Media release

From: CHeBA

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.

Lead author and Leader of CHeBA’s Brain Ageing Research Laboratory, Dr Nady Braidy, said: “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.”

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 (www.continualg.com) 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.