Oxidative injury and inflammatory periodontal diseases: the challenge of anti-oxidants to free radicals and reactive oxygen species

Salivary and Serum Antioxidant and Oxidative Stress Markers in Dental Caries

Dental caries is the most common, chronic, noncommunicable, preventable oral disease worldwide. Oxidation may play an important role in dental caries initiation and progression. Antioxidants in body fluids protect cells. The aim of this study was to evaluate salivary and serum total antioxidant capacity (TAC) and malondialdehyde (MDA) levels in dental caries. A total of 118 healthy caries-free and caries-active male and female students participated. Caries was detected clinically. Unstimulated whole-saliva samples and blood samples were obtained. Sialochemical analysis was carried out by spectrophotometric assay. Data were analyzed with the Student t test using STATA 11. Salivary and serum TAC levels in the case and control groups did not show any significant differences. Mean salivary MDA levels in the case and control groups were 0.71 ± 0.1 and 0.35 ± 0.06 nmol/mL, respectively. The results showed significantly higher levels of salivary and serum MDA in the case group compared to the healthy control group. The oxidative stress marker was significantly higher in the caries group compared to the healthy control group. Antioxidants were not significantly different between the two groups. MDA can be produced by dental caries, resulting in a decrease in antioxidant levels, causing disease progression. Further studies are necessary to determine whether MDA is the cause or effect of the disease.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Hypoxia-inducible transcription factors, HIF1A and HIF2A, increase in aging mucosal tissues

Hypoxia (i.e. oxygen deprivation) activates the hypoxia-signalling pathway, primarily via hypoxia-inducible transcription factors (HIF) for numerous target genes, which mediate angiogenesis, metabolism and coagulation, among other processes to try to replenish tissues with blood and oxygen. Hypoxia signalling dysregulation also commonly occurs during chronic inflammation. We sampled gingival tissues from rhesus monkeys (Macaca mulatta; 3-25 years old) and total RNA was isolated for microarray analysis. HIF1A, HIF1B and HIF2A were significantly different in healthy aged tissues, and both HIF1A and HIF3A were positively correlated with aging. Beyond these transcription factor alterations, analysis of patterns of gene expression involved in hypoxic changes in tissues showed specific increases in metabolic pathway hypoxia-inducible genes, whereas angiogenesis pathway gene changes were more variable in healthy aging tissues across the animals. With periodontitis, aging tissues showed decreases in metabolic gene expression related to carbohydrate/lipid utilization (GBE1, PGAP1, TPI1), energy metabolism and cell cycle regulation (IER3, CCNG2, PER1), with up-regulation of transcription genes and cellular proliferation genes (FOS, EGR1, MET, JMJD6) that are hypoxia-inducible. The potential clinical implications of these results are related to the epidemiological findings of increased susceptibility and expression of periodontitis with aging. More specifically the findings describe that hypoxic stress may exist in aging gingival tissues before documentation of clinical changes of periodontitis and, so, may provide an explanatory molecular risk factor for an elevated capacity of the tissues to express destructive processes in response to changes in the microbial biofilms characteristic of a more pathogenic microbial challenge.

Dietary Fats and Oxidative Stress: A Cross-Sectional Study Among Coronary Artery Disease Subjects Consuming Coconut Oil/Sunflower Oil

Coconut oil has been used by the people of Kerala as a cooking medium for several decades. Due to its alleged hypercholesterolemic activity, general population in recent times is shifting to cooking oils rich in polyunsaturated fats, the most popular being sunflower oil. The effect of long-term consumption of sunflower oil on oxidative stress in humans is not well investigated. We studied oxidative stress among coronary artery disease (CAD) patients who were consuming coconut oil or sunflower oil as a part of their routine diet. Men, aged 35-70 years, with established CAD, who presented to the hospital for routine cardiac evaluations, were enrolled in this observational study. Group 1 and 2 consisted of 73 and 80 subjects consuming coconut oil and sunflower oil respectively for over a period of 2 years. Lipid profile and parameters for oxidative stress were evaluated among them. Conventional lipid parameters did not differ significantly between the two groups. Mean vitamin C concentration was significantly reduced for subjects on sunflower oil compared to those consuming coconut oil (P = 0.044). Malondialdehyde was higher for sunflower oil consumers compared to coconut oil consumers (P < 0.0001). Other parameters such as oxidized LDL, GSH, GPx and SOD were not found to be significantly different between the two groups. The results of the present study show that coconut oil did not induce hypercholesterolemia compared to sunflower oil. On the other hand, sunflower oil group had elevated oxidative stress compared to coconut oil group.

Optimization of the ultrasound-assisted extraction of antioxidant phloridzin from Lithocarpus polystachyus Rehd. using response surface methodology

The purpose of this study was to optimize the extraction process of phloridzin from Lithocarpus polystachyus Rehd. leaves using response surface methodology and to determine the antioxidant capacity of the extract. A Box-Behnken design was used to analyze the effects of ethanol concentration, liquid-solid ratio, soak time and extraction time on the extraction yield of phloridzin. The content of phloridzin was determined by high-performance liquid chromatography. To assess the antioxidant capacity of the extract, three in vitro test systems were used (1,1-,diphenyl-2-picrylhydrazyl, hydroxyl radical scavenging test and reduction force). The optimal parameters obtained by response surface methodology were a volume fraction of ethanol of 64%, a liquid-solid ratio of 37:1, a soaking time of 35 h and a sonication time of 38 min. The proportion of the extraction of phloridzin from L. polystachyus under these industrial process conditions was 3.83%. According to the obtained results, response surface methodology could be suggested as an adequate model for optimizing the extraction process of phloridzin from L. polystachyus. Ultrasound extraction significantly increased the extraction rate of phloridzin, which could be used as an antioxidant in pharmaceutical and food products.

Influence of the Periodontal Disease, the Most Prevalent Inflammatory Event, in Peroxisome Proliferator-Activated Receptors Linking Nutrition and Energy Metabolism

Periodontal disease is considered one of the main pathologic diseases occurring in humans. Its pathologic process involves inflammatory reactions producing periodontal bone resorption and the tooth loss. But some patients do not present an evident clinical inflammation with bone resorption, and in others, the inflammation is prominent without bone resorption. A key question could be to investigate a different way of responding to aggression. Inflammation requires a complex intracellular metabolic process, starting with the harmful recognition and activation of the inflammasome, continues the energy supply with the alteration of oxidative stress conditions, and finishes with the elimination of the aggression with autophagy/apoptosis mechanisms, then concludes with recovery. Peroxisome proliferator-activated receptors (PPARs) are essential molecules produced in inflammation, and its genes and its activation have been related to periodontal disease. Also, an important aspect is the influence of PPARs in bone metabolism; the main periodontitis symptom is bone loss and PPARγ activation that can downregulate the bone resorption in experimental periodontitis, PPARγ-coated titanium dental implant surfaces could carry the antiinflammatory gene and restrain inflammation. PPARs could be one of the meeting background points with atherosclerosis/cardiovascular disease, diabetes and metabolic syndrome showing a modified proinflammatory statement such as it is described in periodontitis.

Opportunistic Pathogen Porphyromonas gingivalis Modulates Danger Signal ATP-Mediated Antibacterial NOX2 Pathways in Primary Epithelial Cells

Porphyromonas gingivalis, a major opportunistic pathogen in the etiology of chronic periodontitis, successfully survives in human gingival epithelial cells (GECs). P. gingivalis abrogates the effects of a host danger molecule, extracellular ATP (eATP)/P2X₇ signaling, such as the generation of reactive oxygen species (ROS) via the mitochondria and NADPH oxidases (NOX) from primary GECs. However, antimicrobial functions of ROS production are thoroughly investigated in myeloid-lineage immune cells and have not been well-understood in epithelial cells. Therefore, this study characterizes antibacterial NOX2 generated ROS and host downstream effects in P. gingivalis infected human primary GECs. We examined the expression of NOX isoforms in the GECs and demonstrate eATP stimulation increased the mRNA expression of NOX2 (p < 0.05). Specific peptide inhibition of NOX2 significantly reduced eATP-mediated ROS as detected by DCFDA probe. The results also showed P. gingivalis infection can temporally modulate NOX2 pathway by reorganizing the localization and activation of cytosolic molecules (p47phox, p67phox, and Rac1) during 24 h of infection. Investigation into downstream biocidal factors of NOX2 revealed an eATP-induced increase in hypochlorous acid (HOCl) in GECs detected by R19-S fluorescent probe, which is significantly reduced by a myeloperoxidase (MPO) inhibitor. MPO activity of the host cells was assayed and found to be positively affected by eATP treatment and/or infection. However, P. gingivalis significantly reduced the MPO product, bactericidal HOCl, in early times of infection upon eATP stimulation. Analysis of the intracellular levels of a major host-antioxidant, glutathione during early infection revealed a substantial decrease (p < 0.05) in reduced glutathione indicative of scavenging of HOCl by P. gingivalis infection and eATP treatment. Examination of the mRNA expression of key enzymes in the glutathione synthesis pathway displayed a marked increase (p < 0.05) in glutamate cysteine ligase (GCL) subunits GCLc and GCLm, glutathione synthetase, and glutathione reductase during the infection. These suggest P. gingivalis modulates the danger signal eATP-induced NOX2 signaling and also induces host glutathione synthesis to likely avoid HOCl mediated clearance. Thus, we characterize for the first time in epithelial cells, an eATP/NOX2-ROS-antibacterial pathway and demonstrate P. gingivalis can circumvent this important antimicrobial defense system potentially for successful persistence in human epithelial tissues.

The Role of Reactive Oxygen Species and Autophagy in Periodontitis and Their Potential Linkage

Periodontitis is a chronic inflammatory disease that causes damage to periodontal tissues, which include the gingiva, periodontal ligament, and alveolar bone. The major cause of periodontal tissue destruction is an inappropriate host response to microorganisms and their products. Specifically, a homeostatic imbalance between reactive oxygen species (ROS) and antioxidant defense systems has been implicated in the pathogenesis of periodontitis. Elevated levels of ROS acting as intracellular signal transducers result in autophagy, which plays a dual role in periodontitis by promoting cell death or blocking apoptosis in infected cells. Autophagy can also regulate ROS generation and scavenging. Investigations are ongoing to elucidate the crosstalk mechanisms between ROS and autophagy. Here, we review the physiological and pathological roles of ROS and autophagy in periodontal tissues. The redox-sensitive pathways related to autophagy, such as mTORC1, Beclin 1, and the Atg12-Atg5 complex, are explored in depth to provide a comprehensive overview of the crosstalk between ROS and autophagy. Based on the current evidence, we suggest that a potential linkage between ROS and autophagy is involved in the pathogenesis of periodontitis.

Melatonin: A Review of Its Potential Functions and Effects on Dental Diseases

Melatonin is a hormone synthesised and secreted by the pineal gland and other organs. Its secretion, controlled by an endogenous circadian cycle, has been proven to exert immunological, anti-oxidant, and anti-inflammatory effects that can be beneficial in the treatment of certain dental diseases. This article is aimed at carrying out a review of the literature published about the use of melatonin in the dental field and summarising its potential effects. In this review article, an extensive search in different databases of scientific journals was performed with the objective of summarising all of the information published on melatonin use in dental diseases, focussing on periodontal diseases and dental implantology. Melatonin released in a natural way into the saliva, or added as an external treatment, may have important implications for dental disorders, such as periodontal disease, as well as in the osseointegration of dental implants, due to its anti-inflammatory and osseoconductive effects. Melatonin has demonstrated to have beneficial effects on dental pathologies, although further research is needed to understand the exact mechanisms of this molecule.

Effect of scaling and root planing on levels of 8-hydroxydeoxyguanosine in gingival crevicular fluid of chronic periodontitis patients with and without Type II diabetes mellitus

Context:

Chronic periodontitis (CP) and diabetes mellitus are associated with increased oxidative damage to DNA with formation of 8-hydroxydeoxyguanosine (8-OHdG). The aim of this study was to evaluate the change in gingival crevicular fluid (GCF) levels of 8-OHdG and glycosylated hemoglobin (HbA1c) by 3 months after scaling and root planing (SRP), in CP patients with and without Type II diabetes mellitus.

Settings and Design:

Sixteen patients with CP, 16 patients with CP and Type II diabetes mellitus (CP-D), and 16 systemically healthy individuals with clinically healthy periodontium who served as controls were included in the study.

Materials and Methods:

The clinical parameters (plaque index [PI], probing depth [PD], clinical attachment level [CAL], and bleeding on probing [BOP%]), HbA1c levels, and GCF 8-OHdG levels were measured at baseline. All the patients except controls were treated with SRP followed by evaluation of the above-mentioned clinical and biochemical parameters after 3 months.

Statistical Analysis Used:

Statistical analysis was performed using paired t-test, independent t-test, and Mann–Whitney U-test.

Results:

After SRP, CP-D group showed a greater reduction in PI, PD, BOP%, and greater gain in CAL when compared to CP patients (P < 0.05). Levels of 8-OHdG and HbA1c in CP-D patients also showed a greater reduction, 3 months after SRP when compared to CP patients (P < 0.05).

Conclusions:

GCF 8-OHdG levels, HbA1c levels, and clinical parameters were reduced significantly in CP and CP-D patients, with maximum reduction achieved in CP-D patients 3 months after SRP.

Antioxidant enzymes in periodontitis

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

Effects of Prunus mume Sieb. et Zucc. extract and its biopolymer encapsulation on a mouse model of colitis

BACKGROUND

Prunus mume suppresses various diseases caused by inflammation response and exhibits antioxidant and free radical-scavenging activities. Therefore this study determined the effect of an aqueous P. mume (PM) extract in a mouse colitis model and investigated the value of biopolymer encapsulation, facilitating targeted delivery to the colon. Colitis was induced by administration of 30 g kg^-1 dextran sulfate sodium to male BALB/c mice for 7 days prior to treatment with vehicle, 50 mg kg^-1 PM extract or biopolymer-encapsulated PM extract, or 50 mg kg^-1 sulfasalazine.

RESULTS

Histological examination of the colon in BALB/c mice showed epithelial destruction and mucosal infiltration of inflammatory cells. These changes were attenuated in PM-treated mice, which had lower levels of inflammatory cytokines, cyclooxygenase 2 and immunoglobulins (IgA, IgM and IgE) compared with the vehicle-treated colitis group. The PM extract showed concentration-dependent radical scavenging and superoxide dismutase-like antioxidant activities.

CONCLUSION

These results indicated that the effects of the PM extract on colitis were not influenced by biopolymer encapsulation and that this PM extract could be a potential therapeutic agent for inflammatory bowel disease. © 2016 Society of Chemical Industry.

Effect of Butyrate on Collagen Expression, Cell Viability, Cell Cycle Progression and Related Proteins Expression of MG-63 Osteoblastic Cells

AIMS

Butyric acid is one major metabolic product generated by anaerobic Gram-negative bacteria of periodontal and root canal infection. Butyric acid affects the activity of periodontal cells such as osteoblasts. The purposes of this study were to investigate the effects of butyrate on MG-63 osteoblasts.

METHODS

MG-63 cells were exposed to butyrate and cell viability was estimated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The mRNA and protein expression of type I collagen and cell cycle-related proteins were measured by reverse-transcriptase polymerase chain reaction (RT-PCR), western blotting or immunofluorescent staining. Cellular production of reactive oxygen species (ROS) was analyzed by 2',7'-dichlorofluorescein (DCF) fluorescence flow cytometry.

RESULTS

Exposure to butyrate suppressed cell proliferation, and induced G2/M (8 and 16 mM) cell cycle arrest of MG-63 cells. Some cell apoptosis was noted. The mRNA expression of cdc2 and cyclin-B1 decreased after exposure to butyrate. The protein expression of type I collagen, cdc2 and cyclin B1 were decreased, whereas the expression of p21, p27 and p57 was stimulated. Under the treatment of butyrate, ROS production in MG-63 cells markedly increased.

CONCLUSIONS

The secretion of butyric acid by periodontal and root canal microorganisms may inhibit bone cell growth and matrix turnover. This is possibly due to induction of cell cycle arrest and ROS generation and inhibition of collagen expression. These results suggest the involvement of butyric acid in the pathogenesis of periodontal and periapical tissue destruction by impairing bone healing responses.

Comparative evaluation of co-enzyme Q10 and Melaleuca alternifolia as antioxidant gels in treatment of chronic periodontitis: A clinical study

Background:

Conventional nonsurgical periodontal therapy has been proven to be an effective treatment for patients with chronic periodontitis. Coenzyme Q10 and tea tree oil (TTO) are known to have potential therapeutic benefits in chronic periodontitis.

Aims:

The aim of the study is to compare the efficacy of Coenzyme Q10 (Perio Q^®) and tea tree oil (Melaleuca alternifolia) gel as an adjunct to scaling and root planing in the treatment of chronic periodontitis.

Materials and Methods:

Patients were divided equally into three groups: Group I (Control group): those receiving placebo gel + SRP, Group II (Test group I): those receiving Perio Q^TM gel + SRP, and Group III (Test group II): those receiving tea tree oil gel + SRP. A total of 15 patients with 45 sites were enrolled in the study. Clinical parameters evaluated were plaque index (PI), gingival bleeding index (GI), probing pocket depth (PPD), and clinical attachment level (CAL).

Statistical Analysis Used:

Paired t-test was applied using SPSS software.

Results:

Mean PPD reduction for Group I, Group II, and Group III was 0.50 ± 0.2, 2.95 ± 0.20, and 2.09 ± 0.15, respectively. Mean CAL reduction for Group I, Group II, and Group III was 0.45 ± 0.22, 2.33 ± 0.04, and 2.28 ± 0.09, respectively. Changes in mean PI scores for Group I, Group II, and Group III were 0.67 ± 017, 1.00 ± 0.11, and 1.08 ± 0.05 and GBI scores were 0.92 ± 0.29, 1.08 ± 0.13, and 0.88 ± 0.28, respectively.

Conclusions:

Coenzyme Q10 and tea tree oil gel proved to be effective in the treatment of chronic periodontitis.

Effects of different fatty acids composition of phosphatidylcholine on brain function of dementia mice induced by scopolamine

BACKGROUND

Phosphatidylcholine (PC), the major source of dietary choline, has been demonstrated to improve the capability of learning and memory in rodent and the amelioration of long-chain n-3 polyunsaturated fatty acids (PUFA) on anti-aging and anti-oxidation is widely known as well. In this study, three kinds of PC were chose to demonstrate the role of different fatty acids composition on glycerol backbone in improving the brain function of mice induced by scopolamine which was used to impair cholinergic system and cause oxidative stress.

METHODS

Male BALB/c mice were randomly divided into 5 groups: model (M) group, control (Con) group, egg yolk lecithin (EL) group, squid PC (SQ-PC) group and sea cucumber PC (SC-PC) group. The intraperitoneal injection of scopolamine hydrobromide (5 mg/kg) was carried out on the 8(th) of group feeding and sustained daily until the end of test. Morris water maze test was used to evaluate the improvement of cognitive decline and the activity of acetylcholinesterase (AchE), superoxide dismutase (SOD) and monoamine oxidase (MAO) and malondialdehyde (MDA) content in brain were measured to assess the physiological changes.

RESULTS

In behavior test, the latency of PC groups was significantly reduced, while number of crossing the platform and time in target quadrant were increased in comparison with M group and the improvements of SQ-PC and SC-PC were better than that of EL (P < 0.05). Similar trend was observed in physiological changes. The AchE activity was effectively decreased and the SOD activity increased in hippocampus, cortex and white matter when comparing PC groups with M group. SQ-PC, SC-PC and EL respectively showed 22.82, 28.80 and 11.81 % decrease in MDA level in brain compared with M group. The MAO activity in white matter of SQ-PC, SC-PC and EL group separately depressed 33.05, 33.64 and 19.73 % in comparison with M group. No significance between SQ-PC and SC-PC was found in these indicators except the SOD activity in hippocampus and white matter. SQ-PC group had a higher SOD activity in hippocampus (103.68U/mg · prot.) and lower in white matter (120.57 U/mg · prot.) than SC-PC group (95.53 U/mg · prot. in hippocampus, 134.49 U/mg · prot. in white matter). PC rich in n-3 PUFA acted more ameliorative effects than that barely contained on the indicators above.

CONCLUSIONS

Different fatty acids composition of PC all could diminish the cognitive decline and biological damage and protect the brain. EPA and DHA partly enhaced to the advantageous effects.

Parameters of oxidative stress in saliva from patients with aggressive and chronic periodontitis

OBJECTIVES

Free radicals play an important role in the onset and progression of many diseases. The aim of this study was to investigate the contribution of oxidative stress in the pathology of aggressive (AgP) and chronic (CP) periodontitis and its relation with the clinical periodontal status.

METHODS

Eighty subjects were divided into two groups: 20 patients with AgP and 20 patients with CP with their 20 corresponding matched controls, based on clinical attachment loss (CAL), probing pocket depth (PPD), and bleeding on probing (BOP). Saliva reactive oxygen species (ROS), lipid peroxidation, and non-enzymatic antioxidant defences were measured by luminol-dependent chemiluminescence assay, as thiobarbituric acid-reactive substances (TBARs) and total radical-trapping antioxidant potential (TRAP), respectively. Pearson's correlation and multivariate analysis were used to determine the relationship between ROS and TBARs and the clinical parameters.

RESULTS

ROS and TBARs were increased in AgP while TRAP was decreased, comparing with CP. In AgP, a strong and positive correlation was observed between ROS and TBARs and they were closely associated with CAL and PPD.

DISCUSSION

In AgP, but not in CP, oxidative stress is a high contributor to periodontal pathology and it is closely associated with the clinical periodontal status.

Nuclear Factor Erythroid 2-Related Factor 2 Down-Regulation in Oral Neutrophils Is Associated with Periodontal Oxidative Damage and Severe Chronic Periodontitis

The balance between reactive oxygen species and antioxidants plays an important role in periodontal health. We previously demonstrated that high reactive oxygen species production by oral polymorphonuclear neutrophils (oPMNs) in chronic periodontitis (CP) refractory to conventional therapy is associated with severe destruction of periodontium. Herein, we show that inhibition of antioxidant production through down-regulation of nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in oPMN, despite enhanced recruitment in the oral cavity, is associated with severe CP. Twenty-four genes in the Nrf2-mediated oxidative stress response pathway were down-regulated in PMNs of diseased patients. Downstream of Nrf2, levels of oPMN superoxide dismutase 1 and catalase were decreased in severe CP, despite increased recruitment. Nrf2(-/-) mice had more severe loss of periodontium in response to periodontitis-inducing subgingival ligatures compared with wild-types. Levels of 8-hydroxy-deoxyguanosine were increased in periodontal lesions of Nrf2(-/-) mice, indicating high oxidative damage. We report, for the first time, Nrf2 pathway down-regulation in oPMNs of patients with severe CP. PMNs of CP patients may be primed for low antioxidant response in the context of high recruitment in the oral cavity, resulting in increased oxidative tissue damage.

Lack of p47(phox) in Akita Diabetic Mice Is Associated with Interstitial Pneumonia, Fibrosis, and Oral Inflammation

Excess reactive oxygen species production is central to the development of diabetic complications. The contribution of leukocyte reactive oxygen species produced by the NADPH oxidase to altered inflammatory responses associated with uncontrolled hyperglycemia is poorly understood. To get insight into the role of phagocytic superoxide in the onset of diabetic complications, we used a model of periodontitis in mice with chronic hyperglycemia and lack of leukocyte p47(phox) (Akita/Ncf1) bred from C57BL/6-Ins2(Akita)/J (Akita) and neutrophil cytosolic factor 1 knockout (Ncf1) mice. Akita/Nfc1 mice showed progressive cachexia starting at early age and increased mortality by six months. Their lungs developed infiltrative interstitial lesions that obliterated air spaces as early as 12 weeks when fungal colonization of lungs also was observed. Neutrophils of Akita/Ncf1 mice had normal degranulation and phagocytic efficiency when compared with wild-type mice. Although Akita/Ncf1 mice had increased prevalence of oral infections and more severe periodontitis compared with wild-type mice, bone loss was only marginally higher compared with Akita and Ncf1 null mice. Altogether these results indicate that lack of leukocyte superoxide production in mice with chronic hyperglycemia results in interstitial pneumonia and increased susceptibility to infections.

Dietary antioxidants and their indispensable role in periodontal health

Periodontitis is an increasing area of interest due to its global prevalence. This inflammatory condition results due to the loss of the critical balance between the virulence factors produced by microorganisms and the inflammatory host response. A number of efforts have been made in the past to address this condition and regain periodontal health. Targeting the root cause by nonsurgical debridement has been considered the gold standard. However, research has shown the possible effects of nutrient deficiency and an imbalanced diet on the periodontium. Therefore, an effort toward the maintenance of optimal conditions as well as improvement of the oral health necessities the introduction of adjunctive nutritional therapy, which can benefit the patients. Antioxidants in the diet have some remarkable benefits and valuable properties that play an irreplaceable role in the maintenance of periodontal health. These have emerged as excellent adjuncts that can enhance the outcomes of conventional periodontal therapy. The aim of this review article is to highlight some of these dietary antioxidants that can make a notable difference by striking a balance between health and disease.

Evaluation of melatonin levels in saliva in gingivitis and periodontitis cases: A pilot study

Objective:

To evaluate the melatonin levels in saliva in gingivitis and periodontitis cases.

Background:

Melatonin has strong antioxidant, free radical scavenging, and immunomodulating properties, acts on osteoblasts directly to stimulate cell proliferation and synthesis of Type I collagen, and promotes bone formation.

Materials and Methods:

A total of thirty participants were selected and divided into three groups (control group, gingivitis group, and periodontitis group). In each group, ten participants were taken. Salivary melatonin was estimated in each of the three groups.

Results:

Results from this study showed that the mean levels of salivary melatonin increased as severity increased from control to periodontitis, i.e., the mean levels were highest in periodontitis followed by gingivitis and least in control group. The melatonin level of all participants was positively and significantly (P < 0.01) correlated with their gingival index (r = 0.85, P < 0.01) and probing depth (r = 0.72, P < 0.01).

Conclusion:

Salivary melatonin level varied with the severity of gingivitis and periodontitis. With increased severity of periodontal disease, the level of salivary melatonin also increased suggesting that salivary melatonin may act as a diagnostic biomarker for periodontal diseases.

Analysis of plasma lipid peroxidation and antioxidant enzymes status in patients of oral leukoplakia: A case control study

Aims and Objectives:

Imbalances between the oxidant-antioxidant status have been implicated in the pathogenesis of several diseases, including oral cancer. Mostly, all oral cancer lesions are preceded by a stage of premalignancy. The present study aims to evaluate lipid peroxidation and antioxidant status in the venous blood of patients with different clinicopathologic stages of leukoplakia.

Materials and Methods:

A case control study was designed with the inclusion of 20 new cases of histopathologically proven leukoplakia of various clinical stages along with an equal number of positive and negative control individuals. The concentrations of thiobarbituric acid reactive substances and the activities of the antioxidant enzymes, namely superoxide dismutase, reduced glutathione, glutathione peroxidase, and catalase, were estimated in plasma using spectrophotometric methods. The data are expressed as mean ± SD. The statistical comparisons between and within the study groups were performed by one-way analysis of variance followed by post hoc analysis. Karl Pearson correlation was performed for the biochemical parameters within the group and between the groups. For statistically significant correlations, simple linear regression was performed.

Results:

Significant enhanced lipid peroxidation (P < 0.001) with a decrease in antioxidants (P < 0.001) was observed in the venous blood of leukoplakia patients compared with positive as well as negative controls. Accordingly, significant (P < 0.001) pattern of progression in thiobarbituric acid reactive substances levels was observed at various clinical stages among patients of both control groups. Among enzymes, glutathione showed significant (P < 0.001) reduction along the stages on comparison with two control groups.

Conclusion:

Enhanced lipid peroxidation and compromised antioxidant defense in plasma indicate the development of oxidative stress. Among the antioxidant enzymes, reduced glutathione and glutathione Pperoxidase may play a decisive role in malignant transformation.

Evaluation of non-surgical therapy on glutathione levels in chronic periodontitis

Objective:

To compare the levels of glutathione (GSH), both oxidized and reduced forms in patients with and without chronic periodontitis in gingival crevicular fluid (GCF).

Materials and Methods:

Twenty GCF samples from maxillary quadrants were collected using capillary micropipettes from the chronic periodontitis patients (test group) at baseline before treatment, at 1-month, 3 months, and 6 months after scaling and root planing and samples from 20 patients without chronic periodontitis (control group) from maxillary quadrants were also collected. GSH, oxidized glutathione (GSSG) levels and GSH: GSSG ratios were determined using the spectrophotometric method.

Statistical Analysis:

Results were concluded for the test over control groups using paired Student's t-test.

Results:

Lower concentrations of GSH (P < 0.001) and GSSG (P < 0.001) were detected in GCF in patients with chronic periodontitis (test group) than patients without chronic periodontitis (control group) at baseline. Treatment had a significant effect in improving the GSH and reducing GSSG levels postscaling and root planing at 1-month and 3 months but not significant effect at 6 months. Scaling and root planing increased the GSH: GSSG ratio (P < 0.001) in the test group as compared to the control group (P < 0.001).

Conclusions:

The concentrations of GSH within GCF are reduced in chronic periodontitis patients. Scaling and root planing (nonsurgical therapy) restores GSH concentration in GCF post 1-month and 3 months along with redox balance (GSH: GSSG ratio), but at 6 months the balance is not maintained. Adjunctive use of micronutritional supplements to boost antioxidant concentration in tissues by preserving GSH or by elevating its level at the inflamed sites is recommended, as nonsurgical periodontal therapy alone is not able to maintain redox balance for longer duration.

Effectiveness of CoQ10 Oral Supplements as an Adjunct to Scaling and Root Planing in Improving Periodontal Health

INTRODUCTION

Deficiency of CoQ 10 was found in human inflamed gingiva and has been found to be responsible for periodontal destruction.

AIM

To evaluate the effectiveness of CoQ 10 supplementation as an adjunct to scaling and rootplaning in reducing gingival inflammation and periodontal pocket depth.

MATERIALS AND METHODS

The study was a randomized, double-blind, controlled, parallel group design clinical trial. Thirty subjects with plaque induced gingival inflammation and having atleast three nonadjacent interproximal sites with a probing pocket depth ≥ 5mm were included in the study. The subjects were randomly divided into two groups. The test group (n=15) in which patients were given oral CoQ10 supplements after scaling and root planing and the control group (n=15) in which patients were given an oral placebo after scaling and rootplaning. The plaque index, gingival index and probing depth were recorded at baseline, 1 month and 3 months. Statistical analysis done by using Student's paired t-test for intragroup comparison and unpaired t-test for inter-group comparison.

RESULTS

Both the groups showed marked reduction of afore mentioned periodontal parameters at one month and three months when compared to baseline. Though there was no significant difference in plaque index and probing pocket depth between the two groups at any given time period, test group showed significant difference in gingival inflammation at one month and three months when compared to control group.

CONCLUSION

In the present study use of Coenzyme Q10 oral supplements as an adjunct to scaling and root planing showed significant reduction in gingival inflammation when compared to scaling and rootplaning alone.

Non-Nutrient, Naturally Occurring Phenolic Compounds with Antioxidant Activity for the Prevention and Treatment of Periodontal Diseases

One of the main factors able to explain the pathophysiological mechanism of inflammatory conditions that occur in periodontal disease is oxidative stress. Given the emerging understanding of this relationship, host-modulatory therapies using antioxidants could be interesting to prevent or slow the breakdown of soft and hard periodontal tissues. In this context, non-nutrient phenolic compounds of various foods and plants have received considerable attention in the last decade. Here, studies focusing on the relationship between different compounds of this type with periodontal disease have been collected. Among them, thymoquinone, coenzyme Q (CoQ), mangiferin, resveratrol, verbascoside and some flavonoids have shown to prevent or ameliorate periodontal tissues damage in animal models. However evidence regarding this effect in humans is poor and only limited to topical treatments with CoQ and catechins. Along with animal experiments, in vitro studies indicate that possible mechanisms by which these compounds might exert their protective effects include antioxidative properties, oxygen and nitrogen scavenging abilities, and also inhibitory effects on cell signaling cascades related to inflammatory processes which have an effect on RNS or ROS production as well as on antioxidant defense systems.

The Antioxidant Effect of Fermented Papaya Preparation in the Oral Cavity

Oxidative stress has been recognized to play important roles in various diseases, including of the oral cavity. However, nutritional supplementation of antioxidants to ameliorate the consequences of oxidative stress is debatable. One caveat is that oxidative status is often measured under non-physiological conditions. Here, we investigated the antioxidant potential of fermented papaya preparation (FPP), a product of yeast fermentation of Carica papaya Linn, under conditions that prevail in the oral cavity. Employing highly sensitive luminol-dependent chemiluminescence assays, we show that its antioxidant capacity was augmented by saliva (up to 20-fold, p < 0.0001, at 10 mg) and its components (mucin, albumin) as well as by red blood cells (RBC) and microorganisms present in the normal and pathological environment of the oral cavity. Polyphenols are major plant antioxidants. Using the Folin-Ciocalteu's assay, a very low amount of phenols was measured in FPP suspended in a salt solution. However, its suspension in saliva, albumin, mucin or RBC produced up to sixfold increase, p < 0.001, compared with the sum of polyphenols assayed separately. The results suggested that these enhancing effects were due to the solubilization of antioxidant polyphenols in FPP by saliva proteins and the binding to RBC and microorganisms, thus increasing their availability and activity. Copyright © 2015 John Wiley & Sons, Ltd.

Possible salivary and serum biomarkers for oral lichen planus

There are few reports concerning the potential for clinical application of oxidative stress (OS) and collagen degradation markers in oral lichen planus (OLP) patients. We investigated the possibility of using some disease-related biomarkers in saliva and serum of OLP patients. Our study included 30 patients with OLP and 30 controls. We evaluated serum and salivary OS biomarkers including 8-OHdG, MDA, uric acid, TAC and GPx. We also investigated collagen degradation markers such as CTX I and MMP-8. We found significantly increased salivary levels of MMP-8 and CTX I in the OLP group compared to controls and significant differences between the OLP and control groups in serum and saliva for 8-OHdG, MDA (significantly increased), uric acid, TAC and GPx (significantly reduced). Currently there are no criteria for evaluating which OLP patients have a greater risk of malignant transformation. In addition to clinical surveillance, the serum and salivary biomarkers that we evaluated may be useful biomarkers for monitoring OLP patients in the future.

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

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

Evaluation of the effect of diacetyl morphine on salivary factors and their changes after methadone therapy

OBJECTIVES

Psychoactive drugs are responsible for pathological changes in the mouth including dental caries, which most troublesome. The aim of the present study was to evaluate the effect of heroin on several salivary factors which are involved in the oral health and their changes after methadone maintenance therapy (MMT).

MATERIALS AND METHODS

Forty patients with heroin abuse history, who referred to Imam Reza Hospital for MMT were included. Saliva sampling was carried out two times; at the first visit (time 1) and repeated 1 month after MMT (time 2). The saliva was analyzed immediately to evaluate the total volume, Ph, CPR, the Uric acid concentration, nitric oxide and antioxidant capacity.

RESULTS

The mean values for saliva volume, pH, CRP, Uric acid, antioxidant and nitric oxide were 0.38 ± 0.14, 7.63 ± 1.22, 5.2 ± 2.3, 1.47 ± 0.8, 0.80 ± 0.23, and 0.26 ± 0.03, respectively at first visit and 0.34 ± 0.22, 7.37 ± 1.01, 6.1 ± 2.6, 2.18 ± 0.9, 0.74 ± 0.3 and 0.29 ± 0.08 after 1 month of MMT. These values are below the normal ranges; however, there was no significant difference between two times in term of saliva volume, pH and saliva component (p > 0.05).

CONCLUSION

Heroin addiction changed the effective salivary factors and therefore could negatively contribute to oral health. These factors were not return to the normal range after 1 month of MMT. Physicians should be informed about focusing on oral health in patients under MMT.

Reduction of Melatonin Level in Patients with Type II Diabetes and Periodontal Diseases

Background and aims. Melatonin is a circulating hormone that is mainly released from the pineal gland. It possesses antioxidant, free-radical scavenging, and immune-enhancing properties. A growing number of studies reveal a complex role for melatonin in influencing various diseases, including diabetes and periodontal diseases. The aim of this study was to examine the possible links between salivary melatonin levels and type II diabetes and periodontal diseases.

Materials and methods. A total of 30 type II diabetic patients, 30 patients with periodontal diseases, 30 type II diabetic patients with periodontal disease and 30 age- and BMI-matched controls were studied. The periodontal status was evaluated by the Community Periodontal Index (CPI). Salivary melatonin levels were determined by a commercial enzyme-linked immunosorbent assay (ELISA) kit.

Results. The mean of salivary melatonin level was significantly lower in patients with either periodontitis or diabetes compared to healthy subjects (P < 0.05). Salivary melatonin concentration decreased in type II diabetic patients and periodontitis patients, and then decreased reaching the lowest levels in type II diabetic patients with periodontal disease.

Conclusion. Based on the results of this study, it can probably be concluded that salivary level of melatonin has an important role in the pathogenesis of diabetes and periodontal diseases. It is also worth noting that this factor could probably be used as a pivotal biological marker in the diagnosis and possible treatment of these diseases, although further research is required to validate this hypothesis.

A comparative evaluation of topical and intrasulcular application of coenzyme Q10 (Perio Q™) gel in chronic periodontitis patients: A clinical study

BACKGROUND AND OBJECTIVES

Coenzyme Q10 is a well-studied antioxidant in the medical literature, but studies regarding its efficacy in periodontal diseases are few. coenzymeoenzyme Q10 serves as an endogenous antioxidant and its increased concentration in the diseased gingiva effectively suppresses advanced periodontal inflammation. The aim of this study is to evaluate the efficacy of coenzyme Q10 (Perio Q™) as an adjunct to scaling and root planing in patients with chronic periodontitis.

MATERIALS AND METHODS

A total of 18 patients were enrolled for the study. The selected subjects were treated in three different quadrants randomly. The control quadrant was treated by scaling and root planing only, while the other two test quadrants were treated by intra-pocket application of gel combined with scaling or root planing and topical applications combined with scaling and root planning, respectively. Clinical parameters such as plaque index, gingival index, gingival bleeding index and probing pocket depth were assessed at baseline and at the 2(nd) week and 4(th) weeks. The results were subjected to statistical analysis.

RESULTS

There was a significant improvement in all clinical parameters in the test sites seen at the end of the 4-week period. Sites with bleeding on probing were reduced more in the test group than in the control group.

CONCLUSION

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

Mucositis and salivary antioxidants in patients undergoing bone marrow transplantation (BMT)

OBJECTIVES

High doses of chemotherapy generate DNA damage in patients undergoing bone marrow transplantation (BMT), due to the production of reactive oxygen species (ROS). In order to evaluate the local defensive effectiveness of the patient undergoing BMT, the concentrations of the antioxidants superoxide dismutase (SOD) and uric acid (UA) were measured in saliva.

STUDY DESIGN

Basal saliva samples were collected from 20 patients undergoing BMT at the Oncology Department, Sanatorio Allende (Córdoba), in the stages: initial, prior to conditioning therapy (I); middle: 7 to 10 days after BMT (M) and final stage, 30 days after discharge from isolation (F). SOD levels were determined using a RANDOX kit (RANSOD superoxide dismutase manual), and for uric acid enzymatic UOD / PAP spectrophotometric method, ( Trinder Color Kit , Wiener Lab) was used.

RESULTS

85% of the patients developed oral mucositis. SOD concentration in the M stage was significantly higher (p<0.01) compared with stage I, and it reversed in stage F. UA concentration was significantly lower (p<0.001) in stage M compared with stage I, and in stage F it recovered the initial values.

CONCLUSIONS

SOD increase in stage M coincided with the appearance of mucositis, which could be interpreted as a defensive mechanism of saliva against oxidative stress produced by chemotherapy. UA decrease in stage M would favour the development of higher degrees of mucositis.

Psidium guajava: A review on its potential as an adjunct in treating periodontal disease

Plants for thousands of years have been used to enhance health and for medicinal purposes. Psidium guajava is one which has an enormous wealth of medicinal value. It for long has been known for its anti-inflammatory, antimicrobial, antioxidant, antidiarrheal, antimutagenic properties. Despite of its widespread biologic uses there is a dearth of information on its therapeutic effect in the treatment of periodontal disease. Hence, this review is an attempt to highlight the potential of P. guajava in the treatment of periodontal disease. Internet databases PubMed, Google Scholar were searched and the most relevant articles were considered for review.

In-vivo effect of andrographolide on alveolar bone resorption induced by Porphyromonas gingivalis and its relation with antioxidant enzymes

Alveolar bone resorption is one of the most important facts in denture construction. Porphyromonas gingivalis (Pg) causes alveolar bone resorption, and morphologic measurements are the most frequent methods to identify bone resorption in periodontal studies. This study has aimed at evaluating the effect of Andrographolide (AND) on alveolar bone resorption in rats induced by Pg. 24 healthy male Sprague Dawley rats were divided into four groups as follows: normal control group and three experimental groups challenged orally with Pg ATCC 33277 five times a week supplemented with 20 mg/kg and 10 mg/kg of AND for twelve weeks. Alveolar bones of the left and right sides of the mandible were assessed by a morphometric method. The bone level, that is, the distance from the alveolar bone crest to cementumenamel junction (CEJ), was measured using 6.1 : 1 zoom stereomicroscope and software. AND reduced the effect of Pg on alveolar bone resorption and decreased the serum levels of Hexanoyl-Lysine (HEL); furthermore the reduced glutathione/oxidised glutathione (GSH/GSSG) ratio in AND treated groups (10 and 20 mg/kg) significantly increased when compared with the Pg group (P < 0.05). We can conclude that AND suppresses alveolar bone resorption caused by Pg in rats.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Total antioxidant capacity of saliva and dental caries

OBJECTIVE

Dental caries is one of the most common infectious diseases worldwide. Saliva has many functions in the oral cavity and is the first line defense against dental caries. Oxidative stress can affect initiation and progression of many inflammatory and infectious diseases such as dental caries. Thus the aim of this study was to evaluate the relationship between total antioxidant capacity (TAC) of saliva and dental caries.

STUDY DESIGN

100 healthy high school students (50 female and 50 male) with age range of 15 -17 years were randomly selected, divided to four groups. Unstimulated whole saliva specimens were collected at the morning. TAC of saliva was evaluated by spectrophotometric assay. Statistical comparisons were performed using Student's t-test, by SPSS 13.

RESULTS

The level of TAC was significantly higher in the saliva of caries active group relative to the caries free subjects. Statistical analysis for male and female groups showed a statistically significant reduction of TAC level in female group.

CONCLUSION

TAC was higher in caries active group. Thus this result showed that total antioxidant capacity may influence in dental caries and activity can be measured by salivary factors and this may be helpful in preventive dentistry.

Locally delivered antioxidant gel as an adjunct to nonsurgical therapy improves measures of oxidative stress and periodontal disease

Purpose

The present study has two aims; firstly, it attempts to verify the presence of oxidative stress by estimating the reactive oxygen species (ROS) levels in periodontal pockets ≥5 mm as compared to controls. The second aim is to evaluate the effect of lycopene as a locally delivered antioxidant gel on periodontal health and on the gingival crevicular fluid (GCF) levels of 8-hydroxydeoxyguanosine (8-OHdG), a marker of oxidative injury.

Methods

Thirty-one subjects participated in this study. In the pretreatment phase, the ROS levels in pockets ≥5 mm were measured by flow cytometry. Three sites in each subject were randomly assigned into each of the following experimental groups: sham group, only scaling and root planing (SRP) was done; placebo group, local delivery of placebo gel after SRP; and lycopene group, local delivery of lycopene gel after SRP. Clinical parameters included recording site-specific measures of GCF 8-OHdG, plaque, gingivitis, probing depth, and clinical attachment level.

Results

The gel, when delivered to the sites with oxidative stress, was effective in increasing clinical attachment and in reducing gingival inflammation, probing depth, and 8-OHdG levels as compared to the placebo and sham sites.

Conclusions

From this trial conducted over a period of 6 months, it was found that locally delivered lycopene seems to be effective in reducing the measures of oxidative stress and periodontal disease.

Effect of low-dose doxycycline on serum oxidative status, gingival antioxidant levels, and alveolar bone loss in experimental periodontitis in rats

BACKGROUND

Subantibiotic doses of doxycycline (low-dose doxycycline [LDD]) have been widely used in periodontal treatment for enzymatic inhibition and related anti-inflammatory properties. The aim of the present study is to verify the possible effects of LDD on oxidative stress in relation to periodontal attachment loss associated with ligature-induced experimental periodontal disease in rats.

METHODS

Thirty female Wistar albino rats were divided into three study groups as follows: 1) control (C) rats; 2) rats with experimental periodontitis (PED); and 3) rats with PED that were treated with doxycycline (PED + LDD). PED was induced by placing ligatures around the cervix of the maxillary second molars for 21 days. The PED + LDD group was treated orally with doxycycline (6 mg/kg) for 21 days after the ligature was placed. After 21 days, the rats were euthanized, and samples of the right maxilla were defleshed and used for histologic and morphometric analyses. The gingival tissue of the left maxilla was used for the analysis of lipid peroxidation (malondialdehyde [MDA]) and antioxidant enzymes (catalase, glutathione peroxidase, and superoxide dismutase). Levels of serum total antioxidant status (TAS)/total oxidant status (TOS) and oxidative stress index (OSI) were also analyzed.

RESULTS

Alveolar bone loss was significantly higher in the PED group compared with the PED + LDD and C groups (P <0.05). Doxycycline exhibited the most prominent inhibition on gingival tissue levels of MDA and antioxidant enzymes (P <0.05). Doxycycline also significantly reduced TOS and OSI levels (P <0.05) but increased the TAS level.

CONCLUSION

Doxycycline helps to prevent periodontal tissue breakdown by inhibiting local and systemic oxidative stress.