Abstract
In this study we attempt to investigate the new role of docosahexaenoic acid (DHA) supplementation on cognitive ability in aged mice. Kunming-line mice were treated with DHA (200, 400 mg/kg body weight/day) for 30 successive days. The cognitive ability of mice was assessed by learning and memory behavioral test; the levels of DHA were assessed by capillary gas chromatography; the levels of dopamine (DA), norepinephrine (NE), and 5-hydroxytryptamine (5-HT) were assessed by high-performance liquid chromatography; the levels of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) proteins were assessed by the enzyme-linked immunosorbent assay method. The results showed the cognitive ability of mice were significantly different between the DHA-treated groups and the aged group, and orally administered DHA can increase the levels of DA, NE and 5-HT, the content of BDNF and NGF proteins in hippocampus, frontal cortex and striatum tissues. In addition, aged-related changes in phospholipid DHA content were seen. Decreases in DHA were mostly corrected by DHA supplementation. These novel data suggest that DHA supplementation can improve the cognitive dysfunction due to aging by increasing the levels of BDNF and NGF protein and the levels of DA, NE, 5-HT to some extent. We speculate that the mechanism of DHA on cognitive ability may have a beneficial effect on signaling networks through modulation of monoamine neurotransmitters and neurotrophic factors in brain aging.
Declaration of interest: This research was funded by the Sichuan Province Science and Technology Platforms Project, the Cellular and Molecular Biology Experiment Platform Construction Project for Chinese Traditional Medicine, Sichuan Finance and Education Project (No. 2005172).