The
dipeptide carnosine has been observed to exert antiaging activity at cellular and whole animal levels. This review discusses the possible mechanisms by which
carnosine may exert antiaging action and considers whether the
dipeptide could be beneficial to humans.
Carnosine's possible
biological activities include scavenger of
reactive oxygen species (ROS) and
reactive nitrogen species (RNS),
chelator of
zinc and
copper ions, and antiglycating and anticross-linking activities.
Carnosine's ability to react with deleterious
aldehydes such as
malondialdehyde,
methylglyoxal, hydroxynonenal, and
acetaldehyde may also contribute to its protective functions. Physiologically
carnosine may help to suppress some secondary complications of diabetes, and the deleterious consequences of ischemic-
reperfusion injury, most likely due to antioxidation and carbonyl-scavenging functions. Other, and much more speculative, possible functions of
carnosine considered include
transglutaminase inhibition, stimulation of proteolysis mediated via effects on
proteasome activity or induction of
protease and
stress-protein gene expression, upregulation of
corticosteroid synthesis, stimulation of
protein repair, and effects on
ADP-ribose metabolism associated with
sirtuin and
poly-ADP-ribose polymerase (PARP) activities. Evidence for
carnosine's possible protective action against secondary
diabetic complications, neurodegeneration,
cancer, and other age-related pathologies is briefly discussed.