Biochemical and molecular evidences on the protection by magnesium oxide nanoparticles of chlorpyrifos-induced apoptosis in human lymphocytes

Chlorpyrifos (CP) is one of the most widely used organophosphate (OP) insecticides in agricultural and residential pest control with its attendant adverse health eff ect. In the present study, it is proposed to investigate the possible modulatory role of magnesium oxide nanoparticles (MgO NPs) against CP-induced toxicity in human lymphocytes and determine the mechanisms lying behind this protection by viability and biochemical assays. Isolated lymphocytes were exposed to 12? g/mL CP either alone or in combination with diff erent concentrations of MgO NPs (0.1? g/mL, 1? g/mL, 10? g/mL, and 100? g/mL). After a 3-day incubation,the viability and oxidative stress markers including cellular mitochondrial activity, caspase-3 and -9 activities, total antioxidant power, lipid peroxidation, and myeloperoxidase (MPO) activity were measured. Also, the levels of tumor necrosis factor-? (TNF-?) as infl ammatoryindex, along with acetylcholinesterase (AChE) activity were measured. Statistical diff erences were determined using one-way analysis of variance (ANOVA) and Dunnett’s multiple comparison tests. It is indicated that CP-exposed lymphocytes treated with MgO NPs resulted in a substantial reduction in the pace of mortality as well as the stages of oxidative stress in a dose-dependent manner. Also, MgO NPs (100? g/mL) meaningfully restored CP-induced increase of TNF-? (P < 0.001) and decrease of AChE activity (P < 0.001) and were capable of preventing CP-treated human lymphocytes from apoptosis (P < 0.001). Our results demonstrate that MgO NPs in approximate 100 nm diameter not only make cells resistant to the toxic properties of CP but also attenuate toxic eff ects of CP,which is demonstrating the potential of MgO NPs to be applied in future immune defi ciency therapeutic strategies.