated in further studies.

A study of chewing muscles: Age-related changes in type I collagen and matrix metalloproteinase-2 expression

OBJECTIVE

In this study, the aim was to investigate the biochemical, physiological and histological changes that occur in masticatory muscles of the masticatory system with aging.

DESIGN

In this study, 14 BALB/c mice were used. Animals were divided into two equal groups of seven. Group I was organized as the group of young animals (n = 7) and Group II as the group of adult animals (n = 7). After routine histological follow-up was performed, the tissues were embedded in paraffin. 4-5 μm thick cross-sections were taken from paraffin-embedded tissues and they were stained with Haemotoxylin and Eosin Type I collagen and Matrix metalloproteinase-2 (MMP-2) immunohistochemically.

RESULTS

It was observed that there was a decrease and shrinking in blood vessels due to aging. In young mice, Type I collagen and MMP-2 immunoreactivity in the masseter muscle tissue showed low staining, while Type I collagen and MMP-2 immunoreactivity in the temporal muscle tissue showed moderate staining. Type I collagen and MMP-2 immunoreactivity were significantly higher in the masseter and temporal muscles of elderly mice (p = 0.001). In the H-score evaluation, MMP-2 immune reactivity was significantly lower in young mice than in older mice (p = 0.001).

CONCLUSION

It was determined that severe pain complications and functional losses are likely to occur with the increase of degeneration due to aging of masticator muscles.

Analysis of oral microbiota in patients with obstructive sleep apnea-associated hypertension

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is an independent risk factor for hypertension (HTN). The oral microbiota plays a pathophysiological role in cardiovascular diseases; however, there are few reports directly investigating and identifying the organisms involved in OSAHS-related HTN. Therefore, this study aimed to identify those organisms. We obtained 139 oral samples and determined the microbiome composition using pyrosequencing and bioinformatic analyses of the 16S rRNA. We examined the fasting levels of cytokines and homocysteine in all participants and analyzed the correlations between the oral microbiota and homocysteine levels. We determined the molecular mechanism underlying HTN by investigating the genetic composition of the strains in the blood. We detected higher relative abundances of Porphyromonas and Aggregatibacter and elevated proinflammatory cytokines in patients with OSAHS of varying severity compared with individuals without OSAHS; however, the two organisms were not measured in the blood samples from all participants. High levels of specific Porphyromonas bacteria were detected in patients with OSAHS with and without HTN, whereas the relative abundance of Aggregatibacter was negatively correlated with the homocysteine level. The receiver operating characteristic curve analysis of controls and patients with OSAHS resulted in area under the curve values of 0.759 and 0.641 for patients with OSAHS with or without HTN, respectively. We found that the predictive function of oral microbiota was different in patients with OSAHS with and without HTN. However, there was no direct invasion by the two organisms causing endothelial cell injury, leading to speculation regarding the other mechanisms that may lead to HTN. Elucidating the differences in the oral microbiome will help us understand the pathogenesis of OSAHS-related HTN.

Metformin prevents against oxidative stress-induced senescence in human periodontal ligament cells

Periodontitis is a chronic infectious disease involving periodontal tissues. Periodontal ligament cells (PDLCs) play an important role in the regeneration of periodontal tissue. However, senescent PDLCs have an impeded regenerative potential. Metformin has been reported to prevent senescence at both the cellular and individual levels. The objectives of the present study were to evaluate the effects of metformin on cellular senescence in human PDLCs (hPDLCs) under oxidative stress. hPDLCs were pretreated with metformin, followed by H₂O₂ exposure. The cell viability, oxidative damage, cellular senescence and osteogenic potential were detected. To inhibit autophagy, hPDLCs were treated with 3-methyladenine before metformin treatment. The present study revealed that H₂O₂ exposure inhibits proliferation, increased lysosomal β-galactosidase activity, augments reactive oxidative species (ROS) accumulation, elevates the oxidative damage, stimulates the expression of senescence-related genes and impedes the activity of the osteogenic differentiation of hPDLCs. Metformin pretreatment could partly reverse the detrimental influences of H₂O₂ on hPDLCs. Moreover, metformin could stimulate autophagy, whereas the inhibition of autophagy with 3-methyladenine reversed the anti-senescence effects of metformin on hPDLCs under oxidative stress. The present study manifested that metformin could alleviate oxidative stress-induced senescence via stimulating autophagy and could partially recover the osteogenic potential of hPDLCs, possibly providing a reference for the discovery of periodontal treatment from the perspective of antisenescence.

Clinical, microbiological and oxidative stress evaluation of periodontitis patients treated with two regimens of systemic antibiotics, adjunctive to non-surgical therapy: A placebo-controlled randomized clinical trial

Aim of research was to evaluate and compare the clinical and microbiological effects of two different regimens of amoxicillin (AMX) and metronidazole (MTZ) combined with non-surgical periodontal therapy in patients with chronic periodontitis (CP), and identify antibiotic-resistant bacteria and changes in oxidative stress (OS). Forty-six patients with generalized CP were randomly assigned to group A [scaling and root planing within 24 h (SRP) + placebo for 7 days), group B [SRP + AMX + MTZ, both 500 mg three times daily (TID), 3 days), and group C [SRP + AMX + MTZ, both 500 mg TID, 7 days). Periodontal pocket depth (PPD-primary outcome), clinical attachment level (CAL), full-mouth bleeding scores (FMBS), plaque scores (FMPS), blood and subgingival plaque were assessed at baseline and after three months. OS was evaluated via derivatives of reactive oxygen metabolites (d-ROMs) and assessments of biological antioxidant potential (BAP). Bacterial profiling was performed by PCR. Antibiotic resistance was evaluated in cultures. PPD, CAL, number of sites with PPD ≥6 mm, their PPD, CAL and FMBS decreased (P<0.05) in all groups, as well as FMPS in groups A and B, and d-ROMs in group C. There were significant differences among groups regarding decreases in the frequency of detection for Aa and Tf. For Aa, there were differences between groups A and C (P=0.048) and between groups B and C (P=0.048), but not between groups A and B; whereas for Tf, groups A and B were different from group C (P<0.001), but not from each other (P=0.920). No resistance to AMX was identified prior to treatment; two strains were resistant after treatment. Before treatment, 13 strains were resistant to MTZ, and 2 were resistant after. One strain in the same patient was sensitive prior to treatment, and later became resistant to both antibiotics. SRP with a 7-day course of antibiotic therapy was more effective for improving clinical parameters, in decrease of detection of several periopathogens, and in improvement of OS when compared to a 3-day regimen. Resistance was found in fewer strains after treatment than before.

Subgingivally delivered coenzyme Q10 in the treatment of chronic periodontitis among smokers: A randomized, controlled clinical study

Background

Coenzyme Q10 is an antioxidant whose efficacy in periodontal diseases is well known. However studies regarding its efficacy in smokers with periodontitis are few. Coenzyme Q10 serves as an endogenous antioxidant and its increased concentration in the diseased gingiva effectively suppresses advanced periodontal inflammation.

Objectives

The aim of this study is to evaluate the efficacy of coenzyme Q10 as an adjunct to scaling and root planing in smokers with chronic periodontitis.

Methods

Total of 40 patients were enrolled for the study. The subjects were divided into control (Scaling and root planing only) and test group (Coenzyme Q10 plus Scaling and root planing). Clinical parameters such as plaque index, modified sulcular bleeding index, probing pocket depth and clinical attachment level. These were assessed at baseline, at 1 month and 3 month. The results were subjected to appropriate statistical analysis.

Results

There was a significant improvement in all clinical parameters in the test sites seen at the end of the 1 month and 3 month period.

Conclusions

Coenzyme Q10 can be said to have a beneficial effect on smokers with periodontitis when used as an adjunct to scaling and root planing.

8-Isoprostane in chronic periodontitis and type II diabetes: Exploring the link

Background. Reactive oxygen species (ROS) are associated with the pathogenesis of inflammatory diseases and have a direct or indirect role in tissue damage constituting oxidative stress. ROS are also involved in impairment of β-cell function during development of diabetes, which leads to genetic ablation of KATP channels, triggering up-regulation of antioxidant enzymes. Several markers of lipid peroxidation, protein oxidation and DNA damage induced by ROS can be measured. Over the last decade, isoprostanes have been considered as the best markers of lipid peroxidation. The aim of this study was to determine the presence of 8-isoprostane in healthy, chronic periodontitis and chronic periodontitis subjects with type II diabetes and to find the correlation between 8-isoprostane levels among groups and with clinical parameters like gingival index, probing depth and clinical attachment levels.

Methods. Ninety subjects were selected and divided into 3 groups: healthy, chronic periodontitis and chronic periodontitis subjects with type II diabetes (n=30 each). Saliva was collected from these subjects after obtaining consent and analyzed for 8-isoprostane levels using ELISA kit. Statistical analysis was performed using Kruskal-Wallis test, Mann-Whitney U test and Spearman’s correlation coefficient (P<0.001).

Results. Statistically significant difference was found in the levels of 8-isoprostane between healthy, chronic periodontitis and chronic periodontitis subjects with type II diabetes and with all clinical parameters.

Conclusion. 8-isoprostane can be considered as a pathophysiological marker to measure oxidative stress in periodontal diseases.

The effects of ginger supplementation on inflammatory, antioxidant, and periodontal parameters in type 2 diabetes mellitus patients with chronic periodontitis under non-surgical periodontal therapy. A double-blind, placebo-controlled trial

BACKGROUND

The aim of this study was to evaluate the effects of ginger supplementation on inflammatory, antioxidant, and periodontal parameters in type 2 diabetes mellitus (T2DM) patients with chronic periodontitis (CP) under non-surgical periodontal therapy (NSPT).

MATERIAL AND METHODS

In this double-blind clinical trial study, 46 T2DM patients with CP were randomly allocated to intervention and control groups and received either 4 tablets 500 mg (2 g) ginger or placebo twice a day for 8 weeks. All patients were treated with NSPT during the intervention period. Serum levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), hs-C-reactive protein (hs-CRP), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), periodontal indices including clinical attachment loss (CAL), bleeding on probing (BOP), pocket depth (PD), and plaque index were evaluated in all subjects pre- and post-intervention.

RESULTS

Following 8 weeks of ginger treatment with NSPT, significant reductions were observed in the mean levels of IL-6 (p=0.001), hs-CRP (p=0.03), TNF-α (p=0.007), CAL, and PD (p<0.001) in the intervention group. The mean serum levels of SOD and GPx were significantly increased in the intervention group after the intervention (p=0.001 and 0.002, respectively). At the end of the study, the mean changes of GPx were significantly higher in the intervention group compared with the control group (p=0.04). Also, after the administration of the ginger with NSPT, significant decrease occurred in the mean change of IL-6 (p=0.009), hs-CRP (p=0.049), TNF-α (p=0.049), CAL (p=0.003), and PD (p=0.04) compared with the control group.

CONCLUSION

It is recommended that ginger supplementation along with NSPT may be effective in the improvement of inflammation, oxidative, and periodontal status in T2DM with CP.

Effects of Chicory Leaf Extract on Serum Oxidative Stress Markers, Lipid Profile and Periodontal Status in Patients With Chronic Periodontitis

AIM

The aim of present study was to evaluate the effects of chicory leaf extract on serum oxidative stress markers, lipid profile, and periodontal status in patients with chronic periodontitis.

METHODS

In this double-blind, randomized controlled clinical trial 40 patients with chronic periodontitis were allocated to intervention and control groups. The intervention group received a 1-gram chicory leaf methanolic extract capsule twice daily for 8 weeks. In the control group, participants received a placebo capsule (containing 1 gram wheat flour) twice daily for 8 weeks. All participants had nonsurgical periodontal therapy during the study. Anthropometric measurements, dietary intake, total antioxidant capacity (TAC), malondialdehyde (MDA), uric acid, lipid profile (total cholesterol [TC], triglycerides [TG], low-density lipoprotein cholesterol [LDL-C], and high-density lipoprotein cholesterol [HDL-C]), and pocket depth (PD) were assessed before and after intervention.

RESULTS

The results showed that mean serum TAC, uric acid, and HDL-C increased and mean serum MDA, TG, LDL-C, and TC decreased significantly in the intervention group compared to their baseline and the control group post-intervention. A significant difference was observed in mean PD between the two groups.

CONCLUSION

Chicory leaf extract as an adjunct nutritional approach with nonsurgical periodontal therapy may be helpful in controlling periodontal status.

Probiotic Cell-Free Supernatants Exhibited Anti-Inflammatory and Antioxidant Activity on Human Gut Epithelial Cells and Macrophages Stimulated with LPS

The incidence of inflammatory bowel disease is increasing all over the world, especially in industrialized countries. The aim of the present work was to verify the anti-inflammatory activity of metabolites. In particular, cell-free supernatants of Lactobacillus acidophilus, Lactobacillus casei, Lactococcus lactis, Lactobacillus reuteri, and Saccharomyces boulardii have been investigated. Metabolites produced by these probiotics were able to downregulate the expression of PGE-2 and IL-8 in human colon epithelial HT-29 cells. Moreover, probiotic supernatants can differently modulate IL-1β, IL-6, TNF-α, and IL-10 production by human macrophages, suggesting a peculiar anti-inflammatory activity. Furthermore, supernatants showed a significant dose-dependent radical scavenging activity. This study suggests one of the mechanisms by which probiotics exert their anti-inflammatory activity affecting directly the intestinal epithelial cells and the underlying macrophages. This study provides a further evidence to support the possible use of probiotic metabolites in preventing and downregulating intestinal inflammation as adjuvant in anti-inflammatory therapy.

Urokinase-plasminogen activator protects periodontal ligament fibroblast from oxidative induced-apoptosis and DNA damage

BACKGROUND AND OBJECTIVE

Urokinase-plasminogen activator (uPA) is a serine protease expressed at high basal level in normal gingival cervical fluid. Despite its known pathologic role in tissue proteolysis in periodontitis, little is known concerning uPA physiological function in oral tissue. Recent evidence in cancer cells has implicated the uPA system in DNA repair and anti-apoptotic pathways. This study is aimed to evaluate the protective function of urokinase against oxidative DNA damage in periodontal ligament (PDL) fibroblast, and to propose a new biological role for uPA in oral cavity.

MATERIAL AND METHODS

PDL cells were isolated from human wisdom teeth obtained from healthy donors. An oxidative stress model was created in which PDL cells were incubated with 20, 30, 40 and 60 μmol/L hydrogen peroxide. Twenty-four hours before and after peroxide treatment, cells were treated with uPA and amiloride. Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide assay, apoptosis by DAPI-staining and annexin V/propidium iodide assay, and DNA breaks by alkaline comet assay. For estimating DNA damage level, γ-H2AX expression was studied using flow cytometry and immunostaining.

RESULTS

The incubation of the peroxide-treated cells with uPA significantly increased cell viability and decreased apoptosis. A significant decrease in the number of γ-H2AX foci was seen at 30 μmol/L hydrogen peroxide in uPA-treated cells. uPA inhibition as a result of amiloride treatment, in turn, induced a reduction in cell viability. In addition, there was a significant decrease in the levels of DNA damage in uPA-treated groups as measured by the comet assay.

CONCLUSION

The present study brings support to the theory that uPA may have a protective role for periodontal tissue and could protect PDL fibroblasts from oxidative DNA damage and apoptosis.

[Protective effects of hydrogen-rich medium on lipopolysaccharides-induced injury in human periodontal ligament cells]

OBJECTIVE

In this study, lipopolysaccharides (LPS) was used to damage human periodontal ligament cells (hPDLCs) and consequently investigate the protective effects of hydrogen on reducing oxidative stress and cell apoptosis rate.

METHODS

hPDLCs were isolated, and then cultured with normal medium+1 μg·mL⁻¹ LPS or with hydrogen-rich medium+
1 μg·mL⁻¹ LPS. Cell proliferation activity was assessed using a cell counting kit-8 (CCK-8), and lactic dehydrogenase (LDH) release was also detected. The activities of superoxide dismutase (SOD) and catalase (CAT), and the level of malonaldehyde (MDA) in supernatants were also measured. Cell apoptosis was detected by flow cytometry at 24 h after LPS stimulation.

RESULTS

CCK-8 results showed that hydrogen could significantly improve hPDLCs growth and decrease cell apoptosis under LPS stimulation (P<0.05). However, no significant difference in LDH release was found between the two groups. The CAT levels significantly increased at 6 and 12 h in the hydrogen-rich medium as compared with the normal medium group (P<0.05, P<0.01, respectively). However, SOD levels were not significant different at each time point. At 6 h after LPS stimulation, the MDA levels in the cell supernatant of hydrogen-rich medium group were significantly reduced as compared with those in the normal medium group (P<0.05).

CONCLUSIONS

The hydrogen-rich medium can effectively improve hPDLCs proliferation activity and antioxidant capacity and reduce apoptosis and oxidative stress under LPS stimulation.

Mesenchymal Stem Cells of Dental Origin for Inducing Tissue Regeneration in Periodontitis: A Mini-Review

Periodontitis is a chronic disease that begins with a period of inflammation of the supporting tissues of the teeth table and then progresses, destroying the tissues until loss of the teeth occurs. The restoration of the damaged dental support apparatus is an extremely complex process due to the regeneration of the cementum, the periodontal ligament, and the alveolar bone. Conventional treatment relies on synthetic materials that fill defects and replace lost dental tissue, but these approaches are not substitutes for a real regeneration of tissue. To address this, there are several approaches to tissue engineering for regenerative dentistry, among them, the use of stem cells. Mesenchymal stem cells (MSC) can be obtained from various sources of adult tissues, such as bone marrow, adipose tissue, skin, and tissues of the orofacial area. MSC of dental origin, such as those found in the bone marrow, have immunosuppressive and immunotolerant properties, multipotency, high proliferation rates, and the capacity for tissue repair. However, they are poorly used as sources of tissue for therapeutic purposes. Their accessibility makes them an attractive source of mesenchymal stem cells, so this review describes the field of dental stem cell research and proposes a potential mechanism involved in periodontal tissue regeneration induced by dental MSC.

Probing depth is an independent risk factor for HbA1c levels in diabetic patients under physical training: a cross-sectional pilot-study

BACKGROUND

This cross-sectional study investigates the potential association between active periodontal disease and high HbA1c levels in type-2-diabetes mellitus subjects under physical training.

METHODS

Women and men with a diagnosis of non-insulin-dependent diabetes mellitus and ongoing physical and an ongoing exercise program were included. Periodontal conditions were assessed according to the CDC-AAP case definitions. Venous blood samples were collected for the quantitative analysis of HbA1c. Associations between the variables were examined with univariate and multivariate regression models.

RESULTS

Forty-four subjects with a mean age of 63.4 ± 7.0 years were examined. Twenty-nine subjects had no periodontitis, 11 had a moderate and 4 had a severe form of periodontal disease. High fasting serum glucose (p < 0.0001), high BMI scores (p = 0.001), low diastolic blood pressure (p = 0.030) and high probing depth (p = 0.036) were significantly associated with high HbA1c levels.

CONCLUSIONS

Within the limitations of this study HbA1c levels are positively associated with high probing pocket depth in patients with non-insulin-dependent diabetes mellitus under physical exercise training. Control and management of active periodontal diseases in non-insulin-dependent patients with diabetes mellitus is reasonable in order to maximize therapeutic outcome of lifestyle interventions.

Oxidative modification of proteins in the process of experimental periodontitis development

The article reveals patterns of changes in the parameters of oxidative modification of proteins for different periods of the inflammatory process in periodontal tissues during periodontitis. Biochemical researches of phenylhydrazones, aldehyde-, and ketone derivatives of neutral and basic proteins were determined in the blood of white rats on the 7th, 14th, and 30th days of the experimental periodontitis development, as well as in intact animals. The method for determination of the oxidative modification of proteins was based on the interaction of oxidized amino acid residues with 2,4-dinitrophenylhydrazine to form 2,4-dinitrophenylhydrazones. At the early stage of experimental periodontitis development, i.e., on the 7th day, an increase in the products of oxidative modification of proteins of basic and neutral nature was observed in the blood serum, but later, on the 14th day, this index changed in opposite direction, i.e., it began to decrease; however, it was higher relative to the intact group of animals. The obtained factual data evidence that under the conditions of experimental periodontitis formation, there is an intensive increase in the level of oxidative modification of proteins especially in the early period of the inflammatory process development.

Modulation of Neutrophil Extracellular Trap and Reactive Oxygen Species Release by Periodontal Bacteria

Oral bacteria are the main trigger for the development of periodontitis, and some species are known to modulate neutrophil function. This study aimed to explore the release of neutrophil extracellular traps (NETs), associated antimicrobial proteins, and reactive oxygen species (ROS) in response to periodontal bacteria, as well as the underlying pathways. Isolated peripheral blood neutrophils were stimulated with 19 periodontal bacteria. NET and ROS release, as well as the expression of NET-bound antimicrobial proteins, elastase, myeloperoxidase, and cathepsin G, in response to these species was measured using fluorescence-based assays. NET and ROS release was monitored after the addition of NADP (NADPH) oxidase pathway modulators and inhibitors of Toll-like receptors (TLRs). Moreover, bacterial entrapment by NETs was visualized microscopically, and bacterial killing was assessed by bacterial culture. Certain microorganisms, e.g., Veillonella parvula and Streptococcus gordonii, stimulated higher levels of ROS and NET release than others. NETs were found to entrap, but not kill, all periodontal bacteria tested. NADPH oxidase pathway modulators decreased ROS production but not NET production in response to the bacteria. Interestingly, TLR inhibitors did not impact ROS and NET release. These data suggest that the variability in the neutrophil response toward different bacteria may contribute to the pathogenesis of periodontal diseases by mechanisms such as bacterial avoidance of host responses and activation of neutrophils. Moreover, our results indicate that bacterium-stimulated NET release may arise in part via NADPH oxidase-independent mechanisms. The role of TLR signaling in bacterium-induced ROS and NET release needs to be further elucidated.

The effect of smoking on inflammatory cell infiltrate subtypes in gingival tissue of patients with chronic periodontitis

Background

Examinations on blood samples and gingival crevicular fluid of subjects with chronic periodontitis showed that smoking increased production of cytokines.

Objective

To evaluate the expression of immune markers on mononuclear inflammatory cell infiltrate at periodontitis and healthy tissue among smoking and non-smoking subjects.

Methods

This case-control study was performed on 41 patients who referred to a clinic of periodontology at a Mashhad dental school in Iran in 2016. The participants were all of Iranian Khorasanian ethnicity with age range of 35–65 years. Gingival biopsies were obtained during routine periodontal flap procedure. Immunohistochemistry using markers of CD20, CD3, CD68, and CD45RO was carried out. Data was analyzed by SPSS version 15, using one-way ANOVA and Tukey HSD test.

Results

Nonsmoker subjects showed significantly greater numbers of CD20+, CD68+, CD3+ cells compared to smoker subjects, both at healthy and periodontitis tissue biopsies (p<0.00), whereas there was no significant difference in terms of CD45RO (p=0.120).

Conclusion

Cigarette smoking, results in infiltrative mononuclear chronic inflammatory cells reduction in connective periodontium.

The Role of NrF2 in the Regulation of Periodontal Health and Disease

Immune-related disease tolerance is an important defense strategy that facilitates the maintenance of health in organs and tissues that are commonly colonized by bacteria. Immune tolerance to dysbiotic, tooth-borne biofilms is a poorly understood yet clinically relevant concept in the immunopathological mechanisms that are involved in the pathogenesis of periodontitis, particularly those related to neutrophil and macrophage responses. In periodontal health, neutrophils and macrophages respond to the formation of pathogenic bacterial biofilms by the production of bactericidal reactive oxygen species (ROS). However, when released in excess, ROS cause tissue damage and exacerbate inflammation. To counter these destructive responses, many cell types, including neutrophils and macrophages, launch a dedicated antioxidant system that limits the cell and tissue-damaging effects of ROS. The expression of antioxidants is primarily regulated by genetic response elements in their promoters. Here we consider the roles of nuclear factor erythroid 2-related factor (NrF2), a transcription factor, and other key regulators of antioxidants. The concept of disease tolerance, neutrophil and macrophage-generated oxidative stress, and their relationship to the pathogenesis of periodontitis is reviewed. We focus on the regulation of NrF2 and recent evidence suggesting that NrF2 plays a central role in host protection against tissue destruction in periodontitis.

Pathways that Regulate ROS Scavenging Enzymes, and Their Role in Defense Against Tissue Destruction in Periodontitis

Periodontitis, an inflammatory disease that affects the tissues surrounding the teeth, is a common disease worldwide. It is caused by a dysregulation of the host inflammatory response to bacterial infection, which leads to soft and hard tissue destruction. In particular, it is the excessive inflammation in response to bacterial plaque that leads to the release of reactive oxygen species (ROS) from neutrophils, which, then play a critical role in the destruction of periodontal tissue. Generally, ROS produced from immune cells exhibit an anti-bacterial effect and play a role in host defense and immune regulation. Excessive ROS, however, can exert cytotoxic effects, cause oxidative damage to proteins, and DNA, can interfere with cell growth and cell cycle progression, and induce apoptosis of gingival fibroblasts. Collectively, these effects enable ROS to directly induce periodontal tissue damage. Some ROS also act as intracellular signaling molecules during osteoclastogenesis, and can thus also play an indirect role in bone destruction. Cells have several protective mechanisms to manage such oxidative stress, most of which involve production of cytoprotective enzymes that scavenge ROS. These enzymes are transcriptionally regulated via NRF2, Sirtuin, and FOXO. Some reports indicate an association between periodontitis and these cytoprotective enzymes' regulatory axes, with superoxide dismutase (SOD) the most extensively investigated. In this review article, we discuss the role of oxidative stress in the tissue destruction manifest in periodontitis, and the mechanisms that protect against this oxidative stress.

Gamma Glutamyl Transpeptidase, Smokeless Tobacco, Chronic Periodontitis: Exploring the Link

INTRODUCTION

Oxidative Stress (OS) is implicated in the pathogenesis of many systemic and oral diseases such as periodontal disease. Smokeless tobacco extract produces apoptosis and causes an imbalance between reactive oxygen species and antioxidants, such as Gamma Glutamyl Transpeptidase (GGT). Epidemiological research implied serum GGT within its normal range to be an early sensitive enzyme related to OS.

AIM

To assess how GGT fares as a biomarker in periodontitis subjects with or without the usage of smokeless tobacco and correlate it with clinical parameters.

MATERIALS AND METHODS

Ninety subjects were divided into three groups of healthy, chronic periodontitis, and smokeless tobacco users with chronic periodontitis from the dental outpatient department of P.M. Nadagouda Memorial Dental College and Hospital. Serum samples of patients were collected after obtaining consent and analyzed for GGT. Statistical Analysis was performed using ANOVA, and Pearson's correlation coefficient.

RESULTS

GGT levels were found to be significantly higher in chronic periodontitis patients compared to smokeless tobacco users with chronic periodontitis and healthy subjects. Conclusion: GGT may be used as a quick, easy and precise marker for measuring OS in patients with chronic periodontitis and smokeless tobacco users.

Is caffeic acid phenethyl ester more protective than doxycycline in experimental periodontitis?

BACKGROUND AND OBJECTIVES

Host modulation therapies (anti-inflammatory drugs, bone-stimulating agents, anti-proteinase etc.) target the inhibition or stabilization of tissue breakdown. The aim of the present study was to evaluate the effects of caffeic acid phenethyl ester (CAPE) and/or low dose doxycycline (LDD) administrations on alveolar bone loss (ABL), serum cytokines and gingival apoptosis, as well as the levels of oxidants and anti-oxidants in rats with ligature-induced periodontitis.

MATERIAL AND METHODS

The animals were randomly divided into five groups: Group C (periodontally healthy), Group PC (Periodontitis+CAPE), Group PD (Periodontitis+LDD), Group PCD (Periodontitis+CAPE+LDD), Group P (Periodontitis). Experimental periodontitis was induced for 14days. Levels of ABL, and the serum cytokines, interleukin (IL)-1 β, IL-6, tumor necrosis factor-α (TNF-α) and IL-10 were assessed as were the levels of the oxidants and anti-oxidants, malondialdehyde (MDA), glutathione (GSH) and glutathione peroxidase (GSH-Px), and levels of gingival apoptosis.

RESULTS

The lowest ABL levels was evident in the PC group, among the experimental groups. There was also less inflammatory infiltration in the PC group than the PD group. IL-1β, IL-6, and IL-10 were lower in the PC group and higher in the P group in comparison to the levels in the other experiment groups. TNF-α levels in the PD group were higher than levels in the PC and PCD groups. The PC and PCD groups did not differ from the C group in regard to MDA levels. The highest GSH-Px level was found in the PC group. Gingival apoptosis in the PC group was not only lower than the PD and PCD groups, but also lower than in the C group.

CONCLUSION

The present study suggests that CAPE has more anti-inflammatory, anti-oxidant and anti-apoptotic effects than LDD, with no additive benefits of a CAPE+LDD combination being evident in rats with periodontitis.

The Impact of Resveratrol Supplementation on Blood Glucose, Insulin, Insulin Resistance, Triglyceride, and Periodontal Markers in Type 2 Diabetic Patients with Chronic Periodontitis

The aim of this study was to investigate the impact of resveratrol supplementation along with non-surgical periodontal treatment on blood glucose, insulin, insulin resistance, triglyceride (TG), and periodontal markers in patients with type 2 diabetes with periodontal disease. In this double-blind clinical trial study, 43 patients with diabetes with chronic periodontitis were participated. Subjects were randomly allocated to intervention and control groups. The intervention and control groups received either 480 mg/day of resveratrol or placebo capsules (two pills) for 4 weeks. Fasting blood glucose, insulin, insulin resistance (homeostasis model assessment of insulin resistance), TGs, and pocket depth were measured in all subjects' pre-intervention and post-intervention. The mean serum levels of fasting insulin and insulin resistance (homeostasis model assessment of insulin resistance) were significantly lower in the intervention group compared with control group (10.42 ± 0.28 and 10.92 ± 0.9; 3.66 ± 0.97 and 4.49 ± 1.56, respectively). There was a significant difference in the mean pocket depth between intervention and control groups (2.35 ± 0.6 and 3.38 ± 0.5, respectively) following intervention. No significant differences were observed in the mean levels of fasting blood glucose and TGs between two groups' post-intervention. It is recommended that resveratrol supplementation may be beneficial as adjuvant therapy along with non-surgical periodontal treatment in insulin resistance and improving periodontal status among patients with diabetes with periodontal disease. Copyright © 2016 John Wiley & Sons, Ltd.

The Role of Nutrition in Periodontal Health: An Update

Periodontal health is influenced by a number of factors such as oral hygiene, genetic and epigenetic factors, systemic health, and nutrition. Many studies have observed that a balanced diet has an essential role in maintaining periodontal health. Additionally, the influences of nutritional supplements and dietary components have been known to affect healing after periodontal surgery. Studies have attempted to find a correlation between tooth loss, periodontal health, and nutrition. Moreover, bone formation and periodontal regeneration are also affected by numerous vitamins, minerals, and trace elements. The aim of this review is to critically appraise the currently available data on diet and maintenance of periodontal health and periodontal healing. The effects of nutritional intervention studies to improve the quality of life and well-being of patients with periodontal disease have been discussed.

2,3,5,4'-Tetrahydroxystilbene-2-O-β-glucoside Isolated from Polygoni Multiflori Ameliorates the Development of Periodontitis

Periodontitis, a chronic infection by periodontopathic bacteria, induces uncontrolled inflammation, which leads to periodontal tissue destruction. 2,3,5,4'-Tetrahydroxystilbene-2-O-beta-glucoside (THSG), a polyphenol extracted from Polygoni Multiflori, reportedly has anti-inflammatory properties. In this study, we investigated the mechanisms of THSG on the Porphyromonas gingivalis-induced inflammatory responses in human gingival fibroblasts and animal modeling of ligature-induced periodontitis. Human gingival fibroblast cells were treated with lipopolysaccharide (LPS) extracted from P. gingivalis in the presence of resveratrol or THSG to analyze the expression of TNF-α, IL-1β, and IL-6 genes. Increased AMP-activated protein kinase (AMPK) activation and SirT1 expression were induced by THSG. Treatment of THSG decreased the expression of LPS-induced inflammatory cytokines, enhanced AMPK activation, and increased the expression of SirT1. In addition, it suppressed the activation of NF-κB when cells were stimulated with P. gingivalis LPS. The anti-inflammatory effect of THSG and P. Multiflori crude extracts was reproduced in ligature-induced periodontitis animal modeling. In conclusion, THSG inhibited the inflammatory responses of P. gingivalis-stimulated human gingival fibroblasts and ameliorated ligature-induced periodontitis in animal model.

de Oliveira M, Brito GAC. Topical HPMC/S-Nitrosoglutathione Solution Decreases Inflammation and Bone Resorption in Experimental Periodontal Disease in Rats

S-nitrosoglutathione (GSNO) is a nitric oxide (NO) donor, which exerts antioxidant, anti-inflammatory, and microbicidal actions. Intragingival application of GSNO was already shown to decrease alveolar bone loss, inflammation and oxidative stress in an experimental periodontal disease (EPD) model. In the present study, we evaluated the potential therapeutic effect of topical applications of hydroxypropylmethylcellulose (HPMC)/GSNO solutions on EPD in Wistar rats. EPD was induced by placing a sterilized nylon (3.0) thread ligature around the cervix of the second left upper molar of the animals, which received topical applications of a HPMC solutions containing GSNO 2 or 10 mM or vehicle (HPMC solution), 1 h prior to the placement of the ligature and then twice daily until sacrifice on day 11. Treatment with HPMC/GSNO 10 mM solution significantly reduced alveolar bone loss, oxidative stress and TNF-α e IL-1β levels in the surrounding gingival tissue, and led to a decreased transcription of RANK and TNF-α genes and elevated bone alkaline phosphatase, compared to the HPMC group. In conclusion, topical application of HPMC/GSNO solution is a potential treatment to reduce inflammation and bone loss in periodontal disease.

Periodontitis in rats induces systemic oxidative stress that is controlled by bone-targeted antiresorptives

BACKGROUND

Periodontitis is a chronic, polymicrobial inflammatory disease that degrades connective tissue and alveolar bone and results in tooth loss. Oxidative stress has been linked to the onset of periodontal tissue breakdown and systemic inflammation, and the success of antiresorptive treatments will rely on how effectively they can ameliorate periodontal disease-induced oxidative stress during oral infection.

METHODS

Rats were infected with polybacterial inoculum consisting of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia, as an oral lavage every other week for 12 weeks. Daily subcutaneous injections of enoxacin, bis-enoxacin, alendronate, or doxycycline were administered for 6 weeks after 6 weeks of polybacterial infection in rats. The serum levels of oxidative stress parameters and antioxidant enzymes, including glutathione peroxidase, superoxide dismutase, and catalase, were evaluated in each of the infected, treated, and sham-infected rats.

RESULTS

Rats infected with the periodontal pathogens displayed a five-fold increase in the oxidative stress index compared with controls as a result of increased levels of serum oxidants and decreases in total antioxidant activity. The overall decrease in antioxidant activity occurred despite increases in three important antioxidant enzymes, suggesting an imbalance between antioxidant macromolecules/small molecules production and antioxidant enzyme levels. Surprisingly, the bone-targeted antiresorptives bis-enoxacin and alendronate inhibited increases in oxidative stress caused by periodontitis. Bis-enoxacin, which has both antiresorptive and antibiotic activities, was more effective than alendronate, which acts only as an antiresorptive.

CONCLUSION

To the best of the authors' knowledge, this is the first study to demonstrate that the increased oxidative stress induced by periodontal infection in rats can be ameliorated by bone-targeted antiresorptives.

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.

Role of nitro-oxidative stress in the pathogenesis of experimental rat periodontitis

Background and aims

Periodontitis is a common chronic adult condition that implicates oxidative damage to gingival tissue, periodontal ligament and alveolar bone. This study aimed at assessing the association between the nitro-oxidative stress and the periodontal tissues destructions in experimental rat periodontitis.

Methods

Periodontitis was induced in 15 male albino rats by repetitive lesions to the gingiva adjacent to the inferior incisors, performed daily, for 16 days. On D1, D3, D6, D8, and D16 the onset and evolution of periodontitis were monitored by clinical and histopathological examinations; blood was collected and serum nitro-oxidative stress was evaluated through total nitrites and nitrates, total oxidative status, total antioxidant capacity, and oxidative stress index.

Results

The results demonstrated that there was a graded and continuous increase in serum levels of total nitrites and nitrates, total oxidative status and oxidative stress index, which was consistent with the severity of periodontal destructions during periodontitis progression. However, total antioxidant capacity was not significantly influenced by the disease progression.

Conclusions

In experimental rat periodontitis, the systemic nitro-oxidative stress was associated with the severity of periodontal destructions assessed clinically and histopathologically. Therefore, systemic nitro-oxidative stress parameters might be used as diagnostic tools in periodontitis.

Consumption of dental treatment in patients with inflammatory bowel disease, a register study

Objective

The aim of this study was to compare the consumption of dental treatment among patients with Crohn´s disease (CD) or ulcerative colitis (UC) compared to age and gender matched control groups.

Design

The study group comprised 2085 patients with CD and 3161 with UC from the Uppsala-Örebro region and from the Stockholm region. The patients in the cohort were diagnosed between 1960 and 1989. Patients up to 70 years of age were included in the study. The two patients groups were compared to age- and gender-matched, randomly selected control groups from the same geographic area comprising a corresponding number of participants.

Results

CD patients had significantly higher total number of procedures registered (p < 0.000). The difference was most pronounced for removable dentures (+65%), fillings in front teeth (+52%) and endodontic treatment (+46%) when Crohn’s patients were compared to controls (p<0.001). The corresponding figures for UC patients were also a significantly higher total number of procedures (p < 0.005), more clinical examinations (p<0.000), fillings in canines and incisors (p < 0.001) and fillings in bicuspids and molars (p < 0.000).

Conclusion

This study demonstrate that CD and UC individuals use more dental treatment compared to an age-gender matched control group, and more caries-related treatments. The difference was most pronounced for restorative treatment in patients with Crohn’s.

Tumor Necrosis Factor Alpha Stimulates Proliferation of Dental Pulp Stem Cells via Akt/Glycogen Synthase Kinase-3β/Cyclin D1 Signaling Pathway

INTRODUCTION

It has been widely accepted that dental pulp stem cells (DPSCs), which are a class of self-renewal and differentiation potential of adult stem cells, play an important role in the repair procession of pulp's inflammation. We investigated whether tumor necrosis factor alpha (TNF-α) could induce the proliferation of DPSCs and clarified the potential mechanism of this proliferation.

METHODS

Cell Counting Kit-8 assay (Dojindo Laboratories, Mashiki-machi, Kumamoto, Japan) and 5-ethynyl-2'-deoxyuridine-based proliferation assays were determined to investigate various concentrations or hours of TNF-α inducing a cell number change of DPSCs. Next, flow cytometry analysis was performed to investigate the main cell cycle phase process of DPSCs. Furthermore, the signaling pathway of TNF-α-induced proliferation of DPSCs was analyzed using Western blot analysis. Then, inhibitors were added to confirm the mechanism of this signaling pathway.

RESULTS

TNF-α induced the proliferation of DPSCs in a dose- and time-dependent manner. Cyclin D1, which controlled the cell cycle process from the G1 to the S phase, was up-regulated by TNF-α in a time-dependent manner, whereas its overexpression alone increased DPSC proliferation. Furthermore, TNF-α was capable of inducing Akt/GSK-3β signaling pathway activation. Blockage of phosphoinositide 3-kinase/Akt by their kinase or genetic inhibitors could significantly reduce TNF-α-induced proliferation of DPSCs.

CONCLUSIONS

This study confirmed that TNF-α induced the proliferation of DPSCs by regulating the Akt/GSK-3β/cyclin D1 signaling pathway and then provided a suitable number for the requirements of cell differentiation.

Change of scaling-induced proinflammatory cytokine on the clinical efficacy of periodontitis treatment

Proinflammatory cytokines are key inflammatory mediators in periodontitis. This study aimed to investigate the relationship between proinflammatory cytokines in saliva and periodontal status. To investigate the usefulness of cytokines in the therapeutic approach for periodontal disease, the relationship between stimulated cytokine changes and the periodontitis treatment outcome was investigated in this study. Saliva was obtained from 22 patients diagnosed by dentists as having chronic periodontitis. The proinflammatory cytokine (interleukin-1α (IL-1α), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor α (TNF-α), and tumor necrosis factor β (TNF-β)) levels were determined using a commercially available kit. The IL-1β and IL-6 levels increased, whereas the TNF-β levels decreased with the severity of periodontitis (4 mm pocket percentage). Poststimulation IL-1α, IL-6, and IL-8 levels were higher in patients who had an improved treatment outcome. The differences of IL-6 levels (cut point: 0.05 μg/g) yielded a sensitivity and specificity of 90.0% and 81.82%, respectively, for predicting the periodontitis treatment outcome. Among the proinflammatory cytokines, stimulated IL-6 was an excellent marker for predicting the periodontitis treatment outcome.

Scaling-stimulated salivary antioxidant changes and oral-health behavior in an evaluation of periodontal treatment outcomes

AIM

Our goal was to investigate associations among scaling-stimulated changes in salivary antioxidants, oral-health-related behaviors and attitudes, and periodontal treatment outcomes.

MATERIALS AND METHODS

Thirty periodontitis patients with at least 6 pockets with pocket depths of >5 mm and more than 16 functional teeth were enrolled in the study. Patients were divided into three groups: an abandoned group (AB group), a nonprogress outcome group (NP group), and an effective treatment group (ET group). Nonstimulated saliva was collected before and after scaling were received to determine superoxide dismutase (SOD) and the total antioxidant capacity (TAOC).

RESULTS

Salivary SOD following scaling significantly increased from 83.09 to 194.30 U/g protein in patients who had irregular dental visit patterns (<1 visit per year). After scaling, the TAOC was significantly higher in patients who had regular dental visits than in patients who had irregular dental visits (3.52 versus 0.70 mmole/g protein, P < 0.01). The scaling-stimulated increase in SOD was related to a higher severity of periodontitis in the NP group, while the scaling-stimulated increase in the TAOC was inversely related to the severity of periodontitis in the AB group.

CONCLUSIONS

These results demonstrate the importance of scaling-stimulated salivary antioxidants as prognostic biomarkers of periodontal treatment.