Periodontal Disease-Induced Atherosclerosis and Oxidative Stress

Comparative Evaluation of Salivary Cathelicidin and 8-Isoprostane Levels Among Smokeless Tobacco Users and Non-users and Their Correlation With Periodontal Health and Disease: A Cross-Sectional Study

Introduction Periodontal diseases arise from host-microbial interactions influenced by tobacco products. Salivary antimicrobial peptides such as salivary cathelicidin and prostaglandins such as 8-isoprostane are part of the inflammatory cascade affecting periodontal disease pathogenesis. Methodology A total of 93 patients, 31 in each group that is healthy, periodontitis, and periodontitis with smokeless tobacco habit patients, were enrolled. The case history was recorded, and clinical examination was performed using periodontal parameter analysis of oral hygiene index simplified (OHIS), Russell's index, periodontal pocket depth (PPD), and clinical attachment level (CAL). The saliva samples were collected and subjected to an enzyme-linked immunosorbent assay (ELISA) to evaluate cathelicidin and 8-isoprostane. The results were analysed and compared statistically. Results The OHIS, Russell's index, pocket probing depth, and CAL were high in patients with periodontitis and tobacco habit (p<0.001). The cathelicidin levels were the highest in patients with periodontitis and the tobacco habit (1.6 g/mL). The level of 8-isoprostane was the highest in patients with periodontitis with tobacco habit (1.8 pg/mL). Smokeless tobacco users showed higher levels of cathelicidin and 8-isoprostane in periodontitis with tobacco than in the healthy group. Conclusion Increased cathelicidin and 8-isoprostane levels in smokeless tobacco users with periodontitis suggest risk biomarkers for tobacco-influenced periodontitis.

The regulatory effect of zinc on the association between periodontitis and atherosclerotic cardiovascular disease: a cross-sectional study based on the National Health and Nutrition Examination Survey

BACKGROUND

Zinc has been proven to be effective against periodontitis, and also reported to reduce the risk of cardiovascular diseases (CVD). This study aims to explore the regulatory effect of zinc intake on the association between periodontitis and atherosclerotic cardiovascular disease (ASCVD).

METHODS

This was a cross-sectional study based on the National Health and Nutrition Examination Survey (NHANES). Logistic regression model was used to explore the association between zinc-RDA or periodontitis and 10-year ASCVD risk ≥ 20%, and results were shown as odds ratio (OR) and 95% confidence interval (95% CI). The regulatory effect of zinc intake on the association between periodontitis and 10-year ASCVD risk ≥ 20% was also assessed using logistic regression model. Subgroup analysis was performed based on age, gender, obesity, education level, lipid-lowering therapy, and dental floss.

RESULTS

6,075 patients were finally included for analysis. Zinc intake reaching the recommended level (OR = 0.82, 95%CI: 0.69-0.98) and periodontitis (OR = 2.47, 95%CI: 2.04-3.00) were found to be associated with 0.82-fold and 2.47-fold odds of 10-year ASCVD risk ≥ 20%, respectively. In addition, we found that the odds of 10-year ASCVD risk ≥ 20% was lower in patients with zinc intake reaching the recommended level than those without [OR (95%CI): 2.25 (1.81-2.80) vs. 2.72 (2.05-3.62)]. The similar regulatory effect was found in patients with age ≥ 60 years and < 60 years, in male and female, with or without obesity, in different education levels, with or without lipid lowering therapy, and with or without use of dental floss (all P < 0.05).

CONCLUSIONS

This study found the regulatory effect of adequate zinc intake on the association between periodontitis and ASCVD, providing guidance for periodontitis patients to decrease the risk of ASCVD.

Thrombus Aspirates From Patients With Acute Ischemic Stroke Are Infiltrated by Viridans Streptococci

BACKGROUND

Acute ischemic stroke may be due to embolism from ruptured atherosclerotic carotid arteries. DNA of oral bacteria, mainly the viridans streptococci group, has been detected in thrombus aspirates of patients with ischemic stroke as well as in carotid endarterectomy samples. Because viridans streptococci are known to possess thrombogenic properties, we studied whether their presence in thrombus aspirates and in carotid artery specimens can be confirmed using bacterial immunohistochemistry.

METHODS AND RESULTS

Thrombus aspirates from 61 patients with ischemic stroke (70.5% men; mean age, 66.8 years) treated with mechanical thrombectomy, as well as carotid endarterectomy samples from 20 symptomatic patients (65.0% men; mean age, 66.2 years) and 48 carotid artery samples from nonstroke autopsy cases (62.5% men; mean age, 66.4 years), were immunostained with an antibody cocktail against 3 species (Streptococcus sanguinis, Streptococcus mitis, and Streptococcus gordonii) of viridans streptococci. Of the thrombus aspirates, 84.8% were immunopositive for viridans streptococci group bacteria, as were 80.0% of the carotid endarterectomy samples, whereas immunopositivity was observed in 31.3% of the carotid artery samples from nonstroke autopsies. Most streptococci were detected inside neutrophil granulocytes, but there were also remnants of bacterial biofilm as well as free bacterial infiltrates in some samples.

CONCLUSIONS

Oral streptococci were found in aspirated thrombi of patients with acute ischemic stroke as well as in carotid artery samples. Our results suggest that viridans streptococci group bacteria may play a role in the pathophysiology of ischemic stroke.

Free Radicals and Obesity-Related Chronic Inflammation Contrasted by Antioxidants: A New Perspective in Coronary Artery Disease

We are surrounded by factors called free radicals (FR), which attach to the molecules our body is made of, first among them the endothelium. Even though FR are to a certain extent a normal factor, nowadays we face an escalating increase in these biologically aggressive molecules. The escalating formation of FR is linked to the increased usage of man-made chemicals for personal care (toothpaste, shampoo, bubble bath, etc.), domestic laundry and dish-washer detergents, and also an ever wider usage of drugs (both prescription and over the counter), especially if they are to be used long-term (years). In addition, tobacco smoking, processed foods, pesticides, various chronic infectious microbes, nutritional deficiencies, lack of sun exposure, and, finally, with a markedly increasing impact, electromagnetic pollution (a terribly destructive factor), can increase the risk of cancer, as well as endothelial dysfunction, owing to the increased production of FR that they cause. All these factors create endothelial damage, but the organism may be able to repair such damage thanks to the intervention of the immune system supported by antioxidants. However, one other factor can perpetuate the state of inflammation, namely obesity and metabolic syndrome with associated hyperinsulinemia. In this review, the role of FR, with a special emphasis on their origin, and of antioxidants, is explored from the perspective of their role in causing atherosclerosis, in particular at the coronary level.

Interactions between systemic diseases and oral microbiota shifts in the aging community: A narrative review

As a gateway to general health and a diverse microbial habitat, the oral cavity is colonized by numerous microorganisms such as bacteria, fungi, viruses, and archaea. Oral microbiota plays an essential role in preserving oral health. Besides, the oral cavity also significantly contributes to systemic health. Physiological aging influences all body systems, including the oral microbial inhabitants. The cited effect can cause diseases by forming dysbiotic communities. Since it has been demonstrated that microbial dysbiosis could disturb the symbiosis state between the host and the resident microorganism, shifting the condition toward a more pathogenic one, this study investigated how the oral microbial shifts in aging could associate with the development or progression of systemic diseases in older adults. The current study focused on the interactions between variations in the oral microbiome and prevalent diseases in older adults, including diabetes mellitus, Sjögren's syndrome, rheumatoid arthritis, pulmonary diseases, cardiovascular diseases, oral candidiasis, Parkinson's disease, Alzheimer's disease, and glaucoma. Underlying diseases can dynamically modify the oral ecology and the composition of its resident oral microbiome. Clinical, experimental, and epidemiological research suggests the associations of systemic disorders with bacteremia and inflammation after oral microbial changes in older adults.

Membrane Fluidity and Oxidative Stress in Patients with Periodontitis

Periodontitis leads to the destruction of dental tissue through polymicrobial interactions, inflammation, and increased oxidative stress. The aim of this study was to measure the levels of nitrates (NO3−), malondialdehyde (MDA), and membranal fluidity (MF) in the gingival tissue of subjects with or without periodontitis. A total of 120 participants from the Dentistry School of the University of Guadalajara were investigated. The study was approved by the ethics committee of our institution, with the registration number of CI-01221. The clinical parameters measured were probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BoP). NO3− was measured using the Greiss reaction, while MDA was determined colorimetrically with the FR12 Kit (Oxford Biomedical Research). Membrane fluidity (MF) was measured using the quotient Ie/Im according to the method of Ortiz and collaborators. The Student t-test, Spearman correlation, and chi-square are used to calculate the results. The results showed higher levels of PD, CAL, and BoP in patients. There was a positive correlation between MF and PD. Moreover, MDA was positively correlated with PD and CAL. Increases in PD resulted in higher levels of NO3−, MDA, and MF. Similarly, increases in CAL resulted in higher levels of MDA and MF in patients. We conclude that PD and CAL facilitated the progression of periodontitis through increases in MDA and MF.

Periodontal Disease in Young Adults as a Risk Factor for Subclinical Atherosclerosis: A Clinical, Biochemical and Immunological Study

Although a strong relationship between periodontal disease (PD) and atherosclerosis was shown in adults, little data are published in younger PD patients. Therefore, this study aimed to investigate and correlate clinical parameters of PD, pro- and immunoregulatory cytokines in gingival crevicular fluid (GCF) and serum, biochemical and hematological parameters associated with atherosclerosis risk, and carotid intima-media thickness (IMT) in our younger study participants (n = 78) (mean age 35.92 ± 3.36 years) who were divided into two equal groups: subjects with and without PD. PD patients had higher values of IMT, hs-CRP, triglycerides, total cholesterol, and LDL; most proinflammatory and Th1/Th17-associated cytokines in GCF; and IL-8, IL-12, IL-18, and IL-17A in serum compared to subjects without PD. These cytokines in GCF positively correlated with most clinical periodontal parameters. Clinical periodontal parameters, TNF-α and IL-8 in GCF and IL-17A, hs-CRP, and LDL in serum, had more significant predictive roles in developing subclinical atherosclerosis (IMT ≥ 0.75 mm) in comparison with other cytokines, fibrinogen, and other lipid status parameters. Hs-CRP correlated better with the proinflammatory cytokines than the parameters of lipid status. Except for serum IL-17A, there was no significant association of clinical and immunological PD parameters with lipid status. Overall, these results suggest that dyslipidemia and PD status seem to be independent risk factors for subclinical atherosclerosis in our younger PD population.

Local delivery of nitric oxide prevents endothelial dysfunction in periodontitis

AIMS

Increased cardiovascular disease risk underlies elevated rates of mortality in individuals with periodontitis. A key characteristic of those with increased cardiovascular risk is endothelial dysfunction, a phenomenon synonymous with deficiencies of bioavailable nitric oxide (NO), and prominently expressed in patients with periodontitis. Also, inorganic nitrate can be reduced to NO in vivo to restore NO levels, leading us to hypothesise that its use may be beneficial in reducing periodontitis-associated endothelial dysfunction. Herein we sought to determine whether inorganic nitrate improves endothelial function in the setting of periodontitis and if so to determine the mechanisms underpinning any responses seen.

METHODS AND RESULTS

Periodontitis was induced in mice by placement of a ligature for 14 days around the second molar. Treatment in vivo with potassium nitrate, either prior to or following establishment of experimental periodontitis, attenuated endothelial dysfunction, as determined by assessment of acetylcholine-induced relaxation of aortic rings, compared to control (potassium chloride treatment). These beneficial effects were associated with a suppression of vascular wall inflammatory pathways (assessed by quantitative-PCR), increases in the anti-inflammatory cytokine interleukin (IL)-10 and reduced tissue oxidative stress due to attenuation of xanthine oxidoreductase-dependent superoxide generation. In patients with periodontitis, plasma nitrite levels were not associated with endothelial function indicating dysfunction.

CONCLUSION

Our results suggest that inorganic nitrate protects against, and can partially reverse pre-existing, periodontitis-induced endothelial dysfunction through restoration of nitrite and thus NO levels. This research highlights the potential of dietary nitrate as adjunct therapy to target the associated negative cardiovascular outcomes in patients with periodontitis.

The oral microbiome in the pathophysiology of cardiovascular disease

Despite advances in our understanding of the pathophysiology of many cardiovascular diseases (CVDs) and expansion of available therapies, the global burden of CVD-associated morbidity and mortality remains unacceptably high. Important gaps remain in our understanding of the mechanisms of CVD and determinants of disease progression. In the past decade, much research has been conducted on the human microbiome and its potential role in modulating CVD. With the advent of high-throughput technologies and multiomics analyses, the complex and dynamic relationship between the microbiota, their 'theatre of activity' and the host is gradually being elucidated. The relationship between the gut microbiome and CVD is well established. Much less is known about the role of disruption (dysbiosis) of the oral microbiome; however, interest in the field is growing, as is the body of literature from basic science and animal and human investigations. In this Review, we examine the link between the oral microbiome and CVD, specifically coronary artery disease, stroke, peripheral artery disease, heart failure, infective endocarditis and rheumatic heart disease. We discuss the various mechanisms by which oral dysbiosis contributes to CVD pathogenesis and potential strategies for prevention and treatment.

The Relationship between Pulse Pressure and Periodontal Disease in Korean Populations with or without Hypertension

Aims: This study evaluated the relationship between pulse pressure (PP) and periodontal disease in Korean adults with or without hypertension (classified as HTN and non-HTN, respectively). Methods: Data on 3496 adults (≥20 years) were obtained from the Korean National Health and Nutrition Examination Survey (2015). We classified those with HTN as SBP ≥ 140 mmHg, DBP ≥ 90 mmHg, or current use of anti-hypertensive medications. Results: There were a few key findings: when logistic regression analysis was applied for periodontal disease (community periodontal index score ≥ 3), the odds ratios (OR) were significantly higher in the high PP (PP > 60 mmHg) than in the normal PP (PP ≤ 60 mmHg) in the HTN group (OR, 2.131; 95% confidence interval (CI), 1.579–2.876). However, periodontal disease was not associated with high PP in the non-HTN group and was not significant (OR, 0.866; 95% CI, 0.494–1.518). Conclusions: In Korean adults, periodontal disease was positively associated with PP in the HTN group but not in the non-HTN group.

The expression of interleukin-1β and nuclear factor erythroid-2 in the periodontitis after treatment of liquid smoke rice hull

Nonsurgical treatment such as scaling and root planing has been the main therapy of periodontal management. However, some individuals are nonresponsive with only mechanical therapy. Rice hull liquid smoke (RH-LS) with higher of phenolic compound supposed to interfere with inflammation process. Thus, the purpose of this study is to investigate the anti-inflammation properties of RH-LS for chronic periodontitis adjunct therapy by observing the expression of nuclear factor erythroid-2 (Nrf-2) and interleukin-1β (IL-1β). Two groups of Wistar rats were used. Control group was induced by 1 × 10⁹ colony-forming unit (CFU)/ml Porphyromonas gingivalis (PG) and treated with aquadest for 2 and 7 days. Meanwhile, the other group was induced by 1 × 10⁹ CFU/ml PG and treated with RH-LS for 2 and 7 days. Two central incisive/mandibulae were dissected and stained with immunohistochemistry for analyzed the expression of Nrf-2 and IL-1β. Data were then analyzed statistically using independent t-test (P = 0.05). Treatment with RH-LS for 7 days showed lower expression of IL-1β (4.00 ± 1.58) than control group (13.60 ± 2.70) and showed higher expression of Nrf-2 (11.60 ± 1.95) than control group (4.20 ± 1.64) (P = 0.000) (P < 0.05). Treatment of RH-LS for 2 days showed higher expression of Nrf-2 (2.20 ± 1.31) than control group (6.80 ± 1.92) (P = 0.003) (P < 0.05). RH-LS showed anti-inflammation properties by elevating the expression of Nrf-2 and depressing expression of IL-1β in periodontitis induced by PG.

Working goal of Brazilein sappan wood as a candidate for SARS-coV-2 antivirus drug against spike (S) glycoprotein, papain-like proteinase, and main protease: In silico study

Brazilein sappan wood, played by Spike (S) glycoprotein, Papain-Like proteinase (PLpro), and Main protease (Mpro), is expected to be a candidate for the antiviral drug SARS-CoV-2, which can inhibit viral attachment to the human body, replication, and transcription processes. The aim of this study was to predict in silico, using the comparative drug hydroxychloroquine, the working goal of brazilein sappan wood as a candidate for the antiviral drug SARS-CoV-2 against protein S, PLpro, and Mpro. The approach used is the in silico docking test using the computer program Molegro Virtual Docker. Receptor used by protein S, Protein Data Bank (PDB) code: 6M0J, NAG_601[E] ligand; PLpro, PDB code: 7JIT, Y95_501[A] ligand; and Mpro, PDB code: 1WOF, I12_1145[A] ligand. Data analysis was carried out by comparing the docking bond energies between the ligands at the target receptor. Silico test results for protein S: ligand bond energy NAG_601 [E] = -59.4555, brazilein = -71.5537, hydroxychloroquine = -79.3704; PLpro protein: Ligand bond energy Y95_501 [A] = -129.561, brazilein = -94.9761, hydroxychloroquine = -100.984; Mpro protein: Ligand bond energy I12 1145 [A] = -141.135, brazilein = -96.6169, hydroxychloroquine = -104.88. The above test results indicate that brazilein sappan wood has potential as a SARS-CoV-2 drug candidate, has a stable bond, and that the biological activity of the compound is stronger against S protein than the proteins of PLpro and Mpro.

Grape Seed Extract Reduces the Degree of Atherosclerosis in Ligature-Induced Periodontitis in Rats - An Experimental Study

The associations between periodontitis and cardiovascular diseases have been intensely studied in recent years. Oxidative stress is involved in the initiation and both progression of periodontitis and atherosclerosis. Antioxidants can reduce the effects of oxidative stress on inflammatory diseases. Our aim was to measure the effects of a grape seed extract (GSE), rich in antioxidants, on atherosclerosis caused by ligature-induced periodontitis in rats. Thirty male Wistar rats were randomly divided into three groups of 10: control group, periodontitis group, and periodontitis group treated with GSE (GSE group). Periodontitis was induced by placing an orthodontic wire around the cervix of the first mandibular molar and keeping it in place for 4 weeks. On days 1, 7 and 28, blood samples were taken to assess oxidative stress and inflammation markers (malondialdehyde and glutathione - MDA, reduced glutathione - GSH, C reactive protein) and lipids. After 4 weeks, the animals were euthanized, and aortas were collected for histopathologic examination. MDA was significantly higher in Periodontitis group compared to the other groups only at day 7. GSH was significantly increased in the Control and GSE groups on days 1 and 7, compared to Periodontitis group and on day 28 higher in GSE vs. Periodontitis groups. C reactive protein was significantly increased in the Periodontitis group on days 1 and 7 compared to both groups. Cholesterol was significantly decreased in the aortas of GSE group at day 28 compared to the Periodontitis group. Oral administration of a grape seed extract reduces the oxidative stress, inflammation and atherosclerosis in a rat model of ligature-induced periodontitis.

Microbiota and cardiovascular disease risk: A scoping review

An increasing number of studies suggests that the oral and the intestinal microbiota may indirectly or directly influence cardiovascular risk. In this regard, the microbiota could act by modifying compounds naturally present in food, both in a potentially atherogenic sense and in a protective sense; on the other hand, specific bacterial strains whose growth could also be facilitated by compounds of alimentary origin, i.e. prebiotics could instead play direct effects on atherogenesis. In other words, the microbiota-food relationship is a bi-directional one in which the latter modifies the former that, in return, produces metabolites with healthful or noxious effects. In this scoping review, we examine some of the microbiota-cardiovascular risk interactions that, in light of the available evidence, can be considered to already enjoy convincing scientific solidity. Notably, we focus on the oral and intestinal microbiota, where research is most active, and we propose some future cardio-preventive opportunities: one would be to develop and test compounds that can inhibit the formation of microbiota-derived noxious molecules. After the development of appropriate, reliable, and inexpensive screening tools for metabotypes, personalized diets can be implemented and pertinent supplements could be prescribed. The other therapeutic and preventive route that could be traveled is that of microbiota modification, via the use of appropriate pro- and prebiotics.

A Diet Rich in Saturated Fat and Cholesterol Aggravates the Effect of Bacterial Lipopolysaccharide on Alveolar Bone Loss in a Rabbit Model of Periodontal Disease

Increasing evidence connects periodontitis with a variety of systemic diseases, including metabolic syndrome, atherosclerosis, and non-alcoholic fatty liver disease (NAFLD). The proposal of this study was to evaluate the role of diets rich in saturated fat and cholesterol in some aspects of periodontal diseases in a lipopolysaccharide (LPS)-induced model of periodontal disease in rabbits and to assess the influence of a periodontal intervention on hyperlipidemia, atherosclerosis, and NAFLD progression to non-alcoholic steatohepatitis. Male rabbits were maintained on a commercial standard diet or a diet rich in saturated fat (3% lard w/w) and cholesterol (1.3% w/w) (HFD) for 40 days. Half of the rabbits on each diet were treated 2 days per week with intragingival injections of LPS from Porphyromonas gingivalis. Morphometric analyses revealed that LPS induced higher alveolar bone loss (ABL) around the first premolar in animals receiving standard diets, which was exacerbated by the HFD diet. A higher score of acinar inflammation in the liver and higher blood levels of triglycerides and phospholipids were found in HFD-fed rabbits receiving LPS. These results suggest that certain dietary habits can exacerbate some aspects of periodontitis and that bad periodontal health can contribute to dyslipidemia and promote NAFLD progression, but only under certain conditions.

Cardiovascular and Autonomic Dysfunction in Murine Ligature-Induced Periodontitis

The present study examined the hemodynamics [arterial pressure (AP), AP variability (APV), heart rate (HR), and heart rate variability (HRV)], cardiac function (echocardiographycally), and myocardial inflammation in Balb/c mice submitted to Periodontitis, through the ligation of the left first molar, or Sham surgical procedure. The first protocol indicated that the AP was similar (136 ± 2 vs. 132 ± 3 mmHg in Sham), while the HR was higher in mice with Periodontitis (475 ± 20 vs. 412 ± 18 bpm in Sham), compared to their Sham counterparts. The APV was higher in mice with Periodontitis when evaluated in the time domain (4.5 ± 0.3 vs. 3.4 ± 0.2 mmHg in Sham), frequency domain (power of the LF band of systolic AP), or through symbolic analysis (patterns 0V + 1V), indicating a sympathetic overactivity. The HRV was similar in the mice with Periodontitis, as compared to their Sham counterparts. In the second protocol, the mice with Periodontitis showed decreased cardiac output (10 ± 0.8 vs. 15 ± 1.4 mL/min in Sham) and ejection fraction (37 ± 3 vs. 47 ± 2% in Sham) associated with increased myocardial cytokines (Interleukin-17, Interleukin-6, and Interleukin-4). This study shows that experimental Periodontitis caused cardiac dysfunction, increased heart cytokines, and sympathetic overactivity, in line with epidemiological studies indicating an increased risk of cardiovascular events in clinical Periodontitis.

Molecular inflammation and oxidative stress are shared mechanisms involved in both myocardial infarction and periodontitis

BACKGROUND AND OBJECTIVE

Our aims were to improve the understanding of the pathogenic relationship between cardiovascular diseases and periodontitis and to generate new perspectives in the prevention and treatment of acute myocardial infarction (AMI) and periodontitis. The present study evaluates possible differences in inflammation, oxidative stress, and autophagy markers among subject suffering AMI, periodontitis, or both, to explore possible common pathogenic mechanisms.

MATERIAL AND METHODS

A total of 260 subjects were enrolled in the study: 106 subjects that survived to a first AMI (AMI group) and 154 subjects had no cardiac events in their clinical record (control group). A questionnaire was used to assess age, height, weight, blood pressure, and heart rate. The clinical probing depth, clinical attachment loss, number of remaining teeth, and average number of sites with bleeding on probing were assessed. Lipid peroxidation and protein levels of phosphorylated AMP-activated protein kinase (p-AMPK) and microtubule-associated proteins 1A/1B-light chain 3-II (LC3-II) were determined in isolated peripheral blood mononuclear cells by thiobarbituric acid reactive substances (TBARS) assay and Western blot, respectively. Plasma levels of interleukin-1β were determined using a commercial ELISA kit. All the obtained variables were compared between subjects suffering an AMI with or without periodontitis and control subject periodontal healthy or with periodontitis.

RESULTS

A higher proportion of subjects suffering AMI + periodontitis than only AMI (without periodontitis) was found. Higher levels of TBARS were found in subjects with periodontitis than in subjects without periodontitis in both AMI and control subjects. Positive correlations between IL-1β levels and TBARS and between IL-1β levels and LC3-II were found only in control subjects.

CONCLUSION

Results from the present study are consistent with the suggestion of periodontitis as a potential risk factor for AMI. Periodontitis association with circulating lipid peroxides in both AMI and control subjects were found. The absence of differences in IL-1β levels between AMI subjects (only AMI vs AMI + periodontitis) suggests that oxidative stress could be the main pathogenic link between AMI and periodontitis.

Effects of an ethanol extract from Lactobacillus paracasei subsp. paracasei NTU 101 fermented skimmed milk on lipopolysaccharide-induced periodontal inflammation in rats

The increased incidence of periodontal disease in recent years has garnered considerable attention. Numerous studies have confirmed that probiotics, such as lactic acid bacteria, can ameliorate periodontal inflammation. The current study aimed to assess the effect of an ethanol extract of Lactobacillus paracasei subsp. paracasei NTU 101-fermented skimmed milk (NTU101FM) on lipopolysaccharide (LPS)-induced periodontal inflammation in rats. NTU101FM ethanol extract significantly ameliorated the weight loss caused by periodontal inflammation. NTU101FM ethanol extract treatment also reduced the oral microbial levels and decreased the levels of alveolar bone loss. Finally, NTU101FM ethanol extract was found to ameliorate periodontal inflammation by decreasing the levels of pro-inflammatory cytokines and reducing oxidative stresses induced by LPS. Overall, our findings demonstrate that NTU101FM ethanol extract could be developed as a functional food that could ameliorate periodontal inflammation.

Role and mechanism of the nod-like receptor family pyrin domain-containing 3 inflammasome in oral disease

OBJECTIVE

To summarize evidence and data from experimental studies regarding the role and mechanism of the Nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome in the pathogenesis of several representative oral diseases.

MATERIALS AND METHODS

A literature search of PubMed and EBSCO was performed. The literature was searched using a combination of keywords, e.g., NLRP3 inflammasome, inflammation, microorganisms, oral inflammatory diseases, and oral immunological diseases.

RESULTS

The initiation and activation of the NLRP3 inflammasome are associated with the pathogenesis and progression of several representative oral diseases, including periodontitis, oral lichen planus, dental pulp disease, and oral cavity squamous cell carcinoma.

CONCLUSIONS

The NLRP3 inflammasome plays a crucial role in the progression of inflammatory and adaptive immune responses. The possible role of the NLRP3 inflammasome in several oral diseases, including not only periodontitis and pulpitis but also mucosal diseases and oral cavity squamous cell carcinoma, may involve the aberrant regulation of inflammatory and immune responses. Understanding the cellular and molecular biology of the NLRP3 inflammasome is necessary because the NLRP3 inflammasome may be a potential therapeutic target for the treatment and prevention of oral inflammatory and immunological diseases.

Chlamydia pneumoniae Infection Exacerbates Atherosclerosis in ApoB100only/LDLR-/- Mouse Strain

Aims

Hyperlipidaemia model animals have been used to elucidate the role of Chlamydia pneumoniae (Cpn) infection in atherosclerosis. The aims of this study were to investigate the proatherogenic effect of multiple Cpn infections in ApoB100only/LDLR^−/− mice which based on lipid profile can be regarded as the most suitable mouse model of human hypercholesterolemia and to compare the lesion development to that in a major atherosclerosis model ApoE^−/− mice.

Methods and Results

Aorta samples of ApoB100only/LDLR^−/− mice infected three times with Cpn were subjected to morphometric analyses. Morphometric evaluation disclosed that Cpn infections exacerbated atherosclerosis development in the aortic root and descending aorta of the mice fed with normal diet. Viable Cpn was detected in the ascending aorta by RT-PCR. Chlamydial 16SrRNA expression showed the presence of viable Cpn in the aorta of infected animals. A similar rate of acceleration of atherosclerosis was observed when the infection protocol was applied in ApoB100only/LDLR^−/− and in ApoE^−/− mice.

Conclusion

Similar to ApoE^−/− mice, ApoB100only/LDLR^−/− mice with more human-relevant serum lipoprotein composition develop increased atherosclerosis after Cpn infections; thus this mouse strain can be used as a model of infection-related atherosclerosis enhancement and can provide further evidence for the proatherogenic influence of Cpn in mice.

Antioxidant effects of melatonin in heart tissue after induction of experimental periodontitis in rats

The aim of this study was to evaluate the effects of melatonin on the oxidative stress in heart tissues after induction of experimental periodontitis in rats. Thirty Wistar Albino male rats were divided into four groups as follows: healthy + saline solution (Hs, n = 7), healthy + melatonin (Hm, n = 7), periodontitis + saline solution (Ps, n = 8), and periodontitis + melatonin (Pm, n = 8). Experimental periodontitis was induced using a ligature placed at the gingival margin of the maxillary second molars. Melatonin was applied intraperitoneally (10 mg/kg) every day for 2 weeks. After sacrificing the rats, serum levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) levels, and melatonin levels were evaluated. The Pm group exhibited lower alveolar bone loss than the Ps group. Melatonin levels increased in the periodontitis groups, and the Pm group had lower MDA levels and higher GSH-Px levels than the Ps group. These findings suggest that melatonin administration reduces MDA and increases GSH-Px levels in heart tissue, and these effects may be due to its antioxidant properties. Further studies are needed to understand the effects of melatonin on the association between periodontitis and cardiovascular disease.

Inflammasome and Oral Diseases

One of the main steps in the development of the life in the earth is multicellularity. It enables cell differentiation and the development of morphological structures within an organism and is an essential factor in how to recognize friendly cells that are part of the multicellular organism and which foreign organisms can be harmful. Recognition includes devices such as the major histocompatibility complex (MHC), and the pattern recognition receptors (PRRs). PRRs are a group of proteins expressed by cells of the innate immune system that identify two classes of products: pathogen-associated molecular patterns (PAMPs), related to microbial pathogens, and damage-associated molecular patterns (DAMPs), associated with cell components that are released during cell damage or death. All these activate the inflammasome, which is a multiprotein oligomer that includes caspase 1, PYCARD, NALP, and caspase 5 (also known as caspase 11 or ICH-3). It is responsible for activation of inflammatory processes and has been shown to induce cell pyroptosis, a programmed cell death distinct from apoptosis, and promotes the maturation of the inflammatory cytokines interleukin 1β (IL-1β) and interleukin 18 (IL-18). We review whether inflammasome is related to diseases that can occur in the oral cavity. The mouth is always a possible environment for the development of pathological conditions because of the wide variety of microorganisms. Small variations in the equilibrium of the oral flora can cause disorders that could affect the organism in a systemic form. We provide data on periodontal disease, candidiasis, herpes virus, oral cancer, caries, and other oral diseases. There are very few papers that study this issue; therefore, we need more investigation and publications about inflammatory molecular processes, and more specifically, related to the inflammasome complex.

Oral health of older residents in care and community dwellers: nursing implications

BACKGROUND

Poor oral health is associated with a reduced quality of life and serious illnesses. Consequently, nurses need to be more aware of oral health to improve the general health of residents in care.

AIM

To evaluate and compare oral health behaviours and levels of salivary haemoglobin and dental biofilm acidogenicity, which can be used to evaluate oral disease activity, between residents and community dwellers in South Korea.

METHODS

This cross-sectional study included 133 participants: 64 residents and 69 community dwellers. All participants completed a questionnaire and tests to measure their salivary haemoglobin and dental biofilm acidogenicity.

RESULTS

A higher percentage of community dwellers than of residents brushed their teeth three times a day, cleaned their tongue, used interdental cleaning devices and had visited a dental clinic within 1 year. The levels of salivary haemoglobin and dental biofilm acidogenicity tended to be higher in residents than in community dwellers.

CONCLUSION

Residents showed poorer oral health behaviours and higher levels of gingival bleeding and acid production by oral bacteria than did community dwellers.

IMPLICATIONS FOR NURSING PRACTICE

Nursing staff should enhance their monitoring of oral hygiene status and provide quality oral care to residents through cooperation with dental professionals.

IMPLICATIONS FOR NURSING AND HEALTH POLICY

Policymakers should be aware that oral health is an essential component of improving general health and well-being and therefore strive to develop policies to promote oral care services provided to residents. Nursing policies, such as mandating oral care and hands-on training in oral care for nursing staff, are important. We also suggest that factors related to oral care be added to the establishment or accreditation standards of care facilities.

Porphyromonas gingivalis and its lipopolysaccharide differently modulate epidermal growth factor-dependent signaling in human gingival epithelial cells

Periodontitis is an inflammatory disease induced by pathogenic bacteria such as Porphyromonas gingivalis. Little is known about epidermal growth factor (EGF) signals in human gingival epithelial cells (HGEC), which are major targets of P. gingivalis, and how the expression of proteins participating in EGF signaling—that is, EGF-receptor (EGFR), suppressor of cytokine signaling-3 (SOCS-3), interferon regulatory factor-1 (IRF-1), and signal transducers and activators of transcription (STAT-3)—are modified. This study aimed to assess the effects of P. gingivalis and its purified lipopolysaccharide (LPS-Pg) on EGF signaling. HGEC were infected for 2 h in a dose-dependent manner with P. gingivalis and with heat-killed P. gingivalis, and activated for 2 and 24 h by 1 µg/mL of purified LPS-Pg. Quantitative reverse transcription polymerase chain reaction and Western blotting were performed to measure mRNA and protein levels for SOCS-3, IRF-1 EGF, EGFR, and STAT-3. The tyrosine-phosphorylation status of STAT-3 was also examined. The results showed that infection of HGEC cells with P. gingivalis, but not with heat-killed P. gingivalis, led to significant reductions in expression levels of mRNAs and proteins for SOCS-3, IRF-1, and EGFR, while LPS-Pg over time significantly increased the expression of these mRNAs and proteins. Tyrosine-phosphorylation of STAT-3 was significantly increased during infection with P. gingivalis and activation by LPS-Pg but not modified during infection with heat-killed P. gingivalis. This study highlights that P. gingivalis and its purified LPS differentially modulated the expression of proteins (SOCS-3, IRF-1, EGFR, and STAT-3) interfering with EGF signaling.

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.