On The Protection by The Combination of CeO2 Nanoparticles and Sodium Selenite on Human Lymphocytes against Chlorpyrifos-Induced Apoptosis In Vitro

OBJECTIVE Chlorpyrifos (CP) as an organophosphorus pesticide is thought to induce oxidative stress in human cells via producing reactive oxygen species (ROS) that leads to the presence of pathologic conditions due to apoptosis along with acetylcholinesterase (AChE) inhibition.This study aimed to evaluate the apoptotic effects of CP and to assess the protective potential of CeO2nanoparticle (CNP) and sodium selenite (SSe) by measuring cascades of apoptosis, oxidative stress, inflammation, and AChE inhibition in human isolated lymphocytes. MATERIALS AND METHODS In the present experimental study, we examined the anti-oxidative and AChE activating potential of CNP and SSe in CP-treated human lymphocytes. Therefore, the lymphocytes were isolated and exposed to CP, CP+CNP, CP+SSe, and CP+CNP+SSe after a three-day incubation. Then tumor necrosis factor-alpha (TNF-α) release, myeloperoxidase (MPO) activity, thiobarbituric acid-reactive substances (TBARS) levels as inflammatory/oxidative stress indices along with AChE activity were assessed. In addition, the apoptotic process was measured by flow cytometry. RESULTS Results showed a significant reduction in the mortality rate, TNF-α, MPO activity, TBARS, and apoptosis rate in cells treated with CNP, SSe and their combination. Interestingly, both CNP and SSe were able to activate AChE which is inhibited by CP. The results supported the synergistic effect of CNP/SSe combination in the prevention of apoptosis along with oxidative stress and inflammatory cascade. CONCLUSION CP induces apoptosis in isolated human lymphocytes via oxidative stress and inflammatory mediators. CP firstly produces ROS, which leads to membrane phospholipid damage. The beneficial effects of CNP and SSe in reduction of CP-induced apoptosis and restoring AChE inhibition relate to their anti-oxidative potentials.