Abstract
Folate, vitamins B-12 and B-6 are essential nutritional components in one-carbon metabolism in different ways and typically increase methylation capacity. This could support methylation of phosphatidylethanolamine (PE) to phosphatidylcholine (PC) by PE- N -methyltransferase (PEMT) in the liver. It has been suggested that PC synthesis by PEMT influence circulating levels of polyunsaturated fatty acids, like docosahexaenoic acid (DHA) (Watkins et al., J Nutr 2003; Pynn et al., J Lipid Res 2011). The aim of the present experiment was to investigate whether dietary enrichment with the three B-vitamins could affect plasma lipid composition and particularly plasma DHA levels in rats. After feeding rats one of four diets with increasing levels of folate, vitamins B-12 and B-6 (0%, 100%, 400%, or 1600% of the recommended daily intake) for 4 weeks, plasma fatty acid composition was analyzed using GC and the polar lipid profile was analyzed at the Kansas Lipidomics Research Center using triple quadrupole MS. In addition, plasma homocysteine concentration was measured as an indicator of methylation capacity. The results of the GC analysis indicate that dietary folate, vitamins B-12 and B-6 dose-dependently increased plasma DHA concentration. Plasma DHA and homocysteine showed a significant negative correlation. Data analysis of the polar lipid profile is ongoing. The first results demonstrate the interdependence between folate, vitamins B-12 and B-6 intake and plasma DHA. In this way, intake of supplemental B-vitamins may increase the availability of DHA for processes like neuronal membrane phospholipid synthesis. The increase in plasma DHA may be explained by the effects of B-vitamins on methylation capacity and subsequent enhancement of PC synthesis by the PEMT pathway. Details on this mechanism, implications for Alzheimer's disease, and pending additional results of the MS analysis will be presented.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call