β-Nicotinamide Mononucleotide, an Anti-Aging Candidate Compound, Is Retained in the Body for Longer than Nicotinamide in Rats

Abstract

The turnover of the oxidized form of nicotinamide adenine dinucleotide (NAD⁺) has attracted interest in regard to longevity. Thus, compounds that can rapidly increase the cellular NAD⁺ concentration have been surveyed by many researchers. Of those, β-nicotinamide mononucleotide (β-NMN) has been focused on. Studies on the biosynthesis of NAD⁺ from β-NMN have been reported at the cellular level, but not at the whole animal level. In the present study, we investigated whether β-NMN is superior to nicotinamide (Nam) as a precursor of NAD⁺ in whole animal experiments. To this end we compared the NAD⁺ concentration in the blood and the urinary excretion amounts of NAD⁺ catabolites. Rats were intraperitoneally injected with β-NMN or Nam. After the injection, blood samples and urine samples were collected at 3-h intervals. The concentration of blood total NAD (NAD11NADH) in each sample showed no significant differences between the two groups. The urinary excretion amounts of NAD⁺ catabolites in the urine samples collected at 3-6 h after the injection were lower in the β-NMN group than in the Nam group. These results suggest that β-NMN is retained in the body for longer than Nam.