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

Does waterpipe smoke induce genotoxicity (DNA damage) in mammalian cells in vivo? A systematic review

The waterpipe works by placing tobacco in a bowl with holes at the bottom, which is connected to a tube leading to a water-filled container. Upon heating the tobacco product with hot charcoal placed atop it, the emanating smoke is inhaled by the user via a hose linked to the water receptacle. The aim of this literature review is to evaluate whether the use of waterpipes can indeed induce genotoxicity in mammalian cells in vivo. Additionally, the study aims to assess the quality of the included research articles on this topic to ensure the reliability of the findings. We performed comprehensive searches in PubMed, SCOPUS, and Web of Science to identify relevant articles published until July 2024. The findings confirmed that waterpipe smoke induces genetic damage. This assertion is supported by the fact that 11 studies (out of 15) received a Strong or Moderate assessment categorization, suggesting that the majority of studies adhered to most technical standards, thereby enhancing the reliability of the research findings. Regarding the types of DNA damage reported, DNA strand breaks, chromosome damage and oxidative DNA damage were found in this review. Taken together, this study holds significant importance in assessing the efficacy of genotoxicity assays in detecting DNA damage due to waterpipe smoke and the comet and micronucleus assays are suitable biomarkers for biomonitoring people who use waterpipe.

State of art of micronuclei assay in exfoliative cytology as a clinical biomarker of genetic damage in oral carcinogenesis: A systematic review and meta-analysis

Oral squamous cell carcinoma (OSCC) is the most common oral malignancy, often preceded by oral potentially malignant disorders (OPMDs). Currently, no clinical biomarker exists to predict malignancy, necessitating OPMD follow-up. Habits and environmental factors, such as smoking, and alcohol consumption, influence OSCC onset. Increased micronuclei (MNs) formation has been observed in the development of OSCC. Non-invasive diagnostic tests like exfoliative cytology offer painless and regular monitoring options. This study evaluates the impact of tobacco, alcohol, and pesticide exposure on MNs occurrence in exfoliative cytology-collected oral mucosal cells, assessing their potential as non-invasive biomarker for OSCC development prediction and monitoring in high-risk patients. Despite results from this meta-analysis supporting the existence of a stepwise increase from controls to patients with OPMD to OSCC, the translation of these findings into clinical practice is limited due to intra- and inter-individual heterogeneity, as well as methodological variability in MNs quantification. Various factors contribute to this heterogeneity, including demographic variables, methodological variability of different laboratories, staining techniques, sample collection location, and patient characteristics. All these points were discussed to provide further insights and improve standardization for future studies.

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.