Overview
Nicotinamide adenine dinucleotide (NAD+) is a dinucleotide coenzyme found in every living cell, where it plays a central role in redox biochemistry and cellular signaling. It exists in two interconvertible forms: the oxidized form (NAD+) and the reduced form (NADH). NAD+ serves as an essential electron carrier in the mitochondrial electron transport chain and is a required substrate for sirtuins (SIRTs) and poly(ADP-ribose) polymerases (PARPs), enzymes that regulate DNA repair, gene expression, and stress responses. NAD+ levels decline with age in multiple tissues, and this decline has been associated with impaired mitochondrial function and reduced cellular resilience in aging research models.
Mechanism
NAD+ participates in hundreds of enzymatic reactions as a hydride acceptor and donor, most critically in glycolysis, the citric acid cycle, and oxidative phosphorylation. As a substrate for sirtuin deacylases (SIRT1-7), NAD+ availability directly regulates sirtuin activity, which in turn modulates mitochondrial biogenesis, fatty acid oxidation, and inflammatory signaling via NF-kB. As a substrate for PARP1 and PARP2, NAD+ is consumed during DNA single-strand break repair. CD38, a membrane-bound NADase whose activity increases with age and inflammation, is another major consumer of NAD+ and contributes to age-related NAD+ depletion.
Research Areas
-
Aging & Longevity Research
NAD+ repletion strategies have been studied extensively in aging models, with research examining effects on mitochondrial function, cellular senescence, and healthspan markers.
-
Sirtuin Biology Research
NAD+ is an obligate substrate for all seven sirtuin family members. Research uses NAD+ supplementation and depletion models to study sirtuin-dependent gene regulation and metabolic adaptation.
-
DNA Repair Research
Studies have examined the relationship between NAD+ availability, PARP activity, and the efficiency of base excision repair and single-strand break resolution in cell culture models.
-
Mitochondrial Function Research
Research has explored NAD+/NADH ratios as indicators of mitochondrial redox state and their relationship to electron transport chain efficiency, ATP production, and reactive oxygen species generation.
Storage
Store lyophilized powder at -20°C in a sealed, desiccated container. NAD+ is hygroscopic and sensitive to light and moisture. Once reconstituted, use promptly — prolonged storage of reconstituted NAD+ solutions is not recommended due to hydrolytic instability.