Background: There is a plethora of studies indicating temporal relationship between utilization
of Omega-3-fatty acids and amelioration of emotional distress including depression. Some studies
have also emerged to indicate the role of fish oil (FO) as adjunct therapy for depressive symptoms in
clinical literature. In order for such view to have heuristic value, pre-clinical behavioral paradigms are needed to scrutinize
whether FO has efficacy as adjunct therapy for depressive symptoms. In order to fill the gap in the literature, this
study examined the effects of FO on behavior in untreated mice, and mice treated with the antidepressant drug fluoxetine.
Method: Male/female mice were randomly grouped and orally treated for 28 days with saline (control), FO (0.05 or 0.1
mL/day), fluoxetine alone (10 mg/kg), and fluoxetine (1 or 10 mg/kg) given with FO (0.05 or 0.1 mL / day). After 28
days, the mice were subjected to two indices of despair and helplessness, viz forced swimming test (FST), and tail suspension
test (TST) along with motor activity.
Results: In the FST, FO at two different doses (0.05mL or 0.1 mL) decreased the immobility time and this effect was not
potentiated by combining fluoxetine. In TST, FO significantly decreased the immobility time compared to control (saline)
at same doses and this effect that was not potentiated by adding fluoxetine. Motor activity was not significantly affected
by any of the treatments.
Conclusion: FO displayed anti-depressant - like action suggested by the FST and TST. Combined treatment with fluoxetine
and FO did not significantly affect the performance of mice on these two tests. This suggest FO has direct bearing on
the present reported behavioral paradigm of despair and helplessness. Future studies to explore molecular the molecular
mechanisms behind the presently observed behavioral effect of FO in this animal model.