Could carnosine suppress zinc-mediated proteasome inhibition and neurodegeneration? Therapeutic potential of a non-toxic but non-patentable dipeptide.

Ageing and neurodegenerative conditions are often associated with proteasome dysfunction, possibly mediated by zinc and/or copper ions. Studies have shown that (i) the olfactory lobe is normally enriched in carnosine and zinc, (ii) carnosine can suppress copper and zinc toxicity in olfactory neurones, (iii) olfactory dysfunction is often associated with neurodegenerative conditions and (iv) elevated levels of zinc are found in brains of Alzheimer's patients. It is suggested that nasal administration of carnosine should be explored as a possible way of suppressing zinc/copper-mediated proteasome inhibition and consequent neurodegeneration.