No abstract

No abstract

Sialic acids (Sia) are postulated to improve cognitive abilities. This study evaluated Sia effects on rat behavior when administered in a free form as N-acetylneuraminic acid (Neu5Ac) or conjugated as 6′-sialyllactose (6′-SL). Rat milk contains Sia, which peaks at Postnatal Day 9 and drops to a minimum by Day 15. To bypass this Sia peak, a cohort of foster mothers was used to raise the experimental pups. A group of pups received a daily oral supplementation of Neu5Ac to mimic the amount naturally present in rat milk, and another group received the same molar amount of Sia as 6′-SL. The control group received water. After weaning, rats were submitted to behavioral evaluation. One year later, behavior was re-evaluated, and in vivo long-term potentiation (LTP) was performed. Brain samples were collected and analyzed at both ages. Adult rats who received Sia performed significantly better in the behavioral assessment and showed an enhanced LTP compared to controls. Within Sia groups, 6′-SL rats showed better scores in some cognitive outcomes compared to Neu5Ac rats. At weaning, an effect on polysialylated-neural cell adhesion molecule (PSA-NCAM) levels in the frontal cortex was only observed in 6′-SL fed rats. Providing Sia during lactation, especially as 6′-SL, improves memory and LTP in adult rats.

No abstract

Several sources of long-chain polyunsaturated fatty acids (LCP) are currently available for infant formula supplementation. These oils differ in their fatty acid composition, the chemical form of the fatty acid esters [triacylglycerols (TG) or phospholipids (PL)] and presence of other lipid components. These differences may affect LCP absorption, distribution and metabolic fate after ingestion. The purpose of the present study was to evaluate the influence of different chemical forms of dietary LCP on the composition of plasma, plasma lipoproteins, liver and jejunum in infant piglets. Thirty pigs (5 d old) were bottle-fed different diets for 4 wk: a control diet (C), a diet containing LCP as TG from tuna and fungal oils (TF-TG) or a diet containing LCP as PL from egg yolk (E-PL). We measured lipid and fatty acid composition of plasma and lipoproteins, as well as lipid composition of liver and intestinal mucosa. The arachidonic and docosahexaenoic acids in HDL-PL were significantly higher in piglets fed the E-PL diet than in those fed the TF-TG diet. Opposite results were found in the LDL-PL diet. No significant differences were found between groups in TG or cholesterol concentrations of plasma or lipoproteins. Arachidonic acid in plasma PL and cholesteryl esters was significantly higher in the E-PL group than in the TF-TG group. The chemical form in which LCP esters are present in different dietary sources influences their distribution in plasma lipoproteins. This may be important for infant nutrition and suggests that not all LCP sources may be biologically equivalent.