Nicotinamide

Nicotinamide is an amide form of niacin, which is also known as vitamin B3, that can be biosynthesized in vivo or obtained through the diet.{63061} It is a precursor in the synthesis of the metabolic cofactor NAD+ and an inhibitor of sirtuin 1 (SIRT1; IC50 = <50 µM).{63062} Nicotinamide (10 µM) increases the activity of serine palmitoyltransferase (SPT) and the biosynthesis of ceramide, glucosylceramide, sphingomyelin, free fatty acids, and cholesterol in primary human keratinocytes.{63063} Nicotinamide (40 µM) induces apoptosis in SNU-398, SNU-739, and HepG2 hepatocellular carcinoma (HCC) cells, and it prevents the formation of neoplastic lesions in a diethylnitrosamine-induced mouse model of HCC.{63064} Unlike niacin, nicotinamide does not reduce plasma lipid levels or induce flushing.{63065,63066,63067}