Comparative Evaluation of Mitochondrial Antioxidants in Oral Potentially Malignant Disorders

Alteration of salivary LPO, MDA, LDH, glutathione, GPx, SOD and vitamins in oral submucous fibrosis: A three-level meta-analysis study

This study aims to investigate the alteration of salivary biomarker profiling in the development of oral submucous fibrosis (OSMF) and to explore the influence of saliva in the diagnosis of OSMF. A systematic search of published articles using the PRISMA guidelines was conducted to identify relevant studies on OSMF and saliva. All eligible studies, including case-control, cross-sectional studies, cohort, and pilot studies, contained the evaluation of salivary biomarker profiling in patients with OSMF. Salivary biomarker data from 28 selected articles were categorized into nine groups, and their mean values were determined. A three-step meta-analysis was performed by grouping salivary biomarker profiling into more heterogeneous categories based on OSMF classification, considering functional, histological, and clinical grading. The salivary biomarker profiling analysis revealed significant alterations in all markers, indicating their efficacy in OSMF diagnosis. Subgroup analyses highlighted significant associations in oxidative stress and protein with increased mean values, particularly emphasizing lipid peroxidase (LPO), malondialdehyde (MDA), and lactate dehydrogenase (LDH). Conversely, decreased mean values were observed in glutathione, glutathione peroxidase (GPx), superoxide dismutase (SOD), and vitamins. Notably, OSMF grading analysis demonstrated a significant difference in weighted effect sizes for histological grading, particularly in stage IV. The study underscores the alteration of specific salivary biomarkers, particularly those associated with LPO, MDA, LDH, glutathione, GPx, SOD, and vitamins, in diagnosing and grading OSMF.

Prx1/PHB2 axis mediates mitophagy in oral leukoplakia cellular senescence

BACKGROUND

Oral leukoplakia (OLK) is the most common oral potentially malignant disorder (OPMD), which can be malignantly transformed into oral squamous cell carcinoma (OSCC). Peroxiredoxin1(Prx1) has been predicted to bind to Prohibitin2 (PHB2), which confers to affect OLK progression; however, the mechanism of Prx1/PHB2 mediated mitophagy involved in OLK remains unclear.

METHODS

This study aimed to explore the mechanism of the Prx1/PHB2 axis on senescence in OLK through mediating mitophagy. The positive rate of Ki67 and the expression of p21, p16, PHB2, and LC3 in human normal, OLK, and OSCC tissues were detected by immunohistochemical staining. The mitophagy and mitochondrial function changes were then analyzed in Prx1 knockdown and Prx1C52S mutations in dysplastic oral keratinocyte (DOK) cells treated with H2O2. In situ Proximity Ligation Assay combined with co-immunoprecipitation was used to detect the interaction between Prx1 and PHB2.

RESULTS

Clinically, the positive rate of Ki67 progressively increased from normal to OLK, OLK with dysplasia, and OSCC. Higher p21, p16, PHB2, and LC3 expression levels were observed in OLK with dysplasia than in normal and OSCC tissues. In vitro, PHB2 and LC3II expression gradually increased with the degree of DOK cell senescence. Prx1/PHB2 regulated mitophagy and affected senescence in H2O2-induced DOK cells. Furthermore, Prx1C52S mutation specifically reduced interaction between Prx1 and PHB2. Prx1Cys52 is associated with mitochondrial reactive oxygen species (ROS) accumulated and cell cycle arrest.

CONCLUSION

Prx1Cys52 functions as a redox sensor that binds to PHB2 and regulates mitophagy in the senescence of OLK, suggesting its potential as a clinical target.

Current status of superoxide dismutase 2 on oral disease progression by supervision of ROS

The recent Global Burden of Disease results have demonstrated that oral diseases are some of the most significant public health challenges facing the world. Owing to its specific localization advantage, superoxide dismutase 2 (SOD2 or MnSOD) has the ability to process the reactive oxygen species (ROS) produced by mitochondrial respiration before anything else, thereby impacting the occurrence and development of diseases. In this review, we summarize the processes of common oral diseases in which SOD2 is involved. SOD2 is upregulated in periodontitis to protect the tissue from the distant damage caused by excessive ROS and further reduce inflammatory progression. SOD2 also participates in the specific pathogenesis of oral cancers and dental diseases. The clinical application prospects of SOD2 in oral diseases will be discussed further, referencing the differences and relationship between oral diseases and other clinical systemic diseases.

Development of Epigallocatechin 3-gallate-Loaded Hydrogel Nanocomposites for Oral Submucous Fibrosis

Oral submucous fibrosis (OSF) is a chronic progressive disease associated with increased collagen deposition and TGF-β1 release. The current therapy and management have been a limited success due to low efficacy and adverse drug reactions. This study aimed to evaluate epigallocatechin 3-gallate (EGCG) encapsulated nanoparticles loaded mucoadhesive hydrogel nanocomposite (HNC) for OSF. Developed HNC formulations were evaluated for their permeation behaviour using in vitro as well as ex vivo studies, followed by evaluation of efficacy and safety by in vivo studies using areca nut extract-induced OSF in rats. The disease condition in OSF-induced rats was assessed by mouth-opening and biochemical markers. The optimized polymeric nanoparticles exhibited the required particle size (162.93 ± 13.81 nm), positive zeta potential (22.50 ± 2.94 mV) with better mucoadhesive strength (0.40 ± 0.002 N), and faster permeation due to interactions of the positively charged surface with the negatively charged buccal mucosal membrane. HNC significantly improved disease conditions by reducing TGF-β1 and collagen concentration without showing toxicity and reverting the fibroid buccal mucosa to normal. Hence, the optimized formulation can be further tested to develop a clinically alternate therapeutic strategy for OSF.

Development and validation of a minimally invasive protocol for assessing oxidative stress markers in exfoliated oral cells

OBJECTIVES

This study aimed to develop and validate a minimally invasive protocol for characterizing oxidative stress markers in exfoliated oral cells.

MATERIALS AND METHODS

Exfoliated oral cells were collected from healthy volunteers. The protocol included the utilization of specific fluorescent probes to measure intracellular reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm) and reduced glutathione (GSH). Cells from each volunteer were divided into the positive and negative control groups, which were, respectively, exposed or not to hydrogen peroxide (H2 O2 ) aiming to induce the oxidative stress. Measurements of cell fluorescence were performed using a microscope equipped with epifluorescence.

RESULTS

The results showed that cells exposed to H2 O2 exhibited significantly higher intracellular expression of ROS compared to unexposed cells (positive control: 3851.25 ± 1227.0 vs, negative control: 1106.07 ± 249.6; p = 0.0338). On the contrary, cells exposed to H2 O2 displayed decreased expression of ΔΨm (p = 0.0226) and GSH (p = 0.0289) when compared to the negative control group (ΔΨm positive control: 14634.39 ± 1529.0 vs, negative control: 18897.60 ± 2338.0; and GSH positive control: 9011.08 ± 1900.0 vs, negative control: 15901.79 ± 2745.0).

CONCLUSIONS

The developed protocol proved to be effective in detecting and quantifying oxidative stress biomarkers, such as ROS, ΔΨm and GSH, in exfoliated oral cells. This minimally invasive approach offers a promising method to assess oxidative stress expression and may be clinically relevant in the evaluation of oral diseases associated with oxidative stress.

Clinical and biochemical assessment of the effect of topical use of coenzyme Q10 versus topical corticosteroid in management of symptomatic oral lichen planus: randomized controlled clinical trial

BACKGROUND

Oral lichen planus (OLP) is a chronic mucocutaneous immunologically mediated condition that has a great adverse effect on oral functions. Corticosteroids are still the first drugs of choice used in the treatment of OLP; however, they have extensive medical side effects. The present study was carried out to assess the clinical therapeutic effect of the topical use of coenzyme Q10 (coQ10 or ubiquinol) versus topical corticosteroids in the management of symptomatic OLP and to determine whether the effect, if any, was due to the powerful antioxidant activity of coQ10.

SUBJECTS AND METHODS

We performed a randomized, double blinded controlled trial at the Faculty of Dentistry, Cairo University, Egypt. The study was conducted on 34 patients suffering from symptomatic OLP. Patients were randomly divided into two groups: intervention group (I),who received topical CoQ10 in the form of mucoadhesive tablets (40% CoQ10) 3 times daily for one month and control group (II),who received topical corticosteroid (kenacort in Orabase: triamcinolone acetonide 0.1% 5-g adhesive paste - dermapharm), 4 times daily for one month. Patients were evaluated at one-week intervals using the clinical parameters (score) of pain (VAS) and lesion size. Additionally, salivary levels of malondialdehyde (MDA) were detected in both groups before and after treatment using ELISA. All recorded data were analysed using independent t test, ANOVA followed by Bonferroni post hoc test for lesion size and salivary level of MDA data and Mann-Whitney U test and Friedman test for VAS data.

RESULTS

Both groups showed a significant reduction in pain and the size of the lesions (p ≤ 0.05) with no statistically significant difference between them (p > 0.05), and this clinical improvement was associated with a reduction in the salivary levels of MDA in both groups.

CONCLUSIONS

The topical use of CoQ10 mucoadhesive tablets was as effective as the topical use of triamcinolone acetonide, and its clinical effect was associated with a reduction in the salivary level of MDA.

TRIAL REGISTRATION

The study protocol was registered at www.

CLINICALTRIAL

gov (NCT04091698) and registration date: 17/9/2019.

A Comprehensive Analysis of the Role of Oxidative Stress in the Pathogenesis and Chemoprevention of Oral Submucous Fibrosis

Oral submucous fibrosis (OSMF) is a chronic oral potentially malignant disorder (OPMD). It is described as a scarring disease of the oral mucosa associated with excess oxidants and insufficient antioxidants. While it is becoming increasingly accepted that oxidative stress results in excessive accumulation of collagen and progressive fibrosis of the submucosal tissues, there is limited data regarding the moderation of oxidative stress to initiate or prevent OSMF. To assess the scope for mechanism-based approaches to prevent or reverse OSMF, we systematically evaluated the existing literature and investigated the role of oxidative stress in the pathogenesis and chemoprevention of OSMF. A search for relevant articles on PubMed and Scopus was undertaken using pre-defined inclusion and exclusion criteria. A total of 78 articles were selected in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. The articles eligible for assessment investigated both OSMF and/or oxidative stress biomarkers or specific antioxidants. Both in vitro and human studies consistently demonstrated variations in oxidative stress biomarker levels in OSMF and revealed an increase in oxidative stress, paralleling the development of the disease. Furthermore, the use of antioxidant supplements was overall associated with an improvement in clinical outcomes. Having identified the significance of oxidative stress in OSMF and the therapeutic potential of antioxidant supplements, this scoping review highlights the need for further well-designed studies in the development of mechanism-based interventions for managing OSMF.

Metabolomics and Transcriptomics Analysis on Metabolic Characteristics of Oral Lichen Planus

Objective

To explore metabolic biomarkers related to erosive and reticulated oral lichen planus (OLP) by non-targeted metabolomics methods and correlate metabolites with gene expression, and to investigate the pathological network pathways of OLP from the perspective of metabolism.

Methods

A total of 153 individuals were enrolled in this study, including 50 patients with erosive oral lichen planus (EOLP), 51 patients with reticulated oral lichen planus (ROLP), and 52 healthy controls (HC). The ultra-high-performance liquid chromatography quadrupole-Orbitrap high-resolution accurate mass spectrometry (UHPLC/Q-Orbitrap HRMS) was used to analyze the metabolites of 40 EOLP, 40 ROLP, and 40 HC samples, and the differential metabolic biomarkers were screened and identified. The regulatory genes were further screened through the shared metabolites between EOLP and ROLP, and cross-correlated with the OLP-related differential genes in the network database. A “gene-metabolite” network was constructed after finding the key differential genes. Finally, the diagnostic efficiency of the biomarkers was verified in the validation set and a diagnostic model was constructed.

Result

Compared with HC group, a total of 19 and 25 differential metabolites were identified in the EOLP group and the ROLP group, respectively. A total of 14 different metabolites were identified between EOLP and ROLP. Two diagnostic models were constructed based on these differential metabolites. There are 14 differential metabolites shared by EOLP and ROLP. The transcriptomics data showed 756 differentially expressed genes, and the final crossover network showed that 19 differential genes were associated with 12 metabolites. Enrichment analysis showed that alanine, aspartate and glutamate metabolism were closely associated with the pathogenesis of OLP.

Conclusion

The metabolic change of different types of OLP were clarified. The potential gene perturbation of OLP was provided. This study provided a strong support for further exploration of the pathogenic mechanism of OLP.

A Meta-Analysis in Assessing Oxidative Stress Using Malondialdehyde in Oral Submucous Fibrosis

Objective This study aimed to evaluate the oxidative stress (OS) marker Malondialdehyde (MDA) in oral submucous fibrosis with available literature.

Materials and Methods We conducted a literature search electronically in PubMed (MeSH), Science Direct, Scopus, and Google Scholar using specific keywords.

Results A systematic search in PubMed, Science Direct, and Google Scholar identified 334 articles. Of these, four were duplicate reports, and three were animal studies. After reading the abstracts of the collected articles, 288 articles were excluded for the following reasons: low quality, not relevant to the research question, or did not meet the inclusion criteria. The remaining 46 articles were chosen for full-text assessment. Finally, the present qualitative synthesis included 23 articles for evaluation. The selected studies in MDA analysis in a random-effects model showed higher heterogeneity (Q = 477.636, p < 0.001, I ² = 95.394%). The standard difference in mean MDA concentration between oral submucous fibrosis (OSMF) and healthy subjects was estimated as 2.73 nmol/mL (95% confidence interval: 2.08–3.38).

Conclusion The selected studies showed significantly higher MDA levels in various biological samples of patients with OSMF. Therefore, further studies are needed to estimate oxidative stress levels by using different biomarkers in OSMF to direct future therapy.