Phytohormones and candidate genes synergistically regulate fruitlet abscission in Areca catechu L.

BACKGROUND: The fruit population of most plants is under the control of a process named "physiological drop" to selectively abort some developing fruitlets. However, frequent fruitlet abscission severely restricts the yield of Areca catechu. To reveal the physiological and molecular variations in this process, we detected the variation of phytohormone levels in abscised and non-abscised fruitlets in A. catechu. RESULTS: The levels of gibberellin acid, jasmonic acid, salicylic acid, abscisic acid and zeatin were elevated, while the indole-3-acetic acid and indole-3-carboxaldehyde levels were declined in the "about-to-abscise" part (AB) of abscission zone (AZ) compared to the "non-abscised" part (CK). Then the differentially expressed genes (DEGs) between AB and CK were screened based on transcriptome data. DEGs involved in phytohormone synthesis, response and transportation were identified as key genes. Genes related to cell wall biosynthesis, degradation, loosening and modification, and critical processes during fruit abscission were identified as role players. In addition, genes encoding transcription factors, such as NAC, ERF, WRKY, MADS and Zinc Finger proteins, showed differentially expressed patterns between AB and CK, were also identified as candidates. CONCLUSIONS: These results unraveled a phytohormone signaling cross talk and key genes involved in the fruitlet abscission process in A. catechu. This study not only provides a theoretical basis for fruitlet abscission in A. catechu, but also identified many candidate genes or potential molecular markers for further breeding of fruit trees.

Fat mass and obesity-associated protein regulates arecoline-exposed oral cancer immune response through programmed cell death-ligand 1.

The high prevalence of oral squamous cell carcinoma (OSCC) in South Asia is associated with habitual areca nut chewing. Arecoline, a primary active carcinogen within areca nut extract, is known to promote OSCC pathological development. Dysregulation of N6-methyladenosine (m6A) modification has begun to emerge as a significant contributor to cancer development and progression. However, the biological effects and molecular mechanisms of m6A modification in arecoline-promoted OSCC malignance remain elusive. We reveal that chronic arecoline exposure substantially induces upregulation of fat mass and obesity-associated protein (FTO), MYC, and programmed cell death-ligand 1 (PD-L1) in OSCC cells. Moreover, upregulation of PD-L1 is observed in OSCC cell lines and tissues and is associated with areca nut chewing in OSCC patients. We also demonstrate that arecoline-induced FTO promotes the stability and expression levels of PD-L1 transcripts through mediating m6A modification and MYC activity, respectively. PD-L1 upregulation confers superior cell proliferation, migration, and resistance to T-cell killing to OSCC cells. Blockage of PD-L1 by administration of anti-PD-L1 antibody shrinks tumor size and improves mouse survival by elevating T-cell-mediated tumor cell killing. Therefore, targeting PD-L1 might be a potential therapeutic strategy for treating PD-L1-positive OSCC patients, especially those with habitual areca nut chewing.

Effects of chemical pretreatments on material solubilization of Areca catechu L. husk: Digestion, biodegradability, and kinetic studies for biogas yield.

This study aimed to understand the pretreatment-aided anaerobic digestion of lignocellulosic residues and to assess the substrate solubilization capacity of pretreatment processes. We evaluated the feasibility of biogas production using chemically pretreated Areca catechu L. (Arecanut husk, AH). AH was pretreated for 24h at two different temperatures-25 °C and 90 °C with four different chemicals viz. H2SO4 (acidic), NaOH (alkaline), H2O2 (oxidative), and ethanol in 1% H2SO4 (organosolv) under each temperature. AH solubilization assessment included analyses of parameters such as volatile solids to total solids (VS:TS) ratio, soluble chemical oxygen demand, total phenolic content, and biomass composition. Alkaline pretreatment of AH at 90 °C resulted in the maximum biogas yield of 683.89mL/gVS, which was 2.3 times more than that obtained using raw AH without pretreatment. Methane content of biogas produced using AH pretreated with 2-10% of NaOH was found to be between 71.53% and 75.06%; methane content of biogas using raw AH was 62.31%. In order to describe the AH degradation patterns, biogas production potential from pretreated AH was evaluated using bacterial kinetic growth models (First-order exponential, logistic, transference, and modified Gompertz models). The modified Gompertz and logistic models (correlation coefficient >0.99) were found to have the best fit of all kinetic models for the cumulative experimental biogas curve. We formulated a multiple linear regression equation depicting the biodegradability index (BI) as a technical tool to determine biomethane production; BI is represented as a function of biomass composition (cellulose, hemicellulose, and lignin), with a high correlation (>0.95). Based on our analyses of AH pretreatment and substrate utilization for biogas production, we propose that the biochemical composition of lignocellulosic residues should be carefully considered to ensure their biodegradability when subjected to anaerobic digestion.

18 F-2-fluoro-2-deoxy-D-glucose-positron emission tomography metabolic pattern assessment in the brain of betel quid dependent individuals.

The primary objective of this study was to identify the metabolic pattern in the brains of betel quid dependent (BQD) individuals using 18 F-2-fluoro-2-deoxy-D-glucose-positron emission tomography (18 F-FDG-PET). A total of 42 individuals (16 BQD individuals and 26 healthy controls, HCs) enrolled at the Department of Nuclear Medicine of Xiangya Hospital underwent brain 18 F-FDG-PET. Group comparisons using statistical parametric mapping (SPM) were performed to identify the 18 F-FDG-PET patterns. Standardized uptake value ratios of anterior cingulate, frontal, thalamus, parietal, occipital, temporal and cerebellum were calculated by SPM. The characteristics of abnormal metabolism in brain regions were quantified using the xjView toolbox, and a 3-D brain map was drawn using BrainNet Viewer. We found significant metabolic reduction in the bilateral middle prefrontal cortex (PFC) and the left orbital frontal gyrus (OFC). In contrast, hypermetabolism was observed in the inferior cerebellum, fusiform, superior cerebellum, parahippocampal, vermis, lingual and thalamus. However, we found no significant difference between the BQD and HC group in the anterior cingulate, thalamus, cerebellum and frontal, temporal, parietal and occipital lobes. In summary, we found abnormal 18 F-FDG-PET metabolic pattern in BQD individuals, and this pattern may help the treatment of BQD.

Identification, Characterization and Antihypertensive Effect In Vivo of a Novel ACE-Inhibitory Heptapeptide from Defatted Areca Nut Kernel Globulin Hydrolysates.

The areca (Areca catechu L.) nut kernel (ANK) is a good potential protein source for its high protein content of 9.89-14.62 g/100 g and a high yield of around 300,000 tons per year in China. However, utilization of the areca nut kernel is limited. To expand the usage of ANK in pharmaceutical or foods industries, areca nut kernel globulin was extracted and angiotensin-I converting enzyme (ACE) inhibition peptides were prepared and identified using gel chromatography, reversed phase HPLC separation, UPLC-ESI-MS/MS analysis and in silico screening. Finally, a novel ACE-inhibitory heptapeptide (Ala-Pro-Lys-Ile-Glu-Glu-Val) was identified and chemically synthesized. The combination pattern between APKIEEV and ACE, and the inhibition kinetics, antihypertensive effect and endothlein-1 inhibition activity of APKIEEV were studied. The results of the molecular docking demonstrated that APKIEEV could bind to four active sites (not the key active sites) of ACE via short hydrogen bonds and demonstrated high ACE-inhibitory activity (IC50: 550.41 µmol/L). Moreover, APKIEEV exhibited a significantly lowering effect on both the systolic blood pressure and diastolic blood pressure of spontaneously hypertensive rats, and had considerable suppression ability on intracellular endothelin-1. These results highlight the potential usage of APKIEEV as ingredients of antihypertensive drugs or functional foods.

Tissue-specific and maturity-dependent distribution of pyridine alkaloids in Areca triandra.

Areca nuts (seeds of Areca catechu L.) are a traditional and popular masticatory in India, Bangladesh, Malaysia, certain parts of China, and some other countries. Four related pyridine alkaloids (arecoline, arecaidine, guvacoline, and guvacine) are considered being the main functional ingredients in areca nut. Until now, A. catechu is the only known species producing these alkaloids in the Arecaceae family. In the present study, we investigated alkaloid contents in 12 Arecaceae species and found that only Areca triandra Roxb. contained these pyridine alkaloids. We further analyzed in more detail tissue-specific and development-related distribution of these alkaloids in leaves, male and female flowers and fruits in different stages of maturity in A. triandra by ultra-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry. Results revealed that the alkaloids were most abundant in young leaves, the pericarp of ripe fruits and the endosperm of unripe fruits in developmental stage 2. Abundance of the 4 different alkaloids in A. triandra fruits varied during maturation. Pericarps of ripe fruits had the highest arecaidine concentration (4.45 mg g-1) and the lowest guvacoline concentration (0.0175 mg g-1), whereas the endosperm of unripe fruits of developmental stage 2 contained the highest guvacoline concentration (3.39 mg g-1) and the lowest guvacine concentration (0.245 mg g-1). We conclude that A. triandra is useful in future as a further valuable source of Areca alkaloids.

Cortactin is a prognostic marker for oral squamous cell carcinoma and its overexpression is involved in oral carcinogenesis.

EMS1 (chromosome eleven, band q13, mammary tumor and squamous cell carcinoma-associated gene 1) gene amplification and the concomitant cortactin overexpression have been reported to associate with poor prognosis and tumor metastasis. In this study, we examined cortactin expression by immunohistochemistry in human oral tumors and murine tongue tumors which were induced by the carcinogen 4-nitroquinoline 1-oxide (4-NQO). The immunostaining results show over- to moderate expression of cortactin in 85% (104/122) of oral squamous cell carcinoma (OSCC) tissues and in all 15 leukoplakia tissues examined. Further, statistical analysis indicates that cortactin overexpression appears to be a predictor for shorter survival and poorer prognosis in OSCC patients. In an animal model, cortactin is shown to upregulate in infiltrating squamous cell carcinoma, papilloma, and epithelia with squamous hyperplasia, indicating that cortactin induction is an early event during oral carcinogenesis. It is suggested that cortactin expression is mediated in the progression of pre-malignancy to papilloma, based on earlier cortactin induction in pre-malignancy preceding cyclin D1 in papilloma. In conclusion, cortactin overexpression is frequently observed in human OSCC and mouse tongue tumors. Thus, cortactin may have an important role in the development of oral tumors in human and mice. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 799-812, 2017.

A conjugate vaccine strategy that induces protective immunity against arecoline.

Betel-quid chewing addiction is the leading cause of oral submucous fibrosis and oral cancer, resulting in significant socio-economic burdens. Vaccination may serve as a promising potential remedy to mitigate the abuse and combat accidental overdose of betel nut. Hapten design is the crucial factor to the development of arecoline vaccine that determines the efficacy of a candidate vaccine. Herein, we reported that two kinds of novel arecoline-based haptens were synthesized and conjugated to Bovine Serum Albumin (BSA) to generate immunogens, which generated antibodies with high affinity for arecoline but reduced binding for guvacoline and no affinity for arecaidine or guvacine. Notably, vaccination with Arec-N-BSA, which via the N-position on the tetrahydropyridine ring (tertiary amine group), led to a higher antibody affinity compared to Arec-CONH-BSA, blunted analgesia and attenuated hypothermia for arecoline.

Gene co-expression network analysis in areca floral organ and the potential role of the AcMADS17 and AcMADS23 in transgenic Arabidopsis.

Areca catechu L., a monocot belonging to the palm family, is monoecious, with female and male flowers separately distributed on the same inflorescence. To discover the molecular mechanism of flower development in Areca, we sequenced different floral samples to generate tissue-specific transcriptomic profiles. We conducted a comparative analysis of the transcriptomic profiles of apical sections of the inflorescence with male flowers and the basal section of the inflorescence with female flowers. Based on the RNA sequencing dataset, we applied weighted gene co-expression network analysis (WGCNA) to identify sepal, petal, stamen, stigma and other specific modules as well as hub genes involved in specific floral organ development. The syntenic and expression patterns of AcMADS-box genes were analyzed in detail. Furthermore, we analyzed the open chromatin regions and transcription factor PI binding sites in male and female flowers by assay for transposase-accessible chromatin sequencing (ATAC-seq) assay. Heterologous expression revealed the important role of AcMADS17 and AcMADS23 in floral organ development. Our results provide a valuable genomic resource for the functional analysis of floral organ development in Areca.

Areca catechu L. ameliorates chronic unpredictable mild stress-induced depression behavior in rats by the promotion of the BDNF signaling pathway.

OBJECTIVES: In this study, we have investigated the anti-depressant effects of the fruit Areca catechu L. (ACL) and elucidated its potential underlying mechanism using a rat model of chronic unpredictable mild stress (CUMS). METHODS: CUMS was induced in rats to establish a depression animal model for 28 days. According to the baseline sucrose preference, the male rats were divided into 6 different groups. They were treated with paroxetine hydrochloride, ACL, and water once a day until the behavioral tests were performed. The levels of corticosterone (CORT), malondialdehyde (MDA), catalase (CAT), and total superoxide dismutase (T-SOD) in serum were detected using a commercial kit, and the concentrations of 5-hydroxytryptamine (5-HT) and dopamine (DA) monoamine neurotransmitters in the brain tissues were detected by liquid chromatography-tandem mass spectrometry. doublecortin (DCX) expression in the hippocampal dentate gyrus (DG) was determined by immunofluorescence, and the relative abundance of brain-derived neurotrophic factor (BDNF), TrkB, PI3K, p-AKT/AKT, PSD-95, and p-GSK-3ß/GSK-3ß of brain tissues were assayed by western blot. RESULTS: ACL markedly increased sucrose preference, decreased the immobility time, and shortened the feeding latency of CUMS-induced rats. CUMS induction resulted in marked changes in the contents of the monoamine neurotransmitters (5-HT and DA) in the hippocampus and cortex of brain tissues and the levels of CORT, MDA, CAT, and T-SOD in serum, whereas ACL administration alleviated these considerable changes. ACL promoted DCX expression in DG and increased the protein levels of BDNF, TrkB, PI3K, p-AKT/AKT, PSD-95, and p-GSK-3ß/GSK-3ß in the brains of CUMS-induced rats. CONCLUSIONS: Our results indicated that ACL may improve depression-like behaviors in CUMS-induced rats by decreasing the hyperfunction and oxidative stress of the hypothalamic-pituitary-adrenal axis, stimulating hippocampal neurogenesis, and activating the BDNF signaling pathway.

Comparison of the psychoactive activity of four primary Areca nut alkaloids in zebrafish by behavioral approach and molecular docking.

Areca palm nut (Areca catechu) has been listed as one of the most addictive substances, along with tobacco, alcohol, and caffeine. It belongs to the family Arecaceae and is widely used in Asia. Areca nut contains seven psychoactive alkaloids; however, the effects of these alkaloids on behaviors are rarely to be addressed in zebrafish. Therefore, this study aims to compare the psychoactive and potential adverse effects of four primary alkaloids (arecoline, arecaidine, guvacine, and guvacoline) isolated from areca nut on zebrafish. We found that four alkaloids induced hyperactivity-like behaviors in zebrafish larvae. Cooperating the results with the previous study, molecular docking scores suggested these alkaloids might bind to multiple muscarinic acetylcholine receptors (mAChRs), and various best binding modes were shown. According to the adult zebrafish behavioral test, arecoline was found to slightly increase the locomotor activity and caused tightening shoaling formations of adult zebrafish. Meanwhile, zebrafish exposed to arecaidine have reduced aggressiveness and conspecific social interaction. Similar to arecaidine, guvacoline treatment also caused abnormalities in zebrafish social behaviors. Furthermore, the fish displayed abnormal exploratory behaviors after being exposed to guvacoline. Interestingly, altered fear response behaviors were only displayed by guvacine-treated fish besides their lower locomotor activity. Based on the results of molecular docking, we hypothesize that the behavior alterations might be a consequence of the interaction between alkaloids and multiple mAChRs in the nervous system. In summary, our study found that each alkaloid specifically affects adult zebrafish behaviors.

Genome-wide investigation of ZINC-IRON PERMEASE (ZIP) genes in Areca catechu and potential roles of ZIPs in Fe and Zn uptake and transport.

Iron (Fe) and Zinc (Zn) are essential nutrient elements for plant growth and development. Here, we observed the effects of Fe and Zn deficiency in seedlings of Areca catechu L. (areca palm), one of the most cultured palm trees in tropic regions. Results revealed that Fe deficiency causes strong chlorosis with the significantly decreased chlorophyll biosynthesis level and photosynthetic activities in the top third young leaf (L3) of seedlings. Zn deficiency caused light chlorosis in all three young leaves which slightly decreased chlorophyll biosynthesis and photosynthetic activities. Analysis of the Fe and Zn concentration in leaves and roots indicated that absorption and distribution of these two ions share cooperative pathways, since Zn deficiency caused Fe increasing, and vice versa. Therefore, we focused on the ZINC-IRON PERMEASE (ZIP) genes in areca trees. From the whole-genome data set we obtained, 6 ZIP genes were classified, and a phylogenetic tree was constructed with other 38 ZIP genes from model plants to find their potential functions. We also analyzed the expression pattern of AcZIP1-6 genes under Zn and Fe deficiency by transcriptomic approaches. With these results, we constructed an expression atlas of AcZIP1-6 genes in leaves and roots of areca seedlings with the dynamic expression levels under Fe and Zn deficient conditions. In conclusion, we provide evidence to understand the absorption and transport of nutrient elements, Fe and Zn, in the tropic agricultural plant A. catechu.

Effect of chewing betel nut on the gut microbiota of Hainanese.

Betel nut chewing (BNC) is prevalent in South Asia and Southeast Asia. BNC can affect host health by modulating the gut microbiota. The aim of this study is to evaluate the effect of BNC on the gut microbiota of the host. Feces samples were obtained from 34 BNC individuals from Ledong and Lingshui, Hainan, China. The microbiota was analyzed by 16S rRNA gene sequencing. BNC decreased the microbial α-diversity. Firmicutes, Bacteroidetes, Actinobacteria, and Proteobacteria were the predominant phyla, accounting for 99.35% of the BNC group. The Firmicutes-to-Bacteroidetes ratio was significantly increased in the BNC group compared to a control group. The abundances of the families Aerococcaceae, Neisseriaceae, Moraxellaceae, Porphyromonadaceae, and Planococcaceae were decreased in the BNC/BNC_Male/BNC_Female groups compared to the control group, whereas the abundances of Coriobacteriaceae, Streptococcaceae, Micrococcaceae, Xanthomonadaceae, Coxiellaceae, Nocardioidaceae, Rhodobacteraceae, and Succinivibrionaceae were increased. In general, the gut microbiome profiles suggest that BNC may have positive effects, such as an increase in the abundance of beneficial microbes and a reduction in the abundance of disease-related microbes. However, BNC may also produce an increase in the abundance of disease-related microbes. Therefore, extraction of prebiotic components could increase the beneficial value of betel nut.

Tobacco Smoking and Association between Betel Nut Chewing and Metabolic Abnormalities Among Military Males: The CHIEF Study.

AIM: To investigate the effect of smoking and alcohol intake on the association between betel nut chewing and each metabolic abnormality. BACKGROUND: Betel nut chewing has been associated with metabolic syndrome. OBJECTIVE: Whether the association is affected by tobacco or alcohol use is not clarified so far. METHODS: The authors conducted a cross-sectional study using 6,657 military males, aged 18-50 years in eastern Taiwan in 2013-2014. Metabolic syndrome was defined according to the International Diabetes Federation's ethnic criteria for Asians. The population was classified as non-betel nut chewers (N =5,749), current chewers with both tobacco and alcohol use (N =615), and current chewers without tobacco and/or alcohol use (N =293). Multiple logistic regression analyses were stepwise adjusted for the confounders including alcohol and tobacco use to determine the association of betel chewing with the metabolic abnormalities. RESULTS: As compared to the non-current chewers, the current chewers with both tobacco/alcohol use and those without had a higher risk of metabolic syndrome (odds ratios (OR) and 95% confidence intervals: 2.46 (2.00-3.02), and 2.04 (1.53-2.73), respectively) after controlling for age, service specialty, total cholesterol levels ≥200 mg/dL and exercise frequency (model 1). The association did not change much in the two chewing groups after additionally adjusting for alcohol consumption (model 2) (OR: 2.49 (1.99-3.12), and 2.04 (1.52-2.73), respectively), whereas the relationship reduced significantly in the chewers with both tobacco/alcohol use rather than those without after further adjusting for smoking (model 3) (OR: 2.18 (1.71-2.78) and 2.02 (1.51-2.71), respectively). This was in parallel with the pattern for the association of betel nut chewing with serum triglycerides >150 mg/dL in the chewers with both tobacco/alcohol use and those without in model 1 (OR: 2.90 (2.40-3.51) and 1.90 (1.45-2.49), respectively, p =0.011), in model 2 (OR: 2.82 (2.30-3.46) and 1.89 (1.44-2.49), respectively, p =0.040), and in model 3 (2.26 (1.81-2.81) and 1.87 (1.42-2.45), respectively, p =0.76). CONCLUSION: Our findings suggest that tobacco smoking but not alcohol intake could increase the relationship of betel nut chewing with metabolic syndrome, which is likely mediated by a synergic effect on increasing serum triglycerides levels.

Is the blood donated by habitual nut quid chewers suitable for use in transfusion?

BACKGROUND/PURPOSE: Betel quid (BQ) chewing is a popular oral masticatory activity, and there are approximately 600 million BQ chewers worldwide. Although chewing BQ has been linked to the patho-genesis of oral cancer, leukoplakia, and oral submucous fibrosis. The question whether the mixed constituents present in areca nut, which may exert cytotoxic effects on red blood cells (RBCs), has never been addressed. METHODS: Heparinized blood specimens were obtained with informed consent from healthy laboratory personnel. RBCs were separated with the standard procedure and adjusted to 10% hematocrit with PBS. Various concentrations of areca nut extract (ANE; 100-800 microg/mL) were added to these RBC preparations and incubated at 37 degrees C for 4 hours. Two portions (0.4 mL each) of the incubated RBCs were then used for measuring osmotic deformability index and for observing RBC morphology with scanning electron microscopy. The remaining RBCs were used for determining membrane sulfhydryl groups and protein profiles by sodium dodecyl sulfate polyacrylamide gel electrophoresis. RESULTS: Blood incubated with various concentrations of ANE showed concentration-dependent decreases in osmotic deformability index and membrane sulfhydryl groups. Membrane protein profiles revealed a significant loss of the band 3 fraction, with the concomitant appearance of several new protein bands in the electropheretogram. Finally, drastic morphological changes of ANE-treated RBCs were observed. CONCLUSION: We suggest that to assure the quality of transfusion, the blood donated by a habitual BQ chewer should be used with caution because of its possible contamination with areca nut ingredients that may be cytotoxic to RBCs.

Melatonin as an inducer of arecoline and their coordinated roles in anti-oxidative activity and immune responses.

Arecoline is one of the main medicinal constituents in areca. Melatonin is an amine molecule with multiple functions in plants and animals. However, the interaction between arecoline and melatonin remains unknown. Herein, metabolomics analysis showed that multiple metabolites including arecoline were induced in areca by exogenous melatonin. In vitro assay demonstrated that the induced arecoline had strong antioxidant capacities, being similar to the traditional function of melatonin. Both arecoline and melatonin could significantly improve plant disease resistance against Colletotrichum kahawae and delay post-harvest physiological deterioration (PPD) of areca fruits, through modulation of the levels of jasmonic acid (JA), salicylic acid (SA), ethylene (ETH) and abscisic acid (ABA), reactive oxygen species (ROS) level as well as glycolytic activity. In addition, animal and cell assays indicated that arecoline and melatonin could commonly enhance anti-inflammatory effects through regulating ROS and hypoxia inducible factor-1α (HIF-1α). Taken together, melatonin could serve as an inducer of arecoline and they show coordinated roles in antioxidative activity and immune responses in areca and animals. This study greatly extends the knowledge of the action of melatonin in areca and animals.

Glutathione S-transferasesP1 AA (105Ile) allele increases oral cancer risk, interacts strongly with c-Jun Kinase and weakly detoxifies areca-nut metabolites.

The Glutathione S-transferases (GSTs) protects cellular DNA against oxidative damage. The role of GSTP1 polymorphism (A313G; Ile105Val) as a susceptibility factor in oral cancer was evaluated in a hospital-based case-control study in North-East India, because the habit of chewing raw areca-nut (RAN) with/without tobacco is common in this region. Genetic polymorphism was investigated by genotyping 445 cases and 444 controls. Individuals with the GSTP1 AA-genotype showed association with the oral cancer (OR = 3.1, 95% CI = 2.4-4.2, p = 0.0002). Even after adjusting for age, sex and habit the AA-genotype is found to be significantly associated with oral cancer (OR = 2.4, 95% CI = 1.7-3.2, p = 0.0001). A protein-protein docking analysis demonstrated that in the GG-genotype the binding geometry between c-Jun Kinase and GSTP1 was disrupted. It was validated by immunohistochemistry in human samples, showing lower c-Jun-phosphorylation and down-regulation of pro-apoptotic genes in normal oral epithelial cells with the AA-genotype. In silico docking revealed that AA-genotype weakly detoxifies the RAN/tobacco metabolites. In addition, experiments revealed a higher level of 8-Oxo-2'-deoxyguanosine induction in tumor samples with the AA-genotype. Thus, habit of using RAN/tobacco and GSTP1 AA-genotype together play a significant role in predisposition to oral cancer risk by showing higher DNA-lesions and lower c-Jun phosphorylation that may inhibit apoptosis.

Influence of betel quid on effect of calcium channel blockers on isoprenaline induced myocardial necrosis in mice.

It is known that chewing Betel quid with tobacco (BQT) or without tobacco (BQ) is a major etiological factor for cardiovascular complications and calcium channel blockers (CCBs) are the major class of drugs prescribed widely for myocardial disturbances. The possible pharmacodynamic interaction between CCBs (verapamil, amlodipine and diltiazem) and BQ/BQT was studied on isoproterenol (ISO)-induced myocardial necrosis in mice. Influence of (CCBs) therapy on pretreated animals at times of myocardial stress were determined by estimating diagnostic marker enzymes such as lactate dehydrogenase (LDH) and creatine phosphokinase isoenzyme (CK-MB) in serum and heart tissue homogenate (HTH). Administration of CCBs to mice pretreated with BQ produced a significant decrease and increase in biomarker enzyme levels in serum and HTH respectively. Further, incorporation of diltiazem and amlodipine in BQT pretreated mice significantly elevated enzyme levels in HTH, whereas, amlodipine administration during BQT treatment showed significant fall in enzyme levels in serum. The results indicated that BQT is cardiotoxic and its effect cannot be reversed using CCBs while BQ is cardioprotective, whose activity was further augmented by amlodipine. Histopathological studies confirmed the biochemical findings.

The effects of an indigenous muscarinic drug, Betel nut (Areca catechu), on the symptoms of schizophrenia: a longitudinal study in Palau, Micronesia.

OBJECTIVE: This study tested the findings of a prior study indicating a therapeutic relationship between consumption of betel nut and symptoms of schizophrenia. METHOD: The subjects were 65 outpatients with diagnoses of schizophrenia or schizoaffective disorder. Symptoms rated with the Positive and Negative Syndrome Scale were compared between high- and low-consumption betel chewers in a repeated-measures design. Movement disorders were assessed with the Abnormal Involuntary Movement Scale and Simpson-Angus Rating Scale. Global health and social functioning were assessed with the Medical Outcomes Study 12-item and 36-item Short-Form Health Surveys, respectively. RESULTS: Male high-consumption betel chewers had significantly milder positive symptoms than low-consumption chewers over 1 year. Betel chewing was not associated with global health, social functioning, or movement disorders. Betel chewing was associated with tobacco use but not with cannabis or alcohol. CONCLUSIONS: These findings have clinical significance in betel-chewing regions and broader implications for theory of muscarinic neurophysiology in schizophrenia.

Betel nut chewing associated with increased risk of arterial stiffness.

BACKGROUND: Betel nut chewing is associated with certain cardiovascular outcomes. Subclinical atherosclerosis may be one link between betel nut chewing and cardiovascular risk. Few studies have examined the association between chewing betel nut and arterial stiffness. The aim of this study was thus to determine the relationship between betel nut chewing and arterial stiffness in a Taiwanese population. METHODS: We enrolled 7540 eligible subjects in National Cheng Kung University Hospital from October 2006 to August 2009. The exclusion criteria included history of cerebrovascular events, coronary artery disease, and taking lipid-lowering drugs, antihypertensives, and hypoglycemic agents. Increased arterial stiffness was defined as brachial-ankle pulse wave velocity (baPWV) ≥1400cm/s. According to their habit of betel nut use, the subjects were categorized into non-, ex-, and current chewers. RESULTS: The prevalence of increased arterial stiffness was 32.7, 43.3, and 43.2% in non-, ex- and current chewers, respectively (p=0.011). Multiple logistic regression analysis revealed that ex-chewers (odds ratio [OR] 1.69, 95% confidence interval (CI)=1.08-2.65) and current chewers (OR 2.29, 95% CI=1.05-4.99) had elevated risks of increased arterial stiffness after adjustment for co-variables. CONCLUSIONS: Both ex- and current betel nut chewing were associated with a higher risk of increased arterial stiffness. Stopping betel nut chewing may thus potentially be beneficial to reduce cardiovascular risk, based on the principals of preventive medicine.