The in vitro toxicology of Swedish snus

Three commercial brands of Swedish snus (SWS), an experimental SWS, and the 2S3 reference moist snuff were each tested in four in vitro toxicology assays. These assays were: Salmonella reverse mutation, mouse lymphoma, in vitro micronucleus, and cytotoxicity. Water extractions of each of the 5 products were tested using several different concentrations; the experimental SWS was also extracted using dimethyl sulfoxide (DMSO). Extraction procedures were verified by nicotine determinations. Results for SWS in the mutagenicity assays were broadly negative: there were occasional positive responses, but these were effectively at the highest concentration only (concentrations well above those suggested by regulatory guidelines), and were often associated with cytotoxicity. The 2S3 reference was unequivocally positive in one of the three conditions of the micronucleus assay (MNA), at the highest concentration only. Positive controls produced the expected responses in each assay. The SWS data are contrasted with data reported for combusted tobacco in the form of cigarettes, where strongly positive responses have been routinely reported for mutagenicity and cytotoxicity. These negative findings in a laboratory setting concur with the large amount of epidemiological data from Sweden, data showing that SWS are associated with considerably lower carcinogenic potential when compared with cigarettes.

Monitoring tobacco-specific N-nitrosamines and nicotine in novel Marlboro and Camel smokeless tobacco products: findings from Round 1 of the New Product Watch

INTRODUCTION

Information on chemical composition of the new oral "spitless" smokeless tobacco products is scarce, and it is not clear whether there is some variability as a function of purchase place or time due to either unintended or intended manufacturing variations or other conditions.

METHODS

We analyzed tobacco-specific N-nitrosamines (TSNA) and nicotine in Marlboro Snus, Camel Snus, and dissolvable Camel products Orbs, Sticks, and Strips that were purchased in various regions of the country during the summer of 2010.

RESULTS

A total of 117 samples were received from different states representing six regions of the country. Levels of unprotonated nicotine in Marlboro Snus and Camel Snus varied significantly by regions, with the differences between the highest and the lowest average regional levels being relatively small in Marlboro Snus (∼1.3-fold) and large in Camel Snus (∼3-fold). Some regional variations in TSNA levels were also observed. Overall, Camel Snus had significantly higher TSNA levels than Marlboro Snus, and Camel Strips had the lowest TSNA levels among all novel products analyzed here. The amount of unprotonated nicotine in the dissolvable Camel products was comparable to the levels found in Marlboro Snus.

CONCLUSIONS

Our study demonstrates some regional variations in the levels of nicotine and TSNA in Marlboro and Camel novel smokeless tobacco products. Continued monitoring of this category of products is needed as the existing products are being test marketed and modified, and new products are being introduced. This information is particularly important given its relevance to Food and Drug Administration regulation of tobacco products.

p53 Codon 72 polymorphism in oral exfoliated cells in a Sudanese population

Earlier studies have investigated the tumor suppressor gene p53 as a co-factor in the development of oral squamous cell carcinoma (OSCC). Our previous studies have indicated that chronic use of Sudanese snuff (toombak) and the presence of human papilloma virus (HPV) may be involved in the high prevalence of OSCC in Sudan. This study investigated the prevalence of p53 codon 72 polymorphism in brush biopsies obtained from a Sudanese population. A total of 174 individuals were included in the study; chronic toombak users (n=152) and non-users (n=22). DNA was extracted from all the samples and genotyped for the codon 72 polymorphism by polymerase chain reaction/restriction fragment length polymorphism. The Arg/Pro genotype was found in 53% of the 174 study participants, compared to 21% found with Arg/Arg and 26% found with Pro/Pro. Stratifying by toombak use, 28 (18%), 45 (29%) and 79 (52%) of the 152 samples from toombak users had Arg/Arg, Pro/Pro and Arg/Pro respectively, compared to 9 (41%), 0 (0%) and 13 (59%) found in the 22 samples from non users. The differences between the samples from toombak users and non users in Arg/Arg and Pro/Pro codon 72 polymorphism and HPV infection were statistically significant (p<0.05). Our study indicated that a high prevalence of the genotype Arg/Pro at the p53 codon 72 may contribute to susceptibility to OSCC, especially in combination with the use of carcinogenic tobacco-specific nitrosamine (TSNA)-rich toombak. Our observations warrant an in-depth study for understanding the role of p53 polymorphism in human oral cancers.

Dietary intake of cadmium from Bangladeshi foods

Human exposure to cadmium (Cd) is associated with various diseases and high levels of Cd have been detected in Bangladeshi population warranting further research to identify the source of this exposure. In this study, Cd levels in 327 and 94 samples of Bangladeshi food and non-food samples, respectively, were determined using inductively coupled plasma mass spectrometry. This is the largest number of Bangladeshi food and nonfood samples investigated for their Cd content. High Cd levels were detected in leafy vegetables (mean 31 [SD 29]μg/kg). Of these vegetables, lal shak (Amaranthus tricolor) contained the highest Cd level (303 μg/kg [wet weight]; mean 100.5 [SD 95]μg/kg). Bangladeshi rice also showed significant concentration of Cd (mean 37.2 [SD 30]μg/kg). Of particular concern is the very high level of Cd detected in some puffed rice, which we attribute to the illegal practice of using urea for whitening the puffed rice. Tobacco leaves, which are commonly consumed during betel quid chewing by Bangladeshis, contain significant levels of Cd (mean 95 [SD 87]μg/kg). The total daily intake (TDI) of Cd from foods for Bangladeshis was estimated to be 34.55 μg/d. This is rather high when compared to the TDI of Cd for other populations. Our analysis reveals that this is mainly due to the very high intake of rice and vegetables, and lower consumption of animal products (which are low in Cd), by the Bangladeshis. We also determined the provisional maximum tolerable daily intake and target hazard quotients values for Cd. Clearly a more balanced diet is necessary to reduce the Cd intake in the Bangladeshi population, especially by reducing the very high intake of rice and certain leafy vegetables. Food manufacturing and agricultural practices needs to be altered to reduce the entry of Cd into the food chain.

PRACTICAL APPLICATION

Exposure to high levels of Cd can be harmful to human health and this study provides a comprehensive analysis of Cd levels in a variety of food items from Bangladesh. The findings are of particular importance to consumers of Bangladeshi foods in both Bangladesh and in other countries. Data obtained will be valuable resources for food safety and regulatory bodies as our study suggests entry of Cd in foods through use of illegal chemicals in food manufacturing processes.

Toxic elements in tobacco and in cigarette smoke: inflammation and sensitization

Biochemically and pathologically, there is strong evidence for both atopic and nonatopic airway sensitization, hyperresponsiveness, and inflammation as a consequence of exposure to tobacco mainstream or sidestream smoke particulate. There is growing evidence for the relation between exposure to mainstream and sidestream smoke and diseases resulting from reactive oxidant challenge and inflammation directly as a consequence of the combined activity of neutrophils, macrophages, dendritic cells, eosinophils, basophils, as a humoral immunological consequence of sensitization, and that the metal components of the particulate play a role in adjuvant effects. As an end consequence, carcinogenicity is a known outcome of chronic inflammation. Smokeless tobacco has been evaluated by the IARC as a group 1 carcinogen. Of the many harmful constituents in smokeless tobacco, oral tissue metallothionein gradients suggest that metals contribute to the toxicity from smokeless tobacco use and possibly sensitization. This work reviews and examines work on probable contributions of toxic metals from tobacco and smoke to pathology observed as a consequence of smoking and the use of smokeless tobacco.

[Smokeless tobacco]

The use of snus (smokeless tobacco) can be detrimental to health. Containing carcinogenic nitrosamines (Swedish snus do not contain nitrosamine). Snus delivers rapidly high doses of nicotine which can lead to dependence. It do not induce bronchial carcinoma differently smoked tobacco. Lesions usually develop in the area of the mouth where the snus is placed. Non-malignant oral lesions include leukoedema, hyperkeratotic lesions of the oral mucosa and localised periodontal disease. The most frequently occurring premalignant lesion is leukoplakia. Studies reveal conflicting evidence about the risk of oral and gastroesophageal cancer with regard to snus users. However, the use of snus has proved to be a risk factor in developing pancreatic cancer and increases the risk of fatal myocardial infarction and ischemic stroke. During pregnancy, snus is associated with an increased risk of pre-eclampsia and premature delivery. Nicotine substitution therapy and bupropion and varenicline reduce withdrawal symptoms and tobacco craving during snus cessation. However, they have not been shown to assist in long-term abstinence. Information concerning potential hazards of using snus products must be incorporated into health educational programmes in order to discourage its use. Snus is not a recommended product to help in stopping to smoke.

The stereoisomers of menthol in selected tobacco products. A brief report

INTRODUCTION

Menthol has long been an important flavorant in tobacco products, and both its historical and present uses are topics of increasing debate. Menthol can exist in eight different stereoisomeric forms (as four enantiomeric pairs) that possess different sensory properties. As regards use in tobacco products, the open scientific literature and available industry documents focus on the D-menthol and l-menthol enantiomeric pair, and in particular on l-menthol, but are ambiguous about the actual importance of D-menthol in tobacco products. This study provides the first openly available measurements regarding the stereoisomeric forms of menthol as found in selected United States sub-brands of smokeless tobacco (SLT), cigarettes, and cigarette smoke.

METHODS

Gas chromatography/mass spectrometry (GC/MS) was applied using a "chiral" GC column to separate and determine the forms of menthol present in headspace air above various samples of United States sub-brands of SLT, cigarette filler material, and cigarette smoke particulate matter. Additional GC × GC/Time-of-flight mass spectrometry measurements were also made.

RESULTS

The dominant form of menthol by far in any of the samples was l-menthol.

CONCLUSIONS

For the selected cigarettes and SLT products tested from the U.S. market, the only form of menthol found was l-menthol. Other forms may be present in products that were not tested. No evidence was found of thermal racemization upon smoking of l-menthol to a d+l mixture.

Betel quid chewing elevates human exposure to arsenic, cadmium and lead

Several studies have reported increased skin lesions in betel quid (a mixture of Piper betel leaves, areca nut, tobacco/flavoured tobacco, lime) chewers compared to non-chewers, exposed to arsenic (As) contaminated drinking water in Bangladesh and India. The current study has determined As, cadmium (Cd) and lead (Pb) levels of betel quids and its components using inductively coupled plasma mass spectrometry (ICP-MS). The highest concentrations of As were found in slaked lime (4.56 mg kg(-1)) followed by Piper betel leaves (0.406 mg kg(-1)) and flavoured tobacco (zarda) (0.285 mg kg(-1)), with a mean concentrations of As in betel quids of 0.035 mg kg(-1) (SD 0.02 mg kg(-1)). Mean concentrations of Cd and Pb in ordinary quids were 0.028 (SD 0.07 mg kg(-1)) and 0.423 (SD 1.4 mg kg(-1)), respectively. We estimated that a daily intake of 6 betel quids could contribute 1.2, 1.9 and 8.5% of the provisional maximum tolerable daily intake (PMDTI) for As, Cd and Pb, respectively. Since betel quid chewing is most prevalent among women, our finding raises concern that women chewers - especially pregnant chewers - may be harming their health and that of their unborn babies through increased exposure to a mixture of toxic elements (As, Cd and Pb).

Evaluating the acute effects of oral, non-combustible potential reduced exposure products marketed to smokers

BACKGROUND

Non-combustible potential reduced exposure products (PREPs; eg, Star Scientific's Ariva; a variety of other smokeless tobacco products) are marketed to reduce the harm associated with smoking. This marketing occurs despite an absence of objective data concerning the toxicant exposure and effects of these PREPs. Methods used to examine combustible PREPs were adapted to assess the acute effects of non-combustible PREPs for smokers.

METHODS

28 overnight abstinent cigarette smokers (17 men, 14 non-white) each completed seven, Latin-squared ordered, approximately 2.5 h laboratory sessions that differed by product administered: Ariva, Marlboro Snus (Philip Morris, USA), Camel Snus (RJ Reynolds, Winston-Salem, North Carolina, USA), Commit nicotine lozenge (GlaxoSmithKline; 2 mg), own brand cigarettes, Quest cigarettes (Vector Tobacco; delivers very low levels of nicotine) and sham smoking (ie, puffing on an unlit cigarette). In each session, the product was administered twice (separated by 60 min), and plasma nicotine levels, expired air CO and subjective effects were assessed regularly.

RESULTS

Non-combustible products delivered less nicotine than own brand cigarettes, did not expose smokers to CO and failed to suppress tobacco abstinence symptoms as effectively as combustible products.

CONCLUSIONS

While decreased toxicant exposure is a potential indicator of harm reduction potential, a failure to suppress abstinence symptoms suggests that currently marketed non-combustible PREPs may not be a viable harm reduction strategy for US smokers. This study demonstrates how clinical laboratory methods can be used to evaluate the short-term effects of non-combustible PREPs for smokers.

Are Australian smokers interested in using low-nitrosamine smokeless tobacco for harm reduction?

AIMS

To determine (1) whether Australian smokers are aware of low-nitrosamine smokeless tobacco (LNSLT) products and (2) whether they would be interested in using LNSLT either as a long-term substitute for smoking or as an aid to quitting, if these products were to become legally available.

METHODS

401 daily smokers were recruited by a market research company to complete an internet questionnaire about their smoking history, knowledge of smokeless tobacco and intentions to purchase LNSLT under different scenarios.

FINDINGS

Just under half (48%) indicated they were willing to buy an LNSLT product. Predictors of an interest in purchasing LNSLT were low income, poorer health, prior SLT use, belief that SLT is less harmful than cigarettes, switching to a lower tar cigarette in the past year, ever using nicotine replacement therapy products for quitting or other reasons, having made a failed cessation attempt in the previous year and not planning to quit smoking. Analysis of quitting and LNSLT purchasing intentions under different scenarios suggest that making LNSLT available at a much lower cost than smoked cigarettes while increasing taxes on cigarettes could provide a greater reduction in the number of smokers than the same tax increase alone. These results support further examination of the potential for LNSLT to reduce smoking-related harm in Australia.

Smokeless tobacco: challenges, products and, cessation

Tobacco companies continue to develop and aggressively market new products for oral use. Most new products are intended to dissolve in the mouth and swallow rather than spit out the juices. These products effectively circumvent smoke-free policies, decrease tobacco cessation efforts, and create individuals who use both smokeless tobacco (ST) and cigarettes. All ST products contain nicotine, carcinogens, and pose multiple health risks. The cancer and health risks associated with ST use extend well beyond the changes in the oral cavity and the risk of oral cancer. Unlike cigarettes, the contents of ST vary widely by brand and product posing difficulty in the use of the available pharmacotherapy for cessation. Although no uniform guidelines exist for the use of pharmacotherapy for smokeless tobacco cessation, research suggests that use of these drugs is effective. The most important motivator for quitting ST cessation remains in the hands of the dentist.

Analysis of 23 polycyclic aromatic hydrocarbons in smokeless tobacco by gas chromatography-mass spectrometry

Smokeless tobacco contains 28 known carcinogens and causes precancerous oral lesions and oral and pancreatic cancer. A recent study conducted by our research team identified eight different polycyclic aromatic hydrocarbons (PAHs) in U.S. moist snuff, encouraging further investigations of this group of toxicants and carcinogens in smokeless tobacco products. In this study, we developed a gas chromatography-mass spectrometry method that allows simultaneous analysis of 23 various PAHs in smokeless tobacco after a simple two-step extraction and purification procedure. The method produced coefficients of variation under 10% for most PAHs. The limits of quantitation for different PAHs varied between 0.3 and 11 ng/g tobacco, starting with a 300 mg sample. The recovery of the stable isotope-labeled internal standards averaged 87%. The method was applied to analysis of 23 moist snuff samples that included various flavors of the most popular U.S. moist snuff brands, as well as 17 samples representing the currently marketed brands of spit-free tobacco pouches, a relatively new type of smokeless tobacco. The sum of all detected PAHs in conventional moist snuff averaged 11.6 (+/-3.7) microg/g dry weight; 20% of this amount was comprised of carcinogenic PAHs. The levels of PAHs in new spit-free tobacco products were much lower than those in moist snuff; the sum of all detected PAHs averaged 1.3 (+/-0.28) microg/g dry weight. Our findings render PAHs one of the most prevalent groups of carcinogens in smokeless tobacco. Urgent measures are required from the U.S. tobacco industry to modify manufacturing processes so that the levels of these toxicants and carcinogens in U.S. moist snuff are greatly reduced.

Detection of p16 promotor hypermethylation in "Maras powder" and tobacco users

BACKGROUND

A plant powder called "Maras powder" is widely used instead of cigarette smoking in the South-Eastern region of Turkey. It has been confirmed that this powder comprises tobacco Nicotiana rustica L.

METHODS

The aim of this study was to assess the effect of Maras powder and cigarette smoking on the P16 promotor hypermethylation. Twenty-two Maras powder users (Group I), 12 cigarette smokers (Group II), and 16 healthy controls who neither smoked nor used Maras powder (Group III) were included in the study. Hypermethylation of the P16 gene was examined using methylation-specific PCR (MSP) method in the blood of the three groups.

RESULTS

Aberrant P16 methylation was found in 7 of the 22 (31.8%) in Group I, in 3 of 12 (25%) in Group II, and in 1 of 16 (6.25%) in Group III.

CONCLUSION

Maras powder may be as harmful as cigarette smoking, leading to hypermethylation in P16 and warrants detailed studies on this subject.

[Smokeless tobacco: a new risk factor for oral health? A review]

Due to migration of different ethnic groups, mainly from Africa and Asia, into Switzerland, many traditional products and habits that have not been seen before were also introduced. Smokeless tobacco (ST)--as one of those habits--is a product of increased use in Switzerland, although no sound epidemiological data are presently available. Numerous studies from North-America, Sweden, Asia and Africa could verify the carcinogenic potency of smokeless tobacco and its effects in the developement of oral cancer and different systemic disorders. For dental professionals and their team it is important to detect ST-associated lesions, and to tell the patients about the potential harmful sequelae of ST products. The present review focusses on the different types of RT products and their effects on oral health.

Approaches, challenges, and experience in assessing free nicotine

Delivery of nicotine in the most desirable form is critical in maintaining people's use of tobacco products. Interpretation of results by tobacco industry scientists, studies that measure free-base nicotine directly in tobacco smoke, and the variability of free-base nicotine in smokeless tobacco products all indicate that the form of nicotine delivered to the tobacco user, in addition to the total amount, is an important factor in whether people continue to use the product following their initial exposure. The physiological impact of nicotine varies with the fraction that is in the free-base form and this leads to continued exposure to other toxic tobacco contents and emissions. In addition to evaluating the total nicotine delivered to the user, measuring the fraction of nicotine in the free-base form is critical in understanding and controlling the influence of nicotine on tobacco use.

Nicotine content and delivery across tobacco products

Nicotine is the principal alkaloid in both commercial and homemade products (e.g., cigarettes, smokeless tobacco, bidis, waterpipes) followed by nornicotine, anabasine, anatabine, and many other basic substances that contain a cyclic nitrogenous nucleus. Tobacco types, leaf position on the plant, agricultural practices, fertilizer treatment, and degree of ripening are among some prominent factors that determine the levels of alkaloids in tobacco leaf. From a random examination of 152 cultivated varieties of Nicotiana tabacum, a range of alkaloid variation between 0.17 and 4.93% was determined. In fact, every step in tobacco production that affects plant metabolism will influence the level of alkaloid content to a certain degree. Depending on blending recipe, type and amount of additives, and product design, all types of tobacco products contain a very wide range of nicotine concentration. However, the ultimate emission of nicotine to the user, exposure, and psychophar-macological effects depend not only on the content and emission, but also on the relationship between the product and the user.

Nicotine psychopharmacology: policy and regulatory

Powerful nerve agent, poison, addictive drug, or wonder medicine of the future? Nicotine has had a long and storied history in pharmacology, physiology, public health and, more recently, in regulatory policy initiatives in the United States and internationally. Psychopharmacology research on nicotine and tobacco came to particular prominence in the latter third of the twentieth century with exploration addressing the role of nicotine in tobacco use, the potential categorization of nicotine as an addictive drug, the pharmacological basis for treatment of tobacco addiction, and the perspective of policy developers seeking to reduce the toll of tobacco use. In fact, the 2005 ratification of the World Health Organization's first global health treaty, the Framework Convention on Tobacco Control, provides further impetus for extending the science foundation for tobacco disease control and policy efforts. Implementation of the treaty's provisions will control tobacco use and reduce the 500 million premature deaths projected to occur in the first half of the twenty-first century from tobacco use. Psychopharmacological research on nicotine and tobacco was important in the rationale and development of the treaty. The public health relevance of psychopharmacology research continues to grow with the realization of the potential of nicotine and related drugs to treat or prevent a diverse range of disorders (e.g., Alzheimer's disease, attention deficit hyperactivity disorder, and pain). Although comprehensive review of the research and implications is beyond the scope of this article, the more modest goal of providing insight into the theoretical, clinical, and policy importance of key psychopharmacology research laboratories over the past few decades is attempted.

New and traditional smokeless tobacco: comparison of toxicant and carcinogen levels

Declining cigarette use and spreading bans on smoking in public places in the United States are encouraging the U.S. cigarette industry to turn to another tobacco category, smokeless tobacco products. Currently, a number of new brands are being test marketed, including Taboka, Marlboro Snus, Camel Snus, and Skoal Dry. We report here levels of tobacco-specific nitrosamines (TSNAs), alkaloids, anions, polycyclic aromatic hydrocarbons (PAH), and volatile aldehydes in these products, and compare them to the most popular traditional moist snuff brands. Total TSNAs averaged 1.97 microg/g dry weight tobacco in Taboka, Marlboro Snus, and Camel Snus, 4.54 microg/g tobacco in Skoal Dry, and 7.42 microg/g tobacco in traditional brands. The amounts of unprotonated nicotine averaged 0.961 mg/g tobacco in Taboka, Marlboro Snus, and Skoal Dry, 7.22 mg/g tobacco in Camel Snus, and 7.57 mg/g tobacco in traditional brands. Levels of minor tobacco alkaloids were relatively high in Taboka, Marlboro Snus, and Skoal Dry, as compared to other products analyzed here. Levels of nitrite and nitrate in new U.S. smokeless tobacco products and the Swedish snus General were lower than those in the other products. Remarkably high levels of chloride and some PAH were observed in the traditional moist snuff. Crotonaldehyde levels were about five times higher in Taboka and Marlboro Snus than in traditional products. The large variation in the levels of some toxicants and carcinogens analyzed here indicates that more effort is required from the U.S. tobacco industry to further reduce their amounts in new and traditional smokeless tobacco products.

Smokeless tobacco and cancer

Use of smokeless tobacco products is common worldwide, with increasing consumption in many countries. Although epidemiological data from the USA and Asia show a raised risk of oral cancer (overall relative risk 2.6 [95% CI 1.3-5.2]), these are not confirmed in northern European studies (1.0 [0.7-1.3]). Risks of oesophageal cancer (1.6 [1.1-2.3]) and pancreatic cancer (1.6 [1.1-2.2]) have also increased, as shown in northern European studies. Results on lung cancer have been inconsistent, with northern European studies suggesting no excess risk. In India and Sudan, more than 50% of oral cancers are attributable to smokeless tobacco products used in those countries, as are about 4% of oral cancers in US men and 20% of oesophageal and pancreatic cancers in Swedish men. Smokeless tobacco products are a major source of carcinogenic nitrosamines; biomarkers of exposure have been developed to quantify exposure as a framework for a carcinogenesis model in people. Animal carcinogenicity studies strongly support clinical results. Cancer risk of smokeless tobacco users is probably lower than that of smokers, but higher than that of non-tobacco users.

A comparative study of the mutagenicity of various types of tobacco products

Toxicological data are an important aspect of tobacco product characterization. In this study, TPM (Total Particulate Matter) (three replicates) was collected from cigarettes [five brands, ISO conditions: puff volume, 35 mL; duration, 2s; interval, 60s (35/2/60)], cigars (two brands, 45/2/30), cigarillos (two brands, 35/2/60), bidis (two brands, 45/2/30), and pipe tobacco (two brands, 50/2/12). TPM was extracted from the Cambridge filter pad using dimethyl sulfoxide (DMSO). Smokeless tobacco (ST) (six brands) was extracted with DMSO using an ultrasonic homogenizer. Both types of extracts were filtered and stored at -80 degrees C. All extracts were analyzed for humectants, water and nicotine. Mutagenic activity was assessed per OECD guideline 471 using Salmonella typhimurium TA98+S9 and TA100+S9. TA98+S9 response (specific activity expressed as revertants/mg nicotine) was greatest for the cigarette fabricated with dark, air-cured tobaccos. Average product responses with TA98+S9 based on nicotine and relative to cigarettes (excluding dark tobacco) were cigars, 242%; cigarillos, 238%; bidis, 91%; and pipe tobacco, 44%. ST response was not significant for TA98+S9. Corresponding values for TA100+S9 were cigars, 189%; cigarillos, 155%; pipe tobacco, 130%; bidis, 114% and ST, 34%. ST TA100+S9 response ranged from a low of 501 to a high of 8547 revertants/mg nicotine, depending on ST composition.

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.

Public health implications of smokeless tobacco use as a harm reduction strategy

Harm reduction strategies involve promoting a product that has adverse health consequences as a substitute for one that has more severe adverse health consequences. Smokeless tobacco low in nitrosamine content offers potential benefits in reducing smoking prevalence rates. Possible harm arises from the potential for such products to serve as a gateway to more harmful tobacco products, public misinterpretation of "less harmful" as "safe," distraction from the public health goal of tobacco elimination, and ethical issues involved in advising those marketing these harmful products. We offer a research agenda to provide a stronger basis for evaluating the risks and benefits of smokeless tobacco as a means of reducing the adverse health effects of tobacco.

The potential impact of a low-nitrosamine smokeless tobacco product on cigarette smoking in the United States: estimates of a panel of experts

OBJECTIVE

To predict the impact on tobacco use in the US of a "harm reduction" policy that requires that the smokeless tobacco product meet low nitrosamine standards, but could be marketed with a warning label consistent with the evidence of relative health risks.

METHODS

Low nitrosamine smokeless tobacco (LN-SLT) and cigarette use are predicted by a panel of experts using a modified Delphi approach. We specify a thought experiment to isolate the changes that would occur after the new LN-SLT policy was implemented.

RESULTS

The panel predicted that the new policy would accelerate a decrease in smoking prevalence from 1.3 to 3.1 percentage points over 5 years compared to the current SLT product policy, with greater effects on males than females. Introduction of the new product was also predicted to result in modest additional use of SLT overall, with the greatest increases among males who initiated tobacco use under the new policy.

CONCLUSION

An overall consensus was reached that the introduction of a new LN-SLT product under strict regulations would increase SLT use, but reduce overall smoking prevalence. This reduction would likely yield substantial health benefits, but uncertainties surround the role of marketing and other tobacco control policies.

Levels of toxins in oral tobacco products in the UK

OBJECTIVE

This study examined the constituents of smokeless tobacco products available in the UK and compared them with products available in India, Sweden, and the USA.

METHODS

Seven UK brands of smokeless tobacco, including a tooth cleaning powder, and four international brands of smokeless tobacco were tested for a range of toxins and known carcinogens, such as tobacco specific N-nitrosamines (TSNA), as well as nicotine availability.

RESULTS

Ten of the 11 brands tested had detectable levels of tobacco specific nitrosamines, which are proven carcinogens, and levels varied 130-fold. All had detectable levels of benzo(a)pyrene, another proven carcinogen (with around 175-fold variation) and several toxic metals (with nearly 150-fold variation). Nicotine availability varied in the UK products from 0.1 mg/g to 63.2 mg/g. All the tobacco products tested are likely to be hazardous to users' health, but the data indicate that it should be possible to reduce key toxins to non-detectable levels.

CONCLUSIONS

Smokeless tobacco products should be regulated and standards set for maximum levels of toxins and carcinogens.

Tobacco-specific nitrosamines in new tobacco products

New tobacco products, designed to attract consumers who are concerned about the health effects of tobacco, have been appearing on the market. Objective evaluation of these products requires, as a first step, data on their potentially toxic constituents. Tobacco-specific nitrosamines (TSNAs) are an important class of carcinogens in tobacco products, but virtually no data were available on their levels in these products. In the present study, we analyzed several new products-Ariva, Stonewall, Exalt, Revel, Smokey Mountain, and Quest-for TSNAs and compared their TSNA levels with those in nicotine replacement products and conventional smokeless tobacco and cigarette brands. TSNAs were not detected in Smokey Mountain, which is a tobacco-free snuff product. The lowest levels among the new products containing tobacco were in Ariva and Stonewall (0.26-0.28 microg/g wet weight of product). The highest levels in the new products were found in Exalt (3.3 microg/g tobacco), whereas Revel and Quest had intermediate amounts. Only trace amounts were found in nicotine replacement products, and conventional brands had levels consistent with those reported in the literature. These results demonstrate that TSNA levels in new tobacco products range from relatively low to comparable with those found in some conventional brands.

Iqmik: a form of smokeless tobacco used among Alaska natives

OBJECTIVES

To describe a homemade form of smokeless tobacco known as Iqmik used among Alaska Natives residing in western Alaska.

METHODS

Individual and small-group interviews were conducted with 23 adult Alaska Natives. The major themes from the interview data were summarized. A chemical analysis was conducted of the alkalinity of a sample of fungus ash used to prepare Iqmik.

RESULTS

Few adverse health effects of using Iqmik were reported. The alkalinity of the sample of fungus ash was high (pH=10.9).

CONCLUSION

The high alkalinity of Iqmik may contribute to the higher rates of tobacco use in this population.

Smokeless tobacco impairs the antioxidant defense in liver, lung, and kidney of rats

The present study was designed to evaluate the effects of long-term use of aqueous extract of gutkha (a form of smokeless tobacco) on the antioxidant defense status and histopathological changes in liver, lung, and kidney of male Wistar rats. Animals were orally administered aqueous extract of smokeless tobacco (AEST) at a low dose (96 mg/kg body weight per day) for 2 and 32 weeks, and at a high dose (960 mg/kg body weight per day) for 2 weeks. High-dose AEST for 2 weeks decreased the hepatic glutathione (GSH) and glutathione peroxidase (GPx), and increased lipid peroxidation (Lpx) by 17%, 19%, and 20%, respectively. Low-dose AEST for 32 weeks significantly decreased (p < 0.05) the antioxidant status in these organs. In liver, AEST decreased GSH levels and the activities of superoxide dismutase (SOD), catalase (CAT), and GPx by 34.6%, 29%, 17.1%, and 17.4%, respectively, but it increased Lpx by 64%. In kidney, GSH, SOD, CAT, and GPx were decreased by 26.6%, 23%, 33%, and 18%, respectively, with an increase of Lpx by 65%. AEST decreased the lung GSH, SOD, CAT, and GPx, and increased lung Lpx by 43%, 28.5%, 37%, 40%, and 24%, respectively. However, no change in the plasma levels of vitamins A, C, and E were observed with AEST treatment. Histopathological findings suggest that administration of AEST at the high dose for 2 weeks or at the low dose for 32 weeks could cause mild to moderate inflammation in liver and lungs. In conclusion, a decrease in the antioxidant defense system and long-term inflammation caused by smokeless tobacco may be risk factors for gutkha-induced pathogenesis.

Polyphenolic antioxidants enhance IgE production

Epidemiological data showed that total IgE and IL-4 levels in cigarette smokers were elevated, comparable to those in the asthmatics. The etiological agent(s) elevating IgE production are not clear. We evaluate whether tobacco polyphenols potentiate IgE production in a rodent model. Mice were fed with rutin or CGA in drinking water during antigen sensitization, followed by antigenic challenge i.p. in alum. CGA and rutin were also delivered in a bolus intraperitoneally or intranasally along with antigens during immunization. Antigen-specific IgE and IgG responses were measured. Enhancement of total IgE responses via i.p. and drinking routes can be achieved at concentrations as low as 0.1% CGA. Furthermore, IgG1 responses but not IgG2a and IgG2b were augmented, indicating a Th2 type of response by CGA. Moreover, both antigen-specific and serum IgE production can be achieved when CGA and antigenic challenges were delivered intranasally in the absence of alum. In contrast, nicotine does not enhance antigen-specific IgE production, and only marginally affects serum IgE levels. The more polarized Th2 development in CGA-treated mice may account for enhancement of both antigen-specific and total IgE responses. High levels of IL-4 but not IFN-gamma or IL-12, were observed in antigen-challenged mesenteric lymph nodes (MLN) cultures from CGA-treated mice. In contrast, significant levels of IL-4, IL-12, and IFN-gamma were observed in antigen-challenged cultures from nicotine-treated mice. This study shows that tobacco polyphenols, CGA and rutin potentiated IgE production in vivo. Polyphenolic antioxidants enhance Th2 development. We propose that IgE production and T cell dichotomy may be critically influenced by the redox microenvironment. Enhanced Th2 development and IgE production henceforth may counteract more severe Th1-mediated tissue damage triggered by environmental oxidative stress.

Tobacco-specific nitrosamines in smokeless tobacco products marketed in India

Smokeless tobacco products are a known cause of oral cancer in India. Carcinogenic tobacco-specific nitrosamines in these products are believed to be at least partially responsible for cancer induction, but there have been no recent analyses of their amounts. We quantified levels of 4 tobacco-specific nitrosamines, N'-nitrosonornicotine (NNN), N'-nitrosoanatabine (NAT), N'-nitrosoanabasine (NAB) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), in 32 products marketed currently in India. Levels of nitrate, nitrite and nicotine were also determined. The highest levels of tobacco-specific nitrosamines were found in certain brands of khaini, zarda and other smokeless tobacco products. Concentrations of NNN and NNK in these products ranged from 1.74-76.9 and 0.08-28.4 microg/g, respectively. Levels of tobacco-specific nitrosamines in gutka were generally somewhat lower than in these products, but still considerably higher than nitrosamine levels in food. Tobacco-specific nitrosamines were rarely detected in supari, which does not contain tobacco, or in tooth powders. The results of our study demonstrate that exposure to substantial amounts of carcinogenic tobacco-specific nitrosamines through use of smokeless tobacco products remains a major problem in India.

Decreased levels of tobacco-specific N-nitrosamines in moist snuff on the Swedish market

Moist snuff, or snus, on the Swedish market in 2001 and 2002 was analyzed for tobacco-specific N-nitrosamines (TSNAs) using a recently developed LC-MS/MS method. All samples of moist snuff analyzed were found to contain detectable levels of N'-nitrosonornicotine (NNN), N'-nitrosoanatabine (NAT), N'-nitrosoanabasine (NAB), and 4-(N-methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). In the survey in 2001, all samples except for one were produced by Swedish Match (n = 14), which is the dominating manufacturer on the Swedish snuff market. In the survey in 2002, samples from both Swedish Match (n = 7) and seven smaller manufacturers (n = 20) were analyzed. Total TSNA levels of between 0.15 and 3.0 microg/g wet weight were found. In the survey in 2001 and 2002, the mean level of the total TSNA content in moist snuff was 1.1 microg/g (n = 14) and 1.0 microg/g (n = 27), respectively. The result of the survey shows that the level of TSNAs in moist snuff on the Swedish market has been greatly reduced since the middle of the 1980s. Clearly, efforts have been made by the manufacturers to reduce the level of TSNAs in snuff.

Surveillance of smokeless tobacco nicotine, pH, moisture, and unprotonated nicotine content

Smokeless tobacco is a complex chemical mixture, including not only the components of the tobacco leaf but also chemicals added during the manufacturing process. Smokeless tobacco contains the addictive chemical nicotine and more than 20 cancer-causing chemicals, including the potent tobacco-specific nitrosamines. The National Toxicology Program of the National Institutes of Health has concluded that oral use of smokeless tobacco is a human carcinogen. Therefore, smokeless tobacco is not a safe alternative to cigarettes. In fact, smokeless tobacco use begins primarily during early adolescence and can lead to nicotine dependence and increased risk of becoming a cigarette smoker. Under the Comprehensive Smokeless Tobacco Health Education Act of 1986 (15 U.S.C. 4401 et seq., Pub. L. 99-252), tobacco manufacturers report annually to the Centers for Disease Control and Prevention (CDC) on the total nicotine, unprotonated nicotine, pH, and moisture content of their smokeless tobacco products. This information is considered "trade secret," or confidential, in accordance with 5 U.S.C. 552(b)(4) and 18 U.S.C. 1905 and cannot be released to the public. In an effort to provide consumers and researchers with information on the nicotine content of smokeless tobacco, CDC arranged for the analysis of popular brands of smokeless tobacco. The results of this CDC study show that pH is a primary factor in the amount of nicotine that is in the most readily absorbable, unprotonated form. Furthermore, this study found that the brands of moist snuff smokeless tobacco with the largest amount of unprotonated nicotine also are the most frequently sold brands.

Polyphenolic antioxidants inhibit peptide presentation by antigen-presenting cells

Antigen-presenting cells (APC) provide two essential signals, e.g., antigenic peptides as well as costimulatory molecules for T-cell activation. Small molecules of smoke tobacco extracts (SM-STE) inhibited antigen presentation of A20 to OVAp-specific T-cell hybridomas. Pretreatment of A20 but not T hybridomas abrogates the APC function. Viability of APC and levels of MHCII, CD40 and B7 of APC were not affected by this treatment. The active principle, inhibiting APC was reproduced with pure tobacco polyphenols, quercetin and its glycoside, rutin. Antioxidant activity of rutin is relevant since rutin downregulated levels of reactive oxygen species (ROS) in phorbol ester-stimulated A20; moreover, another antioxidant, N-acetyl cysteine (NAC) also inhibited antigen presentation, albeit at a higher concentration. Other types of APC, such as bone marrow-derived mast cells (BMMC), MHCII-transfected fibroblast, and splenocytes are affected by tobacco polyphenols. We propose that polyphenols may affect redox-sensitive signal transduction pathway since APC function of PD 98059, MEK inhibitor-pretreated A20 were similarly abrogated. Taken together, we propose that maintaining appropriate intracellular redox of APC is crucial for its antigen-presenting function.

The influence of pH and nicotine concentration in oral moist snuff on mucosal changes and salivary pH in Swedish snuff users

The use of Swedish oral moist snuff is a widespread habit in Sweden. In 1999, 25% of the adult male population and 3.1% of the female population were users of snuff. The aim of the present study was to evaluate how variations in pH and nicotine concentrations of snuff affect the oral mucosa, clinically and histologically, salivary pH and daily nicotine intake in 20 habitual users of loose snuff. The subjects were studied during use of their usual brand, after 12 weeks use of a snuff with lower pH and after another 12 weeks use of a snuff with both lower pH and lower nicotine concentration. Consumption data, oral soft tissue changes, salivary pH and nicotine intake were measured. Further, biopsies were taken from the central part of the clinically observed lesions and histological changes were analysed. The subjects maintained their snuff consumption during the observation periods. The average salivary pH was higher during snuff use than in the morning. Further, it was higher shortly after the snuff was removed than during snuff use. After having switched to the snuff with both lower pH and lower nicotine concentrations, they showed a significant reduction in daily nicotine intake and developed significantly less pronounced clinical and histological changes. These results indicate that nicotine is one of the substances in snuff that has a biological effect on the oral mucosa. However, there also seems to be a synergistic effect between the pH and nicotine concentration in the snuff.

Analysis of tobacco-specific N-nitrosamines in snuff by ethyl acetate extraction and liquid chromatography-tandem mass spectrometry

A rapid, selective and sensitive method for routine analysis of the four tobacco-specific N-nitrosamines, N'-nitrosonornicotine, N'-nitrosoanatabine, N'-nitrosoanabasine and 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone in snuff has been developed. The nitrosamines were isolated by ethyl acetate extraction and analysed by LC-MS-MS. Except for evaporation and filtration, no additional clean-up steps are needed in the proposed method. The detection limits for standard in solvent are between 0.0005 and 0.001 microg/ml (0.005 and 0.01 microg/g).

A sensitive gas chromatographic-tandem mass spectrometric method for detection of alkylating agents in water: application to acrylamide in drinking water, coffee and snuff

A sensitive analytical method for the analysis of acrylamide and other electrophilic agents in water has been developed. The amino acid L-valine served as a nucleophilic trapping agent. The method was applied to the analysis of acrylamide in 0.2-1 mL samples of drinking water or Millipore-filtered water, brewed coffee, or water extracts of snuff. The reaction product, N-(2-carbamoylethyl)valine, was incubated with pentafluorophenyl isothiocyanate to give a pentafluorophenylthiohydantoin (PFPTH) derivative. This derivative was extracted with diethyl ether, separated from excess reagent and impurities by a simple extraction procedure, and analyzed by gas chromatography-tandem mass spectrometry. (2H3)Acrylamide, added before the reaction with L-valine, was used as internal standard. Acrylamide and the related compound, N-methylolacrylamide, gave the same PFPTH derivative. The concentrations of acrylamides were < or = 0.4 nmol L(-1) (< or = 0.03 microg acrylamide L(-1)) in water, 200 to 350 nmol L(-1) in brewed coffee, and 10 to 34 nmol g(-1) snuff in portion bags, respectively. The precision (the coefficient of variation was 5%) and accuracy of the method were good. The detection limit was considerably lower than that of previously published methods for the analysis of acrylamide.