Effect of Conjugated Linoleic Acid on Memory and Reflex Maturation in Rats Treated During Early Life.

In the critical period of neurodevelopment (gestation and lactation), maternal consumption of essential fatty acids (FAs) can alter the offspring cognitive function permanently causing damage. Lipids can regulate neurotrophin and compose brain tissue. However, the effects of maternal consumption of a mixture of conjugated linoleic acid (CLA) on an offspring nervous system are not completely clear. We aimed to investigate the impacts of different CLA concentrations mixed into the maternal diet during early life on neonatal reflex maturation and cognitive functions of the offspring. Three groups were formed: control (CG): receiving a standard diet; CLA1: receiving a diet containing 1% of CLA, and CLA3: receiving a diet containing 3% of CLA, offered during gestation and lactation. After birth, the reflex responses of the offspring were observed from the 1st to the 21st day. After weaning, the animals' anxiety and memory were assessed using open field (OF) and novel object recognition tests. Fatty acids in the breast milk and the offspring's brain were also quantified. The data were analyzed using one-way ANOVA and the Kruskal-Wallis test. CLA1 presented accelerated palmar grasp disappearance versus CLA3 and negative-geotaxis versus CG; and the CLA3 presented increases for most reflexes (cliff-avoidance, vibrissa-placing, negative-geotaxis, and auditory-startle response), and decrease in reflexes palmar grasp and free-fall righting versus CG (p < 0.05). CLA3 group explored less of the OF in the second exposure. CLA1 and CLA3 presented an increased exploration ratio for new objects, which indicates memory improvement. The milk tested from CLA3 demonstrated an increase in polyunsaturated fatty acids (PUFAs), and a decrease in monounsaturated fatty acids. The amount of CLA in milk was greater in CLA1 and CLA3 and in the brain offspring both presented moderated amounts of CLA. Maternal treatment with the CLA mixture induced anticipated reflex maturation and improved memory in the offspring. Even though CLA was detected in the brains in only trace amounts, offspring's brain PUFA and SFA levels were increased. Further studies aimed to delineate the effect of maternal CLA supplementation on offspring's brain lipid metabolism and long-term neurologic outcome are needed to confirm these findings.

Maternal suppplementation with conjugated linoleic acid reduce anxiety and lipid peroxidation in the offspring brain.

BACKGROUND: Maternal consumption of fatty acids can alter neuronal membrane function, synaptic connections, and protect the brain from alterations caused by disturbances such as lipid peroxidation and anxiety in the offspring. We aimed to investigate how the maternal consumption of conjugated linoleic acid (CLA) interferes in anxiety behavior of the offspring and cerebral lipid peroxidation. METHODS: Three groups were formed: control (CG) - diet without CLA; CLA1 - diet containing 1% of CLA; and CLA3 - diet containing 3% of CLA. These diets were offered to the mothers from the 7th day of gestation until the end of lactation. The following behavioral tests were used: Elevated plus maze (EPM), Open Field (OF) and Light-dark Box (LDB). Levels of malondialdehyde (MDA) and glutathione were measured in the offspring's brains. Data were analyzed by ANOVA followed by the Holm-Sidak post-test or the Kruskal-Wallis test (p < 0.05). RESULTS: CLA1 and CLA3 showed higher number of entries in the open arms and time spent in the central area in EPM, they translocated and ambulated more in the clear area of the LDB and presented more rearing in the OF compared to CG (p < 0.05); moreover, they presented higher concentration of glutathione and lower MDA in brain tissue (p < 0.05). LIMITATIONS: We evaluated the effect of maternal consumption of CLA on anxiety and lipid peroxidation in rats' offspring, but a similar study should be performed in humans. CONCLUSIONS: Maternal intake of CLA induced a decrease in the parameters of anxiety and cerebral lipid peroxidation in the offspring.

Effect of diets with goat milk fat supplemented with exercise on anxiety and oxidative stress in the brains of adult rats.

The objective of this study is to evaluate the effects of a diet with goat milk fat supplemented with physical training on markers of oxidative stress in the brain and anxiety behavior in rats. Adult male rats were randomly divided into six groups (n = 10 per group): control sedentary (CON) and exercised (CON-EX) groups, goat milk fat sedentary (GM) and exercised (GM-EX) groups, goat milk fat enriched with CLA sedentary (GM-CLA) and exercised (GM-CLA-EX) groups. The exercised groups were submitted to treadmill running during four weeks. Anxiety parameters were evaluated with the open field (OF) and elevated plus maze (EPM) tests. Malondialdehyde (MDA) and glutathione (GSH) levels were measured in the brain. Compared to the CON and GM groups, the GM-CLA group (p < 0.05), in which the animals were treated with goat milk fat with an increased CLA content, showed higher rearing. All exercised animals presented an increase in grooming when compared to sedentary animals. The number of entries in the open arms and time spent in the open arms was higher in sedentary groups (p < 0.05). MDA levels in the brain were lower in the GM group when compared to those in the CON group (p < 0.05). MDA increased in exercised animals (p < 0.05). GM and GM-CLA groups showed a significant elevation in the GSH levels in the brain. Goat milk fat, however, showed a potential effect on the reduction of oxidative stress, which was associated with a reduction in anxiety behavior. However, this beneficial effect was reversed when exercise was involved.