NAD+

NAD+ (Nicotinamide Adenine Dinucleotide) is an essential cellular coenzyme involved in redox metabolism and energy production across all living systems. It functions as a critical electron carrier by cycling between its oxidized (NAD+) and reduced (NADH) states, enabling mitochondrial oxidative phosphorylation, glycolysis, and tricarboxylic acid (TCA) cycle activity in experimental models. Beyond its central role in bioenergetics, NAD+ serves as a required substrate for NAD+-dependent enzymes including sirtuins and poly(ADP-ribose) polymerases (PARPs), which regulate DNA repair, gene expression, and cellular stress-response signaling.

In vitro systems and structured clinical investigations evaluate endpoints including NAD+/NADH ratios, mitochondrial respiration parameters, ATP production markers, sirtuin activation profiles, PARP-mediated DNA repair signaling, and transcriptional responses associated with oxidative stress regulation. Additional research explores NAD+ salvage pathway dynamics, CD38-associated turnover, muscle metabolism, neuroprotective signaling frameworks, and age-related alterations in cellular bioenergetic capacity.