Investigating the effects of chronic magnesium oxide nanoparticles on aerobic exercise-induced antinociception in adult male rats

Abstract

Background and Objective: Magnesium is a critical cation in human body that can block some receptors and channels associated with nociception. Aerobic exercise (AE) increases pain threshold in athletes. In this study, we investigated the effects of chronic administration of magnesium oxide nanoparticles (MgONPs) and MgO on nociception in the presence and absence of AE-induced analgesia. Materials and Methods: Adult male Wistar rats were divided into six groups: Two controls (saline and exercise groups), four intervention groups: MgONPs and bulk MgO groups (receiving intraperitoneal 1 mg/kg for 5 days/week and 6 weeks) with and without exercise. The exercise groups were trained 30 min using treadmill after the injections. At the end of the 6th week, analgesia time was evaluated by hot plate test. Results: AE significantly reduced pain response compared with the control group (P < 0.01). In addition, both MgO and MgONPs significantly reduced pain response than the control group (P < 0.001). There were no significant differences between analgesic effect of exercise alone and MgO or MgONPs with exercise. Conclusion: The analgesic effects of AE and MgO supplements are probably induced by common mechanisms in the central nervous system.