Effect of walnut protein hydrolysate on scopolamine-induced learning and memory deficits in mice.

A walnut protein hydrolysate (WPH) was prepared by using a mixture of pancreatin and viscozyme L from industrially available defatted walnut meal. The antioxidant effects of WPH were confirmed and quantified by reducing power, oxygen radical absorbance capacity, hydroxyl radical radical-scavenging activity and ABTS+· radical-scavenging activity assays. The protective effects of WPH on scopolamine-induced learning and memory deficits in mice were also evaluated based on in vivo behavioral tests. Results showed that WPH administration would lead to significantly decreased latencies while increased crossing times and target times in the spatial probe test, and increased escape latency and decreased error times in the step-down avoidance test for the scopolamine-induced dementia mice. Biochemical results indicated that the ameliorative effects of WPH on scopolamine-induced dementia mice could be attributed to the significantly increased amount of acetylcholine receptors. Therefore, WPH may be a potential therapeutic agent against Alzheimer's disease.