Objective: Glucocorticoid receptors (GRs) have an important role in mediating the effects of glucocorticoids (GCs) on brain plasticity and mood. GC drugs and elevated cortisol level can cause psychiatric disorders including depression. The B-vitamins have numerous benefits on general health as well as mood, and cognition. The aim was evaluating the effect of vitamin B6 following dexamethasone (DEX)-induced depression in mice, to see if it can be proposed as a remedy for psychiatric problems following GC therapy. Methods: Male mice were housed by six. The immobility time was measured, in the forced swimming test as an animal model of despair and sucrose preference was measured in order to test anhedonia (<65% was taken as a criterion for anhedonia). DEX was administered either single dose (15, 60, 250 mcg/kg) or 15 mcg/kg for 7 consecutive days, vitamin B6 (100 mg/kg) was administered for 7 days. Results: DEX dose dependently increased immobility time that denoted animal depression; as it was 177.5 seconds ± 3 following 60 mcg/kg and 188.3 seconds ± 5 following 250 mcg/kg administration (vs. control animals 164 seconds ± 6, P < 0.01). Premedication with vitamin B6 prevented DEX-induced depression and demonstrated antidepressant effect. It also reduced the immobility time following 7days DEX injection (192.5 seconds ± 6) to 100 seconds ± 5.5; sucrose preference escalated from 50%±3 to 87%±4. Conclusion: Vitamin B6 prevented DEX-induced depression possibly by altering the GR function. Thus Vitamin B6 could be promising in patients suffering from GC-induced psychiatric adverse effects and probably controlling stress and preventing its affective disorder out comes.
Keywords: Cortisol; Depression; Dexamethasone; Forced swimming test; Glucocorticoid; Glucocorticoid receptors; HPA axis; Vitamin B6.