Chapter 3 Carnosine and Its Possible Roles in Nutrition and Health

Role of Aldose Reductase in the Metabolism and Detoxification of Carnosine-Acrolein Conjugates

“…The beneficial effects of carnosine against ischemic injury have been described before (24); however, the mechanisms by which carnosine exerts its antiischemic effects are not known. It has been speculated that carnosine could protect against ischemia by buffering changes in intracellular pH, by increasing the calcium sensitivity of the myofilaments, or by quenching singlet oxygen (23). The present data do not rule out any of these possibilities but instead suggest that carnosine protects against ischemia-reperfusion injury by removing aldehyde derived from lipid oxidation.…”

“…To determine whether carnosine conjugates are also reduced in tissues other than the skeletal muscle, carnosine-propanals were incubated with homogenates of mouse brain and heart. Although skeletal muscle contains the highest levels of carnosine (10 -20 mM), significant levels of carnosine have been also been measured both in the heart and the brain (23). Therefore, in these tissues, carnosine-propanal conjugates could be generated and reduced by AR.…”

“…It is synthesized in tissues with high rates of glycolysis such as the anaerobic white skeletal muscle of birds, horses, and pigs. It is currently believed that during high anaerobic activity carnosine prevents tissue acidification by buffering changes in intracellular pH (23). Nevertheless, high levels of carnosine and related histidyl peptides (anserine, homocarnosine) are also present in aerobic tissues such as the heart and the brain, suggesting that carnosine might have other functions as well.…”

Cell death and diseases related to oxidative stress:4-hydroxynonenal (HNE) in the balance

“…35 Therefore, HNE can impair key areas in the brain, leading to neuronal cell death. Carnosine, as a carbonyl scavenger and antioxidant, can provide protection against HNE and decrease neurodegenerative disorders, 36 but its action is not limited to HNE-dependent damage.…”

Carnosine and cancer: a perspective

“…In general, the positive effects of carnosine are manifold; there is a substantial literature on its protective effects (Quinn et al 1992;Hipkiss 2009b), including astroglial cell protection by NO-trapping (Nicoletti et al 2007) and protection against hypoxia-ischaemia brain damage (Zhang et al 2011). It has been reported that carnosine reduces the development of inflammation and tissue injury associated with spinal cord trauma (Di Paola et al 2011); it also protects lung tissue against bleomycin-induced injury (Cuzzocrea et al 2007) and prevents vascular damage in experimental diabetic retinopathy (Pfister et al 2011).…”