Evaluation of oxidative stress markers in oral lichen planus

Salivary metabolomics in patients with oral lichen planus: a preliminary study based on NMR spectroscopy

OBJECTIVES

The present preliminary study aimed to investigate the salivary metabolic profile in patients with asymptomatic oral lichen planus (OLP) using nuclear magnetic resonance (NMR) spectroscopy.

MATERIAL AND METHODS

Stimulated whole mouth saliva (SWMS) samples were collected from 15 reticular OLP female patients and 15 from age- and sex-matched controls (HCs). A total of 23 metabolites were identified and quantified. Mann-Whitney's U test was used to compare the determined concentration salivary metabolite concentrations between OLP patients and the healthy controls.

RESULTS

The concentration of acetate, methylamine, and pyruvate was elevated, whereas the concentration of tyrosine was decreased in the saliva of OLP patients compared with HCs. To identify a combination of metabolites, multivariate discrimination function analysis (DFA) was conducted. DFA analysis have shown that the most powerful discrimination between the groups was achieved when methylamine and tyrosine were considered as combined biomarkers.

CONCLUSIONS

Salivary tyrosine was of particular interest and a promising finding for the screening of OLP and its progression. Further longitudinal studies are required to establish it as a reliable salivary biomarker in OLP.

CLINICAL RELEVANCE

The salivary metabolic profiling can describe the pathologic characteristics of OLP on non-invasive saliva samples and NMR analysis. Salivary metabolites provide details to considered early detectors and to impact oral health of OLP patients.

Oxidative stress markers in the saliva of patients with oral lichen planus

OBJECTIVE

To evaluate the levels of oxidative stress markers in the saliva of patients with oral lichen planus (OLP).

METHODS

A cross-sectional study was conducted with 22 patients diagnosed both clinically and histologically with OLP (reticular or erosive) and 12 individuals without OLP. Non-stimulated sialometry was performed and oxidative stress (myeloperoxidase - MPO and malondialdehyde - MDA) and antioxidant (superoxide dismutase - SOD and glutathione - GSH) markers were determined in the saliva.

RESULTS

Among the patients with OLP, most were women (n = 19; 86.4%) and reported to have experienced menopause (63.2%). Patients with OLP were mostly in the active stage of the disease (n = 17; 77.3%) and the reticular form was predominant (n = 15; 68.2%). No statistically significant differences were observed when comparing SOD, GSH, MPO and MDA values between individuals with and without OLP, as well as between erosive and reticular forms of OLP (p > 0.05). Patients with inactive OLP presented higher SOD when compared to those with active disease (p = 0.031).

CONCLUSION

Oxidative stress markers in the saliva of patients with OLP were similar to those found in people without OLP, which can be related to the high exposure of the oral cavity environment to several physical, chemical and microbiological stimuli, important generators of the oxidative stress.

Salivary Antioxidants Levels in Patients with Oral Lichen Planus

Background

Oral lichen planus (OLP) is one of the most common diseases of the oral mucosa, which exact pathogenesis remains unknown. Free radicals and reactive oxygen species could play an important role in the pathogenesis of oral lichen planus.

Aims and Objectives

This study aimed to compare the salivary levels of uric acid, superoxide dismutase, glutathione peroxidase, and albumin in the patients with oral lichen planus and healthy subjects.

Materials and Methods

Thirty patients with oral lichen planus and 30 healthy subjects, who were matched for age and sex, were enrolled in this case-control study. The salivary concentration of uric acid, superoxide dismutase, glutathione peroxidase, and albumin were examined in these individuals using the spectrophotometry and coulometric technique. The data were analyzed through Mann-Whitney test and T test by SPSS software (ver. 19).

Results

Salivary uric acid and albumin levels in patients with oral lichen planus and healthy controls were not statistically different (p > 0.05); however, the concentrations of salivary superoxide dismutase in OLP patients (660.4 ± 266.4 U/g protein) and healthy controls (935.73 ± 561.9 U/g protein) were significantly different (p < 0/05). Also, salivary glutathione peroxidase levels in healthy controls (1049.98 ± 964.56 mU/mL) were remarkably higher than OLP patients (244.12 ± 170.78 mU/mL) (p < 0/001).

Conclusion

The salivary superoxide dismutase concentration, as an indicator of antioxidant system, in OLP patients was significantly higher than healthy subjects. The glutathione peroxidase levels in these patients were remarkably lower than healthy controls. It is suggestive that these markers could be effective in pathogenesis of OLP.

Mechanisms of reactive oxygen species in oral lichen planus: A literature review

Oral lichen planus is a chronic non-infectious mucosal inflammatory disease caused by an imbalance between reactive oxygen species homeostasis and antioxidant defense systems. Notably, excessive oxidative stress products result in related autoimmune reactions. Further, it activates signaling pathways related to the development of oral lichen planus, as evidenced by the detection of damage to deoxyribonucleic acid, protein, and lipid. Thus, the mechanisms of reactive oxygen species-mediated oxidative stress in the pathogenesis of oral lichen planus are numerous and complex. In this review, we first introduce oxidative stress and oxidative products. Then, we summarize the role and possible mechanisms of reactive oxygen species-mediated oxidative stress in the pathogenesis of oral lichen planus and present a clinical correlation between oxidative stress and oral lichen planus. Finally, we discuss the current challenges and future perspectives.

Oral lichen planus identification by mid-infrared spectroscopy of oral biofluids: A case-control study

BACKGROUND AND AIMS

This study aims to access the effectiveness of mid-infrared (MIR) spectroscopy on the identification of the reticular form of OLP, following the assessment of gingival crevicular fluid (GCF) and oral mucosa transudate (OMT).

MATERIAL AND METHODS

The trial follows a case-control design. Samples were characterized through MIR spectroscopy and chemometric tools were applied to distinguish between case and control participants, further identifying the spectral regions with the highest contribution to the developed models.

RESULTS

MIR spectroscopy was capable to discriminate between OLP patients and controls with 95.1% and 85.4% of correct predictions, regarding GCF and OMT samples, respectively. Additionally, the spectral regions mostly contributing to the successful prediction were identified, and possibly related with the distinctive presence of amino acids/proteins and oxidative stress mediators in oral biofluids, supporting the role of the immune-inflammatory activation on OLP etiology and disease course.

CONCLUSION

MIR spectroscopy analysis of GCF and OMT may be regarded as an innovative, non-invasive, low cost and sensitive technique, contributing to the identification of the reticular from of OLP.

Modulating the Antioxidant Response for Better Oxidative Stress-Inducing Therapies: How to Take Advantage of Two Sides of the Same Medal?

Oxidative stress-inducing therapies are characterized as a specific treatment that involves the production of reactive oxygen and nitrogen species (RONS) by external or internal sources. To protect cells against oxidative stress, cells have evolved a strong antioxidant defense system to either prevent RONS formation or scavenge them. The maintenance of the redox balance ensures signal transduction, development, cell proliferation, regulation of the mechanisms of cell death, among others. Oxidative stress can beneficially be used to treat several diseases such as neurodegenerative disorders, heart disease, cancer, and other diseases by regulating the antioxidant system. Understanding the mechanisms of various endogenous antioxidant systems can increase the therapeutic efficacy of oxidative stress-based therapies, leading to clinical success in medical treatment. This review deals with the recent novel findings of various cellular endogenous antioxidant responses behind oxidative stress, highlighting their implication in various human diseases, such as ulcers, skin pathologies, oncology, and viral infections such as SARS-CoV-2.

Evaluation of salivary oxidative stress in oral lichen planus using malonaldehyde

Background:

Oral lichen planus is a chronic, mucocutaneous, inflammatory disease, with an unknown etiology. Reactive oxygen species and oxidative damage to the tissues might be the cause. Malonaldehyde (MDA), a low molecular weight end product of lipid peroxidation reaction is a suitable biomarker of endogenous DNA damage. monitoring the oxidant-antioxidant status of saliva may serve as an efficient marker of disease development in oral lichen planus patients.

Aim and Objectives:

To evaluate salivary oxidative stress in oral lichen planus subject using MDA and compare it with control subjects. Furthermore, to compare MDA levels in erosive and hypertrophic lichen planus.

Materials and Methods:

The current study is case–control study. Unstimulated salivary samples in the morning hours were taken from oral lichen planus subjects (n = 25) and controls subjects without any oral disease (n = 25). The saliva was centrifuged at 900 g for 10 min at a temperature of 4°C. Then, the entire filtrate was transferred to Eppendorf test tubes and frozen at–80°C until analysis. Salivary MDA was done through thiobarbituric acid reactive substance assay as per the protocol laid down by the manufacturer (Sigma Aldrich Lipid Peroxidation Assay Kit).

Results:

The data were expressed as the mean ± standard deviation and the statistical analysis was done using Student's t-test using SPSS version 21 IBM software. The salivary level of MDA was significantly higher than that of controls (P < 0.05).

Conclusion:

The higher level of MDA in patients with oral lichen planus suggests that free radicals and the resulting oxidative damage may be important in the pathogenesis of oral lichen planus lesions.

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.

Serum 8-isoprostane levels in patients with resistant oral lichen planus before and after treatment with lycopene: a randomized clinical trial

Background

Oral lichen planus is an autoimmune disease in which topical steroids are the first line of treatment. The adverse effects of systemic corticosteroids prescribed for resistant oral lichen planus cases advocate alternative modalities. Lycopene is an antioxidant with a wide range of beneficial properties. This trial aimed to evaluate the effect of pure lycopene as compared to systemic corticosteroids (Prednisolone) on the symptoms, signs and oxidative stress in patients with erosive oral lichen planus recalcitrant to topical steroids.

Methods

Twenty patients were randomly divided into the test (lycopene) and control (corticosteroids) groups. Numeric rating scale and Escudier et al. (Br J Dermatol 4:765–770, 2007. 10.1111/j.1365-2133.2007.08106.x) lesion scores were assessed at baseline and weeks 4 and 8 from baseline. Serum levels of 8-isoprostane were measured in all patients at baseline and at the end of treatment (week 8).

Results

There was a significant reduction in signs and symptoms after the end of treatment in each group. However, no significant difference was found between the lycopene and the corticosteroids group. Moreover, a significant reduction in 8-isoprostane levels was observed in the lycopene group from baseline and as compared to the control group.

Conclusions

Based on the study results, lycopene is a safe and effective therapeutic modality for resistant oral lichen planus. 8-isoprostane is a biomarker of lipid peroxidation that can be reduced by lycopene.

Trial registration ID: PACTR202003484099670. 'Retrospectively registered on 11/3/2020'.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01711-z.

Expression profile of DNA repair proteins and histone H3 lys-9 acetylation in cutaneous and oral lichen planus

OBJECTIVES

To analyze the expression profile of DNA repair proteins (XRCC1 and APE1) and histone acetylation (H3K9) in oral and cutaneous lichen planus, in order to investigate potential biological markers that can clarify pathogenesis of these lesions.

DESIGN AND RESULTS

The total sample consisted of 89 lichen planus cases (66 oral and 23 cutaneous). Analysis of APE1 and XRCC1 expression was performed by immunohistochemistry in 44 oral and 20 cutaneous lichen planus, whereas the analysis of H3K9 acetylation was performed by immunofluorescence in 42 oral and 11 cutaneous lichen planus.

RESULTS

Immunoreactivity for APE1 and XRCC1 was significantly higher in cutaneous lichen planus than in oral lichen planus (P = 0.003 and P = 0.034, respectively). There was a significant and moderate positive correlation between APE1 and XRCC1 in the oral group (Rho = 0.544; P < 0.0001). In oral cases, there were no statistically significant results comparing APE1 and XRCC1 expression between reticular and erosive cases (P > 0.05). Evaluation of H9K3 histone acetylation levels did not reveal significant results comparing oral to cutaneous lichen planus, neither comparing erosive to reticular (P > 0.05).

CONCLUSIONS

Changes in the expression profile of the DNA repair proteins exerted greater influence in pathogenesis of cutaneous lichen planus than oral lichen planus, in addition, H3K9 histone acetylation is an epigenetic event found in both lesions.

Comparative Evaluation of Mitochondrial Antioxidants in Oral Potentially Malignant Disorders

Various endogenous mitochondria-associated antioxidants protect mitochondria from oxidative stresses such as Superoxide Dismutase 2 (SOD2), Catalase, Glutaredoxin 2 (GLRX2), educed Glutathione (GSH), Glutathione Peroxidase (GPx), and Thioredoxin 2 (TXN2). They protect mitochondria from Reactive Oxygen Species (ROS). Excess ROS causes mitochondrial DNA damage and respiratory chain dysfunction leading to carcinogenesis. In an earlier study we found complex alterations of mitochondrial antioxidants in different stages of oral squamous cell carcinoma. Here, we profiled mitochondrial antioxidants in different oral potentially malignant disorders such as oral leukoplakia (OL), oral lichen planus (OLP), and oral submucous fibrosis (OSMF). Mitochondria was prepared from oral tissues from OL, OLP, and OSMF patients. Biochemical assays and immunoblotting were performed to investigate expression of various mitochondrial antioxidants. Catalase was expressed as Control> OL > OSMF > OLP. GLRX 2 was expressed as OLP> OL >Control >OSMF. GPX1 and GPX4 were expressed as Control >OSMF> OLP > OL. GSH increased in OL and OSMP, but decreased in OLP. SOD2 was expressed as Control >OSMF> OLP > OL. PRX3 was expressed as OL > OLP > OSMF > Control. TXN2 expression was nearly the same in all groups except OL, which showed elevated expression. We conclude that endogenous mitochondria-associated antioxidants show different levels of expressions in various oral potentially malignant disorders.

The Relationship between the Concentration of Salivary Tyrosine and Antioxidants in Patients with Oral Lichen Planus

The diagnosis of oral lichen planus (OLP) is based on clinical examination and histopathological criteria. Noninvasive diagnostics of saliva may be considered as a confirmation of OLP diagnosis and a potential alternative to an invasive method. The objective of the present study was to evaluate the relationship between the level of tyrosine (Tyr) as well as antioxidants like uric acid (UA) and glutathione peroxidase (GPx) activity in the saliva of patients with OLP in comparison with the control group (healthy subjects without any oral changes). A total of 40 patients with OLP and 40 healthy volunteers were selected for the study based on the modified WHO diagnostic (clinical and histopathological) criteria. High-performance liquid chromatography (HPLC) was performed for Tyr concentration, while GPx activity and uric acid levels were determined by a colorimetric method. The concentrations of Tyr, UA, and GPx activity were statistically lowered in OLP patients compared to the control group. All examined parameters correlated strongly and positively with each other. Mean values of salivary UA concentrations differed between the groups of OLP patients (reticular and erosive forms) and controls (206.66 vs. 196.54 vs. 218.49 μmol/L, respectively, p = 0.001). A similar trend was demonstrated in salivary Tyr concentration which differed statistically between the study and control groups (0.08 vs. 0.07 vs. 0.13 μmol/L, respectively, p = 0.001). Determining of a relationship between the concentrations of Tyr, UA, and GPx activity may be useful in the prognosis of OLP. The HPLC method may be employed, as an additional noninvasive diagnostic procedure to screen OLP patients, during the routine diagnostics of salivary biochemical parameters such as aromatic amino acids.

Mitochondrial Dysfunction Pathway Networks and Mitochondrial Dynamics in the Pathogenesis of Pituitary Adenomas

Mitochondrion is a multi-functional organelle, which is associated with various signaling pathway networks, including energy metabolism, oxidative stress, cell apoptosis, cell cycles, autophagy, and immunity process. Mitochondrial proteins have been discovered to modulate these signaling pathway networks, and multiple biological behaviors to adapt to various internal environments or signaling events of human pathogenesis. Accordingly, mitochondrial dysfunction that alters the bioenergetic and biosynthetic state might contribute to multiple diseases, including cell transformation and tumor. Multiomics studies have revealed that mitochondrial dysfunction, oxidative stress, and cell cycle dysregulation signaling pathways operate in human pituitary adenomas, which suggest mitochondria play critical roles in pituitary adenomas. Some drugs targeting mitochondria are found as a therapeutic strategy for pituitary adenomas, including melatonin, melatonin inhibitors, temozolomide, pyrimethamine, 18 beta-glycyrrhetinic acid, gossypol acetate, Yougui pill, T-2 toxin, grifolic acid, cyclosporine A, dopamine agonists, and paeoniflorin. This article reviews the latest experimental evidence and potential biological roles of mitochondrial dysfunction and mitochondrial dynamics in pituitary adenoma progression, potential molecular mechanisms between mitochondria and pituitary adenoma progression, and current status and perspectives of mitochondria-based biomarkers and targeted drugs for effective management of pituitary adenomas.

Evaluation of depression, anxiety and stress levels in patients with oral lichen planus

The pathogenesis of oral lichen planus (OLP) remains to be fully elucidated; however, certain psychoneurological factors may influence the onset and exacerbation of OLP. The aim of the present study is to evaluate the intensity of negative emotions in patients with OLP. A cross-sectional, questionnaire-based study was performed. The sample consisted of 52 subjects, comprising 26 patients with OLP (OLP group) and 26 controls (CTRL group). The Depression Anxiety Stress Scale 21 (DASS-21) was used for psychometric evaluation. The patients were also asked about their attitude toward the disease, treatment, and interference of the disease on daily life. The mean level of depression was 12.54 ± 6.6 in the OLP group and 7.69 ± 5.22 in the CTRL group (P = 0.006). The mean level of anxiety was 11.15 ± 7.95 in the OLP group and 6.62 ± 4.86 in the CTRL group (P = 0.018). The mean stress levels were 8.69 ± 7.06 and 3.85 ± 3.18 in the OLP and CTRL groups, respectively (P = 0.003). Severe and very severe scores of depression and very severe scores of anxiety and stress were present in the OLP group, whereas these emotions were normal in the majority of controls. Depression, stress, and anxiety may be involved in the pathogenesis and course of OLP.

Clinical safety and efficacy of curcumin use for oral lichen planus: a systematic review

Objective: Oral lichen planus (OLP) is a relatively common immunological mucocutaneous disease that causes pain and poor quality of life. Curcumin has been reported to be a safe and effective treatment for OLP. The objective of this review is to evaluate the existing evidence for the safety of curcumin in treating OLP as well as its efficacy compared with that of corticosteroids. Methods: We reviewed the published literature by searching PubMed, EMBASE, EBSCO, and Cochrane Library, and then retrieved and analyzed several variables from patient records. Results: Nine studies met the inclusion criteria, including six randomized, double-blind clinical trials; two pilot clinical trials; and one case report. A total of 259 OLP patients were included in the systematic review. Seven studies showed statistically significant differences in pain severity and clinical appearance of oral lesions after treatment with curcumin for a period of time, compared to baseline (p < .05). Three controlled clinical trials compared the efficacy of curcumin to that of corticosteroids; all of these trials showed no statistically significant differences in pain severity and clinical appearance of oral lesions. Conclusions: Curcumin is a safe treatment and can be used as an adjunct in combination with corticosteroids to reduce pain, burning sensations, and the clinical appearance of oral lesions in OLP patients.

Black pepper and its bioactive constituent piperine: promising therapeutic strategies for oral lichen planus

Oral lichen planus (OLP) is a common T cell-mediated chronic inflammatory disease with malignant potential and unclear etiology. The present study suggests that antigen-specific mechanisms in which dentritic cells, T lymphocytes and NF-κB signaling pathway play critical roles, are involved in the pathogenesis of OLP. Additionally, it has been indicated that altered expression of cyclooxygenase 2 (COX-2) and imbalanced oxidant-antioxidant status as well as psychological issue may act as promoters to the development of OLP. Therapies for OLP are primarily aimed to control symptoms and a specific cure is not yet available. Black pepper and its principle bioactive compound piperine have been reported to possess remarkable pharmacological activities. Not only has piperine been evidenced to exhibit repressive effects on the maturation of dentritic cells, the proliferation, activation and function of T lymphocytes as well as the NF-κB signaling pathway, but also to suppress the overproduction of COX-2 and weaken the oxidative stress. Furthermore, piperine might be a possible agent for alleviating psychological disorders and preventing carcinogenesis. Given all these into consideration, piperine may be a novel and effective therapeutic strategy for OLP.