Effects of Smokeless Tobacco Samples from Tabuk Saudi Arabia on Nitric Oxide Production: A Potential Risk for Cancer and Cardiovascular Diseases.

BACKGROUND: Smokeless tobacco (SLT) is traditionally used in Middle East countries. The several toxic constituents with potential carcinogenicity make it a serious human health risk. Literature regarding their effects on cardiac and cancer disease is lacking in Saudi Arabia. OBJECTIVE: This study was conducted to investigate the adverse effect of 11 different samples of widely used SLT varieties from the Tabuk region - Saudi Arabia, on Nitric Oxide (NO) level and their potential risk on cardiovascular health, etiology and/or progression of cancers. METHODS: Samples were collected from Tabuk, KSA and analyzed by the GC-MS technique. Nitric oxide inhibition was performed using J774.2 macrophages by the Griess method. The retrieved crystallized structure of human inducible nitric oxide synthase (iNOS) from Brookhaven Protein Data Bank Repository PDB I.D: 3E7G with 2.20Å resolution was further prepared by structure using the MOE.2019 tool. The compounds abstracted from 11 different Shammah varieties were sketched by the MOE-Builder tool. Minimization for both receptor and compounds was performed via AMBER99 and MMFF99X force field implemented in MOE. RESULTS: Nine samples (4 - 11) showed a potent suppressive effect on NO production with IC50 values ranging between (16.9-20.4 µg/mL), respectively. The samples (1 & 2) exhibited a moderate level of inhibition with IC50 ranging between 33.2 and 57.4 µg/mL, respectively. Interestingly, sample 4 consisting of compounds (13-15, 19-26, 28) that mostly belongs to the group fatty acid ester and phthalic acid ester showed the most potent suppressive effect. Molecular docking results revealed that the current local SLT constituents presented noticeable potency in different extract samples. CONCLUSION: Variable suppressive effects on NO were detected in the current SLT samples, where sample 4 was the most potent among all. The extract of the latter exhibited molecular interaction with the first shell amino acid residues of Inducible nitric oxide synthase (iNOS), which may anchor the plasticity and selectivity of the compounds present in it. The samples (4 -11) showed a potent inhibitory effect on the NO, where compound 26 (Phthalic acid ester) is common, and its adequate concentration may account for augmented biological activity. These results may effectively highlight their adverse effects on cardiovascular health and etiology and/or progression of cancer and may help in strengthening the social and governmental efforts in minimizing the use of these substances.

Knowledge, attitudes and practices of South Asian immigrants in developed countries regarding oral cancer: an integrative review.

BACKGROUND: Oral cancer is a growing problem worldwide, with high incidence rates in South Asian countries. With increasing numbers of South Asian immigrants in developed countries, a possible rise in oral cancer cases is expected given the high prevalence in their source countries and the continued oral cancer risk behaviours of immigrants. The aim of this review is to synthesise existing evidence regarding knowledge, attitudes and practices of South Asian immigrants in developed countries regarding oral cancer. METHODS: Five electronic databases were systematically searched to identify original, English language articles focussing on oral cancer risk knowledge, attitudes and practices of South Asian immigrants in developed countries. All studies that met the following inclusion criteria were included: conducted among South Asian immigrants in developed countries; explored at least one study outcome (knowledge or attitudes or practices); used either qualitative, quantitative or mixed methods. No restrictions were placed on the publication date, quality and setting of the study. RESULTS: A total of 16 studies involving 4772 participants were reviewed. These studies were mainly conducted in the USA, UK, Italy and New Zealand between 1994 and 2018. Findings were categorised into themes of oral cancer knowledge, attitudes and practices. General lack of oral cancer risk knowledge (43-76%) among participants was reported. More than 50% people were found engaging in one or more oral cancer risk practices like smoking, betel quid/pan/gutka chewing. Some of the participants perceived betel quid/pan/gutka chewing habit good for their health (12-43.6%). CONCLUSION: This review has shown that oral cancer risk practices are prevalent among South Asian immigrants who possess limited knowledge and unfavourable attitude in this area. Culturally appropriate targeted interventions and strategies are needed to raise oral cancer awareness among South Asian communities in developed countries.

Chronic Exposure to Chewing Tobacco Induces Metabolic Reprogramming and Cancer Stem Cell-Like Properties in Esophageal Epithelial Cells.

Tobacco in its smoke and smokeless form are major risk factors for esophageal squamous cell carcinoma (ESCC). However, molecular alterations associated with smokeless tobacco exposure are poorly understood. In the Indian subcontinent, tobacco is predominantly consumed in chewing form. An understanding of molecular alterations associated with chewing tobacco exposure is vital for identifying molecular markers and potential targets. We developed an in vitro cellular model by exposing non-transformed esophageal epithelial cells to chewing tobacco over an eight-month period. Chronic exposure to chewing tobacco led to increase in cell proliferation, invasive ability and anchorage independent growth, indicating cell transformation. Molecular alterations associated with chewing tobacco exposure were characterized by carrying out exome sequencing and quantitative proteomic profiling of parental cells and chewing tobacco exposed cells. Quantitative proteomic analysis revealed increased expression of cancer stem cell markers in tobacco treated cells. In addition, tobacco exposed cells showed the Oxidative Phosphorylation (OXPHOS) phenotype with decreased expression of enzymes associated with glycolytic pathway and increased expression of a large number of mitochondrial proteins involved in electron transport chain as well as enzymes of the tricarboxylic acid (TCA) cycle. Electron micrographs revealed increase in number and size of mitochondria. Based on these observations, we propose that chronic exposure of esophageal epithelial cells to tobacco leads to cancer stem cell-like phenotype. These cells show the characteristic OXPHOS phenotype, which can be potentially targeted as a therapeutic strategy.

Assessment of a 72-hour repeated exposure to Swedish snus extract and total particulate matter from 3R4F cigarette smoke on gingival organotypic cultures.

Swedish snus is a smokeless tobacco product that contains reduced levels of harmful compounds compared with cigarette smoke. In Sweden, where snus use exceeds smoking among men, relatively low rates of major smoking-related diseases have been recorded. To better understand how snus use could align with current tobacco harm reduction strategies, its potential mechanisms of toxicity must be investigated. This study aimed to determine, via a systems toxicology approach, the biological impact of repeated 72-hour exposure of human gingival epithelial organotypic cultures to extracts from both a commercial and a reference snus and the total particulate matter (TPM) from cigarette smoke. At concentrations relevant for human use, cultures treated with snus extracts induced mild, generally reversible biological changes, while TPM treatment induced substantial morphological and inflammatory alterations. Network enrichment analysis and integrative analysis of the global mRNA and miRNA expression profiles indicated a limited and mostly transient impact of the snus extracts, in particular on xenobiotic metabolism, while the effects of TPM were marked and sustained over time. High-confidence miRNAs that might be related to pathological conditions in vivo were identified. This study highlights the limited biological impact of Swedish snus extract on human organotypic gingival cultures.

The Pituri Learning Circle: central Australian Aboriginal women's knowledge and practices around the use of Nicotiana spp. as a chewing tobacco.

INTRODUCTION: Tobacco smoking has a range of known and predictable adverse outcomes, and across the world sustained smoking reduction campaigns are targeted towards reducing individual and public risk and harm. Conversely, more than 87 million women, mostly in low- and middle-income countries, use smokeless tobacco, yet the research examining the effect of this form of tobacco exposure on women is remarkably scant. In central Australia, the chewing of wild Nicotiana spp., a tobacco plant, commonly known as pituri and mingkulpa, is practised by Aboriginal groups across a broad geographical area. Until recently, there had been no health research conducted on the effects of chewing pituri. METHODS: This article reports on one component of a multidimensional pituri research agenda. A narrative approach utilising the methodology of the Learning Circle was used to interview three key senior central Australian Aboriginal women representative of three large geographical language groupings. The participants were selected by a regional Aboriginal women's organisation. With the assistance of interpreters, a semistructured interview, and specific trigger resources, participants provided responses to enable an understanding of the women's ethnobotanical pituri knowledge and practices around the use of pituri within the context of Aboriginal women's lives. Data were transcribed, and by using a constant comparison analysis, emergent themes were categorised. The draft findings and manuscript were translated into the participants' language and validated by the participants. RESULTS: Three themes around pituri emerged: (a) the plants, preparation and use; (b) individual health and wellbeing; and (c) family and community connectedness. The findings demonstrated similar participant ethnobotanical knowledge and practices across the geographical area. The participants clearly articulated the ethnopharmacological knowledge associated with mixing pituri with wood ash to facilitate the extraction of nicotine from Nicotiana spp., the results of which were biochemically verified. The participants catalogued the pleasurable and desired effects obtained from pituri use, the miscellaneous uses of pituri, as well as the adverse effects of pituri overdose and toxicity, the catalogue of which matched those of nicotine. The participants' overarching pituri theme was related to the inherent role pituri has in the connectiveness of people to family, friends and community. CONCLUSIONS: Central Australian Aboriginal women have a firmly established knowledge and understanding of the pharmacological principles related to the content of Nicotiana spp. and the extraction of nicotine from the plant. Widespread use of Nicotiana spp. as a chewing tobacco by Aboriginal populations in the southern, central and western desert regions of Australia is attested to by participants who assert that everyone uses it, with girls in these remote areas commencing use between 5 and 7 years of age. Central Australian Aboriginal people who chew Nicotiana spp. do not consider it to be a tobacco plant, and will strongly refute that they are tobacco users. Central Australian Aboriginal people do not consider that the Western health information regarding tobacco (as a smoked product) is applicable or aligned to their use of pituri. Nicotiana spp. users will deny tobacco use at health assessment. There is a requirement to develop and provide health information on a broader range of tobacco and nicotine products in ways that are considered credible by the Aboriginal population. Health messages around pituri use need to account for the dominant role that pituri occupies in the context of central Australian Aboriginal women's lives.
Information for readers: A consultative organisation of Aboriginal women has as a strategic intent and operational agenda the improvement of Aboriginal women's and children's health across the research region. The group seeks opportunities to enhance their knowledge based on legitimate collaborative research; accordingly, they sought to participate in a range of research activities regarding the use of pituri and women's health outcomes. Of particular note, the group's participants chose to be identified by name in the publication of this research activity. In this article, the term 'Aboriginal' has been chosen by the central Australian women to refer to both themselves and the Aboriginal people in their communities; 'Indigenous' has been chosen to refer to the wider Australian Aboriginal and Torres Strait Islander people. The term Nicotiana spp. is used when referring to the plants from a Western perspective; pituri is used when referring to the plants, the tobacco quid, and the practice of chewing from a general Aboriginal perspective; and mingkulpa is used when the participants are voicing their specific knowledge and practices.

Head and neck cancers in India.

Head and neck cancers constitute a third of the cancer burden in India. These cancers have unique patient characteristics, presentation, and etiological differences from those in the West. Socioeconomic constraints, large patient population, scarcity of trained health workers, and inadequate infrastructure are major challenges faced in the management of these cancers. Despite these constraints, patients are treated with evidence based guidelines that are tailored to the local scenario.

Betel quid chewing alters functional connectivity in frontal and default networks: A resting-state fMRI study.

PURPOSE: To explore the acute effect of betel quid (BQ) use on functional network connectivity by comparing the global functional brain networks and their subsets before and immediately after BQ chewing. MATERIALS AND METHODS: Resting-state functional magnetic resonance imaging (fMRI) was performed in 27 healthy male participants before and just after chewing BQ on a 3.0T scanner with a gradient-echo echo planar imaging sequence. Independent component analysis (ICA) was used to determine components that represent the brain's functional networks and their spatial aspects of functional connectivity. A paired t-test was used for exploring the connectivity differences in each network before and after BQ chewing. RESULTS: Sixteen networks were identified by ICA. Nine of them showed connectivity differences before and after BQ chewing (P < 0.05 false discovery rate corrected): (A) orbitofrontal, (B) left frontoparietal, (C) visual, (D) right frontoparietal, (E) anterior default mode, (F) medial frontal/anterior cingulate (G) frontotemporal, (H) occipital/parietal, (I) occipital/temporal/cerebellum. Moreover, networks A, B, C, D, G, H, and I showed increased connectivity, while networks E and F showed decreased connectivity in participants after BQ chewing compared to before chewing. CONCLUSION: The acute effects of BQ use appear to actively alter functional connectivity of frontal and default networks that are known to play a key role in addictive behavior. LEVEL OF EVIDENCE: 2 J. Magn. Reson. Imaging 2017;45:157-166.

Smokeless tobacco (shammah) in Saudi Arabia: a review of its pattern of use, prevalence, and potential role in oral cancer.

BACKGROUND: Shammah is a traditional form of chewing tobacco [smokeless tobacco, (ST)] that is commonly used in the Middle East especially in Saudi Arabia (KSA), Yemen and Sudan. The Substance Abuse Research Centre (SARC) at Jazan University noted that no adequate research and information on the prevalence of shammah use in the province of Jazan, and KSA as well, has been provided in the scientific literature. MATERIALS AND METHODS: An intensive systematic review of online databases was performed, including AMED (The Allied and Complementary Medicine Database), Biological Abstracts, Cochrane Collection Plus, Dentistry and Oral Sciences Source, E-Journals Database, EBSCO Discovery Service, MEDLINE, PEMSoft, PEP Archive, PsycARTICLES, scopus, Sciencedirect and Google Scholar. RESULTS: Shammah is a mixture of powdered tobacco, lime, ash, black pepper, oils and flavorings. ST in KSA is placed in the buccal or lower labial vestibule of the mouth. The user (or dipper) spits out insoluble debris. The importation of ST products is prohibited in KSA. Accessible information on legislative action to control the use of ST in KSA appeared in 1990. The actual percentage use may be higher, than reported since shammah is illegal in KSA and there may be some reluctance to admit to its use. CONCLUSIONS: This review paper is an initial step in a funded research project by SARC to understand the pattern of use of shammah and provide adequate epidemiological data. One goal of this review is to generate further data for public health education.

Smokeless tobacco increases aneuploidy in oral HPV16 E6/E7-transformed keratinocytes in vitro.

BACKGROUND: The scope of this work was to study synergism between human papillomavirus (HPV) infection and tobacco in vitro, both known to be independent risk factors for oral cancer. METHODS: HPV-positive and HPV-negative oral keratinocytes and oral HPV-negative fibroblasts were exposed to smokeless tobacco extract (STE) prepared from the Scandinavian (STE1) and US-type (STE2) snuff. Cell cycle profiles were determined with flow cytometry, and HPV E6/E7 mRNA expression in HPV-positive cells was assayed using RT-qPCR. RESULTS: The exposure of HPV-positive keratinocytes with STE2 increased the number of aneuploid cells from 27% to 80% of which 44% were in S-phase, while none of the diploid cells were in S-phase. The changes after STE1 exposure were less than seen after STE2: from 27% to 31% of which 34% were in S-phase. STE had no effect on HPV16 E6/E7 expression in HPV-positive keratinocytes. In oral spontaneously transformed, HPV-negative keratinocytes, the number of aneuploid cells at G2-M stage increased after STE1 and STE2 exposure from 3% to 9% and 7%, respectively. In HPV-negative oral fibroblasts, the number of cells at G2-M phase increased from 11% to 21% after STE1 and 29% after STE2 exposure. CONCLUSIONS: The effect of STE varied in the cell lines studied. STE2 increased significantly the proportion of aneuploid cells in HPV-positive oral keratinocytes, but not HPV16 E6/E7 expression. This indicates that tobacco products may enhance the effects of HPV 16 and the risk of DNA aneuploidy increasing risk to malignant transformation.

Histological and ultrastructural studies on the toxic effect of pan masala and its amelioration by Elettaria cardamomum.

AIM: To investigate the histological and ultrastructural changes observed in pan masala intoxicated mammalian testes under the effect of cardamom. METHODS: Male Swiss mice were given pan masala orally at a dose of 2% of the feed and cardamom at a dose of 0.2% of the feed. They were divided into three groups, control (Group I), pan masala-treated (Group II), and a combination of pan masala and cardamom-treated group (Group III). Histologically, the testes of Group II mice displayed degeneration of tubular epithelium, disruption of spermatogenesis, and a marked reduction in germ cells. RESULTS: When cardamom was given, damage was less with fewer distorted cells and also improvement with normal tubules and spermatid differentiation in Group III. Ultrastructurally, pan masala-treated testes showed cytoplasmic vacuolation, shrinkage and pyknotic nuclei of spermatogonia, and abnormal acrosomal granules. CONCLUSION: When cardamom was given, the amelioration process was more evident showing a comparable morphology with control.

Oral submucous fibrosis: a premalignant condition in a 14-year-old Indian girl.

A 14-year-old Indian girl presented with difficulty in mouth opening and burning sensation while eating. On examination, blanching of the oral mucosa with diffuse white pigmented lesion of size 3.5 to 2 cm along with melanotic pigmentation was seen on the left buccal mucosa posteriorly. The patient was diagnosed with oral submucous fibrosis. A comprehensive treatment plan was made based on conservative management that included motivation and intense counselling of the patient and her parents so that she quits the habit of chewing areca nut and tobacco, along with systemic treatment of vitamin B complex supplements, antioxidants, multivitamins and oral physiotherapy. We present this case to highlight the difficulties faced by the clinical practitioners in providing treatment because of the taboos and myths associated with surgical treatment modality in rural population as well as to emphasise the menace of increasing consumption and availability of tobacco and areca nut to children.

Smoking water-pipe, chewing nass and prevalence of heart disease: a cross-sectional analysis of baseline data from the Golestan Cohort Study, Iran.

OBJECTIVE: Water-pipe and smokeless tobacco use have been associated with several adverse health outcomes. However, little information is available on the association between water-pipe use and heart disease (HD). Therefore, we investigated the association of smoking water-pipe and chewing nass (a mixture of tobacco, lime and ash) with prevalent HD. DESIGN: Cross-sectional study. SETTING: Baseline data (collected in 2004-2008) from a prospective population-based study in Golestan Province, Iran. PARTICIPANTS: 50 045 residents of Golestan (40-75 years old; 42.4% men). MAIN OUTCOME MEASURES: ORs and 95% CIs from multivariate logistic regression models for the association of water-pipe and nass use with HD prevalence. RESULTS: A total of 3051 (6.1%) participants reported a history of HD, and 525 (1.1%) and 3726 (7.5%) reported ever water-pipe or nass use, respectively. Heavy water-pipe smoking was significantly associated with HD prevalence (highest level of cumulative use vs never use, OR=3.75; 95% CI 1.52 to 9.22; p for trend=0.04). This association persisted when using different cut-off points, when restricting HD to those taking nitrate compound medications, and among never cigarette smokers. There was no significant association between nass use and HD prevalence (highest category of use vs never use, OR=0.91; 95% CI 0.69 to 1.20). CONCLUSIONS: Our study suggests a significant association between HD and heavy water-pipe smoking. Although the existing evidence suggesting similar biological consequences of water-pipe and cigarette smoking make this association plausible, results of our study were based on a modest number of water-pipe users and need to be replicated in further studies.

Non-enzymatic antioxidant status and biochemical parameters in the consumers of Pan Masala containing tobacco.

BACKGROUND: Tobacco consumption is one of the leading causes of oral submucous fibrosis, oral cancer and even premature death. The present study was designed to compare the biochemical parameters and non- enzymatic antioxidant status and the lipid peroxidation products in pan masala tobacco users as compared with age-matched non-user controls. METHODS: Pan masala and tobacco users of age 33.2±9.94 years and age-matched controls (31.2±4.73 years) were enrolled for the study. Plasma levels of vitamin E, vitamin C, albumin, bilirubin, uric acid, glucose, urea, creatinine, aspartate amino transferase (AST), alanine amino transferase (ALT) were measured by standard methods. Serum malondialdehyde (MDA) levels were estimated as a measure of lipid peroxidation. RESULTS: In the pan masala tobacco users, as compared to the controls, the level of vitamin C (68.5±5.9 vs 97.9±9.03 µmol/L, p≤0.05) vitamin E (18.4±5.3 vs 97.9±9.03 µmol/L, p≤0.001), albumin (37.5±7.01 vs 44.3±9.99 g/L, p≤0.001), and malondialdehyde (10.8±1.29 vs 1.72±1.15 nmol/ml, p≤0.001 ) were found to be significantly altered. Malondialdehyde was significantly correlated with vitamin E (r=1.00, p<0.001) and vitamin C (r =1.00, p<0.001) in pan masala tobacco users. Serum levels of AST (31.0±16.77 IU) and ALT (36.7±31.3 IU) in the pan masala tobacco users were significantly raised as compared to the controls (AST, 25.2±9.51 IU, p=0.038; ALT, 26.2±17.9 IU, p=0.038). CONCLUSION: These findings suggest that pan masala tobacco users are in a state of oxidative stress promoting cellular damage. Non-enzymatic antioxidants are depleted in pan masala tobacco users with subsequent alteration in the biochemical parameters. Supplementation of antioxidants may prevent oxidative damage in pan masala tobacco users.

Effect of methylxanthines (coffee/tea consumers) on oral precancer and oral cancer patients with smoking and smokeless tobacco habits.

AIM: To study, whether the consumption of regular tea/coffee (methylxanthines) increases the risk of oral cancer in patients with smoking and smokeless tobacco habits. MATERIALS AND METHODS: This study was conducted on a total of 90 oral cancer and precancerous patients, from western Maharashtra (India) males in the age group of 20 to 45 years who were with smoking and smokeless tobacco habits; also regular tea/coffee consumers were subjected to biochemical parameters such as aspartate transaminase (AST) and alanine transaminase (ALT) from saliva and serum of patients with oral precancer (submucous fibrosis, leukoplakia) and oral cancer patients and compared with 90-age and sex-matched controls. Individuals consent was taken to measure their biochemical parameters, by using Hafkenscheid method in whole saliva and serum. Statistical analysis of variance (ANOVA) with Tukey's correction for multiple group comparisons was performed using Student t-test. RESULTS: Results show, that a statistically significant increase in value (p < 0.05) in ALT, AST in both saliva and serum was observed in precancerous and oral cancer patients among the study group as compared to the control group. CONCLUSION: In the present study, there was increase in the levels of ALT, AST enzymes in both saliva and serum levels in the study group as compared to the control group which was statistically significant (p < 0.05) suggesting that long-term exposure of methylxanthines results in impairment of salivary gland antioxidant system which may affect the anticarcinogenic action of saliva. CLINICAL SIGNIFICANCE: Oral fluids may be utilized effectively to study the variations in the biochemical constituents of saliva of leukoplakia, submucous fibrosis and oral cancer patients.

Adverse effects of Sudanese toombak vs. Swedish snuff on human oral cells.

BACKGROUND: The high incidence of oral cancer in Sudan has been associated with the use of toombak, the local type of smokeless tobacco. However, its specific effects on human oral cells are not known. We aimed to investigate the effects of toombak on primary normal human oral keratinocytes, fibroblasts, and a dysplastic oral keratinocytic cell line, and to compare them with the effects induced by Swedish snuff. METHOD: Aqueous extracts were prepared from moist toombak and Swedish snuff and added in serial dilutions on in vitro monolayer cultured cells. Cell viability, morphology and growth, DNA double-strand breaks (gammaH2AX staining), expression of phosphatidylserine (Annexin V staining), and cell cycle were assessed after various exposure time periods. RESULTS: Significant decrease in cell number, occurrence of DNA double-strain breaks, morphological and biochemical signs of programmed cell death were detected in all oral cell types exposed to clinically relevant dilutions of toombak extract, although to a lesser extent in normal oral fibroblasts and dysplastic keratinocytes. G2/M-block was also detected in normal oral keratinocytes and fibroblasts exposed to clinically relevant dilutions of toombak extract. Swedish snuff extract had less adverse effects on oral cells, mainly at non-clinically relevant dilutions. CONCLUSION: This study indicates a potential for toombak, higher than for Swedish snuff, to damage human oral epithelium. Dysplastic oral keratinocytes were less sensitive than their normal counterparts, suggesting that they might have acquired a partially resistant phenotype to toombak-induced cytotoxic effects while still being prone to DNA damage that could lead to further malignant progression.

Smokeless tobacco: a gateway to smoking or a way away from smoking.

Recently, tobacco companies have been marketing moist smokeless tobacco products that are 'spitless'. These products have lower concentrations of tobacco-specific nitrosamines and of other harmful chemicals than other tobacco products, but can deliver relatively high doses of nicotine. They are packaged in small sachets, similar to tea bags that are placed between cheek and gum. Global promotion of smokeless tobacco products is hotly debated among tobacco control and public health experts. Proponents point to the Swedish experience where snus (Swedish moist snuff) is widely used as an alternative to cigarette smoking among men. Meanwhile, Sweden has low rates of smoking and a lower rate of respiratory diseases and lung cancers by comparison to other developed countries. The opponents argue that snus has its own risks, that no form of tobacco should ever be promoted; and that 'snus is culture-bound and not transferable to other settings'. Critics also suspect that the tobacco industry will use snus marketing as a 'gateway' to promote cigarettes among young people. Research on the effects of marketing snus to smokers is too limited to support using snus as a harm-reduction tool, and the epidemiological data are not conclusive.

Lipid peroxidation, total antioxidant status, and total thiol levels predict overall survival in patients with oral squamous cell carcinoma.

Tobacco is the major etiological factor for oral cancer development through the generation of oxidative stress. Therefore, markers of oxidative stress such as total antioxidant status, lipid peroxidation, and total thiol levels might be useful to monitor oxidative stress and predict overall survival in oral cancer patients. The study included 140 oral cancer patients and 50 healthy controls, who were classified as with the habit of tobacco and no habit of tobacco. Adjacent normal and malignant tissue samples were collected from oral cancer patients. Plasma and tissue levels of lipid peroxidation, thiol, and total antioxidant status were assayed by spectrophotometric methods. Thiol levels were significantly lower in controls with the habit of tobacco (P= .033), oral cancer patients (P= .0001), and malignant tissues (P= .015) as compared to controls with no habit of tobacco, controls with the habit of tobacco, and adjacent normal tissues, respectively. Tobacco exposure was higher in oral cancer patients than controls with the habit of tobacco. Controls with the habit of tobacco who had lower thiol (odds ratio [OR]=10.58, P= .008) and high tobacco exposure (OR=0.251, P= .05) showed an elevated risk of oral cancer development. Patients showing a lipid peroxidation level above the cutoff level as compared to patients below the cutoff level showed poor overall survival, whereas those with thiol and total antioxidant status levels below the cutoff level as compared to their respective counterparts showed poor overall survival. In conclusion, lipid peroxidation and thiol could be useful for predicting the risk of oral carcinogenesis in healthy tobacco consumers and predicting overall survival of oral cancer patients.

Influence of regular black tea consumption on tobacco associated DNA damage and HPV prevalence in human oral mucosa.

Black tea is more widely consumed than green tea worldwide, particularly in India. Therefore, it is necessary to focus attention on black tea with respect to its health promoting and anti-cancer actions. In order to establish the concept that black tea is a potential candidate for cancer prevention, it is important to provide epidemiological evidence derived from investigations of human populations. In view of this, the objective of the present study was to determine the correlation between nature of black tea consumption and DNA damage in normal subjects with or without tobacco habit and oral cancer patients, taking the latter as positive controls. Much experimental evidence points to associations between tobacco habit and HPV 16 and HPV 18 (Human Papilloma virus) infection. But no studies have taken into account the possible confounding effect of black tea consumption on DNA damage along with HPV infection. A pilot study was therefore undertaken. Comet assay was used to evaluate the DNA damage among normal subjects including tobacco users (n = 86), non-tobacco users (n = 45) and Oral cancer patients (n = 37). Percentage of damaged cells was scored in the buccal squamous cells of all subjects mentioned above. HPV analysis was performed on 79 samples (including 37 oral cancer patients). The evaluation of various confounding factors like age, tenure of tobacco habit and tea habit showed significant associations with DNA damage. The observations strongly indicate that regular intake of black tea at least above four cups can reduce tobacco associated DNA damage among normal tobacco users. HPV prevalence was not seen to be associated with age, tenure of tobacco habit or the tea drinking habit.

Expression of NF-kappaB parallels COX-2 expression in oral precancer and cancer: association with smokeless tobacco.

Nuclear Factor-kappaB (NF-kappaB) activation and COX-2 overexpression have been reported in head and neck cancer, but the relationship between these proteins remains to be investigated. To determine the relationship between NF-kappaB and COX-2 in Smokeless Tobacco (ST) associated oral tumorigenesis, we performed immunohistochemistry in serial sections from 107 OSCCs, 78 oral precancerous lesions (OPLs) (58 hyperplasias, 20 dysplasias) and 15 histologically normal oral tissues and correlated with clinicopathological data. Significant increase in NF-kappaB and COX-2 immunopositivity was observed from normal oral mucosa to OPLs to OSCCs (p = 0.009 and p = 0.002 respectively). Upregulation of NF-kappaB and COX-2 was observed as early as in hyperplasia [p = 0.006; OR = 6.1 and p = 0.003; OR = 7.6, respectively]. Expression of both proteins was found to be significantly associated in OPLs (p = 0.000; OR = 12.6) and OSCCs (p = 0.001; OR = 4.0). Intriguingly, khaini consumption correlated with NF-kappaB immunopositivity in OPLs (p = 0.05, OR = 3.8) and OSCCs (p = 0.01, OR = 3.4) and with COX-2 expression in OPLs (p = 0.03; OR = 4.3). In vitro experimental system of ST associated oral carcinogenesis was used to demonstrate ST (khaini) and NNK mediated activation of NF-kappaB and COX-2, supporting the clinical data. In conclusion, this study demonstrates correlation between over expression of NF-kappaB and COX-2 in early precancerous stages of development of oral cancer and sustained elevation down the tumorigenic pathway, underscoring their potential as targets for early intervention. In vitro studies demonstrated that NNK may be one of the carcinogenic components of ST (khaini) inducing activation of NF-kappaB and COX-2 in oral precancer and cancer cells, suggesting plausible role in ST-induced oral carcinogenesis.