Abstract:
Mechanism of action of both magnesium and zinc in mediating their antidepressant activities is supposed to be
through NMDA receptor antagonism. In the background of similarity in mechanism of action of zinc and
magnesium as antidepressant through antagonism of NMDA receptors and evidences for anticonvulsant
actions of magnesium being mediated through NMDA receptors blockade; present study was designed to test
whether zinc has an additional anticonvulsant activity. Thirty six albino rats of either sex were divided in to 6
groups with 6 animals in each group. Group-I received distilled water (1ml/kg body weight) was control
group. Group-II receiving phenytoin sodium (20mg/kg body weight) was the standard group. Group-III, IV
and V were test groups receiving zinc sulfate at doses of 30mg/kg, 150mg/kg and 300mg/kg respectively.
Animals were screened for anticonvulsant activity by Maximum Electroshock (MES) method and for
generalized CNS depressant effect by photo-actometer method. With regard to anticonvulsant activity there
was no statistically significant differences between any of the zinc sulfate treated groups with control and
standard drug phenytoin. There was no evidence for possible anticonvulsant activity of zinc after single dose
treatment at three selected doses in presence of generalized CNS depressant effect.
