Effect of Polycyclic Aromatic Hydrocarbons Extracted from Indoor Air of Coffee Shops on Oral Squamous Carcinoma Cell (KB/C152): An in Vitro Approach

Abstract

Introduction: The two main causes of indoor air pollution (IAP) are cooking and smoking. Toxic substances, including polycyclic aromatic hydrocarbons (PAHs), recognized as human carcinogens, are present in cooking and tobacco smoke. This study aims to determine the cytotoxicity and genotoxicity of PAHs collected from the indoor air of coffee shops on human cell line (KB/C152) in vitro approach. Materials and methods: Sampling pumps at a 2 l/min flow rate for 5 hours were applied to collect indoor air samples. Next, KB cells in cell culture medium were exposed to different concentrations of extracted PAHs using Methyl Thiazolyl Tetrazolium (MTT) test. Finally, terminal dUTP nick-end labeling (TUNEL) test and cell cycle assessments were both examined using flow cytometry. Results: The MTT test revealed a significant cytotoxic effect on KB cells depending on the PAHs concentrationas compared to the control cell line. The lethal concentration 50 (LC50) value against KB cells was 100 ± 3.09 µg/ml. Accordingly, exposure to extracted PAHs resulted in an arrest in the cell cycle at the sub-G1 checkpoint. The extracted PAHs suppressed the cell cycle in the sub-G1 phase, damaged DNA, and arrested KB cells from proliferating. Additionally, a statistically significant increase in DNA cleavage percentages (p ≤ 0.05) was seen in the TUNEL test, which also showed a dose-dependent increase in DNA damage. Conclusion: Extracted PAHs caused DNA damage and arrested in the cell cycle in epidermoid carcinoma of the mouth cells (KB/C152) in vitro mechanisms. This evaluation highlights mechanisms of exposure to extracted PAHs and their detrimental health effects.