Identification of a novel peptide from β-casein that enhances spatial and object recognition memory in mice.

An increase in the aging population has spurred recent efforts to identify diet and lifestyle changes that help prevent cognitive decline. Several epidemiological investigations and clinical studies have indicated that consuming fermented dairy products prevents cognitive decline. Some peptides from whey including beta-lactolin improve memory impairment; the intake of Camembert cheese has been shown to prevent Alzheimer's in mouse models. To elucidate the molecular mechanisms underlying these preventive effects, we screened peptides from digested casein protein for their ability to improve spatial memory in a scopolamine-induced amnesia mouse model. Administration of KEMPFPKYPVEP peptide from beta-casein at 0.5 mg/kg (54.8 +/- 2.5) and 2 mg/kg (57.9 +/- 3.7) improved memory impairment in the amnesia mice in comparison with control (44.9 +/- 3.4; p = 0.031 and p = 0.042, respectively) and increased dopamine (5.9 +/- 3.8 [control] and 12.4 +/- 6.2 [KEMPFPKYPVEP peptide]) and norepinephrine (7.7 +/- 0.8 [control] and 9.9 +/- 2.0 [KEMPFPKYPVEP peptide]) levels in the frontal cortex (p = 0.039 and p = 0.031, respectively). Collectively, our findings suggest that peptides in fermented dairy products prevent cognitive decline and support previously reported observations.