Preservation of Cognitive Function by Lepidium meyenii (Maca) Is Associated with Improvement of Mitochondrial Activity and Upregulation of Autophagy-Related Proteins in Middle-Aged Mouse Cortex
CONTEXT Lepidium meyenii Walp. (Brassicaceae), most commonly known as "maca", has been used as a food or folk medicine to improve vitality in Peru. Previous research demonstrated that lipid-soluble extract from maca improved swimming endurance capacity. Macamides are considered the typical lipid-soluble markers for maca and proved to have several pharmacological properties, such as improving sexual performance and neuroprotective activies. OBJECTIVE The present study investigates the effects of macamides on endurance capacity and anti-fatigue property in prolonged swimming mice. MATERIALS AND METHODS The Balb/c mice were divided into seven groups: a control group, low-dose groups of N-benzyllinoleamide, N-benzyloleamide, and N-benzylpalmitamide, high-dose groups of these macamides. The macamides groups received the commercial products (12 and 40 mg/kg, ig), while the control group received vehicle for 21 d. On the 14th day, the mice were given the weight-loaded swimming test. On the 21st day, the mice were sacrificed immediately after 90 min swimming, and some biochemical parameters were measured. RESULTS AND DISCUSSION Compared with the control group, exhaustive swimming time was significantly prolonged in high-dose group of N-benzyloleamide (p < 0.05); the levels of lactic acid (LD), blood ammonia (BA), and lactate dehydrogenase (LDH) were significantly decreased (p < 0.05), whereas the levels of liver glycogen (LG) and non-esterified fatty acid (NEFA) were significantly increased (p < 0.05) in high-dose group of N-benzyloleamide. The malondialdehyde (MDA) contents in the brain, muscle, and liver were significantly decreased (p < 0.05), whereas superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activities in the brain, muscle, and liver were significantly increased in high-dose group of N-benzyloleamide (p < 0.05). CONCLUSION The results indicate that N-benzyloleamide has pharmaceutical property against exercise-induced fatigue, and this effect can be explained by the modulated energy metabolism and improved antioxidant status.