Mast Cells: Key Players in the Shadow in Oral Inflammation and in Squamous Cell Carcinoma of the Oral Cavity

Mast Cell Infiltration and Subtype Promote Malignant Transformation of Oral Precancer and Progression of Oral Cancer

The role of mast cell (MC), a common myeloid-derived immune cell, in the development of oral squamous cell carcinoma (OSCC) is unclear. The aim of this study was to investigate MC infiltration in oral precancer and oral cancer. The evaluation of immune cell infiltration and its association with prognosis in OSCC used RNA sequencing and multiple public datasets. Multiplex immunofluorescence was used to explore the infiltration of MC in the microenvironment of OSCC and oral precancer and the interaction with CD8+ cells. The role of MC in OSCC progression was verified by in vivo experiments. The resting MC infiltration was mainly present in oral precancer, whereas activated MC infiltration was significantly higher in OSCC. Activated MC was associated with malignant transformation of oral precancer and poor prognosis of OSCC. In vivo studies showed that MC promoted the growth of OSCC. The infiltration of activated MC was negatively correlated with the infiltration of CD8+ T cells. The subtype of MC containing tryptase without chymase (MCT) was significantly higher in OSCC compared with oral precancer and was associated with poor survival. Furthermore, spatial distance analysis revealed a greater distance between MCT and CD8+ cells, which was also linked to poor prognosis in OSCC. Cox regression analysis showed that MCT could be a potential diagnostic and prognostic biomarker. This study provides new insights into the role of MC in the immune microenvironment of OSCC. It might enhance the immunotherapeutic efficacy of OSCC by developing targeted therapies against MC.

SIGNIFICANCE

In this study, we investigated the role of mast cells (MC) in oral precancer and oral cancer and demonstrated that MCs are involved in oral cancer progression and may serve as a potential diagnostic and prognostic marker. It might improve the immunotherapeutic efficacy through developing targeted therapies against MCs.

Histochemical and immunohistochemical investigation of the number and localization of mast cells in the feline tongue

This is the first study to describe the subtypes, number and distribution of mast cells (MC) in cat tongue by histochemical and immunohistochemical methods. Six male adult felines' tongue tissue samples consist of the study's material. Samples were fixed in 10% formaldehyde. MC number and distribution in the feline tongue were assessed using toluidine blue. Also, sections taken from blocks were stained in alcian blue/safranin O (AB/SO) combined dyes to determine the MC subtypes. The Streptavidin biotin complex method using anti-chymase and anti-tryptase primary antibodies was used for immunohistochemistry. Metachromatic MCs were mainly observed in the lamina propria close to the multilayered keratinized stratified squamous epithelium. The high number of MCs in this region may be because the dorsal surface of the tongue plays an essential role in the defence system of tongue tissue and, thus, of the body as a whole. Additionally, the number of MCs stained with AB (+) (1.7 ± 0.08) in the feline tongue was statistically higher than those with SO (+) (0.18 ± 0.02). This might be interpreted as an indication that MC heterogeneity may be due not only to their staining properties but also to their localization. It is also conceivable that the high histamine content may be a factor in this. Tryptase-positive MCs were found in the loose connective tissue around blood vessels, between the glands, as solitary cells, or in groups of several cells. Chymase-positive MCs were observed more individually rather than in groups. Moreover, chymase-positive MCs were detected to be located in the filiform papillae subepithelial and in the blood vessels' immediate vicinity. Animals often lick themselves to clean themselves and promote healing. For this reason, it is very important to protect the tongue, which is in direct contact with the external environment, against foreign agents. Considering both the functional and protective properties of the tongue, we concluded that MCs may play a role in oral cavity immunity and protective effect.

Mast Cell: A Mysterious Character in Skin Cancer

Cutaneous malignancies represent a real concern and burden for the healthcare system, not only due to their increased frequency, but also due to the significant number of deaths attributed to these types of cancer. The genesis of tumors, their progression and metastasis are highly complex and researched subjects; apparently, mast cells (MCs) constitute an important piece in the complicated jigsaw puzzle of cancer. This article reviews the current knowledge of the roles MCs might play in the development of cutaneous malignancies. Besides their well-known and studied role in allergic reactions, MCs are linked to multiple and various disorders, including cancer. MCs exhibit incredible heterogeneity, being able to secrete numerous mediators that influence the tumor microenvironment and tumor cells. They are involved in many physiological and pathological processes, such as inflammation and angiogenesis. In this context, it is paramount to explore the advancements made so far in elucidating the roles that MCs have in skin cancer because they might provide valuable therapeutic targets in the future. Controversial and conflicting results were obtained across the studies examined.

Human Periapical Odontogenic Granulomas: Aspects of Microvessel Density (MVD), Heterogeneity of Blood Vessels and Mast Cells Density (MCD)

Periapical odontogenic granulomas are among the most encountered pathology that involve the alveolar bone, with severe consequences such as bone resorption, the presence of inflammatory infiltrate and the formation of abnormal vascularization. The present study aimed to quantify the existence of the microvessel density (MVD), mast cell density (MCD) and heterogeneity of the encountered blood vessels. A total of 37 patients diagnosed with odontogenic periapical granulomas were included, and the gender distribution, age and localization of the pathological lesions was assessed. After the surgical removal of the periapical odontogenic granuloma, the collected tissue was fixed in 10% buffered formalin. Primary processing, morphological analysis and immunohistochemical staining was performed in order to characterize the altered tissue. The results outlined the presence of a high number of mast cells, especially in the area of the inflamed tissue; the high heterogeneity of the blood vessels; and increased MVD with positive CD34. The conclusions of the study focus on the key role of the mast cells and their implication in the initiation and development of the angiogenesis process, triggering the inflammatory response of the host. Nevertheless, periapical odontogenic granulomas develop as an inflammatory response to the interaction between the host's immune system and microbial invasion.

Crosstalk of Mast Cells and Natural Killer Cells with Neurons in Chemotherapy-Induced Peripheral Neuropathy

Chemotherapy-induced peripheral neuropathy (CIPN) is a major comorbidity of cancer. Multiple clinical interventions have been studied to effectively treat CIPN, but the results have been disappointing, with no or little efficacy. Hence, understanding the pathophysiology of CIPN is critical to improving the quality of life and clinical outcomes of cancer patients. Although various mechanisms of CIPN have been described in neuropathic anti-cancer agents, the neuroinflammatory process involving cytotoxic/proinflammatory immune cells remains underexamined. While mast cells (MCs) and natural killer (NK) cells are the key innate immune compartments implicated in the pathogenesis of peripheral neuropathy, their role in CIPN has remained under-appreciated. Moreover, the biology of proinflammatory cytokines associated with MCs and NK cells in CIPN is particularly under-evaluated. In this review, we will focus on the interactions between MCs, NK cells, and neuronal structure and their communications via proinflammatory cytokines, including TNFα, IL-1β, and IL-6, in peripheral neuropathy in association with tumor immunology. This review will help lay the foundation to investigate MCs, NK cells, and cytokines to advance future therapeutic strategies for CIPN.

Mast cell expression in oral submucous fibrosis: A systematic review and metanalysis

BACKGROUND

Oral submucous fibrosis (OSMF) is a chronic disorder associated with reduced mouth opening, burning sensation and listed as potentially malignant disorder. The role of mast cells in initiation and progression of this condition has been debated in last few years. It is imperative to understand the definitive role of mast cells and subsequently identify a possible cost-efficient treatment modality for OSMF. This review aimed to study the role of mast cells in OSMF by framing a research question that assessed the mast cell count (MCC), their degranulation and immunohistochemical analyses. We performed a comprehensive search of PubMed, EBSCOhost and general Google search that conceded 26 studies from which 15 articles were finalized for the review. The individual study syntheses revealed increased MCC in OSMF as compared to controls. Also, there was decreased MCC with the progression of OSMF. However, the metanalysis showed high level of heterogeneity as three studies out of eight studies found reduced MCC in disease when compared with controls. There is definite increase in mast cell in OSMF although the cell count falls with the advancement of OSMF. This increases the scope for further research to identify exact mechanism by which mast cells contribute to fibrosis and conduct the drug trials that can inhibit the mechanism. Key words:Oral submucous fibrosis, mast cell count, degranulated mast cells, stages of OSMF.Oral submucous fibrosis, mast cell count, degranulated mast cells, stages of OSMF.

Is CCL2 an Important Mediator of Mast Cell-Tumor Cell Interactions in Oral Squamous Cell Carcinoma?

In this study, we aimed to evaluate the influence of interactions between mast cells (MCs) and oral squamous cell carcinoma (OSCC) tumor cells on tumor proliferation and invasion rates and identify soluble factors mediating this crosstalk. To this end, MC/OSCC interactions were characterized using the human MC cell line LUVA and the human OSCC cell line PCI-13. The influence of an MC-conditioned (MCM) medium and MC/OSCC co-cultures on the proliferative and invasive properties of the tumor cells was investigated, and the most interesting soluble factors were identified by multiplex ELISA analysis. LUVA/PCI-13 co-cultures increased tumor cell proliferation significantly (p = 0.0164). MCM reduced PCI-13 cell invasion significantly (p = 0.0010). CC chemokine ligand 2 (CCL2) secretion could be detected in PCI-13 monocultures and be significantly (p = 0.0161) increased by LUVA/PCI-13 co-cultures. In summary, the MC/OSCC interaction influences tumor cell characteristics, and CCL2 could be identified as a possible mediator.

The Crossroads of Periodontitis and Oral Squamous Cell Carcinoma: Immune Implications and Tumor Promoting Capacities

Periodontitis (PD) is increasingly considered to interact with and promote a number of inflammatory diseases, including cancer. In the case of oral squamous cell carcinoma (OSCC) the local inflammatory response associated with PD is capable of triggering altered cellular events that can promote cancer cell invasion and proliferation of existing primary oral carcinomas as well as supporting the seeding of metastatic tumor cells into the gingival tissue giving rise to secondary tumors. Both the immune and stromal components of the periodontium exhibit phenotypic alterations and functional differences during PD that result in a microenvironment that favors cancer progression. The inflammatory milieu in PD is ideal for cancer cell seeding, migration, proliferation and immune escape. Understanding the interactions governing this attenuated anti-tumor immune response is vital to unveil unexplored preventive or therapeutic possibilities. Here we review the many commonalities between the oral-inflammatory microenvironment in PD and oral-inflammatory responses that are associated with OSCC progression, and how these conditions can act to promote and sustain the hallmarks of cancer.

The mast cell reaction in premalignant and malignant lesions of the head and neck

Head and neck squamous cell carcinoma (HNSCC) is one of the most frequent and aggressive neoplasms of this anatomical region. Many studies evaluated the neoplastic cells, but few works focused on the tumor microenvironment. In the present study, we investigated the distribution and mast cell density (MCD) in malignant and premalignant lesions of the oral cavity, tongue, pharynx, and larynx. There were analyzed 52 specimens of HNSCC, and 15 biopsies taken from patients with dysplasia. Results were compared with those found in a control group of 10 biopsies of oral mucosa from patients with inflammatory diseases. Slides stained with Hematoxylin-Eosin were used for the histopathological diagnosis and grade, and mast cells (MCs) were identified by immunohistochemistry, using anti-MC tryptase. MCs were counted using a method similar to that proposed for microvessel density. We found a significant increase in the number of MCs from the normal oral mucosa until overt carcinoma. Unlike normal tissues, in HNSCC, many MCs were found between tumor cells. We found no relationship between MCs and blood vessels in the tumor area. A significant statistical correlation was found between dysplastic and malignant tumors, but not between tumors with a different grade. Also, it was not found relationship between MCD and the anatomical location of the tumor. Based on these results, we believe that MCD evaluated by anti-MC tryptase is an independent factor of prognosis and reflects an unfavorable outcome.

Mast Cells Positive for c-Kit Receptor and Tryptase Correlate with Angiogenesis in Cancerous and Adjacent Normal Pancreatic Tissue

Background: Mast cells (MCs) contain proangiogenic factors, in particular tryptase, associated with increased angiogenesis in several tumours. With special reference to pancreatic cancer, few data have been published on the role of MCs in angiogenesis in both pancreatic ductal adenocarcinoma tissue (PDAT) and adjacent normal tissue (ANT). In this study, density of mast cells positive for c-Kit receptor (MCDP-c-KitR), density of mast cells positive for tryptase (MCDPT), area of mast cells positive for tryptase (MCAPT), and angiogenesis in terms of microvascular density (MVD) and endothelial area (EA) were evaluated in a total of 45 PDAT patients with stage T_2–3N_0–1M₀. Results: For each analysed tissue parameter, the mean ± standard deviation was evaluated in both PDAT and ANT and differences were evaluated by Student’s t-test (p ranged from 0.001 to 0.005). Each analysed tissue parameter was then correlated to each other one by Pearson t-test analysis (p ranged from 0.01 to 0.03). No other correlation among MCDP-c-KitR, MCDPT, MCAPT, MVD, EA and the main clinical–pathological characteristics was found. Conclusions: Our results suggest that tissue parameters increased from ANT to PDAT and that mast cells are strongly associated with angiogenesis in PDAT. On this basis, the inhibition of MCs through tyrosine kinase inhibitors, such as masitinib, or inhibition of tryptase by gabexate mesylate may become potential novel antiangiogenetic approaches in pancreatic cancer therapy.

Epidemiology and pathological progression of erythematous lip lesions in captive sun bears (Helarctos malayanus)

This study investigates the occurrence of erythematous lip lesions in a captive sun bear population in Cambodia, including the progression of cheilitis to squamous cell carcinoma, and the presence of Ursid gammaherpesvirus 1. Visual assessment conducted in 2015 and 2016 recorded the prevalence and severity of lesions. Opportunistic sampling for disease testing was conducted on a subset of 39 sun bears, with histopathological examination of lip and tongue biopsies and PCR testing of oral swabs and tissue biopsies collected during health examinations. Lip lesions were similarly prevalent in 2015 (66.0%) and 2016 (68.3%). Degradation of lip lesion severity was seen between 2015 and 2016, and the odds of having lip lesions, having more severe lip lesions, and having lip lesion degradation over time, all increased with age. Cheilitis was found in all lip lesion biopsies, with histological confirmation of squamous cell carcinoma in 64.5% of cases. Single biopsies frequently showed progression from dysplasia to neoplasia. Eighteen of 31 sun bears (58.1%) had at least one sample positive for Ursid gammaherpesvirus 1. The virus was detected in sun bears with and without lip lesions, however due to case selection being strongly biased towards those showing lip lesions it was not possible to test for association between Ursid gammaherpesvirus 1 and lip squamous cell carcinoma. Given gammaherpesviruses can play a role in cancer development under certain conditions in other species, we believe further investigation into Ursid gammaherpesvirus 1 as one of a number of possible co-factors in the progression of lip lesions to squamous cell carcinoma is warranted. This study highlights the progressively neoplastic nature of this lip lesion syndrome in sun bears which has consequences for captive and re-release management. Similarly, the detection of Ursid gammaherpesvirus 1 should be considered in pre-release risk analyses, at least until data is available on the prevalence of the virus in wild sun bears.

Nothing to sneeze at: Histamine and histamine receptors in oral carcinogenesis

Oral squamous cell carcinoma (OSCC), the most common oral malignancy, shows an increasing rate of incidence worldwide. In spite of the recent advances in cancer research, OSCC therapy continues to have unfavourable outcomes, and thus, patient's prognosis remains relatively poor. Current research has been devoted to identifying novel therapeutic targets also in the tumour microenvironment (TME). Histamine and its G-protein-coupled receptors (H1R-H4R) play vital roles in multiple cancer-associated processes in TME, where histamine is mainly produced by mast cells. However, oral epithelial cells were recently shown to produce low concentrations of histamine in autocrine and paracrine modes. These findings, together with the discovery of the high-affinity histamine H4 receptor, have led to a massive increase in our understanding of histamine functions. In this review, we aim to summarize the most recent findings regarding histamine and its receptors and their involvement in oral carcinogenesis-from oral potentially malignant disorders (OPMDs) to invasive OSCC. Importantly, histamine receptors are differentially expressed in OPMDs and OSCC. Furthermore, H1R and H4R are associated with clinicopathological characteristics of OSCC patients, suggesting a role in prognosis. Due to the enormous success of histamine-based medications, histamine receptors may also represent promising and viable drug targets in oral cancer.

Roles of a Mast Cell-Specific Receptor MRGPRX2 in Host Defense and Inflammation

Mast cells are multifunctional immune cells that are found most abundantly at host-environment interfaces, such as the skin, respiratory tract, and oral/gastrointestinal mucosa. Not surprisingly, mast cells act as sentinel cells that sense microbial attacks and initiate a protective immune response and promote healing. Although mast cells share many features with other innate immune effector cells, such as neutrophils and macrophages, they uniquely interact closely with blood vessels and release an extensive set of mediators for the recruitment of innate and adaptive immune cells. A novel human G protein-coupled receptor (GPCR), known as Mas-related GPCR-X2 (MRGPRX2, mouse ortholog, MrgprB2), has recently been identified, which is expressed on mast cells but not neutrophils and macrophages. Interestingly, activation of MrgprB2 by bacteria-derived quorum-sensing peptides inhibits bacterial growth, prevents biofilm formation, and leads to the recruitment of neutrophils to effectively clear bacteria. Furthermore, host defense antimicrobial peptides and small-molecule peptide mimetics also activate mast cells via MRGPRX2/B2. MrgprB2-mediated activation of local mast cells also clears cutaneous bacterial infection, promotes healing, and protects against reinfection. In addition to their role in host defense, mast cells contribute to a number of chronic inflammatory diseases such as periodontitis, neurogenic inflammation, and inflammatory pain likely via the activation of MRGPRX2. In this review, we discuss the roles of MRGPRX2/B2 in the clearance of bacterial infection, wound healing, periodontal disease, neurogenic inflammation, and inflammatory pain. We propose that harnessing mast cells' host defense and immunomodulatory properties via the activation of MRGPRX2 may lead to novel approaches for the treatment of drug-resistant bacterial infections. On the other hand, increased MRGPRX2 expression on mast cells and their inappropriate activation may contribute to periodontitis, neurogenic inflammation, and inflammatory pain. Thus, targeting MRGPRX2 could provide novel approaches to modulate these conditions.

Streptococcal H2O2 inhibits IgE-triggered degranulation of RBL-2H3 mast cell/basophil cell line by inducing cell death

Mast cells and basophils are central players in allergic reactions triggered by immunoglobulin E (IgE). They have intracellular granules containing allergic mediators (e.g., histamine, serotonin, inflammatory cytokines, proteases and β-hexosaminidase), and stimulation by IgE-allergen complex leads to the release of such allergic mediators from the granules, that is, degranulation. Mast cells are residents of mucosal surfaces, including those of nasal and oral cavities, and play an important role in the innate defense system. Members of the mitis group streptococci such as Streptococcus oralis, are primary colonizers of the human oral cavity. They produce hydrogen peroxide (H₂O₂) as a by-product of sugar metabolism. In this study, we investigated the effects of streptococcal infection on RBL-2H3 mast cell/basophil cell line. Infection by oral streptococci did not induce degranulation of the cells. Stimulation of the RBL-2H3 cells with anti-dinitrophenol (DNP) IgE and DNP-conjugated human serum albumin triggers degranulation with the release of β-hexosaminidase. We found that S. oralis and other mitis group streptococci inhibited the IgE-triggered degranulation of RBL-2H3 cells. Since mitis group streptococci produce H₂O₂, we examined the effect of S. oralis mutant strain deficient in producing H₂O_2, and found that they lost the ability to suppress the degranulation. Moreover, H₂O₂ alone inhibited the IgE-induced degranulation. Subsequent analysis suggested that the inhibition of degranulation was related to the cytotoxicity of streptococcal H₂O₂. Activated RBL-2H3 cells produce interleukin-4 (IL-4); however, IL-4 production was not induced by streptococcal H₂O₂. Furthermore, an in vivo study using the murine pollen-induced allergic rhinitis model suggested that the streptococcal H₂O₂ reduces nasal allergic reaction. These findings reveal that H₂O₂ produced by oral mitis group streptococci inhibits IgE-stimulated degranulation by inducing cell death. Consequently, streptococcal H₂O₂ can be considered to modulate the allergic reaction in mucosal surfaces.

Mast Cells and Blood Vessels Profile in Oral Carcinogenesis: An Immunohistochemistry Study

Background:

The objectives of the present study were to evaluate angiogenesis and mast cell density in oral epithelial dysplasia and oral squamous cell carcinoma (OSCC).

Materials and Methods:

This was an observational, retrospective and quantitative study. The samples consisted of 60 tissue specimens from patients with squamous cell carcinoma, epithelial dysplasia and controls (n=20/group). Immunohistochemistry was performed using an anti-tryptase antibody to mast cells and anti-CD31 and anti-CD34 for blood vessels and we count the number of mast cells and determine the percentage of CD31 and CD34 antibody staining (vascular density).

Results:

The mast cells had lower density in OSCC compared to control and dysplasia (p = 0.009). In angiogenesis, the expression of CD31 showed a higher percentage of blood vessels in OSCC (p < 0.001), however, CD34 showed no difference between groups (p=0.092). The CD31 antibody presented as a high immunostaining in oral mucosa than CD34.

Conclusions:

The increased vascularity in squamous cell carcinoma suggests that angiogenesis begins when malignant transformation starts that seems to be inversely associated with the number of mast cells.

Dietary Fatty Acids and Other Nutrients in Relation to Inflammation and Particularly to Oral Mucosa Inflammation. A Literature Review

Oral mucosa is site of inflammatory process development. When they are chronic, they provide a microenvironment based on cytokines and inflammatory mediators that contribute to cancer initiation, progression, invasion, and metastasis. Certain dietary fatty acids (FAs) have immunomodulatory, inflammatory, and antiinflammatory effects. This review examined the literature on inflammation, mainly referred to the oral mucosa, and its association with dietary FAs and other nutrients. A Pubmed search of studies published in English until June 2018 was carried out. N-3 FAs have shown immunomodulatory and antiinflammatory activity in certain human diseases. These FAs and their mediators may inhibit inflammation, angiogenesis, and cancer via multiple mechanisms. Studies on cellular models of murine and human intestinal mucosa indicate association between dietary n-3 FA intake and the inflammatory state of mucosa membranes. Nevertheless scarce information on the association between dietary FAs and oral inflammation could be found. Based on the evidence, we hypothesize that n-3 FAs reduce the oral mucosa inflammation thus decreasing the risk of developing precancerous lesions and cancer. Molecular and clinical studies referred to this topic should be carried out as a contribution to the oral cancer prevention.

Role of mast cells in inflammatory and reactive pathologies of pulp, periapical area and periodontium

Mast cells (MCs) have been discovered over 130 years ago; their function was almost exclusively linked to allergic affections. At the time being, it is well known that MCs possess a great variety of roles, in both physiologic and pathologic conditions. In the oral tissues, MCs release different pro-inflammatory cytokines and tumor necrosis factor-alpha that promote leukocyte infiltration in various inflammatory states of the oral cavity. These cells play a key role in the inflammatory process and, as a consequence, their number changes in different pathologic conditions of the oral cavity, such as gingivitis and periodontitis. By understanding the role of MCs in the pathogenesis of different inflammatory diseases of the oral cavity, these cells may become therapeutic targets that could possibly improve the prognosis. Therefore, this review summarizes the current understanding of the role of MCs in various inflammatory pulpal, periapical and periodontal pathophysiological conditions.

The role of basophils as innate immune regulatory cells in allergy and immunotherapy

Basophils are circulating cells that are associated quite exclusively with allergy response and hypersensitivity reactions but their role in the immune network might be much more intriguing and complex than previously expected. The feasibility of testing their biology in vitro for allergy research and diagnosis, due fundamentally to their quite easy availability in the peripheral blood, made them the major source for assessing allergy in the laboratory assay, when yet many further cells such as mast cells and eosinophils are much more involved as effector cells in allergy than circulating basophils. Interestingly, basophil numbers change rarely in peripheral blood during an atopic response, while we might yet observe an increase in eosinophils and modification in the biology of mast cells in the tissue during an hypersensitivity response. Furthermore, the fact that basophils are very scanty in numbers suggests that they should mainly serve as regulatory cells in immunity, rather than effector leukocytes, as still believed by the majority of physicians. In this review we will try to describe and elucidate the possible role of these cells, known as "innate IL4-producing cells" in the immune regulation of allergy and their function in allergen immunotherapy.

Anti-inflammatory effect of ATB-352, a H2S -releasing ketoprofen derivative, on lipopolysaccharide-induced periodontitis in rats

Periodontal disease is the most common cause of tooth loss in humans, is an inflammatory disease initiated by oral microbial biofilm. Given the involvement of the inflammatory pathway in this type of pathology, the main pharmacological strategy for the treatment of periodontitis, is the inhibition of the inflammatory process in order to prevent tissue destruction and bone resorption, a condition associated with a painful state. To do this, the best class of drugs are Non-steroidal anti-inflammatory drugs (NSAIDs), however, the presence of side effects, especially at the gastrointestinal tract, limits their use for long-term therapy. Recently, some evidence shows that derivatives of NSAIDs capable of releasing hydrogen sulphide exhibit lower collateral effects, particularly at the gastric level. In fact, H2S is an endogenous gaseous mediator with a cytoprotective role at the gastric level. In this study, we have compared the protective effects of ketoprofen with ATB-352, a hydrogen sulfide-releasing derivative of ketoprofen, in an experimental model of periodontitis in rat. Periodontitis was induced by a single intragingival injection of 1 μl LPS (10 μg/μl), Our results show that 14 h after intragingival injection of LPS, there was a high tissue damage associated with bone resorption, and in gingivomucosal tissues there was a significant expression of NF-kb p65 and pro-inflammatory cytokine as well as a higher expression of COX-2 and iNOS, activation of the apoptotic process, and also increased levels of NGF expression, often associated with a higher nociceptive perception. Treatment with ATB-352 at the dose of 20mg\kg, was able to reduce the inflammatory process associated with intragingival LPS injection and also had a positive effect on bone resorption and tissue damage.

Anti-inflammatory effects of Artemisia scoparia and its active constituent, 3,5-dicaffeoyl-epi-quinic acid against activated mast cells

OBJECTIVES

Artemisia scoparia Waldst. et Kit. (AS) has been used to treat inflammation, urticaria and hepatitis. However, the scientific studies of AS and its active compound for inflammatory reactions in activated human mast cell line, HMC-1 cells have not yet been elucidated.

MATERIALS AND METHODS

Here, we isolated 3,5-dicaffeoyl-epi-quinic acid (DEQA) from AS butanol fraction. The anti-inflammatory effect of AS and its new active compound, DEQA was examined in HMC-1 cells by studying the following markers: phorbol 12-myristate 13-acetate and calcium ionophore A23187 (PMACI)-induced thymic stromal lymphopoietin (TSLP), tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 secretion and mRNA expression by ELISA and RT-PCR, respectively. Furthermore, mechanism related to anti-inflammatory was examined by Western blotting.

RESULTS

We reported that AS and its new active compound, DEQA significantly reduced TSLP, TNF-α, IL-1β and IL-6 production levels through the reduction of caspase-1 activity. The mRNA expression of these inflammatory cytokine was also reduced via blocking nuclear factor-κB nuclear translocation by AS and DEQA. In addition, AS significantly reduced phosphorylated-c-Jun N-terminal kinase level and DEQA significantly reduced both phosphorylated-c-Jun N-terminal kinase and -p38 mitogen-activated protein kinase levels.

CONCLUSIONS

Therefore, these results indicated that AS and its active compound, DEQA may improve mast cell-mediated inflammatory diseases.