Pathophysiology of
postpartum depression (
PPD) has been associated with many factors, such as neuroendocrine,
neuroinflammation and
neurotransmitter changes.
Fish oil (FO) improves
PPD both in humans and animals. However, little is known with regards to its pharmacology on a
PPD-like rat model. Hence, the current study aimed at investigating the effects of FO on a
PPD-like rat model. Female rats were induced with
PPD-like symptoms and then randomly divided into six groups (n = 6) for two experimental protocols. Protocol 1 consisted of
PPD-like rats (2 mL distilled water),
PPD-like + FO (9 g/kg/d) and
PPD-like +
Fluoxetine (FLX) (15 mg/kg/d) groups of rats, whereas Protocol 2 consisted of
PPD-like rats (2 mL distilled water) + PCPA (
p-chlorophenylalanine) 150 mg/kg,
PPD-like + FO (9 g/kg/d) + PCPA 150 mg/kg and
PPD-like + FLX (15 mg/d) + PCPA 150 mg/kg groups of rats, respectively. All treatments were administered orally for 10 days postpartum, except PCPA, which was given intraperitoneally. Prior to
euthanasia, the
antidepressant-like effect of the FO was evaluated using the forced swimming test (FST) and open field test (OFT) on day 10 postpartum. Biochemical analysis of
serotonin,
serotonin metabolite and
serotonin turnover from their prefrontal cortex and hippocampus were also measured. The results showed that FO decreased immobility time and increased swimming time significantly, but not climbing time in FST. Further, it also decreased
serotonin metabolite and turnover significantly in the hippocampus of the
PPD-like rats. In contrast, administration with PCPA reversed all the outcomes. The
antidepressant-like effects of FO were found to be similar with that of FLX. Thus, it can be concluded that FO exerts its
antidepressant-like effects in
PPD-like rats through modulation of serotonergic system.