Pharmacokinetic aspects of reduced nicotinamide adenin dinucleotide (NADH) in rats

Nicotinamide adenine dinucleotide (NADH) plays a major role in cellular metabolism and mitochondrial dysfunction and is thought that NAD(+)/NADH decrease neuronal degeneration and improve behavioral deficits. This potential use of NAD(+) or NADH as neuroprotective drugs requires an insight on the pharmacokinetic properties of these compounds. For this reason, we assessed the absorption of NADH in the small intestine in vitro using the everted gut sac technique. We show an enteral absorption of the intact NADH molecule. In the gut sac, NADH had a concentration-independent absorption rate of about 5% and the in vivo laser-induced fluorescence spectroscopy revealed a relatively quick absorption of NADH starting after a few minute reaching a plateau (about 5%) after 20-30 minutes. Theses results show that, should NADH be protected against the acidic conditions of the stomach, NADH is absorbed principally in the small intestine.