Supplementation-Induced Change in Muscle Carnosine is Paralleled by Changes in Muscle Metabolism, Protein Glycation and Reactive Carbonyl Species Sequestering

Abstract

Carnosine is a performance-enhancing food supplement with a potential to modulate muscle energy metabolism and toxic metabolites disposal. In this study we explored interrelations between carnosine supplementation (2 g/day, 12 weeks) induced effects on carnosine muscle loading and parallel changes in (i) muscle energy metabolism, (ii) serum albumin glycation and (iii) reactive carbonyl species sequestering in twelve (M/F=10/2) sedentary, overweight-to-obese (BMI: 30.0±2.7 kg/m2) adults (40.1±6.2 years). Muscle carnosine concentration (Proton Magnetic Resonance Spectroscopy; 1H-MRS), dynamics of muscle energy metabolism (Phosphorus Magnetic Resonance Spectroscopy; 31P-MRS), body composition (Magnetic Resonance Imaging; MRI), resting energy expenditure (indirect calorimetry), glucose tolerance (oGTT), habitual physical activity (accelerometers), serum carnosine and carnosinase-1 content/activity (ELISA), albumin glycation, urinary carnosine and carnosine-propanal concentration (mass spectrometry) were measured. Supplementation-induced increase in muscle carnosine was paralleled by improved dynamics of muscle post-exercise phosphocreatine recovery, decreased serum albumin glycation and enhanced urinary carnosine-propanal excretion (all p<0.05). Magnitude of supplementation-induced muscle carnosine accumulation was higher in individuals with lower baseline muscle carnosine, who had lower BMI, higher physical activity level, lower resting intramuscular pH, but similar muscle mass and dietary protein preference. Level of supplementation-induced increase in muscle carnosine correlated with reduction of protein glycation, increase in reactive carbonyl species sequestering, and acceleration of muscle post-exercise phosphocreatine recovery.

State of the Art in the Development of Human Serum Carnosinase Inhibitors

“…However, physical training does not change the concentration of serum carnosinase [ 87 ], and the CNDP1 polymorphism alone is not the main factor determining the muscle concentration of carnosine, which depends mainly on age, gender, and diet [ 57 ]. Interestingly, the muscle concentration of carnosine can be enhanced upon supplementation with a parallel reduction in albumin glycation [ 88 ]. This finding is interesting since albumin glycation is a potential marker of diabetes [ 89 ].…”