A Histochemical Comparison of Feulgen and Papanicolaou Stains in Demonstrating Cytotoxic and Genotoxic Effects of Cigarette Smoking on Human Buccal Mucosa Cells

Background: Different histochemical stains have been applied to demonstrate the cytotoxic and genotoxic effects of cigarette smoking on cells. Feulgen and Papanicolaou were the most popular stains to demonstrate nuclear abnormalities. The aim of this study was to compare Feulgen and Papanicolaou stains in demonstrating the cytotoxic and genotoxic effects of cigarette smoking on exfoliated oral mucosa cells. Methods: A total of 31 cigarette smokers and 15 non-smokers were included in this case-control study. Using a wooden spatula, two samples were taken from each participant. The samples from the left buccal mucosa were stained with Feulgen and the right mucosa with Papanicolaou. The mean number of micronuclei and the number of cells with pyknosis, karyorrhexis, and karyolysis were determined on Feulgen and Papanicolaou-stained slides. The number of counted cells with pyknosis, karyorrhexis, and karyolysis in 1000 cells/subject was recorded. The mean number of micronuclei was determined by the number of counted micronuclei per 1000 cells per subject. Results: The number of micronuclei was not significantly different between Feulgen and Papanicolaou stained samples (P=0.27). Demonstration of karyolysis (P=0.73) and karyorrhexis (P=0.24) was not significantly different between Feulgen and Papanicolaou staining methods. The Feulgen was significantly more effective in demonstrating pyknosis compared to Papanicolaou (P=0.02). Conclusions: Feulgen and Papanicolaou stains had similar effectiveness in demonstrating DNA alterations (micronucleus) and cellular death features (karyorrhexis and karyolysis). Feulgen was preferable to display pyknosis than Papanicolaou.