Interaction between anxiolytic effects of magnesium oxide nanoparticles

Objective(s): In recent years, nanotechnology has produced new forms of materials that are more effective than their predecessors. Magnesium is an essential element in the human body and certain studies have proved that its deficiency can induce anxiety in animals. In this study, the effect of magnesium oxide nanoparticles (MgO NPs) on anxiety, related behaviors, and interaction between their effects and anxiolytic effect of the exercises were examined in comparison to the conventional MgO (cMgO). Materials and Methods: Adult male Wistar rats weighing 190±20 gr were divided into control groups (receiving saline, without physical activity), and exercise groups (receiving cMgO and/or MgO NPs (1 mg/kg i.p.) daily for 6 weeks with or/and without exercise). Exercise groups were performing their daily physical activity protocol 30 minutes after injection. At the end of period, an elevated plus maze apparatus was used to evaluate the anxiety (%pen arm time (%OAT) and %open arm entries (%OAE) and locomotor activity. Results: Exercise significantly increased %OAT and %OAE (P < 0.05). MgO NPs caused an increase in %OAT, while cMgO did not have any effect on %OAT or %OAE. There was no notable difference among anxiety parameters in exercise groups with or without taking MgO NPs. Conclusion: It seems that the anxiolytic effect of exercise and MgO NPs has been mediated through common mechanisms that were a part of the anxiety process of the central nervous system.