Comparison of Cytotoxic Effect of Cigarette and Waterpipe Smoking on Human Buccal Mucosa

Genotoxicity of waterpipe smoking in young adults from Sarajevo, Bosnia & Herzegovina

Background

Waterpipe, also known as a hookah or narghile, is a type of tobacco products consumption device. Recently it has been increasingly popular in Bosnia and Herzegovina and the region. Waterpipe consumers are predominantly adolescents and young adults. Many of them believe in slighter harmful effects of waterpipes, compared to cigarettes. We aimed to determine the DNA damage in oral leukocytes and buccal cells of young individuals who have smoked a waterpipe for more than one year.

Methods

The study group consisted of 40 cigarette non-smokers who regularly smoked a waterpipe on average of once per week. As a control, 40 non-smoking individuals were selected to match smokers for age. All participants in the study were healthy male and female adults from Bosnia and Herzegovina, 18-30 years of age. Before sampling, detailed survey and informed consent have been provided by each participant. Comet assay in oral leukocytes and buccal micronucleus cytome (BMCyt) assay in exfoliated buccal cells were applied.

Results

Almost half of waterpipe smokers (WPS) tasted waterpipe at 15-16 years of age. Comet assay analysis showed increased tail intensity, tail length, and tail moment values among WPS compared to non-smokers (NS) (p = 0.0001, p = 0.0067, and p = 0.0001, respectively). Frequencies of the micronucleated (p = 0.0004), binucleated (p = 0.01), karyorrhectic, (p = 0.0036), and pycnotic cells (p = 0.03) were significantly higher in WPS compared to NS group.

Conclusions

Genotoxicity and DNA damage biomarkers were increased in oral leukocytes and exfoliated buccal cells of young waterpipe smokers from Bosnia and Herzegovina, compared to NS group.

Cytotoxic and Genotoxic Effects of Waterpipe on Oral Health Status: Systematic review and meta-analysis

This systematic review and meta-analysis aimed to assess the cytotoxic and genotoxic impacts of waterpipe smoking on oral health. The databases MEDLINE, Cochrane Library and Dimensions were searched to find studies evaluating whether waterpipe smokers exhibited any cytotoxic or genotoxic effects on their oral cells compared to non-smokers, with regard to mouth neoplasms. Particularly, changes in DNA methylation and p53 expression were assessed. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were adopted for the systematic review. Review Manager was utilised for statistical analysis with a significance level at P <0.05. To assess the grades of the included articles, a risk of bias analysis was summarised. A forest plot, including some of the included articles included, was created regarding the different grades. A total of 20 studies were included in this review. The results showed that waterpipe smoking has cytotoxic and genotoxic effects on oral cells, with a risk difference of 0.16. Although the published articles are few in number, all confirm the devastating effects of waterpipe smoking related to the carcinogenicity. Waterpipe smoking is harmful to oral health. It causes a series of detrimental cellular and genetic modifications such as acanthosis, epithelial dysplasia and hyperparakeratosis. In addition, waterpipe smoke contains several carcinogenic compounds. As it releases many harmful organic compounds, waterpipe smoking increases the incidence of oral cancer.

Cytotoxic and genotoxic effects of cigarette and waterpipe tobacco smoking on buccal mucosa: A systematic review and meta-analysis

Background

Waterpipe tobacco smoking (WTS) is an issue all over the world, although it is particularly prevalent in the Middle East, and Southeast Asia. The genotoxic effects of smoking were reported to be associated with nucleus abnormalities such as micronuclei (MN), karyorrhexis (KR), karyolysis, pyknosis, binucleates, broken eggs, condensed chromatin in exfoliated buccal mucosal cells, and was believed to be associated with apoptosis of cells and was not correlated to the exposure time.

Aim

The aim of this study was to evaluate and compare the cytotoxic and genotoxic effects of cigarette and WTS on buccal mucosa.

Materials and Methods

The pertinent search was done through the computerized literature on MEDLINE, EMBASE, and PUBMED databases, which included case-control, clinical and observational studies regarding the mutagenic effects of cigarettes and WTS in oral tissues. The retraction of data in this study was undertaken from May 2010 to May 2022. A total of 60 articles from the search data were retrieved. This investigation was registered with the research center of Riyadh Elm University for institution review board approval (IRB) and obtained the IRB number "FRP/2021/448/733/707 and the systematic review registration number with respect to PROSPERO is 345417.

Results

After the removal of duplicates, 32 were evaluated for the inclusion and exclusion criteria. Out of 32 articles, twenty studies were evaluated for cytogenetic abnormalities in buccal mucosal cells of waterpipe tobacco smokers (WTS) and cigarette smokers, and 12 were excluded. The mean MN levels in the oral tissues of WTS were more (1.94 ± 0.39) than in non-smokers (1.68 ± 0.35).

Conclusion

Therefore, we conclude that the MN count can be employed as a biomarker and preliminary signal for the identification of changes in oral mucosa among smokers, which develop towards cancer formation.

Comparison of Repair Index in Cigarette and Waterpipe Smokers: A Bio-Monitoring Assessment Using Human Exfoliated Buccal Mucosa Cells

BACKGROUND

Repair index (RI) using DNA changes reveals the activity of carcinogenesis. Cigarette and waterpipe smoking are important contributors to oral cavity malignancy. The RI in cigarette and waterpipe smokers has not been compared so far. The aim of this study was to compare the RI in cigarette and waterpipe smokers using the human exfoliated buccal mucosa cells.

METHODS

The exfoliated buccal mucosa cells of 60 cigarette and waterpipe smokers and 20 nonsmokers were evaluated in a case-control study. The number of micronuclei (MN), broken egg (BE), karyorrhexis (KR), and karyolysis (KL) were counted in 1000 cells from randomly selected fields. The RI = (KL + KR)/(MN + BE) was calculated and compared between subjects and controls. Data were analyzed by one-way analysis of variance (ANOVA), Tukey's Honest Significant Difference (HSD), and Spearman's correlation coefficient test at P < 0.05 probability level.

RESULTS

The difference of MN (P < 0.0001), BE (P < 0.0001), KR (P < 0.0001), and KL (P < 0.0001) count was significant between cigarette smokers, waterpipe smokers, and nonsmokers. The RI was significantly different between groups (P = 0.007). The RI was significantly higher in cigarette smokers compared to waterpipe smokers (P = 0.04) and nonsmokers (P = 0.009).

CONCLUSIONS

The RI was significantly higher in cigarette smokers compared to waterpipe smokers. The finding suggests that due to higher interrupted cellular hemostasis, the risk of carcinoma in waterpipe smokers can be greater than that in cigarette smokers.

Evaluation of the genetic damage to workers in a Greek shipyard

Shipyards are industrial areas where workers are likely exposed to environmental pollutants such as welding fumes, fine organic solvent and dye dust, that render the occupational environment a high risk one. Assessing the risk that workers are exposed to is a high critical factor in improving their working conditions. The present study aims to investigate the potential genetic damage to workers exposed to a harsh environment in a Greek shipyard. It is focused on assessing the percentage of induced micronuclei, as well as on changes in the various cell types of shipyard workers' oral mucosa epithelium by implementing the buccal micronucleus cytome assay. Exposed workers appeared with statistically significant induced micronuclei as compared to office employees. Statistically, significant cell lesions were detected and are related to workers' exposure to environmental conditions. The workers' smoking habit contributed as well to the observed buccal epithelial cell alterations. The observed data signify the high-risk workers are exposed; resulting in the shipyard's management the need to implement measures improving the working environment conditions and to reevaluate the workers' personal protective equipment requirements.

Genotoxicity in Oral Mucosal Epithelial Cells of Petrol Station Attendants: A Micronucleus Study

Introduction:

Occupational exposure to petrol derivatives possesses an increased risk of various cancers including that of the oral mucosa. Scientific studies have shown the correlation of micronuclei assay (MN) with the cytogenotoxic changes in petrol station attendants. However, very few have reported the use of MN assay as a promising tool for assessing the impact of smoking in these workers.

Aim:

To explore the cytogenotoxic damage in exfoliated buccal cells obtained from petrol station attendants and control subjects using the MN assay along with additional effects due to smoking.

Materials and Methods:

The study comprised 60 males who were divided into Group I–IV with each having 15 subjects. These subjects were categorized as exposed smokers, exposed nonsmokers, unexposed smoker group, and unexposed nonsmokers. The MN and additional nuclear abnormalities (karyorrhexis [KH], binucleation [BN], pyknosis [P], and karyolysis [KL]) were calculated in PAP-stained slides.

Results:

Statistically higher mean frequencies of overall nuclear anomalies were observed in petrol pump workers in comparison with the control group. Petrol pump smokers carry the highest nuclear anomalies followed by non-exposed smokers than exposed non-smokers and the count was the least among unexposed non-smoker workers.

Discussion and Conclusion:

The present study indicated that the petrol pump workers are under higher cytogenotoxic damage. Also, smoking added to the frequency of damage. Thus, MN and other nuclear anomalies are in-vitro reliable biomarker assays available and should be routinely employed as a screening tool in their periodic medical evaluation.

Interventions to prevent periodontal disease in tobacco-, alcohol-, and drug-dependent individuals

Substance abuse affects more than one sixth of the world's population. More importantly, the nature of the abuse and the type of addictive substances available to individuals is increasing exponentially. All substances with abusive potential impact both the human immuno-inflammatory system and oral microbial communities, and therefore play a critical role in the etiopathogenesis of periodontal diseases. Evidence strongly supports the efficacy of professionally delivered cessation counseling. Dentists, dental therapists, and hygienists are ideally placed to deliver this therapy, and to spearhead efforts to provide behavioral and pharmacologic support for cessation. The purpose of this review is to examine the biologic mechanisms underlying their role in disease causation, to understand the pharmacologic and behavioral basis for their habituation, and to investigate the efficacy of population-based and personalized interventions in prevention of periodontal disease.

Changes in global DNA methylation and hydroxymethylation in oral mucosa according to tobacco smoke exposure

OBJECTIVE

This prospective clinical study comparatively investigated the effects of tobacco smoking on global methylation and hydroxymethylation in oral epithelial cells.

METHODS

Buccal cells from the inside of the cheeks were collected from 47 individuals, including smokers, former smokers, and never smokers. DNA was extracted using dedicated kits. Methylated and hydroxymethylated DNA fractions were measured using assays similar to enzyme-linked immunosorbent assays. The levels of methylation and hydroxymethylation were compared among groups using unpaired two-tailed t-tests or the Mann-Whitney U test; P < 0.05 was considered statistically significant.

RESULTS

There was no statistically significant difference in the average number of cigarettes between smoker and former smoker groups. Although methylation levels were lower for smokers (3.1%) and former smokers (2.16%), compared with never smokers (4.16%), these differences were not statistically significant. There was a two-fold increase in hydroxymethylation level in never smokers, compared with smokers.

CONCLUSIONS

Our findings suggest that smoking leads to global reductions in both methylation and hydroxymethylation levels in oral epithelial cells in a manner influenced by the intensity and length of exposure to tobacco smoke.

The Effect of Hookah Use on Buccal Mucosa: Evaluation of Repair Index

Background and aim:

Cigarettes, hookah, and tobacco are the most important etiologic factors for oral cancers and dysplastic lesions. This study was undertaken to determine the correlation between hookah use and the percentage of cells with micronucleus, karyorrhexis, karyolysis, and broken egg in the buccal mucosa; and secondly to compare hookah user and non-user in terms of repair index.

Materials and methods:

The present historical cohort study was carried out on 72 samples taken from 36 hookah users and 36 control subjects. Smear samples were obtained from participants’ buccal mucosa for cytological evaluation using Papanicolaou technique. Then, the percentages of cells with micronucleus, karyorrhexis, karyolysis, and broken egg were recorded and the repair index was calculated. Data were analyzed using Mann-Whitney U test.

Results:

A total of 72 samples taken from 36 hookah users and 36 control subjects were evaluated. The means of micronucleus scores in the buccal mucosa cells of hookah users and controls were 10.7±2.6 and 5.8±2.0, the karyorrhexis scores in the hookah users and controls were 0.1±0.06 and 0.04±0.06, and the karyolysis scores in hookah users and controls were 0.16±0.05 and 0.08±0.06, respectively. These differences were statistically significant between hookah users and controls (P<0.001). The broken egg score was 0.66±0.07 for the hookah users and 0.03±0.04 for the control group, revealing a statistically significant difference (P<0.036). Finally, the repair index values were 0.03±0.01 and 0.05±0.13 in hookah users and controls, respectively. This difference was also significant (P<0.026).

Conclusion:

The percentages of cells with micronucleus, karyorrhexis, karyolysis, and broken egg in the buccal mucosa of hookah users were significantly higher than those in control group; in addition, the repair index of the buccal mucosa cells in hookah users was significantly lower than that in the control group.