The brain depends on a continuous supply of energy in the form of adenosine triphosphate (ATP) to fuel its resting and active-state functions. Essential to ATP production is the molecule nicotinamide adenine dinucleotide (NAD+).

As glucose is broken down into smaller molecules by the cells, the chemical bonds holding it together break. The energy held in the broken bonds is harnessed when an electron freed during the process is captured by NAD+, converting it to its reduced form, nicotinamide adenine dinucleotide + hydrogen (NADH). NADH donates the electron to the mitochondria, which use the electron's energy to produce ATP, a process that oxidizes NADH back to NAD+.

Energy metabolism is compromised as we age, evidenced by a reduced NAD+/NADH ratio, which is considered a measure of global brain energy capacity. In neurodegenerative diseases like multiple sclerosis (MS), Parkinson's disease (PD) and amyotrophic lateral sclerosis (ALS), this reduction is much faster and more severe.

Now, researchers from the University of Texas Southwestern (UT Southwestern) Medical Center have conducted two phase 2 clinical trials on patients with MS and PD to see whether treating these neurodegenerative diseases with orally administered gold nanocrystals could restore the NAD+/NADH ratio.

"We are cautiously optimistic that we will be able to prevent or even reverse some neurological disabilities with this strategy," said Peter Sguigna, one of the study's co-authors and lead on the MS trial.

CNM-Au8 is a concentrated suspension of gold nanocrystals whose surfaces catalyze the rapid oxidation of NADH to NAD+, shown to increase the availability of both NAD+ and ATP in in vitro studies. It's also known to cross the blood-brain barrier and penetrate cell membranes.