Areca nut extract suppresses T-cell activation and interferon-gamma production via the induction of oxidative stress

Possible Immunotherapeutic Strategies Based on Carcinogen-Dependent Subgroup Classification for Oral Cancer

The oral cavity serves as an open local organ of the human body, exposed to multiple external factors from the outside environment. Coincidentally, initiation and development of oral cancer are attributed to many external factors, such as smoking and drinking, to a great extent. This phenomenon was partly explained by the genetic abnormalities traditionally induced by carcinogens. However, more and more attention has been attracted to the influence of carcinogens on the local immune status. On the other hand, immune heterogeneity of cancer patients is a huge obstacle for enhancing the clinical efficacy of tumor immunotherapy. Thus, in this review, we try to summarize the current opinions about variant genetic changes and multiple immune alterations induced by different oral cancer carcinogens and discuss the prospects of targeted immunotherapeutic strategies based on specific immune abnormalities caused by different carcinogens, as a predictive way to improve clinical outcomes of immunotherapy-treated oral cancer patients.

Depletion of miR-155 hinders the myofibroblast activities and reactive oxygen species generation in oral submucous fibrosis

BACKGROUND/PURPOSE

Emerging evidence suggests the significance of microRNA-155 (miR-155) in fibrogenesis and oxidative stress accumulation, but its function in oral submucous fibrosis (OSF) has not been investigated. In this study, we assessed the expression of miR-155 and its effects on the maintenance of myofibroblast activation.

METHODS

qRT-PCR was conducted to assess the expression of miR-155 in OSF tissues and fibrotic buccal mucosal fibroblasts (fBMFs) derived from OSF samples. Collagen gel contraction, migration, and invasion capabilities were examined in fBMFs. DCFDA ROS assay was used to examine ROS generation. A luciferase reporter assay was carried out to verify the relationship between miR-155 and its potential target RPTOR.

RESULTS

We showed that the expression of miR-155 was aberrantly upregulated in OSF specimens and fBMFs. Inhibition of miR-155 ameliorated various myofibroblast activities, including collagen gel contraction, migration, and invasion abilities as well as ROS production. Results from the luciferase reporter assay demonstrated that miR-155 directly interacted with its target RPTOR.

CONCLUSION

Taken together, these findings indicate that miR-155 is implicated in the pathogenesis of oxidative stress-associated OSF, possibly through the regulation of RPTOR.

Bioactive compounds and health benefits of some palm species traditionally used in Africa and the Americas - A review

ETHNOPHARMACOLOGICAL RELEVANCE

According to previous ethno-medicinal reviews, Cocos nucifera, Elaeis guineensis and Phoenix dactylifera are among the main palms which are often used on the American and African continents to treat infections, infestations and disorders in the digestive, respiratory, genito-urinary, dermal, endocrine, cardiovascular, muscular-skeletal, mental and neural systems, as well as neoplasms, dental issues and metabolic and nutritional disorders. In addition, one or more species of the wild genera Acrocomia, Areca, Astrocaryum, Attalea, Bactris, Borassus, Calamus, Chamaedorea, Chamaerops, Euterpe, Hyphaene, Mauritia, Oenocarpus and Syagrus have a high number of records of these ethno-medicinal uses. The most used parts of the palm tree are the fruits, followed by roots, seeds, leaves and flower sap.

AIM OF THE STUDY

This review discusses the phytochemical composition and the pharmacological properties of these important ethno-medicinal palms, aiming to provide a contribution to future research prospects.

MATERIALS AND METHODS

Significant information was compiled from an electronic search in widely used international scientific databases (Google Scholar, Science Direct, SciFinder, Web of Science, PubMed, Wiley on line Library, Scielo, ACS Publications), and additional information was obtained from dissertations, theses, books and other relevant websites.

RESULTS

Palms, in general, are rich in oils, terpenoids and phenolic compounds. Fruits of many species are notable for their high content of healthy oils and fat-soluble bioactive compounds, mainly terpenoids, such as pigment carotenoids (and provitamin A), phytosterols, triterpene pentacyclics and tocols (and vitamin E), while other species stood out for their phenolic compounds derived from benzoic and cinnamic acids, along with flavan-3-ol, flavone, flavonol, and stilbene compounds or anthocyanin pigments. In addition to fruits, other parts of the plant such as seeds, leaves, palm heart, flowers and roots are also sources of many bioactive compounds. These compounds are linked to the ethno-medicinal use of many palms that improve human health against infections, infestations and disorders of human systems.

CONCLUSIONS

Palms have provided bioactive samples that validate their effectiveness in traditional medicine. However, the intensive study of all palm species related to ethno-medicinal use is needed, along with selection of the most appropriate palm accessions, ripe stage of the fruit and /or part of the plant. Furthermore, the complete profiles of all phytochemicals, their effects on animal models and human subjects, and toxicological and clinical trials are suggested, which, added to the incorporation of improved technological processes, should represent a significant advance for the implementation of new opportunities with wide benefits for human health.

Thioctic acid in oral submucous fibrosis (India's disease) - A better tomorrow

Oral submucous fibrosis (OSMF), because of its common occurrence in Indian population is known as India's disease. Regardless of diagnostic and therapeutic developments, oral potentially malignant disorders (PMD) and cancers are disseminating at a distressing rate. There is this prerequisite for unrelenting determination to find out apt treatment options so that malignant transformation may be prevented and more so the prevailing morbidity and mortality. Considering the frequency with which oral submucous fibrosis undergoes malignant transformation with free radicals playing a major part, the role of antioxidants in general and thioctic acid also known as alpha lipoic acid (ALA) in particular need to be studied in these individuals. Previous few studies indicated the use of alpha lipoic acid in oral submucous fibrosis patients leading to improvement in signs and symptoms. So, it led us to set forth and propose probable role of thioctic acid in improving symptoms in these patients. As oral submucous fibrosis poses as a threat with its various signs and symptoms and as a potentially malignant disorder as well as considering the role of free radicals in malignant transformation, we proposed the possible mechanisms behind the commonest signs and symptoms in oral submucous fibrosis and role of alpha lipoic acid in managing these signs and symptoms.

Nodal involvement in Oral Squamous Cell Carcinoma (SCC) patients with and without Oral Sub Mucous Fibrosis (OSMF): A Comparative Study

Aim

The aim of the study is to compare and evaluate neck node status of oral cancer patients with and without Oral Sub Mucous Fibrosis (OSMF) treated surgically.

Methodology

A total of 50 patients of Indian origin who were diagnosed with Squamous Cell Carcinoma (SCC) of oral cavity and had not taken any prior treatment were included in the study. Clinical examination and metastatic workup was done for all patients. Patients diagnosed with resectable primary and without distant metastasis were taken up for surgery. For all patients, resected specimens were sent for radical histopathological examination.

Result

The differences in nodal involvement in T₁, T₂ & T₃ sized lesions were non-significant, while in T₄ sized lesions, a statistically significant lower incidence of nodal involvement in patients with-OSMF as compared to patients without OSMF was observed.

Conclusion

Presence of N₀ neck in T₄ lesions in oral SCC patients with OSMF has potential implications on the present pattern of spread and treatment protocols, leading to need for further research with OSMF as independent risk factor for nodal involvement.

Immunomodulatory Effects of Taiwanese Neolitsea Species on Th1 and Th2 Functionality

Neolitsea species, medicinal plants belonging to Lauraceae, contain rich alkaloids, steroids, sesquiterpenoids, and triterpenoids which possess antimicrobial, antioxidant, and anti-inflammatory bioactivities. However, species differences in the immunomodulatory effects and evidence pertaining to the effects of Neolitsea species on adaptive immunity are scarce. This study aimed to evaluate the immunomodulatory properties of ten Taiwanese Neolitsea plants on T helper (Th) cell functionality, especially Th1 and Th2. Most of the 29 crude extracts of Neolitsea were not toxic to splenocytes, except N. buisanensis roots. N. aciculata and N. villosa leaf extracts possessed differential immunomodulatory effects on Th1/Th2 balance. N. aciculata var. variabillima and N. hiiranensis leaf extracts attenuated both Th1 and Th2 cytokines while N. konishii dramatically suppressed IFN-γ production. As N. aciculata var. variabillima and N. konishii leaf extracts significantly attenuated Th1 functionality, we further evaluated their effects on CD4 cells under CD3/CD28 stimulation. N. aciculata var. variabillima significantly suppressed IFN-γ, IL-10, and IL-17, demonstrating the broad suppressive effects on T helper cells; N. konishii significantly suppressed IFN-γ and IL-10 production, while the production of IL-17 was not altered. Collectively, these data demonstrated that leaf extracts of Taiwanese Neolitsea species contain phytochemicals with potentials to be developed as selective immunomodulators.

Linking sources to early effects by profiling urine metabolome of residents living near oil refineries and coal-fired power plants

BACKGROUND

This study aims at identifying metabolic changes linking external exposure to industrial air toxics with oxidative stress biomarkers.

METHODS

We classified 252 study subjects as 111 high vs. 141 low exposure subjects by the distance from their homes to the two main emission sources, oil refineries and coal-fired power plants. We estimated individual's external exposure to heavy metals and polycyclic aromatic hydrocarbons (PAHs) by dispersion and kriging models, respectively. We measured urinary levels of heavy metals and 1-hydroxypyrene (1-OHP) as biomarkers of internal exposure, and 8-OHdG, HNE-MA, 8-isoPGF_2α, and 8-NO₂Gua as biomarkers of early health effects. We used two-dimensional gas chromatography time-of-flight mass spectrometry to identify urine metabolomics. We applied "meet-in-the-middle" approach to identify potential metabolites as putative intermediate biomarkers linking multiple air toxics exposures to oxidative stress with plausible exposures-related pathways.

RESULTS

High exposure subjects showed elevated ambient concentrations of vanadium and PAHs, increased urine concentrations of 1-OHP, vanadium, nickel, copper, arsenic, strontium, cadmium, mercury, and thallium, and higher urine concentrations of all four urine oxidative stress biomarkers compared to low exposure subjects. We identified a profile of putative intermediate biomarkers that were associated with both exposures and oxidative stress biomarkers in participants. Urine metabolomics identified age-dependent biological pathways, including tryptophan metabolism and phenylalanine metabolism in children subjects (aged 9-11), and glycine, serine, and threonine metabolism in elderly subjects (aged>55), that could associate multiple exposures with oxidative stress.

CONCLUSION

By profiling urine biomarkers and metabolomics in children and elderly residents living near a petrochemical complex, we can link their internal exposure to oxidative stress biomarkers through biological pathways associated with common complex chronic diseases and allergic respiratory diseases. The internal exposure may possibly be traced to multiple air toxics emitted from specific sources of oil refineries and coal-fired power plants.

Autophagy mediates oral submucous fibrosis

Oral submucous fibrosis (OSF) is a chronic insidious disease of the oral mucosa, well-recognized as a premalignant condition and commonly found in Southern China. It is primarily caused by the habit of areca nut or gutkha chewing. OSF is believed to be a homeostatic disorder of the extracellular matrix and fibroblast proliferation. The present study demonstrated a novel link between autophagy and OSF. Tissue samples from human OSF showed an overexpression of the autophagy marker microtubule-associated protein 1 light chain 3 using immunohistochemistry and quantitative polymerase chain reaction. With regard to the crucial role of transforming growth factor (TGF)-β in OSF disease, western blot analysis demonstrated that TGF-β signaling was shown to contribute to the activation of autophagy in fibroblasts in vitro; however, a cell apoptosis and MTS assay demonstrated that the suppression of autophagy ameliorated the fibrosis induced by active TGF-β receptor type I signaling, as well as promoted fibroblast apoptosis and suppressed proliferation. Therefore, the present results suggest that autophagy serves a crucial function in OSF.

Areca catechu L. (Arecaceae): a review of its traditional uses, botany, phytochemistry, pharmacology and toxicology

ETHNOPHARMACOLOGICAL RELEVANCE

Areca catechu L. (Arecaceae), widely distributed in South and Southeast Asia, is a popular traditional herbal medicine that can be chewed for the purpose of dispersing accumulated fluid in the abdominal cavity and killing worms. The present paper aims to provide an up-to-date review on the traditional uses and advances in the botany, phytochemistry, pharmacology and toxicology of this plant. Furthermore, the possible trends and a perspective for future research of this plant are also discussed.

MATERIALS AND METHODS

A literature search was performed on A. catechu based on classic books of herbal medicine, PhD. and MSc. dissertations, government reports, the state and local drug standards, scientific databases including Pubmed, SciFinder, Scopus, the Web of Science, Google Scholar, and others. Various types of information regarding this plant are discussed in corresponding parts of this paper. In addition, perspectives for possible future studies of A. catechu are discussed.

RESULTS

The seeds of A. catechu (areca nut) have been widely used in clinical practice in China, India and other South and Southeast Asian Countries. Currently, over 59 compounds have been isolated and identified from A. catechu, including alkaloids, tannins, flavones, triterpenes, steroids, and fatty acids. The extracts and compounds isolated from A. catechu have many pharmacological activities. These include antiparasitic effects, anti-depressive effects, anti-fatigue effects, antioxidant effects, antibacterial and antifungal effects, antihypertensive effects, anti-inflammatory and analgesic effects, anti-allergic effects, the promotion of digestive functions, suppression of platelet aggregation, regulatory effects on blood glucose and lipids, etc. Although arecoline is the primary active constituent of A. catechu, it is also the primary toxic compound. The main toxicities of arecoline are the promotion of oral submucosal fibrosis (OSF) and cytotoxic effects on normal human cells, which involve inducing apoptosis.

CONCLUSION

As an important herbal medicine, A. catechu has potential for the treatment of many diseases, especially parasitic diseases, digestive function disorders, and depression. Many traditional uses of A. catechu have now been validated by current investigations. However, further research should be undertaken to investigate the clinical effects, toxic constituents, target organs, and pharmacokinetics and to establish criteria for quality control for A. catechu-derived medications. In addition, it will be interesting to investigate the active macromolecular compounds and active constituents other than alkaloids in both raw and processed products of A. catechu.

A review of the systemic adverse effects of areca nut or betel nut

Areca nut is widely consumed by all ages groups in many parts of the world, especially south-east Asia. The objective of this review is to systematically review and collate all the published data that are related to the systemic effects of areca nut. The literature search was performed by an electronic search of the Pubmed and Cochrane databases using keywords and included articles published till October 2012. We selected studies that covered the effect of areca nut on metabolism, and a total of 62 studies met the criteria. There is substantial evidence for carcinogenicity of areca nut in cancers of the mouth and esophagus. Areca nut affects almost all organs of the human body, including the brain, heart, lungs, gastrointestinal tract and reproductive organs. It causes or aggravates pre-existing conditions such as neuronal injury, myocardial infarction, cardiac arrhythmias, hepatotoxicity, asthma, central obesity, type II diabetes, hyperlipidemia, metabolic syndrome, etc. Areca nut affects the endocrine system, leading to hypothyroidism, prostate hyperplasia and infertility. It affects the immune system leading to suppression of T-cell activity and decreased release of cytokines. It has harmful effects on the fetus when used during pregnancy. Thus, areca nut is not a harmless substance as often perceived and proclaimed by the manufacturers of areca nut products such as Pan Masala, Supari Mix, Betel quid, etc. There is an urgent need to recognize areca nut as a harmful food substance by the policy makers and prohibit its glamorization as a mouth freshener. Strict laws are necessary to regulate the production of commercial preparations of areca nut.

Inhibitory effects of areca nut extract on expression of complement receptors and fc receptors in human neutrophils

BACKGROUND

Chewing of areca quid increases the prevalence of periodontal diseases. Areca nut extract (ANE) inhibits the phagocytic activity of human neutrophils. This in vitro study investigates the effects of ANE on complement- and antibody-opsonized phagocytosis by neutrophils. Expression of complement receptors, Fc receptors, and F-actin in ANE-treated neutrophils is also analyzed.

METHODS

The viability of ANE-treated neutrophils was determined using the propidium iodide staining method. The possible effects of ANE on the expression of complement receptors and Fc receptors were examined using an immunofluorescence staining method followed by flow cytometry and confocal laser scanning microscopy. The phagocytic activity of neutrophils against complement or immunoglobulin (Ig)G-opsonized fluorescent beads was analyzed using flow cytometry. Expression of F-actin was determined using confocal laser scanning microscopy.

RESULTS

ANE significantly inhibited the production of complement receptors (CR1, CR3, and CR4) and Fc receptors (FcγRII and FcγRIII) in a concentration-dependent manner. Treatment of neutrophils with ANE significantly impaired their ability to phagocytose fluorescent beads. ANE also inhibited phagocytosis of fluorescent beads that were opsonized by complement or IgG. Moreover, expression of F-actin was inhibited after ANE treatment.

CONCLUSIONS

ANE inhibits the complement- and IgG-mediated neutrophil phagocytosis that may result from reduction of the expression of complement receptors, Fc receptors, and F-actin formation after ANE treatment. The findings suggest that areca nut chewing may jeopardize the defensive functions of neutrophils and affect periodontal health.

A high IL-4 production diplotype is associated with an increased risk but better prognosis of oral and pharyngeal carcinomas

OBJECTIVE

Interleukin (IL)-4 is a key cytokine in humoral and adaptive immunity. This study aimed to evaluate the association of IL-4 genetic variants (-590C>T and VNTR in intron 3) with the risk and prognosis of oral and pharyngeal squamous cell carcinoma (OPSCC).

DESIGN

A total of 1215 subjects, which included 623 healthy controls and 592 OPSCC cases (463 oral squamous cell carcinoma (OSCC) and 129 pharyngeal squamous cell carcinoma (PSCC) cases), were recruited. The genotypes were determined by TaqMan real-time assay and PCR-based assay.

RESULTS

The IL-4 genotypes at locus -590C>T and intron 3 VNTR were not correlated with increased risk of OSCC, PSCC, and OPSCC, with the exception of early-stage OPSCC (at -590C>T: T/T vs. C/C+C/T, adjusted odds ratio (AOR)=1.42, 95% CI: 1.02-1.98; at intron 3 VNTR: RP1/RP1 vs. RP2/RP2+RP2/RP1, AOR=1.46, 95% CI: 1.05-2.04). Compared with other IL-4 diplotypes, the T,RP1/T,RP1 diplotype was associated with an increased risk of OPSCC (AOR=1.37, 95% CI: 1.03-1.81), particularly early-stage OSCC (AOR=1.43, 95% CI: 1.02-2.00), PSCC (AOR=2.35, 95% CI: 1.06-5.19), and OPSCC (AOR=1.52, 95% CI: 1.10-2.11). Interactions between the IL-4 diplotype and the alcohol drinking status were found to contribute to the risk of early-stage OPSCC (p=0.024). In addition, the T,RP1/T,RP1 diplotype was correlated with better disease-specific survival (T,RP1/T,RP1 vs. other diplotypes, adjusted hazard ratio=0.70, 95% CI: 0.50-0.97).

CONCLUSION

The T, RP1/T, RP1 diplotype of IL-4 was associated with an increased risk but favourable prognosis of OPSCC.

Oral supplementation with areca-derived polyphenols attenuates food allergic responses in ovalbumin-sensitized mice

Background

Arecae semen, the dried slice of areca nuts, is a traditional Chinese medicine used to treat intestinal parasitosis, rectal tenesmus and diarrhea. Areca nuts contain a rich amount of polyphenols that have been shown to modulate the functionality of mast cells and T cells. The objective of this study is to investigate the effect of polyphenol-enriched areca nut extracts (PANE) against food allergy, a T cell-mediated immune disorder.

Methods

BALB/c mice were left untreated or administered with PANE (0.05% and 0.1%) via drinking water throughout the entire experiment. The mice were sensitized with ovalbumin (OVA) twice by intraperitoneal injection, and then repeatedly challenged with OVA by gavage to induce food allergic responses.

Results

PANE administration attenuated OVA-induced allergic responses, including the occurrence of diarrhea and the infiltration and degranulation of mast cells in the duodenum. The serum level of OVA-specific IgE and the expression of interleukin-4 in the duodenum were suppressed by PANE treatment. In addition, PANE administration induced Gr-1⁺, IL-10⁺ and Gr-1⁺IL-10⁺ cells in the duodenum.

Conclusion

These results demonstrate that oral intake of areca-derived polyphenols attenuates food allergic responses accompanied with a decreased Th2 immunity and an enhanced induction of functional myeloid-derived suppressor cells.

Long-term stimulation of areca nut components results in increased chemoresistance through elevated autophagic activity

BACKGROUND

We previously demonstrated the autophagy-inducing activity in the crude extract of areca nut (ANE) and its 30-100 kDa fraction (ANE 30-100 K). This study aimed to analyze whether chronic ANE and ANE 30-100 K stimulations lead to higher stress resistance and autophagic activity in oral cells, and whether the resulting autophagic status in stimulated cells correlates with stress resistance.

MATERIALS AND METHODS

Malignant cells from the mouth oral epidermoid carcinoma Meng-1 (OECM-1) and blood (Jurkat T) origins were stimulated with non-cytotoxic ANE and ANE 30-100 K for 3 months. Sensitivity to anticancer drugs of and autophagy status in stimulated cells, analyzed respectively by XTT assay and calculating microtubule-associated protein 1 light chain 3-II LC3-II/β-actin ratios from Western blot, were compared to non-treated cells. Autophagy inhibitors, 3-methyladenine (3-MA) and chloroquine (CQ), were used to assess whether autophagy inhibition interferes the altered chemoresistance.

RESULTS

Areca nut extract-stimulated (ANE-s) and ANE 30-100 K-stimulated (30-100 K-s) OECM-1 and Jurkat T cells generally exhibited higher cisplatin and 5-fluorouracil (5-FU) resistances, compared to non-stimulated cells. Most stimulated cells expressed significantly higher levels of LC3-II and Atg4B proteins. Interestingly, these cells also showed stronger tolerances against hypoxia environment and expressed higher LC3-II levels under glucose-deprived and hypoxia conditions. Finally, both 3-MA and CQ alleviated, albeit to different degrees, the increased chemoresistance in ANE-s and/or 30-100 K-s cells.

CONCLUSIONS

Chronic stimulations of ANE or ANE 30-100 K may increase tolerance of oral cancer and leukemia T cells to anticancer drugs, as well as to glucose deprivation and hypoxia conditions, and cause an elevation of autophagy activity responsible for increased drug resistance.

Current Concepts about Areca Nut Chewing

The habit of chewing areca is a habit of great antiquity. The word ‘areca’ is derived from the Malay word adakka (areca nut) or from adakeya, the Indian equivalent. Arecoline, the principal alkaloid in areca nut, acts as an agonist primarily at muscarinic acetylcholine receptors and stimulates the central and autonomic nervous system. This leads to subjective effects of increased well-being, alertness and stamina. It is known to improve concentration and relaxation, with other reported effects including lifting of mood, cariostatic property and also exerts a direct antimicrobial effect against bacteria. Arecaidine may have anxiolytic properties through inhibition of gamma-amino butyric acid (GABA) reuptake.

Despite these general effects, the adverse effects have outweighed them. Betal quid chewing is one of the major risk factors of hepatocarcinoma, oropharyngeal and esophagus cancers. Arecoline, the main areca alkaloid of the betel nut, is reported to have cytotoxic, genotoxic and mutagenic effects in various cells. It shows strong correlation to the incidence of oral submucosal fibrosis, leukoplakia and oral cancer, and has also been found to impose toxic manifestations in immune, hepatic and other defense systems of the recipient.

How to cite this article

Chandak RM, Chandak MG, Rawlani SM. Current Concepts about Areca Nut Chewing. J Contemp Dent 2013;3(2):78-81.

A preliminary study of arecoline and guvacoline presence in the saliva of a "betel-quid" chewer using liquid-chromatography ion trap mass spectrometry

It has been reported that the parasympathomimetic alkaloid arecoline and the nootropic agent guvacoline have been detected in areca nut (Areca catechu L.) during extraction using a basic medium. Here, we have studied the detection of arecoline and guvacoline in vivo in saliva of a "betel-quid" chewer using liquid-chromatography ion trap mass spectrometry. In this paper, we provide evidence that guvacoline is absent in the neutral aqueous extract of betel nut, but is present in abundance in the aqueous extract with added time (pH 11.9). In an in vivo experiment, we demonstrated that guvacoline is present in the salivary extracts in the mouth with time (pH 9.5) and without lime (pH5.3).

Areca nut extracts enhance the development of CD11b(+) Gr-1(+) cells with the characteristics of myeloid-derived suppressor cells in antigen-stimulated mice

BACKGROUND

Areca quid chewing is an etiological factor contributing to the development of oral cancer and pre-cancers, whose pathophysiology has been linked to inflammation and immune deterioration. Myeloid-derived suppressor cells (MDSC) play a key role in the regulation of immunity under certain pathological conditions, such as inflammation and cancer. As areca nut extracts (ANE) have been reported to induce a proinflammatory effect in antigen-stimulated mice, we hypothesized that ANE might enhance the development of MDSC.

METHODS

Ovalbumin (OVA)-sensitized BALB/c mice were daily administered with ANE (5-50 mg/kg), polyphenol-enriched ANE (PANE; 25 mg/kg) or arecoline (5 mg/kg) by intraperitoneal injection for 10 doses. The mouse footpads were then subcutaneously challenged with OVA to induce local inflammatory responses.

RESULTS

ANE and PANE treatment significantly increased the spleen index and the population of CD11b(+) Gr-1(+) cells in the spleen and peripheral blood, whereas arecoline was inactive. In addition, ANE and PANE treatment enhanced the expression of cytokines and enzymes associated with the immunosuppressive function of MDSC, including IL-10, arginase-I and iNOS in splenic CD11b(+) cells. Concordantly, ANE and PANE treatment augmented the infiltration of Gr-1(+) IL-10(+) cells in the footpads challenged with OVA.

CONCLUSIONS

Our results suggested that areca nut constituents, in particular, polyphenols enhanced the development of myeloid-derived suppressor cells in vivo, which may be a critical mechanism linking inflammation and the compromised immunity reported to be associated with the pathophysiology of areca-related oral diseases.

Adenosine A(2A) receptor activation limits chronic granulomatous disease-induced hyperinflammation

Chronic granulomatous disease (CGD) is caused by defects in the NADPH oxidase complex and is characterized by an increased susceptibility to infection. Other significant complications of CGD include autoimmunity and non-infectious hyperinflammatory disorders. We show that a gp91(phox) deficiency leads to the development of phenotypically altered T lymphocytes in mice and that this abnormal, hyperactive phenotype can be modulated by activation of the adenosine A(2A) receptor. T cells isolated from CGD mice produce significantly higher levels of the pro-inflammatory cytokines IFN-γ, IL-2, TNF-α, IL-4 and IL-13 than do WT cells after TCR-mediated activation; treatment with the selective adenosine A(2A) receptor agonist, CGS21680, potently inhibits this response. Additionally, the over exuberant inflammatory response elicited by thioglycollate challenge in gp91(phox) deficient mice is attenuated by CGS21680. These data suggest that treatment with A(2A)R agonists may be an effective therapy by which to regulate the immune system hyperactivity that results from a gp91(phox) deficiency.

Discrepancy of the effects of zinc supplementation on the prevention of radiotherapy-induced mucositis between patients with nasopharyngeal carcinoma and those with oral cancers: subgroup analysis of a double-blind, randomized study

The purpose of this study was to determine the effect of zinc supplementation on radiation-induced mucositis in patients with nasopharyngeal carcinoma (NPC) and those with oral cancers (OC). A total of 100 patients with head and neck cancers engaged in a randomized double blind study. All participants were placed into two randomized groups (experimental and control). The experimental group received a standard dose of zinc supplements, and the control group was given a placebo. Subgroup analyses were performed between 40 NPC and 43 OC patients. It was found that patients with OC in the control group developed Grade 2 and Grade 3 mucositis sooner than those in the experimental group. However, the benefits were not found to extend to patients with NPC. The results indicated that zinc supplementation prescribed in conjunction with radiotherapy postponed the development of severe mucositis solely for patients with OC. The pretreatment oral mucosa condition and areca chewing habit might account for such discrepancy.

Areca-nut extract modulates antigen-specific immunity and augments inflammation in ovalbumin-sensitized mice

Areca-nut chewing has been linked to oral cancer and many other diseases, in which immune deterioration and tissue inflammation are plausibly involved. Recent studies reported that areca-nut extract (ANE) affected the functionality of lymphocytes and neutrophils in vitro. In the present study, we investigated the immunomodulatory effect of ANE in vivo. Ovalbumin (OVA)-sensitized mice were daily administered with ANE (5-50 mg/kg) for 10 doses by intraperitoneal injection from days 1 to 5 and from 8 to 12. The mice were systemically sensitized with OVA on day 3, and their footpads were challenged with OVA to induce delayed-type hypersensitivity (DTH) reactions on day 13. The serum level of OVA-specific IgM and IgG(1) was significantly attenuated by 5 and 25 mg/kg of ANE, whereas OVA-specific IgG(2a) was markedly enhanced by 50 mg/kg of ANE. The production of interferon (IFN)-γ by splenocytes reexposed to OVA in culture was markedly augmented by ANE (25 and 50 mg/kg). In addition, ANE (25 and 50 mg/kg) demonstrated an enhancing effect on DTH reactions, including the tissue swelling, the infiltration of CD3(+) and F4/80(+) cells, and the expression of IFN-γ and tumor necrosis factor (TNF)-α in the footpads challenged with OVA. The phagocytic activity and TNF-α production by the splenic CD11b(+) cells were also enhanced in ANE-treated groups. Taken together, these results demonstrated that ANE modulated antigen-specific immune responses and promoted inflammatory reactions in vivo, which may contribute to immune deregulation associated with areca-related diseases.