Ginseng Protein Reverses Amyloid Beta Peptide and H2O2 Cytotoxicity in Neurons,and Ameliorates Cognitive Impairment in AD Rats Induced by a Combination of D‐Galactose and AlCl3

Ginseng (Panax ginseng C.A. Meyer) is one of the most widely used herbal medicines worldwide. The present study evaluated the neuroprotective effects of ginseng protein (GP) and its possible mechanisms in a cellular and animal model of AD. The results demonstrated that GP (10–100 µg/mL) significantly improved the survival rate of neurons and reduced the cells' apoptosis and the mRNA expression of caspase‐3 and Bax/Bcl‐2. In addition, GP (0.1 g/kg) significantly shortened the escape latency, prolonged the crossing times and the percentage of residence time; reduced the level of Aβ_1–42 and p‐tau, the activity of T‐NOS and iNOS, and the content of MDA and NO, improved the activity of SOD, the concentration of cAMP and the protein expression of p‐PKA/PKA and ‐CREB/CREB. The results demonstrated that GP significantly inhibited Alzheimer‐like pathophysiological changes induced by Aβ_25–35 or H₂O₂ in cells or those induced by D‐gal/ Al in animals. These neuroprotective effects of GP may be associated with the cAMP/PKA/CREB pathway. Also, in combination with our previous studies, these results indicate that the anti‐AD mechanism of GP was likely to activate the CREB pathway through multiple channels. Copyright © 2016 John Wiley & Sons, Ltd.