title: Biochemical and molecular evidences on the protection by magnesium oxide nanoparticles of chlorpyrifos-induced apoptosis in human lymphocytes.
abstract: BACKGROUND
  Chlorpyrifos (CP) is one of the most widely used organophosphate (OP) insecticides in agricultural and residential pest control with its attendant adverse health effect. 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.
  
  
  METHODS
  Isolated lymphocytes were exposed to 12 μg/mL CP either alone or in combination with different concentrations of MgO NPs (0.1 μg/mL, 1 μg/mL, 10 μg/mL, and 100 μg/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-α (TNF-α) as inflammatory index, along with acetylcholinesterase (AChE) activity were measured. Statistical differences were determined using one-way analysis of variance (ANOVA) and Dunnett's multiple comparison tests.
  
  
  RESULTS
  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 μg/mL) meaningfully restored CP-induced increase of TNF-α (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).
  
  
  CONCLUSIONS
  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 effects of CP, which is demonstrating the potential of MgO NPs to be applied in future immune deficiency therapeutic strategies.
authors.affiliation: Toxicology and Poisoning Research Center, Ahar Branch, Ahar, Iran; Pharmaceutical Sciences Research Center, Ahar Branch, Ahar, Iran; Islamic Azad University, Ahar Branch, Ahar, Iran.
authors.forename: Vida
authors.initials: V
authors.lastname: Heydary
authors.affiliation: Toxicology and Poisoning Research Center, Ahar Branch, Ahar, Iran; Pharmaceutical Sciences Research Center, Ahar Branch, Ahar, Iran; Department of Tissue Engineering, School of Advanced Technologies in Medicine, Tehran, Iran.
authors.forename: Mona
authors.initials: M
authors.lastname: Navaei-Nigjeh
authors.affiliation: Toxicology and Poisoning Research Center, Ahar Branch, Ahar, Iran; Pharmaceutical Sciences Research Center, Ahar Branch, Ahar, Iran.
authors.forename: Mahban
authors.initials: M
authors.lastname: Rahimifard
authors.affiliation: Toxicology and Poisoning Research Center, Ahar Branch, Ahar, Iran; Pharmaceutical Sciences Research Center, Ahar Branch, Ahar, Iran.
authors.forename: Azadeh
authors.initials: A
authors.lastname: Mohammadirad
authors.affiliation: Toxicology and Poisoning Research Center, Ahar Branch, Ahar, Iran; Pharmaceutical Sciences Research Center, Ahar Branch, Ahar, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Baeeri
authors.affiliation: Toxicology and Poisoning Research Center, Ahar Branch, Ahar, Iran; Pharmaceutical Sciences Research Center, Ahar Branch, Ahar, Iran; Islamic Azad University, Ahar Branch, Ahar, Iran; Department of Tissue Engineering, School of Advanced Technologies in Medicine, Tehran, Iran; Department of Toxicology and Pharmacology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Abdollahi
keywords: Acetylcholinesterase (AChE); antiapoptotic; antioxidant; chlorpyrifos (CP); human lymphocytes; magnesium oxide nanoparticle (MgO NP); organophosphate (OP); oxidative stress