Author(s): Cong Lu, Li-Ming Dong, Pan Xu, Lan-Lan Bu, Shan-Guang Chen, Ying-Hui Li, Li-Na Qu and Xin-Min Liu

Abstract: Protopanaxatriol (Ppt) is a neuroprotective ginseng extract and has an antioxidative effect in physiological conditions. The potential neuroprotective effects of Ppt are becoming widely recognized and studied. Sleep deprivation (SD) has been associated with memory impairment through induction of oxidative stress. The present study aimed to investigate the effect of Ppt against chronic sleep deprivation (CSD)-induced cognitive impairment and attempted to define the possible mechanisms involved. We found that 2-week CSD induced significant cognitive impairment in mice evaluated by the object location recognition experiment and Morris water maze test. All of these changes induced by CSD were ameliorated by Ppt (20μmol/Kg; 40μmol/Kg) and Modafinil (0.42g/Kg).In addition, Ppt restored the levels/activities of antioxidant defense biomarkers in the cortex and hippocampus, including glutathione reduced (GSH), glutathione oxidized (GSSG), GSH/GSSG ratio, the superoxide dismutase (SOD) enzyme activity, catalase (CAT), and Lipid peroxidation (LPO).These results suggest that Ppt prevents cognitive impairment induced by CSD. The possible mechanism may be attributed to its ability to reduce oxidative stress in cortex and hippocampus.