Oral Submucous Fibrosis: A Review on Etiopathogenesis, Diagnosis, and Therapy

The role of M1 (CD11c) and M2 (CD163) interplay in the pathogenesis of oral submucous fibrosis and its malignant transformation: An immunohistochemical analysis

OBJECTIVES

The M1/M2 macrophage framework is crucial in organ fibrosis and its progression to malignancy. This study investigated the possible role of M1/M2 macrophage interplay in the pathogenesis of oral submucous fibrosis (OSF) and its malignant transformation by analysing immunohistochemical expression of CD11c (M1) and CD163 (M2) markers.

METHODS

Immunohistochemistry was performed using primary antibodies against CD11c and CD163 on ten formalin-fixed paraffin-embedded tissue blocks for each group: (i) Stage 1 OSF, (ii) Stage 2 OSF, (iii) Stage 3 OSF, (iv) Stage 4 OSF, (v) well-differentiated squamous cell carcinoma (WDSCC) with OSF, and (vi) WDSCC without OSF. Ten cases of healthy buccal mucosa (NOM) served as controls.

RESULTS

Epithelial quick scores of M1 (CD11c) in NOM, Stages 1-4 OSF, and WDSCC with and without OSF were 0, 1.8, 2.9, 0.4, 0, 0, and 0, while connective tissue scores were 0, 3.2, 4.3, 2.7, 0.5, 1.2, and 2.4, respectively. Epithelial scores for M2 (CD163) were 0, 0.8, 0.8, 2.1, 0.6, 0.8, and 0.2, and connective tissue scores were 0, 1.8, 2.6, 3.9, 2.2, 5, and 4.4, respectively. Stages 3 and 4 OSF, WDSCC with and without OSF exhibited higher M2/M1 ratios compared to NOM and Stages 1-2 OSF.

CONCLUSION

The interaction between M1 (CD11c) and M2 (CD163) macrophages, leading to M2 polarisation, plays a crucial role in the pathogenesis of OSF and its potential malignant transformation.

Arecoline promotes fibroblast activation and M2-macrophage polarization by up-regulating the expression of IL-4

OBJECTIVE

To determine the biological effects of arecoline on oral submucous fibrosis (OSF).

DESIGN

The differential genes between OSF tissue and normal oral tissue were collected form GSE64216 dataset, analyzed by Gene Expression Omnibus (GEO) database. Real-time PCR and immunohistochemistry were used to analyze the expression of IL-4 gene and protein in oral tissue. Enzyme-linked immunosorbent assay (ELISA) was used to analyze the expression of exocrine IL-4 protein in human oral fibroblasts (HOF) pre-treated by arecoline. Cell Counting Kit-8 (CCK-8) and transwell assays were used to analyze the proliferation and migration of HOF cells, respectively. After IL-4 was knocked down by short hairpin (sh) plasmid, the proliferation and migration of HOF cells were detected. Flow cytometry was used to analyze the proportion of M2-macrophages. Real-time PCR and immunohistochemistry were used to verify the expression of biomarker proteins of macrophages in OSF tissues.

RESULTS

The expression of IL-4 gene and protein were both up-regulated in OSF tissue. Arecoline could enhance the expression of IL-4 gene and exocrine protein in HOF cells, and promote the proliferation and migration of HOF cells. While knockdown of IL-4 could inhibit arecoline-induced proliferation and migration in HOF cells. The results of flow cytometry showed that recombinant human IL-4 (rhIL-4) protein could increase the proportion of M2-macrophages. Similarly, the results of real-time PCR and immunohistochemistry showed the expression of ARG1 (Biomarker proteins of M2-macrophage) was up-regulated in OSF tissues.

CONCLUSION

Arecoline promotes activation of fibroblasts and polarization of M2-macrophages by up-regulating the expression of IL-4.

Comprehensive analysis of clinicopathological characteristics in oral squamous cell carcinoma arising from oral submucous fibrosis: a retrospective study

BACKGROUND

Oral squamous cell carcinoma arising from oral submucous fibrosis is recognized as a clinicopathologically distinct disease. This study aims to summarize and compare the population and clinicopathologic characteristics of OSCC-OSF with other OSCC in Hunan Province, China. The objective is to formulate treatment strategies more in line with regional characteristics.

METHODS

A retrospective review of OSCC cases recruited from the Second Xiangya Hospital from 2010 to 2020 was conducted. A total of 1,413 OSCC patients were selected, including 481 patients with OSCC-OSF and 932 were other OSCC. Population characteristics, risk factors and clinicopathological manifestations were explored in OSCC-OSF and other OSCC, as well as thinprep cytologic test and DNA quantification.

RESULTS

We found that OSCC-OSF patients were younger than those with other OSCC. Both types of disease were predominantly observed in males compared to females. Tumor biopsy analysis indicated that tumor cells within OSCC-OSF patients were more likely to be well differentiated and showed a higher frequency of lymph node metastases. Clinicopathological factors, such as the chewing betel nuts habit and smoking, were more prevalent in OSCC-OSF patients in contrast to other OSCC. DNA quantification revealed that the number of DNA aneuploid cells was higher in OSCC-OSF compared to other OSCCs.

CONCLUSION

In this study, OSCC-OSF is considered a clinicopathologically distinct disease. Compared with other OSCC, OSCC-OSF patients have a higher incidence of nodal metastases, an early clinical TNM stage, and a lower three-year survival rate. Therefore, early diagnosis and treatment are crucial to improving the prognosis of OSCC-OSF.

Emerging roles of the renin-angiotensin system in select oral diseases

OBJECTIVES

The renin-angiotensin system (RAS) plays essential roles in cardiovascular and renal function regulation. Recent studies have shown that the RAS components are widely expressed in oral tissues, but their roles in oral diseases remain underexplored. This review aims to summarize the effects of the RAS in select oral diseases including oral squamous cells carcinoma (OSCC), periodontitis, oral submucous fibrosis (OSF), and ageusia/dysgeusia.

SUBJECTS AND METHODS

Data searches were performed using PubMed, Web of Science and Scopus through July 2024. A narrative overview of current literature was undertaken to synthesize the contexts with elaboration and summary.

RESULTS

In OSCC, ACE/Ang II/AT1R promotes OSCC by inducing angiogenesis, cell proliferation and invasiveness. Conversely, ACE/Ang II/AT2R and ACE2/Ang (1-7)/MasR inhibit OSCC progressions. In periodontitis, ACE/Ang II/AT1R upregulates inflammatory cytokines and promotes osteoclast differentiation factor RANKL, whereas ACE2/Ang (1-7)/MasR exerts opposite effects by preventing inflammation and alveolar bone loss. In OSF, Ang (1-7) counters the profibrotic and proinflammatory action of Ang II. In dysgeusia, Ang II suppresses salt taste responses and enhances sweet taste sensitivities, while Ang (1-7) exhibits opposite effects.

CONCLUSIONS

The RAS cascade plays crucial roles in OSCC, periodontitis, OSF and ageusia/dysgeusia. The imbalanced RAS may aggravate the progression of these diseases.

Comprehensive insights into oral squamous cell carcinoma: Diagnosis, pathogenesis, and therapeutic advances

Oral squamous cell carcinoma (OSCC) is considered the most common type of head and neck squamous cell carcinoma (HNSCC) as it holds 90 % of HNSCC cases that arise from multiple locations in the oral cavity. The last three decades witnessed little progress in the diagnosis and treatment of OSCC the aggressive tumor. However, in-depth knowledge about OSCC's pathogenesis, staging & grading, hallmarks, and causative factors is a prime requirement in advanced diagnosis and treatment for OSCC patients. Therefore present review was intended to comprehend the OSCCs' prevalence, staging & grading, molecular pathogenesis including premalignant stages, various hallmarks, etiology, diagnostic methods, treatment (including FDA-approved drugs with the mechanism of action and side effects), and theranostic agents. The current review updates that for a better understanding of OSCC progress tumor-promoting inflammation, sustained proliferative signaling, and growth-suppressive signals/apoptosis capacity evasion are the three most important hallmarks to be considered. This review suggests that among all the etiology factors the consumption of tobacco is the major contributor to the high incidence rate of OSCC. In OSCC diagnosis biopsy is considered the gold standard, however, toluidine blue staining is the easiest and non-invasive method with high accuracy. Although there are various therapeutic agents available for cancer treatment, however, a few only are approved by the FDA specifically for OSCC treatment. The present review recommends that among all available OSCC treatments, the antibody-based CAR-NK is a promising therapeutic approach for future cancer treatment. Presently review also suggests that theranostics have boosted the advancement of cancer diagnosis and treatment, however, additional work is required to refine the role of theranostics in combination with different modalities in cancer treatment.

The Impact of Oral Microbiome Dysbiosis on the Aetiology, Pathogenesis, and Development of Oral Cancer

Oral squamous cell carcinoma (OSCC) is the most common head and neck cancer. Although the oral cavity is an easily accessible area for visual examination, the OSCC is more often detected at an advanced stage. The global prevalence of OSCC is around 6%, with increasing trends posing a significant health problem due to the increase in morbidity and mortality. The oral cavity microbiome has been the target of numerous studies, with findings highlighting the significant role of dysbiosis in developing OSCC. Dysbiosis can significantly increase pathobionts (bacteria, viruses, fungi, and parasites) that trigger inflammation through their virulence and pathogenicity factors. In contrast, chronic bacterial inflammation contributes to the development of OSCC. Pathobionts also have other effects, such as the impact on the immune system, which can alter immune responses and contribute to a pro-inflammatory environment. Poor oral hygiene and carbohydrate-rich foods can also increase the risk of developing oral cancer. The risk factors and mechanisms of OSCC development are not yet fully understood and remain a frequent research topic. For this reason, this narrative review concentrates on the issue of dysbiosis as the potential cause of OSCC, as well as the underlying mechanisms involved.

Salivary Profile in Oral Submucous Fibrosis: A Scoping Review

Diagnosing oral submucous fibrosis (OSMF) is invariably challenging. The disease can be detected after reaching its final stage and requires complex treatment. Changes in its salivary profile can be used as a reference to see this disorder and as a basis for diagnostic prediction. This study is aimed to analyze the salivary profile as a diagnosis marker in patients with OSMF. The study using Preferred Reporting Items for Systematic Reviews and Meta-analyses was conducted using PubMed, Science Direct, and Scopus databases. A thorough literature search between 1991 and 2023 was performed. Twenty-eight full-text articles were reviewed in detail. Twenty-eight articles were included; a total of 929 patients of OSMF and 826 controls were found. The scoping review showed that levels of salivary protein (including lactate hydrogenase, immunoglobulin G, immunoglobulin A, S1007A protein, 8-hydroxydeoxyguanosine, 8-isoprostane, malondialdehyde, matrix metalloproteinase-12, salivary C-reactive protein, fibrinogen producing factor, salivary miRNA-21, and salivary lipids [cholesterol, high-density lipoprotein, triglyceride) were higher in OSMF. Meanwhile, trace elements (vitamin C, vitamin E, iron, zinc, and magnesium) were lower; only copper was higher in OSMF patients. Alteration in salivary components such as protein, lipid, and trace elements detection can be a basis for providing a noninvasive supportive examination and thus be used as a diagnosis marker of OSMF.

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.

Effect of Jiedu Huayu decoction on oral mucosal Axin and β-catenin expression in oral submucosal fibrosis model rats

OBJECTIVE

To investigate the protective effect of the Chinese herbal formula of Jiedu Huayu decoction (, JHD) on oral mucosa of rats with oral submucosal fibrosis (OSF) and its potential mechanism of action.

METHODS

Sprague-Dawley male OSF model rats were constructed by injection of betaine and topical rubbing and were randomly grouped and administered by gavage for 4 weeks. Mouth opening and buccal mucosa scores interleukin levels and the expression of Axin and β-catenin proteins or genes were measured before and after drug administration.

RESULTS

After treatment with JHD the buccal mucosal lesions of rats were significantly reduced Axin protein and mRNA expression were significantly increased β-catenin protein and mRNA expression were significantly decreased interleukin-1β and interleukin-6 levels were decreased and interleukin-10 levels were increased.

CONCLUSION

The mechanism of action of JHD can effectively alleviate the pathological damage of buccal mucosa in OSF rats which may be related to the promotion of Axin expression and inhibition of β-catenin expression.

SFRP1 reduces neutrophil infiltration and inhibits the Wnt/β-catenin pathway to alleviate oral submucous fibrosis

Oral submucous fibrosis (OSF) is a precancerous condition characterized by oral mucosal atrophy with fibrosis of the submucosal tissue. OSF has a high prevalence, and treatment requires improvement. Our study aims to investigate the role and mechanism of secreted frizzled-related protein 1 (SFRP1) in OSF. We constructed an arecoline-induced OSF mice model. Through Pearson's correlation analysis, we investigated the association between SFRP1 levels and expressions of proteins related to the Wnt/β-catenin signaling pathway, as well as the correlation between SFRP1 levels and the degree of neutrophil infiltration. Moreover, neutrophil infiltration intensity, tissue fibrosis degree, and levels of β-catenin, Cyclin D1, and c-myc were evaluated after SFRP1 overexpression treatment through immunohistochemical and biochemical assays. A Wnt/β-catenin pathway activator was used to investigate the molecular mechanism of SFRP1 in the arecoline-induced OSF cell model. Compared with the control group, mice in the OSF group exhibited increased collagen deposition and more severe fibrosis in the oral mucosal tissue (OMT). In the OMT of OSF mice, the levels of SFRP1 were decreased. The levels of SFRP1 exhibited a negative correlation with the levels of Wnt/β-catenin proteins and neutrophil infiltration in the OMT. Upon SFRP1 overexpression, there was a reduction in neutrophil infiltration and fibrosis in the OMT, as well as inhibition of Wnt/β-catenin-related proteins. In vitro, the Wnt/β-catenin pathway activator further reversed the effect of SFRP1 overexpression on OSF. SFRP1 attenuates OSF by reducing neutrophil infiltration and inhibiting the Wnt/β-catenin pathway.

Computational analysis of phytocompounds in Centella asiatica for its antifibrotic and drug-likeness properties - Herb to drug study

Oral submucous fibrosis (OSMF) is a potentially malignant disorder with no permanent cure that affects the quality of life due to trismus. Computational pharmacology has accelerated the discovery of drug candidates for the treatment of incurable diseases. The present study aimed to screen the compounds of the miracle herb Centella asiatica with drug-likeness properties based on the absorption, distribution, metabolism, and excretion (ADME) properties. The pharmacological actions of these screened compounds against OSMF were identified by network pharmacology, gene ontology, pathway enrichment analysis, molecular docking, and simulation. Fifteen drug-like ligands were identified after virtual screening viz; asiatic acid, kaempferol, quercetin, luteolin, apigenin, bayogenin, gallic acid, isothankunic acid, madecassic acid, madasiatic acid, arjunolic acid, terminolic acid, catechin, epicatechin, and nobiletin. 850 potential targets were predicted for the ligands, which were analyzed against 354 proteins associated with OSMF. Compound pathway analysis and disease pathway analysis identified 53 common proteins. The GO enrichment analysis identified 472 biological process terms, 76 molecular function terms, and 44 cellular component terms. Pathway enrichment analysis predicted 142 KEGG pathways, 35 Biocarta pathways, and 236 Reactome pathways for the target proteins. The analysis revealed that the herb targets crucial events of fibrosis such as inflammation, oxidative stress, apoptosis, collagen deposition, and epithelial-mesenchymal transition. The common 53 proteins were used for protein-protein interaction (PPI) network analysis, which revealed 4 key proteins interacting with the phytocompounds viz; transforming growth factor-β1 (TGF-β1), mothers against decapentaplegic-3 (SMAD-3), mitogen-activated protein kinase-1 (MAPK-1) and proto-oncogene tyrosine-protein kinase (SRC). Molecular docking revealed that all ligands had a good binding affinity to the target proteins. Bayogenin had the highest binding affinity towards MAPK-1 (-9.7 kcal/mol), followed by isothankunic acid towards SRC protein (-9.3 kcal/mol). Madasiatic acid had the highest binding affinity to SMAD-3 (-7.6 kcal/mol) and TGF-β1 (-7.1 kcal/mol). Molecular dynamics simulation demonstrated stable ligand protein interactions of bayogenin and MAPK complex, isothankunic acid and SRC complex. This in silico study is the first to identify potential phytochemicals present in Centella asiatica and their target molecules, which might be responsible for reversing OSMF.

Adiponectin inhibits ROS/NLRP3 inflammatory pathway through FOXO3A to ameliorate oral submucosal fibrosis

Oral submucous fibrosis (OSF) is an oral condition characterized by chronic progression, which may lead to the development of malignancy. Currently, available treatments for OSF only provide temporary relief of symptoms, and there is a limited availability of effective interventions that can effectively cure this condition. In this study, we aimed to investigate whether adiponectin (APN) could ameliorate OSF and the mechanisms involved in it. First, human oral mucosal fibroblasts (HOMFs) were cultured, an OSF model was established using arecoline, and APN and Imiquimod treatment were administered. Then we overexpressed NLRP3 and knocked down FOXO3A. FOXO3A, fibrosis-related factors (ɑ-SMA, COL1A, CTGF), TGF-β1/Smad3 signaling-related factors (TGF-β1, p-Smad3, Smad3), NLRP3 inflammasome-related factors (NLRP3, Caspase-1, IL-1β), and ROS levels were evaluated. Finally, we explored the effect of APN on OSF in mice by in vivo experiments. We found that arecoline significantly increased ɑ-SMA, COL1A, CTGF, and TGF-β1 expressions and promoted Smad3 phosphorylation, while APN significantly inhibited the elevation of these fibrosis-related factors. ROS production was significantly elevated in HOMFs after arecoline treatment, while APN treatment inhibited ROS production. However, the addition of Imiquimod and overexpression of NLRP3 exhibited a trend of elevated ROS, resisting the inhibitory effect of APN. Furthermore, adding Imiquimod and overexpression of NLRP3 elevated ɑ-SMA, COL1A and CTGF and activated TGF-β1/Smad3 signaling pathway. Additionally, knockdown of FOXO3A enhanced APN-inhibited ɑ-SMA and COL1A. In vivo experiments further confirmed that APN ameliorated OSF in mice by inhibiting ROS/NLRP3 inflammatory pathway. In conclusion, APN ameliorated arecoline-induced OSF by promoting FOXO3A expression and downregulating the ROS/NLRP3 pathway.

[Oral submucosal fibrosis induced by active components in areca nut: a network pharmacology-based analysis and validation of the mechanism]

OBJECTIVE

To explore the pharmacologically active components in areca nut that induce oral submucosal fibrosis (OSF) and the possible mechanism.

METHODS

The chemical components in areca nut were analyzed using Thermo QE plus liquid chromatography tandem high-resolution mass spectrometer and Compound discover 3.2 data processing software. The chemical activity of the top 20 compounds was analyzed based on Chinese Pharmacopoeia (2015), PubChem, Chemical book, and SciFinder databases. The potential active components, core targets, biological functions and signaling pathways affecting OSF were analyzed by network pharmacology. The targets of OSF were obtained by integrating Genecards and KEGG databases. The compounds acting on the targets were selected from the Systematic Pharmacology Technology Platform of Traditional Chinese Medicine (TCMSP), and the target-compound, compound-TCM, target-compound-TCM network was constructed. Molecular docking was used to analyze the component-target binding. Immunohistochemistry was used to examine the expressions of key proteins in the PI3K-Akt and MAPK pathways in clinical samples of OSF.

RESULTS

The core intersection target genes between the top 10 active ingredients in areca nut extract and OSF involved mainly the PI3K-Akt and MAPK pathways. In the clinical samples, the expressions of PI3K protein decreased and the expressions p-PI3K, AKT1 and PAkt all increased significantly in OSF tissue, where increased JNK protein expression and enhanced activity of c-Jun and c-Fos transcriptional factors were also detected. The OSF patients had significantly elevated plasma levels of IL-6 and IL-8 compared with healthy individuals.

CONCLUSION

The main active ingredients including arecoline, arecaine, and guvacine are capable of activating the PI3K-Akt and MAPK pathways to promote the expressions of inflammatory mediators IL-6 and IL-8 and induce collagen hyperplasia, thus leading to the occurrence of oral submucosal fibrosis.

Elongated Styloid Process Evaluation Using Panoramic Radiography in Patients With Oral Submucous Fibrosis: A Retrospective Study

Background Oral submucous fibrosis (OSMF) is a chronic condition primarily affecting the buccal mucosa, characterized by fibrotic changes, scarring, and precancerous lesions. Pathologically, it involves inflammation, collagen deposition, and muscular degeneration. Objective This study aimed to assess the prevalence and distribution of elongated styloid process (ESP) in patients diagnosed with OSMF, contributing to the understanding of anatomical variations in this population. Methods A retrospective study was conducted at the Department of Oral Medicine and Radiology of Saveetha Dental College. We collected records of OSMF patients from 2021 to 2023, which included panoramic radiographs. We evaluated the presence, type, and grading of ESP alongside OSMF grades using standardized classifications. Results Out of 125 OSMF patients, 67 (53.6%) had ESP. Type I ESP was most prevalent (83.58%). Bilateral occurrences were more common (52.2%) than unilateral (41.79%). On both sides, type I ESP predominated significantly. Among unilateral cases, left-side occurrences were slightly more frequent. Type I ESP remained predominant regardless of laterality. Conclusion The study highlights the high prevalence of ESP, predominantly type I, in OSMF patients, with bilateral occurrences more common. These findings provide valuable insights into the anatomical variations associated with OSMF, contributing to clinical understanding and potential future research directions.

Longitudinal outcomes of trismus release with free-flap reconstruction in primary and secondary oral submucous fibrosis-related trismus

BACKGROUND

Oral submucous fibrosis is a global health concern associated with betel quid use and results in trismus, which can be either primary or secondary in origin. Severe cases often require trismus release with free-flap reconstruction. This study examined longitudinal outcome trends following trismus release and compared the outcomes of patients with primary and secondary oral submucous fibrosis-related trismus.

METHODS

We conducted a retrospective cohort study by including patients who underwent trismus release between 2013 and 2022. All procedures were performed by a single surgical team to ensure technique standardisation. We measured the maximum mouth opening, the interincisal distance, perioperatively and 1, 2, 3, 4, 6 and 12 months post-operatively. Data were analysed using generalised estimating equations.

RESULTS

A total of 35 patients were included in the study, 17 with primary and 18 with secondary oral submucous fibrosis-related trismus. Initially, patients with primary oral submucous fibrosis-related trismus had greater interincisal distance gains than those with secondary oral submucous fibrosis-related trismus (p = 0.015 and p = 0.025 at 3 and 4 months post-operatively, respectively). However, after 12 months, this initial advantage faded, with comparable interincisal distance improvements in patients with primary and secondary disease, despite the more complex surgical procedures required in secondary cases.

CONCLUSION

Surgeons should carefully consider the benefits of trismus release procedures for patients with secondary oral submucous fibrosis-related trismus by recognising the changes in post-operative outcomes.

Curcumin relieves arecoline-induced oral submucous fibrosis via inhibiting the LTBP2/NF-κB axis

BACKGROUND

Submucosal fibrosis (OSF) of the oral cavity is a chronic scarring disease. Arecoline (Are) is the driving factor for the occurrence and deterioration of OSF. Curcumin plays a vital anti-inflammatory role in Are-induced OSF development. However, its potential pharmacological mechanism needs to be elucidated.

METHODS

The relative molecular level was measured via qRT-PCR or Western blot. MTT assay, transwell assay and flow cytometry detected cell proliferation, migration, and apoptosis. The correlation between hypoxia-inducible factor-1α (HIF-1α) and LTBP2 promoter was confirmed through dual-luciferase reporter assay. ELISA was performed to detect inflammatory cytokines levels.

RESULTS

Curcumin alleviated Are-induced oral mucosal fibroblast cells fibrosis by reducing oral mucosa fibroblasts viability, promoting cell apoptosis, suppressing cell migration, and down-regulating the levels of fibrosis markers and inflammatory factors. Curcumin relieved Are-induced OSF via inhibiting HIF-1α. Mechanically, HIF-1α bound to the promoter of LTBP2 to transcriptionally activated LTBP2. LTBP2 knockdown relieved Are-induced OSF, and curcumin down-regulated LTBP2 via inhibiting HIF-1α to relieve Are-induced OSF. Moreover, curcumin decreased NF-κB signal associated proteins via inhibiting LTBP2 to relieve Are-induced OSF.

CONCLUSION

Curcumin reduced the transcription level of LTBP2 by inhibiting HIF-1α, thereby inactivating NF-κB pathway to alleviate Are-induced OSF.

Traditional Chinese medication for oral submucous fibrosis: A systematic review and network meta-analysis of randomized controlled trials

OBJECTIVE

The purpose of this study was to investigate the effectiveness of various drug therapy methods for treating oral submucous fibrosis (OSF) in terms of increasing mouth opening, reducing VAS score, decreasing lesion area, minimizing side effects, and determining effective proportion.

METHOD

A database search was conducted. Only randomized clinical trials were included, and Cochrane checklist was used for assessing the risk of bias. Stata.17 software was employed and effective treatment ranking was used.

RESULTS

Thirty-one RCT studies, with a total of 2986 patients, were included in the period of 2010-2022. The combination of oral Chinese herbal medicine formulas (OC) and intralesional Salvia miltiorrhiza (ISM) was found to be the most effective treatment in improving mouth opening. For reducing the burning pain, the combination of intralesional steroids (IS) and oral Salvia miltiorrhiza (OSM) was found to be more effective than the others. In terms of lesion area, IS combined with OC was more effective than the others. IS combined with ISM had the highest effective proportion while having the lowest incidence of side effects which mentioned the incidence of side effects.

CONCLUSION

This study indicates that OC and SM can be employed by clinicians for treating OSF effectively.

DNA methyltransferase 3A induces the occurrence of oral submucous fibrosis by promoting the methylation of the von Hippel-Lindau

BACKGROUND

Oral submucous fibrosis (OSF) is associated with malignant disorders. DNA methyltransferase 3A (DNMT3A) is a DNA methylesterase reported to be upregulated in multiple organs and shown to inhibit fibrosis. However, the detailed effect of DNMT3A on OSF remains unclear.

METHODS

To mimic OSF in vitro, oral fibroblasts were exposed to arecoline and molecular biological experiments were performed to detect the function of DNMT3A in OSF.

RESULTS

We found that von Hippel-Lindau (VHL) was downregulated and highly methylated in OSF. Arecoline remarkably increased the viability, invasiveness, and migration of oral fibroblasts, but upregulation of VHL partially reversed these effects. DNMT3A induces DNA hypermethylation in the VHL promoter, and VHL markedly inhibits the level of tenascin-C (TNC) by inducing the ubiquitination of TNC. TNC reversed the inhibitory effect of VHL upregulation on the differentiation of oral fibroblasts into myofibroblasts.

CONCLUSION

DNMT3A induces OSF by promoting methylation of the VHL promoter. Hence, our study provides novel insights into the discovery of novel strategies that can be employed against OSF.

A Patient With Oral Discomfort and Reduced Oral Aperture

A patient had burning and pain in the mouth, reduced oral aperture, white-tan plaques on the oral mucosa, and thickened buccal mucosae bilaterally; biopsy of the lower labial mucosa showed subepithelial fibrosis. She had no history of cigarette smoking or use of chewing tobacco but had current and past history of chewing areca nuts. What is the diagnosis and what would you do next?

Serum and salivary Cu/Zn ratio as a diagnostic biomarker for oral submucosal fibrosis: an analysis of trace metals and LOX gene variants

This study aimed to analyze the serum and salivary levels of copper (Cu), zinc (Zn), iron (Fe), chromium (Cr), manganese (Mn) and the Cu/Zn ratio and investigate the association between LOX gene variants (rs18800449 and rs2288393) and oral submucosal fibrosis (OSMF). A total of 250 subjects were included in the study: OSMF patients (n = 50), areca nut chewers without OSMF (n = 100) and controls (n = 100). Trace metals were measured using an atomic absorption spectrophotometer, while LOX gene variants were genotyped using the tetra primer amplification refractory mutation system (tetra ARMS) polymerase chain reaction (PCR) method. The results showed significant variations in serum and salivary Cu, Zn, Fe and Cr levels and serum Mn concentrations among the three groups (p < 0.0001). Serum Cu levels were significantly higher in OSMF patients, while serum Zn levels were significantly lower. Both serum and salivary Cu/Zn ratios demonstrated a statistically significant difference (p < 0.0001) and diagnostic potential to differentiate OSMF from chewers and controls. However, LOX gene variants did not show an association between OSMF and chewers, except for rs1800449 genotypes, which showed a significant and increased risk with the AA genotype in OSMF patients compared to controls (OR = 7.58; 95%CI 2.30-24.97). The study suggests that trace elements and genetic variants may impact the etiology of OSMF. The findings may aid in early diagnosis, suitable treatment, and as a prognostic indicator for disease progression.

Evaluation of stromal myofibroblasts in oral submucous fibrosis and its malignant transformation: An immunohistochemical study

BACKGROUND

Oral submucous fibrosis (OSF) is a precancerous lesion, with oral squamous cell carcinoma (OSCC) being the most prevalent malignancy affecting the oral mucosa. The malignant transformation of OSF into OSCC is estimated to occur in 7-13% of cases. Myofibroblasts (MFs) play pivotal roles in both physiological and pathological processes, such as wound healing and tumorigenesis, respectively. This study aimed to explore the involvement of MFs in the progression of OSF and its malignant transformation.

MATERIALS AND METHODS

In total, 94 formalin-fixed paraffin-embedded tissue blocks were collected, including normal oral mucosa (NOM; n = 10), early-moderate OSF (EMOSF; n = 29), advanced OSF (AOSF; n = 29), paracancerous OSF (POSF; n = 21), and OSCC (n = 5) samples. Alpha-smooth muscle actin was used for the immunohistochemical identification of MFs.

RESULTS

NOM exhibited infrequent expression of MFs. A higher staining index of MFs was found in AOSF, followed by EMOSF and NOM. Additionally, a significant increase in the staining index of MFs was found from EMOSF to POSF and OSCC. The staining index of MFs in NOM, EMOSF, AOSF, POSF, and OSCC was 0.14 ± 0.2, 1.69 ± 1.4, 2.47 ± 1.2, 3.57 ± 2.6, and 8.86 ± 1.4, respectively. All results were statistically significant (P < 0.05).

CONCLUSIONS

The expression of MFs exhibited a gradual increase as the disease progressed from mild to malignant transformation, indicating the contributory role of MFs in the fibrogenesis and potential tumorigenesis associated with OSF.

Fibroblast activating protein promotes the proliferation, migration, and activation of fibroblasts in oral submucous fibrosis

OBJECTIVES

Fibroblast activating protein (FAP) is associated with various organ fibrosis. However, the expression and molecular function of FAP in oral submucous fibrosis (OSF) is still unclear.

MATERIALS AND METHODS

The high-performance liquid chromatography was used to detect the presence of alkaloids in areca nut extract (ANE). Real-time qPCR, Western blot, and Immunohistochemistry assay were used to analyze the expression of FAP mRNA or protein in OSF and normal oral tissue. A chi-squared test analyzed the relationship between FAP protein expression and clinicopathological data of OSF patients. CCK-8, Wound-healing, and Transwell migration assay were employed to assess the effect of the proliferation and migration ability of hOMF cells with FAP overexpression or knockdown. The expression level of a-SMA, FSP1, and P13K-Akt signaling pathways-related protein in hOMF cells transfected with FAP overexpression or knockdown plasmid was verified by western blot assay.

RESULTS

The four specific areca alkaloids (Arecoline, Guvacine, Arecaidine, and Guvacoline) were successfully detected in the ANE. The viability of hOMF cells was significantly improved in the 50 μg/mL ANE group and was inhibited in the 5 and 50 mg/mL ANE groups. The expression of FAP was upregulated in OSF tissues, and hOMF cells treated with 50 μg/mL ANE and was related to pathology grade, clinical stage, and history of chewing betel nut. Additionally, FAP may promote the proliferation, migration, and activation of hOMF cells through the P13K-Akt signaling pathway.

CONCLUSIONS

This study found that ANE had a bidirectional effect on the viability of hOMF cells, and the FAP gene was a potential therapeutic target in OSF.

Knockdown of Notch Suppresses Epithelial-mesenchymal Transition and Induces Angiogenesis in Oral Submucous Fibrosis by Regulating TGF-β1

Oral submucous fibrosis (OSF) is a chronic disorder with a high malignant transformation rate. Epithelial-mesenchymal transition (EMT) and angiogenesis are key events in OSF. The Notch signaling plays an essential role in the pathogenesis of various fibrotic diseases, including OSF. Our study aimed to explore the effects of Notch on the EMT and angiogenesis processes during the development of OSF. The expression of Notch in OSF tissues versus normal buccal mucosa samples was compared. Arecoline was used to induce myofibroblast transdifferentiation of buccal mucosal fibroblasts (BMFs). Short hairpin RNA technique was used to knockdown Notch in BMFs. Pirfenidone and SRI-011381 were used to inhibit and activate the TGF-β1 signaling pathway in BMFs, respectively. The expression of Notch was markedly upregulated in OSF tissues and fibrotic BMFs. Knockdown of Notch significantly decreased the viability and promoted apoptosis in BMFs subjected to arecoline stimulation. Downregulation of Notch also significantly suppressed the EMT process, as shown by the reduction of N-cadherin and vimentin with concomitant upregulation of E-cadherin. In addition, knockdown of Notch upregulated VEGF and enhanced the angiogenic activity of fBMFs. Moreover, inhibition of TGF-β1 suppressed viability and EMT, promoted apoptosis, and induced angiogenesis of fBMFs, while activation of TGF-β1 significantly diminished the effects of Notch knockdown on fBMFs. Knockdown of Notch suppressed EMT and induced angiogenesis in OSF by regulating TGF-β1, suggesting that the Notch-TGF-β1 pathway may serve as a therapeutic intervention target for OSF.

Plant leads for mitigation of oral submucous fibrosis: Current scenario and future prospect

The aim of this review is to enumerate medicinal plants and their bioactive compounds that may become potential leads in the mitigation of oral submucous fibrosis (OSMF) in the forthcoming future. It is focused on pathophysiology, risk factors, current treatment regimen, potential plant leads, and future therapies for OSMF. Data were extracted from a vast literature survey by using SciFinder, Web of Science, Google Scholar, and PubMed search engines with relevant keywords. Upon literature survey, we found that the phytochemical 'arecoline' present in the areca nut is the main causative agent of OSMF condition. Currently, OSMF is treated by immunomodulatory and anti-inflammatory agents such as corticosteroids, enzymes (hyaluronidase, chymotrypsin, and collagenase), anti-inflammatory mediators (isoxsuprine and pentoxifylline), dietary supplements (vitamins, antioxidants, and micronutrients), and anti-fibrotic cytokines like interferon-gamma that provides short-term symptomatic relief to OSMF patients. However, some plant leads have been proven effective in alleviating symptoms and mitigating OSMF, which ultimately improves the quality of OSMF patients' life. We concluded that plant drugs like lycopene, curcumin, Aloe vera, colchicine, and Glycyrrhiza glabra are effective against OSMF in various in vitro and/or clinical studies and are being used by modern and traditional practitioners.

Evaluation of possible role of fluoride in pathogenesis of oral submucous fibrosis: A pilot study

BACKGROUND

Oral submucous fibrosis (OSMF) is a potentially malignant disorder. Although areca nut chewing is an established risk factor, its low prevalence among nut chewers indicates additional factors likely facilitates pathogenesis. We recently demonstrated high fluoride levels in smokeless tobacco products and hypothesized a potential pathological role of fluoride in OSMF. Further exploring this novel role, this study compared fluoride levels in tissue, serum, and saliva samples from OSMF patients and healthy controls.

METHODS

The ethically approved study included 25 clinically confirmed OSMF patients and 25 healthy matched controls. OSMF cases underwent buccal mucosal incisional biopsy, while controls had buccal mucosa tissue sampling during third molar removal. Fasting venous blood and unstimulated saliva were collected. Fluoride levels were analysed using ion chromatography and expressed as median (IQR).

RESULTS

OSMF cases showed significantly higher fluoride concentrations compared with controls in tissue biopsies (30.1 vs. 0 mg/kg, p < 0.0001), serum (0.4 vs. 0 mg/L, p = 0.005) and saliva (1.3 vs. 0 mg/L, p < 0.0001). Majority (68%) of controls had undetectable fluoride levels across all samples. Tissue fluoride weakly correlated with OSMF severity (r = -0.158, p = 0.334).

CONCLUSION

The preliminary findings demonstrated increased tissue fluoride levels in OSMF patients compared with healthy controls. Along with a previous study showing high fluoride content in smokeless tobacco products, these findings provided early evidence suggesting fluoride could play a contributory role in OSMF pathogenesis. Further large-scale investigation is warranted to definitively establish whether the association between fluoride exposure and OSMF is indicative of causation.

Comparative analysis of trace elements in the saliva and serum of patients with oral submucous fibrosis and squamous cell carcinoma

Of note, one third of oral cancer or oral tissue dysfunction cases are from India, primarily resulting from the consumption of Gutkha, a type of smokeless tobacco prevalent among several Indian populations. Gutkha is a mixture of tobacco, areca nut, slaked lime, catechu, spices, sweeteners and essences. Oral submucous fibrosis (OSMF), which is linked to the consumption of areca nut products and tobacco, is a chronic, precancerous condition of the submucosal tissues. OSMF transforms into oral squamous cell carcinoma (OSCC) at a rate of 7-13%. Gutkha also contains various trace elements, such as copper (Cu), zinc (Zn), selenium (Se) and molybdenum (Mo). Alterations in trace element levels in the body are associated with cancer progression. The present study aimed to determine the levels of serum and salivary trace elements in patients with OSMF and OSCC. A total of 80 patients were selected for the study and were divided into four groups of 20 patients in each (Group A, gutkha intake without OSMF; group B, gutkha intake with OSMF; group C, OSCC; and group D, control). The level of Cu was found to be increased and the levels of Zn, Se and Mo were decreased in the serum of patients with OSMF and OSCC compared with the controls. The salivary levels of these elements were lower compared with those in the serum. Age and sex had no significant effect on the levels of these trace elements. The results of the present study affirm the fact that serum and salivary trace elements are altered in pre-malignant and malignant lesions as the disease progresses. As the composition of saliva often varies, monitoring serum trace element levels as diagnostic and prognostic markers may aid in the early detection of the disease and in the management of the treatment efficacy.

Oral Potentially Malignant Disorders and Oral Cancer in Saudi Arabia: An Epidemiological Review of the Literature

Background: Oral potentially malignant disorders (OPMDs) are a group of chronic oral mucosal diseases associated with an increased risk of malignant transformation. Multiple studies have investigated the prevalence of these conditions in multiple regions; however, there are limited data about the prevalence of OPMDs in the Kingdom of Saudi Arabia (KSA). This paper aims to review the prevalence of OPMDs in the KSA, to ensure better understanding of the population risk and propose a more standardised approach to the diagnosis and management of this group across the KSA. In addition, this review will discuss the prevalence of oral cancer in the KSA, considering independent risk factors for oral cancer development. Methods: Electronic databases including PubMed, Medline, Medscape, ScienceDirect, StatPearls, BMC Oral Health and the Cochrane Library were searched with the keywords "Oral Potentially Malignant Disorders"; "Saudi Arabia"; and "Oral Cancer". Identified articles were reviewed independently by 2 reviewers against defined inclusion and exclusion criteria. Results: 16 studies were included in this review. The prevalence of OPMDs in KSA varies significantly depending on age, gender, social habits, background disease and dental status. Conclusions: This review highlights the need for up-to-date data on the prevalence, distribution, and characteristics of OPMDs in KSA. The diverse prevalence rates and distinct characteristics of various OPMDs emphasise the necessity for targeted preventive measures. As the data on OPMDs in KSA remains limited, future research efforts should prioritise the establishment of comprehensive epidemiological studies to inform effective public health interventions in this region.

Stromal thrombospondin 1 suppresses angiogenesis in oral submucous fibrosis

A decline in mucosal vascularity is a histological hallmark of oral submucous fibrosis (OSF), a premalignant disease that is largely induced by betel quid chewing. However, the lack of available models has challenged studies of angiogenesis in OSF. Here, we found that the expression of thrombospondin 1 (THBS1), an endogenous angiostatic protein, was elevated in the stroma of tissues with OSF. Using a fibroblast-attached organoid (FAO) model, the overexpression of THBS1 in OSF was stably recapitulated in vitro. In the FAO model, treatment with arecoline, a major pathogenic component in areca nuts, enhanced the secretion of transforming growth factor (TGF)-β1 by epithelial cells, which then promoted the expression of THBS1 in fibroblasts. Furthermore, human umbilical vein endothelial cells (HUVECs) were incorporated into the FAO to mimic the vascularized component. Overexpression of THBS1 in fibroblasts drastically suppressed the sprouting ability of endothelial cells in vascularized FAOs (vFAOs). Consistently, treatment with arecoline reduced the expression of CD31 in vFAOs, and this effect was attenuated when the endothelial cells were preincubated with neutralizing antibody of CD36, a receptor of THBS1. Finally, in an arecoline-induced rat OSF model, THBS1 inhibition alleviated collagen deposition and the decline in vascularity in vivo. Overall, we exploited an assembled organoid model to study OSF pathogenesis and provide a rationale for targeting THBS1.

Role and new insights of microfibrillar-associated protein 4 in fibrotic diseases

Fibrosis is one of the most worrisome complications of chronic inflammatory diseases, leading to tissue damage, organ failure, and ultimately, death. The most notable pathological characteristic of fibrosis is the excessive accumulation of extracellular matrix (ECM) components such as collagen and fibronectin adjacent to foci of inflammation or damage. The human microfibrillar-associated protein 4 (MFAP4), an important member of the superfamily of fibrinogen-related proteins, is considered to have an extremely important role in ECM transformation of fibrogenesis. This review summarizes the structure, characteristics, and physiological functions of MFAP4 and the importance of MFAP4 in various fibrotic diseases. Meanwhile, we elaborated the underlying actions and mechanisms of MFAP4 in the development of fibrosis, suggesting that a better understand of MFAP4 broadens novel perspective for early screening, diagnosis, prognostic risk assessment, and treatment of fibrotic diseases.

Antioxidant treatments in patients with oral submucous fibrosis: A systematic review

INTRODUCTION

Oral submucous fibrosis (OSMF) is a well-known precancerous oral lesion, characterized by scarring, tissue fibrosis, and premalignant lesions. The goal of clinical treatment is to reduce inflammation and improve patients' quality of life by enhancing mouth opening among others. Antioxidant treatment has shown promising results in inducing regression of lesions and preventing OSMF in high-risk individuals. This study investigates the effectiveness of various antioxidant agents against OSMF.

MATERIALS AND METHODS

The study followed PRISMA guidelines and searched three scientific databases: PubMed, Web of Science, and Scopus, using specific algorithms related to "antioxidant treatment," "burning sensation," and "mouth opening." The quality assessment of controlled clinical studies adhered to Cochrane guidelines.

RESULTS

The analysis included 19 clinical trials comparing different treatments, including various antioxidants. Aloe vera, curcumin, and lycopene, among others, showed positive outcomes in treating OSMF by improving burning sensation, mouth opening, tongue protrusion, and cheek flexibility.

CONCLUSION

Antioxidant therapies are found to be effective in treating OSMF, even when compared to conventional treatments such as corticosteroids. The study highlights the need for further research and standardization of clinical protocols.

A clinic-pathological research explored the significance of ascorbic acid and iron levels in serum and saliva in premalignant disorder patients at Kanpur, Uttar Pradesh

Context

Oral submucous fibrosis (OSMF), or OSMF, is a well-known, potentially premalignant condition of the oral cavity. Monitoring OSMF widespread effects necessitate interventions in at-risk individuals, ideally before the disease becomes aggressive. Ascorbic acid and iron, for instance, are significant micronutrients in the pathogenesis of OSMF.

Aims

This study aimed to investigate the significance of ascorbic acid and iron levels in serum and saliva in patients with premalignant disorder (OSMF) and to correlate variations in ascorbic acid and iron levels with histopathological grading.

Settings and Design

The present study was conducted on 195 patients over a period of 10 months.

Subjects and Methods

These patients were divided into two groups, Group I (n = 88, Control), Group II (n = 107, clinically diagnosed and histopathologically confirmed cases of OSMF). Serum and salivary ascorbic acid were analyzed by the dintrophenyl hydrazine method, whereas serum and salivary iron were analyzed by the dipyridyl method.

Statistical Analysis Used

Paired t-test and Fisher test were used to compare between the mean and to find the level of significance P value.

Results

The serum and salivary ascorbic acid levels consistently decreased with the progression of histopathological grading of OSMF. Serum and salivary iron levels were also decreased in OSMF patients, and it came as significant.

Conclusions

Excess collagen synthesis during OSMF may have been promoted with ascorbic acid and iron. As a reason, serum and salivary monitoring may be significant in detecting and diagnosing OSMF early on.

Comparative Evaluation of Nasolabial Flap, Buccal Fat Pad and Platysma Myocutaneous Flap for Reconstruction of Oral Sub Mucous Fibrosis Defects

Moderately advanced (stage III) and advanced (stage IV a & b) OSMF requires surgical intervention for management A number of options are available for reconstruction of post OSMF oral cavity defects. In our study we retrospectively compared buccal fat pad, nasolabial flap and platysma flap for reconstruction of the buccal mucosal defects. Patient records were obtained from the medical records section of the Institute and divided into three groups; group A (buccal fat pad), group B (nasolabial group) and group C (platysma flap). Maximal mouth opening and intercommisural distance were the primary outcomes. Kruskal Wallis test was used to test the mean difference between three groups. Mann-Whitney test was used for intergroup comparisons. Wilcoxon signed rank test was used to evaluate the mean difference in outcomes at each follow up interval. A p value of < 0.05 was considered as statistically significant at 95% confidence interval. After 1 year follow up patients in platysma group had significantly better mouth opening (39.84 ± 1.65 mm) compared to both buccal fat pad (36.69 ± 3.41 mm) and nasolabial groups (37.94 ± 0.43 mm). Inter commisural distance was significantly better in patients reconstructed with platysma flap (59.21 ± 0.99 mm) compared to both buccal fat pad (54.11 ± 1 mm) and nasolabial flap (56.84 ± 1.48 mm). Platysma flap lead to significantly better maximal mouth opening compared to both nasolabial and buccal fat pad. Both buccal fat pad and nasolabial lead to comparable mouth opening. Inter commissural distance is maximum with platysma flap followed by nasolabial flap and buccal fat pad.

Atomic force microscopy-mediated mechanobiological profiling of complex human tissues

Tissue mechanobiology is an emerging field with the overarching goal of understanding the interplay between biophysical and biochemical responses affecting development, physiology, and disease. Changes in mechanical properties including stiffness and viscosity have been shown to describe how cells and tissues respond to mechanical cues and modify critical biological functions. To quantitatively characterize the mechanical properties of tissues at physiologically relevant conditions, atomic force microscopy (AFM) has emerged as a highly versatile biomechanical technology. In this review, we describe the fundamental principles of AFM, typical AFM modalities used for tissue mechanics, and commonly used elastic and viscoelastic contact mechanics models to characterize complex human tissues. Furthermore, we discuss the application of AFM-based mechanobiology to characterize the mechanical responses within complex human tissues to track their developmental, physiological/functional, and diseased states, including oral, hearing, and cancer-related tissues. Finally, we discuss the current outlook and challenges to further advance the field of tissue mechanobiology. Altogether, AFM-based tissue mechanobiology provides a mechanistic understanding of biological processes governing the unique functions of tissues.

Emerging role of m6A modification in fibrotic diseases and its potential therapeutic effect

Fibrosis can occur in a variety of organs such as the heart, lung, liver and kidney, and its pathological changes are mainly manifested by an increase in fibrous connective tissue and a decrease in parenchymal cells in organ tissues, and continuous progression can lead to structural damage and organ hypofunction, or even failure, seriously threatening human health and life. N6-methyladenosine (m6A) modification, as one of the most common types of internal modifications of RNA in eukaryotes, exerts a multifunctional role in physiological and pathological processes by regulating the metabolism of RNA. With the in-depth understanding and research of fibrosis, we found that m6A modification plays an important role in fibrosis, and m6A regulators can further participate in the pathophysiological process of fibrosis by regulating the function of specific cells. In our review, we summarized the latest research advances in m6A modification in fibrosis, as well as the specific functions of different m6A regulators. In addition, we focused on the mechanisms and roles of m6A modification in cardiac fibrosis, liver fibrosis, pulmonary fibrosis, renal fibrosis, retinal fibrosis and oral submucosal fibrosis, with the aim of providing new insights and references for finding potential therapeutic targets for fibrosis. Finally, we discussed the prospects and challenges of targeted m6A modification in the treatment of fibrotic diseases.

Comprehensive Assessment of Albumin and Uric Acid Levels in Oral Submucous Fibrosis: A Comparative Case-Control Study Involving Different Risk Groups

Background Oral submucous fibrosis (OSMF) is a premalignant disorder that impacts the oral cavity and pharynx. Major risk factors for OSMF are attributed to the consumption of betel nuts or tobacco. These substances harbor various carcinogens that trigger the production of free radicals and reactive oxygen species. Antioxidants are pivotal in preserving cellular integrity and impeding the oncogenic transformation of body cells. In this context, albumin and uric acid, being primary antioxidants present in body fluids, bestow a defensive effect against this condition. Thus, the present study is designed to elucidate the differential concentration of albumin and uric acid between patient cases and healthy cohorts. Methodology This case-control study was conducted to evaluate the albumin and uric acid levels in individuals diagnosed with OSMF (cases) and compare them with healthy controls for a period of six months. A cohort of 100 individuals was partitioned into four groups, with each group comprising 25 individuals: Group I was made up of healthy individuals; Group II consisted of individuals who chew tobacco and areca nuts but are not affected by OSMF; Group III included individuals who only use tobacco without areca nuts and are afflicted with OSMF; and Group IV comprised individuals who consume a combination of areca nuts and tobacco and are diagnosed with OSMF. Biochemical evaluation was carried out using the BS-380 chemistry autoanalyzer (Mindray, Shenzhen, China), and the quantification of serum albumin and uric acid was performed by the uricase-peroxidase (POD) method with dihydroxybenzene sulfonic acid (DHBS). Results The study cohort of 100 individuals was made up of 70 males and 30 females, with an average age of 42.51 (11.62) years. The comparison of the mean concentration of serum albumin across all groups revealed that healthy controls exhibited the highest serum albumin concentration of 4.284 (0.618), with a statistically significant p-value (0.001) across all groups. A comparison of the mean value of serum uric acid among all groups showed that healthy controls had the highest value of serum uric acid (5.26±1.161), with a considerable p-value (0.001) between all groups. Conclusion The present study concluded that serum biomarkers assessed were high in healthy individuals and consumption of areca nuts, tobacco, and their products was significantly associated with low levels of albumin and uric acid. Therefore, both albumin and uric acid can be used as important biomarkers for uncovering oral premalignant lesions and conditions ahead of time and can also be used in mass screening.

Expression and correlation of the Pi3k/Akt pathway and VEGF in oral submucous fibrosis

Oral submucous fibrosis (OSF) has a high incidence in Asia countries, but its underlying molecular mechanism was not exploited completely. In this research, we investigated the expression of the phosphatidyl inositol 3-kinase (Pi3k)/protein kinase B (Akt) pathway and vascular endothelial growth factor (VEGF) in oral submucosal fibrosis, explore the correlation between the Pi3k/Akt pathway and VEGF, and identify the mechanisms involved in OSF. The pathological changes and fibrosis stages of OSF tissues (n = 30, 10 each of early, moderate and advanced OSF) were determined using Haematoxylin-eosin staining (HE) and Masson staining, respectively. Collagen type I (Col-I), Pi3k, Akt, VEGF, TGF-β and p-Akt expression was detected using immunohistochemistry, qPCR and WB. The correlation between Pi3k, Akt and VEGF was analysed. Col-I expression increased as OSF progressed. However, their expression was downregulated in normal and moderate to advanced OSF tissues. VEGF expression positively correlated with Pi3k and Akt expression. VEGF expression correlated positively and negatively with the Pi3k inhibitor, LY294002 below and above a concentration of 10 μM, respectively. VEGF expression correlated positively with the Pi3k/Ak activator, IGF-1. Due to the synergistic effect between Pi3k/Akt pathway and VEGF on OSF lesions and fibrosis process, targeted Pi3k/Akt pathway regulation can induce VEGF expression and improve ischemia, ultimately treating OSF.

Biological function and clinical application prospect of tsRNAs in digestive system biology and pathology

tsRNAs are small non-coding RNAs originating from tRNA that play important roles in a variety of physiological activities such as RNA silencing, ribosome biogenesis, retrotransposition, and epigenetic inheritance, as well as involvement in cellular differentiation, proliferation, and apoptosis. tsRNA-related abnormalities have a significant influence on the onset, development, and progression of numerous human diseases, including malignant tumors through affecting the cell cycle and specific signaling molecules. This review introduced origins together with tsRNAs classification, providing a summary for regulatory mechanism and physiological function while dysfunctional effect of tsRNAs in digestive system diseases, focusing on the clinical prospects of tsRNAs for diagnostic and prognostic biomarkers. Video Abstract.

Simvastatin Attenuates Areca Nut Extract-Induced Subdermal Fibrosis in Mice by Targeting TGF-β Signaling Pathways

Oral submucous fibrosis (OSMF) is a chronic inflammatory disease and a potentially malignant oral disorder, characterized by fibrosis of the oral mucosa. TGF-β signaling pathways have been implicated in the development of OSMF, with areca nut extract (ANE) contributing to the disease progression. Simvastatin, a statin drug, has demonstrated anti-fibrotic properties in various fibrotic conditions. However, its therapeutic potential in treating OSMF remains unclear. In this study, 8-week-old male BALB/c mice were randomly divided into three groups based on different time points. Each mouse was then treated with four different drug formulations. Post-treatment, specimens were collected for histopathological examination and staining to assess skin thickness, fibrosis, and collagen deposition. ANE treatment alone significantly increased skin thickness and collagen deposition compared to the control group after the 4-week time point. The combined administration of ANE and simvastatin, resulted in a notable reduction in skin thickness and collagen deposition. Western blot analysis revealed that simvastatin effectively suppressed the expression of fibrosis-related proteins, including CTGF, and α-SMA, in ANE-induced subdermal fibrosis. These results suggest that simvastatin has potential therapeutic effects on ANE-induced subdermal fibrosis, providing a foundation for future studies and possible clinical applications.

Polyphenol-based targeted therapy for oral submucous fibrosis

Oral submucous fibrosis (OSF) is a chronic, progressive, and precancerous condition mainly caused by chewing areca nut. Currently, OSF therapy includes intralesional injection of corticosteroids with limited therapeutic success in disease management. Therefore, a combined approach of in silico, in vitro and in vivo drug development can be helpful. Polyphenols are relatively safer than other synthetic counterparts. We used selected polyphenols to shortlist the most suitable compound by in silico tools. Based on the in silico results, epigallocatechin-3-gallate (EGCG), quercetin (QUR), resveratrol, and curcumin had higher affinity and stability with the selected protein targets, transforming growth factor beta-1 (TGF-β1), and lysyl oxidase (LOX). The efficacy of selected polyphenols was studied in primary buccal mucosal fibroblasts followed by in vivo areca nut extract induced rat OSF model. In in vitro studies, the induced fibroblast cells were treated with EGCG and QUR. EGCG was safer at higher concentrations and more efficient in reducing TGF-β1, collagen type-1A2 and type-3A1 mRNA expression than QUR. In vivo studies confirmed that the EGCG hydrogel was efficient in improving the disease conditions compared to the standard treatment betamethasone injection with significant reduction in TGF-β1 and collagen concentrations with increase in mouth opening. EGCG can be considered as a potential, safer and efficient phytomolecule for OSF therapy and its mucoadhesive topical formulation help in the improvement of patient compliance without any side effects. Highlights Potential polyphenols were shortlisted to treat oral submucous fibrosis (OSF) using in silico tools Epigallocatechin 3-gallate (EGCG) significantly reduced TGF-β1 and collagen both in vitro and in vivo EGCG hydrogel enhanced antioxidant defense, modulated inflammation by reducing TGF-β1 and improved mouth opening in OSF rat model.

Exploring Possible Diagnostic Precancerous Biomarkers for Oral Submucous Fibrosis: A Narrative Review

Oral submucous fibrosis (OSF) stands as a progressive oral ailment, designated as a potentially malignant disorder. OSF has gained widespread recognition as a significant precursor to malignant transformation. In the pursuit of dependable, straightforward, and non-invasive diagnostic measures for the early detection of oral malignant progression, research has delved into potential diagnostic biomarkers of OSF. This comprehensive review delves into current investigations that explore the correlation between various biomarkers and OSF. The molecular biomarkers of OSF are categorized based on cytology and sampling methods. Moreover, this review encompasses pertinent studies detailing how these biomarkers are acquired and processed. Within this scope, we scrutinize four potential biomarkers that hold the promise of facilitating the development of diagnostic tools for detecting early-stage OSF.

Comparison of triamcinolone with pentoxifylline and vitamin E efficacy in the treatment of stage 2 and 3 oral submucous fibrosis: A randomized clinical trial

Objective

The objective of this study was to assess the effectiveness of triamcinolone in combination with pentoxifylline and vitamin E in the treatment of patients with level two and three oral submucous fibrosis.

Methods

The study aimed to compare the efficacy of corticosteroid injections (triamcinolone) versus pentoxifylline and vitamin E in the therapy of patients with stage two and three oral submucous fibrosis. A total of 42 participants with indications and features of oral submucous fibrosis were enrolled between January 2020 and September 2021. The patients' age and mouth opening were evaluated, and descriptive statistics and paired t-test were used for analytical investigation.

Results

The study showed a statistically significant improvement in both treatment groups (p = 0.001) concerning pre- and post-treatment deviations. However, when comparing the standard differences in treatment outcomes between the two study groups, only mouth opening exhibited a statistically significant difference (p = 0.001).

Conclusions

The findings indicate that a treatment regimen combining pentoxifylline and triamcinolone can significantly alleviate oral submucous fibrosis symptoms, including mouth opening, pain, and flaring agitation, thereby enhancing the affected individual's quality of life.

Force, alternate movements, snap, suction and vibration functions of tongue are altered in oral submucous fibrosis patients

Background

One of the most common clinical manifestations of oral submucous fibrosis (OSMF) is restricted tongue movements. However, the characterization of involvement is needed to better understand the impairment of its functioning. In the present study, force, alternate movements, snap, suction, and vibration functions of the tongue were investigated in OSMF patients.

Methods

A total of 53 OSMF and 40 healthy individuals were recruited in the present study. Clinical parameters were used for the diagnosis and grading of OSMF. Alternate movements, snap, suction, vibration of the tongue and tongue force were assessed using standard methodology.

Results

Out of 53 OSMF subjects, 22 (42%) were in early stages and 31 (58%) in late stages. There were statistically significant differences between the OSMF and healthy individuals for tongue functions such as protrusion, retraction, lateral movements, altered snap, suction, and tongue vibration (p < 0.00001). All of the aforementioned tongue functions were more affected in advanced stage OSMF than in early stage OSMF (p < 0.00001).

Conclusion

Force, alternate movements, snap, suction and vibration functions of tongue are significantly altered in OSMF patients. The performance of the tongue movements by the OSMF subjects worsened with the disease progression.

Evaluating Alterations of the Oral Microbiome and Its Link to Oral Cancer among Betel Quid Chewers: Prospecting Reversal through Probiotic Intervention

Areca nut and slaked lime, with or without tobacco wrapped in Piper betle leaf, prepared as betel quid, is extensively consumed as a masticatory product in many countries across the world. Betel Quid can promote the malignant transformation of oral lesions as well as trigger benign cellular and molecular changes. In the oral cavity, it causes changes at the compositional level in oral microbiota called dysbiosis. This dysbiosis may play an important role in Oral Cancer in betel quid chewers. The abnormal presence and increase of bacteria Fusobacterium nucleatum, Capnocytophaga gingivalis, Prevotella melaninogenica, Peptostreptococcus sp., Porphyromonas gingivalis, and Streptococcus mitis in saliva and/or other oral sites of the cancer patients has attracted frequent attention for its association with oral cancer development. In the present review, the authors have analysed the literature reports to revisit the oncogenic potential of betel quid and oral microbiome alterations, evaluating the potential of oral microbiota both as a driver and biomarker of oral cancer. The authors have also shared a perspective that the restoration of local microbiota can become a potentially therapeutic or prophylactic strategy for the delay or reversal of lip and oral cavity cancers, especially in high-risk population groups.

Comparison of Immunohistochemical Markers in Oral Submucous Fibrosis and Oral Submucous Fibrosis Transformed to Oral Squamous Cell Carcinoma-A Systematic Review and Meta-Analysis

The objective of the study was to compare the expression of immunohistochemical (IHC) markers of oral submucous fibrosis (OSMF) (non-transformed group) to those of oral squamous cell carcinoma (OSCC) transformed from OSMF (transformed group). The search for comparative cross-sectional studies was carried out in PubMed and Scopus abiding to the PICO criteria, where expression of IHC markers in OSMF were compared with that of OSCC transformed from OSMF. The cellular distribution, number of positive cases, staining intensity, and mean immunoreactive score (IRS) of each IHC marker were evaluated in both groups. A total of 14 studies were included in the systematic review, in which immunoexpression of 15 epithelial and 4 connective tissue biomarkers were evaluated. Expression of β1-integrin, OCT-3, CD1a, CD207, survivin, Dickkopf-1, COX-2, hTERT, CTGF, MDM2, Ki-67, and α-SMA were increased during transformation of OSMF to OSCC. Conversely, expression of PTEN and lysyl oxidase decreased during transformation of OSMF to OSCC. Expression of a group of epithelial markers, such as COX2, hTERT, CTGF, survivin, MDM2, and p53, was 38 times lower in the non-transformed group cases compared to transformed group cases (95% CI: 58% to 10%; p = 0.01; and I² = 90%). Meta-analysis of all markers involved in cell metabolism/apoptosis, which included β1-integrin along with the above markers also suggested 42 times lower expression in the non-transformed group as compared to the transformed group (95% CI: 58% to 10%; p = 0.01; and I² = 90%). Sub-group analyses on cytoplasmic and nuclear epithelial markers were inconclusive. Meta-analysis of connective tissue markers was also inconclusive. No publication bias was found. Instead of delving into numerous markers without a strong basis for their use, it is advisable to further study the markers identified in this study to explore their clinical utility.

Comparison Between Clinical Outcome of Intralesional Human Placental Extract Alone and Topical Application of Placental Extract Gel After Fibrotomy in Oral Submucous Fibrosis

BACKGROUND

Oral submucous fibrosis (OSMF) is a premalignant condition prevalent in our country. Juxtaepithelial inflammation with progressive hyalinization of the lamina propria results in stiffness and fibrosis of the oral mucosa, characterised by trismus, ankyloglossia, and a burning sensation. Various methods of treatment have been tried in these cases, which include placental extract injections and the cutting of fibrous bands. In this study, we aim to compare the outcome of intra-lesional placental extract injection with fibrotomy and placental extract gel application in OSMF.

METHODOLOGY

This prospective interventional study included 58 patients clinically diagnosed with OSMF grades II and III at a rural tertiary care hospital between January 2021 and August 2022. The patients were randomised into two groups: group I received 1 ml of intra-lesional human placental extract injection in the submucosal plane of the buccal mucosa and retro-molar trigone (RMT) once a week for five consecutive weeks, and group II was subjected to a transverse division of fibrotic bands in the submucosal plane under general anaesthesia. The surgical wound was left open, and swabs soaked in human-purified placental extract gel were placed in the wound for two hours twice daily until the surgical wound was epithelialized and healed. The patients in both groups I and II were advised to do jaw opening exercises, and weekly follow-up was done. Findings with regard to maximum mouth opening, colour of mucosa, and burning sensation in the oral cavity based on a Likert scale were documented. At the end of five months, the pre-treatment and post-treatment results documented were compared.

RESULTS

All patients were between 20 and 60 years of age and were addicted to chewing areca nuts with tobacco. Bilateral involvement was present in all patients, with extension into the RMT and soft palate seen in 31%. Improvement in mouth opening was between 4 mm and 6 mm in group II, and relief of burning sensation and mucosal colour was better in group I.

CONCLUSION

Intra-lesional placental extract injections help in the improvement of the mucosa and relief from the burning sensation. Fibrotomy with placental extract gel application is better at relieving trismus in OSMF. Aggressive mouth-opening exercises may improve mouth opening following the above procedures.

Expression of transforming growth factor-β in oral submucous fibrosis: A systematic review

Oral submucous fibrosis (OSF) is a potentially malignant disorder characterised by inflammation and progressive fibrosis. Transforming growth factor-β (TGF-β) has been established as a master regulator of fibrosis in various organs; however, lack of systematic review on expression of TGF-β and its isoforms in OSF restrict the understanding of their behaviour in its pathogenesis. Online electronic databases, such as PubMed Medline, Cochrane Library, Embase, and Scopus, were searched from their respective dates of inception till 31st March 2022. Human studies related to TGF-β expression in histopathologically diagnosed OSF cases, with or without malignant transformation, were included and assessed using a Cochrane risk of bias assessment tool: For non randomised studies of interventions (ACROBAT NRSI). The electronic literature search yielded 394 articles. Of those, ten articles met the inclusion criteria and involved total of 579 OSF patients. The risk of bias (RoB) was low to moderate. These studies demonstrated a significant positive expression of TGF-β and its isoforms in OSF compared to that in normal tissue samples. An increased pan TGF-β expression was observed in the early stages of OSF, and an increased expression of TGF-β1 and TGF-β2 were seen in advanced stages of OSF. Stage wise expression of TGF-β3 has not been discussed in the included studies. No significant relationship was observed between epithelial dysplasia and TGF-β expression in OSF. The distinct pattern in the expression of pan TGF-β, TGF-β1 and TGF-β2 in various stages of OSF indicates their different roles in OSF progression. We believe isoform targeted studies exploring stage wise expression of the marker will open new treatment avenues for OSF.

Expression of p53 as Potential Biomarker in Oral Submucous Fibrosis: An Immunohistochemical Study

Background

Oral submucous fibrosis (OSMF) is potentially malignant disorder known to transform into oral cancer. The malignant transformation is often associated with changes at the genetic level that in turn is reflected by the altered expression of proteins related to cell cycle, proliferation, and apoptosis. Expression of p53 tumor suppressor gene is one of the common findings in human cancers including the oral cancer. Therefore, the early detection of potentially malignant OSMF has been crucial in the inhibition of oral cancer.

Aim and Objectives

To determine the main pathological logical factors and expression of aberrant p53 in OSMF, oral squamous cell carcinomas (OSCC) and in normal patients, to study correlation between p53 expression with clinical staging and histological grading of OSMF.

Materials and Methods

An immunohistochemical (IHC) study was performed for p53 expression on 35 cases of OSMF, 10 cases of OSCC with history of habits and 10 normal patients without any habits.

Results

The expression of p53 showed a significant difference between normal oral mucosa, OSMF and OSCC samples.

Conclusion

The study demonstrated a high incidence of p53 over expression in OSMF and OSCC. The results indicate that p53 over expression may play a role in pathogenesis of OSMF and in the development of Oral squamous cell carcinoma. With early detection of the high-risk patients with OSMF, we can expect to develop more intensive treatment modalities, leading to the reduction in cancer transformation rate from OSMF.

Molecular pathways of oral submucous fibrosis and its progression to malignancy

OBJECTIVE

The review aims to comprehend various factors engaged in the alteration of molecular events resulting in Oral submucous fibrosis (OSMF) and its malignant transformation.

DESIGN

Literature pertinent to pathways involved in OSMF were explored in databases such as PubMed, Scopus and Google Scholar. The relevant literature was reviewed and critically appraised in this narrative review.

RESULTS

Areca nut components influence myriad of cellular molecules such as cytokines, growth factors, myofibroblasts, non-coding RNAs and alter their expression. These aberrantly expressed molecules drive the progression of OSMF from localized inflammation to fibrosis of buccal mucosa. The oral tissue suffers from oxidative stress, hypoxia, autophagy, aberration of cell cycle and DNA damage. Apoptosis of epithelial layer results in its atrophy facilitating deeper penetration of areca nut elements. With the advance of disease, epithelial-mesenchymal transition eventuates and promotes dysplasia. The jeopardized expression of various cellular molecules, suppressed apoptosis, along with increased genetic alterations and neovascularization favors the malignant transformation.

CONCLUSION

OSMF is a progressive disorder with complex mechanism of pathogenesis initiated by inflammation of oral mucosa. Continuous habit of areca nut chewing and the resulting insult to the tissues prevents healing process and is destined to debilitating disease which affects the quality of life with a higher probability of progression to malignancy.

α-Mangostin Inhibits the Activation of Myofibroblasts via Downregulation of Linc-ROR-Mediated TGFB1/Smad Signaling

Oral submucous fibrosis (OSF) is a premalignant disorder and persistent activation of myofibroblasts is implicated in this pathological progression. Increasing attention has been addressed towards non-coding RNA-regulated myofibroblasts activities and the effects of phytochemicals on non-coding RNA modulation are of great importance. In the present study, we examined the anti-fibrosis property of α-mangostin, a xanthone isolated from the pericarp of mangosteen. We found that α-mangostin exhibited inhibitory potency in myofibroblast activities and expression of fibrosis markers at the concentrations that caused neglectable damage to normal cells. Apart from the downregulation of TGF-β1/Smad2 signaling, we found that α-mangostin attenuated the expression of long non-coding RNA LincROR as well. Our results demonstrated that the effects of α-mangostin on myofibroblast activation were reverted when LincROR was overexpressed. Additionally, we showed the expression of LincROR in OSF specimens was elevated and silencing of LincROR successfully attenuated myofibroblast characteristics and TGF-β1/Smad2 activation. Taken together, these findings indicated that the anti-fibrosis effects of α-mangostin merit consideration and may be due to the attenuation of LincROR.

Is Candida albicans a contributor to cancer? A critical review based on the current evidence

The association between Candida albicans (C. albicans) and cancer has been noticed for decades. Whether C. albicans infection is a complication of cancer status or as a contributor to cancer development remains to be discussed. This review systematically summarized the up-to-date knowledge about associations between C. albicans and various types of cancer, and discussed the role of C. albicans in cancer development. Most of the current clinical and animal evidence support the relationship between C. albicans and oral cancer development. However, there is insufficient evidence to demonstrate the role of C. albicans in other types of cancer. Moreover, this review explored the underlying mechanisms for C. albicans promoting cancer. It was hypothesized that C. albicans may promote cancer progression by producing carcinogenic metabolites, inducing chronic inflammation, remodeling immune microenvironment, activating pro-cancer signals, and synergizing with bacteria.