Effects of (+)-octanoylcarnitine in intact myocardium

Metabolomic analysis reveals potential biomarkers and serum metabolomic profiling in spontaneous intracerebral hemorrhage patients using UPLC/quadrupole time-of-flight MS

Spontaneous intracerebral hemorrhage (ICH) accounts for 10-20% of all strokes and contributes to higher mortalities and severe disabilities. The aims of this study were, therefore, to characterize novel biomarkers, metabolic disruptions, and mechanisms involving ICH. A total 30 ICH patients and 30 controls were enrolled in the study, and their clinical characteristics were analyzed. Nontargeted metabolomic analysis was conducted using ultra-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF). Multivariate statistical analysis and receiver operating characteristic curve analysis were used for screening and evaluating the predictive ability of biomarkers. ICH patients showed significantly higher systolic blood pressure, diastolic blood pressure, blood glucose levels, white blood cell counts, neutrophil count, percentage of neutrophils and globulin and a lower albumin/globin ratio when compared with controls. In sum, 11 important metabolites were identified, which were associated with disruption of fatty acid oxidation and sphingolipid and phospholipid metabolism, as well as increased inflammation, oxidative stress, and vascular pathologies. Further multiple logistic regression analyses of these metabolites showed that l-carnitine and phosphatidylcholine (20:3/22:6) have potential as biomarkers of ICH, and the area under the curve, sensitivity, specificity were 0.974, 90%, and 93%, respectively. These findings provide insights into the pathogenesis, early prevention, and diagnosis of ICH.

Antiradical effects in L-propionyl carnitine protection of the heart against ischemia-reperfusion injury: the possible role of iron chelation

L-Propionyl carnitine has been shown to improve the heart's mechanical recovery and other metabolic parameters after ischemia-reperfusion. However, the mechanism of protection is unknown. The two dominating hypotheses are: (i) L-propionyl carnitine can serve as an energy source for heart muscle cells by being enzymatically converted to propionyl-CoA and subsequently utilized in the Krebs cycle (a metabolic hypothesis), and (ii) it can act as an antiradical agent, protecting myocardial cells from oxidative damage (a free radical hypothesis). To test the two possible pathways, we compared the protection afforded to the ischemia-reperfused hearts by L-propionyl carnitine and its optical isomer, D-propionyl carnitine. The latter cannot be enzymatically utilized as an energy source. The Langendorff perfusion technique was used and the hearts were subjected to 40 min of ischemia and 20 min of reperfusion. In analysis of ischemia-reperfused hearts, a strong correlation was found between the recovery of mechanical function and the presence of protein oxidation products (protein carbonyls). Both propionyl carnitines efficiently prevented protein oxidation but L-propionyl carnitine-perfused hearts had two times greater left ventricular developed pressure. The results indicate that both metabolic and antiradical pathway are involved in the protective mechanism of L-propionyl carnitine. To obtain a better insight of the antiradical mechanism of L-propionyl carnitine, we compared the ability of L- and D-propionyl carnitines, L-carnitine, and deferoxamine to interact with: (i) peroxyl radicals, (ii) oxygen radicals, and (iii) iron. We found that none of the carnitine derivatives were able to scavenge peroxyl radicals or superoxide radicals. L- and D-propionyl carnitine and deferoxamine (not L-carnitine) suppressed hydroxyl radical production in the Fenton system, probably by chelating the iron required for the generation of hydroxyl radicals. We suggest that L-propionyl carnitine protects the heart by a dual mechanism: it is an efficient fuel source and an antiradical agent.