Australian researchers have shown that a dietary supplement that increases the levels of a powerful antioxidant in the brain may represent a novel strategy for the treatment and/or prevention of cognitive impairment and debilitating neurodegenerative diseases such as Alzheimer’s disease.

Findings of the study were recently published in the Neurochemistry International Journal.

A team of researchers from UNSW Sydney’s Centre for Healthy Brain Ageing (CHeBA), and the School of Biotechnology and Biomolecular Sciences (BABS), has shown that dietary supplementation with glutathione precursor γ-glutamylcysteine (γ-GC), marketed as GlyteineTM,  reduced oxidative stress, neuroinflammation and amyloid pathology in the brains of transgenic mice, a murine model to study Alzheimer’s disease. The study also found significant cognitive improvements in the mice as determined using the Morris water maze, a test often used to test memory in mice.

The study identifies for the first time that γ-GC as a glutathione-elevating strategy in an Alzheimer’s disease mouse model and is likely to have clinical relevance.

“Cellular depletion of glutathione has been linked to cognitive decline and the development of Alzheimer’s pathology. Supplementation with γ-GC can transiently augment cellular glutathione levels by bypassing the regulation of glutathione homeostasis.”

Dr Nady Braidy, Senior Author & Leader of CHeBA’s Brain Ageing Research Laboratory

Associate Professor Wallace Bridge first became interested in the therapeutic potential of γ-GC in 1998.  His research group’s efforts have culminated in the recent commercialisation of GlyteineTM, which is now available in the ContinualG ( brand of dietary supplements.  In the US, γ-GC has GRAS (Generally Recognized as Safe) status, which enables its sale as a food ingredient. A UNSW sponsored human clinical study, coordinated by A/Prof Bridge, demonstrated a single oral dose γ-GC is bioavailable and can increase intracellular GSH above homeostasis. No other supplement, including N-acetylcysteine (NAC) and glutathione itself, have ever been demonstrated to have such bioavailability. Associate Professor Bridge said: “γ-GC is likely to increase GSH levels in patients with age-related neurodegenerative disorders or other conditions linked to acute and/or chronic GSH depletion which may prove to have therapeutic benefit”.

The team is currently investigating γ-GC’s use in the treatment of other neurodegenerative disorders (including Parkinson’s disease), cystic fibrosis and autism.