Objective: The main objective of this work was to study the memory-enhancing activity of docosahexaenoic acid (DHA) supplementation in normal memory function and scopolamine-induced impaired memory in mice.Methods: The gum acacia suspension of DHA was administered by gavage at the dose of 200 and 300 mg/kg in mice for 30 days to evaluate memory-enhancing potential on normal and scopolamine-induced impaired memory in albino mice. Escape latency in Morris water maze (MWM) and transfer latency (TL) in elevated plus maze (EPM) were recorded, respectively. Mice were given four trial sessions per day to locate the platform for 4 days in MWM model. Scopolamine 1 mg/kg was injected i.p. to produce memory impairment in mice.Result: DHA suspension at the dose of 300 mg/kg showed significant reduction of escape latency and TL as compared to control group, and the effect was comparable to that of standard nootropic agent piracetam at the dose of 100 mg/kg in normal and scopolamine-treated mice. However, DHA at the dose of 200 mg/kg showed significant memory-enhancing effect in only scopolamine-induced impaired memory model.Conclusion: The study revealed that the chronic administration of DHA exhibited significant memory-enhancing activity against both normal as well as scopolamine-treated impaired memory mice groups, however, this effect was more marked on scopolamine-induced memory impairment as compared to normal memory function.

Background: Depressive disorder is a prevalent psychiatric disorder, which affects 21% of the world population. Many drugs which are available as effective antidepressants produce various side effects like sedation weight gain postural hypotension etc., so there is need to develop novel compounds with minimized side effects. Hence this study was aimed to investigate the antidepressant activity of DHA, an omega-3 polyunsaturated fatty acid in albino mice.Methods: Animals were divided into four groups, consisting six mice in each group. Out of these, group I served as control (2% gum acacia), group II and III received test drug in two different doses 200mg/kg and 300mg/kg respectively and group IV received fluoxetine (20mg/kg) as standard drug. To determine the antidepressant-like activity, we used forced swim test and tail suspension test in mice. These methods are based on the observation that a mouse show alternating agitation and immobility; the immobility is indicative of a state of depression.Results: DHA produced significant antidepressant effect at all the doses, as indicated by reduction in immobility times as compared to control in both FST and TST. (P˂0.05) The efficacy of DHA at dose of 300 mg/kg was comparable with that of fluoxetine. DHA at 200mg/kg dose showed significantly less antidepressant activity compared to fluoxetine. (P˂0.05).Conclusions: The result specifies that compared to two doses of DHA (200mg/kg and 300mg/kg), higher dose of DHA found as an effective dose for treating depression produced due to stress.

Background: Inflammation is a tissue reaction to infection, irritation of foreign substance. It is a part of the host defence mechanism but if in excess it becomes harmful. Docosahexaenoic acid (DHA) is omega-3-derivative of alpha-linolenic acid. This study was conducted to determine the anti-inflammatory activity of DHA and its comparison with standard drug diclofenac.Methods: The study was carried out by using inflammatory models in male albino rats. Rats were divided into 4 groups of 6 animals of each. The anti-inflammatory activity was studied with carrageenan induced rat paw edema.  The anti-inflammatory activity of DHA was compared with standard drug diclofenac. The study parameters for acute inflammation was assessment of reduction in inflammation and the percentage inhibition of the paw edema.Results: DHA 200 mg/kg, DHA 300 mg/kg, and diclofenac 10 mg/kg showed 58%, 64%, and 67% reduction in paw volume, respectively. The DHA showed significant (p<0.05) anti-inflammatory activity in both dosages as compared to control and was dose dependent.Conclusions: DHA produced dose dependent anti-inflammatory activity which suggest its probable use in the treatment of inflammation.