Abstract: Objective To study the genotoxicity of chromosomal aberration in vitro of electronic cigarette under good laboratory practices（GLP）. Methods In accordance with the requirements of International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use（ICH）S2（R1） and Organization for Economic Co-operation and Development（OECD） Test Guideline 473 chromosomal aberration test,the Chinese hamster fibroblast cell line（CHL） were used,the final exposure concentrations of Yuekehuanying e-cigarette liquid were set at 409.4,136.5,45.5 and 15.2 μg/mL,while a solvent control group,cyclophosphamide and mitomycin-positive group were set up. The cells were harvested after exposure for approximately 4 hours（with or without metabolic activation system,S9） and approximately 24 hours（without S9）. The cells were counted by Trypan blue staining. After hypotonic,fixed,droplet,and Giemsa staining,1 000 metaphase phase cells and at least 300 metaphase division phase cells were observed to analyze the aberration types. Fisher's exact probability method was used to compare statistical differences. Results Under each exposure condition,no test articles were deposited when cells were collected. The relative cell population multiplication（%） was >50% under each exposure condition for approximately 4 hours with or without S9 metabolic activation system and for approximately 24 hours with or without S9,and the cell division index and the inhibition rate of the division index were within the normal range,and no apparent cytotoxicity was observed. There was no significant increase in the chromosome aberration rate of CHL cells. Conclusion Under the conditions of this study,the electronic cigarettes do not cause a significant increase in the chromosome structural aberration rate of CHL cells,so the results of this experiment are negative.

Key words: Electronic cigarettes, Good laboratory practice, Chromosomal aberration, Genotoxicity