Genotoxic and oxidative stress effects of 2-amino-9H-pyrido[2,3-b]indole in human hepatoma G2 (HepG2) and human lung alveolar epithelial (A549) cells

Abstract2-Amino-9H-pyrido[2,3-b]indole (AαC), which is present in high quantities in cigarette smoke and also in fried food, has been reported to be a probable human carcinogen. However, few studies have reported on the genotoxicity and oxidative stress induced by AαC. This study investigated the genotoxic effects of AαC in human hepatoma G2 (HepG2) and human lung alveolar epithelial (A549) cells using the comet assay. Significant increases in DNA fragment migration indicated that AαC causes serious DNA damage in HepG2 and A549 cells. The role of oxidative stress in the mechanism of AαC-induced genotoxicity was clarified by measuring the level of intracellular reactive oxygen species (ROS), the GSH/GSSG ratio and the formation of 8-hydroxydeoxyguanosine (8-OHdG), a marker of oxidative DNA damage. The results showed that the levels of ROS and 8-OHdG increased, whereas the GSH/GSSG ratio decreased. The concentration of 8-OHdG was positively related to DNA damage. Taken together, these results indicate that ...