RESUMO
To evaluate the behavioral effect of pyridoxine on the antidepressant action of imipramine. Male Wistar albino mice of weights 25-35gms were used. Two experiments were carried out; the first on the acute effect of pyridoxine on the duration of immobility, and the second on the sub-chronic effects of pyridoxine alone and in combination with imipramine. In the first experiment, 4 groups of animals received saline, 65, 125, and 250mg/kg pyridoxine. Forced swimming test [FST] was performed 30 minutes after drug administration. In the second experiment, 6 groups of mice were used. The first group received saline, the second group received imipramine 10 mg/kg, the third group received pyridoxine 65mg/kg, the fourth group received pyridoxine 250mg/kg, the fifth group received combined treatment of imipramine and pyridoxine 65 mg/kg, while the sixth group received a combined treatment of imipramine and pyridoxine 250 mg/kg. Administration of drugs was at 24, 5, and one hour before the test. This work was carried out in the Biotechnology Research Center, Twisha, Libya, in June 2007. Acute administration of pyridoxine did not change the duration of immobility compared to the control group. Sub-chronic administration showed that pyridoxine [65mg/kg] did not change the immobility time, while a higher dose of pyridoxine [250mg/kg] decreased the immobility time. Imipramine at 10mg/kg reduces the immobility time significantly. Pyridoxine did not change imipramine action. Pyridoxine alone may produce an antidepressant effect. Pyridoxine in combination with imipramine did not change the imipramine action