Glycine Propionyl-L-carnitine Modulates Lipid Peroxidation and Nitric Oxide in Human Subjects

Abstract

Objective: To determine the efficacy of glycine propionyl-L-carnitine (GPLC) to decrease lipid peroxidation, elevate nitric oxide, and improve blood lipid profiles in human subjects. Methods: Thirty untrained, normolipidemic subjects performed eight weeks of supervised aerobic exercise while supplementing GPLC at one of two doses (1 or 3 grams daily of PLC + glycine) or placebo, following random assignment in a double-blind manner. Fasting blood samples were analyzed at rest for malondialdehyde, nitric oxide, and lipids before and after the intervention. Results: Malondialdehyde was decreased (p<0.05) from pre- to post-intervention with 1 g GPLC (1.08±0.24 vs. 0.69±0.25 µmol·L -1) and 3 g GPLC (0.94±0.18 vs. 0.66±0.17 µmol·L -1), but did not change statistically (p>0.05) with placebo (1.12±0.21 vs. 1.03±0.23 µmol·L -1). Nitric oxide was increased (p<0.05) from pre- to post-intervention with 3 g GPLC (21.34±2.27 vs. 29.46±3.61 µmol·L -1), but did not change statistically (p>0.05) with 1 g GPLC (23.22±4.13 vs. 26.24±4.32 µmol·L -1) or placebo (24.31±3.90 vs. 26.14±4.11 µmol·L -1). No main effects or interaction effects were noted for blood lipids (p>0.05). Conclusion: GPLC supplementation combined with eight weeks of aerobic exercise decreases lipid peroxidation and elevates nitric oxide, but does not further improve blood lipid profiles in normolipidemic subjects.