effects of sodium selenite and vitamin e on the development of morphine dependency in mice

Background: antioxidant drugs may be useful in preventing morphine-induced dependency by suppressing oxidative stress. vitamin e which has many essential roles in the body is a powerful antioxidant. on the other hand, selenium is an essential trace element that plays a strong role in various biochemical pathways. the aim of this study was to investigate the effects of sodium selenite and vitamin e on morphine-induced dependency in mice. methods: ninety male mice, weighing 20 to 30 g, were randomly divided into 10 groups and were treated as follows: a) saline and b) morphine groups were pretreated (for 2 days) with normal saline (10 ml.kg^-1.day^-1, ip) then daily doses of normal saline (10 ml.kg^-1.day^-1, ip) and morphine (50 mg.kg^-1.day^-1) were added to the injections for the following 4 days, respectively. c, d, e) sodium selenite, f, g, h) vitamin e, i) vitamin e solvent (almond oil) and j) co-administration groups were pretreated (for 2 days) with sodium selenite (0.25, 0.5, 1 mg.kg-1.day-1, ip), vitamin e (20, 40, 60 iu.kg^-1.day^-1, ip), vitamin e solvent (10 ml.kg^-1.day^-1, ip) and combination of the drugs respectively, then morphine doses (50 mg.kg^-1.day^-1, ip) were added to the injections for the following 4 days. withdrawal symptoms were evaluated after injecting naloxone (4 mg/kg/ day). biochemical evaluations were also performed. results: the results showed that co-administration of sodium selenite and vitamin e (at low doses) significantly reduced morphine dependency (p < 0.05). conclusion: the synergistic effect of sodium selenite and vitamin e can be a suitable and efficient approach to reduce dependency.