Mechanisms of the active components from Korean pine nut preventing and treating d-galactose-induced aging rats.

Age-related neuronal injury and oxidative damage are the predominant factors for neurodegenerative diseases like Alzheimer's disease (AD). The aim of this study was to explore whether chronic administration of d-galactose (d-gal) can cause neuronal injury and oxidative damage, and to investigate the neuroprotective and antioxidative effects of the active components (UPNO-1) from Korean pine nut (Pinus koraiensis). Two dosing regimens were designed, one for the evaluation of preventive effects in which the rats were simultaneously administrated d-gal and UPNO-1/fishoil for 12 weeks, the other for the evaluation of therapeutic effects in which the rats were given d-gal for 8 weeks before treated with UPNO-1/selegiline for 8 weeks. The experimental results demonstrated that chronic administration of d-gal produced histopathological changes and increased neuronal apoptosis, and decreased significantly the activities of T-AOC, T-SOD and CAT. Additionally, a comprehensive metabolic profiling of d-gal-treated rats was performed for the first time to investigate the metabolic disorders in the hippocampus, cortex and plasma, and a total of 32 annotated metabolites were significantly increased or decreased in the modeled rats. Major disturbed metabolic pathways were fatty acid, glycerolphospholipid and arachidonic acid metabolic pathways. UPNO-1 significantly diminished neuronal apoptosis, ameliorated histopathological findings, and increased the activities of T-SOD and CAT but not T-AOC. Furthermore, UPNO-1 attenuated the decreased plasma levels of 3-oxooctanoic acid, l-tryptophan, 12-hydroxyheptadecanoic acid, lysophosphatidylcholine (16:0) (LPC(16:0)), LPC(18:3) and LPC(18:1) in the modeled rats. These results illustrated the mechanisms of d-gal induced neurotoxicity and oxidative stress and proved the positive effects of UPNO-1 on preventing and treating d-gal-induced-aging rats.