Proinflammatory and oxidative stress markers in patients with periodontal disease

Effects of periodontal disease on the reproductive performance and offspring of Wistar rats

BACKGROUND

Periodontitis can induce systemic inflammation, and it may affect the testicles and male reproductive performance. This study investigated the effects of periodontitis on the testicles, reproductive performance, and offspring development in male rats.

METHODS

Male Wistar rats were induced with periodontitis by ligating their first molars. After 14 days of inducing periodontal lesions, the animals were observed for an additional 54 days, corresponding to a complete cycle of spermatogenesis. Rats from the periodontitis group (GP, n = 12) and the control group (GC, n = 12) were paired with healthy females (n = 48) for 10 days, equivalent to 2 estrous cycles. Post-mating, the males underwent microtomographic, histological, and reproductive parameter assessments.

RESULTS

Microtomographic analysis revealed higher porosity around the first molar in GP (26 ± 6%) and greater distance between the amelocemental junction and the alveolar bone (1.37 [1.12-1.90] mm), indicative of bone resorption. GP also exhibited significant decreases in final body weight, reduced Sertoli and Leydig cell counts, and lowered testosterone levels compared to GC. Significant morphological alterations in sperm tails were observed in GP compared to GC.

CONCLUSIONS

Periodontitis adversely affected reproductive performance, evoking, and offspring development in male rats. These findings highlight the systemic impacts of periodontal disease on male reproductive health in an animal model.

PLAIN LANGUAGE SUMMARY

Our study investigated how periodontitis can affect male reproductive health in rats and offspring development. We induced periodontitis in male rats and, after a full cycle of sperm production, these rats were mated with healthy females. We observed that the rats with periodontitis had worse reproductive performance compared to the control group without periodontitis. Additionally, the offspring of the rats with periodontitis showed signs of compromised intrauterine development and a higher incidence of congenital malformations. These results highlight that the inflammation caused by periodontitis can have adverse effects beyond the mouth, significantly impacting male reproductive health and offspring development. These findings suggest the need for further research into the clinical implications of periodontitis on reproductive health.

The Influence of Removable Complete Denture on Pro-Oxidant Antioxidant Balance and Redox-Sensitive Inflammation Biomarker NF-ĸB in the Oral Cavity: An Interventional Follow-Up Study

OBJECTIVES

Oxidative stress, an imbalance between the body's natural antioxidant defenses and the production of reactive oxygen species (ROS), can result in serious oral diseases, including oral cancer, periodontal diseases, and oral lichen planus, through the activation of the redox-sensitive transcription factors and inflammation. The purpose of this study was to assess the potential effects of a removable complete denture on the levels of oxidative stress markers, such as lipid peroxidation (MDA), advanced oxidation protein products (AOPP), and catalase, and the quantitative expression of the redox-sensitive transcription factor NF-κB p65 subunit.

MATERIALS AND METHODS

This interventional follow-up study enrolled 40 participants of both sexes aged 28-78 years, with a median age of 56 years, where unstimulated saliva was collected before denture placement, immediately after the denture placement, and 24 h, 7 days, and 30 days after the denture placement. The most prominent ROS overproduction was reported on the seventh day (p < 0.05), followed by a significant fall in antioxidative defense.

RESULTS

The NF-κB p65 subunit, whose expression pattern was highest in the same time period on the seventh day, serves as a signaling molecule for redox imbalance due to ROS production. Over the next 30 days, its levels remained moderately increased compared to the basal value, which may influence pro-inflammatory pathways and the integrity of oral tissue components. These alterations may be induced by the dentures, which can produce high pressures on the supporting tissues or by the synthetic materials used for producing the dentures.

CONCLUSION

Our research may help to clarify the potential pathways by which oxidative stress and redox-sensitive inflammatory mediators, as well as mechanical and chemical irritants, may serve as risk factors for premalignant lesions in the mouth. Further research on this topic is required to understand the molecular mechanisms behind the relationship between inflammation and oral premalignant lesions caused by mechanical and chemical irritation.

Microbiological and Salivary Biomarkers Successfully Predict Site-Specific and Whole-Mouth Outcomes of Nonsurgical Periodontal Treatment

Background/Objectives: Nonsurgical periodontal treatment (NSPT) is the gold-standard technique for treating periodontitis. However, an individual's susceptibility or the inadequate removal of subgingival biofilms could lead to unfavorable responses to NSPT. This study aimed to assess the potential of salivary and microbiological biomarkers in predicting the site-specific and whole-mouth outcomes of NSPT. Methods: A total of 68 periodontitis patients exhibiting 1111 periodontal pockets 4 to 6 mm in depth completed the active phase of periodontal treatment. Clinical periodontal parameters, saliva, and subgingival biofilm samples were collected from each patient at baseline and three months after NSPT. A quantitative PCR assay was used to detect the presence of Fusobaterium nucleatum and Porphyromonas gingivalis in the biofilm samples. Salivary biomarkers including matrix metalloproteinase (MMP)-9, glutathione S-transferase (GST), and Annexin-1 were assayed both qualitatively (Western blot analysis) and quantitively (ELISA). Results: NSPT yielded significant improvements in all clinical parameters, including a reduction in bacterial load and decreased levels of MMP-9 together with increased concentrations of GST and Annexin-1. The binary logistic regression suggested that the overall accuracy of P. gingivalis identification, probing pocket depth, and interproximal sites was 71.1% in predicting successful site-specific outcomes. The salivary biomarker model yielded an overall accuracy of 79.4% in predicting whole-mouth outcomes following NSPT. Conclusions: At baseline, the presence of shallow periodontal pockets at interdental locations with a lower abundance of P. gingivalis is predictive of a favorable response to NSPT at the site level. Decreased salivary MMP-9 associated with increased GST and Annexin-1 levels can predict successful whole-mouth outcomes following NSPT.

Identification of disulfidptosis- and ferroptosis-related transcripts in periodontitis by bioinformatics analysis and experimental validation

Background

Disulfidptosis and ferroptosis are forms of programmed cell death that may be associated with the pathogenesis of periodontitis. Our study developed periodontitis-associated biomarkers combining disulfidptosis and ferroptosis, which provides a new perspective on the pathogenesis of periodontitis.

Methods

Firstly, we obtained the periodontitis dataset from public databases and found disulfidptosis- and ferroptosis-related differentially expressed transcripts based on the disulfidptosis and ferroptosis transcript sets. After that, transcripts that are tissue biomarkers for periodontitis were found using three machine learning methods. We also generated transcript subclusters from two periodontitis microarray datasets: GSE16134 and GSE23586. Furthermore, three transcripts with the best classification efficiency were further screened. Their expression and classification efficacy were validated using qRT-PCR. Finally, periodontal clinical indicators of 32 clinical patients were collected, and the correlation between three transcripts above and periodontal clinical indicators was analyzed.

Results

We identified six transcripts that are tissue biomarkers for periodontitis, the top three transcripts with the best classification, and delineated two expression patterns in periodontitis.

Conclusions

Our study found that disulfidptosis and ferroptosis were associated with immune responses and may involve periodontitis genesis.

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.

Exploring the molecular mechanisms of ferroptosis-related genes in periodontitis: a multi-dataset analysis

PURPOSE

This study aims to elucidate the biological functions of ferroptosis-related genes in periodontitis, along with their correlation to tumor microenvironment (TME) features such as immune infiltration. It aims to provide potential diagnostic markers of ferroptosis for clinical management of periodontitis.

METHODS

Utilizing the periodontitis-related microarray dataset GSE16134 from the Gene Expression Omnibus (GEO) and a set of 528 ferroptosis-related genes identified in prior studies, this research unveils differentially expressed ferroptosis-related genes in periodontitis. Subsequently, a protein-protein interaction network was constructed. Subtyping of periodontitis was explored, followed by validation through immune cell infiltration and gene set enrichment analyses. Two algorithms, randomForest and SVM(Support Vector Machine), were employed to reveal potential ferroptosis diagnostic markers for periodontitis. The diagnostic efficacy, immune correlation, and potential transcriptional regulatory networks of these markers were further assessed. Finally, potential targeted drugs for differentially expressed ferroptosis markers in periodontitis were predicted.

RESULTS

A total of 36 ferroptosis-related genes (30 upregulated, 6 downregulated) were identified from 829 differentially expressed genes between 9 periodontitis samples and the control group. Subsequent machine learning algorithm screening highlighted 4 key genes: SLC1A5(Solute Carrier Family 1 Member 5), SLC2A14(Solute Carrier Family 1 Member 14), LURAP1L(Leucine Rich Adaptor Protein 1 Like), and HERPUD1(Homocysteine Inducible ER Protein With Ubiquitin Like Domain 1). Exploration of these 4 key genes, supported by time-correlated ROC analysis, demonstrated reliability, while immune infiltration results indicated a strong correlation between key genes and immune factors. Furthermore, Gene Set Enrichment Analysis (GSEA) was conducted for the four key genes, revealing enrichment in GO/KEGG pathways that have a significant impact on periodontitis. Finally, the study predicted potential transcriptional regulatory networks and targeted drugs associated with these key genes in periodontitis.

CONCLUSIONS

The ferroptosis-related genes identified in this study, including SLC1A5, SLC2A14, LURAP1L, and HERPUD1, may serve as novel diagnostic and therapeutic targets for periodontitis. They are likely involved in the occurrence and development of periodontitis through mechanisms such as immune infiltration, cellular metabolism, and inflammatory chemotaxis, potentially linking the ferroptosis pathway to the progression of periodontitis. Targeted drugs such as flurofamide, L-733060, memantine, tetrabenazine, and WAY-213613 hold promise for potential therapeutic interventions in periodontitis associated with these ferroptosis-related genes.

A multi-platform analysis of human gingival crevicular fluid reveals ferroptosis as a relevant regulated cell death mechanism during the clinical progression of periodontitis

Ferroptosis is implicated in the pathogenesis of numerous chronic-inflammatory diseases, yet its association with progressive periodontitis remains unexplored. To investigate the involvement and significance of ferroptosis in periodontitis progression, we assessed sixteen periodontitis-diagnosed patients. Disease progression was clinically monitored over twelve weeks via weekly clinical evaluations and gingival crevicular fluid (GCF) collection was performed for further analyses. Clinical metrics, proteomic data, in silico methods, and bioinformatics tools were combined to identify protein profiles linked to periodontitis progression and to explore their potential connection with ferroptosis. Subsequent western blot analyses validated key findings. Finally, a single-cell RNA sequencing (scRNA-seq) dataset (GSE164241) for gingival tissues was analyzed to elucidate cellular dynamics during periodontitis progression. Periodontitis progression was identified as occurring at a faster rate than traditionally thought. GCF samples from progressing and non-progressing periodontal sites showed quantitative and qualitatively distinct proteomic profiles. In addition, specific biological processes and molecular functions during progressive periodontitis were revealed and a set of hub proteins, including SNCA, CA1, HBB, SLC4A1, and ANK1 was strongly associated with the clinical progression status of periodontitis. Moreover, we found specific proteins - drivers or suppressors - associated with ferroptosis (SNCA, FTH1, HSPB1, CD44, and GCLC), revealing the co-occurrence of this specific type of regulated cell death during the clinical progression of periodontitis. Additionally, the integration of quantitative proteomic data with scRNA-seq analysis suggested the susceptibility of fibroblasts to ferroptosis. Our analyses reveal proteins and processes linked to ferroptosis for the first time in periodontal patients, which offer new insights into the molecular mechanisms of progressive periodontal disease. These findings may lead to novel diagnostic and therapeutic strategies.

Glutathione S-transferase M1, T1, and P1 polymorphisms and periodontitis in a Caucasian population: a case-control study

BACKGROUND

Glutathione S-transferases (GSTs) play important roles in protecting cells against oxidative stress and toxic chemicals. This study aimed to investigate the distribution of GSTM1, GSTT1, and GSTP1 variants and their roles in periodontitis susceptibility in a Caucasian population.

METHODS

We analyzed 406 participants, including 204 healthy controls and 203 periodontitis patients. A multiplex polymerase chain reaction (PCR) approach was used to analyze GSTM1 and GSTT1 loci. GSTP1 variants were detected by PCR-haplotyping method in a subgroup of participants (N = 350). Chi-square or Fisher´s exact tests were used to compare genotypic and allelic differences. The Bonferroni method was applied to correct for multiple comparisons (pcorr).

RESULTS

The GSTM1 genotype distribution did not differ significantly between controls and periodontitis patients (p = 0.44). Additionally, the wild/null genotypes of GSTT1, Ile105Val and Ala114Val frequencies of GSTP1 were not significantly different between the two groups after correction for multiple comparisons (p = 0.05, p = 0.55, p = 0.02, pcorr>0.05, respectively). The GSTM1 and GSTP1 Ile105Val gene variants were similarly distributed between non-smokers and smokers in both groups (p = 0.38, p = 0.20, and p = 0.14, p = 0.35, respectively). However, the wild genotype of the GSTT1 and Ala114Ala variant of the GSTP1 genes were present more frequently in non-smoking periodontitis patients than in non-smoking controls (p = 0.03, pcorr>0.05, and p = 0.009, pcorr>0.05, respectively) although their frequencies did not differ between smoking periodontitis patients and smoking controls (p = 0.23, p = 0.68, respectively).

CONCLUSIONS

This study in a Czech Caucasian population did not confirm a highly significant association between GST gene variants and susceptibility to periodontitis, as previously reported by Arshad and colleagues in Pakistanis. However, a weak relationship between GSTT1 and GSTP1 rs1138272 polymorphisms and periodontitis in non-smokers was observed.

Comparative Assessment of Catalase Levels in Peri-Implant Health and Disease

Peri-implant disease pathogenesis is similar to periodontal disease pathogenesis resulting in production of pro-inflammatory mediators. These mediators alter the redox balance leading to decrease in antioxidants, among which catalase is one of the enzymatic antioxidants. The aim of the study was to compare the levels of catalase in peri-implant health and disease. The present observational study was carried out from June 2022 to December 2022 in the Department of Implantology, Saveetha Dental College and Hospitals, Chennai, India. A total of 60 patients with peri-implant health (Group 1; n = 20), peri-implant mucositis (Group 2; n = 20) and peri-implantitis (Group 3; n = 20) were enrolled. Unstimulated salivary samples were collected and subjected to ELISA for catalase analysis. Catalase levels were then compared between the groups using ANOVA. The mean catalase level in peri-implant health, peri-implant mucositis, peri-implanti-tis were 25.07 ± 0.44 U/mL, 18.5 6 ± 0.65 U/mL, and 11.25 ± 0.76 U/mL respectively. The difference between the three groups were statistically significant (P < 0.05). Catalase level decreases with severity of peri-implant diseases. Therefore, catalase can be used as a diagnostic marker for peri-implant diseases.

Assessing the Antioxidant Benefits of Topical Carvacrol and Magnolol Periodontal Hydrogel Therapy in Periodontitis Associated with Diabetes in Wistar Rats

It is well recognized that oxidative stress contributes to chronic stress-induced cytotoxicity, which is a major factor in the progression of many diseases, including periodontitis and diabetes. Formulas based on natural extracts with antioxidant properties are alternative treatment perspectives in the management of such diseases. The aim of our study was to assess how carvacrol and magnolol influence periodontitis associated with diabetes in Wistar rats. Ninety Wistar rats were distributed in nine groups: I-control group; II-diabetes group (D); III-periodontitis group (P); IV-periodontitis and diabetes group (PD); V-periodontitis and diabetes with vehicle alone (PDV); VI-periodontitis and diabetes treated with carvacrol (PDC); VII-periodontitis and diabetes treated with magnolol (PDM); VIII-periodontitis and diabetes treated with carvacrol and magnolol (PDCM); IX-healthy group with vehicle alone (CV). Blood malondialdehyde (MDA) levels and catalase activity levels (CAT) were measured as indicators of oxidative stress and antioxidant capacity, respectively. Where diabetes and periodontitis were induced, MDA was augmented and CAT was depleted significantly. Whether given alone (PDM) or in combination with carvacrol (PDCM), magnolol significantly decreased MDA. Between the PDM group and the PDCM group, there were no notable differences. In Wistar rats with periodontitis related to diabetes, topical use of hydrogels containing magnolol, either alone or in combination with carvacrol, may reduce oxidative stress.

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.

Evaluated periodontal tissues and oxidative stress in rats with neuropathic pain-like behavior

BACKGROUND

Oxidative stress has a critical effect on both persistent pain states and periodontal disease. Voltage-gated sodium NaV1.7 (SCN9A), and transient receptor potential ankyrin 1 (TRPA1) are pain genes. The goal of this study was to investigate oxidative stress markers, periodontal status, SCN9A, and TRPA1 channel expression in periodontal tissues of rats with paclitaxel-induced neuropathic pain-like behavior (NPLB).

METHODS AND RESULTS

Totally 16 male Sprague Dawley rats were used: control (n = 8) and paclitaxel-induced pain (PTX) (n = 8). The alveolar bone loss and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels were analyzed histometrically and immunohistochemically. Gingival superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities (spectrophotometric assay) were measured. The relative TRPA1 and SCN9A genes expression levels were evaluated using quantitative real-time PCR (qPCR) in the tissues of gingiva and brain. The PTX group had significantly higher alveolar bone loss and 8-OHdG compared to the control. The PTX group had significantly lower gingival SOD, GPx and CAT activity than the control groups. The PTX group had significantly higher relative gene expression of SCN9A (p = 0.0002) and TRPA1 (p = 0.0002) than the control in gingival tissues. Increased nociceptive susceptibility may affect the increase in oxidative stress and periodontal destruction.

CONCLUSIONS

Chronic pain conditions may increase TRPA1 and SCN9A gene expression in the periodontium. The data of the current study may help develop novel approaches both to maintain periodontal health and alleviate pain in patients suffering from orofacial pain.

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.

Exogenous glutathione protects against gentamicin-induced acute kidney injury by inhibiting NF-κB pathway, oxidative stress, and apoptosis and regulating PCNA

This study was designed, for the first time, to examine the possible nephroprotective effects of exogenous glutathione (EGSH) (100 mg/kg, intraperitoneally) on gentamicin-induced acute kidney injury (GM-induced AKI). EGSH reduced renal histopathological changes, inflammatory cell infiltration, and improved renal dysfunction in rats with AKI. EGSH ameliorated GM-induced renal oxidative stress by promoting the renal activities of catalase, glutathione peroxidase, and superoxide dismutase and diminishing renal malondialdehyde and serum nitric oxide levels. Interestingly, EGSH inhibited intrinsic apoptosis by downregulating Bax and caspase-3 and upregulating Bcl2 in the kidney of rats with AKI. EGSH decreased GM-induced inflammatory response as reflected by a remarkable decrease in the protein expressions of NF-κB-p65, IL-6, TNF-α, and iNOS and a considerable diminish in myeloperoxidase activity. Finally, EGSH markedly declined proliferative cell nuclear antigen (PCNA) protein expression in the animals with AKI. In summary, EGSH alleviated AKI in rats intoxicated with GM, partially by inhibiting oxidative stress, NF-κB pathway, and intrinsic apoptosis and regulating PCNA.

The Emerging Role of Salivary Oxidative Stress Biomarkers as Prognostic Markers of Periodontitis: New Insights for a Personalized Approach in Dentistry

Periodontitis is a multifactorial and infective oral disease that leads to the destruction of periodontal tissues and tooth loss. Although the treatment of periodontitis has improved recently, the effective treatment of periodontitis and the periodontitis-affected periodontal tissues is still a challenge. Therefore, exploring new therapeutic strategies for a personalized approach is urgent. For this reason, the aim of this study is to summarize recent advances and the potential of oxidative stress biomarkers in the early diagnosis and personalized therapeutic approaches in periodontitis. Recently, ROS metabolisms (ROMs) have been studied in the physiopathology of periodontitis. Different studies show that ROS plays a crucial role in periodontitis. In this regard, the reactive oxygen metabolites (ROMs) started to be searched for the measures of the oxidizing capacity of the plasma understood as the total content of oxygen free radicals (ROS). The oxidizing capacity of plasma is a significant indicator of the body's oxidant state as well as homocysteine (Hcy), sulfur amino acid, which has pro-oxidant effects as it favors the production of superoxide anion. More specifically, the thioredoxin (TRX) and peroxiredoxin (PRX) systems control reactive oxygen species (ROS), such as superoxide and hydroxyl species, to transduce redox signals and change the activities of antioxidant enzymes to remove free radicals. Superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx), among other antioxidant enzymes, change their activity when ROS are produced in order to neutralize free radicals. The TRX system is triggered and transduces redox signals to do this.

Understanding the role of smoking and chronic excess alcohol consumption on reduced caloric intake and the development of sarcopenia

This narrative review provides mechanistic insight into the biological link between smoking and/or chronic excess alcohol consumption, and increased risk of developing sarcopenia. Although the combination of excessive alcohol consumption and smoking is often associated with ectopic adipose deposition, this review is focused on the context of a reduced caloric intake (leading to energy deficit) that also may ensue due to either lifestyle habit. Smoking is a primary cause of periodontitis and chronic obstructive pulmonary disease that both induce swallowing difficulties, inhibit taste and mastication, and are associated with increased risk of muscle atrophy and mitochondrial dysfunction. Smoking may contribute to physical inactivity, energy deficit via reduced caloric intake, and increased systemic inflammation, all of which are factors known to suppress muscle protein synthesis rates. Moreover, chronic excess alcohol consumption may result in gut microbiota dysbiosis and autophagy-induced hyperammonemia, initiating the up-regulation of muscle protein breakdown and down-regulation of muscle protein synthesis via activation of myostatin, AMPK and REDD1, and deactivation of IGF-1. Future research is warranted to explore the link between oral healthcare management and personalised nutrition counselling in light of potential detrimental consequences of chronic smoking on musculoskeletal health outcomes in older adults. Experimental studies should investigate the impact of smoking and chronic excess alcohol consumption on the gut-brain axis, and explore biomarkers of smoking-induced oral disease progression. The implementation of behavioural change interventions and health policies regarding smoking and alcohol intake habits may mitigate the clinical and financial burden of sarcopenia on the healthcare system.

Ferroptosis: A New Development Trend in Periodontitis

Periodontitis is a chronic inflammatory disease associated with bacterial biofilm. It is characterized by loss of periodontal support tissue and has long been considered as a "silent disease". Because it is difficult to prevent and has a health impact that can not be ignored, researchers have been focusing on a mechanism-based treatment model. Ferroptosis is an iron-dependent regulatory form of cell death, that directly or indirectly affects glutathione peroxidase through different signaling pathways, resulting in a decrease in cell antioxidant capacity, accumulation of reactive oxygen species and lipid peroxidation, which cause oxidative cell death and tissue damage. Recently, some studies have proven that iron overload, oxidative stress, and lipid peroxidation exist in the process of periodontitis. Based on this, this article reviews the relationship between periodontitis and ferroptosis, in order to provide a theoretical reference for future research on the prevention and treatment of periodontal disease.

Apitherapy and Periodontal Disease: Insights into In Vitro, In Vivo, and Clinical Studies

Periodontal diseases are caused mainly by inflammation of the gums and bones surrounding the teeth or by dysbiosis of the oral microbiome, and the Global Burden of Disease study (2019) reported that periodontal disease affects 20-50% of the global population. In recent years, more preference has been given to natural therapies compared to synthetic drugs in the treatment of periodontal disease, and several oral care products, such as toothpaste, mouthwash, and dentifrices, have been developed comprising honeybee products, such as propolis, honey, royal jelly, and purified bee venom. In this study, we systematically reviewed the literature on the treatment of periodontitis using honeybee products. A literature search was performed using various databases, including PubMed, Web of Science, ScienceDirect, Scopus, clinicaltrials.gov, and Google Scholar. A total of 31 studies were reviewed using eligibility criteria published between January 2016 and December 2021. In vitro, in vivo, and clinical studies (randomized clinical trials) were included. Based on the results of these studies, honeybee products, such as propolis and purified bee venom, were concluded to be effective and safe for use in the treatment of periodontitis mainly due to their antimicrobial and anti-inflammatory activities. However, to obtain reliable results from randomized clinical trials assessing the effectiveness of honeybee products in periodontal treatment with long-term follow-up, a broader sample size and assessment of various clinical parameters are needed.

Melatonin levels in periodontitis vs. the healthy state: A systematic review and meta-analysis

The aim was to provide a comprehensive qualitative and quantitative assessment of any potential differences in melatonin levels in periodontitis vs. the healthy state. The keyword combination "melatonin" AND "periodontitis" was searched in Web of Science, PubMed, and Scopus. Qualitative analysis and quantitative analysis were performed on articles satisfying the inclusion criteria. Only 14 studies were included in the systematic review, out of which only 10 had quantitative data compatible with a meta-analysis. Ten studies demonstrated low melatonin in periodontitis, three studies demonstrated an initial reduction in melatonin levels followed by elevation with worsening of periodontitis, and one study showed an elevation in melatonin levels in the transition from a healthy state to periodontitis. Grading of recommendations assessment, development, and evaluation revealed that all the included studies had low to very low overall evidence. The meta-analysis revealed a significant reduction (p < .0001) in salivary melatonin levels in chronic periodontitis (3.26 ± 3.44 pg/ml) compared with healthy controls (5.27 ± 5.39 pg/ml), with a mean difference of 2.65 ± 7.84 and a confidence interval of 1.94-3.36. The significantly lower salivary melatonin levels in periodontitis must be inferred with caution given the low quality of the included studies.

Aggravating Effects of Psychological Stress on Ligature-Induced Periodontitis via the Involvement of Local Oxidative Damage and NF-κB Activation

Periodontitis is the leading cause of tooth loss in adults, and psychological factors play an important role in the development of periodontitis. To elucidate the adverse effects of psychological stress on the inflammatory process and redox status of periodontitis tissue, fifty male Sprague-Dawley rats were divided into the control, experimental periodontitis, psychological stress, experimental periodontitis plus psychological stress, and experimental periodontitis plus psychological stress plus fluoxetine groups. Chronic unpredictable mild stress (CUMS) was used to establish psychological stress, and silk ligature was used to induce experimental periodontitis. Four weeks later, stressed rats showed altered behaviour, serum hormone levels, and sucrose preference. More obvious alveolar bone loss and attachment loss and higher protein expressions of inflammatory cytokines were observed in the experimental periodontitis plus psychological stress group. The combination of CUMS and periodontitis had synergistic effects on increasing hypoxia-inducible factor-1α (HIF-1α) protein expression and reactive oxygen species (ROS) and malondialdehyde (MDA) contents and decreasing antioxidant enzyme activities compared with those in the stress or periodontitis groups. Moreover, psychological stress further increased p-IκBα and p-NF-κB p65 protein levels and decreased IκBα protein levels in periodontitis rats. Fluoxetine administration alleviated the adverse effects of psychological stress on the progression of periodontitis in rats. These results hint us that psychological stress could aggravate inflammation in periodontitis tissues, which may be partly due to local worsening of oxidative damage and further activation of the nuclear factor kappa-B (NF-κB) signalling pathway.

Oxidative/anti-oxidative effects of colloidal silver ions and chlorhexidine in saliva and gingival fluid of periodontal patients

Background/Aim. Chronic periodontitis is an inflammatory disease. Oxidative stress is an important factor in periodontitis progress, hence examining the antioxidative properties of antiseptics, such as chlorhexidine (CHX) and silver ions solution (SSI), is a beneficial biomarker in estimating the recovery of tissue impairment during periodontal disease treatment. Methods. This clinical trial was conducted on the control group referred to healthy volunteers and individuals with periodontal disease, divided into two subgroups: before and after applying antiseptic treatments (CHX or SSI). Measurements of oxidative/antioxidative parameters were addressed to determine thiobarbituric acid products (TBARS) concentration and total superoxide dismutase (tSOD) activity in saliva and gingival crevicular fluid (GCF) of periodontal patients. Results. TBARS concentration was increased in saliva before the CHX treatment compared to the periodontal group after the CHX treatment, as well as before both CHX and SSI antiseptic treatment in CGF, compared to controls and periodontal groups after the treatment. Patients before SSI treatment had increased tSOD activity in saliva compared to the control group treated with SSI, as well as compared to patients after the SSI treatment. Additionally, tSOD activity was increased in GCF in patients with periodontitis before antiseptic treatment (CHX, SSI) compared to the control or the group of patients after the appropriate treatment. Conclusion. Our results revealed elevated lipid peroxidation in CGF, which reflected the promotion of oxidative stress during periodontal inflammation. The study suggests that antiseptics with antioxidant properties may reduce tissue damage initiated by periodontal disease. Moreover, the determination of oxidative/antioxidative parameters can be important for diagnosing, monitoring, and prognosis of the clinical state of periodontal patients.

Assessment of Levels of Plasma Oxidative Stress in Patient Having Aggressive Periodontitis before and after Full Mouth Disinfection

Aim:

The primary purpose of the study was to evaluate the levels of oxidative stress in plasma in patients with aggressive periodontitis (AgP) before and after full-mouth disinfection.

Materials and Methods:

Twenty-five healthy controls and 25 participants with aggressive periodontal were assessed for plaque index, probing pocket depth, papillary bleeding index, and clinical attachment level. Periodontal bone support was assessed by taking full mouth periapical radiographs. Full-mouth disinfection of the patient was done within 24 h of clinical assessment of AgP. These parameters were assessed at the baseline and after 8 weeks of initial periodontal therapy. Plasma samples were taken and evaluated for various oxidative stress markers.

Results:

Strong positive correlation was observed among periodontal parameters and levels of enzymatic/nonenzymatic biomarkers for oxidative stress (thiobarbituric acid-reactive substances [TBARS], glutathione peroxidase [GPX], and catalase [CAT]) (P < 0.05), before and after periodontal management. The patients with AgP had high levels of TBARS, GPX, and CAT levels in the plasma matched to the healthy individuals (P < 0.05).

Conclusion:

Enzymatic and nonenzymatic oxidative stress may have a role in the pathogenesis AP. Initial periodontal treatment can lead to the reduction of these stresses.

Effects of Non-Surgical Periodontal Treatment on Reactive Oxygen Metabolites and Glycemic Control in Diabetic Patients with Chronic Periodontitis

BACKGROUND

Periodontal infection may contribute to poor glycemic control and systemic inflammation in diabetic patients. The aim of the present study is to evaluate the efficacy of non-surgical periodontal treatment in diabetic patients by measuring oxidative stress outcomes.

METHODS

Sixty diabetic patients with periodontitis were enrolled, treated with scaling and full-mouth disinfection, and randomly prescribed chlorhexidine mouthwash, antioxidant mouthwash, or ozone therapy. Reactive oxygen metabolites (ROMs), periodontal parameters, and glycated hemoglobin were measured at baseline and then at 1, 3, and 6 months after.

RESULTS

At baseline, all patients presented with pathologic levels of plasmatic ROM (388 ± 21.36 U CARR), higher than the normal population. Probing depth, plaque index, and bleeding on probing values showed significant clinical improvements after treatment, accompanied by significant reductions of plasma ROM levels (p < 0.05). At the 6-month evaluation, the mean ROM relapsed to 332 ± 31.76 U CARR. Glycated hemoglobin decreased significantly (∆ = -0.52 units) after treatment. Both the test groups showed longer-lasting improvements of periodontal parameters.

CONCLUSION

In diabetic patients, periodontal treatment was effective at reducing plasma ROM, which is an indicator of systemic oxidative stress and inflammation. The treatment of periodontal infection might facilitate glycemic control and decrease systemic inflammation.

Effectiveness of Propolis in the Treatment of Periodontal Disease: Updated Systematic Review with Meta-Analysis

In recent times, the use of natural products has gained momentum, either as a treatment or as adjuvants for other drugs in the treatment of different conditions. Propolis is a natural substance produced by bees which has proven useful for treating periodontal disease. This systematic review and meta-analysis gather evidence of the effectiveness of propolis in this kind of condition. The MEDLINE, CENTRAL, PubMed, EMBASE and Web of Science databases were searched for scientific articles to identify the findings published up to October 2020. The MeSH phrases used in the search were: “periodontal diseases AND propolis treatment”; “gingivitis AND propolis treatment”; “periodontitis AND propolis treatment”; “propolis treatment AND oral health”; “propolis AND oxidative stress AND periodontitis”. The Boolean operator “AND” was used to combine the searches. Randomized trials where propolis was used in the treatment of different periodontal conditions were included. Non-randomized clinical studies were systematically reviewed and 224 studies were detected, eight of which met the criteria for inclusion in the meta-analysis. Only three of these were selected for quantitative synthesis. In conclusion, propolis is safe to use and can improve the results of periodontal disease treatment, reducing probing pocket depth compared with treatment with a placebo (difference in means, fixed effects −0.67 [95% CI: −0.84, −0.50]).

Periodontal Disease and Senescent Cells: New Players for an Old Oral Health Problem?

The recent identification of senescent cells in periodontal tissues has the potential to provide new insights into the underlying mechanisms of periodontal disease etiology. DNA damage-driven senescence is perhaps one of the most underappreciated delayed consequences of persistent Gram-negative bacterial infection and inflammation. Although the host immune response rapidly protects against bacterial invasion, oxidative stress generated during inflammation can indirectly deteriorate periodontal tissues through the damage to vital cell macromolecules, including DNA. What happens to those healthy cells that reside in this harmful environment? Emerging evidence indicates that cells that survive irreparable genomic damage undergo cellular senescence, a crucial intermediate mechanism connecting DNA damage and the immune response. In this review, we hypothesize that sustained Gram-negative bacterial challenge, chronic inflammation itself, and the constant renewal of damaged tissues create a permissive environment for the abnormal accumulation of senescent cells. Based on emerging data we propose a model in which the dysfunctional presence of senescent cells may aggravate the initial immune reaction against pathogens. Further understanding of the role of senescent cells in periodontal disease pathogenesis may have clinical implications by providing more sophisticated therapeutic strategies to combat tissue destruction.

Genetic susceptibility analysis of GCLC rs17883901 polymorphism to preeclampsia in Chinese Han women

Preeclampsia (PE) is a specific obstetric disorder that may result in maternal and neonatal morbidity and mortality. Increasing evidence has been indicated that some candidate genes related to oxidative stress, such as glutamate-cysteine ligase, catalytic subunit (GCLC), glutamate-cysteine ligase, modifier subunit (GCLM), involve in the pathogenesis of PE. After the genetic contribution of GCLC rs17883901 polymorphism was analyzed by TaqMan allelic discrimination real-time PCR in 1001 PE patients and 1182 normal pregnant women, a case-control association analysis was performed. Although no statistical difference was found in genetic distribution of rs17883901 in GCLC between PE and control group (χ² = 2.201, p = .333 by genotypic, χ² = 0.524, p = .469, OR = 0.932, 95%CI = 0.771-1.128 by allelic), significant differences in the genotypic frequencies were investigated between mild PE group (χ² = 6.999, p = .030) or late-onset PE group (χ² = 6.197, p = .045) and control group. Furthermore, when dividing the mild PE patients, the late-onset PE patients and the controls into TT/CT + CC, TT + CT/CC, and TT/CC subgroups, we found statistical differences between mild PE and controls (TT/CT + CC:χ² = 5.132, p = .023, OR = 2.948, 95%CI = 1.107-7.854; TT/CC:χ² = 4.564, p = .033, OR = 2.793, 95%CI = 1.046-7.460) as well as late-onset PE and controls (TT/CT + CC:χ² = 4.043, p = .044, OR = 2.248, 95%CI = 1.000-5.055). This is the first study to indicate GCLC rs17883901 polymorphism may be associated with a risk of mild PE and late-onset PE in Chinese Han women. However, additional well-designed studies with multi-ethnic and large-scale samples should be performed to validate our results.

Low-intensity Pulsed Ultrasound regulates alveolar bone homeostasis in experimental Periodontitis by diminishing Oxidative Stress

Periodontitis is a widespread oral disease that results in the loss of alveolar bone. Low-intensity pulsed ultrasound (LIPUS), which is a new therapeutic option, promotes alveolar bone regeneration in periodontal bone injury models. This study investigated the protective effect of LIPUS on oxidative stress in periodontitis and the mechanism underlying this process.

Methods: An experimental periodontitis model was induced by administering a ligature. Immunohistochemistry was performed to detect the expression levels of oxidative stress, osteogenic, and osteoclastogenic markers in vivo. Cell viability and osteogenic differentiation were analyzed using the Cell Counting Kit-8, alkaline phosphatase, and Alizarin Red staining assays. A reactive oxygen species assay kit, lipid peroxidation MDA assay kit, and western blotting were used to determine oxidative stress status in vitro. To verify the role of nuclear factor erythroid 2-related factor 2 (Nrf2), an oxidative regulator, during LIPUS treatment, the siRNA technique and Nrf2^-/- mice were used. The PI3K/Akt inhibitor LY294002 was utilized to identify the effects of the PI3K-Akt/Nrf2 signaling pathway.

Results: Alveolar bone resorption, which was experimentally induced by periodontitis in vivo, was alleviated by LIPUS via activation of Nrf2. Oxidative stress, induced via H₂O₂ treatment in vitro, inhibited cell viability and suppressed osteogenic differentiation. These effects were also alleviated by LIPUS treatment via Nrf2 activation. Nrf2 silencing blocked the antioxidant effect of LIPUS by diminishing heme oxygenase-1 expression. Nrf2^-/- mice were susceptible to ligature-induced periodontitis, and the protective effect of LIPUS on alveolar bone dysfunction was weaker in these mice. Activation of Nrf2 by LIPUS was accompanied by activation of the PI3K/Akt pathway. The oxidative defense function of LIPUS was inhibited by exposure to LY294002 in vitro.

Conclusions: These results demonstrated that LIPUS regulates alveolar bone homeostasis in periodontitis by attenuating oxidative stress via the regulation of PI3K-Akt/Nrf2 signaling. Thus, Nrf2 plays a pivotal role in the protective effect exerted by LIPUS against ligature-induced experimental periodontitis.

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.

Self-Propelled PLGA Micromotor with Chemotactic Response to Inflammation

Local drug delivery systems have recently been developed for multiple diseases that have the requirements of site-specific actions, prolonged delivery periods, and decreased drug dosage to reduce undesirable side effects. The challenge for such systems is to achieve directional and precise delivery in inaccessible narrow lesions, such as periodontal pockets or root canals in deeper portions of the dentinal tubules. The primary strategy to tackle this challenge is fabricating a smart tracking delivery system. Here, drug-loaded biodegradable micromotors showing self-propelled directional movement along a hydrogen peroxide concentration gradient produced by phorbol esters-stimulated macrophages are reported. The drug-loaded poly(lactic-co-glycolic acid) micromotors with asymmetric coverage of enzyme (patch-like enzyme distribution) are prepared by electrospraying and postfunctionalized with catalase via 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide coupling. Doxycycline, a common drug for the treatment of periodontal disease, is selected as a model drug, and the release study by high-performance liquid chromatography is shown that both the postfunctionalization step and the presence of hydrogen peroxide have no negative influence on drug release profiles. The movement behavior in the presence of hydrogen peroxide is confirmed by nanoparticle tracking analysis. An in vitro model is designed and confirmed the response efficiency and directional control of the micromotors toward phorbol esters-stimulated macrophages.

Does Periodontal Inflammation Affect Type 1 Diabetes in Childhood and Adolescence? A Meta-Analysis

The emergence of link between periodontal disease and diabetes has created conditions for analyzing new interdisciplinary approach making toward tackling oral health and systemic issues. As periodontal disease is a readily modifiable risk factor this association has potential clinical implications. The aim of this paper was systematically review the extant literature related to analytics data in order to identify the association between type 1 diabetes (T1DM) in childhood and adolescence with periodontal inflammation. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a database search between 2004 and 2019. A manual search of the literature was conducted as an additional phase of the search process, with the aim of identifying studies that were missed in the primary search. One hundred and thirty-nine records were screened and 10 fulfilled the inclusion criteria. Most studies were of moderate methodological quality. Outcomes included assessments of diabetes and periodontal status. In diabetic populations, compared to healthy subjects, interindividual differences in periodontal status are reflected in higher severity of periodontal inflammation. The most reported barriers to evidence uptake were the intrinsic limits of cross-sectional report data and relevant research, and lack of timely research output. Based on the evidence presented within the literature, the aforementioned biomarkers correlate with poor periodontal status in type 1 diabetic patients. Whilst the corpus of the evidence suggests that there may be an association between periodontal status and type 1 diabetes, study designs and methodological limitations hinder interpretation of the current research.

Poor Oral Health as a Determinant of Malnutrition and Sarcopenia

Aging is accompanied by profound changes in many physiological functions, leading to a decreased ability to cope with stressors. Many changes are subtle, but can negatively affect nutrient intake, leading to overt malnutrition. Poor oral health may affect food selection and nutrient intake, leading to malnutrition and, consequently, to frailty and sarcopenia. On the other hand, it has been highlighted that sarcopenia is a whole-body process also affecting muscles dedicated to chewing and swallowing. Hence, muscle decline of these muscle groups may also have a negative impact on nutrient intake, increasing the risk for malnutrition. The interplay between oral diseases and malnutrition with frailty and sarcopenia may be explained through biological and environmental factors that are linked to the common burden of inflammation and oxidative stress. The presence of oral problems, alone or in combination with sarcopenia, may thus represent the biological substratum of the disabling cascade experienced by many frail individuals. A multimodal and multidisciplinary approach, including personalized dietary counselling and oral health care, may thus be helpful to better manage the complexity of older people. Furthermore, preventive strategies applied throughout the lifetime could help to preserve both oral and muscle function later in life. Here, we provide an overview on the relevance of poor oral health as a determinant of malnutrition and sarcopenia.

Biochemical parameters and oxidative stress markers in Tunisian patients with periodontal disease

BACKGROUND

Oxidative stress is involved in many diseases including diabetes and cancer. Numbers of studies have suggested its involvement in the pathogenesis of periodontal diseases. The aim of this study was to evaluate the levels of biochemical parameters and oxidative stress markers in plasma of healthy and chronic periodontitis patients.

METHODS

One hundred thirty subjects were divided into two groups; patients (mean age = 42 ± 13.6 y.o) and control (mean age = 44.8 ± 12.6 y.o). Patients and healthy subjects were free from any infection, coronary or heart disease, diabetes or liver failure. Total cholesterol, LDLc, HDLc, Triglycerides (TG), creatinine, uric acid (UA), glucose and urea levels as well as the activities of enzymatic antioxidants such as catalase, glutathione reductase (GR) and total antioxidant capacity (TAOC), were measured in plasma samples using colorimetric assays. Statistical differences between groups were determined by Student's t-test and p ≤ 0.05 was considered as significant.

RESULTS

Periodontitis patients exhibited significant decrease in the activities of catalase, TAOC, GR and TG, cholesterol, LDLc, glucose, HDLc, uric acid levels in plasma samples in comparison with healthy subjects. However, no statistically significant differences in the levels of creatinine and urea were observed between the two groups.

CONCLUSION

The reduction of plasma antioxidant activities (Catalase, TAOC, GR) may have a role in the pathogenesis of periodontal diseases. Our findings suggest a decrease in the host capacity to control the damage caused by oxidative stress. Therefore, therapeutic strategies, aiming at modulating the oxidative stress could be considered as potential tools for the prevention or treatment of periodontal diseases and their potential systemic effects on the general health.

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.

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.

Hydrogen peroxide-based products alter inflammatory and tissue damage-related proteins in the gingival crevicular fluid of healthy volunteers: a randomized trial

Hydrogen peroxide (H2O2)-based products are effective in tooth whitening; however, their safety is controversial as they may harm patient tissues/cells. These effects are suggested to be concentration-dependent; nonetheless, to date, there are no reports on H2O2-mediated oxidative damage in the gingival tissue, and neither whether this can be detected in gingival crevicular fluid (GCF) samples. We hypothesize that H2O2 whitening products may cause collateral oxidative tissue damage following in office application. Therefore, H2O2 and nitric oxide (NO) levels were investigated in GCF samples obtained from patients undergoing dental bleaching with H2O2 at different concentrations, in a randomized, double-blind, split-mouth clinical trial. A proteomic analysis of these samples was also performed. H2O2-based whitening products promoted inflammation which was detected in GCF samples and lasted for longer following 35% H2O2 bleaching. This included time-dependent changes in NO levels and in the abundance of proteins associated with NO synthesis, oxidative stress, neutrophil regulation, nucleic acid damage, cell survival and/or tissue regeneration. Overall, H2O2-based products used in office promote inflammation irrespective of their concentration. As the inflammation caused by 35% H2O2 is longer, patients may benefit better from using lower concentrations of this bleaching product, as they may result in less tissue damage.

Adjunctive Effects of a Sub-Antimicrobial Dose of Doxycycline on Clinical Parameters and Potential Biomarkers of Periodontal Tissue Catabolism

Objectives: The aim of the present randomized, double-blind, placebo-controlled, parallel-arm study was to examine the effectiveness of a sub-antimicrobial dose of doxycycline (SDD) in combination with nonsurgical periodontal therapy, compared to nonsurgical periodontal therapy alone, on potential gingival crevicular fluid (GCF) biomarkers of periodontal tissue catabolism related to the clinical outcomes over a 12-month period. Materials and Methods: GCF was collected and clinical parameters were recorded from 30 periodontitis patients randomized either to an SDD or placebo group. The SDD group received SDD (20 mg) b.i.d for 3 months plus scaling and root planing (SRP), while the placebo group was given placebo capsules b.i.d for 3 months plus SRP. The patients were evaluated every 3 months during the 12-month study period. At each visit, clinical parameters and GCF sampling were repeated. Matrix metalloproteinase (MMP)-8, MMP-9, MMP-13, myeloperoxidase (MPO), osteoprotegerin (OPG), and tartrate-resistant acid phosphatase-5 (TRAP-5) were determined by IFMA and ELISA. Results: Significant improvements were observed in all clinical parameters in both groups over 12 months (p < 0.0125) while the SDD group showed significantly better reduction in gingival index (GI) and pocket depth and a gain in clinical attachment compared to the placebo group (p < 0.05). GCF MMP-8 and OPG levels significantly reduced in the SDD group compared to baseline (p < 0.05). GCF MMP-9 significantly decreased in both groups compared to baseline (p < 0.05). GCF MPO significantly decreased at 3 and 9 months in the SDD group, while it significantly decreased at 6 months in the placebo group (p < 0.05). TRAP and MMP-13 could be detected in none of the samples. Conclusions: The present results indicate that three months of adjunctive usage of SDD to nonsurgical periodontal therapy compared to nonsurgical periodontal therapy alone in periodontitis patients results in further improvement of clinical periodontal parameters and GCF markers of periodontal tissue breakdown over a 12-month period. Beneficial effects of adjunctive SDD therapy is likely to be related to the reduced levels of two major periodontitis-associated MMPs, MMP-8 and -9, and their potential oxidative activator MPO.

The association between periodontal disease severity and metabolic syndrome in Vietnamese patients

OBJECTIVE

To investigate the association between periodontal disease severity and metabolic syndrome (MetS) in a group of Vietnamese patients.

METHODS

A total of 412 participants (114 males, 298 females, average age 57.8 ± 5.7 years) including 206 patients with MetS and 206 participants without MetS were selected for this study. Information on sociodemographic characteristics, dental behaviours and smoking status was collected from a self-administrated questionnaire. Periodontal status including plaque index (PI), gingival index (GI) pocket depth (PD) and clinical attachment level (CAL) was recorded. Logistic regression analyses were used to evaluate the association between severity of periodontal disease and MetS with adjustments for related confounders.

RESULTS

The prevalence of moderate and severe periodontitis assessed by GI, PD and CAL was all significantly higher in the MetS group than in the control group and was significantly increased by a number of MetS components. Logistic regression, adjusted for confounders, showed that people with mean PI ≥2.51 or GI ≥1.01 or number of teeth with bleeding on probing of ≥20 teeth or PD ≥3.66 or CAL ≥3.66 showed a significant association with greater OR for MetS compared to counterparts (P < .05). The OR for MetS was 4.06 (95% CI 2.11-7.84) in severe periodontitis patients compared to non-periodontitis participants (P < .001).

CONCLUSION

Much severe and extensive periodontal disease was found in MetS participants and increased with number of MetS components. Participants with higher periodontal parameters had a higher risk of MetS.

Meta-Analysis of the Use of 8-OHdG in Saliva as a Marker of Periodontal Disease

The objective was to collect the available evidence on oxidative stress marker measurements in periodontal patients, focusing specifically on 8-hydroxy-2′-deoxyguanosine (8-OHdG) as a salivary marker of periodontal disease, and to perform meta-analyses to calculate differences in concentration compared to healthy persons. A systematic search in PubMed, Cochrane Library, Embase, and Scopus identified 81 articles. Of these, 38 were duplicates. After reading the abstracts of the remaining 43, 42 were selected for full-text assessment. Finally, 17 articles were included in the qualitative synthesis. Those excluded were of low quality, did not answer the research question, or did not meet the inclusion and exclusion criteria. Of the 17 in the qualitative synthesis, 9 were included in the meta-analysis. The 9 studies in the meta-analysis were combined in a random effects model. Their heterogeneity was high (Q = 3982.02, p < 0.001, I² = 99.8%). The difference in mean 8-OHdG concentration in saliva between periodontal and healthy subjects was estimated at 2.11 ng/ml (95% CI 1.23–2.98). The different saliva collection methods (stimulated/unstimulated) did not explain the heterogeneity. The 8-OHdG levels in saliva of periodontal patients were almost double to those of healthy patients: 8-OHdG is clearly a powerful periodontal disease marker.

Evaluation of the efficacy of Hylotelephium purpureum gel in the treatment of experimental periodontitis

Local drug delivery systems have been proposed for the treatment of periodontitis, and Hylotelephium purpureum may be a suitable agent for use in such a system. The present study aimed to formulate a Hylotelephium purpureum gel (HPG) and evaluate the anti-inflammatory activity and antinociceptive effects of Hylotelephium purpureum and to assess the duration of action and efficacy of HPG in the treatment of experimental periodontitis in a KM mouse model. First, an acute toxicity study was performed, and secondly, xylene-induced mouse-ear edema, acetic acid-induced mouse peritoneal capillary permeability and carrageenan-induced hind-paw edema tests were used to investigate the anti-inflammatory activity of the gel. The acetic acid-induced writhing response and hot-plate tests were used to evaluate the antinociceptive activity. The therapeutic effects of HPG in experimental periodontitis were evaluated and minimum inhibitory concentration of the gel was determined. The results showed that intragastrically administration of 80 ml/kg of HPG produced no toxic effects. There were statistically significant changes in gingival indexes and sulcus bleeding indexes in the high-dose HPG-treated group. The serum levels of superoxide dismutase and glutathione peroxidase were significantly heightened, while the level of malondialdehyde was decreased. HPG exhibited 32.7% inhibition of edema, and altered the peritoneal capillary permeability in mice. The gel had relatively good bacteriostatic and bactericidal effects. It also exhibited antinociceptive activity, as demonstrated by the acetic acid-induced writhing response test and hot-plate test. In summary, the present study demonstrates that HPG is effective in the treatment of experimental periodontitis.

Impact of nonsurgical periodontal therapy on total antioxidant capacity in chronic periodontitis patients

Aim:

The aim of this study was to determine the utility of plasma total antioxidant capacity (TAC) as marker of periodontal disease by estimating TAC of periodontally healthy and chronic periodontitis patients and the impact of scaling and root planning on total antioxidant status of periodontitis patients.

Materials and Methods:

Blood plasma samples were collected from randomly selected eighty individuals (40 periodontally healthy controls and 40 chronic periodontitis patients), with an age range of 20–45 years and were analyzed for TAC by ferric reducing antioxidant power assay. Scaling and root planing was performed in periodontitis patients, and TAC level was measured again after 3 weeks. Data were analyzed with t-test, using SPSS software (PSAW, Windows version 18.0).

Results:

The mean plasma TAC was significantly lower (792.33 ± 124.33 μmol/L, P < 0.001) in chronic periodontitis patients compared to healthy control (1076.08 ± 193.82 μmol/L). Plasma TAC level increased significantly (989.75 ± 96.80, P < 0.001) after scaling and root planing.

Conclusions:

An inverse relationship exists between plasma TAC and severity of chronic periodontitis suggesting disturbed oxidant-antioxidant balance in chronic periodontitis. Scaling and root planing resulted in the restoration of TAC to normal levels. These results are important from the perspective of including antioxidants in periodontal therapy regime to boost up body's antioxidant defense system and to reduce oxidative stress-mediated periodontal tissue damage. We concluded that TAC can be used as a biomarker to evaluate the health of periodontium.

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.

The effects of non-surgical periodontal treatment on glycemic control, oxidative stress balance and quality of life in patients with type 2 diabetes: A randomized clinical trial

Aim

The purpose of this study was to investigate the effects of non-surgical periodontal treatment on hemoglobinA1c (HbA1c) levels, oxidative stress balance and quality of life (QOL) in patients with type 2 diabetes mellitus (T2DM) compared to no periodontal treatment (simple oral hygiene instructions only).

Methods

The design was a 6-month, single-masked, single center, randomized clinical trial. Patients had both T2DM and chronic periodontitis. Forty participants were enrolled between April 2014 and March 2016 at the Nephrology, Diabetology and Endocrinology Department of Okayama University Hospital. The periodontal treatment group (n = 20) received non-surgical periodontal therapy, including scaling and root planing plus oral hygiene instructions, and consecutive supportive periodontal therapy at 3 and 6 months. The control group (n = 17) received only oral hygiene instructions without treatment during the experimental period. The primary study outcome was the change in HbA1c levels from baseline to 3 months. Secondary outcomes included changes in oxidative stress balance (Oxidative-INDEX), the Diabetes Therapy-Related QOL and clinical periodontal parameters from baseline to 3 months and baseline to 6 months.

Results

Changes in HbA1c in the periodontal treatment group were not significantly different with those in the control group at 3 and 6 months. Systemic oxidative stress balance and QOL significantly improved in the periodontal treatment group compared to the control group at 3 months. In the subgroup analysis (moderately poor control of diabetes), the decrease in HbA1c levels in the periodontal treatment group was greater than that in the control group at 3 months but not significant.

Conclusions

In T2DM patients, non-surgical periodontal treatment improved systemic oxidative stress balance and QOL, but did not decrease HbA1c levels at 3 months follow-up.

Trial registration

Current Controlled Trials UMIN-ICDR UMIN 000013278 (Registered April 1, 2014).

Role of the adjunctive antimicrobial photodynamic therapy to periodontal treatment at plasmatic oxidative stress and vascular behavior

BACKGROUND

To evaluate for the first time in vivo the effects of methylene blue (MB) photosensitizer dissolved in ethanol in antimicrobial photodynamic therapy (aPDT) as adjuvant periodontal treatment, at plasmatic oxidative stress and vascular behavior in rat model.

METHODS

Wistar rats were divided into negative control (NC, no periodontitis) and positive control (PC, with periodontitis, without any treatment). The other groups had periodontitis and were treated with scaling and root planing (SRP); SRP+aPDT+MB dissolved in water (aPDT I); SRP+aPDT+MB dissolved in ethanol (aPDT II). The periodontitis was induced by ligature at the mandibular right first molar. At 7/15/30days, rats were euthanized, the plasma was used to determine oxidative stress parameters and gingival tissue for histomorphometric analysis.

RESULTS

PC showed higher thiobarbituric acid reactive substances levels in 7/15/30days. aPDT II was able to block the lipid peroxidation, especially between 15th and 30th days. Glutathione reduced levels were consumed in PC, aPDT I and II groups throughout the experiment. aPDT II increased the vitamin C levels which were restored in this group in the 30th day. aPDT II group showed the highest number of blood vessels.

CONCLUSION

In summary, the aPDT with MB dissolved in ethanol provides better therapeutic responses in periodontitis treatment.

LPS from P. gingivalis Negatively Alters Gingival Cell Mitochondrial Bioenergetics

OBJECTIVE

Oral inflammatory pathologies are linked to increased oxidative stress, thereby partly explaining their relevance in the etiology of systemic disorders. The purpose of this work was to determine the degree to which LPS from Porphyromonas gingivalis, the primary pathogen related to oral inflammation, altered gingival mitochondrial function and reactive oxygen species generation.

METHODS

Human gingival fibroblast (HGF-1) cells were treated with lipopolysaccharide of P. gingivalis. Mitochondrial function was determined via high-resolution respirometry.

P GINGIVALIS

Mitochondrial function was determined via high-resolution respirometry.

RESULTS

LPS-treated HGF-1 cells had significantly higher mitochondrial complex IV and higher rates of mitochondrial respiration. However, this failed to translate into greater ATP production, as ATP production was paradoxically diminished with LPS treatment. Nevertheless, production of the reactive H2O2 was elevated with LPS treatment.

CONCLUSIONS

LPS elicits an increase in gingival cell mitochondria content, with a subsequent increase in reactive oxygen species production (i.e., H2O2), despite a paradoxical reduction in ATP generation. These findings provide an insight into the nature of oxidative stress in oral inflammatory pathologies.

Antimicrobial photodynamic therapy with photosensitizer in ethanol improves oxidative status and gingival collagen in a short-term in periodontitis

BACKGROUND

This study evaluated the antimicrobial photodynamic therapy (aPDT) effects using the methylene blue (MB) in ethanol 20% on systemic oxidative status and collagen content from gingiva of rats with periodontitis.

METHODS

Rats were divided into five experimental groups: NC (negative control; no periodontitis); PC (positive control; periodontitis without any treatment); SRP (periodontitis and scaling and root planing), aPDT I (periodontitis and SRP+aPDT+MB solubilized in water), and aPDT II (periodontitis and SRP+aPDT+MB solubilized in ethanol 20%). After 7days of removal of the ligature, the periodontal treatments were performed. At 7/15/30days, gingival tissue was removed for morphometric analysis. The erythrocytes were used to evaluate systemic oxidative status.

RESULTS

PC group showed higher lipoperoxidation levels at 7/15/30days. aPDT indicated a protective influence in erythrocytes at 15days observed by the elevation in levels of systemic antioxidant defense. aPDT II group was the only one that restored the total collagen area in 15days, and recovered the type I collagen area at the same time point.

CONCLUSIONS

aPDT as an adjunct to the SRP can induce the systemic protective response against oxidative stress periodontitis-induced and recover the gingival collagen, thus promoting the healing periodontal, particularly when the MB is dissolved in ethanol 20%.

Oral health and coronary heart disease

BACKGROUND

It is well documented that there is some correlation between poor oral health in the form of periodontal disease and coronary heart disease (CHD). It is unclear whether this correlation is due to a causal relationship or shared underlying disorder such as inflammation. A suitable integrated model of the CHD pathogenetic pathways relevant to periodontal disease may help to elucidate the association. Such a model is currently not available in literature.

METHODS

A previously developed integrated model of CHD was used to investigate potential pathogenetic pathways linking periodontal disease to CHD biomarkers.

RESULTS

The integrated model was created to provide insight into possible higher-order biological interactions underlying CHD and periodontal disease. In order to simplify these interactions a novel 'connection graph' was developed. It quantitatively illustrates the relationship between periodontal disease and various serological biomarkers of CHD. The pathogenesis of periodontitis shows various possible pathways which could link periodontitis to CHD pathogenesis.

CONCLUSION

An integrated model of CHD was developed which provides a summary of the potential CHD effects of periodontal disease. Further research must refine and validate the model.

Deleterious effect of chronic continuous hypoxia on oral health

OBJECTIVE

To evaluate the effect of chronic continuous hypoxia (CCH) in alveolar bone and its correlation with the inflammatory markers which play a key role in the development of periodontitis.

MATERIAL AND METHODS

Wistar rats were exposed to CCH (600mbar, 3 months). Macroscopic and histological analyses of alveolar bone were performed, together with measurement of oxidative stress and inflammatory parameters in gums and submandibular glands (SMG).

RESULTS

HCC induced cortical alveolar bone loss, decreased interradicular bone volume and increased the periodontal ligament height compared to control rats (p<0.05). CCH enhanced iNOS activity in gums (from 2735,04±662,96 nmol/min/mg proteins to 4289,58±915,63 p<0.05) and in SMG (from 56,71±12,05 nmol/min/mg proteins to 90,15±21,78 p<0.05). PGE₂ did not change in gums or in SMG by means of CCH, while TNFα decreased in gums (p<0.05). Regarding oxidative stress, thiobarbituric acid reactive species concentration in CCH animals was higher both in gums as in SMG, and catalase activity was decreased in SMG.

CONCLUSION

Higher iNOS activity both in gums and SMG under CCH could be associated with the alveolar bone loss observed. The increase in oxidative stress occurring in SMG and gums, together with a lower antioxidant capacity might indicate a deleterious effect of HX in oral health.

Influence of Periodontal Clinical Status on Salivary Levels of Glutathione Reductase

BACKGROUND

Inadequate antioxidant balance may play a role in the excessive tissue breakdown in periodontitis. Because aggressive periodontitis (AgP) not only differs from chronic periodontitis (CP) in terms of clinical manifestations, this study investigates whether the salivary levels of glutathione reductase (GR) may be linked with periodontal status.

METHODS

Saliva samples from patients with CP (n = 121), patients with AgP (n = 18), and healthy controls (n = 69) were collected. Periodontal status was assessed by criteria based on probing depth, clinical attachment level, and extent and severity of periodontal breakdown. GR salivary levels were analyzed by spectrophotometry. The association among GR concentration and CP or AgP was analyzed individually and adjusted for confounding using multivariate binary logistic regression models.

RESULTS

GR levels not only differed significantly between the two periodontitis groups, being significantly greater in patients with AgP, but also were significantly greater than those observed in healthy controls. Synchronously, positive significant correlations between salivary GR concentration and clinical parameters were observed. After binary logistic regression analysis, both GR salivary levels ≥15.38 and ≥24.20 mU/mL were associated independently with CP and AgP, respectively. A significant interaction effect was also detected between increased GR salivary concentration and aging in the CP group.

CONCLUSIONS

Increased GR salivary concentration may be a strong/independent prognostic indicator of the amount and extent of oxidative stress-induced periodontal damage in both CP and AgP. Likewise, saliva samples might reflect an interactive effect of GR levels associated with the aging-related cumulative characteristics of periodontal damage in CP.