Interactions between Carnosine and Captopril on Free Radical Scavenging Activity and Angiotensin-converting Enzyme Activity in vitro

Abstract

Interactions between carnosine (b-alanyl-L-histidine), being plentiful in skeletal muscles and neuronal tissues, and captopril, a widely used angiotensin-converting enzyme (ACE) inhibitor, were examined concerning free radical scavenging activity and ACE activity in vitro. Not only captopril, but also carnosine, at concentrations less than those ordinarily found in muscles and neuronal tissues, signiˆcantly scavenged 2,2′ -azinobis(3-ethylbenzothiazoline-6-sulphonate) (ABTS) radical cations, and inhibited ACE activity. Cupric ions reversed the ABTS scavenging activity of carnosine and captopril, whereas cupric ions strengthened the inhibitory action of carnosine on ACE activity. In contrast, cupric ions antagonized the inhibition of ACE activity induced by ethylenediaminetetraacetic acid, indicating that the inhibitory eŠect of carnosine on ACE activity is not related to the chelating action of carnosine. On the other hand, carnosine and captopril synergistically enhanced the free radical scavenging activity, but not the inhibitory eŠect on the ACE activity. These data suggest that carnosine in its concurrent use with captopril could act as a beneˆcial free radical scavenger, with less danger of overdose, in the inhibition of ACE activity.

Endothelial Function Impairment in Chronic Venous Insufficiency: Effect of Some Cardiovascular Protectant Agents

“…For example, captopril exerts an antioxidant action by limiting the activity of the angiotensin II-stimulated enzyme nicotinamide adenosine dinucleotide phosphate (NADPH) oxidase that increases superoxide anion formation and thus diminishes vascular NO availability 37 as well as by scavenging oxygen free radicals through its sulfhydryl group. 38 Losartan reduces oxidative stress by enhancing superoxide dismutase activity and NO availability. 39 Troglitazone upregulates vascular endothelial growth factor (VEGF) KDR/Flk-1, thus reducing calcium-calmoduline dependence of the NO-synthesizing enzyme eNOS by favoring Ser 1179 phosphorylation 40 ; NO availability is also enhanced through reduced formation and increased degradation of superoxide anion.…”

Muscle Carnosine Metabolism and β-Alanine Supplementation in Relation to Exercise and Training

“…Several other chemical properties of carnosine have been described, among others as an activator of carbonic anhydrase [49] and an inhibitor of angiotensin converting enzyme (ACE) [50]. The physiological relevance of these effects is not intensively studied and lies beyond the scope of this review.…”

Carnosine metabolism in diabetes is altered by reactive metabolites

“…Both peptides have cytoprotective properties. Carnosine scavenges carbonyls (Barski et al 2013;Negre-Salvayre et al 2008;Vistoli et al 2009), inhibits glycation (Alhamdani et al 2007) and acts as ACE inhibitor (Hou et al 2003;Nakagawa et al 2006). Its function as antioxidant is debated (Babizhayev et al 2013;Decker et al 2000;Hipkiss 2011;Mozdan et al 2005;Velez et al 2008).…”