Nicotinamide riboside
Articulo interesante: http://www.marketwatch.com/story/niagen … 2013-06-27
The best candidate today for a NAD+ precursor and Sirtuin promoter might be Nicotinamide riboside, a member of the Niacin family. A lot of research has been done by the Brenner group:
Nicotinamide riboside promotes Sir2 silencing and extends lifespan via Nrk and Urh1/Pnp1/Meu1 pathways to NAD+.Belenky P, Racette FG, Bogan KL, McClure JM, Smith JS, Brenner C.
Departments of Genetics and Biochemistry and the Norris Cotton Cancer Center, Dartmouth Medical School, Rubin 733-HB7937, Lebanon, NH 03756, USA.Although NAD(+) biosynthesis is required for Sir2 functions and replicative lifespan in yeast, alterations in NAD(+) precursors have been reported to accelerate aging but not to extend lifespan. In eukaryotes, nicotinamide riboside is a newly discovered NAD(+) precursor that is converted to nicotinamide mononucleotide by specific nicotinamide riboside kinases, Nrk1 and Nrk2. In this study, we discovered that exogenous nicotinamide riboside promotes Sir2-dependent repression of recombination, improves gene silencing, and extends lifespan without calorie restriction. The mechanism of action of nicotinamide riboside is totally dependent on increased net NAD(+) synthesis through two pathways, the Nrk1 pathway and the Urh1/Pnp1/Meu1 pathway, which is Nrk1 independent. Additionally, the two nicotinamide riboside salvage pathways contribute to NAD(+) metabolism in the absence of nicotinamide-riboside supplementation. Thus, like calorie restriction in the mouse, nicotinamide riboside elevates NAD(+) and increases Sir2 function.
PMID: 17482543 [PubMed – indexed for MEDLINE]
NR se encuentra naturalmente en la leche y la cerveza: http://www.cctec.cornell.edu/events/ctvf12/Sauve.pdf