Molecular pathways regulated by areca nut in the etiopathogenesis of oral submucous fibrosis

Areca nut-induced oral fibrosis - Reassessing the biology of oral submucous fibrosis

BACKGROUND

Oral submucous fibrosis (OSF) is a pathological condition characterized by excessive tissue healing resulting from physical, chemical, or mechanical trauma. Notably, areca nut consumption significantly contributes to the development of oral fibrosis. The current definition of OSF, recognizing its potential for malignant transformation, necessitates a more comprehensive understanding of its pathophysiology and etiology.

HIGHLIGHTS

Areca nut induces fibrotic pathways by upregulating inflammatory cytokines such as TGF-β and expressing additional cytokines. Moreover, it triggers the conversion of fibroblasts to myofibroblasts, characterized by α-SMA and γSMA expression, resulting in accelerated collagen production. Arecoline, a component of areca nut, has been shown to elevate levels of reactive oxygen species, upregulate the expression of various cytokines, and activate specific signaling pathways (MEK, COX2, PI3K), all contributing to fibrosis. Therefore, we propose redefining OSF as "Areca nut-induced oral fibrosis" (AIOF) to align with current epistemology, emphasizing its distinctive association with areca nut consumption. The refined definition enhances our ability to develop targeted interventions, thus contributing to more effective prevention and treatment strategies for oral submucous fibrosis worldwide.

CONCLUSION

Arecoline plays a crucial role as a mediator in fibrosis development, contributing to extracellular matrix accumulation in OSF. The re-evaluation of OSF as AIOF offers a more accurate representation of the condition. This nuanced perspective is essential for distinguishing AIOF from other forms of oral fibrosis and advancing our understanding of the disease's pathophysiology.

A toxicological review of alkaloids

Alkaloids are naturally occurring compounds with complex structures found in natural plants. To further improve the understanding of plant alkaloids, this review focuses on the classification, toxicity and mechanisms of action, providing insight into the occurrence of alkaloid-poisoning events and guiding the safe use of alkaloids in food, supplements and clinical applications. Based on their chemical structure, alkaloids can be divided into organic amines, diterpenoids, pyridines, isoquinolines, indoles, pyrrolidines, steroids, imidazoles and purines. The mechanisms of toxicity of alkaloids, including neurotoxicity, hepatoxicity, nephrotoxicity, cardiotoxicity and cytotoxicity, have also been reviewed. Some cases of alkaloid poisoning have been introduced when used as food or clinically, including accidental food poisoning, excessive consumption, and poisoning caused by the improper use of alkaloids in a clinical setting, and the importance of safety evaluation was illustrated. This review summarizes the toxicity and mechanism of action of alkaloids and provides evidence for the need for the safe use of alkaloids in food, supplements and clinical applications.

Spatial Transcriptomic and Metabolomic Landscapes of Oral Submucous Fibrosis-Derived Oral Squamous Cell Carcinoma and its Tumor Microenvironment

In South and Southeast Asia, the habit of chewing betel nuts is prevalent, which leads to oral submucous fibrosis (OSF). OSF is a well-established precancerous lesion, and a portion of OSF cases eventually progress to oral squamous cell carcinoma (OSCC). However, the specific molecular mechanisms underlying the malignant transformation of OSCC from OSF are poorly understood. In this study, the leading-edge techniques of Spatial Transcriptomics (ST) and Spatial Metabolomics (SM) are integrated to obtain spatial location information of cancer cells, fibroblasts, and immune cells, as well as the transcriptomic and metabolomic landscapes in OSF-derived OSCC tissues. This work reveals for the first time that some OSF-derived OSCC cells undergo partial epithelial-mesenchymal transition (pEMT) within the in situ carcinoma (ISC) region, eventually acquiring fibroblast-like phenotypes and participating in collagen deposition. Complex interactions among epithelial cells, fibroblasts, and immune cells in the tumor microenvironment are demonstrated. Most importantly, significant metabolic reprogramming in OSF-derived OSCC, including abnormal polyamine metabolism, potentially playing a pivotal role in promoting tumorigenesis and immune evasion is discovered. The ST and SM data in this study shed new light on deciphering the mechanisms of OSF-derived OSCC. The work also offers invaluable clues for the prevention and treatment of OSCC.

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.

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.

The Controversial Roles of Areca Nut: Medicine or Toxin?

Areca nut (AN) is used for traditional herbal medicine and social activities in several countries. It was used as early as about A.D. 25-220 as a remedy. Traditionally, AN was applied for several medicinal functions. However, it was also reported to have toxicological effects. In this review article, we updated recent trends of research in addition to acquire new knowledge about AN. First, the history of AN usage from ancient years was described. Then, the chemical components of AN and their biological functions was compared; arecoline is an especially important compound in AN. AN extract has different effects caused by different components. Thus, the dual effects of AN with pharmacological and toxicological effects were summarized. Finally, we described perspectives, trends and challenges of AN. It will provide the insight of removing or modifying the toxic compounds of AN extractions for enhancing their pharmacological activity to treat several diseases in future applications.

Senescence-associated secretory phenotype and its impact on oral immune homeostasis

The senescence-associated secretory phenotype (SASP), which accumulates over the course of normal aging and in age-related diseases, is a crucial driver of chronic inflammation and aging phenotypes. It is also responsible for the pathogenesis of multiple oral diseases. However, the pathogenic mechanism underlying SASP has not yet been fully elucidated. Here, relevant articles on SASP published over the last five years (2017-2022) were retrieved and used for bibliometric analysis, for the first time, to examine SASP composition. More than half of the relevant articles focus on various cytokines (27.5%), growth factors (20.9%), and proteases (20.9%). In addition, lipid metabolites (13.1%) and extracellular vesicles (6.5%) have received increasing attention over the past five years, and have been recognized as novel SASP categories. Based on this, we summarize the evidences demonstrating that SASP plays a pleiotropic role in oral immunity and propose a four-step hypothetical framework for the progression of SASP-related oral pathology-1) oral SASP development, 2) SASP-related oral pathological alterations, 3) pathological changes leading to oral immune homeostasis disruption, and 4) SASP-mediated immune dysregulation escalating oral disease. By targeting specific SASP factors, potential therapies can be developed to treat oral and age-related diseases.

Peri-implant clinicoradiographic status among betel-quid chewers and controls

The aim of the present case-control observational study was to evaluate the peri-implant clinicoradiographic status among betel-quid chewers and controls. Self-reported betel-quid chewers and controls were included. Participants were categorized into 3 groups: Group-1: Individuals chewing betel-quid with tobacco; Group-2: Individuals chewing betel-quid without tobacco; and Group-3: Controls (individuals not using tobacco in any form). Demographic data was collected using a questionnaire. Periodontal and peri-implant clinicoradiologic parameters (plaque and gingival indices [PI and GI], probing depth [PD] and crestal bone loss/marginal bone loss [CBL/MBL]) were assessed. Clinical attachment loss (AL) around teeth was also assessed. Group comparisons were done using the one-way analysis of variance and Bonferroni Post-hoc adjustment tests. Correlation of periodontal and peri-implant inflammatory parameters with the duration of betel-quid chewing habit and duration of placement in the mouth were assessed using logistic regression analysis. P<0.05 was considered statistically significant. Thirty, 30 and 30 patients were included in groups 1, 2 and 3, respectively. Full-mouth PI (P<0.01), GI (P<0.01), clinical AL (P<0.01), PD (P<0.01) and mesial and distal MBL (P<0.01) were higher in groups 1 and 2 than Group-3. Peri-implant mPI (P<0.01), mGI (P<0.01), PD (P<0.01) and MBL/CBL (P<0.01) were significantly higher in groups 1 and 2 than Group-3 with no significant difference in groups 1 and 2. Betel-quid chewing habit either with or without tobacco is a risk-factor of peri-implant soft-tissue inflammation and CBL.

N6-methyladenosine modification contributes to arecoline-mediated oral submucosal fibrosis

BACKGROUND

Oral submucosal fibrosis (OSF) is a precancerous condition that closely related to the habit of chewing betel nut. The OSF patients of 3%-19% may develop cancer, and this probability is increasing year by year. Epigenetics modifications have been reported as part of the pathogenesis of OSF. However, in OSF field, the role and mechanism of arecoline-induced activation of transforming growth factor β (TGF-β) signaling on N6-methyladenosine (m6A) modification remain unclear. In this study, we investigated the effect and mechanism of arecoline on m6A modification.

METHODS

MeRIP-Seq and RNA-seq were performed in arecoline-stimulated cells. Quantitative polymerase chain reaction and western blot were performed to detect the expression of m6A writers and erasers. CCK-8 and flow cytometry analyses were performed to measure the cell viability and apoptosis.

RESULTS

m6A level was increased in OSF tissues compared to normal tissues; arecoline promoted the m6A methyltransferase Mettl3 and Mettl14 through TGF-β. MeRIP-seq and RNA-seq analyses found that MYC was the target gene of Mettl14. In addition, Mettl14 silence reversed the effects of arecoline on cell proliferation and apoptosis in Hacat cells.

CONCLUSION

TGF-β-METTL14-m6A-MYC axis was crucially implicated in arecoline-mediated OSF and may be an effective therapeutic strategy for OSF treatment.

Adipose-derived mesenchymal stem cell exosomes inhibit transforming growth factor-β1-induced collagen synthesis in oral mucosal fibroblasts

Oral submucosal fibrosis (OSF) is a potentially malignant oral disorder that requires the further development of advanced treatment strategies. TGF-β1 has been reported to be the main trigger for the increased collagen production and reduced activity of matrix degradation pathways in OSF. Exosomes are key mediators of paracrine signaling that have been proposed for direct use as therapeutic agents for tissue repair and regeneration. The present study aimed to investigate the effects of human adipose-derived mesenchymal stem cell (ADSC) exosomes (ADSC-Exos) on TGF-β1-treated oral fibroblasts in vitro and to unravel the potential underlying mechanism of action. Oral mucosal fibroblasts were obtained from the buccal tissues of patients without OSF during extraction of the third molar. ADSCs were obtained from three healthy female individuals during liposuction procedures. ADSC-Exos were isolated by ultracentrifugation and identified by electron microscopy, nanoparticle tracking and western blotting. Immunofluorescence and immunocytochemistry staining were performed to measure the expression levels of vimentin and α-smooth muscle actin in the fibroblasts. Reverse transcription-quantitative PCR and western blotting were used to determine the expression levels of mRNAs and proteins associated with collagen production. The p38 MAPK activator anisomycin was used to identify the underlying mechanisms of the effects of ADSC-Exos on TGF-β1-induced collagen synthesis in oral mucosal fibroblasts. The results of the present study revealed that ADSC-Exos exhibited a cup- or sphere-shaped morphology, with a mean diameter of 58.01±16.17 nm. ADSC-Exos were also found to be positive for CD63 and tumor susceptibility 101 expression. ADSC-Exos treatment reversed the TGF-β1-induced upregulation of collagen I and III protein expression. In addition, in the presence of TGF-β1, the expression levels of collagen type I α 1 chain and collagen type III α 1 chain mRNA were downregulated, whilst the expression levels of matrix metalloproteinase (MMP)1 and MMP3 were upregulated following ADSC-Exos treatment. The TGF-β1-induced upregulation in the phosphorylation of p38 in addition to the increased protein expression of collagens I and III were also reversed in fibroblasts following ADSC-Exos treatment. However, anisomycin treatment alleviated these ADSC-Exos-induced changes. In conclusion, findings from the present study suggest that ADSC-Exos may represent a promising strategy for OSF treatment by targeting the p38 MAPK signaling pathway.

Betel Nut Chewing Was Associated with Obstructive Lung Disease in a Large Taiwanese Population Study

The prevalence of betel nut chewing in Taiwan is high at approximately 7%, however, few studies have evaluated the relationship between betel nut chewing and lung disease. Therefore, the aim of this study was to investigate associations between betel nut chewing and lung function in 80,877 participants in the Taiwan Biobank (TWB). We further investigated correlations between betel nut chewing characteristics such as years of use, frequency, daily amount, and accumulative dose, with obstructive lung disease. We used data from the TWB. Lung function was assessed using spirometry measurements of forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1). The participants were classified into normal lung function and obstructive lung function (FEV1/FVC < 70%) groups. The participants were asked questions about betel nut chewing, including years of use, frequency, and daily amount. After multivariable analysis, betel nut chewing (odds ratio [OR] = 1.159; p < 0.001) was significantly associated with FEV1/FVC < 70% in all participants (n = 80,877). Further, in the participants who chewed betel nut (n = 5135), a long duration of betel nut chewing (per 1 year; OR = 1.008; p = 0.012), betel nut use every day (vs. 1–3 days/month; OR = 1.793; p = 0.036), 10–20 quids a day (vs. <10 quids; OR = 1.404; p = 0.019), 21–30 quids a day (vs. <10 quids; OR = 1.662; p = 0.010), ≥31 quids a day (vs. <10 quids; OR = 1.717; p = 0.003), and high cumulative dose (per 1 year × frequency × daily score; OR = 1.001; p = 0.002) were significantly associated with FEV1/FVC < 70%. In this large population-based cohort study, chewing betel nut was associated with obstructive lung disease. Furthermore, a long duration of betel nut chewing, more frequent use, higher daily amount, and high cumulative dose were associated with obstructive lung disease. This suggests that preventing betel nut chewing should be considered to reduce obstructive lung disease in Taiwan.

Adipose-Derived Stem Cell-Derived Extracellular Vesicles Inhibit the Fibrosis of Fibrotic Buccal Mucosal Fibroblasts via the MicroRNA-375/FOXF1 Axis

Oral submucous fibrosis (OSF) is a precancerous lesion. Adipose-derived stem cell- (ADSC-) derived extracellular vesicles (EVs) (ADSC-EVs) regulate multiple oral diseases. Hence, this study explored the mechanism of ADSC-EVs in OSF. ADSCs were transduced with microRNA- (miR-) 375 mimic. ADSC-EVs and miR-375-overexpressed ADSC-EVs (EVs-miR-375) were extracted and identified. miR-375 expression in EVs and fibrotic buccal mucosal fibroblasts (fBMFs) was detected. EV uptake by fBMFs was observed. The targeted relationship between miR-375 and forkhead box protein F1 (FOXF1) was predicted and verified. After EVs-miR-375 treatment or FOXF1 overexpression, fBMF cell proliferation, migration, invasion, and apoptosis were evaluated, and levels of apoptosis-related proteins (cleaved-caspase-3, Bax, and Bcl-2) and fibrosis markers (α-SMA, collagen I, and collagen III) were detected. Functional rescue experiments were further performed to verify the role of the miR-375/FOXF1 axis in OSF. miR-375 was notably upregulated in EVs-miR-375 and EVs-miR-375-treated fBMFs (all P < 0.001). ADSC-EVs carried miR-375 into fBMFs. fBMFs can internalize ADSC-EVs. EVs-miR-375 treatment markedly inhibited fBMF cell proliferation, migration, invasion, and fibrosis and promoted apoptosis (all P < 0.01). Moreover, miR-375 targeted FOXF1 in fBMFs. FOXF1 overexpression promoted fBMF cell biological behaviors and fibrosis, which were reversed after EVs-miR-375 treatment (P < 0.01 or P < 0.001). We highlighted that ADSC-EVs inhibited fBMF fibrosis and then suppressed OSF progression via the miR-375/FOXF1 axis.

Multi-target pharmacological mechanisms of Salvia miltiorrhiza against oral submucous fibrosis: A network pharmacology approach

OBJECTIVES

The herb Salvia miltiorrhiza is used to treat oral submucous fibrosis (OSF); however, the mechanism underlying its efficacy has not been elucidated. As such, a network pharmacology-based approach was applied to investigate the potential mechanisms of Salvia miltiorrhiza against OSF.

MATERIALS AND METHODS

Potential targets of Salvia miltiorrhiza were collected by Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform, Bioinformatics Analysis Tool for Molecular Mechanism of Traditional Chinese Medicine, and Swiss Target Prediction. Potential targets of OSF were collected from DisGeNET, GeneCards, and National Center for Biotechnology Information Gene database. Salvia miltiorrhiza against OSF targets protein-protein interaction and enrichment analyses network were constructed by Cytoscape and Metascape.

RESULTS

Twelve active ingredients from Salvia miltiorrhiza and 57 potential OSF-related targets were identified. The constructed network predicted seven potential key targets of Salvia miltiorrhiza for the treatment of OSF. Functional enrichment analysis showed that biological processes such as cellular response to drugs and pathways such as bladder cancer were mainly regulated by the Salvia miltiorrhiza active ingredient targets. Furthermore, the protein-protein interaction network demonstrated that the molecular complex detection components were mainly related to the ErbB signaling pathway, cancer pathways and IL-17 signaling.

CONCLUSIONS

A network approach was employed to document how Salvia miltiorrhiza active ingredients change various pathways against OSF. Salvia miltiorrhiza active ingredient targets against OSF involved CYP19A1, EGFR, PTPN11, ACHE, TERT, MAPK8 and PGR and were enriched in several signaling pathways.

The Role of Increased Connective Tissue Growth Factor in the Pathogenesis of Oral Submucous Fibrosis and its Malignant Transformation-An Immunohistochemical Study

Connective tissue growth factor (CTGF), a matricellular protein of the CCN family of extracellular matrix-associated heparin-binding proteins, is highly expressed in various organ fibrosis and several malignant tumors. Although a few studies have been conducted using CTGF in oral submucous fibrosis (OSF) and oral squamous cell carcinoma, no study has demonstrated its relation with various stages of OSF and its malignant transformation. The present study investigated the possible role of CTGF in the pathogenesis of OSF and its malignant transformation by using immunohistochemistry. Ten formalin-fixed paraffin-embedded tissue blocks, each of Stage 1 OSF, Stage 2 OSF, Stage 3 OSF, Stage 4 OSF, well- differentiated squamous cell carcinoma (WDSCC) with OSF and WDSCC without OSF were stained for CTGF by immunohistochemistry. Ten cases of healthy buccal mucosa (NOM) were included as controls. The present study demonstrated a statistically significant expression of CTGF in the epithelium and connective tissue of OSF and WDSCC with and without OSF cases against its complete absence in NOM. We observed an upregulation of CTGF expression from NOM to various stages of OSF to WDSCC with or without OSF. A gradual upregulation of the CTGF expression in various stages of OSF to WDSCC (with and without OSF) against its complete absence in NOM suggests that CTGF plays an important role in the pathogenesis of OSF and its malignant transformation.

Multifractal Alterations in Oral Sub-Epithelial Connective Tissue During Progression of Pre-Cancer and Cancer

Bright-field microscopy (BFM) encrypts the optical transillumination profile of the transmitted light attenuated by the complex micro-structural tissue convolutions, manifested by the dense and compact regions of the specimen under examination. The connotations of idiosyncratic tissue interaction dynamics with the onset of pre-cancerous activity are encoded in the BFM acquired oral mucosa histopathological images (OMHI). In the present study, our analysis is focused on the sub-epithelium region of the oral mucosa, which has high clinical significance but sparsely explored in the literature from the textural domain. Histopathology being the gold-standard technique till date, we have used the light microscopic histopathology images for tissue characterization. The tissue-index transmission patches (TITP) from the sub-epithelium region are cropped under the guidance of oral onco-pathologists. After that, the TITPs are characterized for its multi-scale spatial-deformation dynamics, while keeping the intrinsic anisotropic geometry, and local contour connectivity within tolerable limits. With recent studies exhibiting multifractal's potency in diverse biological system analysis, here, we exploit the 2D multifractal detrended fluctuation analysis (2D-MFDFA) on TITPs for exploring a discriminative set of multifractal signatures for healthy, oral potentially malignant disorders and oral cancer tissue sample. The predictive model's competency is validated on an experimentally collected corpus of TITP samples and substantiated via confirmatory data statistics and analysis, showing its inter-class segregation efficacy. Moreover, the 2D-MFDFA analysis evinces the complex multifractal patterns in TITPs, which is due to the presence of composite long-range correlations in the oral mucosa tissue fabric.

Genetic Susceptibility and Protein Expression of Extracellular Matrix Turnover-Related Genes in Oral Submucous Fibrosis

Betel quid (BQ) chewing increased the risk of oral cancer and oral submucous fibrosis (OSMF), an oral premalignant disorder (OPMD) with malignant transformation potential. BQ components such as areca nut (AN), trauma by coarse AN fiber, catechin, copper, alkaloids, stimulated reactive oxygen species (ROS), inflammation and cytotoxicity are suggested to be the contributing factors. They may induce tissue inflammation, proliferation of fibroblasts and collagen deposition, myofibroblast differentiation and contraction, collagen cross-links and inhibit collagen phagocytosis, finally leading to the development of OSMF and oral cancer. These events are mediated by BQ components-induced changes of extracellular matrix (ECM) turnover via regulation of TGF-β1, plasminogen activator inhibitor-1 (PAI-1), cystatin, lysyl oxidase (LOX) and tissue inhibitors of metalloproteinases (TIMPs) and metalloproteinases (MMPs). Genetic susceptibility is also involved in these disease processes. Further understanding the molecular mechanisms of BQ-induced OSMF and oral cancer can be helpful for future disease prevention and treatment.

A pharmacological review of dicoumarol: An old natural anticoagulant agent

Dicoumarol is an oral anticoagulant agent prescribed in clinical for decades. It is a natural hydroxycoumarin discovered from the spoilage of Melilotus officinalis (L.) Pall and is originally discovered as a rodenticide. Due to its structural similarity to that of vitamin K, it significantly inhibits vitamin K epoxide reductase and acts as a vitamin K antagonist. Dicoumarol is mainly used as an anticoagulant to prevent thrombogenesis and to cure vascular thrombosis. Other biological activities besides anticoagulants such as anticancer, antimicrobial, antiviral, etc., have also been documented. The side effects of dicoumarol raise safety concerns for clinical application. In this review, the physicochemical property, the pharmacological activities, the side effects, and the pharmacokinetics of dicoumarol were summarized, aiming to provide a whole picture of the "old" anticoagulant.

The study of placentrex and hydrocortisone as an adjunct treatment in oral submucous fibrosis

BACKGROUND

Submucous fibrosis with a high incidence rate in the Indian subcontinent is a devastating disease affecting the oral cavity and oropharynx.

AIMS AND OBJECTIVE

To evaluate the efficacy of injection placentrex and injection hydrocortisone in oral submucous fibrosis patients in increasing mouth opening, burning sensation, and improve the mucosal lining.

MATERIALS AND METHODS

We recruited 60 patients with Stage II and Stage III of the ailment, who were randomly divided into Group A and Group B. They were administered submucosal injections of hydrocortisone and placentrex along with physiotherapy and oral iron, nutrients, and B-carotene supplements over a period of 2 months.

INTERPRETATIONS AND RESULTS

The pinnacle rate of the incidence was found in the age group of 30 to 40 years among both the genders. Statistically significant difference (P = 0.0001), that is, 5.19 ± 1.33 in Group A and 11.69 ± 1.26 mm in Group B was noted in the mean mouth opening values. Statistically significant difference in burning sensation was noted to be better in Group A than in Group B.

DISCUSSION AND CONCLUSION

Overall hydrocortisone seems to be a better regimen for improving the mucosal health and increasing the mouth opening as compared to placentrix regimen. Although Placentrex is better than hydrocortisone in reducing burning sensation.

Biomedical analysis of New Psychoactive Substances (NPS) of natural origin

New psychoactive substances (NPS) can be divided into two main groups: synthetic molecules and active principles of natural origin. With respect to this latter group, a wide range of alkaloids contained in plants, mainly from Asia and South America, can be included in the class of NPS of natural origin. The majority NPS of natural origin presents stimulant and/or hallucinogenic effects (e.g. Catha edulis and Ayahuasca, respectively) while few of them show sedative and relaxing properties (e.g. kratom). Few information is available in relation to the analytical identification of psychoactive principles contained in the plant material. Moreover, to our knowledge, scarce data are present in literature, about the characterization and quantification of the parent drug in biological matrices from intoxication and fatality cases. In addition, the metabolism of natural active principles has not been yet fully investigated for most of the psychoactive substances from plant material. Consequently, their identification is not frequently performed and produced metabolites are often unknown. To fill this gap, we reviewed the currently available analytical methodologies for the identification and quantification of NPS of natural origin in plant material and, whenever possible, in conventional and non-conventional biological matrices of intoxicated and dead subjects. The psychoactive principles contained in the following plants were investigated: Areca catechu, Argyreia nervosa, Ayahuasca, Catha edulis, Ipomoea violacea, Mandragora officinarum, Mitragyna speciosa, Pausinystalia yohimbe, Piper methisticum, Psilocybe, Rivea corymbosa, Salvia divinorum, Sceletium tortuosum, Lactuca virosa. From the results obtained, it can be evidenced that although several analytical methods for the simultaneous quantification of different molecules from the same plants have been developed and validated, a comprehensive method to detect active compounds from different natural specimens both in biological and non-biological matrices is still lacking.