Carnosine (β-alanyl-L-histidine) is a small dipeptide with numerous activities, including
antioxidant effects, metal ion chelation, proton buffering capacity, and inhibitory effects on protein
carbonylation and glycation. Carnosine has been mostly studied in organs where it is abundant, including
skeletal muscle, cerebral cortex, kidney, spleen, and plasma. Recently, the effect of supplementation
with carnosine has been studied in organs with low levels of carnosine, such as the lung, in animal
models of influenza virus or lipopolysaccharide-induced acute lung injury and pulmonary fibrosis.
Among the known protective effects of carnosine, its antioxidant effect has attracted increasing attention
for potential use in treating lung disease. In this review, we describe the in vitro and in vivo biological
and physiological actions of carnosine. We also report our recent study and discuss the roles of
carnosine or its related compounds in organs where carnosine is present in only small amounts (especially
the lung) and its protective mechanisms.