Nicotine effects on enzymatic antioxidant defenses in human breast and ovarian cell lines

Introduction: Nowadays, the prevalence of nicotine abuse among women has increased dramatically. In the current study, we aimed to investigate the effect of nicotine exposure on breast MCF-7 and ovarian OVCAR-3 cell lines for assessing the toxicity of nicotine in the cells of these organs. Methods: The MCF-7 and OVCAR-3 cells were treated with increasing nicotine concentrations ranging from 0 (control), 10-11, 10^-8 and 10^-6 M for 24h. Effect of nicotine treatments on major antioxidant enzymes catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), cellular levels of glutathione (GSH) and malondialdehyde (MDA) were monitored. Results: We showed that the CAT activity in MCF-7 cells increased only at 10^-6 M dose of nicotine. The GPx and GR activity was decreased at 10^-8 and 10^-6 M of nicotine in MCF-7 cells, but in OVCAR-3 cells, this decrease was significant only at 10^-6 M dose of nicotine. Reduced GSH decrease was statistically significant only at 10^-8 and 10^-6 M of nicotine in MCF-7 cells; otherwise, in OVCAR-3 cells, this decline was significant only at 10^-6 M of nicotine. Nicotine at 10^-8 and 10^-6 M concentration caused a significant increase in MDA levels in MCF-7 cells. Conclusion: This study showed that breast MCF-7 cells are more vulnerable than ovarian OVCAR-3 cells against nicotine-induced oxidative toxicity.