Effects of Magnesium Oxide Nanoparticles on Depression- Like Behavior Induced by Naloxone and Morphine Withdrawal

Background: Our previous studies indicated that nanoparticles of magnesium oxide (nano-MgO) can affect some of morphine withdrawal signs such as anxiety, but their interaction with opioidergic system activity in depression- like behavior induced by morphine withdrawal is not clear. Objectives: The present study aimed at investigating the effects of nano-MgO on depression induced by naloxone and morphine withdrawal in animals. Methods: Adult male NMRI mice were divided in ۲ main groups. For the control group, intraperitoneal (i.p.) injection of nano-MgO (۱, ۲.۵ and ۵ mg/kg) or naloxone (۳ and ۵ mg/kg) and coinjections of naolxone۵ before and after nano-MgO۲.۵ mg/kg were done. The morphine withdrawal group received saline or nano-MgO ۲.۵, ۵ and ۱۰ mg/kg as acute (a single injection at the test day) and chronic injection (coinjected with morphine for ۴ days). To develop morphine dependency, increasing doses of ۲۰, ۴۰, and ۸۰ mg/kg morphine were injected subcutaneously for ۴ days. Then, mice received a final morphine injection (۴۰mg/kg) ۳ hours prior to naloxone (۵ mg/kg (i.p.)) on the test day. Depression- like behavior was assessed by the tail suspension test. Results: Naloxone ۳ and ۵mg/kg induced depression (P < ۰.۰۵ and P < ۰.۰۱, respectively), while acute injection of nano-MgO۲.۵mg/kg after naloxone۵ mg/kg improved depression (P < ۰.۰۱). Morphine withdrawal has induced depression in addicted mice (P < ۰.۰۵), while acute injection of nano-MgO۲.۵ mg/kg (P < ۰.۰۵) and nano-MgO ۵ and ۱۰ mg/kg (P < ۰.۰۱) reduced it. Conclusions: Nano-MgO can reduce depression- like behavior induced by naloxone and morphine withdrawal in animals probably by interaction with opioid receptors.

کلیدواژه ها:

Depression ، Naloxone ، Nanoparticles ، MgO ، Morphine Withdrawal