Salivary biomarkers of oxidative stress and quality of life in patients with oral lichen planus

Do SOD2 and SOD3 gene polymorphisms impact the oral health-related quality of life in Para athletes?

The aim of this study was to evaluate whether polymorphisms in SOD2 and SOD3 genes modulate the oral health-related quality of life (OHRQoL) of Para athletes with dental caries experience. The cross-sectional study included 264 Para athletes (143 in athletics, 61 in weightlifting and 60 in swimming). A trained and calibrated team recorded the decayed, missing and filled teeth index (DMFT). The Brazilian version of the Oral Health Impact Profile (OHIP-14) was used to measure OHRQoL. Genomic DNA was extracted from the athletes' saliva, and genetic polymorphisms in the SOD2 (rs5746136 and rs10370) and SOD3 (rs2855262 and rs13306703) genes were analyzed by real-time polymerase chain reaction. Univariate and multivariate analyses were performed. A multivariate General Linear Model analysis, adjusted for sex, revealed that the SOD3 gene polymorphism (rs2855262) had a significant effect on the psychological disability domain [codominant (p = 0.045) and recessive (p=0.038) models]. The SOD2 gene polymorphism (rs5746136) had a significant effect on the total OHIP-14 score [dominant model (p = 0.038)] and the psychological discomfort [dominant model (p = 0.034)] and physical disability [codominant model (p=0.037)] domains. Presence of the SOD2 rs10370 polymorphism led to statistical differences in the total score [codominant (p = 0.026) and dominant (p = 0.023) models] and the handicap domain scores [codominant (p = 0.027) and dominant (p = 0.032) models]. Polymorphisms of the SOD2 and SOD3 genes may be important biomarkers of OHRQoL in Para athletes with dental caries experience.

The stress experienced in an emergency medical service (EMS): A descriptive study

INTRODUCTION

Stress, described as an adaptation of the body to an event, is a considerable problem among health workers, especially for those who work in emergency situations, as they very often have to face complex situations. It has been proven that stress affects the performance of health professionals, which is why it is interesting to measure it in these situations, to be able to know what methods to implement to reduce it in future events. Despite having previous measurements in healthcare personnel during clinical simulations, this study is relevant because stress has never before been measured in EMS professionals when performing their work.

OBJECTIVE

To determine the acute stress experienced by professionals in an Emergency Medical Service (EMS) when handling five types of clinical emergencies. As secondary objectives, to determine if there were differences in the increases in stress in relation to sex, age, profession, team, and above all, type of emergency handled.

METHOD

The following were measured for the analysis: physiological (mean heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure), and biochemical (salivary alpha amylase (sAA) activity) markers, before (Basal) and after (Post-Stress) the interventions of 27 professionals from an EMS.

RESULTS

In general, the results obtained showed significant differences between the baseline measurement of physiological and biochemical markers versus the post-exposure measurement. Some of the differences in stress levels in relation to sex and professional role are striking.

CONCLUSION

The determination of acute stress experienced by professionals from an EMS in a real emergency showed significant increases in the sAA enzymatic marker of acute stress. These results are the first data published in this regard, and could be used as a reference to follow in clinical simulation in the training of students and the training of nursing professionals.

IMPLICATIONS FOR CLINICAL PRACTICE

Evidence based studies are needed to improve the education and training of emergency and intensive care professionals. The results from are a great step in the analysis of the real stress that professionals are subjected to when they handle different emergencies.

Emerging potential of phototherapy in management of symptomatic oral lichen planus: A systematic review of randomised controlled clinical trials

Phototherapy incorporating photobiomodulation therapy and antimicrobial photodynamic therapy has been utilised as antioxidants in symptomatic oral lichen planus (OLP) management; however, its role of intervention remains controversial. The aim of this systematic review of CRD42021227788 PROSPERO (an international prospective register of systematic reviews in health and social care) registration number was to oversee and determine phototherapy efficacy in patients with symptomatic OLP, identifying and bridging the literature gaps by proposing recommendations for future studies. A search strategy was developed in consistent with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Various electronic databases were exercised to search for randomised controlled clinical trials (RCTs). Several search engines were employed to analyse a total of 177 studies of which nine included. A wide range of utilised laser and light-emitted diode wavelengths between 630 and 808 nm and irradiance ranged between 10 and 13 mW/cm² were noted. 67% of studies reported a high risk of bias and a high heterogeneity obtained from numerical data for quantitative analysis, therefore meta-analysis was impossible to conduct. Despite inconsistency and diversity in phototherapy parameters, treatment protocols, photosensitiser (type, concentration and method of application) and outcome assessment tools, the majority of the studies showed positive results compared with standard care treatments. Hence, a necessity to perform well-designed RCTs with robust methodology is warranted, after acknowledging the current drawbacks and addressing the suggested recommendations highlighted in our review. Moreover, advanced knowledge in understanding further phototherapy-antioxidants molecular mechanistic in symptomatic OLP is required.

Systematic Review and Meta-Analysis of Oxidative Stress and Antioxidant Markers in Oral Lichen Planus

Background

Oral lichen planus (OLP) is a relatively common chronic inflammatory disease of unknown etiology, which might be caused by oxidative stress and impaired antioxidant defense.

Objective

To systematically investigate the markers of oxidative stress and antioxidant systems in the saliva and blood from OLP patients and healthy controls.

Methods

The PubMed, Cochrane Library, and Embase were systematically queried to collect data from studies in which oxidative stress/antioxidant markers from OLP and healthy subjects had been evaluated until March 10, 2021.

Results

A total of 28 studies fulfilled inclusion criteria, and 25 of them, having 849 OLP patients and 1,052 control subjects and analyzing 12 oxidative stress and antioxidant state marker levels, were subjected to meta-analysis. We found a significant decrease in total antioxidant capacity (TAC) and uric acid (UA) and a significant increase in malondialdehyde (MDA) and nitric oxide (NO) levels in the saliva and serum/plasma of OLP patients. Moreover, a significant elevation of 8-hydroxy-deoxyguanosine (8-OHdG) and advanced oxidation protein product (AOOP) level and a decrease in vitamin C were also observed in the saliva of the OLP group. In contrast, salivary vitamin A, zinc, glutathione peroxidase (GPx), vitamin E, and nitrite were not significantly different between the two groups. In single studies, markers of oxidative stresses such as superoxide dismutase (SOD) and 8-isoprostanelevels were elevated in OLP, and antioxidant parameters such as glutathione (GSH) and total protein (TP) levels were dysregulated.

Conclusion

This meta-analysis helps to clarify the profile of oxidative stress and antioxidant state markers in OLP patients although existing evidence is rather heterogeneous and many studies are affected by several limitations. Larger and more standardized studies are warranted to ascertain whether these markers are potential causes or effects of OLP and whether antioxidant therapy improving oxidative stress will be useful.

Micronutrients Profile in Oral Lichen Planus: a Review Literature

Oral lichen planus (OLP) is a relatively common chronic inflammatory disease. The micronutrients are critical factors in health of oral mucous and proper function of immune system. There have not been any review articles for evaluating trace element levels before and after standard treatments of OLP. The purpose of this study is to provide complete review of the association of micronutrients with OLP. Databases including PubMed, Google Scholar, Scopus, and Embase (Ovid) with keywords of oral lichen planus, OLP, oral disorder, micronutrients, trace element, nutrient element, antioxidant, oxidative stress, malnutrition, and essential trace elements, without time limitation (1900-2019) were searched to collect data on related articles. Total number of 58 original articles including 12 randomized clinical trials, 41 case-control, 4 case reports, and 1 cell line research were reviewed in this study. Lower levels of iron and its associated markers, such as hemoglobin and ferritin, increased levels of TIBC; reduced levels of zinc, calcium, vitamin D, vitamin B12, folic acid, and antioxidants such as vitamins C and E; and increased levels of oxidants and homocysteine, have been reported in OLP patients.

Aquaporin3 (AQP3) expression in oral epithelium in oral lichen planus

Lichen Planus is an autoimmune disease of skin and mucous membranes, including oral mucosa and genital organs, with the potential to undergo a malignant transformation. Xerostomia and the salivary gland hypofunction are common manifestations and complications in oral lichen planus (OLP), whose exact cause has not been well defined yet. Aquaporins (AQP) are a family of membrane channel cell proteins which play an important role in the intercellular water permeability. This study for the first time compares the expression of the aquaporin-3 (AQP3) gene in oral tissues of a group of OLP patients and a control group. In this study, 30 OLP patients and 30 healthy individuals were selected. The expression of AQP3 gene was measured using Real-Time PCR method. The expression of the gene in the OLP patients was more than the control group. It could be argued that decreased salivation increases the level of expression of the AQP3 gene in an effort to compensate for this deficiency and prevent the onset of xerostomia (compensatory up-regulation).

Association between oxidative stress and temporomandibular joint dysfunction: A narrative review

BACKGROUND

The role of oxidative stress in temporomandibular disorders (TMDs) has been studied using synovial fluid, to evaluate oxidative stress (im)balance and its potential role in the onset and/or progression of the disease.

OBJECTIVE

This review aimed to evaluate the association between oxidative stress markers and the etiopathogenesis of TMJ dysfunction by means of synovial fluid analysis.

METHODS

Two independent reviewers searched the electronic databases from inception to March 2019: PubMed/MEDLINE, LILACS, SciELO, EMBASE, TRIPDATABASE, SCOPUS, and Google Scholar. The following key search terms were used: Temporomandibular Joint Disorders OR Temporomandibular Joint Disc OR Temporomandibular Joint Dysfunction Syndrome OR Temporomandibular Joint OR Facial Pain AND Free Radicals OR Oxidative Stress. Data were extracted from the selected articles, including study design, sample profile, TMJ disease reported, diagnostic method, reactive oxygen and nitrogen species evaluated, enzymatic and non-enzymatic antioxidants evaluated, and techniques used to measure free radicals and antioxidants.

RESULTS

After title and abstract screening of 6974 results, and full-text reading, 19 studies were included. All selected articles were cross-sectional observational studies. Enzymatic and non-enzymatic antioxidant defences appeared to be reduced in these patients, resulting in the establishment of the oxidative stress process. In addition, the studies showed a positive correlation between the severity of the intra-articular TMD and the increase in oxidative damage.

CONCLUSION

The establishment of oxidative stress, whether by an increase in reactive oxygen/nitrogen species or by a decrease in antioxidant defences, or a combination of both, may be associated with the establishment and maintenance of intra-articular damage.

Larrea divaricata Cav. aqueous extract and nordihydroguariaretic acid modulate oxidative stress in submandibular glands of diabetic rats: a buccal protective in diabetes

Background

Oxidative stress is an imbalance between the levels of reactive oxygen species (ROS), reactive nitrogen species (RNS) and endogenous antioxidants. The aetiology and pathogenesis of several oral diseases are attributed to this process. The antioxidant enzymes secreted in the saliva by submandibular glands maintain oral health through the scavenging of ROS. The objective of this work was to study the capacity of an aqueous extract of L. divaricata (AE), and its majority compound, nordihydroguariaretic acid (NDGA), to modulate the pro-oxidant/antioxidant status in submandibular glands in a model of oxidative stress induced by streptozotocin (STZ) in rats.

Methods

To induce oxidative stress with STZ, a group of animals was treated i.p. with 1 X PBS (control group) and other group was injected i.p. once with STZ (60 mg/kg). Ten days after the treatment, blood samples were taken from the tail vain to determine the glucose levels. Animals with glucose values ≥300 mg/ml were selected.

The submandibular glands of control and STZ treated animals were incubated with either the AE (500 μg/ml) or with NDGA (1.5 μg/ml), and the content of malondialdehyde (MDA), protein carbonyl groups, ROS and RNS, and the activity and expression of peroxidase (Px), superoxide dismutase (SOD) and inducible nitric oxide synthase (iNOS) were assayed.

Results

AE decreased the levels of MDA (^##P < 0.01) and protein carbonyl groups (^#P < 0.05), and modulated the levels of ROS such as hydrogen peroxide (H₂O₂)(^##P < 0.01), superoxide anion (O₂^.-) (^#P < 0.05) and nitric oxide (NO) (^#P < 0.05) in relation to the modulation of Px and iNOS expression. NDGA was found to be involved in these effects.

Conclusions

The antioxidant activity of the AE in the submandibular glands would allow the maintenance of the antioxidant pool to prevent oral oxidative diseases.

Anorexia, Oral Health and Antioxidant Salivary System: A Clinical Study on Adult Female Subjects

The aim of this study was to compare the oral health status and salivary antioxidant system between patients diagnosed with anorexia nervosa (AN) and healthy controls. A total of 25 female AN patients and 25 matched healthy controls were enrolled. Clinical parameters and saliva samples were collected for each patient. Two questionnaires to investigate oral health and hygiene were administered. Superoxide Dismutase (SOD) activity and High Reactive Oxygen Species (hROS) were evaluated. Salivary concentration of SOD was significantly higher in subjects with AN compared with control group (1.010 ± 0.462 vs. 0.579 ± 0.296 U/mL; p = 0.0003). No significant differences between groups were identified for hROS (233.72 ± 88.27 vs. 199.49 ± 74.72; p = 0.15). Data from questionnaires indicated that, although most of the patients recognized the oral hygiene importance in maintaining a good oral health, more than half of them had poor oral hygiene. Altered biochemical composition of saliva in patients with AN could be interpreted as an effective defence mechanism against oxidative stress. Moreover, despite the discrepancy between clinical findings and perception of the oral health in AN population arose, the quality of life of these patients appears not to be significantly affected by their dental condition.

Enhanced In Situ Availability of Aphanizomenon Flos-Aquae Constituents Entrapped in Buccal Films for the Treatment of Oxidative Stress-Related Oral Diseases: Biomechanical Characterization and In Vitro/Ex Vivo Evaluation

In recent years, the key role of oxidative stress in pathogenesis of oral diseases has been emphasized and the use of antioxidant agents has been encouraged. Aphanizomenon flos-aquae (AFA) is a unicellular blue-green alga with antioxidant and anti-inflammatory properties. The aim of this study was the formulation and characterization of mucoadhesive thin layer films loaded with AFA, finalized to the treatment of oxidative stress (OS)-related oral diseases. First, to enhance the bioavailability of AFA constituents, the raw food grade material was appropriately treated by a high frequency homogenization able to disrupt cell walls. Thus, Eudragit^® E100-based buccal films were produced by the solvent casting method, containing 7% and 18% of AFA. The films, characterized by uniformity in thickness, weight, and drug content, showed low swelling degree, good muco-adhesiveness and controlled drug release. The mechanical tests showed elastic moduli of films of almost 5 MPa that is well-suitable for human buccal applications without discomfort, besides biaxial tests highlighted a marked material isotropy. Permeation studies through porcine mucosae demonstrated the ability of films to promote AFA penetration in the tissues, and when sublingually administered, they produced a drug flux up to six-fold higher than an AFA solution. The new formulations represent an interesting alternative for the development of cosmetics and nutraceuticals with a functional appeal containing plant extracts.

Salivary Oxidant/Antioxidant Status in Chronic Temporomandibular Disorders Is Dependent on Source and Intensity of Pain - A Pilot Study

Temporomandibular disorders (TMD) have been associated with altered salivary oxidative status, but the relation with pain source and pain severity isn't clarified. With the aim to assess their interaction with TMD, we compared levels of selected salivary oxidative stress (OS) markers (glutathione peroxidase, superoxide dismutase, total antioxidant capacity (TAC), uric acid, 8-hydroxydeoxyguanosine, malondialdehyde) and salivary cortisol (SC) as a stress indicator, between 20 TMD patients and 15 healthy control subjects. In order to record differences relating to pain source and severity, patients were respectively classified according to specific diagnoses (myofascial pain or disc displacement (DD)), and pain intensity (high or low). TAC was significantly higher in TMD patients than in controls (morning p = 0.015; afternoon p = 0.005). Significant differences were also observed when TAC levels between high-intensity pain patients and controls were compared, as well as between DD patients and controls. In logistic regression analysis, higher levels of TAC were related to DD (morning OR: 1.66, 95%CI: 1.05-2.64, p = 0.029; afternoon OR: 2.10, 95%CI: 1.11-3.98, p = 0.021) and to high-intensity pain (morning OR: 1.81, 95%CI: 1.04-3.15, p = 0.037; afternoon OR: 1.79, 95%CI: 1.02-3.14, p = 0.043). We also found that morning SC was positively correlated with antioxidant parameters in TMD patients. Our data suggest compensatory mechanism as response to higher level of stress. This stress could be extrinsic and lead toward TMD, or intrinsic, emerging from established TMD, or could be both. The intensity and the source of pain should be considered important factors in future investigations evaluating salivary OS markers in TMD patients.

Quality of life and oral potentially malignant disorders: Critical appraisal and prospects

Quality of life (QoL) is a vital and often required health outcome measure that is relevant to patient care. A healthy oral cavity enables person to perform daily activities without any limitations. However, any disturbance may result in impaired QoL. The oral health-remains an essential element of people’s health and well-being. In recent years, the tradition of clinical practice and research has been changed by incorporating QoL assessment, as it helps in assessment of patients’ needs and monitoring treatment responses. Oral potentially malignant disorders (OPMDs) are a group of chronic disorders including oral leukoplakia (OL), oral lichen planus and oral submucous fibrosis (OSF). It is evident that patients with OPMDs experience significant health-related symptoms, functional limitations and psycho-social impairment, compromising their QoL. Moreover, the worsening of QoL has been associated with advanced stages of OPMDs. Despite of increasing number of OPMD cases in recent decades, limited literature is available regarding QoL in this population. Although, there is higher prevalence of habit-related OPMDs, particularly OSF and OL in Southern Asian countries, only a few studies have been performed in these populations. Moreover, these studies administered generic QoL instruments, which offer less sensitivity to clinical changes. However, condition-specific instruments are more sensitive and allows better measurement of QoL. As the impacts of different conditions on OHRQoL may vary, the development and validation of a QoL instrument specific to each clinical entity of OPMDs is currently needed.

Salivary Antioxidant Status in Patients with Oral Lichen Planus: Correlation with Clinical Signs and Evolution during Treatment with Chamaemelum nobile

Oral lichen planus (OLP) is a chronic inflammatory mucocutaneous disease, which manifests as a succession of outbreaks. OLP was associated with salivary oxidative stress. Randomized, double blind, parallel-group study was performed. The sample consisted of 55 clinically and histopathologically diagnosed OLP patients. Twenty-six patients were treated with 2% Chamaemelum nobile gel and 29 with a placebo. Nonstimulated (basal) saliva was collected on the first day of the study and 4 weeks later. Salivary total antioxidant status (TAS) was evaluated by four different methods: two TAC (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid) equivalent antioxidant capacity methods (TAC1 and TAC2), cupric reducing antioxidant capacity (CUPRAC), and ferric reducing ability of plasma (FRAP). At baseline (T1), no statistically significant differences were detected in any of the TAS analytes between the two groups of patients. After four weeks of treatment, a statistically significant increase was detected in FRAP in the placebo group (0.323 [0.090-0.467] versus 0.406 [0.197-0.848] mmol/g⁎10^-3) (P < 0.05). Significant correlations were observed between pain and drainage and TAC1, CUPRAC, and FRAP and between xerostomia and the TAC1, TAC2, CUPRAC, and FRAP. The results of the present study showed that in patients with OLP increases of TAS in saliva are associated with increase in pain and xerostomia and decrease in drainage, suggesting a worsening condition of the patient. The use of Chamaemelum nobile gel would be recommended for disease stabilization.

Impact of oral potentially malignant disorders on quality of life: a systematic review

Although oral potentially malignant disorders (OPMDs) are relatively common and potentially debilitating, literature on quality of life (QoL) in these patients is scanty. The purpose of this paper is to systematically review the literature on QoL in patients with OPMDs. A total of 210 titles were retrieved from electronic and manual databases searched from 1960 until September 2017. Out of these, 25 met our strict inclusion criteria as per the preferred reporting items for systematic reviews and meta-analyses guidelines. Most studies have assessed QoL in patients with oral lichen planus, reports of which cannot be generalized to all patients with OPMD. The findings of the studies differ but, overall, do not provide evidence that OPMD patients have a poorer QoL than healthy subjects.

Within-Subject Reliability and between-Subject Variability of Oxidative Stress Markers in Saliva of Healthy Subjects: A Longitudinal Pilot Study

The present study evaluated diurnal variations and day-to-day fluctuations of salivary oxidative stress (OS) markers in healthy adult individuals. Whole unstimulated saliva was collected at 2 time intervals over 3 consecutive days. Glutathione peroxidase (GPX), superoxide dismutase (SOD), total antioxidant capacity (TAC), and uric acid (UA) were analyzed using spectrophotometric methods, while 8-hydroxydeoxyguanosine (8-OHdG) and malondialdehyde (MDA) were determined using immunoassays. No significant differences for salivary OS markers between men and women were observed. For all examined OS markers, no significant day-to-day variations were demonstrated. Significant diurnal variations were found in salivary GPX, TAC and MDA levels. For SOD, TAC, GPX, and UA, good-to-moderate intraindividual coefficients of variations (CVs) were observed in more than 75% of the subjects. For MDA and 8-OHdG, intraindividual CVs > 35% were observed in 60% and 40% of the subjects, respectively. Between-subject variance was wide for all examined OS markers (CV% 30.08%–85.70%). Due to high intraindividual variability in the salivary concentrations of MDA and 8-OHdG, those markers cannot be reliably verified based on single measurements and multiple measurements over several days would provide more reliable information. Salivary SOD, TAC, GPX, and UA proved stable across three days of measurement. Trial Registration. ClinicalTrials.gov NCT03029494. Registered on 2017-01-19.

Oxidative Stress in Oral Diseases: Understanding Its Relation with Other Systemic Diseases

Oxidative stress occurs in diabetes, various cancers, liver diseases, stroke, rheumatoid arthritis, chronic inflammation, and other degenerative diseases related to the nervous system. The free radicals have deleterious effect on various organs of the body. This is due to lipid peroxidation and irreversible protein modification that leads to cellular apoptosis or programmed cell death. During recent years, there is a rise in the oral diseases related to oxidative stress. Oxidative stress in oral disease is related to other systemic diseases in the body such as periodontitis, cardiovascular, pancreatic, gastric, and liver diseases. In the present review, we discuss the various pathways that mediate oxidative cellular damage. Numerous pathways mediate oxidative cellular damage and these include caspase pathway, PERK/NRF2 pathway, NADPH oxidase 4 pathways and JNK/mitogen-activated protein (MAP) kinase pathway. We also discuss the role of inflammatory markers, lipid peroxidation, and role of oxygen species linked to oxidative stress. Knowledge of different pathways, role of inflammatory markers, and importance of low-density lipoprotein, fibrinogen, creatinine, nitric oxide, nitrates, and highly sensitive C-reactive proteins may be helpful in understanding the pathogenesis and plan better treatment for oral diseases which involve oxidative stress.

Salivary changes in oral mucosal diseases

Saliva is a unique biological fluid that can be easily collected and analyzed with low cost and low morbidity. Therefore, there is a growing attention for using salivary biomarkers in the diagnosis and monitoring of disease progress and response to treatment. Salivary changes have been described in relation to oral mucosal diseases. This article discusses the causes and consequences of salivary hypofunction and presents a review of the literature related to changes in salivary parameters in various oral mucosal diseases and in systemic diseases with possible oral mucosal involvement.

Evaluation of salivary oxidate stress biomarkers, nitric oxide and C-reactive protein in patients with oral lichen planus and burning mouth syndrome

OBJECTIVES

The aim of this study was to evaluate oxidative stress factors and C-reactive protein in the saliva of patients with oral lichen planus (OLP) and burning mouth syndrome (BMS).

METHODS

This consecutive, cross-sectional study included 20 patients with OLP, 19 with burning mouth syndrome (BMS), and 31 control subjects. The oral cavity of each patient was examined and patients responded to a quality of life questionnaire (OHIP-14) and the xerostomia inventory. The following parameters were measured in whole non-stimulated saliva: trolox equivalent antioxidant capacity (TEAC); total antioxidant capacity (TAC); cupric reducing antioxidant capacity (CUPRAC); ferric reducing ability of plasma (FRAP); C-reactive protein (CRP); nitric oxide; nitrates; and nitrites.

RESULTS

The OLP group presented statistically significant differences in reactive oxygen species (ROS) (29 600 cps) in comparison with the control group (39 679 cps) (P < 0.05). In the BMS group, ROS was 29 707 cps with significant difference in comparison with the control group (P < 0.05). Significantly higher salivary nitric oxide (145.7 μmol) and nitrite (141.0 μmol) levels were found in OLP patients in comparison with control group (P < 0.05).

CONCLUSION

Increases in nitric oxide and C-reactive protein were found in the saliva of OLP patients in comparison with BMS and control patients. Further studies are required to confirm these findings.

Salivary and Urinary Total Antioxidant Capacity as Biomarkers of Oxidative Stress in Humans

Total Antioxidant Capacity (TAC) is a biomarker often used in order to investigate oxidative stress in many pathological conditions. Saliva and urine can be collected noninvasively and represent attractive diagnostic fluids for detecting biomarkers of various pathological conditions. The reviewed case-control and intervention studies that measured salivary or urinary TAC revealed that diseases, antioxidant foods, or supplements and age, gender, and lifestyle factors influenced salivary or urinary TAC. Salivary and urinary TAC were particularly affected by oral or renal status, respectively, as well as by infection; therefore these factors must be taken into account in both case-control and intervention studies. Furthermore, some considerations on sample collection and normalization strategies could be made. In particular, unstimulated saliva could be the better approach to measure salivary TAC, whereas 24 h or spontaneous urine collection should be chosen on the basis of the study outcome and of the creatinine clearance. Finally, the uric acid-independent TAC could be the better approach to evaluate red-ox status of body, in particular after nutritional interventions and in diseases associated with hyperuricaemia.

Salivary markers of oxidative stress in oral diseases

Saliva is an interesting alternative diagnostic body fluid with several specific advantages over blood. These include non-invasive and easy collection and related possibility to do repeated sampling. One of the obstacles that hinders the wider use of saliva for diagnosis and monitoring of systemic diseases is its composition, which is affected by local oral status. However, this issue makes saliva very interesting for clinical biochemistry of oral diseases. Periodontitis, caries, oral precancerosis, and other local oral pathologies are associated with oxidative stress. Several markers of lipid peroxidation, protein oxidation and DNA damage induced by reactive oxygen species can be measured in saliva. Clinical studies have shown an association with oral pathologies at least for some of the established salivary markers of oxidative stress. This association is currently limited to the population level and none of the widely used markers can be applied for individual diagnostics. Oxidative stress seems to be of local oral origin, but it is currently unclear whether it is caused by an overproduction of reactive oxygen species due to inflammation or by the lack of antioxidants. Interventional studies, both, in experimental animals as well as humans indicate that antioxidant treatment could prevent or slow-down the progress of periodontitis. This makes the potential clinical use of salivary markers of oxidative stress even more attractive. This review summarizes basic information on the most commonly used salivary markers of oxidative damage, antioxidant status, and carbonyl stress and the studies analyzing these markers in patients with caries or periodontitis.